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Sample records for acceleration measurements life

  1. Accelerated life ac conductivity measurements of CRT oxide cathodes

    NASA Astrophysics Data System (ADS)

    Hashim, A. A.; Barratt, D. S.; Hassan, A. K.; Nabok, A.

    2006-07-01

    The ac conductivity measurements have been carried out for the activated Ba/SrO cathode with additional 5% Ni powder for every 100 h acceleration life time at the temperature around 1125 K. The ac conductivity was studied as a function of temperature in the range 300-1200 K after conversion and activation of the cathode at 1200 K for 1 h in two cathodes face to face closed configuration. The experimental results prove that the hopping conductivity dominate in the temperature range 625-770 K through the traps of the WO 3 associate with activation energy Ea = 0.87 eV, whereas from 500-625 K it is most likely to be through the traps of the Al 2O 3 with activation energy of Ea = 1.05 eV. The hopping conductivity at the low temperature range 300-500 K is based on Ni powder link with some Ba contaminants in the oxide layer stricture which indicates very low activation energy Ea = 0.06 eV.

  2. Accelerated life test for high-power white LED based on spectroradiometric measurement

    NASA Astrophysics Data System (ADS)

    Shen, Haiping; Pan, Jiangen; Feng, Huajun

    2008-03-01

    We implement an accelerated life test for the high-power white LEDs based on spectroradiometric measurement. The luminous flux degradation performances are investigated at both the rated current of 350mA and a higher current of 500mA. The average lifetime of the LEDs is 7057 hours at 350mA and 3508 hours at 500mA. The variations of the color of the white LEDs are studied. The color of the low quality white LEDs changes greatly, while the high quality white LEDs keep their color stable. The degradation performances of the chip and phosphor are studied separately. The quantum efficiency of the phosphor becomes lower from 350mA to 500mA current supply. The LED chip degrades faster than the phosphor during the 500mA high current aging. The luminous flux increase and the peak wavelength shift from 350mA to 500mA current supply are found to be useful lifetime indicating parameters that correlate well to the reliability of the high-power white LEDs.

  3. Space acceleration measurement system description and operations on the First Spacelab Life Sciences Mission

    NASA Technical Reports Server (NTRS)

    Delombard, Richard; Finley, Brian D.

    1991-01-01

    The Space Acceleration Measurement System (SAMS) project and flight units are briefly described. The SAMS operations during the STS-40 mission are summarized, and a preliminary look at some of the acceleration data from that mission are provided. The background and rationale for the SAMS project is described to better illustrate its goals. The functions and capabilities of each SAMS flight unit are first explained, then the STS-40 mission, the SAMS's function for that mission, and the preparation of the SAMS are described. Observations about the SAMS operations during the first SAMS mission are then discussed. Some sample data are presented illustrating several aspects of the mission's microgravity environment.

  4. Measurement of the 135Cs half-life with accelerator mass spectrometry and inductively coupled plasma mass spectrometry

    NASA Astrophysics Data System (ADS)

    MacDonald, C. M.; Cornett, R. J.; Charles, C. R. J.; Zhao, X. L.; Kieser, W. E.

    2016-01-01

    The isotope 135Cs is quoted as having a half-life of 2.3 Myr. However, there are three published values ranging from 1.8 to 3 Myr. This research reviews previous measurements and reports a new measurement of the half-life using newly developed accelerator mass spectrometry (AMS) and inductively coupled plasma mass spectrometry (ICPMS) techniques along with β and γ radiometric analysis. The half-life was determined to be (1.6 ±0.6 ) ×106 yr by AMS and (1.3 ±0.2 ) ×106 yr by ICPMS with 95% confidence. The two values agree with each other but differ from the accepted value by ˜40 % .

  5. Space Acceleration Measurement System

    NASA Technical Reports Server (NTRS)

    1993-01-01

    This training video, presented by the Lewis Research Center's Space Experiments Division, gives a background and detailed instructions for preparing the space acceleration measurement system (SAMS) for use. The SAMS measures, conditions, and records forces of low gravity accelerations, and is used to determine the effect of these forces on various experiments performed in microgravity. Inertial sensors are used to measure positive and negative acceleration over a specified frequency range. The video documents the SAMS' uses in different configurations during shuttle missions.

  6. Microgravity Acceleration Measurement System

    NASA Technical Reports Server (NTRS)

    Foster, William

    2009-01-01

    Microgravity Acceleration Measurement System (MAMS) is an ongoing study of the small forces (vibrations and accelerations) on the ISS that result from the operation of hardware, crew activities, as well as dockings and maneuvering. Results will be used to generalize the types of vibrations affecting vibration-sensitive experiments. Investigators seek to better understand the vibration environment on the space station to enable future research.

  7. SAMS Acceleration Measurements on MIR

    NASA Technical Reports Server (NTRS)

    Moskowitz, Milton E.; Hrovat, Kenneth; Finkelstein, Robert; Reckart, Timothy

    1997-01-01

    During NASA Increment 3 (September 1996 to January 1997), about 5 gigabytes of acceleration data were collected by the Space Acceleration Measurement System (SAMS) onboard the Russian Space Station, Mir. The data were recorded on 11 optical disks and were returned to Earth on STS-81. During this time, SAMS data were collected in the Priroda module to support the following experiments: the Mir Structural Dynamics Experiment (MiSDE) and Binary Colloidal Alloy Tests (BCAT). This report points out some of the salient features of the microgravity environment to which these experiments were exposed. Also documented are mission events of interest such as the docked phase of STS-81 operations, a Progress engine burn, attitude control thruster operation, and crew exercise. Also included are a description of the Mir module orientations, and the panel notations within the modules. This report presents an overview of the SAMS acceleration measurements recorded by 10 Hz and 100 Hz sensor heads. Variations in the acceleration environment caused by unique activities such as crew exercise and life-support fans are presented. The analyses included herein complement those presented in previous mission summary reports published by the Principal Investigator Microgravity Services (PIMS) group.

  8. Acceleration measurements in JEM

    NASA Astrophysics Data System (ADS)

    Ikeda, Toshitami; Murakami, Keiji

    2000-01-01

    Since summer in 1996, National Space Development Agency of Japan (NASDA) has continued a concept study for a microgravity measurement apparatus (MMA) to be installed in the Japanese Experiment Module (JEM). The concept study was finished in 1998, and then we have been proceeding for a basic design. For experiments conducted with some of NASDA payloads in JEM-PM (Pressurized Module), measuring detailed microgravity environment was required. In addition, experiments to be performed with payload equipment attached on the JEM-EF (Exposed Facility) are requiring for obtaining the microgravity measurement data. Thus, we are adding some modification to the concept design of MMA in order to make the common hardware available for measurement of both environment in the JEM-PM and that of the JEM-EF. In this paper, the current development status of Japanese payloads and the modified concept of the MMA are introduced. .

  9. Advanced Microgravity Acceleration Measurement Systems Being Developed

    NASA Technical Reports Server (NTRS)

    Sicker, Ronald J.; Kacpura, Thomas J.

    2002-01-01

    The Advanced Microgravity Acceleration Measurement Systems (AMAMS) project at the NASA Glenn Research Center is part of the Instrument Technology Development program to develop advanced sensor systems. The primary focus of the AMAMS project is to develop microelectromechanical (MEMS) acceleration sensor systems to replace existing electromechanical-sensor-based systems presently used to assess relative gravity levels aboard spacecraft. These systems are used in characterizing both vehicle and payload responses to low-gravity vibroacoustic environments. The collection of microgravity acceleration data has cross-disciplinary utility to the microgravity life and physical sciences and the structural dynamics communities. The inherent advantages of semiconductor-based systems are reduced size, mass, and power consumption, while providing enhanced stability.

  10. Quantitative Accelerated Life Testing of MEMS Accelerometers

    PubMed Central

    Bâzu, Marius; Gălăţeanu, Lucian; Ilian, Virgil Emil; Loicq, Jerome; Habraken, Serge; Collette, Jean-Paul

    2007-01-01

    Quantitative Accelerated Life Testing (QALT) is a solution for assessing the reliability of Micro Electro Mechanical Systems (MEMS). A procedure for QALT is shown in this paper and an attempt to assess the reliability level for a batch of MEMS accelerometers is reported. The testing plan is application-driven and contains combined tests: thermal (high temperature) and mechanical stress. Two variants of mechanical stress are used: vibration (at a fixed frequency) and tilting. Original equipment for testing at tilting and high temperature is used. Tilting is appropriate as application-driven stress, because the tilt movement is a natural environment for devices used for automotive and aerospace applications. Also, tilting is used by MEMS accelerometers for anti-theft systems. The test results demonstrated the excellent reliability of the studied devices, the failure rate in the “worst case” being smaller than 10-7h-1.

  11. Earth Scanner Bearing Accelerated Life Test

    NASA Technical Reports Server (NTRS)

    Dietz, Brian J.; VanDyk, Steven G.; Predmore, Roamer E.

    2000-01-01

    The Moderate Resolution Imaging Spectrometer (MODIS) optical instrument for NASA Goddard will measure biological and physical processes on the Earth's surface and in the lower atmosphere. A key component of the instrument is an extremely accurate scan mirror motor/encoder assembly. Of prime concern in the performance and reliability of the scan motor/encoder is bearing selection and lubrication. This paper describes life testing of the bearings and lubrication selected for the program.

  12. Space Acceleration Measurement System for Free Flyers

    NASA Technical Reports Server (NTRS)

    Kacpura, Thomas J.

    1999-01-01

    Experimenters from the fluids, combustion, materials, and life science disciplines all use the microgravity environment of space to enhance their understanding of fundamental physical phenomena caused by disturbances from events such as spacecraft maneuvers, equipment operations, atmospheric drag, and (for manned flights) crew movement. Space conditions reduce gravity but do not eliminate it. To quantify the level of these disturbances, NASA developed the Space Acceleration Measurement System (SAMS) series to collect data characterizing the acceleration environment on the space shuttles. This information is provided to investigators so that they can evaluate how the microgravity environment affects their experiments. Knowledge of the microgravity environment also helps investigators to plan future experiments. The original SAMS system flew 20 missions on the shuttle as well as on the Russian space station Mir. Presently, Lewis is developing SAMS-II for the International Space Station; it will be a distributed system using digital output sensor heads. The latest operational version of SAMS, SAMS-FF, was originally designed for free flyer spacecraft and unmanned areas. SAMS-FF is a flexible, modular system, housed in a lightweight package, and it uses advances in technology to improve performance. The hardware package consists of a control and data acquisition module, three different types of sensors, data storage devices, and ground support equipment interfaces. Three different types of sensors are incorporated to measure both high- and low-frequency accelerations and the roll rate velocity. Small, low-power triaxial sensor heads (TSH's) offer high resolution and selectable bandwidth, and a special low-frequency accelerometer is available for high-resolution, low-frequency applications. A state-of-the-art, triaxial fiberoptic gyroscope that measures extremely low roll rates is housed in a compact package. The versatility of the SAMS-FF system is shown in the three

  13. Measurement of Coriolis Acceleration with a Smartphone

    ERIC Educational Resources Information Center

    Shaku, Asif; Kraft, Jakob

    2016-01-01

    Undergraduate physics laboratories seldom have experiments that measure the Coriolis acceleration. This has traditionally been the case owing to the inherent complexities of making such measurements. Articles on the experimental determination of the Coriolis acceleration are few and far between in the physics literature. However, because modern…

  14. A Microcomputer-Controlled Measurement of Acceleration.

    ERIC Educational Resources Information Center

    Crandall, A. Jared; Stoner, Ronald

    1982-01-01

    Describes apparatus and method used to allow rapid and repeated measurement of acceleration of a ball rolling down an inclined plane. Acceleration measurements can be performed in an hour with the apparatus interfaced to a Commodore PET microcomputer. A copy of the BASIC program is available from the authors. (Author/JN)

  15. Accelerated life testing effects on CMOS microcircuit characteristics

    NASA Technical Reports Server (NTRS)

    1980-01-01

    The 250 C, 200C and 125C accelerated tests are described. The wear-out distributions from the 250 and 200 C tests were used to estimate the activation energy between the two test temperatures. The duration of the 125 C test was not sufficient to bring the test devices into the wear-out region. It was estimated that, for the most complex of the three devices types, the activation energy between 200 C and 125 C should be at least as high as that between 250 C and 200 C. The practicality of the use of high temperature for the accelerated life tests from the point of view of durability of equipment is assessed. Guidlines for the development of accelerated life-test conditions are proposed. The use of the silicon nitride overcoat to improve the high temperature accelerated life-test characteristics of CMOS microcircuits is described.

  16. Advanced Microgravity Acceleration Measurement Systems (AMAMS) Being Developed

    NASA Technical Reports Server (NTRS)

    Sicker, Ronald J.; Kacpura, Thomas J.

    2003-01-01

    The Advanced Microgravity Acceleration Measurement Systems (AMAMS) project is part of NASA s Instrument Technology Development program to develop advanced sensor systems. The primary focus of the AMAMS project is to develop microelectromechanical systems (MEMS) for acceleration sensor systems to replace existing electromechanical sensor systems presently used to assess relative gravity levels aboard spacecraft. These systems are used to characterize both vehicle and payload responses to low-gravity vibroacoustic environments. The collection of microgravity acceleration data is useful to the microgravity life sciences, microgravity physical sciences, and structural dynamics communities. The inherent advantages of semiconductor-based systems are reduced size, mass, and power consumption, with enhanced long-term calibration stability.

  17. Accelerated battery-life testing - A concept

    NASA Technical Reports Server (NTRS)

    Mccallum, J.; Thomas, R. E.

    1971-01-01

    Test program, employing empirical, statistical and physical methods, determines service life and failure probabilities of electrochemical cells and batteries, and is applicable to testing mechanical, electrical, and chemical devices. Data obtained aids long-term performance prediction of battery or cell.

  18. Measuring residual accelerations in the Spacelab environment

    NASA Technical Reports Server (NTRS)

    Witherow, William K.

    1991-01-01

    A triglycine sulfate (TGS) crystal growth experiment carried out in Spacelab 3 flown onboard the Shuttle orbiter in 1985 is described. The TGS experiment was aimed at examining diffusion limited crystal growth by minimizing convection in the microgravity environment of the Spacelab. During the experiment tiny crystals were found floating free in the growth solution. Since the free crystals were in a viscous fluid, the 'noise' accelerations of the Shuttle were damped out. This made it possible to measure the constant gravitational acceleration by tracking the positions of these crystals. The velocities and accelerations obtained by these measurements are presented.

  19. PRECISE CHARGE MEASUREMENT FOR LASER PLASMA ACCELERATORS

    SciTech Connect

    Nakamura, Kei; Gonsalves, Anthony; Lin, Chen; Sokollik, Thomas; Shiraishi, Satomi; Tilborg, Jeroen van; Osterhoff, Jens; Donahue, Rich; Rodgers, David; Smith, Alan; Byrne, Warren; Leemans, Wim

    2011-07-19

    Cross-calibrations of charge diagnostics are conducted to verify their validity for measuring electron beams produced by laser plasma accelerators (LPAs). Employed diagnostics are a scintillating screen, activation based measurement, and integrating current transformer. The diagnostics agreed within {+-}8 %, showing that they can provide accurate charge measurements for LPAs provided they are used properly.

  20. Measurement of Coriolis Acceleration with a Smartphone

    NASA Astrophysics Data System (ADS)

    Shakur, Asif; Kraft, Jakob

    2016-05-01

    Undergraduate physics laboratories seldom have experiments that measure the Coriolis acceleration. This has traditionally been the case owing to the inherent complexities of making such measurements. Articles on the experimental determination of the Coriolis acceleration are few and far between in the physics literature. However, because modern smartphones come with a raft of built-in sensors, we have a unique opportunity to experimentally determine the Coriolis acceleration conveniently in a pedagogically enlightening environment at modest cost by using student-owned smartphones. Here we employ the gyroscope and accelerometer in a smartphone to verify the dependence of Coriolis acceleration on the angular velocity of a rotatingtrack and the speed of the sliding smartphone.

  1. Space Acceleration Measurement System-II

    NASA Technical Reports Server (NTRS)

    Foster, William

    2009-01-01

    Space Acceleration Measurement System (SAMS-II) is an ongoing study of the small forces (vibrations and accelerations) on the ISS that result from the operation of hardware, crew activities, as well as dockings and maneuvering. Results will be used to generalize the types of vibrations affecting vibration-sensitive experiments. Investigators seek to better understand the vibration environment on the space station to enable future research.

  2. Accelerated life testing effects on CMOS microcircuit characteristics

    NASA Technical Reports Server (NTRS)

    1977-01-01

    Accelerated life tests were performed on CMOS microcircuits to predict their long term reliability. The consistency of the CMOS microcircuit activation energy between the range of 125 C to 200 C and the range 200 C to 250 C was determined. Results indicate CMOS complexity and the amount of moisture detected inside the devices after testing influences time to failure of tested CMOS devices.

  3. Measures that Prolong Work Life.

    ERIC Educational Resources Information Center

    Nusberg, Charlotte

    1986-01-01

    Discusses measures that have been adopted by France, Great Britain, Sweden, the Netherlands, the United States, and Japan to prolong the work life of older workers. Measures include job transfer and exemption, dismissal protection, retirement policies, and reintegration of unemployed older workers. (JOW)

  4. Accelerated life testing effects on CMOS microcircuit characteristics

    NASA Technical Reports Server (NTRS)

    1980-01-01

    This report covers the time period from May 1976 to December 1979 and encompasses the three phases of accelerated testing: Phase 1, the 250 C testing; Phase 2, the 200 C testing; and Phase 3, the 125 C testing. The duration of the test in Phase 1 and Phase 2 was sufficient to take the devices into the wear out region. The wear out distributions were used to estimate the activation energy between the 250 C and the 200 C test temperatures. The duration of the 125 C test, 20,000 hours, was not sufficient to bring the test devices into the wear out region; consequently the third data point at 125 C for determining the consistency of activation energy could not be obtained. It was estimated that, for the most complex of the three device types, the activation energy between 200 C and 125 C should be at least as high as that between 250 C and 200 C. The practicality of the use of high temperature for the accelerated life tests from the point of view of durability of equipment was assessed. Guidelines for the development of accelerated life test conditions were proposed. The use of the silicon nitride overcoat to improve the high temperature accelerated life test characteristics of CMOS microcircuits was explored in Phase 4 of this study and is attached as an appendix to this report.

  5. Orbital Acceleration Research Experiment: Calibration Measurements

    NASA Technical Reports Server (NTRS)

    Blanchard, Robert C.; Nicholson, John Y.; Ritter, James R.; Larman, Kevin T.

