Science.gov

Sample records for high-precision general-purpose detector

  1. High precision thermal neutron detectors

    SciTech Connect

    Radeka, V.; Schaknowski, N.A.; Smith, G.C.; Yu, B.

    1994-12-31

    Two-dimensional position sensitive detectors are indispensable in neutron diffraction experiments for determination of molecular and crystal structures in biology, solid-state physics and polymer chemistry. Some performance characteristics of these detectors are elementary and obvious, such as the position resolution, number of resolution elements, neutron detection efficiency, counting rate and sensitivity to gamma-ray background. High performance detectors are distinguished by more subtle characteristics such as the stability of the response (efficiency) versus position, stability of the recorded neutron positions, dynamic range, blooming or halo effects. While relatively few of them are needed around the world, these high performance devices are sophisticated and fairly complex, their development requires very specialized efforts. In this context, we describe here a program of detector development, based on {sup 3}He filled proportional chambers, which has been underway for some years at the Brookhaven National Laboratory. Fundamental approaches and practical considerations are outlined that have resulted in a series of high performance detectors with the best known position resolution, position stability, uniformity of response and reliability over time, for devices of this type.

  2. General-Purpose Detectors for the Large Hadron Collider

    NASA Astrophysics Data System (ADS)

    Froidevaux, Daniel; Sphicas, Paris

    2006-11-01

    This review describes the two general-purpose experiments, ATLAS and CMS, that have been designed to study proton-proton collisions at 14 TeV, the highest center-of-mass energy ever achieved, at the Large Hadron Collider at CERN in Geneva, Switzerland. These experiments have undergone a long research and development and construction period since 1989 and are now in the middle of a strenuous and exciting integration, installation, and commissioning period. After a brief introduction to the physics context and prospects as perceived today, this review presents an overview of both projects in terms of their global design characteristics. The main features and challenges related to the tracking systems, to the calorimetry, and to the muon spectrometers are described. The various aspects of the trigger and data acquisition systems and of the computing and software are also discussed broadly. Finally, we conclude with the lessons learned during the design and construction years.

  3. Fast, High-Precision Readout Circuit for Detector Arrays

    NASA Technical Reports Server (NTRS)

    Rider, David M.; Hancock, Bruce R.; Key, Richard W.; Cunningham, Thomas J.; Wrigley, Chris J.; Seshadri, Suresh; Sander, Stanley P.; Blavier, Jean-Francois L.

    2013-01-01

    The GEO-CAPE mission described in NASA's Earth Science and Applications Decadal Survey requires high spatial, temporal, and spectral resolution measurements to monitor and characterize the rapidly changing chemistry of the troposphere over North and South Americas. High-frame-rate focal plane arrays (FPAs) with many pixels are needed to enable such measurements. A high-throughput digital detector readout integrated circuit (ROIC) that meets the GEO-CAPE FPA needs has been developed, fabricated, and tested. The ROIC is based on an innovative charge integrating, fast, high-precision analog-to-digital circuit that is built into each pixel. The 128×128-pixel ROIC digitizes all 16,384 pixels simultaneously at frame rates up to 16 kHz to provide a completely digital output on a single integrated circuit at an unprecedented rate of 262 million pixels per second. The approach eliminates the need for off focal plane electronics, greatly reducing volume, mass, and power compared to conventional FPA implementations. A focal plane based on this ROIC will require less than 2 W of power on a 1×1-cm integrated circuit. The ROIC is fabricated of silicon using CMOS technology. It is designed to be indium bump bonded to a variety of detector materials including silicon PIN diodes, indium antimonide (InSb), indium gallium arsenide (In- GaAs), and mercury cadmium telluride (HgCdTe) detector arrays to provide coverage over a broad spectral range in the infrared, visible, and ultraviolet spectral ranges.

  4. High Precision Thermal, Structural and Optical Analysis of an External Occulter Using a Common Model and the General Purpose Multi-Physics Analysis Tool Cielo

    NASA Technical Reports Server (NTRS)

    Hoff, Claus; Cady, Eric; Chainyk, Mike; Kissil, Andrew; Levine, Marie; Moore, Greg

    2011-01-01

    The efficient simulation of multidisciplinary thermo-opto-mechanical effects in precision deployable systems has for years been limited by numerical toolsets that do not necessarily share the same finite element basis, level of mesh discretization, data formats, or compute platforms. Cielo, a general purpose integrated modeling tool funded by the Jet Propulsion Laboratory and the Exoplanet Exploration Program, addresses shortcomings in the current state of the art via features that enable the use of a single, common model for thermal, structural and optical aberration analysis, producing results of greater accuracy, without the need for results interpolation or mapping. This paper will highlight some of these advances, and will demonstrate them within the context of detailed external occulter analyses, focusing on in-plane deformations of the petal edges for both steady-state and transient conditions, with subsequent optical performance metrics including intensity distributions at the pupil and image plane.

  5. General-purpose adaptive edge detector based on an empirical edge model

    SciTech Connect

    Breedlove, J.R. Jr.; Cantoni, V.

    1982-01-01

    We present a new approach to computer edge detection for image mensuration. Our technique uses data from the actual image to build an edge-detector template for a matched filtering algorithm. We show that the procedure is superior to classical, template matching techniques for a computer-generated image and for a very noisy x-ray image.

  6. Highly precise stabilization of intracavity prism-based Er:fiber frequency comb using optical-microwave phase detector.

    PubMed

    Zhang, Shuangyou; Wu, Jiutao; Leng, Jianxiao; Lai, Shunnan; Zhao, Jianye

    2014-11-15

    In this Letter, we demonstrate a fully stabilized Er:fiber frequency comb by using a fiber-based, high-precision optical-microwave phase detector. To achieve high-precision and long-term phase locking of the repetition rate to a microwave reference, frequency control techniques (tuning pump power and cavity length) are combined together as its feedback. Since the pump power has been used for stabilization of the repetition rate, we introduce a pair of intracavity prisms as a regulator for carrier-envelope offset frequency, thereby phase locking one mode of the comb to the rubidium saturated absorption transition line. The stabilized comb performs the same high stability as the reference for the repetition rate and provides a residual frequency instability of 3.6×10(-13) for each comb mode. The demonstrated stabilization scheme could provide a high-precision comb for optical communication, direct frequency comb spectroscopy.

  7. Modeling of high-precision wavefront sensing with new generation of CMT avalanche photodiode infrared detectors.

    PubMed

    Gousset, Silvère; Petit, Cyril; Michau, Vincent; Fusco, Thierry; Robert, Clelia

    2015-12-01

    Near-infrared wavefront sensing allows for the enhancement of sky coverage with adaptive optics. The recently developed HgCdTe avalanche photodiode arrays are promising due to their very low detector noise, but still present an imperfect cosmetic that may directly impact real-time wavefront measurements for adaptive optics and thus degrade performance in astronomical applications. We propose here a model of a Shack-Hartmann wavefront measurement in the presence of residual fixed pattern noise and defective pixels. To adjust our models, a fine characterization of such an HgCdTe array, the RAPID sensor, is proposed. The impact of the cosmetic defects on the Shack-Hartmann measurement is assessed through numerical simulations. This study provides both a new insight on the applicability of cadmium mercury telluride (CMT) avalanche photodiodes detectors for astronomical applications and criteria to specify the cosmetic qualities of future arrays. PMID:26836674

  8. SALT, a dedicated readout chip for high precision tracking silicon strip detectors at the LHCb Upgrade

    NASA Astrophysics Data System (ADS)

    Bugiel, Sz.; Dasgupta, R.; Firlej, M.; Fiutowski, T.; Idzik, M.; Kuczynska, M.; Moron, J.; Swientek, K.; Szumlak, T.

    2016-02-01

    The Upstream Tracker (UT) silicon strip detector, one of the central parts of the tracker system of the modernised LHCb experiment, will use a new 128-channel readout ASIC called SALT. It will extract and digitise analogue signals from the UT sensors, perform digital signal processing and transmit a serial output data. The SALT is being designed in CMOS 130 nm process and uses a novel architecture comprising of analog front-end and fast (40 MSps) ultra-low power (<0.5 mW) 6-bit ADC in each channel. The prototype ASICs of important functional blocks, like analogue front-end, 6-bit SAR ADC, PLL, and DLL, were designed, fabricated and tested. A prototype of an 8-channel version of the SALT chip, comprising all important functionalities was also designed and fabricated. The architecture and design of the SALT, together with the selected preliminary tests results, are presented.

  9. Recent progress of MPPC-based scintillation detectors in high precision X-ray and gamma-ray imaging

    NASA Astrophysics Data System (ADS)

    Kataoka, J.; Kishimoto, A.; Fujita, T.; Nishiyama, T.; Kurei, Y.; Tsujikawa, T.; Oshima, T.; Taya, T.; Iwamoto, Y.; Ogata, H.; Okochi, H.; Ohsuka, S.; Ikeda, H.; Yamamoto, S.

    2015-06-01

    The multi-pixel photon counter (MPPC) is a promising light sensor for various applications, not only in physics experiments but also in nuclear medicine, industry, and even high-energy astrophysics. In this paper, we present the current status and most recent progress of the MPPC-based scintillation detectors, such as (1) a high-precision X-ray and gamma-ray spectral image sensor, (2) next-generation PET detectors with MRI, TOF, and DOI measurement capabilities, and (3) a compact gamma camera for environmental radiation surveys. We first present a new method of fabricating a Ce:GAGG scintillator plate (1 or 2 mm thick) with ultra-fine resolution (0.2 mm/pixel), cut using a dicing saw to create 50 μm wide micro-grooves. When the plate is optically coupled with a large-area MPPC array, excellent spatial resolution of 0.48 mm (FWHM) and energy resolution of 14% (FWHM) are obtained for 122 keV gamma rays. Hence, the detector can act as a convenient "multi-color" imaging device that can potentially be used for future SPECT and photon-counting CT. We then show a prototype system for a high-resolution MPPC-based PET scanner that can realize ≃1 mm (FWHM) spatial resolution, even under a strong magnetic field of 4.7 T. We develop a front-end ASIC intended for future TOF-PET scanner with a 16-channel readout that achieves a coincidence time resolution of 489 ps (FWHM). A novel design for a module with DOI-measurement capability for gamma rays is also presented by measuring the pulse height ratio of double-sided MPPCs coupled at both ends of scintillation crystal block. Finally, we present the concept of a two-plane Compton camera consisting of Ce:GAGG scintillator arrays coupled with thin MPPC arrays. As a result of the thin and compact features of the MPPC device, the camera not only achieves a small size (14×14×15 cm3) and light weight (1.9 kg) but also excellent sensitivity, compared to the conventional PMT-based pinhole camera used in Fukushima. Finally, we briefly

  10. Magnetic Microcalorimeter Gamma Detectors for High-Precision Non-Destructive Analysis, FY14 Extended Annual Report

    SciTech Connect

    Friedrich, S.

    2015-02-06

    Cryogenic gamma (γ) detectors with operating temperatures of ~0.1 K or below offer 10× better energy resolution than conventional high-purity germanium detectors that are currently used for non-destructive analysis (NDA) of nuclear materials. This can greatly increase the accuracy of NDA, especially at low-energies where gamma rays often have similar energies and cannot be resolved by Ge detectors. We are developing cryogenic γ–detectors based on metallic magnetic calorimeters (MMCs), which have the potential of higher resolution, faster count rates and better linearity than other cryogenic detector technologies. High linearity is essential to add spectra from different pixels in detector arrays that are needed for high sensitivity. Here we discuss the fabrication of a new generation of MMC γ–detectors in FY2014, and the resulting improvements in energy resolution and linearity of the new design. As an example of the type of NDA that cryogenic detectors enable, we demonstrate the direct detection of Pu-242 emissions with our MMC γ–detectors in the presence of Pu-240, and show that a quantitative NDA analysis agrees with the mass spectrometry

  11. Reduction of a grid moire pattern by integrating a carbon-interspaced high precision x-ray grid with a digital radiographic detector

    SciTech Connect

    Yoon, Jai-Woong; Park, Young-Guk; Park, Chun-Joo; Kim, Do-Il; Lee, Jin-Ho; Chung, Nag-Kun; Choe, Bo-Young; Suh, Tae-Suk; Lee, Hyoung-Koo

    2007-11-15

    The stationary grid commonly used with a digital x-ray detector causes a moire interference pattern due to the inadequate sampling of the grid shadows by the detector pixels. There are limitations with the previous methods used to remove the moire such as imperfect electromagnetic interference shielding and the loss of image information. A new method is proposed for removing the moire pattern by integrating a carbon-interspaced high precision x-ray grid with high grid line uniformity with the detector for frequency matching. The grid was aligned to the detector by translating and rotating the x-ray grid with respect to the detector using microcontrolled alignment mechanism. The gap between the grid and the detector surface was adjusted with micrometer precision to precisely match the projected grid line pitch to the detector pixel pitch. Considering the magnification of the grid shadows on the detector plane, the grids were manufactured such that the grid line frequency was slightly higher than the detector sampling frequency. This study examined the factors that affect the moire pattern, particularly the line frequency and displacement. The frequency of the moire pattern was found to be sensitive to the angular displacement of the grid with respect to the detector while the horizontal translation alters the phase but not the moire frequency. The frequency of the moire pattern also decreased with decreasing difference in frequency between the grid and the detector, and a moire-free image was produced after complete matching for a given source to detector distance. The image quality factors including the contrast, signal-to-noise ratio and uniformity in the images with and without the moire pattern were investigated.

  12. An Investigation of 154Eu as a High-Precision Multi-{gamma}-Ray Intensity Calibration Standard for Detector Arrays

    SciTech Connect

    Kulp, W.D.; Wood, J.L.; Krane, K. S.; Loats, J.; Schmelzenbach, P.D.; Stapels, C.J.; Norman, E.B.

    2005-05-24

    The decay of 154Eu has been studied using {gamma}-ray singles and {gamma} - {gamma} coincidence spectroscopy with an array of Compton-suppressed Ge detectors. Particular attention to coincidence summing in the analysis, with consideration of detailed decay cascades and angular correlation effects, suggests that previous studies have overlooked necessary corrections. It is concluded that 154Eu provides 26 {gamma} rays that can be used for relative efficiency calibrations from 120 to 1600 keV at the 0.7% precision level and that this precision could be improved in the future.

  13. A general purpose contouring system

    USGS Publications Warehouse

    Evenden, Gerald Ian

    1975-01-01

    Three Decsystem-10 FORTRAN IV programs provide a general purpose system for contouring two-dimensional data. The system can provide both quick or final, publication quality contour maps on either interactive or offline plotting devices. Complete user documentation, with examples, and program listings are presented.

  14. General purpose programmable accelerator board

    DOEpatents

    Robertson, Perry J.; Witzke, Edward L.

    2001-01-01

    A general purpose accelerator board and acceleration method comprising use of: one or more programmable logic devices; a plurality of memory blocks; bus interface for communicating data between the memory blocks and devices external to the board; and dynamic programming capabilities for providing logic to the programmable logic device to be executed on data in the memory blocks.

  15. General purpose steam table library :

    SciTech Connect

    Carpenter, John H.; Belcourt, Kenneth Noel; Nourgaliev, Robert

    2013-08-01

    Completion of the CASL L3 milestone THM.CFD.P7.04 provides a general purpose tabular interpolation library for material properties to support, in particular, standardized models for steam properties. The software consists of three parts, implementations of analytic steam models, a code to generate tables from those models, and an interpolation package to interface the tables to CFD codes such as Hydra-TH. Verification of the standard model is maintained through the entire train of routines. The performance of interpolation package exceeds that of freely available analytic implementation of the steam properties by over an order of magnitude.

  16. General purpose computers in real time

    SciTech Connect

    Biel, J.R.

    1989-09-18

    I see three main trends in the use of general purpose computers in real time. The first is more processing power. The second is the use of higher speed interconnects between computers (allowing more data to be delivered to the processors). The third is the use of larger programs running in the computers. Although there is still work that needs to be done, I believe that all indications are that the online need for general purpose computers should be available for the SCC and LHC machines. 2 figs.

  17. 7 CFR 254.1 - General purpose.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... INDIAN HOUSEHOLDS IN OKLAHOMA § 254.1 General purpose. This part sets the requirement under which... service areas in Oklahoma. This part also sets the conditions for administration of the Food Distribution Program by eligible Oklahoma tribes determined capable by the Department....

  18. 7 CFR 254.1 - General purpose.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... INDIAN HOUSEHOLDS IN OKLAHOMA § 254.1 General purpose. This part sets the requirement under which... service areas in Oklahoma. This part also sets the conditions for administration of the Food Distribution Program by eligible Oklahoma tribes determined capable by the Department....

  19. Field Evaluation of a General Purpose Simulator.

    ERIC Educational Resources Information Center

    Spangenberg, Ronald W.

    The use of a general purpose simulator (GPS) to teach Air Force technicians diagnostic and repair procedures for specialized aircraft radar systems is described. An EC II simulator manufactured by Educational Computer Corporation was adapted to resemble the actual configuration technicians would encounter in the field. Data acquired in the…

  20. 10 CFR 205.350 - General purpose.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 10 Energy 3 2011-01-01 2011-01-01 false General purpose. 205.350 Section 205.350 Energy DEPARTMENT OF ENERGY OIL ADMINISTRATIVE PROCEDURES AND SANCTIONS Electric Power System Permits and Reports... on the electric energy supply systems in the United States so that appropriate Federal...

  1. 10 CFR 205.350 - General purpose.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 10 Energy 3 2010-01-01 2010-01-01 false General purpose. 205.350 Section 205.350 Energy DEPARTMENT OF ENERGY OIL ADMINISTRATIVE PROCEDURES AND SANCTIONS Electric Power System Permits and Reports... on the electric energy supply systems in the United States so that appropriate Federal...

  2. General-Purpose Compression for Efficient Retrieval.

    ERIC Educational Resources Information Center

    Cannane, Adam; Williams, Hugh E.

    2001-01-01

    Discusses compression of databases that reduces space requirements and retrieval times; considers compression of documents in text databases based on semistatic modeling with words; and proposes a scheme for general purpose compression that can be applied to all types of data stored in large collections. (Author/LRW)

  3. 12 CFR 1703.31 - General purposes.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 12 Banks and Banking 7 2010-01-01 2010-01-01 false General purposes. 1703.31 Section 1703.31 Banks... DEVELOPMENT OFHEO ORGANIZATION AND FUNCTIONS RELEASE OF INFORMATION Testimony and Production of Documents in... time of employees for their official duties, maintain the impartial position of OFHEO in litigation...

  4. General-Purpose Image-Data Program

    NASA Technical Reports Server (NTRS)

    Engle, Steven W.

    1988-01-01

    Image Database computer program, IBASE, is general-purpose imagery-information system. Use accomplished either by commands or through hierarchy of menus. Analytical capabilities of IBASE include contigency tables, image filtering (low-, high-, and band-pass), proximity maps, clustering, histograms, regression, slope calculations, scaling, and Boolean manipulations. Also has interface to Cheshire Image Classification expert system. Written in FORTRAN 77.

  5. PRISM: a general purpose programming system

    SciTech Connect

    Rogers, C.R.; O'Hara, S.A.

    1983-03-01

    This paper describes the development, uses, and features of the general purpose programming system PRISM, which is the foundation for future program development by the Computer Programming Branch and is available to all personnel within the Air Force Human Resources Laboratory (AFHRL). PRISM was designed to meet the need for an efficient and reliable programming tool that could be used like a high-order programming language but still provide the operating system interface and hardware controls of assembly language. It has special features that make it an especially powerful tool for new software development. These features were derived from an extensive analysis of coding sequences in existing library programs, interactions between library programs, and the identification of common programming procedures. PRISM was specifically designed for the development of general purpose programs by the Technical Services Division of AFHRL within the Computer Programming Branch; however, it is also an effective and efficient tool for applications programmers.

  6. General-Purpose Graphics-Library Program

    NASA Technical Reports Server (NTRS)

    Rogers, Joseph E.

    1993-01-01

    NASA Device Independent Graphics Library (NASADIG) computer program is general-purpose graphics-library program for use with many computer-based-engineering and management application programs. Software offers many features providing user with flexibility in creating graphics. Includes two- and three-dimensional plotting, splines and polynomial interpolation, area blanking control, multiple log/linear axes, legends and text control, curve-thickness control, and multiple text fonts. Written in ANSI FORTRAN 77.

  7. General-Purpose Software For Computer Graphics

    NASA Technical Reports Server (NTRS)

    Rogers, Joseph E.

    1992-01-01

    NASA Device Independent Graphics Library (NASADIG) is general-purpose computer-graphics package for computer-based engineering and management applications which gives opportunity to translate data into effective graphical displays for presentation. Features include two- and three-dimensional plotting, spline and polynomial interpolation, control of blanking of areas, multiple log and/or linear axes, control of legends and text, control of thicknesses of curves, and multiple text fonts. Included are subroutines for definition of areas and axes of plots; setup and display of text; blanking of areas; setup of style, interpolation, and plotting of lines; control of patterns and of shading of colors; control of legends, blocks of text, and characters; initialization of devices; and setting of mixed alphabets. Written in FORTRAN 77.

  8. Deictic primitives for general purpose navigation

    NASA Technical Reports Server (NTRS)

    Crismann, Jill D.

    1994-01-01

    A visually-based deictic primative used as an elementary command set for general purpose navigation was investigated. It was shown that a simple 'follow your eyes' scenario is sufficient for tracking a moving target. Limitations of velocity, acceleration, and modeling of the response of the mechanical systems were enforced. Realistic paths of the robots were produced during the simulation. Scientists could remotely command a planetary rover to go to a particular rock formation that may be interesting. Similarly an expert at plant maintenance could obtain diagnostic information remotely by using deictic primitives on a mobile are used in the deictic primitives, we could imagine that the exact same control software could be used for all of these applications.

  9. General purpose optimization software for engineering design

    NASA Technical Reports Server (NTRS)

    Vanderplaats, G. N.

    1990-01-01

    The author has developed several general purpose optimization programs over the past twenty years. The earlier programs were developed as research codes and served that purpose reasonably well. However, in taking the formal step from research to industrial application programs, several important lessons have been learned. Among these are the importance of clear documentation, immediate user support, and consistent maintenance. Most important has been the issue of providing software that gives a good, or at least acceptable, design at minimum computational cost. Here, the basic issues developing optimization software for industrial applications are outlined and issues of convergence rate, reliability, and relative minima are discussed. Considerable feedback has been received from users, and new software is being developed to respond to identified needs. The basic capabilities of this software are outlined. A major motivation for the development of commercial grade software is ease of use and flexibility, and these issues are discussed with reference to general multidisciplinary applications. It is concluded that design productivity can be significantly enhanced by the more widespread use of optimization as an everyday design tool.

  10. General-purpose abductive algorithm for interpretation

    NASA Astrophysics Data System (ADS)

    Fox, Richard K.; Hartigan, Julie

    1996-11-01

    Abduction, inference to the best explanation, is an information-processing task that is useful for solving interpretation problems such as diagnosis, medical test analysis, legal reasoning, theory evaluation, and perception. The task is a generative one in which an explanation comprising of domain hypotheses is assembled and used to account for given findings. The explanation is taken to be an interpretation as to why the findings have arisen within the given situation. Research in abduction has led to the development of a general-purpose computational strategy which has been demonstrated on all of the above types of problems. This abduction strategy can be performed in layers so that different types of knowledge can come together in deriving an explanation at different levels of description. Further, the abduction strategy is tractable and offers a very useful tradeoff between confidence in the explanation and completeness of the explanation. This paper will describe this computational strategy for abduction and demonstrate its usefulness towards perceptual problems by examining problem-solving systems in speech recognition and natural language understanding.

  11. The General-Purpose Heat Source Radioisotope Thermoelectric Generator: A Truly General-Purpose Space RTG

    NASA Astrophysics Data System (ADS)

    Bennett, Gary L.; Lombardo, James J.; Hemler, Richard J.; Silverman, Gil; Whitmore, C. W.; Amos, Wayne R.; Johnson, E. W.; Zocher, Roy W.; Hagan, James C.; Englehart, Richard W.

    2008-01-01

    The General-Purpose Heat Source Radioisotope Thermoelectric Generator (GPHS-RTG) was developed for the originally planned International Solar Polar Mission (ISPM). [ISPM would later, with the elimination of the NASA spacecraft, become the Ulysses mission.] At 300 We beginning-of-life (BOL) power, the GPHS-RTG was the most powerful RTG with the highest specific power (5.3 We/kg) of any space RTG. These improved performance attributes of the GPHS-RTG made it attractive for use on the Galileo mission. Subsequently, the GPHS-RTG was selected to power the Cassini spacecraft, which is currently orbiting Saturn, and the New Horizons spacecraft which is on its way to Pluto. Truly, the GPHS-RTG is a ``general-purpose'' space RTG.

  12. 21 CFR 880.6890 - General purpose disinfectants.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 21 Food and Drugs 8 2014-04-01 2014-04-01 false General purpose disinfectants. 880.6890 Section... Miscellaneous Devices § 880.6890 General purpose disinfectants. (a) Identification. A general purpose disinfectant is a germicide intended to process noncritical medical devices and equipment surfaces. A...

  13. 21 CFR 880.6890 - General purpose disinfectants.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 8 2013-04-01 2013-04-01 false General purpose disinfectants. 880.6890 Section... Miscellaneous Devices § 880.6890 General purpose disinfectants. (a) Identification. A general purpose disinfectant is a germicide intended to process noncritical medical devices and equipment surfaces. A...

  14. 21 CFR 880.6890 - General purpose disinfectants.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 21 Food and Drugs 8 2010-04-01 2010-04-01 false General purpose disinfectants. 880.6890 Section... Miscellaneous Devices § 880.6890 General purpose disinfectants. (a) Identification. A general purpose disinfectant is a germicide intended to process noncritical medical devices and equipment surfaces. A...

  15. 21 CFR 880.6890 - General purpose disinfectants.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 21 Food and Drugs 8 2011-04-01 2011-04-01 false General purpose disinfectants. 880.6890 Section... Miscellaneous Devices § 880.6890 General purpose disinfectants. (a) Identification. A general purpose disinfectant is a germicide intended to process noncritical medical devices and equipment surfaces. A...

  16. 21 CFR 880.6890 - General purpose disinfectants.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 8 2012-04-01 2012-04-01 false General purpose disinfectants. 880.6890 Section... Miscellaneous Devices § 880.6890 General purpose disinfectants. (a) Identification. A general purpose disinfectant is a germicide intended to process noncritical medical devices and equipment surfaces. A...

  17. 47 CFR 32.6124 - General purpose computers expense.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 47 Telecommunication 2 2012-10-01 2012-10-01 false General purpose computers expense. 32.6124... General purpose computers expense. This account shall include the costs of personnel whose principal job is the physical operation of general purpose computers and the maintenance of operating systems....

  18. 47 CFR 32.6124 - General purpose computers expense.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 47 Telecommunication 2 2011-10-01 2011-10-01 false General purpose computers expense. 32.6124... General purpose computers expense. This account shall include the costs of personnel whose principal job is the physical operation of general purpose computers and the maintenance of operating systems....

  19. 47 CFR 32.6124 - General purpose computers expense.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 47 Telecommunication 2 2010-10-01 2010-10-01 false General purpose computers expense. 32.6124... General purpose computers expense. This account shall include the costs of personnel whose principal job is the physical operation of general purpose computers and the maintenance of operating systems....

  20. 47 CFR 32.6124 - General purpose computers expense.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 47 Telecommunication 2 2014-10-01 2014-10-01 false General purpose computers expense. 32.6124... General purpose computers expense. This account shall include the costs of personnel whose principal job is the physical operation of general purpose computers and the maintenance of operating systems....

  1. 47 CFR 32.6124 - General purpose computers expense.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 47 Telecommunication 2 2013-10-01 2013-10-01 false General purpose computers expense. 32.6124... General purpose computers expense. This account shall include the costs of personnel whose principal job is the physical operation of general purpose computers and the maintenance of operating systems....

  2. High precision redundant robotic manipulator

    DOEpatents

    Young, K.K.D.

    1998-09-22

    A high precision redundant robotic manipulator for overcoming contents imposed by obstacles or imposed by a highly congested work space is disclosed. One embodiment of the manipulator has four degrees of freedom and another embodiment has seven degrees of freedom. Each of the embodiments utilize a first selective compliant assembly robot arm (SCARA) configuration to provide high stiffness in the vertical plane, a second SCARA configuration to provide high stiffness in the horizontal plane. The seven degree of freedom embodiment also utilizes kinematic redundancy to provide the capability of avoiding obstacles that lie between the base of the manipulator and the end effector or link of the manipulator. These additional three degrees of freedom are added at the wrist link of the manipulator to provide pitch, yaw and roll. The seven degrees of freedom embodiment uses one revolute point per degree of freedom. For each of the revolute joints, a harmonic gear coupled to an electric motor is introduced, and together with properly designed based servo controllers provide an end point repeatability of less than 10 microns. 3 figs.

  3. High precision redundant robotic manipulator

    DOEpatents

    Young, Kar-Keung David

    1998-01-01

    A high precision redundant robotic manipulator for overcoming contents imposed by obstacles or imposed by a highly congested work space. One embodiment of the manipulator has four degrees of freedom and another embodiment has seven degreed of freedom. Each of the embodiments utilize a first selective compliant assembly robot arm (SCARA) configuration to provide high stiffness in the vertical plane, a second SCARA configuration to provide high stiffness in the horizontal plane. The seven degree of freedom embodiment also utilizes kinematic redundancy to provide the capability of avoiding obstacles that lie between the base of the manipulator and the end effector or link of the manipulator. These additional three degrees of freedom are added at the wrist link of the manipulator to provide pitch, yaw and roll. The seven degrees of freedom embodiment uses one revolute point per degree of freedom. For each of the revolute joints, a harmonic gear coupled to an electric motor is introduced, and together with properly designed based servo controllers provide an end point repeatability of less than 10 microns.

  4. High precision beam alignment of electromagnetic wigglers

    SciTech Connect

    Ben-Zvi, I.; Qiu, X.Z.

    1993-01-01

    The performance of Free-Electron Lasers depends critically on the quality of the alignment of the electron beam to the wiggler's magnetic axis and the deviation of this axis from a straight fine. The measurement of the electron beam position requires numerous beam position monitors in the wiggler, where space is at premium. The beam position measurement is used to set beam steerers for an orbit correction in the wiggler. The authors propose an alternative high precision alignment method in which one or two external Beam Position Monitors (BPM) are used. In this technique, the field in the electro-wiggler is modulated section by section and the beam position movement at the external BPM is detected in synchronism with the modulation. A beam offset at the modulated beam section will produce a modulation of the beam position at the detector that is a function of the of the beam offset and the absolute value of the modulation current. The wiggler errors produce a modulation that is a function of the modulation current. It will be shown that this method allows the detection and correction of the beam position at each section in the presence of wiggler errors with a good resolution. Furthermore, it allows one to measure the first and second integrals of the wiggler error over each wiggler section. Lastly, provided that wiggler sections can be degaussed effectively, one can test the deviation of the wiggler's magnetic axis from a straight line.

  5. 22 CFR 211.1 - General purpose and scope; legislation.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 22 Foreign Relations 1 2010-04-01 2010-04-01 false General purpose and scope; legislation. 211.1 Section 211.1 Foreign Relations AGENCY FOR INTERNATIONAL DEVELOPMENT TRANSFER OF FOOD COMMODITIES FOR FOOD USE IN DISASTER RELIEF, ECONOMIC DEVELOPMENT AND OTHER ASSISTANCE § 211.1 General purpose and...

  6. 47 CFR 32.2124 - General purpose computers.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 47 Telecommunication 2 2012-10-01 2012-10-01 false General purpose computers. 32.2124 Section 32... General purpose computers. (a) This account shall include the original cost of computers and peripheral... cost of computers and their associated peripheral devices associated with switching, network...

  7. 47 CFR 32.2124 - General purpose computers.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 47 Telecommunication 2 2013-10-01 2013-10-01 false General purpose computers. 32.2124 Section 32... General purpose computers. (a) This account shall include the original cost of computers and peripheral... cost of computers and their associated peripheral devices associated with switching, network...

  8. 47 CFR 32.2124 - General purpose computers.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 47 Telecommunication 2 2011-10-01 2011-10-01 false General purpose computers. 32.2124 Section 32... General purpose computers. (a) This account shall include the original cost of computers and peripheral... cost of computers and their associated peripheral devices associated with switching, network...

  9. 47 CFR 32.2124 - General purpose computers.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 47 Telecommunication 2 2014-10-01 2014-10-01 false General purpose computers. 32.2124 Section 32... General purpose computers. (a) This account shall include the original cost of computers and peripheral... cost of computers and their associated peripheral devices associated with switching, network...

  10. GRASP: General-purpose Relativistic Atomic Structure Package

    NASA Astrophysics Data System (ADS)

    Grant, I. P.; McKenzie, B. J.; Norrington, P. H.; Mayers, D. F.; Pyper, N. C.

    2016-09-01

    GRASP (General-purpose Relativistic Atomic Structure Package) calculates atomic structure, including energy levels, radiative rates (A-values) and lifetimes; it is a fully relativistic code based on the jj coupling scheme.

  11. 7 CFR 220.1 - General purpose and scope.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... AGRICULTURE CHILD NUTRITION PROGRAMS SCHOOL BREAKFAST PROGRAM § 220.1 General purpose and scope. This part announces the policies and prescribes the regulations necessary to carry out the provisions of section 4...

  12. 7 CFR 1485.10 - General purpose and scope.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... develop, maintain or expand commercial export markets for U.S. agricultural commodities and products. MAP... FOREIGN MARKETS FOR AGRICULTURAL COMMODITIES Market Access Program § 1485.10 General purpose and scope. (a... the Market Access Program (MAP), and a subcomponent of that program, the Export Incentive...

  13. 7 CFR 227.1 - General purpose and scope.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... Agriculture Regulations of the Department of Agriculture (Continued) FOOD AND NUTRITION SERVICE, DEPARTMENT OF AGRICULTURE CHILD NUTRITION PROGRAMS NUTRITION EDUCATION AND TRAINING PROGRAM General § 227.1 General purpose and scope. The purpose of these regulations is to implement section 19 of the Child Nutrition...

  14. 7 CFR 227.1 - General purpose and scope.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... Agriculture Regulations of the Department of Agriculture (Continued) FOOD AND NUTRITION SERVICE, DEPARTMENT OF AGRICULTURE CHILD NUTRITION PROGRAMS NUTRITION EDUCATION AND TRAINING PROGRAM General § 227.1 General purpose and scope. The purpose of these regulations is to implement section 19 of the Child Nutrition...

  15. 7 CFR 240.1 - General purpose and scope.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... nonresidential child or adult care institutions participating in the Child and Adult Care Food Program (7 CFR... Agriculture Regulations of the Department of Agriculture (Continued) FOOD AND NUTRITION SERVICE, DEPARTMENT OF AGRICULTURE CHILD NUTRITION PROGRAMS CASH IN LIEU OF DONATED FOODS § 240.1 General purpose and scope. (a)...

  16. 7 CFR 235.1 - General purpose and scope.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... part 220), the Child and Adult Care Food Program (7 CFR part 226) and the Food Distribution Program (7... Agriculture Regulations of the Department of Agriculture (Continued) FOOD AND NUTRITION SERVICE, DEPARTMENT OF AGRICULTURE CHILD NUTRITION PROGRAMS STATE ADMINISTRATIVE EXPENSE FUNDS § 235.1 General purpose and...

  17. 7 CFR 226.1 - General purpose and scope.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... Agriculture Regulations of the Department of Agriculture (Continued) FOOD AND NUTRITION SERVICE, DEPARTMENT OF AGRICULTURE CHILD NUTRITION PROGRAMS CHILD AND ADULT CARE FOOD PROGRAM General § 226.1 General purpose and... Child and Adult Care Food Program. Section 17 of the National School Lunch Act, as amended,...

  18. 7 CFR 281.1 - General purpose and scope.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... AGRICULTURE FOOD STAMP AND FOOD DISTRIBUTION PROGRAM ADMINISTRATION OF SNAP ON INDIAN RESERVATIONS § 281.1 General purpose and scope. (a) These regulations govern the operation of SNAP on Indian reservations either separately or concurrently with the Food distribution program. In order to assure that SNAP...

  19. 7 CFR 227.1 - General purpose and scope.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... Agriculture Regulations of the Department of Agriculture (Continued) FOOD AND NUTRITION SERVICE, DEPARTMENT OF AGRICULTURE CHILD NUTRITION PROGRAMS NUTRITION EDUCATION AND TRAINING PROGRAM General § 227.1 General purpose and scope. The purpose of these regulations is to implement section 19 of the Child Nutrition...

  20. 7 CFR 227.1 - General purpose and scope.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... Agriculture Regulations of the Department of Agriculture (Continued) FOOD AND NUTRITION SERVICE, DEPARTMENT OF AGRICULTURE CHILD NUTRITION PROGRAMS NUTRITION EDUCATION AND TRAINING PROGRAM General § 227.1 General purpose and scope. The purpose of these regulations is to implement section 19 of the Child Nutrition...

  1. 7 CFR 227.1 - General purpose and scope.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... Agriculture Regulations of the Department of Agriculture (Continued) FOOD AND NUTRITION SERVICE, DEPARTMENT OF AGRICULTURE CHILD NUTRITION PROGRAMS NUTRITION EDUCATION AND TRAINING PROGRAM General § 227.1 General purpose and scope. The purpose of these regulations is to implement section 19 of the Child Nutrition...

  2. Thermoplastic analysis of general-purpose heat-source modules

    NASA Astrophysics Data System (ADS)

    Chang, Y.; Ecker, J. A.

    1993-01-01

    Prior thermoelastic analyses were conducted to assess the thermostructural response of the Galileo radioisotope thermoelectric generators general-purpose heat-source (GPHS) modules upon possible accidental reentry into earth's atmosphere. These analyses are extended through the inclusion of thermoplasticity of the composite material of the GPHS modules. The thermoplastic analysis methods for GPHS composite material are presented.

  3. 7 CFR 240.1 - General purpose and scope.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... nonresidential child or adult care institutions participating in the Child and Adult Care Food Program (7 CFR... Agriculture Regulations of the Department of Agriculture (Continued) FOOD AND NUTRITION SERVICE, DEPARTMENT OF AGRICULTURE CHILD NUTRITION PROGRAMS CASH IN LIEU OF DONATED FOODS § 240.1 General purpose and scope. (a)...

  4. 7 CFR 235.1 - General purpose and scope.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... part 220), the Child and Adult Care Food Program (7 CFR part 226) and the Food Distribution Program (7... Agriculture Regulations of the Department of Agriculture (Continued) FOOD AND NUTRITION SERVICE, DEPARTMENT OF AGRICULTURE CHILD NUTRITION PROGRAMS STATE ADMINISTRATIVE EXPENSE FUNDS § 235.1 General purpose and...

  5. 7 CFR 226.1 - General purpose and scope.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... Agriculture Regulations of the Department of Agriculture (Continued) FOOD AND NUTRITION SERVICE, DEPARTMENT OF AGRICULTURE CHILD NUTRITION PROGRAMS CHILD AND ADULT CARE FOOD PROGRAM General § 226.1 General purpose and... Child and Adult Care Food Program. Section 17 of the National School Lunch Act, as amended,...

  6. 7 CFR 225.1 - General purpose and scope.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... Agriculture Regulations of the Department of Agriculture (Continued) FOOD AND NUTRITION SERVICE, DEPARTMENT OF AGRICULTURE CHILD NUTRITION PROGRAMS SUMMER FOOD SERVICE PROGRAM General § 225.1 General purpose and scope. This part establishes the regulations under which the Secretary will administer a Summer Food...

  7. 7 CFR 220.1 - General purpose and scope.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... Agriculture Regulations of the Department of Agriculture (Continued) FOOD AND NUTRITION SERVICE, DEPARTMENT OF AGRICULTURE CHILD NUTRITION PROGRAMS SCHOOL BREAKFAST PROGRAM § 220.1 General purpose and scope. This part... the Child Nutrition Act of 1966, as amended, which authorizes payments to the States to assist them...

  8. 7 CFR 210.1 - General purpose and scope.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... Agriculture Regulations of the Department of Agriculture (Continued) FOOD AND NUTRITION SERVICE, DEPARTMENT OF AGRICULTURE CHILD NUTRITION PROGRAMS NATIONAL SCHOOL LUNCH PROGRAM General § 210.1 General purpose and scope. (a) Purpose of the program. Section 2 of the National School Lunch Act (42 U.S.C. 1751), states:...

  9. 7 CFR 210.1 - General purpose and scope.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... AGRICULTURE CHILD NUTRITION PROGRAMS NATIONAL SCHOOL LUNCH PROGRAM General § 210.1 General purpose and scope. (a) Purpose of the program. Section 2 of the National School Lunch Act (42 U.S.C. 1751), states: “It... expansion of nonprofit school lunch programs.” Pursuant to this act, the Department provides States...

  10. 7 CFR 226.1 - General purpose and scope.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... Child and Adult Care Food Program. Section 17 of the National School Lunch Act, as amended, authorizes... AGRICULTURE CHILD NUTRITION PROGRAMS CHILD AND ADULT CARE FOOD PROGRAM General § 226.1 General purpose and... service programs for children or adult participants in nonresidential institutions which provide care....

  11. 7 CFR 210.1 - General purpose and scope.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... AGRICULTURE CHILD NUTRITION PROGRAMS NATIONAL SCHOOL LUNCH PROGRAM General § 210.1 General purpose and scope. (a) Purpose of the program. Section 2 of the National School Lunch Act (42 U.S.C. 1751), states: “It... expansion of nonprofit school lunch programs.” Pursuant to this act, the Department provides States...

  12. 7 CFR 226.1 - General purpose and scope.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... Child and Adult Care Food Program. Section 17 of the National School Lunch Act, as amended, authorizes... AGRICULTURE CHILD NUTRITION PROGRAMS CHILD AND ADULT CARE FOOD PROGRAM General § 226.1 General purpose and... service programs for children or adult participants in nonresidential institutions which provide care....

  13. 7 CFR 226.1 - General purpose and scope.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... Child and Adult Care Food Program. Section 17 of the National School Lunch Act, as amended, authorizes... AGRICULTURE CHILD NUTRITION PROGRAMS CHILD AND ADULT CARE FOOD PROGRAM General § 226.1 General purpose and... service programs for children or adult participants in nonresidential institutions which provide care....

  14. 7 CFR 210.1 - General purpose and scope.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... AGRICULTURE CHILD NUTRITION PROGRAMS NATIONAL SCHOOL LUNCH PROGRAM General § 210.1 General purpose and scope. (a) Purpose of the program. Section 2 of the National School Lunch Act (42 U.S.C. 1751), states: “It... expansion of nonprofit school lunch programs.” Pursuant to this act, the Department provides States...

  15. A general purpose feature extractor for light detection and ranging data.

    PubMed

    Li, Yangming; Olson, Edwin B

    2010-01-01

    Feature extraction is a central step of processing Light Detection and Ranging (LIDAR) data. Existing detectors tend to exploit characteristics of specific environments: corners and lines from indoor (rectilinear) environments, and trees from outdoor environments. While these detectors work well in their intended environments, their performance in different environments can be poor. We describe a general purpose feature detector for both 2D and 3D LIDAR data that is applicable to virtually any environment. Our method adapts classic feature detection methods from the image processing literature, specifically the multi-scale Kanade-Tomasi corner detector. The resulting method is capable of identifying highly stable and repeatable features at a variety of spatial scales without knowledge of environment, and produces principled uncertainty estimates and corner descriptors at same time. We present results on both software simulation and standard datasets, including the 2D Victoria Park and Intel Research Center datasets, and the 3D MIT DARPA Urban Challenge dataset.

  16. A general purpose feature extractor for light detection and ranging data.

    PubMed

    Li, Yangming; Olson, Edwin B

    2010-01-01

    Feature extraction is a central step of processing Light Detection and Ranging (LIDAR) data. Existing detectors tend to exploit characteristics of specific environments: corners and lines from indoor (rectilinear) environments, and trees from outdoor environments. While these detectors work well in their intended environments, their performance in different environments can be poor. We describe a general purpose feature detector for both 2D and 3D LIDAR data that is applicable to virtually any environment. Our method adapts classic feature detection methods from the image processing literature, specifically the multi-scale Kanade-Tomasi corner detector. The resulting method is capable of identifying highly stable and repeatable features at a variety of spatial scales without knowledge of environment, and produces principled uncertainty estimates and corner descriptors at same time. We present results on both software simulation and standard datasets, including the 2D Victoria Park and Intel Research Center datasets, and the 3D MIT DARPA Urban Challenge dataset. PMID:22163474

  17. High precision, rapid laser hole drilling

    DOEpatents

    Chang, Jim J.; Friedman, Herbert W.; Comaskey, Brian J.

    2005-03-08

    A laser system produces a first laser beam for rapidly removing the bulk of material in an area to form a ragged hole. The laser system produces a second laser beam for accurately cleaning up the ragged hole so that the final hole has dimensions of high precision.

  18. High precision, rapid laser hole drilling

    DOEpatents

    Chang, Jim J.; Friedman, Herbert W.; Comaskey, Brian J.

    2013-04-02

    A laser system produces a first laser beam for rapidly removing the bulk of material in an area to form a ragged hole. The laser system produces a second laser beam for accurately cleaning up the ragged hole so that the final hole has dimensions of high precision.

  19. High precision, rapid laser hole drilling

    DOEpatents

    Chang, Jim J.; Friedman, Herbert W.; Comaskey, Brian J.

    2007-03-20

    A laser system produces a first laser beam for rapidly removing the bulk of material in an area to form a ragged hole. The laser system produces a second laser beam for accurately cleaning up the ragged hole so that the final hole has dimensions of high precision.

  20. High Precision Pressure Measurement with a Funnel

    ERIC Educational Resources Information Center

    Lopez-Arias, T.; Gratton, L. M.; Oss, S.

    2008-01-01

    A simple experimental device for high precision differential pressure measurements is presented. Its working mechanism recalls that of a hydraulic press, where pressure is supplied by insufflating air under a funnel. As an application, we measure air pressure inside a soap bubble. The soap bubble is inflated and connected to a funnel which is…

  1. High precision measurements in crustal dynamic studies

    NASA Technical Reports Server (NTRS)

    Wyatt, F.; Berger, J.

    1984-01-01

    The development of high-precision instrumentation for monitoring benchmark stability and evaluating coseismic strain and tilt signals is reviewed. Laser strainmeter and tilt observations are presented. Examples of coseismic deformation in several geographic locations are given. Evidence suggests that the Earth undergoes elastic response to abrupt faulting.

  2. A Small Acoustic Goniometer for General Purpose Research.

    PubMed

    Pook, Michael L; Loo, Sin Ming

    2016-01-01

    Understanding acoustic events and monitoring their occurrence is a useful aspect of many research projects. In particular, acoustic goniometry allows researchers to determine the source of an event based solely on the sound it produces. The vast majority of acoustic goniometry research projects used custom hardware targeted to the specific application under test. Unfortunately, due to the wide range of sensing applications, a flexible general purpose hardware/firmware system does not exist for this purpose. This article focuses on the development of such a system which encourages the continued exploration of general purpose hardware/firmware and lowers barriers to research in projects requiring the use of acoustic goniometry. Simulations have been employed to verify system feasibility, and a complete hardware implementation of the acoustic goniometer has been designed and field tested. The results are reported, and suggested areas for improvement and further exploration are discussed. PMID:27136563

  3. Speed Control of General Purpose Engine with Electronic Governor

    NASA Astrophysics Data System (ADS)

    Sawut, Umerujan; Tohti, Gheyret; Takigawa, Buso; Tsuji, Teruo

    This paper presents a general purpose engine speed control system with an electronic governor in order to improve the current system with a mechanical governor which shows unstable characteristics by change of mecanical friction or A/F ratio (Air/Fuel ratio). For the control system above, there are problems that the feedback signal is only a crank angle because of cost and the controlled object is a general purpose engine which is strongly nonlinear. In order to overcome these problems, the system model is shown for the dynamic estimation of the amount of air flow and the robust controller is designed. That is, the proposed system includes the robust sliding-mode controller by the feedback signal of only a crank angle where Genetic Algorithm is applied for the controller design. The simulation and the experiments by MATLAB/Simulink are performed to show the effectiveness of our proposal.

  4. A Small Acoustic Goniometer for General Purpose Research

    PubMed Central

    Pook, Michael L.; Loo, Sin Ming

    2016-01-01

    Understanding acoustic events and monitoring their occurrence is a useful aspect of many research projects. In particular, acoustic goniometry allows researchers to determine the source of an event based solely on the sound it produces. The vast majority of acoustic goniometry research projects used custom hardware targeted to the specific application under test. Unfortunately, due to the wide range of sensing applications, a flexible general purpose hardware/firmware system does not exist for this purpose. This article focuses on the development of such a system which encourages the continued exploration of general purpose hardware/firmware and lowers barriers to research in projects requiring the use of acoustic goniometry. Simulations have been employed to verify system feasibility, and a complete hardware implementation of the acoustic goniometer has been designed and field tested. The results are reported, and suggested areas for improvement and further exploration are discussed. PMID:27136563

  5. General-Purpose Serial Interface For Remote Control

    NASA Technical Reports Server (NTRS)

    Busquets, Anthony M.; Gupton, Lawrence E.

    1990-01-01

    Computer controls remote television camera. General-purpose controller developed to serve as interface between host computer and pan/tilt/zoom/focus functions on series of automated video cameras. Interface port based on 8251 programmable communications-interface circuit configured for tristated outputs, and connects controller system to any host computer with RS-232 input/output (I/O) port. Accepts byte-coded data from host, compares them with prestored codes in read-only memory (ROM), and closes or opens appropriate switches. Six output ports control opening and closing of as many as 48 switches. Operator controls remote television camera by speaking commands, in system including general-purpose controller.

  6. Linear equations in general purpose codes for stiff ODEs

    SciTech Connect

    Shampine, L. F.

    1980-02-01

    It is noted that it is possible to improve significantly the handling of linear problems in a general-purpose code with very little trouble to the user or change to the code. In such situations analytical evaluation of the Jacobian is a lot cheaper than numerical differencing. A slight change in the point at which the Jacobian is evaluated results in a more accurate Jacobian in linear problems. (RWR)

  7. Special or general-purpose hardware for Prolog: A comparison

    SciTech Connect

    Borriello, G.; Cherenson, A.; Danzig, P.; Nelson, M.

    1987-01-01

    This study compares the performance of executing Prolog code on the Berkeley PLM processor (a special-purpose CISC architecture) and the Berkeley SPUR processor (a general-purpose RISC architecture with tagged data). Fourteen standard benchmark programs were run on both the PLM and SPUR simulators. The two implementations were compared with regard to static and dynamic program size, execution speed, and cache performance. The simulated memory system included a direct-mapped mixed instruction and data cache.

  8. New Generation General Purpose Computer (GPC) compact IBM unit

    NASA Technical Reports Server (NTRS)

    1991-01-01

    New Generation General Purpose Computer (GPC) compact IBM unit replaces a two-unit earlier generation computer. The new IBM unit is documented in table top views alone (S91-26867, S91-26868), with the onboard equipment it supports including the flight deck CRT screen and keypad (S91-26866), and next to the two earlier versions it replaces (S91-26869).

  9. A General-Purpose Mesh Generator for Finite Element Codes.

    1984-02-28

    Version 00 INGEN is a general-purpose mesh generator for use in conjunction with two and three dimensional finite element programs. The basic components of INGEN are surface and three-dimensional region generators that use linear-blending interpolation formulae. These generators are based on an i, j, k index scheme, which is used to number nodal points, construct elements, and develop displacement and traction boundary conditions.

  10. The parser generator as a general purpose tool

    NASA Technical Reports Server (NTRS)

    Noonan, R. E.; Collins, W. R.

    1985-01-01

    The parser generator has proven to be an extremely useful, general purpose tool. It can be used effectively by programmers having only a knowledge of grammars and no training at all in the theory of formal parsing. Some of the application areas for which a table-driven parser can be used include interactive, query languages, menu systems, translators, and programming support tools. Each of these is illustrated by an example grammar.

  11. Portable high precision pressure transducer system

    DOEpatents

    Piper, T.C.; Morgan, J.P.; Marchant, N.J.; Bolton, S.M.

    1994-04-26

    A high precision pressure transducer system is described for checking the reliability of a second pressure transducer system used to monitor the level of a fluid confined in a holding tank. Since the response of the pressure transducer is temperature sensitive, it is continually housed in an battery powered oven which is configured to provide a temperature stable environment at specified temperature for an extended period of time. Further, a high precision temperature stabilized oscillator and counter are coupled to a single board computer to accurately determine the pressure transducer oscillation frequency and convert it to an applied pressure. All of the components are powered by the batteries which during periods of availability of line power are charged by an on board battery charger. The pressure readings outputs are transmitted to a line printer and a vacuum fluorescent display. 2 figures.

  12. Portable high precision pressure transducer system

    DOEpatents

    Piper, Thomas C.; Morgan, John P.; Marchant, Norman J.; Bolton, Steven M.

    1994-01-01

    A high precision pressure transducer system for checking the reliability of a second pressure transducer system used to monitor the level of a fluid confined in a holding tank. Since the response of the pressure transducer is temperature sensitive, it is continually housed in an battery powered oven which is configured to provide a temperature stable environment at specified temperature for an extended period of time. Further, a high precision temperature stabilized oscillator and counter are coupled to a single board computer to accurately determine the pressure transducer oscillation frequency and convert it to an applied pressure. All of the components are powered by the batteries which during periods of availability of line power are charged by an on board battery charger. The pressure readings outputs are transmitted to a line printer and a vacuum florescent display.

  13. High-Precision Computation and Mathematical Physics

    SciTech Connect

    Bailey, David H.; Borwein, Jonathan M.

    2008-11-03

    At the present time, IEEE 64-bit floating-point arithmetic is sufficiently accurate for most scientific applications. However, for a rapidly growing body of important scientific computing applications, a higher level of numeric precision is required. Such calculations are facilitated by high-precision software packages that include high-level language translation modules to minimize the conversion effort. This paper presents a survey of recent applications of these techniques and provides some analysis of their numerical requirements. These applications include supernova simulations, climate modeling, planetary orbit calculations, Coulomb n-body atomic systems, scattering amplitudes of quarks, gluons and bosons, nonlinear oscillator theory, Ising theory, quantum field theory and experimental mathematics. We conclude that high-precision arithmetic facilities are now an indispensable component of a modern large-scale scientific computing environment.

  14. Calibration of a high precision rotary table

    NASA Astrophysics Data System (ADS)

    Wang, Heyan; Xue, Zi; Shen, Ni; Huang, Yao

    2015-02-01

    In order to calibrate a high precision rotary table, a calibration system was established to measure the position error and repeatability of rotary table. The position error was measured with a polygon, an index table and an autocollimator to separate the angular error of the polygon from the position error of the rotary table, and the position error of rotary table was calculated using least square method. The rotary table was compensated and calibrated with the position error measured. The repeatability of the rotary table established through 10 times full circle rotations was 0.02 arc second. The measurement results indicated that the combination calibration method was suitable for the calibration of a high precision rotary table. It was found through the analysis that the angular measurement uncertainty was 0.08 arc second.

  15. Portable high precision pressure transducer system

    NASA Astrophysics Data System (ADS)

    Piper, T. C.; Morgan, J. P.; Marchant, N. J.; Bolton, S. M.

    A high precision pressure transducer system for checking the reliability of a second pressure transducer system used to monitor the level of a fluid confined in a holding tank is presented. Since the response of the pressure transducer is temperature sensitive, it is continually housed in a battery powered oven which is configured to provide a temperature stable environment at specified temperature for an extended period of time. Further, a high precision temperature stabilized oscillator and counter are coupled to a single board computer to accurately determine the pressure transducer oscillation frequency and convert it to an applied pressure. All of the components are powered by the batteries which during periods of availability of line power are charged by an on-board battery charger. The pressure readings outputs are transmitted to a line printer and a vacuum fluorescent display.

  16. High-precision arithmetic in mathematical physics

    DOE PAGES

    Bailey, David H.; Borwein, Jonathan M.

    2015-05-12

    For many scientific calculations, particularly those involving empirical data, IEEE 32-bit floating-point arithmetic produces results of sufficient accuracy, while for other applications IEEE 64-bit floating-point is more appropriate. But for some very demanding applications, even higher levels of precision are often required. Furthermore, this article discusses the challenge of high-precision computation, in the context of mathematical physics, and highlights what facilities are required to support future computation, in light of emerging developments in computer architecture.

  17. Installation of new Generation General Purpose Computer (GPC) compact unit

    NASA Technical Reports Server (NTRS)

    1991-01-01

    In the Kennedy Space Center's (KSC's) Orbiter Processing Facility (OPF) high bay 2, Spacecraft Electronics technician Ed Carter (right), wearing clean suit, prepares for (26864) and installs (26865) the new Generation General Purpose Computer (GPC) compact IBM unit in Atlantis', Orbiter Vehicle (OV) 104's, middeck avionics bay as Orbiter Systems Quality Control technician Doug Snider looks on. Both men work for NASA contractor Lockheed Space Operations Company. All three orbiters are being outfitted with the compact IBM unit, which replaces a two-unit earlier generation computer.

  18. Development of a General Purpose Power System Control Board

    SciTech Connect

    Nam, S.H.; Jeong, S.H.; Kim, S.H.; Kim, S.C.; Park, S.S.; Suh, J.H.; Bellomo, P.; Cassel, R.; Larsen, R.; Nguyen, M.N.; /SLAC

    2007-07-23

    In an effort to control modern solid state power modules, a general purpose, multi function power system control board (PSCB) has been under development as a collaboration project between Pohang Accelerator Laboratory (PAL), Korea, and Stanford Linear Accelerator Center (SLAC), USA. The PSCB is an embedded, interlock supervisory, diagnostic, timing, and set-point control board. It is designed to use in various power systems such as sequenced kicker pulsers, solid state RF modulators, simple DC magnet power supplies, etc. The PSCB has the Ethernet communication with the TCP/IP Modbus protocol.

  19. High precision laser forming for microactuation

    NASA Astrophysics Data System (ADS)

    Folkersma, Ger K. G. P.; Römer, G. R. B. E.; Brouwer, D. M.; Huis in't Veld, A. J.

    2014-03-01

    For assembly of micro-devices, such as photonic devices, the precision alignment of components is often critical for their performance. Laser forming, also known as laser-adjusting, can be used to create an integrated microactuator to align the components with sub-micron precision after bonding. In this paper a so-called three-bridge planar manipulator was used to study the laser-material interaction and thermal and mechanical behavior of the laser forming mechanism. A 3-D Finite Element Method (FEM) model and experiments are used to identify the optimal parameter settings for a high precision actuator. The goal in this paper is to investigate how precise the maximum occurring temperature and the resulting displacement are predicted by a 3-D FEM model by comparing with experimental results. A secondary goal is to investigate the resolution of the mechanism and the range of motion. With the experimental setup we measure the displacement and surface temperature in real-time. The time-dependent heat transfer FEM models match closely with experimental results, however the structural model can deviate more than 100% in absolute displacement. Experimentally, a positioning resolution of 0.1μm was achieved, with a total stroke exceeding 20μm. A spread of 10% in the temperature cycles between several experiments was found, which was attributed to a spread in the surface absorptivity. Combined with geometric tolerances, the spread in displacement can be as large as 20%. This implies that feedback control of the laser power, in combination with iterative learning during positioning, is required for high precision alignment. Even though the FEM models deviate substantially from the experiments, the 3-D FEM model predicts the trend in deformation sufficiently accurate to use it for design optimization of high precision 3-D actuators using laser adjusting.

  20. A General Purpose Stacking Technique to Analyze Low Brightness Signal

    NASA Astrophysics Data System (ADS)

    Wavle, Daniel; Leroy, Adam K.; Donovan Meyer, Jennifer

    2015-01-01

    We present an implementation of a general purpose stacking technique in which the detections of bright emission lines are used as priors to analyze low-brightness signal. We demonstrate the use of the technique on ALMA observations of the nuclear region of the nearby galaxy NGC 253 but emphasize its general applicability to a wide class of problems. The conceptual basis for the technique is to use closely associated brighter lines as priors to establish the local velocity (and potentially velocity profile) of a faint line. With this prior, the faint line can be coherently averaged by assuming that it shares a mean velocity with the bright prior. The coherent spectral averaging allows one to more clearly distinguish real astronomical signals from systematic effects, unstable baselines, or imaging artifacts. In our example application, we apply the technique to measure the intensity of faint isotopologues of dense gas tracers in NGC 253, lines that are otherwise hard to distinguish from the noise. The implementation of the code is intended for release as a general purpose cube analysis tool compatible with other astronomical python packages.

  1. General purpose multiplexing device for cryogenic microwave systems

    NASA Astrophysics Data System (ADS)

    Chapman, Benjamin J.; Moores, Bradley A.; Rosenthal, Eric I.; Kerckhoff, Joseph; Lehnert, K. W.

    2016-05-01

    We introduce and experimentally characterize a general purpose device for signal processing in circuit quantum electrodynamics systems. The device is a broadband two-port microwave circuit element with three modes of operation: it can transmit, reflect, or invert incident signals between 4 and 8 GHz. This property makes it a versatile tool for lossless signal processing at cryogenic temperatures. In particular, rapid switching (≤ 15 ns ) between these operation modes enables several multiplexing readout protocols for superconducting qubits. We report the device's performance in a two-channel code domain multiplexing demonstration. The multiplexed data are recovered with fast readout times (up to 400 ns ) and infidelities ≤ 10-2 for probe powers ≥ 7 fW , in agreement with the expectation for binary signaling with Gaussian noise.

  2. Toward a General-Purpose Heterogeneous Ensemble for Pattern Classification

    PubMed Central

    Nanni, Loris; Brahnam, Sheryl; Ghidoni, Stefano; Lumini, Alessandra

    2015-01-01

    We perform an extensive study of the performance of different classification approaches on twenty-five datasets (fourteen image datasets and eleven UCI data mining datasets). The aim is to find General-Purpose (GP) heterogeneous ensembles (requiring little to no parameter tuning) that perform competitively across multiple datasets. The state-of-the-art classifiers examined in this study include the support vector machine, Gaussian process classifiers, random subspace of adaboost, random subspace of rotation boosting, and deep learning classifiers. We demonstrate that a heterogeneous ensemble based on the simple fusion by sum rule of different classifiers performs consistently well across all twenty-five datasets. The most important result of our investigation is demonstrating that some very recent approaches, including the heterogeneous ensemble we propose in this paper, are capable of outperforming an SVM classifier (implemented with LibSVM), even when both kernel selection and SVM parameters are carefully tuned for each dataset. PMID:26413089

  3. CRUSH TESTING OF 9977 GENERAL PURPOSE FISSILE PACKAGINGS

    SciTech Connect

    Smith, A.

    2010-07-28

    The 9977 General Purpose Fissile Package (GPFP) was designed in response to the adoption of the crush test requirement in the US regulations for packages for radioactive materials (10 CFR 71). This presentation on crush testing of the 9977 GPFP Reviews origins of Crush Test Requirements and implementation of crush test requirements in 10 CFR 71. SANDIA testing performed to support the rule making is reviewed. The differences in practice, on the part of the US Department of Energy from those required by the NRC for commercial purposes, are explained. The design features incorporated into the 9977 GPFP to enable it to withstand the crush test and the crush tests performed on the 9977 are described. Lessons learned from crush testing of GPFP packagings are given.

  4. Using a cognitive architecture for general purpose service robot control

    NASA Astrophysics Data System (ADS)

    Puigbo, Jordi-Ysard; Pumarola, Albert; Angulo, Cecilio; Tellez, Ricardo

    2015-04-01

    A humanoid service robot equipped with a set of simple action skills including navigating, grasping, recognising objects or people, among others, is considered in this paper. By using those skills the robot should complete a voice command expressed in natural language encoding a complex task (defined as the concatenation of a number of those basic skills). As a main feature, no traditional planner has been used to decide skills to be activated, as well as in which sequence. Instead, the SOAR cognitive architecture acts as the reasoner by selecting which action the robot should complete, addressing it towards the goal. Our proposal allows to include new goals for the robot just by adding new skills (without the need to encode new plans). The proposed architecture has been tested on a human-sized humanoid robot, REEM, acting as a general purpose service robot.

  5. A Chemical Containment Model for the General Purpose Work Station

    NASA Technical Reports Server (NTRS)

    Flippen, Alexis A.; Schmidt, Gregory K.

    1994-01-01

    Contamination control is a critical safety requirement imposed on experiments flying on board the Spacelab. The General Purpose Work Station, a Spacelab support facility used for life sciences space flight experiments, is designed to remove volatile compounds from its internal airpath and thereby minimize contamination of the Spacelab. This is accomplished through the use of a large, multi-stage filter known as the Trace Contaminant Control System. Many experiments planned for the Spacelab require the use of toxic, volatile fixatives in order to preserve specimens prior to postflight analysis. The NASA-Ames Research Center SLS-2 payload, in particular, necessitated the use of several toxic, volatile compounds in order to accomplish the many inflight experiment objectives of this mission. A model was developed based on earlier theories and calculations which provides conservative predictions of the resultant concentrations of these compounds given various spill scenarios. This paper describes the development and application of this model.

  6. General purpose symbolic simulation tools for electric networks

    SciTech Connect

    Alvarado, F.L.; Lui, Y.

    1988-05-01

    This paper presents research results on the use of computers to solve simulation problems in a way closer to human thinking. With the aid of techniques in AI (Artificial Intelligence), DB (Data Base Systems), and Computer Graphics, a set of general purpose LISP and PASCAL based simulation tools have been developed. Each of these tools solves a specific problem in some stage of simulation. Rule-based and object-oriented symbolic manipulations are extensively used. The tools provide more powerful and accurate modelling capability for complex objects, and permit simplicity and flexibility in implementation. The tools are used to study electrical transient problems, optimal load flow problems, linear control systems, and other simulation problems.

  7. General-Purpose Data-Formatting Input/Output System

    NASA Technical Reports Server (NTRS)

    Busquets, Anthony M.; Hogge, Thomas W.

