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Sample records for accuracy wire scanner

  1. Twisting wire scanner

    International Nuclear Information System (INIS)

    A new type of 'two-in-one' wire scanner is proposed. Recent advances in linear motors' technology make it possible to combine translational and rotational movements. This will allow to scan the beam in two perpendicular directions using a single driving motor and a special fork attached to it. Vertical or horizontal mounting will help to escape problems associated with the 45 deg scanners. Test results of the translational part with linear motors is presented.

  2. Wire Scanner Motion Control Card

    CERN Document Server

    Forde, S E

    2006-01-01

    Scientists require a certain beam quality produced by the accelerator rings at CERN. The discovery potential of LHC is given by the reachable luminosity at its interaction points. The luminosity is maximized by minimizing the beam size. Therefore an accurate beam size measurement is required for optimizing the luminosity. The wire scanner performs very accurate profile measurements, but as it can not be used at full intensity in the LHC ring, it is used for calibrating other profile monitors. As the current wire scanner system, which is used in the present CERN accelerators, has not been made for the required specification of the LHC, a new design of a wire scanner motion control card is part of the LHC wire scanner project. The main functions of this card are to control the wire scanner motion and to acquire the position of the wire. In case of further upgrades at a later stage, it is required to allow an easy update of the firmware, hence the programmable features of FPGAs will be used for this purpose. The...

  3. Improvements to Existing Jefferson Lab Wire Scanners

    Energy Technology Data Exchange (ETDEWEB)

    McCaughan, Michael D. [JLAB; Tiefenback, Michael G. [JLAB; Turner, Dennis L. [JLAB

    2013-06-01

    This poster will detail the augmentation of selected existing CEBAF wire scanners with commercially available hardware, PMTs, and self created software in order to improve the scanners both in function and utility.

  4. Minimisation of the wire position uncertainties of the new CERN vacuum wire scanner

    CERN Document Server

    AUTHOR|(CDS)2069346; Barjau Condomines, A

    In the next years the luminosity of the LHC will be significantly increased. This will require a much higher accuracy of beam profile measurement than actually achievable by the current wire scanner. The new fast wire scanner is foreseen to measure small emittance beams throughout the LHC injector chain, which demands a wire travelling speed up to 20 ms-1 and position measurement accuracy of the order of a few microns. The vibrations of the mechanical parts of the system, and particularly the vibrations of the thin carbon wire, were identified as the major error sources of wire position uncertainty. Therefore the understanding of the wire vibrations is a high priority for the design and operation of the new device. This document presents the work performed to understand the main causes of the wire vibrations observed in one of the existing wire scanner and the new proposed design.

  5. Vibration measurements of a wire scanner - Experimental setup and models

    Science.gov (United States)

    Herranz, Juan; Barjau, Ana; Dehning, Bernd

    2016-03-01

    In the next years the luminosity of the LHC will be significantly increased. This will require a much higher accuracy of beam profile measurement than actually achievable by the current wire scanner. The new performance demands a wire travelling speed up to 20 m s-1 and a position measurement accuracy of the order of 1 μm. The vibrations of the mechanical parts of the system and particularly the vibrations of the thin carbon wire have been identified as the major error sources of wire position uncertainty. Therefore the understanding of the wire vibrations has been given high priority for the design and operation of the new device. This article presents a new strategy to measure the wire vibrations based on the piezoresistive effect of the wire itself. An electronic readout system based on a Wheatstone bridge is used to measure the variation of the carbon wire resistance, which is directly proportional to the wire elongation caused by the oscillations.

  6. The PS Booster Fast Wire Scanner

    CERN Document Server

    Burger, S; Priestnall, K; Raich, U

    2003-01-01

    The very tight emittance budget for LHC type beams makes precise emittance measurements in the injector complex a necessity. The PS machine uses 2 fast wire scanners per transverse plane for emittance measurement of the circulating beams. In order to ease comparison the same type of wire scanners have been newly installed in the upstream machine, the PS Booster, where each of the 4 rings is equipped with 2 wire scanners measuring the horizontal and vertical profiles. Those wire scanners use new and more modern control and readout electronics featuring dedicated intelligent motor movement controllers, which relieves the very stringent real time constraints due to the very high speed of 20m/s. In order to be able to measure primary beams at the very low injection energy of the Booster (50MeV) secondary emission currents from the wire can be measured as well as secondary particle flows at higher primary particle energies during and after acceleration. The solution adopted for the control of the devices is descri...

  7. Comparative evaluation of ultrasound scanner accuracy in distance measurement

    Science.gov (United States)

    Branca, F. P.; Sciuto, S. A.; Scorza, A.

    2012-10-01

    The aim of the present study is to develop and compare two different automatic methods for accuracy evaluation in ultrasound phantom measurements on B-mode images: both of them give as a result the relative error e between measured distances, performed by 14 brand new ultrasound medical scanners, and nominal distances, among nylon wires embedded in a reference test object. The first method is based on a least squares estimation, while the second one applies the mean value of the same distance evaluated at different locations in ultrasound image (same distance method). Results for both of them are proposed and explained.

  8. Thermal analysis for wire scanners in the CSNS Linac

    Science.gov (United States)

    Yang, Tao; Fu, Shinian; Xu, Taoguang; Xu, Zhihong; Meng, Ming; Qiu, Ruiyang; Tian, Jianmin; Zeng, Lei; Li, Peng; Li, Fang; Wang, Biao

    2014-10-01

    3 MeV H- beam from the Radio Frequency Quadrupole (RFQ) will be accelerated to 80 MeV in the CSNS (China Spallation Neutron Source) linear accelerator (Linac). The wire scanner is used to measure the transverse beam profile and the emittance, and the carbon or tungsten wire is considered to use. Thermal analysis of the wire scanners in the Linac is presented in this paper. The maximum temperature (Tm) of the wire decreases as the beam energy increases, and we also calculate the influence of all possible parameters on Tm. Tm of carbon wire is significantly lower than tungsten wire if both the beam parameters and wire geometric parameters are set to the same, which can be attributed to its higher heat capacity and radiant emissivity. In addition, we present the results of sublimation rate of the wire, which show that tungsten wire has a much lower evaporation rate than carbon wire in the same temperature, which can be attributed to the different vapor pressures of the two materials. To limit the thermionic emission, the maximum beam frequency approximately has an exponential relationship with beam rms size at a certain beam pulse width.

  9. LANSCE wire scanner AFE: analysis, design, and fabrication

    International Nuclear Information System (INIS)

    The goal of the design LANSCE-R Wire-Scanner Analog Front-end Electronics is to develop a high-performance, dual-axis wire-scanner analog front-end system implemented in a single cRIO module. This new design accommodates macropulse widths as wide as 700 μs at a maximum pulse rate of 120Hz. A lossey integrator is utilized as the integration element to eliminate the requirement for providing gating signals to each wire scanner. The long macropulse and the high repetition rate present conflicting requirements for the design of the integrator. The long macropulse requires a long integration time constant to assure minimum integrator droop for accurate charge integration, and the high repetition rate requires a short time constant to assure adequate integrator reset between macropulses. Also, grounding is a serious concern due to the small signal levels. This paper reviews the basic Wire Scanner AFE system design implemented in the cRIO-module form factor to capture the charge information from the wire sensors and the grounding topology to assure minimum noise contamination of the wire signals.

  10. Feasibility studies on the direct wire readout on wire scanners in electron accelerators

    International Nuclear Information System (INIS)

    This bachelor thesis deals essentially with the signal processing of a so-called wire scanner, a special monitor, which comes to application in the beam diagnostics of particle accelerators. In this direct wire readout the voltage signal, which is induced by the particle beam in the measurement wire of the wire scanner, shall be directly read out. The aim of this thesis is to show fundamental considerations and perform studies, which study, whether and how in the future by means of a suited data transmission as well as readout electronics conclusion on the most important parameters of the beam, like position and profile, are possible. The measurement system presented here is divided in three main components: Signal measurement, signal preparation, and signal stretching. A suited test facility was developed and is presented in detail, in which then all components, like for instance the transmission cables, the wire-scanner fork, and the developed measurement circuit, are studied, which are of importance for a faultless signal transmission and presentation. Extensive measurements on the single components, as well as calculations for the signal transmission on and in the wire scanner were performed, whereby a good agreement could be found. Thereafter a comparison and a selection of the component used in this project were made. Furthermore improvement proposals, new constructions, and outlooks are presented, which could be of importance in further works.

  11. Mechanical optimisation of a high-precision fast wire scanner at CERN

    CERN Document Server

    Samuelsson, Sebastian; Veness, Raymond

    Wire scanners are instruments used to measure the transverse beam prole in particle accelerators by passing a thin wire through the particle beam. To avoid the issues of vacuum leakage through the bellows and wire failure related to current designs of wire scanners, a new concept for a wire scanner has been developed at CERN. This design has all moving parts inside the beam vacuum and has a nominal wire scanning speed of 20 m/s. The demands on the design associated with this together with the high precision requirements create a need for\

  12. Secondary particle acquisition system for the CERN beam wire scanners upgrade

    International Nuclear Information System (INIS)

    The increasing requirements of CERN experiments make essential the upgrade of beam instrumentation in general, and high accuracy beam profile monitors in particular. The CERN Beam Instrumentation Group has been working during the last years on the Wire Scanners upgrade. These systems cross a thin wire through a circulating beam, the resulting secondary particles produced from beam/wire interaction are detected to reconstruct the beam profile. For the new secondary shower acquisition system, it is necessary to perform very low noise measurements with high dynamic range coverage. The aim is to design a system without tuneable parameters and compatible for any beam wire scanner location at the CERN complex. Polycrystalline chemical vapour deposition diamond detectors (pCVD) are proposed as new detectors for this application because of their radiation hardness, fast response and linearity over a high dynamic range. For the detector readout, the acquisition electronics must be designed to exploit the detector capabilities and perform bunch by bunch measurements at 40MHz. This paper describes the design challenges of such a system, analysing different acquisition possibilities from the signal integrity point of view. The proposed system architecture is shown in detail and the development status presented

  13. Wire Scanner Beam Profile Measurements for the LANSCE Facility

    Energy Technology Data Exchange (ETDEWEB)

    Gilpatrick, John D. [Los Alamos National Laboratory; Gruchalla, Michael E. [Los Alamos National Laboratory; Martinez, Derwin [Los Alamos National Laboratory; Pillai, Chandra [Los Alamos National Laboratory; Rodriguez Esparza, Sergio [Los Alamos National Laboratory; Sedillo, James Daniel [Los Alamos National Laboratory; Smith, Brian G. [Los Alamos National Laboratory

    2012-05-15

    The Los Alamos Neutron Science Center (LANSCE) is replacing beam profile measurement systems, commonly known as Wire Scanners (WS). Using the principal of secondary electron emission, the WS measurement system moves a wire or fiber across an impinging particle beam, sampling a projected transverse-beam distribution. Because existing WS actuators and electronic components are either no longer manufactured or home-built with antiquated parts, a new WS beam profile measurement is being designed, fabricated, and tested. The goals for these new WS's include using off-the-shelf components while eliminating antiquated components, providing quick operation while allowing for easy maintainability, and tolerating external radioactivation. The WS measurement system consists of beam line actuators, a cable plant, an electronics processor chassis, and software located both in the electronics chassis (National Instruments LabVIEW) and in the Central Control Room (EPICS-based client software). This WS measurement system will measure Hand H{sup +} LANSCE-facility beams and will also measure less common beams. This paper describes these WS measurement systems.

  14. EVALUATING PARAMETERS AFFECTING THE GEOREFERENCING ACCURACY OF TERRESTRIAL LASER SCANNERS

    Directory of Open Access Journals (Sweden)

    M. Miri

    2012-09-01

    Full Text Available Today laser scanning is used as a powerful technology in measuring various simple and complex objects in cultural heritage applications. Depending on the size and the complexity of the objects, these measurements are usually made from several stations. Similar to all other surveying techniques, the coordinate systems of such measurements need to be registered. For this, a number of retro-reflective targets visible from different stations are used. In practice, the target centres are entered in the computations. The accuracy of the target centres, therefore, need to be high or the final object coordinates might not be of sufficient accuracy. A number of factors including the distance between a target and the laser scanner, the direction of the target surface with respect to the laser scanner beams, the intensity and the number of reflected laser beams affect the accuracy of target centres. In this paper, various tests are carried out to examine the effect of such factors on the accuracy of coordinates obtained for the target centres. The results show that the distance to the laser scanner and the angle between a target surface and the corresponding laser beams have considerable effects on the locational accuracy of the targets.

  15. The mechatronic design of a fast wire scanner in IHEP U-70 accelerator

    Science.gov (United States)

    Baranov, V. T.; Makhov, S. S.; Savin, D. A.; Terekhov, V. I.

    2016-10-01

    This paper presents the mechatronic design of a fast wire scanner based on a servomotor. The design of the wire scanner is motivated by the need to measure the transverse profile of the high power proton and carbon beams at the IHEP U-70 accelerator. This paper formulates the requirements to the fast wire scanner system for the high intensity proton beam at the U-70 accelerator. The results on the design of electro-mechanical device for the wire scanner with a wire traveling speed 10-20 m/s are presented. The solution consists in a brushless servomotor and standard motor control electronics. High radiation levels in the accelerator enclosure dictate the use of a resolver as the position feedback element.

  16. A wire scanner system for characterizing the BNL energy recovery LINAC beam position monitor system

    Energy Technology Data Exchange (ETDEWEB)

    Michnoff R.; Biscardi, C.; Cerniglia, P.; Degen, C.; Gassner, D.; Hoff, L.; Hulsart, R.

    2012-04-15

    A stepper motor controlled wire scanner system has recently been modified to support testing of the Brookhaven National Laboratory (BNL) Collider-Accelerator department's Energy Recovery Linac (ERL) beam position monitor (BPM) system. The ERL BPM consists of four 9.33 mm diameter buttons mounted at 90 degree spacing in a cube with 1.875 inch inside diameter. The buttons were designed by BNL and fabricated by Times Microwave Systems. Libera brilliance single pass BPM electronic modules with 700 MHz bandpass filter, manufactured by Instrumentation Technologies, will be used to measure the transverse beam positions at 14 locations around the ERL. The wire scanner assembly provides the ability to measure the BPM button response to a pulsed wire, and evaluate and calibrate the Libera position measurement electronics. A description of the wire scanner system and test result data will be presented.

  17. Design and Test of Wire-Scanners for SwissFEL

    CERN Document Server

    Orlandi, G L; Brands, H; Heimgartner, P; Ischebeck, R; Kammerer, A; Löhl, F; Lüscher, R; Mohanmurthy, P; Ozkan, C; Schlott, V; Schulz, L; Rippstein, B; Seiler, C; Trovati, S; Valitutti, P; Zimoch, D

    2016-01-01

    The SwissFEL light-facility will provide coherent X-rays in the wavelength region 7-0.7 nm and 0.7-0.1 nm. In SwissFEL, view-screens and wire-scanners will be used to monitor the transverse profile of a 200/10pC electron beam with a normalized emittance of 0.4/0.2 mm.mrad and a final energy of 5.8 GeV. Compared to view screens, wire-scanners offer a quasi-non-destructive monitoring of the beam transverse profile without suffering from possible micro-bunching of the electron beam. The main aspects of the design, laboratory characterization and beam-test of the SwissFEL wire-scanner prototype will be discussed.

  18. LANSCE-R WIRE-SCANNER ANALOG FRONT-END ELECTRONICS

    International Nuclear Information System (INIS)

    A new AFE is being developed for the new LANSCE-R wire-scanner systems. The new AFE is implemented in a National Instruments Compact RIO (cRIO) module installed a BiRa 4U BiRIO cRIO chassis specifically designed to accommodate the cRIO crate and all the wire-scanner interface, control and motor-drive electronics. A single AFE module provides interface to both X and Y wire sensors using true DC coupled transimpedance amplifiers providing collection of the wire charge signals, real-time wire integrity verification using the normal dataacquisition system, and wire bias of 0V to +/-50V. The AFE system is designed to accommodate comparatively long macropulses (>1ms) with high PRF (>120Hz) without the need to provide timing signals. The basic AFE bandwidth is flat from true DC to 50kHz with a true first-order pole at 50kHz. Numeric integration in the cRIO FPGA provides real-time pulse-to-pulse numeric integration of the AFE signal to compute the total charge collected in each macropulse. This method of charge collection eliminates the need to provide synchronization signals to the wire-scanner AFE while providing the capability to accurately record the charge from long macropulses at high PRF.

  19. Laser and electron beam diagnostics with wire scanners in the XUV-seeding experiment at FLASH

    International Nuclear Information System (INIS)

    The free-electron laser (FLASH) in Hamburg delivers intense femtosecond laser pulses in the extreme ultra violet and soft X-ray spectral range for many kinds of experiments, like material science and femtochemistry. To improve the FEL properties in terms of spectral stability, a direct seeding experiment (sFLASH), using a high harmonic generation source as a seed laser was installed at FLASH. The longitudinal and transversal overlap of the seed laser and electron beam is crucial for the seeding process. Among others, wire scanners are used for measuring the transverse laser and electron beam profiles, to perform the transverse overlap. Wire scanners are scanning a thin wire across the electron beam or the laser while measuring the interaction between electrons or photons with the wire. The interaction produces a flux of secondary particles, which are detected with beam loss monitors or MCP detectors.

  20. Interpretation of Wire-Scanner asymmetric profiles in a Low-Energy ring

    CERN Document Server

    Cieslak-Kowalska, Magdalena Anna

    2016-01-01

    In the CERN PS Booster, wire-scanner profile measurements performed at injection energy are affected by a strong asymmetry. The shape was reproduced with the code PyORBIT, assuming that the effect is due to the beam evolution during the scans, under the influence of space-charge forces and Multiple Coulomb Scattering at the wire itself. Reproducing the transverse profiles during beam evolution allows to use them reliably as input for simulation benchmarking.

  1. A fast wire scanner, used to measure the transverse density distribution of beams circulating in an accelerator or storage ring.

    CERN Multimedia

    Maximilien Brice

    2002-01-01

    Fast wire scanners are used to measure the transverse density distribution of beams circulating in an accelerator or storage ring. In order to minimize blow-up of the beam through multiple Coulomb scattering, the wires are very thin (in the version shown here it is actually a twisted strand of carbon fibres with a total diameter of about 25 microns) and are swept through the beam at high speed (a linear motor, not mounted here, accelerates the wires to up to 20 m/s). One measures either the secondary emission current from the wire, or the signal from a scintillator/photomultiplier combination downstream from the wire scanner receiving the shower from nuclear reactions of beam particles with the wire nuclei. There are four such fast wire scanners in the 26 GeV PS and eight in the 1.4 GeV Booster.

  2. High dynamic range diamond detector acquisition system for beam wire scanner applications

    International Nuclear Information System (INIS)

    The CERN Beam Instrumentation group has been working during the last years on the beam wire scanners upgrade to cope up with the increasing requirements of CERN experiments. These devices are used to measure the beam profile by crossing a thin wire through a circulating beam, the resulting secondary particles produced from beam/wire interaction are detected and correlated with the wire position to reconstruct the beam profile. The upgraded secondary particles acquisition electronics will use polycrystalline chemical vapour deposition (pCVD) diamond detectors for particle shower measurements, with low noise acquisitions performed on the tunnel, near the detector. The digital data is transmitted to the surface through an optical link with the GBT protocol. Two integrator ASICs (ICECAL and QIE10) are being characterized and compared for detector readout with the complete acquisition chain prototype. This contribution presents the project status, the QIE10 front-end performance and the first measurements with the complete acquisition system prototype. In addition, diamond detector signals from particle showers generated by an operational beam wire scanner are analysed and compared with an operational system

  3. On the behavior of a wire of the Wire Scanner in the IPHI diagnosis line

    International Nuclear Information System (INIS)

    A proton beam of 3 MeV energy and 100 mA intensity during 200 μs and a period T a second crosses an 150 mm x 33 μm carbon wire. The particles in the packet are distributed according to a di-Gaussian law with σX = 2 mm and σY = 6 mm. In these conditions the wire of the X plane centered in the beam acquires a peak temperature of about 1800 deg. C. The intensity of the secondary electron current recovered on the wire amounts about 306 μA. The thermo-electronic current for a time t = 200 μs (at the period T) has an intensity of 45 μA, i.e. 15% of the nominal signal. These figures for current are orders of magnitude, particularly for the thermo-electronic current where an intervening parameter is affected by a high uncertainty. The calculation method gives the spatial and time distribution of the temperatures by taking into account the radiative and conductive thermic transfers as well as the linearity of the materials characteristics as functions depending on temperature

  4. Feasibility studies on the direct wire readout on wire scanners in electron accelerators; Durchfuehrbarkeitsstudien zur direkten Drahtauslese an Wirescannern in Elektronen-Beschleunigern

    Energy Technology Data Exchange (ETDEWEB)

    Markert, Michael

    2010-10-15

    This bachelor thesis deals essentially with the signal processing of a so-called wire scanner, a special monitor, which comes to application in the beam diagnostics of particle accelerators. In this direct wire readout the voltage signal, which is induced by the particle beam in the measurement wire of the wire scanner, shall be directly read out. The aim of this thesis is to show fundamental considerations and perform studies, which study, whether and how in the future by means of a suited data transmission as well as readout electronics conclusion on the most important parameters of the beam, like position and profile, are possible. The measurement system presented here is divided in three main components: Signal measurement, signal preparation, and signal stretching. A suited test facility was developed and is presented in detail, in which then all components, like for instance the transmission cables, the wire-scanner fork, and the developed measurement circuit, are studied, which are of importance for a faultless signal transmission and presentation. Extensive measurements on the single components, as well as calculations for the signal transmission on and in the wire scanner were performed, whereby a good agreement could be found. Thereafter a comparison and a selection of the component used in this project were made. Furthermore improvement proposals, new constructions, and outlooks are presented, which could be of importance in further works.

  5. The Potential of Light Laser Scanners Developed for Unmanned Aerial Vehicles - The Review and Accuracy

    Science.gov (United States)

    Pilarska, M.; Ostrowski, W.; Bakuła, K.; Górski, K.; Kurczyński, Z.

    2016-10-01

    Modern photogrammetry and remote sensing have found small Unmanned Aerial Vehicles (UAVs) to be a valuable source of data in various branches of science and industry (e.g., agriculture, cultural heritage). Recently, the growing role of laser scanning in the application of UAVs has also been observed. Laser scanners dedicated to UAVs consist of four basic components: a laser scanner (LiDAR), an Inertial Measurement Unit (IMU), a Global Navigation Satellite System (GNSS) receiver and an on-board computer. The producers of the system provide users with detailed descriptions of the accuracies separately for each component. However, the final measurement accuracy is not given. This paper reviews state-of-the-art of laser scanners developed specifically for use on a UAV, presenting an overview of several constructions that are available nowadays. The second part of the paper is focussed on analysing the influence of the sensor accuracies on the final measurement accuracy. Mathematical models developed for Airborne Laser Scanning (ALS) accuracy analyses are used to estimate the theoretical accuracies of different scanners with conditions typical for UAV missions. Finally, the theoretical results derived from the mathematical simulations are compared with an experimental use case.

  6. Quantification of terrestrial laser scanner (TLS) elevation accuracy in oil palm plantation for IFSAR improvement

    Science.gov (United States)

    Muhadi, N. A.; Abdullah, A. F.; Kassim, M. S. M.

    2016-06-01

    In order to ensure the oil palm productivity is high, plantation site should be chosen wisely. Slope is one of the essential factors that need to be taken into consideration when doing a site selection. High quality of plantation area map with elevation information is needed for decision-making especially when dealing with hilly and steep area. Therefore, accurate digital elevation models (DEMs) are required. This research aims to increase the accuracy of Interferometric Synthetic Aperture Radar (IFSAR) by integrating Terrestrial Laser Scanner (TLS) to generate DEMs. However, the focus of this paper is to evaluate the z-value accuracy of TLS data and Real-Time Kinematic GPS (RTK-GPS) as a reference. Besides, this paper studied the importance of filtering process in developing an accurate DEMs. From this study, it has been concluded that the differences of z-values between TLS and IFSAR were small if the points were located on route and when TLS data has been filtered. This paper also concludes that laser scanner (TLS) should be set up on the route to reduce elevation error.

  7. Beam Emittance Measurement with Laser Wire Scanners in the ILC Beam Delivery System

    Energy Technology Data Exchange (ETDEWEB)

    Agapov, I.; /CERN; Blair, G.A.; /Royal Holloway, U. of London; Woodley, M.; /SLAC

    2008-02-01

    Accurate measurement of the beam phase-space is essential for the next generation of electron accelerators. A scheme for beam optics optimization and beam matrix reconstruction algorithms for the diagnostics section of the beam delivery system of the International Linear Collider based on laser-wire beam profile monitors are discussed. Possible modes of operation of the laser-wire system together with their corresponding performance are presented. Based on these results, prospects for reconstructing the ILC beam emittance from representative laser-wire beam size measurements are evaluated.

  8. Micron-scale laser-wire scanner for the KEK Accelerator Test Facility extraction line

    Science.gov (United States)

    Boogert, Stewart T.; Blair, Grahame A.; Boorman, Gary; Bosco, Alessio; Deacon, Lawrence C.; Karataev, Pavel; Aryshev, Alexander; Fukuda, Masafumi; Terunuma, Nobihiro; Urakawa, Junji; Corner, Laura; Delerue, Nicolas; Foster, Brian; Howell, David; Newman, Myriam; Senanayake, Rohan; Walczak, Roman; Ganaway, Fred

    2010-12-01

    A laser-wire transverse electron beam size measurement system has been constructed and operated at the Accelerator Test Facility (ATF) extraction line at KEK. The construction of the system is described in detail along with the environment of the ATF related to the laser wire. A special set of electron beam optics was developed to generate an approximately 1μm vertical focus at the laser-wire location. The results of our operation at the ATF extraction line are presented, where a minimum rms electron beam size of 4.8±0.3μm was measured, and smaller electron beam sizes can be measured by developing the method further. The beam size at the laser-wire location was changed using quadrupoles and the resulting electron beam size measured, and vertical emittance extracted.

  9. Temporal Stability of the Velodyne HDL-64E S2 Scanner for High Accuracy Scanning Applications

    Directory of Open Access Journals (Sweden)

    Craig Glennie

    2011-03-01

    Full Text Available The temporal stability and static calibration and analysis of the Velodyne HDL‑64E S2 scanning LiDAR system is discussed and analyzed. The mathematical model for measurements for the HDL-64E S2 scanner is updated to include misalignments between the angular encoder and scanner axis of rotation, which are found to be a marginally significant source of error. It is reported that the horizontal and vertical laser offsets cannot reliably be obtained with the current calibration model due to their high correlation with the horizontal and vertical offsets. By analyzing observations from two separate HDL-64E S2 scanners it was found that the temporal stability of the horizontal angle offset is near the quantization level of the encoder, but the vertical angular offset, distance offset and distance scale are slightly larger than expected. This is felt to be due to long term variations in the scanner range, whose root cause is as of yet unidentified. Nevertheless, a temporally averaged calibration dataset for each of the scanners resulted in a 25% improvement in the 3D planar misclosure residual RMSE over the standard factory calibration model.

  10. Rapid, high-accuracy detection of strabismus and amblyopia using the pediatric vision scanner

    NARCIS (Netherlands)

    S.E. Loudon (Sjoukje); C.A. Rook (Caitlin); D.S. Nassif (Deborah); N.V. Piskun (Nadya); D.G. Hunter (David)

    2011-01-01

    textabstractPurpose. The Pediatric Vision Scanner (PVS) detects strabismus by identifying ocular fixation in both eyes simultaneously. This study was undertaken to assess the ability of the PVS to identify patients with amblyopia or strabismus, particularly anisometropic amblyopia with no measurable

  11. Test Measurements of a 20 ms-1 Carbon Wire Beam Scanner

    CERN Document Server

    De Freitas, J; Emery, J; Herranz Alvarez, J F; Koujili, M; Ramos, D; Sapinski, M; Ait-Amira, Y; Djerdir, A

    2011-01-01

    This paper pre­sents the de­sign of the ac­tu­a­tor for the fast and high ac­cu­ra­cy Wire Scan­ner sys­tem. The ac­tu­a­tor con­sists of a ro­tary brushless syn­chronous motor with the per­ma­nent mag­net rotor in­stalled in­side the vac­u­um cham­ber and the sta­tor in­stalled out­side. The fork, per­ma­nent mag­net rotor and two an­gu­lar po­si­tion sen­sors are mount­ed on the same axis and lo­cat­ed in­side the beam vac­u­um cham­ber. The system has to re­sist a bake-out tem­per­a­ture of 200 C and ion­iz­ing radi­a­tion up to tenths of kGy/year. Max­i­mum wire trav­el­ling speed of 20 m/s and a po­si­tion mea­sure­ment ac­cu­ra­cy of 4 um is re­quired. Therefore, the sys­tem must avoid gen­er­at­ing vi­bra­tion and electromagnet­ic in­ter­fer­ence. A dig­i­tal feed­back con­troller will allow max­i­mum flex­i­bil­i­ty for the loop pa­ram­e­ters and feeds the 3-phase lin­ear power driv­er. The per­for­mance of the pr...

  12. Evaluation of Clouds and the Earth's Radiant Energy System (CERES) Scanner Pointing Accuracy using a Coastline Detection System

    Science.gov (United States)

    Currey, Chris; Smith, Lou; Neely, Bob

    1998-01-01

    Clouds and the Earth's Radiant Energy System (CERES) is a National Aeronautics and Space Administration (NASA) investigation to examine the role of clouds in the radiative energy flow through the Earth-atmosphere system. The first CERES scanning radiometer was launched on November 27, 1997 into a 35 inclination, 350 km altitude orbit, on the Tropical Rainfall Measuring Mission (TRMM) spacecraft. The CERES instrument consists of a three channel scanning broadband radiometer. The spectral bands measure shortwave (0.3 - 5 microns), window (8 - 12 microns), and total (0.3 - 100 microns) radiation reflected or emitted from the Earth-atmosphere system. Each Earth viewing measurement is geolocated to the Earth fixed coordinate system using satellite ephemeris, Earth rotation and geoid, and instrument pointing data. The interactive CERES coastline detection system is used to assess the accuracy of the CERES geolocation process. By analyzing radiative flux gradients at the boundaries of ocean and land masses, the accuracy of the scanner measurement locations may be derived for the CERES/TRMM instrument/satellite system. The resulting CERES measurement location errors are within 10% of the nadir footprint size. Precise pointing knowledge of the Visible and Infrared Scanner (VIRS) is required for convolution of cloud properties onto the CERES footprint; initial VIRS coastline results are included.

  13. Comparison of the Accuracy of Canon KU-1 IOL Measurer and VPLUS A/B Scanner in Axial Length Measurement

    Institute of Scientific and Technical Information of China (English)

    Chuyin Chen; Zhende Lin; Bo Feng; Yonghua Li

    2003-01-01

    Purpose: To evaluate the accuracy of Canon KU-1 IOL measurer (Japanese Canon Company) and VPLUS A/B scanner (French Quantel Company) in axial length (AL)measurement.Methods:Canon KU-1 IOL measurer and VPLUS A/B scanner were used to measure axial length of human cataractous eyes before cataract surgery. Two hundred and twentytwo cases (433 eyes) were involved. The results were compared and the postoperative visual acuity, refractive results were recorded during the follow-ups to evaluate the accuracy of the two instruments.Results:In the 222 cases (433 eyes), the absolute value of the measurement differences was 0.4 mm or above in 35 eyes, 0.8 mm or above in 17 eyes, 1.2 mm or above in 12 eyes,2.0mm or above in 5 eyes. The refractive error was less than 2.0D in all patients. The mean values of ocular axial length by the two methods were 23.82 mm and 23.83 mm respectively and the difference had no statistic significance with compared t test ( P=0.902, two tail, or=0.01).Conclusion:The accurate AL measurements can be obtained with the two instruments and the measurement results should be analyzed comprehensively to obtain accurate values in the complicated cases.

  14. A protocol for evaluating the accuracy of 3D body scanners

    NARCIS (Netherlands)

    Kouchi, M.; Mochimaru, M.; Bradtmiller, B.; Daanen, H.A.M.; Li, P.; Nacher, B.A.; Nam, Y.

    2012-01-01

    Scan-derived landmarks locations and surface shapes are more and more used, but there is no commonly accepted protocol for evaluating the accuracy of these measurements. Therefore we propose a protocol for evaluating the accuracy of surface shape and the repeatability of scan-derived landmark locati

  15. Geometric accuracy of dynamic MLC tracking with an implantable wired electromagnetic transponder

    Energy Technology Data Exchange (ETDEWEB)

    Ravkilde, Thomas; Hoejbjerre, Klaus; Fledelius, Walther; Worm, Esben (Dept. of Oncology, Aarhus Univ. Hospital (Denmark)), e-mail: thomravk@rm.dk; Keall, Paul J. (Central Clinical School, Univ. of Sydney (Australia); Dept. of Radiation Oncology, Stanford Univ. (United States)); Poulsen, Per R. (Dept. of Oncology, Aarhus Univ. Hospital (Denmark); Inst. of Clinical Medicine, Aarhus Univ. (Denmark))

    2011-08-15

    Background. Tumor motion during radiotherapy delivery can substantially deteriorate the target dose distribution. A promising method to overcome this problem is dynamic multi-leaf collimator (DMLC) tracking. The purpose of this phantom study was to integrate a wired electromagnetic (EM) transponder localization system with DMLC tracking and to investigate the geometric accuracy of the integrated system. Material and methods. DMLC tracking experiments were performed on a Trilogy accelerator with a prototype DMLC tracking system. A wired implantable EM transponder was mounted on a motion stage with a 3 mm tungsten sphere used for target visualization in continuous portal images. The three dimensional (3D) transponder position signal was used for DMLC aperture adaption. The motion stage was programmed to reproduce eight representative patient-measured trajectories for prostate and for lung tumors. The tracking system latency was determined and prediction was used for the lung tumor trajectories to account for the latency. For each trajectory, three conformal fields with a 10 cm circular MLC aperture and 72 s treatment duration were delivered: (1) a 358 deg arc field; (2) an anterior static field; and (3) a lateral static field. The tracking error was measured as the difference between the marker position and the MLC aperture in the portal images. Results. The tracking system latency was 140 ms. The mean root-mean-square (rms) of the 3D transponder localization error was 0.53/0.54 mm for prostate/lung tumor trajectories. The mean rms of the two dimensional (2D) tracking error was 0.69 mm (prostate) and 0.98 mm (lung tumors) with tracking and 3.4 mm (prostate) and 5.3 mm (lung tumors) without tracking. Conclusions. DMLC tracking was integrated with a wired EM transponder localization system and investigated for arc and static field delivery. The system provides sub-mm geometrical errors for most trajectories

  16. Study on Detection of 3D Laser Scanner Positional Accuracy%三维激光扫描仪点位精度检测研究

    Institute of Scientific and Technical Information of China (English)

    王鸣霄; 戴相喜; 王正强

    2013-01-01

    3D laser scanner is a new fast mean to acquire 3d coordinates of ground objects ,has many increasing in-comparable advantages than traditional measuring means and has wide application prospect .Aim to obtain the actual ac-curacy of its scanning data ,so as to confirm its range of application;this paper designed an experiment ,detection accuracy through surveying the same area using both 3 d laser scanner and total station instrument ,finally get the general accuracy information of 3 d laser scanner ,offer data support to confirm its application range .%三维激光扫描仪扫描作为一种新型的地物三维坐标快速获取手段,具有传统测量手段很多无法比拟的优势,具有广阔的应用前景。为了解其扫描所得点的实际精度,以便确定其适用领域,本文设计实验,采用三维激光扫描仪和全站仪重复测量的方法对其进行检测,得到三维激光扫描仪精度的基本情况,为确定其适用范围提供数据支持。

  17. High-Precision Surface Inspection: Uncertainty Evaluation within an Accuracy Range of 15μm with Triangulation-based Laser Line Scanners

    Science.gov (United States)

    Dupuis, Jan; Kuhlmann, Heiner

    2014-06-01

    Triangulation-based range sensors, e.g. laser line scanners, are used for high-precision geometrical acquisition of free-form surfaces, for reverse engineering tasks or quality management. In contrast to classical tactile measuring devices, these scanners generate a great amount of 3D-points in a short period of time and enable the inspection of soft materials. However, for accurate measurements, a number of aspects have to be considered to minimize measurement uncertainties. This study outlines possible sources of uncertainties during the measurement process regarding the scanner warm-up, the impact of laser power and exposure time as well as scanner’s reaction to areas of discontinuity, e.g. edges. All experiments were performed using a fixed scanner position to avoid effects resulting from imaging geometry. The results show a significant dependence of measurement accuracy on the correct adaption of exposure time as a function of surface reflectivity and laser power. Additionally, it is illustrated that surface structure as well as edges can cause significant systematic uncertainties.

  18. 三维激光扫描仪精度测试及应用%Accuracy testing and application of 3D laser scanner

    Institute of Scientific and Technical Information of China (English)

    张铁军; 沈家海; 申文永

    2015-01-01

    The basic principle of 3D laser scanner, and the test methods of its positional accuracy in pile surveying were introduced in this paper. According to engineering requirements, we arranged control points, chose columns under the viaduct in land as observation target, measured the center coordinates respectively using 3D laser scanner and total station, analyzed the measuring accuracy of 3D laser scanner based on total station measuring results, and explored its application in engineering surveying.%介绍了三维激光扫描仪的基本原理及其应用于桩基测量精度分析的测试方法。按照工程需求,布置控制点,选择陆地高架桥下的圆柱作为观测目标,分别用三维激光扫描仪和全站仪测量出圆心坐标,以全站仪测量成果为基准,分析三维激光扫描仪的测量精度,探索其在工程测量中的应用。

  19. Note: Optical and electronic design of an amplitude-modulated continuous-wave laser scanner for high-accuracy distance measurement

    Energy Technology Data Exchange (ETDEWEB)

    Jang, Junhwan; Hwang, Sungui; Park, Kyihwan, E-mail: khpark@gist.ac.kr [School of Mechatronics, Gwangju Institute of Science and Technology, 123 Cheomdangwagi-ro, Buk-gu, Gwangju (Korea, Republic of)

    2015-04-15

    To utilize a time-of-flight-based laser scanner as a distance measurement sensor, the measurable distance and accuracy are the most important performance parameters to consider. For these purposes, the optical system and electronic signal processing of the laser scanner should be optimally designed in order to reduce a distance error caused by the optical crosstalk and wide dynamic range input. Optical system design for removing optical crosstalk problem is proposed in this work. Intensity control is also considered to solve the problem of a phase-shift variation in the signal processing circuit caused by object reflectivity. The experimental results for optical system and signal processing design are performed using 3D measurements.

  20. Quantitative evaluation for the accuracy of dental model three-dimensional scanner%牙颌模型三维扫描仪精度定量评价

    Institute of Scientific and Technical Information of China (English)

    宋杨; 孙玉春; 赵一姣; 王勇; 吕培军

    2013-01-01

    目的:建立一种牙颌模型三维扫描仪精度的定量评价方法,应用该方法对3Shape D700商品化扫描仪进行精度这一核心指标的定量评价.方法:在三维逆向软件中设计一个整体外形类似于牙弓的标准几何样块,用高精度数控加工技术加工,利用此样块评价分析牙颌模型扫描仪关键技术指标,包括单次扫描精度、空间一致性、重复扫描精度共3项指标.结果:3 Shape D700商品化扫描仪的单次扫描精度结果为(15.00±10.84)μm,和厂家说明书给出的精度结果20μm差异无统计学意义(P=0.053);此外,空间一致性(垂直方向和水平方向,P =0.524)和重复扫描精度(垂直方向P=0.633,水平方向P=0.221)的检测结果差异亦无统计学意义.结论:使用该方法评价牙科扫描仪精度,可以避免手工选点法存在的观察者误差,是有效可行的.%To establish a method to evaluate dental model three-dimensional scanner quantitatively, and to evaluate the accuracy which is a core indicator of 3Shape D700 scanner. Methods; A standard geometric model similar to the dental arch was designed by three-dimensional reverse software and processed by high precision CNC (computer numerical control) processing technology. Core indicators of dental model three-dimensional scanner including single scanning accuracy, space consistency and rescan accuracy were evaluated. Results; The result of single scanning accuracy of 3Shape D700 scanner was (15.00 ±10. 84) μm, and there was no statistics difference between the accuracy given by manufacturer ' s instructions which is 20 μm ( P - 0.053 ) , and same as the results of space consistency ( compare the accuracy in vertical direction and horizontal direction, P =0. 524) and rescan accuracy (compare the rescan accuracy in vertical direction, P = 0.633, and in horizontal direction P = 0.221). Conclusion; It is feasible to evaluate accuracy of dental model three-dimensional scanner by this method, which

  1. Research Into the Collimation and Horizontal Axis Errors Influence on the Z+F Laser Scanner Accuracy of Verticality Measurement

    Science.gov (United States)

    Sawicki, J.; Kowalczyk, M.

    2016-06-01

    Aim of this study was to appoint values of collimation and horizontal axis errors of the laser scanner ZF 5006h owned by Department of Geodesy and Cartography, Warsaw University of Technology, and then to determine the effect of those errors on the results of measurements. An experiment has been performed, involving measurement of the test field , founded in the Main Hall of the Main Building of the Warsaw University of Technology, during which values of instrumental errors of interest were determined. Then, an universal computer program that automates the proposed algorithm and capable of applying corrections to measured target coordinates or even entire point clouds from individual stations, has been developed.

  2. A simple digital-optical system to improve accuracy of hot-wire measurements

    International Nuclear Information System (INIS)

    A high precision traverse mechanism with micro-resolution was designed to capture accurately the velocity profile of the very thin turbulent attachment line on a swept body. To ensure that the traverse mechanism could position the hot wire reliably, a simple digital optical system was designed to check the performance of the traverse by measuring the displacement of the hot wire: a vertical displacement of 2.4 µm was achievable and this could be further reduced to 0.6 µm using micro-stepping. Due to the simplicity of the set-up it was equally useful for probe wall positioning and the velocity profiles captured clearly demonstrated that the optical set-up helped in resolving the near wall flow more accurately, regardless of the thinness of the boundary layer. The captured data compare well with the results from similar investigations, with arguably higher precision achieved. (paper)

  3. Diagnostic accuracy of state-of-the-art MDCT scanners without gantry tilt in patients with oral and oropharyngeal cancer

    Energy Technology Data Exchange (ETDEWEB)

    Bannas, Peter, E-mail: p.bannas@uke.de [Department of Diagnostic and Interventional Radiology, University Hospital Hamburg-Eppendorf, Martinistr. 52, 20246 Hamburg (Germany); Habermann, Christian R., E-mail: c.habermann@uke.de [Department of Diagnostic and Interventional Radiology, University Hospital Hamburg-Eppendorf, Martinistr. 52, 20246 Hamburg (Germany); Jung, Caroline, E-mail: cjung@uke.de [Department of Diagnostic and Interventional Radiology, University Hospital Hamburg-Eppendorf, Martinistr. 52, 20246 Hamburg (Germany); Bley, Thorsten A., E-mail: t.bley@uke.de [Department of Diagnostic and Interventional Radiology, University Hospital Hamburg-Eppendorf, Martinistr. 52, 20246 Hamburg (Germany); Ittrich, Harald, E-mail: Ittrich@uke.de [Department of Diagnostic and Interventional Radiology, University Hospital Hamburg-Eppendorf, Martinistr. 52, 20246 Hamburg (Germany); Adam, Gerhard, E-mail: g.adam@uke.de [Department of Diagnostic and Interventional Radiology, University Hospital Hamburg-Eppendorf, Martinistr. 52, 20246 Hamburg (Germany); Koops, Andreas, E-mail: koops@uke.de [Department of Diagnostic and Interventional Radiology, University Hospital Hamburg-Eppendorf, Martinistr. 52, 20246 Hamburg (Germany)

    2012-12-15

    Purpose: Current CT-protocols for staging oral and oropharyngeal cancer include primary transversal slices and secondary tilted slices to avoid artifact-producing regions of dental metalwork. Some of the latest MDCT scanners do not allow gantry tilt. Hence, we assessed the relevance of secondary tilted slices in tumor staging. Materials and methods: Scans of a tiltable 64-row MDCT-scanner of 82 patients with oral or oropharyngeal cancer were retrospectively and independently evaluated twice by three readers: once using the primary transversal scans only, and once taking the transversal and secondary tilted scans into account. Tumor diameters and TN-stage were determined with both methods. Artifacts on transversal scans were analyzed using a 3-point-ranking-scale. Results: Image quality was impaired by severe artifacts in 24% of transversal slices of the oral cavity and in 12% of the oropharynx. The three readers detected an average of 57.7 ± 2.1 of 82 tumors (70%) on transversal CT slices. An average of 6.3 ± 0.6 more tumors (8%) were detected when transversal studies were evaluated in conjunction with secondary tilted slices, leading to a significantly (p = 0.0156–0.0313) increased average detection rate of 64.0 ± 2.0 tumors (78%). Moreover, secondary tilted slices led to a correction of underestimated tumor stages in up to six patients (7.3%). Conclusion: Tilted slices that avoid artifact-producing regions of dental metalwork significantly improve the reader's sensitivity and are of incremental value for staging of oral and oropharyngeal cancers.

  4. Diagnostic accuracy of state-of-the-art MDCT scanners without gantry tilt in patients with oral and oropharyngeal cancer

    International Nuclear Information System (INIS)

    Purpose: Current CT-protocols for staging oral and oropharyngeal cancer include primary transversal slices and secondary tilted slices to avoid artifact-producing regions of dental metalwork. Some of the latest MDCT scanners do not allow gantry tilt. Hence, we assessed the relevance of secondary tilted slices in tumor staging. Materials and methods: Scans of a tiltable 64-row MDCT-scanner of 82 patients with oral or oropharyngeal cancer were retrospectively and independently evaluated twice by three readers: once using the primary transversal scans only, and once taking the transversal and secondary tilted scans into account. Tumor diameters and TN-stage were determined with both methods. Artifacts on transversal scans were analyzed using a 3-point-ranking-scale. Results: Image quality was impaired by severe artifacts in 24% of transversal slices of the oral cavity and in 12% of the oropharynx. The three readers detected an average of 57.7 ± 2.1 of 82 tumors (70%) on transversal CT slices. An average of 6.3 ± 0.6 more tumors (8%) were detected when transversal studies were evaluated in conjunction with secondary tilted slices, leading to a significantly (p = 0.0156–0.0313) increased average detection rate of 64.0 ± 2.0 tumors (78%). Moreover, secondary tilted slices led to a correction of underestimated tumor stages in up to six patients (7.3%). Conclusion: Tilted slices that avoid artifact-producing regions of dental metalwork significantly improve the reader's sensitivity and are of incremental value for staging of oral and oropharyngeal cancers.

  5. Development of response models for the Earth Radiation Budget Experiment (ERBE) sensors. Part 3: ERBE scanner measurement accuracy analysis due to reduced housekeeping data

    Science.gov (United States)

    Choi, Sang H.; Chrisman, Dan A., Jr.; Halyo, Nesim

    1987-01-01

    The accuracy of scanner measurements was evaluated when the sampling frequency of sensor housekeeping (HK) data was reduced from once every scan to once every eight scans. The resulting increase in uncertainty was greatest for sources with rapid or extreme temperature changes. This analysis focused on the mirror attenuator mosaic (MAM) baffle and plate and scanner radiometer baffle due to their relatively high temperature changes during solar calibrations. Since only solar simulator data were available, the solar temperatures were approximated on these components and the radiative and thermal gradients in the MAM baffle due to reflected sunlight. Of the two cases considered for the MAM plate and baffle temperatures, one uses temperatures obtained from the ground calibration. The other attempt uses temperatures computed from the MAM baffle model. This analysis shows that the heat input variations due largely to the solar radiance and irradiance during a scan cycle are small. It also demonstrates that reasonable intervals longer than the current HK data acquisition interval should not significantly affect the estimation of a radiation field in the sensor field-of-view.

  6. The effect of CT scanner parameters and 3D volume rendering techniques on the accuracy of linear, angular, and volumetric measurements of the mandible

    Science.gov (United States)

    Whyms, B.J.; Vorperian, H.K.; Gentry, L.R.; Schimek, E.M.; Bersu, E.T.; Chung, M.K.

    2013-01-01

    Objectives This study investigates the effect of scanning parameters on the accuracy of measurements from three-dimensional multi-detector computed tomography (3D-CT) mandible renderings. A broader range of acceptable parameters can increase the availability of CT studies for retrospective analysis. Study Design Three human mandibles and a phantom object were scanned using 18 combinations of slice thickness, field of view, and reconstruction algorithm and three different threshold-based segmentations. Measurements of 3D-CT models and specimens were compared. Results Linear and angular measurements were accurate, irrespective of scanner parameters or rendering technique. Volume measurements were accurate with a slice thickness of 1.25 mm, but not 2.5 mm. Surface area measurements were consistently inflated. Conclusions Linear, angular and volumetric measurements of mandible 3D-CT models can be confidently obtained from a range of parameters and rendering techniques. Slice thickness is the primary factor affecting volume measurements. These findings should also apply to 3D rendering using cone-beam-CT. PMID:23601224

  7. RIEGL LMS-Z390i三维激光扫描仪测角精度评定方法研究%Research of Methods on the Angle Accuracy Behavior of RIEGL LMS-Z390i Laser Scanner

    Institute of Scientific and Technical Information of China (English)

    张启福; 孙现申; 王贺; 王力

    2012-01-01

    提出了一种新的三维激光扫描仪测角精度评定方法,用TM5100电子经纬仪建立角度基准,以RIEGLLMS-Z390i激光扫描仪观测的点云坐标反算出的角度作为观测值,在考虑轴系误差的影响基础上,建立了平差模型,通过最小二乘解算出激光扫描仪的水平、垂直测角精度分别为0.002 7°、0.001 5°,评定出该方法的可行性.%A new method to assess the angle accuracy of 3D Laser Scanner is presented. TM5100 electronic theodolite was used to set up datum angle,and the angle accuracy of RIEGL LMS-Z390i Laser Scanner was assessed. The observed angle was obtained by 3D coordinate of point-clouds,and the analysed axes errors of 3D Laser Scanner is used to set up the calibration model. According to the least squares adjustment,the angle accuracy were 0. 002 7° and 0. 001 5°, so the new method was feasible.

  8. Proton scanner

    International Nuclear Information System (INIS)

    The scanner is based on the nuclear scattering of high energy protons by the nucleons (protons and neutrons) included in the atomic nuclei. Because of the wide scattering angle, three coordinates in space of the interaction point can be computed, giving directly three dimensional radiographs. Volumic resolution is of about a few cubic-millimeters. Because the base interaction is the strong nuclear force, the atomic dependence of the information obtained is different from that of the X-ray scanner, for which the base interaction is electro-magnetic force. (orig./VJ)

  9. Quantitative evaluation of the measurement accuracy of 2 three-dimensional facial scanners%2种三维颜面部扫描仪测量精度的定量评价

    Institute of Scientific and Technical Information of China (English)

    赵一姣; 熊玉雪; 杨慧芳; 吕培军; 孙玉春; 王勇

    2016-01-01

    Objective:To evaluate the actual measurement accuracy of 2 three-dimensional(3D)facial scanners for real person. Methods:3D digital face models of 1 0 volunteers with normal ficial form were obtained by 3dMD and FaceScan facial scanners respec-tively.The measurement values of 1 0 feature lengths and 5 feature angles were measured on each 3D model by the software respective-ly.The reference values of all characteristics were acquired by line laser scanner (Faro)with high accuracy.Statistical and surveying analysis were taken between the measurement values and reference values.Facial morphology measurement error and actual accuracy of facial scanners were obtained finally.Data were statistically analysed.Results:The length measurement accuracy of 3dMD and FaceS-can was(-0.37 ±0.68)mm and (-0.29 ±0.53)mm(P =0.223),the angle measurement accuracy was (-0.22 ±2.1 4)°and (0.1 2 ±2.69)°(P =0.428),respectively.Conclusion:The 3D data of ficial morphology obtained by the 2 scanners are not signifi-cantly different.%目的:对三维颜面部扫描仪进行真人实际测量精度评价。方法:分别应用三维颜面部扫描仪3dMD 和 FaceScan 获取10名正常面型志愿者的三维面相数字模型,测量每个模型上的10个特征线段长度和5个特征角度,并分别与高精度线激光扫描仪(Faro)获取的参考值进行统计学分析和测量学分析,计算面貌特征测量误差与实际测量精度。结果:3dMD 和 FaceS-can 对正常面型人群的长度测量精度分别为(-0.37±0.68)mm 和(-0.29±0.53)mm(P =0.223),角度测量精度分别为(-0.22±2.14)°和(0.12±2.69)°(P =0.428)。结论:2种三维面部扫描仪获取的三维面相数据无显著差异。

  10. Scanner calibration revisited

    Directory of Open Access Journals (Sweden)

    Pozhitkov Alexander E

    2010-07-01

    Full Text Available Abstract Background Calibration of a microarray scanner is critical for accurate interpretation of microarray results. Shi et al. (BMC Bioinformatics, 2005, 6, Art. No. S11 Suppl. 2. reported usage of a Full Moon BioSystems slide for calibration. Inspired by the Shi et al. work, we have calibrated microarray scanners in our previous research. We were puzzled however, that most of the signal intensities from a biological sample fell below the sensitivity threshold level determined by the calibration slide. This conundrum led us to re-investigate the quality of calibration provided by the Full Moon BioSystems slide as well as the accuracy of the analysis performed by Shi et al. Methods Signal intensities were recorded on three different microarray scanners at various photomultiplier gain levels using the same calibration slide from Full Moon BioSystems. Data analysis was conducted on raw signal intensities without normalization or transformation of any kind. Weighted least-squares method was used to fit the data. Results We found that initial analysis performed by Shi et al. did not take into account autofluorescence of the Full Moon BioSystems slide, which led to a grossly distorted microarray scanner response. Our analysis revealed that a power-law function, which is explicitly accounting for the slide autofluorescence, perfectly described a relationship between signal intensities and fluorophore quantities. Conclusions Microarray scanners respond in a much less distorted fashion than was reported by Shi et al. Full Moon BioSystems calibration slides are inadequate for performing calibration. We recommend against using these slides.

  11. On Improving Accuracy of Finite-Element Solutions of the Effective-Mass Schrödinger Equation for Interdiffused Quantum Wells and Quantum Wires

    Science.gov (United States)

    Topalović, D. B.; Arsoski, V. V.; Pavlović, S.; Čukarić, N. A.; Tadić, M. Ž.; Peeters, F. M.

    2016-01-01

    We use the Galerkin approach and the finite-element method to numerically solve the effective-mass Schrödinger equation. The accuracy of the solution is explored as it varies with the range of the numerical domain. The model potentials are those of interdiffused semiconductor quantum wells and axially symmetric quantum wires. Also, the model of a linear harmonic oscillator is considered for comparison reasons. It is demonstrated that the absolute error of the electron ground state energy level exhibits a minimum at a certain domain range, which is thus considered to be optimal. This range is found to depend on the number of mesh nodes N approximately as α0 logeα1(α2N), where the values of the constants α0, α1, and α2 are determined by fitting the numerical data. And the optimal range is found to be a weak function of the diffusion length. Moreover, it was demonstrated that a domain range adaptation to the optimal value leads to substantial improvement of accuracy of the solution of the Schrödinger equation. Supported by the Ministry of Education, Science, and Technological Development of Serbia and the Flemish fund for Scientific Research (FWO Vlaanderen)

  12. Network Security Scanner

    OpenAIRE

    G. MURALI; M.Pranavi; Y.Navateja; K. Bhargavi

    2011-01-01

    Network Security Scanner (NSS) is a tool that allows auditing and monitoring remote network computers for possible vulnerabilities, checks your network for all potential methods that a hacker might use to attack it. Network Security Scanner is a complete networking utilities package that includes a wide range of tools for network security auditing, vulnerability Auditing, scanning, monitoring and more. Network Security Scanner (NSS) is an easy to use, intuitive network security scanner that c...

  13. The Threading Hole Processing Position and Accuracy of Numerical Control Electrospark Wire-electrode Cutting%数控电火花线切割穿丝孔加工位置及精度影响

    Institute of Scientific and Technical Information of China (English)

    王晖; 杨德治

    2011-01-01

    With the mold industry and other manufacturing industry's rapid development, the electrospark wire-electrode cutting of various process parameters such as size precision, surface roughness and so put forward more and more requirements. In the electrospark wire-electrode cutting processing through the wire hole is a frequently encountered problems, threading hole is the starting point of molybdenum wire moving relative to a workpiece, but also the procedures for the implementation of the starting position. The threading hole location on machining accuracy and cutting speed are in a great relationship, this paper lay the threading hole position and accuracy are discussed.%随着模具产业和其它加工制造业的飞速发展,对电火花线切割各项工艺指标如尺寸精度、表面粗糙度等都提出了越来越高的要求。在电火花线切割加工中打穿丝孔是一个经常遇到的基本问题,穿丝孔是钼丝相对于工件运动的起点,同时也是程序执行的起始位置。穿丝孔的位置对于加工精度及切割速度关系甚大,文中就打好穿丝孔位置及精度问题进行了论述。

  14. Verification of a CT scanner using a miniature step gauge

    OpenAIRE

    Cantatore, Angela; Andreasen, J.L.; Carmignato, S; Müller, Pavel; De Chiffre, Leonardo

    2011-01-01

    The work deals with performance verification of a CT scanner using a 42mm miniature replica step gauge developed for optical scanner verification. Errors quantification and optimization of CT system set-up in terms of resolution and measurement accuracy are fundamental for use of CT scanning in dimensional metrology. Influence of workpiece orientation, magnification, source-object-detector distances and surface extraction method on metrological performances of a CT scanner was evaluated. Resu...