    1995-01-01

    The Orbital Acceleration Research Experiment (OARE), which has flown on STS-40, STS-50, and STS-58, contains a three-axis accelerometer with a single, nonpendulous, electrostatically suspended proofmass, which can resolve accelerations to the 10(sub -9) g level. The experiment also contains a full calibration station to permit in situ bias and scale-factor calibration. This on-orbit calibration capability eliminates the large uncertainty of ground-based calibrations encountered with accelerometers flown in the past on the Orbiter, and thus provides absolute acceleration measurement accuracy heretofore unachievable. This is the first time accelerometer scale-factor measurements have been performed on orbit. A detailed analysis of the calibration process is given, along with results of the calibration factors from the on-orbit OARE flight measurements on STS-58. In addition, the analysis of OARE flight-maneuver data used to validate the scale-factor measurements in the sensor's most sensitive range are also presented. Estimates on calibration uncertainties are discussed. These uncertainty estimates provides bounds on the STS-58 absolute acceleration measurements for future applications.

  6. Cycle life of nickel-hydrogen cells. II - Accelerated cycle life test

    NASA Technical Reports Server (NTRS)

    Lim, H. S.; Verzwyvelt, S. A.

    1986-01-01

    A cycle life test of nickel-hydrogen (Ni/H2) cells containing electrolytes of various KOH concentrations and a sintered-type nickel electrode were carried out at 23 C using a 45-min accelerated low earth orbit (LEO) cycle regime at 80 percent depth of discharge. Ten cells containing 21 to 36 percent KOH were tested. Since this accelerated test regime accelerated the cycle life roughly twice as fast as a typical LEO regime, the present results indicate that the cells with 26 percent KOH may last over 5 years in an 80 percent depth-of-discharge cycling in an LEO regime. Cells with lower KOH concentrations (21 to 23.5 percent) also showed longer cycle life than those with KOH concentrations of 31 percent or higher, although the life was shorter than those with 26 percent KOH.

  7. Gravity Acceleration Measurements Using a Soundcard

    ERIC Educational Resources Information Center

    Abellan-Garcia, Francisco J.; Garcia-Gamuz, Jose Antonio; Valerdi-Perez, Ramon P.; Ibanez-Mengual, Jose A.

    2012-01-01

    The aim of this paper is to determine the acceleration due to gravity "g", using a simple and low-cost experimental device. The time taken for a metallic ball to travel a predetermined distance is measured and recorded by a series of optical sensors. Four pairs of sensors are placed along the external surface of a vertical methacrylate tube at…

  8. Miniature piezoelectric triaxial accelerometer measures cranial accelerations

    NASA Technical Reports Server (NTRS)

    Deboo, G. J.; Rogallo, V. L.

    1966-01-01

    Tiny triaxial accelerometer whose sensing elements are piezoelectric ceramic beams measures human cranial accelerations when a subject is exposed to a centrifuge or other simulators of g environments. This device could be considered for application in dental, medical, and automotive safety research.

  9. Accelerated life testing effects on CMOS microcircuit characteristics, phase 1

    NASA Technical Reports Server (NTRS)

    Maximow, B.

    1976-01-01

    An accelerated life test of sufficient duration to generate a minimum of 50% cumulative failures in lots of CMOS devices was conducted to provide a basis for determining the consistency of activation energy at 250 C. An investigation was made to determine whether any thresholds were exceeded during the high temperature testing, which could trigger failure mechanisms unique to that temperature. The usefulness of the 250 C temperature test as a predictor of long term reliability was evaluated.

  10. Atomic References for Measuring Small Accelerations

    NASA Technical Reports Server (NTRS)

    Maleki, Lute; Yu, Nan

    2009-01-01

    Accelerometer systems that would combine the best features of both conventional (e.g., mechanical) accelerometers and atom interferometer accelerometers (AIAs) have been proposed. These systems are intended mainly for use in scientific research aboard spacecraft but may also be useful on Earth in special military, geological, and civil-engineering applications. Conventional accelerometers can be sensitive, can have high dynamic range, and can have high frequency response, but they lack accuracy and long-term stability. AIAs have low frequency response, but they offer high sensitivity, and high accuracy for measuring small accelerations. In a system according to the proposal, a conventional accelerometer would be used to perform short-term measurements of higher-frequency components of acceleration, while an AIA would be used to provide consistent calibration of, and correction of errors in, the measurements of the conventional accelerometer in the lower-frequency range over the long term. A brief description of an AIA is prerequisite to a meaningful description of a system according to the proposal. An AIA includes a retroreflector next to one end of a cell that contains a cold cloud of atoms in an ultrahigh vacuum. The atoms in the cloud are in free fall. The retroreflector is mounted on the object, the acceleration of which is to be measured. Raman laser beams are directed through the cell from the end opposite the retroreflector, then pass back through the cell after striking the retroreflector. The Raman laser beams together with the cold atoms measure the relative acceleration, through the readout of the AIA, between the cold atoms and the retroreflector.

  11. Application of accelerated tool life tests to machining of titanium

    SciTech Connect

    Stagner, R.T.

    1980-09-01

    The tool life of several commercial C-2 grade cutting tools used in machining titanium was estimated using two experimental techniques, the quick facing test and the multipass facing test. Comparisons among the tools tested were made statistically by analyzing differences in regression equations derived from test data. Tool life end points were determined by operator judgement, tool force analysis, and tool wear measurement. Of the ten tools tested, nine had the same life under the test conditions.

  12. [Weekly control measurement at the linear accelerator].

    PubMed

    Christ, G

    1983-05-01

    Weekly control measurements taken at the linear accelerator of the Medizinisches Strahleninstitut der Universität Tübingen are described which largely exceed those prescribed by the "Richtlinien Strahlenschutz in der Medizin" (instructions about radioprotection in medicine). Since the determination of the field homogeneity and the energy of electron and X-ray radiation is very time-consuming, a largely automatized procedure has been elaborated which is presented in this study. PMID:6857748

  13. A statistical treatment of accelerated life test data for copper-water heat pipes

    NASA Astrophysics Data System (ADS)

    Murakami, M.; Arai, K.; Kojima, Y.

    1988-03-01

    A statistical method is proposed to treat accelerated life test data conducted at several elevated temperatures for a sufficient number of commercially available Cu-water heat pipes to predict the operation life. The temperature distribution measurements periodically carried out yield both data sets concerning the temperature drop and the gas column length as measures of noncondensible gas accumulation. The gas analysis with a mass spectrometer is also carried out to obtain the gas quantity data. A method of unified regression analysis to take account of the acceleration factor resulted from a number of elevated test temperatures is proposed to establish a method to predict the long term performance degradation from life test data. The mutual correlations among three kinds of data sets are also discussed.

  14. Microgravity acceleration measurement and environment characterization science (17-IML-1)

    NASA Technical Reports Server (NTRS)

    1992-01-01

    The Space Acceleration Measurement System (SAMS) is a general purpose instrumentation system designed to measure the accelerations onboard the Shuttle Orbiter and Shuttle/Spacelab vehicles. These measurements are used to support microgravity experiments and investigation into the microgravity environment of the vehicle. Acceleration measurements can be made at locations remote from the SAMS main instrumentation unit by the use of up to three remote triaxial sensor heads. The prime objective for SAMS on the International Microgravity Lab (IML-1) mission will be to measure the accelerations experienced by the Fluid Experiment System (FES). The SAMS acceleration measurements for FES will be complemented by low level, low frequency acceleration measurements made by the Orbital Acceleration Research Experiment (OARE) installed on the shuttle. Secondary objectives for SAMS will be to measure accelerations at several specific locations to enable the acceleration transfer function of the Spacelab module to be analyzed. This analysis effort will be in conjunction with similar measurements analyses on other Spacelab missions.

  15. Highly accelerated life testing for the 1210 Digital Ruggedized Display

    NASA Astrophysics Data System (ADS)

    Becker, Bruce; Phillips, Ruth

    1998-09-01

    The 1210 Digital Ruggedized Display (1210 DRD) was designed and built for a harsh military environment. The 1210 DRD uses a single 1280 X 1024 Digital Micromirror Device (DMDTM) as a reflective image source. Through the use of Highly Accelerated Life Testing we have verified and validated the 1210 DRD through rigorous thermal, vibration, and combined environment testing. The results prove the DMD-based 1210 DRD to be a very rugged display that can meet and exceed the requirements of displays used in military applications.

  16. SAMS Acceleration Measurement on Mir From March to September 1996

    NASA Technical Reports Server (NTRS)

    Moskowitz, Milton E.; Hrovat, Ken; Truong, Duc; Reckart, Timothy

    1997-01-01

    During NASA Increment 2 (March to September 1996), over 15 gigabytes of acceleration data were collected by the Space Acceleration Measurement System (SAMS) onboard the Russian Space Station, Mir. The data were recorded on 55 optical disks and were returned to Earth on STS-79. During this time, SAMS data were collected in the Kristall and Kvant modules, and in the Priroda module to support the following experiments: the Queen's University Experiments in Liquid Diffusion (QUELD), the Technological Evaluation of the MIM (TEM), the Forced Flow Flame Spreading Test (FFFT), and Candle Flames in Microgravity (CFM). This report points out some of the salient features of the microgravity environment to which these experiments were exposed. Also documented are mission events of interest such as the docked phase of STS-76 operations, an extravehicular activity (EVA) to install and deploy solar panels on the Kvant module, a Progress engine burn to raise Mir's altitude, and an on-orbit SAMS calibration procedure. Also included are a description of the Mir module orientations, and the panel notations within the modules. This report presents an overview of the SAMS acceleration measurements recorded by 10 Hz and 100 Hz sensor heads. Variations in the acceleration environment caused by unique activities such as crew exercise and life-support fans are presented. The analyses included herein complement those presented in previous mission summary reports published by the Principal Investigator Microgravity Services (PIMS) group.

  17. Precise charge measurement for laser plasma accelerators

    NASA Astrophysics Data System (ADS)

    Nakamura, Kei; Gonsalves, Anthony; Lin, Chen; Sokollik, Thomas; Shiraishi, Satomi; van Tilborg, Jeroen; Smith, Alan; Rodgers, Dave; Donahue, Rick; Byrne, Warren; Leemans, Wim

    2011-10-01

    A comprehensive study of charge diagnostics was conducted to verify their validity for measuring electron beams produced by laser plasma accelerators (LPAs). The electron energy dependence of a scintillating screen (Lanex Fast) was studied with sub-nanosecond electron beams ranging from 106 MeV to 1522 MeV at the Lawrence Berkeley National Laboratory Advanced Light Source (ALS) synchrotron booster accelerator. Using an integrating current transformer as a calibration reference, the sensitivity of the Lanex Fast was found to decrease by 1% per 100 MeV increase of the energy. By using electron beams from LPA, cross calibrations of the charge were carried out with an integrating current transformer, scintillating screen (Lanex from Kodak), and activation based measurement. The diagnostics agreed within ~8%, showing that they all can provide accurate charge measurements for LPAs provided necessary cares. Work supported by the Office of Science, Office of High Energy Physics, of the U.S. Department of Energy under Contract No. DE-AC02-05CH11231.

  18. Emittance measurements from the LLUMC proton accelerator

    NASA Astrophysics Data System (ADS)

    Coutrakon, G.; Gillespie, G. H.; Hubbard, J.; Sanders, E.

    2005-12-01

    A new method of calculating beam emittances at the extraction point of a particle accelerator is presented. The technique uses the optimization programs NPSOL and MINOS developed at Stanford University in order to determine the initial values of beam size, divergence and correlation parameters (i.e. beam sigma matrix, σij) that best fit measured beam parameters. These σij elements are then used to compute the Twiss parameters α, β, and the phase space area, ε, of the beam at the extraction point. Beam size measurements in X and Y throughout the transport line were input to the optimizer along with the magnetic elements of bends, quads, and drifts. The σij parameters were optimized at the accelerator's extraction point by finding the best agreement between these measured beam sizes and those predicted by TRANSPORT. This expands upon a previous study in which a "trial and error" technique was used instead of the optimizer software, and which yielded similar results. The Particle Beam Optics Laboratory (PBO Lab™) program used for this paper integrates particle beam optics and other codes into a single intuitive graphically-based computing environment. This new software provides a seamless interface between the NPSOL and MINOS optimizer and TRANSPORT calculations. The results of these emittance searches are presented here for the eight clinical energies between 70 and 250 MeV currently being used at LLUMC.

  19. Polarization measurement of laser-accelerated protons

    SciTech Connect

    Raab, Natascha; Engels, Ralf; Engin, Ilhan; Greven, Patrick; Holler, Astrid; Lehrach, Andreas; Maier, Rudolf; Büscher, Markus; Cerchez, Mirela; Swantusch, Marco; Toncian, Monika; Toncian, Toma; Willi, Oswald; Gibbon, Paul; Karmakar, Anupam

    2014-02-15

    We report on the successful use of a laser-driven few-MeV proton source to measure the differential cross section of a hadronic scattering reaction as well as on the measurement and simulation study of polarization observables of the laser-accelerated charged particle beams. These investigations were carried out with thin foil targets, illuminated by 100 TW laser pulses at the Arcturus laser facility; the polarization measurement is based on the spin dependence of hadronic proton scattering off nuclei in a Silicon target. We find proton beam polarizations consistent with zero magnitude which indicates that for these particular laser-target parameters the particle spins are not aligned by the strong magnetic fields inside the laser-generated plasmas.

  20. Long-term storage life of light source modules by temperature cycling accelerated life test

    NASA Astrophysics Data System (ADS)

    Ningning, Sun; Manqing, Tan; Ping, Li; Jian, Jiao; Xiaofeng, Guo; Wentao, Guo

    2014-05-01

    Light source modules are the most crucial and fragile devices that affect the life and reliability of the interferometric fiber optic gyroscope (IFOG). While the light emitting chips were stable in most cases, the module packaging proved to be less satisfactory. In long-term storage or the working environment, the ambient temperature changes constantly and thus the packaging and coupling performance of light source modules are more likely to degrade slowly due to different materials with different coefficients of thermal expansion in the bonding interface. A constant temperature accelerated life test cannot evaluate the impact of temperature variation on the performance of a module package, so the temperature cycling accelerated life test was studied. The main failure mechanism affecting light source modules is package failure due to solder fatigue failure including a fiber coupling shift, loss of cooling efficiency and thermal resistor degradation, so the Norris-Landzberg model was used to model solder fatigue life and determine the activation energy related to solder fatigue failure mechanism. By analyzing the test data, activation energy was determined and then the mean life of light source modules in different storage environments with a continuously changing temperature was simulated, which has provided direct reference data for the storage life prediction of IFOG.

  1. Energy Measurement in a Plasma Wakefield Accelerator

    SciTech Connect

    Ischebeck, R

    2007-07-06

    In the E-167 plasma wakefield acceleration experiment, electrons with an initial energy of 42GeV are accelerated in a meter-scale lithium plasma. Particles are leaving plasma with a large energy spread. To determine the spectrum of the accelerated particles, a two-plane spectrometer has been set up.

  2. Tritium measurements with a tandem accelerator

    NASA Astrophysics Data System (ADS)

    Middleton, R.; Klein, J.; Fink, D.

    1990-06-01

    Tritium concentrations ( 3H: 2H) of less than 10 -15 are readily measurable with almost any tandem accelerator and with an overall detection efficiency as high as 4.5%. The isobar, 3He, and other potential sources of interference (mainly 6Li, 2H and 1H) can all be removed by an absorber in front of the triton detector, so there is little need for analyzing elements other than the negative-and positive-ion magnets found on most tandems. The technique is particularly well suited for detecting tritium in deuterium absorbed in a metal and testing for cold fusion. We caution that tritium can occur in commercial deuterium and heavy water from sources other than cold fusion; one sample was observed to have a tritium-to-deuterium ratio of 10 -10.

  3. Design of MEMS accelerometer based acceleration measurement system for automobiles

    NASA Astrophysics Data System (ADS)

    Venkatesh, K. Arun; Mathivanan, N.

    2012-10-01

    Design of an acceleration measurement system using a MEMS accelerometer to measure acceleration of automobiles in all the three axes is presented. Electronic stability control and anti-lock breaking systems in automobiles use the acceleration measurements to offer safety in driving. The system uses an ARM microcontroller to quantize the outputs of accelerometer and save the measurement data on a microSD card. A LabVIEW program has been developed to analyze the longitudinal acceleration measurement data and test the measurement system. Random noises generated and added with measurement data during measurement are filtered by a Kalman filter implemented in LabVIEW. Longitudinal velocity of the vehicle is computed from the measurement data and displayed on a graphical chart. Typical measurement of velocity of a vehicle at different accelerations and decelerations is presented.

  4. Mir Cooperative Solar Array Project Accelerated Life Thermal Cycling Test

    NASA Technical Reports Server (NTRS)

    Hoffman, David J.; Scheiman, David A.

    1996-01-01

    The Mir Cooperative Solar Array (MCSA) project was a joint U.S./Russian effort to build a photovoltaic (PV) solar array and deliver it to the Russian space station Mir. The MCSA will be used to increase the electrical power on Mir and provide PV array performance data in support of Phase 1 of the International Space Station. The MCSA was brought to Mir by space shuttle Atlantis in November 1995. This report describes an accelerated thermal life cycle test which was performed on two samples of the MCSA. In eight months time, two MCSA solar array 'mini' panel test articles were simultaneously put through 24,000 thermal cycles. There was no significant degradation in the structural integrity of the test articles and no electrical degradation, not including one cell damaged early and removed from consideration. The nature of the performance degradation caused by this one cell is briefly discussed. As a result of this test, changes were made to improve some aspects of the solar cell coupon-to-support frame interface on the flight unit. It was concluded from the results that the integration of the U.S. solar cell modules with the Russian support structure would be able to withstand at least 24,000 thermal cycles (4 years on-orbit). This was considered a successful development test.

  5. Voltage stress effects on microcircuit accelerated life test failure rates

    NASA Technical Reports Server (NTRS)

    Johnson, G. M.

    1976-01-01

    The applicability of Arrhenius and Eyring reaction rate models for describing microcircuit aging characteristics as a function of junction temperature and applied voltage was evaluated. The results of a matrix of accelerated life tests with a single metal oxide semiconductor microcircuit operated at six different combinations of temperature and voltage were used to evaluate the models. A total of 450 devices from two different lots were tested at ambient temperatures between 200 C and 250 C and applied voltages between 5 Vdc and 15 Vdc. A statistical analysis of the surface related failure data resulted in bimodal failure distributions comprising two lognormal distributions; a 'freak' distribution observed early in time, and a 'main' distribution observed later in time. The Arrhenius model was shown to provide a good description of device aging as a function of temperature at a fixed voltage. The Eyring model also appeared to provide a reasonable description of main distribution device aging as a function of temperature and voltage. Circuit diagrams are shown.