    1990-01-01

    Multiplexable input/output (I/O) system developed as interface between host computer and real-time, fixed-base simulator cockpit. Unit designed to be general-purpose interface and operated through virtually any 8- or 16-bit, transistor/transistor-logic-level, parallel-I/O port with or without handshaking. Accepts byte-coded data in form of data blocks from host computer and routes data to various system I/O modules like discrete outputs, lamp drivers, and seven-segment-display drivers. Formats and routes data from input modules back to host computer. Other modules designed to drive alphanumeric displays and communications interfaces and to serve as analog-to-digital and digital-to-analog converter modules.

  8. A fast general-purpose clustering algorithm based on FPGAs for high-throughput data processing

    NASA Astrophysics Data System (ADS)

    Annovi, A.; Beretta, M.

    2010-05-01

    We present a fast general-purpose algorithm for high-throughput clustering of data "with a two-dimensional organization". The algorithm is designed to be implemented with FPGAs or custom electronics. The key feature is a processing time that scales linearly with the amount of data to be processed. This means that clustering can be performed in pipeline with the readout, without suffering from combinatorial delays due to looping multiple times through all the data. This feature makes this algorithm especially well suited for problems where the data have high density, e.g. in the case of tracking devices working under high-luminosity condition such as those of LHC or super-LHC. The algorithm is organized in two steps: the first step (core) clusters the data; the second step analyzes each cluster of data to extract the desired information. The current algorithm is developed as a clustering device for modern high-energy physics pixel detectors. However, the algorithm has much broader field of applications. In fact, its core does not specifically rely on the kind of data or detector it is working for, while the second step can and should be tailored for a given application. For example, in case of spatial measurement with silicon pixel detectors, the second step performs center of charge calculation. Applications can thus be foreseen to other detectors and other scientific fields ranging from HEP calorimeters to medical imaging. An additional advantage of this two steps approach is that the typical clustering related calculations (second step) are separated from the combinatorial complications of clustering. This separation simplifies the design of the second step and it enables it to perform sophisticated calculations achieving offline quality in online applications. The algorithm is general purpose in the sense that only minimal assumptions on the kind of clustering to be performed are made.

  9. High precision radial velocities with GIANO spectra

    NASA Astrophysics Data System (ADS)

    Carleo, I.; Sanna, N.; Gratton, R.; Benatti, S.; Bonavita, M.; Oliva, E.; Origlia, L.; Desidera, S.; Claudi, R.; Sissa, E.

    2016-06-01

    Radial velocities (RV) measured from near-infrared (NIR) spectra are a potentially excellent tool to search for extrasolar planets around cool or active stars. High resolution infrared (IR) spectrographs now available are reaching the high precision of visible instruments, with a constant improvement over time. GIANO is an infrared echelle spectrograph at the Telescopio Nazionale Galileo (TNG) and it is a powerful tool to provide high resolution spectra for accurate RV measurements of exoplanets and for chemical and dynamical studies of stellar or extragalactic objects. No other high spectral resolution IR instrument has GIANO's capability to cover the entire NIR wavelength range (0.95-2.45 μm) in a single exposure. In this paper we describe the ensemble of procedures that we have developed to measure high precision RVs on GIANO spectra acquired during the Science Verification (SV) run, using the telluric lines as wavelength reference. We used the Cross Correlation Function (CCF) method to determine the velocity for both the star and the telluric lines. For this purpose, we constructed two suitable digital masks that include about 2000 stellar lines, and a similar number of telluric lines. The method is applied to various targets with different spectral type, from K2V to M8 stars. We reached different precisions mainly depending on the H-magnitudes: for H ˜ 5 we obtain an rms scatter of ˜ 10 m s-1, while for H ˜ 9 the standard deviation increases to ˜ 50 ÷ 80 m s-1. The corresponding theoretical error expectations are ˜ 4 m s-1 and 30 m s-1, respectively. Finally we provide the RVs measured with our procedure for the targets observed during GIANO Science Verification.

  10. High precision Woelter optic calibration facility

    SciTech Connect

    Morales, R.I.; Remington, B.A.; Schwinn, T.

    1994-05-02

    We have developed an off-line facility for very precise characterization of the reflectance and spatial resolution of the grazing incidence Woelter Type 1 x-ray optics used at Nova. The primary component of the facility is a high brightness, ``point`` x-ray source consisting of a focussed DC electron beam incident onto a precision manipulated target/pinhole array. The data are recorded with a selection of detectors. For imaging measurements we use direct exposure x-ray film modules or an x-ray CCD camera. For energy-resolved reflectance measurements, we use lithium drifted silicon detectors and a proportional counter. An in situ laser alignment system allows precise location and rapid periodic alignment verification of the x-ray point source, the statically mounted Woelter optic, and the chosen detector.

  11. General purpose, field-portable cell-based biosensor platform.

    PubMed

    Gilchrist, K H; Barker, V N; Fletcher, L E; DeBusschere, B D; Ghanouni, P; Giovangrandi, L; Kovacs, G T

    2001-09-01

    There are several groups of researchers developing cell-based biosensors for chemical and biological warfare agents based on electrophysiologic monitoring of cells. In order to transition such sensors from the laboratory to the field, a general-purpose hardware and software platform is required. This paper describes the design, implementation, and field-testing of such a system, consisting of cell-transport and data acquisition instruments. The cell-transport module is a self-contained, battery-powered instrument that allows various types of cell-based modules to be maintained at a preset temperature and ambient CO(2) level while in transit or in the field. The data acquisition module provides 32 channels of action potential amplification, filtering, and real-time data streaming to a laptop computer. At present, detailed analysis of the data acquired is carried out off-line, but sufficient computing power is available in the data acquisition module to enable the most useful algorithms to eventually be run real-time in the field. Both modules have sufficient internal power to permit realistic field-testing, such as the example presented in this paper. PMID:11544049

  12. General-purpose event generators for LHC physics

    SciTech Connect

    Buckley, Andy; Butterworth, Jonathan; Gieseke, Stefan; Grellscheid, David; Hoche, Stefan; Hoeth, Hendrik; Krauss, Frank; Lonnblad, Leif; Nurse, Emily; Richardson, Peter; Schumann, Steffen; Seymour, Michael H.; Sjostrand, Torbjorn; Skands, Peter; Webber, Bryan; /Cambridge U.

    2011-03-03

    We review the physics basis, main features and use of general-purpose Monte Carlo event generators for the simulation of proton-proton collisions at the Large Hadron Collider. Topics included are: the generation of hard-scattering matrix elements for processes of interest, at both leading and next-to-leading QCD perturbative order; their matching to approximate treatments of higher orders based on the showering approximation; the parton and dipole shower formulations; parton distribution functions for event generators; non-perturbative aspects such as soft QCD collisions, the underlying event and diffractive processes; the string and cluster models for hadron formation; the treatment of hadron and tau decays; the inclusion of QED radiation and beyond-Standard-Model processes. We describe the principal features of the Ariadne, Herwig++, Pythia 8 and Sherpa generators, together with the Rivet and Professor validation and tuning tools, and discuss the physics philosophy behind the proper use of these generators and tools. This review is aimed at phenomenologists wishing to understand better how parton-level predictions are translated into hadron-level events as well as experimentalists wanting a deeper insight into the tools available for signal and background simulation at the LHC.

  13. High-Speed General Purpose Genetic Algorithm Processor.

    PubMed

    Hoseini Alinodehi, Seyed Pourya; Moshfe, Sajjad; Saber Zaeimian, Masoumeh; Khoei, Abdollah; Hadidi, Khairollah

    2016-07-01

    In this paper, an ultrafast steady-state genetic algorithm processor (GAP) is presented. Due to the heavy computational load of genetic algorithms (GAs), they usually take a long time to find optimum solutions. Hardware implementation is a significant approach to overcome the problem by speeding up the GAs procedure. Hence, we designed a digital CMOS implementation of GA in [Formula: see text] process. The proposed processor is not bounded to a specific application. Indeed, it is a general-purpose processor, which is capable of performing optimization in any possible application. Utilizing speed-boosting techniques, such as pipeline scheme, parallel coarse-grained processing, parallel fitness computation, parallel selection of parents, dual-population scheme, and support for pipelined fitness computation, the proposed processor significantly reduces the processing time. Furthermore, by relying on a built-in discard operator the proposed hardware may be used in constrained problems that are very common in control applications. In the proposed design, a large search space is achievable through the bit string length extension of individuals in the genetic population by connecting the 32-bit GAPs. In addition, the proposed processor supports parallel processing, in which the GAs procedure can be run on several connected processors simultaneously.

  14. Programming methodology for a general purpose automation controller

    NASA Technical Reports Server (NTRS)

    Sturzenbecker, M. C.; Korein, J. U.; Taylor, R. H.

    1987-01-01

    The General Purpose Automation Controller is a multi-processor architecture for automation programming. A methodology has been developed whose aim is to simplify the task of programming distributed real-time systems for users in research or manufacturing. Programs are built by configuring function blocks (low-level computations) into processes using data flow principles. These processes are activated through the verb mechanism. Verbs are divided into two classes: those which support devices, such as robot joint servos, and those which perform actions on devices, such as motion control. This programming methodology was developed in order to achieve the following goals: (1) specifications for real-time programs which are to a high degree independent of hardware considerations such as processor, bus, and interconnect technology; (2) a component approach to software, so that software required to support new devices and technologies can be integrated by reconfiguring existing building blocks; (3) resistance to error and ease of debugging; and (4) a powerful command language interface.

  15. Nondestructive inspection of General Purpose Heat Source (GPHS) girth welds

    SciTech Connect

    Reimus, M.A.H.; George, T.G.; Lynch, C.

    1998-12-31

    The General-Purpose Heat Source (GPHS) provides power for space missions by transmitting the heat of {sup 238}Pu decay to an array of thermoelectric elements. The GPHS is fabricated using iridium capsules, TIG welded, to contain the {sup 238}PuO{sub 2} fuel pellet. GPHS capsules will be utilized in the upcoming Cassini mission to explore Saturn and its moons. The physical integrity of the girth weld is important to mission safety and performance. Since experience in the past had revealed a potential for initiation of small cracks in the girth weld overlap zone, a nondestructive inspection of the capsule weld is required. A ultrasonic method was used to inspect the welds of capsules fabricated for the Galileo mission. The instrument, transducer, and method used were state of the art at the time (early 1980s). The ultrasonic instrumentation and methods used to inspect the Cassini GPHSs was significantly upgraded from those used for the Galileo mission. GPHSs that had ultrasonic reflectors that exceeded the reject specification level were subsequently inspected with radiography to provide additional engineering data used to accept/reject the heat source. This paper describes the Galileo-era ultrasonic instrumentation and methods and the subsequent upgrades made to support testing of Cassini GPHSs. Also discussed is the data obtained from radiographic examination and correlation to ultrasonic examination results.

  16. The General Purpose Work Station, a spacious microgravity workbench

    NASA Technical Reports Server (NTRS)

    Dalton, Bonnie P.; Schmidt, Greg K.; Savage, P. D.

    1992-01-01

    The General Purpose Work Station (GPWS) is a laboratory multiuse facility, as demonstrated during the Spacelab Life Sciences 1 (SLS-1) flight. The unit provided particulate containment under varying conditions, served as an effective work space for manipulating live animals, e.g., rats, served as a containment facility for fixatives, and was proposed for use to conduct in-flight maintenance during connector pin repair. The cabinet has a front door large enough to allow installation of a full-size microscope in-flight and is outfitted with a side window to allow delivery of items into the cabinet without exposure to the spacelab atmosphere. Additional support subsystems include inside cabinet mounting, surgical glove fine manipulations capability, and ac or dc power supply for experiment equipment, as will be demonstrated during Spacelab J. The GPWS, integrated and maintained in a double flight-rack, interfaces to spacelab systems including water cooling, avionics and cabin air, and power. Verification has been completed for multiple spacelab scenarios including SLS-2, SL-J, and SLS-3.

  17. ALEPH2 - A general purpose Monte Carlo depletion code

    SciTech Connect

    Stankovskiy, A.; Van Den Eynde, G.; Baeten, P.; Trakas, C.; Demy, P. M.; Villatte, L.

    2012-07-01

    The Monte-Carlo burn-up code ALEPH is being developed at SCK-CEN since 2004. A previous version of the code implemented the coupling between the Monte Carlo transport (any version of MCNP or MCNPX) and the ' deterministic' depletion code ORIGEN-2.2 but had important deficiencies in nuclear data treatment and limitations inherent to ORIGEN-2.2. A new version of the code, ALEPH2, has several unique features making it outstanding among other depletion codes. The most important feature is full data consistency between steady-state Monte Carlo and time-dependent depletion calculations. The last generation general-purpose nuclear data libraries (JEFF-3.1.1, ENDF/B-VII and JENDL-4) are fully implemented, including special purpose activation, spontaneous fission, fission product yield and radioactive decay data. The built-in depletion algorithm allows to eliminate the uncertainties associated with obtaining the time-dependent nuclide concentrations. A predictor-corrector mechanism, calculation of nuclear heating, calculation of decay heat, decay neutron sources are available as well. The validation of the code on the results of REBUS experimental program has been performed. The ALEPH2 has shown better agreement with measured data than other depletion codes. (authors)

  18. General Purpose Unfolding Program with Linear and Nonlinear Regularizations.

    1987-05-07

    Version 00 The interpretation of several physical measurements requires the unfolding or deconvolution of the solution of Fredholm integral equations of the first kind. Examples include neutron spectroscopy with activation detectors, moderating spheres, or proton recoil measurements. LOUHI82 is designed to be applicable to a large number of physical problems and to be extended to incorporate other unfolding methods.

  19. Highly Parallel, High-Precision Numerical Integration

    SciTech Connect

    Bailey, David H.; Borwein, Jonathan M.

    2005-04-22

    This paper describes a scheme for rapidly computing numerical values of definite integrals to very high accuracy, ranging from ordinary machine precision to hundreds or thousands of digits, even for functions with singularities or infinite derivatives at endpoints. Such a scheme is of interest not only in computational physics and computational chemistry, but also in experimental mathematics, where high-precision numerical values of definite integrals can be used to numerically discover new identities. This paper discusses techniques for a parallel implementation of this scheme, then presents performance results for 1-D and 2-D test suites. Results are also given for a certain problem from mathematical physics, which features a difficult singularity, confirming a conjecture to 20,000 digit accuracy. The performance rate for this latter calculation on 1024 CPUs is 690 Gflop/s. We believe that this and one other 20,000-digit integral evaluation that we report are the highest-precision non-trivial numerical integrations performed to date.

  20. High Precision Rovibrational Spectroscopy of OH+

    NASA Astrophysics Data System (ADS)

    Markus, Charles R.; Hodges, James N.; Perry, Adam J.; Kocheril, G. Stephen; Müller, Holger S. P.; McCall, Benjamin J.

    2016-02-01

    The molecular ion OH+ has long been known to be an important component of the interstellar medium. Its relative abundance can be used to indirectly measure cosmic ray ionization rates of hydrogen, and it is the first intermediate in the interstellar formation of water. To date, only a limited number of pure rotational transitions have been observed in the laboratory making it necessary to indirectly calculate rotational levels from high-precision rovibrational spectroscopy. We have remeasured 30 transitions in the fundamental band with MHz-level precision, in order to enable the prediction of a THz spectrum of OH+. The ions were produced in a water cooled discharge of O2, H2, and He, and the rovibrational transitions were measured with the technique Noise Immune Cavity Enhanced Optical Heterodyne Velocity Modulation Spectroscopy. These values have been included in a global fit of field free data to a 3Σ- linear molecule effective Hamiltonian to determine improved spectroscopic parameters which were used to predict the pure rotational transition frequencies.

  1. Pitch evaluation of high-precision gratings

    NASA Astrophysics Data System (ADS)

    Lu, Yancong; Zhou, Changhe; Wei, Chunlong; Jia, Wei; Xiang, Xiansong; Li, Yanyang; Yu, Junjie; Li, Shubin; Wang, Jin; Liu, Kun; Wei, Shengbin

    2014-11-01

    Optical encoders and laser interferometers are two primary solutions in nanometer metrology. As the precision of encoders depends on the uniformity of grating pitches, it is essential to evaluate pitches accurately. We use a CCD image sensor to acquire grating image for evaluating the pitches with high precision. Digital image correlation technique is applied to filter out the noises. We propose three methods for determining the pitches of grating with peak positions of correlation coefficients. Numerical simulation indicated the average of pitch deviations from the true pitch and the pitch variations are less than 0.02 pixel and 0.1 pixel for these three methods when the ideal grating image is added with salt and pepper noise, speckle noise, and Gaussian noise. Experimental results demonstrated that our method can measure the pitch of the grating accurately, for example, our home-made grating with 20μm period has 475nm peak-to-valley uniformity with 40nm standard deviation during 35mm range. Another measurement illustrated that our home-made grating has 40nm peak-to-valley uniformity with 10nm standard deviation. This work verified that our lab can fabricate high-accuracy gratings which should be interesting for practical application in optical encoders.

  2. High precision innovative micropump for artificial pancreas

    NASA Astrophysics Data System (ADS)

    Chappel, E.; Mefti, S.; Lettieri, G.-L.; Proennecke, S.; Conan, C.

    2014-03-01

    The concept of artificial pancreas, which comprises an insulin pump, a continuous glucose meter and a control algorithm, is a major step forward in managing patient with type 1 diabetes mellitus. The stability of the control algorithm is based on short-term precision micropump to deliver rapid-acting insulin and to specific integrated sensors able to monitor any failure leading to a loss of accuracy. Debiotech's MEMS micropump, based on the membrane pump principle, is made of a stack of 3 silicon wafers. The pumping chamber comprises a pillar check-valve at the inlet, a pumping membrane which is actuated against stop limiters by a piezo cantilever, an anti-free-flow outlet valve and a pressure sensor. The micropump inlet is tightly connected to the insulin reservoir while the outlet is in direct communication with the patient skin via a cannula. To meet the requirement of a pump dedicated to closed-loop application for diabetes care, in addition to the well-controlled displacement of the pumping membrane, the high precision of the micropump is based on specific actuation profiles that balance effect of pump elasticity in low-consumption push-pull mode.

  3. Use of general purpose graphics processing units with MODFLOW

    USGS Publications Warehouse

    Hughes, Joseph D.; White, Jeremy T.

    2013-01-01

    To evaluate the use of general-purpose graphics processing units (GPGPUs) to improve the performance of MODFLOW, an unstructured preconditioned conjugate gradient (UPCG) solver has been developed. The UPCG solver uses a compressed sparse row storage scheme and includes Jacobi, zero fill-in incomplete, and modified-incomplete lower-upper (LU) factorization, and generalized least-squares polynomial preconditioners. The UPCG solver also includes options for sequential and parallel solution on the central processing unit (CPU) using OpenMP. For simulations utilizing the GPGPU, all basic linear algebra operations are performed on the GPGPU; memory copies between the central processing unit CPU and GPCPU occur prior to the first iteration of the UPCG solver and after satisfying head and flow criteria or exceeding a maximum number of iterations. The efficiency of the UPCG solver for GPGPU and CPU solutions is benchmarked using simulations of a synthetic, heterogeneous unconfined aquifer with tens of thousands to millions of active grid cells. Testing indicates GPGPU speedups on the order of 2 to 8, relative to the standard MODFLOW preconditioned conjugate gradient (PCG) solver, can be achieved when (1) memory copies between the CPU and GPGPU are optimized, (2) the percentage of time performing memory copies between the CPU and GPGPU is small relative to the calculation time, (3) high-performance GPGPU cards are utilized, and (4) CPU-GPGPU combinations are used to execute sequential operations that are difficult to parallelize. Furthermore, UPCG solver testing indicates GPGPU speedups exceed parallel CPU speedups achieved using OpenMP on multicore CPUs for preconditioners that can be easily parallelized.

  4. Use of general purpose graphics processing units with MODFLOW.

    PubMed

    Hughes, Joseph D; White, Jeremy T

    2013-01-01

    To evaluate the use of general-purpose graphics processing units (GPGPUs) to improve the performance of MODFLOW, an unstructured preconditioned conjugate gradient (UPCG) solver has been developed. The UPCG solver uses a compressed sparse row storage scheme and includes Jacobi, zero fill-in incomplete, and modified-incomplete lower-upper (LU) factorization, and generalized least-squares polynomial preconditioners. The UPCG solver also includes options for sequential and parallel solution on the central processing unit (CPU) using OpenMP. For simulations utilizing the GPGPU, all basic linear algebra operations are performed on the GPGPU; memory copies between the central processing unit CPU and GPCPU occur prior to the first iteration of the UPCG solver and after satisfying head and flow criteria or exceeding a maximum number of iterations. The efficiency of the UPCG solver for GPGPU and CPU solutions is benchmarked using simulations of a synthetic, heterogeneous unconfined aquifer with tens of thousands to millions of active grid cells. Testing indicates GPGPU speedups on the order of 2 to 8, relative to the standard MODFLOW preconditioned conjugate gradient (PCG) solver, can be achieved when (1) memory copies between the CPU and GPGPU are optimized, (2) the percentage of time performing memory copies between the CPU and GPGPU is small relative to the calculation time, (3) high-performance GPGPU cards are utilized, and (4) CPU-GPGPU combinations are used to execute sequential operations that are difficult to parallelize. Furthermore, UPCG solver testing indicates GPGPU speedups exceed parallel CPU speedups achieved using OpenMP on multicore CPUs for preconditioners that can be easily parallelized. PMID:23281733

  5. Use of general purpose graphics processing units with MODFLOW.

    PubMed

    Hughes, Joseph D; White, Jeremy T

    2013-01-01

    To evaluate the use of general-purpose graphics processing units (GPGPUs) to improve the performance of MODFLOW, an unstructured preconditioned conjugate gradient (UPCG) solver has been developed. The UPCG solver uses a compressed sparse row storage scheme and includes Jacobi, zero fill-in incomplete, and modified-incomplete lower-upper (LU) factorization, and generalized least-squares polynomial preconditioners. The UPCG solver also includes options for sequential and parallel solution on the central processing unit (CPU) using OpenMP. For simulations utilizing the GPGPU, all basic linear algebra operations are performed on the GPGPU; memory copies between the central processing unit CPU and GPCPU occur prior to the first iteration of the UPCG solver and after satisfying head and flow criteria or exceeding a maximum number of iterations. The efficiency of the UPCG solver for GPGPU and CPU solutions is benchmarked using simulations of a synthetic, heterogeneous unconfined aquifer with tens of thousands to millions of active grid cells. Testing indicates GPGPU speedups on the order of 2 to 8, relative to the standard MODFLOW preconditioned conjugate gradient (PCG) solver, can be achieved when (1) memory copies between the CPU and GPGPU are optimized, (2) the percentage of time performing memory copies between the CPU and GPGPU is small relative to the calculation time, (3) high-performance GPGPU cards are utilized, and (4) CPU-GPGPU combinations are used to execute sequential operations that are difficult to parallelize. Furthermore, UPCG solver testing indicates GPGPU speedups exceed parallel CPU speedups achieved using OpenMP on multicore CPUs for preconditioners that can be easily parallelized.

  6. Operation of general purpose stepping motor controllers at the National Synchrotron Light Source

    SciTech Connect

    Stubblefield, F.W.

    1986-10-01

    A prototype and four copies of a general purpose subsystem for mechanical positioning of detectors, samples, and beam line optical elements which constitute experiments at the National Synchrotron Light Source facility of Brookhaven National Laboratory have been constructed and placed into operation. Construction of a sixth subsystem is nearing completion. The subsystems effect mechanical positioning by controlling a set of stepping motors and their associated position encoders. The units are general purpose in the sense that they receive commands over a standard 9600 baud asynchronous serial line compatible with the RS-232-C electrical signal standard, generate TTL-compatible streams of stepping pulses which can be used with a wide variety of stepping motors, and read back position values from a number of different types and models of position encoder. The basic structure of the motor controller subsystem will be briefly reviewed. Short descriptions of the positioning apparatus actuated at each of the test and experiment stations employing a motor control unit are given. Additions and enhancements to the subsystem made in response to problems indicated by actual operation of the four installed units are described in more detail.

  7. Operation of general purpose stepping motor controllers at the National Synchrotron Light Source

    SciTech Connect

    Stubblefield, F.W.

    1987-02-01

    A prototype and four copies of a general purpose subsystem for mechanical positioning of detectors, samples, and beam line optical elements which constitute experiments at the National Synchrotron Light Source facility of Brookhaven National Laboratory have been constructed and placed into operation. Construction of a sixth subsystem is nearing completion. The subsystems effect mechanical positioning by controlling a set of stepping motors and their associated position encoders. The units are general purpose in the sense that they receive commands over a standard 9600 baud asynchronous serial line compatible with the RS-232-C electrical signal standard, generate TTL-compatible streams of stepping pulses which can be used with a wide variety of stepping motors, and read back position values from a number of different types and models of position encoder. The basic structure of the motor controller subsystem is briefly reviewed. Short descriptions of the positioning apparatus actuated at each of the test and experiment stations employing a motor control unit are given. Additions and enhancements to the sub-system made in response to problems indicated by actual operation of the four installed units are described in more detail.

  8. High Precision Isotopic Reference Material Program

    NASA Astrophysics Data System (ADS)

    Mann, J. L.; Vocke, R. D.

    2007-12-01

    Recent developments in thermal ionization and inductively coupled plasma multicollector mass spectrometers have lead to "high precision" isotope ratio measurements with uncertainties approaching a few parts in 106. These new measurement capabilities have revolutionized the study of isotopic variations in nature by increasing the number of elements showing natural variations by almost a factor of two, and new research areas are actively opening up in climate change, health, ecology, geology and forensic studies. Because the isotopic applications are impacting very diverse fields, there is at present little effective coordination between research laboratories over reference materials and the values to apply to those materials. NIST had originally developed the techniques for producing accurate isotopic characterizations, culminating in the NIST Isotopic SRM series. The values on existing materials however are insufficiently precise and, in some cases, may be isotopically heterogeneous. A new generation of isotopic standards is urgently needed and will directly affect the quality and scope of emergent applications and ensure that the results being derived from these diverse fields are comparable. A series of new isotopic reference materials similar to the NIST 3100 single element solution series is being designed for this purpose and twelve elements have been selected as having the most pressing need. In conjunction with other expert users and National Metrology Institutes, an isotopic characterization of the respective 12 selected ampoules from the NIST single element solution series is currently underway. In this presentation the preliminary results of this screening will be discussed as well as the suitability of these materials in terms of homogeneity and purity, long term stability and availability, and isotopic relevance. Approaches to value assignment will also be discussed.

  9. Fiber Scrambling for High Precision Spectrographs

    NASA Astrophysics Data System (ADS)

    Kaplan, Zachary; Spronck, J. F. P.; Fischer, D.

    2011-05-01

    The detection of Earth-like exoplanets with the radial velocity method requires extreme Doppler precision and long-term stability in order to measure tiny reflex velocities in the host star. Recent planet searches have led to the detection of so called "super-Earths” (up to a few Earth masses) that induce radial velocity changes of about 1 m/s. However, the detection of true Earth analogs requires a precision of 10 cm/s. One of the largest factors limiting Doppler precision is variation in the Point Spread Function (PSF) from observation to observation due to changes in the illumination of the slit and spectrograph optics. Thus, this stability has become a focus of current instrumentation work. Fiber optics have been used since the 1980's to couple telescopes to high-precision spectrographs, initially for simpler mechanical design and control. However, fiber optics are also naturally efficient scramblers. Scrambling refers to a fiber's ability to produce an output beam independent of input. Our research is focused on characterizing the scrambling properties of several types of fibers, including circular, square and octagonal fibers. By measuring the intensity distribution after the fiber as a function of input beam position, we can simulate guiding errors that occur at an observatory. Through this, we can determine which fibers produce the most uniform outputs for the severest guiding errors, improving the PSF and allowing sub-m/s precision. However, extensive testing of fibers of supposedly identical core diameter, length and shape from the same manufacturer has revealed the "personality” of individual fibers. Personality describes differing intensity patterns for supposedly duplicate fibers illuminated identically. Here, we present our results on scrambling characterization as a function of fiber type, while studying individual fiber personality.

  10. New High Precision Linelist of H_3^+

    NASA Astrophysics Data System (ADS)

    Hodges, James N.; Perry, Adam J.; Markus, Charles; Jenkins, Paul A., II; Kocheril, G. Stephen; McCall, Benjamin J.

    2014-06-01

    As the simplest polyatomic molecule, H_3^+ serves as an ideal benchmark for theoretical predictions of rovibrational energy levels. By strictly ab initio methods, the current accuracy of theoretical predictions is limited to an impressive one hundredth of a wavenumber, which has been accomplished by consideration of relativistic, adiabatic, and non-adiabatic corrections to the Born-Oppenheimer PES. More accurate predictions rely on a treatment of quantum electrodynamic effects, which have improved the accuracies of vibrational transitions in molecular hydrogen to a few MHz. High precision spectroscopy is of the utmost importance for extending the frontiers of ab initio calculations, as improved precision and accuracy enable more rigorous testing of calculations. Additionally, measuring rovibrational transitions of H_3^+ can be used to predict its forbidden rotational spectrum. Though the existing data can be used to determine rotational transition frequencies, the uncertainties are prohibitively large. Acquisition of rovibrational spectra with smaller experimental uncertainty would enable a spectroscopic search for the rotational transitions. The technique Noise Immune Cavity Enhanced Optical Heterodyne Velocity Modulation Spectroscopy, or NICE-OHVMS has been previously used to precisely and accurately measure transitions of H_3^+, CH_5^+, and HCO^+ to sub-MHz uncertainty. A second module for our optical parametric oscillator has extended our instrument's frequency coverage from 3.2-3.9 μm to 2.5-3.9 μm. With extended coverage, we have improved our previous linelist by measuring additional transitions. O. L. Polyansky, et al. Phil. Trans. R. Soc. A (2012), 370, 5014--5027. J. Komasa, et al. J. Chem. Theor. Comp. (2011), 7, 3105--3115. C. M. Lindsay, B. J. McCall, J. Mol. Spectrosc. (2001), 210, 66--83. J. N. Hodges, et al. J. Chem. Phys. (2013), 139, 164201.

  11. CLOUDCLOUD : general-purpose instrument monitoring and data managing software

    NASA Astrophysics Data System (ADS)

    Dias, António; Amorim, António; Tomé, António

    2016-04-01

    An effective experiment is dependent on the ability to store and deliver data and information to all participant parties regardless of their degree of involvement in the specific parts that make the experiment a whole. Having fast, efficient and ubiquitous access to data will increase visibility and discussion, such that the outcome will have already been reviewed several times, strengthening the conclusions. The CLOUD project aims at providing users with a general purpose data acquisition, management and instrument monitoring platform that is fast, easy to use, lightweight and accessible to all participants of an experiment. This work is now implemented in the CLOUD experiment at CERN and will be fully integrated with the experiment as of 2016. Despite being used in an experiment of the scale of CLOUD, this software can also be used in any size of experiment or monitoring station, from single computers to large networks of computers to monitor any sort of instrument output without influencing the individual instrument's DAQ. Instrument data and meta data is stored and accessed via a specially designed database architecture and any type of instrument output is accepted using our continuously growing parsing application. Multiple databases can be used to separate different data taking periods or a single database can be used if for instance an experiment is continuous. A simple web-based application gives the user total control over the monitored instruments and their data, allowing data visualization and download, upload of processed data and the ability to edit existing instruments or add new instruments to the experiment. When in a network, new computers are immediately recognized and added to the system and are able to monitor instruments connected to them. Automatic computer integration is achieved by a locally running python-based parsing agent that communicates with a main server application guaranteeing that all instruments assigned to that computer are

  12. General-Purpose Driver For Arrays Of Photodetectors

    NASA Technical Reports Server (NTRS)

    Shu, Peter K.; Travis, Jeffrey W.; Lee, John T. S.

    1993-01-01

    Electronic system containing both digital and analog circuits supplies clock waveforms at frequencies up to 12 MHz and/or bias voltages in 16 output channels. Designed to provide low-noise driving signals for any of variety of arrays of photodetectors. Clock waveform and/or bias in each channel adjusted independently of others to suit requirements of specific array of detectors. System offers primary advantage (adjustability) of prior laboratory systems, but at cost, power, and size like those of prior dedicated, field-deployed systems.

  13. Polymeric MST - high precision at low cost

    NASA Astrophysics Data System (ADS)

    Elderstig, Håkan; Larsson, Olle

    1997-09-01

    A low-cost production process for fabrication of polymeric microstructures from micromachined silicon is demonstrated in a splice for the splicing of optical fibers and an optical motherboard. Measurements on splices showed less than 0.5 dB insertion losses. The prototype polymeric motherboard concisted of an optical receiver module. The detector that was mounted on the polymeric optical motherboard detected about 70% of the transferred light. Measurements with modulated light indicates an optical bandwidth of 5 GHz at 2 V reverse current on the pin-diode.

  14. Simulations for the NIFFTE High Precision TPC

    NASA Astrophysics Data System (ADS)

    Thornton, Remington

    2010-10-01

    The Neutron Induced Fission Fragment Tracking Experiment has designed a Time Projection Chamber (TPC) to measure neutron induced fission cross-section measurements of the major actinides to sub-1% precision over a wide incident neutron energy range. These measurements are necessary to design the next generation of nuclear power plants. In order to design a TPC capable of making these measurements, a precise simulation was required to ensure better track reconstruction. Using the Geometry And Tracking (Geant4) simulation platform along with standalone code, a complete simulation package has been written. Asynchronous trigger, 3-D charge diffusion, capacitive charge sharing, digitization, random trigger cells, and noise from the electronics have been modeled inside the detector response simulation, along with code that generates bi-products of fission events for Geant4. This talk will discuss the current status and future planned developments of this work including the efforts to make this code reusable for future TPC projects.

  15. General purpose talking laboratory instrument for the visually handicapped

    NASA Astrophysics Data System (ADS)

    Salt, Alger; Lunney, David; Hartness, Richard

    1980-12-01

    The instrument described here was designed as a laboratory aid for the visually handicapped. It is basically a 3 1/2-digit multimeter with speech output; however, it has added functions which extend its usefulness beyond the ability to measure the usual ranges of ac and dc voltage and current. The device can function as a thermometer, a pH meter, a 6-digit timer, and an events counter. Two voltage-to-frequency (V/F) converters make it useful as an audible comparator and peak detector. An integrator is realized by using the counter to count the pulse train from a V/F converter which monitors the input signal. A low-level differential channel is provided for interfacing to instruments with recorder outputs, such as gas chromatographs. Spoken values of measured quantities are accompanied by sign, decimal point, and units. The instrument can also interface with other digital devices through 42 lines of parallel digital input-output. It can convert seven parallel BCD digits into speech or it can output BCD data from its counter or converter to a microcomputer.

  16. Operation of a general purpose stepping motor-encoder positioning subsystem at the National Synchrotron Light Source

    SciTech Connect

    Stubblefield, F.W.

    1985-11-01

    Four copies of a general purpose subsystem for mechanical positioning of detectors, samples, and beam line optical elements which constitute experiments at the National Synchrotron Light Source facility of Brookhaven National Laboratory have been constructed and placed into operation. Construction of a fifth subsystem unit is nearing completion. The subsystems affect mechanical positioning by controlling a set of stepping motor-encoder pairs. The units are general purpose in the sense that they receive commands over a 9600 baud asynchronous serial line compatible with the RS-232-C electrical signal standard, generate TTL-compatible streams of stepping pulses which can be used with a wide variety of stepping motors, and read back position values from a number of different types and models of position encoder. The basic structure of the motor controller subsystem is briefly reviewed. Additions to the subsystem made in response to problems indicated by actual operation of the four installed units are described in more detail.

  17. HIGH-PRECISION ASTROMETRY WITH A DIFFRACTIVE PUPIL TELESCOPE

    SciTech Connect

    Guyon, Olivier; Eisner, Josh A.; Angel, Roger; Woolf, Neville J.; Bendek, Eduardo A.; Milster, Thomas D.; Mark Ammons, S.; Shao, Michael; Shaklan, Stuart; Levine, Marie; Nemati, Bijan; Pitman, Joe; Woodruff, Robert A.; Belikov, Ruslan

    2012-06-01

    Astrometric detection and mass determination of Earth-mass exoplanets require sub-{mu}as accuracy, which is theoretically possible with an imaging space telescope using field stars as an astrometric reference. The measurement must, however, overcome astrometric distortions, which are much larger than the photon noise limit. To address this issue, we propose to generate faint stellar diffraction spikes using a two-dimensional grid of regularly spaced small dark spots added to the surface of the primary mirror (PM). Accurate astrometric motion of the host star is obtained by comparing the position of the spikes to the background field stars. The spikes do not contribute to scattered light in the central part of the field and therefore allow unperturbed coronagraphic observation of the star's immediate surroundings. Because the diffraction spikes are created on the PM and imaged on the same focal plane detector as the background stars, astrometric distortions affect equally the diffraction spikes and the background stars and are therefore calibrated. We describe the technique, detail how the data collected by the wide-field camera are used to derive astrometric motion, and identify the main sources of astrometric error using numerical simulations and analytical derivations. We find that the 1.4 m diameter telescope, 0.3 deg{sup 2} field we adopt as a baseline design achieves 0.2 {mu}as single measurement astrometric accuracy. The diffractive pupil concept thus enables sub-{mu}as astrometry without relying on the accurate pointing, external metrology, or high-stability hardware required with previously proposed high-precision astrometry concepts.

  18. 41 CFR 60-741.40 - General purpose and applicability of the affirmative action program requirement.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... requirement. (a) General purpose. An affirmative action program is a management tool designed to ensure equal... measurable objectives, quantitative analyses, and internal auditing and reporting systems that measure...

  19. High precision spectroscopy and imaging in THz frequency range

    NASA Astrophysics Data System (ADS)

    Vaks, Vladimir L.

    2014-03-01

    Application of microwave methods for development of the THz frequency range has resulted in elaboration of high precision THz spectrometers based on nonstationary effects. The spectrometers characteristics (spectral resolution and sensitivity) meet the requirements for high precision analysis. The gas analyzers, based on the high precision spectrometers, have been successfully applied for analytical investigations of gas impurities in high pure substances. These investigations can be carried out both in absorption cell and in reactor. The devices can be used for ecological monitoring, detecting the components of chemical weapons and explosive in the atmosphere. The great field of THz investigations is the medicine application. Using the THz spectrometers developed one can detect markers for some diseases in exhaled air.

  20. Detectors

    DOEpatents

    Orr, Christopher Henry; Luff, Craig Janson; Dockray, Thomas; Macarthur, Duncan Whittemore; Bounds, John Alan; Allander, Krag

    2002-01-01

    The apparatus and method provide techniques through which both alpha and beta emission determinations can be made simultaneously using a simple detector structure. The technique uses a beta detector covered in an electrically conducting material, the electrically conducting material discharging ions generated by alpha emissions, and as a consequence providing a measure of those alpha emissions. The technique also offers improved mountings for alpha detectors and other forms of detectors against vibration and the consequential effects vibration has on measurement accuracy.

  1. General purpose nonlinear system solver based on Newton-Krylov method.

    SciTech Connect

    2013-12-01

    KINSOL is part of a software family called SUNDIALS: SUite of Nonlinear and Differential/Algebraic equation Solvers [1]. KINSOL is a general-purpose nonlinear system solver based on Newton-Krylov and fixed-point solver technologies [2].

  2. Layered compression for high-precision depth data.

    PubMed

    Miao, Dan; Fu, Jingjing; Lu, Yan; Li, Shipeng; Chen, Chang Wen

    2015-12-01

    With the development of depth data acquisition technologies, access to high-precision depth with more than 8-b depths has become much easier and determining how to efficiently represent and compress high-precision depth is essential for practical depth storage and transmission systems. In this paper, we propose a layered high-precision depth compression framework based on an 8-b image/video encoder to achieve efficient compression with low complexity. Within this framework, considering the characteristics of the high-precision depth, a depth map is partitioned into two layers: 1) the most significant bits (MSBs) layer and 2) the least significant bits (LSBs) layer. The MSBs layer provides rough depth value distribution, while the LSBs layer records the details of the depth value variation. For the MSBs layer, an error-controllable pixel domain encoding scheme is proposed to exploit the data correlation of the general depth information with sharp edges and to guarantee the data format of LSBs layer is 8 b after taking the quantization error from MSBs layer. For the LSBs layer, standard 8-b image/video codec is leveraged to perform the compression. The experimental results demonstrate that the proposed coding scheme can achieve real-time depth compression with satisfactory reconstruction quality. Moreover, the compressed depth data generated from this scheme can achieve better performance in view synthesis and gesture recognition applications compared with the conventional coding schemes because of the error control algorithm. PMID:26415171

  3. VIEW OF MICROMACHINING, HIGH PRECISION EQUIPMENT USED TO CUSTOM MAKE ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    VIEW OF MICRO-MACHINING, HIGH PRECISION EQUIPMENT USED TO CUSTOM MAKE SMALL PARTS. LUMPS OF CLAY; SHOWN IN THE PHOTOGRAPH, WERE USED TO STABILIZE PARTS BEING MACHINED. (11/1/87) - Rocky Flats Plant, Stainless Steel & Non-Nuclear Components Manufacturing, Southeast corner of intersection of Cottonwood & Third Avenues, Golden, Jefferson County, CO

  4. A high precision gamma-ray spectrometer for the Mars-94 mission

    SciTech Connect

    Mitrofanov, I.G.; Anfimov, D.S.; Chernenko, A.M.

    1994-06-01

    The high precision gamma-ray spectrometer (PGS) is scheduled to be launched on the Mars-94 mission in October 1994, and to go into an elliptical polar orbit around Mars. The PGS consists of two high-purity germanium (Ge) detectors, associated electronics, and a passive cooler and will be mounted on one of the solar panels. The PGS will measure nuclear gamma-ray emissions from the martian surface, cosmic gamma-ray bursts, and the high-energy component of solar flares in the broad energy range from 50 KeV to 8 MeV using 4096 energy channels.

  5. Strategy for Realizing High-Precision VUV Spectro-Polarimeter

    NASA Astrophysics Data System (ADS)

    Ishikawa, R.; Narukage, N.; Kubo, M.; Ishikawa, S.; Kano, R.; Tsuneta, S.

    2014-12-01

    Spectro-polarimetric observations in the vacuum ultraviolet (VUV) range are currently the only means to measure magnetic fields in the upper chromosphere and transition region of the solar atmosphere. The Chromospheric Lyman-Alpha Spectro-Polarimeter (CLASP) aims to measure linear polarization at the hydrogen Lyman- α line (121.6 nm). This measurement requires a polarization sensitivity better than 0.1 %, which is unprecedented in the VUV range. We here present a strategy with which to realize such high-precision spectro-polarimetry. This involves the optimization of instrument design, testing of optical components, extensive analyses of polarization errors, polarization calibration of the instrument, and calibration with onboard data. We expect that this strategy will aid the development of other advanced high-precision polarimeters in the UV as well as in other wavelength ranges.

  6. Note: High precision measurements using high frequency gigahertz signals

    NASA Astrophysics Data System (ADS)

    Jin, Aohan; Fu, Siyuan; Sakurai, Atsunori; Liu, Liang; Edman, Fredrik; Pullerits, Tõnu; Öwall, Viktor; Karki, Khadga Jung

    2014-12-01

    Generalized lock-in amplifiers use digital cavities with Q-factors as high as 5 × 108 to measure signals with very high precision. In this Note, we show that generalized lock-in amplifiers can be used to analyze microwave (giga-hertz) signals with a precision of few tens of hertz. We propose that the physical changes in the medium of propagation can be measured precisely by the ultra-high precision measurement of the signal. We provide evidence to our proposition by verifying the Newton's law of cooling by measuring the effect of change in temperature on the phase and amplitude of the signals propagating through two calibrated cables. The technique could be used to precisely measure different physical properties of the propagation medium, for example, the change in length, resistance, etc. Real time implementation of the technique can open up new methodologies of in situ virtual metrology in material design.

  7. Note: High precision measurements using high frequency gigahertz signals.

    PubMed

    Jin, Aohan; Fu, Siyuan; Sakurai, Atsunori; Liu, Liang; Edman, Fredrik; Pullerits, Tõnu; Öwall, Viktor; Karki, Khadga Jung

    2014-12-01

    Generalized lock-in amplifiers use digital cavities with Q-factors as high as 5 × 10(8) to measure signals with very high precision. In this Note, we show that generalized lock-in amplifiers can be used to analyze microwave (giga-hertz) signals with a precision of few tens of hertz. We propose that the physical changes in the medium of propagation can be measured precisely by the ultra-high precision measurement of the signal. We provide evidence to our proposition by verifying the Newton's law of cooling by measuring the effect of change in temperature on the phase and amplitude of the signals propagating through two calibrated cables. The technique could be used to precisely measure different physical properties of the propagation medium, for example, the change in length, resistance, etc. Real time implementation of the technique can open up new methodologies of in situ virtual metrology in material design.

  8. High-precision spectroscopy of hydrogen molecular ions

    NASA Astrophysics Data System (ADS)

    Zhong, Zhen-Xiang; Tong, Xin; Yan, Zong-Chao; Shi, Ting-Yun

    2015-05-01

    In this paper, we overview recent advances in high-precision structure calculations of the hydrogen molecular ions ( and HD+), including nonrelativistic energy eigenvalues and relativistic and quantum electrodynamic corrections. In combination with high-precision measurements, it is feasible to precisely determine a molecular-based value of the proton-to-electron mass ratio. An experimental scheme is presented for measuring the rovibrational transition frequency (v,L) : (0,0) → (6,1) in HD+, which is currently underway at the Wuhan Institute of Physics and Mathematics. Project supported by the National Natural Science Foundation of China (Grants Nos. 11474316, 11004221, 10974224, and 11274348), the “Hundred Talent Program” of Chinese Academy of Sciences. Yan Zong-Chao was supported by NSERC, SHARCnet, ACEnet of Canada, and the CAS/SAFEA International Partnership Program for Creative Research Teams.

  9. The high precision measurement of the 144Ce activity in the SOX experiment

    NASA Astrophysics Data System (ADS)

    Di Noto, L.; Agostini, M.; Althenmüller, K.; Appel, S.; Bellini, G.; Benziger, J.; Berton, N.; Bick, D.; Bonfini, G.; Bravo—Berguño, D.; Caccianiga, B.; Calaprice, F.; Caminata, A.; Cavalcante, P.; Cereseto, R.; Chepurnov, A.; Choi, K.; Cribier, M.; DAngelo, D.; Davini, S.; Derbin, A.; Drachnev, I.; Durero, M.; Etenko, A.; Farinon, S.; Fischer, V.; Fomenko, K.; Franco, D.; Gabriele, F.; Gaffiot, J.; Galbiati, C.; Ghiano, C.; Giammarchi, M.; Göeger-Neff, M.; Goretti, A.; Gromov, M.; Hagner, C.; Houdy, Th; Hungerford, E.; Ianni, Aldo; Ianni, Andrea; Jonquères, N.; Jedrzejczak, K.; Kaiser, M.; Kobychev, V.; Korablev, D.; Korga, G.; Kornoukhov, V.; Kryn, D.; Lachenmaier, T.; Lasserre, T.; Laubenstein, M.; Lehnert, T.; Link, J.; Litvinovich, E.; Lombardi, F.; Lombardi, P.; Ludhova, L.; Lukyanchenko, G.; Machulin, I.; Manecki, S.; Maneschg, W.; Marcocci, S.; Maricic, J.; Mention, G.; Meroni, E.; Meyer, M.; Miramonti, L.; Misiaszek, M.; Montuschi, M.; Mosteiro, P.; Muratova, V.; Musenich, R.; Neumair, B.; Oberauer, L.; Obolensky, M.; Ortica, F.; Pallavicini, M.; Papp, L.; Perasso, L.; Pocar, A.; Ranucci, G.; Razeto, A.; Re, A.; Romani, A.; Roncin, R.; Rossi, C.; Rossi, N.; Schönert, S.; Scola, L.; Semenov, D.; Simgen, H.; Skorokhvatov, M.; Smirnov, O.; Sotnikov, A.; Sukhotin, S.; Suvorov, Y.; Tartaglia, R.; Testera, G.; Thurn, J.; Toropova, M.; Veyssière, C.; Vivier, M.; Unzhakov, E.; Vogelaar, R. B.; von Feilitzsch, F.; Wang, H.; Weinz, S.; Winter, J.; Wojcik, M.; Wurm, M.; Yokley, Z.; Zaimidoroga, O.; Zavatarelli, S.; Zuber, K.; Zuzel, G.

    2016-02-01

    In order to perform a resolutive measurement to clarify the neutrino anomalies and to observe possible short distance neutrino oscillations, the SOX (Short distance neutrino Oscillations with BoreXino) experiment is under construction. In the first phase, a 100 kCi 144Ce-144Pr antineutrino source will be placed under the Borexino detector at the Laboratori Nazionali del Gran Sasso (LNGS), in center of Italy, and the rate measurement of the antineutrino events, observed by the very low radioactive background Borexino detector, will be compared with the high precision (< 1%) activity measurement performed by two calorimeters. The source will be embedded in a 19 mm thick tungsten alloy shield and both the calorimeters have been conceived for measuring the thermal heat absorbed by a water flow. In this report the design of the calorimeters will be described in detail and very preliminary results will be also shown.

  10. Location of end-points in high-precision coulometry.

    PubMed

    Koch, W F; Poe, D P; Diehl, H

    1975-07-01

    A computer has been used to fit a cubic equation to experimental data obtained in the region of the end-point in high-precision coulometric titrations of 4-aminopyridine and tris(hydroxy-methyl) aminomethane. For these weak bases, the two end-points (points of inflexion calculated by setting the second derivative equal to zero) obtained by choosing first time, and secondly pH, as the independent variable, are in good agreement.

  11. Some comments on high precision study of neutrino oscillations

    NASA Astrophysics Data System (ADS)

    Bilenky, S. M.

    2015-07-01

    I discuss here some problems connected with the high precision study of neutrino oscillations. In the general case of n-neutrino mixing I derive a convenient expression for transition probability in which only independent terms (and mass-squared differences) enter. For three-neutrino mixing I discuss a problem of a definition of a large (atmospheric) neutrino mass-squared difference. I comment also possibilities to reveal the character of neutrino mass spectrum in future reactor neutrino experiments.

  12. System and method for high precision isotope ratio destructive analysis

    SciTech Connect

    Bushaw, Bruce A; Anheier, Norman C; Phillips, Jon R

    2013-07-02

    A system and process are disclosed that provide high accuracy and high precision destructive analysis measurements for isotope ratio determination of relative isotope abundance distributions in liquids, solids, and particulate samples. The invention utilizes a collinear probe beam to interrogate a laser ablated plume. This invention provides enhanced single-shot detection sensitivity approaching the femtogram range, and isotope ratios that can be determined at approximately 1% or better precision and accuracy (relative standard deviation).

  13. 41 CFR 60-2.10 - General purpose and contents of affirmative action programs.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 41 Public Contracts and Property Management 1 2014-07-01 2014-07-01 false General purpose and contents of affirmative action programs. 60-2.10 Section 60-2.10 Public Contracts and Property Management...) An affirmative action program is a management tool designed to ensure equal employment opportunity....

  14. Selection and Use of General-Purpose Programming Languages--Overview. Volume 1.

    ERIC Educational Resources Information Center

    Cugini, John V.

    This study presents a review of selection factors for the seven major general-purpose programming languages: Ada, BASIC, C, COBOL, FORTRAN, PASCAL, and PL/I. The factors covered include not only the logical operations within each language, but also the advantages and disadvantages stemming from the current computing environment, e.g., software…

  15. Reentry thermal testing of a general purpose heat source fueled clad

    SciTech Connect

    Peterson, D.E.; Frantz, C.E.

    1982-03-01

    A General Purpose Heat Source (GPHS) module was exposed to heat treatments simulating an isothermal prelaunch condition, followed by thermal pulses corresponding to atmospheric reentry. Helium release rates were determined during each heating and modeled after simple diffusion theory. Following the tests, the module was examined metallurgically with no evidence of swelling of the cladding nor degradation of the fuel.

  16. 41 CFR 60-2.10 - General purpose and contents of affirmative action programs.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... contents of affirmative action programs. 60-2.10 Section 60-2.10 Public Contracts and Property Management... EMPLOYMENT OPPORTUNITY, DEPARTMENT OF LABOR 2-AFFIRMATIVE ACTION PROGRAMS Purpose and Contents of Affirmative Action Programs § 60-2.10 General purpose and contents of affirmative action programs. (a) Purpose....

  17. An Evaluation of Classroom Activities and Exercises in ELT Classroom for General Purposes Course

    ERIC Educational Resources Information Center

    Zohrabi, Mohammad

    2011-01-01

    It is through effective implementation of activities and exercises which students can be motivated and consequently lead to language learning. However, as an insider, the experience of teaching English for General Purposes (EGP) course indicates that it has some problems which need to be modified. In order to evaluate the EGP course,…

  18. Research on Automatic Classification, Indexing and Extracting: A General-Purpose Frequency Program.

    ERIC Educational Resources Information Center

    Baker, F. T.; Williams, John H., Jr.

    To support studies in automatic indexing, classification and extracting, a general purpose frequency program was developed to further theoretical and practical understanding of text word distributions. While the program is primarily designed for counting strings of character-oriented data, it can be used without change for counting any items which…

  19. Distributed high-precision time transfer through passive optical networks

    NASA Astrophysics Data System (ADS)

    Wu, Guiling; Hu, Liang; Zhang, Hao; Chen, Jianping

    2014-09-01

    We propose a one-point to multipoint distributed time transfer through passive optical networks using a time division multiple access (TDMA) based two-way time transfer. The clock at each clock user node is, in turn, compared with the high-precision reference clock at a master node by a two-way time transfer during assigned subperiods. The corresponding TDMA control protocol and time transfer units for the proposed scheme are designed and implemented. A 1×8 experimental system with a 20 km single-mode fiber in each subpath is demonstrated. The results show that a standard deviation of <60 ps can be reached in each comparison subperiod.

  20. Globular Cluster Streams as Galactic High-Precision Scales

    NASA Astrophysics Data System (ADS)

    Küpper, Andreas H. W.; Balbinot, Eduardo; Bonaca, Ana; Johnston, Kathryn V.; Hogg, David W.; Kroupa, Pavel; Santiago, Basilio X.

    2016-08-01

    Tidal streams of globular clusters are ideal tracers of the Galactic gravitational potential. Compared to the few known, complex and diffuse dwarf-galaxy streams, they are kinematically cold, have thin morphologies and are abundant in the halo of the Milky Way. Their coldness and thinness in combination with potential epicyclic substructure in the vicinity of the stream progenitor turns them into high-precision scales. With the example of Palomar 5, we demonstrate how modeling of a globular cluster stream allows us to simultaneously measure the properties of the disrupting globular cluster, its orbital motion, and the gravitational potential of the Milky Way.

  1. High precision applications of the global positioning system

    NASA Technical Reports Server (NTRS)

    Lichten, Stephen M.

    1991-01-01

    The Global Positioning System (GPS) is a constellation of U.S. defense navigation satellites which can be used for military and civilian positioning applications. A wide variety of GPS scientific applications were identified and precise positioning capabilities with GPS were already demonstrated with data available from the present partial satellite constellation. Expected applications include: measurements of Earth crustal motion, particularly in seismically active regions; measurements of the Earth's rotation rate and pole orientation; high-precision Earth orbiter tracking; surveying; measurements of media propagation delays for calibration of deep space radiometric data in support of NASA planetary missions; determination of precise ground station coordinates; and precise time transfer worldwide.

  2. Future high precision experiments and new physics beyond Standard Model

    SciTech Connect

    Luo, Mingxing

    1993-04-01

    High precision (< 1%) electroweak experiments that have been done or are likely to be done in this decade are examined on the basis of Standard Model (SM) predictions of fourteen weak neutral current observables and fifteen W and Z properties to the one-loop level, the implications of the corresponding experimental measurements to various types of possible new physics that enter at the tree or loop level were investigated. Certain experiments appear to have special promise as probes of the new physics considered here.

  3. Future high precision experiments and new physics beyond Standard Model

    SciTech Connect

    Luo, Mingxing.

    1993-01-01

    High precision (< 1%) electroweak experiments that have been done or are likely to be done in this decade are examined on the basis of Standard Model (SM) predictions of fourteen weak neutral current observables and fifteen W and Z properties to the one-loop level, the implications of the corresponding experimental measurements to various types of possible new physics that enter at the tree or loop level were investigated. Certain experiments appear to have special promise as probes of the new physics considered here.

  4. High precision photon flux determination for photon tagging experiments

    SciTech Connect

    Teymurazyan, A; Ahmidouch, A; Ambrozewicz, P; Asratyan, A; Baker, K; Benton, L; Burkert, V; Clinton, E; Cole, P; Collins, P; Dale, D; Danagoulian, S; Davidenko, G; Demirchyan, R; Deur, A; Dolgolenko, A; Dzyubenko, G; Ent, R; Evdokimov, A; Feng, J; Gabrielyan, M; Gan, L; Gasparian, A; Glamazdin, A; Goryachev, V; Hardy, K; He, J; Ito, M; Jiang, L; Kashy, D; Khandaker, M; Kolarkar, A; Konchatnyi, M; Korchin, A; Korsch, W; Kosinov, O; Kowalski, S; Kubantsev, M; Kubarovsky, V; Larin, I; Lawrence, D; Li, X; Martel, P; Matveev, V; McNulty, D; Mecking, B; Milbrath, B; Minehart, R; Miskimen, R; Mochalov, V; Nakagawa, I; Overby, S; Pasyuk, E; Payen, M; Pedroni, R; Prok, Y; Ritchie, B; Salgado, C; Shahinyan, A; Sitnikov, A; Sober, D; Stepanyan, S; Stevens, W; Underwood, J; Vasiliev, A; Vishnyakov, V; Wood, M; Zhou, S

    2014-07-01

    The Jefferson Laboratory PrimEx Collaboration has developed and implemented a method to control the tagged photon flux in photoproduction experiments at the 1% level over the photon energy range from 4.9 to 5.5 GeV. This method has been successfully implemented in a high precision measurement of the neutral pion lifetime. Here, we outline the experimental equipment and the analysis techniques used to accomplish this. These include the use of a total absorption counter for absolute flux calibration, a pair spectrometer for online relative flux monitoring, and a new method for post-bremsstrahlung electron counting.

  5. Strategies for high-precision Global Positioning System orbit determination

    NASA Technical Reports Server (NTRS)

    Lichten, Stephen M.; Border, James S.

    1987-01-01

    Various strategies for the high-precision orbit determination of the GPS satellites are explored using data from the 1985 GPS field test. Several refinements to the orbit determination strategies were found to be crucial for achieving high levels of repeatability and accuracy. These include the fine tuning of the GPS solar radiation coefficients and the ground station zenith tropospheric delays. Multiday arcs of 3-6 days provided better orbits and baselines than the 8-hr arcs from single-day passes. Highest-quality orbits and baselines were obtained with combined carrier phase and pseudorange solutions.

  6. High-precision micro/nano-scale machining system

    DOEpatents

    Kapoor, Shiv G.; Bourne, Keith Allen; DeVor, Richard E.

    2014-08-19

    A high precision micro/nanoscale machining system. A multi-axis movement machine provides relative movement along multiple axes between a workpiece and a tool holder. A cutting tool is disposed on a flexible cantilever held by the tool holder, the tool holder being movable to provide at least two of the axes to set the angle and distance of the cutting tool relative to the workpiece. A feedback control system uses measurement of deflection of the cantilever during cutting to maintain a desired cantilever deflection and hence a desired load on the cutting tool.

  7. GENERATION AND CONTROL OF HIGH PRECISION BEAMS AT LEPTON ACCELERATORS

    SciTech Connect

    Yu-Chiu Chao

    2007-06-25

    Parity violation experiments require precision manipulation of helicity-correlated beam coordinates on target at the nm/nrad-level. Achieving this unprecedented level of control requires a detailed understanding of the particle optics and careful tuning of the beam transport to keep anomalies from compromising the design adiabatic damping. Such efforts are often hindered by machine configuration and instrumentation limitations at the low energy end. A technique has been developed at CEBAF including high precision measurements, Mathematica-based analysis for obtaining corrective solutions, and control hardware/software developments for realizing such level of control at energies up to 5 GeV.

  8. High-precision measurements of global stellar magnetic fields

    NASA Astrophysics Data System (ADS)

    Plachinda, S. I.

    2014-06-01

    This paper presents a brief history of the development of devices and techniques for high-precision measurements of stellar magnetic fields. Two main approaches for the processing of spectral-polarimetric observations are described: the method of least-squares deconvolution (LSD), which is used to find a mean-weighted average of the normalized polarization profile using a set of spectral lines, and a method in which each individual spectral line is used to determine the magnetic field, viz., the single line method (SL). The advantages and disadvantages of the LSD and SL methods are discussed.

  9. High precision capacitive beam phase probe for KHIMA project

    NASA Astrophysics Data System (ADS)

    Hwang, Ji-Gwang; Yang, Tae-Keun; Forck, Peter

    2016-11-01

    In the medium energy beam transport (MEBT) line of KHIMA project, a high precision beam phase probe monitor is required for a precise tuning of RF phase and amplitude of Radio Frequency Quadrupole (RFQ) accelerator and IH-DTL linac. It is also used for measuring a kinetic energy of ion beam by time-of-flight (TOF) method using two phase probes. The capacitive beam phase probe has been developed. The electromagnetic design of the high precision phase probe was performed to satisfy the phase resolution of 1° (@200 MHz). It was confirmed by the test result using a wire test bench. The measured phase accuracy of the fabricated phase probe is 1.19 ps. The pre-amplifier electronics with the 0.125 ∼ 1.61 GHz broad-band was designed and fabricated for amplifying the signal strength. The results of RF frequency and beam energy measurement using a proton beam from the cyclotron in KIRAMS is presented.

  10. High-Precision Computation: Mathematical Physics and Dynamics

    SciTech Connect

    Bailey, D. H.; Barrio, R.; Borwein, J. M.

    2010-04-01

    At the present time, IEEE 64-bit oating-point arithmetic is suficiently accurate for most scientic applications. However, for a rapidly growing body of important scientic computing applications, a higher level of numeric precision is required. Such calculations are facilitated by high-precision software packages that include high-level language translation modules to minimize the conversion e ort. This pa- per presents a survey of recent applications of these techniques and provides someanalysis of their numerical requirements. These applications include supernova simulations, climate modeling, planetary orbit calculations, Coulomb n-body atomic systems, studies of the one structure constant, scattering amplitudes of quarks, glu- ons and bosons, nonlinear oscillator theory, experimental mathematics, evaluation of orthogonal polynomials, numerical integration of ODEs, computation of periodic orbits, studies of the splitting of separatrices, detection of strange nonchaotic at- tractors, Ising theory, quantum held theory, and discrete dynamical systems. We conclude that high-precision arithmetic facilities are now an indispensable compo- nent of a modern large-scale scientic computing environment.

  11. A High Precision Terahertz Wave Image Reconstruction Algorithm

    PubMed Central

    Guo, Qijia; Chang, Tianying; Geng, Guoshuai; Jia, Chengyan; Cui, Hong-Liang

    2016-01-01

    With the development of terahertz (THz) technology, the applications of this spectrum have become increasingly wide-ranging, in areas such as non-destructive testing, security applications and medical scanning, in which one of the most important methods is imaging. Unlike remote sensing applications, THz imaging features sources of array elements that are almost always supposed to be spherical wave radiators, including single antennae. As such, well-developed methodologies such as Range-Doppler Algorithm (RDA) are not directly applicable in such near-range situations. The Back Projection Algorithm (BPA) can provide products of high precision at the the cost of a high computational burden, while the Range Migration Algorithm (RMA) sacrifices the quality of images for efficiency. The Phase-shift Migration Algorithm (PMA) is a good alternative, the features of which combine both of the classical algorithms mentioned above. In this research, it is used for mechanical scanning, and is extended to array imaging for the first time. In addition, the performances of PMA are studied in detail in contrast to BPA and RMA. It is demonstrated in our simulations and experiments described herein that the algorithm can reconstruct images with high precision. PMID:27455269

  12. A High Precision Terahertz Wave Image Reconstruction Algorithm.

    PubMed

    Guo, Qijia; Chang, Tianying; Geng, Guoshuai; Jia, Chengyan; Cui, Hong-Liang

    2016-01-01

    With the development of terahertz (THz) technology, the applications of this spectrum have become increasingly wide-ranging, in areas such as non-destructive testing, security applications and medical scanning, in which one of the most important methods is imaging. Unlike remote sensing applications, THz imaging features sources of array elements that are almost always supposed to be spherical wave radiators, including single antennae. As such, well-developed methodologies such as Range-Doppler Algorithm (RDA) are not directly applicable in such near-range situations. The Back Projection Algorithm (BPA) can provide products of high precision at the the cost of a high computational burden, while the Range Migration Algorithm (RMA) sacrifices the quality of images for efficiency. The Phase-shift Migration Algorithm (PMA) is a good alternative, the features of which combine both of the classical algorithms mentioned above. In this research, it is used for mechanical scanning, and is extended to array imaging for the first time. In addition, the performances of PMA are studied in detail in contrast to BPA and RMA. It is demonstrated in our simulations and experiments described herein that the algorithm can reconstruct images with high precision. PMID:27455269

  13. High-precision camera distortion measurements with a ``calibration harp''

    NASA Astrophysics Data System (ADS)

    Tang, Zhongwei; Grompone von Gioi, Rafael; Monasse, Pascal; Morel, Jean-Michel

    2012-10-01

    This paper addresses the high precision measurement of the distortion of a digital camera from photographs. Traditionally, this distortion is measured from photographs of a flat pattern which contains aligned elements. Nevertheless, it is nearly impossible to fabricate a very flat pattern and to validate its flatness. This fact limits the attainable measurable precisions. In contrast, it is much easier to obtain physically very precise straight lines by tightly stretching good quality strings on a frame. Taking literally "plumb-line methods", we built a "calibration harp" instead of the classic flat patterns to obtain a high precision measurement tool, demonstrably reaching 2/100 pixel precisions. The harp is complemented with the algorithms computing automatically from harp photographs two different and complementary lens distortion measurements. The precision of the method is evaluated on images corrected by state-of-the-art distortion correction algorithms, and by popular software. Three applications are shown: first an objective and reliable measurement of the result of any distortion correction. Second, the harp permits to control state-of-the art global camera calibration algorithms: It permits to select the right distortion model, thus avoiding internal compensation errors inherent to these methods. Third, the method replaces manual procedures in other distortion correction methods, makes them fully automatic, and increases their reliability and precision.