  15. Scanner matching optimization

    Science.gov (United States)

    Kupers, Michiel; Klingbeil, Patrick; Tschischgale, Joerg; Buhl, Stefan; Hempel, Fritjof

    2009-03-01

    Cost of ownership of scanners for the manufacturing of front end layers is becoming increasingly expensive. The ability to quickly switch the production of a layer to another scanner in case it is down is important. This paper presents a method to match the scanner grids in the most optimal manner so that use of front end scanners in effect becomes interchangeable. A breakdown of the various components of overlay is given and we discuss methods to optimize the matching strategy in the fab. A concern here is how to separate the scanner and process induced effects. We look at the relative contributions of intrafield and interfield errors caused by the scanner and the process. Experimental results of a method to control the scanner grid are presented and discussed. We compare the overlay results before and after optimizing the scanner grids and show that the matching penalty is reduced by 20%. We conclude with some thoughts on the need to correct the remaining matching errors.

  16. wire chamber

    CERN Multimedia

    1967-01-01

    Magnetoscriptive readout wire chamber.Multi-wire detectors contain layers of positively and negatively charged wires enclosed in a chamber full of gas. A charged particle passing through the chamber knocks negatively charged electrons out of atoms in the gas, leaving behind positive ions. The electrons are pulled towards the positively charged wires. They collide with other atoms on the way, producing an avalanche of electrons and ions. The movement of these electrons and ions induces an electric pulse in the wires which is collected by fast electronics. The size of the pulse is proportional to the energy loss of the original particle.

  17. wire chamber

    CERN Multimedia

    Proportional multi-wire chamber. Multi-wire detectors contain layers of positively and negatively charged wires enclosed in a chamber full of gas. A charged particle passing through the chamber knocks negatively charged electrons out of atoms in the gas, leaving behind positive ions. The electrons are pulled towards the positively charged wires. They collide with other atoms on the way, producing an avalanche of electrons and ions. The movement of these electrons and ions induces an electric pulse in the wires which is collected by fast electronics. The size of the pulse is proportional to the energy loss of the original particle. Proportional wire chambers allow a much quicker reading than the optical or magnetoscriptive readout wire chambers.

  18. Metal Optics For Laser Profile Scanners

    Science.gov (United States)

    Klauke, T.; Hock, F.

    1987-01-01

    Laser scanners are a valuable tool for qualitiy control in hostile hot and vibrating environments. Their high measuring speed allows time minimisation of disturbing influences. The loss of accuracy of systems due to thermal distortion could be minimised by designing mechanical-optical systems with low temperature gradients and small differences between thermal expansions of the components. For application in the forging production a laser scanner measuring in situ a series of profile lines describing the hot forging tools has been designed using aluminium for all distortion sensitive mechanical and optical components.

  19. Gaseous wire detectors

    International Nuclear Information System (INIS)

    This article represents a series of three lectures describing topics needed to understand the design of typical gaseous wire detectors used in large high energy physics experiments; including the electrostatic design, drift of electrons in the electric and magnetic field, the avalanche, signal creation, limits on the position accuracy as well as some problems one encounters in practical operations

  20. Cobalt-60 Container Scanner

    Institute of Scientific and Technical Information of China (English)

    1999-01-01

    This paper presents a special container scanner in which the radiation source is a conventional radiography 60Co projector of (100-300)×3 .7×1010Bq. With a specia l sensitive array detector, invented by Institute of Nuclear Energy Technology ( INET) of Tsinghua University and other technical innovations, t he characteristics of the 60Co scanner qualify it for use in c ontainer insp ection. Its contrast indicator (CI) and image quality indicator (IQI) for 10 0 mm steel are equal to 0.7% and 2.5%, respectively, and the steel penetration ( SP) is about 240 mm. The 60Co container scanner is much more ec onomical and more reliable than those scanners using an accelerator source. Also, its penetr ation ability is much better than that of an X-ray machine scanner. This paper p resents the system design, the main difficulties and their technical solutions, the inspection characteristics and the special features of the 60Co sc anner.

  1. wire chamber

    CERN Multimedia

    Was used in ISR (Intersecting Storage Ring) split field magnet experiment. Multi-wire detectors contain layers of positively and negatively charged wires enclosed in a chamber full of gas. A charged particle passing through the chamber knocks negatively charged electrons out of atoms in the gas, leaving behind positive ions. The electrons are pulled towards the positively charged wires. They collide with other atoms on the way, producing an avalanche of electrons and ions. The movement of these electrons and ions induces an electric pulse in the wires which is collected by fast electronics. The size of the pulse is proportional to the energy loss of the original particle.

  2. Characterization of color scanners based on SVR

    Science.gov (United States)

    Li, Bin; Zhang, Yi-xin

    2012-01-01

    By researching the principle of colorimetric characterization method and Support Vector Regression (SVR), we analyze the feasibility of nonlinear transformation from scanner RGB color space to CIELAB color space based on SVR and built a new characterization model. Then we use the MATLABR2009a software to make a data simulation experiment to verify the accuracy of this model and figure out the color differences by CIEDE2000 color difference formula. Based on CIEDE2000 color difference formula, the average, the maximum and the minimum color differences of the training set are 1.2376, 2.5593 and 0.2182, the average, the maximum and the minimum color differences of the text set are 1.9318, 4.1421 and 0.4228. From the experimental results, we can make a conclusion that SVR can realize the nonlinear transformation from scanner RGB color space to CIELAB color space and the model satisfies the accuracy of scanner characterization. Therefore, SVR can be used into the color scanner characterization management.

  3. Network Security Scanner

    Directory of Open Access Journals (Sweden)

    G. Murali

    2011-11-01

    Full Text Available Network Security Scanner (NSS is a tool that allows auditing and monitoring remote network computers for possible vulnerabilities, checks your network for all potential methods that a hacker might use to attack it. Network Security Scanner is a complete networking utilities package that includes a wide range of tools for network security auditing, vulnerability Auditing, scanning, monitoring and more. Network Security Scanner (NSS is an easy to use, intuitive network security scanner that can quickly scan and audit your network computers for vulnerabilities, exploits, and information enumerations. Vulnerability management is an on-going process that protects your valuable data and it is a key component of an effective information security strategy, which provides comprehensive, preemptive protection against threats to your enterprise security. N.S.S is built on an architecture that allows for high reliability and scalability that caters for both medium and large sized networks. NSS consists of six modules. They are Host Scanning, Port Scanning, Pinging, NSLookup, Vulnerability Auditing and Trace route. NSS also performs live host detection, operating system identification, SNMP Auditing. Finds rouge services and open TCP and UDP ports. The ability varies to perform scanning over the network identifying the live hosts and guess the operating system of the remote hosts and installed programs into the remote hosts. Apart identifying the live hosts we could map the ports and list the services which are running in the host.

  4. Freestanding Complex Optical Scanners.

    Science.gov (United States)

    Frisbie, David A.

    A complex freestanding optical mark recognition (OMR) scanner is one which is not on-line to an external processor; it has intelligence stemming from an internal processor located within the unit or system. The advantages and disadvantages of a complex OMR can best be assessed after identifying the scanning needs and constraints of the potential…

  5. Ionization beam scanner

    CERN Multimedia

    CERN PhotoLab

    1973-01-01

    Inner structure of an ionization beam scanner, a rather intricate piece of apparatus which permits one to measure the density distribution of the proton beam passing through it. On the outside of the tank wall there is the coil for the longitudinal magnetic field, on the inside, one can see the arrangement of electrodes creating a highly homogeneous transverse electric field.

  6. Microarray Scanner for Fluorescence Detection

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    A novel pseudo confocal microarray scanner is introduced, in which one dimension scanning is performed by a galvanometer optical scanner and a telecentric objective, another dimension scanning is performed by a stepping motor.

  7. Current Concept of Geometrical Accuracy

    OpenAIRE

    Görög Augustín; Görögová Ingrid

    2014-01-01

    Within the solving VEGA 1/0615/12 research project "Influence of 5-axis grinding parameters on the shank cutter´s geometric accuracy", the research team will measure and evaluate geometrical accuracy of the produced parts. They will use the contemporary measurement technology (for example the optical 3D scanners). During the past few years, significant changes have occurred in the field of geometrical accuracy. The objective of this contribution is to analyse the current standards in the fiel...

  8. Application of intra-oral dental scanners in the digital workflow of implantology

    NARCIS (Netherlands)

    W.J. van der Meer; F.S. Andriessen; D. Wismeijer; Y. Ren

    2012-01-01

    Intra-oral scanners will play a central role in digital dentistry in the near future. In this study the accuracy of three intra-oral scanners was compared. Materials and methods: A master model made of stone was fitted with three high precision manufactured PEEK cylinders and scanned with three intr

  9. Geometric calibration between PET scanner and structured light scanner

    DEFF Research Database (Denmark)

    Kjer, Hans Martin; Olesen, Oline Vinter; Paulsen, Rasmus Reinhold;

    2011-01-01

    is a structured light scanner placed just above the patient tunnel on the High Resolution Research Tomograph (HRRT, Siemens). It continuously registers point clouds of a part of the patient's face. The relative motion is estimated as the rigid transformation between frames. A geometric calibration between...... the HRRT scanner and the tracking system is needed in order to reposition the PET listmode data or image frames in the HRRT scanner coordinate system. This paper presents a method where obtained transmission scan data is segmented in order to create a point cloud of the patient's head. The point clouds...

  10. Distribution of Energy Deposited in Plastic Tubing and Copper-Wire Insulation by Electron Beam Irradiation

    DEFF Research Database (Denmark)

    Pedersen, Walther Batsberg; Miller, Arne; Pejtersen, K.;

    1978-01-01

    Scanned electron beam treatment is used to improve the physical properties of certain polymers, such as shrinkable plastic tubing and insulated wire and cable. Tubing or wires are passed at high speed under the beam scanner, and the material is irradiated to absorbed doses of several Mrad...

  11. Nogle muligheder i scanner data

    DEFF Research Database (Denmark)

    Juhl, Hans Jørn

    2000-01-01

    I artiklen gives en diskussion af en række af de muligheder for effektivisering af marketingaktiviteter, der er til stede for såvel mærkevareudbyder som detaillist, ved udnyttelse af information fra scanner data......I artiklen gives en diskussion af en række af de muligheder for effektivisering af marketingaktiviteter, der er til stede for såvel mærkevareudbyder som detaillist, ved udnyttelse af information fra scanner data...

  12. Densitometry of autoradiographs by scanner

    International Nuclear Information System (INIS)

    One of the advantages of the autoradiography technique is the possibility of obtaining the distribution of the chemical elements over the whole surface samples. A method for transformation of the autoradiography image into an electronic format with the use of the digital document scanners of different types has been developed for computer analysis purposes. It is shown that the technique developed allows us to obtain the two-dimensional distribution of optical density of autoradiograms, replacing one-dimensional densitometry with the using of a microphotometer. A comparison with conventional densitometry is presented. In our work we examined both Small Office Home Office (SOHO) and drum type scanners. Drum scanners give a linear response within a wide range of optical density (up to 2.5), whereas SOHO-scanners possess a linear dependence characteristics up to 0.5. We have demonstrated that the response of SOHO-scanners can be approximated reasonably well by an exponential dependence permitting the optical density measurement to be extended to 2. The effects of the driver as well as of other parameters (gamma, contrast, brightness, filters and etc.) on the final image were studied. The digital scanners were used as tools for 2-D densitometry to investigate the distribution of Co, Fe, Pt and Ir bearing phases in geological samples

  13. Calibration of Images with 3D range scanner data

    OpenAIRE

    Adalid López, Víctor Javier

    2009-01-01

    Projecte fet en col.laboració amb EPFL 3D laser range scanners are used in extraction of the 3D data in a scene. Main application areas are architecture, archeology and city planning. Thought the raw scanner data has a gray scale values, the 3D data can be merged with colour camera image values to get textured 3D model of the scene. Also these devices are able to take a reliable copy in 3D form objects, with a high level of accuracy. Therefore, they scanned scenes can be use...

  14. Estimating Single Tree Stem Volume of Pinus sylvestris Using Airborne Laser Scanner and Multispectral Line Scanner Data

    Directory of Open Access Journals (Sweden)

    Barbara Koch

    2011-05-01

    Full Text Available So far, only a few studies have been carried out in central European forests to estimate individual tree stem volume of pine trees from high resolution remote sensing data. In this article information derived from airborne laser scanner and multispectral line scanner data were tested to predict the stem volume of 178 pines (Pinus sylvestris in a study site in the south-west of Germany. First, tree crowns were automatically delineated using both multispectral and laser scanner data. Next, tree height, crown diameter and crown volume were derived for each crown segment. All combinations of the derived tree features were used as explanatory variables in allometric models to predict the stem volume. A model with tree height and crown diameter had the best performance with respect to the prediction accuracy determined by a leave-one-out cross-validation: Root Mean Square Error (RMSE = 24.02% and Bias = 1.36%.

  15. Aircraft Scanners = NASA Digital Aerial Scanners (TMS, TIMS, NS001): Pre 1996

    Data.gov (United States)

    U.S. Geological Survey, Department of the Interior — The Aircraft Scanners data set contains digital imagery acquired from several multispectral scanners including NS-001 Mutispectral scanner, Daedalus thematic mapper...

  16. Impact of topographic mask models on scanner matching solutions

    Science.gov (United States)

    Tyminski, Jacek K.; Pomplun, Jan; Renwick, Stephen P.

    2014-03-01

    Of keen interest to the IC industry are advanced computational lithography applications such as Optical Proximity Correction of IC layouts (OPC), scanner matching by optical proximity effect matching (OPEM), and Source Optimization (SO) and Source-Mask Optimization (SMO) used as advanced reticle enhancement techniques. The success of these tasks is strongly dependent on the integrity of the lithographic simulators used in computational lithography (CL) optimizers. Lithographic mask models used by these simulators are key drivers impacting the accuracy of the image predications, and as a consequence, determine the validity of these CL solutions. Much of the CL work involves Kirchhoff mask models, a.k.a. thin masks approximation, simplifying the treatment of the mask near-field images. On the other hand, imaging models for hyper-NA scanner require that the interactions of the illumination fields with the mask topography be rigorously accounted for, by numerically solving Maxwell's Equations. The simulators used to predict the image formation in the hyper-NA scanners must rigorously treat the masks topography and its interaction with the scanner illuminators. Such imaging models come at a high computational cost and pose challenging accuracy vs. compute time tradeoffs. Additional complication comes from the fact that the performance metrics used in computational lithography tasks show highly non-linear response to the optimization parameters. Finally, the number of patterns used for tasks such as OPC, OPEM, SO, or SMO range from tens to hundreds. These requirements determine the complexity and the workload of the lithography optimization tasks. The tools to build rigorous imaging optimizers based on first-principles governing imaging in scanners are available, but the quantifiable benefits they might provide are not very well understood. To quantify the performance of OPE matching solutions, we have compared the results of various imaging optimization trials obtained

  17. EFFECTS OF WIRE LAG IN WIRE ELECTRICAL DISCHARGE MACHINING (WEDM

    Directory of Open Access Journals (Sweden)

    S. K. SINHA

    2010-11-01

    Full Text Available WEDM is very useful wherever complex geometry with tight tolerances needs to be generated on hard materials. In view of modern and sophisticated technology readily available these days, the expectation of accuracy in WEDM is ever-increasing, and therefore, techniques for the improvement in WEDM must be developed. The main cause of inaccuracy is wire-lag, the cause and effect of which is described in the present work, along with a technique to obviate the problem in straight cutting. In a subsequent paper, a software approach (since the problem gets too complicated for improvement of accuracy in contour cutting is described.

  18. Temporal analysis of multispectral scanner data.

    Science.gov (United States)

    Richardson, A. J.; Wiegand, C. L.; Torline, R. J.

    1973-01-01

    Multispectral scanner reflectance data were sampled for bare soil, cotton, sorghum, corn, and citrus at four dates during a growing season (April, May, June, and July 1969) to develop a time-dependent signature for crop and soil discrimination. Discrimination tests were conducted for single-date and multidate formats using training and test data sets. For classifications containing several crops, the multidate or temporal approach improved discrimination compared with the single-date approach. The multidate approach also preserved recognition accuracy better in going from training fields to test fields than the single-date analysis. The spectral distinctiveness of bare soil versus vegetation resulted in essentially equal discrimination using single-date versus multidate data for those two categories.

  19. Barcode scanner for ring dosemeters

    International Nuclear Information System (INIS)

    A barcode scanner for circular bar codes was developed as an additional module for a dosimeter-reader manufactured in the USA. The new scanner had to fulfill all existing interface specifications (power supply, serial interface) to be integrated seamlessly into the existing instrument. The size of the barcode reader had to be compact enough to fit into the instrument without the need for additional external components. The barcode scanner has been realized using image processing technology. The system is designed in a way to fulfill all the functions of the 'old' laser barcode scanner (decoding of linear codes) plus the additional function of decoding circular barcodes in parallel. The system consists of CCD (charge coupled device) camera, infrared illumination, image processing hardware (frame grabber) and computer. The computer runs an image processing software developed in C. The result of the development effort is a fully functional prototype that is to be adapted for serial production (with minor modifications) by the US-manufacturer. (author)

  20. A virtual spectral CT scanner

    International Nuclear Information System (INIS)

    Full text: Spectral computed tomography (sCT) brings a promise of improved tissue discrimination when compared to conventional CT. At the heart of this new technology are energy selective photon counting detectors (PCD) combined with theorics on how to select optimal energy bins for discriminating two or more materials. Several theories have been published on how to select these energy bins, but so far the diagnostic utility of optimised sCT has not been fully exploited. This work presents a first step towards a virtual sCT scanner based on the well bench marked BEAMnrc Monte Carlo code and the computer power of the University of Canterbury BlueFern supe computer. A computational model of a recently developed sCT scanner (MARS-CT) has been developed to produce virtual X-ray projection data through an imaging object. The energy and position of all transmitted photons impinging on the detector plane can be extracted without the additional complications introduced by non ideal behaviour (such as charge-sharing) of current detectors. The photons are grouped into selective energy bins to produce energy selective projection images of the imaging object (see Fig. I). This enables the comparison of conventional CT with optimised spectral CT. Furthermore, the virtual sCT scanner is an ideal tool to compare and evaluate the different theoretical models (which optimise different metrics) in terms of relevant clinical parameters such as image contrast. In further work we are planning to include the physical limitations of the detector so the virtual sCT scanner closely resembles the MARS CT scanner.

  1. Scanner color management model based on improved back-propagation neural network

    Institute of Scientific and Technical Information of China (English)

    Xinwu Li

    2008-01-01

    Scanner color management is one of the key techniques for color reproduction in information optics.A new scanner color management model is presented based on analyzing rendering principle of scanning objects.In this model,a standard color target is taken as experimental sample.Color blocks in color shade area are used to substitute complete color space to solve the difficulties in selecting experimental color blocks.Immune genetic algorithm is used to correct back-propagation neural network(BPNN)to speed up the convergence of the model.Experimental results show that the model can improve the accuracy of scanner color management.

  2. Application of Intra-Oral Dental Scanners in the Digital Workflow of Implantology

    OpenAIRE

    Wicher J van der Meer; Frank S Andriessen; Daniel Wismeijer; Yijin Ren

    2012-01-01

    Intra-oral scanners will play a central role in digital dentistry in the near future. In this study the accuracy of three intra-oral scanners was compared. Materials and methods: A master model made of stone was fitted with three high precision manufactured PEEK cylinders and scanned with three intra-oral scanners: the CEREC (Sirona), the iTero (Cadent) and the Lava COS (3M). In software the digital files were imported and the distance between the centres of the cylinders and the angulation b...

  3. Wire bonding in microelectronics

    CERN Document Server

    Harman, George G

    2010-01-01

    Wire Bonding in Microelectronics, Third Edition, has been thoroughly revised to help you meet the challenges of today's small-scale and fine-pitch microelectronics. This authoritative guide covers every aspect of designing, manufacturing, and evaluating wire bonds engineered with cutting-edge techniques. In addition to gaining a full grasp of bonding technology, you'll learn how to create reliable bonds at exceedingly high yields, test wire bonds, solve common bonding problems, implement molecular cleaning methods, and much more. Coverage includes: Ultrasonic bonding systems and technologies, including high-frequency systems Bonding wire metallurgy and characteristics, including copper wire Wire bond testing Gold-aluminum intermetallic compounds and other interface reactions Gold and nickel-based bond pad plating materials and problems Cleaning to improve bondability and reliability Mechanical problems in wire bonding High-yield, fine-pitch, specialized-looping, soft-substrate, and extreme-temperature wire bo...

  4. A New Proton CT Scanner

    CERN Document Server

    Coutrakon, G; Boi, S; Dyshkant, A; Erdelyi, B; Hedin, D; Johnson, E; Krider, J; Rykalin, V; Uzunyan, S A; Zutshi, V; Fordt, R; Sellberg, G; Rauch, J E; Roman, M; Rubinov, P; Wilson, P; Naimuddin, M

    2014-01-01

    The design, construction, and preliminary testing of a second generation proton CT scanner is presented. All current treatment planning systems at proton therapy centers use X-ray CT as the primary imaging modality for treatment planning to calculate doses to tumor and healthy tissues. One of the limitations of X-ray CT is in the conversion of X-ray attenuation coefficients to relative (proton) stopping powers, or RSP. This results in more proton range uncertainty, larger target volumes and therefore, more dose to healthy tissues. To help improve this, we present a novel scanner capable of high dose rates, up to 2~MHz, and large area coverage, 20~x~24~cm$^2$, for imaging an adult head phantom and reconstructing more accurate RSP values.

  5. Wire harness twisting aid

    Science.gov (United States)

    Casey, E. J.; Commadore, C. C.; Ingles, M. E.

    1980-01-01

    Long wire bundles twist into uniform spiral harnesses with help of simple apparatus. Wires pass through spacers and through hand-held tool with hole for each wire. Ends are attached to low speed bench motor. As motor turns, operator moves hand tool away forming smooth twists in wires between motor and tool. Technique produces harnesses that generate less radio-frequency interference than do irregularly twisted cables.

  6. Free-space wavelength-multiplexed optical scanner demonstration.

    Science.gov (United States)

    Yaqoob, Zahid; Riza, Nabeel A

    2002-09-10

    Experimental demonstration of a no-moving-parts free-space wavelength-multiplexed optical scanner (W-MOS) is presented. With fast tunable lasers or optical filters and planar wavelength dispersive elements such as diffraction gratings, this microsecond-speed scanner enables large several-centimeter apertures for subdegree angular scans. The proposed W-MOS design incorporates a unique optical amplifier and variable optical attenuator combination that enables the calibration and modulation of the scanner response, leading to any desired scanned laser beam power shaping. The experimental setup uses a tunable laser centered at 1560 nm and a 600-grooves/mm blazed reflection grating to accomplish an angular scan of 12.92 degrees as the source is tuned over an 80-nm bandwidth. The values for calculated maximum optical beam divergance, required wavelength resolution, beam-pointing accuracy, and measured scanner insertion loss are 1.076 mrad, 0.172 nm, 0.06 mrad, and 4.88 dB, respectively.

  7. Free-space wavelength-multiplexed optical scanner demonstration.

    Science.gov (United States)

    Yaqoob, Zahid; Riza, Nabeel A

    2002-09-10

    Experimental demonstration of a no-moving-parts free-space wavelength-multiplexed optical scanner (W-MOS) is presented. With fast tunable lasers or optical filters and planar wavelength dispersive elements such as diffraction gratings, this microsecond-speed scanner enables large several-centimeter apertures for subdegree angular scans. The proposed W-MOS design incorporates a unique optical amplifier and variable optical attenuator combination that enables the calibration and modulation of the scanner response, leading to any desired scanned laser beam power shaping. The experimental setup uses a tunable laser centered at 1560 nm and a 600-grooves/mm blazed reflection grating to accomplish an angular scan of 12.92 degrees as the source is tuned over an 80-nm bandwidth. The values for calculated maximum optical beam divergance, required wavelength resolution, beam-pointing accuracy, and measured scanner insertion loss are 1.076 mrad, 0.172 nm, 0.06 mrad, and 4.88 dB, respectively. PMID:12224780

  8. Vacuum Attachment for XRF Scanner

    Science.gov (United States)

    Schramm, Harry F.; Kaiser, Bruce

    2005-01-01

    Vacuum apparatuses have been developed for increasing the range of elements that can be identified by use of x-ray fluorescent (XRF) scanners of the type mentioned in the two immediately preceding articles. As a consequence of the underlying physical principles, in the presence of air, such an XRF scanner is limited to analysis of chlorine and elements of greater atomic number. When the XRF scanner is operated in a vacuum, it extends the range of analysis to lower atomic numbers - even as far as aluminum and sodium. Hence, more elements will be available for use in XRF labeling of objects as discussed in the two preceding articles. The added benefits of the extended capabilities also have other uses for NASA. Detection of elements of low atomic number is of high interest to the aerospace community. High-strength aluminum alloys will be easily analyzed for composition. Silicon, a major contaminant in certain processes, will be detectable before the process is begun, possibly eliminating weld or adhesion problems. Exotic alloys will be evaluated for composition prior to being placed in service where lives depend on them. And in the less glamorous applications, such as bolts and fasteners, substandard products and counterfeit items will be evaluated at the receiving function and never allowed to enter the operation

  9. Laser Wire Stripper

    Science.gov (United States)

    1983-01-01

    NASA-developed space shuttle technology is used in a laser wire stripper designed by Raytheon Company. Laser beams cut through insulation on a wire without damaging conductive metal, because laser radiation that melts plastic insulation is reflected by the metal. The laser process is fast, clean, precise and repeatable. It eliminates quality control problems and the expense of rejected wiring.

  10. MR-based motion correction for PET imaging using wired active MR microcoils in simultaneous PET-MR: Phantom study

    Energy Technology Data Exchange (ETDEWEB)

    Huang, Chuan; Brady, Thomas J.; El Fakhri, Georges; Ouyang, Jinsong, E-mail: ouyang.jinsong@mgh.harvard.edu [Center for Advanced Medical Imaging Sciences, Division of Nuclear Medicine and Molecular Imaging, Department of Imaging, Massachusetts General Hospital, Boston, Massachusetts 02114 and Department of Radiology, Harvard Medical School, Boston, Massachusetts 02115 (United States); Ackerman, Jerome L. [Martinos Center for Biomedical Imaging, Massachusetts General Hospital, Charlestown, Massachusetts 02129 and Department of Radiology, Harvard Medical School, Boston, Massachusetts 02115 (United States); Petibon, Yoann [Center for Advanced Medical Imaging Sciences, Division of Nuclear Medicine and Molecular Imaging, Department of Imaging, Massachusetts General Hospital, Boston, Massachusetts 02114 (United States)

    2014-04-15

    Purpose: Artifacts caused by head motion present a major challenge in brain positron emission tomography (PET) imaging. The authors investigated the feasibility of using wired active MR microcoils to track head motion and incorporate the measured rigid motion fields into iterative PET reconstruction. Methods: Several wired active MR microcoils and a dedicated MR coil-tracking sequence were developed. The microcoils were attached to the outer surface of an anthropomorphic{sup 18}F-filled Hoffman phantom to mimic a brain PET scan. Complex rotation/translation motion of the phantom was induced by a balloon, which was connected to a ventilator. PET list-mode and MR tracking data were acquired simultaneously on a PET-MR scanner. The acquired dynamic PET data were reconstructed iteratively with and without motion correction. Additionally, static phantom data were acquired and used as the gold standard. Results: Motion artifacts in PET images were effectively removed by wired active MR microcoil based motion correction. Motion correction yielded an activity concentration bias ranging from −0.6% to 3.4% as compared to a bias ranging from −25.0% to 16.6% if no motion correction was applied. The contrast recovery values were improved by 37%–156% with motion correction as compared to no motion correction. The image correlation (mean ± standard deviation) between the motion corrected (uncorrected) images of 20 independent noise realizations and static reference was R{sup 2} = 0.978 ± 0.007 (0.588 ± 0.010, respectively). Conclusions: Wired active MR microcoil based motion correction significantly improves brain PET quantitative accuracy and image contrast.

  11. MR-based motion correction for PET imaging using wired active MR microcoils in simultaneous PET-MR: Phantom study

    International Nuclear Information System (INIS)

    Purpose: Artifacts caused by head motion present a major challenge in brain positron emission tomography (PET) imaging. The authors investigated the feasibility of using wired active MR microcoils to track head motion and incorporate the measured rigid motion fields into iterative PET reconstruction. Methods: Several wired active MR microcoils and a dedicated MR coil-tracking sequence were developed. The microcoils were attached to the outer surface of an anthropomorphic18F-filled Hoffman phantom to mimic a brain PET scan. Complex rotation/translation motion of the phantom was induced by a balloon, which was connected to a ventilator. PET list-mode and MR tracking data were acquired simultaneously on a PET-MR scanner. The acquired dynamic PET data were reconstructed iteratively with and without motion correction. Additionally, static phantom data were acquired and used as the gold standard. Results: Motion artifacts in PET images were effectively removed by wired active MR microcoil based motion correction. Motion correction yielded an activity concentration bias ranging from −0.6% to 3.4% as compared to a bias ranging from −25.0% to 16.6% if no motion correction was applied. The contrast recovery values were improved by 37%–156% with motion correction as compared to no motion correction. The image correlation (mean ± standard deviation) between the motion corrected (uncorrected) images of 20 independent noise realizations and static reference was R2 = 0.978 ± 0.007 (0.588 ± 0.010, respectively). Conclusions: Wired active MR microcoil based motion correction significantly improves brain PET quantitative accuracy and image contrast

  12. Gamma scanner conceptual design report

    International Nuclear Information System (INIS)

    The Fuels and Materials Examination Facility (FMEF) will include several stations for the nondestructive examination of irradiated fuels. One of these stations will be the gamma scanner which will be employed to detect gamma radiation from the irradiated fuel pins. The conceptual design of the gamma scan station is described. The gamma scanner will use a Standard Exam Stage (SES) as a positioner and transport mechanism for the fuel pins which it will obtain from a magazine. A pin guide mechanism mounted on the face of the collimator will assure that the fuel pins remain in front of the collimator during scanning. The collimator has remotely adjustable tungsten slits and can be manually rotated to align the slit at various angles. A shielded detector cart located in the operating corridor holds an intrinsic germanium detector and associated sodium-iodide anticoincidence detector. The electronics associated with the counting system consist of standard NIM modules to process the detector signals and a stand-alone multichannel analyzer (MCA) for counting data accumulation. Data from the MCA are bussed to the station computer for analysis and storage on magnetic tape. The station computer controls the collimator, the MCA, a source positioner and the SES through CAMAC-based interface hardware. Most of the electronic hardware is commercially available but some interfaces will require development. Conceptual drawings are included for mechanical hardware that must be designed and fabricated

  13. Modeling of a piezoelectric micro-scanner

    CERN Document Server

    Chaehoi, A; Cornez, D; Kirk, K

    2008-01-01

    Micro-scanners have been widely used in many optical applications. The micro-scanner presented in this paper uses multimorph-type bending actuators to tilt a square plate mirror. This paper presents a complete analytical model of the piezoelectric micro-scanner. This theoretical model based on strength of material equations calculates the force generated by the multimorphs on the mirror, the profile of the structure and the angular deflection of the mirror. The proposed model, used to optimize the design of the piezoelectric silicon micro-scanner, is intended for further HDL integration, allowing in this way system level simulation and optimization.

  14. REMEDY OF WIRE LAG IN WIRE ELECTRICAL DISCHARGE MACHINING (WEDM

    Directory of Open Access Journals (Sweden)

    S. K. SINHA

    2010-12-01

    Full Text Available WEDM is extensively used these days for generating complex geometries with tight tolerances on difficult-tomachine materials. Therefore, demand for improvement in precision has been ever increasing. The main source of inaccuracy is wire-lag, the cause and effect of which is well-known. Research has been going on to overcome this drawback. So far, the techniques suggested for improvement in accuracy are, in general, based on monitoring the machining process at hardware-level, which is not only tedious but involves extra expenditure also. In the present paper, a software approach for improvement in accuracy is described, which does not require any additional investment on the machine, and still gives very good results.

  15. Selecting a CT scanner for cardiac imaging: the heart of the matter.

    Science.gov (United States)

    Lewis, Maria A; Pascoal, Ana; Keevil, Stephen F; Lewis, Cornelius A

    2016-09-01

    Coronary angiography to assess the presence and degree of arterial stenosis is an examination now routinely performed on CT scanners. Although developments in CT technology over recent years have made great strides in improving the diagnostic accuracy of this technique, patients with certain characteristics can still be "difficult to image". The various groups will benefit from different technological enhancements depending on the type of challenge they present. Good temporal and spatial resolution, wide longitudinal (z-axis) detector coverage and high X-ray output are the key requirements of a successful CT coronary angiography (CTCA) scan. The requirement for optimal patient dose is a given. The different scanner models recommended for CTCA all excel in different aspects. The specification data presented here for these scanners and the explanation of the impact of the different features should help in making a more informed decision when selecting a scanner for CTCA. PMID:27302494

  16. Wire + Arc Additive Manufacturing

    OpenAIRE

    Williams, Stewart W.; Martina, Filomeno; Addison, Adrian C.; Ding, Jialuo; Pardal, Goncalo; Colegrove, Paul A.

    2016-01-01

    Depositing large components (>10 kg) in titanium, aluminium, steel and other metals is possible using Wire + Arc Additive Manufacturing. This technology adopts arc welding tools and wire as feedstock for additive manufacturing purposes. High deposition rates, low material and equipment costs, and good structural integrity make Wire+Arc Additive Manufacturing a suitable candidate for replacing the current method of manufacturing from solid billets or large forgings, especially with regards to ...

  17. Wire-bond inspection in IC assembly

    Science.gov (United States)

    Rajeswari, Mandava; Rodd, Mike G.

    1996-02-01

    Wire-bonding in IC assembly process involves making a physical connection between the IC 'die' and the 'lead' by bonding wires between the two. Inspection of wire-bond quality is a' highly labor-intensive process and currently efforts are being made to automate it. This paper presents the results of a research conducted into developing a comprehensive automated wire- bond visual inspection system that is capable of performing final accept/reject inspection, providing on-line process feedback, and assisting in process validation. The proposed inspection system consists of the inspection of the bond on a bond pad, the bond on a lead and the inter-connecting wire between a bond pad and its corresponding lead. The algorithms are based on simple and easily extractable features that ensure achieving the desired accuracy and speed. A novel but simple illumination system is proposed to obtain the images of the inter- connecting wires. The proposed system is validated using several state-of-the-art IC samples. This work is sponsored by the Ministry of Science Technology and Environment, Malaysia and Intel Technology Pvt. Ltd., Malaysia.

  18. Photovoltaic Wire Project

    Data.gov (United States)

    National Aeronautics and Space Administration — This Small Business Innovation Research Phase I project will investigate a new architecture for photovoltaic devices based on nanotechnology: photovoltaic wire. The...

  19. 1998 wire development workshop proceedings

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1998-04-01

    This report consists of vugraphs of the presentations at the conference. The conference was divided into the following sessions: (1) First Generation Wire Development: Status and Issues; (2) First Generation Wire in Pre-Commercial Prototypes; (3) Second Generation Wire Development: Private Sector Progress and Issues; (4) Second Generation Wire Development: Federal Laboratories; and (5) Fundamental Research Issues for HTS Wire Development.

  20. 1998 wire development workshop proceedings

    International Nuclear Information System (INIS)

    This report consists of vugraphs of the presentations at the conference. The conference was divided into the following sessions: (1) First Generation Wire Development: Status and Issues; (2) First Generation Wire in Pre-Commercial Prototypes; (3) Second Generation Wire Development: Private Sector Progress and Issues; (4) Second Generation Wire Development: Federal Laboratories; and (5) Fundamental Research Issues for HTS Wire Development

  1. Research regarding wires elastic deformations influence on joints positioning of a wire-driven robotic arm

    Science.gov (United States)

    Ciofu, C.; Stan, G.

    2016-08-01

    In this paper, we present the influence of driving wires deformation on positioning precision of joints from an elephant's trunk robotic arm. Robotic arms driven by wires have the joint accuracy largely depending on wires rigidity. The joint moment of resistance causes elastic deformation of wires and it is determined by: manipulated object load, weight loads previous to the analyzed joint and inherent resistance moment of joint. Static load analysis emphasizes the particular wires elastic deformation of each driven joint from an elephant's trunk robotic arm with five degrees of freedom. We consider the case of a constant manipulated load. Errors from each driving system of joints are not part of the closed loop system. Thus, precision positioning depends on wires elastic deformation which is about microns and causes angle deviation of joints about tens of minutes of sexagesimal degrees. The closer the joints to base arm the smaller positioning precision of joint. The obtained results are necessary for further compensation made by electronic corrections in the programming algorithm of the elephant's trunk robotic arm to improve accuracy.

  2. Wire Array Photovoltaics

    Science.gov (United States)

    Turner-Evans, Dan

    Over the past five years, the cost of solar panels has dropped drastically and, in concert, the number of installed modules has risen exponentially. However, solar electricity is still more than twice as expensive as electricity from a natural gas plant. Fortunately, wire array solar cells have emerged as a promising technology for further lowering the cost of solar. Si wire array solar cells are formed with a unique, low cost growth method and use 100 times less material than conventional Si cells. The wires can be embedded in a transparent, flexible polymer to create a free-standing array that can be rolled up for easy installation in a variety of form factors. Furthermore, by incorporating multijunctions into the wire morphology, higher efficiencies can be achieved while taking advantage of the unique defect relaxation pathways afforded by the 3D wire geometry. The work in this thesis shepherded Si wires from undoped arrays to flexible, functional large area devices and laid the groundwork for multijunction wire array cells. Fabrication techniques were developed to turn intrinsic Si wires into full p-n junctions and the wires were passivated with a-Si:H and a-SiNx:H. Single wire devices yielded open circuit voltages of 600 mV and efficiencies of 9%. The arrays were then embedded in a polymer and contacted with a transparent, flexible, Ni nanoparticle and Ag nanowire top contact. The contact connected >99% of the wires in parallel and yielded flexible, substrate free solar cells featuring hundreds of thousands of wires. Building on the success of the Si wire arrays, GaP was epitaxially grown on the material to create heterostructures for photoelectrochemistry. These cells were limited by low absorption in the GaP due to its indirect bandgap, and poor current collection due to a diffusion length of only 80 nm. However, GaAsP on SiGe offers a superior combination of materials, and wire architectures based on these semiconductors were investigated for multijunction

  3. X-ray microtomographic scanners

    Energy Technology Data Exchange (ETDEWEB)

    Syryamkin, V. I., E-mail: klestov-simon@mail.ru; Klestov, S. A., E-mail: klestov-simon@mail.ru [National Research Tomsk State University, Tomsk, 634050 (Russian Federation)

    2015-11-17

    The article studies the operating procedures of an X-ray microtomographic scanner and the module of reconstruction and analysis 3D-image of a test sample in particular. An algorithm for 3D-image reconstruction based on image shadow projections and mathematical methods of the processing are described. Chapter 1 describes the basic principles of X-ray tomography and general procedures of the device developed. Chapters 2 and 3 are devoted to the problem of resources saving by the system during the X-ray tomography procedure, which is achieved by preprocessing of the initial shadow projections. Preprocessing includes background noise removing from the images, which reduces the amount of shadow projections in general and increases the efficiency of the group shadow projections compression. In conclusion, the main applications of X-ray tomography are presented.

  4. Combined PET/MRI scanner

    Science.gov (United States)

    Schlyer, David; Woody, Craig L.; Rooney, William; Vaska, Paul; Stoll, Sean; Pratte, Jean-Francois; O'Connor, Paul

    2007-10-23

    A combined PET/MRI scanner generally includes a magnet for producing a magnetic field suitable for magnetic resonance imaging, a radiofrequency (RF) coil disposed within the magnetic field produced by the magnet and a ring tomograph disposed within the magnetic field produced by the magnet. The ring tomograph includes a scintillator layer for outputting at least one photon in response to an annihilation event, a detection array coupled to the scintillator layer for detecting the at least one photon outputted by the scintillator layer and for outputting a detection signal in response to the detected photon and a front-end electronic array coupled to the detection array for receiving the detection signal, wherein the front-end array has a preamplifier and a shaper network for conditioning the detection signal.

  5. Laser Scanner For Automatic Storage

    Science.gov (United States)

    Carvalho, Fernando D.; Correia, Bento A.; Rebordao, Jose M.; Rodrigues, F. Carvalho

    1989-01-01

    The automated magazines are beeing used at industry more and more. One of the problems related with the automation of a Store House is the identification of the products envolved. Already used for stock management, the Bar Codes allows an easy way to identify one product. Applied to automated magazines, the bar codes allows a great variety of items in a small code. In order to be used by the national producers of automated magazines, a devoted laser scanner has been develloped. The Prototype uses an He-Ne laser whose beam scans a field angle of 75 degrees at 16 Hz. The scene reflectivity is transduced by a photodiode into an electrical signal, which is then binarized. This digital signal is the input of the decodifying program. The machine is able to see barcodes and to decode the information. A parallel interface allows the comunication with the central unit, which is responsible for the management of automated magazine.

  6. 3D whole body scanners revisited

    NARCIS (Netherlands)

    Daanen, H.A.M.; Haar, F.B. ter

    2013-01-01

    An overview of whole body scanners in 1998 (H.A.M. Daanen, G.J. Van De Water. Whole body scanners, Displays 19 (1998) 111-120) shortly after they emerged to the market revealed that the systems were bulky, slow, expensive and low in resolution. This update shows that new developments in sensing and

  7. Sewer Scanner and Evaluation Technology (SSET)

    OpenAIRE

    ECT Team, Purdue

    2007-01-01

    The investment in sanitary sewer collection system represent a major component of $20 trillion of U.S. investment in civil infrastructure systems. Sewer Scanner and Evaluation Technology (SSET) will overcome weaknesses of the closed circuit television and provide the engineer with more and higher quality information for rehabilitation decision making process by utilizing optical scanner and gyroscope technology.

  8. Discriminant analyses of Bendix scanner data

    Science.gov (United States)

    Richardson, A. J.; Wiegand, C. L.; Leamer, R. W.; Gerbermann, A. H.; Torline, R. J.

    1972-01-01

    Flights over Weslaco, Texas are discussed, using the 9-channel Bendix scanner, providing calibrated data in the 380 to 1000 nm wavelength interval. These flights were at 2000 ft. These data gave seasonal coverage from the time signals, representing mainly the soil background. The ground truth data are provided; signature processing studies relating scanner data to ground truth were also carried out.

  9. Ensuring Wire Alignment for the New COMPASS Drift Chamber

    Science.gov (United States)

    Cromis, Megan; Compass Dc5 Team

    2014-09-01

    COMPASS is a fixed-target experiment at CERN investigating the internal structure of the proton. Polarized Drell-Yan measurements at COMPASS will explore how the quark orbital angular momentum contributes to the spin of the proton. To enable this measurement, several straw tube chambers need to be replaced due to long term wear. One of the replacement chambers, drift chamber DC5, is being built at Old Dominion University based on a prototype from UIUC and existing COMPASS drift chambers. DC5 consists of 4 wire planes with 513 wires (256 [20 μm] sense wires and 257 [100 μm] field wires alternating) and 4 wire planes at a 10 degree offset with 641 wires each. Each of these 4616 wires need to be aligned within either 100 μm (sense wire) or 200 μm (field wire) of the center of the solder pad to ensure the accuracy of the drift chamber. Problems that arose during stringing include initial alignment of the wire and efficient soldering techniques. Also, because the field wires charged at -1750 volts will be 4 mm from the sense wires, there should be no gaps or points in the solder to prevent arcing. This poster will discuss the alignment techniques, soldering methods, testing, and repair process for the wires. COMPASS is a fixed-target experiment at CERN investigating the internal structure of the proton. Polarized Drell-Yan measurements at COMPASS will explore how the quark orbital angular momentum contributes to the spin of the proton. To enable this measurement, several straw tube chambers need to be replaced due to long term wear. One of the replacement chambers, drift chamber DC5, is being built at Old Dominion University based on a prototype from UIUC and existing COMPASS drift chambers. DC5 consists of 4 wire planes with 513 wires (256 [20 μm] sense wires and 257 [100 μm] field wires alternating) and 4 wire planes at a 10 degree offset with 641 wires each. Each of these 4616 wires need to be aligned within either 100 μm (sense wire) or 200 μm (field wire

  10. Automating wiring formboard design

    NARCIS (Netherlands)

    Van den Berg, T.

    2013-01-01

    Increase in aircraft wiring complexity call for manufacturing design improvements to reduce cost and lead-time. To achieve such improvements, a joint research project was performed by the Flight Performance and Propulsion (FPP) group and Fokker Elmo BV, the second largest aircraft wiring harness man

  11. 2016 MOST WIRED.

    Science.gov (United States)

    Barr, Paul; Butcher, Lola; Hoppszallern, Suzanna

    2016-07-01

    This year's IT survey shows that hospitals are aggressively fighting cyber crime and looking for ways to use data to help in the transition to value-based care. Find out who made the 2016 lists of Most Wired, Most Advanced, Most Improved and Most Wired-Small and Rural. PMID:27526506

  12. A dedicated tool for PET scanner simulations using FLUKA

    International Nuclear Information System (INIS)

    Positron emission tomography (PET) is a well-established medical imaging technique. It is based on the detection of pairs of annihilation gamma rays from a beta+-emitting radionuclide, usually inoculated in the body via a biologically active molecule. Apart from its wide-spread use for clinical diagnosis, new applications are proposed. This includes notably the usage of PET for treatment monitoring of radiation therapy with protons and ions. PET is currently the only available technique for non-invasive monitoring of ion beam dose delivery, which was tested in several clinical pilot studies. For hadrontherapy, the distribution of positron emitters, produced by the ion beam, can be analyzed to verify the correct treatment delivery. The adaptation of previous PET scanners to new environments and the necessity of more precise diagnostics by better image quality triggered the development of new PET scanner designs. The use of Monte Carlo (MC) codes is essential in the early stages of the scanner design to simulate the transport of particles and nuclear interactions from therapeutic ion beams or radioisotopes and to predict radiation fields in tissues and radiation emerging from the patient. In particular, range verification using PET is based on the comparison of detected and simulated activity distributions. The accuracy of the MC code for the relevant physics processes is obviously essential for such applications. In this work we present new developments of the physics models with importance for PET monitoring and integrated tools for PET scanner simulations for FLUKA, a fully-integrated MC particle-transport code, which is widely used for an extended range of applications (accelerator shielding, detector and target design, calorimetry, activation, dosimetry, medical physics, radiobiology, ...). The developed tools include a PET scanner geometry builder and a dedicated scoring routine for coincident event determination. The geometry builder allows the efficient

  13. Current Concept of Geometrical Accuracy

    Directory of Open Access Journals (Sweden)

    Görög Augustín

    2014-06-01

    Full Text Available Within the solving VEGA 1/0615/12 research project "Influence of 5-axis grinding parameters on the shank cutter´s geometric accuracy", the research team will measure and evaluate geometrical accuracy of the produced parts. They will use the contemporary measurement technology (for example the optical 3D scanners. During the past few years, significant changes have occurred in the field of geometrical accuracy. The objective of this contribution is to analyse the current standards in the field of geometric tolerance. It is necessary to bring an overview of the basic concepts and definitions in the field. It will prevent the use of outdated and invalidated terms and definitions in the field. The knowledge presented in the contribution will provide the new perspective of the measurement that will be evaluated according to the current standards.

  14. Optical design for POS hologram scanner

    Science.gov (United States)

    Yamazaki, Kozo; Ichikawa, Toshiyuki; Ikeda, Hiroyuki; Inagaki, Takefumi

    1986-08-01

    This paper presents newly developed optical design techniques for a shallow-type POS hologram scanner. POS scanner optical design involves design of the scan pattern to read the bar code and design of the detection system. For scan pattern design, we have developed a "readability map" method and a "scanning diagram" method. Detection system design took into account laser safety standards, and we used a technique for estimating the power of the detected signal. We have realized a shallow-type POS hologram scanner which is only 16cm high and can be operated from a sitting position.

  15. Immediate Feedback on Accuracy and Performance: The Effects of Wireless Technology on Food Safety Tracking at a Distribution Center

    Science.gov (United States)

    Goomas, David T.

    2012-01-01

    The effects of wireless ring scanners, which provided immediate auditory and visual feedback, were evaluated to increase the performance and accuracy of order selectors at a meat distribution center. The scanners not only increased performance and accuracy compared to paper pick sheets, but were also instrumental in immediate and accurate data…

  16. Development of a mixed pixel filter for improved dimension estimation using AMCW laser scanner

    Science.gov (United States)

    Wang, Qian; Sohn, Hoon; Cheng, Jack C. P.

    2016-09-01

    Accurate dimension estimation is desired in many fields, but the traditional dimension estimation methods are time-consuming and labor-intensive. In the recent decades, 3D laser scanners have become popular for dimension estimation due to their high measurement speed and accuracy. Nonetheless, scan data obtained by amplitude-modulated continuous-wave (AMCW) laser scanners suffer from erroneous data called mixed pixels, which can influence the accuracy of dimension estimation. This study develops a mixed pixel filter for improved dimension estimation using AMCW laser scanners. The distance measurement of mixed pixels is firstly formulated based on the working principle of laser scanners. Then, a mixed pixel filter that can minimize the classification errors between valid points and mixed pixels is developed. Validation experiments were conducted to verify the formulation of the distance measurement of mixed pixels and to examine the performance of the proposed mixed pixel filter. Experimental results show that, for a specimen with dimensions of 840 mm × 300 mm, the overall errors of the dimensions estimated after applying the proposed filter are 1.9 mm and 1.0 mm for two different scanning resolutions, respectively. These errors are much smaller than the errors (4.8 mm and 3.5 mm) obtained by the scanner's built-in filter.

  17. Absolute Temperature Monitoring Using RF Radiometry in the MRI Scanner.

    Science.gov (United States)

    El-Sharkawy, Abdel-Monem M; Sotiriadis, Paul P; Bottomley, Paul A; Atalar, Ergin

    2006-11-01

    Temperature detection using microwave radiometry has proven value for noninvasively measuring the absolute temperature of tissues inside the body. However, current clinical radiometers operate in the gigahertz range, which limits their depth of penetration. We have designed and built a noninvasive radiometer which operates at radio frequencies (64 MHz) with ∼100-kHz bandwidth, using an external RF loop coil as a thermal detector. The core of the radiometer is an accurate impedance measurement and automatic matching circuit of 0.05 Ω accuracy to compensate for any load variations. The radiometer permits temperature measurements with accuracy of ±0.1°K, over a tested physiological range of 28° C-40° C in saline phantoms whose electric properties match those of tissue. Because 1.5 T magnetic resonance imaging (MRI) scanners also operate at 64 MHz, we demonstrate the feasibility of integrating our radiometer with an MRI scanner to monitor RF power deposition and temperature dosimetry, obtaining coarse, spatially resolved, absolute thermal maps in the physiological range. We conclude that RF radiometry offers promise as a direct, noninvasive method of monitoring tissue heating during MRI studies and thereby providing an independent means of verifying patient-safe operation. Other potential applications include titration of hyper- and hypo-therapies. PMID:18026562

  18. A Cross-Platform Smartphone Brain Scanner

    DEFF Research Database (Denmark)

    Larsen, Jakob Eg; Stopczynski, Arkadiusz; Stahlhut, Carsten;

    We describe a smartphone brain scanner with a low-costwireless 14-channel Emotiv EEG neuroheadset interfacingwith multiple mobile devices. This personal informaticssystem enables minimally invasive and continuouscapturing of brain imaging data in natural settings. Thesystem applies an inverse...

  19. How flatbed scanners upset accurate film dosimetry.

    Science.gov (United States)

    van Battum, L J; Huizenga, H; Verdaasdonk, R M; Heukelom, S

    2016-01-21

    Film is an excellent dosimeter for verification of dose distributions due to its high spatial resolution. Irradiated film can be digitized with low-cost, transmission, flatbed scanners. However, a disadvantage is their lateral scan effect (LSE): a scanner readout change over its lateral scan axis. Although anisotropic light scattering was presented as the origin of the LSE, this paper presents an alternative cause. Hereto, LSE for two flatbed scanners (Epson 1680 Expression Pro and Epson 10000XL), and Gafchromic film (EBT, EBT2, EBT3) was investigated, focused on three effects: cross talk, optical path length and polarization. Cross talk was examined using triangular sheets of various optical densities. The optical path length effect was studied using absorptive and reflective neutral density filters with well-defined optical characteristics (OD range 0.2-2.0). Linear polarizer sheets were used to investigate light polarization on the CCD signal in absence and presence of (un)irradiated Gafchromic film. Film dose values ranged between 0.2 to 9 Gy, i.e. an optical density range between 0.25 to 1.1. Measurements were performed in the scanner's transmission mode, with red-green-blue channels. LSE was found to depend on scanner construction and film type. Its magnitude depends on dose: for 9 Gy increasing up to 14% at maximum lateral position. Cross talk was only significant in high contrast regions, up to 2% for very small fields. The optical path length effect introduced by film on the scanner causes 3% for pixels in the extreme lateral position. Light polarization due to film and the scanner's optical mirror system is the main contributor, different in magnitude for the red, green and blue channel. We concluded that any Gafchromic EBT type film scanned with a flatbed scanner will face these optical effects. Accurate dosimetry requires correction of LSE, therefore, determination of the LSE per color channel and dose delivered to the film.

  20. Copper wire bonding

    CERN Document Server

    Chauhan, Preeti S; Zhong, ZhaoWei; Pecht, Michael G

    2014-01-01

    This critical volume provides an in-depth presentation of copper wire bonding technologies, processes and equipment, along with the economic benefits and risks.  Due to the increasing cost of materials used to make electronic components, the electronics industry has been rapidly moving from high cost gold to significantly lower cost copper as a wire bonding material.  However, copper wire bonding has several process and reliability concerns due to its material properties.  Copper Wire Bonding book lays out the challenges involved in replacing gold with copper as a wire bond material, and includes the bonding process changes—bond force, electric flame off, current and ultrasonic energy optimization, and bonding tools and equipment changes for first and second bond formation.  In addition, the bond–pad metallurgies and the use of bare and palladium-coated copper wires on aluminum are presented, and gold, nickel and palladium surface finishes are discussed.  The book also discusses best practices and re...

  1. Time-Domain Simulation of Three Dimensional Quantum Wires.

    Science.gov (United States)

    Sullivan, Dennis M; Mossman, Sean; Kuzyk, Mark G

    2016-01-01

    A method is presented to calculate the eigenenergies and eigenfunctions of quantum wires. This is a true three-dimensional method based on a direct implementation of the time-dependent Schrödinger equation. It makes no approximations to the Schrödinger equation other than the finite-difference approximation of the space and time derivatives. The accuracy of our method is tested by comparing it to analytical results in a cylindrical wire. PMID:27124603

  2. Radiographic verification of pedicle screw pilot hole placement in thoracic spine using Kirschner wires versus spiral wires

    Institute of Scientific and Technical Information of China (English)

    LIU Yi 刘一; ZHANG Shao-kun 张绍昆; MIAO Wei-wei 苗巍巍; SHAN Yu-xing 单玉兴; SUN Da-hui 孙大辉; WANG Bai 王柏; LI Yin-liang 李印良; HUANG Xiao-gang 黄晓刚

    2003-01-01

    Objective: To evaluate the feasibility of the pedicle screw pilot holes placement in thoracic spine using the spiral wires as the guide pin.Methods: The pedicle screw pilot holes were drilled within the center of the pedicle and the lateral and medial pedicle walls were violated in 9 human dried thoracic vertebrae.Kirschner wires or spiral wires were separately placed in the holes, and then the posteroanterior and lateral radiographs were taken.The radiographs were evaluated by 3 experienced spine surgeons and 3 young orthopedists.After radiographs were shown to these observers, they combined the posteroanterior and lateral radiographs in each place and determined whether the pedicle screw pilot hole violated the pedicle cortex or not.The results were analyzed by a statistical software.Results: Sensitivity, specificity and accuracy of the method using spiral wires to detect pedicle pilot hole placement were significantly higher than those of using Kirschner wires.With a true posteroanterior radiograph, the sensitivity, specificity and accuracy of the method using spiral wires approximated or attained 100%.Conclusions: The method of intrapedicular pilot hole placement verification using spiral wires is effective for guiding the accurate placement of pedicle screws.

  3. MEMS temperature scanner: principles, advances, and applications

    Science.gov (United States)

    Otto, Thomas; Saupe, Ray; Stock, Volker; Gessner, Thomas

    2010-02-01

    Contactless measurement of temperatures has gained enormous significance in many application fields, ranging from climate protection over quality control to object recognition in public places or military objects. Thereby measurement of linear or spatially temperature distribution is often necessary. For this purposes mostly thermographic cameras or motor driven temperature scanners are used today. Both are relatively expensive and the motor drive devices are limited regarding to the scanning rate additionally. An economic alternative are temperature scanner devices based on micro mirrors. The micro mirror, attached in a simple optical setup, reflects the emitted radiation from the observed heat onto an adapted detector. A line scan of the target object is obtained by periodic deflection of the micro scanner. Planar temperature distribution will be achieved by perpendicularly moving the target object or the scanner device. Using Planck radiation law the temperature of the object is calculated. The device can be adapted to different temperature ranges and resolution by using different detectors - cooled or uncooled - and parameterized scanner parameters. With the basic configuration 40 spatially distributed measuring points can be determined with temperatures in a range from 350°C - 1000°C. The achieved miniaturization of such scanners permits the employment in complex plants with high building density or in direct proximity to the measuring point. The price advantage enables a lot of applications, especially new application in the low-price market segment This paper shows principle, setup and application of a temperature measurement system based on micro scanners working in the near infrared range. Packaging issues and measurement results will be discussed as well.