  6. Andy Sessler: The Full Life of an Accelerator Physicist

    NASA Astrophysics Data System (ADS)

    Kim, Kwang-Je; Budnitz, Robert J.; Winick, Herman

    2015-02-01

    This article describes the distinguished career of Andrew M. Sessler, the visionary former director of the Lawrence Berkeley National Laboratory (LBNL), one of the most influential accelerator physicists, and a strong, dedicated human-rights activist. Andy died on 17 April 2014 from cancer at age 85. He grew up in New York City, and attended Harvard (BA in Mathematics, 1949) and then Columbia (PhD in Physics, 1953.) After an NSF postdoc at Cornell with Hans Bethe and a stint on the faculty at the Ohio State University in 1954-59, he joined the Lawrence Radiation Laboratory (now LBNL) in 1959, and spent the remainder of his career there. Although Andy l his mark on several areas of physics, including nuclear structure theory, elementary-particle physics, and many-body problems, his lasting and most important contributions came from his efforts in accelerator physics and engineering, to which he devoted most of his life's work. In collaboration with his colleagues of the legendary Midwestern Universities Research Association, he developed theories for the RF acceleration process and the collective instability phenomena, helping to realize the colliding-beam accelerators with which most of the high-energy-physics discoveries of the last few decades have been made. His work in connection with the free-electron-laser (FEL) amplifier for high-power microwave generation constructed at the Lawrence Livermore National Laboratory anticipated the optical-guiding and the self-amplified spontaneous-emission principles, upon which the success of the X-ray FELs as the fourth-generation light sources is based. Throughout his career Andy made major contributions to issues related to the impact of science and technology on society. He helped usher in a new era of research on energy efficiency and sustainable-energy technology and was instrumental in building the research agendas in those areas for the Atomic Energy Commission (AEC) and later the Department of Energy. With a lifelong

  7. Andy Sessler: The Full Life of an Accelerator Physicist

    NASA Astrophysics Data System (ADS)

    Kim, Kwang-Je; Budnitz, Robert J.; Winick, Herman

    This article describes the distinguished career of Andrew M. Sessler, the visionary former director of the Lawrence Berkeley National Laboratory (LBNL), one of the most influential accelerator physicists, and a strong, dedicated human-rights activist. Andy died on 17 April 2014 from cancer at age 85. He grew up in New York City, and attended Harvard (BA in Mathematics, 1949) and then Columbia (PhD in Physics, 1953.) After an NSF postdoc at Cornell with Hans Bethe and a stint on the faculty at the Ohio State University in 1954-59, he joined the Lawrence Radiation Laboratory (now LBNL) in 1959, and spent the remainder of his career there. Although Andy left his mark on several areas of physics, including nuclear structure theory, elementary-particle physics, and many-body problems, his lasting and most important contributions came from his efforts in accelerator physics and engineering, to which he devoted most of his life's work. In collaboration with his colleagues of the legendary Midwestern Universities Research Association, he developed theories for the RF acceleration process and the collective instability phenomena, helping to realize the colliding-beam accelerators with which most of the high-energy-physics discoveries of the last few decades have been made. His work in connection with the free-electron-laser (FEL) amplifier for high-power microwave generation constructed at the Lawrence Livermore National Laboratory anticipated the optical-guiding and the self-amplified spontaneous-emission principles, upon which the success of the X-ray FELs as the fourth-generation light sources is based. Throughout his career Andy made major contributions to issues related to the impact of science and technology on society. He helped usher in a new era of research on energy efficiency and sustainable-energy technology and was instrumental in building the research agendas in those areas for the Atomic Energy Commission (AEC) and later the Department of Energy. With a

  8. Don't Use Airtracks to Measure Gravity Acceleration.

    ERIC Educational Resources Information Center

    Kluk, Edward; Lopez, John L.

    1992-01-01

    Presents one way, using simple materials available in hardware stores, to obtain accurate measurements of gravity acceleration in student laboratories. Analyzes a time-of-flight measuring scheme and discusses the experimental arrangements to make the measurements. (MDH)

  9. Summary Report of Mission Acceleration Measurements for STS-78. Launched June 20, 1996

    NASA Technical Reports Server (NTRS)

    Hakimzadeh, Roshanak; Hrovat, Kenneth; McPherson, Kevin M.; Moskowitz, Milton E.; Rogers, Melissa J. B.

    1997-01-01

    The microgravity environment of the Space Shuttle Columbia was measured during the STS-78 mission using accelerometers from three different instruments: the Orbital Acceleration Research Experiment, the Space Acceleration Measurement System and the Microgravity Measurement Assembly. The quasi-steady environment was also calculated in near real-time during the mission by the Microgravity Analysis Workstation. The Orbital Acceleration Research Experiment provided investigators with real-time quasi-steady acceleration measurements. The Space Acceleration Measurement System recorded higher frequency data on-board for post-mission analysis. The Microgravity Measurement Assembly provided investigators with real-time quasi-steady and higher frequency acceleration measurements. The Microgravity Analysis Workstation provided calculation of the quasi-steady environment. This calculation was presented to the science teams in real-time during the mission. The microgravity environment related to several different Orbiter, crew and experiment operations is presented and interpreted in this report. A radiator deploy, the Flight Control System checkout, and a vernier reaction control system reboost demonstration had minimal effects on the acceleration environment, with excitation of frequencies in the 0.01 to 10 Hz range. Flash Evaporator System venting had no noticeable effect on the environment while supply and waste water dumps caused excursions of 2 x lO(exp -6) to 4 x 10(exp -6) g in the Y(sub b) and Z(sub b) directions. Crew sleep and ergometer exercise periods can be clearly seen in the acceleration data, as expected. Accelerations related to the two Life Science Laboratory Equipment Refrigerator/Freezers were apparent in the data as are accelerations caused by the Johnson Space Center Projects Centrifuge. As on previous microgravity missions, several signals are present in the acceleration data for which a source has not been identified. The causes of these accelerations

  10. An experimental demonstration that early-life competitive disadvantage accelerates telomere loss

    PubMed Central

    Nettle, Daniel; Monaghan, Pat; Gillespie, Robert; Brilot, Ben; Bedford, Thomas; Bateson, Melissa

    2015-01-01

    Adverse experiences in early life can exert powerful delayed effects on adult survival and health. Telomere attrition is a potentially important mechanism in such effects. One source of early-life adversity is the stress caused by competitive disadvantage. Although previous avian experiments suggest that competitive disadvantage may accelerate telomere attrition, they do not clearly isolate the effects of competitive disadvantage from other sources of variation. Here, we present data from an experiment in European starlings (Sturnus vulgaris) that used cross-fostering to expose siblings to divergent early experience. Birds were assigned either to competitive advantage (being larger than their brood competitors) or competitive disadvantage (being smaller than their brood competitors) between days 3 and 12 post-hatching. Disadvantage did not affect weight gain, but it increased telomere attrition, leading to shorter telomere length in disadvantaged birds by day 12. There were no effects of disadvantage on oxidative damage as measured by plasma lipid peroxidation. We thus found strong evidence that early-life competitive disadvantage can accelerate telomere loss. This could lead to faster age-related deterioration and poorer health in later life. PMID:25411450

  11. An experimental demonstration that early-life competitive disadvantage accelerates telomere loss.

    PubMed

    Nettle, Daniel; Monaghan, Pat; Gillespie, Robert; Brilot, Ben; Bedford, Thomas; Bateson, Melissa

    2015-01-01

    Adverse experiences in early life can exert powerful delayed effects on adult survival and health. Telomere attrition is a potentially important mechanism in such effects. One source of early-life adversity is the stress caused by competitive disadvantage. Although previous avian experiments suggest that competitive disadvantage may accelerate telomere attrition, they do not clearly isolate the effects of competitive disadvantage from other sources of variation. Here, we present data from an experiment in European starlings (Sturnus vulgaris) that used cross-fostering to expose siblings to divergent early experience. Birds were assigned either to competitive advantage (being larger than their brood competitors) or competitive disadvantage (being smaller than their brood competitors) between days 3 and 12 post-hatching. Disadvantage did not affect weight gain, but it increased telomere attrition, leading to shorter telomere length in disadvantaged birds by day 12. There were no effects of disadvantage on oxidative damage as measured by plasma lipid peroxidation. We thus found strong evidence that early-life competitive disadvantage can accelerate telomere loss. This could lead to faster age-related deterioration and poorer health in later life. PMID:25411450

  12. Improvement of Space Shuttle Main Engine Low Frequency Acceleration Measurements

    NASA Technical Reports Server (NTRS)

    Stec, Robert C.

    1999-01-01

    The noise floor of low frequency acceleration data acquired on the Space Shuttle Main Engines is higher than desirable. Difficulties of acquiring high quality acceleration data on this engine are discussed. The approach presented in this paper for reducing the acceleration noise floor focuses on a search for an accelerometer more capable of measuring low frequency accelerations. An overview is given of the current measurement system used to acquire engine vibratory data. The severity of vibration, temperature, and moisture environments are considered. Vibratory measurements from both laboratory and rocket engine tests are presented.

  13. Acceleration and Velocity Sensing from Measured Strain

    NASA Technical Reports Server (NTRS)

    Pak, Chan-Gi; Truax, Roger

    2016-01-01

    A simple approach for computing acceleration and velocity of a structure from the strain is proposed in this study. First, deflection and slope of the structure are computed from the strain using a two-step theory. Frequencies of the structure are computed from the time histories of strain using a parameter estimation technique together with an Autoregressive Moving Average model. From deflection, slope, and frequencies of the structure, acceleration and velocity of the structure can be obtained using the proposed approach. shape sensing, fiber optic strain sensor, system equivalent reduction and expansion process.

  14. Acceleration and Velocity Sensing from Measured Strain

    NASA Technical Reports Server (NTRS)

    Pak, Chan-Gi; Truax, Roger

    2015-01-01

    A simple approach for computing acceleration and velocity of a structure from the strain is proposed in this study. First, deflection and slope of the structure are computed from the strain using a two-step theory. Frequencies of the structure are computed from the time histories of strain using a parameter estimation technique together with an autoregressive moving average model. From deflection, slope, and frequencies of the structure, acceleration and velocity of the structure can be obtained using the proposed approach. Simple harmonic motion is assumed for the acceleration computations, and the central difference equation with a linear autoregressive model is used for the computations of velocity. A cantilevered rectangular wing model is used to validate the simple approach. Quality of the computed deflection, acceleration, and velocity values are independent of the number of fibers. The central difference equation with a linear autoregressive model proposed in this study follows the target response with reasonable accuracy. Therefore, the handicap of the backward difference equation, phase shift, is successfully overcome.

  15. Time Domain Measurement of Moving Object Speed Using Acceleration Sensor

    NASA Astrophysics Data System (ADS)

    Koyama, Kazunori; Noro, Mitsuo; Hirata, Akimasa; Fujiwara, Osamu

    In this study, we proposed a time-domain measurement method of moving object speed with a commercially available acceleration sensor. The sensor of this kind is normally used to measure the acceleration of a stationary vibration object, while it is not applicable to the measurement of a transient moving object due to the frequency response of the sensor itself. An impulsive sensor response was derived from the free-drop movement of a metallic sphere. The deconvolution allows the sensor to measure the acceleration in the time domain, which was validated through the measurement of the speed of a hand-held metal piece approaching a target.

  16. Early life stress accelerates behavioral and neural maturation of the hippocampus in male mice.

    PubMed

    K G, Bath; G, Manzano-Nieves; H, Goodwill

    2016-06-01

    Early life stress (ELS) increases the risk for later cognitive and emotional dysfunction. ELS is known to truncate neural development through effects on suppressing cell birth, increasing cell death, and altering neuronal morphology, effects that have been associated with behavioral profiles indicative of precocious maturation. However, how earlier silencing of growth drives accelerated behavioral maturation has remained puzzling. Here, we test the novel hypothesis that, ELS drives a switch from growth to maturation to accelerate neural and behavioral development. To test this, we used a mouse model of ELS, fragmented maternal care, and a cross-sectional dense sampling approach focusing on hippocampus and measured effects of ELS on the ontogeny of behavioral development and biomarkers of neural maturation. Consistent with previous work, ELS was associated with an earlier developmental decline in expression of markers of cell proliferation (Ki-67) and differentiation (doublecortin). However, ELS also led to a precocious arrival of Parvalbumin-positive cells, led to an earlier switch in NMDA receptor subunit expression (marker of synaptic maturity), and was associated with an earlier rise in myelin basic protein expression (key component of the myelin sheath). In addition, in a contextual fear-conditioning task, ELS accelerated the timed developmental suppression of contextual fear. Together, these data provide support for the hypothesis that ELS serves to switch neurodevelopment from processes of growth to maturation and promotes accelerated development of some forms of emotional learning. PMID:27155103

  17. [Life expectancy and median life in life tables: the historical emergence of these measures].

    PubMed

    Lombardo, E

    1985-01-01

    The author describes the development of two measures used in life tables, life expectancy and median length of life. These measures were developed during the course of correspondence between the Dutch brothers Christiaan and Lodewijk Huygens in 1669. (summary in ENG, FRE) PMID:12314148

  18. Presentation on a Space Acceleration Measurement System (SAMS)

    NASA Technical Reports Server (NTRS)

    Chase, Theodore L.

    1990-01-01

    The primary objective of the Space Acceleration Measurement Systems (SAMS) project is to provide an acceleration measurement system capable of serving a wide variety of space experiments. The design of the system being developed under this project takes into consideration requirements for experiments located in the middeck, in the orbiter bay, and in Spacelab. In addition to measuring, conditioning, and recording accelerations, the system will be capable of performing complex calculations and interactive control. The main components consist of a remote triaxial optical storage device. In operation, the triaxial sensor head produces output signals in response to acceleration inputs. These signals are preamplified, filtered and converted into digital data which is then transferred to optical memory. The system design is modular, facilitating both software and hardware upgrading as technology advances. Two complete acceleration measurement flight systems will be build and tested under this project.

  19. Gait analysis using gravitational acceleration measured by wearable sensors.

    PubMed

    Takeda, Ryo; Tadano, Shigeru; Todoh, Masahiro; Morikawa, Manabu; Nakayasu, Minoru; Yoshinari, Satoshi

    2009-02-01

    A novel method for measuring human gait posture using wearable sensor units is proposed. The sensor units consist of a tri-axial acceleration sensor and three gyro sensors aligned on three axes. The acceleration and angular velocity during walking were measured with seven sensor units worn on the abdomen and the lower limb segments (both thighs, shanks and feet). The three-dimensional positions of each joint are calculated from each segment length and joint angle. Joint angle can be estimated mechanically from the gravitational acceleration along the anterior axis of the segment. However, the acceleration data during walking includes three major components; translational acceleration, gravitational acceleration and external noise. Therefore, an optimization analysis was represented to separate only the gravitational acceleration from the acceleration data. Because the cyclic patterns of acceleration data can be found during constant walking, a FFT analysis was applied to obtain some characteristic frequencies in it. A pattern of gravitational acceleration was assumed using some parts of these characteristic frequencies. Every joint position was calculated from the pattern under the condition of physiological motion range of each joint. An optimized pattern of the gravitational acceleration was selected as a solution of an inverse problem. Gaits of three healthy volunteers were measured by walking for 20s on a flat floor. As a result, the acceleration data of every segment was measured simultaneously. The characteristic three-dimensional walking could be shown by the expression using a stick figure model. In addition, the trajectories of the knee joint in the horizontal plane could be checked by visual imaging on a PC. Therefore, this method provides important quantitive information for gait diagnosis. PMID:19121522

  20. Measuring meaning in life following cancer

    PubMed Central

    Jim, Heather S.; Purnell, Jason Q.; Richardson, Susan A.; Golden-Kreutz, Deanna; Andersen, Barbara L.

    2007-01-01

    Meaning in life is a multi-faceted construct that has been conceptualized in diverse ways. It refers broadly to the value and purpose of life, important life goals, and for some, spirituality. We developed a measure of meaning in life derived from this conceptualization and designed to be a synthesis of relevant theoretical and empirical traditions. Two samples, all cancer patients, provided data for scale development and psychometric study. From exploratory and confirmatory factor analyses the Meaning in Life Scale (MiLS) emerged, and includes four aspects: Harmony and Peace, Life Perspective, Purpose and Goals, Confusion and Lessened Meaning, and Benefits of Spirituality. Supporting data for reliability (internal consistency, test–retest) and construct validity (convergent, discriminant, individual differences) are provided. The MiLS offers a theoretically based and psychometrically sound assessment of meaning in life suitable for use with cancer patients. PMID:16838197

  1. NODAL — The second life of the accelerator control language

    NASA Astrophysics Data System (ADS)

    Cuisinier, G.; Perriollat, F.; Ribeiro, P.; Kagarmanov, A.; Kovaltsov, V.

    1994-12-01

    NODAL has been a popular interpreter language for accelerator controls since the beginning of the 1970s. NODAL has been rewritten in the C language to be easily portable to the different computer platforms which are in use in accelerator controls. The paper describes the major features of this new version of NODAL, the major software packages which are available through this implementation, the platforms on which it is currently running, and some relevant performances. The experience gained during the rejuvenation project of the CERN accelerator control systems is presented. The benefit of this is discussed, in particular in a view of the prevailing strong constraints in personnel and money resources.

  2. Measuring quality of life: risks and benefits.

    PubMed

    Schipper, H; Levitt, M

    1985-10-01

    Quality of life research is an emerging science of particular relevance to clinical cancer research. The development and utilization of valid and reliable quality of life measures as outcome parameters may profoundly alter the clinical trials process. Such measures, contrary to prevailing opinion, may be as accurate and precise as conventional measures, but considerably more relevant to the trials process. However, lack of rigor in the evaluation of such indices and uncritical interpretation of results may seriously compromise the credibility of the concept. This overview of the current status of quality of life research is designed to provide a perspective from which to evaluate ongoing development. PMID:3899354

  3. Measuring the quality of later life.

    PubMed Central

    O'Boyle, C A

    1997-01-01

    This paper examines quality of life as a scientific construct with a wide range of applications. The assessment of patients' quality of life is assuming increasing importance in medicine and health care. Illnesses, diseases and their treatments can have significant impacts on such areas of functioning as mobility, mood, life satisfaction, sexuality, cognition and ability to fulfil occupational, social and family roles. The emerging quality of life construct may be viewed as a paradigm shift in outcome measurement since it shifts the focus of attention from symptoms to functioning. This holistic approach more clearly establishes the patient as the centre of attention and subsumes many of the traditional measures of outcome. Quality of life assessment is particularly relevant to ageing populations both for healthy elderly and for those who develop chronic diseases where maintenance of quality of life rather than cure may be the primary goal of treatment. This paper introduces the concept of quality of life and describes the significant difficulties in definition, measurement and interpretation that must be addressed before such measures can be used as reliable and valid indicators of disease impact and treatment outcomes. It is argued that approaches to quality of life assessment in the elderly should incorporate advances in knowledge about the psychological adaptation to ageing. Consequently, the unique perspective of the individual on his or her own quality of life must be incorporated into outcome assessments aimed at improving the quality of health care. Incorporating measures of subjective outcome such as quality of life into policy decisions on resource allocation in health care will prove one of the major challenges for health services over the next decade. PMID:9460072

  4. Accelerated life testing and temperature dependence of device characteristics in GaAs CHFET devices

    NASA Technical Reports Server (NTRS)

    Gallegos, M.; Leon, R.; Vu, D. T.; Okuno, J.; Johnson, A. S.