  14. General purpose simulation system of the data management system for Space Shuttle mission 18

    NASA Technical Reports Server (NTRS)

    Bengtson, N. M.; Mellichamp, J. M.; Smith, O. C.

    1976-01-01

    A simulation program for the flow of data through the Data Management System of Spacelab and Space Shuttle was presented. The science, engineering, command and guidance, navigation and control data were included. The programming language used was General Purpose Simulation System V (OS). The science and engineering data flow was modeled from its origin at the experiments and subsystems to transmission from Space Shuttle. Command data flow was modeled from the point of reception onboard and from the CDMS Control Panel to the experiments and subsystems. The GN&C data flow model handled data between the General Purpose Computer and the experiments and subsystems. Mission 18 was the particular flight chosen for simulation. The general structure of the program is presented, followed by a user's manual. Input data required to make runs are discussed followed by identification of the output statistics. The appendices contain a detailed model configuration, program listing and results.

  15. Study of highly precise outdoor characterization technique for photovoltaic modules in terms of reproducibility

    NASA Astrophysics Data System (ADS)

    Fukabori, Akihiro; Takenouchi, Takakazu; Matsuda, Youji; Tsuno, Yuki; Hishikawa, Yoshihiro

    2015-08-01

    In this study, novel outdoor measurements were conducted for highly precise characterization of photovoltaic (PV) modules by measuring current-voltage (I-V) curves with fast sweep speeds and module’s temperature, and with a PV sensor for reference. Fast sweep speeds suppressed the irradiance variation. As a result, smooth I-V curves were obtained and the PV parameter deviation was suppressed. The module’s temperature was measured by attaching resistive temperature detector sensors on the module’s backsheet. The PV sensor was measured synchronously with the PV module. The PV parameters including Isc, Pmax, Voc, and FF were estimated after correcting the I-V curves using the IEC standards. The reproducibility of Isc, Pmax, Voc, and FF relative to the outdoor fits was evaluated as 0.43, 0.58, 0.24, and 0.23%, respectively. The results demonstrate that highly precise measurements are possible using a PV measurement system with the three above-mentioned features.

  16. IDSOLVER: A general purpose solver for nth-order integro-differential equations

    NASA Astrophysics Data System (ADS)

    Gelmi, Claudio A.; Jorquera, Héctor

    2014-01-01

    Many mathematical models of complex processes may be posed as integro-differential equations (IDE). Many numerical methods have been proposed for solving those equations, but most of them are ad hoc thus new equations have to be solved from scratch for translating the IDE into the framework of the specific method chosen. Furthermore, there is a paucity of general-purpose numerical solvers that free the user from additional tasks.

  17. The role of overset grids in the development of the general purpose CFD code

    NASA Technical Reports Server (NTRS)

    Belk, Davy M.

    1995-01-01

    A discussion of the strengths and weaknesses of overset composite grid and solution technology is given, along with a sampling of current work in the area. Major trends are identified, and the observation is made that generalized and hybridized overset methods provide a natural framework for combining disparate mesh types and physics models. Because of this, the author concludes that overset methods will be the foundation for the general purpose computational fluid dynamics programs of the future.

  18. High-precision buffer circuit for suppression of regenerative oscillation

    NASA Technical Reports Server (NTRS)

    Tripp, John S.; Hare, David A.; Tcheng, Ping

    1995-01-01

    Precision analog signal conditioning electronics have been developed for wind tunnel model attitude inertial sensors. This application requires low-noise, stable, microvolt-level DC performance and a high-precision buffered output. Capacitive loading of the operational amplifier output stages due to the wind tunnel analog signal distribution facilities caused regenerative oscillation and consequent rectification bias errors. Oscillation suppression techniques commonly used in audio applications were inadequate to maintain the performance requirements for the measurement of attitude for wind tunnel models. Feedback control theory is applied to develop a suppression technique based on a known compensation (snubber) circuit, which provides superior oscillation suppression with high output isolation and preserves the low-noise low-offset performance of the signal conditioning electronics. A practical design technique is developed to select the parameters for the compensation circuit to suppress regenerative oscillation occurring when typical shielded cable loads are driven.

  19. Slow Control System for the NIFFTE High Precision TPC

    NASA Astrophysics Data System (ADS)

    Thornton, Remington

    2010-11-01

    The Neutron Induced Fission Fragment Tracking Experiment (NIFFTE) has designed a Time Projection Chamber (TPC) to measure neutron induced fission cross-section measurements of the major actinides to sub-1% precision over a wide incident neutron energy range. These measurements are necessary to design the next generation of nuclear power plants. In order to achieve our high precision goals, an accurate and efficient slow control system must be implemented. Custom software has been created to control the hardware through Maximum Integration Data Acquisition System (MIDAS). This includes reading room and device temperature, setting the high voltage power supplies, and reading voltages. From hardware to software, an efficient design has been implemented and tested. This poster will present the setup and data from this slow control system.

  20. High precision u/th dating of first Polynesian settlement.

    PubMed

    Burley, David; Weisler, Marshall I; Zhao, Jian-xin

    2012-01-01

    Previous studies document Nukuleka in the Kingdom of Tonga as a founder colony for first settlement of Polynesia by Lapita peoples. A limited number of radiocarbon dates are one line of evidence supporting this claim, but they cannot precisely establish when this event occurred, nor can they afford a detailed chronology for sequent occupation. High precision U/Th dates of Acropora coral files (abraders) from Nukuleka give unprecedented resolution, identifying the founder event by 2838±8 BP and documenting site development over the ensuing 250 years. The potential for dating error due to post depositional diagenetic alteration of ancient corals at Nukuleka also is addressed through sample preparation protocols and paired dates on spatially separated samples for individual specimens. Acropora coral files are widely distributed in Lapita sites across Oceania. U/Th dating of these artifacts provides unparalleled opportunities for greater precision and insight into the speed and timing of this final chapter in human settlement of the globe.

  1. High-precision thermal and electrical characterization of thermoelectric modules

    SciTech Connect

    Kolodner, Paul

    2014-05-15

    This paper describes an apparatus for performing high-precision electrical and thermal characterization of thermoelectric modules (TEMs). The apparatus is calibrated for operation between 20 °C and 80 °C and is normally used for measurements of heat currents in the range 0–10 W. Precision thermometry based on miniature thermistor probes enables an absolute temperature accuracy of better than 0.010 °C. The use of vacuum isolation, thermal guarding, and radiation shielding, augmented by a careful accounting of stray heat leaks and uncertainties, allows the heat current through the TEM under test to be determined with a precision of a few mW. The fractional precision of all measured parameters is approximately 0.1%.

  2. Flight Test Performance of a High Precision Navigation Doppler Lidar

    NASA Technical Reports Server (NTRS)

    Pierrottet, Diego; Amzajerdian, Farzin; Petway, Larry; Barnes, Bruce; Lockard, George

    2009-01-01

    A navigation Doppler Lidar (DL) was developed at NASA Langley Research Center (LaRC) for high precision velocity measurements from a lunar or planetary landing vehicle in support of the Autonomous Landing and Hazard Avoidance Technology (ALHAT) project. A unique feature of this DL is that it has the capability to provide a precision velocity vector which can be easily separated into horizontal and vertical velocity components and high accuracy line of sight (LOS) range measurements. This dual mode of operation can provide useful information, such as vehicle orientation relative to the direction of travel, and vehicle attitude relative to the sensor footprint on the ground. System performance was evaluated in a series of helicopter flight tests over the California desert. This paper provides a description of the DL system and presents results obtained from these flight tests.

  3. High-precision digital charge-coupled device TV system

    NASA Astrophysics Data System (ADS)

    Vishnevsky, Grigory I.; Ioffe, S. A.; Berezin, V. Y.; Rybakov, M. I.; Mikhaylov, A. V.; Belyaev, L. V.

    1991-06-01

    In certain test, measurement, and research applications of CCD TV systems, the greater accuracy than usual 8-bit frame-grabbers can provide is demanded without the system being too expensive. The paper presents the concept and features of the high-precision low-cost digital CCD TV system intended for obtaining 12-bit monochrome images of immobile or relatively slow moving objects. The increase in accuracy is achieved by the specific digitization procedure -- one column per frame, which combines the benefits of a slow A/D converter with real-time TV imaging compatibility. To reduce speed restrictions on sample- and-hold circuits, a zoomed pixel read out cycle, corresponding to the pixel to be digitized, is proposed. The system provides great flexibility in choice of integration times and readout rates by means of a programmable readout sequencer, and is easily adaptable to various user demands and CCDs types.

  4. High Precision Assembly Line Synthesis for Molecules with Tailored Shapes

    PubMed Central

    Burns, Matthew; Essafi, Stephanie; Bame, Jessica R.; Bull, Stephanie P.; Webster, Matthew P.; Balieu, Sebastien; Dale, James W.; Butts, Craig P.; Harvey, Jeremy N.; Aggarwal, Varinder K.

    2014-01-01

    Molecular assembly lines, where molecules undergo iterative processes involving chain elongation and functional group manipulation are hallmarks of many processes found in Nature. We have sought to emulate Nature in the development of our own molecular assembly line through iterative homologations of boronic esters. Here we report a reagent (α-lithioethyl triispopropylbenzoate) which inserts into carbon-boron bonds with exceptionally high fidelity and stereocontrol. Through repeated iteration we have converted a simple boronic ester into a complex molecule (a carbon chain with ten contiguous methyl groups) with remarkably high precision over its length, its stereochemistry and therefore its shape. Different stereoisomers were targeted and it was found that they adopted different shapes (helical/linear) according to their stereochemistry. This work should now enable scientists to rationally design and create molecules with predictable shape, which could have an impact in all areas of molecular sciences where bespoke molecules are required. PMID:25209797

  5. Flow-Based Systems for Rapid and High-Precision Enzyme Kinetics Studies

    PubMed Central

    Hartwell, Supaporn Kradtap; Grudpan, Kate

    2012-01-01

    Enzyme kinetics studies normally focus on the initial rate of enzymatic reaction. However, the manual operation of steps of the conventional enzyme kinetics method has some drawbacks. Errors can result from the imprecise time control and time necessary for manual changing the reaction cuvettes into and out of the detector. By using the automatic flow-based analytical systems, enzyme kinetics studies can be carried out at real-time initial rate avoiding the potential errors inherent in manual operation. Flow-based systems have been developed to provide rapid, low-volume, and high-precision analyses that effectively replace the many tedious and high volume requirements of conventional wet chemistry analyses. This article presents various arrangements of flow-based techniques and their potential use in future enzyme kinetics applications. PMID:22577614

  6. High precision (14 bit), high density (octal) analog to digital converter for spectroscopy applications.

    PubMed

    Subramaniam, E T; Jain, Mamta; Bhowmik, R K; Tripon, Michel

    2008-10-01

    Nuclear and particle physics experiments with large number of detectors require signal processing and data collection strategies that call for the ability to collect large amount of data while not sacrificing the precision and accuracy of the data being collected. This paper deals with the development of a high precision pulse peak detection, analog to digital converter (ADC) module with eight independent channels in plug-in daughter card motherboard model, best suited for spectroscopy experiments. This module provides multiple channels without cross-talk and of 14 bit resolution, while maintaining high density (each daughter card has an area of just 4.2(")x0.51(")) and exhibiting excellent integral nonlinearity (< or = +/-2 mV or +/-0.02% full scale reading) and differential nonlinearity (< or = +/-1%). It was designed, developed and tested, in house, and gives added advantages of cost effectiveness and ease of maintenance. PMID:19044710

  7. High precision (14 bit), high density (octal) analog to digital converter for spectroscopy applications

    NASA Astrophysics Data System (ADS)

    Subramaniam, E. T.; Jain, Mamta; Bhowmik, R. K.; Tripon, Michel

    2008-10-01

    Nuclear and particle physics experiments with large number of detectors require signal processing and data collection strategies that call for the ability to collect large amount of data while not sacrificing the precision and accuracy of the data being collected. This paper deals with the development of a high precision pulse peak detection, analog to digital converter (ADC) module with eight independent channels in plug-in daughter card motherboard model, best suited for spectroscopy experiments. This module provides multiple channels without cross-talk and of 14 bit resolution, while maintaining high density (each daughter card has an area of just 4.2″×0.51″) and exhibiting excellent integral nonlinearity (≤±2 mV or ±0.02% full scale reading) and differential nonlinearity (≤±1%). It was designed, developed and tested, in house, and gives added advantages of cost effectiveness and ease of maintenance.

  8. A high precision optical angle measuring instrument for large optical axis offsets

    NASA Astrophysics Data System (ADS)

    Xie, Jing; Tan, Zuojun

    2014-09-01

    In many industrial activities such as manufacturing and inspection, optical axis offsets measurement is an essential process for keeping and improving the quality of products. The laser autocollimation method is improved to detect the large angular displacement with high precision by using a re-imaging technology. A large optical screen made of frosted glass is located at the focal position of the objective lens instead of the detector. A precision CCD imaging system was employed to measure the displacement of the light spot on the optical screen. The sub-pixel position of center of the light spot can be obtained accurately through the centroid and Gaussian fit methods. The actual test results show that the total systematic error of the optical angle measuring instrument in the mode of measuring the range 8°×8° does not exceed 0.16'.

  9. High-precision photometry for K2 Campaign 1

    NASA Astrophysics Data System (ADS)

    Huang, C. X.; Penev, K.; Hartman, J. D.; Bakos, G. Á.; Bhatti, W.; Domsa, I.; de Val-Borro, M.

    2015-12-01

    The two reaction wheel K2 mission promises and has delivered new discoveries in the stellar and exoplanet fields. However, due to the loss of accurate pointing, it also brings new challenges for the data reduction processes. In this paper, we describe a new reduction pipeline for extracting high-precision photometry from the K2 data set, and present public light curves for the K2 Campaign 1 target pixel data set. Key to our reduction is the derivation of global astrometric solutions from the target stamps, from which accurate centroids are passed on for high-precision photometry extraction. We extract target light curves for sources from a combined UCAC4 and EPIC catalogue - this includes not only primary targets of the K2 campaign 1, but also any other stars that happen to fall on the pixel stamps. We provide the raw light curves, and the products of various detrending processes aimed at removing different types of systematics. Our astrometric solutions achieve a median residual of ˜0.127 arcsec. For bright stars, our best 6.5 h precision for raw light curves is ˜20 parts per million (ppm). For our detrended light curves, the best 6.5 h precision achieved is ˜15 ppm. We show that our detrended light curves have fewer systematic effects (or trends, or red-noise) than light curves produced by other groups from the same observations. Example light curves of transiting planets and a Cepheid variable candidate, are also presented. We make all light curves public, including the raw and detrended photometry, at http://k2.hatsurveys.org.

  10. High-Precision Distribution of Highly Stable Optical Pulse Trains with 8.8 × 10−19 instability

    PubMed Central

    Ning, B.; Zhang, S. Y.; Hou, D.; Wu, J. T.; Li, Z. B.; Zhao, J. Y.

    2014-01-01

    The high-precision distribution of optical pulse trains via fibre links has had a considerable impact in many fields. In most published work, the accuracy is still fundamentally limited by unavoidable noise sources, such as thermal and shot noise from conventional photodiodes and thermal noise from mixers. Here, we demonstrate a new high-precision timing distribution system that uses a highly precise phase detector to obviously reduce the effect of these limitations. Instead of using photodiodes and microwave mixers, we use several fibre Sagnac-loop-based optical-microwave phase detectors (OM-PDs) to achieve optical-electrical conversion and phase measurements, thereby suppressing the sources of noise and achieving ultra-high accuracy. The results of a distribution experiment using a 10-km fibre link indicate that our system exhibits a residual instability of 2.0 × 10−15 at1 s and8.8 × 10−19 at 40,000 s and an integrated timing jitter as low as 3.8 fs in a bandwidth of 1 Hz to 100 kHz. This low instability and timing jitter make it possible for our system to be used in the distribution of optical-clock signals or in applications that require extremely accurate frequency/time synchronisation. PMID:24870442

  11. Superconducting Tunnel Junctions for High-Precision EUV Spectroscopy

    NASA Astrophysics Data System (ADS)

    Ponce, F.; Carpenter, M. H.; Cantor, R.; Friedrich, S.

    2016-08-01

    We have characterized the photon response of superconducting tunnel junctions in the extreme ultraviolet energy range below 100 eV with a pulsed 355 nm laser. The detectors are operated at rates up to 5000 counts/s, are very linear in energy and have an energy resolution between 0.9 and 2 eV. We observe multiple peaks that correspond to an integer number of photons with a Poissonian probability distribution and that can be used for high-accuracy energy calibration. The uncertainty of the centroid depends on the detector resolution and the counting statistics and can be as low as 1 meV for well-separated peaks with >10^5 counts. We discuss the precision of the peak centroid as a function of detector resolution and total number of counts and the accuracy of the energy calibration.

  12. Study on high precision Shack-Hartmann wave sensor

    NASA Astrophysics Data System (ADS)

    Liu, Zhiying; Fu, Yuegang

    2014-09-01

    Shack-Hartman wave sensor is applied widely in wave-front process with real-time and stable advantages. To increase the testing accuracy of Shack-Hartman sensor, the centroid testing accuracy must be increased first. But the centroid testing accuracy is decided by the detector performance, which is at the system focal plane. The testing accuracy will decrease with detector pixel size increasing. Based on micro-scanning system, the detector in Shack-Hartman wave sensor will receive four images of the wave-front under test. They are rebuilt to a single image after digital image procession. The centroid is calculated and wav-front is rebuilt by wave-front processor. The pixel distance is subdivided to 1/N along X and Y direction respectively with micro-scanning system. N*N is the detected image frames. The sub-pixel shifting images are rebuilt to a whole image after digital image procession. And the resolving power is realized to be increased finally. With application of micro-scanning in Shack-Hartman wave sensor, the system error due to detector accuracy in Shack-Hartman will be decreased. Consequently, the requirement on detector will be decreased. The resolving power of detector is improved greatly. As a result, the image quality testing accuracy of Shack-Hartman wave-front is improved. The image quality testing accuracy of traditional Shack-Hartman wave-front sensor will be increased within the original field of view. And the application range of Shack-Hartman wave sensor is also enlarged effectively.

  13. High-precision analysis of the solar twin HIP 100963

    NASA Astrophysics Data System (ADS)

    Yana Galarza, Jhon; Meléndez, Jorge; Ramírez, Ivan; Yong, David; Karakas, Amanda I.; Asplund, Martin; Liu, Fan

    2016-05-01

    Context. HIP 100963 was one of the first solar twins identified. Although some high-precision analyses are available, a comprehensive high-precision study of chemical elements from different nucleosynthetic sources is still lacking from which to obtain potential new insights on planets, stellar evolution, and Galactic chemical evolution (GCE). Aims: We analyze and investigate the origin of the abundance pattern of HIP 100963 in detail, in particular the pattern of the light element Li, the volatile and refractory elements, and heavy elements from the s- and r-processes. Methods: We used the HIRES spectrograph on the Keck I telescope to acquire high-resolution (R ≈ 70 000) spectra with a high signal-to-noise ratio (S/N ≈ 400-650 per pixel) of HIP 100963 and the Sun for a differential abundance analysis. We measured the equivalent widths (EWs) of iron lines to determine the stellar parameters by employing the differential spectroscopic equilibrium. We determined the composition of volatile, refractory, and neutron-capture elements through a differential abundance analysis with respect to the Sun. Results: The stellar parameters we found are Teff = 5818 ± 4 K, log g = 4.49 ± 0.01 dex, vt = 1.03 ± 0.01km s-1, and [Fe/H] = -0.003 ± 0.004 dex. These low errors allow us to compute a precise mass (1.03+0.02-0.01 M⊙) and age (2.0 ± 0.4 Gyr), obtained using Yonsei-Yale isochrones. Using our [Y/Mg] ratio, we have determined an age of 2.1 ± 0.4 Gyr, in agreement with the age computed using isochrones. Our isochronal age also agrees with the age determined from stellar activity (2.4 ± 0.3 Gyr). We study the abundance pattern with condensation temperature (Tcond) taking corrections by the GCE into account. We show that the enhancements of neutron-capture elements are explained by contributions from both the s- and r-process. The lithium abundance follows the tight Li-age correlation seen in other solar twins. Conclusions: We confirm that HIP 100963 is a solar twin

  14. High-precision Velocimetry Reveals δ Cephei's Secret Companion

    NASA Astrophysics Data System (ADS)

    Anderson, Richard I.; Sahlmann, Johannes; Holl, Berry; Eyer, Laurent

    2015-08-01

    The search for extra-solar planets has driven tremendous improvements in the precision of radial velocities measured with high-resolution echelle spectrographs. However, relatively few studies have as of yet exploited the present-day extreme (m/s) instrumental precision to study Cepheid variable stars.We have been observing the prototype of classical Cepheids, δ Cephei, since September 2011 using the HERMES spectrograph mounted to the Mercator telescope located at the Roque de los Muchachos Observatory on the island of La Palma. Being one of the most-studied variable stars, we originally chose δ Cephei as a maximum-precision reference for other Cepheids in our sample. To our great surprise however, we discovered a clear orbital signature in the homogeneous HERMES data. Adding in radial velocity data from the literature, we then determined δ Cephei's orbit (cf. Anderson et al. 2015, arXiv:1503.04116). The high orbital eccentricity (e=0.647) leads to close pericenter passages (rmin ~ 9.5 RδCep) which suggest an intriguing past that requires further study, since Cepheids are well-known magnifying glasses for stellar evolution (Kippenhahn & Weigert 1994). We furthermore determined a new parallax to δ Cephei (using Hipparcos data) that is in tension with previous estimates and shows that the orbit will have to be accounted for when measuring δ Cephei's parallax with Gaia.While some of our HERMES data are as precise as 9 m/s, we found correlated excess residuals when removing the reference pulsation model and orbital motion from the HERMES radial velocity data, leaving an RMS of 47 m/s. These higher-than-expected residuals are reminiscent of the "period-jitter" or "flickering" observed in high-precision photometry of Cepheids obtained with the Kepler and MOST satellites. This reveals a fortuitous synergy between variable stars studies and the field of exoplanet research and opens the window for a better understanding of Cepheid pulsations via high-precision

  15. General-Purpose Heat Source safety verification test series: SVT-1 through SVT-6

    SciTech Connect

    Pavone, D.; George, T.G.; Frantz, C.E.

    1985-06-01

    The General-Purpose Heat Source (GPHS) is a modular heat source that will supply energy for Radioisotope Thermoelectric Generators (RTGs) in space missions. The Safety Verification Tests (SVTs) are performed to assess the plutonia containment capability of heat source modules subjected to certain accident environments. This interim report described the GPHS module configuration, the test environment, and the response of the module components following simulated reentry and solid Earth impact. The specific test environment of these initial six tests results from failure of the booster rocket to place the spacecraft in a proper trajectory and subsequent reentry of the GPHS modules from Earth orbit. 36 figs.

  16. General-Purpose Heat Source safety verification test series: SVT-1 through SVT-6

    NASA Astrophysics Data System (ADS)

    Pavone, D.; George, T. G.; Frantz, C. E.

    1985-06-01

    The General-Purpose Heat Source (GPHS) is a modular heat source that will supply energy for Radioisotope Thermoelectric Generators (RTGs) in space missions. The Safety Verification Tests (SVTs) are performed to assess the plutonium containment capability of heat source modules subjected to certain accident environments. This interim report described the GPHS module configuration, the test environment, and the response of the module components following simulated reentry and solid Earth impact. The specific test environment of these initial six tests results from failure of the booster rocket to place the spacecraft in a proper trajectory and subsequent reentry of the GPHS modules from Earth orbit.

  17. A simplified, general-purpose deep-space ranging correlator design

    NASA Technical Reports Server (NTRS)

    Tausworthe, R. C.; Smith, J. R.

    1988-01-01

    A much-simplified, yet more general-purpose multi-channel deep-space ranging system correlator design that was used in past JPL spacecraft ranging systems is described. The method applies to detection of both single-component and multiple-component ranging codes, in either sequential (mu) or composite (pi) transmitted forms, and using either pseudonoise or square-wave components. Using this design, the Phobos Probe ranging system correlator computational complexity was reduced by over three orders of magnitude in multiply-and-add circuits and 45,000 bits of accumulator storage.

  18. General purpose pulse shape analysis for fast scintillators implemented in digital readout electronics

    NASA Astrophysics Data System (ADS)

    Asztalos, Stephen J.; Hennig, Wolfgang; Warburton, William K.

    2016-01-01

    Pulse shape discrimination applied to certain fast scintillators is usually performed offline. In sufficiently high-event rate environments data transfer and storage become problematic, which suggests a different analysis approach. In response, we have implemented a general purpose pulse shape analysis algorithm in the XIA Pixie-500 and Pixie-500 Express digital spectrometers. In this implementation waveforms are processed in real time, reducing the pulse characteristics to a few pulse shape analysis parameters and eliminating time-consuming waveform transfer and storage. We discuss implementation of these features, their advantages, necessary trade-offs and performance. Measurements from bench top and experimental setups using fast scintillators and XIA processors are presented.

  19. General-purpose heat source project and space nuclear safety fuels program. Progress report, February 1980

    SciTech Connect

    Maraman, W.J.

    1980-05-01

    This formal monthly report covers the studies related to the use of /sup 238/PuO/sub 2/ in radioisotopic power systems carried out for the Advanced Nuclear Systems and Projects Division of the Los Alamos Scientific Laboratory. The two programs involved are: General-Purpose Heat Source Development and Space Nuclear Safety and Fuels. Most of the studies discussed here are of a continuing nature. Results and conclusions described may change as the work continues. Published reference to the results cited in this report should not be made without the explicit permission of the person in charge of the work.

  20. Generalized Fluid System Simulation Program (GFSSP) Version 6 - General Purpose Thermo-Fluid Network Analysis Software

    NASA Technical Reports Server (NTRS)

    Majumdar, Alok; Leclair, Andre; Moore, Ric; Schallhorn, Paul

    2011-01-01

    GFSSP stands for Generalized Fluid System Simulation Program. It is a general-purpose computer program to compute pressure, temperature and flow distribution in a flow network. GFSSP calculates pressure, temperature, and concentrations at nodes and calculates flow rates through branches. It was primarily developed to analyze Internal Flow Analysis of a Turbopump Transient Flow Analysis of a Propulsion System. GFSSP development started in 1994 with an objective to provide a generalized and easy to use flow analysis tool for thermo-fluid systems.

  1. GPHS (General Purpose Heat Source) uranium oxide encapsulations supporting satellite safety tests

    SciTech Connect

    Kanne, W.R.

    1989-04-24

    General Purpose Heat Source (GPHS) simulant-fueled capsules were assembled, welded, nondestructively examined, and shipped to Los Alamos National Laboratory (LANL) for satellite safety tests. Simulant-fueled iridium capsules contain depleted uranium oxide pellets that serve as a stand-in for plutonium-238 oxide pellets. Information on forty seven capsules prepared during 1987 and 1988 is recorded in this memorandum along with a description of the processes used for encapsulation and evaluation. LANL expects to use all capsules for destructive safety tests, which are under way. Test results so far have demonstrated excellent integrity of the Savannah River capsule welds. 10 refs., 5 figs., 3 tabs.

  2. Real-time radar signal processing using GPGPU (general-purpose graphic processing unit)

    NASA Astrophysics Data System (ADS)

    Kong, Fanxing; Zhang, Yan Rockee; Cai, Jingxiao; Palmer, Robert D.

    2016-05-01

    This study introduces a practical approach to develop real-time signal processing chain for general phased array radar on NVIDIA GPUs(Graphical Processing Units) using CUDA (Compute Unified Device Architecture) libraries such as cuBlas and cuFFT, which are adopted from open source libraries and optimized for the NVIDIA GPUs. The processed results are rigorously verified against those from the CPUs. Performance benchmarked in computation time with various input data cube sizes are compared across GPUs and CPUs. Through the analysis, it will be demonstrated that GPGPUs (General Purpose GPU) real-time processing of the array radar data is possible with relatively low-cost commercial GPUs.

  3. A high-precision synchronization circuit for clock distribution

    NASA Astrophysics Data System (ADS)

    Chong, Lu; Hongzhou, Tan; Zhikui, Duan; Yi, Ding

    2015-10-01

    In this paper, a novel structure of a high-precision synchronization circuit, HPSC, using interleaved delay units and a dynamic compensation circuit is proposed. HPSCs are designed for synchronization of clock distribution networks in large-scale integrated circuits, where high-quality clocks are required. The application of a hybrid structure of a coarse delay line and dynamic compensation circuit performs roughly the alignment of the clock signal in two clock cycles, and finishes the fine tuning in the next three clock cycles with the phase error suppressed under 3.8 ps. The proposed circuit is implemented and fabricated using a SMIC 0.13 μm 1P6M process with a supply voltage at 1.2 V. The allowed operation frequency ranges from 200 to 800 MHz, and the duty cycle ranges between [20%, 80%]. The active area of the core circuits is 245 × 134 μm2, and the power consumption is 1.64 mW at 500 MHz.

  4. High precision metrology of domes and aspheric optics

    NASA Astrophysics Data System (ADS)

    Murphy, Paul E.; Fleig, Jon; Forbes, Greg; Tricard, Marc

    2005-05-01

    Many defense systems have a critical need for high-precision, complex optics. However, fabrication of high quality, advanced optics is often seriously hampered by the lack of accurate and affordable metrology. QED's Subaperture Stitching Interferometer (SSI®) provides a breakthrough technology, enabling the automatic capture of precise metrology data for large and/or strongly curved (concave and convex) parts. QED"s SSI complements next-generation finishing technologies, such as Magnetorheological Finishing (MRF®), by extending the effective aperture, accuracy and dynamic range of a phase-shifting interferometer. This workstation performs automated sub-aperture stitching measurements of spheres, flats, and mild aspheres. It combines a six-axis precision stage system, a commercial Fizeau interferometer, and specially developed software that automates measurement design, data acquisition, and the reconstruction of the full-aperture figure error map. Aside from the correction of sub-aperture placement errors (such as tilts, optical power, and registration effects), our software also accounts for reference-wave error, distortion and other aberrations in the interferometer"s imaging optics. The SSI can automatically measure the full aperture of high numerical aperture surfaces (such as domes) to interferometric accuracy. The SSI extends the usability of a phase measuring interferometer and allows users with minimal training to produce full-aperture measurements of otherwise untestable parts. Work continues to extend this technology to measure aspheric shapes without the use of dedicated null optics. This SSI technology will be described, sample measurement results shown, and various manufacturing applications discussed.

  5. High precision measurement of electrical resistance across endothelial cell monolayers.

    PubMed

    Tschugguel, W; Zhegu, Z; Gajdzik, L; Maier, M; Binder, B R; Graf, J

    1995-05-01

    Effects of vasoactive agonists on endothelial permeability was assessed by measurement of transendothelial electrical resistance (TEER) of human umbilical vein endothelial cells (HUVECs) grown on porous polycarbonate supports. Because of the low values of TEER obtained in this preparation (< 5 omega cm2) a design of an Ussing type recording chamber was chosen that provided for a homogeneous electric field across the monolayer and for proper correction of series resistances. Precision current pulses and appropriate rates of sampling and averaging of the voltage signal allowed for measurement of < 0.1 omega resistance changes of the endothelium on top of a 21 omega series resistance of the support and bathing fluid layers. Histamine (10 microM) and thrombin (10 U/ml) induced an abrupt and substantial decrease of TEER, bradykinin (1 microM) was less effective, PAF (380 nM) and LTC4 (1 microM) had no effect. TEER was also reduced by the calcium ionophore A-23187 (10 microM). The technique allows for measurements of TEER in low resistance monolayer cultures with high precision and time resolution. The results obtained extend previous observations in providing quantitative data on the increase of permeability of HUVECs in response to vasoactive agonists.

  6. High precision relocation of earthquakes at Iliamna Volcano, Alaska

    USGS Publications Warehouse

    Statz-Boyer, P.; Thurber, C.; Pesicek, J.; Prejean, S.

    2009-01-01

    In August 1996, a period of elevated seismicity commenced beneath Iliamna Volcano, Alaska. This activity lasted until early 1997, consisted of over 3000 earthquakes, and was accompanied by elevated emissions of volcanic gases. No eruption occurred and seismicity returned to background levels where it has remained since. We use waveform alignment with bispectrum-verified cross-correlation and double-difference methods to relocate over 2000 earthquakes from 1996 to 2005 with high precision (~ 100??m). The results of this analysis greatly clarify the distribution of seismic activity, revealing distinct features previously hidden by location scatter. A set of linear earthquake clusters diverges upward and southward from the main group of earthquakes. The events in these linear clusters show a clear southward migration with time. We suggest that these earthquakes represent either a response to degassing of the magma body, circulation of fluids due to exsolution from magma or heating of ground water, or possibly the intrusion of new dikes beneath Iliamna's southern flank. In addition, we speculate that the deeper, somewhat diffuse cluster of seismicity near and south of Iliamna's summit indicates the presence of an underlying magma body between about 2 and 4??km depth below sea level, based on similar features found previously at several other Alaskan volcanoes. ?? 2009 Elsevier B.V.

  7. High Precision Polarimetry of the Epsilon Aurigae Eclipse

    NASA Astrophysics Data System (ADS)

    Wiktorowicz, Sloane

    2013-07-01

    Polarimetry of the epsilon Aurigae eclipse has the potential to discern the stellar latitude occulted by the companion's dusty disk, which may directly test interferometric results. In addition, the limb polarization of the primary star may be measured, which is an effect predicted by S. Chandrasekhar and verified by spatially resolved observations of the Sun. I will present B band, polarimetric observations of epsilon Aurigae taken over six nights in September and October 2009 using the POLISH high precision polarimeter at the Lick 3-m telescope. Polarimetric precision achieved during each night is of order 1 part in 10^5. Extensive post-eclipse observations have been taken with the significantly upgraded POLISH2 polarimeter at Lick Observatory. This instrument simultaneously measures all four Stokes parameters (I, Q, U, and V) and achieves precision within 2.0 times the photon shot noise limit over an entire observing run. This work is supported by a NExScI Sagan Fellowship, UC Lab Fees Research Grant, and UCO/Lick Observatory.

  8. Interferometric apparatus for ultra-high precision displacement measurement

    NASA Technical Reports Server (NTRS)

    Zhao, Feng (Inventor)

    2004-01-01

    A high-precision heterodyne interferometer measures relative displacement by creating a thermally-insensitive system generally not subject to polarization leakage. By using first and second light beams separated by a small frequency difference (.DELTA.f), beams of light at the first frequency (f.sub.0) are reflected by co-axial mirrors, the first mirror of which has a central aperture through which the light is transmitted to and reflected by the second mirror. Prior to detection, the light beams from the two mirrors are combined with light of the second and slightly different frequency. The combined light beams are separated according to the light from the mirrors. The change in phase (.DELTA..phi.) with respect to the two signals is proportional to the change in distance of Fiducial B by a factor of wavelength (.lambda.) divided by 4.pi. (.DELTA.L=.lambda..DELTA..phi.1/(4.pi.)). In a second embodiment, a polarizing beam splitting system can be used.

  9. Highly precise and compact ultrahigh vacuum rotary feedthrough

    NASA Astrophysics Data System (ADS)

    Aiura, Y.; Kitano, K.

    2012-03-01

    The precision and rigidity of compact ultrahigh vacuum (UHV) rotary feedthroughs were substantially improved by preparing and installing an optimal crossed roller bearing with mounting holes. Since there are mounting holes on both the outer and inner races, the bearing can be mounted directly to rotary and stationary stages without any fixing plates and housing. As a result, it is possible to increase the thickness of the bearing or the size of the rolling elements in the bearing without increasing the distance between the rotating and fixing International Conflat flanges of the UHV rotary feedthrough. Larger rolling elements enhance the rigidity of the UHV rotary feedthrough. Moreover, owing to the structure having integrated inner and outer races and mounting holes, the performance is almost entirely unaffected by the installation of the bearing, allowing for a precise optical encoder to be installed in the compact UHV rotary feedthrough. Using position feedback via a worm gear system driven by a stepper motor and a precise rotary encoder, the actual angle of the compact UHV rotary feedthrough can be controlled with extremely high precision.

  10. Report on APMP supplementary comparison: high precision roundness measurement

    NASA Astrophysics Data System (ADS)

    Buajarern, J.; Naoi, K.; Baker, A.; Zi, X.; Tsai, C.-L.; Eom, T. B.; Leng, T. S.; Kruger, O.

    2016-01-01

    A regional supplementary comparison, APMP.L-S4, was held in 2012 to demonstrate the equivalence of routine calibration services offered by NMIs to clients. Participants in this APMP.L-S4 comparison agreed to apply multi-step method for spidle error separation in order to yield the high precision roundness measurement. Eight laboratories from NMIs participated in this supplementary comparison; NIMT, NMIJ, NMIA, NIM, CMS/ITRI, KRISS, NMC/A*STAR and NMISA. This report describes the measurement results of 2 glass hemispheres and 2 softgauges. The calibrations of this comparison were carried out by participants during the period from March 2012 to May 2013. The results show that there is a degree of equivalence within 0.8 for all measurands. Hence, there is a close agreement between the measurements. Main text To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/. The final report has been peer-reviewed and approved for publication by the CCL, according to the provisions of the CIPM Mutual Recognition Arrangement (CIPM MRA).

  11. Silicon avalanche pixel sensor for high precision tracking

    NASA Astrophysics Data System (ADS)

    D'Ascenzo, N.; Marrocchesi, P. S.; Moon, C. S.; Morsani, F.; Ratti, L.; Saveliev, V.; Savoy Navarro, A.; Xie, Q.

    2014-03-01

    The development of an innovative position sensitive pixelated sensor to detect and measure with high precision the coordinates of the ionizing particles is proposed. The silicon avalanche pixel sensors (APiX) is based on the vertical integration of avalanche pixels connected in pairs and operated in coincidence in fully digital mode and with the processing electronics embedded on the chip. The APiX sensor addresses the need to minimize the material budget and related multiple scattering effects in tracking systems requiring a high spatial resolution in the presence of the large track occupancy. The expected operation of the new sensor features: low noise, low power consumption and suitable radiation tolerance. The APiX device provides on-chip digital information on the position of the coordinate of the impinging charged particle and can be seen as the building block of a modular system of pixelated arrays, implementing a sparsified readout. The technological challenges are the 3D integration of the device under CMOS processes and integration of processing electronics.

  12. Photonic systems for high precision radial velocity measurements

    NASA Astrophysics Data System (ADS)

    Halverson, Samuel

    2016-01-01

    I will discuss new instrumentation and techniques designed to maximize the Doppler radial velocity (RV) measurement precision of next generation exoplanet discovery instruments. These systems include a novel wavelength calibration device based on an all-fiber fabry-perot interferometer, a compact and efficient optical fiber image scrambler based on a single high-index ball lens, and a unique optical fiber mode mixer. These systems have been developed specifically to overcome three technological hurdles that have classically hindered high precision RV measurements in both the optical and near-infrared (NIR), namely: lack of available wavelength calibration sources, inadequate decoupling of the spectrograph from variable telescope illumination, and speckle-induced noise due to mode interference in optical fibers. The instrumentation presented here will be applied to the Habitable-zone Planet Finder, a NIR RV instrument designed to detect rocky planets orbiting in the habitable zones of nearby M-dwarfs, and represents a critical technological step towards the detection of potentially habitable Earth-like planets. While primarily focused in the NIR, many of these systems will be adapted to future optical RV instruments as well, such as NASA's new Extreme Precision Doppler Spectrometer for the WIYN telescope.

  13. High-precision impedance spectroscopy: a strategy demonstrated on PZT.

    PubMed

    Boukamp, Bernard A; Blank, Dave H A

    2011-12-01

    Electrochemical impedance spectroscopy (EIS) has been recognized as a very powerful tool for studying charge and mass transport and transfer in a wide variety of electrically or electrochemically active systems. Sophisticated modeling programs make it possible to extract parameters from the impedance data, thus contributing to a better understanding of the system or material properties. For an accurate analysis, a correct modeling function is needed; this is often in the form of an equivalent circuit. It is not always possible to define the modeling function from visual inspection of the impedance dispersion. Small contributions to the overall dispersion can be masked, and hence overlooked. In this publication, a strategy is presented for high-precision impedance data analysis. A Kramers-Kronig test is used for the essential data validation. An iterative process of partial analysis and subtraction assists in deconvoluting the impedance spectrum, yielding both a vi- able model function and a set of necessary starting values for the full complex nonlinear least squares (CNLS) modeling. The advantage and possibilities of this strategy are demonstrated with an analysis of the ionic and electronic conductivity of lead zirconate titanate (PZT) as functions of temperature and oxygen partial pressure. PMID:23443688

  14. Neural Networks for Computer Vision: A Framework for Specifications of a General Purpose Vision System

    NASA Astrophysics Data System (ADS)

    Skrzypek, Josef; Mesrobian, Edmond; Gungner, David J.

    1989-03-01

    The development of autonomous land vehicles (ALV) capable of operating in an unconstrained environment has proven to be a formidable research effort. The unpredictability of events in such an environment calls for the design of a robust perceptual system, an impossible task requiring the programming of a system bases on the expectation of future, unconstrained events. Hence, the need for a "general purpose" machine vision system that is capable of perceiving and understanding images in an unconstrained environment in real-time. The research undertaken at the UCLA Machine Perception Laboratory addresses this need by focusing on two specific issues: 1) the long term goals for machine vision research as a joint effort between the neurosciences and computer science; and 2) a framework for evaluating progress in machine vision. In the past, vision research has been carried out independently within different fields including neurosciences, psychology, computer science, and electrical engineering. Our interdisciplinary approach to vision research is based on the rigorous combination of computational neuroscience, as derived from neurophysiology and neuropsychology, with computer science and electrical engineering. The primary motivation behind our approach is that the human visual system is the only existing example of a "general purpose" vision system and using a neurally based computing substrate, it can complete all necessary visual tasks in real-time.

  15. General Purpose Data-Driven Online System Health Monitoring with Applications to Space Operations

    NASA Technical Reports Server (NTRS)

    Iverson, David L.; Spirkovska, Lilly; Schwabacher, Mark

    2010-01-01

    Modern space transportation and ground support system designs are becoming increasingly sophisticated and complex. Determining the health state of these systems using traditional parameter limit checking, or model-based or rule-based methods is becoming more difficult as the number of sensors and component interactions grows. Data-driven monitoring techniques have been developed to address these issues by analyzing system operations data to automatically characterize normal system behavior. System health can be monitored by comparing real-time operating data with these nominal characterizations, providing detection of anomalous data signatures indicative of system faults, failures, or precursors of significant failures. The Inductive Monitoring System (IMS) is a general purpose, data-driven system health monitoring software tool that has been successfully applied to several aerospace applications and is under evaluation for anomaly detection in vehicle and ground equipment for next generation launch systems. After an introduction to IMS application development, we discuss these NASA online monitoring applications, including the integration of IMS with complementary model-based and rule-based methods. Although the examples presented in this paper are from space operations applications, IMS is a general-purpose health-monitoring tool that is also applicable to power generation and transmission system monitoring.

  16. High Precision Bright-Star Astrometry with the USNO Astrometric CMOS Hybrid Camera System

    NASA Astrophysics Data System (ADS)

    Secrest, Nathan; Dudik, Rachel; Berghea, Ciprian T.; Hennessy, Greg; Dorland, Bryan

    2015-05-01

    While GAIA will provide excellent positional measurements of hundreds of millions of stars between 5 < mag < 20, an ongoing challenge in the field of high-precision differential astrometry is the positional accuracy of very bright stars (mag < 5), due to the enormous dynamic range between bright stars of interest, such as those in the Hipparcos catalog, and their background field stars, which are especially important for differential astrometry. Over the past few years, we have been testing the USNO Astrometric CMOS Hybrid Camera System (UAHC), which utilizes an H4RG-10 detector in windowing mode, as a possible solution to the NOFS USNO Bright Star Astrometric Database (UBAD). In this work, we discuss the results of an astrometric analysis of single-epoch Hipparcos data taken with the UAHC from the 1.55m Kaj Strand Astrometric Reflector at NOFS from June 27-30, 2014. We discuss the calibration of this data, as well as an astrometric analysis pipeline we developed that will enable multi-epoch differential and absolute astrometry with the UAHC. We find that while the overall differential astrometric stability of data taken with the UAHC is good (5-10 mas single-measurement precision) and comparable to other ground-based astrometric camera systems, bright stars in the detector window suffer from several systematic effects, such as insufficient window geometry and centroiding failures due to read-out artifacts - both of which can be significantly improved with modifications to the electronics, read-out speed and microcode.

  17. High-precision branching-ratio measurement for the superallowed β+ emitter 74Rb

    NASA Astrophysics Data System (ADS)

    Dunlop, R.; Ball, G. C.; Leslie, J. R.; Svensson, C. E.; Towner, I. S.; Andreoiu, C.; Chagnon-Lessard, S.; Chester, A.; Cross, D. S.; Finlay, P.; Garnsworthy, A. B.; Garrett, P. E.; Glister, J.; Hackman, G.; Hadinia, B.; Leach, K. G.; Rand, E. T.; Starosta, K.; Tardiff, E. R.; Triambak, S.; Williams, S. J.; Wong, J.; Yates, S. W.; Zganjar, E. F.

    2013-10-01

    A high-precision branching-ratio measurement for the superallowed β+ decay of 74Rb was performed at the TRIUMF Isotope Separator and Accelerator (ISAC) radioactive ion-beam facility. The scintillating electron-positron tagging array (SCEPTAR), composed of 10 thin plastic scintillators, was used to detect the emitted β particles; the 8π spectrometer, an array of 20 Compton-suppressed HPGe detectors, was used for detecting γ rays that were emitted following Gamow-Teller and nonanalog Fermi β+ decays of 74Rb; and the Pentagonal Array of Conversion Electron Spectrometers (PACES), an array of 5 Si(Li) detectors, was employed for measuring β-delayed conversion electrons. Twenty-three excited states were identified in 74Kr following 8.241(4)×108 detected 74Rb β decays. A total of 58 γ-ray and electron transitions were placed in the decay scheme, allowing the superallowed branching ratio to be determined as B0=99.545(31)%. Combined with previous half-life and Q-value measurements, the superallowed branching ratio measured in this work leads to a superallowed ft value of 3082.8(65) s. Comparisons between this superallowed ft value and the world-average-corrected Ft¯ value, as well as the nonanalog Fermi branching ratios determined in this work, provide guidance for theoretical models of the isospin-symmetry-breaking corrections in this mass region.

  18. A high precision calorimeter for the SOX experiment

    NASA Astrophysics Data System (ADS)

    Papp, L.; Agostini, M.; Altenmüller, K.; Appel, S.; Caminata, A.; Cereseto, R.; Di Noto, L.; Farinon, S.; Musenich, R.; Neumair, B.; Oberauer, L.; Pallavicini, M.; Schönert, S.; Testera, G.; Zavatarelli, S.

    2016-07-01

    The SOX (Short distance neutrino Oscillations with BoreXino) experiment is being built to discover or reject eV-scale sterile neutrinos by observing short baseline oscillations of active-to-sterile neutrinos [1]. For this purpose, a 100 kCi 144Ce-144Pr antineutrino generator (CeSOX) will be placed under the BOREXINO detector at the Laboratori Nazionali del Gran Sasso. Thanks to its large size and very low background, BOREXINO is an ideal detector to discover or reject eV-scale sterile neutrinos. To reach the maximal sensitivity, we aim at determining the neutrino flux emitted by the antineutrino generator with a < 1 % accuracy. With this goal, TU München and INFN Genova are developing a vacuum calorimeter, which is designed to measure the source-generated heat with high accuracy.

  19. Highly precise and robust packaging of optical components

    NASA Astrophysics Data System (ADS)

    Leers, Michael; Winzen, Matthias; Liermann, Erik; Faidel, Heinrich; Westphalen, Thomas; Miesner, Jörn; Luttmann, Jörg; Hoffmann, Dieter

    2012-03-01

    In this paper we present the development of a compact, thermo-optically stable and vibration and mechanical shock resistant mounting technique by soldering of optical components. Based on this technique a new generation of laser sources for aerospace applications is designed. In these laser systems solder technique replaces the glued and bolted connections between optical component, mount and base plate. Alignment precision in the arc second range and realization of long term stability of every single part in the laser system is the main challenge. At the Fraunhofer Institute for Laser Technology ILT a soldering and mounting technique has been developed for high precision packaging. The specified environmental boundary conditions (e.g. a temperature range of -40 °C to +50 °C) and the required degrees of freedom for the alignment of the components have been taken into account for this technique. In general the advantage of soldering compared to gluing is that there is no outgassing. In addition no flux is needed in our special process. The joining process allows multiple alignments by remelting the solder. The alignment is done in the liquid phase of the solder by a 6 axis manipulator with a step width in the nm range and a tilt in the arc second range. In a next step the optical components have to pass the environmental tests. The total misalignment of the component to its adapter after the thermal cycle tests is less than 10 arc seconds. The mechanical stability tests regarding shear, vibration and shock behavior are well within the requirements.

  20. General purpose dynamic Monte Carlo with continuous energy for transient analysis

    SciTech Connect

    Sjenitzer, B. L.; Hoogenboom, J. E.

    2012-07-01

    For safety assessments transient analysis is an important tool. It can predict maximum temperatures during regular reactor operation or during an accident scenario. Despite the fact that this kind of analysis is very important, the state of the art still uses rather crude methods, like diffusion theory and point-kinetics. For reference calculations it is preferable to use the Monte Carlo method. In this paper the dynamic Monte Carlo method is implemented in the general purpose Monte Carlo code Tripoli4. Also, the method is extended for use with continuous energy. The first results of Dynamic Tripoli demonstrate that this kind of calculation is indeed accurate and the results are achieved in a reasonable amount of time. With the method implemented in Tripoli it is now possible to do an exact transient calculation in arbitrary geometry. (authors)

  1. Movement analysis of upper limb during resistance training using general purpose robot arm "PA10"

    NASA Astrophysics Data System (ADS)

    Morita, Yoshifumi; Yamamoto, Takashi; Suzuki, Takahiro; Hirose, Akinori; Ukai, Hiroyuki; Matsui, Nobuyuki

    2005-12-01

    In this paper we perform movement analysis of an upper limb during resistance training. We selected sanding training, which is one type of resistance training for upper limbs widely performed in occupational therapy. Our final aims in the future are to quantitatively evaluate the therapeutic effect of upper limb motor function during training and to develop a new rehabilitation training support system. For these purposes, first of all we perform movement analysis using a conventional training tool. By measuring upper limb motion during the sanding training we perform feature abstraction. Next we perform movement analysis using the simulated sanding training system. This system is constructed using the general purpose robot arm "PA10". This system enables us to measure the force/torque exerted by subjects and to easily change the load of resistance. The control algorithm is based on impedance control. We found these features of the upper limb motion during the sanding training.

  2. Conceptual Trade Study of General Purpose Heat Source Powered Stirling Converter Configurations

    NASA Technical Reports Server (NTRS)

    Turpin, J. B.

    2007-01-01

    This Technical Manual describes a parametric study of general purpose heat source (GPHS) powered Stirling converter configurations. This study was performed in support of MSFC s efforts to establish the capability to perform non-nuclear system level testing and integration of radioisotope power systems. Six different GPHS stack configurations at a total of three different power levels (80, 250, and 500 W(sub e) were analyzed. The thermal profiles of the integrated GPHS modules (for each configuration) were calculated to determine maximum temperatures for comparison to allowable material limits. Temperature profiles for off-nominal power conditions were also assessed in order to better understand how power demands from the Stirling engine impact the performance of a given configuration.

  3. Fostering ontology alignment sharing: a general-purpose RDF mapping format.

    PubMed

    Anguita, Alberto; Escrich, Ana; Maojo, Victor

    2013-01-01

    RDF has established in the last years as the language for describing, publishing and sharing biomedical resources. Following this trend, a great amount of RDF-based data sources, as well as ontologies, have appeared. Using a common language as RDF has provided a unified syntactic for sharing resources, but the semantics remain as the main cause of heterogeneity, hampering data integration and homogenization efforts. To overcome this issue, ontology alignment based solutions have been typically used. However, alignment information is usually codified using ad-hoc formats. In this paper, we present a general purpose ontology mapping format, totally independent from the homogenization approach to be applied. The format is accompanied with a Java API that offers mapping construction and parsing features, as well as some basic algorithms for applying it to data translation solutions.

  4. GPACC program cost work breakdown structure-dictionary. General purpose aft cargo carrier study, volume 3

    NASA Technical Reports Server (NTRS)

    1985-01-01

    The results of detailed cost estimates and economic analysis performed on the updated Model 101 configuration of the general purpose Aft Cargo Carrier (ACC) are given. The objective of this economic analysis is to provide the National Aeronautics and Space Administration (NASA) with information on the economics of using the ACC on the Space Transportation System (STS). The detailed cost estimates for the ACC are presented by a work breakdown structure (WBS) to ensure that all elements of cost are considered in the economic analysis and related subsystem trades. Costs reported by WBS provide NASA with a basis for comparing competing designs and provide detailed cost information that can be used to forecast phase C/D planning for new projects or programs derived from preliminary conceptual design studies. The scope covers all STS and STS/ACC launch vehicle cost impacts for delivering payloads to a 160 NM low Earth orbit (LEO).

  5. THERMAL TESTING OF PROTOTYPE GENERAL PURPOSE FISSILE PACKAGES USING A FURNACE

    SciTech Connect

    Smith, A; Lawrence Gelder, L; Paul Blanton, P

    2007-02-16

    The 9977/9978 General Purpose Fissile Package (GPFP) was designed by SRNL to replace the DOT 6M Specification Package and ship Plutonium and Uranium metals and oxides. Urethane foam was used for the overpack to ensure the package would withstand the 10CFR71.73(c)(2) crush test, which is a severe test for drum-type packages. In addition, it was necessary to confirm that the urethane foam configuration provided adequate thermal protection for the containment vessel during the subsequent 10CFR71.73(c)(4) thermal test. Development tests were performed on early prototype test specimens of different diameter overpacks and a range of urethane foam densities. The thermal test was performed using an industrial furnace. Test results were used to optimize the selection of package diameter and foam density, and provided the basis for design enhancements incorporated into the final package design.

  6. Strong scaling of general-purpose molecular dynamics simulations on GPUs

    NASA Astrophysics Data System (ADS)

    Glaser, Jens; Nguyen, Trung Dac; Anderson, Joshua A.; Lui, Pak; Spiga, Filippo; Millan, Jaime A.; Morse, David C.; Glotzer, Sharon C.

    2015-07-01

    We describe a highly optimized implementation of MPI domain decomposition in a GPU-enabled, general-purpose molecular dynamics code, HOOMD-blue (Anderson and Glotzer, 2013). Our approach is inspired by a traditional CPU-based code, LAMMPS (Plimpton, 1995), but is implemented within a code that was designed for execution on GPUs from the start (Anderson et al., 2008). The software supports short-ranged pair force and bond force fields and achieves optimal GPU performance using an autotuning algorithm. We are able to demonstrate equivalent or superior scaling on up to 3375 GPUs in Lennard-Jones and dissipative particle dynamics (DPD) simulations of up to 108 million particles. GPUDirect RDMA capabilities in recent GPU generations provide better performance in full double precision calculations. For a representative polymer physics application, HOOMD-blue 1.0 provides an effective GPU vs. CPU node speed-up of 12.5 ×.

  7. General Purpose Graphics Processing Unit Based High-Rate Rice Decompression and Reed-Solomon Decoding.

    SciTech Connect

    Loughry, Thomas A.

    2015-02-01

    As the volume of data acquired by space-based sensors increases, mission data compression/decompression and forward error correction code processing performance must likewise scale. This competency development effort was explored using the General Purpose Graphics Processing Unit (GPGPU) to accomplish high-rate Rice Decompression and high-rate Reed-Solomon (RS) decoding at the satellite mission ground station. Each algorithm was implemented and benchmarked on a single GPGPU. Distributed processing across one to four GPGPUs was also investigated. The results show that the GPGPU has considerable potential for performing satellite communication Data Signal Processing, with three times or better performance improvements and up to ten times reduction in cost over custom hardware, at least in the case of Rice Decompression and Reed-Solomon Decoding.

  8. GPP user`s guide - a general-purpose postprocessor for wind turbine data analysis

    SciTech Connect

    Buhl, Jr, M L

    1995-01-01

    GPP (pronounced {open_quotes}jeep{close_quotes}) is a General-Purpose Postprocessor for wind turbine data analysis. The author, a member of the Wind Technology Division (WTD) of the National Renewable Energy Laboratory (NREL), developed GPP to postprocess test data and simulation predictions. GPP reads data into large arrays and allows the user to run many types of analyses on the data stored in memory. It runs on inexpensive computers common in the wind industry. One can even use it on a laptop in the field. The author wrote the program in such a way as to make it easy to add new types of analyses and to port it to many types of computers. Although GPP is very powerful and feature-rich, it is still very easy to learn and to use. Exhaustive error trapping prevents one from losing valuable work due to input errors. GPP will, hopefully, make a significant impact on engineering productivity in the wind industry.

  9. General purpose software for efficient uncertainty management of large finite element models

    PubMed Central

    Patelli, Edoardo; Murat Panayirci, H.; Broggi, Matteo; Goller, Barbara; Beaurepaire, Pierre; Pradlwarter, Helmut J.; Schuëller, Gerhart I.

    2012-01-01

    The aim of this paper is to demonstrate that stochastic analyses can be performed on large and complex models within affordable costs. Stochastic analyses offer a much more realistic approach for analysis and design of components and systems although generally computationally demanding. Hence, resorting to efficient approaches and high performance computing is required in order to reduce the execution time. A general purpose software that provides an integration between deterministic solvers (i.e. finite element solvers), efficient algorithms for uncertainty management and high performance computing is presented. The software is intended for a wide range of applications, which includes optimization analysis, life-cycle management, reliability and risk analysis, fatigue and fractures simulation, robust design. The applicability of the proposed tools for practical applications is demonstrated by means of a number of case studies of industrial interest involving detailed models. PMID:22474398

  10. Comparison of future battery systems for application to general-purpose electric vehicles

    SciTech Connect

    O'Connell, L.G.

    1980-08-01

    The results are presented of a study to compare the aluminium/air battery as a general purpose automobile power source with those secondary batteries evaluated in a four year study entitled Energy Storage Systems for Automobile Propulsion. The results of this study were published in three interim reports, one each in 1977, 1978 and 1979. The final report is being published in 1980. The aluminum/air battery had not developed early enough to be included in the evaluation. Recent progress on this battery makes it important to compare it on a vehicle system basis to other possible future batteries. The analysis techniques used in the comparison were the same as for the four-year study.

  11. Modification of hot cells for general purpose heat source assembly at the Radioisotope Power Systems Facility

    NASA Astrophysics Data System (ADS)

    Carteret, B. A.

    1991-09-01

    Eight existing, unused hot cells currently are being modified for use in the Radioisotope Power Systems Facility (RPSF) to assemble Pu-238 fueled heat sources for radioisotope thermoelectric generators (RTGs). Four air atmosphere cells will be used for storage, decanning, and decontamination of the iridium-clad radioisotope fuel. The remaining four argon atmosphere cells will be used to assemble fuel and graphite components for production and packaging of general purpose heat source (GPHS) assembly modules, which provide heat to drive the thermoelectric conversion process in the generators. The hot cells will be equipped to perform remote and glovebox-type operations. They will provide shielding and contamination control measures to reduce worker radiation exposure to levels within current U.S. Department of Energy (DOE) guidelines. Designs emphasize the Westinghouse Hanford Company (Westinghouse Hanford) as low as reasonably achievable (ALARA) radiation protection policy.

  12. Modification of hot cells for general purpose heat source assembly at the radioisotope power systems facility

    NASA Astrophysics Data System (ADS)

    Carteret, Betty A.

    1992-01-01

    Eight existing, unused hot cells currently are being modified for use in the Radioisotope Power Systems Facility (RPSF) to assemble 238Pu-fueled heat sources for Radioisotope Thermoelectric Generators (RTGs). Four air atmosphere cells will be used for storage, decanning, and decontamination of the iridium-clad radioisotope fuel. The remaining four argon atmosphere cells will be used to assemble fuel and graphite components for production and packaging of general purpose heat source (GPHS) assembly modules, which provide heat to drive the thermoelectric conversion process in the generators. The hot cells will be equipped to perform remote and glovebox-type operations. They will provide shielding and contamination control measures to reduce worker radiation exposure to levels within current U.S. Department of Energy (DOE) guidelines. Designs emphasize the Westinghouse Hanford Company (Westinghouse Hanford) as low as reasonably achievable (ALARA) radiation protection policy.

  13. General-purpose heat source safety verification test series: SVT-11 through SVT-13

    SciTech Connect

    George, T.G.; Pavone, D.

    1986-05-01

    The General-Purpose Heat Source (GPHS) is a modular component of the radioisotope thermoelectric generator that will provide power for the Galileo and Ulysses (formerly ISPM) space missions. The GPHS provides power by transmitting the heat of /sup 238/Pu ..cap alpha..-decay to an array of thermoelectric elements. Because the possibility of an orbital abort always exists, the heat source was designed and constructed to minimize plutonia release in any accident environment. The Safety Verification Test (SVT) series was formulated to evaluate the effectiveness of GPHS plutonia containment after atmospheric reentry and Earth impact. The first two reports (covering SVT-1 through SVT-10) described the results of flat, side-on, and angular module impacts against steel targets at 54 m/s. This report describes flat-on module impacts against concrete and granite targets, at velocities equivalent to or higher than previous SVTs.

  14. General-purpose heat source safety verification test series: SVT-7 through SVT-10

    NASA Astrophysics Data System (ADS)

    George, T. G.; Pavone, D.

    1985-09-01

    The General-Purpose Heat Source (GPHS) is a modular component of the radioisotope thermoelectric generator that will supply power for the Galileo and Ulysses (formerly ISPM) space missions. The GPHS provides power by transmitting the heat of (238)PuO2 (ALPHA)-decay to an array of thermoelectric elements. Because the possibility of an orbital abort always exists, the heat source was designed and constructed to minimize plutonia release in any accident environment. The Safety Verification Test (SVT) series was formulated to evaluate the effectiveness of GPHS plutonia containment after atmospheric reentry and Earth impact. The first report (covering SVT-1 through SVT-6) described the results of flat and side-on module impacts. This report describes module impacts at angles of 15(0) and 30(0).

  15. General-Purpose Heat Source Safety Verification Test series: SVT-7 through SVT-10

    SciTech Connect

    George, T.G.; Pavone, D.

    1985-09-01

    The General-Purpose Heat Source (GPHS) is a modular component of the radioisotope thermoelectric generator that will supply power for the Galileo and Ulysses (formerly ISPM) space missions. The GPHS provides power by transmitting the heat of /sup 238/PuO/sub 2/ ..cap alpha..-decay to an array of thermoelectric elements. Because the possibility of an orbital abort always exists, the heat source was designed and constructed to minimize plutonia release in any accident environment. The Safety Verification Test (SVT) series was formulated to evaluate the effectiveness of GPHS plutonia containment after atmospheric reentry and Earth impact. The first report (covering SVT-1 through SVT-6) described the results of flat and side-on module impacts. This report describes module impacts at angles of 15/sup 0/ and 30/sup 0/.

  16. General-purpose heat source development: Safety test program. Postimpact evaluation, design iteration test 1

    NASA Astrophysics Data System (ADS)

    Schonfeld, F. W.

    1984-04-01

    The general purpose heat source (GPHS) provides power for space missions by transmitting the heat of (238)PuO decay to thermoelectric elements. Because of the inevitable return of certain missions, the heat source must be designed and constructed to survive reentry and Earth impact. The Design Iteration Test (DIT) series is part of an ongoing impact test program. The first DIT used a full GPHS module containing two graphite impact shells (GISs); each GIS contained two iridium (0.3 wt%) capsules filled with (238)PuO. It was impacted at 57 m/s and 930 C. All four fuel capsules survived and none was breached. However, serious cracking of the iridium alloy capsules was found; some cracks extended through approx. 70% of the wall thickness. Postimpact analyses of the unit are described with emphasis on weld structure and performance.

  17. General-purpose heat source safety verification test series: SVT-11 through SVT-13

    NASA Astrophysics Data System (ADS)

    George, T. G.; Pavone, D.

    1986-05-01

    The General-Purpose Heat Source (GPHS) is a modular component of the radioisotope thermoelectric generator that will provide power for the Galileo and Ulysses (formerly ISPM) space missions. The GPHS provides power by transmitting the heat of Pu -decay to an array of thermoelectric elements. Because the possibility of an orbital abort always exists, the heat source was designed and constructed to minimize plutonia release in any accident environment. The Safety Verification Test (SVT) series was formulated to evaluate the effectiveness of GPHS plutonia containment after atmospheric reentry and Earth impact. The first two reports (covering SVT-1 through SVT-10) described the results of flat, side-on, and angular module impacts against steel targets at 54 m/s. This report describes flat-on module impacts against concrete and granite targets, at velocities equivalent to or higher than previous SVTs.

  18. STARS: An integrated general-purpose finite element structural, aeroelastic, and aeroservoelastic analysis computer program

    NASA Technical Reports Server (NTRS)

    Gupta, Kajal K.

    1991-01-01

    The details of an integrated general-purpose finite element structural analysis computer program which is also capable of solving complex multidisciplinary problems is presented. Thus, the SOLIDS module of the program possesses an extensive finite element library suitable for modeling most practical problems and is capable of solving statics, vibration, buckling, and dynamic response problems of complex structures, including spinning ones. The aerodynamic module, AERO, enables computation of unsteady aerodynamic forces for both subsonic and supersonic flow for subsequent flutter and divergence analysis of the structure. The associated aeroservoelastic analysis module, ASE, effects aero-structural-control stability analysis yielding frequency responses as well as damping characteristics of the structure. The program is written in standard FORTRAN to run on a wide variety of computers. Extensive graphics, preprocessing, and postprocessing routines are also available pertaining to a number of terminals.