  4. a Light-Weight Laser Scanner for Uav Applications

    Science.gov (United States)

    Tommaselli, A. M. G.; Torres, F. M.

    2016-06-01

    Unmanned Aerial Vehicles (UAV) have been recognized as a tool for geospatial data acquisition due to their flexibility and favourable cost benefit ratio. The practical use of laser scanning devices on-board UAVs is also developing with new experimental and commercial systems. This paper describes a light-weight laser scanning system composed of an IbeoLux scanner, an Inertial Navigation System Span-IGM-S1, from Novatel, a Raspberry PI portable computer, which records data from both systems and an octopter UAV. The performance of this light-weight system was assessed both for accuracy and with respect to point density, using Ground Control Points (GCP) as reference. Two flights were performed with the UAV octopter carrying the equipment. In the first trial, the flight height was 100 m with six strips over a parking area. The second trial was carried out over an urban park with some buildings and artificial targets serving as reference Ground Control Points. In this experiment a flight height of 70 m was chosen to improve target response. Accuracy was assessed based on control points the coordinates of which were measured in the field. Results showed that vertical accuracy with this prototype is around 30 cm, which is acceptable for forest applications but this accuracy can be improved using further refinements in direct georeferencing and in the system calibration.

  5. A LIGHT-WEIGHT LASER SCANNER FOR UAV APPLICATIONS

    Directory of Open Access Journals (Sweden)

    A. M. G. Tommaselli

    2016-06-01

    Full Text Available Unmanned Aerial Vehicles (UAV have been recognized as a tool for geospatial data acquisition due to their flexibility and favourable cost benefit ratio. The practical use of laser scanning devices on-board UAVs is also developing with new experimental and commercial systems. This paper describes a light-weight laser scanning system composed of an IbeoLux scanner, an Inertial Navigation System Span-IGM-S1, from Novatel, a Raspberry PI portable computer, which records data from both systems and an octopter UAV. The performance of this light-weight system was assessed both for accuracy and with respect to point density, using Ground Control Points (GCP as reference. Two flights were performed with the UAV octopter carrying the equipment. In the first trial, the flight height was 100 m with six strips over a parking area. The second trial was carried out over an urban park with some buildings and artificial targets serving as reference Ground Control Points. In this experiment a flight height of 70 m was chosen to improve target response. Accuracy was assessed based on control points the coordinates of which were measured in the field. Results showed that vertical accuracy with this prototype is around 30 cm, which is acceptable for forest applications but this accuracy can be improved using further refinements in direct georeferencing and in the system calibration.

  6. Cognition for robot scanner based remote welding

    Science.gov (United States)

    Thombansen, U.; Ungers, Michael

    2014-02-01

    The effort for reduced cycle times in manufacturing has supported the development of remote welding systems which use a combination of scanners for beam delivery and robots for scanner positioning. Herein, close coupling of both motions requires a precise command of the robot trajectory and the scanner positioning to end up with a combined beam delivery. Especially the path precision of the robot plays a vital role in this kinematic chain. In this paper, a sensor system is being presented which allows tracking the motion of the laser beam against the work piece. It is based on a camera system which is coaxially connected to the scanner thus observing the relative motion of the laser beam relative to the work piece. The acquired images are processed with computer vision algorithms from the field of motion detection. The suitability of the algorithms is being demonstrated with a motion tracking tool which visualizes the homogeneity of the tracking result. The reported solution adds cognitive capabilities to manufacturing systems for robot scanner based materials processing. It allows evaluation of the relative motion between work piece and the laser beam. Moreover, the system can be used to adapt system programming during set-up of a manufacturing task or to evaluate the functionality of a manufacturing system during production. The presented sensor system will assist in optimizing manufacturing processes.

  7. Distribution of wire deformation within strands of wire ropes

    Institute of Scientific and Technical Information of China (English)

    MA Jun; GE Shi-rong; ZHANG De-kun

    2008-01-01

    Using ANSYS software, we developed a modeling program for several kinds of wire ropes with metal cores and built a geometric model for the 6x19 IWS wire rope. Through proper grid partitioning, a finite element model for calculating the deformation of wire rope was obtained. Completely constraining one end of the wire rope and applying an axial force to the other end, we established the boundary conditions for solving the model. In addition, we numerically simulated the stress and deformation of the wire, obtaining the deformation distribution of each wire within the wire rope under different laying directions.At the end, a tensile test of the 6x19 IWS wire rope was carried out and the results of simulation and experiment compared.

  8. Feasibility study of small animal imaging using clinical PET/CT scanner

    Science.gov (United States)

    Hsu, Wen-Lin; Chen, Chia-Lin; Wang, Ze-Jing; Wu, Tung-Hsin; Liu, Dai-Wei; Lee, Jason J. S.

    2007-02-01

    The feasibility of small animal imaging using a clinical positron emission tomography/computed tomography (PET/CT) scanner with [F-18]-fluoro-2-deoxy- D-glucose (FDG) was evaluated. Two protocols in PET/CT system, single-mouse high-resolution mode (SHR) and multi-mouse high throughput mode (MHT) protocol were employed to investigate the ability of the scanner and also explored the performance differences between microPET and clinical PET/CT. In this study, we have found that even the clinical PET/CT scanner could not compete with the microPET scanner, especially in spatial resolution; the high-resolution CT image could advance the anatomical information to sub-millimeter level. Besides, CT-based attenuation correction can improve the image uniformity characteristics and quantification accuracy, and the large bore of a human whole-body scanner broadens the possibility of high throughput studies. Considering all the benefits, clinical PET/CT imaging might be a potential alternative for small animal study.

  9. Wiring and lighting

    CERN Document Server

    Kitcher, Chris

    2013-01-01

    Wiring and Lighting provides a comprehensive guide to DIY wiring around the home. It sets out the regulations and legal requirements surrounding electrical installation work, giving clear guidelines that will enable the reader to understand what electrical work they are able to carry out, and what the testing and certification requirements are once the work is completed. Topics covered include: Different types of circuits; Types of cables and cable installation under floors and through joists; Isolating, earthing and bonding; Accessory boxes and fixings; Voltage bands; Detailed advice on safe

  10. Modern wiring practice

    CERN Document Server

    Steward, W E

    2012-01-01

    Continuously in print since 1952, Modern Wiring Practice has now been fully revised to provide an up-to-date source of reference to building services design and installation in the 21st century. This compact and practical guide addresses wiring systems design and electrical installation together in one volume, creating a comprehensive overview of the whole process for contractors and architects, as well as electricians and other installation engineers. Best practice is incorporated throughout, combining theory and practice with clear and accessible explanation, all

  11. Electric wiring domestic

    CERN Document Server

    Coker, A J

    1992-01-01

    Electric Wiring: Domestic, Tenth Edition, is a clear and reliable guide to the practical aspects of domestic electric wiring. Intended for electrical contractors, installation engineers, wiremen and students, its aim is to provide essential up to date information on modern methods and materials in a simple, clear, and concise manner. The main changes in this edition are those necessary to bring the work into line with the 16th Edition of the Regulations for Electrical Installations issued by the Institution of Electrical Engineers. The book begins by introducing the basic features of domestic

  12. Characterization of the Ferrara animal PET scanner

    CERN Document Server

    Di Domenico, G; Damiani, C; Del Guerra, A; Gilardi, M C; Motta, A; Zavattini, G

    2002-01-01

    A dedicated small animal PET scanner, YAPPET, was designed and built at Ferrara University. Each detector consists of a 20x20 matrix of 2x2x30 mm sup 3 YAP:Ce finger-like crystals glued together and directly coupled to a Hamamatsu position sensitive photomultiplier. The scanner is made from four detectors positioned on a rotating gantry at a distance of 7.5 cm from the center and the field of view (FOV) is 4 cm both in the transaxial direction and in the axial direction. The system operates in 3D acquisition mode. The performance parameters of YAPPET scanner such as spatial, energy and time resolution, as well as its sensitivity and counting rate have been determined. The average spatial resolution over the whole FOV is 1.8 mm at FWHM and 4.2 mm at FWTM. The sensitivity at the center is 640 cps/mu Ci.

  13. Task force report on computerized tomographic scanners

    Energy Technology Data Exchange (ETDEWEB)

    1978-10-01

    Computerized axial tomography (CAT) scanning was the focus of a task force established by the Bergen-Passaic Health Systems Agency in New Jersey. The task force reviewed the literature on CAT technology and its applications, surveyed four northeastern hospitals with operating CAT scanning installations, and created three working subcommittees which produced written reports. It was agreed by task force members that certain criteria should be used when evaluating applications for CAT scanners, e.g., service area, staff resources, emergency room activity, radiotherapy, 24-hour scanner coverage, the medically indigent, and cost. Overall, it was determined that CAT is a proven diagnostic tool of significant value and that it should be available to residents of the Bergen-Passaic health service area. Since the CAT field is rapidly evolving and changing, however, it was not possible to define quantitatively the long-term need for and supply of CAT scanners in the region. Appendixes present supporting data on the task force findings.

  14. Electro-optic and acousto-optic laser beam scanners

    Science.gov (United States)

    Heberle, Johannes; Bechtold, Peter; Strauß, Johannes; Schmidt, Michael

    2016-03-01

    Electro-optical deflectors (EOD) and acousto-optical deflectors (AOD) are based on deflection of laser light within a solid state medium. As they do not contain any moving parts, they yield advantages compared to mechanical scanners which are conventionally used for laser beam deflection. Even for arbitrary scan paths high feed rates can be achieved. In this work the principles of operation and characteristic properties of EOD and AOD are presented. Additionally, a comparison to mirror based mechanical deflectors regarding deflection angles, speed and accuracy is made in terms of resolvable spots and the rate of resolvable spots. Especially, the latter one is up to one order of magnitude higher for EOD and AOD systems compared to conventional systems. Further characteristic properties such as response time, damage threshold, efficiency and beam distortions are discussed. Solid state laser beam deflectors are usually characterized by small deflection angles but high angular deflection velocities. As mechanical deflectors exhibit opposite properties an arrangement of a mechanical scanner combined with a solid state deflector provides a solution with the benefits of both systems. As ultrashort pulsed lasers with average power above 100 W and repetition rates in the MHz range have been available for several years this approach can be applied to fully exploit their capabilities. Thereby, pulse overlap can be reduced and by this means heat affected zones are prevented to provide proper processing results.

  15. Compact beamforming in medical ultrasound scanners

    DEFF Research Database (Denmark)

    Tomov, Borislav Gueorguiev

    2003-01-01

    compact implementation of the beamformer compared to the case where conventional A/D conversion is used. The compact and economic beamforming is a key aspect in the progress of medical ultrasound imaging. Currently, 64 or 128 channels are widely used in scanners, top-of-the-range scanners have 256...... with an introduction into medical ultrasound, its basic principles, system evolution and its place among medical imaging techniques. Then, ultrasound acoustics is introduced, as a necessary base for understanding the concepts of acoustic focusing and beamforming, which follow. The necessary focusing information...

  16. Functional Extensions To High Performance Document Scanners

    Science.gov (United States)

    Green, W. B.; Chansky, L. M.; Land, R. A.; Van den Heuvel, R. C.; Kraemer, E. J.; Steele, L. W.; Sherrill, C. J.

    1989-07-01

    Document processing systems based on electronic imaging technology are evolving rapidly, motivated by technology advances in optical storage, image scanners, image compression, high speed digital communications, and high resolution displays. These evolving systems require high speed reliable image scanning systems to create the digital image data base that is at the heart of the applications addressed by these evolving systems. High speed production document scanners must provide the capability of converting a wide variety of input material into high quality digital imagery. The required capabilities include: (i) the ability to scan varying sizes and weights of paper, (ii) image enhancement techniques adequate to produce quality imagery from a document material that may depart significantly from standard high contrast black and white office correspondence, (iii) standard compression options, and (iv) a standard interface to a host or control processor providing full control of all scanner operations and all image processing options. As electronic document processing systems proliferate, additional capabilities will be required to support automated or semi-automated document indexing and selective capture of document content. Capabilities now present on microfilming systems will be required as options or features on document capture systems. These capabilities will include: endorsers, bar code readers, and optical character recognition (OCR) capability. Bar code and OCR capabilities will be required to support automated indexing of scanned material, and OCR capability within specific areas of scanned document material will be required to support indexing and specific application needs. These features will also be supported and controlled through a standard host interface. This paper describes the architecture of the TDC DocuScan Digital Image Scanner. The scanner is a double-sided scanner that produces compressed imagery of both sides of a scanned page in under two

  17. Medical imaging with a microwave tomographic scanner.

    Science.gov (United States)

    Jofre, L; Hawley, M S; Broquetas, A; de los Reyes, E; Ferrando, M; Elias-Fusté, A R

    1990-03-01

    A microwave tomographic scanner for biomedical applications is presented. The scanner consists of a 64 element circular array with a useful diameter of 20 cm. Electronically scanning the transmitting and receiving antennas allows multiview measurements with no mechanical movement. Imaging parameters are appropriate for medical use: a spatial resolution of 7 mm and a contrast resolution of 1% for a measurement time of 3 s. Measurements on tissue-simulating phantoms and volunteers, together with numerical simulations, are presented to assess the system for absolute imaging of tissue distribution and for differential imaging of physiological, pathological, and induced changes in tissues. PMID:2329003

  18. A simple scanner for Compton tomography

    CERN Document Server

    Cesareo, R; Brunetti, A; Golosio, B; Castellano, A

    2002-01-01

    A first generation CT-scanner was designed and constructed to carry out Compton images. This CT-scanner is composed of a 80 kV, 5 mA X-ray tube and a NaI(Tl) X-ray detector; the tube is strongly collimated, generating a X-ray beam of 2 mm diameter, whilst the detector is not collimated to collect Compton photons from the whole irradiated cylinder. The performances of the equipment were tested contemporaneous transmission and Compton images.

  19. One hundred angstrom niobium wire

    Science.gov (United States)

    Cline, H. E.; Rose, R. M.; Wulff, J.

    1968-01-01

    Composite of fine niobium wires in copper is used to study the size and proximity effects of a superconductor in a normal matrix. The niobium rod was drawn to a 100 angstrom diameter wire on a copper tubing.

  20. 2D X-ray scanner and its uses in laboratory reservoir characterization measurements

    Energy Technology Data Exchange (ETDEWEB)

    Maloney, D.; Doggett, K.

    1997-08-01

    X-ray techniques are used in petroleum laboratories for a variety of reservoir characterization measurements. This paper describes the configuration of a 2D X-ray scanner and many of the ways in which it simplifies and improves accuracy`s of laboratory measurements. Linear X-ray scanners are most often used to provide descriptions of fluid saturations within core plugs during flow tests. We configured our linear scanner for both horizontal and vertical movement. Samples can be scanned horizontally, vertically, or according to horizontal and vertical grids. X-ray measurements are fast, allowing measurements of two- and three-phase fluid saturations during both steady- and unsteady-state flow processes. Rock samples can be scanned while they are subjected to stress, pore pressure, and temperature conditions simulating those of a petroleum reservoir. Many types of measurements are possible by selecting appropriate X-ray power settings, dopes, filters, and collimator configurations. The scanner has been used for a variety of applications besides fluid saturation measurements. It is useful for measuring porosity distributions in rocks, concentrations of X-ray dopes within flow streams during tracer tests, gap widths in fracture flow cells, fluid interface levels in PVT cells and fluid separators, and other features and phenomena.

  1. Wire chamber conference

    International Nuclear Information System (INIS)

    This booklet contains program and the abstracts of the papers presented at the conference, most of them dealing with performance testing of various types of wire chambers. The publication of proceedings is planned as a special issue of 'Nuclear instruments and methods' later on. All abstracts are in English. An author index for the book of abstracts is given. (A.N.)

  2. Practical wiring in SI units

    CERN Document Server

    Miller, Henry A

    2013-01-01

    Practical Wiring, Volume 1 is a 13-chapter book that first describes some of the common hand tools used in connection with sheathed wiring. Subsequent chapters discuss the safety in wiring, cables, conductor terminations, insulating sheathed wiring, conductor sizes, and consumer's control equipments. Other chapters center on socket outlets, plugs, lighting subcircuits, lighting accessories, bells, and primary and secondary cells. This book will be very valuable to students involved in this field of interest.

  3. Wire EDM for Refractory Materials

    Science.gov (United States)

    Zellars, G. R.; Harris, F. E.; Lowell, C. E.; Pollman, W. M.; Rys, V. J.; Wills, R. J.

    1982-01-01

    In an attempt to reduce fabrication time and costs, Wire Electrical Discharge Machine (Wire EDM) method was investigated as tool for fabricating matched blade roots and disk slots. Eight high-strength nickel-base superalloys were used. Computer-controlled Wire EDM technique provided high quality surfaces with excellent dimensional tolerances. Wire EDM method offers potential for substantial reductions in fabrication costs for "hard to machine" alloys and electrically conductive materials in specific high-precision applications.

  4. Design, construction, characterization, and application of a hyperspectral microarray scanner.

    Science.gov (United States)

    Sinclair, Michael B; Timlin, Jerilyn A; Haaland, David M; Werner-Washburne, Margaret

    2004-04-01

    We describe the design, construction, and operation of a hyperspectral microarray scanner for functional genomic research. The hyperspectral instrument operates with spatial resolutions ranging from 3 to 30 microm and records the emission spectrum between 490 and 900 nm with a spectral resolution of 3 nm for each pixel of the microarray. This spectral information, when coupled with multivariate data analysis techniques, allows for identification and elimination of unwanted artifacts and greatly improves the accuracy of microarray experiments. Microarray results presented in this study clearly demonstrate the separation of fluorescent label emission from the spectrally overlapping emission due to the underlying glass substrate. We also demonstrate separation of the emission due to green fluorescent protein expressed by yeast cells from the spectrally overlapping autofluorescence of the yeast cells and the growth media.

  5. A PET scanner developed by CERN

    CERN Multimedia

    Laurent Guiraud

    1998-01-01

    This image shows a Position Emission Tomography (PET) scanner at the Hopital Cantonal Universitaire de Genève. Development of the multiwire proportional chamber at CERN in the mid-1970s was soon seen as a potential device for medical imaging. It is much more sensitive than previous devices and greatly reduced the dose of radiation received by the patient.

  6. 21 CFR 892.1220 - Fluorescent scanner.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Fluorescent scanner. 892.1220 Section 892.1220 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED... the body to certain x-rays or low-energy gamma rays. This generic type of device may include...

  7. Learning and Teaching with a Computer Scanner

    Science.gov (United States)

    Planinsic, G.; Gregorcic, B.; Etkina, E.

    2014-01-01

    This paper introduces the readers to simple inquiry-based activities (experiments with supporting questions) that one can do with a computer scanner to help students learn and apply the concepts of relative motion in 1 and 2D, vibrational motion and the Doppler effect. We also show how to use these activities to help students think like…

  8. Traveling wire electrode increases productivity of Electrical Discharge Machining /EDM/ equipment

    Science.gov (United States)

    Kotora, J., Jr.; Smith, S. V.

    1967-01-01

    Traveling wire electrode on electrical discharge machining /EDM/ equipment reduces the time requirements for precision cutting. This device enables cutting with a minimum of lost material and without inducing stress beyond that inherent in the material. The use of wire increases accuracy and enables tighter tolerances to be maintained.

  9. Occurrence and characteristics of mutual interference between LIDAR scanners

    Science.gov (United States)

    Kim, Gunzung; Eom, Jeongsook; Park, Seonghyeon; Park, Yongwan

    2015-05-01

    The LIDAR scanner is at the heart of object detection of the self-driving car. Mutual interference between LIDAR scanners has not been regarded as a problem because the percentage of vehicles equipped with LIDAR scanners was very rare. With the growing number of autonomous vehicle equipped with LIDAR scanner operated close to each other at the same time, the LIDAR scanner may receive laser pulses from other LIDAR scanners. In this paper, three types of experiments and their results are shown, according to the arrangement of two LIDAR scanners. We will show the probability that any LIDAR scanner will interfere mutually by considering spatial and temporal overlaps. It will present some typical mutual interference scenario and report an analysis of the interference mechanism.

  10. Moisture-insensitive optical fingerprint scanner based on polarization resolved in-finger scattered light.

    Science.gov (United States)

    Back, Seon-Woo; Lee, Yong-Geon; Lee, Sang-Shin; Son, Geun-Sik

    2016-08-22

    A moisture-insensitive optical fingerprint scanner (FPS) that is based on polarization resolved in-finger light is proposed and realized. Incident visible light, which is selectively fed to a fingerprint sample via a polarization beam splitter (PBS), is deemed to be partially scattered backward by tissues associated with the skin of the finger. The backscattered light is mostly index-guided in the ridge comprising the fingerprint, which has a higher refractive index, and is drastically dispersed in the valley, which is typically filled with water or air and so has a lower index. However, when light reflects directly off the surface of the finger skin, it fundamentally prevents the scanned image from being determined. The proposed FPS produces bright and dark intensity patterns that are alternately created on the surface of the PBS and correspond to the ridges and valleys, respectively. Thus, this method can especially distinguish between a fake synthetic fingerprint and a genuine fingerprint due to its use of in-finger scattered light. The scanner has been rigorously designed by carrying out ray-optic simulations depending on the wavelength, with tissue-induced scattering taken into account. The device was constructed by incorporating a wire-grid type PBS in conjunction with visible LED sources, including blue, green and red. The scanner adopting a blue LED, which exhibits the strongest light scattering, resulted in the best fingerprint image, enabling enhanced fidelity under the wet and dry situations. Finally, a fake synthetic fingerprint could be successfully discriminated. PMID:27557199

  11. Wired to freedom

    DEFF Research Database (Denmark)

    Bertilsson, Margareta; Jepsen, Kim Sune Karrasch

    2015-01-01

    Cochlear Implantation is now regarded as the most successful medical technology. It carries promises to provide deaf/hearing impaired individuals with a technological sense of hearing and an access to participate on a more equal level in social life. In this article, we explore the adoption...... dimension of life science through a notion of public politics adopted from the political theory of John Dewey. We show how cochlear implantation engages different social imaginaries on the collective and individual levels and we suggest that users share an imaginary of being “wired to freedom” that involves...... new access to social life, continuous communicative challenges, common practices, and experiences. In looking at their lives as “wired to freedom,” we hope to promote a wider spectrum of civic participation in the benefit of future life science developments within and beyond the field of Cochlear...

  12. From Wires to Cosmology

    CERN Document Server

    Amin, Mustafa A

    2015-01-01

    We provide a statistical framework for characterizing stochastic particle production in the early universe via a precise correspondence to current conduction in wires with impurities. Our approach is particularly useful when the microphysics is uncertain and the dynamics are complex, but only coarse-grained information is of interest. We study scenarios with multiple interacting fields and derive the evolution of the particle occupation numbers from a Fokker-Planck equation. At late times, the typical occupation numbers grow exponentially which is the analog of Anderson localization for disordered wires. Some statistical features of the occupation numbers show hints of universality in the limit of a large number of interactions and/or a large number of fields. For test cases, excellent agreement is found between our analytic results and numerical simulations.

  13. Randomly Wired Multistage Networks

    OpenAIRE

    Maggs, Bruce M.

    1993-01-01

    Randomly wired multistage networks have recently been shown to outperform traditional multistage networks in three respects. First, they have fast deterministic packet-switching and circuit-switching algorithms for routing permutations. Second, they are nonblocking, and there are on-line algorithms for establishing new connections in them, even if many requests for connections are made simultaneously. Finally, and perhaps most importantly, they are highly fault tolerant.

  14. Dual-Antenna Terrestrial Laser Scanner Georeferencing Using Auxiliary Photogrammetric Observations

    Directory of Open Access Journals (Sweden)

    Benjamin Wilkinson

    2015-09-01

    Full Text Available Terrestrial laser scanning typically requires the use of artificial targets for registration and georeferencing the data. This equipment can be burdensome to transport and set up, representing expense in both time and labor. Environmental factors such as terrain can sometimes make target placement dangerous or impossible, or lead to weak network geometry and therefore degraded product accuracy. The use of additional sensors can help reduce the required number of artificial targets and, in some cases, eliminate the need for them altogether. The research presented here extends methods for direct georeferencing of terrestrial laser scanner data using a dual GNSS antenna apparatus with additional photogrammetric observations from a scanner-mounted camera. Novel combinations of observations and processing methods were tested on data collected at two disparate sites in order to find the best method in terms of processing efficiency and product quality. In addition, a general model for the scanner and auxiliary data is given which can be used for least-squares adjustment and uncertainty estimation in similar systems with varied and diverse configurations. We found that the dual-antenna system resulted in cm-level accuracy practical for many applications and superior to conventional one-antenna systems, and that auxiliary photogrammetric observation significantly increased accuracy of the dual-antenna solution.

  15. Magnetoconductance of quantum wires

    Science.gov (United States)

    Ferreira, Gerson J.; Sammarco, Filipe; Egues, Carlos

    2010-03-01

    At low temperatures the conductance of a quantum wires exhibit characteristic plate-aus due to the quantization of the transverse modes [1]. In the presence of high in-plane magnetic fields these spin-split transverse modes cross. Recently, these crossings were observed experimentally [2] via measurements of the differential conductance as a function of the gate voltage and the in-plane magnetic-field. These show structures described as either anti-crossings or magnetic phase transitions. Motivated by our previous works on magnetotransport in 2DEGs via the Spin Density Functional Theory (SDFT) [3], here we propose a similar model to investigate the magnetoconductance of quantum wires. We use (i) the SDFT via the Kohn-Sham self-consistent scheme within the local spin density approximation to obtain the electronic structure and (ii) the Landauer-Buettiker formalism to calculate the conductance of a quantum wire. Our results show qualitative agreement with the data of Ref. [2]. [1] B. J. van Wees et al., Phys. Rev. Lett. 60, 848 (1988). [2] A. C. Graham et al., Phys. Rev. Lett. 100, 226804 (2008). [3] H. J. P. Freire, and J. C. Egues, Phys. Rev. Lett. 99, 026801 (2007); G. J. Ferreira, and J. Carlos Egues, J. Supercond. Nov. Mag., in press; G. J. Ferreira, H. J. P. Freire, J. Carlos Egues, submitted.

  16. Sensitivity booster for DOI-PET scanner by utilizing Compton scattering events between detector blocks

    Energy Technology Data Exchange (ETDEWEB)

    Yoshida, Eiji, E-mail: rush@nirs.go.jp; Tashima, Hideaki; Yamaya, Taiga

    2014-11-01

    In a conventional PET scanner, coincidence events are measured with a limited energy window for detection of photoelectric events in order to reject Compton scatter events that occur in a patient, but Compton scatter events caused in detector crystals are also rejected. Scatter events within the patient causes scatter coincidences, but inter crystal scattering (ICS) events have useful information for determining an activity distribution. Some researchers have reported the feasibility of PET scanners based on a Compton camera for tracing ICS into the detector. However, these scanners require expensive semiconductor detectors for high-energy resolution. In the Anger-type block detector, single photons interacting with multiple detectors can be obtained for each interacting position and complete information can be gotten just as for photoelectric events in the single detector. ICS events in the single detector have been used to get coincidence, but single photons interacting with multiple detectors have not been used to get coincidence. In this work, we evaluated effect of sensitivity improvement using Compton kinetics in several types of DOI-PET scanners. The proposed method promises to improve the sensitivity using coincidence events of single photons interacting with multiple detectors, which are identified as the first interaction (FI). FI estimation accuracy can be improved to determine FI validity from the correlation between Compton scatter angles calculated on the coincidence line-of-response. We simulated an animal PET scanner consisting of 42 detectors. Each detector block consists of three types of scintillator crystals (LSO, GSO and GAGG). After the simulation, coincidence events are added as information for several depth-of-interaction (DOI) resolutions. From the simulation results, we concluded the proposed method promises to improve the sensitivity considerably when effective atomic number of a scintillator is low. Also, we showed that FI estimate

  17. 21 CFR 892.1330 - Nuclear whole body scanner.

    Science.gov (United States)

    2010-04-01

    ...) MEDICAL DEVICES RADIOLOGY DEVICES Diagnostic Devices § 892.1330 Nuclear whole body scanner. (a) Identification. A nuclear whole body scanner is a device intended to measure and image the distribution of... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Nuclear whole body scanner. 892.1330 Section...

  18. Applications of Optical Scanners in an Academic Center.

    Science.gov (United States)

    Molinari, Carol; Tannenbaum, Robert S.

    1995-01-01

    Describes optical scanners, including how the technology works; applications in data management and research; development of instructional materials; and providing community services. Discussion includes the three basic types of optical scanners: optical character recognition (OCR), optical mark readers (OMR), and graphic scanners. A sidebar…

  19. Dual wire welding torch and method

    Science.gov (United States)

    Diez, Fernando Martinez; Stump, Kevin S.; Ludewig, Howard W.; Kilty, Alan L.; Robinson, Matthew M.; Egland, Keith M.

    2009-04-28

    A welding torch includes a nozzle with a first welding wire guide configured to orient a first welding wire in a first welding wire orientation, and a second welding wire guide configured to orient a second welding wire in a second welding wire orientation that is non-coplanar and divergent with respect to the first welding wire orientation. A method of welding includes moving a welding torch with respect to a workpiece joint to be welded. During moving the welding torch, a first welding wire is fed through a first welding wire guide defining a first welding wire orientation and a second welding wire is fed through a second welding wire guide defining a second welding wire orientation that is divergent and non-coplanar with respect to the first welding wire orientation.

  20. Right wire in orthodontics: a review

    OpenAIRE

    Ali, Hashim

    2015-01-01

    Quality of orthodontic wire such as stiffness, hardness, resiliency, elasticity and working range are important determinants of the effectivenes of tooth movement. Commonly used types of orthodontic arch wire:1) stainless steel(ss) wire, 2) conventional nickel- titanium (NiTi)alloy wire,3) improved super elastic NiTi- alloy wire( also called low hysteresis(LH)wire), and titanium molybdenum alloy(TMA) wire.

  1. Electrothermal MEMS fiber scanner for optical endomicroscopy.

    Science.gov (United States)

    Seo, Yeong-Hyeon; Hwang, Kyungmin; Park, Hyeon-Cheol; Jeong, Ki-Hun

    2016-02-22

    We report a novel MEMS fiber scanner with an electrothermal silicon microactuator and a directly mounted optical fiber. The microactuator comprises double hot arm and cold arm structures with a linking bridge and an optical fiber is aligned along a silicon fiber groove. The unique feature induces separation of resonant scanning frequencies of a single optical fiber in lateral and vertical directions, which realizes Lissajous scanning during the resonant motion. The footprint dimension of microactuator is 1.28 x 7 x 0.44 mm3. The resonant scanning frequencies of a 20 mm long optical fiber are 239.4 Hz and 218.4 Hz in lateral and vertical directions, respectively. The full scanned area indicates 451 μm x 558 μm under a 16 Vpp pulse train. This novel laser scanner can provide many opportunities for laser scanning endomicroscopic applications.

  2. Compact conscious animal positron emission tomography scanner

    Science.gov (United States)

    Schyler, David J.; O'Connor, Paul; Woody, Craig; Junnarkar, Sachin Shrirang; Radeka, Veljko; Vaska, Paul; Pratte, Jean-Francois; Volkow, Nora

    2006-10-24

    A method of serially transferring annihilation information in a compact positron emission tomography (PET) scanner includes generating a time signal for an event, generating an address signal representing a detecting channel, generating a detector channel signal including the time and address signals, and generating a composite signal including the channel signal and similarly generated signals. The composite signal includes events from detectors in a block and is serially output. An apparatus that serially transfers annihilation information from a block includes time signal generators for detectors in a block and an address and channel signal generator. The PET scanner includes a ring tomograph that mounts onto a portion of an animal, which includes opposing block pairs. Each of the blocks in a block pair includes a scintillator layer, detection array, front-end array, and a serial encoder. The serial encoder includes time signal generators and an address signal and channel signal generator.

  3. Laser scanner 3D terrestri e mobile

    Directory of Open Access Journals (Sweden)

    Mario Ciamba

    2013-08-01

    Full Text Available Recentemente si è svolto a Roma un evento dimostrativo per informare, professionisti e ricercatori del settore inerente il rilievo strumentale, sulle recenti innovazioni che riguardano i laser scanner 3d. Il mercato della strumentazione dedicata al rilevamento architettonico e dell'ambiente, offre molte possibilità di scelta. Oggi i principali marchi producono strumenti sempre più efficienti ed ideati per ambiti di applicazione specifici, permettendo ai professionisti, la giusta scelta in termini di prestazioni ed economia.A demonstration event was recently held in Rome with the aim to inform professionals and researchers on recent innovations on instrumental survey related to the 3d laser scanner. The market of instrumentation for architectural survey offers many possibilitiesof choice. Today the major brands produce instruments that are more efficient and designed for specific areas of application, allowing the right choice in terms of performance and economy.

  4. Get Mobile – The Smartphone Brain Scanner

    DEFF Research Database (Denmark)

    Stahlhut, Carsten; Stopczynski, Arkadiusz; Petersen, Michael Kai;

    This demonstration will provide live-interaction with a smartphone brain scanner consisting of a low-cost wireless 14-channel EEG headset (Emotiv Epoc) and a mobile device. With our system it is possible to perform real-time functional brain imaging on a smartphone device, including stimulus deli......) that are based on Linux operating systems. Thus our system runs on multiple platforms, including Maemo/MeeGo based smartphones, Android-based smartphones and tablet devices....

  5. Determining Block Detector Positions for PET Scanners

    OpenAIRE

    Pierce, Larry; Miyaoka, Robert; Lewellen, Tom; Alessio, Adam; Kinahan, Paul

    2009-01-01

    We present an algorithm for accurate localization of block detectors in a positron emission tomography (PET) scanner. Accurate reconstruction of PET images requires precise knowledge of the physical position and orientation of the detectors. However, in some systems, block detector positioning and orientation can have relatively large tolerances, leading to implicit errors in the coincidence line-of-response (LOR) positioning. To compensate we utilize a rotating point source phantom where the...

  6. Evaluation of a pulsed terrestrial laser scanner based on ISO standards

    International Nuclear Information System (INIS)

    The evaluation of the accuracy and precision of measuring equipment is critical in order to achieve results that meet the specifications of a given project. Standard calibration models and field procedures exist for all traditional surveying instruments, but are still lacking for recently developed technologies like terrestrial laser scanners (TLS). The main reason is limited knowledge of errors that affect these systems, owing to the proprietary design of the scanners and their software, and the integration of many potential sources of error. Owing to the difficulty of separating the different error sources of TLS, it is proposed in this paper that a test procedure can assess the overall achievable precision for a scanner instrument without individual errors being known. The proposed tests are based on the International Organization for Standardization specifications for geodetic instruments (www.iso.org). The tests can be performed in either a controlled or uncontrolled environment, which is advantageous for on-the-job calibration. A pulsed terrestrial laser scanner (Leica Scanstation 2) was used as a test subject and the evaluation results indicated that the specific instrument performed well within the manufacturer’s specifications. (paper)

  7. Scanner-based macroscopic color variation estimation

    Science.gov (United States)

    Kuo, Chunghui; Lai, Di; Zeise, Eric

    2006-01-01

    Flatbed scanners have been adopted successfully in the measurement of microscopic image artifacts, such as granularity and mottle, in print samples because of their capability of providing full color, high resolution images. Accurate macroscopic color measurement relies on the use of colorimeters or spectrophotometers to provide a surrogate for human vision. The very different color response characteristics of flatbed scanners from any standard colorimetric response limits the utility of a flatbed scanner as a macroscopic color measuring device. This metamerism constraint can be significantly relaxed if our objective is mainly to quantify the color variations within a printed page or between pages where a small bias in measured colors can be tolerated as long as the color distributions relative to the individual mean values is similar. Two scenarios when converting color from the device RGB color space to a standardized color space such as CIELab are studied in this paper, blind and semi-blind color transformation, depending on the availability of the black channel information. We will show that both approaches offer satisfactory results in quantifying macroscopic color variation across pages while the semi-blind color transformation further provides fairly accurate color prediction capability.

  8. A near-infrared confocal scanner

    Science.gov (United States)

    Lee, Seungwoo; Yoo, Hongki

    2014-06-01

    In the semiconductor industry, manufacturing of three-dimensional (3D) packages or 3D integrated circuits is a high-performance technique that requires combining several functions in a small volume. Through-silicon vias, which are vertical electrical connections extending through a wafer, can be used to direct signals between stacked chips, thus increasing areal density by stacking and connecting multiple patterned chips. While defect detection is essential in the semiconductor manufacturing process, it is difficult to identify defects within a wafer or to monitor the bonding results between bonded surfaces because silicon and many other semiconductor materials are opaque to visible wavelengths. In this context, near-infrared (NIR) imaging is a promising non-destructive method to detect defects within silicon chips, to inspect bonding between chips and to monitor the chip alignment since NIR transmits through silicon. In addition, a confocal scanner provides high-contrast, optically-sectioned images of the specimen due to its ability to reject out-of-focus noise. In this study, we report an NIR confocal scanner that rapidly acquires high-resolution images with a large field of view through silicon. Two orthogonal line-scanning images can be acquired without rotating the system or the specimen by utilizing two orthogonally configured resonant scanning mirrors. This NIR confocal scanner can be efficiently used as an in-line inspection system when manufacturing semiconductor devices by rapidly detecting defects on and beneath the surface.

  9. Review of wire chamber aging

    International Nuclear Information System (INIS)

    This paper makes an overview of the wire chamber aging problems as a function of various chamber design parameters. It emphasizes the chemistry point of view and many examples are drawn from the plasma chemistry field as a guidance for a possible effort in the wire chamber field. The paper emphasizes the necessity of variable tuning, the importance of purity of the wire chamber environment, as well as it provides a practical list of presently known recommendations. In addition, several models of the wire chamber aging are qualitatively discussed. The paper is based on a summary talk given at the Wire Chamber Aging Workshop held at LBL, Berkeley on January 16-17, 1986. Presented also at Wire Chamber Conference, Vienna, February 25-28, 1986. 74 refs., 18 figs., 11 tabs

  10. Telescope with a wide field of view internal optical scanner

    Science.gov (United States)

    Degnan, III, John James (Inventor); Zheng, Yunhui (Inventor)

    2012-01-01

    A telescope with internal scanner utilizing either a single optical wedge scanner or a dual optical wedge scanner and a controller arranged to control a synchronous rotation of the first and/or second optical wedges, the wedges constructed and arranged to scan light redirected by topological surfaces and/or volumetric scatterers. The telescope with internal scanner further incorporates a first converging optical element that receives the redirected light and transmits the redirected light to the scanner, and a second converging optical element within the light path between the first optical element and the scanner arranged to reduce an area of impact on the scanner of the beam collected by the first optical element.

  11. THERMAL CONDUCTIVITY OF METALLIC WIRES

    Institute of Scientific and Technical Information of China (English)

    LU XIANG; GU JI-HUA; CHU JUN-HAO

    2001-01-01

    The effect of radial thickness on the thermal conductivity of a free standing wire is investigated. The thermal conductivity is evaluated using the Boltzmann equation. A simple expression for the reduction in conductivity due to the increase of boundary scattering is presented. A comparison is made between the experimental results of indium wires and the theoretical calculations. It is shown that this decrease of conductivity in wires is smaller than that in film where heat flux is perpendicular to the surface.

  12. Shot noise in parallel wires

    OpenAIRE

    Lagerqvist, Johan; Chen, Yu-Chang; Di Ventra, Massimiliano

    2004-01-01

    We report first-principles calculations of shot noise properties of parallel carbon wires in the regime in which the interwire distance is much smaller than the inelastic mean free path. We find that, with increasing interwire distance, the current approaches rapidly a value close to twice the current of each wire, while the Fano factor, for the same distances, is still larger than the Fano factor of a single wire. This enhanced Fano factor is the signature of the correlation between electron...

  13. On the Model Checking of the SpaceWire Link Interface

    Directory of Open Access Journals (Sweden)

    Jie Zhang

    2013-02-01

    Full Text Available In this paper we display a practical approach adopted for the formal verification of SpaceWire using model checking to solve state explosion. SpaceWire is a high-speed, full-duplex serial bus standard which is applied in aerospace, so its functions have a very high accuracy requirements. In order to prove the design of the SpaceWire was faithfully implements the SpaceWire protocol’s specification , we present our experience on the model checking of SpaceWire link interface using the Cadence SMV tool. We applied environment state machine to overcome state explosion and successfully  verified  a number of relevant properties about transmitter and controller of the SpaceWire in reasonable CPU time.  

  14. Wire communication engineering

    International Nuclear Information System (INIS)

    This book describes wire telecommunication engineering/ It is divided into eleven chapter, which deal with Introduction with development of telecommunication, voice and sound wave and communication network, Telegraphy with summary of telegraphy, code of telegraphy, communication speed, morse and telex, Telephone on structure, circuit and image telephone, Traffic on telecommunication traffic, transmission of line about theory, cable line and loaded cable, carrier communication with carrier telegraphy and carrier telephone, optical communication with types, structure, specialty, laser and equipment, DATA, Mobile telecommunication on summary, mobile telephone, radio paging and digital mobile telecommunication, ISDN with channel of ISDN, and service of ISDN, and design of telecommunication.

  15. Wiring regulations in brief

    CERN Document Server

    Tricker, Ray

    2012-01-01

    Tired of trawling through the Wiring Regs?Perplexed by Part P?Confused by cables, conductors and circuits?Then look no further! This handy guide provides an on-the-job reference source for Electricians, Designers, Service Engineers, Inspectors, Builders, Students, DIY enthusiastsTopic-based chapters link areas of working practice - such as cables, installations, testing and inspection, special locations - with the specifics of the Regulations themselves. This allows quick and easy identification of the official requirements relating to the situati

  16. Flying spot laser triangulation scanner using lateral synchronization for surface profile precision measurement.

    Science.gov (United States)

    Zhang, Hanlin; Ren, Yongjie; Liu, Changjie; Zhu, Jigui

    2014-07-10

    High-speed surface profile measurement with high precision is crucial for target inspection and quality control. In this study, a laser scanner based on a single point laser triangulation displacement sensor and a high-speed rotating polygon mirror is proposed. The autosynchronized scanning scheme is introduced to alleviate the trade-off between the field of view and the range precision, which is the inherent deficiency of the conventional triangulation. The lateral synchronized flying spot technology has excellent characteristics, such as programmable and larger field of view, high immunity to ambient light or secondary reflections, high optical signal-to-noise ratio, and minimum shadow effect. Owing to automatic point-to-point laser power control, high accuracy and superior data quality are possible when measuring objects featuring varying surface characteristics even in demanding applications. The proposed laser triangulation scanner is validated using a laboratory-built prototype and practical considerations for design and implementation of the system are described, including speckle noise reduction method and real-time signal processing. A method for rapid and accurate calibration of the laser triangulation scanner using lookup tables is also devised, and the system calibration accuracy is generally smaller than ±0.025  mm. Experimental results are presented and show a broad application prospect for fast surface profile precision measurement.

  17. Clinical experience with the first combined positron emission tomography/computed tomography scanner in Australia.

    Science.gov (United States)

    Lau, W F Eddie; Binns, David S; Ware, Robert E; Ramdave, Shakher; Cachin, Florent; Pitman, Alexander G; Hicks, Rodney J

    2005-02-21

    Metabolic imaging with fluorine-18-fluorodeoxyglucose positron emission tomography (FDG-PET) is increasing rapidly worldwide because of superior accuracy compared with conventional non-invasive techniques used for evaluating cancer. Limited anatomical information from FDG-PET images alone dictates that complementary use with structural imaging is required to optimise benefit. Recently, combined positron emission tomography/computed tomography (PET/CT) scanners have overtaken standalone PET scanners as the most commonly purchased PET devices. We describe our experience of over 5500 scans performed since the first PET/CT scanner in Australia was commissioned at the Peter MacCallum Cancer Centre (PMCC), Melbourne, in January 2002. Clinical indications for PET/CT scans performed at PMCC largely reflect current Medicare reimbursement policy. Advantages of PET/CT include greater patient comfort and higher throughput, greater diagnostic certainty and accuracy, improved biopsy methods, and better treatment planning. We believe PET/CT will underpin more effective and efficient imaging paradigms for many common tumours, and lead to a decrease in imaging costs. PMID:15720173

  18. The Current in a Wire

    Science.gov (United States)

    Thompson, Keith

    2009-01-01

    This little problem arose because I was frustrated with the standard electromagnetism texts, which show the magnetic field due to a current-bearing wire outside the wire [proportional to] 1/r and inside [proportional to] r. However, they never point out that the moving electrons must be influenced by the magnetic field created by the other moving…

  19. Wire metamaterials: physics and applications.

    Science.gov (United States)

    Simovski, Constantin R; Belov, Pavel A; Atrashchenko, Alexander V; Kivshar, Yuri S

    2012-08-16

    The physics and applications of a broad class of artificial electromagnetic materials composed of lattices of aligned metal rods embedded in a dielectric matrix are reviewed. Such structures are here termed wire metamaterials. They appear in various settings and can operate from microwaves to THz and optical frequencies. An important group of these metamaterials is a wire medium possessing extreme optical anisotropy. The study of wire metamaterials has a long history, however, most of their important and useful properties have been revealed and understood only recently, especially in the THz and optical frequency ranges where the wire media correspond to the lattices of microwires and nanowires, respectively. Another group of wire metamaterials are arrays and lattices of nanorods of noble metals whose unusual properties are driven by plasmonic resonances.

  20. Suspect Height Estimation Using the Faro Focus(3D) Laser Scanner.

    Science.gov (United States)

    Johnson, Monique; Liscio, Eugene

    2015-11-01

    At present, very little research has been devoted to investigating the ability of laser scanning technology to accurately measure height from surveillance video. The goal of this study was to test the accuracy of one particular laser scanner to estimate suspect height from video footage. The known heights of 10 individuals were measured using an anthropometer. The individuals were then recorded on video walking along a predetermined path in a simulated crime scene environment both with and without headwear. The difference between the known heights and the estimated heights obtained from the laser scanner software were compared using a one-way t-test. The height estimates obtained from the software were not significantly different from the known heights whether individuals were wearing headwear (p = 0.186) or not (p = 0.707). Thus, laser scanning is one technique that could potentially be used by investigators to determine suspect height from video footage.

  1. Rectification of single and multiple frames of satellite scanner imagery using points and edges as control

    Science.gov (United States)

    Paderes, F. C., Jr.; Mikhail, E. M.; Foerstner, W.

    1984-01-01

    Rectification of single and overlapping multiple scanner frames produced by such satellite-borne scanners as the LANDSAT MSS was carried out using a newly developed comprehensive parametric model. Tests with both simulated and real image data demonstrate conclusively that this model in general is superior to the widely used polynomial model, and that the simultaneous rectification of overlapping frames using least squares techniques yields a high accuracy than sngle frame rectification due to the inclusion of tie points between the image frames. Used to control, edges or lines, whic are much more likely to be found in images, can replace conventional control points and can easily be implemented into the least squares approach. An efficient algorithm for findng corresponding points in image paris was developed which can be used for determining tie points between image frames and thus increase the ecnomy of the whole rectification procedure.

  2. Fast beam steering with full polarization control using a galvanometric optical scanner and polarization controller

    CERN Document Server

    Jofre, M; Steinlechner, F; Oliverio, N; Torres, J P; Pruneri, V; Mitchell, M W; 10.1364/OE.20.012247

    2012-01-01

    Optical beam steering is a key element in many industrial and scientific applications like in material processing, information technologies, medical imaging and laser display. Even though galvanometer-based scanners offer flexibility, speed and accuracy at a relatively low cost, they still lack the necessary control over the polarization required for certain applications. We report on the development of a polarization steerable system assembled with a fiber polarization controller and a galvanometric scanner, both controlled by a digital signal processor board. The system implements control of the polarization decoupled from the pointing direction through a feed-forward control scheme. This enables to direct optical beams to a desired direction without affecting its initial polarization state. When considering the full working field of view, we are able to compensate polarization angle errors larger than 0.2 rad, in a temporal window of less than $\\sim 20$ ms. Given the unification of components to fully cont...

  3. Positron Scanner for Locating Brain Tumors

    Science.gov (United States)

    Rankowitz, S.; Robertson, J. S.; Higinbotham, W. A.; Rosenblum, M. J.

    1962-03-01

    A system is described that makes use of positron emitting isotopes for locating brain tumors. This system inherently provides more information about the distribution of radioactivity in the head in less time than existing scanners which use one or two detectors. A stationary circular array of 32 scintillation detectors scans a horizontal layer of the head from many directions simultaneously. The data, consisting of the number of counts in all possible coincidence pairs, are coded and stored in the memory of a Two-Dimensional Pulse-Height Analyzer. A unique method of displaying and interpreting the data is described that enables rapid approximate analysis of complex source distribution patterns. (auth)

  4. Inter laboratory comparison of industrial CT scanners

    DEFF Research Database (Denmark)

    Angel, Jais Andreas Breusch; Cantatore, Angela; De Chiffre, Leonardo

    2012-01-01

    In this report results from an intercomparison of industrial CT scanners are presented. Three audit items, similar to common industrial parts, were selected for circulation: a single polymer part with complex geometry (Item 1), a simple geometry part made of two polymers (Item 2) and a miniature...... step gauge produced using a polymer replica material (Item 3). The items circulated among six participants in Denmark and Germany. The circulation took place between March 2011 and June 2011. The items were measured according to a given protocol....

  5. System analysis of bar code laser scanner

    Science.gov (United States)

    Wang, Jianpu; Chen, Zhaofeng; Lu, Zukang

    1996-10-01

    This paper focuses on realizing the three important aspects of bar code scanner: generating a high quality scanning light beam, acquiring a fairly even distribution characteristic of light collection, achieving a low signal dynamic range over a large depth of field. To do this, we analyze the spatial distribution and propagation characteristics of scanning laser beam, the vignetting characteristic of optical collection system and their respective optimal design; propose a novel optical automatic gain control method to attain a constant collection over a large working depth.

  6. Biomedical Imaging and Sensing using Flatbed Scanners

    OpenAIRE

    Göröcs, Zoltán; Ozcan, Aydogan

    2014-01-01

    In this Review, we provide an overview of flatbed scanner based biomedical imaging and sensing techniques. The extremely large imaging field-of-view (e.g., ~600–700 cm2) of these devices coupled with their cost-effectiveness provide unique opportunities for digital imaging of samples that are too large for regular optical microscopes, and for collection of large amounts of statistical data in various automated imaging or sensing tasks. Here we give a short introduction to the basic features o...

  7. Nano-storage wires.

    Science.gov (United States)

    Lee, Dong Jun; Kim, Eunji; Kim, Daesan; Park, Juhun; Hong, Seunghun

    2013-08-27

    We report the development of "nano-storage wires" (NSWs), which can store chemical species and release them at a desired moment via external electrical stimuli. Here, using the electrodeposition process through an anodized aluminum oxide template, we fabricated multisegmented nanowires composed of a polypyrrole segment containing adenosine triphosphate (ATP) molecules, a ferromagnetic nickel segment, and a conductive gold segment. Upon the application of a negative bias voltage, the NSWs released ATP molecules for the control of motor protein activities. Furthermore, NSWs can be printed onto various substrates including flexible or three-dimensional structured substrates by direct writing or magnetic manipulation strategies to build versatile chemical storage devices. Since our strategy provides a means to store and release chemical species in a controlled manner, it should open up various applications such as drug delivery systems and biochips for the controlled release of chemicals.

  8. Portable optical fiber probe-based spectroscopic scanner for rapid cancer diagnosis: a new tool for intraoperative margin assessment.

    Directory of Open Access Journals (Sweden)

    Niyom Lue

    Full Text Available There continues to be a significant clinical need for rapid and reliable intraoperative margin assessment during cancer surgery. Here we describe a portable, quantitative, optical fiber probe-based, spectroscopic tissue scanner designed for intraoperative diagnostic imaging of surgical margins, which we tested in a proof of concept study in human tissue for breast cancer diagnosis. The tissue scanner combines both diffuse reflectance spectroscopy (DRS and intrinsic fluorescence spectroscopy (IFS, and has hyperspectral imaging capability, acquiring full DRS and IFS spectra for each scanned image pixel. Modeling of the DRS and IFS spectra yields quantitative parameters that reflect the metabolic, biochemical and morphological state of tissue, which are translated into disease diagnosis. The tissue scanner has high spatial resolution (0.25 mm over a wide field of view (10 cm × 10 cm, and both high spectral resolution (2 nm and high spectral contrast, readily distinguishing tissues with widely varying optical properties (bone, skeletal muscle, fat and connective tissue. Tissue-simulating phantom experiments confirm that the tissue scanner can quantitatively measure spectral parameters, such as hemoglobin concentration, in a physiologically relevant range with a high degree of accuracy (<5% error. Finally, studies using human breast tissues showed that the tissue scanner can detect small foci of breast cancer in a background of normal breast tissue. This tissue scanner is simpler in design, images a larger field of view at higher resolution and provides a more physically meaningful tissue diagnosis than other spectroscopic imaging systems currently reported in literatures. We believe this spectroscopic tissue scanner can provide real-time, comprehensive diagnostic imaging of surgical margins in excised tissues, overcoming the sampling limitation in current histopathology margin assessment. As such it is a significant step in the development of a

  9. Integrated Electro-optical Laser-Beam Scanners

    Science.gov (United States)

    Boord, Warren T.

    1990-01-01

    Scanners using solid-state devices compact, consume little power, and have no moving parts. Integrated electro-optical laser scanner, in conjunction with external lens, points outgoing beam of light in any number of different directions, depending on number of upper electrodes. Offers beam-deflection angles larger than those of acousto-optic scanners. Proposed for such diverse applications as nonimpact laser printing, color imaging, ranging, barcode reading, and robotic vision.

  10. Interferometric Laser Scanner for Direction Determination.

    Science.gov (United States)

    Kaloshin, Gennady; Lukin, Igor

    2016-01-01

    In this paper, we explore the potential capabilities of new laser scanning-based method for direction determination. The method for fully coherent beams is extended to the case when interference pattern is produced in the turbulent atmosphere by two partially coherent sources. The performed theoretical analysis identified the conditions under which stable pattern may form on extended paths of 0.5-10 km in length. We describe a method for selecting laser scanner parameters, ensuring the necessary operability range in the atmosphere for any possible turbulence characteristics. The method is based on analysis of the mean intensity of interference pattern, formed by two partially coherent sources of optical radiation. Visibility of interference pattern is estimated as a function of propagation pathlength, structure parameter of atmospheric turbulence, and spacing of radiation sources, producing the interference pattern. It is shown that, when atmospheric turbulences are moderately strong, the contrast of interference pattern of laser scanner may ensure its applicability at ranges up to 10 km. PMID:26805841

  11. Interferometric Laser Scanner for Direction Determination.

    Science.gov (United States)

    Kaloshin, Gennady; Lukin, Igor

    2016-01-21

    In this paper, we explore the potential capabilities of new laser scanning-based method for direction determination. The method for fully coherent beams is extended to the case when interference pattern is produced in the turbulent atmosphere by two partially coherent sources. The performed theoretical analysis identified the conditions under which stable pattern may form on extended paths of 0.5-10 km in length. We describe a method for selecting laser scanner parameters, ensuring the necessary operability range in the atmosphere for any possible turbulence characteristics. The method is based on analysis of the mean intensity of interference pattern, formed by two partially coherent sources of optical radiation. Visibility of interference pattern is estimated as a function of propagation pathlength, structure parameter of atmospheric turbulence, and spacing of radiation sources, producing the interference pattern. It is shown that, when atmospheric turbulences are moderately strong, the contrast of interference pattern of laser scanner may ensure its applicability at ranges up to 10 km.

  12. Interferometric Laser Scanner for Direction Determination

    Directory of Open Access Journals (Sweden)

    Gennady Kaloshin

    2016-01-01

    Full Text Available In this paper, we explore the potential capabilities of new laser scanning-based method for direction determination. The method for fully coherent beams is extended to the case when interference pattern is produced in the turbulent atmosphere by two partially coherent sources. The performed theoretical analysis identified the conditions under which stable pattern may form on extended paths of 0.5–10 km in length. We describe a method for selecting laser scanner parameters, ensuring the necessary operability range in the atmosphere for any possible turbulence characteristics. The method is based on analysis of the mean intensity of interference pattern, formed by two partially coherent sources of optical radiation. Visibility of interference pattern is estimated as a function of propagation pathlength, structure parameter of atmospheric turbulence, and spacing of radiation sources, producing the interference pattern. It is shown that, when atmospheric turbulences are moderately strong, the contrast of interference pattern of laser scanner may ensure its applicability at ranges up to 10 km.