    2002-01-01

    Accelerated life testing of GaAs complementary heterojunction field effect transistors (CHFET) was carried out. Temperature dependence of single and synchronous rectifier CHFET device characteristics were also obtained.

  5. Outcome Measures in Quality of Life.

    PubMed

    Tate, D G; Dijkers, M; Johnson-Greene, L

    1996-01-01

    The concept of quality of life (QOL) represents a new paradigm in rehabilitation research and cSinical care. Three measurement approaches have been used to investigate QOL of individuals: (1) evaluative or subjective, (2) objective, and (3) quality adjusted life year (QALY). QALYs represent the utility approach to measurement with emphasis on value of, desirability of, or preference for conditions or status. When the condition in question isdefined as health, health-related quality of life (HQOL) measures are employed. Very few studies are found in the literature addressing QOL of stroke patients. Among studies reviewed, HQOL measures are often used. A summary of these studies and discussion of limitations associated with QOL measures utilized are provided. PMID:27620148

  6. Development of an Accelerated Test Design for Predicting the Service Life of the Solar Array at Mead, Nebraska

    NASA Technical Reports Server (NTRS)

    Gaines, G. B.; Thomas, R. E.; Noel, G. T.; Shilliday, T. S.; Wood, V. E.; Carmichael, D. C.

    1979-01-01

    An accelerated life test is described which was developed to predict the life of the 25 kW photovoltaic array installed near Mead, Nebraska. A quantitative model for accelerating testing using multiple environmental stresses was used to develop the test design. The model accounts for the effects of thermal stress by a relation of the Arrhenius form. This relation was then corrected for the effects of nonthermal environmental stresses, such as relative humidity, atmospheric pollutants, and ultraviolet radiation. The correction factors for the nonthermal stresses included temperature-dependent exponents to account for the effects of interactions between thermal and nonthermal stresses on the rate of degradation of power output. The test conditions, measurements, and data analyses for the accelerated tests are presented. Constant-temperature, cyclic-temperature, and UV types of tests are specified, incorporating selected levels of relative humidity and chemical contamination and an imposed forward-bias current and static electric field.

  7. Design of the fiber optic support system and fiber bundle accelerated life test for VIRUS

    NASA Astrophysics Data System (ADS)

    Soukup, Ian M.; Beno, Joseph H.; Hayes, Richard J.; Heisler, James T.; Mock, Jason R.; Mollison, Nicholas T.; Good, John M.; Hill, Gary J.; Vattiat, Brian L.; Murphy, Jeremy D.; Anderson, Seth C.; Bauer, Svend M.; Kelz, Andreas; Roth, Martin M.; Fahrenthold, Eric P.

    2010-07-01

    The quantity and length of optical fibers required for the Hobby-Eberly Telescope* Dark Energy eXperiment (HETDEX) create unique fiber handling challenges. For HETDEX‡, at least 33,600 fibers will transmit light from the focal surface of the telescope to an array of spectrographs making up the Visible Integral-Field Replicable Unit Spectrograph (VIRUS). Up to 96 Integral Field Unit (IFU) bundles, each containing 448 fibers, hang suspended from the telescope's moving tracker located more than 15 meters above the VIRUS instruments. A specialized mechanical system is being developed to support fiber optic assemblies onboard the telescope. The discrete behavior of 448 fibers within a conduit is also of primary concern. A life cycle test must be conducted to study fiber behavior and measure Focal Ratio Degradation (FRD) as a function of time. This paper focuses on the technical requirements and design of the HETDEX fiber optic support system, the electro-mechanical test apparatus for accelerated life testing of optical fiber assemblies. Results generated from the test will be of great interest to designers of robotic fiber handling systems for major telescopes. There is concern that friction, localized contact, entanglement, and excessive tension will be present within each IFU conduit and contribute to FRD. The test apparatus design utilizes six linear actuators to replicate the movement of the telescope over 65,000 accelerated cycles, simulating five years of actual operation.

  8. Two wire wakefield measurements of the DARHT accelerator cell

    SciTech Connect

    Nelson, S.D.; Vella, M.

    1998-05-01

    One of the characteristics specifying the performance of an accelerator cell as it relates to the electron beam, is the Wakefield impedance. The real part of the transverse wakefield impedance relates to offsets of the beam as it travels through the accelerator cell. To verify that the cell operates as expected, and that simulations and design predictions of the cell are within acceptable parameters (before building more cells) it is desirable to measure the wakefield impedance using the traditional two-wire technique. This technique benefits from its reproducibility and physical simplicity but is complicated by the need to fabricate a test fixture. But once the fixture is fabricated, it is simple to measure any number of accelerator cells. The following is a description of the two-wire measurement technique as performed at Lawrence Berkeley Lab (LBL) on a prototype DARHT accelerator cell.

  9. Measurements of Acceleration Due to Gravity.

    ERIC Educational Resources Information Center

    Crummett, Bill

    1990-01-01

    The principle means by which g has been measured are summarized. Discussed are "Kater's Reversible Pendulum," falling rules, and interferometry methods. Types of corrections and various sources of uncertainty are considered. (CW)

  10. Vertical acceleration of Icelandic crust measured by continuous GPS geodesy

    NASA Astrophysics Data System (ADS)

    Compton, K. C.; Bennett, R. A.; Hreinsdottir, S.; Adalgeirsdottir, G.

    2013-12-01

    We present current vertical crustal velocity and acceleration fields for Iceland as measured by 62 continuously operating GPS stations. After analyzing available CGPS data from 1995 to present and manually repairing breaks and removing transient earthquake and volcanic deformation signals, we calculate velocities and accelerations by fitting a second order polynomial model consisting of a coordinate offset term and two additional terms representing the time-averaged coordinate velocity and acceleration. Our velocity estimates agree closely with previously published velocity fields and show a broad region of rapid uplift in central Iceland, with near zero uplift observed near coastal regions. The largest vertical velocities occur near the center of the island, between the Vatnajökull and Hofsjökull ice sheets at rates exceeding 20 mm/yr. Velocity uncertainties have a mean of ~0.1mm/yr. The pattern of acceleration mimics that of the velocity field such that the velocity contrast between the interior and coastal regions is being enhanced. Largest positive accelerations of ~1.5 mm/yr2 are observed in central Iceland and acceleration uncertainties have a mean of ~0.2mm/yr2. Previous studies have modeled rapid uplift in Iceland as an isostatic response to loss of ice mass from the central Iceland ice sheets. We propose that the accelerating uplift is a result of accelerating ice mass loss, with possible implications for climate driven glacial retreat and models for ice loss and isostatic adjustment.

  11. Quality of life: does measurement help?

    PubMed

    Bergsma, J; Engel, G L

    1988-01-01

    'Quality of life' is a very frequently applied concept nowadays. One may doubt whether everyone has the same connotation in mind while using this expression and why 'quality of life' attracts so much attention. Is the idea a very old one or is it a new and noble value? It is argued here that changes such as in the number of aged people and of chronically disabled people, combined with spectacular developments in medical technology and with a rise in knowledge and assertivity, created an increased awareness of 'quality of life' and its interaction with medicine. Moreover, limitations to budgets and technological developments trigger an interest in new arguments. 'Quality of life' plays an increasing role in all sorts of medical decisions, be it in policy decisions or in individual clinical decisions, be it formally assessed or implicitly weighted. A number of examples is briefly described to illustrate the very broad and diffuse use of quality of life as a criterion. Subsequently we have tried to operationalize the concept on 4 levels: macro, meso, personal and physical. The macro level applies to the meaning of life in a society; assessments of quality of life play a role, for instance, in discussions on euthanasia and in political decisions on medical investments. Examples of the meso level are the hospital, with its internal processes and its ties to the rest of the world, but also the patient in his social environment. On the personal level the individual's frames of reference on health, illness, future, pain and hope - both of the patient and the doctor - are being considered. It is argued that legitimation of important decisions, investments and interventions requires measurement of quality of life in an objective way and on different levels. Quantifying quality, however, appears hardly feasible. Therefore 'quality of life' is frequently measured at the fourth level only, the level of physical activities. Confining measurement to the measurable induces the

  12. Kr II laser-induced fluorescence for measuring plasma acceleration.

    PubMed

    Hargus, W A; Azarnia, G M; Nakles, M R

    2012-10-01

    We present the application of laser-induced fluorescence of singly ionized krypton as a diagnostic technique for quantifying the electrostatic acceleration within the discharge of a laboratory cross-field plasma accelerator also known as a Hall effect thruster, which has heritage as spacecraft propulsion. The 728.98 nm Kr II transition from the metastable 5d(4)D(7/2) to the 5p(4)P(5/2)(∘) state was used for the measurement of laser-induced fluorescence within the plasma discharge. From these measurements, it is possible to measure velocity as krypton ions are accelerated from near rest to approximately 21 km/s (190 eV). Ion temperature and the ion velocity distributions may also be extracted from the fluorescence data since available hyperfine splitting data allow for the Kr II 5d(4)D(7/2)-5p(4)P(5/2)(∘) transition lineshape to be modeled. From the analysis, the fluorescence lineshape appears to be a reasonable estimate for the relatively broad ion velocity distributions. However, due to an apparent overlap of the ion creation and acceleration regions within the discharge, the distributed velocity distributions increase ion temperature determination uncertainty significantly. Using the most probable ion velocity as a representative, or characteristic, measure of the ion acceleration, overall propellant energy deposition, and effective electric fields may be calculated. With this diagnostic technique, it is possible to nonintrusively characterize the ion acceleration both within the discharge and in the plume. PMID:23126755

  13. Model measurements for new accelerating techniques

    SciTech Connect

    Aronson, S.; Haseroth, H.; Knott, J.; Willis, W.

    1988-06-01

    We summarize the work carried out for the past two years, concerning some different ways for achieving high-field gradients, particularly in view of future linear lepton colliders. These studies and measurements on low power models concern the switched power principle and multifrequency excitation of resonant cavities. 15 refs., 12 figs.

  14. Measurement of Impact Acceleration: Mouthpiece Accelerometer Versus Helmet Accelerometer

    PubMed Central

    Higgins, Michael; Halstead, P. David; Snyder-Mackler, Lynn; Barlow, David

    2007-01-01

    Context: Instrumented helmets have been used to estimate impact acceleration imparted to the head during helmet impacts. These instrumented helmets may not accurately measure the actual amount of acceleration experienced by the head due to factors such as helmet-to-head fit. Objective: To determine if an accelerometer attached to a mouthpiece (MP) provides a more accurate representation of headform center of gravity (HFCOG) acceleration during impact than does an accelerometer attached to a helmet fitted on the headform. Design: Single-factor research design in which the independent variable was accelerometer position (HFCOG, helmet, MP) and the dependent variables were g and Severity Index (SI). Setting: Independent impact research laboratory. Intervention(s): The helmeted headform was dropped (n = 168) using a National Operating Committee on Standards for Athletic Equipment (NOCSAE) drop system from the standard heights and impact sites according to NOCSAE test standards. Peak g and SI were measured for each accelerometer position during impact. Main Outcome Measures: Upon impact, the peak g and SI were recorded for each accelerometer location. Results: Strong relationships were noted for HFCOG and MP measures, and significant differences were seen between HFCOG and helmet g measures and HFCOG and helmet SI measures. No statistically significant differences were noted between HFCOG and MP g and SI measures. Regression analyses showed a significant relationship between HFCOG and MP measures but not between HFCOG and helmet measures. Conclusions: Upon impact, MP acceleration (g) and SI measurements were closely related to and more accurate in measuring HFCOG g and SI than helmet measurements. The MP accelerometer is a valid method for measuring head acceleration. PMID:17597937

  15. Summary Report of Mission Acceleration Measurements for STS-89

    NASA Technical Reports Server (NTRS)

    Hrovat, Kenneth; McPherson, Kevin

    1999-01-01

    Support of microgravity research on the 89th flight of the Space Transportation System (STS-89) and a continued effort to characterize the acceleration environment of the Space Shuttle Orbiter and the Mir Space Station form the basis for this report. For the STS-89 mission, the Space Shuttle Endeavour was equipped with a Space Acceleration Measurement System (SAMS) unit, which collected more than a week's worth of data. During docked operations with Mir, a second SAMS unit collected approximately a day's worth of data yielding the only set of acceleration measurements recorded simultaneously on the two spacecraft. Based on the data acquired by these SAMS units, this report serves to characterize a number of acceleration events and quantify their impact on the local nature of the accelerations experienced at the Mechanics of Granular Materials (MGM) experiment location. Crew activity was shown to nearly double the median root-mean-square (RMS) acceleration level calculated below 10 Hz, while the Enhanced Orbiter Refrigerator/Freezer operating at about 22 Hz was a strong acceleration source in the vicinity of the MGM location. The MGM science requirement that the acceleration not exceed plus or minus 1 mg was violated numerous times during their experiment runs; however, no correlation with sample instability has been found to this point. Synchronization between the SAMS data from Endeavour and from Mir was shown to be close much of the time, but caution with respect to exact timing should be exercised when comparing these data. When orbiting as a separate vehicle prior to docking, Endeavour had prominent structural modes above 3 Hz, while Mir exhibited a cluster of modes around 1 Hz. When mated, a transition to common modes was apparent in the two SAMS data sets. This report is not a comprehensive analysis of the acceleration data, so those interested in further details should contact the Principal Investigator Microgravity Services team at the National Aeronautics

  16. Instrumentation for accelerated life tests of concentrator solar cells.

    PubMed

    Núñez, N; Vázquez, M; González, J R; Jiménez, F J; Bautista, J

    2011-02-01

    Concentrator photovoltaic is an emergent technology that may be a good economical and efficient alternative for the generation of electricity at a competitive cost. However, the reliability of these new solar cells and systems is still an open issue due to the high-irradiation level they are subjected to as well as the electrical and thermal stresses that they are expected to endure. To evaluate the reliability in a short period of time, accelerated aging tests are essential. Thermal aging tests for concentrator photovoltaic solar cells and systems under illumination are not available because no technical solution to the problem of reaching the working concentration inside a climatic chamber has been available. This work presents an automatic instrumentation system that overcomes the aforementioned limitation. Working conditions have been simulated by forward biasing the solar cells to the current they would handle at the working concentration (in this case, 700 and 1050 times the irradiance at one standard sun). The instrumentation system has been deployed for more than 10 000 h in a thermal aging test for III-V concentrator solar cells, in which the generated power evolution at different temperatures has been monitored. As a result of this test, the acceleration factor has been calculated, thus allowing for the degradation evolution at any temperature in addition to normal working conditions to be obtained. PMID:21361622

  17. Low-cost tape system measures velocity of acceleration

    NASA Technical Reports Server (NTRS)

    Hartenstein, R.

    1964-01-01

    By affixing perforated magnetic recording tape to the falling end of a body, acceleration and velocity were measured. The measurement was made by allowing the tape to pass between a light source and a photoelectric sensor. Data was obtained from a readout device.

  18. Measurement of acceleration using an instrumented railgun projectile

    NASA Astrophysics Data System (ADS)

    Littrell, Donald M.; Jamison, Keith A.; Hudson, Roger D.; Fernandez, Michael J.; Ager, Scott A.

    1992-06-01

    An instrumented package has been accelerated in a railgun projectile to measure the inbore acceleration as a function of time. Direct, continuous acceleration profiles have been repeatedly obtained with this package during electromagnetic launch and downrange soft catch. These proof-of-principle experiments were conducted using a square bore railgun and off-the-shelf components for the in situ measurement, digitization, and storage of acceleration data. A continuous record of the entire launch event clearly shows gas injection, electromagnetic propulsion, and downrange deceleration in a soft catch recovery system. The launch package was subject to peak accelerations of nearly 30 kilogees (2.8 x 105 m/sq. sec) in the electromagnetic propulsion phase of the launch. Velocity and position data obtained through integration of this data are correlated with velocity data derived from conventional static diagnostic (e.g., magnetic flux loops) to validate the technique. The peak acceleration was slightly more than anticipated from the electrical current delivered to the railgun, and this deviation is examined. The paper presents a description of the experimental apparatus, acquired data, a comparison of the data with code simulations, and suggestions for future work.

  19. Development of a wireless displacement measurement system using acceleration responses.

    PubMed

    Park, Jong-Woong; Sim, Sung-Han; Jung, Hyung-Jo; Spencer, Billie F

    2013-01-01

    Displacement measurements are useful information for various engineering applications such as structural health monitoring (SHM), earthquake engineering and system identification. Most existing displacement measurement methods are costly, labor-intensive, and have difficulties particularly when applying to full-scale civil structures because the methods require stationary reference points. Indirect estimation methods converting acceleration to displacement can be a good alternative as acceleration transducers are generally cost-effective, easy to install, and have low noise. However, the application of acceleration-based methods to full-scale civil structures such as long span bridges is challenging due to the need to install cables to connect the sensors to a base station. This article proposes a low-cost wireless displacement measurement system using acceleration. Developed with smart sensors that are low-cost, wireless, and capable of on-board computation, the wireless displacement measurement system has significant potential to impact many applications that need displacement information at multiple locations of a structure. The system implements an FIR-filter type displacement estimation algorithm that can remove low frequency drifts typically caused by numerical integration of discrete acceleration signals. To verify the accuracy and feasibility of the proposed system, laboratory tests are carried out using a shaking table and on a three storey shear building model, experimentally confirming the effectiveness of the proposed system. PMID:23881123

  20. Measurement of vehicle-load using capacitance and acceleration transducers

    NASA Astrophysics Data System (ADS)

    Yang, S.; Yang, W.; Yang, Y.

    2007-07-01

    Over-loading is a common problem in some developing countries. Currently, large and fixed measurement systems are used to measure the load of vehicles travelling on highways. This paper presents an on-vehicle measuring device, which is based on measurement of change in capacitance due to variation in distance between electrodes mounted on vehicles. The on-vehicle leaf springs are used as a key part of the weighing transducer. Acceleration transducers are used to measure the vehicle's forward and the vertical accelerations. A feature of this on-vehicle measuring device is that it can provide both static and dynamic load measurements. The drivers can check the load in the cab, and the highway inspectors can check the load at any time and any place through radio communication, thus identifying over-loaded vehicles.