  19. Generic functional requirements for a NASA general-purpose data base management system

    NASA Technical Reports Server (NTRS)

    Lohman, G. M.

    1981-01-01

    Generic functional requirements for a general-purpose, multi-mission data base management system (DBMS) for application to remotely sensed scientific data bases are detailed. The motivation for utilizing DBMS technology in this environment is explained. The major requirements include: (1) a DBMS for scientific observational data; (2) a multi-mission capability; (3) user-friendly; (4) extensive and integrated information about data; (5) robust languages for defining data structures and formats; (6) scientific data types and structures; (7) flexible physical access mechanisms; (8) ways of representing spatial relationships; (9) a high level nonprocedural interactive query and data manipulation language; (10) data base maintenance utilities; (11) high rate input/output and large data volume storage; and adaptability to a distributed data base and/or data base machine configuration. Detailed functions are specified in a top-down hierarchic fashion. Implementation, performance, and support requirements are also given.

  20. Forward Modeling of Electromagnetic Methods Using General Purpose Finite Element Software

    NASA Astrophysics Data System (ADS)

    Butler, S. L.

    2015-12-01

    Electromagnetic methods are widely used in mineral exploration and environmental applications and are increasingly being used in hydrocarbon exploration. Forward modeling of electromagnetic methods remains challenging and is mostly carried out using purpose-built research software. General purpose commercial modeling software has become increasingly flexible and powerful in recent years and is now capable of modeling field geophysical electromagnetic techniques. In this contribution, I will show examples of the use of commercial finite element modeling software Comsol Multiphysics for modeling frequency and time-domain electromagnetic techniques as well as for modeling the Very Low Frequency technique and magnetometric resistivity. Comparisons are made with analytical solutions, benchmark numerical solutions, analog experiments and field data. Although some calculations take too long to be practical as part of an inversion scheme, I suggest that modeling of this type will be useful for modeling novel techniques and for educational purposes.

  1. An evaluation of alternate production methods for Pu-238 general purpose heat source pellets

    SciTech Connect

    Mark Borland; Steve Frank

    2009-06-01

    For the past half century, the National Aeronautics and Space Administration (NASA) has used Radioisotope Thermoelectric Generators (RTG) to power deep space satellites. Fabricating heat sources for RTGs, specifically General Purpose Heat Sources (GPHSs), has remained essentially unchanged since their development in the 1970s. Meanwhile, 30 years of technological advancements have been made in the applicable fields of chemistry, manufacturing and control systems. This paper evaluates alternative processes that could be used to produce Pu 238 fueled heat sources. Specifically, this paper discusses the production of the plutonium-oxide granules, which are the input stream to the ceramic pressing and sintering processes. Alternate chemical processes are compared to current methods to determine if alternative fabrication processes could reduce the hazards, especially the production of respirable fines, while producing an equivalent GPHS product.

  2. A General Purpose Connections type CTI Server Based on SIP Protocol and Its Implementation

    NASA Astrophysics Data System (ADS)

    Watanabe, Toru; Koizumi, Hisao

    In this paper, we propose a general purpose connections type CTI (Computer Telephony Integration) server that provides various CTI services such as voice logging where the CTI server communicates with IP-PBX using the SIP (Session Initiation Protocol), and accumulates voice packets of external line telephone call flowing between an IP telephone for extension and a VoIP gateway connected to outside line networks. The CTI server realizes CTI services such as voice logging, telephone conference, or IVR (interactive voice response) with accumulating and processing voice packets sampled. Furthermore, the CTI server incorporates a web server function which can provide various CTI services such as a Web telephone directory via a Web browser to PCs, cellular telephones or smart-phones in mobile environments.

  3. Simrank: Rapid and sensitive general-purpose k-mer search tool

    SciTech Connect

    DeSantis, T.Z.; Keller, K.; Karaoz, U.; Alekseyenko, A.V; Singh, N.N.S.; Brodie, E.L; Pei, Z.; Andersen, G.L; Larsen, N.

    2011-04-01

    Terabyte-scale collections of string-encoded data are expected from consortia efforts such as the Human Microbiome Project (http://nihroadmap.nih.gov/hmp). Intra- and inter-project data similarity searches are enabled by rapid k-mer matching strategies. Software applications for sequence database partitioning, guide tree estimation, molecular classification and alignment acceleration have benefited from embedded k-mer searches as sub-routines. However, a rapid, general-purpose, open-source, flexible, stand-alone k-mer tool has not been available. Here we present a stand-alone utility, Simrank, which allows users to rapidly identify database strings the most similar to query strings. Performance testing of Simrank and related tools against DNA, RNA, protein and human-languages found Simrank 10X to 928X faster depending on the dataset. Simrank provides molecular ecologists with a high-throughput, open source choice for comparing large sequence sets to find similarity.

  4. A general purpose subroutine for fast fourier transform on a distributed memory parallel machine

    NASA Technical Reports Server (NTRS)

    Dubey, A.; Zubair, M.; Grosch, C. E.

    1992-01-01

    One issue which is central in developing a general purpose Fast Fourier Transform (FFT) subroutine on a distributed memory parallel machine is the data distribution. It is possible that different users would like to use the FFT routine with different data distributions. Thus, there is a need to design FFT schemes on distributed memory parallel machines which can support a variety of data distributions. An FFT implementation on a distributed memory parallel machine which works for a number of data distributions commonly encountered in scientific applications is presented. The problem of rearranging the data after computing the FFT is also addressed. The performance of the implementation on a distributed memory parallel machine Intel iPSC/860 is evaluated.

  5. GPP user's guide: A general-purpose postprocessor for wind turbine data analysis

    NASA Astrophysics Data System (ADS)

    Buhl, M. L., Jr.

    1995-01-01

    GPP is a General-Purpose Postprocessor for wind turbine data analysis. The author, a member of the Wind Technology Division (WTD) of the National Renewable Energy Laboratory (NREL), developed GPP to postprocess test data and simulation predictions. GPP reads data into large arrays and allows the user to run many types of analyses on the data stored in memory. It runs on inexpensive computers common in the wind industry. One can even use it on a laptop in the field. The author wrote the program in such a way as to make it easy to add new types of analyses and to port it to many types of computers. Although GPP is very powerful and feature-rich, it is still very easy to learn and to use. Exhaustive error trapping prevents one from losing valuable work due to input errors. GPP will, hopefully, make a significant impact on engineering productivity in the wind industry.

  6. General purpose computational tools for simulation and analysis of medium-energy backscattering spectra

    NASA Astrophysics Data System (ADS)

    Weller, Robert A.

    1999-06-01

    This paper describes a suite of computational tools for general-purpose ion-solid calculations, which has been implemented in the platform-independent computational environment Mathematica®. Although originally developed for medium energy work (beam energies < 300 keV), they are suitable for general, classical, non-relativistic calculations. Routines are available for stopping power, Rutherford and Lenz-Jensen (screened) cross sections, sputtering yields, small-angle multiple scattering, and back-scattering-spectrum simulation and analysis. Also included are a full range of supporting functions, as well as easily accessible atomic mass and other data on all the stable isotopes in the periodic table. The functions use common calling protocols, recognize elements and isotopes by symbolic names and, wherever possible, return symbolic results for symbolic inputs, thereby facilitating further computation. A new paradigm for the representation of backscattering spectra is introduced.

  7. Design of the SLAC RCE Platform: A General Purpose ATCA Based Data Acquisition System

    SciTech Connect

    Herbst, R.; Claus, R.; Freytag, M.; Haller, G.; Huffer, M.; Maldonado, S.; Nishimura, K.; O'Grady, C.; Panetta, J.; Perazzo, A.; Reese, B.; Ruckman, L.; Thayer, J. G.; Weaver, M.

    2015-01-23

    The SLAC RCE platform is a general purpose clustered data acquisition system implemented on a custom ATCA compliant blade, called the Cluster On Board (COB). The core of the system is the Reconfigurable Cluster Element (RCE), which is a system-on-chip design based upon the Xilinx Zynq family of FPGAs, mounted on custom COB daughter-boards. The Zynq architecture couples a dual core ARM Cortex A9 based processor with a high performance 28nm FPGA. The RCE has 12 external general purpose bi-directional high speed links, each supporting serial rates of up to 12Gbps. 8 RCE nodes are included on a COB, each with a 10Gbps connection to an on-board 24-port Ethernet switch integrated circuit. The COB is designed to be used with a standard full-mesh ATCA backplane allowing multiple RCE nodes to be tightly interconnected with minimal interconnect latency. Multiple shelves can be clustered using the front panel 10-gbps connections. The COB also supports local and inter-blade timing and trigger distribution. An experiment specific Rear Transition Module adapts the 96 high speed serial links to specific experiments and allows an experiment-specific timing and busy feedback connection. This coupling of processors with a high performance FPGA fabric in a low latency, multiple node cluster allows high speed data processing that can be easily adapted to any physics experiment. RTEMS and Linux are both ported to the module. The RCE has been used or is the baseline for several current and proposed experiments (LCLS, HPS, LSST, ATLAS-CSC, LBNE, DarkSide, ILC-SiD, etc).

  8. Developing and implementing a high precision setup system

    NASA Astrophysics Data System (ADS)

    Peng, Lee-Cheng

    The demand for high-precision radiotherapy (HPRT) was first implemented in stereotactic radiosurgery using a rigid, invasive stereotactic head frame. Fractionated stereotactic radiotherapy (SRT) with a frameless device was developed along a growing interest in sophisticated treatment with a tight margin and high-dose gradient. This dissertation establishes the complete management for HPRT in the process of frameless SRT, including image-guided localization, immobilization, and dose evaluation. The most ideal and precise positioning system can allow for ease of relocation, real-time patient movement assessment, high accuracy, and no additional dose in daily use. A new image-guided stereotactic positioning system (IGSPS), the Align RT3C 3D surface camera system (ART, VisionRT), which combines 3D surface images and uses a real-time tracking technique, was developed to ensure accurate positioning at the first place. The uncertainties of current optical tracking system, which causes patient discomfort due to additional bite plates using the dental impression technique and external markers, are found. The accuracy and feasibility of ART is validated by comparisons with the optical tracking and cone-beam computed tomography (CBCT) systems. Additionally, an effective daily quality assurance (QA) program for the linear accelerator and multiple IGSPSs is the most important factor to ensure system performance in daily use. Currently, systematic errors from the phantom variety and long measurement time caused by switching phantoms were discovered. We investigated the use of a commercially available daily QA device to improve the efficiency and thoroughness. Reasonable action level has been established by considering dosimetric relevance and clinic flow. As for intricate treatments, the effect of dose deviation caused by setup errors remains uncertain on tumor coverage and toxicity on OARs. The lack of adequate dosimetric simulations based on the true treatment coordinates from

  9. High precision measurement and analysis of colloidal monolayers

    PubMed Central

    Milne, Graham; Zhao, Yongxi; Chiu, Daniel T.

    2010-01-01

    This paper describes an imaging algorithm for analyzing colloidal monolayers, including the measurement of particle-to-particle distances with nanometer-scale resolution, the automated detection of defects and edges, as well as determining the uniformity of the colloid size distribution. The algorithm also allows for the automatic detection and measurement of scaling introduced by non-square detector pixels - a common problem in imaging. As an application, we demonstrate the use of this method for spatially calibrating digital video microscopy systems that can be applied in situations where conventional methods may be inappropriate. Here, we provide an overview of the workings of the algorithm, which we have made freely available. PMID:20353161

  10. Dielectrophoresis-Based Sample Handling in General-Purpose Programmable Diagnostic Instruments

    PubMed Central

    Gascoyne, Peter R. C.; Vykoukal, Jody V.

    2009-01-01

    As the molecular origins of disease are better understood, the need for affordable, rapid, and automated technologies that enable microscale molecular diagnostics has become apparent. Widespread use of microsystems that perform sample preparation and molecular analysis could ensure that the benefits of new biomedical discoveries are realized by a maximum number of people, even those in environments lacking any infrastructure. While progress has been made in developing miniaturized diagnostic systems, samples are generally processed off-device using labor-intensive and time-consuming traditional sample preparation methods. We present the concept of an integrated programmable general-purpose sample analysis processor (GSAP) architecture where raw samples are routed to separation and analysis functional blocks contained within a single device. Several dielectrophoresis-based methods that could serve as the foundation for building GSAP functional blocks are reviewed including methods for cell and particle sorting, cell focusing, cell ac impedance analysis, cell lysis, and the manipulation of molecules and reagent droplets. PMID:19684877

  11. General-Purpose Heat Source Development: Safety Verification Test Program. Flyer plate test series

    SciTech Connect

    Cull, T.A.; Pavone, D.

    1986-09-01

    The General-Purpose Heat Source (GPHS) is a modular component of a radioisotope thermoelectric generator (RTG) that will provide electric power for space missions. The initial RTG applications will be for the NASA Galileo and the ESA Ulysses missions. Each of the 18 GPHS modules in an RTG contains four /sup 238/PuO/sub 2/-fueled clads and generates 250 W/sub (t)/. A series of Safety Verification Tests (SVTs) has been conducted to assess the ability of the GPHS fueled clads to contain the plutonia in accident environments. Because a launch pad or postlaunch explosion of the Space Transportation System Vehicle (space shuttle) is one conceivable accident, the SVT plan included a series of tests to simulate the fragment environment that the RTG and GPHS modules would experience in such an event. These tests deal specifically with the flat-on collision of flyer-plate-type fragments with bare, simulant-fueled (depleted UO/sub 2/) clads. Results of these tests suggest that the fueled clad is only minimally breached by collision with 3.53-mm-thick flyer-plate-type fragments of space shuttle alloy at velocities up to 1170 m/s. However, collision of a 38.1-mm-thick plate with a bare GPHS clad, at a velocity of 270 m/s, results in a total release of fuel.

  12. A general purpose model for the condensed phases of water: TIP4P/2005.

    PubMed

    Abascal, J L F; Vega, C

    2005-12-15

    A potential model intended to be a general purpose model for the condensed phases of water is presented. TIP4P/2005 is a rigid four site model which consists of three fixed point charges and one Lennard-Jones center. The parametrization has been based on a fit of the temperature of maximum density (indirectly estimated from the melting point of hexagonal ice), the stability of several ice polymorphs and other commonly used target quantities. The calculated properties include a variety of thermodynamic properties of the liquid and solid phases, the phase diagram involving condensed phases, properties at melting and vaporization, dielectric constant, pair distribution function, and self-diffusion coefficient. These properties cover a temperature range from 123 to 573 K and pressures up to 40,000 bar. The model gives an impressive performance for this variety of properties and thermodynamic conditions. For example, it gives excellent predictions for the densities at 1 bar with a maximum density at 278 K and an averaged difference with experiment of 7 x 10(-4) g/cm3.

  13. Application of NASA General-Purpose Solver to Large-Scale Computations in Aeroacoustics

    NASA Technical Reports Server (NTRS)

    Watson, Willie R.; Storaasli, Olaf O.

    2004-01-01

    Of several iterative and direct equation solvers evaluated previously for computations in aeroacoustics, the most promising was the NASA-developed General-Purpose Solver (winner of NASA's 1999 software of the year award). This paper presents detailed, single-processor statistics of the performance of this solver, which has been tailored and optimized for large-scale aeroacoustic computations. The statistics, compiled using an SGI ORIGIN 2000 computer with 12 Gb available memory (RAM) and eight available processors, are the central processing unit time, RAM requirements, and solution error. The equation solver is capable of solving 10 thousand complex unknowns in as little as 0.01 sec using 0.02 Gb RAM, and 8.4 million complex unknowns in slightly less than 3 hours using all 12 Gb. This latter solution is the largest aeroacoustics problem solved to date with this technique. The study was unable to detect any noticeable error in the solution, since noise levels predicted from these solution vectors are in excellent agreement with the noise levels computed from the exact solution. The equation solver provides a means for obtaining numerical solutions to aeroacoustics problems in three dimensions.

  14. General-Purpose Expression of Structural Connectivity in the Parallel Solution Scheme and Its Application

    NASA Astrophysics Data System (ADS)

    Isobe, Daigoro; Yagi, Atsushi; Sato, Shunsuke

    In this paper, an algorithm for the general-purpose expression of structural connectivity is developed and implemented into the parallel solution scheme, which was previously proposed and successively applied to the feed-forward control of link mechanisms under various boundary conditions. The parallel solution scheme calculates the inverse dynamics of link systems by using a matrix-form equation separated into individual terms of different parameters. Therefore, the connectivity of link members can be expressed explicitly by one of the matrices, the member length matrix. Generated forces for the control can also be considered, without using any Jacobian matrices, simply by adding the values into one of the components in the equation, the vector related to nodal forces. We describe the forming process of the member length matrix and verify the validity of the calculated torque values, by presenting simple numerical results and experimental results for a structure-varying link system. We also perform a force control experiment on a quick motion, two-arm link system holding an object, where both generated forces and dynamical effects should be considered. Numerical and experimental results show the validity and the extensive ability of the scheme.

  15. ABAQUS-EPGEN: a general-purpose finite-element code. Volume 4. Systems manual

    SciTech Connect

    Hibbitt, H.D.; Karlsson, B.I.; Sorensen, E.P.

    1985-06-01

    This document is the Systems Manual for ABAQUS/EPGEN, a general purpose finite element computer program designed specifically to serve advanced structural analysis needs. ABAQUS/EPGEN is a large, modular, software system, made up of libraries of finite elements, constitutive models, arithmetic routines, and executive level routines that control the flow through the program to provide various analysis procedures. ABAQUS has extensive data files which are managed independently from the engineering/modeling code. The program is written in FORTRAN 77, with additional conventions within the language to ensure that the code is readily portable across different computers and operating systems. This includes support of fully single and fully double precision versions. This manual documents the system design of the code, including detailed descriptions of data file contents, and dictionaries of subroutines and common blocks. This outline can help programmers and development engineers understand the structure of the code and its use on different computers and operating systems. The highly sophisticated, nonlinear computer code supports advanced structural analyses for nuclear and fossil fuel power plant designs. The ABAQUS-EPGEN code analyzes such general nonlinear phenomena as fluid-structure interactions, reinforced concrete behavior, thermal stress, fracture mechanics, and high-temperature structural behavior. 18 refs.

  16. Practical Implementation of Prestack Kirchhoff Time Migration on a General Purpose Graphics Processing Unit

    NASA Astrophysics Data System (ADS)

    Liu, Guofeng; Li, Chun

    2016-08-01

    In this study, we present a practical implementation of prestack Kirchhoff time migration (PSTM) on a general purpose graphic processing unit. First, we consider the three main optimizations of the PSTM GPU code, i.e., designing a configuration based on a reasonable execution, using the texture memory for velocity interpolation, and the application of an intrinsic function in device code. This approach can achieve a speedup of nearly 45 times on a NVIDIA GTX 680 GPU compared with CPU code when a larger imaging space is used, where the PSTM output is a common reflection point that is gathered as I[nx][ny][nh][nt] in matrix format. However, this method requires more memory space so the limited imaging space cannot fully exploit the GPU sources. To overcome this problem, we designed a PSTM scheme with multi-GPUs for imaging different seismic data on different GPUs using an offset value. This process can achieve the peak speedup of GPU PSTM code and it greatly increases the efficiency of the calculations, but without changing the imaging result.

  17. Evaluation and characterization of General Purpose Heat Source girth welds for the Cassini mission

    SciTech Connect

    Lynch, C.M.; Moniz, P.F.; Reimus, M.A.H.

    1998-12-31

    General Purpose Heat Sources (GPHSs) are components of Radioisotopic thermoelectric Generators (RTGs) which provide electric power for deep space missions. Each GPHS consists of a {sup 238}Pu oxide ceramic pellet encapsulated in a welded iridium alloy shell which forms a protective barrier against the release of plutonia in the unlikely event of a launch-pad failure or reentry incident. GPHS fueled clad girth weld flaw detection was paramount to ensuring this safety function, and was accomplished using both destructive and non-destructive evaluation techniques. The first girth weld produced from each welding campaign was metallographically examined for flaws such as incomplete weld penetration, cracks, or porosity which would render a GPHS unacceptable for flight applications. After an acceptable example weld was produced, the subsequently welded heat sources were evaluated non-destructively for flaws using ultrasonic immersion testing. Selected heat sources which failed ultrasonic testing would be radiographed, and/or, destructively evaluated to further characterize and document anomalous indications. Metallography was also performed on impacted heat sources to determine the condition of the welds.

  18. General-Purpose Heat Source development: safety test program. Postimpact evaluation, Design Iteration Test 2

    SciTech Connect

    Schonfeld, F.W.; George, T.G.

    1984-06-01

    The General-Purpose Heat Source (GPHS) provides power for space missions by transmitting the heat of /sup 238/PuO/sub 2/ decay to thermoelectric elements. Because of the inevitable return of certain missions, the heat source must be Designed and constructed to survive both re-entry and Earth impact. The Design Iteration Test (DIT) series is part of an ongoing test program. In the first Design Iteration Test (DIT-1), a full GPHS module ontaining four iridium-alloy capsules loaded with /sup 238/PuO/sub 2/ was impacted at 57 m/s and 930/sup 0/C. All four capsules survived and none was breached. The capsules used in DIT-1 were loaded and welded at Los Alamos. The second Design Iteration Test (DIT-2) also used a full GPHS module and was impacted at 58 m/s and 930/sup 0/C. The four iridium-alloy capsules used in this test were loaded and welded at the Savannah River Plant (SRP). Postimpact examination revealed that two capsules had survived and two capsules had breached; a small quantity (approx. = 50 ..mu..g) of /sup 238/PuO/sub 2/ was released from the breached capsules. Internal cracking similar to that observed in the DIT-1 capsules was evident in all four of the DIT-2 capsules. Postimpact analyses of the units are described with emphasis on weld structure and performance.

  19. General-purpose heat source development: Safety test program. Postimpact evaluation, design iteration test 5

    NASA Astrophysics Data System (ADS)

    George, T. G.; Schonfeld, F. W.

    1984-12-01

    The general-purpose heat source (GPHS) provides power for space missions by transmitting the heat of Pu-238 decay to thermoelectric elements. Because of the inevitable return of certain aborted missions, the heat source must be designed and constructed to survive both reentry and Earth impact. The design iteration test (DIT) series is part of an ongoing impact test program. The DIT-5 was designed to compare the impact response of a GPHS fueled clad that was welded with a four-pole arc oscillator with the impact response of a clad welded with a two-pole oscillator. In DIT-5 a partial GPHS module containing two fueled clads was impacted at 60.5 m/s and 930 C. The fuel capsules were severly deformed by the impact; both clads breached. The capsule welded with a four-pole oscillator failed extensively. Neither failure was related to the welding technique. Postimpact analyses of the test components are described, with emphasis on microstructure and impact response.

  20. Design evolution and verification of the general-purpose heat source

    SciTech Connect

    Schock, A

    1980-01-01

    The General-Purpose Heat Source (GPHS) is a radioisotope heat source for use in space power systems. It employs a modular design, to make it adaptable to a wide range of energy conversion systems and power levels. Each 250 W module is completely autonomous, with its own passive safety provisions to prevent fuel release under all abort modes, including atmospheric reentry and earth impact. Prior development tests had demonstrated good impact survival as long as the iridium fuel capsules retained their ductility. This requires high impact temperatures, typically above 900/sup 0/C and reasonably fine grain size, which in turn requires avoidance of excessive operating temperatures and reentry temperatures. These three requirements - on operating, reentry, and impact temperatures - are in mutual conflict, since thermal design changes to improve any one of these temperatures tend to worsen one or both of the others. This conflict creates a difficult design problem, which for a time threatened the success of the program. The present paper describes how this problem was overcome by successive design revisions, supplemented by thermal analyses and confirmatory vibration and impact tests; and how this may be achieved while raising the specific power of the GPHS to 83 W/lb, a 50% improvement over previously flown radioisotope heat sources.

  1. General-Purpose Heat Source Development: safety test program. Postimpact evaluation, Design Iteration Test 4

    SciTech Connect

    George, T.G.; Schonfeld, F.W.

    1984-12-01

    The General-Purpose Heat Source (GPHS) provides power for space missions by transmitting the heat of /sup 238/Pu decay to thermoelectric elements. Because of the inevitable return of certain aborted missions, the heat source must be designed and constructed to survive both re-entry and Earth impact. The Design Iteration Test (DIT) series is part of an ongoing test program. The fourth test (DIT-4) was designed to evaluate the effect on impact behavior of changing the procedure used at the Mound Facility (MF) to remove surface defects from drawn cups. The change involved switching from a manual abrasion technique to a motorized, rubber-bonded abrasive wheel. In DIT-4 a partial GPHS module containing two fueled clads (one cleaned manually, and one cleaned with an abrasive wheel) was impacted at a velocity of 58 m/s and a temperature of 930/sup 0/C. Both capsules were severely deformed by the impact and contained large internal cracks. Although the manually cleaned capsule breached, the breaching crack was only 2 ..mu..m wide and released negligible amounts of fuel. There did not appear to be any correlation between cleaning method and capsule performance. Postimpact analyses of the DIT-4 test components are described with emphasis on microstructure and impact response.

  2. General-Purpose Heat Source Development: safety test program. Postimpact evaluation, Design Iteration Test 5

    SciTech Connect

    George, T.G.; Schonfeld, F.W.

    1984-12-01

    The General-Purpose Heat Source (GPHS) provides power for space missions by transmitting the heat of /sup 238/Pu decay to thermoelectric elements. Because of the inevitable return of certain aborted missions, the heat source must be designed and constructed to survive both re-entry and Earth impact. The Design Iteration Test (DIT) series is part of an ongoing impact test program. The fifth test (DIT-5) was designed to compare the impact response of a GPHS fueled clad that had been welded with a four-pole arc oscillator with the impact response of a clad welded with a two-pole oscillator. In DIT-5 a partial GPHS module containing two fueled clads (one welded with a four-pole oscillator and one welded with a two-pole oscillator) was impacted at 60.5 m/s and 930/sup 0/C. The fuel capsules were severely deformed by the impact; both clads breached. The capsule welded with a four-pole oscillator failed extensively. Neither failure was related to the welding technique. Postimpact analyses of the test components are described, with emphasis on microstructure and impact response.

  3. General-purpose heat source: Research and development program. Process evaluation, fuel pellet GF-47

    SciTech Connect

    Reimus, M.A.H.; George, T.G.

    1995-12-01

    The general-purpose heat source (GPHS) provides power for space missions by transmitting the heat of {sup 238}Pu decay to an array of thermoelectric elements. Because the potential for a launch abort or return from orbit exists for any space mission, the heat source must be designed and constructed to survive credible accident environments. Previous testing conducted in support of the Galileo and Ulysses missions has documented the response of the GPHS heat source to a variety of fragment-impact, aging, atmospheric reentry, and Earth-impact conditions. Although heat sources for previous missions were fabricated by the Westinghouse Savannah River Company (WSRC), GPHS fueled-clads required for the Cassini mission to Saturn will be fabricated by Los Alamos National Laboratory (LANL). This evaluation is part of an ongoing program to determine the similarity of GPHS fueled clads and fuel pellets fabricated at LANL to those fabricated at WSRC. Pellet GF-47, which was fabricated at LANL in late 1994, was submitted for chemical and ceramographic analysis. The results indicated that the pellet had a chemical makeup and microstructure within the range of material fabricated at WSRC in the early 1980s.

  4. General-Purpose Heat Source development: Safety Verification Test Program. Bullet/fragment test series

    SciTech Connect

    George, T.G.; Tate, R.E.; Axler, K.M.

    1985-05-01

    The radioisotope thermoelectric generator (RTG) that will provide power for space missions contains 18 General-Purpose Heat Source (GPHS) modules. Each module contains four /sup 238/PuO/sub 2/-fueled clads and generates 250 W/sub (t)/. Because a launch-pad or post-launch explosion is always possible, we need to determine the ability of GPHS fueled clads within a module to survive fragment impact. The bullet/fragment test series, part of the Safety Verification Test Plan, was designed to provide information on clad response to impact by a compact, high-energy, aluminum-alloy fragment and to establish a threshold value of fragment energy required to breach the iridium cladding. Test results show that a velocity of 555 m/s (1820 ft/s) with an 18-g bullet is at or near the threshold value of fragment velocity that will cause a clad breach. Results also show that an exothermic Ir/Al reaction occurs if aluminum and hot iridium are in contact, a contact that is possible and most damaging to the clad within a narrow velocity range. The observed reactions between the iridium and the aluminum were studied in the laboratory and are reported in the Appendix.

  5. Advanced Ultrasonic Inspection Techniques for General Purpose Heat Source Fueled Clad Closure Welds

    SciTech Connect

    Moyer, M.W.

    2001-01-11

    A radioisotope thermoelectric generator is used to provide a power source for long-term deep space missions. This General Purpose Heat Source (GPHS) is fabricated using iridium clad vent sets to contain the plutonium oxide fuel pellets. Integrity of the closure weld is essential to ensure containment of the plutonium. The Oak Ridge Y-12 Plant took the lead role in developing the ultrasonic inspection for the closure weld and transferring the inspection to Los Alamos National Laboratory for use in fueled clad inspection for the Cassini mission. Initially only amplitude and time-of-flight data were recorded. However, a number of benign geometric conditions produced signals that were larger than the acceptance threshold. To identify these conditions, a B-scan inspection was developed that acquired full ultrasonic waveforms. Using a test protocol the B-scan inspection was able to identify benign conditions such as weld shield fusion and internal mismatch. Tangential radiography was used to confirm the ultrasonic results. All but two of 29 fueled clads for which ultrasonic B-scan data was evaluated appeared to have signals that could be attributed to benign geometric conditions. This report describes the ultrasonic inspection developed at Y-12 for the Cassini mission.

  6. BCI2000: a general-purpose brain-computer interface (BCI) system.

    PubMed

    Schalk, Gerwin; McFarland, Dennis J; Hinterberger, Thilo; Birbaumer, Niels; Wolpaw, Jonathan R

    2004-06-01

    Many laboratories have begun to develop brain-computer interface (BCI) systems that provide communication and control capabilities to people with severe motor disabilities. Further progress and realization of practical applications depends on systematic evaluations and comparisons of different brain signals, recording methods, processing algorithms, output formats, and operating protocols. However, the typical BCI system is designed specifically for one particular BCI method and is, therefore, not suited to the systematic studies that are essential for continued progress. In response to this problem, we have developed a documented general-purpose BCI research and development platform called BCI2000. BCI2000 can incorporate alone or in combination any brain signals, signal processing methods, output devices, and operating protocols. This report is intended to describe to investigators, biomedical engineers, and computer scientists the concepts that the BC12000 system is based upon and gives examples of successful BCI implementations using this system. To date, we have used BCI2000 to create BCI systems for a variety of brain signals, processing methods, and applications. The data show that these systems function well in online operation and that BCI2000 satisfies the stringent real-time requirements of BCI systems. By substantially reducing labor and cost, BCI2000 facilitates the implementation of different BCI systems and other psychophysiological experiments. It is available with full documentation and free of charge for research or educational purposes and is currently being used in a variety of studies by many research groups. PMID:15188875

  7. Applications of artificial intelligence to space station: General purpose intelligent sensor interface

    NASA Technical Reports Server (NTRS)

    Mckee, James W.

    1988-01-01

    This final report describes the accomplishments of the General Purpose Intelligent Sensor Interface task of the Applications of Artificial Intelligence to Space Station grant for the period from October 1, 1987 through September 30, 1988. Portions of the First Biannual Report not revised will not be included but only referenced. The goal is to develop an intelligent sensor system that will simplify the design and development of expert systems using sensors of the physical phenomena as a source of data. This research will concentrate on the integration of image processing sensors and voice processing sensors with a computer designed for expert system development. The result of this research will be the design and documentation of a system in which the user will not need to be an expert in such areas as image processing algorithms, local area networks, image processor hardware selection or interfacing, television camera selection, voice recognition hardware selection, or analog signal processing. The user will be able to access data from video or voice sensors through standard LISP statements without any need to know about the sensor hardware or software.

  8. Production of general purpose heat source (GPHS) using advanced manufacturing methods

    NASA Astrophysics Data System (ADS)

    Miller, Roger G.

    1996-03-01

    Mankind will continue to explore the stars through the use of unmanned space craft until the technology and costs are compatible with sending travelers to the outer planets of our solar system and beyond. Unmanned probes of the present and future will be necessary to develop the necessary technologies and obtain information that will make this travel possible. Because of the significant costs incurred, the use of modern manufacturing technologies must be used to lower the investment needed even when shared by international partnerships. For over the last 30 years, radioisotopes have provided the heat from which electrical power is extracted. Electric power for future spacecraft will be provided by either Radioisotope Thermoelectric Generators (RTG), Radioisotopic Thermophotovoltaic systems (RTPV), radioisotope Stirling systems, or a combination of these. All of these systems will be thermally driven by General Purpose Heat Source (GPHS) fueled clad in some configuration. The GPHS clad contains a 238PuO2 pellet encapsulated in an iridium alloy container. Historically, the fabrication of the iridium alloy shells has been performed at EG&G Mound and Oak Ridge National Laboratory (ORNL), and girth welding at Westinghouse Savannah River Corporation (WSRC) and Los Alamos National Laboratory (LANL). This paper will describe the use of laser processing for welding, drilling, cutting, and machining with other manufacturing methods to reduce the costs of producing GPHS fueled clad components and compléted assemblies. Incorporation of new quality technologies will compliment these manufacturing methods to reduce cost.

  9. Nondestructive inspection of General Purpose Heat Source (GPHS) fueled clad girth welds

    SciTech Connect

    Reimus, M. A. H.; George, T. G.; Lynch, C.; Padilla, M.; Moniz, P.; Guerrero, A.; Moyer, M. W.; Placr, A.

    1998-01-15

    The General-Purpose Heat Source (GPHS) provides power for space missions by transmitting the heat of {sup 238}Pu decay to an array of thermoelectric elements. The GPHS is fabricated using an iridium-alloy to contain the {sup 238}PuO{sub 2} fuel pellet. GPHS capsules will be utilized in the upcoming Cassini mission to explore Saturn and its moons. The physical integrity of the girth weld is important to mission safety and performance. Because past experience had revealed a potential for initiation of small cracks in the girth weld overlap zone, a nondestructive inspection of each capsule weld is required. An ultrasonic method was used to inspect the welds of capsules fabricated for the Galileo mission. The instrument, transducer, and method used were state of the art at the time (early 1980s). The ultrasonic instrumentation and methods used to inspect the Cassini GPHSs was significantly upgraded from those used for the Galileo mission. GPHSs that had ultrasonic reflectors in excess of the reject specification level were subsequently inspected with radiography to provide additional engineering data used to accept/reject the heat source. This paper describes the Galileo-era ultrasonic instrumentation and methods and the subsequent upgrades made to support testing of Cassini GPHSs. Also discussed is the data obtained from radiographic examination and correlation to ultrasonic examination results.

  10. Nondestructive inspection of General Purpose Heat Source (GPHS) fueled clad girth welds

    SciTech Connect

    Reimus, M.A.; George, T.G.; Lynch, C.; Padilla, M.; Moniz, P.; Guerrero, A.; Moyer, M.W.; Placr, A.

    1998-01-01

    The General-Purpose Heat Source (GPHS) provides power for space missions by transmitting the heat of {sup 238}Pu decay to an array of thermoelectric elements. The GPHS is fabricated using an iridium-alloy to contain the {sup 238}PuO{sub 2} fuel pellet. GPHS capsules will be utilized in the upcoming Cassini mission to explore Saturn and its moons. The physical integrity of the girth weld is important to mission safety and performance. Because past experience had revealed a potential for initiation of small cracks in the girth weld overlap zone, a nondestructive inspection of each capsule weld is required. An ultrasonic method was used to inspect the welds of capsules fabricated for the Galileo mission. The instrument, transducer, and method used were state of the art at the time (early 1980s). The ultrasonic instrumentation and methods used to inspect the Cassini GPHSs was significantly upgraded from those used for the Galileo mission. GPHSs that had ultrasonic reflectors in excess of the reject specification level were subsequently inspected with radiography to provide additional engineering data used to accept/reject the heat source. This paper describes the Galileo-era ultrasonic instrumentation and methods and the subsequent upgrades made to support testing of Cassini GPHSs. Also discussed is the data obtained from radiographic examination and correlation to ultrasonic examination results. {copyright} {ital 1998 American Institute of Physics.}

  11. Explosion overpressure test series: General-Purpose Heat Source development: Safety Verification Test program

    SciTech Connect

    Cull, T.A.; George, T.G.; Pavone, D.

    1986-09-01

    The General-Purpose Heat Source (GPHS) is a modular, radioisotope heat source that will be used in radioisotope thermoelectric generators (RTGs) to supply electric power for space missions. The first two uses will be the NASA Galileo and the ESA Ulysses missions. The RTG for these missions will contain 18 GPHS modules, each of which contains four /sup 238/PuO/sub 2/-fueled clads and generates 250 W/sub (t)/. A series of Safety Verification Tests (SVTs) was conducted to assess the ability of the GPHS modules to contain the plutonia in accident environments. Because a launch pad or postlaunch explosion of the Space Transportation System vehicle (space shuttle) is a conceivable accident, the SVT plan included a series of tests that simulated the overpressure exposure the RTG and GPHS modules could experience in such an event. Results of these tests, in which we used depleted UO/sub 2/ as a fuel simulant, suggest that exposure to overpressures as high as 15.2 MPa (2200 psi), without subsequent impact, does not result in a release of fuel.

  12. General-purpose heat source project and space nuclear safety and fuels program. Progress report

    SciTech Connect

    Maraman, W.J.

    1980-02-01

    Studies related to the use of /sup 238/PuO/sub 2/ in radioisotopic power systems carried out for the Advanced Nuclear Systems and Projects Division of LASL are presented. The three programs involved are: general-purpose heat source development; space nuclear safety; and fuels program. Three impact tests were conducted to evaluate the effects of a high temperature reentry pulse and the use of CBCF on impact performance. Additionally, two /sup 238/PuO/sub 2/ pellets were encapsulated in Ir-0.3% W for impact testing. Results of the clad development test and vent testing are noted. Results of the environmental tests are summarized. Progress on the Stirling isotope power systems test and the status of the improved MHW tests are indicated. The examination of the impact failure of the iridium shell of MHFT-65 at a fuel pass-through continued. A test plan was written for vibration testing of the assembled light-weight radioisotopic heater unit. Progress on fuel processing is reported.

  13. deconSTRUCT: general purpose protein database search on the substructure level.

    PubMed

    Zhang, Zong Hong; Bharatham, Kavitha; Sherman, Westley A; Mihalek, Ivana

    2010-07-01

    deconSTRUCT webserver offers an interface to a protein database search engine, usable for a general purpose detection of similar protein (sub)structures. Initially, it deconstructs the query structure into its secondary structure elements (SSEs) and reassembles the match to the target by requiring a (tunable) degree of similarity in the direction and sequential order of SSEs. Hierarchical organization and judicious use of the information about protein structure enables deconSTRUCT to achieve the sensitivity and specificity of the established search engines at orders of magnitude increased speed, without tying up irretrievably the substructure information in the form of a hash. In a post-processing step, a match on the level of the backbone atoms is constructed. The results presented to the user consist of the list of the matched SSEs, the transformation matrix for rigid superposition of the structures and several ways of visualization, both downloadable and implemented as a web-browser plug-in. The server is available at http://epsf.bmad.bii.a-star.edu.sg/struct_server.html.

  14. General-Purpose Heat Source: Research and development program: Cold-Process Verification Test Series

    SciTech Connect

    Reimus, M.A.H.; George, T.G.

    1996-06-01

    The General-Purpose Heat Source (GPHS) provides power for space missions by transmitting the heat of {sup 238}Pu decay to an array of thermoelectric elements. Because any space mission could experience a launch abort or return from orbit, the heat source must be designed and constructed to survive credible accident environments. Previous testing conducted in support of the Galileo and Ulysses missions documented the response of GPHSs and individual GPHS capsules fueled with {sup 238}UO{sub 2} ({sup 235}U-depleted) to a variety of explosive overpressure and impact events. In the early 1990s, Los Alamos National Laboratory (LANL) resumed fabrication of {sup 238}UO{sub 2} GPHS pellets. The Cold-Process Verification (CPV) Test Series was designed to compare the response of GPHS heat sources loaded with recently fabricated hot- and cold-pressed {sup 238}UO{sub 2} pellets to the response of urania pellets used in the Galileo and Ulysses performance tests. This report documents eleven bare-capsule impacts and one impact of a fully loaded GPHS module. All of the failures observed in the bare-clad impact tests were similar to failures observed in previous safety tests. No failures occurred in the module impact test.

  15. Implementation and performance of a general purpose graphics processing unit in hyperspectral image analysis

    NASA Astrophysics Data System (ADS)

    van der Werff, H. M. A.; Bakker, W. H.

    2014-02-01

    A graphics processing unit (GPU) can perform massively parallel computations at relatively low cost. Software interfaces like NVIDIA CUDA allow for General Purpose computing on a GPU (GPGPU). Wrappers of the CUDA libraries for higher-level programming languages such as MATLAB and IDL allow its use in image processing. In this paper, we implement GPGPU in IDL with two distance measures frequently used in image classification, Euclidean distance and spectral angle, and apply these to hyperspectral imagery. First we vary the data volume of a synthetic dataset by changing the number of image pixels, spectral bands and classification endmembers to determine speed-up and to find the smallest data volume that would still benefit from using graphics hardware. Then we process real datasets that are too large to fit in the GPU memory, and study the effect of resulting extra data transfers on computing performance. We show that our GPU algorithms outperform the same algorithms for a central processor unit (CPU), that a significant speed-up can already be obtained on relatively small datasets, and that data transfers in large datasets do not significantly influence performance. Given that no specific knowledge on parallel computing is required for this implementation, remote sensing scientists should now be able to implement and use GPGPU for their data analysis.

  16. Environmental assessment of general-purpose heat source safety verification testing

    SciTech Connect

    1995-02-01

    This Environmental Assessment (EA) was prepared to identify and evaluate potential environmental, safety, and health impacts associated with the Proposed Action to test General-Purpose Heat Source (GPHS) Radioisotope Thermoelectric Generator (RTG) assemblies at the Sandia National Laboratories (SNL) 10,000-Foot Sled Track Facility, Albuquerque, New Mexico. RTGs are used to provide a reliable source of electrical power on board some spacecraft when solar power is inadequate during long duration space missions. These units are designed to convert heat from the natural decay of radioisotope fuel into electrical power. Impact test data are required to support DOE`s mission to provide radioisotope power systems to NASA and other user agencies. The proposed tests will expand the available safety database regarding RTG performance under postulated accident conditions. Direct observations and measurements of GPHS/RTG performance upon impact with hard, unyielding surfaces are required to verify model predictions and to ensure the continual evolution of the RTG designs that perform safely under varied accident environments. The Proposed Action is to conduct impact testing of RTG sections containing GPHS modules with simulated fuel. End-On and Side-On impact test series are planned.

  17. A general-purpose approach to computer-aided dynamic analysis of a flexible helicopter

    NASA Technical Reports Server (NTRS)

    Agrawal, Om P.

    1988-01-01

    A general purpose mathematical formulation is described for dynamic analysis of a helicopter consisting of flexible and/or rigid bodies that undergo large translations and rotations. Rigid body and elastic sets of generalized coordinates are used. The rigid body coordinates define the location and the orientation of a body coordinate frame (global frame) with respect to an inertial frame. The elastic coordinates are introduced using a finite element approach in order to model flexible components. The compatibility conditions between two adjacent elements in a flexible body are imposed using a Boolean matrix, whereas the compatibility conditions between two adjacent bodies are imposed using the Lagrange multiplier approach. Since the form of the constraint equations depends upon the type of kinematic joint and involves only the generalized coordinates of the two participating elements, then a library of constraint elements can be developed to impose the kinematic constraint in an automated fashion. For the body constraints, the Lagrange multipliers yield the reaction forces and torques of the bodies at the joints. The virtual work approach is used to derive the equations of motion, which are a system of differential and algebraic equations that are highly nonlinear. The formulation presented is general and is compared with hard-wired formulations commonly used in helicopter analysis.

  18. High-precision analysis of SF6 at ambient level

    NASA Astrophysics Data System (ADS)

    Lim, J. S.; Moon, D. M.; Kim, J. S.; Yun, W.-T.; Lee, J.

    2013-09-01

    This work reports on the development of a technique for the precise analysis of ambient SF6. This technique, which involves a gas chromatograph/electron capture detector (GC-ECD) coupled with an Activated Alumina-F1 (AA-F1) column, performed well in the measurements, particularly in terms of accuracy, which complies with the World Meteorological Organization (WMO)-recommended compatibility of 0.02 ppt. Compared to the Porapak Q technique, we observed a sharper peak shape for the SF6 stream, which substantiates the improvement in the analytical precision. The traceability to the WMO scale was tested by calibrating the GC-ECD/AA-F1 analyser using five SF6 standards provided by the WMO/Global Atmosphere Watch (GAW) Central Calibration Laboratory (CCL) for SF6 (NOAA, United States of America). After calibration by various methods, the GC-ECD/AA-F1 accurately estimated the mole fraction of SF6 in the working standard prepared by the World Calibration Centre for SF6 operated by the Korea Meteorological Administration (KMA)/Korea Research Institute of Standards and Science (KRISS). Among the calibration methods, the two-point calibration method emerged to be the most economical procedure in terms of the data quality and measurement time. It was found that the KRISS scale of SF6/N2 was biased by 0.13 ppt when compared to the WMO scale of SF6/air; this bias is probably due to a different matrix.

  19. Radio emission from Supernovae and High Precision Astrometry

    NASA Astrophysics Data System (ADS)

    Perez-Torres, M. A.

    1999-11-01

    The present thesis work makes contributions in two scientific fronts: differential astrometry over the largest angular scales ever attempted (approx. 15 arcdegrees) and numerical simulations of radio emission from very young supernovae. In the first part, we describe the results of the use of very-long-baseline interferometry (VLBI) in one experiment designed to measure with very high precision the angular distance between the radio sources 1150+812 (QSO) and 1803+784 (BL Lac). We observed the radio sources on 19 November 1993 using an intercontinental array of radio telescopes, which simultaneously recorded at 2.3 and 8.4 GHz. VLBI differential astrometry is capable, Nature allowing, of yielding source positions with precisions well below the milliarcsecond level. To achieve this precision, we first had to accurately model the rotation of the interferometric fringes via the most precise models of Earth Orientation Parameters (EOP; precession, polar motion and UT1, nutation). With this model, we successfully connected our phase delay data at both frequencies and, using difference astrometric techniques, determined the coordinates of 1803+784 relative to those of 1150+812-within the IERS reference frame--with an standard error of about 0.6 mas in each coordinate. We then corrected for several effects including propagation medium (mainly the atmosphere and ionosphere), and opacity and source-structure effects within the radio sources. We stress that our dual-frequency measurements allowed us to accurately subtract the ionosphere contribution from our data. We also used GPS-based TEC measurements to independently find the ionosphere contribution, and showed that these contributions agree with our dual-frequency measurements within about 2 standard deviations in the less favorables cases (the longest baselines), but are usually well within one standard deviation. Our estimates of the relative positions, whether using dual-frequency-based or GPS-based ionosphere

  20. Development of a micro-CMM with scanning touch probe and high-precision coplanar platform

    NASA Astrophysics Data System (ADS)

    Chu, Chih-Liang; Lu, Chin-Tu; Chen, Hung-Chi; Ke, Jhih-Sian; Chang, Chao-Ming

    2013-10-01

    This study develops a micro-CMM incorporating a scanning touch probe and a high-precision coplanar platform. The measurement performance of the proposed system was enhanced through the use of a rigid aluminum double-arch-bridge structure to support the scanning touch probe. For the working stage, a linear motor was used for long-stroke positioning and a piezoelectric actuator was then employed to fine-tune the positioning so as to achieve a requirement of highprecision. The platform has two characteristics: (i) the driving and measuring axes are designed along the same line so that Abbe error of the stage can be eliminated; (ii) the coplanar design makes the X and Y axes reach a goal of two-axis concurrent. The aforementioned two designs can reduce the error of the platform so that the micro-CMM reaches a positioning accuracy of ±0.1μm for a working volume of 80×80×40 mm3. Furthermore, the reliability of the probe mechanism of three degrees of freedom was analyzed and validated. The sensor coordinates a laser diode with Position Sensor Detectors (PSD) working with an optical path to measure placement of Z-axis and angle placement of XY-axis. By validation through an experiment, the three dimensional scanning touch probe developed by this study has a measuring range of ±1mm × ±1mm × 1mm with a unidirectional repeatability of 0.6μm.

  1. Development of high precision laser measurement to Space Debris and Applications in SHAO

    NASA Astrophysics Data System (ADS)

    Zhang, Zhongping; Chen, Juping; Xiong, Yaoheng; Han, Xingwei

    2016-07-01

    Artificial space debris has become the focus during the space exploration because of producing the damage for the future active spacecrafts and high precision measurement for space debris are required for debris surveillance and collision avoidance. Laser ranging technology is inherently high accurate and will play an important role in precise orbit determination, accurate catalog of space debris. Shanghai Astronomical Observatory (SHAO) of CAS, has been developing the technology of laser measurement to space debris for several years. According to characteristics of laser echoes from space debris and the experiences of relevant activities, high repetition rate, high power laser system and low dark noise APD detector with high quantum efficiency and high transmissivity of narrow bandwidth spectral filter are applied to laser measurement to space debris in SHAO. With these configurations, great achievements of laser measurement to space debris are made with hundreds of passes of laser data from space debris in the distance between 500km and 2500km with Radar Cross Section (RCS) of more than 10 m^{2} to less than 0.5m^{2} at the measuring precision of less than 1m (RMS). For better application of laser ranging technology, Chinese Space Debris Observation network, consisting of Shanghai, Changchun and Kunming station, has been preliminary developed and the coordinated observation has been performed to increase the measuring efficiency for space debris. It is referred from data that laser ranging technology can be as the essential high accuracy measurement technology in the study of space debris.

  2. Opportunities for High Precision Photometric Measurements of Variable Stars: Kepler Guest Investigator Program

    NASA Astrophysics Data System (ADS)

    Borucki, W. J.; Koch, D. G.; Basri, G. S.; Latham, D. W.; Howell, S. B.

    2004-12-01

    The Kepler Mission is designed to detect terrestrial planets by monitoring the flux of more than 100,000 dwarf stars for a period of four years at a cadence of 4/hour. During the early portion of the mission when the telemetry rate is high, approximately 170,000 stars will be monitored. The photometric precision for 6.5-hour integration periods will be 20 ppm to 89 ppm for 12th to 15th magnitude stars, respectively. Prior to the launch, multiband photometry of all target stars will be made to estimate spectral type, brightness temperature, and luminosity class. To the extent possible, the initial target list will exclude evolved stars and those known to be variable. Sometime after the first year, the target list will be trimmed by removing those stars found to be too variable to detect planets unless requests for continued observations are received from the stellar astrophysics community. A Guest Observer program is being developed to accommodate those wishing to observe targets in the 140 square degree Kepler field of view centered at RA 19h 22m 40s, Dec +44° 30'. A webtool is available to assess whether your favorite object is on the Kepler detectors. This program represents an unprecedented opportunity to obtain extremely high precision photometry over very long (typically 3 month) intervals with almost continuous coverage. At any given time there will be 2000-3000 Guest Observer targets (a few of which can be observed with a one-minute cadence).

  3. High Precision Bright-Star Astrometry with the USNO Astrometric CMOS Hybrid Camera System

    NASA Astrophysics Data System (ADS)

    Secrest, Nathan; Dudik, Rachel; Berghea, Ciprian; Hennessy, Greg; Dorland, Bryan

    2015-08-01

    While GAIA will provide excellent positional measurements of hundreds of millions of stars between 5 < mag < 20, an ongoing challenge in the field of high-precision differential astrometry is the positional accuracy of very bright stars (mag < 5), due to the enormous dynamic range between bright stars of interest, such as those in the Hipparcos catalog, and their background field stars, which are especially important for differential astrometry. Over the past few years, we have been testing the USNO Astrometric CMOS Hybrid Camera System (UAHC), which utilizes an H4RG-10 detector in windowing mode, as a possible solution to the NOFS USNO Bright Star Astrometric Database (UBAD). In this work, we discuss the results of an astrometric analysis of single-epoch Hipparcos data taken with the UAHC from the 1.55m Kaj Strand Astrometric Reflector at NOFS from June 27-30, 2014. We discuss the calibration of this data, as well as an astrometric analysis pipeline we developed that will enable multi-epoch differential and absolute astrometry with the UAHC. We find that while the overall differential astrometric stability of data taken with the UAHC is good (5-10 mas single-measurement precision) and comparable to other ground-based astrometric camera systems, bright stars in the detector window suffer from several systematic effects, such as insufficient window geometry and centroiding failures due to read-out artifacts—both of which can be significantly improved with modifications to the electronics, read-out speed and microcode.

  4. Development of Metallic Magnetic Calorimeters for High Precision Measurements of Calorimetric Re-187 and Ho-163 Spectra

    NASA Technical Reports Server (NTRS)

    Ranitzsch, P. C.-O.; Porst, J.-P.; Kempf, S.; Pies, C.; Schafer, S.; Hengstler, D.; Fleischmann, A.; Enss, C.; Gastaldo, L.

    2012-01-01

    The measurement of calorimetric spectra following atomic weak decays, beta (b) and electron capture (EC), of nuclides having a very low Q-value, can provide an impressively high sensitivity to a non-vanishing neutrino mass. The achievable sensitivity in this kind of experiments is directly connected to the performance of the used detectors. In particular an energy resolution of a few eV and a pulse formation time well below 1 microsecond are required. Low temperature Metallic Magnetic Calorimeters (MMCs) for soft X-rays have already shown an energy resolution of 2.0 eV FWHM and a pulse rise-time of about 90 ns for fully micro-fabricated detectors. We present the use of MMCs for high precision measurements of calorimetric spectra following the beta-decay of Re-187 and the EC of Ho-163. We show results obtained with detectors optimized for Re-187 and for Ho-163 experiments respectively. While the detectors equipped with superconducting Re absorbers have not yet reached the aimed performance, a first detector prototype with a Au absorber having implanted Ho-163 ions already shows excellent results. An energy resolution of 12 eV FWHM and a rise time of 90 ns were measured.

  5. Production of general purpose heat source (GPHS) using advanced manufacturing methods

    SciTech Connect

    Miller, R.G.

    1996-03-01

    Mankind will continue to explore the stars through the use of unmanned space craft until the technology and costs are compatible with sending travelers to the outer planets of our solar system and beyond. Unmanned probes of the present and future will be necessary to develop the necessary technologies and obtain information that will make this travel possible. Because of the significant costs incurred, the use of modern manufacturing technologies must be used to lower the investment needed even when shared by international partnerships. For over the last 30 years, radioisotopes have provided the heat from which electrical power is extracted. Electric power for future spacecraft will be provided by either Radioisotope Thermoelectric Generators (RTG), Radioisotopic Thermophotovoltaic systems (RTPV), radioisotope Stirling systems, or a combination of these. All of these systems will be thermally driven by General Purpose Heat Source (GPHS) fueled clad in some configuration. The GPHS clad contains a {sup 238}PuO{sub 2} pellet encapsulated in an iridium alloy container. Historically, the fabrication of the iridium alloy shells has been performed at EG&G Mound and Oak Ridge National Laboratory (ORNL), and girth welding at Westinghouse Savannah River Corporation (WSRC) and Los Alamos National Laboratory (LANL). This paper will describe the use of laser processing for welding, drilling, cutting, and machining with other manufacturing methods to reduce the costs of producing GPHS fueled clad components and compl{acute e}ted assemblies. Incorporation of new quality technologies will compliment these manufacturing methods to reduce cost. {copyright} {ital 1996 American Institute of Physics.}

  6. A General-Purpose Optimization Engine for Multi-Disciplinary Design Applications

    NASA Technical Reports Server (NTRS)

    Patnaik, Surya N.; Hopkins, Dale A.; Berke, Laszlo

    1996-01-01

    A general purpose optimization tool for multidisciplinary applications, which in the literature is known as COMETBOARDS, is being developed at NASA Lewis Research Center. The modular organization of COMETBOARDS includes several analyzers and state-of-the-art optimization algorithms along with their cascading strategy. The code structure allows quick integration of new analyzers and optimizers. The COMETBOARDS code reads input information from a number of data files, formulates a design as a set of multidisciplinary nonlinear programming problems, and then solves the resulting problems. COMETBOARDS can be used to solve a large problem which can be defined through multiple disciplines, each of which can be further broken down into several subproblems. Alternatively, a small portion of a large problem can be optimized in an effort to improve an existing system. Some of the other unique features of COMETBOARDS include design variable formulation, constraint formulation, subproblem coupling strategy, global scaling technique, analysis approximation, use of either sequential or parallel computational modes, and so forth. The special features and unique strengths of COMETBOARDS assist convergence and reduce the amount of CPU time used to solve the difficult optimization problems of aerospace industries. COMETBOARDS has been successfully used to solve a number of problems, including structural design of space station components, design of nozzle components of an air-breathing engine, configuration design of subsonic and supersonic aircraft, mixed flow turbofan engines, wave rotor topped engines, and so forth. This paper introduces the COMETBOARDS design tool and its versatility, which is illustrated by citing examples from structures, aircraft design, and air-breathing propulsion engine design.

  7. A general-purpose development environment for intelligent computer-aided training systems

    NASA Technical Reports Server (NTRS)

    Savely, Robert T.

    1990-01-01

    Space station training will be a major task, requiring the creation of large numbers of simulation-based training systems for crew, flight controllers, and ground-based support personnel. Given the long duration of space station missions and the large number of activities supported by the space station, the extension of space shuttle training methods to space station training may prove to be impractical. The application of artificial intelligence technology to simulation training can provide the ability to deliver individualized training to large numbers of personnel in a distributed workstation environment. The principal objective of this project is the creation of a software development environment which can be used to build intelligent training systems for procedural tasks associated with the operation of the space station. Current NASA Johnson Space Center projects and joint projects with other NASA operational centers will result in specific training systems for existing space shuttle crew, ground support personnel, and flight controller tasks. Concurrently with the creation of these systems, a general-purpose development environment for intelligent computer-aided training systems will be built. Such an environment would permit the rapid production, delivery, and evolution of training systems for space station crew, flight controllers, and other support personnel. The widespread use of such systems will serve to preserve task and training expertise, support the training of many personnel in a distributed manner, and ensure the uniformity and verifiability of training experiences. As a result, significant reductions in training costs can be realized while safety and the probability of mission success can be enhanced.

  8. The PennBMBI: Design of a General Purpose Wireless Brain-Machine-Brain Interface System.

    PubMed

    Liu, Xilin; Zhang, Milin; Subei, Basheer; Richardson, Andrew G; Lucas, Timothy H; Van der Spiegel, Jan

    2015-04-01

    In this paper, a general purpose wireless Brain-Machine-Brain Interface (BMBI) system is presented. The system integrates four battery-powered wireless devices for the implementation of a closed-loop sensorimotor neural interface, including a neural signal analyzer, a neural stimulator, a body-area sensor node and a graphic user interface implemented on the PC end. The neural signal analyzer features a four channel analog front-end with configurable bandpass filter, gain stage, digitization resolution, and sampling rate. The target frequency band is configurable from EEG to single unit activity. A noise floor of 4.69 μVrms is achieved over a bandwidth from 0.05 Hz to 6 kHz. Digital filtering, neural feature extraction, spike detection, sensing-stimulating modulation, and compressed sensing measurement are realized in a central processing unit integrated in the analyzer. A flash memory card is also integrated in the analyzer. A 2-channel neural stimulator with a compliance voltage up to ± 12 V is included. The stimulator is capable of delivering unipolar or bipolar, charge-balanced current pulses with programmable pulse shape, amplitude, width, pulse train frequency and latency. A multi-functional sensor node, including an accelerometer, a temperature sensor, a flexiforce sensor and a general sensor extension port has been designed. A computer interface is designed to monitor, control and configure all aforementioned devices via a wireless link, according to a custom designed communication protocol. Wireless closed-loop operation between the sensory devices, neural stimulator, and neural signal analyzer can be configured. The proposed system was designed to link two sites in the brain, bridging the brain and external hardware, as well as creating new sensory and motor pathways for clinical practice. Bench test and in vivo experiments are performed to verify the functions and performances of the system.

  9. Using general-purpose computing on graphics processing units (GPGPU) to accelerate the ordinary kriging algorithm

    NASA Astrophysics Data System (ADS)

    Gutiérrez de Ravé, E.; Jiménez-Hornero, F. J.; Ariza-Villaverde, A. B.; Gómez-López, J. M.

    2014-03-01

    Spatial interpolation methods have been applied to many disciplines, the ordinary kriging interpolation being one of the methods most frequently used. However, kriging comprises a computational cost that scales as the cube of the number of data points. Therefore, one most pressing problems in geostatistical simulations is that of developing methods that can reduce the computational time. Weights calculation and then the estimate for each unknown point is the most time-consuming step in ordinary kriging. This work investigates the potential reduction in execution time by selecting the suitable operations involved in this step to be parallelized by using general-purpose computing on graphics processing units (GPGPU) and Compute Unified Device Architecture (CUDA). This study has been performed by taking into account comparative studies between graphic and central processing units on two different machines, a personal computer (GPU, GeForce 9500, and CPU, AMD Athlon X2 4600) and a server (GPU, Tesla C1060, and CPU, Xeon 5600). In addition, two data types (float and double) have been considered in the executions. The experimental results indicate that parallel implementation of matrix inverse by using GPGPU and CUDA will be enough to reduce the execution time of weights calculation and estimation for each unknown point and, as a result, the global performance time of ordinary kriging. In addition, suitable array dimensions for using the available parallelized code have been determined for each case. Thus, it is possible to obtain relevant saved times compared to those resulting from considering wider parallelized extension. This fact demonstrates the convenience of carrying out this kind of study in other interpolation calculation methodologies using matrices.

  10. A general purpose FASTBUS master (GPM) and memory module (DSM) for online applications

    SciTech Connect

    Muller, H.

    1986-02-01

    The GPM is a high performance Fastbus master/slave, driven by 68 000 (or optionally 68 020/68 881 processors). Developed for general purpose applications it will perform control, trigger and diagnostic functions in three different experiments at CERN (DELPHI, L3, VIRTUS). Commercially available as single-board Fastbus master/slave, the GPM is a cheap processor component which can be connected to the DSM Fastbus dual-slave memory to perform as a low-level trigger processor, event formatter or data-spy. The GPM supports interprocessor interrupts via a Fastbus CSR register, interrupts on events in the Fastbus (like SR), and external interrupts. The GPM is equipped with 1/2 Mbyte of RAM, 1/4 Mbyte of ROM and a 32 Kbyte Fastbus I/O buffer. Any Fastbus operation can be generated as mixture of autonomous block transfers and assembly-language instructions which are directly executed in Fastbus. Powerful diagnostics can be performed by the possibility to address its own slave-port, via the Fastbus and the applicability of the debugging monitor commands to individual Fastbus/68 000 cycles. A terminal and host connection is available. The DMA supported parallel port can be used for interface applications. For external interrupts and coaxial pulse I/O, a NIM pulse interface is available. The 2 Mbyte Dual Slave Memory (DSM) can be used either as a stand-alone Fastbus memory, or as a memory extension module of a GPM, with independent I/O on crate and cable segments. It supports linear or circular buffer concepts and can be used as a data-spy on5cable segments.

  11. The PennBMBI: Design of a General Purpose Wireless Brain-Machine-Brain Interface System.

    PubMed

    Liu, Xilin; Zhang, Milin; Subei, Basheer; Richardson, Andrew G; Lucas, Timothy H; Van der Spiegel, Jan

    2015-04-01

    In this paper, a general purpose wireless Brain-Machine-Brain Interface (BMBI) system is presented. The system integrates four battery-powered wireless devices for the implementation of a closed-loop sensorimotor neural interface, including a neural signal analyzer, a neural stimulator, a body-area sensor node and a graphic user interface implemented on the PC end. The neural signal analyzer features a four channel analog front-end with configurable bandpass filter, gain stage, digitization resolution, and sampling rate. The target frequency band is configurable from EEG to single unit activity. A noise floor of 4.69 μVrms is achieved over a bandwidth from 0.05 Hz to 6 kHz. Digital filtering, neural feature extraction, spike detection, sensing-stimulating modulation, and compressed sensing measurement are realized in a central processing unit integrated in the analyzer. A flash memory card is also integrated in the analyzer. A 2-channel neural stimulator with a compliance voltage up to ± 12 V is included. The stimulator is capable of delivering unipolar or bipolar, charge-balanced current pulses with programmable pulse shape, amplitude, width, pulse train frequency and latency. A multi-functional sensor node, including an accelerometer, a temperature sensor, a flexiforce sensor and a general sensor extension port has been designed. A computer interface is designed to monitor, control and configure all aforementioned devices via a wireless link, according to a custom designed communication protocol. Wireless closed-loop operation between the sensory devices, neural stimulator, and neural signal analyzer can be configured. The proposed system was designed to link two sites in the brain, bridging the brain and external hardware, as well as creating new sensory and motor pathways for clinical practice. Bench test and in vivo experiments are performed to verify the functions and performances of the system. PMID:25769171

  12. General-Purpose Heat Source development: Extended series test program large fragment tests

    SciTech Connect

    Cull, T.A.