  13. Quest for an open MRI scanner.

    Science.gov (United States)

    Bertora, Franco; Borceto, Alice; Viale, Andrea; Sandini, Giulio

    2014-01-01

    A study of the motor cortex during the programming, execution and mental representation of voluntary movement is of great relevance; its evaluation in conditions close to reality is necessary, given the close integration of the visuomotor, sensory feedback and proprioceptive systems, as of yet, a functional Magnetic Resonance Imaging (fMRI) scanner allowing a human subject to maintain erect stance, observe the surroundings and conserve limb freedom is still a dream. The need for high field suggests a solenoid magnet geometry that forces an unnatural posture that affects the results, particularly when the motor cortex is investigated. In contrast in a motor functional study, the scanner should allow the subject to sit or stand, with unobstructed sight and unimpeded movement. Two approaches are presented here to solve this problem. In the first approach, an increased field intensity in an open magnet is obtained lining the "back wall" of the cavity with a sheet of current: this boosts the field intensity at the cost of the introduction of a gradient, which has to be canceled by the introduction of an opposite gradient; The second approach is an adaptation of the "double doughnut" architecture, in which the cavity widens at the center to provide additional room for the subject. The detailed design of this kind of structure has proven the feasibility of the solution. PMID:25227008

  14. Antenna Near-Field Probe Station Scanner

    Science.gov (United States)

    Zaman, Afroz J. (Inventor); Lee, Richard Q. (Inventor); Darby, William G. (Inventor); Barr, Philip J. (Inventor); Lambert, Kevin M (Inventor); Miranda, Felix A. (Inventor)

    2011-01-01

    A miniaturized antenna system is characterized non-destructively through the use of a scanner that measures its near-field radiated power performance. When taking measurements, the scanner can be moved linearly along the x, y and z axis, as well as rotationally relative to the antenna. The data obtained from the characterization are processed to determine the far-field properties of the system and to optimize the system. Each antenna is excited using a probe station system while a scanning probe scans the space above the antenna to measure the near field signals. Upon completion of the scan, the near-field patterns are transformed into far-field patterns. Along with taking data, this system also allows for extensive graphing and analysis of both the near-field and far-field data. The details of the probe station as well as the procedures for setting up a test, conducting a test, and analyzing the resulting data are also described.

  15. A Compact Vertical Scanner for Atomic Force Microscopes

    Directory of Open Access Journals (Sweden)

    Jae Hong Park

    2010-11-01

    Full Text Available A compact vertical scanner for an atomic force microscope (AFM is developed. The vertical scanner is designed to have no interference with the optical microscope for viewing the cantilever. The theoretical stiffness and resonance of the scanner are derived and verified via finite element analysis. An optimal design process that maximizes the resonance frequency is performed. To evaluate the scanner’s performance, experiments are performed to evaluate the travel range, resonance frequency, and feedback noise level. In addition, an AFM image using the proposed vertical scanner is generated.

  16. Plasma chemistry in wire chambers

    International Nuclear Information System (INIS)

    The phenomenology of wire chamber aging is discussed and fundamentals of proportional counters are presented. Free-radical polymerization and plasma polymerization are discussed. The chemistry of wire aging is reviewed. Similarities between wire chamber plasma (>1 atm dc-discharge) and low-pressure rf-discharge plasmas, which have been more widely studied, are suggested. Construction and use of a system to allow study of the plasma reactions occurring in wire chambers is reported. A proportional tube irradiated by an 55Fe source is used as a model wire chamber. Condensable species in the proportional tube effluent are concentrated in a cryotrap and analyzed by gas chromatography/mass spectrometry. Several different wire chamber gases (methane, argon/methane, ethane, argon/ethane, propane, argon/isobutane) are tested and their reaction products qualitatively identified. For all gases tested except those containing methane, use of hygroscopic filters to remove trace water and oxygen contaminants from the gas resulted in an increase in the average molecular weight of the products, consistent with results from low-pressure rf-discharge plasmas. It is suggested that because water and oxygen inhibit polymer growth in the gas phase that they may also reduce polymer deposition in proportional tubes and therefore retard wire aging processes. Mechanistic implications of the plasma reactions of hydrocarbons with oxygen are suggested. Unresolved issues in this work and proposals for further study are discussed

  17. Design of a portable CAT scanner for utility pole inspection

    International Nuclear Information System (INIS)

    Work is under way at the University of Missouri, Columbia (UMC) to design, build, and test a portable computerized axial tomography (CAT) device for the nondestructive, field imaging of wooden utility poles. CAT is a well-established medical technology that has recently been applied to a number of industrial applications. Wooden utility poles are prone to rot and decay at ground level; current techniques to assess this loss of strength are relatively primitive, i.e., tapping the pole (hitting the pole with a hammer) or boring into the pole for samples and then testing inside the bore hole with an electrical pulse device. The accuracy in identifying poles needing replacement using these techniques is ∼ 70%. Since the cost of replacing a pole ranges from hundreds to thousands of dollars, an accurate, nondestructive method is needed. CAT can accurately image a wooden utility pole (since the size, density, and atomic elements of a pole are similar to the human head to torso), as was confirmed by imaging poles using the UMC nuclear engineering EMI-1010 medical scanner. Detailed images have been produced showing the ring structure of the wood and voids due to rot or decay. Images approaching this quality have also been produced on living trees using semiportable systems by other researchers

  18. Identification of scanner models by comparison of scanned hologram images.

    Science.gov (United States)

    Sugawara, Shigeru

    2014-08-01

    A method to identify scanner models that had been used to forge low-level counterfeit currencies was proposed in this study. The method identified a scanner model by characterizing differences between hologram images that exist in low-level counterfeit currencies. Twenty scanners of 18 different models were used to make samples of hologram images used in this study. The method was divided into two steps: identification of capturing conditions and identification of the scanner model. The first proposed protocol used correlations of spatial distribution of brightness to identify capturing conditions. A second proposed protocol used correlations of color distributions to identify a scanner model. The effectiveness of the protocols was demonstrated with numerical methods and sample images. The preliminary study revealed that it is necessary to consider the orientation of the holograms when the scanner models were identified, but 180° rotations can be ignored. Moreover, it is necessary to consider position in the main scanning direction of the bed for charged-coupled-device scanners. The demonstration showed that the first protocol could correctly identify the capturing conditions of almost all hologram images. However, one image could not be identified correctly; the protocol could distinguish images captured by charged-coupled-device scanners and those captured by contact image sensor scanners if the hologram was placed on the right or left edge of the scanner bed, but could not distinguish them if the hologram was placed on the inside. The demonstration also showed that the second protocol could correctly identify scanner models of all hologram images.

  19. Scanner OPC signatures: automatic vendor-to-vendor OPE matching

    Science.gov (United States)

    Renwick, Stephen P.

    2009-03-01

    As 193nm lithography continues to be stretched and the k1 factor decreases, optical proximity correction (OPC) has become a vital part of the lithographer's tool kit. Unfortunately, as is now well known, the design variations of lithographic scanners from different vendors cause them to have slightly different optical-proximity effect (OPE) behavior, meaning that they print features through pitch in distinct ways. This in turn means that their response to OPC is not the same, and that an OPC solution designed for a scanner from Company 1 may or may not work properly on a scanner from Company 2. Since OPC is not inexpensive, that causes trouble for chipmakers using more than one brand of scanner. Clearly a scanner-matching procedure is needed to meet this challenge. Previously, automatic matching has only been reported for scanners of different tool generations from the same manufacturer. In contrast, scanners from different companies have been matched using expert tuning and adjustment techniques, frequently requiring laborious test exposures. Automatic matching between scanners from Company 1 and Company 2 has remained an unsettled problem. We have recently solved this problem and introduce a novel method to perform the automatic matching. The success in meeting this challenge required three enabling factors. First, we recognized the strongest drivers of OPE mismatch and are thereby able to reduce the information needed about a tool from another supplier to that information readily available from all modern scanners. Second, we developed a means of reliably identifying the scanners' optical signatures, minimizing dependence on process parameters that can cloud the issue. Third, we carefully employed standard statistical techniques, checking for robustness of the algorithms used and maximizing efficiency. The result is an automatic software system that can predict an OPC matching solution for scanners from different suppliers without requiring expert intervention.

  20. Asymmetric gradient coil design for use in a short, open bore magnetic resonance imaging scanner

    Science.gov (United States)

    Wang, Yaohui; Liu, Feng; Li, Yu; Tang, Fangfang; Crozier, Stuart

    2016-08-01

    A conventional cylindrical whole-body MRI scanner has a long bore that may cause claustrophobia for some patients in addition to being inconvenient for healthcare workers accessing the patient. A short-bore scanner usually offers a small sized imaging area, which is impractical for imaging some body parts, such as the torso. This work proposes a novel asymmetric gradient coil design that offers a full-sized imaging area close to one end of the coil. In the new design, the primary and shielding coils are connected at one end whilst separated at the other, allowing the installation of the cooling system and shim trays. The proposed coils have a larger wire gap, higher efficiency, lower inductance, less resistance and a higher figure of merit than the non-connected coils. This half-connected coil structure not only improves the coils' electromagnetic performance, but also slightly attenuates acoustic radiation at most frequencies when compared to a non-connected gradient coil. It is also quieter in some frequency bands than a conventional symmetric gradient coil.

  1. Demonstrating Forces between Parallel Wires.

    Science.gov (United States)

    Baker, Blane

    2000-01-01

    Describes a physics demonstration that dramatically illustrates the mutual repulsion (attraction) between parallel conductors using insulated copper wire, wooden dowels, a high direct current power supply, electrical tape, and an overhead projector. (WRM)

  2. Wire Jewelry/Black History.

    Science.gov (United States)

    Daniel, Robert A.; Robinson, Charles C.

    1984-01-01

    Described is a project which made the study of Black history more real to fifth graders by having them make wire jewelry, smaller versions of the ornate filigreed ironwork produced by slave blacksmiths. (RM)

  3. Wire ropes tension, endurance, reliability

    CERN Document Server

    Feyrer, Klaus

    2015-01-01

    The main goal of this book is to present the methods used to calculate the most important parameters for ropes, and to explain how they are applied on the basis of numerous sample calculations. The book, based on the most important chapters of the German book DRAHTSEILE, has been updated to reflect the latest developments, with the new edition especially focusing on computational methods for wire ropes. Many new calculations and examples have also been added to facilitate the dimensioning and calculation of mechanical characteristics of wire ropes. This book offers a valuable resource for all those working with wire ropes, including construction engineers, operators and supervisors of machines and installations involving wire ropes.

  4. An improved image algorithm for CT scanners

    International Nuclear Information System (INIS)

    A common artifact in CT head-section images is a cupping or broad ''whitening'' effect near the skull which is due at least in part to the polychromaticity of the x-ray beam. In this paper, a general method is presented for removing this artifact empirically by a combination of two approaches. The gross cupping is removed by modifying the raw transmission data prior to reconstruction. The residual whitening near the bone is removed by conveniently modifying the reconstruction-filter function. Examples of the modifications are shown using the ASE CT scanner. The method convolves or deconvolves the CT image with an appropriate point spread function. Since the filter-function modifications conceptually done in real space rather than in frequency space, the details of the modifications are more easily understood

  5. Gigapixel microscopy using a flatbed scanner

    CERN Document Server

    Zheng, Guoan; Yang, Changhuei

    2012-01-01

    Microscopy imaging systems with a very wide field-of-view (FOV) are highly sought in biomedical applications. In this paper, we report a wide FOV microscopy imaging system that uses a low-cost scanner and a closed-circuit-television (CCTV) lens. We show that such an imaging system is capable to capture a 10 mm * 7.5 mm FOV image with 0.77 micron resolution, resulting in 0.54 gigapixels (109 pixels) across the entire image (26400 pixels * 20400 pixels). The resolution and field curve of the proposed system were characterized by imaging a USAF resolution target and a hole-array target. A 1.6 gigapixel microscopy image (0.54 gigapixel with 3 colors) of a pathology slide was acquired by using such a system for application demonstration.

  6. Composite conductor containing superconductive wires

    Energy Technology Data Exchange (ETDEWEB)

    Larson, W.L.; Wong, J.

    1974-03-26

    A superconductor cable substitute made by coworking multiple rods of superconductive niobium--titanium or niobium--zirconium alloy with a common copper matrix to extend the copper and rods to form a final elongated product which has superconductive wires distributed in a reduced cross-section copper conductor with a complete metallurgical bond between the normal-conductive copper and the superconductor wires contained therein is described. The superconductor cable can be in the form of a tube.

  7. Topology Optimized Photonic Wire Splitters

    DEFF Research Database (Denmark)

    Frandsen, Lars Hagedorn; Borel, Peter Ingo; Jensen, Jakob Søndergaard;

    2006-01-01

    Photonic wire splitters have been designed using topology optimization. The splitters have been fabricated in silicon-on-insulator material and display broadband low-loss 3dB splitting in a bandwidth larger than 100 nm.......Photonic wire splitters have been designed using topology optimization. The splitters have been fabricated in silicon-on-insulator material and display broadband low-loss 3dB splitting in a bandwidth larger than 100 nm....

  8. Radiation dosimetry of computed tomography x-ray scanners

    International Nuclear Information System (INIS)

    This report describes the development and application of the methods employed in National Radiation Laboratory (NRL) surveys of computed tomography x-ray scanners (CT scanners). It includes descriptions of the phantoms and equipment used, discussion of the various dose parameters measured, the principles of the various dosimetry systems employed and some indication of the doses to occupationally exposed personnel

  9. A ’Millipede’ scanner model - Energy consumption and performance

    NARCIS (Netherlands)

    Engelen, Johan B.C.; Khatib, Mohammed G.

    2008-01-01

    This short report (1) describes an energy model for the seek and read/write operations in a mass-balanced Y-scanner for parallel-probe storage by IBM [1] and (2) updates the settings of the MEMS model in DiskSim with recent published figures from this XY-scanner. To speedup system simulations, a str

  10. Flux profile scanners for scattered high-energy electrons

    CERN Document Server

    Hicks, R S; Arroyo, C; Breuer, M; Celli, J; Chudakov, E; Kumar, K S; Olson, M; Peterson, G A; Pope, K; Ricci, J; Savage, J; Souder, P A

    2005-01-01

    The paper describes the design and performance of flux integrating Cherenkov scanners with air-core reflecting light guides used in a high-energy, high-flux electron scattering experiment at the Stanford Linear Accelerator Center. The scanners were highly radiation resistant and provided a good signal to background ratio leading to very good spatial resolution of the scattered electron flux profile scans.

  11. Vision Assisted Laser Scanner Navigation for Autonomous Robots

    DEFF Research Database (Denmark)

    Andersen, Jens Christian; Andersen, Nils Axel; Ravn, Ole

    2008-01-01

    This paper describes a navigation method based on road detection using both a laser scanner and a vision sensor. The method is to classify the surface in front of the robot into traversable segments (road) and obstacles using the laser scanner, this classifies the area just in front of the robot (2...

  12. 49 CFR 236.74 - Protection of insulated wire; splice in underground wire.

    Science.gov (United States)

    2010-10-01

    ... underground wire. 236.74 Section 236.74 Transportation Other Regulations Relating to Transportation (Continued... wire; splice in underground wire. Insulated wire shall be protected from mechanical injury. The insulation shall not be punctured for test purposes. Splice in underground wire shall have...

  13. 49 CFR 234.241 - Protection of insulated wire; splice in underground wire.

    Science.gov (United States)

    2010-10-01

    ... underground wire. 234.241 Section 234.241 Transportation Other Regulations Relating to Transportation... of insulated wire; splice in underground wire. Insulated wire shall be protected from mechanical injury. The insulation shall not be punctured for test purposes. A splice in underground wire shall...

  14. 1 mil gold bond wire study.

    Energy Technology Data Exchange (ETDEWEB)

    Huff, Johnathon; McLean, Michael B.; Jenkins, Mark W.; Rutherford, Brian Milne

    2013-05-01

    In microcircuit fabrication, the diameter and length of a bond wire have been shown to both affect the current versus fusing time ratio of a bond wire as well as the gap length of the fused wire. This study investigated the impact of current level on the time-to-open and gap length of 1 mil by 60 mil gold bond wires. During the experiments, constant current was provided for a control set of bond wires for 250ms, 410ms and until the wire fused; non-destructively pull-tested wires for 250ms; and notched wires. The key findings were that as the current increases, the gap length increases and 73% of the bond wires will fuse at 1.8A, and 100% of the wires fuse at 1.9A within 60ms. Due to the limited scope of experiments and limited data analyzed, further investigation is encouraged to confirm these observations.

  15. HTS Wire Development Workshop: Proceedings

    Energy Technology Data Exchange (ETDEWEB)

    1994-07-01

    The 1994 High-Temperature Superconducting Wire Development Workshop was held on February 16--17 at the St. Petersburg Hilton and Towers in St. Petersburg, Florida. The meeting was hosted by Florida Power Corporation and sponsored by the US Department of Energy`s Superconductivity Program for Electric Power Systems. The meeting focused on recent high-temperature superconducting wire development activities in the Department of Energy`s Superconductivity Systems program. The meeting opened with a general discussion on the needs and benefits of superconductivity from a utility perspective, the US global competitiveness position, and an outlook on the overall prospects of wire development. The meeting then focused on four important technology areas: Wire characterization: issues and needs; technology for overcoming barriers: weak links and flux pinning; manufacturing issues for long wire lengths; and physical properties of HTS coils. Following in-depth presentations, working groups were formed in each technology area to discuss the most important current research and development issues. The working groups identified research areas that have the potential for greatly enhancing the wire development effort. These areas are discussed in the summary reports from each of the working groups. This document is a compilation of the workshop proceedings including all general session presentations and summary reports from the working groups.

  16. Track counting and thickness measurement of LR115 radon detectors using a commercial image scanner

    International Nuclear Information System (INIS)

    An original optical method for track counting and film thickness determination of etched LR115 radon detectors was developed. The method offers several advantages compared with standard techniques. In particular, it is non-destructive, very simple and rather inexpensive, since it uses a commercial scanner and a free software. The complete analysis and the calibration procedure carried out for the determination of radon specific activity are reported. A comparison with the results of spark counting defines the accuracy and the precision of the new technique. (authors)

  17. Necessity and clinical application of diagnostic CT in PET-CT scanner

    International Nuclear Information System (INIS)

    PET scanning has a definite clinical impact on diagnosis, initial staging, restaging, monitoring therapeutic effects of malignancies, and on assessment of myocardial viability. Whereas, PET scans has false positive diagnosis and false negative diagnosis of malignant lesions. It leads to reduce specifity in PET imaging. application of diagnostic CT, especially applying contrast enhanced CT scans, three dimensional technique, CTA(CT angiography), CT perfusion and CT virtual endoscopy can realize dominance complementation with PET and CT, PET-CT imaging diagnosis combines with PET and CT diagnostic technique, it improves sensitivity, specifity, and accuracy in clinical application of PET-CT scanner. (authors)

  18. A Movable Phantom Design for Quantitative Evaluation of Motion Correction Studies on High Resolution PET Scanners

    DEFF Research Database (Denmark)

    Olesen, Oline Vinter; Svarer, C.; Sibomana, M.;

    2010-01-01

    method. The phantom is able to perform stepwise and continuous axial rotations with submillimeter accuracy, and the movements are repeatable. The scans were acquired on the high resolution research tomograph dedicated brain scanner. The scans were reconstructed with the new 3-D ordered subset expectation......, movable, mechanical PET phantom to simulate patients' head movements while being scanned. This can be used for evaluating motion correction methods. A low-cost phantom controlled by a rotary stage motor was built and tested for axial rotations of 1 degrees - 10 degrees with the multiple acquisition frame...... assessment tool for the development and evaluation of future motion correction methods....

  19. On the spectral quality of scanner illumination with LEDs

    Science.gov (United States)

    Cui, Chengwu

    2013-01-01

    Document scanner illumination has evolved along with general illumination technologies. LEDs have become more and more popular as the illumination sources for document scanning. LED technologies provide a wide range of choices both in terms of structural design and spectral compositions. In this report, we examine some popular LED technologies used for document scanner. We evaluate the color rendering performance of scanner models with different illumination technologies by examining their rendering of the Macbeth ColorChecker™ in sRGB. We found that more phosphors in phosphor conversion types of white LEDs may not be necessarily advantageous in terms of scanner color rendering performance. Also CIS type of scanner may be sensitive to the peak wavelength shift and can be particularly problematic when the peaks are out of certain range.

  20. Immersion and dry ArF scanners enabling 22nm HP production and beyond

    Science.gov (United States)

    Uehara, Yusaku; Ishikawa, Jun; Kohno, Hirotaka; Tanaka, Eiichiro; Ohba, Masanori; Shibazaki, Yuichi

    2012-03-01

    Streamlign innovations, sufficient overlay accuracy for critical layers, as well as maximized productivity can be achieved. Furthermore, CoO will be significantly improved, which is the vital benefit when comparing ArF dry vs. immersion scanners. In this paper / presentation the latest S621D and S320F performance data will be introduced.

  1. Automatic inventory of components by laser 3D scanner; Inventario de automatico de componentes mediante laser escaner 3D

    Energy Technology Data Exchange (ETDEWEB)

    Rodriguez Garcia, R.; Munoz Prieto, C.; Sarti Fernandez, F.

    2014-07-01

    One of the existing needs in nuclear decommissioning projects is to provide an inventory of components to be dismantled, which is available from its spatial location and elements that exist in your environment. The Laser scanner technology is a system of data acquisition that allows 3D models composed of millions of points, it's models with pinpoint accuracy and are available in a very short space of time. (Author)

  2. Target Price Accuracy

    OpenAIRE

    Alexander G. Kerl

    2011-01-01

    This study analyzes the accuracy of forecasted target prices within analysts’ reports. We compute a measure for target price forecast accuracy that evaluates the ability of analysts to exactly forecast the ex-ante (unknown) 12-month stock price. Furthermore, we determine factors that explain this accuracy. Target price accuracy is negatively related to analyst-specific optimism and stock-specific risk (measured by volatility and price-to-book ratio). However, target price accuracy is positive...

  3. Profound influence of microarray scanner characteristics on gene expression ratios: analysis and procedure for correction

    Directory of Open Access Journals (Sweden)

    Myklebost Ola

    2004-02-01

    Full Text Available Abstract Background High throughput gene expression data from spotted cDNA microarrays are collected by scanning the signal intensities of the corresponding spots by dedicated fluorescence scanners. The major scanner settings for increasing the spot intensities are the laser power and the voltage of the photomultiplier tube (PMT. It is required that the expression ratios are independent of these settings. We have investigated the relationships between PMT voltage, spot intensities, and expression ratios for different scanners, in order to define an optimal scanning procedure. Results All scanners showed a limited intensity range from 200 to 50 000 (mean spot intensity, for which the expression ratios were independent of PMT voltage. This usable intensity range was considerably less than the maximum detection range of the PMTs. The use of spot and background intensities outside this range led to errors in the ratios. The errors at high intensities were caused by saturation of pixel intensities within the spots. An algorithm was developed to correct the intensities of these spots, and, hence, extend the upper limit of the usable intensity range. Conclusions It is suggested that the PMT voltage should be increased to avoid intensities of the weakest spots below the usable range, allowing the brightest spots to reach the level of saturation. Subsequently, a second set of images should be acquired with a lower PMT setting such that no pixels are in saturation. Reliable data for spots with saturation in the first set of images can easily be extracted from the second set of images by the use of our algorithm. This procedure would lead to an increase in the accuracy of the data and in the number of data points achieved in each experiment compared to traditional procedures.

  4. Evaluation of spatial resolution in image acquisition by optical flatbed scanners for radiochromic film dosimetry

    Science.gov (United States)

    Asero, G.; Greco, C.; Gueli, A. M.; Raffaele, L.; Spampinato, S.

    2016-03-01

    Introduction: Radiochromic films are two-dimensional dosimeters that do not require developing and give values of absorbed dose with accuracy and precision. Since this dosimeter colours directly after irradiation, it can be digitized with commercial optical flatbed scanners to obtain a calibration curve that links blackening of the film with dose. Although the film has an intrinsic high spatial resolution, the scanner determines the actual resolution of this dosimeter, in particular the "dot per inch" (dpi) parameter. The present study investigates the effective spatial resolution of a scanner used for Gafchromic® XR-QA2 film (designed for radiology Quality Assurance) analysis. Material and methods: The quantitative evaluation of the resolution was performed with the Modulation Transfer Function (MTF) method, comparing the nominal resolution with the experimental one. The analysis was performed with two procedures. First, the 1951 USAF resolution test chart, a tool that tests the performance of optical devices, was used. Secondly, a combined system of mammography X-ray tube, XR-QA2 film and a bar pattern object was used. In both cases the MTF method has been applied and the results were compared. Results: The USAF and the film images have been acquired with increasing dpi and a standard protocol for radiochromic analysis, to evaluate horizontal and vertical and resolution. The effective resolution corresponds to the value of the MTF at 50%. In both cases and for both procedures, it was verified that, starting from a dpi value, the effective resolution saturates. Conclusion: The study found that, for dosimetric applications, the dpi of the scanner have to be adjusted to a reasonable value because, if too high, it requires high scanning and computational time without providing additional information.

  5. Californium Recovery from Palladium Wire

    Energy Technology Data Exchange (ETDEWEB)

    Burns, Jon D. [Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States)

    2014-08-01

    The recovery of 252Cf from palladium-252Cf cermet wires was investigated to determine the feasibility of implementing it into the cermet wire production operation at Oak Ridge National Laboratory’s Radiochemical Engineering Development Center. The dissolution of Pd wire in 8 M HNO3 and trace amounts of HCl was studied at both ambient and elevated temperatures. These studies showed that it took days to dissolve the wire at ambient temperature and only 2 hours at 60°C. Adjusting the ratio of the volume of solvent to the mass of the wire segment showed little change in the kinetics of dissolution, which ranged from 0.176 mL/mg down to 0.019 mL/mg. A successful chromatographic separation of 153Gd, a surrogate for 252Cf, from Pd was demonstrated using AG 50x8 cation exchange resin with a bed volume of 0.5 mL and an internal diameter of 0.8 cm.

  6. ASSESSING PATHOLOGIES ON VILLAMAYOR STONE (SALAMANCA, SPAIN BY TERRESTRIAL LASER SCANNER INTENSITY DATA

    Directory of Open Access Journals (Sweden)

    J. García-Talegón

    2015-02-01

    Full Text Available This paper deals with the assessing of pathologies in façades using a variety of intensity data provided by different terrestrial laser scanner. In particular, a complex building built in the Villamayor Stone that is to be candidate as a Global Heritage Stone Resource has been chosen as study case. The Villamayor Stone were quarrying for the construction and ornamentation of monuments in Salamanca, declared World Heritage City by UNESCO in 1988. The objective of this paper is to assess the pathologies of Villamayor Stone and compare the results obtained through the laser techniques with the classical techniques of mapped pathologies (i.e. visual inspection. For that intensity data coming from laser scanners will be used as non-destructive techniques applied to the façades and several retired plaques (after of building restoration of Villamayor Stone with pathologies (fissures, scales, loss of matter, humidity/biological colonization carried to the laboratory. Subsequently it will perform different comparisons between the accuracy reached with the different sensors and a high precision model setup on laboratory which performs as “ground truth”. In particular, the following objectives will be pursued: i accuracy assessment of the results obtained in in situ and laboratory; ii an automation or semi-automation of the detection of pathologies in Villamayor Stone; iii discriminate the different types of Villamayor Stone used in the façades in function of the radiometric response; iv establish a methodology for detection and assessing of pathologies based on laser scanner intensity data applied to monuments and modern buildings built in Villamayor Stone.

  7. Assessing Pathologies on Villamayor Stone (salamanca, Spain) by Terrestrial Laser Scanner Intensity Data

    Science.gov (United States)

    García-Talegón, J.; Calabrés, S.; Fernández-Lozano, J.; Iñigo, A. C.; Herrero-Fernández, H.; Arias-Pérez, B.; González-Aguilera, D.

    2015-02-01

    This paper deals with the assessing of pathologies in façades using a variety of intensity data provided by different terrestrial laser scanner. In particular, a complex building built in the Villamayor Stone that is to be candidate as a Global Heritage Stone Resource has been chosen as study case. The Villamayor Stone were quarrying for the construction and ornamentation of monuments in Salamanca, declared World Heritage City by UNESCO in 1988. The objective of this paper is to assess the pathologies of Villamayor Stone and compare the results obtained through the laser techniques with the classical techniques of mapped pathologies (i.e. visual inspection). For that intensity data coming from laser scanners will be used as non-destructive techniques applied to the façades and several retired plaques (after of building restoration) of Villamayor Stone with pathologies (fissures, scales, loss of matter, humidity/biological colonization) carried to the laboratory. Subsequently it will perform different comparisons between the accuracy reached with the different sensors and a high precision model setup on laboratory which performs as "ground truth". In particular, the following objectives will be pursued: i) accuracy assessment of the results obtained in in situ and laboratory; ii) an automation or semi-automation of the detection of pathologies in Villamayor Stone; iii) discriminate the different types of Villamayor Stone used in the façades in function of the radiometric response; iv) establish a methodology for detection and assessing of pathologies based on laser scanner intensity data applied to monuments and modern buildings built in Villamayor Stone.

  8. Development of an algorithm to measure defect geometry using a 3D laser scanner

    Science.gov (United States)

    Kilambi, S.; Tipton, S. M.

    2012-08-01

    Current fatigue life prediction models for coiled tubing (CT) require accurate measurements of the defect geometry. Three-dimensional (3D) laser imaging has shown promise toward becoming a nondestructive, non-contacting method of surface defect characterization. Laser imaging provides a detailed photographic image of a flaw, in addition to a detailed 3D surface map from which its critical dimensions can be measured. This paper describes algorithms to determine defect characteristics, specifically depth, width, length and projected cross-sectional area. Curve-fitting methods were compared and implicit algebraic fits have higher probability of convergence compared to explicit geometric fits. Among the algebraic fits, the Taubin circle fit has the least error. The algorithm was able to extract the dimensions of the flaw geometry from the scanned data of CT to within a tolerance of about 0.127 mm, close to the tolerance specified for the laser scanner itself, compared to measurements made using traveling microscopes. The algorithm computes the projected surface area of the flaw, which could previously only be estimated from the dimension measurements and the assumptions made about cutter shape. Although shadows compromised the accuracy of the shape characterization, especially for deep and narrow flaws, the results indicate that the algorithm with laser scanner can be used for non-destructive evaluation of CT in the oil field industry. Further work is needed to improve accuracy, to eliminate shadow effects and to reduce radial deviation.

  9. Accurately measuring volume of soil samples using low cost Kinect 3D scanner

    Science.gov (United States)

    van der Sterre, Boy-Santhos; Hut, Rolf; van de Giesen, Nick

    2013-04-01

    The 3D scanner of the Kinect game controller can be used to increase the accuracy and efficiency of determining in situ soil moisture content. Soil moisture is one of the principal hydrological variables in both the water and energy interactions between soil and atmosphere. Current in situ measurements of soil moisture either rely on indirect measurements (of electromagnetic constants or heat capacity) or on physically taking a sample and weighing it in a lab. The bottleneck in accurately retrieving soil moisture using samples is the determining of the volume of the sample. Currently this is mostly done by the very time consuming "sand cone method" in which the volume were the sample used to sit is filled with sand. We show that 3D scanner that is part of the 150 game controller extension "Kinect" can be used to make 3D scans before and after taking the sample. The accuracy of this method is tested by scanning forms of known volume. This method is less time consuming and less error-prone than using a sand cone.

  10. A wired - impressa e digital

    OpenAIRE

    Pontes, Sara Raquel Machado

    2015-01-01

    O tema abordado neste relatório de estágio é a revista Wired impressa vs. digital. Tendo em conta, que uma das primeiras revistas a ser publicadas para Ipad foi a Wired, um periódico icónico que aborda assuntos referentes à tecnologia, decidi realizar uma análise exaustiva desta revista de forma a relacionar estes dois mundos tão díspares. Para tal, dividi este trabalho em duas partes distintas, sendo a primeira delas divididas em dois capítulos. No primeiro capítulo faz-se uma breve contextu...

  11. Wire system aging assessment and condition monitoring (WASCO)

    International Nuclear Information System (INIS)

    Nuclear facilities rely on electrical wire systems to perform a variety of functions for successful operation. Many of these functions directly support the safe operation of the facility; therefore, the continued reliability of wire systems, even as they age, is critical. Condition Monitoring (CM) of installed wire systems is an important part of any aging program, both during the first 40 years of the qualified life and even more in anticipation of the license renewal for a nuclear power plant. This report describes a method for wire system condition monitoring, developed at the Halden Reactor Project, which is based on Frequency Domain Reflectometry. This method resulted in the development of a system called LIRA (LIne Resonance Analysis), which can be used on-line to detect any local or global changes in the cable electrical parameters as a consequence of insulation faults or degradation. LIRA is composed of a signal generator, a signal analyser and a simulator that can be used to simulate several failure/degradation scenarios and assess the accuracy and sensitivity of the LIRA system. Chapter 5 of this report describes an complementary approach based on positron measurement techniques, used widely in defect physics due to the high sensitivity to micro defects, in particular open volume defects. This report describes in details these methodologies, the results of field experiments and the proposed future work. (au)

  12. Time-optimized laser micro machining by using a new high dynamic and high precision galvo scanner

    Science.gov (United States)

    Jaeggi, Beat; Neuenschwander, Beat; Zimmermann, Markus; Zecherle, Markus; Boeckler, Ernst W.

    2016-03-01

    High accuracy, quality and throughput are key factors in laser micro machining. To obtain these goals the ablation process, the machining strategy and the scanning device have to be optimized. The precision is influenced by the accuracy of the galvo scanner and can further be enhanced by synchronizing the movement of the mirrors with the laser pulse train. To maintain a high machining quality i.e. minimum surface roughness, the pulse-to-pulse distance has also to be optimized. Highest ablation efficiency is obtained by choosing the proper laser peak fluence together with highest specific removal rate. The throughput can now be enhanced by simultaneously increasing the average power, the repetition rate as well as the scanning speed to preserve the fluence and the pulse-to-pulse distance. Therefore a high scanning speed is of essential importance. To guarantee the required excellent accuracy even at high scanning speeds a new interferometry based encoder technology was used, that provides a high quality signal for closed-loop control of the galvo scanner position. Low inertia encoder design enables a very dynamic scanner system, which can be driven to very high line speeds by a specially adapted control solution. We will present results with marking speeds up to 25 m/s using a f = 100 mm objective obtained with a new scanning system and scanner tuning maintaining a precision of about 5 μm. Further it will be shown that, especially for short line lengths, the machining time can be minimized by choosing the proper speed which has not to be the maximum one.

  13. 21 CFR 892.1300 - Nuclear rectilinear scanner.

    Science.gov (United States)

    2010-04-01

    ...) Identification. A nuclear rectilinear scanner is a device intended to image the distribution of radionuclides in the body by means of a detector (or detectors) whose position moves in two directions with respect...

  14. Feature-space transformation improves supervised segmentation across scanners

    DEFF Research Database (Denmark)

    van Opbroek, Annegreet; Achterberg, Hakim C.; de Bruijne, Marleen

    2015-01-01

    Image-segmentation techniques based on supervised classification generally perform well on the condition that training and test samples have the same feature distribution. However, if training and test images are acquired with different scanners or scanning parameters, their feature distributions....... This transformation is learned from unlabeled images of subjects scanned on both the training scanner and the test scanner. We evaluated our method on hippocampus segmentation on 27 images of the Harmonized Hippocampal Protocol (HarP), a heterogeneous dataset consisting of 1.5T and 3T MR images. The results showed...... can be very different, which can hurt the performance of such techniques. We propose a feature-space-transformation method to overcome these differences in feature distributions. Our method learns a mapping of the feature values of training voxels to values observed in images from the test scanner...

  15. Agricultural Applications and Requirements for Thermal Infrared Scanners

    Science.gov (United States)

    Wiegand, C. L.

    1971-01-01

    Some of the applications of thermal scanner data in agriculture are presented along with illustrations of some of the factors affecting the temperature of plants, soil, and water. Examples of thermal imagery are included.

  16. Landsat 1-5 Multispectral Scanner V1

    Data.gov (United States)

    National Aeronautics and Space Administration — Abstract: The Landsat Multispectral Scanner (MSS) was a sensor onboard Landsats 1 through 5 and acquired images of the Earth nearly continuously from July 1972 to...

  17. Whole-body 3D scanner and scan data report

    Science.gov (United States)

    Addleman, Stephen R.

    1997-03-01

    With the first whole-body 3D scanner now available the next adventure confronting the user is what to do with all of the data. While the system was built for anthropologists, it has created interest among users from a wide variety of fields. Users with applications in the fields of anthropology, costume design, garment design, entertainment, VR and gaming have a need for the data in formats unique to their fields. Data from the scanner is being converted to solid models for art and design and NURBS for computer graphics applications. Motion capture has made scan data move and dance. The scanner has created a need for advanced application software just as other scanners have in the past.

  18. Data scanner system of the BELLE silicon vertex detector

    Energy Technology Data Exchange (ETDEWEB)

    Fukunaga, C. [Tokyo Metropolitan Univ. (Japan); Korhonen, T. [Univ. of Helsinki (Finland). Research Inst. of High Energy Physics; Tanaka, M.; Ikeda, H. [National Lab. for High Energy Physics, Tsukuba, Ibaraki (Japan). Dept. of Physics

    1996-02-01

    A data scanner system, which is a part of the front-end data acquisition system of the BELLE silicon vertex detector, makes an analog-to-digital conversion of preamplified signals from the detector and stores digitized data into local memory. The sequence control and buffer managing are performed by a software process of an on-board CPU. With this data scanner system, the authors can achieve data taking with less than 10% dead time up to 800 Hz trigger rate.

  19. 30 CFR 57.12047 - Guy wires.

    Science.gov (United States)

    2010-07-01

    ... Underground § 57.12047 Guy wires. Guy wires of poles supporting high-voltage transmission lines shall meet the... “Safety Rules for the Installation and Maintenance of Electric Supply and Communication Lines”...

  20. Accurate modeling of a DOI capable small animal PET scanner using GATE

    International Nuclear Information System (INIS)

    In this work we developed a Monte Carlo (MC) model of the Sedecal Argus pre-clinical PET scanner, using GATE (Geant4 Application for Tomographic Emission). This is a dual-ring scanner which features DOI compensation by means of two layers of detector crystals (LYSO and GSO). Geometry of detectors and sources, pulses readout and selection of coincidence events were modeled with GATE, while a separate code was developed in order to emulate the processing of digitized data (for example, customized time windows and data flow saturation), the final binning of the lines of response and to reproduce the data output format of the scanner's acquisition software. Validation of the model was performed by modeling several phantoms used in experimental measurements, in order to compare the results of the simulations. Spatial resolution, sensitivity, scatter fraction, count rates and NECR were tested. Moreover, the NEMA NU-4 phantom was modeled in order to check for the image quality yielded by the model. Noise, contrast of cold and hot regions and recovery coefficient were calculated and compared using images of the NEMA phantom acquired with our scanner. The energy spectrum of coincidence events due to the small amount of 176Lu in LYSO crystals, which was suitably included in our model, was also compared with experimental measurements. Spatial resolution, sensitivity and scatter fraction showed an agreement within 7%. Comparison of the count rates curves resulted satisfactory, being the values within the uncertainties, in the range of activities practically used in research scans. Analysis of the NEMA phantom images also showed a good agreement between simulated and acquired data, within 9% for all the tested parameters. This work shows that basic MC modeling of this kind of system is possible using GATE as a base platform; extension through suitably written customized code allows for an adequate level of accuracy in the results. Our careful validation against experimental

  1. Relative accuracy evaluation.

    Directory of Open Access Journals (Sweden)

    Yan Zhang

    Full Text Available The quality of data plays an important role in business analysis and decision making, and data accuracy is an important aspect in data quality. Thus one necessary task for data quality management is to evaluate the accuracy of the data. And in order to solve the problem that the accuracy of the whole data set is low while a useful part may be high, it is also necessary to evaluate the accuracy of the query results, called relative accuracy. However, as far as we know, neither measure nor effective methods for the accuracy evaluation methods are proposed. Motivated by this, for relative accuracy evaluation, we propose a systematic method. We design a relative accuracy evaluation framework for relational databases based on a new metric to measure the accuracy using statistics. We apply the methods to evaluate the precision and recall of basic queries, which show the result's relative accuracy. We also propose the method to handle data update and to improve accuracy evaluation using functional dependencies. Extensive experimental results show the effectiveness and efficiency of our proposed framework and algorithms.

  2. Relative accuracy evaluation.

    Science.gov (United States)

    Zhang, Yan; Wang, Hongzhi; Yang, Zhongsheng; Li, Jianzhong

    2014-01-01

    The quality of data plays an important role in business analysis and decision making, and data accuracy is an important aspect in data quality. Thus one necessary task for data quality management is to evaluate the accuracy of the data. And in order to solve the problem that the accuracy of the whole data set is low while a useful part may be high, it is also necessary to evaluate the accuracy of the query results, called relative accuracy. However, as far as we know, neither measure nor effective methods for the accuracy evaluation methods are proposed. Motivated by this, for relative accuracy evaluation, we propose a systematic method. We design a relative accuracy evaluation framework for relational databases based on a new metric to measure the accuracy using statistics. We apply the methods to evaluate the precision and recall of basic queries, which show the result's relative accuracy. We also propose the method to handle data update and to improve accuracy evaluation using functional dependencies. Extensive experimental results show the effectiveness and efficiency of our proposed framework and algorithms. PMID:25133752

  3. Laboratory and field portable system for calibrating airborne multispectral scanners

    International Nuclear Information System (INIS)

    Manufacturers of airborne multispectral scanners suggest procedures for calibration and alignment that are usually awkward and even questionable. For example, the procedures may require: separating the scanner from calibration and alignment sources by 100 feet or more, employing folding mirrors, tampering with the detectors after the procedures are finished, etc. Under the best of conditions such procedures require about three hours yielding questionable confidence in the results; under many conditions, however, procedures commonly take six to eight hours, yielding no satisfactory results. EG and G, Inc. has designed and built a calibration and alignment system for airborne scanners which solves those problems, permitting the procedures to be carried out in about two to three hours. This equipment can be quickly disassembled, transported with the scanner in all but the smallest single engine aircraft, and reassembled in a few hours. The subsystems of this equipment are commonly available from manufacturers of optical and electronic equipment. The other components are easily purchased, or fabricated. The scanner discussed is the Model DS-1260 digital line scanner manufactured by Daedalus Enterprises, Inc. It is a dual-sensor system which is operated in one of two combination of sensors: one spectrometer head (which provides simultaneous coverage in ten visible channels) and one thermal infrared detector, or simply two thermal infrared detectors

  4. Novel Wiring Technologies for Aerospace Applications

    Science.gov (United States)

    Gibson, Tracy L.; Parrish, Lewis M.

    2014-01-01

    Because wire failure in aerospace vehicles could be catastrophic, smart wiring capabilities have been critical for NASA. Through the years, researchers at Kennedy Space Center (KSC) have developed technologies, expertise, and research facilities to meet this need. In addition to aerospace applications, NASA has applied its knowledge of smart wiring, including self-healing materials, to serve the aviation industry. This webinar will discuss the development efforts of several wiring technologies at KSC and provide insight into both current and future research objectives.

  5. Getting "Wired" for McLuhan's Cyberculture.

    Science.gov (United States)

    McMurdo, George

    1995-01-01

    Examines the introduction of the computing magazine, "Wired", into the United Kingdom's (UK) market. Presents conversations with the founder and editorial staff of the UK edition, and discusses the accessibility of "Wired" via the World Wide Web. Describes 10 articles from United States "Wired" back-issues and presents critiques of a utopian…

  6. Accuracy testing of a new intraoral 3D camera.

    Science.gov (United States)

    Mehl, A; Ender, A; Mörmann, W; Attin, T

    2009-01-01

    Surveying intraoral structures by optical means has reached the stage where it is being discussed as a serious clinical alternative to conventional impression taking. Ease of handling and, more importantly, accuracy are important criteria for the clinical suitability of these systems. This article presents a new intraoral camera for the Cerec procedure. It reports on a study investigating the accuracy of this camera and its potential clinical indications. Single-tooth and quadrant images were taken with the camera and the results compared to those obtained with a reference scanner and with the previous 3D camera model. Differences were analyzed by superimposing the data records. Accuracy was higher with the new camera than with the previous model, reaching up to 19 microm in single-tooth images. Quadrant images can also be taken with sufficient accuracy (ca 35 microm) and are simple to perform in clinical practice, thanks to built-in shake detection in automatic capture mode.

  7. Accuracy Analysis of a Low-Cost Platform for Positioning and Navigation

    Science.gov (United States)

    Hofmann, S.; Kuntzsch, C.; Schulze, M. J.; Eggert, D.; Sester, M.

    2012-07-01

    This paper presents an accuracy analysis of a platform based on low-cost components for landmark-based navigation intended for research and teaching purposes. The proposed platform includes a LEGO MINDSTORMS NXT 2.0 kit, an Android-based Smartphone as well as a compact laser scanner Hokuyo URG-04LX. The robot is used in a small indoor environment, where GNSS is not available. Therefore, a landmark map was produced in advance, with the landmark positions provided to the robot. All steps of procedure to set up the platform are shown. The main focus of this paper is the reachable positioning accuracy, which was analyzed in this type of scenario depending on the accuracy of the reference landmarks and the directional and distance measuring accuracy of the laser scanner. Several experiments were carried out, demonstrating the practically achievable positioning accuracy. To evaluate the accuracy, ground truth was acquired using a total station. These results are compared to the theoretically achievable accuracies and the laser scanner's characteristics.

  8. Target Price Accuracy

    Directory of Open Access Journals (Sweden)

    Alexander G. Kerl

    2011-04-01

    Full Text Available This study analyzes the accuracy of forecasted target prices within analysts’ reports. We compute a measure for target price forecast accuracy that evaluates the ability of analysts to exactly forecast the ex-ante (unknown 12-month stock price. Furthermore, we determine factors that explain this accuracy. Target price accuracy is negatively related to analyst-specific optimism and stock-specific risk (measured by volatility and price-to-book ratio. However, target price accuracy is positively related to the level of detail of each report, company size and the reputation of the investment bank. The potential conflicts of interests between an analyst and a covered company do not bias forecast accuracy.

  9. Rethinking Empathic Accuracy

    OpenAIRE

    Meadors, Joshua

    2014-01-01

    The present study is a methodological examination of the implicit empathic accuracy measure introduced by Zaki, Ochsner, and Bolger (2008). Empathic accuracy (EA) is defined as the ability to understand another person's thoughts and feelings (Ickes, 1993). Because this definition is similar to definitions of cognitive empathy (e.g., Shamay-Tsoory, 2011) and because affective empathy does not appear to be related to empathic accuracy (Zaki et al., 2008), the Basic Empathy Scale--which measures...

  10. The Truth about Accuracy

    OpenAIRE

    Buekens, Filip; Truyen, Frederik

    2014-01-01

    When we evaluate the outcomes of investigative actions as justified or unjustified, good or bad, rational or irrational, we make, in a broad sense of the term, evaluative judgments about them. We look at operational accuracy as a desirable and evaluable quality of the outcomes and explore how the concepts of accuracy and precision, on the basis of insights borrowed from pragmatics and measurement theory, can be seen to do useful work in epistemology. Operational accuracy (but not metaphysical...

  11. A finite element model for independent wire rope core with double helical geometry subjected to axial loads

    Indian Academy of Sciences (India)

    Cengiz Erdonmez; C Erdem Imrak

    2011-12-01

    Due to the complex geometry of wires within a wire rope, it is difficult to model and analyse independent wire rope core accurately (IWRC). In this paper, a more realistic three-dimensional modelling approach and finite element analysis of wire ropes are explained. Single helical geometry is enough to model simple straight strand while IWRC has a more complex geometry by inclusion of double helical wires in outer strands. Taking the advantage of the double helical wires, three-dimensional IWRCs modelling is applied for both right regular lay and lang lay IWRCs. Wire-by-wire based results are gathered by using the proposed modelling and analysis method under various loading conditions. Illustrative examples are given for those show the accuracy and the robustness of the present FE analysis scheme with considering frictional properties and contact interactions between wires. FE analysis results are compared with the analytical and available test results and show reasonable agreement with a simpler and more practical approach.

  12. Transport through multiply connected quantum wires

    OpenAIRE

    Das, Sourin; Rao, Sumathi

    2003-01-01

    We study transport through multiply coupled carbon nano-tubes (quantum wires) and compute the conductances through the two wires as a function of the two gate voltages $g_1$ and $g_2$ controlling the chemical potential of the electrons in the two wires. We find that there is an {\\it equilibrium} cross-conductance, and we obtain its dependence on the temperature and length of the wires. The effective action of the model for the wires in the strong coupling (equivalently Coulomb interaction) li...

  13. RESEARCH AND PRACTICE ON NONDESTRUCTIVE FLAW DETECTION INSTALLATION FOR WIRE-CORE BELT

    Institute of Scientific and Technical Information of China (English)

    刘志河; 张海涛; 绍庆龙

    1997-01-01

    Electromagnetic self-induction theory and computer are adopted and study of online monitoring technique for wire-core belt is conducted, the study shows that there is direct proportion between distance I of broken ends and output volt V, when I≥60 mm, V keeps constantly, the running speed v of wire-core belt has no big effect on output volt V, there is inverse proportion between the height h from probe to the surface of the belt and output volt V, when h≥30mm, V tends to be zero. Based on the test result, on-line monitoring installation is developed, the practice proved that the accuracy of broken wire monitoring can be above 95%, the monitoring accuracy of joint twitch can be 0.04 V/mm.

  14. Accuracy of complete-arch dental impressions: a new method of measuring trueness and precision

    OpenAIRE

    Ender, Andreas; Mehl, Albert

    2013-01-01

    STATEMENT OF PROBLEM: A new approach to both 3-dimensional (3D) trueness and precision is necessary to assess the accuracy of intraoral digital impressions and compare them to conventionally acquired impressions. PURPOSE: The purpose of this in vitro study was to evaluate whether a new reference scanner is capable of measuring conventional and digital intraoral complete-arch impressions for 3D accuracy. MATERIAL AND METHODS: A steel reference dentate model was fabricated and measured with a...

  15. Digital dental surface registration with laser scanner for orthodontics set-up planning

    Science.gov (United States)

    Alcaniz-Raya, Mariano L.; Albalat, Salvador E.; Grau Colomer, Vincente; Monserrat, Carlos A.

    1997-05-01

    We present an optical measuring system based on laser structured light suitable for its diary use in orthodontics clinics that fit four main requirements: (1) to avoid use of stone models, (2) to automatically discriminate geometric points belonging to teeth and gum, (3) to automatically calculate diagnostic parameters used by orthodontists, (4) to make use of low cost and easy to use technology for future commercial use. Proposed technique is based in the use of hydrocolloids mould used by orthodontists for stone model obtention. These mould of the inside of patient's mouth are composed of very fluent materials like alginate or hydrocolloids that reveal fine details of dental anatomy. Alginate mould are both very easy to obtain and very low costly. Once captured, alginate moulds are digitized by mean of a newly developed and patented 3D dental scanner. Developed scanner is based in the optical triangulation method based in the projection of a laser line on the alginate mould surface. Line deformation gives uncalibrated shape information. Relative linear movements of the mould with respect to the sensor head gives more sections thus obtaining a full 3D uncalibrated dentition model. Developed device makes use of redundant CCD in the sensor head and servocontrolled linear axis for mould movement. Last step is calibration to get a real and precise X, Y, Z image. All the process is done automatically. The scanner has been specially adapted for 3D dental anatomy capturing in order to fulfill specific requirements such as: scanning time, accuracy, security and correct acquisition of 'hidden points' in alginate mould. Measurement realized on phantoms with known geometry quite similar to dental anatomy present errors less than 0,1 mm. Scanning of global dental anatomy is 2 minutes, and generation of 3D graphics of dental cast takes approximately 30 seconds in a Pentium-based PC.

  16. Performance of a volumetric CT scanner based upon a flat-panel imager

    Science.gov (United States)

    Jaffray, David A.; Siewerdsen, Jeffrey H.; Drake, Douglas G.

    1999-05-01

    approximately 900 to 1100. The contrast sensitivity of the CBCT system and the conventional scanner was compared using these same materials. Images of a uniform water bath were acquired for characterization of the response uniformity and the dependence of noise on exposure. The spatial frequency response characteristics of the system were measured using a steel wire, from which the point spread function and modulation transfer function were determined. Finally, the soft-tissue contrast and spatial resolution of the CBCT system was demonstrated in volumetric images of a euthanized rat. The image quality was compared to images of the same subject acquired with an equivalent technique on the commercial scanner. A table-top CBCT scanner based upon an a- Si:H FPI has been constructed, and a system for CBCT image acquisition, processing, and reconstruction has been implemented. This system is capable of producing high-quality volumetric images. Reconstructions were generated from 300 radiographs (100 kVp; 1 mAs per projection) obtained at 1.2 degree increments through 360 degrees. Image acquisition and reconstruction required approximately 30 min and approximately 2 h 20 min (250 MHz UltraSparc), respectively. The system has demonstrated signal and noise performance comparable to that of commercial CT scanners. The imaging performance of the prototype supports the hypothesis that FPIs can be employed in computed tomography applications.

  17. Characterization of a Large, Low-Cost 3D Scanner

    Directory of Open Access Journals (Sweden)

    Jeremy Straub

    2015-01-01

    Full Text Available Imagery-based 3D scanning can be performed by scanners with multiple form factors, ranging from small and inexpensive scanners requiring manual movement around a stationary object to large freestanding (nearly instantaneous units. Small mobile units are problematic for use in scanning living creatures, which may be unwilling or unable to (or for the very young and animals, unaware of the need to hold a fixed position for an extended period of time. Alternately, very high cost scanners that can capture a complete scan within a few seconds are available, but they are cost prohibitive for some applications. This paper seeks to assess the performance of a large, low-cost 3D scanner, presented in prior work, which is able to concurrently capture imagery from all around an object. It provides the capabilities of the large, freestanding units at a price point akin to the smaller, mobile ones. This allows access to 3D scanning technology (particularly for applications requiring instantaneous imaging at a lower cost. Problematically, prior analysis of the scanner’s performance was extremely limited. This paper characterizes the efficacy of the scanner for scanning both inanimate objects and humans. Given the importance of lighting to visible light scanning systems, the scanner’s performance under multiple lighting configurations is evaluated, characterizing its sensitivity to lighting design.

  18. Moths on the Flatbed Scanner: The Art of Joseph Scheer

    Directory of Open Access Journals (Sweden)

    Stephen L. Buchmann

    2011-12-01

    Full Text Available During the past decade a few artists and even fewer entomologists discovered flatbed scanning technology, using extreme resolution graphical arts scanners for acquiring high magnification digital images of plants, animals and inanimate objects. They are not just for trip receipts anymore. The special attributes of certain scanners, to image thick objects is discussed along with the technical features of the scanners including magnification, color depth and shadow detail. The work of pioneering scanner artist, Joseph Scheer from New York’s Alfred University is highlighted. Representative flatbed-scanned images of moths are illustrated along with techniques to produce them. Collecting and preparing moths, and other objects, for scanning are described. Highlights of the Fulbright sabbatical year of professor Scheer in Arizona and Sonora, Mexico are presented, along with comments on moths in science, folklore, art and pop culture. The use of flatbed scanners is offered as a relatively new method for visualizing small objects while acquiring large files for creating archival inkjet prints for display and sale.

  19. Practical circuits with Physarum Wires

    OpenAIRE

    Whiting, James G. H.; Mayne, Richard; Moody, Nadine; Costello, Ben de Lacy; Adamatzky, Andrew

    2015-01-01

    Purpose: Protoplasmic tubes of Physarum polycephalum, also know as Physarum Wires (PW), have been previously suggested as novel bio- electronic components. Until recently, practical examples of electronic circuits using PWs have been limited. These PWs have been shown to be self repairing, offering significant advantage over traditional electronic components. This article documents work performed to produce practical circuits using PWs. Method: We have demonstrated through manufacture and tes...

  20. The transmaxillary K-wire.

    Science.gov (United States)

    Silverton, J. S.; Bostwick, J.; Jurkiewicz, M. J.

    1978-01-01

    The transmaxillary K-wire is a simple, fast, safe, and effective technique for the fixation of unstable tractured malar bones. Combined with other techniques such as interdental fixation it simplifies and provides the fixation of the Le Fort II fracture or osteotomy and certain osteotomies used for facial advancement. The technique of insertion is described and illustrated. Images Fig. 4 Fig. 5 Fig. 6 PMID:666241

  1. Fast and accurate line scanner based on white light interferometry

    Science.gov (United States)

    Lambelet, Patrick; Moosburger, Rudolf

    2013-04-01

    White-light interferometry is a highly accurate technology for 3D measurements. The principle is widely utilized in surface metrology instruments but rarely adopted for in-line inspection systems. The main challenges for rolling out inspection systems based on white-light interferometry to the production floor are its sensitivity to environmental vibrations and relatively long measurement times: a large quantity of data needs to be acquired and processed in order to obtain a single topographic measurement. Heliotis developed a smart-pixel CMOS camera (lock-in camera) which is specially suited for white-light interferometry. The demodulation of the interference signal is treated at the level of the pixel which typically reduces the acquisition data by one orders of magnitude. Along with the high bandwidth of the dedicated lock-in camera, vertical scan-speeds of more than 40mm/s are reachable. The high scan speed allows for the realization of inspection systems that are rugged against external vibrations as present on the production floor. For many industrial applications such as the inspection of wafer-bumps, surface of mechanical parts and solar-panel, large areas need to be measured. In this case either the instrument or the sample are displaced laterally and several measurements are stitched together. The cycle time of such a system is mostly limited by the stepping time for multiple lateral displacements. A line-scanner based on white light interferometry would eliminate most of the stepping time while maintaining robustness and accuracy. A. Olszak proposed a simple geometry to realize such a lateral scanning interferometer. We demonstrate that such inclined interferometers can benefit significantly from the fast in-pixel demodulation capabilities of the lock-in camera. One drawback of an inclined observation perspective is that its application is limited to objects with scattering surfaces. We therefore propose an alternate geometry where the incident light is

  2. Gigapixel inline digital holographic microscopy using a consumer scanner

    CERN Document Server

    Shimobaba, Tomoyoshi; Kakue, Takashi; Oikawa, Minoru; Okada, Naohisa; Endo, Yutaka; Hirayama, Ryuji; Masuda, Nobuyuki; Ito, Tomoyoshi

    2013-01-01

    We demonstrate a gigapixel inline digital holographic microscopy using a consumer scanner. The consumer scanner can maximally scan an A4 size image (297mm x 210mm) with 4800 dpi (= 5.29 um), theoretically achieving a resolution of 56,144 x 39,698 = 2.22 gigapixels. The system using a consumer scanner has a simple structure, compared with synthetic aperture digital holography using a camera mounted on a two-dimensional moving stage. In this demonstration, we captured an inline hologram with 23,602 x 18,023 pixels (= 0.43 gigapixels). In addition, to accelerate the reconstruction time of the gigapixel hologram and decrease the amount of memory for the reconstruction, we applied the band-limited double-step Fresnel diffraction to the reconstruction.