  1. Metabolic acceleration and the evolution of human brain size and life history.

    PubMed

    Pontzer, Herman; Brown, Mary H; Raichlen, David A; Dunsworth, Holly; Hare, Brian; Walker, Kara; Luke, Amy; Dugas, Lara R; Durazo-Arvizu, Ramon; Schoeller, Dale; Plange-Rhule, Jacob; Bovet, Pascal; Forrester, Terrence E; Lambert, Estelle V; Thompson, Melissa Emery; Shumaker, Robert W; Ross, Stephen R

    2016-05-19

    Humans are distinguished from the other living apes in having larger brains and an unusual life history that combines high reproductive output with slow childhood growth and exceptional longevity. This suite of derived traits suggests major changes in energy expenditure and allocation in the human lineage, but direct measures of human and ape metabolism are needed to compare evolved energy strategies among hominoids. Here we used doubly labelled water measurements of total energy expenditure (TEE; kcal day(-1)) in humans, chimpanzees, bonobos, gorillas and orangutans to test the hypothesis that the human lineage has experienced an acceleration in metabolic rate, providing energy for larger brains and faster reproduction without sacrificing maintenance and longevity. In multivariate regressions including body size and physical activity, human TEE exceeded that of chimpanzees and bonobos, gorillas and orangutans by approximately 400, 635 and 820 kcal day(-1), respectively, readily accommodating the cost of humans' greater brain size and reproductive output. Much of the increase in TEE is attributable to humans' greater basal metabolic rate (kcal day(-1)), indicating increased organ metabolic activity. Humans also had the greatest body fat percentage. An increased metabolic rate, along with changes in energy allocation, was crucial in the evolution of human brain size and life history. PMID:27144364

  2. Mechanical Component Lifetime Estimation Based on Accelerated Life Testing with Singularity Extrapolation

    NASA Astrophysics Data System (ADS)

    Zhang, C.; Chuckpaiwong, I.; Liang, S. Y.; Seth, B. B.

    2002-07-01

    Life testing under nominal operating conditions of mechanical parts with high mean lifetime between failure (MTBF) often consumes a significant amount of time and resources, rendering such procedures expensive and impractical. As a result, the technology of accelerated life testing (ALT) has been developed for testing at high stress levels (e.g. temperature, voltage, pressure, corrosive media, load, vibration amplitude, etc.) so that it can be extrapolated—through a physically reasonable statistical model—to obtain estimations of life at lower, normal stress levels or even limit stress levels. However, the issue of prediction accuracy associated with extrapolating data outside the range of testing, or even to a singularity level (no stress), has not yet been fully addressed. In this research, an accelerator factor is introduced into an inverse power law model to estimate the life distribution in terms of time and stresses. Also, a generalized Eyring model is set up for singularity extrapolation in handling limit stress level conditions. The procedure to calibrate the associated shape factors based on the maximum likelihood principle is also formulated. The methodology implementation, based on a one-main-step, multiple-step-stress test scheme, is experimentally illustrated with tapered roller bearing under the stress of environmental corrosion as a case study. The experimental results show that the developed accelerated life test model can effectively evaluate the life probability of a bearing based on accelerated testing data when extrapolating to the stress levels within or outside the range of testing.

  3. Absolute acceleration measurements on STS-50 from the Orbital Acceleration Research Experiment (OARE)

    NASA Technical Reports Server (NTRS)

    Blanchard, Robert C.; Nicholson, John Y.; Ritter, James R.

    1994-01-01

    Orbital Acceleration Research Experiment (OARE) data on Space Transportation System (STS)-50 have been examined in detail during a 2-day time period. Absolute acceleration levels have been derived at the OARE location, the orbiter center-of-gravity, and at the STS-50 spacelab Crystal Growth Facility. During the interval, the tri-axial OARE raw telemetered acceleration measurements have been filtered using a sliding trimmed mean filter in order to remove large acceleration spikes (e.g., thrusters) and reduce the noise. Twelve OARE measured biases in each acceleration channel during the 2-day interval have been analyzed and applied to the filtered data. Similarly, the in situ measured x-axis scale factors in the sensor's most sensitive range were also analyzed and applied to the data. Due to equipment problem(s) on this flight, both y- and z-axis sensitive range scale factors were determined in a separate process using orbiter maneuvers and subsequently applied to the data. All known significant low-frequency corrections at the OARE location (i.e., both vertical and horizontal gravity-gradient, and rotational effects) were removed from the filtered data in order to produce the acceleration components at the orbiter center-of-gravity, which are the aerodynamic signals along each body axis. Results indicate that there is a force being applied to the Orbiter in addition to the aerodynamic forces. The OARE instrument and all known gravitational and electromagnetic forces have been reexamined, but none produces the observed effect. Thus, it is tentatively concluded that the orbiter is creating the environment observed. At least part of this force is thought to be due to the Flash Evaporator System.

  4. Compact all-fiber interferometer system for shock acceleration measurement

    NASA Astrophysics Data System (ADS)

    Zhao, Jiang; Pi, Shaohua; Hong, Guangwei; Zhao, Dong; Jia, Bo

    2013-08-01

    Acceleration measurement plays an important role in a variety of fields in science and engineering. In particular, the accurate, continuous and non-contact recording of the shock acceleration profiles of the free target surfaces is considered as a critical technique in shock physics. Various kinds of optical interferometers have been developed to monitor the motion of the surfaces of shocked targets since the 1960s, for instance, the velocity interferometer system for any reflector, the fiber optic accelerometer, the photonic Doppler velocimetry system and the displacement interferometer. However, most of such systems rely on the coherent quasi-monochromatic illumination and discrete optic elements, which are costly in setting-up and maintenance. In 1996, L. Levin et al reported an interferometric fiber-optic Doppler velocimeter with high-dynamic range, in which fiber-coupled components were used to replace the discrete optic elements. However, the fringe visibility of the Levin's system is low because of the coupled components, which greatly limits the reliability and accuracy in the shock measurement. In this paper, a compact all-fiber interferometer system for measuring the shock acceleration is developed and tested. The advantage of the system is that not only removes the non-interfering light and enhances the fringe visibility, but also reduces polarization induced signal fading and the polarization induced phase shift. Moreover, it also does not require a source of long coherence length. The system bases entirely on single-mode fiber optics and mainly consists of a polarization beam splitter, a faraday rotator, a depolarizer and a 3×3 single-mode fiber coupler which work at 1310 nm wavelength. The optical systems of the interferometer are described and the experimental results compared with a shock acceleration calibration system with a pneumatic exciter (PneuShockTM Model 9525C by The Modal Shop) are reported. In the shock acceleration test, the

  5. Kr II laser-induced fluorescence for measuring plasma acceleration

    SciTech Connect

    Hargus, W. A. Jr.

    2012-10-15

    We present the application of laser-induced fluorescence of singly ionized krypton as a diagnostic technique for quantifying the electrostatic acceleration within the discharge of a laboratory cross-field plasma accelerator also known as a Hall effect thruster, which has heritage as spacecraft propulsion. The 728.98 nm Kr II transition from the metastable 5d{sup 4}D{sub 7/2} to the 5p{sup 4}P{sub 5/2}{sup Ring-Operator} state was used for the measurement of laser-induced fluorescence within the plasma discharge. From these measurements, it is possible to measure velocity as krypton ions are accelerated from near rest to approximately 21 km/s (190 eV). Ion temperature and the ion velocity distributions may also be extracted from the fluorescence data since available hyperfine splitting data allow for the Kr II 5d{sup 4}D{sub 7/2}-5p{sup 4}P{sub 5/2}{sup Ring-Operator} transition lineshape to be modeled. From the analysis, the fluorescence lineshape appears to be a reasonable estimate for the relatively broad ion velocity distributions. However, due to an apparent overlap of the ion creation and acceleration regions within the discharge, the distributed velocity distributions increase ion temperature determination uncertainty significantly. Using the most probable ion velocity as a representative, or characteristic, measure of the ion acceleration, overall propellant energy deposition, and effective electric fields may be calculated. With this diagnostic technique, it is possible to nonintrusively characterize the ion acceleration both within the discharge and in the plume.

  6. Accelerator mass spectrometry for measurement of long-lived radioisotopes

    SciTech Connect

    Elmore, D.; Phillips, F.M.

    1987-05-01

    Particle accelerators, such as those built for research in nuclear physics, can also be used together with magnetic and electrostatic mass analyzers to measure rare isotopes at very low abundance ratios. All molecular ions can be eliminated when accelerated to energies of millions of electron volts. Some atomic isobars can be eliminated with the use of negative ions; others can be separated at high energies by measuring their rate of energy loss in a detector. The long-lived radioisotopes /sup 10/Be, /sup 14/C, /sup 26/Al, /sup 36/Cl, and /sup 129/I can now be measured in small natural samples having isotopic abundances in the range 10/sup -12/ to 10/sup -15/ and as few as 10/sup 5/ atoms. In the past few years, research applications of accelerator mass spectrometry have been concentrated in the earth sciences (climatology, cosmochemistry, environmental chemistry, geochronology, glaciology, hydrology, igneous petrogenesis, minerals exploration, sedimentology, and volcanology), in anthropology and archaeology (radiocarbon dating), and in physics (searches for exotic particles and measurement of half-lives). In addition, accelerator mass spectrometry may become an important tool for the materials and biological sciences. 98 references, 4 figures, 2 tables.

  7. Prediction of reliability on thermoelectric module through accelerated life test and Physics-of-failure

    NASA Astrophysics Data System (ADS)

    Choi, Hyoung-Seuk; Seo, Won-Seon; Choi, Duck-Kyun

    2011-09-01

    Thermoelectric cooling module (TEM) which is electric device has a mechanical stress because of temperature gradient in itself. It means that structure of TEM is vulnerable in an aspect of reliability but research on reliability of TEM was not performed a lot. Recently, the more the utilization of thermoelectric cooling devices grows, the more the needs for life prediction and improvement are increasing. In this paper, we investigated life distribution, shape parameter of the TEM through accelerated life test (ALT). And we discussed about how to enhance life of TEM through the Physics-of-failure. Experimental results of ALT showed that the thermoelectric cooling module follows the Weibull distribution, shape parameter of which is 3.6. The acceleration model is coffin Coffin-Manson and material constant is 1.8.

  8. Preliminary OARE absolute acceleration measurements on STS-50

    NASA Technical Reports Server (NTRS)

    Blanchard, Robert C.; Nicholson, John Y.; Ritter, James

    1993-01-01

    On-orbit Orbital Acceleration Research Experiment (OARE) data on STS-50 was examined in detail during a 2-day time period. Absolute acceleration levels were derived at the OARE location, the orbiter center-of-gravity, and at the STS-50 spacelab Crystal Growth Facility. The tri-axial OARE raw acceleration measurements (i.e., telemetered data) during the interval were filtered using a sliding trimmed mean filter in order to remove large acceleration spikes (e.g., thrusters) and reduce the noise. Twelve OARE measured biases in each acceleration channel during the 2-day interval were analyzed and applied to the filtered data. Similarly, the in situ measured x-axis scale factors in the sensor's most sensitive range were also analyzed and applied to the data. Due to equipment problem(s) on this flight, both y- and z- axis sensitive range scale factors were determined in a separate process (using the OARE maneuver data) and subsequently applied to the data. All known significant low-frequency corrections at the OARE location (i.e., both vertical and horizontal gravity-gradient, and rotational effects) were removed from the filtered data in order to produce the acceleration components at the orbiter's center-of-gravity, which are the aerodynamic signals along each body axes. Results indicate that there is a force of unknown origin being applied to the Orbiter in addition to the aerodynamic forces. The OARE instrument and all known gravitational and electromagnetic forces were reexamined, but none produce the observed effect. Thus, it is tentatively concluded that the Orbiter is creating the environment observed.

  9. Preliminary OARE absolute acceleration measurements on STS-50

    NASA Astrophysics Data System (ADS)

    Blanchard, Robert C.; Nicholson, John Y.; Ritter, James

    1993-02-01

    On-orbit Orbital Acceleration Research Experiment (OARE) data on STS-50 was examined in detail during a 2-day time period. Absolute acceleration levels were derived at the OARE location, the orbiter center-of-gravity, and at the STS-50 spacelab Crystal Growth Facility. The tri-axial OARE raw acceleration measurements (i.e., telemetered data) during the interval were filtered using a sliding trimmed mean filter in order to remove large acceleration spikes (e.g., thrusters) and reduce the noise. Twelve OARE measured biases in each acceleration channel during the 2-day interval were analyzed and applied to the filtered data. Similarly, the in situ measured x-axis scale factors in the sensor's most sensitive range were also analyzed and applied to the data. Due to equipment problem(s) on this flight, both y- and z- axis sensitive range scale factors were determined in a separate process (using the OARE maneuver data) and subsequently applied to the data. All known significant low-frequency corrections at the OARE location (i.e., both vertical and horizontal gravity-gradient, and rotational effects) were removed from the filtered data in order to produce the acceleration components at the orbiter's center-of-gravity, which are the aerodynamic signals along each body axes. Results indicate that there is a force of unknown origin being applied to the Orbiter in addition to the aerodynamic forces. The OARE instrument and all known gravitational and electromagnetic forces were reexamined, but none produce the observed effect. Thus, it is tentatively concluded that the Orbiter is creating the environment observed.

  10. Position, velocity and acceleration estimates from the noisy radar measurements

    NASA Astrophysics Data System (ADS)

    Ramachandra, K. V.

    1984-04-01

    A two-dimensional Kalman tracking filter is described for obtaining optimum estimates of position, velocity and acceleration of an aircraft whose acceleration is perturbed due to maneuvers and/or other random factors. In a track-while-scan operation, a two-dimensional radar sensor is assumed to measure the range and bearing of the vehicle at uniform sampling intervals of time T seconds through random noise. The steady-state gain characteristics of the filter have been analytically obtained and the computer results are presented.

  11. Space acceleration measurement system triaxial sensor head error budget

    NASA Astrophysics Data System (ADS)

    Thomas, John E.; Peters, Rex B.; Finley, Brian D.

    1992-01-01

    The objective of the Space Acceleration Measurement System (SAMS) is to measure and record the microgravity environment for a given experiment aboard the Space Shuttle. To accomplish this, SAMS uses remote triaxial sensor heads (TSH) that can be mounted directly on or near an experiment. The errors of the TSH are reduced by calibrating it before and after each flight. The associated error budget for the calibration procedure is discussed here.

  12. Measurements of beat wave accelerated electrons in a toroidal plasma

    SciTech Connect

    Rogers, J.H.; Hwang, D.W. |

    1992-06-01

    Electrons are accelerated by large amplitude electron plasma waves driven by counter-propagating microwaves with a difference frequency approximately equal to the electron plasma frequency. Energetic electrons are observed only when the phase velocity of the wave is in the range 3v{sub e} < v{sub ph} < 7v{sub e} (v{sub ph} was varied 2v{sub e} < v{sub ph} < 10v{sub e}), where v{sub e} is the electron thermal velocity, (kT{sub e}/m{sub e}){sup {1/2}}. As the phase velocity increases, fewer electrons are accelerated to higher velocities. The measured current contained in these accelerated electrons has the power dependence predicted by theory, but the magnitude is lower than predicted.

  13. Summary Status of the Space Acceleration Measurement System (SAMS), September 1993

    NASA Technical Reports Server (NTRS)

    DeLombard, Richard

    1994-01-01

    The Space Acceleration Measurement System (SAMS) was developed to measure the microgravity acceleration environment to which NASA science payloads are exposed during microgravity science missions on the shuttle. Six flight units have been fabricated to date. The inaugural flight of a SAMS unit was on STS-40 in June 1991 as part of the First Spacelab Life Sciences mission. Since that time, SAMS has flown on six additional missions and gathered eighteen gigabytes of data representing sixty-eight days of microgravity environment. The SAMS units have been flown in the shuttle middeck and cargo bay, in the Spacelab module, and in the Spacehab module. This paper summarizes the missions and experiments which SAMS has supported. The quantity of data and the utilization of the SAMS data is described. Future activities are briefly described for the SAMS project and the Microgravity Measurement and Analysis project (MMAP) to support science experiments and scientists with microgravity environment measurement and analysis.

  14. Life prediction of 808nm high power semiconductor laser by accelerated life test of constant current stress

    NASA Astrophysics Data System (ADS)

    Yao, Nan; Li, Wei; Zhao, Yihao; Zhong, Li; Liu, Suping; Ma, Xiaoyu

    2015-10-01

    High power semiconductor laser is widely used because of its high transformation efficiency, good working stability, compact volume and simple driving requirements. Laser's lifetime is very long, but tests at high levels of stress can speed up the failure process and shorten the times to failure significantly. So accelerated life test is used here for forecasting the lifetime of 808nm CW GaAs/AlGaAs high power semiconductor laser that has an output power of 1W under 1.04A. Accelerated life test of constant current stress based on the Inverse Power Law Relationship was designed. Tests were conducted under 1.3A, 1.6A and 1.9A at room temperature. It is the first time that this method is used in the domestic research of laser's lifetime prediction. Applying Weibull Distribution to describe the lifetime distribution and analyzing the data of times to failure, characteristics lifetime's functional relationship model with current is achieved. Then the characteristics lifetime under normal current is extrapolated, which is 9473h. Besides, to confirm the validity of the functional relationship model, we conduct an additional accelerated life test under 1.75A. Based on this experimental data we calculated the characteristics lifetime corresponding to 1.75A that is 171h, while the extrapolated characteristics lifetime from the former functional relationship model is 162h. The two results shows 5% deviation that is very low and acceptable, which indicates that the test design is reasonable and authentic.

  15. Measuring quality of life in muscular dystrophy

    PubMed Central

    Abresch, Richard T.; Biesecker, Barbara; Conway, Kristin Caspers; Heatwole, Chad; Peay, Holly; Scal, Peter; Strober, Jonathan; Uzark, Karen; Wolff, Jodi; Margolis, Marjorie; Blackwell, Angela; Street, Natalie; Montesanti, Angela; Bolen, Julie

    2015-01-01

    Objectives: The objectives of this study were to develop a conceptual model of quality of life (QOL) in muscular dystrophies (MDs) and review existing QOL measures for use in the MD population. Methods: Our model for QOL among individuals with MD was developed based on a modified Delphi process, literature review, and input from patients and patient advocacy organizations. Scales that have been used to measure QOL among patients with MD were identified through a literature review and evaluated using the COSMIN (Consensus-Based Standards for the Selection of Health Measurement Instruments) checklist. Results: The Comprehensive Model of QOL in MD (CMQM) captures 3 broad domains of QOL (physical, psychological, and social), includes factors influencing self-reported QOL (disease-related factors, support/resources, and expectations/aspirations), and places these concepts within the context of the life course. The literature review identified 15 QOL scales (9 adult and 6 pediatric) that have been applied to patients with MD. Very few studies reported reliability data, and none included data on responsiveness of the measures to change in disease progression, a necessary psychometric property for measures included in treatment and intervention studies. No scales captured all QOL domains identified in the CMQM model. Conclusions: Additional scale development research is needed to enhance assessment of QOL for individuals with MD. Item banking and computerized adaptive assessment would be particularly beneficial by allowing the scale to be tailored to each individual, thereby minimizing respondent burden. PMID:25663223

  16. Speed Kills, Speed Thrills: Constraining and Enabling Accelerations in Academic Work-Life

    ERIC Educational Resources Information Center

    Vostal, Filip

    2015-01-01

    Intensification, speed of change and faster pace of life have recently emerged as significant issues in studies analysing the current academic climate. This article takes up the "social acceleration thesis" as a conceptual resource for capturing the relationship between the individual experience of time and the changing structure and…

  17. Systems approach to measuring short-duration acceleration transients

    NASA Astrophysics Data System (ADS)

    Schelby, F.