    1989-08-01

    General-Purpose Heat Source radioisotope thermoelectric generators (GPHS-RTGs) will provide electric power for the NASA Galileo and European Space Agency Ulysses missions. Each GPHS-RTG comprises two major components: GPHS modules, which provide thermal energy, and a thermoelectric converter, which converts the thermal energy into electric power. Each of the 18 GPHS modules in a GPHS-RTG contains four /sup 238/PuO/sub 2/-fueled capsules. LANL conducted a series of safety verification tests on the GPHS-RTG before the scheduled May 1986 launch of the Galileo spacecraft to assess the ability of the GPHS modules to contain the plutonia in potential accident environments. As a result of the Challenger 51-L accident in January 1986, NASA postponed the launch of Galileo; the launch vehicle was reconfigured and the spacecraft trajectory was modified. These actions prompted NASA to reevaluate potential mission accidents, and an extended series safety test program was initiated. The program included a series of large fragment tests that simulated the collision of solid rocket booster (SRB) fragments, generated in an SRB motor case rupture or resulting from a range safety officer SRB destruct action, with the GPHS-RTG. The tests indicated that fueled clads, inside a converter, will not breach or release fuel after a square (142 cm on a side) SRB fragment impacts flat-on at velocities up to 212 m/s, and that only the leading fueled capsules breach and release fuel after the square SRB fragment impacts the modules, inside the converter, edge-on at 95 m/s. 8 refs., 32 figs., 7 tabs.

  13. High-precision determination of iron oxidation state in silicate glasses using XANES

    SciTech Connect

    Cottrell, Elizabeth; Kelley, Katherine A.; Lanzirotti, Antonio; Fischer, Rebecca A.

    2009-11-04

    Fe K-edge X-ray absorption near-edge structure (XANES) and Moessbauer spectra were collected on natural basaltic glasses equilibrated over a range of oxygen fugacity (QFM - 3.5 to QFM + 4.5). The basalt compositions and fO{sub 2} conditions were chosen to bracket the natural range of redox conditions expected for basalts from mid-ocean ridge, ocean island, back-arc basin, and arc settings, in order to develop a high-precision calibration for the determination of Fe{sup 3+}/{Sigma}Fe in natural basalts. The pre-edge centroid energy, corresponding to the 1s {yields} 3d transition, was determined to be the most robust proxy for Fe oxidation state, affording significant advantages compared to the use of other spectral features. A second-order polynomial models the correlation between the centroid and Fe{sup 3+}/{Sigma}Fe, yielding a precision of {+-} 0.0045 in Fe{sup 3+}/{Sigma}Fe for glasses with Fe{sup 3+}/{Sigma}Fe > 8%, which is comparable to the precision of wet chemistry. This high precision relies on a Si (311) monochromator to better define the Fe{sup 2+} and Fe{sup 3+} transitions, accurate and robust modeling of the pre-edge feature, dense fO{sub 2}-coverage and compositional appropriateness of reference glasses, and application of a non-linear drift correction. Through re-analysis of the reference glasses across three synchrotron beam sessions, we show that the quoted precision can be achieved (i.e., analyses are reproducible) across multiple synchrotron beam sessions, even when spectral collection conditions (detector parameters or sample geometry) change. Rhyolitic glasses were also analyzed and yield a higher centroid energy at a given Fe{sup 3+}/{Sigma}Fe than basalts, implying that major variations in melt structure affect the relationship between centroid position and Fe{sup 3+}/{Sigma}Fe, and that separate calibrations are needed for the determination of oxidation state in basalts and rhyolites.

  14. Coated Particles Fuel Compact-General Purpose Heat Source for Advanced Radioisotope Power Systems

    NASA Astrophysics Data System (ADS)

    El-Genk, Mohamed S.; Tournier, Jean-Michel

    2003-01-01

    Coated Particles Fuel Compacts (CPFC) have recently been shown to offer performance advantage for use in Radioisotope Heater Units (RHUs) and design flexibility for integrating at high thermal efficiency with Stirling Engine converters, currently being considered for 100 We. Advanced Radioisotope Power Systems (ARPS). The particles in the compact consist of 238PuO2 fuel kernels with 5-μm thick PyC inner coating and a strong ZrC outer coating, whose thickness depends on the maximum fuel temperature during reentry, the fuel kernel diameter, and the fraction of helium gas released from the kernels and fully contained by the ZrC coating. In addition to containing the helium generated by radioactive decay of 238Pu for up to 10 years before launch and 10-15 years mission lifetime, the kernels are intentionally sized (>= 300 μm in diameter) to prevent any adverse radiological effects on reentry. This paper investigates the advantage of replacing the four iridium-clad 238PuO2 fuel pellets, the two floating graphite membranes, and the two graphite impact shells in current State-Of-The-Art (SOA) General Purpose Heat Source (GPHS) with CPFC. The total mass, thermal power, and specific power of the CPFC-GPHS are calculated as functions of the helium release fraction from the fuel kernels and maximum fuel temperature during reentry from 1500 K to 2400 K. For the same total mass and volume as SOA GPHS, the generated thermal power by single-size particles CPFC-GPHS is 260 W at Beginning-Of-Mission (BOM), versus 231 W for the GPHS. For an additional 10% increase in total mass, the CPFC-GPHS could generate 340 W BOM; 48% higher than SOA GPHS. The corresponding specific thermal power is 214 W/kg, versus 160 W/kg for SOA GPHS; a 34% increase. Therefore, for the same thermal power, the CPFC-GPHS is lighter than SOA GPHS, while it uses the same amount of 238PuO2 fuel and same aeroshell. For the same helium release fraction and fuel temperature, binary-size particles CPFC-GPHS could

  15. Variable Conductance Heat Pipe Cooling of Stirling Convertor and General Purpose Heat Source

    NASA Technical Reports Server (NTRS)

    Tarau, Calin; Schwendeman, Carl; Anderson, William G.; Cornell, Peggy A.; Schifer, Nicholas A.

    2013-01-01

    In a Stirling Radioisotope Power System (RPS), heat must be continuously removed from the General Purpose Heat Source (GPHS) modules to maintain the modules and surrounding insulation at acceptable temperatures. The Stirling convertor normally provides this cooling. If the Stirling convertor stops in the current system, the insulation is designed to spoil, preventing damage to the GPHS at the cost of an early termination of the mission. An alkali-metal Variable Conductance Heat Pipe (VCHP) can be used to passively allow multiple stops and restarts of the Stirling convertor. In a previous NASA SBIR Program, Advanced Cooling Technologies, Inc. (ACT) developed a series of sodium VCHPs as backup cooling systems for Stirling RPS. The operation of these VCHPs was demonstrated using Stirling heater head simulators and GPHS simulators. In the most recent effort, a sodium VCHP with a stainless steel envelope was designed, fabricated and tested at NASA Glenn Research Center (GRC) with a Stirling convertor for two concepts; one for the Advanced Stirling Radioisotope Generator (ASRG) back up cooling system and one for the Long-lived Venus Lander thermal management system. The VCHP is designed to activate and remove heat from the stopped convertor at a 19 degC temperature increase from the nominal vapor temperature. The 19 degC temperature increase from nominal is low enough to avoid risking standard ASRG operation and spoiling of the Multi-Layer Insulation (MLI). In addition, the same backup cooling system can be applied to the Stirling convertor used for the refrigeration system of the Long-lived Venus Lander. The VCHP will allow the refrigeration system to: 1) rest during transit at a lower temperature than nominal; 2) pre-cool the modules to an even lower temperature before the entry in Venus atmosphere; 3) work at nominal temperature on Venus surface; 4) briefly stop multiple times on the Venus surface to allow scientific measurements. This paper presents the experimental

  16. Upscaling from research watersheds: an essential stage of trustworthy general-purpose hydrologic model building

    NASA Astrophysics Data System (ADS)

    McNamara, J. P.; Semenova, O.; Restrepo, P. J.

    2011-12-01

    Highly instrumented research watersheds provide excellent opportunities for investigating hydrologic processes. A danger, however, is that the processes observed at a particular research watershed are too specific to the watershed and not representative even of the larger scale watershed that contains that particular research watershed. Thus, models developed based on those partial observations may not be suitable for general hydrologic use. Therefore demonstrating the upscaling of hydrologic process from research watersheds to larger watersheds is essential to validate concepts and test model structure. The Hydrograph model has been developed as a general-purpose process-based hydrologic distributed system. In its applications and further development we evaluate the scaling of model concepts and parameters in a wide range of hydrologic landscapes. All models, either lumped or distributed, are based on a discretization concept. It is common practice that watersheds are discretized into so called hydrologic units or hydrologic landscapes possessing assumed homogeneous hydrologic functioning. If a model structure is fixed, the difference in hydrologic functioning (difference in hydrologic landscapes) should be reflected by a specific set of model parameters. Research watersheds provide the possibility for reasonable detailed combining of processes into some typical hydrologic concept such as hydrologic units, hydrologic forms, and runoff formation complexes in the Hydrograph model. And here by upscaling we imply not the upscaling of a single process but upscaling of such unified hydrologic functioning. The simulation of runoff processes for the Dry Creek research watershed, Idaho, USA (27 km2) was undertaken using the Hydrograph model. The information on the watershed was provided by Boise State University and included a GIS database of watershed characteristics and a detailed hydrometeorological observational dataset. The model provided good simulation results in

  17. Parallelized computation for computer simulation of electrocardiograms using personal computers with multi-core CPU and general-purpose GPU.

    PubMed

    Shen, Wenfeng; Wei, Daming; Xu, Weimin; Zhu, Xin; Yuan, Shizhong

    2010-10-01

    Biological computations like electrocardiological modelling and simulation usually require high-performance computing environments. This paper introduces an implementation of parallel computation for computer simulation of electrocardiograms (ECGs) in a personal computer environment with an Intel CPU of Core (TM) 2 Quad Q6600 and a GPU of Geforce 8800GT, with software support by OpenMP and CUDA. It was tested in three parallelization device setups: (a) a four-core CPU without a general-purpose GPU, (b) a general-purpose GPU plus 1 core of CPU, and (c) a four-core CPU plus a general-purpose GPU. To effectively take advantage of a multi-core CPU and a general-purpose GPU, an algorithm based on load-prediction dynamic scheduling was developed and applied to setting (c). In the simulation with 1600 time steps, the speedup of the parallel computation as compared to the serial computation was 3.9 in setting (a), 16.8 in setting (b), and 20.0 in setting (c). This study demonstrates that a current PC with a multi-core CPU and a general-purpose GPU provides a good environment for parallel computations in biological modelling and simulation studies.

  18. Parallelized computation for computer simulation of electrocardiograms using personal computers with multi-core CPU and general-purpose GPU.

    PubMed

    Shen, Wenfeng; Wei, Daming; Xu, Weimin; Zhu, Xin; Yuan, Shizhong

    2010-10-01

    Biological computations like electrocardiological modelling and simulation usually require high-performance computing environments. This paper introduces an implementation of parallel computation for computer simulation of electrocardiograms (ECGs) in a personal computer environment with an Intel CPU of Core (TM) 2 Quad Q6600 and a GPU of Geforce 8800GT, with software support by OpenMP and CUDA. It was tested in three parallelization device setups: (a) a four-core CPU without a general-purpose GPU, (b) a general-purpose GPU plus 1 core of CPU, and (c) a four-core CPU plus a general-purpose GPU. To effectively take advantage of a multi-core CPU and a general-purpose GPU, an algorithm based on load-prediction dynamic scheduling was developed and applied to setting (c). In the simulation with 1600 time steps, the speedup of the parallel computation as compared to the serial computation was 3.9 in setting (a), 16.8 in setting (b), and 20.0 in setting (c). This study demonstrates that a current PC with a multi-core CPU and a general-purpose GPU provides a good environment for parallel computations in biological modelling and simulation studies. PMID:20674066

  19. A micron resolution optical scanner for characterization of silicon detectors

    SciTech Connect

    Shukla, R. A.; Dugad, S. R. Gopal, A. V.; Gupta, S. K.; Prabhu, S. S.; Garde, C. S.

    2014-02-15

    The emergence of high position resolution (∼10 μm) silicon detectors in recent times have highlighted the urgent need for the development of new automated optical scanners of micron level resolution suited for characterizing microscopic features of these detectors. More specifically, for the newly developed silicon photo-multipliers (SiPM) that are compact, possessing excellent photon detection efficiency with gain comparable to photo-multiplier tube. In a short time, since their invention the SiPMs are already being widely used in several high-energy physics and astrophysics experiments as the photon readout element. The SiPM is a high quantum efficiency, multi-pixel photon counting detector with fast timing and high gain. The presence of a wide variety of photo sensitive silicon detectors with high spatial resolution requires their performance evaluation to be carried out by photon beams of very compact spot size. We have designed a high resolution optical scanner that provides a monochromatic focused beam on a target plane. The transverse size of the beam was measured by the knife-edge method to be 1.7 μm at 1 − σ level. Since the beam size was an order of magnitude smaller than the typical feature size of silicon detectors, this optical scanner can be used for selective excitation of these detectors. The design and operational details of the optical scanner, high precision programmed movement of target plane (0.1 μm) integrated with general purpose data acquisition system developed for recording static and transient response photo sensitive silicon detector are reported in this paper. Entire functionality of scanner is validated by using it for selective excitation of individual pixels in a SiPM and identifying response of active and dead regions within SiPM. Results from these studies are presented in this paper.

  20. High-rate dead-time corrections in a general purpose digital pulse processing system.

    PubMed

    Abbene, Leonardo; Gerardi, Gaetano

    2015-09-01

    Dead-time losses are well recognized and studied drawbacks in counting and spectroscopic systems. In this work the abilities on dead-time correction of a real-time digital pulse processing (DPP) system for high-rate high-resolution radiation measurements are presented. The DPP system, through a fast and slow analysis of the output waveform from radiation detectors, is able to perform multi-parameter analysis (arrival time, pulse width, pulse height, pulse shape, etc.) at high input counting rates (ICRs), allowing accurate counting loss corrections even for variable or transient radiations. The fast analysis is used to obtain both the ICR and energy spectra with high throughput, while the slow analysis is used to obtain high-resolution energy spectra. A complete characterization of the counting capabilities, through both theoretical and experimental approaches, was performed. The dead-time modeling, the throughput curves, the experimental time-interval distributions (TIDs) and the counting uncertainty of the recorded events of both the fast and the slow channels, measured with a planar CdTe (cadmium telluride) detector, will be presented. The throughput formula of a series of two types of dead-times is also derived. The results of dead-time corrections, performed through different methods, will be reported and discussed, pointing out the error on ICR estimation and the simplicity of the procedure. Accurate ICR estimations (nonlinearity < 0.5%) were performed by using the time widths and the TIDs (using 10 ns time bin width) of the detected pulses up to 2.2 Mcps. The digital system allows, after a simple parameter setting, different and sophisticated procedures for dead-time correction, traditionally implemented in complex/dedicated systems and time-consuming set-ups.

  1. High-rate dead-time corrections in a general purpose digital pulse processing system

    PubMed Central

    Abbene, Leonardo; Gerardi, Gaetano

    2015-01-01

    Dead-time losses are well recognized and studied drawbacks in counting and spectroscopic systems. In this work the abilities on dead-time correction of a real-time digital pulse processing (DPP) system for high-rate high-resolution radiation measurements are presented. The DPP system, through a fast and slow analysis of the output waveform from radiation detectors, is able to perform multi-parameter analysis (arrival time, pulse width, pulse height, pulse shape, etc.) at high input counting rates (ICRs), allowing accurate counting loss corrections even for variable or transient radiations. The fast analysis is used to obtain both the ICR and energy spectra with high throughput, while the slow analysis is used to obtain high-resolution energy spectra. A complete characterization of the counting capabilities, through both theoretical and experimental approaches, was performed. The dead-time modeling, the throughput curves, the experimental time-interval distributions (TIDs) and the counting uncertainty of the recorded events of both the fast and the slow channels, measured with a planar CdTe (cadmium telluride) detector, will be presented. The throughput formula of a series of two types of dead-times is also derived. The results of dead-time corrections, performed through different methods, will be reported and discussed, pointing out the error on ICR estimation and the simplicity of the procedure. Accurate ICR estimations (nonlinearity < 0.5%) were performed by using the time widths and the TIDs (using 10 ns time bin width) of the detected pulses up to 2.2 Mcps. The digital system allows, after a simple parameter setting, different and sophisticated procedures for dead-time correction, traditionally implemented in complex/dedicated systems and time-consuming set-ups. PMID:26289270

  2. 21 CFR 862.2050 - General purpose laboratory equipment labeled or promoted for a specific medical use.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ..., DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES CLINICAL CHEMISTRY AND CLINICAL TOXICOLOGY DEVICES Clinical Laboratory Instruments § 862.2050 General purpose laboratory equipment labeled or... (general controls). The device is identified in paragraph (a) of this section and is exempt from...

  3. BLASTbus electronics: general-purpose readout and control for balloon-borne experiments

    NASA Astrophysics Data System (ADS)

    Benton, S. J.; Ade, P. A.; Amiri, M.; Angilè, F. E.; Bock, J. J.; Bond, J. R.; Bryan, S. A.; Chiang, H. C.; Contaldi, C. R.; Crill, B. P.; Devlin, M. J.; Dober, B.; Doré, O. P.; Farhang, M.; Filippini, J. P.; Fissel, L. M.; Fraisse, A. A.; Fukui, Y.; Galitzki, N.; Gambrel, A. E.; Gandilo, N. N.; Golwala, S. R.; Gudmundsson, J. E.; Halpern, M.; Hasselfield, M.; Hilton, G. C.; Holmes, W. A.; Hristov, V. V.; Irwin, K. D.; Jones, W. C.; Kermish, Z. D.; Klein, J.; Korotkov, A. L.; Kuo, C. L.; MacTavish, C. J.; Mason, P. V.; Matthews, T. G.; Megerian, K. G.; Moncelsi, L.; Morford, T. A.; Mroczkowski, T. K.; Nagy, J. M.; Netterfield, C. B.; Novak, G.; Nutter, D.; O'Brient, R.; Ogburn, R. W.; Pascale, E.; Poidevin, F.; Rahlin, A. S.; Reintsema, C. D.; Ruhl, J. E.; Runyan, M. C.; Savini, G.; Scott, D.; Shariff, J. A.; Soler, J. D.; Thomas, N. E.; Trangsrud, A.; Truch, M. D.; Tucker, C. E.; Tucker, G. S.; Tucker, R. S.; Turner, A. D.; Ward-Thompson, D.; Weber, A. C.; Wiebe, D. V.; Young, E. Y.

    2014-07-01

    We present the second generation BLASTbus electronics. The primary purposes of this system are detector readout, attitude control, and cryogenic housekeeping, for balloon-borne telescopes. Readout of neutron transmutation doped germanium (NTD-Ge) bolometers requires low noise and parallel acquisition of hundreds of analog signals. Controlling a telescope's attitude requires the capability to interface to a wide variety of sensors and motors, and to use them together in a fast, closed loop. To achieve these different goals, the BLASTbus system employs a flexible motherboard-daughterboard architecture. The programmable motherboard features a digital signal processor (DSP) and field-programmable gate array (FPGA), as well as slots for three daughterboards. The daughterboards provide the interface to the outside world, with versions for analog to digital conversion, and optoisolated digital input/output. With the versatility afforded by this design, the BLASTbus also finds uses in cryogenic, thermometry, and power systems. For accurate timing control to tie everything together, the system operates in a fully synchronous manner. BLASTbus electronics have been successfully deployed to the South Pole, and own on stratospheric balloons.

  4. A simple method for rapid, high-precision isotope measurements of small samples with MC-ICP-MS

    NASA Astrophysics Data System (ADS)

    Kamenov, G. D.; Mueller, P. A.; Gilli, A.; Coyner, S. J.; Nielsen, S. H.

    2006-12-01

    A key factor for accurate and precise isotopic measurements is optimal signal to noise ratio, which makes analyses of very small samples challenging due to the small number of available analyte ions. If, however, the analysis time can be drastically reduced, then very small samples (e.g., 1ng) can be analyzed by placing the analyte ions in small volumes (e.g., 0.1ml). This will result in 10ppb sample solution and will give acceptable signal to noise ratio on Faraday detectors on modern MC-ICP-MS instruments. The signal from a 0.1ml solution, however, will last no more than a minute and very few ratios will be acquired with traditional isotope measurement protocols. In a series of experiments with standard reference materials and samples we established that high-precision isotopic ratio measurements can be obtained in much shorter times compared to traditional methods for isotopic analyses using TIMS and MC-ICP-MS. The protocol utilizes the Nu Plasma TRA (time-resolved analysis) software operating with a 0.2 second acquisition time (i.e., 300 isotopic ratios/minute). Using a low- flow nebulizer, only 0.1-0.2 ml of sample solution is required for 1-2 minutes signal duration. Consequently, placing the available analytical ions in small volume leads to higher signal to noise ratio that results in precise isotopic analyses, regardless of the very short acquisition times employed during the experiments. This technique can be applied for analyses of virtually any isotope system, as we demonstrate with examples for Sr, Nd, and Pb isotopic measurements. In addition to high-precision isotopic analyses of very small samples on Faraday detectors, another advantage of this protocol is enhanced lab productivity because overall analysis time is significantly reduced.

  5. Development of a high precision dosimetry system for the measurement of surface dose rate distribution for eye applicators

    SciTech Connect

    Eichmann, Marion; Fluehs, Dirk; Spaan, Bernhard

    2009-10-15

    Purpose: The therapeutic outcome of the therapy with ophthalmic applicators is highly dependent on the application of a sufficient dose to the tumor, whereas the dose applied to the surrounding tissue needs to be minimized. The goal for the newly developed apparatus described in this work is the determination of the individual applicator surface dose rate distribution with a high spatial resolution and a high precision in dose rate with respect to time and budget constraints especially important for clinical procedures. Inhomogeneities of the dose rate distribution can be detected and taken into consideration for the treatment planning. Methods: In order to achieve this, a dose rate profile as well as a surface profile of the applicator are measured and correlated with each other. An instrumental setup has been developed consisting of a plastic scintillator detector system and a newly designed apparatus for guiding the detector across the applicator surface at a constant small distance. It performs an angular movement of detector and applicator with high precision. Results: The measurements of surface dose rate distributions discussed in this work demonstrate the successful operation of the measuring setup. Measuring the surface dose rate distribution with a small distance between applicator and detector and with a high density of measuring points results in a complete and gapless coverage of the applicator surface, being capable of distinguishing small sized spots with high activities. The dosimetrical accuracy of the measurements and its analysis is sufficient (uncertainty in the dose rate in terms of absorbed dose to water is <7%), especially when taking the surgical techniques in positioning of the applicator on the eyeball into account. Conclusions: The method developed so far allows a fully automated quality assurance of eye applicators even under clinical conditions. These measurements provide the basis for future calculation of a full 3D dose rate

  6. 15 CFR 744.17 - Restrictions on certain exports and reexports of general purpose microprocessors for “military...

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... incorporation into: a military item described on the U.S. Munitions List (USML) (22 CFR part 121, International... reexports of general purpose microprocessors for âmilitary end-usesâ and to âmilitary end-users.â 744.17... microprocessors for “military end-uses” and to “military end-users.” (a) General prohibition. In addition to...

  7. APL/JHU free flight tests of the General Purpose Heat Source module. Testing: 5-7 March 1984

    SciTech Connect

    Baker, W.M. II

    1984-01-01

    Purpose of the test was to obtain statistical information on the dynamics of the General Purpose Heat Source (GPHS) module at terminal speeds. Models were designed to aerodynamically and dynamically represent the GPHS module. Normal and high speed photographic coverage documented the motion of the models. This report documents test parameters and techniques for the free-spin tests. It does not include data analysis.

  8. Quality of healthcare websites: A comparison of a general-purpose vs. domain-specific search engine.

    PubMed

    Abraham, Joanna; Reddy, Madhu

    2007-10-11

    In a pilot study, we had five typical Internet users evaluate the quality of health websites returned by a general-purpose search engine (Google) and a healthcare-specific search engine (Healthfinder). The evaluators used a quality criteria developed by Mitretek/Health Information Technology Institute. Although both search engines provided high quality health websites, we found some important differences between the two types of search engines.

  9. High-precision B(E2) measurements of semi-magic 58,60,62,64Ni by Coulomb excitation

    SciTech Connect

    Allmond, James M; Brown, Alex; Stuchbery, Andrew E; Galindo-Uribarri, Alfredo {nmn}; Padilla-Rodal, Elizabeth; Radford, David C; Batchelder, J. C.; Howard, Meredith E; Liang, J Felix; Manning, Brett M; Varner Jr, Robert L; Yu, Chang-Hong

    2014-01-01

    High-precision reduced electric-quadrupole transition probabilities B(E2) have been measured from single-step Coulomb excitation of semi-magic 58,60,62,64 Ni (Z = 28) beams at 1.8 MeV per nucleon on a natural carbon target. The energy loss of the nickel beams through the carbon target were directly measured with a zero-degree Bragg detector and the absolute B(E2) values were normalized by Rutherford scattering. The B(E2) values disagree with recent lifetime studies that employed the Doppler-shift attenuation method. The present high-precision B(E2) values reveal an asymmetry about 62 Ni, midshell between N = 28 and 40, with larger values towards 56 Ni (Z = N = 28). The experimental B(E2) values are compared with shell-model calculations in the full pf model space and the results indicate a soft 56 Ni core.

  10. Research on high-precision hole measurement based on robot vision method

    NASA Astrophysics Data System (ADS)

    Song, Li-mei; Li, Da-peng; Qin, Ming-cui; Li, Zong-yan; Chang, Yu-lan; Xi, Jiang-tao

    2014-09-01

    A high-precision vision detection and measurement system using mobile robot is established for the industry field detection of motorcycle frame hole and its diameter measurement. The robot path planning method is researched, and the non-contact measurement method with high precision based on visual digital image edge extraction and hole spatial circle fitting is presented. The Canny operator is used to extract the edge of captured image, the Lagrange interpolation algorithm is utilized to determine the missing image edge points and calculate the centroid, and the least squares fitting method is adopted to fit the image edge points. Experimental results show that the system can be used for the high-precision real-time measurement of hole on motorcycle frame. The absolute standard deviation of the proposed method is 0.026 7 mm. The proposed method can not only improve the measurement speed and precision, but also reduce the measurement error.

  11. Towards high precision measurements of nuclear g-factors for the Be isotopes

    NASA Astrophysics Data System (ADS)

    Takamine, A.; Wada, M.; Okada, K.; Ito, Y.; Schury, P.; Arai, F.; Katayama, I.; Imamura, K.; Ichikawa, Y.; Ueno, H.; Wollnik, H.; Schuessler, H. A.

    2016-06-01

    We describe the present status of future high-precision measurements of nuclear g-factors utilizing laser-microwave double and laser-microwave-rf triple resonance methods for online-trapped, laser-cooled radioactive beryllium isotope ions. These methods have applicability to other suitably chosen isotopes and for beryllium show promise in deducing the hyperfine anomaly of 11Be with a sufficiently high precision to study the nuclear magnetization distribution of this one-neutron halo nucleus in a nuclear-model-independent manner.

  12. Machine vision for high-precision volume measurement applied to levitated containerless material processing

    SciTech Connect

    Bradshaw, R.C.; Schmidt, D.P.; Rogers, J.R.; Kelton, K.F.; Hyers, R.W.

    2005-12-15

    By combining the best practices in optical dilatometry with numerical methods, a high-speed and high-precision technique has been developed to measure the volume of levitated, containerlessly processed samples with subpixel resolution. Containerless processing provides the ability to study highly reactive materials without the possibility of contamination affecting thermophysical properties. Levitation is a common technique used to isolate a sample as it is being processed. Noncontact optical measurement of thermophysical properties is very important as traditional measuring methods cannot be used. Modern, digitally recorded images require advanced numerical routines to recover the subpixel locations of sample edges and, in turn, produce high-precision measurements.

  13. Diamond turning of high-precision roll-to-roll imprinting molds for fabricating subwavelength gratings

    NASA Astrophysics Data System (ADS)

    Liu, Chun-Wei; Yan, Jiwang; Lin, Shih-Chieh

    2016-06-01

    Diamond turning of high-precision molds is a vital process for the roll-to-roll-based ultraviolet resin imprinting process in fabricating subwavelength gratings. The effects of the grating shape and grating period on diffraction efficiencies and diffraction angles were simulated. Experiments were then conducted to examine the effects of shape design, grating period, and cutting speed on machinability of the mold. According to the optical measurement results, the performance of the subwavelength gratings matched the design well at various incident angles. The results confirm that diamond turning of high-precision molds is a feasible approach for ensuring the continual mass production of subwavelength gratings.

  14. Machine Vision for High Precision Volume Measurement Applied to Levitated Containerless Materials Processing

    NASA Technical Reports Server (NTRS)

    Bradshaw, R. C.; Schmidt, D. P.; Rogers, J. R.; Kelton, K. F.; Hyers, R. W.

    2005-01-01

    By combining the best practices in optical dilatometry with new numerical methods, a high-speed and high precision technique has been developed to measure volume of levitated, containerlessly processed samples with sub- pixel resolution. Containerless processing provides the ability to study highly reactive materials without the possibility of contamination affecting thermo-physical properties. Levitation is a common technique used to isolate a sample as it is being processed. Noncontact optical measurement of thermo-ophysical properties is very important as traditional measuring methods cannot be used. Modern, digitally recorded images require advanced numerical routines to recover the sub-pixel locations of sample edges and, in turn produce high precision measurements.

  15. Future particle detector systems

    NASA Astrophysics Data System (ADS)

    Clark, Allan G.

    2000-09-01

    Starting with a short summary of the major new experimental physics programs, we attempt to motivate the reasons why existing general-purpose detectors at Hadron Colliders are what they are, why they are being upgraded, and why new facilities are being constructed. The CDF and ATLAS detectors are used to illustrate these motivations. Selected physics results from the CDF experiment provide evidence for limitations on the detector performance, and new physics opportunities motivate both machine and detector upgrades. This is discussed with emphasis on the improved physics reach of the CDF experiment at the Fermilab Tevatron (√s =2 TeV). From 2005, the Large Hadron Collider (LHC) at CERN will become operational at a collision energy of √s =14 TeV, seven times larger than at the Tevatron Collider. To exploit the physics capability of the LHC, several large detectors are being constructed. The detectors are significantly more complex than those at the Tevatron Collider because of physics and operational constraints. The detector design and technology of the aspects of the large general-purpose detector ATLAS is described.

  16. General purpose rocket furnace

    NASA Technical Reports Server (NTRS)

    Aldrich, B. R.; Whitt, W. D. (Inventor)

    1979-01-01

    A multipurpose furnace for space vehicles used for material processing experiments in an outer space environment is described. The furnace contains three separate cavities designed to process samples of the widest possible range of materials and thermal requirements. Each cavity contains three heating elements capable of independent function under the direction of an automatic and programmable control system. A heat removable mechanism is also provided for each cavity which operates in conjunction with the control system for establishing an isothermally heated cavity or a wide range of thermal gradients and cool down rates. A monitoring system compatible with the rocket telemetry provides furnace performance and sample growth rate data throughout the processing cycle.

  17. An expert system for choosing the best combination of options in a general-purpose program for automated design synthesis

    NASA Technical Reports Server (NTRS)

    Rogers, J. L., Jr.; Barthelemy, J. F. M.

    1985-01-01

    An expert system was developed to aid a user of the Automated Design Synthesis (ADS) general-purpose optimization computer program in selecting the best combination of strategy, optimizer, and one-dimensional search options for solving a problem. There are approximately 100 such combinations available in ADS. The knowledge base contains over 200 rules, and is divided into three categories: constrained problems, unconstrained problems, and constrained problems treated as unconstrained problems. The inference engine is written in LISP and is available on DEC-VAX and IBM PC/XT computers.

  18. Preliminary reentry safety assessment of the General Purpose Heat Source module for the Cassini mission: Aerospace Nuclear Safety Program

    SciTech Connect

    Conn, D.W.; Brenza, P.T.

    1993-04-01

    As asked by the U. S. Department of Energy/Office of Special Applications, and in support of the Environmental Impact Statement for the Cassini mission, The Johns Hopkins University/Applied Physics Laboratory (JHU/APL) has conducted preliminary one-dimensional ablation and thermal analyses of the General Purpose Heat Source (GPHS). The predicted earth entry conditions provided by the Jet Propulsion Laboratory (JPL) for a Cassini Venus-Venus-Earth-Jupiter Gravity Assist (VVEJGA) trajectory were used as initial conditions. The results of this study which constitute the initial reentry analysis assessment leading to the Cassini Updated Safety, Analysis Report (USAR) are discussed in this document.

  19. Preliminary reentry safety assessment of the General Purpose Heat Source module for the Cassini mission: Aerospace Nuclear Safety Program

    NASA Astrophysics Data System (ADS)

    Conn, D. W.; Brenza, P. T.

    1993-04-01

    As asked by the U.S. Department of Energy/Office of Special Applications, and in support of the Environmental Impact Statement for the Cassini mission, The Johns Hopkins University/Applied Physics Laboratory (JHU/APL) has conducted preliminary one dimensional ablation and thermal analyses of the General Purpose Heat Source (GPHS). The predicted earth entry conditions provided by the Jet Propulsion Laboratory (JPL) for a Cassini Venus - Venus - Earth - Jupiter gravity assist (VVEJGA) trajectory were used as initial conditions. The results of this study, which constitute the initial reentry analysis assessment leading to the Cassini Updated Safety Analysis Report (USAR), are discussed in this document.

  20. General-purpose heat source project and space nuclear safety and fuels program. Progress reportt, January 1980

    SciTech Connect

    Maraman, W.J.

    1980-04-01

    This formal monthly report covers the studies related to the use of /sup 238/PuO/sub 2/ in radioisotopic power systems carried out for the Advanced Nuclear Systems and Projects Division of the Los Alamos Scientific Laboratory. The two programs involved are the general-purpose heat source development and space nuclear safety and fuels. Most of the studies discussed here are of a continuing nature. Results and conclusions described may change as the work continues. Published reference to the results cited in this report should not be made without the explicit permission of the person in charge of the work.

  1. Proton-proton bremsstrahlung calculation: Comparison with recent high-precision experimental results

    SciTech Connect

    Li Yi; Liou, M.K.; Schreiber, W.M.

    2005-08-01

    Proton-proton bremsstrahlung cross sections and analyzing powers have been calculated at 190 MeV by using a one-boson-exchange model. The results are compared with the recently published high-precision Kernfysisch-Versneller-Instituut (KVI) data. Satisfactory agreement between theory and experiment has been found.

  2. Classification of LIDAR Data for Generating a High-Precision Roadway Map

    NASA Astrophysics Data System (ADS)

    Jeong, J.; Lee, I.

    2016-06-01

    Generating of a highly precise map grows up with development of autonomous driving vehicles. The highly precise map includes a precision of centimetres level unlike an existing commercial map with the precision of meters level. It is important to understand road environments and make a decision for autonomous driving since a robust localization is one of the critical challenges for the autonomous driving car. The one of source data is from a Lidar because it provides highly dense point cloud data with three dimensional position, intensities and ranges from the sensor to target. In this paper, we focus on how to segment point cloud data from a Lidar on a vehicle and classify objects on the road for the highly precise map. In particular, we propose the combination with a feature descriptor and a classification algorithm in machine learning. Objects can be distinguish by geometrical features based on a surface normal of each point. To achieve correct classification using limited point cloud data sets, a Support Vector Machine algorithm in machine learning are used. Final step is to evaluate accuracies of obtained results by comparing them to reference data The results show sufficient accuracy and it will be utilized to generate a highly precise road map.

  3. Research on machining error compensation in high-precision surface grinding machine for optical aspheric elements

    NASA Astrophysics Data System (ADS)

    Ke, Xiaolong; Guo, Yinbiao; Zhang, Shihan; Huang, Hao

    2010-10-01

    Using aspheric component in optical system can correct optical aberration, acquire high imaging quality, improve the optical characteristic, simplify system structure, and reduce system volume. Nowadays, high-precision surface grinding machine is an important approach to processing optical aspheric elements. However, because of the characteristics of optical aspheric elements, the processing method makes a higher demand to whole performance of surface grinding machine, and hardly to achieve ideal machining effect. Taking high generality and efficiency into account, this paper presents a compensation method for machining errors of high-precision surface grinding machine, which bases on optical aspheric elements, to achieve high-precision machining for all kinds of optical aspheric elements. After compensation, the machining accuracy of grinding machine could reach 2um/200×200mm. The research bases on NC surface grinding machine which is self developed. First of all, this paper introduces machining principle for optical aspheric elements on the grinding machine. And then error sources which producing errors are analyzed. By contacting and non-contacting measurement sensors, measurement software which is self designed realizes on-position measure for grinded workpiece, then fits surface precision and machining errors. Through compensation software for machining error which is self designed, compensation algorithm is designed and translated compensation data into G-code for the high-precision grinding machine to achieve compensation machining. Finally, by comparison between machining error compensation before and after processing, the experiments for this purpose are done to validate the compensation machining accuracy.

  4. Human factors in equipment development for the Space Shuttle - A study of the general purpose work station

    NASA Technical Reports Server (NTRS)

    Junge, M. K.; Giacomi, M. J.

    1981-01-01

    The results of a human factors test to assay the suitability of a prototype general purpose work station (GPWS) for biosciences experiments on the fourth Spacelab mission are reported. The evaluation was performed to verify that users of the GPWS would optimally interact with the GPWS configuration and instrumentation. Six male subjects sat on stools positioned to allow assimilation of the zero-g body posture. Trials were run concerning the operator viewing angles facing the console, the console color, procedures for injecting rates with dye, a rat blood cell count, mouse dissection, squirrel monkey transfer, and plant fixation. The trials were run for several days in order to gage improvement or poor performance conditions. Better access to the work surface was found necessary, together with more distinct and better located LEDs, better access window latches, clearer sequences on control buttons, color-coded sequential buttons, and provisions made for an intercom system when operators of the GPWS work in tandem.

  5. Evaluation of Aqueous and Powder Processing Techniques for Production of Pu-238-Fueled General Purpose Heat Sources

    SciTech Connect

    Not Available

    2008-06-01

    This report evaluates alternative processes that could be used to produce Pu-238 fueled General Purpose Heat Sources (GPHS) for radioisotope thermoelectric generators (RTG). Fabricating GPHSs with the current process has remained essentially unchanged since its development in the 1970s. Meanwhile, 30 years of technological advancements have been made in the fields of chemistry, manufacturing, ceramics, and control systems. At the Department of Energy’s request, alternate manufacturing methods were compared to current methods to determine if alternative fabrication processes could reduce the hazards, especially the production of respirable fines, while producing an equivalent GPHS product. An expert committee performed the evaluation with input from four national laboratories experienced in Pu-238 handling.

  6. Ground and flight experience with a strapdown inertial measuring unit and a general purpose airborne digital computer

    NASA Technical Reports Server (NTRS)

    Wolf, T. D.; Mccracken, R. C.

    1973-01-01

    Ground and flight tests were conducted to investigate the problems associated with using a strapdown inertial flight data system. The objectives of this investigation were to develop a three axis inertial attitude reference system, to evaluate a self-alignment technique, and to examine the problem of time-sharing a general purpose computer for the several tasks required of it. The performance of the strapdown platform/computer system that was developed was sufficiently accurate for the tasks attempted. For flights on the order of 45 minutes duration, attitude angle errors of + or -.035 radian (+ or -2 deg) in all axes were observed. Laboratory tests of the self-alignment technique gave accuracies of + or -.00075 radian in pitch and roll axes and + or -0.0045 radian in the yaw axis. Self-alignment flight results were inconsistent, since a stable solution was not obtained on windy days because of aircraft rocking motions.

  7. An expert system for choosing the best combination of options in a general purpose program for automated design synthesis

    NASA Technical Reports Server (NTRS)

    Rogers, J. L.; Barthelemy, J.-F. M.

    1986-01-01

    An expert system called EXADS has been developed to aid users of the Automated Design Synthesis (ADS) general purpose optimization program. ADS has approximately 100 combinations of strategy, optimizer, and one-dimensional search options from which to choose. It is difficult for a nonexpert to make this choice. This expert system aids the user in choosing the best combination of options based on the users knowledge of the problem and the expert knowledge stored in the knowledge base. The knowledge base is divided into three categories; constrained problems, unconstrained problems, and constrained problems being treated as unconstrained problems. The inference engine and rules are written in LISP, contains about 200 rules, and executes on DEC-VAX (with Franz-LISP) and IBM PC (with IQ-LISP) computers.

  8. General-purpose heat source: Research and development program. Radioisotope thermoelectric generator impact tests: RTG-1 and RTG-2

    SciTech Connect

    Reimus, M.A.H.; Hinckley, J.E.; George, T.G.

    1996-07-01

    The General-Purpose Heat Source (GPHS) provides power for space missions by transmitting the heat of {sup 238}Pu decay to an array of thermoelectric elements in a radioisotope thermoelectric generator (RTG). Because the potential for a launch abort or return from orbit exists for any space mission, the heat source response to credible accident scenarios is being evaluated. The first two RTG Impact Tests were designed to provide information on the response of a fully loaded RTG to end-on impact against a concrete target. The results of these tests indicated that at impact velocities up to 57 m/s the converter shell and internal components protect the GPHS capsules from excessive deformation. At higher velocities, some of the internal components of the RTG interact with the GPHS capsules to cause excessive localized deformation and failure.

  9. General-purpose heat source: Research and development program, radioisotope thermoelectric generator/thin fragment impact test

    SciTech Connect

    Reimus, M.A.H.; Hinckley, J.E.

    1996-11-01

    The general-purpose heat source provides power for space missions by transmitting the heat of {sup 238}Pu decay to an array of thermoelectric elements in a radioisotope thermoelectric generator (RTG). Because the potential for a launch abort or return from orbit exists for any space mission, the heat source response to credible accident scenarios is being evaluated. This test was designed to provide information on the response of a loaded RTG to impact by a fragment similar to the type of fragment produced by breakup of the spacecraft propulsion module system. The results of this test indicated that impact by a thin aluminum fragment traveling at 306 m/s may result in significant damage to the converter housing, failure of one fueled clad, and release of a small quantity of fuel.

  10. Fast-response, high-precision carbon monoxide sensor using a tunable diode laser absorption technique

    NASA Technical Reports Server (NTRS)

    Sachse, Glen W.; Hill, Gerald F.; Wade, Larry O.; Perry, Murray G.

    1987-01-01

    A tunable diode laser instrument, denoted as DACOM (Differential Absorption CO Measurement), has been developed to meet the fast-response, high-precision CO measurement needs of the GTE (Global Tropospheric Experiment) program. Under the GTE program, DACOM participated in the three field missions of CITE 1 (Chemical Instrumentation Test and Evaluation 1), a project involving the intercomparison of trace gas measurement techniques. DACOM performance, including analyses of measurement error sources, is discussed for the ground-based mission at Wallops Island, VA (summer 1983), and two missions on the NASA CV-990 (fall 1983 and spring 1984). Examples of fast-response (about 1 s), high-precision (+ or - 1 part per billion by volume, + or - 1.5 percent of reading) airborne data are included to illustrate the capability of this instrument.

  11. Geological effect of high-precise gravimetric and magnetic surveys in Yangqiao prospect in Biyang depression

    SciTech Connect

    Rongyuan, W.; Zhaoling, Y.; Zhangmin, G.; Xiaoliu, W. )

    1991-01-01

    This paper reports on Yangqiao prospect in Biyang depression which is an area where very high-degree exploration has been done. The complicated seismic and geological conditions in the border area of the depression cause very poor seismic data, so that exact structural configuration can not be known. Thus, high-precise gravimetric-magnetic surveys were done. The interpretations of gravimetric and magnetic data are mainly based on the properties of gravitational and magnetic fields. Local gravimetric and magnetic anomalies at Wangzhuang were discovered by performing forward fitting of observed gravimetric and magnetic data. The repeated seismic interpretation by reference to the gravimetric-magnetic interpretation result confirms the existence of an anticline structure in the local gravimetric and magnetic anomaly area. The effect of direct hydrocarbon prediction using high- precise gravimetric and magnetic data were checked in known Anpeng and Xiaermen oil fields. The check shows good effect.

  12. Process influences and correction possibilities for high precision injection molded freeform optics

    NASA Astrophysics Data System (ADS)

    Dick, Lars; Risse, Stefan; Tünnermann, Andreas

    2016-08-01

    Modern injection molding processes offer a cost-efficient method for manufacturing high precision plastic optics for high volume applications. Besides form deviation of molded freeform optics, internal material stress is a relevant influencing factor for the functionality of a freeform optics in an optical system. This paper illustrates dominant influence parameters of an injection molding process relating to form deviation and internal material stress based on a freeform demonstrator geometry. Furthermore, a deterministic and efficient way for 3D mold correcting of systematic, asymmetrical shrinkage errors is shown to reach micrometer range shape accuracy at diameters up to 40 mm. In a second case, a stress-optimized parameter combination using unusual molding conditions was 3D corrected to reach high precision and low stress freeform polymer optics.

  13. VizieR Online Data Catalog: High-precision abundances for stars with planets (Ramirez+, 2014)

    NASA Astrophysics Data System (ADS)

    Ramirez, I.; Melendez, J.; Asplund, M.

    2013-11-01

    High-precision stellar parameters and chemical abundances are presented for 111 stars; 52 of them are late-F type dwarfs and 59 are metal-rich solar analogs. The atomic linelist employed in the derivation of chemical abundances is also given. This linelist includes hyperfine structure parameters for some species. The stars' isochrone masses and ages are also reported, along with estimates of chromospheric activity. (5 data files).

  14. High-precision gravity network to monitor temporal variations in gravity across Yucca Mountain, Nevada

    SciTech Connect

    Harris, R.N.; Ponce, D.A.

    1988-12-31

    Repeatable high-precision gravity surveys provide a method of monitoring temporal variations in the gravity field. Fluctuations in the gravity field may indicate water table changes, crustal deformation, or precursors to volcanism and earthquakes. This report describes a high-precision gravity loop which has been established across Yucca Mountain, Nevada in support of the Nevada Nuclear Waste Storage Investigations (NNWSI) program. The purpose of this gravity loop is to monitor temporal variations in gravity across Yucca Mountain in an effort to interpret and predict the stability of the tectonic framework and changes in the subsurface density field. Studies of the tectonic framework which include volcanic hazard seismicity, and faulting studies are in progress. Repeat high-precision gravity surveys are less expensive and can be made more rapidly than a corresponding leveling survey. High-precision gravity surveys are capable of detecting elevation changes of 3 to 5 cm, and thus can be employed as an efficient tool for monitoring vertical crustal movements while supplementing or partially replacing leveling data. The Yucca Mountain gravity network has been tied to absolute gravity measurements established in southern Nevada. These ties provide an absolute datum for comparing repeat occupations of the gravity network, and provide a method of monitoring broad-scale changes in gravity. Absolute gravity measurements were also made at the bottom and top of the Charleston Peak calibration loop in southern Nevada. These absolute gravity measurements provide local control of calibrating gravity meters over the gravity ranges observed at Yucca Mountain. 13 refs., 7 figs., 3 tabs.

  15. Ultrashort pulse Cr4+:YAG laser for high precision infrared frequency interval measurements

    PubMed Central

    Alcock, A. J.; Ma, P.; Poole, P. J.; Chepurov, S.; Czajkowski, A.; Bernard, J. E.; Madej, A. A.; Fraser, J. M.; Mitchell, I. V.; Sorokina, I. T.; Sorokin, E.

    2010-01-01

    A cavity stabilized, SESAM mode-locked Cr4+:YAG laser capable of generating sub-100 fs pulses has been developed. Locking the 130-MHz pulse repetition frequency to that of a hydrogen maser-referenced frequency synthesizer provides a 30-nm wide frequency comb for the 1530-nm wavelength region. In conjunction with a pair of acetylene stabilized, external cavity diode lasers, this laser provides a high precision measurement tool for the determination of acetylene transition frequencies. PMID:19498916

  16. Selection and use of TLDS for high precision NERVA shielding measurements

    NASA Technical Reports Server (NTRS)

    Woodsum, H. C.

    1972-01-01

    An experimental evaluation of thermoluminescent dosimeters was performed in order to select high precision dosimeters for a study whose purpose is to measure gamma streaming through the coolant passages of a simulated flight type internal NERVA reactor shield. Based on this study, the CaF2 chip TLDs are the most reproducible dosimeters with reproducibility generally within a few percent, but none of the TLDs tested met the reproducibility criterion of plus or minus 2%.

  17. Development of High Precision Metal Micro-Electro-Mechanical-Systems Column for Portable Surface Acoustic Wave Gas Chromatograph

    NASA Astrophysics Data System (ADS)

    Iwaya, Takamitsu; Akao, Shingo; Sakamoto, Toshihiro; Tsuji, Toshihiro; Nakaso, Noritaka; Yamanaka, Kazushi

    2012-07-01

    In the field of environmental measurement and security, a portable gas chromatograph (GC) is required for the on-site analysis of multiple hazardous gases. Although the gas separation column has been downsized using micro-electro-mechanical-systems (MEMS) technology, an MEMS column made of silicon and glass still does not have sufficient robustness and a sufficiently low fabrication cost for a portable GC. In this study, we fabricated a robust and inexpensive high-precision metal MEMS column by combining diffusion-bonded etched stainless-steel plates with alignment evaluation using acoustic microscopy. The separation performance was evaluated using a desktop GC with a flame ionization detector and we achieved the high separation performance comparable to the best silicon MEMS column fabricated using a dynamic coating method. As an application, we fabricated a palm-size surface acoustic wave (SAW) GC combining this column with a ball SAW sensor and succeeded in separating and detecting a mixture of volatile organic compounds.

  18. Time-resolved optical spectrometer based on a monolithic array of high-precision TDCs and SPADs

    NASA Astrophysics Data System (ADS)

    Tamborini, Davide; Markovic, Bojan; Di Sieno, Laura; Contini, Davide; Bassi, Andrea; Tisa, Simone; Tosi, Alberto; Zappa, Franco

    2013-12-01

    We present a compact time-resolved spectrometer suitable for optical spectroscopy from 400 nm to 1 μm wavelengths. The detector consists of a monolithic array of 16 high-precision Time-to-Digital Converters (TDC) and Single-Photon Avalanche Diodes (SPAD). The instrument has 10 ps resolution and reaches 70 ps (FWHM) timing precision over a 160 ns full-scale range with a Differential Non-Linearity (DNL) better than 1.5 % LSB. The core of the spectrometer is the application-specific integrated chip composed of 16 pixels with 250 μm pitch, containing a 20 μm diameter SPAD and an independent TDC each, fabricated in a 0.35 μm CMOS technology. In front of this array a monochromator is used to focus different wavelengths into different pixels. The spectrometer has been used for fluorescence lifetime spectroscopy: 5 nm spectral resolution over an 80 nm bandwidth is achieved. Lifetime spectroscopy of Nile blue is demonstrated.

  19. Comparison of nitrous oxide (N2O) analyzers for high-precision measurements of atmospheric mole fractions

    NASA Astrophysics Data System (ADS)

    Lebegue, Benjamin; Schmidt, Martina; Ramonet, Michel; Wastine, Benoit; Yver Kwok, Camille; Laurent, Olivier; Belviso, Sauveur; Guemri, Ali; Philippon, Carole; Smith, Jeremiah; Conil, Sebastien

    2016-03-01

    Over the last few decades, in situ measurements of atmospheric N2O mole fractions have been performed using gas chromatographs (GCs) equipped with electron capture detectors. This technique, however, becomes very challenging when trying to detect the small variations of N2O as the detectors are highly nonlinear and the GCs at remote stations require a considerable amount of maintenance by qualified technicians to maintain good short-term and long-term repeatability. With new robust optical spectrometers now available for N2O measurements, we aim to identify a robust and stable analyzer that can be integrated into atmospheric monitoring networks, such as the Integrated Carbon Observation System (ICOS). In this study, we present the most complete comparison of N2O analyzers, with seven analyzers that were developed and commercialized by five different companies. Each instrument was characterized during a time period of approximately 8 weeks. The test protocols included the characterization of the short-term and long-term repeatability, drift, temperature dependence, linearity and sensitivity to water vapor. During the test period, ambient air measurements were compared under field conditions at the Gif-sur-Yvette station. All of the analyzers showed a standard deviation better than 0.1 ppb for the 10 min averages. Some analyzers would benefit from improvements in temperature stability to reduce the instrument drift, which could then help in reducing the frequency of calibrations. For most instruments, the water vapor correction algorithms applied by companies are not sufficient for high-precision atmospheric measurements, which results in the need to dry the ambient air prior to analysis.

  20. High precision position control of voice coil motor based on single neuron PID

    NASA Astrophysics Data System (ADS)

    Li, Liyi; Chen, Qiming; Tan, Guangjun; Zhu, He

    2013-01-01

    Voice coil motor(VCM) is widely used in high-speed and high-precision positioning control system in recent years. However, there are system uncertainty, nonlinear, modeling error, and external disturbances in the high-precision positioning control system, traditional PID control method is difficult to achieve precise positioning control. In this paper, a new position control strategy with a single neuron controller which has the capability of self-studying and self-adapting composed with PID controller is put forward, and the feedforward compensator is added to improve the dynamic response of the system in the position loop. Moreover, the disturbance observer is designed to suppress model parameter uncertainty and external disturbance signal in the current loop. In addition, the problem of high precision position control of VCM under the influence of significant disturbances is addressed, which including the gas-lubricated damping, the spring, the back EMF and ripple forces, on the basis, the mathematical model of VCM is established accurately. The simulation results show that this kind of controller can improve the dynamic characteristic and strengthen the robustness of the system, and the current loop with disturbance observer can also restrain disturbance and high frequency.

  1. High precision measurement of the proton charge radius: The PRad experiment

    SciTech Connect

    Meziane, Mehdi

    2013-11-01

    The recent high precision measurements of the proton charge radius performed at PSI from muonic hydrogen Lamb shift puzzled the hadronic physics community. A value of 0.8418 {+-} 0.0007 fm was extracted which is 7{sigma} smaller than the previous determinations obtained from electron-proton scattering experiments and based on precision spectroscopy of electronic hydrogen. An additional extraction of the proton charge radius from electron scattering at Mainz is also in good agreement with these "electronic" determinations. An independent measurement of the proton charge radius from unpolarized elastic ep scattering using a magnetic spectrometer free method was proposed and fully approved at Jefferson Laboratory in June 2012. This novel technique uses the high precision calorimeter HyCal and a windowless hydrogen gas target which makes possible the extraction of the charge radius at very forward angles and thus very low momentum transfer Q{sup 2} up to 10{sup -4} (GeV/c){sup 2} with an unprecedented sub-percent precision for this type of experiment. In this paper, after a review of the recent progress on the proton charge radius extraction and the new high precision experiment PRad will be presented.

  2. High precision measurement of the proton charge radius: The PRad experiment

    SciTech Connect

    Meziane, Mehdi; Collaboration: PRad Collaboration

    2013-11-07

    The recent high precision measurements of the proton charge radius performed at PSI from muonic hydrogen Lamb shift puzzled the hadronic physics community. A value of 0.8418 ± 0.0007 fm was extracted which is 7σ smaller than the previous determinations obtained from electron-proton scattering experiments and based on precision spectroscopy of electronic hydrogen. An additional extraction of the proton charge radius from electron scattering at Mainz is also in good agreement with these 'electronic' determinations. An independent measurement of the proton charge radius from unpolarized elastic ep scattering using a magnetic spectrometer free method was proposed and fully approved at Jefferson Laboratory in June 2012. This novel technique uses the high precision calorimeter HyCal and a windowless hydrogen gas target which makes possible the extraction of the charge radius at very forward angles and thus very low momentum transfer Q{sup 2} up to 10{sup −4} (GeV/c){sup 2} with an unprecedented sub-percent precision for this type of experiment. In this paper, after a review of the recent progress on the proton charge radius extraction and the new high precision experiment PRad will be presented.

  3. High-precision extreme-mass-ratio inspirals in black hole perturbation theory and post-Newtonian theory

    NASA Astrophysics Data System (ADS)

    Forseth, Erik Robert

    The recent detection of gravitational wave (GW) signal GW150914 by the Advanced LIGO experiment has inaugurated the long-anticipated era of GW astronomy. This event saw the merger of two black holes, having roughly 36 and 29 solar masses, as well as the ringdown of the resulting 62 solar mass black hole. The energy emitted in gravitational radiation was equivalent to about three solar masses. The detection underscored the importance of theoretical models for not only isolating signal from noise, but especially for the accurate estimation of source parameters. The two-body problem in Einstein's general theory has no exact solution, and so the development of these models is highly nontrivial. We present in this thesis a set of original results on the dynamics of the inspiral for a class of binary systems known as extreme-mass-ratio inspirals (EMRIs), comprised of a small compact object (generically a stellar mass black hole) in orbit about a supermassive black hole. Our work also has potential application to intermediate-mass-ratio inspirals (IMRIs). IMRIs are thought to be a potentially strong source for ground-based GW experiments such as Advanced LIGO/VIRGO. Though not generally a good source for the LIGO network, EMRIs on the other hand are well-suited for detection by proposed space-based detectors, e.g. eLISA. Our work particularly constitutes a program of developing computational tools, methods, and results for eccentric E/IMRIs, which are thought to be astrophysically important but are much more challenging to model theoretically compared with circular orbits. We begin with a brief review of relevant parts of general relativity (GR) theory, followed by overviews of two prevailing approximation formalisms in GR, black hole perturbation (BHP) theory and post-Newtonian (PN) theory. Our first original result is a high-precision computation of the first-order gravitational metric perturbation using a Lorenz gauge frequency domain procedure. Next, we present a fast

  4. STICK: Spike Time Interval Computational Kernel, a Framework for General Purpose Computation Using Neurons, Precise Timing, Delays, and Synchrony.

    PubMed

    Lagorce, Xavier; Benosman, Ryad

    2015-11-01

    There has been significant research over the past two decades in developing new platforms for spiking neural computation. Current neural computers are primarily developed to mimic biology. They use neural networks, which can be trained to perform specific tasks to mainly solve pattern recognition problems. These machines can do more than simulate biology; they allow us to rethink our current paradigm of computation. The ultimate goal is to develop brain-inspired general purpose computation architectures that can breach the current bottleneck introduced by the von Neumann architecture. This work proposes a new framework for such a machine. We show that the use of neuron-like units with precise timing representation, synaptic diversity, and temporal delays allows us to set a complete, scalable compact computation framework. The framework provides both linear and nonlinear operations, allowing us to represent and solve any function. We show usability in solving real use cases from simple differential equations to sets of nonlinear differential equations leading to chaotic attractors. PMID:26378879

  5. GPHS-RTG system explosion test direct course experiment 5000. [General Purpose Heat Source-Radioisotope Thermoelectric Generator

    SciTech Connect

    Not Available

    1984-03-01

    The General Purpose Heat Source-Radioisotope Thermoelectric Generator (GPHS-RTG) has been designed and is being built to provide electrical power for spacecrafts to be launched on the Space Shuttle. The objective of the RTG System Explosion Test was to expose a mock-up of the GPHS-RTG with a simulated heat source to the overpressure and impulse representative of a potential upper magnitude explosion of the Space Shuttle. The test was designed so that the heat source module would experience an overpressure at which the survival of the fuel element cladding would be expected to be marginal. Thus, the mock-up was placed where the predicted incident overpressure would be 1300 psi. The mock-up was mounted in an orientation representative of the launch configuration on the spacecraft to be used on the NASA Galileo Mission. The incident overpressure measured was in the range of 1400 to 2100 psi. The mock-up and simulated heat source were destroyed and only very small fragments were recovered. This damage is believed to have resulted from a combination of the overpressure and impact by very high velocity fragments from the ANFO sphere. Post-test analysis indicated that extreme working of the iridium clad material occurred, indicative of intensive impulsive loading on the metal.

  6. Cafe Variome: general-purpose software for making genotype-phenotype data discoverable in restricted or open access contexts.

    PubMed

    Lancaster, Owen; Beck, Tim; Atlan, David; Swertz, Morris; Thangavelu, Dhiwagaran; Veal, Colin; Dalgleish, Raymond; Brookes, Anthony J

    2015-10-01

    Biomedical data sharing is desirable, but problematic. Data "discovery" approaches-which establish the existence rather than the substance of data-precisely connect data owners with data seekers, and thereby promote data sharing. Cafe Variome (http://www.cafevariome.org) was therefore designed to provide a general-purpose, Web-based, data discovery tool that can be quickly installed by any genotype-phenotype data owner, or network of data owners, to make safe or sensitive content appropriately discoverable. Data fields or content of any type can be accommodated, from simple ID and label fields through to extensive genotype and phenotype details based on ontologies. The system provides a "shop window" in front of data, with main interfaces being a simple search box and a powerful "query-builder" that enable very elaborate queries to be formulated. After a successful search, counts of records are reported grouped by "openAccess" (data may be directly accessed), "linkedAccess" (a source link is provided), and "restrictedAccess" (facilitated data requests and subsequent provision of approved records). An administrator interface provides a wide range of options for system configuration, enabling highly customized single-site or federated networks to be established. Current uses include rare disease data discovery, patient matchmaking, and a Beacon Web service.

  7. GPU Based General-Purpose Parallel computing to Solve Nuclear Reactor In-Core fuel Management Design and Operation Problem

    SciTech Connect

    Prayudhatama, D.; Waris, A.; Kurniasih, N.; Kurniadi, R.

    2010-06-22

    In-core fuel management study is a crucial activity in nuclear power plant design and operation. Its common problem is to find an optimum arrangement of fuel assemblies inside the reactor core. Main objective for this activity is to reduce the cost of generating electricity, which can be done by altering several physical properties of the nuclear reactor without violating any of the constraints imposed by operational and safety considerations. This research try to address the problem of nuclear fuel arrangement problem, which is, leads to the multi-objective optimization problem. However, the calculation of the reactor core physical properties itself is a heavy computation, which became obstacle in solving the optimization problem by using genetic algorithm optimization.This research tends to address that problem by using the emerging General Purpose Computation on Graphics Processing Units (GPGPU) techniques implemented by C language for CUDA (Compute Unified Device Architecture) parallel programming. By using this parallel programming technique, we develop parallelized nuclear reactor fitness calculation, which is involving numerical finite difference computation. This paper describes current prototype of the parallel algorithm code we have developed on CUDA, that performs one hundreds finite difference calculation for nuclear reactor fitness evaluation in parallel by using GPU G9 Hardware Series developed by NVIDIA.

  8. Progress Towards a High-Precision Infrared Spectroscopic Survey of the H_3^+ Ion

    NASA Astrophysics Data System (ADS)

    Perry, Adam J.; Hodges, James N.; Markus, Charles R.; Kocheril, G. Stephen; Jenkins, Paul A., II; McCall, Benjamin J.

    2015-06-01

    The trihydrogen cation, H_3^+, represents one of the most important and fundamental molecular systems. Having only two electrons and three nuclei, H_3^+ is the simplest polyatomic system and is a key testing ground for the development of new techniques for calculating potential energy surfaces and predicting molecular spectra. Corrections that go beyond the Born-Oppenheimer approximation, including adiabatic, non-adiabatic, relativistic, and quantum electrodynamic corrections are becoming more feasible to calculate. As a result, experimental measurements performed on the H_3^+ ion serve as important benchmarks which are used to test the predictive power of new computational methods. By measuring many infrared transitions with precision at the sub-MHz level it is possible to construct a list of the most highly precise experimental rovibrational energy levels for this molecule. Until recently, only a select handful of infrared transitions of this molecule have been measured with high precision (˜ 1 MHz). Using the technique of Noise Immune Cavity Enhanced Optical Heterodyne Velocity Modulation Spectroscopy, we are aiming to produce the largest high-precision spectroscopic dataset for this molecule to date. Presented here are the current results from our survey along with a discussion of the combination differences analysis used to extract the experimentally determined rovibrational energy levels. O. Polyansky, et al., Phil. Trans. R. Soc. A (2012), 370, 5014. M. Pavanello, et al., J. Chem. Phys. (2012), 136, 184303. L. Diniz, et al., Phys. Rev. A (2013), 88, 032506. L. Lodi, et al., Phys. Rev. A (2014), 89, 032505. J. Hodges, et al., J. Chem. Phys (2013), 139, 164201.

  9. Proceedings, High-Precision $\\alpha_s$ Measurements from LHC to FCC-ee

    SciTech Connect

    d'Enterria, David; Skands, Peter Z.

    2015-01-01

    This document provides a writeup of all contributions to the workshop on "High precision measurements of $\\alpha_s$: From LHC to FCC-ee" held at CERN, Oct. 12--13, 2015. The workshop explored in depth the latest developments on the determination of the QCD coupling $\\alpha_s$ from 15 methods where high precision measurements are (or will be) available. Those include low-energy observables: (i) lattice QCD, (ii) pion decay factor, (iii) quarkonia and (iv) $\\tau$ decays, (v) soft parton-to-hadron fragmentation functions, as well as high-energy observables: (vi) global fits of parton distribution functions, (vii) hard parton-to-hadron fragmentation functions, (viii) jets in $e^\\pm$p DIS and $\\gamma$-p photoproduction, (ix) photon structure function in $\\gamma$-$\\gamma$, (x) event shapes and (xi) jet cross sections in $e^+e^-$ collisions, (xii) W boson and (xiii) Z boson decays, and (xiv) jets and (xv) top-quark cross sections in proton-(anti)proton collisions. The current status of the theoretical and experimental uncertainties associated to each extraction method, the improvements expected from LHC data in the coming years, and future perspectives achievable in $e^+e^-$ collisions at the Future Circular Collider (FCC-ee) with $\\cal{O}$(1--100 ab$^{-1}$) integrated luminosities yielding 10$^{12}$ Z bosons and jets, and 10$^{8}$ W bosons and $\\tau$ leptons, are thoroughly reviewed. The current uncertainty of the (preliminary) 2015 strong coupling world-average value, $\\alpha_s(m_Z)$ = 0.1177 $\\pm$ 0.0013, is about 1\\%. Some participants believed this may be reduced by a factor of three in the near future by including novel high-precision observables, although this opinion was not universally shared. At the FCC-ee facility, a factor of ten reduction in the $\\alpha_s$ uncertainty should be possible, mostly thanks to the huge Z and W data samples available.