  3. Spectral reflectance estimation using a six-color scanner

    Science.gov (United States)

    Tominaga, Shoji; Kohno, Satoshi; Kakinuma, Hirokazu; Nohara, Fuminori; Horiuchi, Takahiko

    2009-01-01

    A method is proposed for estimating the spectral reflectance function of an object surface by using a six-color scanner. The scanner is regarded as a six-band spectral imaging system, since it captures six color channels in total from two separate scans using two difference lamps. First, we describe the basic characteristics of the imaging systems for a HP color scanner and a multiband camera used for comparison. Second, we describe a computational method for recovering surface-spectral reflectances from the noisy sensor outputs. A LMMSE estimator is presented as an optimal estimator. We discuss the reflectance estimation for non-flat surfaces with shading effect. A solution method is presented for the reliable reflectance estimation. Finally, the performance of the proposed method is examined in detail on experiments using the Macbeth Color Checker and non-flat objects.

  4. Dental impressions using 3D digital scanners: virtual becomes reality.

    Science.gov (United States)

    Birnbaum, Nathan S; Aaronson, Heidi B

    2008-10-01

    The technologies that have made the use of three-dimensional (3D) digital scanners an integral part of many industries for decades have been improved and refined for application to dentistry. Since the introduction of the first dental impressioning digital scanner in the 1980s, development engineers at a number of companies have enhanced the technologies and created in-office scanners that are increasingly user-friendly and able to produce precisely fitting dental restorations. These systems are capable of capturing 3D virtual images of tooth preparations, from which restorations may be fabricated directly (ie, CAD/CAM systems) or fabricated indirectly (ie, dedicated impression scanning systems for the creation of accurate master models). The use of these products is increasing rapidly around the world and presents a paradigm shift in the way in which dental impressions are made. Several of the leading 3D dental digital scanning systems are presented and discussed in this article.

  5. Landslide Monitoring Using Terrestrial Laser Scanner: Georeferencing and Canopy Filtering Issues in a Case Study

    Science.gov (United States)

    Barbarella, M.; Fiani, M.

    2012-07-01

    In order to define a methodology that faces the major critical issues, we used a Terrestrial Laser Scanner to monitor a large landslide that caused significant disruptions both to an important state road and to a major railway line in Italy. To survey the landslide we used three different models of Terrestrial Laser Scanners, including a "full wave form" one, potentially useful for filtering vegetation from the data. The output of each measurement campaign is a Digital Surface Model referred to a unique reference system. Starting from the DSMs we produced the Digital Terrain Models, one for each survey. The use of different models of TLS together with the software packages recommended by the companies for data processing, allowed us to compare the surveys and to evaluate the reliability and the accuracy of results. The comparison of data has been useful in order to identify and analyse over time the areas of greatest deformation and the directions of landslide movement and it also gives us some elements about the validity of the technique in this kind of applications. The laser surveys have shown a strong dynamic of the slope but have also highlighted some difficulties in order to efficiently filtering the data. Using two different kinds of TLS, full wave form and mono eco, on the same portion of landslide allows us to make comparisons between the two methodologies for landslide monitoring in a real-world context.

  6. Measurement of Rotor Blade Deformations of Wind Energy Converters with Laser Scanners

    International Nuclear Information System (INIS)

    Wind energy converters in operation are exposed to high stresses which result in large deformations of the rotor blades. In this paper a method for determination of deformations of rotating rotor blades is presented using multiple synchronous laser scanners and cameras. In a first step, multiple scanners in 1D mode are used which record cross sections at different positions along the rotor blades. By comparing the recorded cross sections with a CAD model of the rotor blade, the deformations in out-of-plane and torsional direction can be derived. In order to ensure that the positions of the cross sections are defined in the coordinate system of the wind energy converter, the nacelle is pre-scanned and a 3D transformation is performed using known coordinates from the manufacturer. To account for the relatively slow movement of the nacelle, it is observed by a photogrammetric camera. The results of the nacelle's motion are considered in the analysis of the 1D data. First test recordings were carried out with different measurement frequencies to enable comparisons of accuracy. Furthermore, first results of the cross-section measurements are presented. For the next step the 3D scans will be evaluated which have been acquired using a further instrument simultaneously with the 1D scans. In the same way as before the 3D points will be transferred to the reference system of the nacelle, and then combined with the 1D data

  7. A Novel Low-Cost Adaptive Scanner Concept for Mobile Robots

    Directory of Open Access Journals (Sweden)

    Ivo Stančić

    2014-12-01

    Full Text Available A fundamental problem in mobile robot applications is the need for accurate knowledge of the position of a vehicle for localizing itself and for avoiding obstacles in its path. In the search for a solution to this problem, researchers and engineers have developed different sensors, systems and techniques. Modern mobile robots relay information obtained from a variety of sensors and sophisticated data fusion algorithms. In this paper, a novel concept for a low-cost adaptive scanner based on a projected light pattern is proposed. The main advantage of the proposed system is its adaptivity, which enables the rapid scanning of the robot’s surroundings in search of obstacles and a more detailed scan of a single object to retrieve its surface configuration and perform some limited analyses. This paper addresses the concept behind such a scanner, where a proof-of-concept is achieved using an office DLP projector. During the measurements, the accuracy of the proposed system was tested on obstacles and objects with known configurations. The obtained results are presented and analyzed, and conclusions about the system’s performance and possible improvements are discussed.

  8. PET/CT scanners: a hardware approach to image fusion.

    Science.gov (United States)

    Townsend, David W; Beyer, Thomas; Blodgett, Todd M

    2003-07-01

    New technology that combines positron tomography with x-ray computed tomography (PET/CT) is available from all major vendors of PET imaging equipment: CTI, Siemens, GE, Philips. Although not all vendors have made the same design choices as those described in this review all have in common that their high performance design places a commercial CT scanner in tandem with a commercial PET scanner. The level of physical integration is actually less than that of the original prototype design where the CT and PET components were mounted on the same rotating support. There will undoubtedly be a demand for PET/CT technology with a greater level of integration, and at a reduced cost. This may be achieved through the design of a scanner specifically for combined anatomical and functional imaging, rather than a design combining separate CT and PET scanners, as in the current approaches. By avoiding the duplication of data acquisition and image reconstruction functions, for example, a more integrated design should also allow cost savings over current commercial PET/CT scanners. The goal is then to design and build a device specifically for imaging the function and anatomy of cancer in the most optimal and effective way, without conceptualizing it as combined PET and CT. The development of devices specifically for imaging a particular disease (eg, cancer) differs from the conventional approach of, for example, an all-purpose anatomical imaging device such as a CT scanner. This new concept targets more of a disease management approach rather than the usual division into the medical specialties of radiology (anatomical imaging) and nuclear medicine (functional imaging). PMID:12931321

  9. Scanner baseliner monitoring and control in high volume manufacturing

    Science.gov (United States)

    Samudrala, Pavan; Chung, Woong Jae; Aung, Nyan; Subramany, Lokesh; Gao, Haiyong; Gomez, Juan-Manuel

    2016-03-01

    We analyze performance of different customized models on baseliner overlay data and demonstrate the reduction in overlay residuals by ~10%. Smart Sampling sets were assessed and compared with the full wafer measurements. We found that performance of the grid can still be maintained by going to one-third of total sampling points, while reducing metrology time by 60%. We also demonstrate the feasibility of achieving time to time matching using scanner fleet manager and thus identify the tool drifts even when the tool monitoring controls are within spec limits. We also explore the scanner feedback constant variation with illumination sources.

  10. Free-space wavelength-multiplexed optical scanner.

    Science.gov (United States)

    Yaqoob, Z; Rizvi, A A; Riza, N A

    2001-12-10

    A wavelength-multiplexed optical scanning scheme is proposed for deflecting a free-space optical beam by selection of the wavelength of the light incident on a wavelength-dispersive optical element. With fast tunable lasers or optical filters, this scanner features microsecond domain scan setting speeds and large- diameter apertures of several centimeters or more for subdegree angular scans. Analysis performed indicates an optimum scan range for a given diffraction order and grating period. Limitations include beam-spreading effects based on the varying scanner aperture sizes and the instantaneous information bandwidth of the data-carrying laser beam.

  11. Free-space wavelength-multiplexed optical scanner.

    Science.gov (United States)

    Yaqoob, Z; Rizvi, A A; Riza, N A

    2001-12-10

    A wavelength-multiplexed optical scanning scheme is proposed for deflecting a free-space optical beam by selection of the wavelength of the light incident on a wavelength-dispersive optical element. With fast tunable lasers or optical filters, this scanner features microsecond domain scan setting speeds and large- diameter apertures of several centimeters or more for subdegree angular scans. Analysis performed indicates an optimum scan range for a given diffraction order and grating period. Limitations include beam-spreading effects based on the varying scanner aperture sizes and the instantaneous information bandwidth of the data-carrying laser beam. PMID:18364951

  12. Evaluation of the accuracy of shoe fitting in older people using three-dimensional foot scanning

    OpenAIRE

    Menz, Hylton B; Auhl, Maria; Ristevski, Sonja; Frescos, Nicoletta; Munteanu, Shannon E

    2014-01-01

    Background Ill-fitting footwear is a common problem in older people. The objective of this study was to determine the accuracy of shoe fitting in older people by comparing the dimensions of allocated shoes to foot dimensions obtained with a three-dimensional (3D) scanner. Methods The shoe sizes of 56 older people were determined with the Brannock device®, and weightbearing foot scans were obtained with the FotoScan 3D scanner (Precision 3D Ltd, Weston-super-mare, UK). Participants were provid...

  13. "Cut wires grating – single longitudinal wire" planar metastructure to achieve microwave magnetic resonance in a single wire

    Directory of Open Access Journals (Sweden)

    Galina Kraftmakher

    2012-08-01

    Full Text Available Here we present metastructures containing cut-wire grating and a single longitudinal cut-wire orthogonal to grating’s wires. Experimental investigations at microwaves show these structures can provide strong magnetic resonant response of a single nonmagnetic cut-wire in dependence on configuration and sizes in the case when metastructures are oriented along the direction of wave propagation and cut-wires of grating are parallel to the electric field of a plane electromagnetic wave. It is suggested a concept of magnetic response based on antiparallel resonant currents excited by magnetic field of surface polaritons in many spatial LC-circuits created from cut-wire pairs of a grating and section of longitudinal cut-wire. Three separately observed resonant effects connected with grating, LC-circuits and with longitudinal cut-wire have been identified applying measurements in waveguides, cutoff waveguides and free space. To tune and mark resonance split cut-wires are loaded with varactor diodes.

  14. A Vibrating Wire System For Quadrupole Fiducialization

    Energy Technology Data Exchange (ETDEWEB)

    Wolf, Zachary

    2010-12-13

    A vibrating wire system is being developed to fiducialize the quadrupoles between undulator segments in the LCLS. This note provides a detailed analysis of the system. The LCLS will have quadrupoles between the undulator segments to keep the electron beam focused. If the quadrupoles are not centered on the beam axis, the beam will receive transverse kicks, causing it to deviate from the undulator axis. Beam based alignment will be used to move the quadrupoles onto a straight line, but an initial, conventional alignment must place the quadrupole centers on a straight line to 100 {micro}m. In the fiducialization step of the initial alignment, the position of the center of the quadrupole is measured relative to tooling balls on the outside of the quadrupole. The alignment crews then use the tooling balls to place the magnet in the tunnel. The required error on the location of the quadrupole center relative to the tooling balls must be less than 25 {micro}m. In this note, we analyze a system under construction for the quadrupole fiducialization. The system uses the vibrating wire technique to position a wire onto the quadrupole magnetic axis. The wire position is then related to tooling balls using wire position detectors. The tooling balls on the wire position detectors are finally related to tooling balls on the quadrupole to perform the fiducialization. The total 25 {micro}m fiducialization error must be divided between these three steps. The wire must be positioned onto the quadrupole magnetic axis to within 10 {micro}m, the wire position must be measured relative to tooling balls on the wire position detectors to within 15 {micro}m, and tooling balls on the wire position detectors must be related to tooling balls on the quadrupole to within 10 {micro}m. The techniques used in these three steps will be discussed. The note begins by discussing various quadrupole fiducialization techniques used in the past and discusses why the vibrating wire technique is our method

  15. Online process monitoring at quasi-simultaneous laser transmission welding using a 3D-scanner with integrated pyrometer

    Science.gov (United States)

    Schmailzl, A.; Steger, S.; Dostalek, M.; Hierl, S.

    2016-03-01

    Quasi-simultaneous laser transmission welding is a well-known joining technique for thermoplastics and mainly used in the automotive as well as in the medical industry. For process control usually the so called set-path monitoring is used, where the weld is specified as "good" if the irradiation time is inside a defined confidence interval. However, the detection of small-sized gaps or thermal damaged zones is not possible with this technique. The analyzation of the weld seam temperature during welding offers the possibility to overcome this problem. In this approach a 3D-scanner is used instead of a scanner with flat-field optic. By using a pyrometer in combination with a 3D-scanner no color-corrected optic is needed in order to provide that laser- and detection-spot are concentric. Experimental studies on polyethylene T-joints have shown that the quality of the signal is adequate, despite the use of an optical setup with a long working distance and a small optical aperture. The effects on temperature are studied for defects like a gap in the joining zone. Therefore a notch was milled into the absorbent polymer. In case of producing housings for electronic parts the effect of an electrical wire between the joining partners is also investigated. Both defects can be identified by a local temperature deviation even at a feed rate of four meters per second. Furthermore a strategy for signal-processing is demonstrated. By this, remaining defects can be identified. Consequently an online detection of local defects is possible, which makes a dynamic process control feasible.

  16. Vibrating Wire for Beam Profile Scanning

    CERN Document Server

    Arutunian, S G; Mailian, M R; Sinenko, I G; Vasiniuk, I E

    1999-01-01

    The method for measurement of transverse profile (emittance) of the bunch by detecting of radiation arising scattering at of the bunch on the scanning wire is wide-spread. In this work the information about scattering bunch is proposed to measure using the oscillation frequency of the tightened scanning wire. In such way the system of radiation (or secondary particles) extraction and measurement can be removed. Dependence of oscillations frequency on beam scattering is determined by several factors, including changes of wire tension caused by transverse force of the beam, influence of beam self field. Preliminary calculations show that influence caused by wire heating will dominate. We have studied strain gauges on the basis of vibrating wire from various materials (tungsten, beryl bronze, niobium zirconium alloys). A scheme of self oscillations generation by alternating current in autogeneration circuit with automatic frequency adjustment was selected. Special method of wire fixation and elimination of trans...

  17. Impiego della tecnologia laser scanner su mezzo mobile terrestre per il city modelling

    Directory of Open Access Journals (Sweden)

    Giorgio Vassena

    2009-03-01

    Full Text Available Use of laser scanner on mobile equipment for city modellingThe use of GPS/INS systems on mobile instrumental equipment for 3D city modelling is more and more widespread as advanced technology of survey. These systems offer good versatility, even if with some problems linked to urban canyon and to the drift of inertial systems.In urban contest it seems also profitable the employmentof classical topographic equipment for surveying of position of mobile mean in the 3D and colour data acquisition phase. This technology, easy to use, guarantees a good efficacy on urban scale and accuracies of alignment comparable to those of consolidated technology. The employment of equipment commonly available from operators makes the method proposed economically favourable, results being equal.

  18. Novel Aerial 3D Mapping System Based on UAV Platforms and 2D Laser Scanners

    Directory of Open Access Journals (Sweden)

    David Roca

    2016-01-01

    Full Text Available The acquisition of 3D geometric data from an aerial view implies a high number of advantages with respect to terrestrial acquisition, the greatest being that aerial view allows the acquisition of information from areas with no or difficult accessibility, such as roofs and tops of trees. If the aerial platform is copter-type, other advantages are present, such as the capability of displacement at very low-speed, allowing for a more detailed acquisition. This paper presents a novel Aerial 3D Mapping System based on a copter-type platform, where a 2D laser scanner is integrated with a GNSS sensor and an IMU for the generation of georeferenced 3D point clouds. The accuracy and precision of the system are evaluated through the measurement of geometries in the point clouds generated by the system, as well as through the geolocation of target points for which the real global coordinates are known.

  19. Multi-Target Detection from Full-Waveform Airborne Laser Scanner Using Phd Filter

    Science.gov (United States)

    Fuse, T.; Hiramatsu, D.; Nakanishi, W.

    2016-06-01

    We propose a new technique to detect multiple targets from full-waveform airborne laser scanner. We introduce probability hypothesis density (PHD) filter, a type of Bayesian filtering, by which we can estimate the number of targets and their positions simultaneously. PHD filter overcomes some limitations of conventional Gaussian decomposition method; PHD filter doesn't require a priori knowledge on the number of targets, assumption of parametric form of the intensity distribution. In addition, it can take a similarity between successive irradiations into account by modelling relative positions of the same targets spatially. Firstly we explain PHD filter and particle filter implementation to it. Secondly we formulate the multi-target detection problem on PHD filter by modelling components and parameters within it. At last we conducted the experiment on real data of forest and vegetation, and confirmed its ability and accuracy.

  20. Enhanced Algorithms for Estimating Tree Trunk Diameter Using 2D Laser Scanner

    Directory of Open Access Journals (Sweden)

    Ola Ringdahl

    2013-10-01

    Full Text Available Accurate vehicle localization in forest environments is still an unresolved problem. Global navigation satellite systems (GNSS have well known limitations in dense forest, and have to be combined with for instance laser based SLAM algorithms to provide satisfying accuracy. Such algorithms typically require accurate detection of trees, and estimation of tree center locations in laser data. Both these operations depend on accurate estimations of tree trunk diameter. Diameter estimations are important also for several other forestry automation and remote sensing applications. This paper evaluates several existing algorithms for diameter estimation using 2D laser scanner data. Enhanced algorithms, compensating for beam width and using multiple scans, were also developed and evaluated. The best existing algorithms overestimated tree trunk diameter by ca. 40%. Our enhanced algorithms, compensating for laser beam width, reduced this error to less than 12%.

  1. Diagnosing Eyewitness Accuracy

    OpenAIRE

    Russ, Andrew

    2015-01-01

    Eyewitnesses frequently mistake innocent people for the perpetrator of an observed crime. Such misidentifications have led to the wrongful convictions of many people. Despite this, no reliable method yet exists to determine eyewitness accuracy. This thesis explored two new experimental methods for this purpose. Chapter 2 investigated whether repetition priming can measure prior exposure to a target and compared this with observers’ explicit eyewitness accuracy. Across three experiments slower...

  2. Anomalous Thermal Transport in Quantum Wires

    OpenAIRE

    Fazio, Rosario; Hekking, F. W. J.; Khmelnitskii, D. E.

    1997-01-01

    We study thermal transport in a one-dimensional quantum wire, connected to reservoirs. Despite of the absence of electron backscattering, interactions in the wire strongly influence thermal transport. Electrons propagate with unitary transmission through the wire and electric conductance is not affected. Energy, however, is carried by bosonic excitations (plasmons) which suffer from scattering even on scales much larger than the Fermi wavelength. If the electron density varies randomly, plasm...

  3. Wire Whip Keeps Spray Nozzle Clean

    Science.gov (United States)

    Carroll, H. R.

    1982-01-01

    Air-turbine-driven wire whip is clamped near spray-gun mount. When spray gun is installed, wire whip is in position to remove foam buildup from nozzle face. Two lengths of wire 1 to 2 inches long and about 0.03 inch in thickness are used. Foam spray would be prevented from accumulating on nozzle face by increasing purge flow and cutting vortex-generating grooves inside cap and on nozzle flats.

  4. Wrapped Wire Detects Rupture Of Pressure Vessel

    Science.gov (United States)

    Hunt, James B.

    1990-01-01

    Simple, inexpensive technique helps protect against damage caused by continuing operation of equipment after rupture or burnout of pressure vessel. Wire wrapped over area on outside of vessel where breakthrough most likely. If wall breaks or burns, so does wire. Current passing through wire ceases, triggering cutoff mechanism stopping flow in vessel to prevent further damage. Applied in other situations in which pipes or vessels fail due to overpressure, overheating, or corrosion.

  5. IEE wiring regulations explained and illustrated

    CERN Document Server

    Scaddan, Brian

    2013-01-01

    The IEE Wiring Regulations Explained and Illustrated, Second Edition discusses the recommendations of the IEE Regulations for the Electrical Equipment of Buildings for the safe selection or erection of wiring installations. The book emphasizes earthing, bonding, protection, and circuit design of electrical wirings. The text reviews the fundamental requirements for safety, earthing systems, the earth fault loop impedance, and supplementary bonding. The book also describes the different types of protection, such as protection against mechanical damage, overcurrent, under voltage (which prevents

  6. The impact of simulated MRI scanner background noise on visual attention processes as measured by the EEG

    Science.gov (United States)

    Kobald, S. Oliver; Getzmann, Stephan; Beste, Christian; Wascher, Edmund

    2016-01-01

    Environmental noise is known to affect personal well-being as well as cognitive processes. Besides daily life, environmental noise can also occur in experimental research settings, e.g. when being in a magnetic resonance scanner. Scanner background noise (SBN) might pose serious confounds for experimental findings, even when non-auditory settings are examined. In the current experiment we tested if SBN alters bottom-up and top-down related processes of selective visual attention mechanisms. Participants completed two blocks of a visual change detection task, one block in silence and one block under SBN exposure. SBN was found to decrease accuracy in measures of visual attention. This effect was modulated by the temporal occurrence of SBN. When SBN was encountered in the first block, it prevented a significant improvement of accuracy in the second block. When SBN appeared in the second block, it significantly decreased accuracy. Neurophysiological findings showed a strong frontal positivity shift only when SBN was present in the first block, suggesting an inhibitory process to counteract the interfering SBN. Common correlates of both top-down and bottom-up processes of selective visual attention were not specifically affected by SBN exposure. Further research appears necessary to entirely rule out confounds of SBN in assessing visual attention. PMID:27324456

  7. Cone beam optical computed tomography for gel dosimetry I: scanner characterization

    Energy Technology Data Exchange (ETDEWEB)

    Olding, Tim; Holmes, Oliver; Schreiner, L John, E-mail: tim.olding@krcc.on.c [Department of Physics, Queen' s University, Kingston, ON, K7L 3N6 (Canada)

    2010-05-21

    The ongoing development of easily accessible, fast optical readout tools promises to remove one of the barriers to acceptance of gel dosimetry as a viable tool in cancer clinics. This paper describes the characterization of a number of basic properties of the Vista(TM) cone beam CCD-based optical scanner, which can obtain high resolution reconstructed data in less than 20 min total imaging and reconstruction time. The suitability of a filtered back projection cone beam reconstruction algorithm is established for optically absorbing dosimeters using this scanner configuration. The system was then shown to be capable of imaging an optically absorbing media-filled 1 L polyethylene terephthalate (PETE) jar dosimeter to a reconstructed voxel resolution of 0.5 x 0.5 x 0.5 mm{sup 3}. At this resolution, more than 60% of the imaged volume in the dosimeter exhibits minimal spatial distortion, a measurement accuracy of 3-4% and the mean to standard deviation signal-to-noise ratio greater than 100 over an optical absorption range of 0.06-0.18 cm{sup -1}. An inter-day scan precision of 1% was demonstrated near the upper end of this range. Absorption measurements show evidence of stray light perturbation causing artifacts in the data, which if better managed would improve the accuracy of optical readout. Cone beam optical attenuation measurements of scattering dosimeters, on the other hand, are nonlinearly affected by angled scatter stray light. Scatter perturbation leads to significant cupping artifacts and other inaccuracies that greatly limit the readout of scattering polymer gel dosimeters with cone beam optical CT.

  8. Wired

    Science.gov (United States)

    Carlowicz, Michael

    Every American grade school and library ought to have free access to the Internet, and universities and institutions ought to have better access, according to the Clinton Administration.In an October 10 speech in Knoxville, Tennessee, President Clinton proposed that all of the nation's 100,000 public schools and 9,000 libraries receive a two-tiered E-rate (education rate) for access to Internet services. All schools and libraries should receive basic connections for free, as well as deep discounts on video conferencing and highspeed connections (with prices influenced by how much the school can afford to pay). The basic connections (and part of the cost of the more sophisticated connections) would be paid from a special federal fund that currently provides below-cost phone service to households in poor and rural areas. That fund is currently drawn from fees assessed on local and long-distance telephone providers; the Clinton Administration would have cable operators and cellular service providers contribute as well. Companies that provide Internet services would be paid at the best available commercial rate.

  9. Wired

    Institute of Scientific and Technical Information of China (English)

    2013-01-01

    迄今为止,已有45000个项目借助在线捐赠成功完成众筹,金额总计达5亿美元以上。其中绝大部分(据估计为80%)来自Kickstarter网站,这家网站如今几乎成了“众筹”这一术语的代名词。

  10. Uniform wire segmentation algorithm of distributed interconnects

    Institute of Scientific and Technical Information of China (English)

    Yin Guoli; Lin Zhenghui

    2007-01-01

    A uniform wire segmentation algorithm for performance optimization of distributed RLC interconnects was proposed in this paper. The optimal wire length for identical segments and buffer size for buffer insertion are obtained through computation and derivation, based on a 2-pole approximation model of distributed RLC interconnect. For typical inductance value and long wires under 180nm technology, experiments show that the uniform wire segmentation technique proposed in the paper can reduce delay by about 27% ~ 56% , while requires 34%~69% less total buffer usage and thus 29% to 58% less power consumption. It is suitable for long RLC interconnect performance optimization.

  11. Aircraft Wiring Support Equipment Integration Laboratory (AWSEIL)

    Data.gov (United States)

    Federal Laboratory Consortium — Purpose: The Aircraft Wiring Support Equipment Integration Laboratory (AWSEIL) provides a variety of research, design engineering and prototype fabrication services...

  12. Implementation of virtual simulation with a wide-bore multislice helcalct scanner

    International Nuclear Information System (INIS)

    Full text: Multislice large-bore CT scanners specifically designed for radiotherapy have very recently become available. The issues relating to these type of scanners in radiotherapy and the implementation of virtual simulation are therefore of much current interest. A GE LightSpeed RT 4-slice helical CT scanner with a 80 cm bore size was installed in the radiation oncology department of the Newcastle Mater Hospital. This replaced our only simulator, a conventional unit. Specific issues relating to the imaging performance, and virtual simulation process with the large-bore multislice scanner were studied to ensure an accurate radiotherapy process. The detector array fully samples a 50 cm diameter scan circle. The reconstructed diameter can be increased to 65 cm with partial sampling of the extra volume. The GE Advantage Sim (ASim) virtual simulation software was commissioned, with transfer of CT images and DICOM RT plans to the Pinnacle radiotherapy planning system (RTPS) for dose calculation. Some specific issues investigated were: 1) The image quality performance for image reconstruction with the 65 cm area compared to 50 cm was measured with a line-pair phantom. 2) The accuracy of CT numbers with lateral position was assessed with a commercial electron density phantom. 3) Couch lateral movement and sag during acquisition were measured with the couch weighted with 86 kg. 4) The accuracy of the transfer of plans from ASim to Pinnacle was verified with known plan geometries. Image resolution throughout the entire CT image was found to be significantly lower when scan reconstruction was performed with 65 cm scan circle compared to 50 cm. The 0.3, 0.38 and 0.5 1p/mm bars were clearly distinguishable with the 50 cm reconstruction compared to only the 0.3 1p/mm bars in the 65 cm reconstruction. 2) CT numbers varied significantly outside the 50 cm reconstructed area. 3) Couch lateral movement during scanning was within 1 mm. Couch sag was 4 mm at the imaging plane

  13. Landsat-D thematic mapper simulation using aircraft multispectral scanner data

    Science.gov (United States)

    Clark, J.; Bryant, N. A.

    1977-01-01

    A simulation of imagery from the upcoming Landsat-D Thematic Mapper was accomplished by using selected channels of aircraft 24-channel multispectral scanner data. The purpose was to simulate Thematic Mapper 30-meter resolution imagery, to compare its spectral quality with the original aircraft MSS data, and to determine changes in thematic classification accuracy for the simulated imagery. The original resolution of approximately 7.5 meters IFOV and simulated resolution of 15, 30, and 60 meters were used to indicate the trend of spectral quality and classification accuracy. The study was based in a 6.5 square kilometer area of urban Los Angeles having a diversity of land use. The original imagery was reduced in resolution by two related methods: pixel matrix averaging, and matrix smoothing with a unity box filter, followed by matrix averaging. Thematic land use classification using training sites and a Bayesian maximum-likelihood algorithm was performed at three levels of standard deviation - 1.0, 2.0, and 3.0 sigma. Plots of relative standard deviation showed that for larger training sites with a normal distribution of data, as the resolution decreased, the distribution range of density values decreased. Also, the classification accuracies for three levels of standard deviation increased as resolution decreased. However, the indication is that a point of diminishing returns had been reached, and 30 meters IFOV should be the best for multispectral classification of urban scenes.

  14. A building extraction approach for Airborne Laser Scanner data utilizing the Object Based Image Analysis paradigm

    Science.gov (United States)

    Tomljenovic, Ivan; Tiede, Dirk; Blaschke, Thomas

    2016-10-01

    In the past two decades Object-Based Image Analysis (OBIA) established itself as an efficient approach for the classification and extraction of information from remote sensing imagery and, increasingly, from non-image based sources such as Airborne Laser Scanner (ALS) point clouds. ALS data is represented in the form of a point cloud with recorded multiple returns and intensities. In our work, we combined OBIA with ALS point cloud data in order to identify and extract buildings as 2D polygons representing roof outlines in a top down mapping approach. We performed rasterization of the ALS data into a height raster for the purpose of the generation of a Digital Surface Model (DSM) and a derived Digital Elevation Model (DEM). Further objects were generated in conjunction with point statistics from the linked point cloud. With the use of class modelling methods, we generated the final target class of objects representing buildings. The approach was developed for a test area in Biberach an der Riß (Germany). In order to point out the possibilities of the adaptation-free transferability to another data set, the algorithm has been applied "as is" to the ISPRS Benchmarking data set of Toronto (Canada). The obtained results show high accuracies for the initial study area (thematic accuracies of around 98%, geometric accuracy of above 80%). The very high performance within the ISPRS Benchmark without any modification of the algorithm and without any adaptation of parameters is particularly noteworthy.

  15. COMPUTER PROCESSING OF MULTISPECTRAL SCANNER DATA OVER COAL STRIP MINES

    Science.gov (United States)

    There is little doubt that remote sensing techniques can be effectively applied to the task of monitoring coal strip mine progress and reclamation work. Aircraft multispectral scanner data acquired over six coal strip mines in the states of Wyoming, Montana, Colorado, and Arizona...

  16. Hologram Scanner Design And Fabrication In Dichromated Gelatin (DCG)

    Science.gov (United States)

    Rallison, Richard; Lowe, Rick

    1983-07-01

    Two major applications of holographic scanners are considered, the first is the code reader scanner now in use in supermarkets and soon to be used in automated warehousing. The second is the multipurpose line scanner currently used in line printers and soon to be included in automated inspection systems. Code reader facets perform multiple functions, each one deflects and focuses laser light at a unique angle and scans a short arc, the return light from a bar code is collimated by the same facet and is subsequently focused through a small aperture. Ambient light is diffracted at other angles and focused at points all around the aperture giving a high signal to noise ratio and the large high efficiency facets gather sufficient return light so that photo diodes and low power lasers can be used in the system. Line scanners can be made in a large variety of sizes and configurations inexpensively and with perfect fidelity, each one being a holographic replica of a master hologram. Focused arcs as well as parallel straight lines and even arbitrary computer generated scans are possible. The limitations and considerations of such devices are discussed along with design criteria related to fabrication problems and actual production line results.

  17. FMRI scanner noise interaction with affective neural processes.

    Directory of Open Access Journals (Sweden)

    Stavros Skouras

    Full Text Available The purpose of the present study was the investigation of interaction effects between functional MRI scanner noise and affective neural processes. Stimuli comprised of psychoacoustically balanced musical pieces, expressing three different emotions (fear, neutral, joy. Participants (N=34, 19 female were split into two groups, one subjected to continuous scanning and another subjected to sparse temporal scanning that features decreased scanner noise. Tests for interaction effects between scanning group (sparse/quieter vs continuous/noisier and emotion (fear, neutral, joy were performed. Results revealed interactions between the affective expression of stimuli and scanning group localized in bilateral auditory cortex, insula and visual cortex (calcarine sulcus. Post-hoc comparisons revealed that during sparse scanning, but not during continuous scanning, BOLD signals were significantly stronger for joy than for fear, as well as stronger for fear than for neutral in bilateral auditory cortex. During continuous scanning, but not during sparse scanning, BOLD signals were significantly stronger for joy than for neutral in the left auditory cortex and for joy than for fear in the calcarine sulcus. To the authors' knowledge, this is the first study to show a statistical interaction effect between scanner noise and affective processes and extends evidence suggesting scanner noise to be an important factor in functional MRI research that can affect and distort affective brain processes.

  18. Dosimetric evaluation of a 320 detector row CT scanner unit

    International Nuclear Information System (INIS)

    The technologic improvements in Multislice scanners include the increment in the X-ray beam width. Some new CT scanners are equipped with a 320 detector row which allows a longitudinal coverage of 160 mm and a total of 640 slices for a single rotation. When such parameters are used the length of the traditional pencil chamber (10 cm) is no more appropriate to measure the standard weighted computed tomography dose index (CTDIw) value. Dosimetric measurements were performed on a 640 slices Toshiba Aquilion One CT scanner using common instrumentation available in Medical Physics Departments. For the measurements in air, two different ionization chambers were completely exposed to the beam. Dosimeters showed an acceptable agreement in the measurements. To evaluate the actual shape of the dose profile strips of Gafchromic XRQA film were used. Films were previously calibrated on site. From the graphic response of the scanned film it is possible to evaluate the full width at half maximum (FWHM) of the dose profile which represent the actual beam width. Computed Tomography Dose Index (CTDI) and Dose Length Product (DLP) need to be changed when the beam width of the CT scanner is over 100 mm. To perform dose evaluation with the conventional instrumentation, two parameters should be considered: the average absorbed dose and the actual beam width. To measure the average absorbed dose, the conventional ionization chamber can be used. For the measurement of the width of the dose profile, Gafchromic XRQA film seemed to be suitable

  19. Benchmarking Advanced Control Algorithms for a Laser Scanner System

    DEFF Research Database (Denmark)

    Stoustrup, Jakob; Ordys, A.W.; Smillie, I.

    1996-01-01

    The paper describes tests performed on the laser scanner system toassess feasibility of modern control techniques in achieving a requiredperformance in the trajectory following problem. The two methods tested areQTR H-infinity and Predictive Control. The results are ilustated ona simulation example....

  20. Scanners, optical character readers, Cyrillic alphabet and Russian translations

    Science.gov (United States)

    Johnson, Gordon G.

    1995-01-01

    The writing of code for capture, in a uniform format, of bit maps of words and characters from scanner PICT files is presented. The coding of Dynamic Pattern Matched for the identification of the characters, words and sentences in preparation for translation is discussed.

  1. Electro-optic and Acousto-optic Laser Beam Scanners

    NARCIS (Netherlands)

    Römer, G.R.B.E.; Bechtold, P.

    2014-01-01

    Optical solid state deflectors rely on the electro-optical or acousto-optic effect. These Electro-Optical Deflectors (EODs) and Acousto-Optical Deflectors (AODs) do not contain moving parts and therefore exhibit high deflection velocities and are free of drawbacks associated with mechanical scanners. A

  2. FE modeling of Cu wire bond process and reliability

    NARCIS (Netherlands)

    Yuan, C.A.; Weltevreden, E.R.; Akker, P. van den; Kregting, R.; Vreugd, J. de; Zhang, G.Q.

    2011-01-01

    Copper based wire bonding technology is widely accepted by electronic packaging industry due to the world-wide cost reduction actions (compared to gold wire bond). However, the mechanical characterization of copper wire differs from the gold wire; hence the new wire bond process setting and new bond

  3. THERMO-MECHANICALLY PROCESSED ROLLED WIRE FOR HIGH-STRENGTH ON-BOARD WIRE

    Directory of Open Access Journals (Sweden)

    V. A. Lutsenko

    2011-01-01

    Full Text Available It is shown that at twisting of wire of diameter 1,83 mm, produced by direct wire drawing of thermomechanically processed rolled wire of diameter 5,5 mm of steel 90, metal stratification is completely eliminated at decrease of carbon, manganese and an additional alloying of chrome.

  4. NMR of geophysical drill cores with a mobile Halbach scanner

    International Nuclear Information System (INIS)

    This thesis is devoted to a mobile NMR with an improved Halbach scanner. This is a lightweight tube-shaped magnet with sensitive volume larger and a homogeneity of the magnetic field higher than the previous prototype version. The improved Halbach scanner is used for analysis of water-saturated drill cores and plugs with diameters up to 60 mm. To provide the analysis, the standard 1D technique with the CPMG sequence as well as 2D correlation experiments were successfully applied and adapted to study properties of fluid-saturated sediments. Afterwards the Halbach scanner was calibrated to fast non-destructive measurements of porosity, relaxation time distributions, and estimation of permeability. These properties can be calculated directly from the NMR data using the developed methodology. Any independent measurements of these properties with other methods are not needed. One of the main results of this work is the development of a new NMR on-line core scanner for measurements of porosity in long cylindrical and semi cylindrical drill cores. Also dedicated software was written to operate the NMR on-line core scanner. The physical background of this work is the study of the diffusion influence on transverse relaxation. The diffusion effect in the presence of internal gradients in porous media was probed by 1D and 2D experiments. The transverse relaxation time distributions obtained from 1D and from 2D experiments are comparable but different in fine details. Two new methodologies were developed based on the results of this study. First is the methodology quantifying the influence of diffusion in the internal gradients of water-saturated sediments on transverse relaxation from 2D correlation experiments. The second one is the correction of the permeability estimation from the NMR data taking in account the influence of the diffusion. Furthermore, PFG NMR technique was used to study restricted diffusion in the same kind of samples. Preliminary results are reported

  5. NMR of geophysical drill cores with a mobile Halbach scanner

    Energy Technology Data Exchange (ETDEWEB)

    Talnishnikh, E.

    2007-08-21

    This thesis is devoted to a mobile NMR with an improved Halbach scanner. This is a lightweight tube-shaped magnet with sensitive volume larger and a homogeneity of the magnetic field higher than the previous prototype version. The improved Halbach scanner is used for analysis of water-saturated drill cores and plugs with diameters up to 60 mm. To provide the analysis, the standard 1D technique with the CPMG sequence as well as 2D correlation experiments were successfully applied and adapted to study properties of fluid-saturated sediments. Afterwards the Halbach scanner was calibrated to fast non-destructive measurements of porosity, relaxation time distributions, and estimation of permeability. These properties can be calculated directly from the NMR data using the developed methodology. Any independent measurements of these properties with other methods are not needed. One of the main results of this work is the development of a new NMR on-line core scanner for measurements of porosity in long cylindrical and semi cylindrical drill cores. Also dedicated software was written to operate the NMR on-line core scanner. The physical background of this work is the study of the diffusion influence on transverse relaxation. The diffusion effect in the presence of internal gradients in porous media was probed by 1D and 2D experiments. The transverse relaxation time distributions obtained from 1D and from 2D experiments are comparable but different in fine details. Two new methodologies were developed based on the results of this study. First is the methodology quantifying the influence of diffusion in the internal gradients of water-saturated sediments on transverse relaxation from 2D correlation experiments. The second one is the correction of the permeability estimation from the NMR data taking in account the influence of the diffusion. Furthermore, PFG NMR technique was used to study restricted diffusion in the same kind of samples. Preliminary results are reported

  6. A COST EFFECTIVE MULTI-SPECTRAL SCANNER FOR NATURAL GAS DETECTION

    Energy Technology Data Exchange (ETDEWEB)

    Yudaya Sivathanu; Jongmook Lim; Vinoo Narayanan

    2004-10-25

    The objective of this project is to design, fabricate and field demonstrate a cost effective, multi-spectral scanner for natural gas leak detection in transmission and distribution pipelines. During the first year of the project, a laboratory version of the multi-spectral scanner was designed, fabricated, and tested at En'Urga Inc. The multi-spectral scanner was also evaluated using a blind DoE study at RMOTC. The performance of the scanner was inconsistent during the blind DoE study. However, most of the leaks were outside the view of the multi-spectral scanner. Therefore, a definite evaluation of the capability of the scanner was not obtained. Despite the results, sufficient number of plumes was detected fully confirming the feasibility of the multi-spectral scanner. During the second year, a rugged prototype scanner will be developed and evaluated, both at En'Urga Inc. and any potential field sites.

  7. Kalibrasi Single-Normal Hot-Wire Probe Sigmond Cohn Alloy 851 untuk Aliran Jet Terpulsasi

    OpenAIRE

    Hariyo Priambudi Setyo Pratomo; Klaus Bremhorst

    2006-01-01

    Calibration of a Sigmond Cohn alloy 851 single normal hot-wire probe was performed with a stationary calibration method with a range of nozzle exit velocity from 2 up to 80 m/s. The calibration aims to determine the best calibration response equation associated with the accuracy of curve fit. The curve fit accuracy test shows that the extended power-law equation provides a better curve fit than the simple power-law equation. A look-up table method used can improve the accuracy of curve fit of...

  8. Evaluating Measurement Accuracy

    CERN Document Server

    Rabinovich, Semyon G

    2010-01-01

    The goal of Evaluating Measurement Accuracy: A Practical Approach is to present methods for estimating the accuracy of measurements performed in industry, trade, and scientific research. Although multiple measurements are the focus of current theory, single measurements are the ones most commonly used. This book answers fundamental questions not addressed by present theory, such as how to discover the complete uncertainty of a measurement result. In developing a general theory of processing experimental data, this book, for the first time, presents the postulates of the theory of measurements. It introduces several new terms and definitions about the relationship between the accuracy of measuring instruments and measurements utilizing these instruments. It also offers well-grounded and practical methods for combining the components of measurement inaccuracy. From developing the theory of indirect measurements to proposing new methods of reduction in place of the traditional ones, this work encompasses the ful...

  9. Effect of mixing scanner types and reconstruction kernels on the characterization of lung parenchymal pathologies: emphysema, interstitial pulmonary fibrosis and normal non-smokers

    Science.gov (United States)

    Xu, Ye; van Beek, Edwin J.; McLennan, Geoffrey; Guo, Junfeng; Sonka, Milan; Hoffman, Eric

    2006-03-01

    In this study we utilize our texture characterization software (3-D AMFM) to characterize interstitial lung diseases (including emphysema) based on MDCT generated volumetric data using 3-dimensional texture features. We have sought to test whether the scanner and reconstruction filter (kernel) type affect the classification of lung diseases using the 3-D AMFM. We collected MDCT images in three subject groups: emphysema (n=9), interstitial pulmonary fibrosis (IPF) (n=10), and normal non-smokers (n=9). In each group, images were scanned either on a Siemens Sensation 16 or 64-slice scanner, (B50f or B30 recon. kernel) or a Philips 4-slice scanner (B recon. kernel). A total of 1516 volumes of interest (VOIs; 21x21 pixels in plane) were marked by two chest imaging experts using the Iowa Pulmonary Analysis Software Suite (PASS). We calculated 24 volumetric features. Bayesian methods were used for classification. Images from different scanners/kernels were combined in all possible combinations to test how robust the tissue classification was relative to the differences in image characteristics. We used 10-fold cross validation for testing the result. Sensitivity, specificity and accuracy were calculated. One-way Analysis of Variances (ANOVA) was used to compare the classification result between the various combinations of scanner and reconstruction kernel types. This study yielded a sensitivity of 94%, 91%, 97%, and 93% for emphysema, ground-glass, honeycombing, and normal non-smoker patterns respectively using a mixture of all three subject groups. The specificity for these characterizations was 97%, 99%, 99%, and 98%, respectively. The F test result of ANOVA shows there is no significant difference (p <0.05) between different combinations of data with respect to scanner and convolution kernel type. Since different MDCT and reconstruction kernel types did not show significant differences in regards to the classification result, this study suggests that the 3-D AMFM can

  10. Raising the Barcode Scanner: Technology and Productivity in the Retail Sector

    OpenAIRE

    Emek Basker

    2011-01-01

    Barcodes and barcode scanners transformed the grocery industry in the 1970s. I use store-level data from the 1972, 1977, and 1982 Census of Retail Trade, matched to data on store scanner installations, to estimate scanners' effect on labor productivity. I find that scanners increased a store's labor productivity, on average, by approximately 4.5 percent in the first few years. The effect was larger in stores carrying more packaged products, consistent with the presence of network externalitie...

  11. Flywheel system using wire-wound rotor

    Science.gov (United States)

    Chiao, Edward Young; Bender, Donald Arthur; Means, Andrew E.; Snyder, Philip K.

    2016-06-07

    A flywheel is described having a rotor constructed of wire wound onto a central form. The wire is prestressed, thus mitigating stresses that occur during operation. In another aspect, the flywheel incorporates a low-loss motor using electrically non-conducting permanent magnets.

  12. Microfabricated wire arrays for Z-pinch.

    Energy Technology Data Exchange (ETDEWEB)

    Spahn, Olga Blum; Rowen, Adam M.; Cich, Michael Joseph; Peake, Gregory Merwin; Arrington, Christian L.; Nash, Thomas J.; Klem, John Frederick; Romero, Dustin Heinz

    2008-10-01

    Microfabrication methods have been applied to the fabrication of wire arrays suitable for use in Z. Self-curling GaAs/AlGaAs supports were fabricated as an initial route to make small wire arrays (4mm diameter). A strain relief structure that could be integrated with the wire was designed to allow displacements of the anode/cathode connections in Z. Electroplated gold wire arrays with integrated anode/cathode bus connections were found to be sufficiently robust to allow direct handling. Platinum and copper plating processes were also investigated. A process to fabricate wire arrays on any substrate with wire thickness up to 35 microns was developed. Methods to handle and mount these arrays were developed. Fabrication of wire arrays of 20mm diameter was demonstrated, and the path to 40mm array fabrication is clear. With some final investment to show array mounting into Z hardware, the entire process to produce a microfabricated wire array will have been demonstrated.

  13. WIRED magazine announces rave awards nominees

    CERN Multimedia

    2002-01-01

    WIRED Magazine has anounced the nominees for its fourth annual WIRED Rave Awards, celebrating innovation and the individuals transforming commerce and culture. Jeffrey Hangst of the University of Aarhus has been nominated in the science category, for his work on the ATHENA Experiment, CERN (1/2 page).

  14. Topological transition in coated wire medium

    CERN Document Server

    Gorlach, Maxim A; Slobozhanyuk, Alexey P; Bogdanov, Andrey A; Belov, Pavel A

    2016-01-01

    We develop a theory of nonlocal homogenization for metamaterial consisting of parallel metallic wires with dielectric coating. It is demonstrated that manipulation of dielectric contrast between wire dielectric shell and host material results in switching of metamaterial dispersion regime from elliptic to the hyperbolic one, i.e. the topological transition takes place. We confirm our theoretical predictions by full-wave numerical simulations.

  15. A new generation of PET scanners for small animal studies

    International Nuclear Information System (INIS)

    Complete text of publication follows. Research on small animal PET scanners has been a hot topic in recent years. These devices are used in the preclinical phases of drug tests and during the development of new radiopharmaceuticals. They also provide a cost efficient way to test new materials, new design concepts and new technologies that later can be used to build more efficient human medical imaging devices. The development of a PET scanner requires expertise on different fields, therefore a consortium was formed that brought together Hungarian academic and industrial partners: the Nuclear Research Institute (which has experience in the development of nuclear detectors and data acquisition systems), the PET Center of the University of Debrecen (which has clinical experience in the application of nuclear imaging devices and background in image processing software), Mediso Ltd. (which has been developing, manufacturing, selling and servicing medical imaging devices since 1990) and other academic partners. This consortium has been working together since 2003: the knowledge base acquired during the development of our small animal PET scanners (miniPET-I and miniPET-II) is now being utilized to build a commercial multimodal human PET scanner. The operation of a PET scanner is based on the simultaneous detection ('coincidence') of two gamma photons originating from a positron annihilation. In traditional PET scanners coincidence is detected by a central unit during the measurement. In our system there is no such central module: all detected single gamma events are recorded (list mode data acquisition), and the list of events are processed using a computer cluster (built from PCs). The usage of independent detector modules and commercial components reduce both development and maintenance costs. Also, this mode of data acquisition is more suitable for development purposes, since once the data is collected and stored it can be used many times to test different signal

  16. A Cost Effective Multi-Spectral Scanner for Natural Gas Detection

    Energy Technology Data Exchange (ETDEWEB)

    Yudaya Sivathanu; Jongmook Lim; Vinoo Narayanan; Seonghyeon Park

    2005-12-07

    The objective of this project is to design, fabricate and demonstrate a cost effective, multi-spectral scanner for natural gas leak detection in transmission and distribution pipelines. During the first year of the project, a laboratory version of the multi-spectral scanner was designed, fabricated, and tested at EnUrga Inc. The multi-spectral scanner was also evaluated using a blind Department of Energy study at the Rocky Mountain Oilfield Testing Center. The performance of the scanner was inconsistent during the blind study. However, most of the leaks were outside the view of the multi-spectral scanner that was developed during the first year of the project. Therefore, a definite evaluation of the capability of the scanner was not obtained. Despite the results, sufficient number of plumes was detected fully confirming the feasibility of the multi-spectral scanner. During the second year, the optical design of the scanner was changed to improve the sensitivity of the system. Laboratory tests show that the system can reliably detect small leaks (20 SCFH) at 30 to 50 feet. A prototype scanner was built and evaluated during the second year of the project. Only laboratory evaluations were completed during the second year. The laboratory evaluations show the feasibility of using the scanner to determine natural gas pipeline leaks. Further field evaluations and optimization of the scanner are required before commercialization of the scanner can be initiated.

  17. Addressing Spatial Variability of Surface-Layer Wind with Long-Range WindScanners

    DEFF Research Database (Denmark)

    Berg, Jacob; Vasiljevic, Nikola; Kelly, Mark C.;

    2015-01-01

    of the WindScanner data is high, although the fidelity of the estimated vertical velocity component is significantly limited by the elevation angles of the scanner heads. The system of long-range WindScanners presented in this paper is close to being fully operational, with the pilot study herein serving...

  18. Realization of a Strained Atomic Wire Superlattice.

    Science.gov (United States)

    Song, Inkyung; Goh, Jung Suk; Lee, Sung-Hoon; Jung, Sung Won; Shin, Jin Sung; Yamane, Hiroyuki; Kosugi, Nobuhiro; Yeom, Han Woong

    2015-11-24

    A superlattice of strained Au-Si atomic wires is successfully fabricated on a Si surface. Au atoms are known to incorporate into the stepped Si(111) surface to form a Au-Si atomic wire array with both one-dimensional (1D) metallic and antiferromagnetic atomic chains. At a reduced density of Au, we find a regular array of Au-Si wires in alternation with pristine Si nanoterraces. Pristine Si nanoterraces impose a strain on the neighboring Au-Si wires, which modifies both the band structure of metallic chains and the magnetic property of spin chains. This is an ultimate 1D version of a strained-layer superlattice of semiconductors, defining a direction toward the fine engineering of self-assembled atomic-scale wires. PMID:26446292

  19. Wire and Cable Cold Bending Test

    Science.gov (United States)

    Colozza, Anthony

    2010-01-01

    One of the factors in assessing the applicability of wire or cable on the lunar surface is its flexibility under extreme cold conditions. Existing wire specifications did not address their mechanical behavior under cold, cryogenic temperature conditions. Therefore tests were performed to provide this information. To assess this characteristic 35 different insulated wire and cable pieces were cold soaked in liquid nitrogen. The segments were then subjected to bending and the force was recorded. Any failure of the insulation or jacketing was also documented for each sample tested. The bending force tests were performed at room temperature to provide a comparison to the change in force needed to bend the samples due to the low temperature conditions. The results from the bending tests were plotted and showed how various types of insulated wire and cable responded to bending under cold conditions. These results were then used to estimate the torque needed to unroll the wire under these low temperature conditions.

  20. The Truth about Accuracy

    NARCIS (Netherlands)

    Buekens, F.A.I.; Truyen, Frederick; Martini, Carlo; Boumans, Marcel

    2014-01-01

    When we evaluate the outcomes of investigative actions as justified or unjustified, good or bad, rational or irrational, we make, in a broad sense of the term, evaluative judgements about them. We look at operational accuracy as a desirable and evaluable quality of the outcomes and explore how the c

  1. An interactive method based on the live wire for segmentation of the breast in mammography images.

    Science.gov (United States)

    Zewei, Zhang; Tianyue, Wang; Li, Guo; Tingting, Wang; Lu, Xu

    2014-01-01

    In order to improve accuracy of computer-aided diagnosis of breast lumps, the authors introduce an improved interactive segmentation method based on Live Wire. This paper presents the Gabor filters and FCM clustering algorithm is introduced to the Live Wire cost function definition. According to the image FCM analysis for image edge enhancement, we eliminate the interference of weak edge and access external features clear segmentation results of breast lumps through improving Live Wire on two cases of breast segmentation data. Compared with the traditional method of image segmentation, experimental results show that the method achieves more accurate segmentation of breast lumps and provides more accurate objective basis on quantitative and qualitative analysis of breast lumps.

  2. An Interactive Method Based on the Live Wire for Segmentation of the Breast in Mammography Images

    Directory of Open Access Journals (Sweden)

    Zhang Zewei

    2014-01-01

    Full Text Available In order to improve accuracy of computer-aided diagnosis of breast lumps, the authors introduce an improved interactive segmentation method based on Live Wire. This paper presents the Gabor filters and FCM clustering algorithm is introduced to the Live Wire cost function definition. According to the image FCM analysis for image edge enhancement, we eliminate the interference of weak edge and access external features clear segmentation results of breast lumps through improving Live Wire on two cases of breast segmentation data. Compared with the traditional method of image segmentation, experimental results show that the method achieves more accurate segmentation of breast lumps and provides more accurate objective basis on quantitative and qualitative analysis of breast lumps.

  3. In Situ Electrochemical Deposition of Microscopic Wires

    Science.gov (United States)

    Yun, Minhee; Myung, Nosang; Vasquez, Richard

    2005-01-01

    A method of fabrication of wires having micron and submicron dimensions is built around electrochemical deposition of the wires in their final positions between electrodes in integrated circuits or other devices in which the wires are to be used. Heretofore, nanowires have been fabricated by a variety of techniques characterized by low degrees of controllability and low throughput rates, and it has been necessary to align and electrically connect the wires in their final positions by use of sophisticated equipment in expensive and tedious post-growth assembly processes. The present method is more economical, offers higher yields, enables control of wire widths, and eliminates the need for post-growth assembly. The wires fabricated by this method could be used as simple electrical conductors or as transducers in sensors. Depending upon electrodeposition conditions and the compositions of the electroplating solutions in specific applications, the wires could be made of metals, alloys, metal oxides, semiconductors, or electrically conductive polymers. In this method, one uses fabrication processes that are standard in the semiconductor industry. These include cleaning, dry etching, low-pressure chemical vapor deposition, lithography, dielectric deposition, electron-beam lithography, and metallization processes as well as the electrochemical deposition process used to form the wires. In a typical case of fabrication of a circuit that includes electrodes between which microscopic wires are to be formed on a silicon substrate, the fabrication processes follow a standard sequence until just before the fabrication of the microscopic wires. Then, by use of a thermal SiO-deposition technique, the electrodes and the substrate surface areas in the gaps between them are covered with SiO. Next, the SiO is electron-beam patterned, then reactive-ion etched to form channels having specified widths (typically about 1 m or less) that define the widths of the wires to be formed. Drops

  4. Accuracy study of new computer-assisted orthopedic surgery software

    Energy Technology Data Exchange (ETDEWEB)

    Sidon, Eli [Department of Orthopaedic Surgery, Beilinson-Rabin Medical Center, Petach Tikva (Israel); Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv (Israel); Steinberg, Ely L., E-mail: steinberge@tasmc.health.gov.il [Department of Orthopaedic Surgery, Tel-Aviv Medical Center, Tel Aviv (Israel); Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv (Israel)

    2012-12-15

    Purpose: The new computerized system is based on image analysis and designed to aid in orthopedic surgeries by virtual trajectory of the guide wire, intra-operative planning and various measurements. Validation of the accuracy and safety of any computer-aided surgery system is essential before implementing it clinically. We examined the accuracy of guide-wire length and angle measurements and fusion of multiple adjacent images (panoramic view image, PVI{sup ®}) of the new software. Methods: This is a 2-part study. Part I: twenty guide wires were drilled to various depths in a synthetic femur model and the results obtained by the software measurements were compared with manual measurements by a caliper and a depth gauge. Part II: a sawbone femur shaft was osteotomized and various inclinations of >10° to the varus or valgus angles were tested. The manually obtained measurements of angles and lengths were compared to the new computerized system software PVI. Results: There was a significant positive linear correlation between all groups of the computerized length and the control measurements (r > 0.983, p < 0.01). There was no significant difference among different distances, angles or positions from the image intensifier. There was a significant positive linear correlation between the angle and length measurement on the PVI and the control measurement (r > 0.993, p < 0.01). Conclusions: The new computerized software has high reliability in performing measurements of length using an aiming, positioning and referring device intra-operatively.