    It is common for failures to occur when attempting to acquire acceleration structural response measurements during crash, impact, and pyrotechnic testing. The structural response of a mechanical system to severe transient loading is commonly measured by accelerometers which are less than ideal. In particular, their amplitude-frequency response has one or more resonant peaks so that the output of the accelerometer may not be an exact replica of the input if the transient input stimulus contains frequencies near these resonant peaks, signal distortion, over-ranging of signal conditioning electronics, or even failure of the sensing element may occur. These and other problems have spurred the development of a new acceleration-measuring system which incorporates the following features; Transduction Element; Connectors; Mounting; Electronics; and Transducer Resonance.

  18. Toward a Direct Measurement of the Cosmic Acceleration

    NASA Astrophysics Data System (ADS)

    Darling, Jeremiah K.

    2013-01-01

    We present precise redshift measurements and place model-free constraints on cosmic acceleration and the acceleration of the Solar System in a universal context. HI 21 cm absorption lines observed over multiple epochs can constrain the secular redshift drift or the proper acceleration, Δv/Δto, with high precision. A comparison of literature analog spectra to contemporary digital spectra shows significant acceleration almost certainly attributable to systematic instrumental or calibration errors. However, robust constraints have been obtained by using digital data from a single telescope, the Green Bank Telescope. An ensemble of 10 objects spanning z = 0.09-0.69 observed over 13.5 years show Δz/Δto = (-1.8 ± 1.2) × 10-8 yr-1 or Δv/Δto = -4.0 ± 3.0 m s-1 yr-1. The best constraint from a single object, 3C286 at = 0.692153275(85), is dz/dto = (1.5 ± 4.7) × 10-8 yr-1 or Δv/Δto = 2.7 ± 8.4 m s-1 yr-1. These measurements are three orders of magnitude larger than the expected acceleration in the concordance dark energy cosmology at z=0.5, Δz/Δto = 2 × 10-11 yr-1 or Δv/Δto = 0.3 cm s-1 yr-1, but they demonstrate a lack of secular redshift drift in absorption line systems and the long-term frequency stability of modern radio telescopes. This measurement likewise constrains the barycentric proper acceleration in a cosmological reference frame (as opposed to the Galactic pulsar-defined reference frame), but currently lacks the precision of quasar proper motion observations. A comparison of rest-frame UV metal absorption lines to the HI 21 cm line places improved constraints on the cosmic variation of physical constants: Δ(α2 gp μ)/(α2 gp μ) = (-3.5 ± 1.4) × 10-6 in the redshift range z=0.24-2.04, consistent with no variation. We estimate that the cosmic acceleration could be directly measured with this technique in about 300 years using modern telescopes or in about 12 years using a Square Kilometer Array, provided that new systematic effects do

  19. Measuring the acceleration due to gravity using an IR transceiver

    NASA Astrophysics Data System (ADS)

    AbdElazem, Sohaib; Al-Basheer, Watheq

    2015-07-01

    In this paper, we present a new technique to study the dynamics of a free-falling object in a lab setting and to measure the acceleration due to gravity g using a simple and economic setup. The precise measurement of time taken for an object to fall freely passing an infrared (IR) transceiver is utilized to deduce the acceleration due to gravity. The reflected IR intensity from a free-falling 0.19 m rod of equally spaced white stripes of 0.01 m is detected and sent to a digital oscilloscope to observe and record the falling time period of each stripe. By fitting recorded elapsed falling times to the well-known quadratic equation of motion under constant acceleration, an accurate value of the acceleration due to gravity of g = 9.8092 ± 0.0384 m s-2 is obtained. In addition to its accuracy, the proposed technique is safer and more economic than most of the other currently used setups to determine g in undergraduate teaching labs. This study may provide undergraduate lab instructors with an efficient teaching technique for a traditional classroom experiment.

  20. Radiation measurements at the Advanced Photon Source (APS) linear accelerator

    SciTech Connect

    Moe, H.J.; Vacca, J.H.; Veluri, V.R.; White, M.

    1995-07-01

    The injector and source of particles for the Advanced Photon Source is a 2856-MHz, S-band, electron-positron linear accelerator (linac). It produces electrons with energies up to 650 MeV or positrons with energies up to 450 MeV. Radiation measurements were made during normal electron and positron operation, as well as during several beam loss scenarios. Neutron and gamma measurements made outside the shielding walls during normal operation are within DOE guidelines. Measured radiation fields are compared to predicted levels for different conditions.

  1. Measurement of acceleration in femtosecond laser-plasmas

    SciTech Connect

    Haessner, R.; Theobald, W.; Niedermeier, S.; Michelmann, K.; Feurer, T.; Schillinger, H.; Sauerbrey, R.

    1998-02-20

    Accelerations up to 4x10{sup 19} m/s{sup 2} are measured in femtosecond laser-produced plasmas at intensities of 10{sup 18} W/cm{sup 2} using the Frequency Resolved Optical Gating (FROG) technique. A high density plasma is formed by focusing an ultrashort unchirped laser pulse on a plane carbon target and part of the reflected pulse is eventually detected by a FROG autocorrelator. Radiation pressure and thermal pressure accelerate the plasma which causes a chirp in the reflected laser pulse. The retrieved phase and amplitude information reveal that the plasma motion is dominated by the large light pressure which pushes the plasma into the target. This is supported by theoretical estimates and by the results of independently measured time integrated spectra of the reflected pulse.

  2. Vibrational measurement for commissioning SRF Accelerator Test Facility at Fermilab

    SciTech Connect

    McGee, M.W.; Leibfritz, J.; Martinez, A.; Pischalnikov, Y.; Schappert, W.; /Fermilab

    2011-03-01

    The commissioning of two cryomodule components is underway at Fermilab's Superconducting Radio Frequency (SRF) Accelerator Test Facility. The research at this facility supports the next generation high intensity linear accelerators such as the International Linear Collider (ILC), a new high intensity injector (Project X) and other future machines. These components, Cryomodule No.1 (CM1) and Capture Cavity II (CC2), which contain 1.3 GHz cavities are connected in series in the beamline and through cryogenic plumbing. Studies regarding characterization of ground motion, technical and cultural noise continue. Mechanical transfer functions between the foundation and critical beamline components have been measured and overall system displacement characterized. Baseline motion measurements given initial operation of cryogenic, vacuum systems and other utilities are considered.

  3. Microgravity Acceleration Measurement System (MAMS) Flight Configuration Verification and Status

    NASA Technical Reports Server (NTRS)

    Wagar, William

    2000-01-01

    The Microgravity Acceleration Measurement System (MAMS) is a precision spaceflight instrument designed to measure and characterize the microgravity environment existing in the US Lab Module of the International Space Station. Both vibratory and quasi-steady triaxial acceleration data are acquired and provided to an Ethernet data link. The MAMS Double Mid-Deck Locker (DMDL) EXPRESS Rack payload meets all the ISS IDD and ICD interface requirements as discussed in the paper which also presents flight configuration illustrations. The overall MAMS sensor and data acquisition performance and verification data are presented in addition to a discussion of the Command and Data Handling features implemented via the ISS, downlink and the GRC Telescience Center displays.

  4. Measurement of the Decelerating Wake in a Plasma Wakefield Accelerator

    SciTech Connect

    Blumenfeld, I.; Decker, F. J.; Hogan, M. J.; Ischebeck, R.; Iverson, R. H.; Kirby, N.; Siemann, R. H.; Walz, D. R.; Clayton, C. E.; Huang, C.; Joshi, C.; Lu, W.; Marsh, K. A.; Mori, W. B.; Zhou, M.; Katsouleas, T.; Muggli, P.; Oz, E.

    2009-01-22

    Recent experiments at SLAC have shown that high gradient acceleration of electrons is achievable in meter scale plasmas. Results from these experiments show that the wakefield is sensitive to parameters in the electron beam which drives it. In the experiment the bunch lengths were varied systematically at constant charge. The effort to extract a measurement of the decelerating wake from the maximum energy loss of the electron beam is discussed.

  5. Summary of SLAC's SEY Measurement On Flat Accelerator Wall Materials

    SciTech Connect

    Le Pimpec, F.; /PSI, Villigen /SLAC

    2007-06-08

    The electron cloud effect (ECE) causes beam instabilities in accelerator structures with intense positively charged bunched beams. Reduction of the secondary electron yield (SEY) of the beam pipe inner wall is effective in controlling cloud formation. We summarize SEY results obtained from flat TiN, TiZrV and Al surfaces carried out in a laboratory environment. SEY was measured after thermal conditioning, as well as after low energy, less than 300 eV, particle exposure.

  6. Quality of life measures for food allergy.

    PubMed

    Flokstra-de Blok, B M J; Dubois, A E J

    2012-07-01

    Food allergy has become an emerging health problem in Western societies. Although food allergy is characterized by a relatively low mortality and an almost continual absence of physical symptoms, food allergic patients are continually confronted with the possibility of potentially severe reactions and the necessity of dietary vigilance. Health-related quality of life (HRQL) may be the only meaningful outcome measure available for food allergy measuring this continuous burden. HRQL may be measured with generic or disease-specific instruments. Generic instruments may be relatively unresponsive to differences or changes in health status, whereas disease-specific instruments are generally more sensitive for relatively subtle problems related to a particular illness. Recently, a number of disease-specific questionnaires have become available to measure the HRQL of food allergic patients. An important area for further research is the interpretation of the outcome of HRQL measures. In this respect, the minimal clinically important difference (MCID) is of special interest. In combination with the numbers needed to treat (NNT), this may give an ultimate insight into the clinical relevance of an intervention. Since there is still no cure for food allergy, the only available treatment is strict avoidance of the culprit food and provision of emergency treatment. The double-blind placebo-controlled food challenge (DBPCFC) is considered to be the gold standard for diagnosing food allergy. A number of studies have investigated the perceptions of parents whose children underwent a DBPCFC. In contrast to the parental perception, there is much currently still unknown about the effects of undergoing a DBPCFC in the perceptions of patients. In addition to the research on MCID and NNT of food allergy HRQL questionnaires, further research should focus on deriving quality-adjusted life years (QALYs) from food allergy HRQL questionnaires and the application of food allergy HRQL

  7. Measuring quality of life in cardiac spouses.

    PubMed

    Ebbesen, L S; Guyatt, G H; McCartney, N; Oldridge, N B

    1990-01-01

    The purpose of this study was to develop an objective instrument to measure changes in quality of life of spouses of post-myocardial infarction (MI) patients, and to determine its responsiveness and validity. A 70-item list of potential areas of concern was compiled; the 25 most frequent and important concerns comprised the framework of the final questionnaire. The questions on the Quality of Life Questionnaire for Cardiac Spouses (QL-SP) were categorized into the Emotional Function Dimension (EFD), and the Physical and Social Function Dimension (PSFD). Subjects (n = 39) completed the QL-SP and a battery of established questionnaires at home, 1-2 weeks post-hospital discharge for the patient, and 8 weeks later. Scores on the QL-SP between visits were improved for both the EFD (t = 5.56, p less than 0.001), and the PSFD (t = 6.11, p less than 0.001). The agreement between predicted and observed relationships between the dimension changes and other index changes, as measured statistically by a kappa with Cicchetti weights, was significant (kappa w = 0.43, p = 0.0012). The QL-SP appears to be responsive and valid, and may be useful in evaluating clinical and research intervention strategies. PMID:2324789

  8. Radionuclide measurements by accelerator mass spectrometry at Arizona

    NASA Technical Reports Server (NTRS)

    Jull, A. J. T.; Donahue, D. J.; Zabel, T. H.

    1986-01-01

    Over the past years, Tandem Accelerator Mass Spectrometry (TAMS) has become established as an important method for radionuclide analysis. In the Arizona system the accelerator is operated at a thermal voltage of 1.8MV for C-14 analysis, and 1.6 to 2MV for Be-10. Samples are inserted into a cesium sputter ion source in solid form. Negative ions sputtered from the target are accelerated to about 25kV, and the injection magnet selects ions of a particular mass. Ions of the 3+ charge state, having an energy of about 9MeV are selected by an electrostatic deflector, surviving ions pass through two magnets, where only ions of the desired mass-energy product are selected. The final detector is a combination ionization chamber to measure energy loss (and hence, Z), and a silicon surface-barrier detector which measures residual energy. After counting the trace iosotope for a fixed time, the injected ions are switched to the major isotope used for normalization. These ions are deflected into a Faraday cup after the first high-energy magnet. Repeated measurements of the isotope ratio of both sample and standards results in a measurement of the concentration of the radionuclide. Recent improvements in sample preparation for C-14 make preparation of high-beam current graphite targets directly from CO2 feasible. Except for some measurements of standards and backgrounds for Be-10 measurements to date have been on C-14. Although most results have been in archaeology and quaternary geology, studies have been expanded to include cosmogenic C-14 in meteorites. The data obtained so far tend to confirm the antiquity of Antarctic meteorites from the Allan Hills site. Data on three samples of Yamato meteorites gave terrestrial ages of between about 3 and 22 thousand years.

  9. High data-rate atom interferometer for measuring acceleration

    SciTech Connect

    McGuinness, Hayden J.; Rakholia, Akash V.; Biedermann, Grant W.

    2012-01-02

    We demonstrate a high data-rate light-pulse atom interferometer for measuring acceleration. The device is optimized to operate at rates between 50 Hz to 330 Hz with sensitivities of 0.57{mu}g/{radical}(Hz) to 36.7{mu}g/{radical}(Hz), respectively. Our method offers a dramatic increase in data rate and demonstrates a path to applications in highly dynamic environments. The performance of the device can largely be attributed to the high recapture efficiency of atoms from one interferometer measurement cycle to another.

  10. Sonic boom measurements from accelerating supersonic tracked sleds

    NASA Technical Reports Server (NTRS)

    Reed, J. W.

    1974-01-01

    Supersonic sled tests on the Sandia 1524-m (5000-ft) track generate sonic booms of sufficient intensity to allow some airblast measurements at distance scales not obtained from wind tunnel or flight tests. During acceleration, an emitted curved boom wave propagates to a caustic, or focus. Detailed measurements around these caustics may help to clarify the overpressure magnification which can occur from real aircraft operations. Six fixed pressure gages have been operated to document the general noise field, and a mobile array of twelve gages.

  11. SAMS Acceleration Measurements on Mir (NASA Increment 4)

    NASA Technical Reports Server (NTRS)

    DeLombard, Richard

    1998-01-01

    During NASA Increment 4 (January to May 1997), about 5 gigabytes of acceleration data were collected by the Space Acceleration Measurements System (SAMS) onboard the Russian Space Station, Mir. The data were recorded on 28 optical disks which were returned to Earth on STS-84. During this increment, SAMS data were collected in the Priroda module to support the Mir Structural Dynamics Experiment (MiSDE), the Binary Colloidal Alloy Tests (BCAT), Angular Liquid Bridge (ALB), Candle Flames in Microgravity (CFM), Diffusion Controlled Apparatus Module (DCAM), Enhanced Dynamic Load Sensors (EDLS), Forced Flow Flame Spreading Test (FFFr), Liquid Metal Diffusion (LMD), Protein Crystal Growth in Dewar (PCG/Dewar), Queen's University Experiments in Liquid Diffusion (QUELD), and Technical Evaluation of MIM (TEM). This report points out some of the salient features of the microgravity environment to which these experiments were exposed. Also documented are mission events of interest such as the docked phase of STS-84 operations, a Progress engine bum, Soyuz vehicle docking and undocking, and Progress vehicle docking. This report presents an overview of the SAMS acceleration measurements recorded by 10 Hz and 100 Hz sensor heads. The analyses included herein complement those presented in previous summary reports prepared by the Principal Investigator Microgravity Services (PIMS) group.

  12. Three Component Velocity and Acceleration Measurement Using FLEET

    NASA Technical Reports Server (NTRS)

    Danehy, Paul M.; Bathel, Brett F.; Calvert, Nathan; Dogariu, Arthur; Miles, Richard P.

    2014-01-01

    The femtosecond laser electronic excitation and tagging (FLEET) method has been used to measure three components of velocity and acceleration for the first time. A jet of pure N2 issuing into atmospheric pressure air was probed by the FLEET system. The femtosecond laser was focused down to a point to create a small measurement volume in the flow. The long-lived lifetime of this fluorescence was used to measure the location of the tagged particles at different times. Simultaneous images of the flow were taken from two orthogonal views using a mirror assembly and a single intensified CCD camera, allowing two components of velocity to be measured in each view. These different velocity components were combined to determine three orthogonal velocity components. The differences between subsequent velocity components could be used to measure the acceleration. Velocity accuracy and precision were roughly estimated to be +/-4 m/s and +/-10 m/s respectively. These errors were small compared to the approx. 100 m/s velocity of the subsonic jet studied.

  13. Summary report of mission acceleration measurements for Spacehab-01, STS-57 launched 21 June 1993

    NASA Technical Reports Server (NTRS)

    Finley, Brian; Grodsinsky, Carlos; Delombard, Richard

    1994-01-01

    The maiden voyage of the commercial Spacehab laboratory module onboard the STS-57 mission was integrated with several accelerometer packages, one of which was the Space Acceleration Measurement System (SAMS). The June 21st 1993, launch was the seventh successful mission for the Office of Life and Microgravity Sciences and Application's (OLMSA) SAMS unit. This flight was also complemented by a second accelerometer system. The Three Dimensional Microgravity Accelerometer (3-DMA), a Code C funded acceleration measurement system, offering an on-orbit residual calibration as a reference for the unit's four triaxial accelerometers. The SAMS accelerometer unit utilized three remote triaxial sensor heads mounted on the forward Spacehab module bulkhead and on one centrally located experiment locker door. These triaxial heads had filter cut-offs set to 5, 50, and 1000 Hz. The mission also included other experiment specific accelerometer packages in various locations.

  14. Bayesian Analysis of Step-Stress Accelerated Life Test with Exponential Distribution

    SciTech Connect

    Lee, J.; Pan, R.

    2012-04-01

    In this article, we propose a general Bayesian inference approach to the step-stress accelerated life test with type II censoring. We assume that the failure times at each stress level are exponentially distributed and the test units are tested in an increasing order of stress levels. We formulate the prior distribution of the parameters of life-stress function and integrate the engineering knowledge of product failure rate and acceleration factor into the prior. The posterior distribution and the point estimates for the parameters of interest are provided. Through the Markov chain Monte Carlo technique, we demonstrate a nonconjugate prior case using an industrial example. It is shown that with the Bayesian approach, the statistical precision of parameter estimation is improved and, consequently, the required number of failures could be reduced.