  10. High-precision lattice calculation of the decay constants fB and fBs

    NASA Astrophysics Data System (ADS)

    Detar, Carleton; Bazavov, Alexei; Bernard, Claude; Bouchard, Christopher; Brown, Nathan; Du, Daping; El Khadra, Aida; Freeland, Elizabeth; Gamiz, Elvira; Gottlieb, Steven; Na, Heechang; Heller, Urs; Komijani, Javad; Kronfeld, Andreas; Laiho, John; MacKenzie, Paul; Neil, Ethan; Simone, James; Sugar, Robert; Toussaint, Douglas; van de Water, Ruth; Zhou, Ran; Fermilab Lattice Collaboration; MILC Collaboration

    2016-03-01

    We present preliminary, high-precision results for the hadronic decay constants of the B and the Bs mesons from lattice QCD simulations using a highly improved quark formulation for both heavy and light valence quarks. Calculations are carried out with several heavy valence-quark masses on lattice ensembles with 2+1+1 flavors of HISQ sea quarks at five lattice spacings and three light sea quark mass ratios mud /ms , including approximately physical sea quark masses. This range of parameters provides excellent control of the continuum limit and of heavy-quark discretization errors. Present affiliation: Ohio Supercomputer Center.

  11. Highly precise digital image stabilization scheme for a hybrid stabilizing system

    NASA Astrophysics Data System (ADS)

    Kim, Jin-Hyung; Byun, Keun-Yung; Ko, Sung-Jea

    2010-07-01

    We propose a highly precise digital image stabilization (DIS) scheme for a hybrid stabilizing system. The stabilizing system adopts a hybrid method of using both optical image stabilization (OIS) and DIS. In the stabilizing system, OIS prestabilizes the original unstable image using gyro-sensors, and the resultant image obtained from OIS is post-stabilized using DIS to remove the residual jitters less than one pixel. The proposed DIS, which is newly designed using control-grid interpolation, can remove not only translational jitters but also rotational ones simultaneously. Experimental results show that the proposed hybrid image stabilizer achieves considerable performance improvement against conventional stabilization techniques.

  12. A Fission Time Projection Chamber for High Precision Cross Section Measurements

    NASA Astrophysics Data System (ADS)

    Snyder, Lucas; Greife, Uwe

    2010-11-01

    The design of next generation nuclear reactors and other nuclear applications are increasingly dependent on advanced simulations. Sensitivity studies have shown a need for high precision nuclear data to improve the predictive capabilities of these simulations. The Neutron Induced Fission Fragment Tracking Experiment (NIFFTE) collaboration has constructed and is currently testing a prototype Time Projection Chamber (TPC) designed to measure fission cross sections to a higher accuracy than is capable with existing technology. In this talk, I will discuss the status of the fission TPC and progress on collecting the first set of data from ^252Cf spontaneous fission.

  13. A simple high-precision Jacob's staff design for the high-resolution stratigrapher

    USGS Publications Warehouse

    Elder, W.P.

    1989-01-01

    The new generation of high-resolution stratigraphic research depends upon detailed bed-by-bed analysis to enhance regional correlation potential. The standard Jacob's staff is not an efficient and precise tool for measuring thin-bedded strata. The high-precision Jacob's staff design presented and illustrated in this paper meets the qualifications required of such an instrument. The prototype of this simple design consists of a sliding bracket that holds a Brunton-type compass at right angles to a ruled-off staff. This instrument provides rapid and accurate measurement of both thick- or thin-bedded sequences, thus decreasing field time and increasing stratigraphic precision. -Author

  14. On the recovery of gravity anomalies from high precision altimeter data

    NASA Technical Reports Server (NTRS)

    Lelgemann, D.

    1976-01-01

    A model for the recovery of gravity anomalies from high precision altimeter data is derived which consists of small correction terms to the inverse Stokes' formula. The influence of unknown sea surface topography in the case of meandering currents such as the Gulf Stream is discussed. A formula was derived in order to estimate the accuracy of the gravity anomalies from the known accuracy of the altimeter data. It is shown that for the case of known harmonic coefficients of lower order the range of integration in Stokes inverse formula can be reduced very much.

  15. Research on high precision equal-angle scanning method in rotary kiln temperature measurement system

    NASA Astrophysics Data System (ADS)

    Dai, Shaosheng; Guo, Zhongyuan; You, Changhui; Liu, Jinsong; Cheng, Yang; Tang, Huaming

    2016-05-01

    Aiming at traditional horizontal equal-angle scanning method's disadvantage of measurement error, a high precision equal-angle scanning method is proposed, the proposed method establishes a tilt scanning model by the following steps: introducing height variable, precisely calculating the viewing angle, building scanning model. The model is used to calculate scanning position on rotary kiln's surface, which helps to locate and track temperature variation. The experiment shows that the proposed method can effectively improve the precision of temperature spots' location on the rotary kiln surface.

  16. Lightweight Metal Matrix Composite Segmented for Manufacturing High-Precision Mirrors

    NASA Technical Reports Server (NTRS)

    Vudler, Vladimir

    2012-01-01

    High-precision mirrors for space applications are traditionally manufactured from one piece of material, such as lightweight glass sandwich or beryllium. The purpose of this project was to develop and test the feasibility of a manufacturing process capable of producing mirrors out of welded segments of AlBeMet(Registered Trademark) (AM162H). AlBeMet(Registered Trademark) is a HIP'd (hot isostatic pressed) material containing approximately 62% beryllium and 38% aluminum. As a result, AlBeMet shares many of the benefits of both of those materials for use in high performance mirrors, while minimizing many of their weaknesses.

  17. High-precision frequency measurements in the THz spectral region using an unstabilized femtosecond laser

    NASA Astrophysics Data System (ADS)

    Füser, Heiko; Judaschke, Rolf; Bieler, Mark

    2011-09-01

    We perform high-precision frequency measurements in the THz frequency range using an unstabilized femtosecond laser. A simple and flexible algorithm is used to correct the beating signal resulting from the THz source and one comb line of the rectified optical comb for fluctuations of the laser repetition rate. Using this technique, we demonstrate an accuracy of our measurement device as high as (9 ± 3) . 10-14 for the measurement of a 100 GHz source. This is two orders of magnitude better than previous precision measurements in this frequency range employing femtosecond lasers.

  18. The high precision control of the satellites formation for diffraction imaging

    NASA Astrophysics Data System (ADS)

    Yang, Guang; He, Liang; Song, Ting; Sun, Binglei; Hao, Tianwei

    2016-01-01

    To satisfy need of high resolution observation from space. This article elaborates a method of high precision spacecraft formation control based on file diffraction theory. Improving the spacecraft control accuracy to millimeter is a challenge. With the method in this article this challenge can be solved. The algorithm in this article concerning the vibration of spacecraft and based on dynamic modeling of even relative quaternion theory deduced a method of attitude and orbit integrated control. Using this control algorithm to simulation can get the result that it can make the spacecraft integrate formation control as the technical basis of space high resolution observation.

  19. Use of terrestrial laser scanning technology for long term high precision deformation monitoring.

    PubMed

    Vezočnik, Rok; Ambrožič, Tomaž; Sterle, Oskar; Bilban, Gregor; Pfeifer, Norbert; Stopar, Bojan

    2009-01-01

    The paper presents a new methodology for high precision monitoring of deformations with a long term perspective using terrestrial laser scanning technology. In order to solve the problem of a stable reference system and to assure the high quality of possible position changes of point clouds, scanning is integrated with two complementary surveying techniques, i.e., high quality static GNSS positioning and precise tacheometry. The case study object where the proposed methodology was tested is a high pressure underground pipeline situated in an area which is geologically unstable.

  20. High precision measurements of the neutron spin structure in Hall A at Jlab

    SciTech Connect

    Annand, R M; Cates, G; Cisbani, E; Franklin, G B; Liyanage, N; Puckett, A; Rosner, G; Wojtsekhowski, B; Zheng, X

    2012-04-01

    Conclusions of this presentation are: (1) JLab energy upgrade will offer new exciting opportunities to study the nucleon (spin) structure such as high precision, unexplored phase space, flavor decomposition; (2) Large technological efforts is in progress to optimally exploit these opportunities; (3) HallA will be the first hall to get the new beam, first experiment expected to run in 2014; (4) A1n likely one of the first experiments to take data in the new 12 GeV era; and (5) SIDIS exp. will follow in couple of years.

  1. Determination of migration monomer styrene from GPPS (general purpose polystyrene) and HIPS (high impact polystyrene) cups to hot drinks.

    PubMed

    Khaksar, Mohammad-Reza; Ghazi-Khansari, Mahmoud

    2009-03-01

    In this study, 162 samples were analysed for monomer styrene content with using high performance liquid chromatography (HPLC) method in hot tea, milk, cocoa milk. The monomer styrene content, expressed in microg/l of drink and the level of migration of styrene monomer were varied from 0.61 to 8.15 for hot tea, from 0.65 to 8.30 for hot milk, from 0.71 to 8.65 for hot cocoa milk in GPPS (general purpose polystyrene), from 0.48 to 6.85 for hot tea, from 0.61 to 7.65 for hot milk, from 0.72 to 7.78 for hot cocoa milk in HIPS (high performance polystyrene) cups in different temperatures and times. The estimated limit of detection of (HPLC) method for all samples was 0.001 mg/kg. There is linear regression for styrene monomer from 1 to 10 ng/ml. Several samples spiked with a known amount of styrene monomer. The results of the recovery in study for styrene monomer were determinate to be mean, 96.1 +/- 1.92 to 99.7 +/- 1.15%. The results of this study indicate that styrene monomer from polystyrene disposable into hot and fat drinks was migrated and this migration was highly dependent on fat content and temperature of drinks. The derived concentration of styrene monomer in this study was above the EPA (Environmental protection agency) recommended level, especially in MCLG (Maximum contaminant level goal) standard. More study is needed to further elucidate this finding.

  2. GPHS motion studies for heat pulse intervals of reentries from gravity-assist trajectories. [General Purpose Heat Source Module (GPHS)

    SciTech Connect

    Lucero, E.F.; Sharbaugh, R.C.

    1990-03-01

    Motion studies of the General Purpose Heat Source Module, GPHS, were conducted in the heat pulse interval associated with entries from earth gravity assist trajectories. The APL six-degree-of-freedom reentry program designated TMAGRA6C was used. The objectives of the studies were to (1) determine the effect of ablation on GPHS motion, and (2) determine whether the GPHS module entering the earth's atmosphere from an earth-gravity-assist trajectory has a preferred orientation during the heat pulse phase of reentry. The results are given in summary form for easy visualization of the initial conditions investigated and to provide a quick-look of the resulting motion. Detail of the motion is also given for the parameters of interest for each case studied. Selected values of initial pitch rate, roll rate, and combinations of these within the range 0[degree] to 1000[degrees]/sec were investigated for initial reentry angles of -7[degrees] (shallow) and -90[degrees] (steep) and initial angles of attack of 0[degree] (broadface to the wind) and 90[degrees]. Although the studies are not exhaustive, a sufficient number of reentry conditions (initial altitude, reentry angle, angle of attack, rotational motion) have been investigated to deduce certain trends. The results also provide information on additional reentry conditions that need to be investigated. The present results show four GPHS orientations that predominate - all with some pitch oscillations and rolling motion. These are: angles of attack, [alpha][sub R] of 0[degree], 30[degrees], 90[degrees] and tumbling. It should be assumed that all these orientations are equally probable because only combinations of two initial reentry angles, [gamma][sub 0], and two values of [alpha][sub R]. have been investigated. Further the probability for any given initial rate on orientation is not known.

  3. The EB factory project. I. A fast, neural-net-based, general purpose light curve classifier optimized for eclipsing binaries

    SciTech Connect

    Paegert, Martin; Stassun, Keivan G.; Burger, Dan M.

    2014-08-01

    We describe a new neural-net-based light curve classifier and provide it with documentation as a ready-to-use tool for the community. While optimized for identification and classification of eclipsing binary stars, the classifier is general purpose, and has been developed for speed in the context of upcoming massive surveys such as the Large Synoptic Survey Telescope. A challenge for classifiers in the context of neural-net training and massive data sets is to minimize the number of parameters required to describe each light curve. We show that a simple and fast geometric representation that encodes the overall light curve shape, together with a chi-square parameter to capture higher-order morphology information results in efficient yet robust light curve classification, especially for eclipsing binaries. Testing the classifier on the ASAS light curve database, we achieve a retrieval rate of 98% and a false-positive rate of 2% for eclipsing binaries. We achieve similarly high retrieval rates for most other periodic variable-star classes, including RR Lyrae, Mira, and delta Scuti. However, the classifier currently has difficulty discriminating between different sub-classes of eclipsing binaries, and suffers a relatively low (∼60%) retrieval rate for multi-mode delta Cepheid stars. We find that it is imperative to train the classifier's neural network with exemplars that include the full range of light curve quality to which the classifier will be expected to perform; the classifier performs well on noisy light curves only when trained with noisy exemplars. The classifier source code, ancillary programs, a trained neural net, and a guide for use, are provided.

  4. The EB Factory Project. I. A Fast, Neural-net-based, General Purpose Light Curve Classifier Optimized for Eclipsing Binaries

    NASA Astrophysics Data System (ADS)

    Paegert, Martin; Stassun, Keivan G.; Burger, Dan M.

    2014-08-01

    We describe a new neural-net-based light curve classifier and provide it with documentation as a ready-to-use tool for the community. While optimized for identification and classification of eclipsing binary stars, the classifier is general purpose, and has been developed for speed in the context of upcoming massive surveys such as the Large Synoptic Survey Telescope. A challenge for classifiers in the context of neural-net training and massive data sets is to minimize the number of parameters required to describe each light curve. We show that a simple and fast geometric representation that encodes the overall light curve shape, together with a chi-square parameter to capture higher-order morphology information results in efficient yet robust light curve classification, especially for eclipsing binaries. Testing the classifier on the ASAS light curve database, we achieve a retrieval rate of 98% and a false-positive rate of 2% for eclipsing binaries. We achieve similarly high retrieval rates for most other periodic variable-star classes, including RR Lyrae, Mira, and delta Scuti. However, the classifier currently has difficulty discriminating between different sub-classes of eclipsing binaries, and suffers a relatively low (~60%) retrieval rate for multi-mode delta Cepheid stars. We find that it is imperative to train the classifier's neural network with exemplars that include the full range of light curve quality to which the classifier will be expected to perform; the classifier performs well on noisy light curves only when trained with noisy exemplars. The classifier source code, ancillary programs, a trained neural net, and a guide for use, are provided.

  5. Prediction of the applicability of active damping elements in high-precision machines

    NASA Astrophysics Data System (ADS)

    Holterman, Jan; de Vries, Theo J. A.

    2004-07-01

    The Smart Disc project at the Drebbel Institute of the University of Twente is aimed at the development of active structural elements for high-precision machines. The active elements consist of a piezoelectric position actuator and a collocated piezoelectric force sensor. As the actuators and sensors are collocated, the elements are especially suited for implementing robust active damping. The decision whether or not to incorporate active damping elements in a high-precision machine should ideally be made in an early design stage, i.e., at a time at which only limited knowledge of the vibration problem is available. Despite the uncertainties that may exist at that stage, one would like to be able to roughly predict the amount of damping that could possibly be obtained. For that reason, the present paper is concerned with the development of an analysis tool that may help in predicting the applicability of active damping elements in a mechanical structure of which only a rough model is available. Based on extensive simulations, several practical rules of thumb are given for the requirements for the mechanical structure and the active elements, in order to enable the realisation of relative damping values as high as 10%.

  6. Accurate time delay technology in simulated test for high precision laser range finder

    NASA Astrophysics Data System (ADS)

    Chen, Zhibin; Xiao, Wenjian; Wang, Weiming; Xue, Mingxi

    2015-10-01

    With the continuous development of technology, the ranging accuracy of pulsed laser range finder (LRF) is higher and higher, so the maintenance demand of LRF is also rising. According to the dominant ideology of "time analog spatial distance" in simulated test for pulsed range finder, the key of distance simulation precision lies in the adjustable time delay. By analyzing and comparing the advantages and disadvantages of fiber and circuit delay, a method was proposed to improve the accuracy of the circuit delay without increasing the count frequency of the circuit. A high precision controllable delay circuit was designed by combining the internal delay circuit and external delay circuit which could compensate the delay error in real time. And then the circuit delay accuracy could be increased. The accuracy of the novel circuit delay methods proposed in this paper was actually measured by a high sampling rate oscilloscope actual measurement. The measurement result shows that the accuracy of the distance simulated by the circuit delay is increased from +/- 0.75m up to +/- 0.15m. The accuracy of the simulated distance is greatly improved in simulated test for high precision pulsed range finder.

  7. Optimization design about gimbal structure of high-precision autonomous celestial navigation tracking mirror system

    NASA Astrophysics Data System (ADS)

    Huang, Wei; Yang, Xiao-xu; Han, Jun-feng; Wei, Yu; Zhang, Jing; Xie, Mei-lin; Yue, Peng

    2016-01-01

    High precision tracking platform of celestial navigation with control mirror servo structure form, to solve the disadvantages of big volume and rotational inertia, slow response speed, and so on. It improved the stability and tracking accuracy of platform. Due to optical sensor and mirror are installed on the middle-gimbal, stiffness and resonant frequency requirement for high. Based on the application of finite element modality analysis theory, doing Research on dynamic characteristics of the middle-gimbal, and ANSYS was used for the finite element dynamic emulator analysis. According to the result of the computer to find out the weak links of the structure, and Put forward improvement suggestions and reanalysis. The lowest resonant frequency of optimization middle-gimbal avoid the bandwidth of the platform servo mechanism, and much higher than the disturbance frequency of carrier aircraft, and reduces mechanical resonance of the framework. Reaching provides a theoretical basis for the whole machine structure optimization design of high-precision of autonomous Celestial navigation tracking mirror system.

  8. High Precision Oxygen Three Isotope Analysis of Wild-2 Particles and Anhydrous Chondritic Interplanetary Dust Particles

    NASA Technical Reports Server (NTRS)

    Nakashima, D.; Ushikubo, T.; Zolensky, Michael E.; Weisberg, M. K.; Joswiak, D. J.; Brownlee, D. E.; Matrajt, G.; Kita, N. T.

    2011-01-01

    One of the most important discoveries from comet Wild-2 samples was observation of crystalline silicate particles that resemble chondrules and CAIs in carbonaceous chondrites. Previous oxygen isotope analyses of crystalline silicate terminal particles showed heterogeneous oxygen isotope ratios with delta(sup 18)O to approx. delta(sup 17)O down to -50% in the CAI-like particle Inti, a relict olivine grain in Gozen-sama, and an olivine particle. However, many Wild-2 particles as well as ferromagnesian silicates in anhydrous interplanetary dust particles (IDPs) showed Delta(sup 17)O values that cluster around -2%. In carbonaceous chondrites, chondrules seem to show two major isotope reservoirs with Delta(sup 17)O values at -5% and -2%. It was suggested that the Delta(sup 17)O = -2% is the common oxygen isotope reservoir for carbonaceous chondrite chondrules and cometary dust, from the outer asteroid belt to the Kuiper belt region. However, a larger dataset with high precision isotope analyses (+/-1-2%) is still needed to resolve the similarities or distinctions among Wild-2 particles, IDPs and chondrules in meteorites. We have made signifi-cant efforts to establish routine analyses of small particles (< or =10micronsm) at 1-2% precision using IMS-1280 at WiscSIMS laboratory. Here we report new results of high precision oxygen isotope analyses of Wild-2 particles and anhydrous chondritic IDPs, and discuss the relationship between the cometary dust and carbonaceous chondrite chondrules.

  9. A high-precision instrument for analyzing nonlinear dynamic behavior of bearing cage

    NASA Astrophysics Data System (ADS)

    Yang, Z.; Chen, H.; Yu, T.; Li, B.

    2016-08-01

    The high-precision ball bearing is fundamental to the performance of complex mechanical systems. As the speed increases, the cage behavior becomes a key factor in influencing the bearing performance, especially life and reliability. This paper develops a high-precision instrument for analyzing nonlinear dynamic behavior of the bearing cage. The trajectory of the rotational center and non-repetitive run-out (NRRO) of the cage are used to evaluate the instability of cage motion. This instrument applied an aerostatic spindle to support and spin test the bearing to decrease the influence of system error. Then, a high-speed camera is used to capture images when the bearing works at high speeds. A 3D trajectory tracking software tema Motion is used to track the spot which marked the cage surface. Finally, by developing the matlab program, a Lissajous' figure was used to evaluate the nonlinear dynamic behavior of the cage with different speeds. The trajectory of rotational center and NRRO of the cage with various speeds are analyzed. The results can be used to predict the initial failure and optimize cage structural parameters. In addition, the repeatability precision of instrument is also validated. In the future, the motorized spindle will be applied to increase testing speed and image processing algorithms will be developed to analyze the trajectory of the cage.

  10. High-precision three-dimensional coordinate measurement with subwavelength-aperture-fiber point diffraction interferometer

    NASA Astrophysics Data System (ADS)

    Wang, Daodang; Xu, Yangbo; Chen, Xixi; Wang, Fumin; Kong, Ming; Zhao, Jun

    2014-11-01

    To overcome the accuracy limitation due to the machining error of standard parts in measurement system, a threedimensional coordinate measurement method with subwavelength-aperture-fiber point diffraction interferometer (PDI) is proposed, in which the high-precision measurement standard is obtained from the ideal point-diffracted spherical wavefront instead of standard components. On the basis of the phase distribution demodulated from point-diffraction interference field, high-precision three-dimensional coordinate measurement is realized with numerical iteration optimization algorithm. The subwavelength-aperture fiber is used as point-diffraction source to get precise and highenergy spherical wavefront within high aperture angle range, by which the conflict between diffraction wave angle and energy in traditional PDI can be avoided. Besides, a double-iterative method based on Levenbery-Marquardt algorithm is proposed to realize precise reconstruct three-dimensional coordinate. The analysis shows that the proposed method can reach the measurement precision better than microns within a 200×200×300 (in unit of mm) working volume. This measurement method does not rely on the initial iteration value in numerical coordinate reconstruction, and also has high measurement precision, large measuring range, fast processing speed and preferable anti-noise ability. It is of great practicality for measurement of three-dimensional coordinate and calibration of measurement system.

  11. HIGH-PRECISION ASTROMETRIC MILLIMETER VERY LONG BASELINE INTERFEROMETRY USING A NEW METHOD FOR ATMOSPHERIC CALIBRATION

    SciTech Connect

    Rioja, M.; Dodson, R.

    2011-04-15

    We describe a new method which achieves high-precision very long baseline interferometry (VLBI) astrometry in observations at millimeter (mm) wavelengths. It combines fast frequency-switching observations, to correct for the dominant non-dispersive tropospheric fluctuations, with slow source-switching observations, for the remaining ionospheric dispersive terms. We call this method source-frequency phase referencing. Provided that the switching cycles match the properties of the propagation media, one can recover the source astrometry. We present an analytic description of the two-step calibration strategy, along with an error analysis to characterize its performance. Also, we provide observational demonstrations of a successful application with observations using the Very Long Baseline Array at 86 GHz of the pairs of sources 3C274 and 3C273 and 1308+326 and 1308+328 under various conditions. We conclude that this method is widely applicable to mm-VLBI observations of many target sources, and unique in providing bona fide astrometrically registered images and high-precision relative astrometric measurements in mm-VLBI using existing and newly built instruments, including space VLBI.

  12. High-precision thickness setting models for titanium alloy plate cold rolling without tension

    NASA Astrophysics Data System (ADS)

    Wang, Xiaochen; Yang, Quan; He, Fei; Sun, Youzhao; Xiao, Huifang

    2015-03-01

    Due to its highly favorable physical and chemical properties, titanium and titanium alloy are widely used in a variety of industries. Because of the low output of a single batch, plate cold rolling without tension is the most common rolling production method for titanium alloy. This method is lack of on-line thickness closed-loop control, with carefully thickness setting models for precision. A set of high-precision thickness setting models are proposed to suit the production method. Because of frequent variations in rolling specification, a model structural for the combination of analytical models and statistical models is adopted to replace the traditional self-learning method. The deformation resistance and friction factor, the primary factors which affect model precision, are considered as the objectives of statistical modeling. Firstly, the coefficient fitting of deformation resistance analytical model based on over-determined equations set is adopted. Additionally, a support vector machine(SVM) is applied to the modeling of the deformation resistance and friction factor. The setting models are applied to a 1450 plate-coiling mill for titanium alloy plate rolling, and then thickness precision is found consistently to be within 3%, exceeding the precision of traditional setting models with a self-learning method based on a large number of stable rolling data. Excellent application performance is obtained. The proposed research provides a set of high-precision thickness setting models which are well adapted to the characteristics of titanium alloy plate cold rolling without tension.

  13. Aspects of ultra-high-precision diamond machining of RSA 443 optical aluminium

    NASA Astrophysics Data System (ADS)

    Mkoko, Z.; Abou-El-Hossein, K.

    2015-08-01

    Optical aluminium alloys such as 6061-T6 are traditionally used in ultra-high precision manufacturing for making optical mirrors for aerospace and other applications. However, the optics industry has recently witnessed the development of more advanced optical aluminium grades that are capable of addressing some of the issues encountered when turning with single-point natural monocrystalline diamond cutters. The advent of rapidly solidified aluminium (RSA) grades has generally opened up new possibilities for ultra-high precision manufacturing of optical components. In this study, experiments were conducted with single-point diamond cutters on rapidly solidified aluminium RSA 443 material. The objective of this study is to observe the effects of depth of cut and feed rate at a fixed rotational speed on the tool wear rate and resulting surface roughness of diamond turned specimens. This is done to gain further understanding of the rate of wear on the diamond cutters versus the surface texture generated on the RSA 443 material. The diamond machining experiments yielded machined surfaces which are less reflective but with consistent surface roughness values. Cutting tools were observed for wear through scanning microscopy; relatively low wear pattern was evident on the diamond tool edge. The highest tool wear were obtained at higher depth of cut and increased feed rate.

  14. A high-precision instrument for analyzing nonlinear dynamic behavior of bearing cage.

    PubMed

    Yang, Z; Chen, H; Yu, T; Li, B

    2016-08-01

    The high-precision ball bearing is fundamental to the performance of complex mechanical systems. As the speed increases, the cage behavior becomes a key factor in influencing the bearing performance, especially life and reliability. This paper develops a high-precision instrument for analyzing nonlinear dynamic behavior of the bearing cage. The trajectory of the rotational center and non-repetitive run-out (NRRO) of the cage are used to evaluate the instability of cage motion. This instrument applied an aerostatic spindle to support and spin test the bearing to decrease the influence of system error. Then, a high-speed camera is used to capture images when the bearing works at high speeds. A 3D trajectory tracking software tema Motion is used to track the spot which marked the cage surface. Finally, by developing the matlab program, a Lissajous' figure was used to evaluate the nonlinear dynamic behavior of the cage with different speeds. The trajectory of rotational center and NRRO of the cage with various speeds are analyzed. The results can be used to predict the initial failure and optimize cage structural parameters. In addition, the repeatability precision of instrument is also validated. In the future, the motorized spindle will be applied to increase testing speed and image processing algorithms will be developed to analyze the trajectory of the cage. PMID:27587158

  15. The Silicon Pixel Detector for ALICE Experiment

    SciTech Connect

    Fabris, D.; Bombonati, C.; Dima, R.; Lunardon, M.; Moretto, S.; Pepato, A.; Bohus, L. Sajo; Scarlassara, F.; Segato, G.; Shen, D.; Turrisi, R.; Viesti, G.; Anelli, G.; Boccardi, A.; Burns, M.; Campbell, M.; Ceresa, S.; Conrad, J.; Kluge, A.; Kral, M.

    2007-10-26

    The Inner Tracking System (ITS) of the ALICE experiment is made of position sensitive detectors which have to operate in a region where the track density may be as high as 50 tracks/cm{sup 2}. To handle such densities detectors with high precision and granularity are mandatory. The Silicon Pixel Detector (SPD), the innermost part of the ITS, has been designed to provide tracking information close to primary interaction point. The assembly of the entire SPD has been completed.

  16. High-precision comparison of the antiproton-to-proton charge-to-mass ratio.

    PubMed

    Ulmer, S; Smorra, C; Mooser, A; Franke, K; Nagahama, H; Schneider, G; Higuchi, T; Van Gorp, S; Blaum, K; Matsuda, Y; Quint, W; Walz, J; Yamazaki, Y

    2015-08-13

    Invariance under the charge, parity, time-reversal (CPT) transformation is one of the fundamental symmetries of the standard model of particle physics. This CPT invariance implies that the fundamental properties of antiparticles and their matter-conjugates are identical, apart from signs. There is a deep link between CPT invariance and Lorentz symmetry--that is, the laws of nature seem to be invariant under the symmetry transformation of spacetime--although it is model dependent. A number of high-precision CPT and Lorentz invariance tests--using a co-magnetometer, a torsion pendulum and a maser, among others--have been performed, but only a few direct high-precision CPT tests that compare the fundamental properties of matter and antimatter are available. Here we report high-precision cyclotron frequency comparisons of a single antiproton and a negatively charged hydrogen ion (H(-)) carried out in a Penning trap system. From 13,000 frequency measurements we compare the charge-to-mass ratio for the antiproton (q/m)p- to that for the proton (q/m)p and obtain (q/m)p-/(q/m)p − 1 =1(69) × 10(-12). The measurements were performed at cyclotron frequencies of 29.6 megahertz, so our result shows that the CPT theorem holds at the atto-electronvolt scale. Our precision of 69 parts per trillion exceeds the energy resolution of previous antiproton-to-proton mass comparisons as well as the respective figure of merit of the standard model extension by a factor of four. In addition, we give a limit on sidereal variations in the measured ratio of <720 parts per trillion. By following the arguments of ref. 11, our result can be interpreted as a stringent test of the weak equivalence principle of general relativity using baryonic antimatter, and it sets a new limit on the gravitational anomaly parameter of |α − 1| < 8.7 × 10(-7). PMID:26268189

  17. Development of a facility for high-precision irradiation of cells with carbon ions

    SciTech Connect

    Goethem, Marc-Jan van; Niemantsverdriet, Maarten; Brandenburg, Sytze; Langendijk, Johannes A.; Coppes, Robert P.; Luijk, Peter van

    2011-01-15

    Purpose: Compared to photons, using particle radiation in radiotherapy reduces the dose and irradiated volume of normal tissues, potentially reducing side effects. The biological effect of dose deposited by particles such as carbon ions, however, differs from that of dose deposited by photons. The inaccuracy in models to estimate the biological effects of particle radiation remains the most important source of uncertainties in particle therapy. Improving this requires high-precision studies on biological effects of particle radiation. Therefore, the authors aimed to develop a facility for reproducible and high-precision carbon-ion irradiation of cells in culture. The combined dose nonuniformity in the lateral and longitudinal direction should not exceed {+-}1.5%. Dose to the cells from particles than other carbon ions should not exceed 5%. Methods: A uniform lateral dose distribution was realized using a single scatter foil and quadrupole magnets. A modulator wheel was used to create a uniform longitudinal dose distribution. The choice of beam energy and the optimal design of these components was determined using GEANT4 and SRIM Monte Carlo simulations. Verification of the uniformity of the dose distribution was performed using a scintillating screen (lateral) and a water phantom (longitudinal). The reproducibility of dose delivery between experiments was assessed by repeated measurements of the spatial dose distribution. Moreover, the reproducibility of dose-response measurements was tested by measuring the survival of irradiated HEK293 cells in three independent experiments. Results: The relative contribution of dose from nuclear reaction fragments to the sample was found to be <5% when using 90 MeV/u carbon ions. This energy still allows accurate dosimetry conforming to the IAEA Report TRS-398, facilitating comparison to dose-effect data obtained with other radiation qualities. A 1.3 mm long spread-out Bragg peak with a diameter of 30 mm was created, allowing

  18. Capability study for ozone high-precision retrieval with JEM/SMILES

    NASA Astrophysics Data System (ADS)

    Takahashi, Chikako; Suzuki, Makoto; Ochiai, Satoshi; Takayanagi, Masahiro

    One of the most unique characteristics of JEM/SMILES observation is its high sensitivity (500K system noise by employing 4K cooled SIS mixer) in detecting atmospheric limb emission in the submillimeter wave range, which are band A (624.3-625.5 GHz), band B (625.1-626.3 GHz), and band C (649.1-650.3 GHz). It observes limb emission from atmospheric minor constituents in the stratosphere, such as O3 , ClO, HCl, HNO3 , HOCl, CH3 CN, HO2 , BrO, O3 isotopes etc. The JEM/SMILES mission is mainly devoted to studying precise halogen chemistry related to ozone destruction. Spatial coverage is near global, that is the nominal latitude coverage is 38S - 65N owing to tilting the antenna beam to 45 degree left from the direction of orbital motion. It is highly expected that SMILES observation path encounters the atmosphere in the elongated polar voltex toward lower latitude in the northern hemisphere. The sensitivity of SMILES can be utilized for its unique observations, one is the detection of trace species which has never been observed in acceptable precision, and the other is high precision observation of major species such as O3 and HCl. This paper discusses how the ozone high-precision retrieval with the JEM/SMILES can be achieved based on the operational retrieval algorithm. The JEM/SMILES observes ozone absorption line at 625.37GHz in lower observation bands, band A and band B. As the JEM/SMILES is a high sensitive sensor, the high-precision retrieval is expected, the minimum precision of retrieved ozone height profile is 0.5% at about 30km under ideal condition, which is better than existing similar sensors, such as Aura/MLS and Odin/SMR. It is also discussed height resolutions (3.5-4.1 km nominally determined by the instrument) as trade off with precision. Thus these two factors should be decided by a kind of trade-off considering scientific requirements. The information content is used to optimize these factors and we clarify the precision, the height resolution, and

  19. Determination of the half-life of 213Fr with high precision

    NASA Astrophysics Data System (ADS)

    Fisichella, M.; Musumarra, A.; Farinon, F.; Nociforo, C.; Del Zoppo, A.; Figuera, P.; La Cognata, M.; Pellegriti, M. G.; Scuderi, V.; Torresi, D.; Strano, E.

    2013-07-01

    High-precision measurement of half-life and Qα value of neutral and highly charged α emitters is a major subject of investigation currently. In this framework, we recently pushed half-life measurements of neutral emitters to a precision of a few per mil. This result was achieved by using different techniques and apparatuses at Istituto Nazionale di Fisica Nucleare Laboratori Nazionali del Sud (INFN-LNS) and GSI Darmstadt. Here we report on 213Fr half-life determination [T1/2(213Fr) = 34.14±0.06 s] at INFN-LNS, detailing the measurement protocol used. Direct comparison with the accepted value in the literature shows a discrepancy of more than three sigma. We propose this new value as a reference, discussing previous experiments.

  20. Vibratory response modeling and verification of a high precision optical positioning system.

    SciTech Connect

    Barraza, J.; Kuzay, T.; Royston, T. J.; Shu, D.

    1999-06-18

    A generic vibratory-response modeling program has been developed as a tool for designing high-precision optical positioning systems. Based on multibody dynamics theory, the system is modeled as rigid-body structures connected by linear elastic elements, such as complex actuators and bearings. The full dynamic properties of each element are determined experimentally or theoretically, then integrated into the program as inertial and stiffness matrices. Utilizing this program, the theoretical and experimental verification of the vibratory behavior of a double-multilayer monochromator support and positioning system is presented. Results of parametric design studies that investigate the influence of support floor dynamics and highlight important design issues are also presented. Overall, good matches between theory and experiment demonstrate the effectiveness of the program as a dynamic modeling tool.

  1. Limiting Energy Dissipation Induces Glassy Kinetics in Single-Cell High-Precision Responses

    NASA Astrophysics Data System (ADS)

    Das, Jayajit

    2016-03-01

    Single cells often generate precise responses by involving dissipative out-of-thermodynamic equilibrium processes in signaling networks. The available free energy to fuel these processes could become limited depending on the metabolic state of an individual cell. How does limiting dissipation affect the kinetics of high precision responses in single cells? I address this question in the context of a kinetic proofreading scheme used in a simple model of early time T cell signaling. I show using exact analytical calculations and numerical simulations that limiting dissipation qualitatively changes the kinetics in single cells marked by emergence of slow kinetics, large cell-to-cell variations of copy numbers, temporally correlated stochastic events (dynamic facilitation), and, ergodicity breaking. Thus, constraints in energy dissipation, in addition to negatively affecting ligand discrimination in T cells, can create a fundamental difficulty in interpreting single cell kinetics from cell population level results.

  2. High-precision masses of neutron-deficient rubidium isotopes using a Penning trap mass spectrometer

    SciTech Connect

    Kellerbauer, A.; Audi, G.; Guenaut, C.; Lunney, D.; Beck, D.; Herfurth, F.; Kluge, H.-J.; Weber, C.; Yazidjian, C.; Blaum, K.; Bollen, G.; Schwarz, S.; Herlert, A.; Schweikhard, L.

    2007-10-15

    The atomic masses of the neutron-deficient radioactive rubidium isotopes {sup 74-77,79,80,83}Rb have been measured with the Penning trap mass spectrometer ISOLTRAP. Using the time-of-flight cyclotron resonance technique, relative mass uncertainties ranging from 1.6x10{sup -8} to 5.6x10{sup -8} were achieved. In all cases, the mass precision was significantly improved as compared with the prior Atomic-Mass Evaluation; no significant deviations from the literature values were observed. The exotic nuclide {sup 74}Rb, with a half-life of only 65 ms, is the shortest-lived nuclide on which a high-precision mass measurement in a Penning trap has been carried out. The significance of these measurements for a check of the conserved-vector-current hypothesis of the weak interaction and the unitarity of the Cabibbo-Kobayashi-Maskawa matrix is discussed.

  3. Versatile, kinetically controlled, high precision electrohydrodynamic writing of micro/nanofibers

    PubMed Central

    Huang, YongAn; Duan, Yongqing; Ding, Yajiang; Bu, Ningbin; Pan, Yanqiao; Lu, Nanshu; Yin, Zhouping

    2014-01-01

    Direct writing of hierarchical micro/nanofibers have recently gained popularity in flexible/stretchable electronics due to its low cost, simple process and high throughput. A kinetically controlled mechanoelectrospinning (MES) is developed to directly write diversified hierarchical micro/nanofibers in a continuous and programmable manner. Unlike conventional near-field electrospinning, our MES method introduces a mechanical drawing force, to simultaneously enhance the positioning accuracy and morphology controllability. The MES is predominantly controlled by the substrate speed, the nozzle-to-substrate distance, and the applied voltage. As a demonstration, smooth straight, serpentine, self-similar, and bead-on-string structures are direct-written on silicon/elastomer substrates with a resolution of 200 nm. It is believed that MES can promote the low-cost, high precision fabrication of flexible/stretchable electronics or enable the direct writing of the sacrificial structures for nanoscale lithography. PMID:25091829

  4. High precision Multifrequency Electrical Impedance Tomography System and Preliminary imaging results on saline tank.

    PubMed

    Xuetao, Shi; Fusheng, You; Feng, Fu; Ruigang, Liu; Xiuzhen, Dong

    2005-01-01

    To establish a high precision data acquisition system for multi-frequency electrical impedance tomography (EIT), a series of methods were introduced. Those methods include building a driving signal with up to four frequency components to diminish the effect of the dynamic change of tissues resistivity, extracting the impedance information by a digital demodulator that can improve the SNR by 8 times. The system that established can work at a wide range from 1.6kHz to 380kHz. Its CMRR is 74dB at 100kHz. The output impedance of current source is 2MΩ at that frequency. And measurement precision on a 100ohm resistor is better than -80dB in full bandwidth. Both the quasi-static and the dynamic imaging results based on a saline tank can reflect the resistivity changes inside the phantom clearly. Therefore, the system was competent in multifrequency EIT research work.

  5. Communication: High precision sub-Doppler infrared spectroscopy of the HeH{sup +} ion

    SciTech Connect

    Perry, Adam J.; Hodges, James N.; Markus, Charles R.; Kocheril, G. Stephen; McCall, Benjamin J.

    2014-09-14

    The hydrohelium cation, HeH{sup +}, serves as an important benchmark for ab initio calculations that take into account non-adiabatic, relativistic, and quantum electrodynamic effects. Such calculations are capable of predicting molecular transitions to an accuracy of ∼300 MHz or less. However, in order to continue to push the boundaries on these calculations, new measurements of these transitions are required. Here we measure seven rovibrational transitions in the fundamental vibrational band to a precision of ∼1 MHz using the technique of Noise Immune Cavity Enhanced Optical Heterodyne Velocity Modulation Spectroscopy. These newly measured transitions are included in a fit to the rotation-vibration term values to derive refined spectroscopic constants in the v = 0 and v = 1 vibrational states, as well as to calculate rotation-vibration energy levels with high precision.

  6. Flux Leakage Measurements for Defect Characterization Using a High Precision 3-AXIAL Gmr Magnetic Sensor

    NASA Astrophysics Data System (ADS)

    Pelkner, M.; Blome, M.; Reimund, V.; Thomas, H.-M.; Kreutzbruck, M.

    2011-06-01

    High-precision magnetic field sensors are of increasing interest in non destructive testing (NDT). In particular GMR-sensors (giant magneto resistance) are qualified because of their high sensitivity, high signal-to-noise ratio and high spatial resolution. With a GMR-gradiometer and a 3D-GMR-magnetometer we performed magnetic flux leakage measurements of artificial cracks and cracks of a depth of ≤50 μm still could be dissolved with a sufficient high signal-to-noise ratio. A semi-analytic magnetic dipole model that allows realistic GMR sensor characteristics to be incorporated is used for swiftly predicting magnetic stray fields. The reliable reconstruction based on measurements of artificial rectangular-shaped defects is demonstrated.

  7. A cell for high-precision constant-current coulometry with external generation of titrant.

    PubMed

    Knoeck, J; Diehl, H

    1969-05-01

    A cell has been designed for the high-precision coulometric titration, with externally generated titrant, of materials which otherwise undergo undesirable reactions at the working electrodes. With this cell potassium dichromate has been titrated, via its hydrolysis reaction, with hydroxyl ion generated at the cathode, cathodic reduction of the chromium(VI) being circumvented. In this cell 99.9% of the titrant required is generated in one chamber and transferred to another for reaction; the titration is then completed with titrant generated at a second, drip-type electrode working at much lower current. By means of commercially available Leeds and Northrup coulometric titration electrical equipment, titration of NBS 136b Potassium Dichromate gave a purity of 99.976%, standard deviation 0.005%, and of NBS 84d Potassium Acid Phthalate (done as a check) 99.991%, standard deviation 0.005%, both values being in excellent agreement with other work.

  8. A Direct Comparison of Two High Precision Relative Gravity Meters at Optimal Performance

    NASA Astrophysics Data System (ADS)

    van Westrum, D.

    2015-12-01

    NGS has maintained and operated GWR Superconducting Gravimeter #024 since 1995. It has been widely considered one of the most quiet instruments from that era. It was recently upgraded with state of the art electronics and its operating parameters reoptimzied. A Micro-g LaCoste gPhoneX, installed on a high precision tilt table, was collocated with the SG at the Table Mountain Geophysical Observatory near Boulder, CO and the two instruments operated side by side for approximately two months. Results in both the frequency domain and selected time series from large seismic signals (e.g. earthquakes) will be presented, allowing for a direct comparison between the instruments in identical, ideal conditions.

  9. High-precision measurement of pixel positions in a charge-coupled device.

    PubMed

    Shaklan, S; Sharman, M C; Pravdo, S H

    1995-10-10

    The high level of spatial uniformity in modern CCD's makes them excellent devices for astrometric instruments. However, at the level of accuracy envisioned by the more ambitious projects such as the Astrometric Imaging Telescope, current technology produces CCD's with significant pixel registration errors. We describe a technique for making high-precision measurements of relative pixel positions. We measured CCD's manufactured for the Wide Field Planetary Camera II installed in the Hubble Space Telescope. These CCD's are shown to have significant step-and-repeat errors of 0.033 pixel along every 34th row, as well as a 0.003-pixel curvature along 34-pixel stripes. The source of these errors is described. Our experiments achieved a per-pixel accuracy of 0.011 pixel. The ultimate shot-noise limited precision of the method is less than 0.001 pixel.

  10. High Precision Measurement of the Proton Elastic Form Factor Ratio at Low Q2

    SciTech Connect

    Xiaohui Zhan

    2009-12-01

    A high precision measurement of the proton elastic form factor ratio µpGEp/GMp in the range Q2 = 0.3–0.7 GeV2/c2 was performed using recoil polarimetry in Jefferson Lab Hall A. In this low Q2 range, previous data from LEDEX [5] along with many fits and calculations [2, 3, 4] indicate substantial deviations of the ratio from unity. In this new measurement, with 80% polarized electron beam for 24 days, we are able to achieve <1% statistical uncertainty. Preliminary results are a few percent lower than expected from previous world data and fits, indicating a smaller GEp at this region. Beyond the intrinsic interest in nucleon structure, the improved form factor measurements also have implications for DVCS, determinations of the proton Zemach radius and strangeness form factors through parity violation experiments.

  11. Status and outlook of CHIP-TRAP: The Central Michigan University high precision Penning trap

    NASA Astrophysics Data System (ADS)

    Redshaw, M.; Bryce, R. A.; Hawks, P.; Gamage, N. D.; Hunt, C.; Kandegedara, R. M. E. B.; Ratnayake, I. S.; Sharp, L.

    2016-06-01

    At Central Michigan University we are developing a high-precision Penning trap mass spectrometer (CHIP-TRAP) that will focus on measurements with long-lived radioactive isotopes. CHIP-TRAP will consist of a pair of hyperbolic precision-measurement Penning traps, and a cylindrical capture/filter trap in a 12 T magnetic field. Ions will be produced by external ion sources, including a laser ablation source, and transported to the capture trap at low energies enabling ions of a given m / q ratio to be selected via their time-of-flight. In the capture trap, contaminant ions will be removed with a mass-selective rf dipole excitation and the ion of interest will be transported to the measurement traps. A phase-sensitive image charge detection technique will be used for simultaneous cyclotron frequency measurements on single ions in the two precision traps, resulting in a reduction in statistical uncertainty due to magnetic field fluctuations.

  12. Versatile, kinetically controlled, high precision electrohydrodynamic writing of micro/nanofibers.

    PubMed

    Huang, YongAn; Duan, Yongqing; Ding, Yajiang; Bu, Ningbin; Pan, Yanqiao; Lu, Nanshu; Yin, Zhouping

    2014-08-05

    Direct writing of hierarchical micro/nanofibers have recently gained popularity in flexible/stretchable electronics due to its low cost, simple process and high throughput. A kinetically controlled mechanoelectrospinning (MES) is developed to directly write diversified hierarchical micro/nanofibers in a continuous and programmable manner. Unlike conventional near-field electrospinning, our MES method introduces a mechanical drawing force, to simultaneously enhance the positioning accuracy and morphology controllability. The MES is predominantly controlled by the substrate speed, the nozzle-to-substrate distance, and the applied voltage. As a demonstration, smooth straight, serpentine, self-similar, and bead-on-string structures are direct-written on silicon/elastomer substrates with a resolution of 200 nm. It is believed that MES can promote the low-cost, high precision fabrication of flexible/stretchable electronics or enable the direct writing of the sacrificial structures for nanoscale lithography.

  13. High-precision control of LSRM based X-Y table for industrial applications.

    PubMed

    Pan, J F; Cheung, Norbert C; Zou, Yu

    2013-01-01

    The design of an X-Y table applying direct-drive linear switched reluctance motor (LSRM) principle is proposed in this paper. The proposed X-Y table has the characteristics of low cost, simple and stable mechanical structure. After the design procedure is introduced, an adaptive position control method based on online parameter identification and pole-placement regulation scheme is developed for the X-Y table. Experimental results prove the feasibility and its priority over a traditional PID controller with better dynamic response, static performance and robustness to disturbances. It is expected that the novel two-dimensional direct-drive system find its applications in high-precision manufacture area.

  14. High-precision optomechanical lens system for space applications assembled by a local soldering technique

    NASA Astrophysics Data System (ADS)

    Pleguezuelo, Pol Ribes; Koechlin, Charlie; Hornaff, Marcel; Kamm, Andreas; Beckert, Erik; Fiault, Guillaume; Eberhardt, Ramona; Tünnermann, Andreas

    2016-06-01

    Soldering using metallic solder alloys is an alternative to adhesive bonding. Laser-based soldering processes are especially well suited for the joining of optical components made of fragile and brittle materials such as glass, ceramics, and optical crystals. This is due to a localized and minimized input of thermal energy. Solderjet bumping technology has been used to assemble a lens mount breadboard using specifications and requirements found for the optical beam expander for the European Space Agency EarthCare Mission. The silica lens and a titanium barrel have been designed and assembled with this technology in order to withstand the stringent mission demands of handling high mechanical and thermal loads without losing the optical performance. Finally, a high-precision optomechanical lens mount has been assembled with minimal localized stress (<1 MPa) showing outstanding performance in terms of wave-front error and beam depolarization ratio before and after environmental tests.

  15. Third-eye guided telemeter for high-precision positional measurement

    NASA Astrophysics Data System (ADS)

    Pettiti, Giuseppe; Cumani, Aldo; Grattoni, Paolo; Guiducci, Antonio; Pollastri, Fabrizio; Rebaglia, Bruno

    1994-02-01

    The telemeter is a high precision positional tracking device that works by triangulation over the angular measurements provided by two or more telegoniometers. Each of the latter is composed of a TV camera with a teleobjective, looking at the working space through a pair of orthogonal mirrors. A problem with this kind of structure is the automation of the initial pointing of the telegoniometers on the target. We propose to add a third camera with a wide- angle lens framing the whole workspace to provide the line of sight on which the target must lie. In this work we present this `three-eyes' structure and discuss its calibration, as well as the problems related to the strategy for scanning the line of sight and for detecting the tracking condition. Two possible applications to robot qualification and autonomous navigation also are presented.

  16. High precision measurements of the diamond Hugoniot in and above the melt region

    SciTech Connect

    Hicks, D; Boehly, T; Celliers, P; Bradley, D; Eggert, J; McWilliams, R S; Collins, G

    2008-08-05

    High precision laser-driven shock wave measurements of the diamond principal Hugoniot have been made at pressures between 6 and 19 Mbar. Shock velocities were determined with 0.3-1.1% precision using a velocity interferometer. Impedance matching analysis, incorporating systematic errors in the equation-of-state of the quartz standard, was used to determine the Hugoniot with 1.2-2.7% precision in density. The results are in good agreement with published ab initio calculations which predict a small negative melt slope along the Hugoniot, but disagree with previous laser-driven shock wave experiments which had observed a large density increase in the melt region. In the extensive solid-liquid coexistence regime between 6 and 10 Mbar these measurements indicate that the mixed phase may be slightly more dense than would be expected from a simple interpolation between liquid and solid Hugoniots.

  17. Closed tubes preparation of graphite for high-precision AMS radiocarbon analysis

    NASA Astrophysics Data System (ADS)

    Hajdas, I.; Michczynska, D.; Bonani, G.; Maurer, M.; Wacker, L.

    2009-04-01

    Radiocarbon dating is an established tool applied in Geochronology. Technical developments of Accelerator Mass Spectrometry AMS, which allow measurements of samples containing less than 1 mg of carbon, opened opportunities for new applications. Moreover, high resolution records of the past changes require high-resolution chronologies i.e. sampling for 14C dating. In result, the field of applications is rapidly expanding and number of radiocarbon analysis is growing rapidly. Nowadays dedicated 14C AMS machines have great capacity for analysis but in order to keep up with the demand for analysis and provide the results as fast as possible a very efficient way of sample preparation is required. Sample preparation for 14C AMS analysis consists of two steps: separation of relevant carbon from the sample material (removing contamination) and preparation of graphite for AMS analysis. The last step usually involves reaction of CO2 with H2, in the presence of metal catalyst (Fe or Co) of specific mesh size heated to 550-625°C, as originally suggested by Vogel et al. (1984). Various graphitization systems have been built in order to fulfil the requirement of sample quality needed for high-precision radiocarbon data. In the early 90ties another method has been proposed (Vogel 1992) and applied by few laboratories mainly for environmental or biomedical samples. This method uses TiH2 as a source of H2 and can be easily and flexibly applied to produce graphite. Sample of CO2 is frozen in to the tube containing pre-conditioned Zn/TiH2 and Fe catalyst. Torch sealed tubes are then placed in the stepwise heated oven at 500/550°C and left to react for several hours. The greatest problem is the lack of control of the reaction completeness and considerable fractionation. However, recently reported results (Xu et al. 2007) suggest that high precision dating using graphite produced in closed tubes might be possible. We will present results of radiocarbon dating of the set of standards

  18. Versatile, kinetically controlled, high precision electrohydrodynamic writing of micro/nanofibers

    NASA Astrophysics Data System (ADS)

    Huang, Yongan; Duan, Yongqing; Ding, Yajiang; Bu, Ningbin; Pan, Yanqiao; Lu, Nanshu; Yin, Zhouping

    2014-08-01

    Direct writing of hierarchical micro/nanofibers have recently gained popularity in flexible/stretchable electronics due to its low cost, simple process and high throughput. A kinetically controlled mechanoelectrospinning (MES) is developed to directly write diversified hierarchical micro/nanofibers in a continuous and programmable manner. Unlike conventional near-field electrospinning, our MES method introduces a mechanical drawing force, to simultaneously enhance the positioning accuracy and morphology controllability. The MES is predominantly controlled by the substrate speed, the nozzle-to-substrate distance, and the applied voltage. As a demonstration, smooth straight, serpentine, self-similar, and bead-on-string structures are direct-written on silicon/elastomer substrates with a resolution of 200 nm. It is believed that MES can promote the low-cost, high precision fabrication of flexible/stretchable electronics or enable the direct writing of the sacrificial structures for nanoscale lithography.

  19. High-precision follow-up observations of Near-Earth Objects

    NASA Astrophysics Data System (ADS)

    Ramanjooloo, Yudish; Tholen, David J.; Fohring, Dora; Hung, Denise

    2016-10-01

    We present the latest results of ongoing high-precision astrometric follow-up observations of Near-Earth Objects (NEOs) using the University of Hawaii 2.24 metre telescope (currently 7.5 arcmin FOV), the Canada-France-Hawaii Telescope (CFHT; 1 degree FOV) with MegaPrime, and the Subaru Hyper Suprime-Cam (1.5 degree FOV). The combination of excellent observing conditions at Maunakea, and the use of no filter to maximise our throughput efficiency, allows us to recover targets having V < 24, and sometimes V < 25 under ideal conditions. We frequently achieve astrometric accuracy limited by the reference catalog and plan to improve on this capability with the implementation of the GAIA catalog. This work is funded by NASA grant NXX13AI64G.

  20. A numerical method for determining highly precise electron energy distribution functions from Langmuir probe characteristics

    SciTech Connect

    Bang, Jin-Young; Chung, Chin-Wook

    2010-12-15

    Electron energy distribution functions (EEDFs) were determined from probe characteristics using a numerical ac superimposed method with a distortion correction of high derivative terms by varying amplitude of a sinusoidal perturbation voltage superimposed onto the dc sweep voltage, depending on the related electron energy. Low amplitude perturbation applied around the plasma potential represented the low energy peak of the EEDF exactly, and high amplitude perturbation applied around the floating potential was effective to suppress noise or distortion of the probe characteristic, which is fatal to the tail electron distribution. When a small random noise was imposed over the stabilized prove characteristic, the numerical differentiation method was not suitable to determine the EEDF, while the numerical ac superimposed method was able to obtain a highly precise EEDF.

  1. High-precision method for submicron-aperture fiber point-diffraction wavefront measurement.

    PubMed

    Wang, Daodang; Xu, Yangbo; Liang, Rongguang; Kong, Ming; Zhao, Jun; Zhang, Baowu; Li, Wei

    2016-04-01

    It is a key issue to measure the point-diffraction wavefront error, which determines the achievable accuracy of point-diffraction interferometer (PDI). A high-precision method based on shearing interferometry is proposed to measure submicron-aperture fiber point-diffraction wavefront with high numerical aperture (NA). To obtain the true shearing point-diffraction wavefront, a double-step calibration method based on three-dimensional coordinate reconstruction and symmetric lateral displacement compensation is proposed to calibrate the geometric aberration in the case of high NA and large lateral wavefront displacement. The calibration can be carried out without any prior knowledge about the system configuration parameters. With the true shearing wavefront, the differential Zernike polynomials fitting method is applied to reconstruct the point-diffraction wavefront. Numerical simulation and experiments have been carried out to demonstrate the accuracy and feasibility of the proposed measurement method, and a good measurement accuracy is achieved. PMID:27137002

  2. Atomic Hydrogen as High-Precision Field Standard for High-Field EPR

    PubMed Central

    Stoll, Stefan; Ozarowski, Andrew; Britt, R. David; Angerhofer, Alexander

    2010-01-01

    We introduce atomic hydrogen trapped in an octaisobutylsilsesquioxane nanocage (H@iBuT8) as a new molecular high-precision magnetic field standard for high-field EPR spectroscopy of organic radicals and other systems with signals around g = 2. Its solid-state EPR spectrum consists of two narrow lines separated by about 51 mT and centered at g ≈ 2. The isotropic g factor is 2.00294(3) and essentially temperature independent. The isotopic 1H hyperfine coupling constant is 1416.8(2) MHz below 70 K and decreases slightly with increasing temperature to 1413.7(1) MHz at room temperature. The spectrum of the standard does not overlap with those of most organic radicals, and it can be easily prepared and is stable at room temperature. PMID:20813570

  3. Non-contact high precision measurement of surface form tolerances and central thickness for optical elements

    NASA Astrophysics Data System (ADS)

    Lou, Ying

    2010-10-01

    The traditional contact measuring methods could not satisfy the current optical elements measuring requirements. Noncontact high precision measuring theory, principle and instrument of the surface form tolerances and central thickness for optical elements were studied in the paper. In comparison with other types of interferometers, such as Twyman-Green and Mach-Zehnder, a Fizeau interferometer has the advantages of having fewer optical components, greater accuracy, and is easier to use. Some relations among the 3/A(B/C), POWER/PV and N/ΔN were studied. The PV with POWER removed can be the reference number of ΔN. The chromatic longitudinal aberration of a special optical probe can be used for non-contanct central thickness measurement.

  4. High-precision locations of the microseismicity preceding the 2002-2003 Mt. Etna eruption

    NASA Astrophysics Data System (ADS)

    Gambino, S.; Mostaccio, A.; Patanè, D.; Scarfì, L.; Ursino, A.

    2004-09-01

    To recognize possible signals of intrusive processes leading to the last 2002-2003 flank eruption at Mt. Etna, we analyzed the spatial pattern of microseismicity between August 2001 and October 2002 and calculated 23 fault plane solutions (FPSs) for shocks with magnitude greater than 2.5. By applying the double-difference approach of Waldhauser and Ellsworth [2000] on 3D locations, we found that most of the scattered epicentral locations further collapse in roughly linear features. High-precision locations evidenced a distribution of earthquakes along two main alignments, oriented NE-SW to ENE-WSW and NW-SE, matching well both with the known tectonic and volcanic lineaments of Etna and FPSs results. Moreover, microseismicity and swarms located along the NNW-SSE volcano-genetic trend suggest, together with geodetic data and volcanological evidence that progressive magma refilling has occurred since February 2002.

  5. [High Precision Identification of Igneous Rock Lithology by Laser Induced Breakdown Spectroscopy].

    PubMed

    Wang, Chao; Zhang, Wei-gang; Yan, Zhi-quan

    2015-09-01

    In the field of petroleum exploration, lithology identification of finely cuttings sample, especially high precision identification of igneous rock with similar property, has become one of the geological problems. In order to solve this problem, a new method is proposed based on element analysis of Laser-Induced Breakdown Spectroscopy (LIBS) and Total Alkali versus Silica (TAS) diagram. Using independent LIBS system, factors influencing spectral signal, such as pulse energy, acquisition time delay, spectrum acquisition method and pre-ablation are researched through contrast experiments systematically. The best analysis conditions of igneous rock are determined: pulse energy is 50 mJ, acquisition time delay is 2 μs, the analysis result is integral average of 20 different points of sample's surface, and pre-ablation has been proved not suitable for igneous rock sample by experiment. The repeatability of spectral data is improved effectively. Characteristic lines of 7 elements (Na, Mg, Al, Si, K, Ca, Fe) commonly used for lithology identification of igneous rock are determined, and igneous rock samples of different lithology are analyzed and compared. Calibration curves of Na, K, Si are generated by using national standard series of rock samples, and all the linearly dependent coefficients are greater than 0.9. The accuracy of quantitative analysis is investigated by national standard samples. Element content of igneous rock is analyzed quantitatively by calibration curve, and its lithology is identified accurately by the method of TAS diagram, whose accuracy rate is 90.7%. The study indicates that LIBS can effectively achieve the high precision identification of the lithology of igneous rock.

  6. A novel approach for high precision rapid potentiometric titrations: application to hydrazine assay.

    PubMed

    Sahoo, P; Malathi, N; Ananthanarayanan, R; Praveen, K; Murali, N

    2011-11-01

    We propose a high precision rapid personal computer (PC) based potentiometric titration technique using a specially designed mini-cell to carry out redox titrations for assay of chemicals in quality control laboratories attached to industrial, R&D, and nuclear establishments. Using this technique a few microlitre of sample (50-100 μl) in a total volume of ~2 ml solution can be titrated and the waste generated after titration is extremely low comparing to that obtained from the conventional titration technique. The entire titration including online data acquisition followed by immediate offline analysis of data to get information about concentration of unknown sample is completed within a couple of minutes (about 2 min). This facility has been created using a new class of sensors, viz., pulsating sensors developed in-house. The basic concept in designing such instrument and the salient features of the titration device are presented in this paper. The performance of the titration facility was examined by conducting some of the high resolution redox titrations using dilute solutions--hydrazine against KIO(3) in HCl medium, Fe(II) against Ce(IV) and uranium using Davies-Gray method. The precision of titrations using this innovative approach lies between 0.048% and 1.0% relative standard deviation in different redox titrations. With the evolution of this rapid PC based titrator it was possible to develop a simple but high precision potentiometric titration technique for quick determination of hydrazine in nuclear fuel dissolver solution in the context of reprocessing of spent nuclear fuel in fast breeder reactors.

  7. A high precision dual feedback discrete control system designed for satellite trajectory simulator

    NASA Astrophysics Data System (ADS)

    Liu, Ximin; Liu, Liren; Sun, Jianfeng; Xu, Nan

    2005-08-01

    Cooperating with the free-space laser communication terminals, the satellite trajectory simulator is used to test the acquisition, pointing, tracking and communicating performances of the terminals. So the satellite trajectory simulator plays an important role in terminal ground test and verification. Using the double-prism, Sun etc in our group designed a satellite trajectory simulator. In this paper, a high precision dual feedback discrete control system designed for the simulator is given and a digital fabrication of the simulator is made correspondingly. In the dual feedback discrete control system, Proportional- Integral controller is used in velocity feedback loop and Proportional- Integral- Derivative controller is used in position feedback loop. In the controller design, simplex method is introduced and an improvement to the method is made. According to the transfer function of the control system in Z domain, the digital fabrication of the simulator is given when it is exposed to mechanism error and moment disturbance. Typically, when the mechanism error is 100urad, the residual standard error of pitching angle, azimuth angle, x-coordinate position and y-coordinate position are 0.49urad, 6.12urad, 4.56urad, 4.09urad respectively. When the moment disturbance is 0.1rad, the residual standard error of pitching angle, azimuth angle, x-coordinate position and y-coordinate position are 0.26urad, 0.22urad, 0.16urad, 0.15urad respectively. The digital fabrication results demonstrate that the dual feedback discrete control system designed for the simulator can achieve the anticipated high precision performance.

  8. Computational Calorimetry: High-Precision Calculation of Host–Guest Binding Thermodynamics

    PubMed Central

    2015-01-01

    We present a strategy for carrying out high-precision calculations of binding free energy and binding enthalpy values from molecular dynamics simulations with explicit solvent. The approach is used to calculate the thermodynamic profiles for binding of nine small molecule guests to either the cucurbit[7]uril (CB7) or β-cyclodextrin (βCD) host. For these systems, calculations using commodity hardware can yield binding free energy and binding enthalpy values with a precision of ∼0.5 kcal/mol (95% CI) in a matter of days. Crucially, the self-consistency of the approach is established by calculating the binding enthalpy directly, via end point potential energy calculations, and indirectly, via the temperature dependence of the binding free energy, i.e., by the van’t Hoff equation. Excellent agreement between the direct and van’t Hoff methods is demonstrated for both host–guest systems and an ion-pair model system for which particularly well-converged results are attainable. Additionally, we find that hydrogen mass repartitioning allows marked acceleration of the calculations with no discernible cost in precision or accuracy. Finally, we provide guidance for accurately assessing numerical uncertainty of the results in settings where complex correlations in the time series can pose challenges to statistical analysis. The routine nature and high precision of these binding calculations opens the possibility of including measured binding thermodynamics as target data in force field optimization so that simulations may be used to reliably interpret experimental data and guide molecular design. PMID:26523125

  9. Computational Calorimetry: High-Precision Calculation of Host-Guest Binding Thermodynamics.

    PubMed

    Henriksen, Niel M; Fenley, Andrew T; Gilson, Michael K

    2015-09-01

    We present a strategy for carrying out high-precision calculations of binding free energy and binding enthalpy values from molecular dynamics simulations with explicit solvent. The approach is used to calculate the thermodynamic profiles for binding of nine small molecule guests to either the cucurbit[7]uril (CB7) or β-cyclodextrin (βCD) host. For these systems, calculations using commodity hardware can yield binding free energy and binding enthalpy values with a precision of ∼0.5 kcal/mol (95% CI) in a matter of days. Crucially, the self-consistency of the approach is established by calculating the binding enthalpy directly, via end point potential energy calculations, and indirectly, via the temperature dependence of the binding free energy, i.e., by the van't Hoff equation. Excellent agreement between the direct and van't Hoff methods is demonstrated for both host-guest systems and an ion-pair model system for which particularly well-converged results are attainable. Additionally, we find that hydrogen mass repartitioning allows marked acceleration of the calculations with no discernible cost in precision or accuracy. Finally, we provide guidance for accurately assessing numerical uncertainty of the results in settings where complex correlations in the time series can pose challenges to statistical analysis. The routine nature and high precision of these binding calculations opens the possibility of including measured binding thermodynamics as target data in force field optimization so that simulations may be used to reliably interpret experimental data and guide molecular design.