  5. Accuracy study of new computer-assisted orthopedic surgery software

    International Nuclear Information System (INIS)

    Purpose: The new computerized system is based on image analysis and designed to aid in orthopedic surgeries by virtual trajectory of the guide wire, intra-operative planning and various measurements. Validation of the accuracy and safety of any computer-aided surgery system is essential before implementing it clinically. We examined the accuracy of guide-wire length and angle measurements and fusion of multiple adjacent images (panoramic view image, PVI®) of the new software. Methods: This is a 2-part study. Part I: twenty guide wires were drilled to various depths in a synthetic femur model and the results obtained by the software measurements were compared with manual measurements by a caliper and a depth gauge. Part II: a sawbone femur shaft was osteotomized and various inclinations of >10° to the varus or valgus angles were tested. The manually obtained measurements of angles and lengths were compared to the new computerized system software PVI. Results: There was a significant positive linear correlation between all groups of the computerized length and the control measurements (r > 0.983, p 0.993, p < 0.01). Conclusions: The new computerized software has high reliability in performing measurements of length using an aiming, positioning and referring device intra-operatively.

  6. Photoacoustic imaging using an 8-beam Fabry-Perot scanner

    Science.gov (United States)

    Huynh, Nam; Ogunlade, Olumide; Zhang, Edward; Cox, Ben; Beard, Paul

    2016-03-01

    The planar Fabry Perot (FP) photoacoustic scanner has been shown to provide exquisite high resolution 3D images of soft tissue structures in vivo to depths up to approximately 10mm. However a significant limitation of current embodiments of the concept is low image acquisition speed. To increase acquisition speed, a novel multi-beam scanner architecture has been developed. This enables a line of equally spaced 8 interrogation beams to be scanned simultaneously across the FP sensor and the photoacoustic signals detected in parallel. In addition, an excitation laser operating at 200Hz was used. The combination of parallelising the detection and the high pulse repetition frequency (PRF) of the excitation laser has enabled dramatic reductions in image acquisition time to be achieved. A 3D image can now be acquired in 10 seconds and 2D images at video rates are now possible.

  7. Optimization and characterization of PET scanners for Medical Imaging

    OpenAIRE

    Cucciati,

    2014-01-01

    Positron emission tomography is an imaging technique that appeared to be a valid instrument for cancers detection and neuro-imaging studies. Since first models built during 1960s, an incredible effort has been done by researchers to develop scanners more and more advanced with higher specificity and efficiency. Monte Carlo simulations have shown to be a very important tool during design phase of PET prototypes thanks to their ability to simulate systems with many coupled degrees of freedom, a...

  8. An innovative optical and chemical drill core scanner

    OpenAIRE

    Sjöqvist, A. S. L.; M. Arthursson; A. Lundström; Calderón Estrada, E.; Inerfeldt, A.; Lorenz, H.

    2015-01-01

    We describe a new innovative drill core scanner that semi-automatedly analyses drill cores directly in drill core trays with X-ray fluorescence spectrometry, without the need for much sample preparation or operator intervention. The instrument is fed with entire core trays, which are photographed at high resolution and scanned by a 3-D profiling laser. Algorithms recognise the geometry of the core tray, number of slots, location of the drill cores, calculate the optimal scanning path, and exe...

  9. Whole brain CT perfusion on a 320-slice CT scanner

    Directory of Open Access Journals (Sweden)

    Jai Jai Shiva Shankar

    2011-01-01

    Full Text Available Computed tomography perfusion (CTP has been criticized for limited brain coverage. This may result in inadequate coverage of the lesion, inadequate arterial input function, or omission of the lesion within the target perfusion volume. The availability of 320-slice CT scanners offers whole brain coverage. This minimizes the chances of misregistration of lesions regardless of location, and makes the selection of the arterial input function easy. We present different clinical scenarios in which whole brain CTP is especially useful.

  10. Determination of cerebral blood flow with the EMI CT scanner

    International Nuclear Information System (INIS)

    Cerebral blood flow (CBF) determinations were made in seven baboons and two patients with the EMI CT dedicated head scanner. The method for determining the CBF was tested and measurements were made during physiological states elicited by changes in pCO2 and depth of anaesthesia. The method has a number of advantages, particularly for assessing CBF responses to pCO2 changes. (author)

  11. Determining the surface roughness coefficient by 3D Scanner

    OpenAIRE

    Karmen Fifer Bizjak

    2010-01-01

    Currently, several test methods can be used in the laboratory to determine the roughness of rock joint surfaces.However, true roughness can be distorted and underestimated by the differences in the sampling interval of themeasurement methods. Thus, these measurement methods produce a dead zone and distorted roughness profiles.In this paper a new rock joint surface roughness measurement method is presented, with the use of a camera-typethree-dimensional (3D) scanner as an alternative to curren...

  12. Experimental characterization of the Clear-PEM scanner spectrometric performance

    Science.gov (United States)

    Bugalho, R.; Carriço, B.; Ferreira, C. S.; Frade, M.; Ferreira, M.; Moura, R.; Ortigão, C.; Pinheiro, J. F.; Rodrigues, P.; Rolo, I.; Silva, J. C.; Trindade, A.; Varela, J.

    2009-10-01

    In the framework of the Clear-PEM project for the construction of a high-resolution and high-specificity scanner for breast cancer imaging, a Positron Emission Mammography tomograph has been developed and installed at the Instituto Português de Oncologia do Porto hospital. The Clear-PEM scanner is mainly composed by two planar detector heads attached to a robotic arm, trigger/data acquisition electronics system and computing servers. The detector heads hold crystal matrices built from 2 × 2 × 20 mm3 LYSO:Ce crystals readout by Hamamatsu S8550 APD arrays. The APDs are optically coupled to both ends of the 6144 crystals in order to extract the DOI information for each detected event. Each one of 12288 APD's pixels is read and controlled by Application Specific Integrated Circuits water-cooled by an external cooling unit. The Clear-PEM frontend boards innovative design results in a unprecedented integration of the crystal matrices, APDs and ASICs, making Clear-PEM the PET scanner with the highest number of APD pixels ever integrated so far. In this paper, the scanner's main technical characteristics, calibration strategies and the first spectrometric performance evaluation in a clinical environment are presented. The first commissioning results show 99.7% active channels, which, after calibration, have inter-pixel and absolute gain distributions with dispersions of, respectively, 12.2% and 15.3%, demonstrating that despite the large number of channels, the system is uniform. The mean energy resolution at 511 keV is of 15.9%, with a 8.8% dispersion, and the mean CDOI-1 is 5.9%/mm, with a 7.8% dispersion. The coincidence time resolution, at 511 keV, for a energy window between 400 and 600 keV, is 5.2 ns FWHM.

  13. Dynamic 3D computed tomography scanner for vascular imaging

    Science.gov (United States)

    Lee, Mark K.; Holdsworth, David W.; Fenster, Aaron

    2000-04-01

    A 3D dynamic computed-tomography (CT) scanner was developed for imaging objects undergoing periodic motion. The scanner system has high spatial and sufficient temporal resolution to produce quantitative tomographic/volume images of objects such as excised arterial samples perfused under physiological pressure conditions and enables the measurements of the local dynamic elastic modulus (Edyn) of the arteries in the axial and longitudinal directions. The system was comprised of a high resolution modified x-ray image intensifier (XRII) based computed tomographic system and a computer-controlled cardiac flow simulator. A standard NTSC CCD camera with a macro lens was coupled to the electro-optically zoomed XRII to acquire dynamic volumetric images. Through prospective cardiac gating and computer synchronized control, a time-resolved sequence of 20 mm thick high resolution volume images of porcine aortic specimens during one simulated cardiac cycle were obtained. Performance evaluation of the scanners illustrated that tomographic images can be obtained with resolution as high as 3.2 mm-1 with only a 9% decrease in the resolution for objects moving at velocities of 1 cm/s in 2D mode and static spatial resolution of 3.55 mm-1 with only a 14% decrease in the resolution in 3D mode for objects moving at a velocity of 10 cm/s. Application of the system for imaging of intact excised arterial specimens under simulated physiological flow/pressure conditions enabled measurements of the Edyn of the arteries with a precision of +/- kPa for the 3D scanner. Evaluation of the Edyn in the axial and longitudinal direction produced values of 428 +/- 35 kPa and 728 +/- 71 kPa, demonstrating the isotropic and homogeneous viscoelastic nature of the vascular specimens. These values obtained from the Dynamic CT systems were not statistically different (p less than 0.05) from the values obtained by standard uniaxial tensile testing and volumetric measurements.

  14. Scanner tags, comic book piracy and participatory culture

    OpenAIRE

    Delwiche, Aaron

    2014-01-01

    To learn more about the motivations of individuals who scan and distribute comic books, this study reports findings from a content analysis of 389 scanner tags extracted from comic books posted on the torrent network Pirate Bay. Coded according to four categories linked to the literature on comic fandom and participatory culture, tags were analyzed in terms of recognition, aesthetic style, textual signifiers, and visual signifiers. Though comic book pirates seek recognition from their peers, ...

  15. The Issue of Documentation of Hardly Accessible Historical Monuments by Using of Photogrammetry and Laser Scanner Techniques

    Directory of Open Access Journals (Sweden)

    Karol Bartoš

    2011-12-01

    Full Text Available This article deals with issues of measuring hardly accessible historical monuments on the example of the Slanec castle, Slovakia. In the first phase the convergence case of close-range photogrammetry was applied using digital camera Pentax K10D. Subsequently was created its 3D model in the PhotoModeler Scanner software. Special attention was paid to shape of ground, surroundings and characteristic of object of interest about choice of the right method and technique of making digital images. Processing of images was made with the highest possible accuracy with respect to the used method and apparatus. As a result of processing, the exact spatial model was made, which was exported to different formats. Also digital photo-plan with real photo textures and vector drawings was made. In the next phase the whole object of castle was measured with the laser scanner Leica ScanStation C10 and the final point cloud was processed in the best available software. The results obtained by both methods were compared in comparable digital formats with respect to the positional accuracy of final models. In the final phase is planned to obtain images appropriate for convergence case of photogrammetry using digital camera placed on a carrier on the MikroKopter HexaKopter controlled from the ground. Then the final comparison and further analysis of all acquired models can be made.

  16. Using Laser Scanners to Augment the Systematic Error Pointing Model

    Science.gov (United States)

    Wernicke, D. R.

    2016-08-01

    The antennas of the Deep Space Network (DSN) rely on precise pointing algorithms to communicate with spacecraft that are billions of miles away. Although the existing systematic error pointing model is effective at reducing blind pointing errors due to static misalignments, several of its terms have a strong dependence on seasonal and even daily thermal variation and are thus not easily modeled. Changes in the thermal state of the structure create a separation from the model and introduce a varying pointing offset. Compensating for this varying offset is possible by augmenting the pointing model with laser scanners. In this approach, laser scanners mounted to the alidade measure structural displacements while a series of transformations generate correction angles. Two sets of experiments were conducted in August 2015 using commercially available laser scanners. When compared with historical monopulse corrections under similar conditions, the computed corrections are within 3 mdeg of the mean. However, although the results show promise, several key challenges relating to the sensitivity of the optical equipment to sunlight render an implementation of this approach impractical. Other measurement devices such as inclinometers may be implementable at a significantly lower cost.

  17. Assessment of aec system response in ge 16 slices scanner

    International Nuclear Information System (INIS)

    Computed Tomography scanners equipped with system for Automatic Exposure Control ( AEC ) have been recently installed into clinical practice in Macedonia. Assessment of their AEC settings and performances is important task from patient doses and images quality point of view . This study was done by analyzing of CT examinations in patients in the City Hospital ' 8 September' in Skopje. The examinations were carried out by GE Bright Speed 16 slices scanner equipped with AEC system . In all patients were applied the same protocol with constant acquisition parameters was applied , and images were reconstructed by standard mode . Patient dimensions and image noise were measured from the scouts and axial images. From DICOM header the information related to dose, TCM and slice position were extracted . It was found that scanner automatic exposure system adjusts exposure mainly according to maximal patient lateral dimension (LR) and applying the same Noise Index (NI) value in patients with different size does not provides necessarily the same image noise level. In patients which LR dimension was less than 30 cm it was found that AEC adjusts tube current at the minimum of m A interval with no modulation throughout different body parts. (Author)

  18. Determining the surface roughness coefficient by 3D Scanner

    Directory of Open Access Journals (Sweden)

    Karmen Fifer Bizjak

    2010-12-01

    Full Text Available Currently, several test methods can be used in the laboratory to determine the roughness of rock joint surfaces.However, true roughness can be distorted and underestimated by the differences in the sampling interval of themeasurement methods. Thus, these measurement methods produce a dead zone and distorted roughness profiles.In this paper a new rock joint surface roughness measurement method is presented, with the use of a camera-typethree-dimensional (3D scanner as an alternative to current methods. For this study, the surfaces of ten samples oftuff were digitized by means of a 3D scanner, and the results were compared with the corresponding Rock JointCoefficient (JRC values. Up until now such 3D scanner have been mostly used in the automotive industry, whereastheir use for comparison with obtained JRC coefficient values in rock mechanics is presented here for the first time.The proposed new method is a faster, more precise and more accurate than other existing test methods, and is apromising technique for use in this area of study in the future.

  19. The Edinburgh Pipe Phantom: characterising ultrasound scanners beyond 50 MHz

    Energy Technology Data Exchange (ETDEWEB)

    Moran, C M [Medical Physics, University of Edinburgh, Edinburgh, EH16 4TJ (United Kingdom); Ellis, W; Janeczko, A; Pye, S D [Medical Physics Department, NHS Lothian University Hospitals Division, Royal Infirmary, Edinburgh EH16 4SA (United Kingdom); Bell, D, E-mail: carmel.moran@ed.ac.uk [Precision Acoustics Ltd, Hampton Farm Business Park, Dorset, DT2 8QH (United Kingdom)

    2011-02-01

    The ability to measure the imaging performance of pre-clinical and clinical ultrasound scanners is important but difficult to achieve objectively. The Edinburgh Pipe Phantom was originally developed to assess the technical performance of clinical scanners up to 15MHz. It comprises a series of anechoic cylinders with diameters 0.4 - 8mm embedded in agar-based tissue mimic. This design enables measurement of the characteristics (Resolution Integral R, Depth of Field L{sub R}, Characteristic Resolution D{sub R}) of grey-scale images with transducer centre frequencies from about 2.5 to 15MHz. We describe further development of the Edinburgh Pipe Phantom as a tool for characterising ultrasound scanners with centre frequencies up to at least 50MHz. This was achieved by moulding a series of anechoic pipe structures (diameters 0.045 - 1.5mm) into a block of agar-based tissue mimic. We report measurements of R, L{sub R} and D{sub R} for a series of 10 transducers (5 single element and 5 array transducers) designed for pre-clinical scanning, with centre frequencies in the range 15-55 MHz. Values of R ranged from 18-72 for single element transducers and 49-58 for linear array transducers. In conclusion, the pre-clinical pipe phantom was able to successfully determine the imaging characteristics of ultrasound probes up to 55MHz.

  20. Experimental study of free abrasive wire sawing by using multi-strands wire

    Institute of Scientific and Technical Information of China (English)

    Yao Chunyan; Wang Jinsheng; Peng Wei; Jin Xin; Chen Shijie

    2013-01-01

    Grains in the slurry can be brought into cutting zone by steel wire with a certain speed to achieve the purpose of removing the workpiece material in the free abrasive wire sawing machining. Because its own of multi-strands characteristics,we use it to replace the steel wire to do slicing experiment. In this paper,multi-strands wire is made by seven metal wires and has many grooves on its surface. Compared with steel wire,it can carry more grains into cutting zone which is conducive to improving the slicing efficiency. We do some comparative slic-ing experiments by applying multi-strands wire (ϕ0.25 mm) and steel wire (ϕ0.25 mm) to cut optical glass (K9). The results show that slicing efficiency and the surface roughness of the workpiece sliced by using multi-strands wire are better than that by using steel wire,but the kerf width of the former is wider than that of the latter in the same experimental conditions.

  1. PubMed vs. HighWire Press: a head-to-head comparison of two medical literature search engines.

    Science.gov (United States)

    Vanhecke, Thomas E; Barnes, Michael A; Zimmerman, Janet; Shoichet, Sandor

    2007-09-01

    PubMed and HighWire Press are both useful medical literature search engines available for free to anyone on the internet. We measured retrieval accuracy, number of results generated, retrieval speed, features and search tools on HighWire Press and PubMed using the quick search features of each. We found that using HighWire Press resulted in a higher likelihood of retrieving the desired article and higher number of search results than the same search on PubMed. PubMed was faster than HighWire Press in delivering search results regardless of search settings. There are considerable differences in search features between these two search engines.

  2. The Accuracy of Multiples

    Directory of Open Access Journals (Sweden)

    Stauropoulos Antonios

    2011-01-01

    Full Text Available Problem statement: Equity valuation with the use of multiples is widely used by academics and practitioners concerning its functionality. This study aims to explore the sensitivity of three multiples in terms of accuracy. Approach: Price-to-Sales (P/S multiple, the price-to-book value of equity (P/B multiple and the Price-to-Earnings (P/E multiple are three multiples under consideration, using both current and one-year-ahead earnings forecasts. Results: Evidence of empirical results show that, the multiples P/mdfy1 and P/mnfy1 are effective in terms of accuracy, with their means being negatively biased and their medians being positively biased. Finally, current earnings are identified as more appropriate value driver for the calculation of the P/E ratio by terms of accuracy. The results can be considered as reliable owing to the large sample and the procedure followed for its selection. Conclusion: This study offers a better understanding of the valuation approach through the use of multiples, in order analysts assumption to be more carefully and properly chosen and their results to be more accurately produced.

  3. Investigation of beam steering performances in rotation Risley-prism scanner.

    Science.gov (United States)

    Li, Anhu; Sun, Wansong; Yi, Wanli; Zuo, Qiyou

    2016-06-13

    Rotation Risley-prism scanner appears to be the most promising solution to high-accuracy beam scanning and target tracking. In the paper, some important issues crucial to the function implementation are thoroughly investigated. First the forming law of scan blind zone relative to double-prism structural parameters is explored by a quantitative analysis method. Then the nonlinear relationship between the rotation speeds of double prisms and the change rate of beam deviation angle is presented, and the beam scan singularity is indicated as an essential factor that confines the beam scan region. Finally, the high-accuracy radial scan theory is verified to illustrate the important application owing to the high reduction ratio from the rotation angles of double prisms to the deviation angles of the emergent beam. The research not only reveals the inner mechanisms of the Risley-prism beam scanning in principle, but also provide a foundation for the nonlinear control of various beam scan modes. PMID:27410303

  4. Depth Of Modulation And Spot Size Selection In Bar-Code Laser Scanners

    Science.gov (United States)

    Barkan, Eric; Swartz, Jerome

    1982-04-01

    Many optical and electronic considerations enter into the selection of optical spot size in flying spot laser scanners of the type used in modern industrial and commerical environments. These include: the scale of the symbols to be read, optical background noise present in the symbol substrate, and factors relating to the characteristics of the signal processor. Many 'front ends' consist of a linear signal conditioner followed by nonlinear conditioning and digitizing circuitry. Although the nonlinear portions of the circuit can be difficult to characterize mathematically, it is frequently possible to at least give a minimum depth of modulation measure to yield a worst-case guarantee of adequate performance with respect to digitization accuracy. Depth of modulation actually delivered to the nonlinear circuitry will depend on scale, contrast, and noise content of the scanned symbol, as well as the characteristics of the linear conditioning circuitry (eg. transfer function and electronic noise). Time and frequency domain techniques are applied in order to estimate the effects of these factors in selecting a spot size for a given system environment. Results obtained include estimates of the effects of the linear front end transfer function on effective spot size and asymmetries which can affect digitization accuracy. Plots of convolution-computed modulation patterns and other important system properties are presented. Considerations are limited primarily to Gaussian spot profiles but also apply to more general cases. Attention is paid to realistic symbol models and to implications with respect to printing tolerances.

  5. Fine Surveying and 3D Modeling Approach for Wooden Ancient Architecture via Multiple Laser Scanner Integration

    Directory of Open Access Journals (Sweden)

    Qingwu Hu

    2016-03-01

    Full Text Available A multiple terrestrial laser scanner (TLS integration approach is proposed for the fine surveying and 3D modeling of ancient wooden architecture in an ancient building complex of Wudang Mountains, which is located in very steep surroundings making it difficult to access. Three-level TLS with a scalable measurement distance and accuracy is presented for data collection to compensate for data missed because of mutual sheltering and scanning view limitations. A multi-scale data fusion approach is proposed for data registration and filtering of the different scales and separated 3D data. A point projection algorithm together with point cloud slice tools is designed for fine surveying to generate all types of architecture maps, such as plan drawings, facade drawings, section drawings, and doors and windows drawings. The section drawings together with slicing point cloud are presented for the deformation analysis of the building structure. Along with fine drawings and laser scanning data, the 3D models of the ancient architecture components are built for digital management and visualization. Results show that the proposed approach can achieve fine surveying and 3D documentation of the ancient architecture within 3 mm accuracy. In addition, the defects of scanning view and mutual sheltering can overcome to obtain the complete and exact structure in detail.

  6. Evaluation of transmission methodology and attenuation correction for the microPET Focus 220 animal scanner

    Energy Technology Data Exchange (ETDEWEB)

    Lehnert, Wencke [School of Medical Radiation Sciences, Faculty of Health Sciences, University of Sydney, PO Box 170, Lidcombe NSW 1825 (Australia); Meikle, Steven R [School of Medical Radiation Sciences, Faculty of Health Sciences, University of Sydney, PO Box 170, Lidcombe NSW 1825 (Australia); Siegel, Stefan [Siemens Preclinical Solutions, 810 Innovation Drive, Knoxville, TN 37932 (United States); Newport, Danny [Siemens Preclinical Solutions, 810 Innovation Drive, Knoxville, TN 37932 (United States); Banati, Richard B [School of Medical Radiation Sciences, Faculty of Health Sciences, University of Sydney, PO Box 170, Lidcombe NSW 1825 (Australia); Rosenfeld, Anatoly B [Centre for Medical Radiation Physics, University of Wollongong, Wollongong NSW 2522 (Australia)

    2006-08-21

    An accurate, low noise estimate of photon attenuation in the subject is required for quantitative microPET studies of molecular tracer distributions in vivo. In this work, several transmission-based measurement techniques were compared, including coincidence mode with and without rod windowing, singles mode with two different energy sources ({sup 68}Ge and {sup 57}Co), and postinjection transmission scanning. In addition, the effectiveness of transmission segmentation and the propagation of transmission bias and noise into the emission images were examined. The {sup 57}Co singles measurements provided the most accurate attenuation coefficients and superior signal-to-noise ratio, while {sup 68}Ge singles measurements were degraded due to scattering from the object. Scatter correction of {sup 68}Ge transmission data improved the accuracy for a 10 cm phantom but over-corrected for a mouse phantom. {sup 57}Co scanning also resulted in low bias and noise in postinjection transmission scans for emission activities up to 20 MBq. Segmentation worked most reliably for transmission data acquired with {sup 57}Co but the minor improvement in accuracy of attenuation coefficients and signal-to-noise may not justify its use, particularly for small subjects. We conclude that {sup 57}Co singles transmission scanning is the most suitable method for measured attenuation correction on the microPET Focus 220 animal scanner.

  7. Wire-rope emplacement of diagnostics systems

    International Nuclear Information System (INIS)

    The study reported here was initiated to determine if, with the Cable Downhole System (CDS) currently under development, there is an advantage to using continuous wire rope to lower the emplacement package to the bottom of the hole. A baseline design using two wire ropes as well as several alternatives are discussed in this report. It was concluded that the advantages of the wire-rope emplacement system do not justify the cost of converting to such a system, especially for LLNL's maximum emplacement package weights

  8. Detectors Ensure Function, Safety of Aircraft Wiring

    Science.gov (United States)

    2013-01-01

    Pedro Medelius waited patiently in his lab at Kennedy Space Center. He had just received word that a colleague was bringing over a cable from a Space Shuttle solid rocket booster to test Medelius new invention. Medelius was calm until his colleague arrived, with about 30 other people. "Talk about testing under pressure," says Medelius. "There were people there from the Navy, the Air Force, and the Federal Aviation Administration." After the group s arrival, Medelius took a deep breath and connected his Standing Wave Reflectometer (SWR) to the cable. He wiggled the cable around, and the display showed a fault (a short or open circuit in wire) about an inch and a half inside the connector on the cable. His colleague questioned the results, because he had already checked that area on the cable. Medelius used the SWR to check again but got the same result. "That is when we took the cable apart and looked inside," Medelius says. "Lo and behold, that was exactly where the fault was." The impetus for Medelius new wire inspection technology came about in 1999 when one of the space shuttles lost power due to a fault somewhere in its more than 200 miles of electrical wiring. "The backup circuit was activated and prevented a major dysfunction, but nevertheless, there was a problem with the wiring," Medelius describes. Even though technicians used a device called a multimeter to measure the electrical current to find which wire had a fault, it could not pinpoint exactly where on the wire the fault was located. For that, technicians had to visually inspect the wire. "Sometimes they would have to remove the whole wire assembly and visually inspect every single wire. It was a very tedious operation because the wires are behind cabinets. They go all over the place in the shuttle," says Medelius. "NASA needed an instrument capable of telling them exactly where the faults were occurring." To meet NASA s needs for a highly precise device to inspect electrical power bundles, wires

  9. Copper Wire Bonding Concerns and Best Practices

    Science.gov (United States)

    Chauhan, Preeti; Zhong, Z. W.; Pecht, Michael

    2013-08-01

    Copper wire bonding of microelectronic parts has developed as a means to cut the costs of using the more mature technology of gold wire bonding. However, with this new technology, changes in the bonding processes as well as bonding metallurgy can affect product reliability. This paper discusses the challenges associated with copper wire bonding and the solutions that the industry has been implementing. The paper also provides information to enable customers to conduct qualification and reliability tests on microelectronic packages to facilitate adoption in their target applications.

  10. Analytical methods to characterize heterogeneous raw material for thermal spray process: cored wire Inconel 625

    Science.gov (United States)

    Lindner, T.; Bonebeau, S.; Drehmann, R.; Grund, T.; Pawlowski, L.; Lampke, T.

    2016-03-01

    In wire arc spraying, the raw material needs to exhibit sufficient formability and ductility in order to be processed. By using an electrically conductive, metallic sheath, it is also possible to handle non-conductive and/or brittle materials such as ceramics. In comparison to massive wire, a cored wire has a heterogeneous material distribution. Due to this fact and the complex thermodynamic processes during wire arc spraying, it is very difficult to predict the resulting chemical composition in the coating with sufficient accuracy. An Inconel 625 cored wire was used to investigate this issue. In a comparative study, the analytical results of the raw material were compared to arc sprayed coatings and droplets, which were remelted in an arc furnace under argon atmosphere. Energy-dispersive X-ray spectroscopy (EDX) and X-ray fluorescence (XRF) analysis were used to determine the chemical composition. The phase determination was performed by X-ray diffraction (XRD). The results were related to the manufacturer specifications and evaluated in respect to differences in the chemical composition. The comparison between the feedstock powder, the remelted droplets and the thermally sprayed coatings allows to evaluate the influence of the processing methods on the resulting chemical and phase composition.

  11. Key technique of a detection sensor for coal mine wire ropes

    Institute of Scientific and Technical Information of China (English)

    WANG Hong-yao; XU Zhao; HUA Gang; TIAN Jie; ZHOU Bing-bing; LU Yan-hong; CHEN Feng-jun

    2009-01-01

    Wire ropes, employed extensively in coal mine hoists and transportation systems are subject to damage due to wear,corrosion and fatigue. The extent of damage and the carrying capacity of ropes are closely related to the sense of safety by staff and equipments. Magnetic flux leakage detection method (MFL), as an effective method, is these days widely used in detection of bro-ken strands of wire ropes. In order to improve the accuracy of detection of flaws in wire ropes by magnetic flux leakage (MFL), the effect of the distance between a sensor and the surface of a wire rope (i.e., lift-off) on detection by magnetic flux leakage was in-vestigated. An analysis of the main principles for the choice of lift-off is described by us and a new method that improves the struc-ture of the detector is proposed from the point of view of the design of a magnetic circuit, to restrain the impact of fluctuations of sensor lift-off. The effect of this kind of method is validated by simulation and computation. The results show that the detection sensitivity is markedly increased by this method. Furthermore, the signal-to-noise ratio (SNR) can be increased by over 28%. This method will lend itself to offer reliable scientific information to optimize the structure of excitation devices and improve the accu-racy of MFL detection.

  12. Power and Energy of Exploding Wires

    Science.gov (United States)

    Valancius, Cole

    2015-06-01

    Exploding wires are used in many high-energy applications, such as initiating explosives. Analysis of gold wire burst in detonator applications has shown Burst Current and Action metrics to be incapable of explaining burst phenomenon as the inductance of a firing circuit is changed. Energy Density better captures the correlation between different wire geometries, different electrical inputs, and explosive initiation. This idea has been expanded upon, to analyze the burst properties in Power-Energy space. Further inconsistencies in the understanding of wire burst and its relation to peak voltage have been found. An argument will be made for redefining the definition of burst. The result is a more broad understanding of rapid metal phase transition and the physical applications of the released shock wave.

  13. Beam Profiling through Wire Chambing Tracking

    CERN Document Server

    Nash, W

    2013-01-01

    This note describes the calibration of the Delay Wire Chambers (DWCs) used during test runs of CALICE’s Tungsten Digital Hadron Calorimeter (W-DHCAL) prototype in CERN’s SPS beam line (10 – 300 GeV).

  14. 30 CFR 56.12047 - Guy wires.

    Science.gov (United States)

    2010-07-01

    ... wires of poles supporting high-voltage transmission lines shall meet the requirements for grounding or... Installation and Maintenance of Electric Supply and Communication Lines” (also referred to as National...

  15. Highly stretchable wrinkled gold thin film wires

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Joshua, E-mail: joshuk7@uci.edu; Park, Sun-Jun; Nguyen, Thao [Department of Chemical Engineering and Materials Science, University of California, Irvine, California 92697 (United States); Chu, Michael [Department of Biomedical Engineering, University of California, Irvine, California 92697 (United States); Pegan, Jonathan D. [Department of Materials and Manufacturing Technology, University of California, Irvine, California 92697 (United States); Khine, Michelle, E-mail: mkhine@uci.edu [Department of Chemical Engineering and Materials Science, University of California, Irvine, California 92697 (United States); Department of Biomedical Engineering, University of California, Irvine, California 92697 (United States)

    2016-02-08

    With the growing prominence of wearable electronic technology, there is a need to improve the mechanical reliability of electronics for more demanding applications. Conductive wires represent a vital component present in all electronics. Unlike traditional planar and rigid electronics, these new wearable electrical components must conform to curvilinear surfaces, stretch with the body, and remain unobtrusive and low profile. In this paper, the piezoresistive response of shrink induced wrinkled gold thin films under strain demonstrates robust conductive performance in excess of 200% strain. Importantly, the wrinkled metallic thin films displayed negligible change in resistance of up to 100% strain. The wrinkled metallic wires exhibited consistent performance after repetitive strain. Importantly, these wrinkled thin films are inexpensive to fabricate and are compatible with roll to roll manufacturing processes. We propose that these wrinkled metal thin film wires are an attractive alternative to conventional wires for wearable applications.

  16. t matrix of metallic wire structures

    Energy Technology Data Exchange (ETDEWEB)

    Zhan, T. R., E-mail: phystrzhan@gmail.com; Chui, S. T., E-mail: chui@bartol.udel.edu [Bartol Research Institute, University of Delaware, Newark, Delaware 19716 (United States)

    2014-04-14

    To study the electromagnetic resonance and scattering properties of complex structures of which metallic wire structures are constituents within multiple scattering theory, the t matrix of individual structures is needed. We have recently developed a rigorous and numerically efficient equivalent circuit theory in which retardation effects are taken into account for metallic wire structures. Here, we show how the t matrix can be calculated analytically within this theory. We illustrate our method with the example of split ring resonators. The density of states and cross sections for scattering and absorption are calculated, which are shown to be remarkably enhanced at resonant frequencies. The t matrix serves as the basic building block to evaluate the interaction of wire structures within the framework of multiple scattering theory. This will open the door to efficient design and optimization of assembly of wire structures.

  17. 47 CFR 32.2321 - Customer premises wiring.

    Science.gov (United States)

    2010-10-01

    ... 47 Telecommunication 2 2010-10-01 2010-10-01 false Customer premises wiring. 32.2321 Section 32... Customer premises wiring. (a) This account shall include all amounts transferred from the former Account 232, Station Connections, inside wiring subclass. (b) Embedded Customer Premises Wiring is...

  18. Modelling aluminium wire bond reliability in high power OMP devices

    NARCIS (Netherlands)

    Kregting, R.; Yuan, C.A.; Xiao, A.; Bruijn, F. de

    2011-01-01

    In a RF power application such as the OMP, the wires are subjected to high current (because of the high power) and high temperature (because of the heat from IC and joule-heating from the wire itself). Moreover, the wire shape is essential to the RF performance. Hence, the aluminium wire is preferre

  19. Audio wiring guide how to wire the most popular audio and video connectors

    CERN Document Server

    Hechtman, John

    2012-01-01

    Whether you're a pro or an amateur, a musician or into multimedia, you can't afford to guess about audio wiring. The Audio Wiring Guide is a comprehensive, easy-to-use guide that explains exactly what you need to know. No matter the size of your wiring project or installation, this handy tool provides you with the essential information you need and the techniques to use it. Using The Audio Wiring Guide is like having an expert at your side. By following the clear, step-by-step directions, you can do professional-level work at a fraction of the cost.

  20. Graphene wire medium: Homogenization and application

    DEFF Research Database (Denmark)

    Andryieuski, Andrei; Chigrin, Dmitry N.; Lavrinenko, Andrei

    2012-01-01

    In this contribution we analyze numerically the optical properties of the graphene wire medium, which unit cell consists of a stripe of graphene embedded into dielectric. We propose a simple method for retrieval of the isofrequency contour and effective permittivity tensor. As an example...... of the graphene wire medium application we demonstrate a reconfigurable hyperlens for the terahertz subwavelength imaging capable of resolving two sources with separation λ0/5 in the far-field....

  1. Tracking with wire chambers at high luminosities

    Energy Technology Data Exchange (ETDEWEB)

    Hanson, G.G. (Indiana Univ., Bloomington, IN (USA) Stanford Linear Accelerator Center, Menlo Park, CA (USA))

    1989-12-01

    Radiation damage and rate limitations impose severe constraints on wire chambers at the SSC. Possible conceptual designs for wire chamber tracking systems that satisfy these constraints are discussed. Computer simulation studies of tracking in such systems are presented. Simulations of events from interesting physics at the SSC, including hits from minimum bias background events, are examined. Results of some preliminary pattern recognition studies are given. 11 refs., 10 figs.

  2. Novel use of the "buddy"wire.

    LENUS (Irish Health Repository)

    O'Hare, A

    2008-12-29

    Summary: During interventional procedures the tortuosity of the vasculature hampers catheter stability. The buddy wire may be used to aid and maintain vascular access.We describe a case of acute subarachnoid haemorrhage secondary to dissecting aneurysm of the vertebral artery.We discuss the value of the buddy wire during balloon occlusion of the vertebral artery not as it is typically used, but to actually prevent the balloon repeatedly entering the posterior inferior cerebellar artery during the procedure.

  3. 'Chrysanthemum petal' arrangements of silver nano wires.

    Science.gov (United States)

    Cui, Hui-Wang; Jiu, Jin-Ting; Sugahara, Tohru; Nagao, Shijo; Suganuma, Katsuaki; Uchida, Hiroshi

    2014-12-01

    Highly ordered 'Chrysanthemum petal' arrangements of silver nano wires were fabricated in a biodegradable polymer of polyvinyl alcohol using a simple one-step blending method without any template. The degree of the arrangement increased with the decreasing content of polyvinyl alcohol. The mechanism for the formation of these 'Chrysanthemum petal' arrangements was discussed specifically. These 'Chrysanthemum petal' arrangements will be helpful to increase the electrical conductivity of silver nano wires films. PMID:25397618

  4. A Magnetic Sensor with Amorphous Wire

    Directory of Open Access Journals (Sweden)

    Dongfeng He

    2014-06-01

    Full Text Available Using a FeCoSiB amorphous wire and a coil wrapped around it, we have developed a sensitive magnetic sensor. When a 5 mm long amorphous wire with the diameter of 0.1 mm was used, the magnetic field noise spectrum of the sensor was about 30 pT/ÖHz above 30 Hz. To show the sensitivity and the spatial resolution, the magnetic field of a thousand Japanese yen was scanned with the magnetic sensor.

  5. Metallurgical investigation of wire breakage of tyre bead grade

    OpenAIRE

    Piyas Palit; Souvik Das; Jitendra Mathur

    2015-01-01

    Tyre bead grade wire is used for tyre making application. The wire is used as reinforcement inside the polymer of tyre. The wire is available in different size/section such as 1.6–0.80 mm thin Cu coated wire. During tyre making operation at tyre manufacturer company, wire failed frequently. In this present study, different broken/defective wire samples were collected from wire mill for detailed investigation of the defect. The natures of the defects were localized and similar in nature. The f...

  6. Evaluation of scanners for C-scan imaging in nondestructive inspection of aircraft

    Energy Technology Data Exchange (ETDEWEB)

    Gieske, J.H.

    1994-04-01

    The goal of this project was to produce a document that contains information on the usability and performance of commercially available, fieldable, and portable scanner systems as they apply to aircraft NDI inspections. In particular, the scanners are used to generate images of eddy current, ultrasonic, or bond tester inspection data. The scanner designs include manual scanners, semiautomated scanners, and fully automated scanners. A brief description of the functionality of each scanner type, a sketch, and a fist of the companies that support the particular design are provided. Vendors of each scanner type provided hands-on demonstrations of their equipment on real aircraft samples in the FAA Aging Aircraft Nondestructive Inspection Validation Center (AANC) in Albuquerque, NM. From evaluations recorded during the demonstrations, a matrix of scanner features and factors and ranking of the capabilities and limitations of the design, portability, articulation, performance, usability, and computer hardware/software was constructed to provide a quick reference for comparing the different scanner types. Illustrations of C-scan images obtained during the demonstration are shown.

  7. Chemistry of radiation damage to wire chambers

    Energy Technology Data Exchange (ETDEWEB)

    Wise, J.

    1992-08-01

    Proportional counters are used to study aspects of radiation damage to wire chambers (wire aging). Principles of low-pressure, rf plasma chemistry are used to predict the plasma chemistry in electron avalanches (1 atm, dc). (1) Aging is studied in CF{sub 4}/iC{sub 4}H{sub 10} gas mixtures. Wire deposits are analyzed by Auger electron spectroscopy. An apparent cathode aging process resulting in loss of gain rather than in a self-sustained current is observed in CF{sub 4}-rich gases. A four-part model considering plasma polymerization of the hydrocarbon, etching of wire deposits by CF{sub 4}, acceleration of deposition processes in strongly etching environments, and reactivity of the wire surface is developed to understand anode wire aging in CF{sub 4}/iC{sub 4}H{sub 10} gases. Practical guidelines suggested by the model are discussed. (2) Data are presented to suggest that trace amounts of Freons do not affect aging rates in either dimethyl ether or Ar/C{sub 2}H{sub 6}. Apparent loss of gain is explained by attachment of primary electrons to a continuously increasing concentration of Freon 11 (CCl{sub 3}F) in the counter gas. An increase in the concentration of Freon 11 in dimethyl ether is caused by a distillation process in the gas supply bottle and is a natural consequence of the unequal volatilities of the two compounds.

  8. Needleless electrospinning with twisted wire spinneret

    Science.gov (United States)

    Holopainen, Jani; Penttinen, Toni; Santala, Eero; Ritala, Mikko

    2015-01-01

    A needleless electrospinning setup named ‘Needleless Twisted Wire Electrospinning’ was developed. The polymer solution is electrospun from the surface of a twisted wire set to a high voltage and collected on a cylindrical collector around the wire. Multiple Taylor cones are simultaneously self-formed on the downward flowing solution. The system is robust and simple with no moving parts aside from the syringe pump used to transport the solution to the top of the wire. The structure and process parameters of the setup and the results on the preparation of polyvinyl pyrrolidone (PVP), hydroxyapatite (HA) and bioglass fibers with the setup are presented. PVP fiber sheets with areas of 40 × 120 cm2 and masses up to 1.15 g were prepared. High production rates of 5.23 g h-1 and 1.40 g h-1 were achieved for PVP and HA respectively. The major limiting factor of the setup is drying of the polymer solution on the wire during the electrospinning process which will eventually force to interrupt the process for cleaning of the wire. Possible solutions to this problem and other ways to develop the setup are discussed. The presented system provides a simple way to increase the production rate and area of fiber sheet as compared with the conventional needle electrospinning.

  9. Subchannel Analysis of Wire Wrapped SCWR Assembly

    Directory of Open Access Journals (Sweden)

    Jianqiang Shan

    2014-01-01

    Full Text Available Application of wire wrap spacers in SCWR can reduce pressure drop and obtain better mixing capability. As a consequence, the required coolant pumping power is decreased and the coolant temperature profile inside the fuel bundle is flattened which will obviously decrease the peak cladding temperature. The distributed resistance model for wire wrap was developed and implemented in ATHAS subchannel analysis code. The HPLWR wire wrapped assembly was analyzed. The results show that: (1 the assembly with wire wrap can obtain a more uniform coolant temperature profile than the grid spaced assembly, which will result in a lower peak cladding temperature; (2 the pressure drop in a wire wrapped assembly is less than that in a grid spaced assembly, which can reduce the operating power of pump effectively; (3 the wire wrap pitch has significant effect on the flow in the assembly. Smaller Hwire/Drod will result in stronger cross flow a more uniform coolant temperature profile, and also a higher pressure drop.

  10. Adsorption of iodine on silver wire

    International Nuclear Information System (INIS)

    It is an important process in which iodine is adsorbed on silver wire during the preparation of 125I seed sources. In this paper, a technique of adsorption of iodine on silver wire was studied. The influence of several factors, such as the type of reagent for halogenation, the time for halogenation, the time for adsorption, pH value, ion concentration, carrier iodine and so on, on the utilization rate of 131I was investigated, and the effectiveness of our proposed technique for adsorption of iodine on silver wire was confirmed. The procedure is summarized as follows: silver wire acidification: using 4 mol/L HNO3 as halogenation agent, stirring acidified for 20 min; silver wire halogenation: used 2 mol/L NaClO3 as halogenated agent, halogenation for 3 h; adsorption of iodine on silver wire: room temperature, pH value for the reaction is about 3, the time for adsorption is 30 min, carrier iodine is 27.5 μg. Original radioactivity of reaction solution was determined based on radioactivity of source-core that user required. (authors)

  11. Chemistry of radiation damage to wire chambers

    International Nuclear Information System (INIS)

    Proportional counters are used to study aspects of radiation damage to wire chambers (wire aging). Principles of low-pressure, rf plasma chemistry are used to predict the plasma chemistry in electron avalanches (1 atm, dc). (1) Aging is studied in CF4/iC4H10 gas mixtures. Wire deposits are analyzed by Auger electron spectroscopy. An apparent cathode aging process resulting in loss of gain rather than in a self-sustained current is observed in CF4-rich gases. A four-part model considering plasma polymerization of the hydrocarbon, etching of wire deposits by CF4, acceleration of deposition processes in strongly etching environments, and reactivity of the wire surface is developed to understand anode wire aging in CF4/iC4H10 gases. Practical guidelines suggested by the model are discussed. (2) Data are presented to suggest that trace amounts of Freons do not affect aging rates in either dimethyl ether or Ar/C2H6. Apparent loss of gain is explained by attachment of primary electrons to a continuously increasing concentration of Freon 11 (CCl3F) in the counter gas. An increase in the concentration of Freon 11 in dimethyl ether is caused by a distillation process in the gas supply bottle and is a natural consequence of the unequal volatilities of the two compounds

  12. Simplified Calculation of Maximum Wire Tension in case of Short Circuit

    OpenAIRE

    I. I. Sergey; A. P. Andrukevich

    2007-01-01

    Modified method for a simplified calculation of a maximum wire tension in case of a short circuit. This method makes it possible to take into account a real trajectory of their movement and elements of a switch-gear. An accuracy evaluation of the simplified calculation has been done with the help of a calculative experiment using a BusEf computer software. A correction factor has been obtained to take into account an influence of insulator strings on a tension value.

  13. Modeling inelastic phonon scattering in atomic- and molecular-wire junctions

    DEFF Research Database (Denmark)

    Paulsson, Magnus; Frederiksen, Thomas; Brandbyge, Mads

    2005-01-01

    Computationally inexpensive approximations describing electron-phonon scattering in molecular-scale conductors are derived from the nonequilibrium Green's function method. The accuracy is demonstrated with a first-principles calculation on an atomic gold wire. Quantitative agreement between...... the full nonequilibrium Green's function calculation and the newly derived expressions is obtained while simplifying the computational burden by several orders of magnitude. In addition, analytical models provide intuitive understanding of the conductance including nonequilibrium heating and provide...

  14. Status of Project GRAND's Proportional Wire Chamber Array

    CERN Document Server

    Poirier, J; Barchie, J; D'Andrea, C; Dunford, M; Green, M; Gress, J; Lin, T; Race, D; Skibba, R; Van Laecke, G; Wysocki, M

    2001-01-01

    Project GRAND is an extensive air shower array of proportional wire chambers. It has 64 stations in a 100m x 100m area; each station has eight planes of proportional wire chambers with a 50 mm steel absorber plate above the bottom two planes. This arrangement of planes, each 1.25 square meters of area, allow an angular measurement for each track to 0.25 degrees in each of two projections. The steel absorber plate allows a measurement of the identity of each muon track to 96% accuracy. Two data-taking triggers allow data to be simultaneously taken for a) extensive air showers (multiple coincidence station hits) at about 1 Hz and b) single muons (single tracks of identified muons) at 2000 Hz. Eight on-line computers pre-analyze the single track data and store the results on magnetic tape in compacted form with a minimum of computer dead-time. One additional computer reads data from the shower triggers and records this raw data on a separate magnetic tape with no pre-analysis.

  15. Radiochromic film dosimetry with flatbed scanners: A fast and accurate method for dose calibration and uniformity correction with single film exposure

    International Nuclear Information System (INIS)

    Film dosimetry is an attractive tool for dose distribution verification in intensity modulated radiotherapy (IMRT). A critical aspect of radiochromic film dosimetry is the scanner used for the readout of the film: the output needs to be calibrated in dose response and corrected for pixel value and spatial dependent nonuniformity caused by light scattering; these procedures can take a long time. A method for a fast and accurate calibration and uniformity correction for radiochromic film dosimetry is presented: a single film exposure is used to do both calibration and correction. Gafchromic EBT films were read with two flatbed charge coupled device scanners (Epson V750 and 1680Pro). The accuracy of the method is investigated with specific dose patterns and an IMRT beam. The comparisons with a two-dimensional array of ionization chambers using a 18x18 cm2 open field and an inverse pyramid dose pattern show an increment in the percentage of points which pass the gamma analysis (tolerance parameters of 3% and 3 mm), passing from 55% and 64% for the 1680Pro and V750 scanners, respectively, to 94% for both scanners for the 18x18 open field, and from 76% and 75% to 91% for the inverse pyramid pattern. Application to an IMRT beam also shows better gamma index results, passing from 88% and 86% for the two scanners, respectively, to 94% for both. The number of points and dose range considered for correction and calibration appears to be appropriate for use in IMRT verification. The method showed to be fast and to correct properly the nonuniformity and has been adopted for routine clinical IMRT dose verification

  16. Temperature dependence of APD-based PET scanners

    International Nuclear Information System (INIS)

    Purpose: Solid state detectors such as avalanche photodiodes (APDs) are increasingly being used in PET detectors. One of the disadvantages of APDs is the strong decrease of their gain factor with increasing ambient temperature. The light yield of most scintillation crystals also decreases when ambient temperature is increased. Both effects lead to considerable temperature dependence of the performance of APD-based PET scanners. In this paper, the authors propose a model for this dependence and the performance of the LabPET8 APD-based small animal PET scanner is evaluated at different temperatures.Methods: The model proposes that the effect of increasing temperature on the energy histogram of an APD-based PET scanner is a compression of the histogram along the energy axis. The energy histogram of the LabPET system was acquired at 21 °C and 25 °C to verify the validity of this model. Using the proposed model, the effect of temperature on system sensitivity was simulated for different detector temperature coefficients and temperatures. Subsequently, the effect of short term and long term temperature changes on the peak sensitivity of the LabPET system was measured. The axial sensitivity profile was measured at 21 °C and 24 °C following the NEMA NU 4-2008 standard. System spatial resolution was also evaluated. Furthermore, scatter fraction, count losses and random coincidences were evaluated at different temperatures. Image quality was also investigated.Results: As predicted by the model, the photopeak energy at 25 °C is lower than at 21 °C with a shift of approximately 6% per °C. Simulations showed that this results in an approximately linear decrease of sensitivity when temperature is increased from 21 °C to 24 °C and energy thresholds are constant. Experimental evaluation of the peak sensitivity at different temperatures showed a strong linear correlation for short term (2.32 kcps/MBq/°C = 12%/°C, R = −0.95) and long term (1.92 kcps/MBq/°C = 10%/

  17. Magnetic Alignment of Pulsed Solenoids Using the Pulsed Wire Method

    International Nuclear Information System (INIS)

    A unique application of the pulsed-wire measurement method has been implemented for alignment of 2.5 T pulsed solenoid magnets. The magnetic axis measurement has been shown to have a resolution of better than 25 (micro)m. The accuracy of the technique allows for the identification of inherent field errors due to, for example, the winding layer transitions and the current leads. The alignment system is developed for the induction accelerator NDCX-II under construction at LBNL, an upgraded Neutralized Drift Compression experiment for research on warm dense matter and heavy ion fusion. Precise alignment is essential for NDCX-II, since the ion beam has a large energy spread associated with the rapid pulse compression such that misalignments lead to corkscrew deformation of the beam and reduced intensity at focus. The ability to align the magnetic axis of the pulsed solenoids to within 100 pm of the induction cell axis has been demonstrated.

  18. Magnetic Alignment of Pulsed Solenoids Using the Pulsed Wire Method

    Energy Technology Data Exchange (ETDEWEB)

    Arbelaez, D.; Madur, A.; Lipton, T.M.; Waldron, W.L.; Kwan, J.W.

    2011-04-01

    A unique application of the pulsed-wire measurement method has been implemented for alignment of 2.5 T pulsed solenoid magnets. The magnetic axis measurement has been shown to have a resolution of better than 25 {micro}m. The accuracy of the technique allows for the identification of inherent field errors due to, for example, the winding layer transitions and the current leads. The alignment system is developed for the induction accelerator NDCX-II under construction at LBNL, an upgraded Neutralized Drift Compression experiment for research on warm dense matter and heavy ion fusion. Precise alignment is essential for NDCX-II, since the ion beam has a large energy spread associated with the rapid pulse compression such that misalignments lead to corkscrew deformation of the beam and reduced intensity at focus. The ability to align the magnetic axis of the pulsed solenoids to within 100 pm of the induction cell axis has been demonstrated.

  19. The Analysis of the High Speed Wire Drawing Process of High Carbon Steel Wires Under Hydrodynamic Lubrication Conditions

    Directory of Open Access Journals (Sweden)

    Suliga M.

    2015-04-01

    Full Text Available In this work the analysis of the wire drawing process in hydrodynamic dies has been done. The drawing process of φ5.5 mm wire rod to the final wire of φ1.7 mm was conducted in 12 passes, in drawing speed range of 5-25 m/s. For final wires of φ1.7 mm the investigation of topography of wire surface, the amount of lubricant on the wire surface and the pressure of lubricant in hydrodynamic dies were determined. Additionally, in the work selected mechanical properties of the wires have been estimated.

  20. Design and performance evaluation of a coplanar multimodality scanner for rodent imaging

    Energy Technology Data Exchange (ETDEWEB)

    Lage, E; Vaquero, J J; Sisniega, A; Tapias, G; Abella, M; Rodriguez-Ruano, A; Desco, M [Unidad de Medicina y Cirugia Experimental, Hospital General Universitario Gregorio Maranon, Madrid (Spain); Espana, S [Departamento de Fisica Atomica, Molecular y Nuclear, Facultad de Ciencias Fisicas, Universidad Complutense, Madrid (Spain); Ortuno, J E [Networking Research Center on Bioengineering, Biomaterials and Nanomedicine (CIBER-BBN), Zaragoza (Spain); Udias, A [Departamento de Estadistica e Investigacion Operativa, Universidad Rey Juan Carlos, Fuenlabrada (Spain)], E-mail: elage@mce.hggm.es

    2009-09-21

    This work reports on the development and performance evaluation of the VrPET/CT, a new multimodality scanner with coplanar geometry for in vivo rodent imaging. The scanner design is based on a partial-ring PET system and a small-animal CT assembled on a rotatory gantry without axial displacement between the geometric centers of both fields of view (FOV). We report on the PET system performance based on the NEMA NU-4 protocol; the performance characteristics of the CT component are not included herein. The accuracy of inter-modality alignment and the imaging capability of the whole system are also evaluated on phantom and animal studies. Tangential spatial resolution of PET images ranged between 1.56 mm at the center of the FOV and 2.46 at a radial offset of 3.5 cm. The radial resolution varies from 1.48 mm to 1.88 mm, and the axial resolution from 2.34 mm to 3.38 mm for the same positions. The energy resolution was 16.5% on average for the entire system. The absolute coincidence sensitivity is 2.2% for a 100-700 keV energy window with a 3.8 ns coincident window. The scatter fraction values for the same settings were 11.45% for a mouse-sized phantom and 23.26% for a rat-sized phantom. The peak noise equivalent count rates were also evaluated for those phantoms obtaining 70.8 kcps at 0.66 MBq/cc and 31.5 kcps at 0.11 MBq/cc, respectively. The accuracy of inter-modality alignment is below half the PET resolution, and the image quality of biological specimens agrees with measured performance parameters. The assessment presented in this study shows that the VrPET/CT system is a good performance small-animal imager, while the cost derived from a partial ring detection system is substantially reduced as compared with a full-ring PET tomograph.

  1. Scatter fraction of the J-PET tomography scanner

    CERN Document Server

    Kowalski, P; Raczyński, L; Alfs, D; Bednarski, T; Białas, P; Czerwiński, E; Gajos, A; Głowacz, B; Jasińska, J; Kamińska, D; Korcyl, G; Kozik, T; Krzemień, W; Kubicz, E; Mohammad, M; Niedźwiecki, Sz; Pałka, M; Pawlik-Niedźwiecka, M; Rudy, Z; Silarski, M; Smyrski, J; Strzelecki, A; Wieczorek, A; Zgardzińska, B; Zieliński, M; Moskal, P

    2016-01-01

    A novel Positron Emission Tomography system, based on plastic scintillators, is being developed by the J-PET collaboration. In this article we present the simulation results of the scatter fraction, representing one of the parameters crucial for background studies defined in the NEMA-NU-2-2012 norm. We elaborate an event selection methods allowing to suppress events in which gamma quanta were scattered in the phantom or underwent the multiple scattering in the detector. The estimated scatter fraction for the single-layer J-PET scanner varies from 37% to 53% depending on the applied energy threshold.

  2. A new electronic read-out for the YAPPET scanner

    CERN Document Server

    Damiani, C; Malaguti, R; Guerra, A D; Domenico, G D; Zavattini, G

    2002-01-01

    A small animal PET-SPECT scanner (YAPPET) prototype was built at the Physics Department of the Ferrara University and is presently being used at the Nuclear Medicine Department for radiopharmaceutical studies on rats. The first YAPPET prototype shows very good performances, but needs some improvements before it can be fully used for intensive radiopharmaceutical research. The main problem of the actual prototype is its heavy electronics, based on NIM and CAMAC standard modules. For this reason a new, compact read-out electronics was developed and tested. The results of a first series of tests made on the first prototype will be presented in the paper.