  15. Early-life stress and reproductive cost: A two-hit developmental model of accelerated aging?

    PubMed

    Shalev, Idan; Belsky, Jay

    2016-05-01

    Two seemingly independent bodies of research suggest a two-hit model of accelerated aging, one highlighting early-life stress and the other reproduction. The first, informed by developmental models of early-life stress, highlights reduced longevity effects of early adversity on telomere erosion, whereas the second, informed by evolutionary theories of aging, highlights such effects with regard to reproductive cost (in females). The fact that both early-life adversity and reproductive effort are associated with shorter telomeres and increased oxidative stress raises the prospect, consistent with life-history theory, that these two theoretical frameworks currently informing much research are tapping into the same evolutionary-developmental process of increased senescence and reduced longevity. Here we propose a mechanistic view of a two-hit model of accelerated aging in human females through (a) early-life adversity and (b) early reproduction, via a process of telomere erosion, while highlighting mediating biological embedding mechanisms that might link these two developmental aging processes. PMID:27063083

  16. The Awful Truth About Zero-Gravity: Space Acceleration Measurement System; Orbital Acceleration Research Experiment

    NASA Technical Reports Server (NTRS)

    2002-01-01

    Earth's gravity holds the Shuttle in orbit, as it does satellites and the Moon. The apparent weightlessness experienced by astronauts and experiments on the Shuttle is a balancing act, the result of free-fall, or continuously falling around Earth. An easy way to visualize what is happening is with a thought experiment that Sir Isaac Newton did in 1686. Newton envisioned a mountain extending above Earth's atmosphere so that friction with the air would be eliminated. He imagined a cannon atop the mountain and aimed parallel to the ground. Firing the cannon propels the cannonball forward. At the same time, Earth's gravity pulls the cannonball down to the surface and eventual impact. Newton visualized using enough powder to just balance gravity so the cannonball would circle the Earth. Like the cannonball, objects orbiting Earth are in continuous free-fall, and it appears that gravity has been eliminated. Yet, that appearance is deceiving. Activities aboard the Shuttle generate a range of accelerations that have effects similar to those of gravity. The crew works and exercises. The main data relay antenna quivers 17 times per second to prevent 'stiction,' where parts stick then release with a jerk. Cooling pumps, air fans, and other systems add vibration. And traces of Earth's atmosphere, even 200 miles up, drag on the Shuttle. While imperceptible to us, these vibrations can have a profound impact on the commercial research and scientific experiments aboard the Shuttle. Measuring these forces is necessary so that researchers and scientists can see what may have affected their experiments when analyzing data. On STS-107 this service is provided by the Space Acceleration Measurement System for Free Flyers (SAMS-FF) and the Orbital Acceleration Research Experiment (OARE). Precision data from these two instruments will help scientists analyze data from their experiments and eliminate outside influences from the phenomena they are studying during the mission.

  17. MEASURING EARLY LIFE DISPARITY IN INDIA.

    PubMed

    Singh, Akansha; Ladusingh, Laishram

    2016-08-01

    Early life disparity - defined as the average life years lost due to death by the age of 60 years - can be used to assess more systematically the effect of savings from death at a young age. In addition, it can give valuable insight into the consequences of death in the early stages of life. Early life disparity can further be categorized into child life disparity (0-14 years) and adult life disparity (15-60 years). This study estimated early life disparity using complete life tables for the period 1970-1975 to 2006-2010, which were constructed from abridged life tables and death rates provided by the Sample Registration System (SRS) in India. The contribution of premature deaths to the difference in life disparity was estimated using a replacement algorithm. The findings clearly indicated an overall declining trend in early life disparity in India, with a notable reduction in child life disparity, and a deceleration of adult life disparity during the period 1970-1975 to 2006-2010. Interstate variations in early life disparity were seen to converge with time. Decomposition analysis suggested that these variations could be minimized further by averting death during childhood. PMID:26537823

  18. Summary Report of Mission Acceleration Measurements for STS-95

    NASA Technical Reports Server (NTRS)

    McPherson, Kevin; Hrovat, Kenneth

    2000-01-01

    John H. Glenn's historic return to space was a primary focus of the STS-95 mission. The Hubble Space Telescope (HST) Orbital Systems Test (HOST). an STS-95 payload, was an in-flight demonstration of HST components to be installed during the next HST servicing mission. One of the components under evaluation was the cryocooler for the Near Infrared Camera and Multi-Object Spectrometer (NICMOS). Based on concerns about vibrations from the operation of the NICMOS cryocooler affecting the overall HST line-of-sight requirements, the Space Acceleration Measurement System for Free-Flyers (SAMS-FF) was employed to measure the vibratory environment of the STS-95 mission, including any effects introduced by the NICMOS cryocooler. The STS-95 mission represents the first STS mission supported by SAMS-FF. Utilizing a Control and Data Acquisition Unit (CDU) and two triaxial sensor heads (TSH) mounted on the HOST support structure in Discovery's cargo bay, the SAMS-FF and the HOST project were able to make vibratory measurements both on-board the vibration-isolated NICMOS cryocooler and off-board the cryocooler mounting plate. By comparing the SAMS-FF measured vibrations on-board and off-board the NICMOS cryocooler, HST engineers could assess the cryocooler g-jitter effects on the HST line-of-sight requirements. The acceleration records from both SAMS-FF accelerometers were analyzed and significant features of the microgravity environment are detailed in this report.

  19. Measurement of heat load density profile on acceleration grid in MeV-class negative ion accelerator

    NASA Astrophysics Data System (ADS)

    Hiratsuka, Junichi; Hanada, Masaya; Kojima, Atsushi; Umeda, Naotaka; Kashiwagi, Mieko; Miyamoto, Kenji; Yoshida, Masafumi; Nishikiori, Ryo; Ichikawa, Masahiro; Watanabe, Kazuhiro; Tobari, Hiroyuki

    2016-02-01

    To understand the physics of the negative ion extraction/acceleration, the heat load density profile on the acceleration grid has been firstly measured in the ITER prototype accelerator where the negative ions are accelerated to 1 MeV with five acceleration stages. In order to clarify the profile, the peripheries around the apertures on the acceleration grid were separated into thermally insulated 34 blocks with thermocouples. The spatial resolution is as low as 3 mm and small enough to measure the tail of the beam profile with a beam diameter of ˜16 mm. It was found that there were two peaks of heat load density around the aperture. These two peaks were also clarified to be caused by the intercepted negative ions and secondary electrons from detailed investigation by changing the beam optics and gas density profile. This is the first experimental result, which is useful to understand the trajectories of these particles.

  20. Measurement of heat load density profile on acceleration grid in MeV-class negative ion accelerator.

    PubMed

    Hiratsuka, Junichi; Hanada, Masaya; Kojima, Atsushi; Umeda, Naotaka; Kashiwagi, Mieko; Miyamoto, Kenji; Yoshida, Masafumi; Nishikiori, Ryo; Ichikawa, Masahiro; Watanabe, Kazuhiro; Tobari, Hiroyuki

    2016-02-01

    To understand the physics of the negative ion extraction/acceleration, the heat load density profile on the acceleration grid has been firstly measured in the ITER prototype accelerator where the negative ions are accelerated to 1 MeV with five acceleration stages. In order to clarify the profile, the peripheries around the apertures on the acceleration grid were separated into thermally insulated 34 blocks with thermocouples. The spatial resolution is as low as 3 mm and small enough to measure the tail of the beam profile with a beam diameter of ∼16 mm. It was found that there were two peaks of heat load density around the aperture. These two peaks were also clarified to be caused by the intercepted negative ions and secondary electrons from detailed investigation by changing the beam optics and gas density profile. This is the first experimental result, which is useful to understand the trajectories of these particles. PMID:26932019

  1. TOWARD A DIRECT MEASUREMENT OF THE COSMIC ACCELERATION

    SciTech Connect

    Darling, Jeremy

    2012-12-20

    We present precise H I 21 cm absorption line redshifts observed in multiple epochs to directly constrain the secular redshift drift z-dot or the cosmic acceleration, {Delta}v/{Delta}t{sub circle}. A comparison of literature analog spectra to contemporary digital spectra shows significant acceleration likely attributable to systematic instrumental errors. However, we obtain robust constraints using primarily Green Bank Telescope digital data. Ten objects spanning z = 0.09-0.69 observed over 13.5 years show z-dot = (-2.3 {+-} 0.8) Multiplication-Sign 10{sup -8} yr{sup -1} or {Delta}v/{Delta}t{sub circle} = -5.5 {+-} 2.2 m s{sup -1} yr{sup -1}. The best constraint from a single object, 3C 286 at (z) = 0.692153275(85), is z-dot = (1.6 {+-} 4.7) Multiplication-Sign 10{sup -8} yr{sup -1} or {Delta}v/{Delta}t{sub circle} = 2.8 {+-} 8.4 m s{sup -1} yr{sup -1}. These measurements are three orders of magnitude larger than the theoretically expected acceleration at z = 0.5, z-dot = 2 Multiplication-Sign 10{sup -11} yr{sup -1} or {Delta}v/{Delta}t{sub circle} = 0.3 cm s{sup -1} yr{sup -1}, but they demonstrate the lack of peculiar acceleration in absorption line systems and the long-term frequency stability of modern radio telescopes. A comparison of UV metal absorption lines to the 21 cm line improves constraints on the cosmic variation of physical constants: {Delta}({alpha}{sup 2} g{sub p} {mu})/{alpha}{sup 2} g{sub p} {mu} = (- 1.2 {+-} 1.4) Multiplication-Sign 10{sup -6} in the redshift range z = 0.24-2.04. The linear evolution over the last 10.4 Gyr is (- 0.2 {+-} 2.7) Multiplication-Sign 10{sup -16} yr{sup -1}, consistent with no variation. The cosmic acceleration could be directly measured in {approx}125 years using current telescopes or in {approx}5 years using a Square Kilometer Array, but systematic effects will arise at the 1 cm s{sup -1} yr{sup -1} level.

  2. SAMS Acceleration Measurements on Mir from June to November 1995

    NASA Technical Reports Server (NTRS)

    DeLombard, Richard; Hrovat, Ken; Moskowitz, Milton; McPherson, Kevin

    1996-01-01

    The NASA Microgravity Science and Applications Division (MSAD) sponsors science experiments on a variety of microgravity carriers, including sounding rockets, drop towers, parabolic aircraft, and Orbiter missions. The MSAD sponsors the Space Acceleration Measurement System (SAMS) to support microgravity science experiments with acceleration measurements to characterize the microgravity environment to which the experiments were exposed. The Principal Investigator Microgravity Services project at the NASA Lewis Research Center supports principal investigators of microgravity experiments as they evaluate the effects of varying acceleration levels on their experiments. In 1993, a cooperative effort was started between the United States and Russia involving science utilization of the Russian Mir space station by scientists from the United States and Russia. MSAD is currently sponsoring science experiments participating in the Shuttle-Mir Science Program in cooperation with the Russians on the Mir space station. Included in the complement of MSAD experiments and equipment is a SAMS unit In a manner similar to Orbiter mission support, the SAMS unit supports science experiments from the U.S. and Russia by measuring the microgravity environment during experiment operations. The initial SAMS supported experiment was a Protein Crystal Growth (PCG) experiment from June to November 1995. SAMS data were obtained during the PCG operations on Mir in accordance with the PCG Principal Investigator's requirements. This report presents an overview of the SAMS data recorded to support this PCG experiment. The report contains plots of the SAMS 100 Hz sensor head data as an overview of the microgravity environment, including the STS-74 Shuttle-Mir docking.

  3. Second-order state estimation experiments using acceleration measurements

    NASA Technical Reports Server (NTRS)

    Belvin, W. K.

    1992-01-01

    The estimation of dynamic states for feedback control of structural systems using second-order differential equations and acceleration measurements is described. The formulation of the observer model, and the design of the observer gains is discussed in detail. It is shown the second-order observer is highly stable because the stability constraints on the observer gains are model independent. The limitation of the proposed observer is the need for 'nearly' collocated actuators and accelerometers. Experimental results using a control-structure interaction testbed are presented that show the second-order observer provided more stability than a Kalman filter estimator without decreasing closed-loop performance.

  4. Tracking accelerated aging of composites with ultrasonic attenuation measurements

    SciTech Connect

    Chinn, D.J.; Durbin, P.F.; Thomas, G.H.; Groves, S.E.

    1996-10-01

    Composite materials are steadily replacing traditional materials in many industries. For many carbon composite materials, particularly in aerospace applications, durability is a critical design parameter which must be accurately characterized. Lawrence Livermore National Laboratory (LLNL) and Boeing Commercial Airplane Group have established a cooperative research and development agreement (CRADA) to assist in the high speed research program at Boeing. LLNL`s expertise in fiber composites, computer modeling, mechanical testing, chemical analysis and nondestructive evaluation (ND) will contribute to the study of advanced composite materials in commercial aerospace applications. Through thermo-mechanical experiments with periodic chemical analysis and nondestructive evaluation, the aging mechanisms in several continuous fiber polymer composites will be studied. Several measurement techniques are being studied for their correlation with aging. This paper describes through-transmission ultrasonic attenuation measurements of isothermally aged composite materials and their use as a tracking parameter for accelerated aging.

  5. Hadron production measurements to constrain accelerator neutrino beams

    SciTech Connect

    Korzenev, Alexander

    2015-07-15

    A precise prediction of expected neutrino fluxes is required for a long-baseline accelerator neutrino experiment. The flux is used to measure neutrino cross sections at the near detector, while at the far detector it provides an estimate of the expected signal for the study of neutrino oscillations. In the talk several approaches to constrain the ν flux are presented. The first is the traditional one when an interaction chain for the neutrino parent hadrons is stored to be weighted later with real measurements. In this approach differential hadron cross sections are used which, in turn, are measured in ancillary hadron production experiments. The approach is certainly model dependent because it requires an extrapolation to different incident nucleon momenta assuming x{sub F} scaling as well as extrapolation between materials having different atomic numbers. In the second approach one uses a hadron production yields off a real target exploited in the neutrino beamline. Yields of neutrino parent hadrons are parametrized at the surface of the target, thus one avoids to trace the particle interaction history inside the target. As in the case of the first approach, a dedicated ancillary experiment is mandatory. Recent results from the hadron production experiments – NA61/SHINE at CERN (measurements for T2K) and MIPP at Fermilab (measurements for NuMI) – are reviewed.

  6. Hadron production measurements to constrain accelerator neutrino beams

    NASA Astrophysics Data System (ADS)

    Korzenev, Alexander

    2015-07-01

    A precise prediction of expected neutrino fluxes is required for a long-baseline accelerator neutrino experiment. The flux is used to measure neutrino cross sections at the near detector, while at the far detector it provides an estimate of the expected signal for the study of neutrino oscillations. In the talk several approaches to constrain the ν flux are presented. The first is the traditional one when an interaction chain for the neutrino parent hadrons is stored to be weighted later with real measurements. In this approach differential hadron cross sections are used which, in turn, are measured in ancillary hadron production experiments. The approach is certainly model dependent because it requires an extrapolation to different incident nucleon momenta assuming xF scaling as well as extrapolation between materials having different atomic numbers. In the second approach one uses a hadron production yields off a real target exploited in the neutrino beamline. Yields of neutrino parent hadrons are parametrized at the surface of the target, thus one avoids to trace the particle interaction history inside the target. As in the case of the first approach, a dedicated ancillary experiment is mandatory. Recent results from the hadron production experiments - NA61/SHINE at CERN (measurements for T2K) and MIPP at Fermilab (measurements for NuMI) - are reviewed.

  7. Precision Magnet Measurements for X-Band Accelerator Quadrupole Triplets

    SciTech Connect

    Marsh, R A; Anderson, S G; Armstrong, J P

    2012-05-16

    An X-band test station is being developed at LLNL to investigate accelerator optimization for future upgrades to mono-energetic gamma-ray (MEGa-Ray) technology at LLNL. Beamline magnets will include an emittance compensation solenoid, windowpane steering dipoles, and quadrupole magnets. Demanding tolerances have been placed on the alignment of these magnets, which directly affects the electron bunch beam quality. A magnet mapping system has been established at LLNL in order to ensure the delivered magnets match their field specification, and the mountings are aligned and capable of reaching the specified alignment tolerances. The magnet measurement system will be described which uses a 3-axis Lakeshore gauss probe mounted on a 3-axis translation stage. Alignment accuracy and precision will be discussed, as well as centering measurements and analysis. The dependence on data analysis over direct multi-pole measurement allows a significant improvement in useful alignment information. Detailed analysis of measurements on the beamline quadrupoles will be discussed, including multi-pole content both from alignment of the magnets, and the intrinsic level of multi-pole magnetic field.

  8. Effects of changing from non-accelerated to accelerated MRI for follow-up in brain atrophy measurement.

    PubMed

    Leung, Kelvin K; Malone, Ian M; Ourselin, Sebastien; Gunter, Jeffrey L; Bernstein, Matt A; Thompson, Paul M; Jack, Clifford R; Weiner, Michael W; Fox, Nick C

    2015-02-15

    Stable MR acquisition is essential for reliable measurement of brain atrophy in longitudinal studies. One attractive recent advance in MRI is to speed up acquisition using parallel imaging (e.g. reducing volumetric T1-weighted acquisition scan times from around 9 to 5 min). In some studies, a decision to change to an accelerated acquisition may have been deliberately taken, while in others repeat scans may occasionally be accidentally acquired with an accelerated acquisition. In ADNI, non-accelerated and accelerated scans were acquired in the same scanning session on each individual. We investigated the impact on brain atrophy as measured by k-means normalized boundary shift integral (KN-BSI) and deformation-based morphometry when changing from non-accelerated to accelerated MRI acquisitions over a 12-month interval using scans of 422 subjects from ADNI. KN-BSIs were calculated using both a non-accelerated baseline scan and non-accelerated 12-month scans (i.e. consistent acquisition), and a non-accelerated baseline scan and an accelerated 12-month scan (i.e. changed acquisition). Fluid-based non-rigid registration was also performed on those scans to estimate the brain atrophy rate. We found that the effect on KN-BSI and fluid-based non-rigid registration depended on the scanner manufacturer. For KN-BSI, in Philips and Siemens scanners, the change had very little impact on the measured atrophy rate (increase of 0.051% in Philips and -0.035% in Siemens from consistent acquisition to changed acquisition), whereas, in GE, the change caused a mean reduction of 0.65% in the brain atrophy rate. This is likely due to the difference in tissue contrast between gray matter and cerebrospinal fluid in the non-accelerated and accelerated scans in GE, which uses IR-FSPGR instead of MP-RAGE. For fluid-based non-rigid registration, the change caused a mean increase of 0.29% in the brain atrophy rate in the changed acquisition compared with consistent acquisition in Philips

  9. High spatial resolution measurements of ram accelerator gas dynamic phenomena

    NASA Technical Reports Server (NTRS)

    Hinkey, J. B.; Burnham, E. A.; Bruckner, A. P.