  10. [High Precision Identification of Igneous Rock Lithology by Laser Induced Breakdown Spectroscopy].

    PubMed

    Wang, Chao; Zhang, Wei-gang; Yan, Zhi-quan

    2015-09-01

    In the field of petroleum exploration, lithology identification of finely cuttings sample, especially high precision identification of igneous rock with similar property, has become one of the geological problems. In order to solve this problem, a new method is proposed based on element analysis of Laser-Induced Breakdown Spectroscopy (LIBS) and Total Alkali versus Silica (TAS) diagram. Using independent LIBS system, factors influencing spectral signal, such as pulse energy, acquisition time delay, spectrum acquisition method and pre-ablation are researched through contrast experiments systematically. The best analysis conditions of igneous rock are determined: pulse energy is 50 mJ, acquisition time delay is 2 μs, the analysis result is integral average of 20 different points of sample's surface, and pre-ablation has been proved not suitable for igneous rock sample by experiment. The repeatability of spectral data is improved effectively. Characteristic lines of 7 elements (Na, Mg, Al, Si, K, Ca, Fe) commonly used for lithology identification of igneous rock are determined, and igneous rock samples of different lithology are analyzed and compared. Calibration curves of Na, K, Si are generated by using national standard series of rock samples, and all the linearly dependent coefficients are greater than 0.9. The accuracy of quantitative analysis is investigated by national standard samples. Element content of igneous rock is analyzed quantitatively by calibration curve, and its lithology is identified accurately by the method of TAS diagram, whose accuracy rate is 90.7%. The study indicates that LIBS can effectively achieve the high precision identification of the lithology of igneous rock. PMID:26669148

  11. Non-contact profiling for high precision fast asphere topology measurement

    NASA Astrophysics Data System (ADS)

    Petter, Jürgen; Berger, Gernot

    2013-04-01

    Quality control in the fabrication of high precision optics these days needs nanometer accuracy. However, the fast growing number of optics with complex aspheric shapes demands an adapted measurement method as existing metrology systems more and more reach their limits. In this contribution the authors present a unique and highly flexible approach for measuring spheric and aspheric optics with diameters from 2mm up to 420mm and with almost unlimited spheric departures. Based on a scanning point interferometer the system combines the high precision and the speed of an optical interferometer with the high form flexibility of a classical tactile scanning system. This enables the measurement of objects with steep or strongly changing slopes such as "pancake" or "gull wing" objects. The high accuracy of ±50nm over the whole surface is achieved by using a full reference concept ensuring the position control even over long scanning paths. The core of the technology is a multiwavelength interferometer (MWLI); by use of several wavelengths this sensor system allows for the measurement of objects with polished as well as with ground surfaces. Furthermore, a large absolute measurement range facilitates measuring surfaces with steps or discontinuities like diffractive structures or even segmented objects. As all the measurements can be done using one and the same system, a direct comparison is possible during production and after finishing an object. The contribution gives an insight into the functionality of the MWLI-sensor as well as into the concept of the reference system of the scanning metrology system. Furthermore, samples of application are discussed.

  12. A fast high-precision six-degree-of-freedom relative position sensor

    NASA Astrophysics Data System (ADS)

    Hughes, Gary B.; Macasaet, Van P.; Griswold, Janelle; Sison, Claudia A.; Lubin, Philip; Meinhold, Peter; Suen, Jonathan; Brashears, Travis; Zhang, Qicheng; Madajian, Jonathan

    2016-03-01

    Lasers are commonly used in high-precision measurement and profiling systems. Some laser measurement systems are based on interferometry principles, and others are based on active triangulation, depending on requirements of the application. This paper describes an active triangulation laser measurement system for a specific application wherein the relative position of two fixed, rigid mechanical components is to be measured dynamically with high precision in six degrees of freedom (DOF). Potential applications include optical systems with feedback to control for mechanical vibration, such as target acquisition devices with multiple focal planes. The method uses an array of several laser emitters mounted on one component. The lasers are directed at a reflective surface on the second component. The reflective surface consists of a piecewise-planar pattern such as a pyramid, or more generally a curved reflective surface such as a hyperbolic paraboloid. The reflected spots are sensed at 2-dimensional photodiode arrays on the emitter component. Changes in the relative position of the emitter component and reflective surface will shift the location of the reflected spots within photodiode arrays. Relative motion in any degree of freedom produces independent shifts in the reflected spot locations, allowing full six-DOF relative position determination between the two component positions. Response time of the sensor is limited by the read-out rate of the photodiode arrays. Algorithms are given for position determination with limits on uncertainty and sensitivity, based on laser and spot-sensor characteristics, and assuming regular surfaces. Additional uncertainty analysis is achievable for surface irregularities based on calibration data.

  13. Pile-up corrections for high-precision superallowed β decay half-life measurements via γ-ray photopeak counting

    NASA Astrophysics Data System (ADS)

    Grinyer, G. F.; Svensson, C. E.; Andreoiu, C.; Andreyev, A. N.; Austin, R. A. E.; Ball, G. C.; Bandyopadhyay, D.; Chakrawarthy, R. S.; Finlay, P.; Garrett, P. E.; Hackman, G.; Hyland, B.; Kulp, W. D.; Leach, K. G.; Leslie, J. R.; Morton, A. C.; Pearson, C. J.; Phillips, A. A.; Sarazin, F.; Schumaker, M. A.; Smith, M. B.; Valiente-Dobón, J. J.; Waddington, J. C.; Williams, S. J.; Wong, J.; Wood, J. L.; Zganjar, E. F.

    2007-09-01

    A general technique that corrects γ-ray gated β decay-curve data for detector pulse pile-up is presented. The method includes corrections for non-zero time-resolution and energy-threshold effects in addition to a special treatment of saturating events due to cosmic rays. This technique is verified through a Monte Carlo simulation and experimental data using radioactive beams of Na26 implanted at the center of the 8π γ-ray spectrometer at the ISAC facility at TRIUMF in Vancouver, Canada. The β-decay half-life of Na26 obtained from counting 1809-keV γ-ray photopeaks emitted by the daughter Mg26 was determined to be T=1.07167±0.00055 s following a 27σ correction for detector pulse pile-up. This result is in excellent agreement with the result of a previous measurement that employed direct β counting and demonstrates the feasibility of high-precision β-decay half-life measurements through the use of high-purity germanium γ-ray detectors. The technique presented here, while motivated by superallowed-Fermi β decay studies, is general and can be used for all half-life determinations (e.g. α-, β-, X-ray, fission) in which a γ-ray photopeak is used to select the decays of a particular isotope.

  14. High-precision mass measurement of N = Z = 34 nuclides for RP-process simulations and developments for the LEBIT facility

    NASA Astrophysics Data System (ADS)

    Savory, Joshua J.

    The Low Energy Beam and Ion Trap (LEBIT) facility at the National Superconducting Cyclotron Laboratory (NSCL) performs high precision mass measurements of rare isotopes. Within this work mass measurements in the N ≈ Z ≈ 34 region were performed by Penning trap mass spectrometry. Mass measurements of nuclei in this region are important for understanding the rp process, a driving mechanism behind type I x-ray bursts. The masses measured were 68Se, 70Se, 70mBr, and 71Br and experimental uncertainties ranging from 0.5 keV for 68Se to 15 keV for 70mBr were achieved. Using the LEBIT results along with theoretical Coulomb displacement energies [1] more reliable mass predictions were obtained for 70Kr and 71Kr. The new and improved data were used as input for rp process network calculations. An increase in the effective lifetime of the waiting point nucleus 685se was observed, thus confirming it as a large source of delay in the rp process. More precise information was also obtained on the luminosity during a type I x-ray burst and on the distribution of the final abundances after a burst. Beam manipulation and detection are an important part of the high precision mass measurement process performed at the LEBIT facility. Several upgrades to the LEBIT facility for improved beam quality, control, and observation are presented. The properties of ion pulses ejected from the facility's beam cooler and buncher were investigated and optimized for improved contaminant ion detection and removal. To increase the ion detection efficiency after the Penning trap a multichannel plate detector was implemented in a Daly detector configuration. These upgrades were instrumental in moving the LEBIT facility towards measurements of nuclei with lower yields and higher levels of contaminant.

  15. The ESPAT tool: a general-purpose DSS shell for solving stochastic optimization problems in complex river-aquifer systems

    NASA Astrophysics Data System (ADS)

    Macian-Sorribes, Hector; Pulido-Velazquez, Manuel; Tilmant, Amaury

    2015-04-01

    Stochastic programming methods are better suited to deal with the inherent uncertainty of inflow time series in water resource management. However, one of the most important hurdles in their use in practical implementations is the lack of generalized Decision Support System (DSS) shells, usually based on a deterministic approach. The purpose of this contribution is to present a general-purpose DSS shell, named Explicit Stochastic Programming Advanced Tool (ESPAT), able to build and solve stochastic programming problems for most water resource systems. It implements a hydro-economic approach, optimizing the total system benefits as the sum of the benefits obtained by each user. It has been coded using GAMS, and implements a Microsoft Excel interface with a GAMS-Excel link that allows the user to introduce the required data and recover the results. Therefore, no GAMS skills are required to run the program. The tool is divided into four modules according to its capabilities: 1) the ESPATR module, which performs stochastic optimization procedures in surface water systems using a Stochastic Dual Dynamic Programming (SDDP) approach; 2) the ESPAT_RA module, which optimizes coupled surface-groundwater systems using a modified SDDP approach; 3) the ESPAT_SDP module, capable of performing stochastic optimization procedures in small-size surface systems using a standard SDP approach; and 4) the ESPAT_DET module, which implements a deterministic programming procedure using non-linear programming, able to solve deterministic optimization problems in complex surface-groundwater river basins. The case study of the Mijares river basin (Spain) is used to illustrate the method. It consists in two reservoirs in series, one aquifer and four agricultural demand sites currently managed using historical (XIV century) rights, which give priority to the most traditional irrigation district over the XX century agricultural developments. Its size makes it possible to use either the SDP or

  16. Ultra-fast digital tomosynthesis reconstruction using general-purpose GPU programming for image-guided radiation therapy.

    PubMed

    Park, Justin C; Park, Sung Ho; Kim, Jin Sung; Han, Youngyih; Cho, Min Kook; Kim, Ho Kyung; Liu, Zhaowei; Jiang, Steve B; Song, Bongyong; Song, William Y

    2011-08-01

    The purpose of this work is to demonstrate an ultra-fast reconstruction technique for digital tomosynthesis (DTS) imaging based on the algorithm proposed by Feldkamp, Davis, and Kress (FDK) using standard general-purpose graphics processing unit (GPGPU) programming interface. To this end, the FDK-based DTS algorithm was programmed "in-house" with C language with utilization of 1) GPU and 2) central processing unit (CPU) cards. The GPU card consisted of 480 processing cores (2 x 240 dual chip) with 1,242 MHz processing clock speed and 1,792 MB memory space. In terms of CPU hardware, we used 2.68 GHz clock speed, 12.0 GB DDR3 RAM, on a 64-bit OS. The performance of proposed algorithm was tested on twenty-five patient cases (5 lung, 5 liver, 10 prostate, and 5 head-and-neck) scanned either with a full-fan or half-fan mode on our cone-beam computed tomography (CBCT) system. For the full-fan scans, the projections from 157.5°-202.5° (45°-scan) were used to reconstruct coronal DTS slices, whereas for the half-fan scans, the projections from both 157.5°-202.5° and 337.5°-22.5° (2 x 45°-scan) were used to reconstruct larger FOV coronal DTS slices. For this study, we chose 45°-scan angle that contained ~80 projections for the full-fan and ~160 projections with 2 x 45°-scan angle for the half-fan mode, each with 1024 x 768 pixels with 32-bit precision. Absolute pixel value differences, profiles, and contrast-to-noise ratio (CNR) calculations were performed to compare and evaluate the images reconstructed using GPU- and CPU-based implementations. The time dependence on the reconstruction volume was also tested with (512 x 512) x 16, 32, 64, 128, and 256 slices. In the end, the GPU-based implementation achieved, at most, 1.3 and 2.5 seconds to complete full reconstruction of 512 x 512 x 256 volume, for the full-fan and half-fan modes, respectively. In turn, this meant that our implementation can process > 13 projections-per-second (pps) and > 18 pps for the full

  17. High precision multi-genome scale reannotation of enzyme function by EFICAz

    PubMed Central

    Arakaki, Adrian K; Tian, Weidong; Skolnick, Jeffrey

    2006-01-01

    Background The functional annotation of most genes in newly sequenced genomes is inferred from similarity to previously characterized sequences, an annotation strategy that often leads to erroneous assignments. We have performed a reannotation of 245 genomes using an updated version of EFICAz, a highly precise method for enzyme function prediction. Results Based on our three-field EC number predictions, we have obtained lower-bound estimates for the average enzyme content in Archaea (29%), Bacteria (30%) and Eukarya (18%). Most annotations added in KEGG from 2005 to 2006 agree with EFICAz predictions made in 2005. The coverage of EFICAz predictions is significantly higher than that of KEGG, especially for eukaryotes. Thousands of our novel predictions correspond to hypothetical proteins. We have identified a subset of 64 hypothetical proteins with low sequence identity to EFICAz training enzymes, whose biochemical functions have been recently characterized and find that in 96% (84%) of the cases we correctly identified their three-field (four-field) EC numbers. For two of the 64 hypothetical proteins: PA1167 from Pseudomonas aeruginosa, an alginate lyase (EC 4.2.2.3) and Rv1700 of Mycobacterium tuberculosis H37Rv, an ADP-ribose diphosphatase (EC 3.6.1.13), we have detected annotation lag of more than two years in databases. Two examples are presented where EFICAz predictions act as hypothesis generators for understanding the functional roles of hypothetical proteins: FLJ11151, a human protein overexpressed in cancer that EFICAz identifies as an endopolyphosphatase (EC 3.6.1.10), and MW0119, a protein of Staphylococcus aureus strain MW2 that we propose as candidate virulence factor based on its EFICAz predicted activity, sphingomyelin phosphodiesterase (EC 3.1.4.12). Conclusion Our results suggest that we have generated enzyme function annotations of high precision and recall. These predictions can be mined and correlated with other information sources to generate

  18. High-Precision Stable Isotope Analyses with the NanoSIMS 50L (Invited)

    NASA Astrophysics Data System (ADS)

    Hauri, E. H.; Wang, J.; Papineau, D.; Hillion, F.

    2009-12-01

    The in situ measurement of isotope ratios at high precision has always been a goal of secondary ion mass spectrometery (SIMS). The NanoSIMS 50L is a third-generation ion microprobe developed by Cameca and modified in collaboration with the Carnegie Institution of Washington. This instrument encorporates a number of design and functional improvements over the stock NS50, including precise stepper motor control over all slits, apertures and stage movements, a larger magnet, and a modified multicollector (6 moveable and 1 fixed) capable of holding both Faraday cups and miniature multi-dynode electron multipliers. The instrument is capable of attaining a minimum beam diameter of <50 nanometers with Cs and <200 nanometers with oxygen, a factor of 5-10 improvement over the IMS6F/7F/1280 generation of instruments. The CIW instrument is also the first NanoSIMS to be fitted with multiple Faradays and associated high-precision electrometers. Most tests to date have been performed on conductive Fe-bearing sulfides mouted in indium and polished with near-zero relief. With Cs, a routine primary beam diameter of 100 nm is obtained with 1-2pA of current, sufficient to yield 1MHz of 32S from pyrite at >6000 MRP. A 2.5 nA Cs beam with a diameter of 700 nm yields 90 pA of 32S from pyrite at >6000 MRP, sufficient to analyze 32S-33S-34S on Faraday cups and 36S in EM @ >10,000 cps. Specification tests immediately after installation in 2005 demonstrated a reproducibility of <0.3‰ (1σ) in 10 analyses within a single sputter crater on Balmat pyrite, and this was subsequently improved to 0.15‰ (1σ) in 2006. Further tests showed that reproducibility on separate craters of a single grain, and separate craters in separate Balmat pyrite grains located in different holes of the sample holder, were improved to better than 0.2‰ (1σ) through careful attention to reproducibility of sample height (Z-axis control) and centering of the secondary ion beam in the entrance slit of the mass

  19. High-precision temporal constraints on intrusive magmatism of the Siberian Traps

    NASA Astrophysics Data System (ADS)

    Burgess, Seth; Bowring, Sam; Pavlov, Volodia E.; Veselovsky, Roman V.

    2014-05-01

    The broad temporal coincidence between large igneous province magmatism and some of the most severe biotic/environmental crises in Earth history has led many to infer a causal connection between the two. Notable examples include the end-Permian mass extinction and eruption/emplacement of the Siberian Traps large igneous province (LIP) and the end-Triassic mass extinction and the Central Atlantic Magmatic Province. In models proposing a causal connection between LIP magmatism and the environmental changes that lead to mass extinction, gases and particulates injected into the atmosphere are thought to cause abrupt changes in climate and ocean chemistry sufficient to drive mass extinction of marine and terrestrial biota. Magmatism has been proposed to cause voluminous volatile release via contact metamorphism of the sedimentary rocks. In the case of the Siberian Traps LIP, the compositions of sedimentary rocks (carbonates, evaporates, organic-rich shales) that host sills and dikes are ideal for greenhouse gas generation. When coupled with the enormous volume of Siberian LIP intrusive rocks, there is the potential for volatile generation on a scale necessary to drive environmental changes and mass extinction. This model must be tested by comparing the timing of intrusive magmatism with that of the mass extinction. Coupled high-precision geochronology and astrochronology have constrained the timing of biotic crisis and associated environmental perturbations from the deca-millennial to sub-millennial timescale, suggesting that the biotic crisis was abrupt, occurring over < 100 ka. Published geochronology on sills and dikes from the LIP are sparse and lack the necessary precision to resolve the relative timing of the two events outside of age uncertainty. We present new high-precision U-Pb zircon geochronology on seventeen gabbroic sills from throughout the magmatic province. This includes samples from the mineralized and differentiated intrusions in the Noril'sk region

  20. Development and Validation of High Precision Thermal, Mechanical, and Optical Models for the Space Interferometry Mission

    NASA Technical Reports Server (NTRS)

    Lindensmith, Chris A.; Briggs, H. Clark; Beregovski, Yuri; Feria, V. Alfonso; Goullioud, Renaud; Gursel, Yekta; Hahn, Inseob; Kinsella, Gary; Orzewalla, Matthew; Phillips, Charles

    2006-01-01

    SIM Planetquest (SIM) is a large optical interferometer for making microarcsecond measurements of the positions of stars, and to detect Earth-sized planets around nearby stars. To achieve this precision, SIM requires stability of optical components to tens of picometers per hour. The combination of SIM s large size (9 meter baseline) and the high stability requirement makes it difficult and costly to measure all aspects of system performance on the ground. To reduce risks, costs and to allow for a design with fewer intermediate testing stages, the SIM project is developing an integrated thermal, mechanical and optical modeling process that will allow predictions of the system performance to be made at the required high precision. This modeling process uses commercial, off-the-shelf tools and has been validated against experimental results at the precision of the SIM performance requirements. This paper presents the description of the model development, some of the models, and their validation in the Thermo-Opto-Mechanical (TOM3) testbed which includes full scale brassboard optical components and the metrology to test them at the SIM performance requirement levels.

  1. High-precision gamma-ray spectroscopy for enhancing production and application of medical isotopes

    NASA Astrophysics Data System (ADS)

    McCutchan, E. A.; Sonzogni, A. A.; Smith, S. V.; Muench, L.; Nino, M.; Greene, J. P.; Carpenter, M. P.; Zhu, S.; Chillery, T.; Chowdhury, P.; Harding, R.; Lister, C. J.

    2015-10-01

    Nuclear medicine is a field which requires precise decay data for use in planning radionuclide production and in imaging and therapeutic applications. To address deficiencies in decay data, sources of medical isotopes were produced and purified at the Brookhaven Linear Isotope Producer (BLIP) then shipped to Argonne National Laboratory where high-precision, gamma-ray measurements were performed using Gammasphere. New decay schemes for a number of PET isotopes and the impact on dose calculations will be presented. To investigate the production of next-generation theranostic or radiotherapeutic isotopes, cross section measurements with high energy protons have also been explored at BLIP. The 100-200 MeV proton energy regime is relatively unexplored for isotope production, thus offering high discovery potential but at the same time a challenging analysis due to the large number of open channels at these energies. Results of cross sections deduced from Compton-suppressed, coincidence gamma-ray spectroscopy performed at Lowell will be presented, focusing on the production of platinum isotopes by irradiating natural platinum foils with 100 to 200 MeV protons. DOE Isotope Program is acknowledged for funding ST5001030. Work supported by the US DOE under Grant DE-FG02-94ER40848 and Contracts DE-AC02-98CH10946 and DE-AC02-06CH11357.

  2. New high-precision 40Ar/39Ar ages on Oligocene volcanic rocks of northwestern Kenya

    NASA Astrophysics Data System (ADS)

    Brown, Francis H.; Jicha, Brian R.

    2016-02-01

    New, high-precision 40Ar/39Ar ages from volcanic rocks in northwestern Kenya are provided for some areas of exposure in this remote area. We report seven 40Ar/39Ar ages generated from single crystal total fusion experiments on alkali feldspar separated from volcanic rocks in the Mogila, Songot, and Lokwanamur Ranges and the Gatome valley. A rhyolite from the lower part of the sequence in the Mogila Range yielded ages of 32.31 ± 0.06 Ma and 32.33 ± 0.07 Ma, and a rhyolite near the top of that sequence yielded 31.67 ± 0.04 Ma. A single sample from the Songot Range yielded an age of 32.49 ± 0.07 Ma, slightly older than the rocks collected from Mogila. In both ranges the early Oligocene rhyolites are underlain by basalts, as is also the case in the Labur Range. Ages of 25.95 ± 0.03 Ma, 25.91 ± 0.04 Ma, and 27.15 ± 0.03 Ma were measured on alkali feldspar from rhyolites from the Lokwanamur Range, and the nearby Gatome valley. All of these rocks are part of an episode of widespread volcanism in northwestern Kenya in the mid-to late Oligocene that is not currently known from the Ethiopian Rift Valley.

  3. High-precision radiocarbon dating and historical biblical archaeology in southern Jordan.

    PubMed

    Levy, Thomas E; Higham, Thomas; Bronk Ramsey, Christopher; Smith, Neil G; Ben-Yosef, Erez; Robinson, Mark; Münger, Stefan; Knabb, Kyle; Schulze, Jürgen P; Najjar, Mohammad; Tauxe, Lisa

    2008-10-28

    Recent excavations and high-precision radiocarbon dating from the largest Iron Age (IA, ca. 1200-500 BCE) copper production center in the southern Levant demonstrate major smelting activities in the region of biblical Edom (southern Jordan) during the 10th and 9th centuries BCE. Stratified radiocarbon samples and artifacts were recorded with precise digital surveying tools linked to a geographic information system developed to control on-site spatial analyses of archaeological finds and model data with innovative visualization tools. The new radiocarbon dates push back by 2 centuries the accepted IA chronology of Edom. Data from Khirbat en-Nahas, and the nearby site of Rujm Hamra Ifdan, demonstrate the centrality of industrial-scale metal production during those centuries traditionally linked closely to political events in Edom's 10th century BCE neighbor ancient Israel. Consequently, the rise of IA Edom is linked to the power vacuum created by the collapse of Late Bronze Age (LB, ca. 1300 BCE) civilizations and the disintegration of the LB Cypriot copper monopoly that dominated the eastern Mediterranean. The methodologies applied to the historical IA archaeology of the Levant have implications for other parts of the world where sacred and historical texts interface with the material record.

  4. High-precision, automated integration of multiple isothermal titration calorimetric thermograms: new features of NITPIC

    PubMed Central

    Scheuermann, Thomas H.; Brautigam, Chad A.

    2014-01-01

    Isothermal titration calorimetry (ITC) has become a standard and widely available tool to measure the thermodynamic parameters of macromolecular associations. Modern applications of the method, including global analysis and drug screening, require the acquisition of multiple sets of data; sometimes these data sets number in the hundreds. Therefore, there is a need for quick, precise, and automated means to process the data, particularly at the first step of data analysis, which is commonly the integration of the raw data to yield an interpretable isotherm. Herein, we describe enhancements to an algorithm that previously has been shown to provide an automated, unbiased, and high-precision means to integrate ITC data. These improvements allow for the speedy and precise serial integration of an unlimited number of ITC data sets, and they have been implemented in the freeware program NITPIC, version 1.1.0. We present a comprehensive comparison of the performance of this software against an older version of NITPIC and a current version of Origin, which is commonly used for integration. The new methods recapitulate the excellent performance of the previous versions of NITPIC while speeding it up substantially, and their precision is significantly better than that of Origin. This new version of NITPIC is therefore well suited to the serial integration of many ITC data sets. PMID:25524420

  5. Direct high-precision measurement of the magnetic moment of the proton.

    PubMed

    Mooser, A; Ulmer, S; Blaum, K; Franke, K; Kracke, H; Leiteritz, C; Quint, W; Rodegheri, C C; Smorra, C; Walz, J

    2014-05-29

    One of the fundamental properties of the proton is its magnetic moment, µp. So far µp has been measured only indirectly, by analysing the spectrum of an atomic hydrogen maser in a magnetic field. Here we report the direct high-precision measurement of the magnetic moment of a single proton using the double Penning-trap technique. We drive proton-spin quantum jumps by a magnetic radio-frequency field in a Penning trap with a homogeneous magnetic field. The induced spin transitions are detected in a second trap with a strong superimposed magnetic inhomogeneity. This enables the measurement of the spin-flip probability as a function of the drive frequency. In each measurement the proton's cyclotron frequency is used to determine the magnetic field of the trap. From the normalized resonance curve, we extract the particle's magnetic moment in terms of the nuclear magneton: μp = 2.792847350(9)μN. This measurement outperforms previous Penning-trap measurements in terms of precision by a factor of about 760. It improves the precision of the forty-year-old indirect measurement, in which significant theoretical bound state corrections were required to obtain µp, by a factor of 3. By application of this method to the antiproton magnetic moment, the fractional precision of the recently reported value can be improved by a factor of at least 1,000. Combined with the present result, this will provide a stringent test of matter/antimatter symmetry with baryons.

  6. Research on high precision centering assembly method of roll edge optical elements

    NASA Astrophysics Data System (ADS)

    Liu, Hua; Liu, Xiaomei

    2015-08-01

    In order to improve the imaging quality of target imaging optical system, in the special environment of large temperature difference, the centering assembly precision of roll edge optical elements was studied. According to the hole-axis coordinate error theory of mechanics, by analyzing the factors affected the precision of mechanical heating surface, combining with the existing method to eliminate error and centering assembly process, a new kind of high precision centering assembly method was put forward. Using additional grinding device to grinding roll edge of optical element, eliminate the machining error on the surface of the mechanical hot working, thus improve the centering assembly precision between the roll edge optical element and lens tube. The result of experiment shows that the centering precision can reach less than 3μm when assembled optical element after roll edge using new centering assembly method, and improved by 25% compared to the traditional method of roll edge optical elements are assembled directly after hot working. New assembly method with additional grinding device can improve the centering assembly precision of roll edge optical elements, and greatly reduce the difficulty of optical design of such optical imaging system using in large temperature difference environment, when meet the same image quality.

  7. A high precision phase reconstruction algorithm for multi-laser guide stars adaptive optics

    NASA Astrophysics Data System (ADS)

    He, Bin; Hu, Li-Fa; Li, Da-Yu; Xu, Huan-Yu; Zhang, Xing-Yun; Wang, Shao-Xin; Wang, Yu-Kun; Yang, Cheng-Liang; Cao, Zhao-Liang; Mu, Quan-Quan; Lu, Xing-Hai; Xuan, Li

    2016-09-01

    Adaptive optics (AO) systems are widespread and considered as an essential part of any large aperture telescope for obtaining a high resolution imaging at present. To enlarge the imaging field of view (FOV), multi-laser guide stars (LGSs) are currently being investigated and used for the large aperture optical telescopes. LGS measurement is necessary and pivotal to obtain the cumulative phase distortion along a target in the multi-LGSs AO system. We propose a high precision phase reconstruction algorithm to estimate the phase for a target with an uncertain turbulence profile based on the interpolation. By comparing with the conventional average method, the proposed method reduces the root mean square (RMS) error from 130 nm to 85 nm with a 30% reduction for narrow FOV. We confirm that such phase reconstruction algorithm is validated for both narrow field AO and wide field AO. Project supported by the National Natural Science Foundation of China (Grant Nos. 11174274, 11174279, 61205021, 11204299, 61475152, and 61405194) and State Key Laboratory of Applied Optics, Changchun Institute of Optics, Fine Mechanics and Physics, Chinese Academy of Sciences.

  8. High-precision automatic online measurement system of engine block top surface holes

    NASA Astrophysics Data System (ADS)

    Yongqiang, Shi; Changku, Sun; Yukun, Ma; Hongxu, Duan; Peng, Wang

    2012-05-01

    The measurement of holes in the engine block top surface determines the general coupling effect of the engine. All of these holes are strictly restricted by the requirements of the dimensional tolerance and the geometrical tolerance, which determines the final engine quality. At present, these holes are measured mostly by the coordinate measuring machine (CMM) in the production line, and meeting the industry demands of automation, rapidity, and online testing with the method is difficult. A new rapid solution measuring the holes in the engine block top surface is proposed, which is based on the combination of multiple visual sensors. The flexible location method of the block is designed, and the global data fusion model based on multiple visual sensors is studied. Finally, the unified correction model of the lens distortion and the system inclination is proposed, and a revised system model with more precision is researched. The CMM measures the holes sizes and the spatial relationship between holes, and the data obtained are substituted into the global data fusion model to complete the system on-site rapid calibration. The experimental results show that the scheme is feasible. The measurement system can meet the production line needs of intelligence, rapidity, and high precision.

  9. Study of fringe tracking for high-precision space-based interferometers

    NASA Astrophysics Data System (ADS)

    Padilla, Carlos E.; Karlov, Valeri I.; Li, Jun; Chun, Hon M.; Tsitsiklis, John N.; Reasenberg, Robert D.

    1995-06-01

    The purpose of the fringe tracking algorithms is to maintain lock on the target star after acquisition and to obtain the most accurate estimate possible of the scientific quantity (or quantities) of interest in the presence of dynamic disturbances to the spacecraft/interferometer ensemble. This study carries out an analysis of the performance and robustness achievable by four candidate estimation techniques when applied to an ultra-high-precision fringe tracking task (5 micro-arcsecond ultimate accuracy). The first class of fringe trackers studied include the Extended Kalman Filter. This class is followed by extensions to second and third order nonlinear filters developed by the authors. The higher order filters have expanded regions of convergence. Third, we consider the use of an invariant filter (IF) to estimate the angle between two target stars (using POINTS as a test case). The IF offers the advantage of improved robustness in the dynamical case, being in effect `invariant' to dynamics. Finally Discrete Bayes Algorithms make use of Bayes' decision rule to propagate the a posteriori distribution of the true parameter and take into account the discrete character of the Poisson photon arrival events. Variations of these algorithms, known as multiple hypotheses trackers, offer great promise for dim star tracking. An exploration of filter performance with respect to several parameters is carried out analytically and selected Monte Carlo simulations are carried out both to verify analytical predictions and to study performance.

  10. High-precision lead isotopes and stripy plumes: Revisiting the Society chain in French Polynesia

    NASA Astrophysics Data System (ADS)

    Cordier, Carole; Chauvel, Catherine; Hémond, Christophe

    2016-09-01

    An increasing number of geochemical studies looked for spatial organization of the isotopic variations along Pacific volcanic island chains (e.g., Hawaii, Marquesas, Samoa and Society Islands) in order to discuss the possible zoning of the plume conduits. Here, we reexamine the occurrence of isotopic stripes in the Society archipelago in French Polynesia, using new Sr-Nd-Hf-Pb isotope ratios of sixty-six lavas from six islands (Mehetia, Moorea, Maupiti, Huahine, Raiatea, Bora-Bora). We demonstrate that the Pb isotope variability observed using literature data is an analytical artifact related to the poor control of mass fractionation during Pb measurements by conventional TIMS technique. New MC-ICP-MS Pb data demonstrate that the isotopic stripes as previously defined disappear. They rather show that individual islands cover a significant part of the entire isotopic range of the chain. We suggest, therefore, that the dominant characteristic of the Society plume is small-scale heterogeneities, evenly distributed within the plume conduit. At a global scale, we show that some ocean island chains with similar geochemical and isotopic characteristics, such as Samoa and Society Islands, define different arrays when variations of Nd with high-precision Pb isotopes are considered. We proposed that this puzzling observation might record differences in recycling age of the basalt + sediment mixture subducted into the mantle and sampled by mantle plume.

  11. High-precision x-ray spectroscopy in few-electron ions

    NASA Astrophysics Data System (ADS)

    LeBigot, E. O.; Boucard, S.; Covita, D. S.; Gotta, D.; Gruber, A.; Hirtl, A.; Fuhrmann, H.; Indelicato, P.; dos Santos, J. M. F.; Schlesser, S.; Simons, L. M.; Stingelin, L.; Trassinelli, M.; Veloso, J. F. C. A.; Wasser, A.; Zmeskal, J.

    2009-05-01

    The experimental and spectrum analysis procedures that led to about 15 new, high-precision, relative x-ray line energy measurements are presented. The measured lines may be used as x-ray reference lines in the 2.4-3.1 keV range. Applications also include tests of the atomic theory, and in particular of quantum electrodynamics and of relativistic many-body theory calculations. The lines originate from 2- to 4-electron ions of sulfur (Z=16), chlorine (Z=17) and argon (Z=18). The precision reached for their energy ranges from a few parts per million (ppm) to about 50 ppm. This places the new measurements among the most precise performed in mid-Z highly charged ions (Z is the nuclear charge number). The elements of the experimental setup are described: the ion source (an electron cyclotron resonance ion trap), the spectrometer (a single, spherically bent crystal spectrometer), as well as the spectrum acquisition camera (low-noise, high-efficiency CCD). The spectrum analysis procedure, which is based on a full simulation of the spectrometer response function, is also presented.

  12. A High Precision Position Sensor Design and Its Signal Processing Algorithm for a Maglev Train

    PubMed Central

    Xue, Song; Long, Zhiqiang; He, Ning; Chang, Wensen

    2012-01-01

    High precision positioning technology for a kind of high speed maglev train with an electromagnetic suspension (EMS) system is studied. At first, the basic structure and functions of the position sensor are introduced and some key techniques to enhance the positioning precision are designed. Then, in order to further improve the positioning signal quality and the fault-tolerant ability of the sensor, a new kind of discrete-time tracking differentiator (TD) is proposed based on nonlinear optimal control theory. This new TD has good filtering and differentiating performances and a small calculation load. It is suitable for real-time signal processing. The stability, convergence property and frequency characteristics of the TD are studied and analyzed thoroughly. The delay constant of the TD is figured out and an effective time delay compensation algorithm is proposed. Based on the TD technology, a filtering process is introduced in to improve the positioning signal waveform when the sensor is under bad working conditions, and a two-sensor switching algorithm is designed to eliminate the positioning errors caused by the joint gaps of the long stator. The effectiveness and stability of the sensor and its signal processing algorithms are proved by the experiments on a test train during a long-term test run. PMID:22778582

  13. Can we use high precision metal isotope analysis to improve our understanding of cancer?

    PubMed

    Larner, Fiona

    2016-01-01

    High precision natural isotope analyses are widely used in geosciences to trace elemental transport pathways. The use of this analytical tool is increasing in nutritional and disease-related research. In recent months, a number of groups have shown the potential this technique has in providing new observations for various cancers when applied to trace metal metabolism. The deconvolution of isotopic signatures, however, relies on mathematical models and geochemical data, which are not representative of the system under investigation. In addition to relevant biochemical studies of protein-metal isotopic interactions, technological development both in terms of sample throughput and detection sensitivity of these elements is now needed to translate this novel approach into a mainstream analytical tool. Following this, essential background healthy population studies must be performed, alongside observational, cross-sectional disease-based studies. Only then can the sensitivity and specificity of isotopic analyses be tested alongside currently employed methods, and important questions such as the influence of cancer heterogeneity and disease stage on isotopic signatures be addressed.

  14. The Spring 1985 high precision baseline test of the JPL GPS-based geodetic system

    NASA Technical Reports Server (NTRS)

    Davidson, John M.; Thornton, Catherine L.; Stephens, Scott A.; Blewitt, Geoffrey; Lichten, Stephen M.; Sovers, Ojars J.; Kroger, Peter M.; Skrumeda, Lisa L.; Border, James S.; Neilan, Ruth E.

    1987-01-01

    The Spring 1985 High Precision Baseline Test (HPBT) was conducted. The HPBT was designed to meet a number of objectives. Foremost among these was the demonstration of a level of accuracy of 1 to 2:10 to the 7th power, or better, for baselines ranging in length up to several hundred kilometers. These objectives were all met with a high degree of success, with respect to the demonstration of system accuracy in particular. The results from six baselines ranging in length from 70 to 729 km were examined for repeatability and, in the case of three baselines, were compared to results from colocated VLBI systems. Repeatability was found to be 5:10 to the 8th power (RMS) for the north baseline coordinate, independent of baseline length, while for the east coordinate RMS repeatability was found to be larger than this by factors of 2 to 4. The GPS-based results were found to be in agreement with those from colocated VLBI measurements, when corrected for the physical separations of the VLBI and CPG antennas, at the level of 1 to 2:10 to the 7th power in all coordinates, independent of baseline length. The results for baseline repeatability are consistent with the current GPA error budget, but the GPS-VLBI intercomparisons disagree at a somewhat larger level than expected. It is hypothesized that these differences may result from errors in the local survey measurements used to correct for the separations of the GPS and VLBI antenna reference centers.

  15. A high-precision sampling scheme to assess persistence and transport characteristics of micropollutants in rivers.

    PubMed

    Schwientek, Marc; Guillet, Gaëlle; Rügner, Hermann; Kuch, Bertram; Grathwohl, Peter

    2016-01-01

    Increasing numbers of organic micropollutants are emitted into rivers via municipal wastewaters. Due to their persistence many pollutants pass wastewater treatment plants without substantial removal. Transport and fate of pollutants in receiving waters and export to downstream ecosystems is not well understood. In particular, a better knowledge of processes governing their environmental behavior is needed. Although a lot of data are available concerning the ubiquitous presence of micropollutants in rivers, accurate data on transport and removal rates are lacking. In this paper, a mass balance approach is presented, which is based on the Lagrangian sampling scheme, but extended to account for precise transport velocities and mixing along river stretches. The calculated mass balances allow accurate quantification of pollutants' reactivity along river segments. This is demonstrated for representative members of important groups of micropollutants, e.g. pharmaceuticals, musk fragrances, flame retardants, and pesticides. A model-aided analysis of the measured data series gives insight into the temporal dynamics of removal processes. The occurrence of different removal mechanisms such as photooxidation, microbial degradation, and volatilization is discussed. The results demonstrate, that removal processes are highly variable in time and space and this has to be considered for future studies. The high precision sampling scheme presented could be a powerful tool for quantifying removal processes under different boundary conditions and in river segments with contrasting properties.

  16. High-precision iron isotope measurements of terrestrial and lunar materials

    NASA Astrophysics Data System (ADS)

    Beard, Brian L.; Johnson, Clark M.

    1999-06-01

    We present the analytical methods that have been developed for the first high-precision Fe isotope analyses that clearly identify naturally-occurring, mass-dependent isotope fractionation. A double-spike approach is used, which allows rigorous correction of instrumental mass fractionation. Based on 21 analyses of an ultra pure Fe standard, the external precision (1-SD) for measuring the isotopic composition of Fe is ±0.14 ‰/mass; for demonstrated reproducibility on samples, this precision exceeds by at least an order of magnitude that of previous attempts to empirically control instrumentally-produced mass fractionation (Dixon et al., 1993). Using the double-spike method, 15 terrestrial igneous rocks that range in composition from peridotite to rhyolite, 5 high-Ti lunar basalts, 5 Fe-Mn nodules, and a banded iron formation have been analyzed for their iron isotopic composition. The terrestrial and lunar igneous rocks have the same isotopic compositions as the ultra pure Fe standard, providing a reference Fe isotope composition for the Earth and Moon. In contrast, Fe-Mn nodules and a sample of a banded iron formation have iron isotope compositions that vary over a relatively wide range, from δ 56Fe = +0.9 to -1.2 ‰; this range is 15 times the analytical errors of our technique. These natural isotopic fractionations are interpreted to reflect biological ("vital") effects, and illustrate the great potential Fe isotope studies have for studying modern and ancient biological processes.

  17. Two Fabry-Perot interferometers for high precision wavelength calibration in the near-infrared

    NASA Astrophysics Data System (ADS)

    Schäfer, Sebastian; Reiners, Ansgar

    2012-09-01

    The most frequently used standard light sources for spectroscopic high precision wavelength calibration are hollow cathode lamps. These lamps, however, do not provide homogeneous line distribution and intensities. Particularly in the infrared, the number of useful lines is severely limited and the spectrum is contaminated by lines of the filler gas. With the goal of achieving sub m/s stability in the infrared, as required for detecting earthlike extra-solar planets, we are developing two passively stabilized Fabry-Perot interferometers for the red visible (600-1050nm) and near infrared wavelength regions (900-1350nm). Each of the two interferometers can produce ~15,000 lines of nearly constant brightness. The Fabry-Perot interferometers aim at a RV calibration precision of 10cm/s and are optimized in line shape and spacing for the infrared planet hunting CARMENES spectrograph that is currently being built for the Calar Alto 3.5m telescope. Here we present the first results of our work.

  18. An Online Gravity Modeling Method Applied for High Precision Free-INS.

    PubMed

    Wang, Jing; Yang, Gongliu; Li, Jing; Zhou, Xiao

    2016-01-01

    For real-time solution of inertial navigation system (INS), the high-degree spherical harmonic gravity model (SHM) is not applicable because of its time and space complexity, in which traditional normal gravity model (NGM) has been the dominant technique for gravity compensation. In this paper, a two-dimensional second-order polynomial model is derived from SHM according to the approximate linear characteristic of regional disturbing potential. Firstly, deflections of vertical (DOVs) on dense grids are calculated with SHM in an external computer. And then, the polynomial coefficients are obtained using these DOVs. To achieve global navigation, the coefficients and applicable region of polynomial model are both updated synchronously in above computer. Compared with high-degree SHM, the polynomial model takes less storage and computational time at the expense of minor precision. Meanwhile, the model is more accurate than NGM. Finally, numerical test and INS experiment show that the proposed method outperforms traditional gravity models applied for high precision free-INS. PMID:27669261

  19. Laser ablation and high precision patterning of biomaterials and intraocular lenses

    NASA Astrophysics Data System (ADS)

    Serafetinides, A. A.; Spyratou, E.; Makropoulou, M.

    2010-10-01

    The use of intraocular lenses (IOL) is the most promising method for restoring excellent vision in cataract surgery. In addition, multifocal intraocular lenses for good distant and near vision are investigated. Several new materials, techniques and patterns are studied for the formation and etching of intraocular lenses in order to improve their optical properties and reduce the diffractive aberrations. As pulsed laser ablation is well established as a universal tool for surface processing of organic polymer materials, this study was focused in using laser ablation with short and ultra short laser pulses for surface modification of PMMA and intraocular lenses, instead of using other conventional techniques. The main advantage of using very short laser pulses, e.g. of ns, ps or fs duration, is that heat diffusion into the polymer material is negligible. As a result high precision patterning of the sample, without thermal damage of the surroundings, becomes possible. In this study, laser ablation was performed using commercially available hydrophobic acrylic IOLs, hydrophilic acrylic IOLs, and PMMA IOLs, with various diopters. We investigated the ablation efficiency and the phenomenology of the etched patterns by testing the ablation rate, versus laser energy fluence, at several wavelengths and the surface modification with atomic force microscopy (AFM), or scanning electron microscopy (SEM). The irradiated polymers have different optical properties, at the applied wavelengths, and therefore, present different ablation behaviour and morphology of the laser ablated crater walls and surrounding surfaces. The experimental results, some theoretical assumptions for mathematical modeling of the relevant ablation mechanisms are discussed.

  20. High-precision mass measurements of 25Al and 30P at JYFLTRAP

    NASA Astrophysics Data System (ADS)

    Canete, L.; Kankainen, A.; Eronen, T.; Gorelov, D.; Hakala, J.; Jokinen, A.; Kolhinen, V. S.; Koponen, J.; Moore, I. D.; Reinikainen, J.; Rinta-Antila, S.

    2016-05-01

    The masses of the astrophysically relevant nuclei 25Al and 30P have been measured with a Penning trap for the first time. The mass-excess values for 25Al ( Δ = -8915.962(63) keV) and 30P ( Δ = -20200.854(64) keV) obtained with the JYFLTRAP double Penning trap mass spectrometer are in good agreement with the Atomic Mass Evaluation 2012 values but ≈ 5-10 times more precise. A high precision is required for calculating resonant proton-capture rates of astrophysically important reactions 25Al ( p, γ)26Si and 30P( p, γ)31S . In this work, Q_{(p,γ)} = 5513.99(13) keV and Q_{(p,γ)} = 6130.64(24) keV were obtained for 25Al and 30P , respectively. The effect of the more precise values on the resonant proton-capture rates has been studied. In addition to nuclear astrophysics, the measured QEC value of 25Al , 4276.805(45) keV, is relevant for studies of T = 1/2 mirror beta decays which have a potential to be used to test the Conserved Vector Current hypothesis.

  1. A polynomial phase-shift algorithm for high precision three-dimensional profilometry

    NASA Astrophysics Data System (ADS)

    Deng, Fuqin; Liu, Chang; Sze, Wuifung; Deng, Jiangwen; Fung, Kenneth S. M.; Lam, Edmund Y.

    2013-03-01

    The perspective effect is common in real optical systems using projected patterns for machine vision applications. In the past, the frequencies of these sinusoidal patterns are assumed to be uniform at different heights when reconstructing moving objects. Therefore, the error caused by a perspective projection system becomes pronounced in phase-measuring profilometry, especially for some high precision metrology applications such as measuring the surfaces of the semiconductor components at micrometer level. In this work, we investigate the perspective effect on phase-measuring profilometry when reconstructing the surfaces of moving objects. Using a polynomial to approximate the phase distribution under a perspective projection system, which we call a polynomial phase-measuring profilometry (P-PMP) model, we are able to generalize the phase-measuring profilometry model discussed in our previous work and solve the phase reconstruction problem effectively. Furthermore, we can characterize how the frequency of the projected pattern changes according to the height variations and how the phase of the projected pattern distributes in the measuring space. We also propose a polynomial phase-shift algorithm (P-PSA) to correct the phase-shift error due to perspective effect during phase reconstruction. Simulation experiments show that the proposed method can improve the reconstruction quality both visually and numerically.

  2. Recent developments for high-precision mass measurements of the heaviest elements at SHIPTRAP

    NASA Astrophysics Data System (ADS)

    Minaya Ramirez, E.; Ackermann, D.; Blaum, K.; Block, M.; Droese, C.; Düllmann, Ch. E.; Eibach, M.; Eliseev, S.; Haettner, E.; Herfurth, F.; Heßberger, F. P.; Hofmann, S.; Marx, G.; Nesterenko, D.; Novikov, Yu. N.; Plaß, W. R.; Rodríguez, D.; Scheidenberger, C.; Schweikhard, L.; Thirolf, P. G.; Weber, C.

    2013-12-01

    Atomic nuclei far from stability continue to challenge our understanding. For example, theoretical models have predicted an “island of stability” in the region of the superheavy elements due to the closure of spherical proton and neutron shells. Depending on the model, these are expected at Z = 114, 120 or even 126 and N = 172 or 184. Valuable information on the road to the island of stability is derived from high-precision mass measurements, which give direct access to binding energies of short-lived trans-uranium nuclei. Recently, direct mass measurements at SHIPTRAP have been extended to nobelium and lawrencium isotopes around the deformed shell gap N = 152. In order to further extend mass measurements to the region of superheavy elements, new technical developments are required to increase the performance of our setup. The sensitivity will increase through the implementation of a new detection method, where observation of one single ion is sufficient. Together with the use of a more efficient gas stopping cell, this will us allow to significantly enhance the overall efficiency of SHIPTRAP.

  3. Development and simulation of microfluidic Wheatstone bridge for high-precision sensor

    NASA Astrophysics Data System (ADS)

    Shipulya, N. D.; Konakov, S. A.; VKrzhizhanovskaya, V.

    2016-08-01

    In this work we present the results of analytical modeling and 3D computer simulation of microfluidic Wheatstone bridge, which is used for high-accuracy measurements and precision instruments. We propose and simulate a new method of a bridge balancing process by changing the microchannel geometry. This process is based on the “etching in microchannel” technology we developed earlier (doi:10.1088/1742-6596/681/1/012035). Our method ensures a precise control of the flow rate and flow direction in the bridge microchannel. The advantage of our approach is the ability to work without any control valves and other active electronic systems, which are usually used for bridge balancing. The geometrical configuration of microchannels was selected based on the analytical estimations. A detailed 3D numerical model was based on Navier-Stokes equations for a laminar fluid flow at low Reynolds numbers. We investigated the behavior of the Wheatstone bridge under different process conditions; found a relation between the channel resistance and flow rate through the bridge; and calculated the pressure drop across the system under different total flow rates and viscosities. Finally, we describe a high-precision microfluidic pressure sensor that employs the Wheatstone bridge and discuss other applications in complex precision microfluidic systems.

  4. HIGH PRECISION K-SHELL PHOTOABSORPTION CROSS SECTIONS FOR ATOMIC OXYGEN: EXPERIMENT AND THEORY

    SciTech Connect

    McLaughlin, B. M.; Ballance, C. P.; Bowen, K. P.; Gardenghi, D. J.; Stolte, W. C. E-mail: ballance@physics.auburn.edu E-mail: dgardenghi@gmail.com

    2013-07-01

    Photoabsorption of atomic oxygen in the energy region below the 1s {sup -1} threshold in X-ray spectroscopy from Chandra and XMM-Newton is observed in a variety of X-ray binary spectra. Photoabsorption cross sections determined from an R-matrix method with pseudo-states and new, high precision measurements from the Advanced Light Source (ALS) are presented. High-resolution spectroscopy with E/{Delta}E Almost-Equal-To 4250 {+-} 400 was obtained for photon energies from 520 eV to 555 eV at an energy resolution of 124 {+-} 12 meV FWHM. K-shell photoabsorption cross section measurements were made with a re-analysis of previous experimental data on atomic oxygen at the ALS. Natural line widths {Gamma} are extracted for the 1s {sup -1}2s {sup 2}2p {sup 4}({sup 4} P)np {sup 3} P Degree-Sign and 1s {sup -1}2s {sup 2}2p {sup 4}({sup 2} P)np {sup 3} P Degree-Sign Rydberg resonances series and compared with theoretical predictions. Accurate cross sections and line widths are obtained for applications in X-ray astronomy. Excellent agreement between theory and the ALS measurements is shown which will have profound implications for the modeling of X-ray spectra and spectral diagnostics.

  5. THE APPLICATION OF MULTIVIEW METHODS FOR HIGH-PRECISION ASTROMETRIC SPACE VLBI AT LOW FREQUENCIES

    SciTech Connect

    Dodson, R.; Rioja, M.; Imai, H.; Asaki, Y.; Hong, X.-Y.; Shen, Z.

    2013-06-15

    High-precision astrometric space very long baseline interferometry (S-VLBI) at the low end of the conventional frequency range, i.e., 20 cm, is a requirement for a number of high-priority science goals. These are headlined by obtaining trigonometric parallax distances to pulsars in pulsar-black hole pairs and OH masers anywhere in the Milky Way and the Magellanic Clouds. We propose a solution for the most difficult technical problems in S-VLBI by the MultiView approach where multiple sources, separated by several degrees on the sky, are observed simultaneously. We simulated a number of challenging S-VLBI configurations, with orbit errors up to 8 m in size and with ionospheric atmospheres consistent with poor conditions. In these simulations we performed MultiView analysis to achieve the required science goals. This approach removes the need for beam switching requiring a Control Moment Gyro, and the space and ground infrastructure required for high-quality orbit reconstruction of a space-based radio telescope. This will dramatically reduce the complexity of S-VLBI missions which implement the phase-referencing technique.

  6. A micro-computer based system for high precision temperature measurement using Platinum RTD's

    NASA Astrophysics Data System (ADS)

    Matthew, W. T.

    1982-07-01

    A micro-computer controlled system for 10 channel high precision temperature data acquisition has been developed. The temperature sensing elements are Platinum Resistance Thermometer Devices (RTD's). Probe construction, using standard, commercially available RTD elements is described and wiring and switching requirements for the 4-wire resistance measurements are noted. The system consists of a Digital Equipment Corp. MINC-11 Computer linked, via IEEE-488 interface bus cables, to a HP (Hewlett-Packard) 34555A Digital Volt/Ohm Meter, an HP-3495A Scanner/Multiplexer, and, during calibration, a HP 2804A Quartz Thermometer. Two programs are employed: one for probe calibration and the other for the temperature measurement application. In the calibration program, the ten probes are individually calibrated against the Quartz Thermometer which has an absolute accuracy specification of + or 0.04 C. A proportional control water bath having a thermal stability specification of + or - 0.004 C provided the common thermal medium during calibration. Currently a three point calibration spanning 6 C (37 to 43 C) is employed. The individual probe constants are computed and recorded on a computer file for access via the temperature measurement program. An initial evaluation of the precision of the calibrated RTD system against the Quartz Thermometer reading yielded an overall precision of + or - 0.0004 C and worst case error of less than + or - 0.01 C.

  7. High-precision radiocarbon dating and historical biblical archaeology in southern Jordan

    PubMed Central

    Levy, Thomas E.; Higham, Thomas; Bronk Ramsey, Christopher; Smith, Neil G.; Ben-Yosef, Erez; Robinson, Mark; Münger, Stefan; Knabb, Kyle; Schulze, Jürgen P.; Najjar, Mohammad; Tauxe, Lisa

    2008-01-01

    Recent excavations and high-precision radiocarbon dating from the largest Iron Age (IA, ca. 1200–500 BCE) copper production center in the southern Levant demonstrate major smelting activities in the region of biblical Edom (southern Jordan) during the 10th and 9th centuries BCE. Stratified radiocarbon samples and artifacts were recorded with precise digital surveying tools linked to a geographic information system developed to control on-site spatial analyses of archaeological finds and model data with innovative visualization tools. The new radiocarbon dates push back by 2 centuries the accepted IA chronology of Edom. Data from Khirbat en-Nahas, and the nearby site of Rujm Hamra Ifdan, demonstrate the centrality of industrial-scale metal production during those centuries traditionally linked closely to political events in Edom's 10th century BCE neighbor ancient Israel. Consequently, the rise of IA Edom is linked to the power vacuum created by the collapse of Late Bronze Age (LB, ca. 1300 BCE) civilizations and the disintegration of the LB Cypriot copper monopoly that dominated the eastern Mediterranean. The methodologies applied to the historical IA archaeology of the Levant have implications for other parts of the world where sacred and historical texts interface with the material record. PMID:18955702

  8. High precision landing site mapping and rover localization for Chang'e-3 mission

    NASA Astrophysics Data System (ADS)

    Liu, ZhaoQin; Di, KaiChang; Peng, Man; Wan, WenHui; Liu, Bin; Li, LiChun; Yu, TianYi; Wang, BaoFeng; Zhou, JianLiang; Chen, HongMin

    2015-01-01

    This paper presents the comprehensive results of landing site topographic mapping and rover localization in Chang'e-3 mission. High-precision topographic products of the landing site with extremely high resolutions (up to 0.05 m) were generated from descent images and registered to CE-2 DOM. Local DEM and DOM with 0.02 m resolution were produced routinely at each waypoint along the rover traverse. The lander location was determined to be (19.51256°W, 44.11884°N, -2615.451 m) using a method of DOM matching. In order to reduce error accumulation caused by wheel slippage and IMU drift in dead reckoning, cross-site visual localization and DOM matching localization methods were developed to localize the rover at waypoints; the overall traveled distance from the lander is 114.8 m from cross-site visual localization and 111.2 m from DOM matching localization. The latter is of highest accuracy and has been verified using a LRO NAC image where the rover trajeactory is directly identifiable. During CE-3 mission operations, landing site mapping and rover localization products including DEMs and DOMs, traverse maps, vertical traverse profiles were generated timely to support teleoperation tasks such as obstacle avoidance and rover path planning.

  9. High precision U-PB geochronology and implications for the tectonic evolution of the Superior Province

    NASA Technical Reports Server (NTRS)

    Davis, D. W.; Corfu, F.; Krogh, T. E.

    1986-01-01

    The underlying mechanisms of Archean tectonics and the degree to which modern plate tectonic models are applicable early in Earth's history continue to be a subject of considerable debate. A precise knowledge of the timing of geological events is of the utmost importance in studying this problem. The high precision U-Pb method has been applied in recent years to rock units in many areas of the Superior Province. Most of these data have precisions of about + or - 2-3 Ma. The resulting detailed chronologies of local igneous development and the regional age relationships furnish tight constraints on any Archean tectonic model. Superior province terrains can be classified into 3 types: (1) low grade areas dominated by meta-volcanic rocks (greenstone belts); (2) high grade, largely metaplutonic areas with abundant orthogneiss and foliated to massive I-type granitoid bodies; and (3) high grade areas with abundant metasediments, paragneiss and S-type plutons. Most of the U-Pb age determinations have been done on type 1 terrains with very few having been done in type 3 terrains. A compilation of over 120 ages indicates that the major part of igneous activity took place in the period 2760-2670 Ma, known as the Kenoran event. This event was ubiquitous throughout the Superior Province.

  10. A novel power source for high-precision, highly efficient micro w-EDM

    NASA Astrophysics Data System (ADS)

    Chen, Shun-Tong; Chen, Chi-Hung

    2015-07-01

    The study presents the development of a novel power source for high-precision, highly efficient machining of micropart microstructures using micro wire electrical discharge machining (w-EDM). A novel power source based on a pluri resistance-capacitance (pRC) circuit that can generate a high-frequency, high-peak current with a short pulse train is proposed and designed to enhance the performance of micro w-EDM processes. Switching between transistors is precisely controlled in the designed power source to create a high-frequency short-pulse train current. Various microslot cutting tests in both aluminum and copper alloys are conducted. Experimental results demonstrate that the pRC power source creates instant spark erosion resulting in markedly less material for removal, diminishing discharge crater size, and consequently an improved surface finish. A new evaluation approach for spark erosion ability (SEA) to assess the merits of micro EDM power sources is also proposed. In addition to increasing the speed of micro w-EDM by increasing wire feed rates by 1.6 times the original feed rate, the power source is more appropriate for machining micropart microstructures since there is less thermal breaking. Satisfactory cutting of an elaborate miniature hook-shaped structure and a high-aspect ratio microstructure with a squared-pillar array also reveal that the developed pRC power source is effective, and should be very useful in the manufacture of intricate microparts.

  11. A new, high-precision measurement of the X-ray Cu K α spectrum

    NASA Astrophysics Data System (ADS)

    Mendenhall, Marcus H.; Cline, James P.; Henins, Albert; Hudson, Lawrence T.; Szabo, Csilla I.; Windover, Donald

    2016-03-01

    One of the primary measurement issues addressed with NIST Standard Reference Materials (SRMs) for powder diffraction is that of line position. SRMs for this purpose are certified with respect to lattice parameter, traceable to the SI through precise measurement of the emission spectrum of the X-ray source. Therefore, accurate characterization of the emission spectrum is critical to a minimization of the error bounds on the certified parameters. The presently accepted sources for the SI traceable characterization of the Cu K α emission spectrum are those of Härtwig, Hölzer et al., published in the 1990s. The structure of the X-ray emission lines of the Cu K α complex has been remeasured on a newly commissioned double-crystal instrument, with six-bounce Si (440) optics, in a manner directly traceable to the SI definition of the meter. In this measurement, the entire region from 8020 eV to 8100 eV has been covered with a highly precise angular scale and well-defined system efficiency, providing accurate wavelengths and relative intensities. This measurement is in modest disagreement with reference values for the wavelength of the Kα1 line, and strong disagreement for the wavelength of the Kα2 line.

  12. Methods for high precision 14C AMS measurement of atmospheric CO2 at LLNL

    SciTech Connect

    Graven, H D; Guilderson, T P; Keeling, R F

    2006-10-18

    Development of {sup 14}C analysis with precision better than 2{per_thousand} has the potential to expand the utility of {sup 14}CO{sub 2} measurements for carbon cycle investigations as atmospheric gradients currently approach traditional measurement precision of 2-5{per_thousand}. The AMS facility at the Center for Accelerator Mass Spectrometry, Lawrence Livermore National Laboratory, produces high and stable beam currents that enable efficient acquisition times for large numbers of {sup 14}C counts. One million {sup 14}C atoms can be detected in approximately 25 minutes, suggesting that near 1{per_thousand} counting precision is economically feasible at LLNL. The overall uncertainty in measured values is ultimately determined by the variation between measured ratios in several sputtering periods of the same sample and by the reproducibility of replicate samples. Experiments on the collection of one million counts on replicate samples of CO{sub 2} extracted from a whole air cylinder show a standard deviation of 1.7{per_thousand} in 36 samples measured over several wheels. This precision may be limited by the reproducibility of Oxalic Acid I standard samples, which is considerably poorer. We outline the procedures for high-precision sample handling and analysis that have enabled reproducibility in the cylinder extraction samples at the <2{per_thousand} level and describe future directions to continue increasing measurement precision at LLNL.

  13. A high precision phase reconstruction algorithm for multi-laser guide stars adaptive optics

    NASA Astrophysics Data System (ADS)

    He, Bin; Hu, Li-Fa; Li, Da-Yu; Xu, Huan-Yu; Zhang, Xing-Yun; Wang, Shao-Xin; Wang, Yu-Kun; Yang, Cheng-Liang; Cao, Zhao-Liang; Mu, Quan-Quan; Lu, Xing-Hai; Xuan, Li

    2016-09-01

    Adaptive optics (AO) systems are widespread and considered as an essential part of any large aperture telescope for obtaining a high resolution imaging at present. To enlarge the imaging field of view (FOV), multi-laser guide stars (LGSs) are currently being investigated and used for the large aperture optical telescopes. LGS measurement is necessary and pivotal to obtain the cumulative phase distortion along a target in the multi-LGSs AO system. We propose a high precision phase reconstruction algorithm to estimate the phase for a target with an uncertain turbulence profile based on the interpolation. By comparing with the conventional average method, the proposed method reduces the root mean square (RMS) error from 130 nm to 85 nm with a 30% reduction for narrow FOV. We confirm that such phase reconstruction algorithm is validated for both narrow field AO and wide field AO. Project supported by the National Natural Science Foundation of China (Grant Nos. 11174274, 11174279, 61205021, 11204299, 61475152, and 61405194) and State Key Laboratory of Applied Optics, Changchun Institute of Optics, Fine Mechanics and Physics, Chinese Academy of Sciences.

  14. High-precision, automated integration of multiple isothermal titration calorimetric thermograms: new features of NITPIC.

    PubMed

    Scheuermann, Thomas H; Brautigam, Chad A

    2015-04-01

    Isothermal titration calorimetry (ITC) has become a standard and widely available tool to measure the thermodynamic parameters of macromolecular associations. Modern applications of the method, including global analysis and drug screening, require the acquisition of multiple sets of data; sometimes these data sets number in the hundreds. Therefore, there is a need for quick, precise, and automated means to process the data, particularly at the first step of data analysis, which is commonly the integration of the raw data to yield an interpretable isotherm. Herein, we describe enhancements to an algorithm that previously has been shown to provide an automated, unbiased, and high-precision means to integrate ITC data. These improvements allow for the speedy and precise serial integration of an unlimited number of ITC data sets, and they have been implemented in the freeware program NITPIC, version 1.1.0. We present a comprehensive comparison of the performance of this software against an older version of NITPIC and a current version of Origin, which is commonly used for integration. The new methods recapitulate the excellent performance of the previous versions of NITPIC while speeding it up substantially, and their precision is significantly better than that of Origin. This new version of NITPIC is therefore well suited to the serial integration of many ITC data sets. PMID:25524420

  15. A high-precision sampling scheme to assess persistence and transport characteristics of micropollutants in rivers.

    PubMed

    Schwientek, Marc; Guillet, Gaëlle; Rügner, Hermann; Kuch, Bertram; Grathwohl, Peter

    2016-01-01

    Increasing numbers of organic micropollutants are emitted into rivers via municipal wastewaters. Due to their persistence many pollutants pass wastewater treatment plants without substantial removal. Transport and fate of pollutants in receiving waters and export to downstream ecosystems is not well understood. In particular, a better knowledge of processes governing their environmental behavior is needed. Although a lot of data are available concerning the ubiquitous presence of micropollutants in rivers, accurate data on transport and removal rates are lacking. In this paper, a mass balance approach is presented, which is based on the Lagrangian sampling scheme, but extended to account for precise transport velocities and mixing along river stretches. The calculated mass balances allow accurate quantification of pollutants' reactivity along river segments. This is demonstrated for representative members of important groups of micropollutants, e.g. pharmaceuticals, musk fragrances, flame retardants, and pesticides. A model-aided analysis of the measured data series gives insight into the temporal dynamics of removal processes. The occurrence of different removal mechanisms such as photooxidation, microbial degradation, and volatilization is discussed. The results demonstrate, that removal processes are highly variable in time and space and this has to be considered for future studies. The high precision sampling scheme presented could be a powerful tool for quantifying removal processes under different boundary conditions and in river segments with contrasting properties. PMID:26283620

  16. High precision optical cavity length and width measurements using double modulation.

    PubMed

    Staley, A; Hoak, D; Effler, A; Izumi, K; Dwyer, S; Kawabe, K; King, E J; Rakhmanov, M; Savage, R L; Sigg, D

    2015-07-27

    We use doubly phase modulated light to measure both the length and the linewidth of an optical resonator with high precision. The first modulation is at RF frequencies and is set near a multiple of the free spectral range, whereas the second modulation is at audio frequencies to eliminate offset errors at DC. The light in transmission or in reflection of the optical resonator is demodulated while sweeping the RF frequency over the optical resonance. We derive expressions for the demodulated power in transmission, and show that the zero crossings of the demodulated signal in transmission serve as a precise measure of the cavity linewidth at half maximum intensity. We demonstrate the technique on two resonant cavities, with lengths 16 m and a 4 km, and achieve an absolute length accuracy as low as 70 ppb. The cavity width for the 16 m cavity was determined with an accuracy of approximately 6000 ppm. Through an analysis of the systematic errors we show that this result could be substantially improved with the reduction of technical sources of uncertainty. PMID:26367601

  17. High-Precision Temperature Control of a Crystal Growth Furnace at 1,500 C

    NASA Technical Reports Server (NTRS)

    Stenzel, Ch.; Hess, A.; Croell, A.; Breuer, D.; Sauermann, H.