  3. An automated geometric correction system for airborne multispectral scanner imagery

    International Nuclear Information System (INIS)

    The United States Department of Energy (USDOE) maintains a Remote Sensing Laboratory (RSL) to support nuclear related programs of the US Government. The mission of the organization includes both emergency response and more routine environmental assessments of nuclear facilities. The USDOE RSL maintains a small fleet of specially equipped aircraft that are used as platforms for remote sensor systems. The aircraft include helicopters, light aircraft, and a business jet suitable for high altitude acquisitions. Multispectral scanners flown on these platforms are subject to geometric distortions related to variations in aircraft orientation (pitch, roll, and yaw), position, and velocity during data acquistions

  4. Applicability of optical scanner method for fine root dynamics

    Science.gov (United States)

    Kume, Tomonori; Ohashi, Mizue; Makita, Naoki; Khoon Kho, Lip; Katayama, Ayumi; Matsumoto, Kazuho; Ikeno, Hidetoshi

    2016-04-01

    Fine root dynamics is one of the important components in forest carbon cycling, as ~60 % of tree photosynthetic production can be allocated to root growth and metabolic activities. Various techniques have been developed for monitoring fine root biomass, production, mortality in order to understand carbon pools and fluxes resulting from fine roots dynamics. The minirhizotron method is now a widely used technique, in which a transparent tube is inserted into the soil and researchers count an increase and decrease of roots along the tube using images taken by a minirhizotron camera or minirhizotron video camera inside the tube. This method allows us to observe root behavior directly without destruction, but has several weaknesses; e.g., the difficulty of scaling up the results to stand level because of the small observation windows. Also, most of the image analysis are performed manually, which may yield insufficient quantitative and objective data. Recently, scanner method has been proposed, which can produce much bigger-size images (A4-size) with lower cost than those of the minirhizotron methods. However, laborious and time-consuming image analysis still limits the applicability of this method. In this study, therefore, we aimed to develop a new protocol for scanner image analysis to extract root behavior in soil. We evaluated applicability of this method in two ways; 1) the impact of different observers including root-study professionals, semi- and non-professionals on the detected results of root dynamics such as abundance, growth, and decomposition, and 2) the impact of window size on the results using a random sampling basis exercise. We applied our new protocol to analyze temporal changes of root behavior from sequential scanner images derived from a Bornean tropical forests. The results detected by the six observers showed considerable concordance in temporal changes in the abundance and the growth of fine roots but less in the decomposition. We also examined

  5. Computed tomography scanner applied to soil compaction studies

    International Nuclear Information System (INIS)

    The soil compaction problem was studied using a first generation computed tomography scanner (CT). This apparatus gets images of soil cross sections samples, with resolution of a few millimeters. We performed the following laboratory and field experiments: basic experiments of equipment calibrations and resolutions studies; measurements of compacted soil thin layers; measurements of soil compaction caused by agricultural tools; stress-strain modelling in confined soil sample, with several moisture degree; characterizations of soil bulk density profile with samples collected in a hole (trench), comparing with a cone penetrometer technique. (author)

  6. Inspection of Samples using a fast Millimetre Wave Scanner

    International Nuclear Information System (INIS)

    Millimeterwaves and terahertz sensors can cover a broad field of applications ranging from production control to security scanners. The outstanding features are the transparency of many materials like textiles, paper and plastics in this frequency region, the good contrast of any humid or dense dielectric material and the capability to employ miniaturized RF systems and small antenna apertures or dielectric probes. A stand-alone-millimetre-wave-imager, SAMMY, was developed and built, to demonstrate the outstanding features of this part of the electromagnetic spectrum for material inspection.

  7. Inspection of Samples using a fast Millimetre Wave Scanner

    Science.gov (United States)

    Hommes, A.; Nüssler, D.; Warok, P.; Krebs, C.; Heinen, S.; Essen, H.

    2011-08-01

    Millimeterwaves and terahertz sensors can cover a broad field of applications ranging from production control to security scanners. The outstanding features are the transparency of many materials like textiles, paper and plastics in this frequency region, the good contrast of any humid or dense dielectric material and the capability to employ miniaturized RF systems and small antenna apertures or dielectric probes. A stand-alone-millimetre-wave-imager, SAMMY, was developed and built, to demonstrate the outstanding features of this part of the electromagnetic spectrum for material inspection.

  8. Optical monitoring of scoliosis by 3D medical laser scanner

    Science.gov (United States)

    Rodríguez-Quiñonez, Julio C.; Sergiyenko, Oleg Yu.; Preciado, Luis C. Basaca; Tyrsa, Vera V.; Gurko, Alexander G.; Podrygalo, Mikhail A.; Lopez, Moises Rivas; Balbuena, Daniel Hernandez

    2014-03-01

    Three dimensional recording of the human body surface or anatomical areas have gained importance in many medical applications. In this paper, our 3D Medical Laser Scanner is presented. It is based on the novel principle of dynamic triangulation. We analyze the method of operation, medical applications, orthopedically diseases as Scoliosis and the most common types of skin to employ the system the most proper way. It is analyzed a group of medical problems related to the application of optical scanning in optimal way. Finally, experiments are conducted to verify the performance of the proposed system and its method uncertainty.

  9. Compact implementation of dynamic receive apodization in ultrasound scanners

    DEFF Research Database (Denmark)

    Tomov, Borislav Gueorguiev; Jensen, Jørgen Arendt

    2004-01-01

    The image quality in medical ultrasound scanners is determined by several factors, one of which is the ability of the receive beamformer to change the aperture weighting function with depth and beam angle. In digital beamformers, precise dynamic apodization can be achieved by representing the fun...... operate at 129.82 MHz and occupies 1.28 million gates. Simulated in Matlab, a 64-channel beamformer provides gray scale image with around 55 dB dynamic range. The beamformed data can also be used for flow estimation....

  10. A new electronic read-out for the YAPPET scanner

    International Nuclear Information System (INIS)

    A small animal PET-SPECT scanner (YAPPET) prototype was built at the Physics Department of the Ferrara University and is presently being used at the Nuclear Medicine Department for radiopharmaceutical studies on rats. The first YAPPET prototype shows very good performances, but needs some improvements before it can be fully used for intensive radiopharmaceutical research. The main problem of the actual prototype is its heavy electronics, based on NIM and CAMAC standard modules. For this reason a new, compact read-out electronics was developed and tested. The results of a first series of tests made on the first prototype will be presented in the paper

  11. Analysis framework for the J-PET scanner

    CERN Document Server

    Krzemień, W; Gruntowski, A; Stola, K; Trybek, D; Bednarski, T; Białas, P; Czerwiński, E; Kamińska, D; Kapłon, L; Kochanowski, A; Korcyl, G; Kowal, J; Kowalski, P; Kozik, T; Kubicz, E; Moskal, P; Niedźwiecki, Sz; Pałka, M; Raczyński, L; Rudy, Z; Salabura, P; Sharma, N G; Silarski, M; Słomski, A; Smyrski, J; Strzelecki, A; Wieczorek, A; Wiślicki, W; Zieliński, M; Zoń, N

    2015-01-01

    J-PET analysis framework is a flexible, lightweight, ROOT-based software package which provides the tools to develop reconstruction and calibration procedures for PET tomography. In this article we present the implementation of the full data-processing chain in the J-PET framework which is used for the data analysis of the J-PET tomography scanner. The Framework incorporates automated handling of PET setup parameters' database as well as high level tools for building data reconstruction procedures. Each of these components is briefly discussed.

  12. Performance evaluation of a high-sensitivity large-aperture small-animal PET scanner. ClairvivoPET

    International Nuclear Information System (INIS)

    In this study, we evaluated the performance of a newly commercialized small-animal positron emission tomography (PET) scanner, ClairvivoPET, which provides significant advantages in spatial resolution, sensitivity, and quantitative accuracy. This scanner consists of depth of interaction detector modules with a large axial extent of 151 mm and an external 137Cs source for attenuation correction. Physical performances, resolution, sensitivity, scatter fraction (SF), counting rate including noise equivalent count (NEC) rate, quantitative accuracy versus activity strength, and transmission accuracy, were measured and evaluated. Animal studies were also performed. Transaxial spatial resolution, measured with a capillary tube, was 1.54 mm at the center and 2.93 mm at a radial offset of 40 mm. The absolute sensitivity was 8.2% at the center, and SFs for mouse- and rat-sized phantoms were 10.7% and 24.2%, respectively. Peak NEC rates for mouse- and rat-sized uniform cylindrical phantoms were 328 kcps at 173 kBq/ml and 119 kcps at 49 kBq/ml, respectively. The quantitative stability of emission counts against activity strength was within 2% over 5 half-lives, ranging from 0.6 MBq to 30 MBq. Transmission measurement based on segmented attenuation correction allowed 6-min and 10-min scans for mouse- and rat-sized cylindrical phantoms, respectively. Rat imaging injected with 18F-NaF resulted in visibility of fine bone structures, and mouse imaging injected with 18F-D-fluoromethyl tyrosine demonstrated the feasibility of using this system to obtain simultaneous time activity curves from separate regions, such as for the heart and tumors. ClairvivoPET is well suited to quantitative imaging even with short scan times, and will provide a number of advantages in new drug development and for kinetic measurement in molecular imaging. (author)

  13. Using compressive sensing to recover images from PET scanners with partial detector rings

    Energy Technology Data Exchange (ETDEWEB)

    Valiollahzadeh, SeyyedMajid, E-mail: sv4@rice.edu [Department of Electrical and Computer Engineering, Rice University, 6100 Main Street, Houston, Texas 77005 and Department of Imaging Physics Unit 1352, The University of Texas MD Anderson Cancer Center, 1515 Holcombe Boulevard, Houston, Texas 77030 (United States); Clark, John W. [Department of Electrical and Computer Engineering, Rice University, 6100 Main Street, Houston, Texas 77005 (United States); Mawlawi, Osama [Department of Imaging Physics Unit 1352, The University of Texas MD Anderson Cancer Center, 1515 Holcombe Boulevard, Houston, Texas 77030 (United States)

    2015-01-15

    from six patient studies were investigated using the same strategy of the phantom study. The recovered images using WTV and TV as well as the partially sampled images from all three experiments were then compared with the fully sampled images (the baseline). Comparisons were done by calculating the mean error (%bias), root mean square error (RMSE), contrast recovery (CR), and SNR of activity concentration in regions of interest drawn in the background as well as the disks, spheres, and lesions. Results: For the simulation study, the mean error, RMSE, and CR for the WTV (TV) recovered images were 0.26% (0.48%), 2.6% (2.9%), 97% (96%), respectively, when compared to baseline. For the partially sampled images, these results were 22.5%, 45.9%, and 64%, respectively. For the simulation study, the average SNR for the baseline was 41.7 while for WTV (TV), recovered image was 44.2 (44.0). The phantom study showed similar trends with 5.4% (18.2%), 15.6% (18.8%), and 78% (60%), respectively, for the WTV (TV) images and 33%, 34.3%, and 69% for the partially sampled images. For the phantom study, the average SNR for the baseline was 14.7 while for WTV (TV) recovered image was 13.7 (11.9). Finally, the average of these values for the six patient studies for the WTV-recovered, TV, and partially sampled images was 1%, 7.2%, 92% and 1.3%, 15.1%, 87%, and 27%, 25.8%, 45%, respectively. Conclusions: CS with WTV is capable of recovering PET images with good quantitative accuracy from partially sampled data. Such an approach can be used to potentially reduce the cost of scanners while maintaining good image quality.

  14. Accuracy evaluation of 3D lidar data from small UAV

    Science.gov (United States)

    Tulldahl, H. M.; Bissmarck, Fredrik; Larsson, Hâkan; Grönwall, Christina; Tolt, Gustav

    2015-10-01

    A UAV (Unmanned Aerial Vehicle) with an integrated lidar can be an efficient system for collection of high-resolution and accurate three-dimensional (3D) data. In this paper we evaluate the accuracy of a system consisting of a lidar sensor on a small UAV. High geometric accuracy in the produced point cloud is a fundamental qualification for detection and recognition of objects in a single-flight dataset as well as for change detection using two or several data collections over the same scene. Our work presented here has two purposes: first to relate the point cloud accuracy to data processing parameters and second, to examine the influence on accuracy from the UAV platform parameters. In our work, the accuracy is numerically quantified as local surface smoothness on planar surfaces, and as distance and relative height accuracy using data from a terrestrial laser scanner as reference. The UAV lidar system used is the Velodyne HDL-32E lidar on a multirotor UAV with a total weight of 7 kg. For processing of data into a geographically referenced point cloud, positioning and orientation of the lidar sensor is based on inertial navigation system (INS) data combined with lidar data. The combination of INS and lidar data is achieved in a dynamic calibration process that minimizes the navigation errors in six degrees of freedom, namely the errors of the absolute position (x, y, z) and the orientation (pitch, roll, yaw) measured by GPS/INS. Our results show that low-cost and light-weight MEMS based (microelectromechanical systems) INS equipment with a dynamic calibration process can obtain significantly improved accuracy compared to processing based solely on INS data.

  15. Comparison of back side chrome focus monitor to focus self-metrology of an immersion scanner

    Science.gov (United States)

    D'havé, Koen; Machida, Takahiro; Laidler, David; Cheng, Shaunee

    2007-03-01

    Monitoring of the focus performance is recognized to be an important part of a periodic scanner health check, but can one simply apply all techniques that have been used for dry scanners to immersion scanners? And if so how do such techniques compare to scanner self-metrology tests that are used to set up the tool? In this paper we look at one specific off-line focus characterization technique, Back Side Chrome (BSC), which we then try to match with results obtained from two self-metrology focus tests, available on the scanner chosen for this work. The latter tests are also used to set up the immersion scanner. We point out a few concerns, discuss their effect and indicate that for each generation of immersion tool one should redo the entire exercise.

  16. INFLUENCE OF PROCESS PARAMETERS ON DIMENSIONAL ACCURACY OF PARTS MANUFACTURED USING FUSED DEPOSITION MODELLING TECHNOLOGY

    Directory of Open Access Journals (Sweden)

    Filip Górski

    2013-09-01

    Full Text Available The paper presents the results of experimental study – part of research of additive technology using thermoplastics as a build material, namely Fused Deposition Modelling (FDM. Aim of the study was to identify the relation between basic parameter of the FDM process – model orientation during manufacturing – and a dimensional accuracy and repeatability of obtained products. A set of samples was prepared – they were manufactured with variable process parameters and they were measured using 3D scanner. Significant differences in accuracy of products of the same geometry, but manufactured with different set of process parameters were observed.

  17. Monte Carlo simulation of efficient data acquisition for an entire-body PET scanner

    Energy Technology Data Exchange (ETDEWEB)

    Isnaini, Ismet; Obi, Takashi [Tokyo Institute of Technology, 4259 Nagatsuta-cho, Midori-ku, Yokohama 226-8503 (Japan); Yoshida, Eiji, E-mail: rush@nirs.go.jp [National Institute of Radiological Sciences, 4-9-1 Inage-ku, Chiba 263-8555 (Japan); Yamaya, Taiga [National Institute of Radiological Sciences, 4-9-1 Inage-ku, Chiba 263-8555 (Japan)

    2014-07-01

    Conventional PET scanners can image the whole body using many bed positions. On the other hand, an entire-body PET scanner with an extended axial FOV, which can trace whole-body uptake images at the same time and improve sensitivity dynamically, has been desired. The entire-body PET scanner would have to process a large amount of data effectively. As a result, the entire-body PET scanner has high dead time at a multiplex detector grouping process. Also, the entire-body PET scanner has many oblique line-of-responses. In this work, we study an efficient data acquisition for the entire-body PET scanner using the Monte Carlo simulation. The simulated entire-body PET scanner based on depth-of-interaction detectors has a 2016-mm axial field-of-view (FOV) and an 80-cm ring diameter. Since the entire-body PET scanner has higher single data loss than a conventional PET scanner at grouping circuits, the NECR of the entire-body PET scanner decreases. But, single data loss is mitigated by separating the axially arranged detector into multiple parts. Our choice of 3 groups of axially-arranged detectors has shown to increase the peak NECR by 41%. An appropriate choice of maximum ring difference (MRD) will also maintain the same high performance of sensitivity and high peak NECR while at the same time reduces the data size. The extremely-oblique line of response for large axial FOV does not contribute much to the performance of the scanner. The total sensitivity with full MRD increased only 15% than that with about half MRD. The peak NECR was saturated at about half MRD. The entire-body PET scanner promises to provide a large axial FOV and to have sufficient performance values without using the full data.

  18. Changes in views on digital intraoral scanners among dental hygienists after training in digital impression taking

    OpenAIRE

    Park, Hye-Ran; Park, Ji-Man; Chun, Youn-Sic; Lee, Kkot-Nim; Kim, Minji

    2015-01-01

    Backgrounds Despite the rapid development of digital dentistry, the use of digital intraoral scanners remains limited. The aim of this study was to evaluate the changes in views on intraoral scanners among dental hygienists after training. Methods Thirty-four dental hygienists with >3 years of clinical experience participated and were divided into 2 groups : iTero and Trios groups. Participants of each group practiced the usage of both intraoral scanners, for total 12 times over 4 sessions, Q...

  19. Measurement of electron density and effective atomic number by dual-energy scan using a 320-detector computed tomography scanner with raw data-based analysis: a phantom study.

    Science.gov (United States)

    Tatsugami, Fuminari; Higaki, Toru; Kiguchi, Masao; Tsushima, So; Taniguchi, Akira; Kaichi, Yoko; Yamagami, Takuji; Awai, Kazuo

    2014-01-01

    We evaluated the accuracy of the electron densities and effective atomic numbers determined by raw data-based dual-energy analysis on a 320-detector computed tomography scanner. The mean (SD) errors between the measured and true electron densities and between the measured and true effective atomic numbers were 1.3% (1.5%) and 3.1% (3.2%), respectively. Electron densities and effective atomic numbers can be determined with high accuracy, which may help to improve accuracy in radiotherapy treatment planning. PMID:24983439

  20. Recording Scan Data in Photographic Colour During Live Time. I. From the Conventional Scanner. II. From a Ten Detector Scanner

    International Nuclear Information System (INIS)

    The authors have developed instruments for scan recording in colour, combining the speed, versatility and silence of the cathode-ray tube, the contrast and latitude of a photographic process, and the rapid development of Polaroid colour film. I. The electron beam of a modified cathode-ray oscilloscope is made to track the motion of the scanner detector. The beam is normally off but is flashed on at each impulse from the scanner analyser. The screen is photographed in colour during a time exposure through a train of colour filters driven back and forth through the lens system of the camera by a servo mechanism controlled by the ratemeter circuit of the scanner. The instrument is calibrated so that the maximum intensity photographs in red. As count- rates decrease, other filters are driven into place to photograph the screen in continuously varying saturated hues of orange, yellow, green, blue and violet. Examples are shown from scans of models and from our 17 000 clinical colour scan library, demonstrating enhanced contrast, extended dynamic range, and quantitative information at a glance. II. More recently, the authors have designed an instrument for recording scan data in colour from a ten detector moving scanner system. As usually employed, the Dynapix presents scan data on the screen of a cathode-ray tube as flashes of varying intensity appearing sequentially in rows and columns at a repetition frequency up to 200/sec, and too rapid for our system previously described. In the new colour version of the instrument, colour filters mounted in a wheel between the lens elements of the camera are driven at a continuous 9 400 rev/min. The electron beam is pulsed by intensity modulated time delay so that an input signal of maximum amplitude delays the flash until red filter is traversing the lens opening. Signals of lesser amplitude are converted to decreasing time delays, resulting in flashes photographing as corresponding hues of orange, through violet. The recording

  1. Irradiation in helical scanner: doses estimation, parameters choice; Irradiation en scanner helicoidal: estimation des doses, choix des parametres

    Energy Technology Data Exchange (ETDEWEB)

    Cordoliani, Y.S.; Boyer, B.; Jouan, E.; Beauvais, H

    2001-07-01

    The new generation of helical scanners improves the diagnosis abilities and the service done to the patients. The rational use allows to give the patients a ratio benefit/risk far better than the almost medical examinations. It is particularly true for over sixty years old aged people, that have a null genetic risk and a practically null carcinogen risk; However, for young adults and children, it is necessary to banish any useless irradiation and limit exposure to the strict necessary for the diagnosis. It is necessary to develop a radiation protection culture, possible by the radiation doses index display and doses benchmarks knowledge. (N.C.)

  2. Operation of the preclinical head scanner for proton CT

    Science.gov (United States)

    Sadrozinski, H. F.-W.; Geoghegan, T.; Harvey, E.; Johnson, R. P.; Plautz, T. E.; Zatserklyaniy, A.; Bashkirov, V.; Hurley, R. F.; Piersimoni, P.; Schulte, R. W.; Karbasi, P.; Schubert, K. E.; Schultze, B.; Giacometti, V.

    2016-09-01

    We report on the operation and performance tests of a preclinical head scanner developed for proton computed tomography (pCT). After extensive preclinical testing, pCT is intended to be employed in support of proton therapy treatment planning and pre-treatment verification in patients undergoing particle-beam therapy. In order to assess the performance of the scanner, we have performed CT scans with 200 MeV protons from both the synchrotron of the Loma Linda University Medical Center (LLUMC) and the cyclotron of the Northwestern Medicine Chicago Proton Center (NMCPC). The very high sustained rate of data acquisition, exceeding one million protons per second, allowed a full 360° scan to be completed in less than 7 min. The reconstruction of various phantoms verified accurate reconstruction of the proton relative stopping power (RSP) and the spatial resolution in a variety of materials. The dose for an image with better than 1% uncertainty in the RSP is found to be close to 1 mGy.

  3. Evaluation of Fingerprint Images Captured by Optical Fingerprint Scanner

    Science.gov (United States)

    Takeuchi, Hideyo; Matsumoto, Noriyuki; Kuwayama, Kiyoaki; Umezaki, Taizo

    In this paper, we propose the way to evaluate fingerprint image-quality and how to discriminate remnants from captured images. First, we investigate evaluating fingerprint image-quality. Fingerprint image-quality can be digitized using the "measure" we proposed. We simulate using the dataset consists of 1425 fingerprint images captured from 57 people in Feb, which contains a lot of faded images. In the simulation using all our database, recognition rate is 95.6% while type II error is 0.01%. Recognition rate is improved to 98.1%, with rejecting 3.7% faded images evaluated by our measure from the database. Recognition rate is improved to 99.6%, rejecting 14.2% faded images. And we investigate the way to apply the measure of image-quality to fingerprint verification device with customer’s satisfaction in real world. Next we propose the way to discriminate between remnants and fingerprint images captured from optical scanner by using frequency analysis. We can perfectly prevent the fingerprint verification device from malfunctioning caused by remnant, when strong flashlight or direct sunlight slant in optical scanner in real world.

  4. An automated breast ultrasound scanner with integrated photoacoustic tomography

    Science.gov (United States)

    Kelly, Corey J.; Moradi, Hamid; Salcudean, Septimiu E.

    2016-03-01

    We have integrated photo-acoustic imaging into an automated breast ultrasound scanner (ABUS) with the goal of simultaneously performing ultrasound (US) and multi-spectral photo-acoustic tomography (PAT). This was accomplished with minimal change to the existing automated scanner by coupling laser light into an optical fiber for flexible and robust light delivery. We present preliminary tomography data acquired with this setup, including a simple resolution-testing geometry and a tissue phantom. Integrating PAT into the ABUS such that breast imaging is possible will require illumination from below the transducer dome. To that end, we are moving towards a fiber-based, localized illumination geometry which is fixed relative to the transducer. By illuminating locally (only near the current acquisition slice), this approach reduces overall light exposure at the tissue surface, allowing higher light intensity per acquisition (which translates to higher absorber contrast), while remaining below safe exposure thresholds. We present time-domain simulations of photo-acoustic imaging under non-uniform illumination conditions, and test one potential weighting scheme which can be used to extract absorber locations.

  5. Calibrated and geocoded clutter from an airborne multispectral scanner

    Science.gov (United States)

    Heuer, Markus; Bruehlmann, Ralph; John, Marc-Andre; Schmid, Konrad J.; Hueppi, Rudolph; Koenig, Reto

    1999-07-01

    Robustness of automatic target recognition (ATR) to varying observation conditions and countermeasures is substantially increased by use of multispectral sensors. Assessment of such ATR systems is performed by captive flight tests and simulations (HWIL or complete modeling). Although the clutter components of a scene can be generated with specified statistics, clutter maps directly obtained from measurement are required for validation of a simulation. In addition, urban scenes have non-stationary characteristics and are difficult to simulate. The present paper describes a scanner, data acquisition and processing system used for the generation of realistic clutter maps incorporating infrared, passive and active millimeter wave channels. The sensors are mounted on a helicopter with coincident line-of-sight, enabling us to measure consistent clutter signatures under varying observation conditions. Position and attitude data from GPS and an inertial measurement unit, respectively, are used to geometrically correct the raw scanner data. After sensor calibration the original voltage signals are converted to physical units, i.e. temperatures and reflectivities, describing the clutter independently of the scanning sensor, thus allowing us the use of the clutter maps in tests of a priori unknown multispectral sensors. The data correction procedures are described and results are presented.

  6. Commissioning of a passive rod scanner at INB

    Energy Technology Data Exchange (ETDEWEB)

    Junqueira, Fabio da Silva; Oliveira, Carlos A.; Palheiros, Franklin, E-mail: carlossilva@inb.gov.br, E-mail: franklin@inb.gov.br [Industrias Nucleares do Brasil (INB), Resende, RJ (Brazil). Superintendencia de Engenharia do Combustivel; Fernandez, Pablo Jesus Piñer, E-mail: pineiro@tecnatom.es [Tecnatom, San Sebastian de los Reyes, Madrid (Spain)

    2015-07-01

    For the 21st reload for Angra 1, a shift from Standard to Advanced fuel design will be introduced, where the fuel assemblies under the new design will contain fuel rods with axial blanket, in line with ELETRONUCLEAR's requirement for a higher energy efficient reactor fuel. Additionally, fuel rods for Angra 2 and 3, using gadolinium type burnable poison, have to be submitted to inspections due to the demand for the same type of inspection, which cannot be certified at INB currently. In keeping with CNEN regulations, every fuel-assembly component must be inspected and certified by a qualified method. Nevertheless, INB lacks the means to perform the certification-required inspection aimed at determining the uranium enrichment and presence of gadolinium pellets inside the closed rods. Hence, the use is necessary of a scanner capable of inspecting differently enriched fuel rods and/or gadolinium pellets (axial blanket). This work aims to present the recent Passive Rod Scanner installed at INB with most advance technology in the area, making possible to completely fulfill Angra 1, 2 and 3 rods inspection at INB Resende site. (author)

  7. Design of a small animal MR compatible PET scanner

    International Nuclear Information System (INIS)

    Using a combination of Monte-Carlo simulations and experimental measurements, the authors have designed a small animal MR compatible PET (McPET) scanner for simultaneous PET and MR imaging of mice and rats in vivo. The scanner consists of one ring of 480 LSO crystals arranged in 3 layers with 160 crystals per layer. The crystal dimensions are 2 x 3 x 7.5 mm3. This was based on a target resolution of 2.5 mm and simulations showing that a depth of 7.5 mm avoided significant depth of interaction effects across the desired field of view. The system diameter of 11.2 cm is large enough to accommodate the animal positioned inside a stereotactic frame. Each crystal will be coupled through 2 mm diameter optical fibers to multi-channel PMT's which reside outside the main magnetic field. Through 50 cm of optical fiber, a photopeak is clearly seen and the measured energy resolution is 25%. Prototype optical fiber connectors have been tested to increase the flexibility of the system and result in a light loss of only 6%. The proposed system will have adequate resolution and sensitivity for a number of applications in small animals and will be the first practical device for simultaneous in vivo imaging with PET and MR

  8. Quality control in computed tomography X-ray scanners

    International Nuclear Information System (INIS)

    Practical methods of estimating computed tomography X-ray scanner imaging performance treat the scanner as a black box, the measurements usually being non-invasive. The performance of individual components or groups of components within the system is not usually measured. The digital nature of the imaging process allows direct numerical assessment of the actual imaging parameters. This approach is used for type and acceptance testing as well as quality control, the type and acceptance tests providing the baseline for subsequent quality control measurements. The usual X-ray imaging parameters of noise, resolution and dose can all be used for quality control purposes, but the relative emphasis between these parameters will differ when compared with type or acceptance testing. Other simple measurements may be of equal use. All manufacturers suggest quality control protocols of varying complexity using a wide range of phantom designs. Where quality control is undertaken routinely, it is usually the manufacturer's protocols that are followed. It is pertinent to ask whether the quality control measurements currently suggested are necessary and/or sufficient. (author)

  9. Ultra-High-Resolution Computed Tomography of the Lung: Image Quality of a Prototype Scanner

    OpenAIRE

    Kakinuma, Ryutaro; Moriyama, Noriyuki; Muramatsu, Yukio; Gomi, Shiho; Suzuki, Masahiro; Nagasawa, Hirobumi; Kusumoto, Masahiko; Aso, Tomohiko; Muramatsu, Yoshihisa; Tsuchida, Takaaki; Tsuta, Koji; Maeshima, Akiko Miyagi; Tochigi, Naobumi; Watanabe, Shun-ichi; SUGIHARA, Naoki

    2015-01-01

    Purpose: The image noise and image quality of a prototype ultra-high-resolution computed tomography (U-HRCT) scanner was evaluated and compared with those of conventional high-resolution CT (C-HRCT) scanners. Materials and Methods: This study was approved by the institutional review board. A U-HRCT scanner prototype with 0.25 mm × 4 rows and operating at 120 mAs was used. The C-HRCT images were obtained using a 0.5 mm × 16 or 0.5 mm × 64 detector-row CT scanner operating at 150 mAs. Images fr...

  10. Ultra-High-Resolution Computed Tomography of the Lung: Image Quality of a Prototype Scanner

    OpenAIRE

    Ryutaro Kakinuma; Noriyuki Moriyama; Yukio Muramatsu; Shiho Gomi; Masahiro Suzuki; Hirobumi Nagasawa; Masahiko Kusumoto; Tomohiko Aso; Yoshihisa Muramatsu; Takaaki Tsuchida; Koji Tsuta; Akiko Miyagi Maeshima; Naobumi Tochigi; Shun-Ichi Watanabe; Naoki Sugihara

    2015-01-01

    Purpose The image noise and image quality of a prototype ultra-high-resolution computed tomography (U-HRCT) scanner was evaluated and compared with those of conventional high-resolution CT (C-HRCT) scanners. Materials and Methods This study was approved by the institutional review board. A U-HRCT scanner prototype with 0.25 mm x 4 rows and operating at 120 mAs was used. The C-HRCT images were obtained using a 0.5 mm x 16 or 0.5 mm x 64 detector-row CT scanner operating at 150 mAs. Images from...

  11. Research regarding the influence of driving-wires length change on positioning precision of a robotic arm

    Science.gov (United States)

    Ciofu, C.; Stan, G.

    2016-08-01

    The paper emphasise positioning precision of an elephant's trunk robotic arm which has joints driven by wires with variable length while operating The considered 5 degrees of freedom robotic arm has a particular structure of joint that makes possible inner actuation with wire-driven mechanism. We analyse solely the length change of wires as a consequence due inner winding and unwinding on joints for certain values of rotational angles. Variations in wires length entail joint angular displacements. We analyse positioning precision by taking into consideration equations from inverse kinematics of the elephant's trunk robotic arm. The angular displacements of joints are considered into computational method after partial derivation of positioning equations. We obtain variations of wires length at about tenths of micrometers. These variations employ angular displacements which are about minutes of sexagesimal degree and, thus, define positioning precision of elephant's trunk robotic arms. The analytical method is used for determining aftermath design structure of an elephant's trunk robotic arm with inner actuation through wires on positioning precision. Thus, designers could take suitable decisions on accuracy specifications limits of the robotic arm.

  12. Assembly for activity distribution measurement of wires

    International Nuclear Information System (INIS)

    Activation method is used as a basic method for the neutron fluence measurement in the LVR-15 research reactor. Activation foils have usually been used as the monitors. At present an assembly for the measurement of linear specific activity distribution of wires has been developed. The assembly allows the activation wires to be used for neutron fluence measurement mainly in the reactor core. More detailed results of linear distribution and simpler handling with radioactive material are the advantages of activation wires compared with foils. More difficult calibration and processing of measured data are disadvantages on the other hand. The assembly consists of a spectrometer with HPGe detector for gamma activity measurement, a Pb shielding collimator around the detector, an outer Pb shielding, a transporting equipment and a controlling PC. The diameter of the collimator is 20 mm. The wire from Cu, Fe, Ni or Co material with diameter of 0.3 mm to 1.0 mm is placed on a support Al stick with diameter of 6 mm. After irradiation the stick with the wire is placed in the transporting equipment above the Pb shielding collimator and measured. Response function for the point radiation source on the line, where the wire is placed during the measurement, is the main characteristic of the assembly. The response function also depends on the energy of gamma radiation. The design of the Pb shielding collimator is described and the measured response functions for a few point radiation sources are given in the paper. During the measurement the stick with the wire moves above the collimator aperture and the peak count rates depending on position of wire with step of 10 mm to 50 mm are measured. As the response function for point source has not the ideal rectangular distribution (i.e. constant positive value above the collimator aperture and zero value for points out of the aperture) the evaluation of activities is not so simple as for measurement of individual samples. In the paper the

  13. High Accuracy, Two-Dimensional Read-Out in Multiwire Proportional Chambers

    Science.gov (United States)

    Charpak, G.; Sauli, F.

    1973-02-14

    In most applications of proportional chambers, especially in high-energy physics, separate chambers are used for measuring different coordinates. In general one coordinate is obtained by recording the pulses from the anode wires around which avalanches have grown. Several methods have been imagined for obtaining the position of an avalanche along a wire. In this article a method is proposed which leads to the same range of accuracies and may be preferred in some cases. The problem of accurate measurements for large-size chamber is also discussed.

  14. Forgotten Kirschner Wire Causing Severe Hematuria

    Directory of Open Access Journals (Sweden)

    Santosh Kumar

    2014-01-01

    Full Text Available Kirschner wire (K-wire is commonly used in the treatment of hip fracture and its migration into pelvis leading to bladder injury is a very rare complication. Nonremoval of these devices either because of lack of followup or because of prolonged requirement due to disease process is associated with this complication. We report a case of a patient who presented with acute onset severe hematuria with clot retention secondary to perforation of bladder by a migrated K-wire placed earlier, for the treatment of hip fracture. Initial imaging showed its presence in the soft tissues of the pelvis away from the major vascular structures. Patient was taken for emergency laparotomy and wire was removed after cystotomy. Postoperative period was uneventful and patient was discharged in satisfactory condition. K-wires are commonly used in the management of fracture bones and their migration has been reported in the literature although such migration in the intrapelvic region involving bladder is very rare. Early diagnosis and prompt removal of such foreign bodies are required to avert potentially fatal involvement of major structures.

  15. EVALUATION OF INDUCTANCE WITH ELECTRICAL WIRES

    Directory of Open Access Journals (Sweden)

    V. Kudry

    2016-08-01

    Full Text Available In this paper proved the possibility of developing passive electronic inductive elements based replace metal wire that is wound inductor, the wire is made of electret. The relative permeability of the electret S  10 000, several orders of magnitude greater than the permeability of conventional insulation materials, i < 10, resulting current in the wire acquires properties bias current. The essence of innovation is to replace the source of of magnetic induction flow that pervades the core of the coil. According to the theory of electrodynamics, current bias, in contrast to conduction current, generated no movement of charge along the wire, but the change of the charge in the local volume.Equivalence bias current and conduction current is manifested in the possibility of forming a magnetic field. The flow through magnetic induction coil core regardless of the current it generates, creates voltage at its ends.The paper also shows the numeric characteristics that determine the effective frequency range, specified the reason why electric a wire with і < 10 can not generate magnetic flux through the core and serve as a passive reactive component.

  16. Optimal welding of beta titanium orthodontic wires.

    Science.gov (United States)

    Nelson, K R; Burstone, C J; Goldberg, A J

    1987-09-01

    Today the orthodontist is confronted by an array of new orthodontic wire materials that, when applied to appliance design, can vastly increase the flexibility and versatility of therapy. Welded joints, especially for the newer titanium alloy wires, provide a means to extend the useful applications of these materials. The purpose of this study was to determine the optimum settings for electrical resistance welding of various configurations of titanium-molybdenum (TMA) wires. Specimens were of a t-joint configuration and were mechanically tested in torsion to simulate the failure mode most often observed in clinical practice. Variables included wire size, wire orientation, and welding voltage. Results indicated that excellent welds can be obtained with very little loss of strength and ductility in the area of the weld joint. Torsional loads at failure were at least 90% of the unwelded base material. Although a wide range of voltage settings resulted in high-strength welds, typically a narrow range of voltages yielded optimal ductility.

  17. Reticence, Accuracy and Efficacy

    Science.gov (United States)

    Oreskes, N.; Lewandowsky, S.

    2015-12-01

    James Hansen has cautioned the scientific community against "reticence," by which he means a reluctance to speak in public about the threat of climate change. This may contribute to social inaction, with the result that society fails to respond appropriately to threats that are well understood scientifically. Against this, others have warned against the dangers of "crying wolf," suggesting that reticence protects scientific credibility. We argue that both these positions are missing an important point: that reticence is not only a matter of style but also of substance. In previous work, Bysse et al. (2013) showed that scientific projections of key indicators of climate change have been skewed towards the low end of actual events, suggesting a bias in scientific work. More recently, we have shown that scientific efforts to be responsive to contrarian challenges have led scientists to adopt the terminology of a "pause" or "hiatus" in climate warming, despite the lack of evidence to support such a conclusion (Lewandowsky et al., 2015a. 2015b). In the former case, scientific conservatism has led to under-estimation of climate related changes. In the latter case, the use of misleading terminology has perpetuated scientific misunderstanding and hindered effective communication. Scientific communication should embody two equally important goals: 1) accuracy in communicating scientific information and 2) efficacy in expressing what that information means. Scientists should strive to be neither conservative nor adventurous but to be accurate, and to communicate that accurate information effectively.

  18. Obstacle negotiation control for a mobile robot suspended on overhead ground wires by optoelectronic sensors

    Science.gov (United States)

    Zheng, Li; Yi, Ruan

    2009-11-01

    Power line inspection and maintenance already benefit from developments in mobile robotics. This paper presents mobile robots capable of crossing obstacles on overhead ground wires. A teleoperated robot realizes inspection and maintenance tasks on power transmission line equipment. The inspection robot is driven by 11 motor with two arms, two wheels and two claws. The inspection robot is designed to realize the function of observation, grasp, walk, rolling, turn, rise, and decline. This paper is oriented toward 100% reliable obstacle detection and identification, and sensor fusion to increase the autonomy level. An embedded computer based on PC/104 bus is chosen as the core of control system. Visible light camera and thermal infrared Camera are both installed in a programmable pan-and-tilt camera (PPTC) unit. High-quality visual feedback rapidly becomes crucial for human-in-the-loop control and effective teleoperation. The communication system between the robot and the ground station is based on Mesh wireless networks by 700 MHz bands. An expert system programmed with Visual C++ is developed to implement the automatic control. Optoelectronic laser sensors and laser range scanner were installed in robot for obstacle-navigation control to grasp the overhead ground wires. A novel prototype with careful considerations on mobility was designed to inspect the 500KV power transmission lines. Results of experiments demonstrate that the robot can be applied to execute the navigation and inspection tasks.

  19. Testing the Suitability of a Terrestrial 2D LiDAR Scanner for Canopy Characterization of Greenhouse Tomato Crops.

    Science.gov (United States)

    Llop, Jordi; Gil, Emilio; Llorens, Jordi; Miranda-Fuentes, Antonio; Gallart, Montserrat

    2016-01-01

    Canopy characterization is essential for pesticide dosage adjustment according to vegetation volume and density. It is especially important for fresh exportable vegetables like greenhouse tomatoes. These plants are thin and tall and are planted in pairs, which makes their characterization with electronic methods difficult. Therefore, the accuracy of the terrestrial 2D LiDAR sensor is evaluated for determining canopy parameters related to volume and density and established useful correlations between manual and electronic parameters for leaf area estimation. Experiments were performed in three commercial tomato greenhouses with a paired plantation system. In the electronic characterization, a LiDAR sensor scanned the plant pairs from both sides. The canopy height, canopy width, canopy volume, and leaf area were obtained. From these, other important parameters were calculated, like the tree row volume, leaf wall area, leaf area index, and leaf area density. Manual measurements were found to overestimate the parameters compared with the LiDAR sensor. The canopy volume estimated with the scanner was found to be reliable for estimating the canopy height, volume, and density. Moreover, the LiDAR scanner could assess the high variability in canopy density along rows and hence is an important tool for generating canopy maps. PMID:27608025

  20. An effective scatter correction method based on single scatter simulation for a 3D whole-body PET scanner

    Institute of Scientific and Technical Information of China (English)

    Gao Fei; Yamada Ryoko; Watanabe Mitsuo; Liu Hua-Feng

    2009-01-01

    Hamamatsu SHR74000 is a newly designed full three-dimensional(3D)whole body positron emission tomography (PET)scanner with small crystal size and large field of view(FOV).With the improvement of sensitivity,the scatter events increase significantly at the same time,especially for large objects.Monte Carlo simulations help US to understand the scatter phenomena and provide good references for scatter correction.In this paper,we introduce an effective scatter correction method based on single scatter simulation for the new PET scanner,which accounts for the full 3D scatter correction.With the results from Monte Carlo simulations,we implement a new scale method with special concentration on scatter events from outside the axial FOV and multiple scatter events.The effects of scatter correction are investigated and evaluated by phantom experiments;the results show good improvements in quantitative accuracy and contrast of the images,even for large objects.

  1. Degradation of the z- resolution due to a longitudinal motion with a 64-channel CT scanner.

    Science.gov (United States)

    Grosjean, Romain; Sauer, Benoît; Guerra, Rui Matias; Blum, Alain; Felblinger, Jacques; Hubert, Jacques

    2007-01-01

    Isotropic acquisitions are routinely achievable with 64- channel CT scanners,. As it predecessors, it includes MultiPlanar Reformation (MPR) projection for the reconstruction of two-dimensional images and volume rendering for the creation of three dimensional images. The accuracy of images obtained with these postprocessing methods depends on the spatial resolution of image data acquired along the long axis of the patient (ie longitudinal, or z-inis spatial resolution). But physiologic motions can appear during a Computed Tomography (CT) exam and can leacd to a degradation of this spatial resolution. By using two different phantoms and a dynamic platform, we have studied the influence of a z-axis linear motion on the MPR images quality. Our results show that the corruption of the data results in the loss of information about the form, the contrast and/or the size of the scanned object. This corruption of data can lead to diagnostic errors by mimicking diseases or by masking physiologic details. PMID:18002987

  2. Degradation of the z- resolution due to a longitudinal motion with a 64-channel CT scanner.

    Science.gov (United States)

    Grosjean, Romain; Sauer, Benoît; Guerra, Rui Matias; Blum, Alain; Felblinger, Jacques; Hubert, Jacques

    2007-01-01

    Isotropic acquisitions are routinely achievable with 64- channel CT scanners,. As it predecessors, it includes MultiPlanar Reformation (MPR) projection for the reconstruction of two-dimensional images and volume rendering for the creation of three dimensional images. The accuracy of images obtained with these postprocessing methods depends on the spatial resolution of image data acquired along the long axis of the patient (ie longitudinal, or z-inis spatial resolution). But physiologic motions can appear during a Computed Tomography (CT) exam and can leacd to a degradation of this spatial resolution. By using two different phantoms and a dynamic platform, we have studied the influence of a z-axis linear motion on the MPR images quality. Our results show that the corruption of the data results in the loss of information about the form, the contrast and/or the size of the scanned object. This corruption of data can lead to diagnostic errors by mimicking diseases or by masking physiologic details.

  3. Optimization of Brain T2 Mapping Using Standard CPMG Sequence In A Clinical Scanner

    Science.gov (United States)

    Hnilicová, P.; Bittšanský, M.; Dobrota, D.

    2014-04-01

    In magnetic resonance imaging, transverse relaxation time (T2) mapping is a useful quantitative tool enabling enhanced diagnostics of many brain pathologies. The aim of our study was to test the influence of different sequence parameters on calculated T2 values, including multi-slice measurements, slice position, interslice gap, echo spacing, and pulse duration. Measurements were performed using standard multi-slice multi-echo CPMG imaging sequence on a 1.5 Tesla routine whole body MR scanner. We used multiple phantoms with different agarose concentrations (0 % to 4 %) and verified the results on a healthy volunteer. It appeared that neither the pulse duration, the size of interslice gap nor the slice shift had any impact on the T2. The measurement accuracy was increased with shorter echo spacing. Standard multi-slice multi-echo CPMG protocol with the shortest echo spacing, also the smallest available interslice gap (100 % of slice thickness) and shorter pulse duration was found to be optimal and reliable for calculating T2 maps in the human brain.

  4. A portable intra-oral scanner based on sinusoidal pattern of fast phase-shifting

    Science.gov (United States)

    Jan, Chia-Ming; Lin, Ying-Chieh

    2016-03-01

    This paper presented our current research about the intra-oral scanner made by MIRDC. Utilizing the sinusoidal pattern for fast phase-shifting technique to deal with 3D digitalization of human dental surface profile, the development of pseudo-phase shifting digital projection can easily achieve one type of full-field scanning instead of the common technique of the laser line scanning. Based on traditional Moiré method, we adopt projecting fringes and retrieve phase reconstruction to forward phase unwrapping. The phase difference between the plane and object can be exactly calculated from the desired fringe images, and the surface profile of object was probably reconstructed by using the phase differences information directly. According to our algorithm of space mapping between projections and capturing orientation exchange of our intra-oral scanning configuration, the system we made certainly can be proved to achieve the required accuracy of +/-10μm to deal with intra-oral scanning on the basis of utilizing active triangulation method. The final purpose aimed to the scanning of object surface profile with its size about 10x10x10mm3.

  5. Optimizing resistance of round hollow wire at high frequency

    Institute of Scientific and Technical Information of China (English)

    FENG Yong-jian; ZHANG Tao

    2003-01-01

    The results and methods of calculation of resistance of hollow wire in gigahertz range by Bessel function are given. According to the results of computation, it is found that the resistor of conductor can be optimized using hollow wire with specific wall thickness. At high frequency the current distribution across a circular hollow wire is at surface of wire, which is called skin depth. We found that optimum wall thickness is proportional to skin depth and the phase abrupt change point of H field. Theoretical analysis and mechanism optimized round hollow wire will be presented in this paper. The calculation indicates that cylindrical hollow wire can be optimized to decrease resistance above 8%.

  6. Optimization of the Single Staggered Wire and Tube Heat Exchanger

    OpenAIRE

    Arsana I Made; Susianto; Budhikarjono Kusno; Altway Ali

    2016-01-01

    Wire and tube heat exchanger consists of a coiled tube, and wire is welded on the two sides of it in normal direction of the tube. Generally,wire and tube heat exchanger uses inline wire arrangement between the two sides, whereas in this study, it used staggered wire arrangement that reduces the restriction of convection heat transfer. This study performed the optimization of single staggered wire and tube heat exchanger to increase the capacity and reduce the mass of the heat exchanger. Opti...

  7. Rapid Real-Time SpaceWire Emulation

    Science.gov (United States)

    Mudie, Stephen; Parkes, Steve; Dunstan, Martin

    2015-09-01

    The SpaceWire Electronic Ground Support Equipment (EGSE) test and development unit from STAR-Dundee can be used to very rapidly emulate real-time behaviour of SpaceWire equipment. The behaviour of the equipment to emulate is described in a script using a SpaceWire specific scripting language. Once configured the SpaceWire EGSE unit operates independent of software. This paper describes three camera emulation scripts to demonstrate the rapid real-time SpaceWire emulation possible using the SpaceWire EGSE.

  8. Emulating Wired Backhaul with Wireless Network Coding

    DEFF Research Database (Denmark)

    Thomsen, Henning; De Carvalho, Elisabeth; Popovski, Petar

    2014-01-01

    In this paper we address the need for wireless network densification. We propose a solution wherein the wired backhaul employed in heterogeneous cellular networks is replaced with wireless links, while maintaining the rate requirements of the uplink and downlink traffic of each user. The first...... component of our solution consists of a two-way, two-phase communication between the macro base station and a user in a small cell through the small cell base station. The second component consists of an optimized adjustment of the transmit power from the macro base station during the multiple access phase......, the uplink traffic to the user, remains identical to the one performed in a wired system. In the broadcast phase, the decoding of the downlink traffic can also be guaranteed to remain identical. Hence, our solution claims an emulation of a wired backhaul with wireless network coding with same performance. We...

  9. Induced voltage in an open wire

    CERN Document Server

    Morawetz, K; Trupp, A

    2015-01-01

    A puzzle arising from Faraday's law is considered and solved concerning the question which voltage is induced in an open wire feeling a time-varying homogeneous magnetic field. The longitudinal electric field contributes 1/3 and the transverse field 2/3 to the induced voltage. The representation of a homogeneous and time-varying magnetic field implies unavoidably a certain symmetry point or line dependent on the geometry of the source. As a consequence the induced voltage of an open wire is found to be the area covered with respect to the symmetry line or point perpendicular to the magnetic field. This in turn allows to find the symmetry points of a magnetic field source by measuring the voltage of an open wire. We present two exactly solvable models for a symmetry point and for a symmetry line. The results are applicable to open circuit problems and for astrophysical applications.

  10. Reusable Hot-Wire Cable Cutter

    Science.gov (United States)

    Pauken, Michael T.; Steinkraus, Joel M.

    2010-01-01

    During the early development stage of balloon deployment systems for missions, nichrome wire cable cutters were often used in place of pyro-actuated cutters. Typically, a nichrome wire is wrapped around a bundle of polymer cables with a low melting point and connected to a relay-actuated electric circuit. The heat from the nichrome reduces the strength of the cable bundle, which quickly breaks under a mechanical load and can thus be used as a release mechanism for a deployment system. However, the use of hand-made heated nichrome wire for cutters is not very reliable. Often, the wrapped nichrome wire does not cut through the cable because it either pulls away from its power source or does not stay in contact with the cable being cut. Because nichrome is not readily soldered to copper wire, unreliable mechanical crimps are often made to connect the nichrome to an electric circuit. A self-contained device that is reusable and reliable was developed to sever cables for device release or deployment. The nichrome wire in this new device is housed within an enclosure to prevent it from being damaged by handling. The electric power leads are internally connected within the unit to the nichrome wire using a screw terminal connection. A bayonet plug, a quick and secure method of connecting the cutter to the power source, is used to connect the cutter to the power leads similar to those used in pyro-cutter devices. A small ceramic tube [0.25-in. wide 0.5-in. long (.6.4-mm wide 13-mm long)] houses a spiraled nichrome wire that is heated when a cable release action is required. The wire is formed into a spiral coil by wrapping it around a mandrel. It is then laid inside the ceramic tube so that it fits closely to the inner surface of the tube. The ceramic tube provides some thermal and electrical insulation so that most of the heat generated by the wire is directed toward the cable bundle in the center of the spiral. The ceramic tube is cemented into an aluminum block, which

  11. Ultrasonic Welding of Wires and Cables

    Science.gov (United States)

    Heinz, Stefan; Wagner, Guntram; Eifler, Dietmar

    2012-03-01

    In the automobile industry, ultrasonic metal welding is an established method. At the Institute of Materials Science and Engineering (WKK) at the University of Kaiserslautern, Germany, systematic investigations of the weldability of Al-wires and flat flexible copper cables were carried out. In the case of Al-wires, joints with cross-sectional area of up to 80 mm2 and tensile shear load of about 3500 N were finally realized. Furthermore, methods to reduce unintentional adherence between the sonotrode coupling face and the Al-wires were developed. To realize FFC joints, ultrasonic spot welding systems and ultrasonic torsion welding systems were used. A central purpose of these investigations is the development of a system to enable welding through the insulation of the FFC without weakening the base material.

  12. Accuracy assessment of a mobile terrestrial lidar survey at Padre Island National Seashore

    Science.gov (United States)

    Lim, Samsung; Thatcher, Cindy A.; Brock, John C.; Kimbrow, Dustin R.; Danielson, Jeffrey J.; Reynolds, B.J.

    2013-01-01

    The higher point density and mobility of terrestrial laser scanning (light detection and ranging (lidar)) is desired when extremely detailed elevation data are needed for mapping vertically orientated complex features such as levees, dunes, and cliffs, or when highly accurate data are needed for monitoring geomorphic changes. Mobile terrestrial lidar scanners have the capability for rapid data collection on a larger spatial scale compared with tripod-based terrestrial lidar, but few studies have examined the accuracy of this relatively new mapping technology. For this reason, we conducted a field test at Padre Island National Seashore of a mobile lidar scanner mounted on a sport utility vehicle and integrated with a position and orientation system. The purpose of the study was to assess the vertical and horizontal accuracy of data collected by the mobile terrestrial lidar system, which is georeferenced to the Universal Transverse Mercator coordinate system and the North American Vertical Datum of 1988. To accomplish the study objectives, independent elevation data were collected by conducting a high-accuracy global positioning system survey to establish the coordinates and elevations of 12 targets spaced throughout the 12 km transect. These independent ground control data were compared to the lidar scanner-derived elevations to quantify the accuracy of the mobile lidar system. The performance of the mobile lidar system was also tested at various vehicle speeds and scan density settings (e.g. field of view and linear point spacing) to estimate the optimal parameters for desired point density. After adjustment of the lever arm parameters, the final point cloud accuracy was 0.060 m (east), 0.095 m (north), and 0.053 m (height). The very high density of the resulting point cloud was sufficient to map fine-scale topographic features, such as the complex shape of the sand dunes.

  13. Temperature effect on DNA molecular wires

    Science.gov (United States)

    Bui, Christopher Minh

    The demand of technology and information today has further pushed the fabrication process of nanotechnology, yet there are limits and obstacles set by the primary laws of physics. Therefore, researchers are pursuing alternative technologies. Deoxyribonucleic acids (DNA) molecular wire is one advantageous option due to its unique characteristics including self-assembly and naturally small; size. This thesis reports the temperature effect on the electrical properties of a double-stranded ?-DNA molecular wire. The data will help expand the DNA wire application and functionality. Thus, the data supports the charge hopping theory on DNA electrical conductivity. Diverse amount of literatures has demonstrated that DNA experiences a biochemical alteration when exposed under different temperature conditions. This change will also cause a change in the electrical properties. In this research, DNA will hang between two gold covered microelectrodes with a distance of 10 to 12 microns. The microelectrodes are fabricated through negative lithography techniques. Then, the samples were exposed to a numerous range of temperature from 25°C to 180°C and went through varying cycles of heating and cooling. The experimental results revealed that the DNA experienced a hysteresis like behavior where the impedance differed between the heating and cooling phase. The impedance of the DNA molecular wire increased when exposed to higher temperature. Furthermore, the impedance stops increasing after a certain amount of heat cycles before the DNA structure failed. The biology and thermodynamics of the DNA wire was analyzed due to the temperature hysteresis effect. The melting temperature and the bond dissociation temperature were evaluated to determine the cause of the impedance trends. The studies and analysis of the temperature effect provided certain insights towards the charge hopping transport mechanism. The thesis concludes with possible applications relating to the temperature effect of

  14. Ultra-High-Resolution Computed Tomography of the Lung: Image Quality of a Prototype Scanner.

    Directory of Open Access Journals (Sweden)

    Ryutaro Kakinuma

    Full Text Available The image noise and image quality of a prototype ultra-high-resolution computed tomography (U-HRCT scanner was evaluated and compared with those of conventional high-resolution CT (C-HRCT scanners.This study was approved by the institutional review board. A U-HRCT scanner prototype with 0.25 mm x 4 rows and operating at 120 mAs was used. The C-HRCT images were obtained using a 0.5 mm x 16 or 0.5 mm x 64 detector-row CT scanner operating at 150 mAs. Images from both scanners were reconstructed at 0.1-mm intervals; the slice thickness was 0.25 mm for the U-HRCT scanner and 0.5 mm for the C-HRCT scanners. For both scanners, the display field of view was 80 mm. The image noise of each scanner was evaluated using a phantom. U-HRCT and C-HRCT images of 53 images selected from 37 lung nodules were then observed and graded using a 5-point score by 10 board-certified thoracic radiologists. The images were presented to the observers randomly and in a blinded manner.The image noise for U-HRCT (100.87 ± 0.51 Hounsfield units [HU] was greater than that for C-HRCT (40.41 ± 0.52 HU; P < .0001. The image quality of U-HRCT was graded as superior to that of C-HRCT (P < .0001 for all of the following parameters that were examined: margins of subsolid and solid nodules, edges of solid components and pulmonary vessels in subsolid nodules, air bronchograms, pleural indentations, margins of pulmonary vessels, edges of bronchi, and interlobar fissures.Despite a larger image noise, the prototype U-HRCT scanner had a significantly better image quality than the C-HRCT scanners.

  15. Vegetated landslide monitoring: target tracking with terrestrial laser scanner

    Science.gov (United States)

    Franz, Martin; Carrea, Dario; Abellan, Antonio; Derron, Marc-Henri; Jaboyedoff, Michel

    2013-04-01

    Monitoring landslides with terrestrial LiDAR is currently a well-known technique. One problem often encountered is the vegetation that produces shadow areas on the scans. Indeed, the points behind the obstacle are hidden and are absent from the point cloud. Thereby, locations monitored with terrestrial laser scanner are mostly rock instabilities and few vegetated landslides, being difficult or even impossible to survey vegetated slopes using this method. The Peney landslide (Geneva, Switzerland) is partially vegetated by bushes and trees, and in order to monitor its displacements during the drawdown of the Verbois reservoir located at its base, which activates the movement, an alternative solution has to be found. The Goal of this study are: (1) to illustrate a technique to monitor vegetated landslides with a terrestrial laser scanner and (2) to compare the both manual and automatic methods for displacement vectors extraction. We installed 14 targets, four of which are in stable areas which are considered as references. Targets are made of expanded polystyrene, two are spherical and 12 are cubic. They were installed on metallic poles ranging between 2 to 4 meters high. The LiDAR device was located on a fixed point on a pontoon on the reservoir opposite bank. The whole area, including the targets, needed three scans to be entirely covered and was scanned 10 times along on two weeks (duration of drawdown - filling). The acquired point clouds were cleaned and georeferenced. In order to determine the displacements for every target, two methods (manual and automatic) were used. The manual method consists on manual selection of, for example, the apex of the cubes, and so to have its 3D coordinates for a comparison in time. The automatic method uses an algorithm that recognises shapes trough time series. The obtained displacements were compared with classical measurement methods (theodolite and extensometer) showing good resemblance of results, indicating the validity of

  16. Construction and accuracy assessment of patient-specific biocompatible drill template for cervical anterior transpedicular screw (ATPS insertion: an in vitro study.

    Directory of Open Access Journals (Sweden)

    Maoqing Fu

    Full Text Available BACKGROUND: With the properties of three-column fixation and anterior-approach-only procedure, anterior transpedicular screw (ATPS is ideal for severe multilevel traumatic cervical instabilities. However, the accurate insertion of ATPS remains challenging. Here we constructed a patient-specific biocompatible drill template and evaluated its accuracy in assisting ATPS insertion. METHODS: After ethical approval, 24 formalin-preserved cervical vertebrae (C2-C7 were CT scanned. 3D reconstruction models of cervical vertebra were obtained with 2-mm-diameter virtual pin tracts at the central pedicles. The 3D models were used for rapid prototyping (RP printing. A 2-mm-diameter Kirschner wire was then inserted into the pin tract of the RP model before polymethylmethacrylate was used to construct the patient-specific biocompatible drill template. After removal of the anterior soft tissue, a 2-mm-diameter Kirschner wire was inserted into the cervical pedicle with the assistance of drill template. Cadaveric cervical spines with pin tracts were subsequently scanned using the same CT scanner. A 3D reconstruction was performed of the scanned spines to get 3D models of the vertebrae containing the actual pin tracts. The deviations were calculated between 3D models with virtual and actual pin tracts at the middle point of the cervical pedicle. 3D models of 3.5 mm-diameter screws were used in simulated insertion to grade the screw positions. FINDINGS: The patient-specific biocompatible drill template was constructed to assist ATPS insertion successfully. There were no significant differences between medial/lateral deviations (P = 0.797 or between superior/inferior deviations (P = 0.741. The absolute deviation values were 0.82±0.75 mm and 1.10±0.96 mm in axial and sagittal planes, respectively. In the simulated insertion, the screws in non-critical position were 44/48 (91.7%. CONCLUSIONS: The patient-specific drill template is biocompatible, easy

  17. Physarum wires: Self-growing self-repairing smart wires made from slime mould

    CERN Document Server

    Adamatzky, Andrew

    2013-01-01

    We report experimental laboratory studies on developing conductive pathways, or wires, using protoplasmic tubes of plasmodium of acellular slime mould Physarum polycephalum. Given two pins to be connected by a wire, we place a piece of slime mould on one pin and an attractant on another pin. Physarum propagates towards the attract and thus connects the pins with a protoplasmic tube. A protoplasmic tube is conductive, can survive substantial over-voltage and can be used to transfer electrical current to lightning and actuating devices. In experiments we show how to route Physarum wires with chemoattractants and electrical fields. We demonstrate that Physarum wire can be grown on almost bare breadboards and on top of electronic circuits. The Physarum wires can be insulated with a silicon oil without loss of functionality. We show that a Physarum wire self-heals: end of a cut wire merge together and restore the conductive pathway in several hours after being cut. Results presented will be used in future designs ...

  18. Development of the Axial Instability in Low Wire Number Wire Array Z-Pinches

    Science.gov (United States)

    Knapp, P. F.; Bell, K. S.; Blesener, I. C.; Chalenski, D. A.; Greenly, J. B.; Martin, M. R.; McBride, R. D.; Pikuz, S. A.; Shelkovenko, T. A.; Hammer, D. A.; Kusse, B. R.

    2008-11-01

    We are investigating the development of the axial instability that occurs on wires in wire-array Z-pinches, which manifests itself as a modulation of the size of the coronal plasma. The modulation is evidently a result of non-uniform ablation of material from the wire core. It is known that the wavelength of this modulation reaches a constant as the pinch develops that is a strong function of the material and little else, thus it is known as the fundamental mode. In these experiments we have been imaging individual wires with laser shadowgraphy primarily in low wire number, large wire diameter arrays made with Al, Cu, Ag and other wires. We document the development of this modulation from the beginning of plasma formation and show the wavelength and amplitude growth as a function of time. The magnetic field is also measured using B-dot probes inside the array. The change from a closed to an open field topology and its relation to the instability growth will be discussed.This research was supported by the Stewardship Sciences Academic Alliances program of the National Nuclear Security Administration under DOE Cooperative agreement DE-FC03-02NA00057 and by Sandia National Laboratories contract AO258.

  19. Percutaneous K-wire fixation of distal radius fractures: Our results of leaving the wire outside

    Directory of Open Access Journals (Sweden)

    K T Madhukar

    2013-01-01

    Full Text Available Background: Distal radius fracture is one of the common injuries seen in casualty often managed by closed reduction and percutaneous pinning. Aim: The purpose of this prospective study is to determine the incidence of infection following percutaneous wire fixation of distal radius fractures and it′s bearing on the outcome in the management of distal radius fractures. Materials and Methods: We studied eighty-eight cases of closed distal end radius fractures managed with closed reduction and percutaneous Kirschner wires (K-wires fixation with splinting for pintract infection. Results: Out of the 88 cases included in the study, 14 cases had pintract infections that were mild to moderate in nature. In 6 cases of early K-wire removal due to pintract infection, shortening of radius, malunion, reduced finger grip and poor functional outcome was noticed. Pintract infections resulted in extended hospital stay, early pin removal, decreased functional outcome, malunion of distal radius and requirement of second surgery to correct the deformity and to improve functional outcome. However, percutaneous K-wire fixation with keeping the wire outside has been advocated and routinely performed, though incidence of pintract infection and complications arising from early removal of K-wires cannot be ignored. Conclusion: Therefore, our study proposes to bury the pin ends under the skin to reduce complications and to achieve better functional outcomes.

  20. Evaluation of the health risk of body backscatter x ray scanners; Evaluation du risque sanitaire des scanners corporels a rayons X backscatter

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2010-07-01

    Following the attempted attack between Amsterdam and Detroit on the 25 december 2009, the council of interior safety decided a quick display of equipment using more efficient imaging techniques than metals detectors usually in place in French airports. Two technologies of devices are susceptible to be implemented on the airports: scanners using non ionizing radiation, (called millimetric waves) or scanners using ionizing radiation (x radiation, measurement by backscattering called backscatter). This report evaluates the dosimetric impact and the sanitary risk of backscatter x ray scanners and formulates recommendations to authorities to allow them to rule on the type of technology to use. Then, this report gives leads to conceive elements of information to communicate to travelers susceptible to be controlled by a such scanner in a foreign airport. (N.C.)

  1. Results from some anode wire aging tests

    International Nuclear Information System (INIS)

    Using twin setups to test anode wire aging in small gas avalanche tubes, a variety of different gas mixtures were tried and other parameters were varied to study their effects upon the gain drop, nomalized to charge transfer: - 1/Q dI/I. This was found to be quite sensitive to the purity of the gases, and also sensitive to the nominal gain and the gas flow rate. The wire surface material can also significantly affect the aging, as can additives, such as ethanol or water vapor. Certain gas mixtures have been found to be consistent with zero aging at the sensitivity level of this technique

  2. FRICTION COEFFICIENT OF DIAMOND WIRE SAW

    Directory of Open Access Journals (Sweden)

    Siniša Dunda

    1998-12-01

    Full Text Available In order to estimate the diamond wire saw upon quarrying of dimension stone, it is necessary to know the value of a friction coefficient on the driving pulley of the saw. Therefore the numerical value of the friction coefficient between diamond wire and coating of a driving pulley was determined in experimental way. The experiments were conducted under different working conditions. The resulting average value of the friction coefficient upon working in wet and muddy conditions amounted to µ = 0,32.

  3. A FLYING WIRE SYSTEM IN THE AGS.

    Energy Technology Data Exchange (ETDEWEB)

    HUANG,H.; BUXTON,W.; MAHLER,G.; MARUSIC,A.; ROSER,T.; SMITH,G.; SYPHERS,M.; WILLIAMS,N.; WITKOVER,R.

    1999-03-29

    As the AGS prepares to serve as the injector for RHIC, monitoring and control of the beam transverse emittance become a major and important topic. Before the installation of the flying wire system, the emittance was measured with ionization profile monitors in the AGS, which require correction for space charge effects. It is desirable to have a second means of measuring profile that is less depend on intensity. A flying wire system has been installed in the AGS recently to perform this task. This paper discusses the hardware and software setup and the capabilities of the system.

  4. A semi-analytical study of positive corona discharge in wire-plane electrode configuration

    Science.gov (United States)

    Yanallah, K.; Pontiga, F.; Chen, J. H.

    2013-08-01

    Wire-to-plane positive corona discharge in air has been studied using an analytical model of two species (electrons and positive ions). The spatial distributions of electric field and charged species are obtained by integrating Gauss's law and the continuity equations of species along the Laplacian field lines. The experimental values of corona current intensity and applied voltage, together with Warburg's law, have been used to formulate the boundary condition for the electron density on the corona wire. To test the accuracy of the model, the approximate electric field distribution has been compared with the exact numerical solution obtained from a finite element analysis. A parametrical study of wire-to-plane corona discharge has then been undertaken using the approximate semi-analytical solutions. Thus, the spatial distributions of electric field and charged particles have been computed for different values of the gas pressure, wire radius and electrode separation. Also, the two dimensional distribution of ozone density has been obtained using a simplified plasma chemistry model. The approximate semi-analytical solutions can be evaluated in a negligible computational time, yet provide precise estimates of corona discharge variables.

  5. EDITORIAL More than a wire More than a wire

    Science.gov (United States)

    Demming, Anna

    2010-10-01

    Nanowires are the natural evolution of the connections in circuits when scaled down to nanometre sizes. On closer inspection, of course, the role of nanowires in developing new technologies is much more than just a current-bearing medium. By sizing the diameters of these objects down to the nanoscale, their properties become increasingly sensitive to factors such as the gas composition, temperature and incident light of their surrounding environment, as well as defects and variations in diameter. What becomes important in modern electronics innovations is not just what is connected, but how. Nanowires had already begun to attract the attention of researchers in the early 1990s as advances in imaging and measurement devices invited researchers to investigate the properties of these one-dimensional structures [1, 2]. This interest has sparked ingenious ways of fabricating nanowires such as the use of a DNA template. A collaboration of researchers at Louisiana Tech University in the US hs provided an overview of various methods to assemble conductive nanowires on a DNA template, including a summary of different approaches to stretching and positioning the templates [3]. Work in this area demonstrates a neat parallel for the role of DNA molecules as the building blocks of life and the foundations of nanoscale device architectures. Scientists at HP Labs in California are using nanowires to shrink the size of logic arrays [4]. One aspect of electronic interconnects that requires particular attention at nanoscale sizes is the effect of defects. The researchers at HP Labs demonstrate that their approach, which they name FPNI (field-programmable nanowire interconnect), is extremely tolerant of the high defect rates likely to be found in these nanoscale structures, and allows reduction in size and power without significantly sacrificing the clock rate. Another issue in scaling down electronics is the trend for an increasing resistivity with decreasing wire width. Researchers

  6. Comparison of Analysis, Simulation, and Measurement of Wire-to-Wire Crosstalk. Part 1

    Science.gov (United States)

    Bradley, Arthur T.; Yavoich, Brian James; Hodson, Shame M.; Godley, Richard Franklin

    2010-01-01

    In this investigation, we compare crosstalk analysis, simulation, and measurement results for electrically short configurations. Methods include hand calculations, PSPICE simulations, Microstripes transient field solver, and empirical measurement. In total, four representative physical configurations are examined, including a single wire over a ground plane, a twisted pair over a ground plane, generator plus receptor wires inside a cylindrical conduit, and a single receptor wire inside a cylindrical conduit. Part 1 addresses the first two cases, and Part 2 addresses the final two. Agreement between the analysis, simulation, and test data is shown to be very good.

  7. Applications of the Coastal Zone Color Scanner in oceanography

    Science.gov (United States)

    Mcclain, C. R.

    1988-01-01

    Research activity has continued to be focused on the applications of the Coastal Zone Color Scanner (CZCS) imagery in oceanography. A number of regional studies were completed including investigations of temporal and spatial variability of phytoplankton populations in the South Atlantic Bight, Northwest Spain, Weddell Sea, Bering Sea, Caribbean Sea and in tropical Atlantic Ocean. In addition to the regional studies, much work was dedicated to developing ancillary global scale meteorological and hydrographic data sets to complement the global CZCS processing products. To accomplish this, SEAPAK's image analysis capability was complemented with an interface to GEMPAK (Severe Storm Branch's meteorological analysis software package) for the analysis and graphical display of gridded data fields. Plans are being made to develop a similar interface to SEAPAK for hydrographic data using EPIC (a hydrographic data analysis package developed by NOAA/PMEL).

  8. ARIES segmented gamma-ray scanner user manual

    International Nuclear Information System (INIS)

    The segmented gamma-ray scatter (SGS) designated as Win SGS at the Los Alamos Plutonium Facility has been installed and is intended for use in quantifying the radioisotope content of DOE-STD-3013-96 equivalent containers. The SGS features new software written in C and a new user interface that runs under Microsoft Windows trademark. The operation of the ARIES Segmented Gamma-ray Scanner is documented in this manual. It covers user instructions as well as hardware and software details. Additional information is found in the documentation for the commercially available components and modules that compose the SGS. The objective of the ARIES project is to demonstrate technology to dismantle plutonium pits from excess nuclear weapons, convert the plutonium to a metal ingot or an oxide powder, package the metal or oxide, and verify the contents of the package by nondestructive assay

  9. Detector characterization for an inline PET scanner in hadrontherapy

    International Nuclear Information System (INIS)

    Our group at the 'Institut de Physique Nucleaire de Lyon' (IPNL) is working on physics and detectors for medical imaging. We are presently developing a small animal Positron Emission Tomograph (PET) scanner prototype with an innovative slow control and data acquisition features, for a demonstration purpose and within the crystal clear international collaboration. We also investigate a feasibility study of an online PET dedicated for inline and in situ dose deposition control in hadrontherapy. Here, we present the characterization setup and method we used to calibrate the detector heads of our PET prototype. Each of these heads consists of a single block continuous scintillating LySO crystal coupled to a multi-anode photomultiplier equipped with its proper acquisition readout chain

  10. NOAA-NASA Coastal Zone Color Scanner Reanalysis Effort

    International Nuclear Information System (INIS)

    Satellite observations of global ocean chlorophyll span more than two decades. However, incompatibilities between processing algorithms prevent us from quantifying natural variability. We applied a comprehensive reanalysis to the Coastal Zone Color Scanner (CZCS) archive, called the National Oceanic and Atmospheric Administration and National Aeronautics and Space Administration (NOAA-NASA) CZCS reanalysis (NCR) effort. NCR consisted of (1) algorithm improvement (AI), where CZCS processing algorithms were improved with modernized atmospheric correction and bio-optical algorithms and (2) blending where in situ data were incorporated into the CZCS AI to minimize residual errors. Global spatial and seasonal patterns of NCR chlorophyll indicated remarkable correspondence with modern sensors, suggesting compatibility. The NCR permits quantitative analyses of interannual and interdecadal trends in global ocean chlorophyll

  11. Two-dimensional optical scanner with monolithically integrated glass microlens

    Science.gov (United States)

    Yoo, Sunghyun; Jin, Joo-Young; Ha, Joon-Geun; Ji, Chang-Hyeon; Kim, Yong-Kweon

    2014-05-01

    A miniaturized two-dimensional forward optical scanner with a monolithically integrated glass microlens was developed for microendoscopic imaging applications. The fabricated device measures 2.26 × 1.97 × 0.62 mm3 in size and a through-silicon microlens with a diameter of 400 µm and numerical aperture of 0.37 has been successfully integrated within the silicon layer. An XY stage structure with lens shuttle and comb actuators was designed, and proprietary glass isolation blocks were utilized in mechanical and electric isolation of X- and Y-axis actuators. Resonant frequencies of the stage in X and Y directions were 3.238 and 2.198 kHz and quality factors were 168 and 69.1, respectively, at atmospheric pressure. Optical scanning test has been performed and scan angles of ±4.7° and ±4.9° were achieved for X and Y directions, respectively.

  12. Low cost flatbed scanner label-free biosensor

    Science.gov (United States)

    Aygun, Ugur; Avci, Oguzhan; Seymour, Elif; Sevenler, Derin D.; Urey, Hakan; Ünlü, M. Selim; Ozkumur, Ayca Yalcin

    2016-03-01

    In this paper, we demonstrate utilization of a commercial flatbed document scanner as a label-free biosensor for highthroughput imaging of DNA and protein microarrays. We implemented an interferometric sensing technique through use of a silicon/oxide layered substrate, and easy to implement hardware modifications such as re-aligning moving parts and inserting a custom made sample plate. With a cost as low as 100USD, powered by a USB cable, and scan speed of 30 seconds for a 4mm x 4 mm area with ~10μm lateral resolution, the presented system offers a super low cost, easy to use alternative to commercially available label-free systems.

  13. Electromagnetic biaxial vector scanner using radial magnetic field.

    Science.gov (United States)

    Han, Aleum; Cho, Ah Ran; Ju, Suna; Ahn, Si-Hong; Bu, Jong-Uk; Ji, Chang-Hyeon

    2016-07-11

    We present an electromagnetic biaxial vector-graphic scanning micromirror. In contrast to conventional electromagnetic actuators using linear magnetic field, proposed device utilizes a radial magnetic field and uniquely designed current paths to enable the 2 degree-of-freedom scanning motion. As the radial field is generated by concentrically assembled magnets placed under the scanner die, large driving torque can be generated without the aid of hermetic packaging and relatively small device volume can be achieved. Mechanical half scan angle of 6.43° and 4.20° have been achieved at DC current of 250mA and 350mA for horizontal and vertical scans, respectively. Forced actuation along both scan axes has been realized by feedback control. PMID:27410851

  14. Modeling of estuarne chlorophyll a from an airborne scanner

    Science.gov (United States)

    Khorram, Siamak; Catts, Glenn P.; Cloern, James E.; Knight, Allen W.

    1987-01-01

    Near simultaneous collection of 34 surface water samples and airborne multispectral scanner data provided input for regression models developed to predict surface concentrations of estuarine chlorophyll a. Two wavelength ratios were employed in model development. The ratios werechosen to capitalize on the spectral characteristics of chlorophyll a, while minimizing atmospheric influences. Models were then applied to data previously acquired over the study area thre years earlier. Results are in the form of color-coded displays of predicted chlorophyll a concentrations and comparisons of the agreement among measured surface samples and predictions basedon coincident remotely sensed data. The influence of large variations in fresh-water inflow to the estuary are clearly apparent in the results. The synoptic view provided by remote sensing is another method of examining important estuarine dynamics difficult to observe from in situ sampling alone.

  15. Attenuation correction for the NIH ATLAS small animal PET scanner

    CERN Document Server

    Yao, Rutao; Liow, JeihSan; Seidel, Jurgen

    2003-01-01

    We evaluated two methods of attenuation correction for the NIH ATLAS small animal PET scanner: 1) a CT-based method that derives 511 keV attenuation coefficients (mu) by extrapolation from spatially registered CT images; and 2) an analytic method based on the body outline of emission images and an empirical mu. A specially fabricated attenuation calibration phantom with cylindrical inserts that mimic different body tissues was used to derive the relationship to convert CT values to (I for PET. The methods were applied to three test data sets: 1) a uniform cylinder phantom, 2) the attenuation calibration phantom, and 3) a mouse injected with left bracket **1**8F right bracket FDG. The CT-based attenuation correction factors were larger in non-uniform regions of the imaging subject, e.g. mouse head, than the analytic method. The two methods had similar correction factors for regions with uniform density and detectable emission source distributions.

  16. Absolute dosimetric characterization of Gafchromic EBT3 and HDv2 films using commercial flat-bed scanners and evaluation of the scanner response function variability

    Science.gov (United States)

    Chen, S. N.; Gauthier, M.; Bazalova-Carter, M.; Bolanos, S.; Glenzer, S.; Riquier, R.; Revet, G.; Antici, P.; Morabito, A.; Propp, A.; Starodubtsev, M.; Fuchs, J.

    2016-07-01

    Radiochromic films (RCF) are commonly used in dosimetry for a wide range of radiation sources (electrons, protons, and photons) for medical, industrial, and scientific applications. They are multi-layered, which includes plastic substrate layers and sensitive layers that incorporate a radiation-sensitive dye. Quantitative dose can be retrieved by digitizing the film, provided that a prior calibration exists. Here, to calibrate the newly developed EBT3 and HDv2 RCFs from Gafchromic™, we used the Stanford Medical LINAC to deposit in the films various doses of 10 MeV photons, and by scanning the films using three independent EPSON Precision 2450 scanners, three independent EPSON V750 scanners, and two independent EPSON 11000XL scanners. The films were scanned in separate RGB channels, as well as in black and white, and film orientation was varied. We found that the green channel of the RGB scan and the grayscale channel are in fact quite consistent over the different models of the scanner, although this comes at the cost of a reduction in sensitivity (by a factor ˜2.5 compared to the red channel). To allow any user to extend the absolute calibration reported here to any other scanner, we furthermore provide a calibration curve of the EPSON 2450 scanner based on absolutely calibrated, commercially available, optical density filters.

  17. Online correction of scanning probe microscopes with pixel accuracy

    DEFF Research Database (Denmark)

    Dirscherl, Kai

    2000-01-01

    during the scan process. The s ignal of the sensors can be used as closed loop feedback signal. At first a model is set up to describe the measured hysteresis. An ordinary linear differential equation proves to yield the desired accuracy of 0.2% when simulating the measured hysteresis. This is done...... by using a least-squares-fitting technique. After having successfully simulated the measured non-linearities, the model is inverted in order to form an algorithm for online correction during the scan process. Also the online algorithm is tested on two different scanners. The residual non.......2% measuring uncertainty, but the piezo changes arbitrarily in the its sensitivity. Further results of this thesis include the simulation of transient hysteresis as occurs at a change of scan conditions. This is also applied to the z-direction. Here an overshoot at a large step is qualitatively simulated...

  18. Effective dose range for dental cone beam computed tomography scanners

    International Nuclear Information System (INIS)

    Objective: To estimate the absorbed organ dose and effective dose for a wide range of cone beam computed tomography scanners, using different exposure protocols and geometries. Materials and methods: Two Alderson Radiation Therapy anthropomorphic phantoms were loaded with LiF detectors (TLD-100 and TLD-100H) which were evenly distributed throughout the head and neck, covering all radiosensitive organs. Measurements were performed on 14 CBCT devices: 3D Accuitomo 170, Galileos Comfort, i-CAT Next Generation, Iluma Elite, Kodak 9000 3D, Kodak 9500, NewTom VG, NewTom VGi, Pax-Uni3D, Picasso Trio, ProMax 3D, Scanora 3D, SkyView, Veraviewepocs 3D. Effective dose was calculated using the ICRP 103 (2007) tissue weighting factors. Results: Effective dose ranged between 19 and 368 μSv. The largest contributions to the effective dose were from the remainder tissues (37%), salivary glands (24%), and thyroid gland (21%). For all organs, there was a wide range of measured values apparent, due to differences in exposure factors, diameter and height of the primary beam, and positioning of the beam relative to the radiosensitive organs. Conclusions: The effective dose for different CBCT devices showed a 20-fold range. The results show that a distinction is needed between small-, medium-, and large-field CBCT scanners and protocols, as they are applied to different indication groups, the dose received being strongly related to field size. Furthermore, the dose should always be considered relative to technical and diagnostic image quality, seeing that image quality requirements also differ for patient groups. The results from the current study indicate that the optimisation of dose should be performed by an appropriate selection of exposure parameters and field size, depending on the diagnostic requirements.

  19. A z gain nonuniformity correction for multislice volumetric CT scanners.

    Science.gov (United States)

    Besson, G; Hu, H; Xie, M; He, D; Seidenschnur, G; Bromberg, N

    2000-05-01

    This paper presents a calibration and correction method for detector cell gain variations. A key functionality of current CT scanners is to offer variable slice thickness to the user. To provide this capability in multislice volumetric scanners, while minimizing costs, it is necessary to combine the signals of several detector cells in z, when the desired slice thickness is larger than the minimum provided by a single cell. These combined signals are then pre-amplified, digitized, and transmitted to the system for further processing. The process of combining the output of several detector cells with nonuniform gains can introduce numerical errors when the impinging x-ray signal presents a variation along z over the range of combined cells. These numerical errors, which by nature are scan dependent, can lead to artifacts in the reconstructed images, particularly when the numerical errors vary from channel-to-channel (as the filtered-backprojection filter includes a high-pass filtering along the channel direction, within a given slice). A projection data correction algorithm has been developed to subtract the associated numerical errors. It relies on the ability of calibrating the individual cell gains. For effectiveness and data flow reasons, the algorithm works on a single slice basis, without slice-to-slice exchange of information. An initial error vector is calculated by applying a high-pass filter to the projection data. The essence of the algorithm is to correlate that initial error vector, with a calibration vector obtained by applying the same high-pass filter to various z combinations of the cell gains (each combination representing a basis function for a z expansion). The solution of the least-square problem, obtained via singular value decomposition, gives the coefficients of a polynomial expansion of the signal z slope and curvature. From this information, and given the cell gains, the final error vector is calculated and subtracted from the projection

  20. Development of a proton Computed Tomography (pCT) scanner at NIU

    CERN Document Server

    Uzunyan, S A; Boi, S; Coutrakon, G; Dyshkant, A; Erdelyi, B; Gearhart, A; Hedin, D; Johnson, E; Krider, J; Zutshi, V; Ford, R; Fitzpatrick, T; Sellberg, G; Rauch, J E; Roman, M; Rubinov, P; Wilson, P; Lalwani, K; Naimuddin, M

    2013-01-01

    We describe the development of a proton Computed Tomography (pCT) scanner at Northern Illinois University (NIU) in collaboration with Fermilab and Delhi University. This paper provides an overview of major components of the scanner and a detailed description of the data acquisition system (DAQ).

  1. FormScanner: Open-Source Solution for Grading Multiple-Choice Exams

    Science.gov (United States)

    Young, Chadwick; Lo, Glenn; Young, Kaisa; Borsetta, Alberto

    2016-01-01

    The multiple-choice exam remains a staple for many introductory physics courses. In the past, people have graded these by hand or even flaming needles. Today, one usually grades the exams with a form scanner that utilizes optical mark recognition (OMR). Several companies provide these scanners and particular forms, such as the eponymous…

  2. Calibration between a Laser Range Scanner and an Industrial Robot Manipulator

    DEFF Research Database (Denmark)

    Andersen, Thomas Timm; Andersen, Nils Axel; Ravn, Ole

    2014-01-01

    In this paper we present a method for findingthe transformation between a laser scanner and a robotmanipulator. We present the design of a flat calibration targetthat can easily fit between a laser scanner and a conveyor belt,making the method easily implementable in a manufacturingline.We prove ...

  3. A prototype fan-beam optical CT scanner for 3D dosimetry

    Energy Technology Data Exchange (ETDEWEB)

    Campbell, Warren G.; Rudko, D. A.; Braam, Nicolas A.; Jirasek, Andrew [University of Victoria, Victoria, British Columbia V8P 5C2 (Canada); Wells, Derek M. [British Columbia Cancer Agency, Vancouver Island Centre, Victoria, British Columbia V8R 6V5 (Canada)

    2013-06-15

    flask registration technique was shown to achieve submillimetre and subdegree placement accuracy. Dosimetry protocol investigations emphasize the need to allow gel dosimeters to cool gradually and to be scanned while at room temperature. Preliminary tests show that considerable noise reduction can be achieved with sinogram filtering and by binning image pixels into more clinically relevant grid sizes. Conclusions: This paper describes a new optical CT scanner for 3D radiation dosimetry. Tests demonstrate that it is capable of imaging both absorption-based and scatter-based samples of high opacities. Imaging protocol and gel dosimeter manufacture techniques have been adapted to produce optimal reconstruction results. These optimal results will require suitable filtering and binning techniques for noise reduction purposes.

  4. A prototype fan-beam optical CT scanner for 3D dosimetry

    International Nuclear Information System (INIS)

    technique was shown to achieve submillimetre and subdegree placement accuracy. Dosimetry protocol investigations emphasize the need to allow gel dosimeters to cool gradually and to be scanned while at room temperature. Preliminary tests show that considerable noise reduction can be achieved with sinogram filtering and by binning image pixels into more clinically relevant grid sizes. Conclusions: This paper describes a new optical CT scanner for 3D radiation dosimetry. Tests demonstrate that it is capable of imaging both absorption-based and scatter-based samples of high opacities. Imaging protocol and gel dosimeter manufacture techniques have been adapted to produce optimal reconstruction results. These optimal results will require suitable filtering and binning techniques for noise reduction purposes.

  5. Contactless 2-dimensional laser sensor for 3-dimensional wire position and tension measurements

    CERN Document Server

    Prall, Matthias; Joehren, R; Ortjohann, H W; Reinhardt, M; Weinheimer, Ch

    2009-01-01

    We have developed a contact-free 2-dimensional laser sensor with which the position of wires can be measured in 3 dimensions with an accuracy of better than 10 micrometer and with which the tension of the wires can be determined with an accuracy of 0.04 N. These measurements can be made from a distance of 15 cm. The sensor consists of commercially available laser pointers, lenses, color filters and photodiodes. In our application we have used this laser sensor together with an automated 3 dimensional coordinate table. For a single position measurement, the laser sensor is moved by the 3-dimensional coordinate table in a plane and determines the coordinates at which the wires intersect with this plane. The position of the plane itself (the third coordinate) is given by the third axis of the measurement table which is perpendicular to this plane. The control and readout of the table and the readout of the laser sensor were realized with LabVIEW. The precision of the position measurement in the plane was determi...

  6. Spectroscopic properties of colloidal indium phosphide quantum wires

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Lin-Wang; Wang, Fudong; Yu, Heng; Li, Jingbo; Hang, Qingling; Zemlyanov, Dmitry; Gibbons, Patrick C.; Wang, Lin-Wang; Janes, David B.; Buhro, William E.

    2008-07-11

    Colloidal InP quantum wires are grown by the solution-liquid-solid (SLS) method, and passivated with the traditional quantum dots surfactants 1-hexadecylamine and tri-n-octylphosphine oxide. The size dependence of the band gaps in the wires are determined from the absorption spectra, and compared to other experimental results for InP quantum dots and wires, and to the predictions of theory. The photoluminescence behavior of the wires is also investigated. Efforts to enhance photoluminescence efficiencies through photochemical etching in the presence of HF result only in photochemical thinning or photo-oxidation, without a significant influence on quantum-wire photoluminescence. However, photo-oxidation produces residual dot and rod domains within the wires, which are luminescent. The results establish that the quantum-wire band gaps are weakly influenced by the nature of the surface passivation, and that colloidal quantum wires have intrinsically low photoluminescence efficiencies.

  7. STRUCTURE AND CHARACTERISTICS OF PATENTED HIGH-CARBON WIRE

    Directory of Open Access Journals (Sweden)

    A. Ju. Borisenko

    2011-01-01

    Full Text Available The influence of bainite structure on mechanical characteristics of wire of steel 80 after patenting is studied. The quantity and structure state of bainite, providing high complex of mechanical characteristics of high-carbon wire, is determined.

  8. A REVIEW ON INNOVATION OF WIRE STRAIGHTENING CUTTING MACHINE

    Directory of Open Access Journals (Sweden)

    ASHVIN S. PATEL,

    2011-05-01

    Full Text Available Now days, there are wide verity of wire products like welding electrode, weld mesh, heat treated kitchen baskets, automobile spark plugs and exhaust valves etc. For manufacturing all aboveproducts, wire is used as primary element and is to be straighten from coil form. Now straighten wire is to be cut into wire rod as per required length. For these sequential operations, wire straighteningcutting machine is used. Now days, conventional type wire straightening cutting machine are being used in which wire is cut by stopper cutter head which is limited by its length as well as feeding speed. This paper surveys straightening and cutting process used in such machines. Although this review cannot be collectively exhaustive, it may be considered as a valuable guide for researchers who are interested to develop next generation of wire straightening cutting machines.

  9. Radiation of relativistic electrons in a periodic wire structure

    Energy Technology Data Exchange (ETDEWEB)

    Soboleva, V.V., E-mail: sobolevaveronica@mail.ru; Naumenko, G.A.; Bleko, V.V.

    2015-07-15

    We present in this work the experimental investigation of the interaction of relativistic electron field with periodic wire structures. We used two types of the targets in experiments: flat wire target and sandwich wire target that represent the right triangular prism. The measurements were done in millimeter wavelength region (10–40 mm) on the relativistic electron beam with energy of 6.2 MeV in far-field zone. We showed that bunched electron beam passing near wire metamaterial prism generates coherent Cherenkov radiation. The experiments with flat wire target were carried out in two geometries. In the first geometry the electron beam passed close to the flat wire target surface. In the second case the electron beam passed through the flat wire structure with generation of a coherent backward transition radiation (CBTR). The comparison of the Cherenkov radiation intensity and BTR intensity from the flat wire target and from the flat conductive target (conventional BTR) was made.

  10. Modular Wiring Offers Cost Savings and Future Flexibility.

    Science.gov (United States)

    Ewald, Mike; Ewald, Ann O'Connor

    2002-01-01

    Discusses the advantages of modular wiring, a prefabricated wiring system that replaces branch circuits in buildings. Advantages include on-site and day-to-day labor savings, and future technology cost advantages. Includes questions to ask manufacturers. (EV)

  11. A comparative evaluation of Cone Beam Computed Tomography (CBCT) and Multi-Slice CT (MSCT). Part II: On 3D model accuracy

    NARCIS (Netherlands)

    X. Liang; I. Lambrichts; Y. Sun; K. Denis; B. Hassan; L. Li; R. Pauwels; R. Jacobs

    2010-01-01

    Aim: The study aim was to compare the geometric accuracy of three-dimensional (3D) surface model reconstructions between five Cone Beam Computed Tomography (CBCT) scanners and one Multi-Slice CT (MSCT) system. Materials and methods: A dry human mandible was scanned with five CBCT systems (NewTom 3G,

  12. SU-E-P-11: Comparison of Image Quality and Radiation Dose Between Different Scanner System in Routine Abdomen CT

    International Nuclear Information System (INIS)

    Purpose To evaluate image quality and radiation dose of routine abdomen computed tomography exam with the automatic current modulation technique (ATCM) performed in two different brand 64-slice CT scanners in our site. Materials and Methods A retrospective review of routine abdomen CT exam performed with two scanners; scanner A and scanner B in our site. To calculate standard deviation of the portal hepatic level with a region of interest of 12.5 mm x 12.5mm represented to the image noise. The radiation dose was obtained from CT DICOM image information. Using Computed tomography dose index volume (CTDIv) to represented CT radiation dose. The patient data in this study were with normal weight (about 65–75 Kg). Results The standard deviation of Scanner A was smaller than scanner B, the scanner A might with better image quality than scanner B. On the other hand, the radiation dose of scanner A was higher than scanner B(about higher 50–60%) with ATCM. Both of them, the radiation dose was under diagnostic reference level. Conclusion The ATCM systems in modern CT scanners can contribute a significant reduction in radiation dose to the patient. But the reduction by ATCM systems from different CT scanner manufacturers has slightly variation. Whatever CT scanner we use, it is necessary to find the acceptable threshold of image quality with the minimum possible radiation exposure to the patient in agreement with the ALARA principle

  13. SU-E-P-11: Comparison of Image Quality and Radiation Dose Between Different Scanner System in Routine Abdomen CT

    Energy Technology Data Exchange (ETDEWEB)

    Liao, S; Wang, Y; Weng, H [Chiayi Chang Gung Memorial Hospital of The C.G.M.F, Puzi City, Chiayi County, Taiwan (China)

    2015-06-15

    Purpose To evaluate image quality and radiation dose of routine abdomen computed tomography exam with the automatic current modulation technique (ATCM) performed in two different brand 64-slice CT scanners in our site. Materials and Methods A retrospective review of routine abdomen CT exam performed with two scanners; scanner A and scanner B in our site. To calculate standard deviation of the portal hepatic level with a region of interest of 12.5 mm x 12.5mm represented to the image noise. The radiation dose was obtained from CT DICOM image information. Using Computed tomography dose index volume (CTDIv) to represented CT radiation dose. The patient data in this study were with normal weight (about 65–75 Kg). Results The standard deviation of Scanner A was smaller than scanner B, the scanner A might with better image quality than scanner B. On the other hand, the radiation dose of scanner A was higher than scanner B(about higher 50–60%) with ATCM. Both of them, the radiation dose was under diagnostic reference level. Conclusion The ATCM systems in modern CT scanners can contribute a significant reduction in radiation dose to the patient. But the reduction by ATCM systems from different CT scanner manufacturers has slightly variation. Whatever CT scanner we use, it is necessary to find the acceptable threshold of image quality with the minimum possible radiation exposure to the patient in agreement with the ALARA principle.

  14. Determining Geometric Accuracy in Turning

    Institute of Scientific and Technical Information of China (English)

    Kwong; Chi; Kit; A; Geddam

    2002-01-01

    Mechanical components machined to high levels of ac cu racy are vital to achieve various functional requirements in engineering product s. In particular, the geometric accuracy of turned components play an important role in determining the form, fit and function of mechanical assembly requiremen ts. The geometric accuracy requirements of turned components are usually specifi ed in terms of roundness, straightness, cylindricity and concentricity. In pract ice, the accuracy specifications achievable are infl...

  15. Uav-Based Acquisition of 3d Point Cloud - a Comparison of a Low-Cost Laser Scanner and Sfm-Tools

    Science.gov (United States)

    Mader, D.; Blaskow, R.; Westfeld, P.; Maas, H.-G.

    2015-08-01

    The Project ADFEX (Adaptive Federative 3D Exploration of Multi Robot System) pursues the goal to develop a time- and cost-efficient system for exploration and monitoring task of unknown areas or buildings. A fleet of unmanned aerial vehicles equipped with appropriate sensors (laser scanner, RGB camera, near infrared camera, thermal camera) were designed and built. A typical operational scenario may include the exploration of the object or area of investigation by an UAV equipped with a laser scanning range finder to generate a rough point cloud in real time to provide an overview of the object on a ground station as well as an obstacle map. The data about the object enables the path planning for the robot fleet. Subsequently, the object will be captured by a RGB camera mounted on the second flying robot for the generation of a dense and accurate 3D point cloud by using of structure from motion techniques. In addition, the detailed image data serves as basis for a visual damage detection on the investigated building. This paper focuses on our experience with use of a low-cost light-weight Hokuyo laser scanner onboard an UAV. The hardware components for laser scanner based 3D point cloud acquisition are discussed, problems are demonstrated and analyzed, and a quantitative analysis of the accuracy potential is shown as well as in comparison with structure from motion-tools presented.

  16. High-speed two-dimensional laser scanner based on Bragg gratings stored in photothermorefractive glass.

    Science.gov (United States)

    Yaqoob, Zahid; Arain, Muzammil A; Riza, Nabeel A

    2003-09-10

    A high-speed free-space wavelength-multiplexed optical scanner with high-speed wavelength selection coupled with narrowband volume Bragg gratings stored in photothermorefractive (PTR) glass is reported. The proposed scanner with no moving parts has a modular design with a wide angular scan range, accurate beam pointing, low scanner insertion loss, and two-dimensional beam scan capabilities. We present a complete analysis and design procedure for storing multiple tilted Bragg-grating structures in a single PTR glass volume (for normal incidence) in an optimal fashion. Because the scanner design is modular, many PTR glass volumes (each having multiple tilted Bragg-grating structures) can be stacked together, providing an efficient throughput with operations in both the visible and the infrared (IR) regions. A proof-of-concept experimental study is conducted with four Bragg gratings in independent PTR glass plates, and both visible and IR region scanner operations are demonstrated.

  17. A COST EFFECTIVE MULTI-SPECTRAL SCANNER FOR NATURAL GAS DETECTION

    Energy Technology Data Exchange (ETDEWEB)

    Yudaya Sivathanu; Jongmook Lim; Vinoo Narayanan

    2004-04-01

    The objective of this project is to design, fabricate and field demonstrate a cost effective, multi-spectral scanner for natural gas leak detection in transmission and distribution pipelines. During the first six months of the project, the design for a laboratory version of the multispectral scanner was completed. The optical, mechanical, and electronic design for the scanner was completed. The optical design was analyzed using Zeemax Optical Design software and found to provide sufficiently resolved performance for the scanner. The electronic design was evaluated using a bread board and very high signal to noise ratios were obtained. Fabrication of a laboratory version of the multi-spectral scanner is currently in progress. A technology status report and a research management plan was also completed during the same period.

  18. High-speed two-dimensional laser scanner based on Bragg gratings stored in photothermorefractive glass.

    Science.gov (United States)

    Yaqoob, Zahid; Arain, Muzammil A; Riza, Nabeel A

    2003-09-10

    A high-speed free-space wavelength-multiplexed optical scanner with high-speed wavelength selection coupled with narrowband volume Bragg gratings stored in photothermorefractive (PTR) glass is reported. The proposed scanner with no moving parts has a modular design with a wide angular scan range, accurate beam pointing, low scanner insertion loss, and two-dimensional beam scan capabilities. We present a complete analysis and design procedure for storing multiple tilted Bragg-grating structures in a single PTR glass volume (for normal incidence) in an optimal fashion. Because the scanner design is modular, many PTR glass volumes (each having multiple tilted Bragg-grating structures) can be stacked together, providing an efficient throughput with operations in both the visible and the infrared (IR) regions. A proof-of-concept experimental study is conducted with four Bragg gratings in independent PTR glass plates, and both visible and IR region scanner operations are demonstrated. PMID:14503693

  19. Image beam from a wire laser

    NARCIS (Netherlands)

    Orlova, E.E.; Hovenier, J.N.; De Visser, P.J.; Gao, J.R.

    2015-01-01

    We demonstrate the formation of a narrow beam from a long (L≫λ) laser with subwavelength transverse dimensions (wire laser) as an image of the subwavelength laser waveguide formed by a spherical lens. The beam is linearly diverging with the angle determined by the ratio of the wavelength to the lens

  20. Technological improvements in wire rod mills

    Energy Technology Data Exchange (ETDEWEB)

    Lestani, M.

    1996-07-01

    The paper deals with the latest rolling technologies and hi-tech equipment developed by Danieli-mogardshammar to ensure top performance of modern wire rod mills. In particular, a high reduction sizing mill, a twin module fast finishing block and a high speed cropping shear are presented. (authors)

  1. Studying superconducting Nb3Sn wire

    CERN Multimedia

    AUTHOR|(CDS)2099575

    2015-01-01

    Studying superconducting Nb3Sn wire. From the current experience from LHC and HL-LHC we know that the performance requirements for Nb3Sn conductor for future circular collider are challenging and should exceed that of present state-of-the-art materials.

  2. 75 FR 4584 - Wire Decking From China

    Science.gov (United States)

    2010-01-28

    ... to the extent permitted by section 201.8 of the Commission's rules, as amended, 67 FR 68036 (November..., 67 FR 68168, 68173 (November 8, 2002). Additional written submissions to the Commission, including... COMMISSION Wire Decking From China AGENCY: United States International Trade Commission. ACTION:...

  3. Lorentz Contraction and Current-Carrying Wires

    Science.gov (United States)

    van Kampen, Paul

    2008-01-01

    The force between two parallel current-carrying wires is investigated in the rest frames of the ions and the electrons. A straightforward Lorentz transformation shows that what appears as a purely magnetostatic force in the ion frame appears as a combined magnetostatic and electrostatic force in the electron frame. The derivation makes use of a…

  4. 3D Wire 2015 Gamification Report

    DEFF Research Database (Denmark)

    Jordi, Moréton; F, Escribano; J. L., Farias;

    This document is a general report on the implementation of gamification in 3D Wire 2015 event. As the second gamification experience in this event, we have delved deeply in the previous objectives (attracting public areas less frequented exhibition in previous years and enhance networking) and ha...

  5. 49 CFR 393.28 - Wiring systems.

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 5 2010-10-01 2010-10-01 false Wiring systems. 393.28 Section 393.28 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL MOTOR CARRIER SAFETY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION FEDERAL MOTOR CARRIER SAFETY REGULATIONS PARTS AND ACCESSORIES NECESSARY FOR SAFE OPERATION Lamps,...

  6. Tunable permeability of magnetic wires at microwaves

    Energy Technology Data Exchange (ETDEWEB)

    Panina, L.V., E-mail: lpanina@plymouth.ac.uk [National University of Science and Technology, MISiS, Moscow (Russian Federation); Institute for Design Problems in Microelectronics, RAN, Moscow (Russian Federation); Makhnovskiy, D.P. [School of Computing and Mathematics, University of Plymouth (United Kingdom); Morchenko, A.T.; Kostishin, V.G. [National University of Science and Technology, MISiS, Moscow (Russian Federation)

    2015-06-01

    This paper presents the analysis into microwave magnetic properties of magnetic microwires and their composites in the context of applications in wireless sensors and tunable microwave materials. It is demonstrated that the intrinsic permeability of wires has a wide frequency dispersion with relatively large values in the GHz band. In the case of a specific magnetic anisotropy this results in a tunable microwave impedance which could be used for distributed wireless sensing networks in functional composites. The other range of applications is related with developing the artificial magnetic dielectrics with large and tunable permeability. The composites with magnetic wires with a circumferential anisotropy have the effective permeability which differs substantially from unity for a relatively low concentration (less than 10%). This can make it possible to design the wire media with a negative and tunable index of refraction utilising natural magnetic properties of wires. - Highlights: • Applications of magnetic microwires for functional composites and distributed sensor networks are proposed. • Diluted composites with magnetic microwires can demonstrate tunable left-handed properties. • Large microwave permeability combined with a specific magnetic structure lead to a large and sensitive microwave magnetoimpedance. • Microwave magnetoimpedance highly sensitive to temperature is demonstrated.

  7. Numerical Simulation of Wire-Coating

    DEFF Research Database (Denmark)

    Wapperom, Peter; Hassager, Ole

    1999-01-01

    A finite element program has been used to analyze the wire-coating process of an MDPE melt. The melt is modeled by a nonisothermal Carreau model. The emphasis is on predicting an accurate temperature field. Therefore, it is necessary to include the heat conduction in the metal parts. A comparison...

  8. Ultra-Wideband Design of the Wire Conical Antenna

    Institute of Scientific and Technical Information of China (English)

    WANG Qi; HE Qing-qiang

    2005-01-01

    Using the wire construction technique, a conical monopole antenna is fabricated. With the method of moments, the dependences of the voltage standing wave ratio (VSWR) on the number of the trapezoid wire elements, conical angles, wire radius, etc. are investigated. The calculation and the experiment show that the designed wire conical antenna has the ultra-wideband property and can be used for the engineering.

  9. Modelling wire-to-wire corona discharge action on aerodynamics and comparison with experiment

    Energy Technology Data Exchange (ETDEWEB)

    Mateo-Velez, J-C [ONERA, 2 avenue Edouard Belin, 31055 Toulouse (France); Degond, P [Institut de Mathematiques, Universite Paul Sabatier, 118 route de Narbonne, 31062 Toulouse Cedex (France); Rogier, F [ONERA, 2 avenue Edouard Belin, 31055 Toulouse (France); Seraudie, A [ONERA, 2 avenue Edouard Belin, 31055 Toulouse (France); Thivet, F [ONERA, 2 avenue Edouard Belin, 31055 Toulouse (France)

    2008-02-07

    The purpose of this paper is to propose a simple model for plasma generation and effect on fluids at atmospheric pressure. Experiments are conducted using a wire-to-wire corona discharge actuator in a subsonic boundary layer flow. Velocity gains of several metres per second are observed. A quasi-2D numerical model of the discharge is proposed and explains the creation of two corona discharges around the electrodes. A one-way approach of the plasma aerodynamics coupling gives access to the ionic wind. It is confirmed that the actuator accelerates the flow from the anode to the cathode. Order of magnitudes of the ionic wind and flow velocity profiles are close to experiments. A first attempt to perform a 2D simulation of the wire-to-wire discharge is presented as the starting point of future works.

  10. Evaluation of wedge-shaped phantoms for assessment of scanner display as a part of quality control of scanner performance

    International Nuclear Information System (INIS)

    Image manipulation in modern rectilinear scanners comprises background subtraction and contrast enhancement facilities. It has been the aim of this investigation to develop simple quality assurance methods suitable for checking the function of these features on a routine basis. Several types of phantoms have been investigated: an absorption step wedge, an emission step wedge and an emission continuous wedge. The absorption step wedge when used with a usual gamma-camera checking source gave the least satisfactory results. The emission step wedge is best suited for test procedures for background subtraction of the colour printer display and for contrast enhancement of the photo display, whereas the emission continuous wedge gave best results in testing the contrast enhancement of the colour printer display. An evaluation of the relative merits of the phantoms indicates that the emission step wedge is best suited for quality assurance tests. (author)

  11. 49 CFR 236.723 - Circuit, double wire; line.

    Science.gov (United States)

    2010-10-01

    ... § 236.723 Circuit, double wire; line. An electric circuit not employing a common return wire; a circuit... 49 Transportation 4 2010-10-01 2010-10-01 false Circuit, double wire; line. 236.723 Section 236.723 Transportation Other Regulations Relating to Transportation (Continued) FEDERAL...

  12. Low-Inductance Wiring For Parallel Switching Transistors

    Science.gov (United States)

    Veatch, M. S.; Landis, D. M.

    1990-01-01

    Simple configuration for wiring of multiple parallel-connected switching transistors minimizes stray wiring inductance while providing for use of balancing transformers, which equalize currents in transistors. Currents balanced on twisted pairs of wires. Because twisted pairs carry both "hot-side" and return currents, this configuration has relatively low inductance.

  13. 30 CFR 75.510 - Energized trolley wires; repair.

    Science.gov (United States)

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Energized trolley wires; repair. 75.510 Section 75.510 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR COAL MINE SAFETY... Energized trolley wires; repair. Energized trolley wires may be repaired only by a person trained to...

  14. Quantum stability and magic lengths of metal atom wires

    Science.gov (United States)

    Cui, Ping; Choi, Jin-Ho; Lan, Haiping; Cho, Jun-Hyung; Niu, Qian; Yang, Jinlong; Zhang, Zhenyu

    2016-06-01

    Metal atom wires represent an important class of nanomaterials in the development of future electronic devices and other functional applications. Using first-principles calculations within density functional theory, we carry out a systematic study of the quantum stability of freestanding atom wires consisting of prototypical metal elements with s -, s p -, and s d -valence electrons. We explore how the quantum mechanically confined motion and local bonding of the valence electrons in these different wire systems can dictate their overall structural stability and find that the formation energy of essentially all the wires oscillates with respect to their length measured by the number n of atoms contained in the wires, establishing the existence of highly preferred (or magic) lengths. Furthermore, different wire classes exhibit distinctively different oscillatory characteristics and quantum stabilities. Alkali metal wires possessing an unpaired s valence electron per atom exhibit simple damped even-odd oscillations. In contrast, Al and Ga wires containing three s2p1 valence electrons per atom generally display much larger and undamped even-odd energy oscillations due to stronger local bonding of the p orbitals. Among the noble metals, the s -dominant Ag wires behave similarly to the linear alkali metal wires, while Au and Pt wires distinctly prefer to be structurally zigzagged due to strong relativistic effects. These findings are discussed in connection with existing experiments and should also be instrumental in future experimental realization of different metal atom wires in freestanding or supported environments with desirable functionalities.

  15. Plasmon assisted transport through disordered array of quantum wires

    OpenAIRE

    Chudnovskiy, A. L.

    2004-01-01

    Phononless plasmon assisted thermally activated transport through a long disordered array of finite length quantum wires is investigated analytically. Generically strong electron plasmon interaction in quantum wires results in a qualitative change of the temperature dependence of thermally activated resistance in comparison to phonon assisted transport. At high temperatures, the thermally activated resistance is determined by the Luttinger liquid interaction parameter of the wires.

  16. A Laser-Wire System for the International Linear Collider

    Energy Technology Data Exchange (ETDEWEB)

    Delerue, N.; Dixit, S.; Gannaway, F.; Howell, D.; Qurshi, M.; Blair, G.; Boogert, S.; Boorman, G.; Driouichi, C.; Deacon, L.; Aryshev, A.; Karataev, P.; Terunuma, N.; Urakawa, J.; Brachmann, A.; Frisch, J.; Ross, M.; /Oxford U. /Royal Holloway, U. of London /KEK, Tsukuba /SLAC

    2009-04-30

    A new laser-wire has been installed in the extraction line of the ATF at KEK. It aims at demonstrating that laser-wires can be used to measure micrometre scale beam size. In parallel, studies have been made to specify a laser suitable for the ILC laser-wires.

  17. Thermal Aware Floorplanning Incorporating Temperature Dependent Wire Delay Estimation

    DEFF Research Database (Denmark)

    Winther, AndreasThor; Liu, Wei; Nannarelli, Alberto;

    2015-01-01

    Temperature has a negative impact on metal resistance and thus wire delay. In state-of-the-art VLSI circuits, large thermal gradients usually exist due to the uneven distribution of heat sources. The difference in wire temperature can lead to performance mismatch because wires of the same length ...

  18. A laser-wire system for the International Linear Collider

    Indian Academy of Sciences (India)

    Nicolas Delerue; Sudhir Dixit; Fred Gannaway; David Howell; Myriam Qurshi; Grahame Blair; Stewart Boogert; Gary Boorman; Chafik Driouichi; Lawerence Deacon; Alexander Aryshev; Pavel Karataev; Nobuhiro Terunnuma; Junji urakawa; Axel Brachmann; Joe Frisch; Marc Ross

    2007-12-01

    A new laser-wire has been installed in the extraction line of the ATF at KEK. It aims at demonstrating that laser-wires can be used to measure micrometre scale beam size. In parallel, studies have been made to specify a laser suitable for the ILC laser-wires.

  19. Communication and Wiring in the Cortical Connectome

    Directory of Open Access Journals (Sweden)

    Julian eBudd

    2012-10-01

    Full Text Available In cerebral cortex, the huge mass of axonal wiring that carries information between near and distant neurons is thought to provide the neural substrate for cognitive and perceptual function. The goal of mapping the connectivity of cortical axons at different spatial scales, the cortical connectome, is to trace the paths of information flow in cerebral cortex. To appreciate the relationship between the connectome and cortical function, we need to discover the nature and purpose of the wiring principles underlying cortical connectivity. A popular explanation has been that axonal length is strictly minimized both within and between cortical regions. In contrast, we have hypothesized the existence of a multi-scale principle of cortical wiring where to optimise communication there is a trade-off between spatial (construction and temporal (routing costs. Here, using recent evidence concerning cortical spatial networks we critically evaluate this hypothesis at neuron, local circuit, and pathway scales. We report three main conclusions. First, the axonal and dendritic arbor morphology of single neocortical neurons may be governed by a similar wiring principle, one that balances the conservation of cellular material and conduction delay. Second, the same principle may be observed for fibre tracts connecting cortical regions. Third, the absence of sufficient local circuit data currently prohibits any meaningful assessment of the hypothesis at this scale of cortical organization. To avoid neglecting neuron and microcircuit levels of cortical organization, the connectome framework should incorporate more morphological description. In addition, structural analyses of temporal cost for cortical circuits should take account of both axonal conduction and neuronal integration delays, which appear mostly of the same order of magnitude. We conclude the hypothesized trade-off between spatial and temporal costs may potentially offer a powerful explanation for

  20. Effects of CT image segmentation methods on the accuracy of long bone 3D reconstructions.

    Science.gov (United States)

    Rathnayaka, Kanchana; Sahama, Tony; Schuetz, Michael A; Schmutz, Beat

    2011-03-01

    An accurate and accessible image segmentation method is in high demand for generating 3D bone models from CT scan data, as such models are required in many areas of medical research. Even though numerous sophisticated segmentation methods have been published over the years, most of them are not readily available to the general research community. Therefore, this study aimed to quantify the accuracy of three popular image segmentation methods, two implementations of intensity thresholding and Canny edge detection, for generating 3D models of long bones. In order to reduce user dependent errors associated with visually selecting a threshold value, we present a new approach of selecting an appropriate threshold value based on the Canny filter. A mechanical contact scanner in conjunction with a microCT scanner was utilised to generate the reference models for validating the 3D bone models generated from CT data of five intact ovine hind limbs. When the overall accuracy of the bone model is considered, the three investigated segmentation methods generated comparable results with mean errors in the range of 0.18-0.24 mm. However, for the bone diaphysis, Canny edge detection and Canny filter based thresholding generated 3D models with a significantly higher accuracy compared to those generated through visually selected thresholds. This study demonstrates that 3D models with sub-voxel accuracy can be generated utilising relatively simple segmentation methods that are available to the general research community.