    2012-01-01

    For crystal growth of semiconductor materials a short-term temperature stability of 0.1 C at 1500 C is one of the essential parameters to be addressed for achieving high-quality crystals. Hence, for temperature monitoring and control with high precision in a floating zone furnace two sets of thermo-sensors, type B thermocouples and optical fibre thermometers, have been implemented and successfully operated in the furnace for more than 2000 h. The optical fibre thermometers consist of an optical system made of sapphire (two fibres plus a prism in between for deflection) and transmit the infra-red radiation of the heater to the outside of the hot core of the furnace for pyrometric temperature measurement. A dedicated control algorithm has been set up which controlled the power settings to the individual heaters. Both sensor types showed no degradation after this period and yielded a short-term stability at 1200 C of 0.05 C (optical fibre thermometers), respectively 0.08 C (thermocouples).

  18. A high precision position sensor design and its signal processing algorithm for a maglev train.

    PubMed

    Xue, Song; Long, Zhiqiang; He, Ning; Chang, Wensen

    2012-01-01

    High precision positioning technology for a kind of high speed maglev train with an electromagnetic suspension (EMS) system is studied. At first, the basic structure and functions of the position sensor are introduced and some key techniques to enhance the positioning precision are designed. Then, in order to further improve the positioning signal quality and the fault-tolerant ability of the sensor, a new kind of discrete-time tracking differentiator (TD) is proposed based on nonlinear optimal control theory. This new TD has good filtering and differentiating performances and a small calculation load. It is suitable for real-time signal processing. The stability, convergence property and frequency characteristics of the TD are studied and analyzed thoroughly. The delay constant of the TD is figured out and an effective time delay compensation algorithm is proposed. Based on the TD technology, a filtering process is introduced in to improve the positioning signal waveform when the sensor is under bad working conditions, and a two-sensor switching algorithm is designed to eliminate the positioning errors caused by the joint gaps of the long stator. The effectiveness and stability of the sensor and its signal processing algorithms are proved by the experiments on a test train during a long-term test run.

  19. High-precision control of piezoelectric nanopositioning stages using hysteresis compensator and disturbance observer

    NASA Astrophysics Data System (ADS)

    Gu, Guo-Ying; Zhu, Li-Min; Su, Chun-Yi

    2014-10-01

    This paper proposes a novel high-performance control scheme with hysteresis compensator and disturbance observer for high-precision motion control of a nanopositioning stage driven by a piezoelectric stack actuator (PSA). In the developed control scheme, a real-time inverse hysteresis compensator (IHC) with the modified Prandtl-Ishlinskii model is firstly designed to compensate for the asymmetric hysteresis nonlinearity of the PSA. Due to the imperfect compensation, the dynamics behaviors of the PSA-actuated stage with the IHC can be treated as a linear dynamic system plus a lumped disturbance term. Owing to the unknown nature of this lumped disturbance term, a disturbance observer (DOB) is used as a means for disturbance rejection. With the DOB, a tracking controller is finally designed and implemented to stabilize the position error. To verify the proposed control scheme, a real-time experimental platform with a PSA-actuated nanopositioning stage is built, and extensive experimental tests are performed. The comparative experimental results demonstrate the effectiveness and improved performance of the developed control approach in terms of the maximum-value errors, root-mean-square-value errors and hysteresis compensation.

  20. Diode Laser-based Sensor for High Precision Measurements of Ambient CO2

    NASA Astrophysics Data System (ADS)

    Sonnenfroh, D. M.; Parameswaran, K.; Varner, R.

    2008-12-01

    We report on the development of a new, high precision sensor for monitoring ambient CO2. This economical, robust, autonomous CO2 sensor is intended for widespread deployment in networks. We have developed a tunable diode laser-based absorption spectrometer, operating at a wavelength of 2 "Ým, which utilizes Integrated Cavity Output Spectroscopy (ICOS) to create an optical pathlength of 60 m in a physical pathlength of 20 cm. The sensor also uses Wavelength Modulation Spectroscopy for high sensitivity detection. We have achieved a precision of better than 1 part in 3000 for the dry air mixing ratio of CO2 for a 1 minute averaging period. The sensor design ensures a measurement cell having a small sample volume, which decreases the consumption of calibration gases. We also use an integrated dedicated microprocessor-based controller and signal processing electronics to achieve a small footprint. The sensor measures 20 x 43 x 56 cm and weighs 15 kg. The prototype was demonstrated at the University of New Hampshire's Atmospheric Observatory at Thompson Farm, in Durham, NH during June and July 2008. It was successfully intercompared with an NDIR sensor and operated automatically around the clock for 6 weeks. It was also intercompared with the NOAA NDIR sensor at the Boulder Atmospheric Observatory in Erie, CO in September 2008.

  1. High precision quantum-chemical treatment of adsorption: Benchmarking physisorption of molecular hydrogen on graphane.

    PubMed

    Usvyat, Denis

    2015-09-14

    A multilevel hierarchical ab initio protocol for calculating adsorption on non-conducting surfaces is presented. It employs fully periodic treatment, which reaches local Møller-Plesset perturbation theory of second order (MP2) with correction for the basis set incompleteness via the local F12 technique. Post-MP2 corrections are calculated using finite clusters. That includes the coupled cluster treatment in the local and canonical frameworks (up to perturbative quadruples) and correlated core (with MP2). Using this protocol, the potential surface of hydrogen molecules adsorbed on graphane was computed. According to the calculations, hydrogen molecules are adsorbed on graphane in a perpendicular to the surface orientation with the minimum of the potential surface of around -3.6 kJ/mol located at the distance of 3.85 Å between the bond center of the hydrogen molecule and the mid-plane of graphane. The adsorption sites along the path from the downward-pointing carbon to the ring center of the graphane are energetically virtually equally preferable, which can enable nearly free translations of hydrogen molecules along these paths. Consequently, the hydrogen molecules on graphane most likely form a non-commensurate monolayer. The analysis of the remaining errors reveals a very high accuracy of the computed potential surface with an error bar of a few tenths of a kJ/mol. The obtained results are a high-precision benchmark for further theoretical and experimental studies of hydrogen molecules interacting with graphane.

  2. High precision quantum-chemical treatment of adsorption: Benchmarking physisorption of molecular hydrogen on graphane

    NASA Astrophysics Data System (ADS)

    Usvyat, Denis

    2015-09-01

    A multilevel hierarchical ab initio protocol for calculating adsorption on non-conducting surfaces is presented. It employs fully periodic treatment, which reaches local Møller-Plesset perturbation theory of second order (MP2) with correction for the basis set incompleteness via the local F12 technique. Post-MP2 corrections are calculated using finite clusters. That includes the coupled cluster treatment in the local and canonical frameworks (up to perturbative quadruples) and correlated core (with MP2). Using this protocol, the potential surface of hydrogen molecules adsorbed on graphane was computed. According to the calculations, hydrogen molecules are adsorbed on graphane in a perpendicular to the surface orientation with the minimum of the potential surface of around -3.6 kJ/mol located at the distance of 3.85 Å between the bond center of the hydrogen molecule and the mid-plane of graphane. The adsorption sites along the path from the downward-pointing carbon to the ring center of the graphane are energetically virtually equally preferable, which can enable nearly free translations of hydrogen molecules along these paths. Consequently, the hydrogen molecules on graphane most likely form a non-commensurate monolayer. The analysis of the remaining errors reveals a very high accuracy of the computed potential surface with an error bar of a few tenths of a kJ/mol. The obtained results are a high-precision benchmark for further theoretical and experimental studies of hydrogen molecules interacting with graphane.

  3. Creating high-stability high-precision bipolar trim power supply

    SciTech Connect

    Chen, Zhe; Merz, William A.

    2012-07-01

    Thomas Jefferson National Accelerator Facility (TJNAF) is founded by the US Department of Energy (DOE) office of science for the technology advancement and physics research in electron beam accelerator. This facility has the state of the art technology to carry out world-class cutting-edge experiments for the nucleus composition and atomic characteristics identification and exploration for the nature of the matter in the universe. A continuous wave electron beam is featured for such experiments, thus precise and stable trim power supply is required to meet such purpose. This paper demonstrates the challenges and solutions to design, assemble, fabrication and test such high-precision high-stability power supplies. This paper presents the novel design and first article test of the ±20A ±75V bipolar, 100ppm stability level current-regulated high-power trim power supplies for the beam manipulation. This special design can provide valuable documentation and reference values for future designs and special applications in particle accelerator power supply creation.

  4. High precision quantum-chemical treatment of adsorption: Benchmarking physisorption of molecular hydrogen on graphane

    SciTech Connect

    Usvyat, Denis

    2015-09-14

    A multilevel hierarchical ab initio protocol for calculating adsorption on non-conducting surfaces is presented. It employs fully periodic treatment, which reaches local Møller-Plesset perturbation theory of second order (MP2) with correction for the basis set incompleteness via the local F12 technique. Post-MP2 corrections are calculated using finite clusters. That includes the coupled cluster treatment in the local and canonical frameworks (up to perturbative quadruples) and correlated core (with MP2). Using this protocol, the potential surface of hydrogen molecules adsorbed on graphane was computed. According to the calculations, hydrogen molecules are adsorbed on graphane in a perpendicular to the surface orientation with the minimum of the potential surface of around −3.6 kJ/mol located at the distance of 3.85 Å between the bond center of the hydrogen molecule and the mid-plane of graphane. The adsorption sites along the path from the downward-pointing carbon to the ring center of the graphane are energetically virtually equally preferable, which can enable nearly free translations of hydrogen molecules along these paths. Consequently, the hydrogen molecules on graphane most likely form a non-commensurate monolayer. The analysis of the remaining errors reveals a very high accuracy of the computed potential surface with an error bar of a few tenths of a kJ/mol. The obtained results are a high-precision benchmark for further theoretical and experimental studies of hydrogen molecules interacting with graphane.

  5. High Precision Ranging and Range-Rate Measurements over Free-Space-Laser Communication Link

    NASA Technical Reports Server (NTRS)

    Yang, Guangning; Lu, Wei; Krainak, Michael; Sun, Xiaoli

    2016-01-01

    We present a high-precision ranging and range-rate measurement system via an optical-ranging or combined ranging-communication link. A complete bench-top optical communication system was built. It included a ground terminal and a space terminal. Ranging and range rate tests were conducted in two configurations. In the communication configuration with 622 data rate, we achieved a two-way range-rate error of 2 microns/s, or a modified Allan deviation of 9 x 10 (exp -15) with 10 second averaging time. Ranging and range-rate as a function of Bit Error Rate of the communication link is reported. They are not sensitive to the link error rate. In the single-frequency amplitude modulation mode, we report a two-way range rate error of 0.8 microns/s, or a modified Allan deviation of 2.6 x 10 (exp -15) with 10 second averaging time. We identified the major noise sources in the current system as the transmitter modulation injected noise and receiver electronics generated noise. A new improved system will be constructed to further improve the system performance for both operating modes.

  6. High-Precision Determination of the Pion-Nucleon σ Term from Roy-Steiner Equations.

    PubMed

    Hoferichter, Martin; Ruiz de Elvira, Jacobo; Kubis, Bastian; Meißner, Ulf-G

    2015-08-28

    We present a determination of the pion-nucleon (πN) σ term σ_{πN} based on the Cheng-Dashen low-energy theorem (LET), taking advantage of the recent high-precision data from pionic atoms to pin down the πN scattering lengths as well as of constraints from analyticity, unitarity, and crossing symmetry in the form of Roy-Steiner equations to perform the extrapolation to the Cheng-Dashen point in a reliable manner. With isospin-violating corrections included both in the scattering lengths and the LET, we obtain σ_{πN}=(59.1±1.9±3.0)  MeV=(59.1±3.5)  MeV, where the first error refers to uncertainties in the πN amplitude and the second to the LET. Consequences for the scalar nucleon couplings relevant for the direct detection of dark matter are discussed. PMID:26371645

  7. High-precision measurements of wetland sediment elevation. II The rod surface elevation table

    USGS Publications Warehouse

    Cahoon, D.R.; Lynch, J.C.; Perez, B.C.; Segura, B.; Holland, R.D.; Stelly, C.; Stephenson, G.; Hensel, P.

    2002-01-01

    A new high-precision device for measuring sediment elevation in emergent and shallow water wetland systems is described. The rod surface-elevation table (RSET) is a balanced, lightweight mechanical leveling device that attaches to both shallow ( 1 m in order to be stable. The pipe is driven to refusal but typically to a depth shallower than the rod bench mark because of greater surface resistance of the pipe. Thus, the RSET makes it possible to partition change in sediment elevation over shallower (e.g., the root zone) and deeper depths of the sediment profile than is possible with the SET. The confidence intervals for the height of an individual pin measured by two different operators with the RSET under laboratory conditions were A? 1.0 and A? 1.5 mm. Under field conditions, confidence intervals for the measured height of an individual pin ranged from A? 1.3 mm in a mangrove forest up to A? 4.3 mm in a salt marsh.

  8. Three-dimensional microscopic elemental analysis using an automated high-precision serial sectioning system.

    PubMed

    Fujisaki, Kazuhiro; Yokota, Hideo; Furushiro, Naomichi; Komatani, Shintaro; Ohzawa, Sumito; Sato, Yoshimichi; Matsunaga, Daisuke; Himeno, Ryutaro; Higuchi, Toshiro; Makinouchi, Akitake

    2011-04-01

    The elemental composition and microscopic-level shape of inclusions inside industrial materials are considered important factors in fracture analytical studies. In this work, a three-dimensional (3D) microscopic elemental analysis system based on a serial sectioning technique was developed to observe the internal structure of such materials. This 3D elemental mapping system included an X-ray fluorescence analyzer and a high-precision milling machine. Control signals for the X-ray observation process were automatically sent from a data I/O system synchronized with the precision positioning on the milling machine. Composite specimens were used to confirm the resolution and the accuracy of 3D models generated from this system. Each of the two specimens was composed of three metal wires of 0.5 mm diameter braided into a single twisted wire that was placed inside a metal pipe; the pipe was then filled with either epoxy resin or Sn. The milling machine was used to create a mirror-finish cross-sectional surface on these specimens, and elemental analyses were performed. The twisted wire structure was clearly observed in the resulting 3D models. This system enables automated investigation of the 3D internal structure of materials as well as the identification of their elemental components.

  9. Modeling and Analysis of Phase Fluctuation in a High-Precision Roll Angle Measurement Based on a Heterodyne Interferometer.

    PubMed

    Huang, Junhui; Wang, Zhao; Gao, Jianmin; Yu, Bao

    2016-01-01

    Heterodyne interferometry is a high-precision method applied in roll angle measurements. Phase metering is essential for high precision. During a high-precision measurement, a phase fluctuation appears even when the roll angle does not vary, which has never been analyzed before. Herein, the reason for the phase fluctuation is revealed, which results from the frequency-difference fluctuation and time difference between measurement and reference beams. A mathematical model of that phase-fluctuation mechanism is established, and that model provides a theoretical basis for analyzing and reducing the phase fluctuation. The impact that the main factors have on the phase metering is analyzed quantitatively, and experiments are carried out to validate the model. Finally, the phase fluctuation decreases to 0.02° by frequency reduction, which conversely verifies the theoretical model. PMID:27490552

  10. Contributed Review: Application of voice coil motors in high-precision positioning stages with large travel ranges

    NASA Astrophysics Data System (ADS)

    Shan, Guanqiao; Li, Yingzi; Zhang, Liwen; Wang, Zhenyu; Zhang, Yingxu; Qian, Jianqiang

    2015-10-01

    Recent interest in high-precision positioning stages with large travel ranges has sparked renewed attention to the development of voice coil motors (VCMs). Due to their large output force, VCMs can actuate more complicated flexure structures, eliminate rail friction, and improve positioning speed. The VCM structure is both compact and flexible; hence, it is convenient to design VCMs for a variety of stage structures. Furthermore, VCMs combined with other actuators are able to achieve large travel ranges with high precision. In this paper, we summarize the principles and control methods of a typical VCM, and we analyze its properties, including thrust force, acceleration, and response time. We then present recent research on high-precision VCM positioning stages with large travel ranges.

  11. Contributed Review: Application of voice coil motors in high-precision positioning stages with large travel ranges.

    PubMed

    Shan, Guanqiao; Li, Yingzi; Zhang, Liwen; Wang, Zhenyu; Zhang, Yingxu; Qian, Jianqiang

    2015-10-01

    Recent interest in high-precision positioning stages with large travel ranges has sparked renewed attention to the development of voice coil motors (VCMs). Due to their large output force, VCMs can actuate more complicated flexure structures, eliminate rail friction, and improve positioning speed. The VCM structure is both compact and flexible; hence, it is convenient to design VCMs for a variety of stage structures. Furthermore, VCMs combined with other actuators are able to achieve large travel ranges with high precision. In this paper, we summarize the principles and control methods of a typical VCM, and we analyze its properties, including thrust force, acceleration, and response time. We then present recent research on high-precision VCM positioning stages with large travel ranges.

  12. A novel approach for pulse width measurements with a high precision (8 ps RMS) TDC in an FPGA

    NASA Astrophysics Data System (ADS)

    Ugur, C.; Linev, S.; Michel, J.; Schweitzer, T.; Traxler, M.

    2016-01-01

    High precision time measurements are a crucial element in particle identification experiments, which likewise require pulse width information for Time-over-Threshold (ToT) measurements and charge measurements (correlated with pulse width). In almost all of the FPGA-based TDC applications, pulse width measurements are implemented using two of the TDC channels for leading and trailing edge time measurements individually. This method however, requires twice the number of resources. In this paper we present the latest precision improvements in the high precision TDC (8 ps RMS) developed before [1], as well as the novel way of measuring ToT using a single TDC channel, while still achieving high precision (as low as 11.7 ps RMS). The effect of voltage, generated by a DC-DC converter, over the precision is also discussed. Finally, the outcome of the temperature change over the pulse width measurement is shown and a correction method is suggested to limit the degradation.

  13. Modeling and Analysis of Phase Fluctuation in a High-Precision Roll Angle Measurement Based on a Heterodyne Interferometer

    PubMed Central

    Huang, Junhui; Wang, Zhao; Gao, Jianmin; Yu, Bao

    2016-01-01

    Heterodyne interferometry is a high-precision method applied in roll angle measurements. Phase metering is essential for high precision. During a high-precision measurement, a phase fluctuation appears even when the roll angle does not vary, which has never been analyzed before. Herein, the reason for the phase fluctuation is revealed, which results from the frequency-difference fluctuation and time difference between measurement and reference beams. A mathematical model of that phase-fluctuation mechanism is established, and that model provides a theoretical basis for analyzing and reducing the phase fluctuation. The impact that the main factors have on the phase metering is analyzed quantitatively, and experiments are carried out to validate the model. Finally, the phase fluctuation decreases to 0.02° by frequency reduction, which conversely verifies the theoretical model. PMID:27490552

  14. Contributed Review: Application of voice coil motors in high-precision positioning stages with large travel ranges.

    PubMed

    Shan, Guanqiao; Li, Yingzi; Zhang, Liwen; Wang, Zhenyu; Zhang, Yingxu; Qian, Jianqiang

    2015-10-01

    Recent interest in high-precision positioning stages with large travel ranges has sparked renewed attention to the development of voice coil motors (VCMs). Due to their large output force, VCMs can actuate more complicated flexure structures, eliminate rail friction, and improve positioning speed. The VCM structure is both compact and flexible; hence, it is convenient to design VCMs for a variety of stage structures. Furthermore, VCMs combined with other actuators are able to achieve large travel ranges with high precision. In this paper, we summarize the principles and control methods of a typical VCM, and we analyze its properties, including thrust force, acceleration, and response time. We then present recent research on high-precision VCM positioning stages with large travel ranges. PMID:26520932

  15. Progress in Bathymetric Surveys: Combining High Precision Positioning in Real Time with a Continuous Vertical Datum in Remote Areas

    NASA Astrophysics Data System (ADS)

    Lévesque, S.; Robin, C. M. I.; MacLeod, K.; Fadaie, K.

    2014-12-01

    For most of its bathymetric survey activities, the Canadian Hydrographic Service (CHS) requires high precision, three dimensional positioning. As part of a pilot project, one of its launches was equipped with a GNSS receiver processing a high precision correction service in real time (HP-GPS*C) via the internet using satellite telecommunication. This service was provided by Natural Resources Canada/Canadian Geodetic Survey (NRCan/CGS). The bathymetric data from a survey in eastern Hudson Bay performed by CHS in Fall 2013 was post -processed using different standard methods. This resulted in high precision positions that were compared with positions corrected with the real-time precise point positioning (PPP) service (HP-GPS*C) from NRCan/CGS. CHS bathymetric surveys must be referred to chart datum, the hydrographical vertical datum defined for use on nautical charts. In the Canadian north, another limitation to high precision bathymetric work is the availability of tide observations and/or predictions. The territory is vast and tide data is limited in space and in time while predicted tides are not always accurate. This makes reductions of bathymetric soundings to Chart datum difficult. To address this problem, CHS and NRCan/CGS have collaborated to produce a Continuous Vertical Datum for Canadian Waters (CVDCW), which incorporates data from NRCan's geoid model, tide gauge and GPS data, satellite altimetry, and ocean models. Thus high precision positioning provides ellipsoidal heights for the bathymetric depths, and the CVDCW allows to correct these ellipsoidal heights to chart datum. Comparisons of the bathymetry from the pilot survey corrected for tide data versus the bathymetry referred to its ellipsoidal height corrected to chart datum with the CVDCW are given to demonstrate the relative changes to the depths. This also illustrates the advantage of a continuous vertical datum with its potential to be combined with real-time high precision positioning.

  16. High Precision, Directly Determined Radii and Effective Temperatures for Giant Stars

    NASA Astrophysics Data System (ADS)

    van Belle, Gerard

    have demonstrated the potential of all aspects of this program, and through the proposed effort will unify the diverse components to study these giants. A homogenous catalog of linear radii and effective temperatures for hundreds of giants will be generated, which in turn will be used to calibrate radius and temperature scales for application to the broad population of giants. Significance. Fundamental temperature and radius scales are used throughout stellar astrophysics, including stellar structure studies, stellar modeling, galactic spectral synthesis, planet detection studies, and star formation theory. We expect to reduce the error in effective temperature calibration by 2-4x, and the error in linear radius by 2-3x or more. A high- precision improvement to these scales will, in turn, broadly advance a wide swath of studies that depend on precisely knowing the radii and temperature of stars. This proposal aims to produce the definitive linear radius and effective temperature scales for giants. A significant improvement in the determinations of the radii and effective temperatures of giant stars across the HR diagram will have far reaching consequences across the broad expanse of astrophysical research. Relevance to NASA. High-precision calibrations of temperature scales are essential to flux calibrations of past and ongoing NASA science satellite observations, such as those from Spitzer and WISE, and a significantly improved linear radius reference markedly improves Kepler discoveries in both the exoplanet and asteroseismology areas. In addition to the high scientific potential of this program, it also provides technical benefits by furthering interferometric techniques that will be critical for future high angular resolution astronomy.

  17. HPMSS(High Precision Magnetic Survey System) and InterRidge

    NASA Astrophysics Data System (ADS)

    Isezaki, N.; Sayanagi, K.

    2012-12-01

    From the beginning of 1990s to the beginning of 2000s, the Japanese group of IntreRidge conducted many cruises for three component magnetic survey using Shipboard Three Component Magnetometer (STCM) and Deep Towed Three Component Magnetometer (DTCM) in the world wide oceans. We have been developing HPMSS during this time with support of Dr.Tamaki(the late representative of InterRidge Japan) who understood the advantages of three component geomagnetic anomalies (TCGA). TCGA measured by STCM determines the direction of geomagnetic anomaly lineations precisely at every point where TCGA were observed, which playes the important role in magnetic anomaly lineation analysis. Even in the beginning of 2000s, almost all marine magnetic scientists believed that the total intensity anomly (TIA) is the better data than TCGA for analysis because the scalar magnetometers (e.g. proton precession magnetometer) have the better accuracy than any other magnetometers (e.g.flux gate magnetometer (FGM)). We employed the high accrate gyroscope (e.g.ring lase gyroscope (RLG)/optical fiber gyroscope (OFG)) to improve the accuracy of STCM/DTCM equipped with FGM. Moreover we employed accurate and precise FGM which was selected among the market. Finally we developed the new magnetic survey system with high precision usable as airborn, shipboard and dee-ptowed magnetometers which we call HPMSS(High Precision Magnetic Survey System). As an optional equipment, we use LAN to communicate between a data aquisiitin part and a data logging part, and GPS for a position fix. For the deep-towed survey, we use the acoustic position fix (super short base line method) and the acoustic communication to monitor the DTCM status. First we used HPMSS to obtain the magnetization structure of the volcanic island, Aogashima located 300km south of Tokyo using a hellcopter in 2006 and 2009. Next we used HPMSS installed in DTCM in 2010,2011 and 2012 using R/V Bosei-maru belonging to Tokai University. Also we used

  18. Frontiers of QC Laser spectroscopy for high precision isotope ratio analysis of greenhouse gases

    NASA Astrophysics Data System (ADS)

    Emmenegger, Lukas; Mohn, Joachim; Harris, Eliza; Eyer, Simon; Ibraim, Erkan; Tuzson, Béla

    2016-04-01

    An important milestone for laser spectroscopy was achieved when isotope ratios of greenhouse gases were reported at precision levels that allow addressing research questions in environmental sciences. Real-time data with high temporal resolution at moderate cost and instrument size make the optical approach highly attractive, complementary to the well-established isotope-ratio mass-spectrometry (IRMS) method. Especially appealing, in comparison to IRMS, is the inherent specificity to structural isomers having the same molecular mass. Direct absorption in the MIR in single or dual QCL configuration has proven highly reliable for the sta-ble isotopes of CO2, N2O and CH4. The longest time series of real-time measurements is currently available for δ13C and δ18O in CO2 at the high-alpine station Jung-fraujoch. At this well-equipped site, QCL based direct absorption spectroscopy (QCLAS) measurements are ongoing since 2008 1,2. Applications of QCLAS for N2O and CH4 stable isotopes are considerably more challenging because of the lower atmospheric mixing ratios, especially for the less abundant species, such as N218O and CH3D. For high precision (< 0.1 ‰) measurements in ambient air, QCLAS may be combined with a fully automated preconcentration unit yielding an up to 500 times concentration increase and the capability to separate the target gas from spectral interferants by se-quential desorption 3. Here, we review our recent developments on high precision isotope ratio analysis of greenhouse gases, with special focus on the isotopic species of N2O and CH4. Furthermore, we show environ-mental applications illustrating the highly valuable information that isotope ratios of atmospheric trace gases can carry. For example, the intramolecular distribution of 15N in N2O gives important information on the geochemical cycle of N2O4-6, while the analysis of δ13C and δ D in CH4 may be applied to disentangle microbial, fossil and landfill sources 7. 1 Sturm, P., Tuzson, B

  19. High precision series solutions of differential equations: Ordinary and regular singular points of second order ODEs

    NASA Astrophysics Data System (ADS)

    Noreen, Amna; Olaussen, Kåre

    2012-10-01

    A subroutine for a very-high-precision numerical solution of a class of ordinary differential equations is provided. For a given evaluation point and equation parameters the memory requirement scales linearly with precision P, and the number of algebraic operations scales roughly linearly with P when P becomes sufficiently large. We discuss results from extensive tests of the code, and how one, for a given evaluation point and equation parameters, may estimate precision loss and computing time in advance. Program summary Program title: seriesSolveOde1 Catalogue identifier: AEMW_v1_0 Program summary URL: http://cpc.cs.qub.ac.uk/summaries/AEMW_v1_0.html Program obtainable from: CPC Program Library, Queen's University, Belfast, N. Ireland Licensing provisions: Standard CPC licence, http://cpc.cs.qub.ac.uk/licence/licence.html No. of lines in distributed program, including test data, etc.: 991 No. of bytes in distributed program, including test data, etc.: 488116 Distribution format: tar.gz Programming language: C++ Computer: PC's or higher performance computers. Operating system: Linux and MacOS RAM: Few to many megabytes (problem dependent). Classification: 2.7, 4.3 External routines: CLN — Class Library for Numbers [1] built with the GNU MP library [2], and GSL — GNU Scientific Library [3] (only for time measurements). Nature of problem: The differential equation -s2({d2}/{dz2}+{1-ν+-ν-}/{z}{d}/{dz}+{ν+ν-}/{z2})ψ(z)+{1}/{z} ∑n=0N vnznψ(z)=0, is solved numerically to very high precision. The evaluation point z and some or all of the equation parameters may be complex numbers; some or all of them may be represented exactly in terms of rational numbers. Solution method: The solution ψ(z), and optionally ψ'(z), is evaluated at the point z by executing the recursion A(z)={s-2}/{(m+1+ν-ν+)(m+1+ν-ν-)} ∑n=0N Vn(z)A(z), ψ(z)=ψ(z)+A(z), to sufficiently large m. Here ν is either ν+ or ν-, and Vn(z)=vnz. The recursion is initialized by A(z)=δzν,for n

  20. High-precision mapping of seismicity in the 2014 Bárdarbunga volcanic episode

    NASA Astrophysics Data System (ADS)

    Vogfjörd, Kristín S.; Hensch, Martin; Gudmundsson, Gunnar B.; Jónsdóttir, Kristín

    2015-04-01

    The Bárdarbunga volcano and its associated fissure swarm in Iceland's Eastern volcanic zone is a highly active system with over 20 eruptions in the last 11 centuries. The location of this active volcano and much of the fissure swarm under several hundred metres thick ice gives rise to multiple hazards, including explosive, subglacial eruptions and associated subglacial floods (jökulhlaups), as well as fissure eruptions extruding large volumes of lava. After a decade of increasing seismic activity, volcanic unrest at Bárdarbunga suddenly escalated into a minor subglacial eruption on 16 August 2014. In the following weeks seismic activity soared and surface deformation of tens of cm were observed, caused by rifting and a dyke intrusion, which propagated 48 km northward from the central volcano (Sigmundsson et al., 2014). The dyke propagation stopped just outside the glacial margin and ended in a fissure eruption at Holuhraun at the end of August. At the time of writing the eruption is ongoing, having extruded a lava volume of over 1 km3 and released high rates of SO2 into the atmosphere. Over twenty thousand microearthquakes have been recorded. Initially most were in the dyke, but after the first two weeks the activity around the caldera rim increased and over 70 shallow earthquakes with MW > 5 have been located along the caldera rim accompanied by caldera subsidence. At the onset of the unrest on 16 August, the seismicity was located in the caldera and north of the caldera rim, but already in the first few hours the activity propagated out of the caldera to the SE. Still, the activity continued for a few days in the fissure swarm to the NE of the rim. High-precision earthquake locations in the propagating dyke have revealed its very detailed, planar rifting segments, with the events distributed over a 3-4 km depth range, and mostly between 6 and 9 km. These very planar event distributions are highly unusual in volcanic areas and strongly suggest rifting of

  1. A High Precision Method for Quantitative Measurements of Reactive Oxygen Species in Frozen Biopsies

    PubMed Central

    Lindgren, Mikael; Gustafsson, Håkan

    2014-01-01

    Objective An electron paramagnetic resonance (EPR) technique using the spin probe cyclic hydroxylamine 1-hydroxy-3-methoxycarbonyl-2,2,5,5-tetramethylpyrrolidine (CMH) was introduced as a versatile method for high precision quantification of reactive oxygen species, including the superoxide radical in frozen biological samples such as cell suspensions, blood or biopsies. Materials and Methods Loss of measurement precision and accuracy due to variations in sample size and shape were minimized by assembling the sample in a well-defined volume. Measurement was carried out at low temperature (150 K) using a nitrogen flow Dewar. The signal intensity was measured from the EPR 1st derivative amplitude, and related to a sample, 3-carboxy-proxyl (CP•) with known spin concentration. Results The absolute spin concentration could be quantified with a precision and accuracy better than ±10 µM (k = 1). The spin concentration of samples stored at −80°C could be reproduced after 6 months of storage well within the same error estimate. Conclusion The absolute spin concentration in wet biological samples such as biopsies, water solutions and cell cultures could be quantified with higher precision and accuracy than normally achievable using common techniques such as flat cells, tissue cells and various capillary tubes. In addition; biological samples could be collected and stored for future incubation with spin probe, and also further stored up to at least six months before EPR analysis, without loss of signal intensity. This opens for the possibility to store and transport incubated biological samples with known accuracy of the spin concentration over time. PMID:24603936

  2. High-precision timing of 42 millisecond pulsars with the European Pulsar Timing Array

    NASA Astrophysics Data System (ADS)

    Desvignes, G.; Caballero, R. N.; Lentati, L.; Verbiest, J. P. W.; Champion, D. J.; Stappers, B. W.; Janssen, G. H.; Lazarus, P.; Osłowski, S.; Babak, S.; Bassa, C. G.; Brem, P.; Burgay, M.; Cognard, I.; Gair, J. R.; Graikou, E.; Guillemot, L.; Hessels, J. W. T.; Jessner, A.; Jordan, C.; Karuppusamy, R.; Kramer, M.; Lassus, A.; Lazaridis, K.; Lee, K. J.; Liu, K.; Lyne, A. G.; McKee, J.; Mingarelli, C. M. F.; Perrodin, D.; Petiteau, A.; Possenti, A.; Purver, M. B.; Rosado, P. A.; Sanidas, S.; Sesana, A.; Shaifullah, G.; Smits, R.; Taylor, S. R.; Theureau, G.; Tiburzi, C.; van Haasteren, R.; Vecchio, A.

    2016-05-01

    We report on the high-precision timing of 42 radio millisecond pulsars (MSPs) observed by the European Pulsar Timing Array (EPTA). This EPTA Data Release 1.0 extends up to mid-2014 and baselines range from 7-18 yr. It forms the basis for the stochastic gravitational-wave background, anisotropic background, and continuous-wave limits recently presented by the EPTA elsewhere. The Bayesian timing analysis performed with TEMPONEST yields the detection of several new parameters: seven parallaxes, nine proper motions and, in the case of six binary pulsars, an apparent change of the semimajor axis. We find the NE2001 Galactic electron density model to be a better match to our parallax distances (after correction from the Lutz-Kelker bias) than the M2 and M3 models by Schnitzeler. However, we measure an average uncertainty of 80 per cent (fractional) for NE2001, three times larger than what is typically assumed in the literature. We revisit the transverse velocity distribution for a set of 19 isolated and 57 binary MSPs and find no statistical difference between these two populations. We detect Shapiro delay in the timing residuals of PSRs J1600-3053 and J1918-0642, implying pulsar and companion masses m_p=1.22_{-0.35}^{+0.5} M_{⊙}, m_c = 0.21_{-0.04}^{+0.06} M_{⊙} and m_p=1.25_{-0.4}^{+0.6} M_{⊙}, m_c = 0.23_{-0.05}^{+0.07} M_{⊙}, respectively. Finally, we use the measurement of the orbital period derivative to set a stringent constraint on the distance to PSRs J1012+5307 and J1909-3744, and set limits on the longitude of ascending node through the search of the annual-orbital parallax for PSRs J1600-3053 and J1909-3744.

  3. High Precision Fe Isotope Analysis in low Concentration Samples by High Resolution MC-ICPMS

    NASA Astrophysics Data System (ADS)

    Chung, C.; Wu, J.; You, C.

    2009-12-01

    Iron availability has been shown to be the main limitation factor for phytoplankton growth in the ocean. However, due to the limitation of analytical technique, the database of dissolved Fe concentrations and isotope ratio distribution in the ocean is still very limited. In particular, the iron sources to the ocean remain uncertain. Aeolian dust from the continental is considered as the primary source, also the digenetic dissolution at the continental margins is proposed to contribute significant portion of iron content of the sea surface water. The field of Fe isotope geochemistry has seen important developments in methodology and scope since the advent of Multi-Collector Inductively Coupled Plasma Mass Spectrometry (MC-ICPMS). Although increasing the number of replicates in High Resolution MC-ICPMS reduces the uncertainty related to instability in instrumental mass bias and counting statistics, many other parameters include mass fractionation during column separation, matrix effect in ICPMS analysis and the presence of isobaric interferences can affect the precision and accuracy of Fe isotopic analyses. In this study, a high precision analytical method of Fe isotope measurement for low concentration samples was developed using HR-MC-ICPMS. Several parameters that may affect the accuracy and precision of 56Fe/54Fe result such as background, instrumental mass discrimination, isobaric interferences, type of introduction system and acid molarity were identified and evaluated. External precisions better than 0.04‰ for δ56Fe can be achieve using only 10ng of iron sample with APEX and X-cone as introduction system. Significant improvement in terms of sample size was made. This method can be applied on very low concentration samples such as coral and seawater.

  4. A demonstration of high precision GPS orbit determination for geodetic applications

    NASA Technical Reports Server (NTRS)

    Lichten, S. M.; Border, J. S.

    1987-01-01

    High precision orbit determination of Global Positioning System (GPS) satellites is a key requirement for GPS-based precise geodetic measurements and precise low-earth orbiter tracking, currently under study at JPL. Different strategies for orbit determination have been explored at JPL with data from a 1985 GPS field experiment. The most successful strategy uses multi-day arcs for orbit determination and includes fine tuning of spacecraft solar pressure coefficients and station zenith tropospheric delays using the GPS data. Average rms orbit repeatability values for 5 of the GPS satellites are 1.0, 1.2, and 1.7 m in altitude, cross-track, and down-track componenets when two independent 5-day fits are compared. Orbit predictions up to 24 hours outside the multi-day arcs agree within 4 m of independent solutions obtained with well tracked satellites in the prediction interval. Baseline repeatability improves with multi-day as compared to single-day arc orbit solutions. When tropospheric delay fluctuations are modeled with process noise, significant additional improvement in baseline repeatability is achieved. For a 246-km baseline, with 6-day arc solutions for GPS orbits, baseline repeatability is 2 parts in 100 million (0.4-0.6 cm) for east, north, and length components and 8 parts in 100 million for the vertical component. For 1314 and 1509 km baselines with the same orbits, baseline repeatability is 2 parts in 100 million for the north components (2-3 cm) and 4 parts in 100 million or better for east, length, and vertical components.

  5. Measuring High-Precision Astrometry with the Infrared Array Camera on the Spitzer Space Telescope

    NASA Astrophysics Data System (ADS)

    Esplin, T. L.; Luhman, K. L.

    2016-01-01

    The Infrared Array Camera (IRAC) on the Spitzer Space Telescope currently offers the greatest potential for high-precision astrometry of faint mid-IR sources across arcminute-scale fields, which would be especially valuable for measuring parallaxes of cold brown dwarfs in the solar neighborhood and proper motions of obscured members of nearby star-forming regions. To more fully realize IRAC's astrometric capabilities, we have sought to minimize the largest sources of uncertainty in astrometry with its 3.6 and 4.5 μm bands. By comparing different routines that estimate stellar positions, we have found that Point Response Function (PRF) fitting with the Spitzer Science Center's Astronomical Point Source Extractor produces both the smallest systematic errors from varying intra-pixel sensitivity and the greatest precision in measurements of positions. In addition, self-calibration has been used to derive new 7th and 8th order distortion corrections for the 3.6 and 4.5 μm arrays of IRAC, respectively. These corrections are suitable for data throughout the mission of Spitzer when a time-dependent scale factor is applied to the corrections. To illustrate the astrometric accuracy that can be achieved by combining PRF fitting with our new distortion corrections, we have applied them to archival data for a nearby star-forming region, arriving at total astrometric errors of ∼20 and 70 mas at signal to noise ratios of 100 and 10, respectively. Based on observations made with the Spitzer Space Telescope, which is operated by the Jet Propulsion Laboratory, California Institute of Technology under a contract with NASA.

  6. A low noise and high precision linear power supply with thermal foldback protection

    NASA Astrophysics Data System (ADS)

    Carniti, P.; Cassina, L.; Gotti, C.; Maino, M.; Pessina, G.

    2016-05-01

    A low noise and high precision linear power supply was designed for use in rare event search experiments with macrobolometers. The circuit accepts at the input a "noisy" dual supply voltage up to ±15 V and gives at the output precise, low noise, and stable voltages that can be set between ±3.75 V and ±12.5 V in eight 1.25 V steps. Particular care in circuit design, component selection, and proper filtering results in a noise spectral density of 50 nV / √{ Hz } at 1 Hz and 20 nV / √{ Hz } white when the output is set to ±5 V. This corresponds to 125 nV RMS (0.8 μV peak to peak) between 0.1 Hz and 10 Hz, and 240 nV RMS (1.6 μV peak to peak) between 0.1 Hz and 100 Hz. The power supply rejection ratio (PSRR) of the circuit is 100 dB at low frequency, and larger than 40 dB up to high frequency, thanks to a proper compensation design. Calibration allows to reach a precision in the absolute value of the output voltage of ±70 ppm, or ±350 μV at ±5 V, and to reduce thermal drifts below ±1 ppm/∘C in the expected operating range. The maximum peak output current is about 6 A from each output. An original foldback protection scheme was developed that dynamically limits the maximum output current to keep the temperature of the output transistors within their safe operating range. An add-on card based on an ARM Cortex-M3 microcontroller is devoted to the monitoring and control of all circuit functionalities and provides remote communication via CAN bus.

  7. High-precise DEM Generation Using Envisat/ERS-2 Cross-interferometry

    NASA Astrophysics Data System (ADS)

    Lee, W.; Jung, H.; Lu, Z.; Zhang, L.

    2010-12-01

    Cross-interferometric synthetic aperture radar (CInSAR) technique from ERS-2 and Envisat images is capable of generating submeter-accuracy digital elevation model (DEM). However, it is very difficult to produce high-quality CInSAR-derived DEM due to the difference in the azimuth and range pixel size between ERS-2 and Envisat images as well as the small height ambiguity of CInSAR interferogram. In this study, we have proposed an efficient method to overcome the problems, produced a high-quality DEM over northern Alaska, and assessed the accuracy of the CInSAR-derived DEM with an airborne InSAR-derived DEM, which has the spatial resolution of 5 meters, from U.S. Geological Survey. In the proposed method, azimuth common band filtering in the radar raw data processing and DEM-assisted SAR coregistration are applied to mitigate the mis-registration due to the difference in the azimuth and range pixel size and large baseline, and differential SAR interferogram (DInSAR) created by using the low-quality DEM is used for reducing the unwrapping error occurred by the high fringe rate of CInSAR interferogram. From accuracy assessment, in flat area, the precision of CInSAR-derived DEM was approximately 4.2 m and 70cm in the horizontal and vertical directions, respectively, and the ground resolution estimated by the wave number analysis was about 15m. However, most errors occurred in around water area (like lake). And generating time is different between Airborne DEM (July, 2002) and CInSAR DEM(January, 2008). Focus on land area (not around water), vertical accuracy is highly improved about submeter unit. Our results indicate that high-precise DEM of submeter-accuracy can be generated by the proposed method.

  8. Development of a High Precision and Stability Ambient N2O and CO Analyzer

    NASA Astrophysics Data System (ADS)

    Zhou, Jingang; Hoffnagle, John; Tan, Sze; Dong, Feng; Fleck, Derek; Yiu, John; Huang, Kuan; Leggett, Graham; He, Yonggang

    2016-04-01

    With a global warming potential of nearly 300, N2O is a critically important greenhouse gas, contributing about 5 % of the US total GHG emissions. Agriculture soil management practices are the dominant source of anthropogenic N2O emissions, contributing nearly 75 % of US N2O emissions. In urban areas, vehicle tailpipe emissions and waste water treatment plants are significant sources of N2O. We report here a new mid-infrared laser-based cavity ring-down spectrometer (Picarro G5310) that was recently developed to simultaneously measure sub-ppb ambient concentrations of two key greenhouse gas species, N2O and CO, while measuring H2O as well. It combines a quantum cascade laser with a proprietary 3-mirror optical cavity. The ambient N2O and CO measurement precisions are 0.1ppb (10sec), 0.014ppb (600sec), and 0.006ppb (3000sec); and the measurements could even be averaged down over 3 hours, giving measurement precisions of 0.003ppb. The measurable N2O and CO ranges have been tested up to 2.5ppm. With the high precision and unparalleled stability, G5310 is believed a promising tool for long-term monitoring in atmospheric sciences. The new optical analyzer was set up to monitor N2O and CO (G5310), along with CO2 and CH4(G4301), in ambient air obtained from a 10 meter tower in Santa Clara, California. Evidence of contributions from traffic and a nearby sewage treatment facility were expected in the measurement data.

  9. HIGH-PRECISION PREDICTIONS FOR THE ACOUSTIC SCALE IN THE NONLINEAR REGIME

    SciTech Connect

    Seo, Hee-Jong; Eckel, Jonathan; Eisenstein, Daniel J.; Mehta, Kushal; Metchnik, Marc; Padmanabhan, Nikhil; Pinto, Phillip; Takahashi, Ryuichi; White, Martin; Xu, Xiaoying

    2010-09-10

    We measure shifts of the acoustic scale due to nonlinear growth and redshift distortions to a high precision using a very large volume of high-force-resolution simulations. We compare results from various sets of simulations that differ in their force, volume, and mass resolution. We find a consistency within 1.5-sigma for shift values from different simulations and derive shift alpha(z) -1 = (0.300\\pm 0.015)% [D(z)/D(0)]^{2} using our fiducial set. We find a strong correlation with a non-unity slope between shifts in real space and in redshift space and a weak correlation between the initial redshift and low redshift. Density-field reconstruction not only removes the mean shifts and reduces errors on the mean, but also tightens the correlations: after reconstruction, we recover a slope of near unity for the correlation between the real and redshift space and restore a strong correlation between the low and the initial redshifts. We derive propagators and mode-coupling terms from our N-body simulations and compared with Zeldovich approximation and the shifts measured from the chi^2 fitting, respectively. We interpret the propagator and the mode-coupling term of a nonlinear density field in the context of an average and a dispersion of its complex Fourier coefficients relative to those of the linear density field; from these two terms, we derive a signal-to-noise ratio of the acoustic peak measurement. We attempt to improve our reconstruction method by implementing 2LPT and iterative operations: we obtain little improvement. The Fisher matrix estimates of uncertainty in the acoustic scale is tested using 5000 (Gpc/h)^3 of cosmological PM simulations from Takahashi et al. (2009). (abridged)

  10. High-precision reflectometry of multilayer coatings for extreme ultraviolet lithography

    SciTech Connect

    Wedowski, M; Underwood, J H; Gullikson, E M; Bajt, S; Folta, J A; Kearney, P A; Montcalm, C; Spiller, E

    1999-12-29

    Synchrotron-based reflectometry is an important technique for the precise determination of optical properties of reflective multilayer coatings for Extreme Ultraviolet Lithography (EUVL). Multilayer coatings enable normal incidence reflectances of more than 65% in the wavelength range between 11 and 15 nm. In order to achieve high resolution and throughput of EUVL systems, stringent requirements not only apply to their mechanical and optical layout, but also apply to the optical properties of the multilayer coatings. Therefore, multilayer deposition on near-normal incidence optical surfaces of projection optics, condenser optics and reflective masks requires suitable high-precision metrology. Most important, due to their small bandpass on the order of only 0.5 nm, all reflective multilayer coatings in EUVL systems must be wavelength-matched to within {+-}0.05 nm. In some cases, a gradient of the coating thickness is necessary for wavelength matching at variable average angle of incidence in different locations on the optical surfaces. Furthermore, in order to preserve the geometrical figure of the optical substrates, reflective multilayer coatings need to be uniform to within 0.01 nm in their center wavelength. This requirement can only be fulfilled with suitable metrology, which provides a precision of a fraction of this value. In addition, for the detailed understanding and the further development of reflective multilayer coatings a precision in the determination of peak reflectances is desirable on the order of 0.1%. Substrates up to 200 mm in diameter and 15 kg in mass need to be accommodated. Above requirements are fulfilled at beamline 6.3.2 of the Advanced Light Source (ALS) in Berkeley. This beamline proved to be precise within 0.2% (ms) for reflectance and 0.002 nm (rms) for wavelength.

  11. High-precision micromilling for low-cost fabrication of metal mold masters

    NASA Astrophysics Data System (ADS)

    Hupert, Mateusz L.; Guy, W. J.; Llopis, Shawn D.; Situma, Catherine; Rani, Sudheer; Nikitopoulos, Dimitris E.; Soper, Steven A.

    2006-01-01

    High-precision micromilling was employed as a cost-efficient method preparation of metal masters useful in fabrication of polymer microfluidic devices through replication techniques. In first application, a brass mold master was used for hot embossing of microchip electrophoresis devices in poly(methyl methacrylate) (PMMA). The sidewalls of the milled microstructures were characterized by a maximum average roughness (R a) of 110 nm and mean peak height (R pm) of 320 nm. SEM imaging showed a transfer of the sidewall roughness from the molding tool to the polymer microdevice. The electroosmotic flow (EOF) values for micromilled-based microchannels were comparable to ones in the LiGA-prepared devices (sidewall R a = 20 nm) with values of ca. 3.7 x 10 -4 cm2V -1s -1 (20 mM TBE buffer, pH 8.2), indicating insignificant effects of wall roughness on the bulk EOF. Numerical simulations showed that the additional volumes present in an injection cross due to curvature of the corners produced by micromilling lead to elongated sample plugs. PMMA microchip electrophoresis devices were used for a separation of pUC19 Sau3AI double-stranded DNA. The plate numbers achieved exceeded 1 million m -1 and were comparable to the plate numbers for the LiGA-based devices of similar geometry. In second application brass master was used as tool for preparation of poly(dimethylsiloxane) PDMS stencils for patterning of DNA microarrays onto a PMMA substrate. Four zip code probes immobilized onto the PMMA surface directed allele-specic ligation products containing mutations in the KRAS2 gene (12.2D, 12.2A, 12.2V, and 13.4D) to the appropriate address of a universal array with minimal amounts of crosshybridization or misligation.

  12. High-precision genetic mapping of behavioral traits in the diversity outbred mouse population

    PubMed Central

    Logan, R W; Robledo, R F; Recla, J M; Philip, V M; Bubier, J A; Jay, J J; Harwood, C; Wilcox, T; Gatti, D M; Bult, C J; Churchill, G A; Chesler, E J

    2013-01-01

    Historically our ability to identify genetic variants underlying complex behavioral traits in mice has been limited by low mapping resolution of conventional mouse crosses. The newly developed Diversity Outbred (DO) population promises to deliver improved resolution that will circumvent costly fine-mapping studies. The DO is derived from the same founder strains as the Collaborative Cross (CC), including three wild-derived strains. Thus the DO provides more allelic diversity and greater potential for discovery compared to crosses involving standard mouse strains. We have characterized 283 male and female DO mice using open-field, light–dark box, tail-suspension and visual-cliff avoidance tests to generate 38 behavioral measures. We identified several quantitative trait loci (QTL) for these traits with support intervals ranging from 1 to 3 Mb in size. These intervals contain relatively few genes (ranging from 5 to 96). For a majority of QTL, using the founder allelic effects together with whole genome sequence data, we could further narrow the positional candidates. Several QTL replicate previously published loci. Novel loci were also identified for anxiety- and activity-related traits. Half of the QTLs are associated with wild-derived alleles, confirming the value to behavioral genetics of added genetic diversity in the DO. In the presence of wild-alleles we sometimes observe behaviors that are qualitatively different from the expected response. Our results demonstrate that high-precision mapping of behavioral traits can be achieved with moderate numbers of DO animals, representing a significant advance in our ability to leverage the mouse as a tool for behavioral genetics PMID:23433259

  13. Globular Cluster Streams as Galactic High-Precision Scales - The Poster Child Palomar 5

    NASA Astrophysics Data System (ADS)

    Kupper, Andreas Hans Wilhelm; Balbinot, Eduardo; Bonaca, Ana; Johnston, Kathryn V.; Hogg, David W.; Kroupa, Pavel; Santiago, Basilio

    2015-01-01

    We model the tidal stream of the Milky Way globular cluster Palomar 5 (Pal 5), and show that the unique geometry of the problem yields powerful constraints on the model parameters characterizing the Local Standard of Rest (LSR), the Milky Way and Pal 5 itself. Using only SDSS data and a few radial velocities from the literature, we find that the distance of the Sun from the Galactic Center is 8.30+/-0.25 kpc, and the LSR transverse velocity is 242+/-16 km/s. Assuming that the dark halo of the Galaxy follows a NFW density profile, we fit it with a virial mass of (1.6+/-0.4) 1012Msun, a virial radius of 195+/-19 kpc, and hence a rather low concentration of 5+/-2. Moreover, we find it with a flattening of qz = 0.95(+0.16)(-0.12) to be essentially spherical - at least within the inner 25 kpc, which are effectively probed by Pal 5. We also determine Pal 5's mass, distance and proper motions independently from other methods, which enables us to perform vital cross-checks for these methods. We conclude that finding more globular cluster streams is essential for mapping out the structure of the halo of our Galaxy to high precision. Finally, we point out that all our best-fit models yield similar substructure patterns as the ones observed in the Pal 5 stream within about 5 kpc of the cluster. The origin of these substructures is epicylic motion of stars along the stream. Such epicylic substructures have to be taken into account when searching tidal streams for signs of past encounters with dark-matter subhalos

  14. Highly precise and developmentally programmed genome assembly in Paramecium requires ligase IV-dependent end joining.

    PubMed

    Kapusta, Aurélie; Matsuda, Atsushi; Marmignon, Antoine; Ku, Michael; Silve, Aude; Meyer, Eric; Forney, James D; Malinsky, Sophie; Bétermier, Mireille

    2011-04-01

    During the sexual cycle of the ciliate Paramecium, assembly of the somatic genome includes the precise excision of tens of thousands of short, non-coding germline sequences (Internal Eliminated Sequences or IESs), each one flanked by two TA dinucleotides. It has been reported previously that these genome rearrangements are initiated by the introduction of developmentally programmed DNA double-strand breaks (DSBs), which depend on the domesticated transposase PiggyMac. These DSBs all exhibit a characteristic geometry, with 4-base 5' overhangs centered on the conserved TA, and may readily align and undergo ligation with minimal processing. However, the molecular steps and actors involved in the final and precise assembly of somatic genes have remained unknown. We demonstrate here that Ligase IV and Xrcc4p, core components of the non-homologous end-joining pathway (NHEJ), are required both for the repair of IES excision sites and for the circularization of excised IESs. The transcription of LIG4 and XRCC4 is induced early during the sexual cycle and a Lig4p-GFP fusion protein accumulates in the developing somatic nucleus by the time IES excision takes place. RNAi-mediated silencing of either gene results in the persistence of free broken DNA ends, apparently protected against extensive resection. At the nucleotide level, controlled removal of the 5'-terminal nucleotide occurs normally in LIG4-silenced cells, while nucleotide addition to the 3' ends of the breaks is blocked, together with the final joining step, indicative of a coupling between NHEJ polymerase and ligase activities. Taken together, our data indicate that IES excision is a "cut-and-close" mechanism, which involves the introduction of initiating double-strand cleavages at both ends of each IES, followed by DSB repair via highly precise end joining. This work broadens our current view on how the cellular NHEJ pathway has cooperated with domesticated transposases for the emergence of new mechanisms

  15. The research of the high precision universal stable reconnaissance platform in near space

    NASA Astrophysics Data System (ADS)

    Yang, Hong-tao; Cao, Jian-zhong; Fan, Zhe-yuan; Chen, Wei-ning

    2011-08-01

    The appliance of military was recognized more and more ,It is important that pod can bear the weight of the availability payload achieve the observation to the earth in 20km-100km area and work in the all-weather. The stable platform can load high imaging spectrometer, the thermal infrared imager, the infrared radiometer, the millimeter waves radar, the laser weapon and so on,in order to realize reconnaissance and attacking integrative and warning the long-distant missile. The stabilization accuracy of platform is prior to 20μrad and burden heavy load to the best of one's abilities. It used high precision velocity and acceleration gyroscope to fulfill the stabilization of the platform. Light-weight design by using new composite material and optimizing design. It was adapt to the near space environment better by structure design and simulation analysis.Enhance its basic frequency and sure the rigid of the frame platform .In addition, the structure of platform apply the two-axis and four-frame and use the method of FEA to fulfill the optimum design in order to attain the object of light-weight.In consider to the precision of the platform I establish the math model and make use of the monte carlo method to appraise and analysis the error that affect the precision of the platform. After emulating by the software of the Matlab to verify the results. It is apply the method that link the platform and aerocraft by mounting the no angular displacement shock absorbers on the elevator mechanism. This kind of design insulate the angular vibration and minish the linear vibration to ensure the image quality.

  16. High-precision GPS autonomous platforms for sea ice dynamics and physical oceanography

    NASA Astrophysics Data System (ADS)

    Elosegui, P.; Wilkinson, J.; Olsson, M.; Rodwell, S.; James, A.; Hagan, B.; Hwang, B.; Forsberg, R.; Gerdes, R.; Johannessen, J.; Wadhams, P.; Nettles, M.; Padman, L.

    2012-12-01

    Project "Arctic Ocean sea ice and ocean circulation using satellite methods" (SATICE), is the first high-rate, high-precision, continuous GPS positioning experiment on sea ice in the Arctic Ocean. The SATICE systems collect continuous, dual-frequency carrier-phase GPS data while drifting on sea ice. Additional geophysical measurements also collected include ocean water pressure, ocean surface salinity, atmospheric pressure, snow-depth, air-ice-ocean temperature profiles, photographic imagery, and others, enabling sea ice drift, freeboard, weather, ice mass balance, and sea-level height determination. Relatively large volumes of data from each buoy are streamed over a satellite link to a central computer on the Internet in near real time, where they are processed to estimate the time-varying buoy positions. SATICE system obtains continuous GPS data at sub-minute intervals with a positioning precision of a few centimetres in all three dimensions. Although monitoring of sea ice motions goes back to the early days of satellite observations, these autonomous platforms bring out a level of spatio-temporal detail that has never been seen before, especially in the vertical axis. These high-resolution data allows us to address new polar science questions and challenge our present understanding of both sea ice dynamics and Arctic oceanography. We will describe the technology behind this new autonomous platform, which could also be adapted to other applications that require high resolution positioning information with sustained operations and observations in the polar marine environment, and present results pertaining to sea ice dynamics and physical oceanography.

  17. Project GeoWSN: High precision but low-cost GNSS landslide monitoring in Austria

    NASA Astrophysics Data System (ADS)

    Koch, Daniel; Brandstätter, Michael; Kühtreiber, Norbert

    2014-05-01

    At present, GNSS monitoring of landslides is an accepted and approved method to detect movements of slopes at risk in the sub-centimetre level. However, high-precision geodetic GNSS-receivers are expensive, therefore this monitoring method is not widely applied. Recently low-cost GNSS-receivers are conquering the geodetic market and are well suited for a cost effective and yet precise GNSS-monitoring. During the project GeoWSN, which was funded by the Austrian Research Promotion Agency (FFG), an applicable low-cost monitoring system was developed at Graz University of Technology. The system is based on a so-called Wireless Sensor Network (WSN) consisting of low-cost GNSS-receivers, temperature and humidity sensors and inertial measurement units. Additionally energy-harvesting technologies and power-saving algorithms provide that the system is energy- autarkic. For real-time applications, a communication link between the sensor nodes is implemented. The relative positioning method RTK (Real Time Kinematic) is applied to reach the highest possible accuracy. The GeoWSN sensor nodes enable the detection of possible movements in the real-time processed positions of the sensor nodes. To ensure a real-time evaluation and interpretation of the data, the current status of the slope can be acquired by a local warning centre. Therefore, affected people can be warned within a short latency. Several test-scenarios have shown the acceptance of the system at the warning centre of Styria, Austria. This contribution should give an overview of the main idea of a low-cost warning system and results of the project GeoWSN.

  18. High-precision CTE measurement of hybrid C/SiC composite for cryogenic space telescopes

    NASA Astrophysics Data System (ADS)

    Enya, K.; Yamada, N.; Imai, T.; Tange, Y.; Kaneda, H.; Katayama, H.; Kotani, M.; Maruyama, K.; Naitoh, M.; Nakagawa, T.; Onaka, T.; Suganuma, M.; Ozaki, T.; Kume, M.; Krödel, M. R.

    2012-01-01

    This paper presents highly precise measurements of thermal expansion of a "hybrid" carbon-fiber reinforced silicon carbide composite, HB-Cesic® - a trademark of ECM, in the temperature region of ˜310-10 K. Whilst C/SiC composites have been considered to be promising for the mirrors and other structures of space-borne cryogenic telescopes, the anisotropic thermal expansion has been a potential disadvantage of this material. HB-Cesic® is a newly developed composite using a mixture of different types of chopped, short carbon-fiber, in which one of the important aims of the development was to reduce the anisotropy. The measurements indicate that the anisotropy was much reduced down to 4% as a result of hybridization. The thermal expansion data obtained are presented as functions of temperature using eighth-order polynomials separately for the horizontal (XY-) and vertical (Z-) directions of the fabrication process. The average CTEs and their dispersion (1σ) in the range 293-10 K derived from the data for the XY- and Z-directions were 0.805 ± 0.003 × 10-6 K-1 and 0.837 ± 0.001 × 10-6 K-1, respectively. The absolute accuracy and the reproducibility of the present measurements are suggested to be better than 0.01 × 10-6 K-1 and 0.001 × 10-6 K-1, respectively. The residual anisotropy of the thermal expansion was consistent with our previous speculation regarding carbon-fiber, in which the residual anisotropy tended to lie mainly in the horizontal plane.

  19. Capability for ozone high-precision retrieval on JEM/SMILES observation

    NASA Astrophysics Data System (ADS)

    Takahashi, Chikako; Suzuki, Makoto; Mitsuda, Chihiro; Ochiai, Satoshi; Manago, Naohiro; Hayashi, Hiroo; Iwata, Yoshitaka; Imai, Koji; Sano, Takuki; Takayanagi, Masahiro; Shiotani, Masato

    2011-09-01

    We estimate the capability of ozone (O 3) retrieval with the Superconducting Submillimeter-Wave Limb-Emission Sounder (SMILES) instrument attached to the Exposed Facility of the Japanese Experiment Module (JEM) on the International Space Station (ISS). SMILES carries a 4-K mechanical refrigerator to cool superconducting devices in space. Since SMILES has high sensitivity thanks to the superconducting receiver, it is expected that SMILES has ability to retrieve O 3 profiles more precisely than the previous millimeter-submillimeter limb measurements from satellites. We examine the random error and the systematic error of O 3 vertical profiles based on the launch-ready retrieval algorithm developed for SMILES. The best random error with single-scan spectra is 0.4% at an altitude of 30 km with 3 km vertical resolution in the mid-latitudes. The random error is better than 5% in the altitude region from 15 to 70 km in the nighttime and from 15 to 55 km in the daytime with 3 km vertical resolution in the mid-latitudes. By averaging ten profiles, the random error is improved to 1% at 70 km altitude in the nighttime and to 5% in the daytime. Using SMILES, we expect to determine the diurnal variation of O 3 vertical profiles with high precision in the upper stratosphere. Finally, the retrieval capability of O 3 in the lower stratosphere is estimated. When retrieving spectral data using two receiver bands (624.32-626.32 GHz and 649.12-650.32 GHz) the random error above 13 km in the mid-latitudes and above 15 km in the tropics is expected to be better than 5% under clear sky conditions.

  20. High Precision Imaging of Microscopic Spread of Glioblastoma with a Targeted Ultrasensitive SERRS Molecular Imaging Probe

    PubMed Central

    Huang, Ruimin; Harmsen, Stefan; Samii, Jason M.; Karabeber, Hazem; Pitter, Kenneth L.; Holland, Eric C.; Kircher, Moritz F.

    2016-01-01

    The dismal prognosis of patients with malignant brain tumors such as glioblastoma multiforme (GBM) is attributed mostly to their diffuse growth pattern and early microscopic tumor spread to distant regions of the brain. Because the microscopic tumor foci cannot be visualized with current imaging modalities, it remains impossible to direct treatments optimally. Here we explored the ability of integrin-targeted surface-enhanced resonance Raman spectroscopy (SERRS) nanoparticles to depict the true tumor extent in a GBM mouse model that closely mimics the pathology in humans. The recently developed SERRS-nanoparticles have a sensitivity of detection in the femtomolar range. An RGD-peptide-conjugated version for integrin-targeting (RGD-SERRS) was compared directly to its non-targeted RAD-SERRS control in the same mice via Raman multiplexing. Pre-blocking with RGD peptide before injection of RGD-SERRS nanoparticles was used to verify the specificity of integrin-targeting. In contrast to the current belief that the enhanced permeability and retention (EPR) effect results in a baseline uptake of nanoparticles regardless of their surface chemistry, integrin-targeting was shown to be highly specific, with markedly lower accumulation after pre-blocking. While the non-targeted SERRS particles enabled delineation of the main tumor, the RGD-SERRS nanoparticles afforded a major improvement in visualization of the true extent and the diffuse margins of the main tumor. This included the detection of unexpected tumor areas distant to the main tumor, tracks of migrating cells of 2-3 cells in diameter, and even isolated distant tumor cell clusters of less than 5 cells. This Raman spectroscopy-based nanoparticle-imaging technology holds promise to allow high precision visualization of the true extent of malignant brain tumors. PMID:27279902