    1992-01-01

    High spatial resolution experimental tube wall pressure measurements of ram accelerator gas dynamic phenomena are presented. The projectile resembles the centerbody of a ramjet and travels supersonically through a tube filled with a combustible gaseous mixture, with the tube acting as the outer cowling. Pressure data are recorded as the projectile passes by sensors mounted in the tube wall at various locations along the tube. Data obtained by using a special highly instrumented section of tube has allowed the recording of gas dynamic phenomena with a spatial resolution on the order of one tenth the projectile length. High spatial resolution tube wall pressure data from the three regimes of propulsion studied to date (subdetonative, transdetonative, and superdetonative) are presented and reveal the 3D character of the flowfield induced by projectile fins and the canting of the projectile body relative to the tube wall. Also presented for comparison to the experimental data are calculations made with an inviscid, 3D CFD code.

  10. Low-level 14C measurements and Accelerator Mass Spectrometry

    SciTech Connect

    Litherland, A.E.; Beukens, R.P.; Zhao, X.-L.; Kieser, W.E.; Gove, H.E.

    2005-09-08

    Accelerator Mass Spectrometry (AMS) and isotope enrichment were used in 1991 to estimate that the 14C content of methane in natural gas was {<=}1.6x10-18 of the total carbon. The low content of 14C in underground hydrocarbons was verified later in the remarkable results from the Borexino test scintillation counter for solar neutrino studies. Since then studies of the 14C background problem have demonstrated that much of the background originally observed in the AMS measurements can, in principle, be eliminated. However, many difficulties and other backgrounds are to be faced as the limit for AMS is pushed still further towards possibly a ratio of < 10-21. These will be discussed.

  11. Accelerated cycle life performance for ovonic nickel-metal hydride cells

    NASA Technical Reports Server (NTRS)

    Otzinger, Burton M.

    1991-01-01

    Nickel-Metal Hydride (Ni-MH) rechargeable batteries have emerged as the leading candidate for commercial replacement of nickel-cadmium (Ni-Cd) batteries. An important incentive is that the Ni-MH cell provides approximately twice the capacity of a Ni-Cd cell for a given size. A six-cell battery was committed to an accelerated cycle life test to determine the effect of separation type on performance. Results of the test may also show the Ni-MH battery to be a replacement candidate for the aerospace Ni-Cd battery.

  12. Accelerated life tests of specimen heat pipe from Communication Technology Satellite (CTS) project

    NASA Technical Reports Server (NTRS)

    Tower, L. K.; Kaufman, W. B.

    1977-01-01

    A gas-loaded variable conductance heat pipe of stainless steel with methanol working fluid identical to one now on the CTS satellite was life tested in the laboratory at accelerated conditions for 14 200 hours, equivalent to about 70 000 hours at flight conditions. The noncondensible gas inventory increased about 20 percent over the original charge. The observed gas increase is estimated to increase operating temperature by about 2.2 C, insufficient to harm the electronic gear cooled by the heat pipes in the satellite. Tests of maximum heat input against evaporator elevation agree well with the manufacturer's predictions.

  13. Magnetic Shielding of the Acceleration Channel Walls in a Long-Life Hall Thruster

    NASA Technical Reports Server (NTRS)

    Mikellides, Ioannis G.; Katz, Ira; Hofer, Richard R.; Goebel, Dan M.; de Grys, Kristi; Mathers, Alex

    2010-01-01

    In a Qualification Life Test (QLT) of the BPT-4000 Hall thruster that recently accumulated greater than 10,000 h it was found that the erosion of the acceleration channel practically stopped after approximately 5,600 h. Numerical simulations of this thruster using a 2-D axisymmetric, magnetic field-aligned-mesh (MFAM) plasma solver reveal that the process that led to this significant reduction of the erosion was multifaceted. It is found that when the channel receded from its early-in-life geometry to its steady-state configuration several changes in the near-wall plasma and sheath were induced by the magnetic field that, collectively, constituted an effective shielding of the walls from any significant ion bombardment. Because all such changes in the behavior of the ionized gas near the eroding surfaces were caused by the topology of the magnetic field there, we term this process "magnetic shielding."

  14. Measurements of high-energy radiation generation from laser-wakefield accelerated electron beams

    SciTech Connect

    Schumaker, W. Vargas, M.; Zhao, Z.; Behm, K.; Chvykov, V.; Hou, B.; Maksimchuk, A.; Nees, J.; Yanovsky, V.; Thomas, A. G. R.; Krushelnick, K.; Sarri, G.; Dromey, B.; Zepf, M.

    2014-05-15

    Using high-energy (∼0.5 GeV) electron beams generated by laser wakefield acceleration (LWFA), bremsstrahlung radiation was created by interacting these beams with various solid targets. Secondary processes generate high-energy electrons, positrons, and neutrons, which can be measured shot-to-shot using magnetic spectrometers, short half-life activation, and Compton scattering. Presented here are proof-of-principle results from a high-resolution, high-energy gamma-ray spectrometer capable of single-shot operation, and high repetition rate activation diagnostics. We describe the techniques used in these measurements and their potential applications in diagnosing LWFA electron beams and measuring high-energy radiation from laser-plasma interactions.

  15. Closeout Report for the Refractory Metal Accelerated Heat Pipe Life Test Activity

    NASA Technical Reports Server (NTRS)

    Martin, J.; Reid, R.; Stewart, E.; Hickman, R.; Mireles, O.

    2013-01-01

    With the selection of a gas-cooled reactor, this heat pipe accelerated life test activity was closed out and its resources redirected. The scope of this project was to establish the long-term aging effects on Mo-44.5%Re sodium heat pipes when subjected to space reactor temperature and mass fluences. To date, investigators have demonstrated heat pipe life tests of alkali metal systems up to .50,000 hours. Unfortunately, resources have not been available to examine the effect of temperature, mass fluence, or impurity level on corrosion or to conduct post-test forensic examination of heat pipes. The key objective of this effort was to establish a cost/time effective method to systematically test alkali metal heat pipes with both practical and theoretical benefits. During execution of the project, a heat pipe design was established, a majority of the laboratory test equipment systems specified, and operating and test procedures developed. Procurements for the heat pipe units and all major test components were underway at the time the stop work order was issued. An extremely important outcome was the successful fabrication of an annular wick from Mo-5%Re screen (the single, most difficult component to manufacture) using a hot isostatic pressing technique. This Technical Publication (TP) includes specifics regarding the heat pipe calorimeter water-cooling system, vendor design for the radio frequency heating system, possible alternative calorimeter designs, and progress on the vanadium equilibration technique. The methods provided in this TP and preceding project documentation would serve as a good starting point to rapidly implement an accelerated life test. Relevant test data can become available within months, not years, and destructive examination of the first life test heat pipe might begin within 6 months of test initiation. Final conclusions could be drawn in less than a quarter of the mission duration for a long-lived, fission-powered, deep space probe.

  16. Plutonium measurements by accelerator mass spectrometry at LLNL

    SciTech Connect

    McAninch, J E; Hamilton, T F; Broan, T A; Jokela, T A; Knezovich, T J; Ognibene, T J; Proctor, I D; Roberts, M L; Southon, J R; Vogel, J S; Sideras-Haddad, E

    1999-10-26

    Mass spectrometric methods provide sensitive, routine, and cost-effective analyses of long-lived radionuclides. Here the authors report on the status of work at Lawrence Livermore National Laboratory (LLNL) to develop a capability for actinide measurements by accelerator mass spectrometry (AMS) to take advantage of the high potential of AMS for rejection of interferences. This work demonstrates that the LLNL AMS spectrometer is well-suited for providing high sensitivity, robust, high throughput measurements of plutonium concentrations and isotope ratios. Present backgrounds are {approximately}2 x 10{sup 7}atoms per sample for environmental samples prepared using standard alpha spectrometry protocols. Recent measurements of {sup 239+240}Pu and {sup 241}Pu activities and {sup 240}Pu/{sup 239}Pu isotope ratios in IAEA reference materials agree well with IAEA reference values and with alpha spectrometry and recently published ICP-MS results. Ongoing upgrades of the AMS spectrometer are expected to reduce backgrounds below 1 x 10{sup 6} atoms per sample while allowing simplifications of the sample preparation chemistry. These simplifications will lead to lower per-sample costs, higher throughput, faster turn around and, ultimately, to larger and more robust data sets.

  17. High-Precision Half-Life Measurements for the Superallowed β+ emitter 10C

    NASA Astrophysics Data System (ADS)

    Dunlop, Michelle

    2014-09-01

    High precision measurements of superallowed Fermi beta transitions between 0+ isobaric analogue states allow for stringent tests of the electroweak interaction described by the Standard Model. These transitions provide an experimental probe of the unitary of the Cabibbo-Kobayashi-Maskawa matrix, the Conserved-Vector-Current hypothesis, as well as set limits on the existence of scalar currents in the weak interaction. Half-life measurements for the lightest of the superallowed emitters are of particular interest as the low-Z superallowed decays are most sensitive to a possible scalar current contribution. The half-life of 10C can be measured by directly counting the β particles or measuring the γ-ray activity following β decay. Previous results for the 10C half-life measured via these two methods differ at the 1.5 σ level, motivating further independent measurements of the 10C half-life using both techniques. Recent 10C half-life measurements via both gamma-ray photo-peak and direct beta counting were performed at TRIUMF's Isotope Separator and Accelerator facility. This presentation will highlight the importance of these measurements and preliminary half-life results will be presented.

  18. High-precision half-life measurements for the superallowed β+ emitter 10C

    NASA Astrophysics Data System (ADS)

    Dunlop, Michelle

    2015-10-01

    High precision measurements of the ft values for superallowed Fermi beta transitions between 0+ isobaric analogue states allow for stringent tests of the electroweak interaction described by the Standard Model. These transitions provide an experimental probe of the unitary of the Cabibbo-Kobayashi-Maskawa matrix, the Conserved-Vector-Current hypothesis, as well as set limits on the existence of scalar currents in the weak interaction. Half-life measurements for the lightest of the superallowed emitters are of particular interest as the low-Z superallowed decays are most sensitive to a possible scalar current contribution. The half-life of 10C can be measured by directly counting the β particles or by measuring the γ-ray activity following β decay. Previous results for the 10C half-life measured via these two methods differ at the 1.3 σ level, motivating further measurements of the 10C half-life using both techniques. Recent 10C half-life measurements via both gamma-ray photo-peak and direct beta counting were performed at TRIUMF's Isotope Separator and Accelerator facility. This presentation will highlight the importance of these measurements and half-life results will be presented.

  19. FemtoMolar measurements using accelerator mass spectrometry.

    PubMed

    Salehpour, Mehran; Forsgard, Niklas; Possnert, Göran

    2009-03-01

    Accelerator mass spectrometry (AMS) is an ultra-sensitive analytical method suitable for the detection of sub-nM concentrations of labeled biological substances such as pharmaceutical drugs in body fluids. A limiting factor in extending the concentration measurements to the sub-pM range is the natural (14)C content in living tissues. This was circumvented by separating the labeled drug from the tissue matrix, using standard high-performance liquid chromatography (HPLC) procedures. As the separated total drug amount is in the few fg range, it is not possible to use a standard AMS sample preparation method, where mg sizes are required. We have utilized a sensitive carbon carrier method where a (14)C-deficient compound is added to the HPLC fractions and the composite sample is prepared and analyzed by AMS. Using 50 microL human blood plasma aliquots, we have demonstrated concentration measurements below 20 fM, containing sub-amol amounts of the labeled drug. The method has the immediate potential of operating in the sub-fM region. PMID:19177507

  20. Conceptualizing and Measuring Family Quality of Life

    ERIC Educational Resources Information Center

    Summers, J. A.; Poston, D. J.; Turnbull, A. P.; Marquis, J.; Hoffman, L.; Mannan, H.; Wang, M.

    2005-01-01

    Background: Increasing emphasis on family-centred approaches to services and supports for families of children with disabilities has surfaced the issue of accountability for family outcomes. We present a review of literature about the impacts of children with disabilities on families as a backdrop to proposing family quality of life as a concept…

  1. [Effect of epitalon and melatonin on life span and spontaneous carcinogenesis in senescence accelerated mice (SAM)].

    PubMed

    Anisimov, V N; Popovich, I G; Zabezhinskiĭ, M A; Rozenfel'd, S V; Khavinson, V Kh; Semenchenko, A V; Iashin, A I

    2005-01-01

    Female senescence accelerated mice SAMP-1. (prone) and SAMR-1 (resistant) were exposed 5 times a week monthly to melatonin (with drinking water 20mg/ml during the night hours) or to s.c. injections of epitalon (Ala-Glu-Asp-Gly) at a single dose 1mkg/mouse. Control mice were intact or exposed to injection of 0.1 ml normal saline. The body weight and temperature, food consumption, estrous function were monitored regularly. The life span and tumor incidence were evaluated as well. As age advanced, the weight increased whereas food consumption and body temperature did not change. There was no significant substrain difference in these parameters. Exposure to melatonin or epitalon also failed to influence those indices. As age advanced, the incidence of irregular estrous cycles increased both in SAMP-1 and SAMR-1, whereas the treatment with both melatonin and epitalon prevented such disturbances. SAMP-1 revealed some features of accelerated aging as compared to SAMR-1. The mean life span of the 10% of the last survivors among treated SAMP-1 was shorter than that of SAMR-1, aging rate increased and mortality doubling time decreased. There was a direct correlation between body mass of the two substrains at the age of 3 and 12 months matched by body mass increase and longer life span. Melatonin or epitalon treatment was followed by longer mean and maximum survival in the 10% of the last survivors among SAMP-1. Melatonin involved decreased aging rate and increased mortality doubling time. Malignant lymphomas predominated in SAM without any significant difference in frequency between the substrains. While melatonin failed to influence tumor incidence or term of detection in SAMP-1, neither did epitalon affect frequency. However, it was followed by longer survival in tumor-free animals. No link between melatonin or epitalon treatment, on the one hand, and carcinogenesis, on the other, was reported in SAMR-1. PMID:15909815

  2. Accelerated test methods for life prediction of hermetic motor insulation systems exposed to alternative refrigerant/lubricant mixtures. Final report

    SciTech Connect

    Ellis, P.F. II; Ferguson, A.F.

    1995-04-19

    In 1992, the Air-Conditioning and Refrigeration Technology Institute, Inc. (ARTI) contracted Radian Corporation to ascertain whether an improved accelerated test method or procedure could be developed that would allow prediction of the life of motor insulation materials used in hermetic motors for air-conditioning and refrigeration equipment operated with alternative refrigerant/lubricant mixtures. Phase 1 of the project, Conceptual Design of an accelerated test method and apparatus, was successfully completed in June 1993. The culmination of that effort was the concept of the Simulated Stator Unit (SSU) test. The objective of the Phase 2 limited proof-of-concept demonstration was to: answer specific engineering/design questions; design and construct an analog control sequencer and supporting apparatus; and conduct limited tests to determine the viability of the SSU test concept. This report reviews the SSU test concept, and describes the results through the conclusion of the proof-of-concept prototype tests in March 1995. The technical design issues inherent in transforming any conceptual design to working equipment have been resolved, and two test systems and controllers have been constructed. Pilot tests and three prototype tests have been completed, concluding the current phase of work. One prototype unit was tested without thermal stress loads. Twice daily insulation property measurements (IPMs) on this unit demonstrated that the insulation property measurements themselves did not degrade the SSU.

  3. Accelerated test methods for life prediction of hermetic motor insulation systems exposed to alternative refrigerant/lubricant mixtures

    NASA Astrophysics Data System (ADS)

    Ellis, P. F., II; Ferguson, A. F.

    1995-04-01

    In 1992, the Air-Conditioning and Refrigeration Technology Institute, Inc. (ARTI) contracted Radian Corporation to ascertain whether an improved accelerated test method or procedure could be developed that would allow prediction of the life of motor insulation materials used in hermetic motors for air-conditioning and refrigeration equipment operated with alternative refrigerant/lubricant mixtures. Phase 1 of the project, Conceptual Design of an accelerated test method and apparatus, was successfully completed in June 1993. The culmination of that effort was the concept of the Simulated Stator Unit (SSU) test. The objective of the Phase 2 limited proof-of-concept demonstration was to: answer specific engineering/design questions; design and construct an analog control sequencer and supporting apparatus; and conduct limited tests to determine the viability of the SSU test concept. This report reviews the SSU test concept, and describes the results through the conclusion of the proof-of-concept prototype tests in March 1995. The technical design issues inherent in transforming any conceptual design to working equipment have been resolved, and two test systems and controllers have been constructed. Pilot tests and three prototype tests have been completed, concluding the current phase of work. One prototype unit was tested without thermal stress loads. Twice daily insulation property measurements (IPM's) on this unit demonstrated that the insulation property measurements themselves did not degrade the SSU.

  4. Bottom of the Heap: Having Heavier Competitors Accelerates Early-Life Telomere Loss in the European Starling, Sturnus vulgaris

    PubMed Central

    Nettle, Daniel; Monaghan, Pat; Boner, Winnie; Gillespie, Robert; Bateson, Melissa

    2013-01-01

    Early-life adversity is associated with poorer health and survival in adulthood in humans and other animals. One pathway by which early-life environmental stressors could affect the adult phenotype is via effects on telomere dynamics. Several studies have shown that early-life adversity is associated with relatively short telomeres, but these are often cross-sectional and usually correlational in design. Here, we present a novel experimental system for studying the relationship between early-life adversity and telomere dynamics using a wild bird, the European starling (Sturnus vulgaris). We used cross-fostering to experimentally assign sibling chicks to either small or large broods for twelve days of the growth period. We measured telomere length in red blood cells using quantitative PCR near the beginning of the experimental manipulation (4 days old), at the end of the experimental manipulation (15 days old), and once the birds were independent (55 days old). Being in a larger brood slowed growth and retarded wing development and the timing of fledging. We found no evidence that overall brood size affected telomere dynamics. However, the greater the number of competitors above the focal bird in the within-brood size hierarchy, the greater was the telomere loss during the period of the experimental manipulation. The number of competitors below the focal in the hierarchy had no effect. The effect of heavier competitors was still evident when we controlled for the weight of the focal bird at the end of the manipulation, suggesting it was not due to retarded growth per se. Moreover, the impact of early competition on telomeres was still evident at independence, suggesting persistence beyond early life. Our study provides experimental support for the hypothesis that social stress, in this case induced by the presence of a greater number of dominant competitors, accelerates the rate of telomere loss. PMID:24386235

  5. Accelerated calendar and pulse life analysis of lithium-ion cells

    NASA Astrophysics Data System (ADS)

    Jungst, Rudolph G.; Nagasubramanian, Ganesan; Case, Herbert L.; Liaw, Bor Yann; Urbina, Angel; Paez, Thomas L.; Doughty, Daniel H.

    Sandia National Laboratories has been studying calendar and pulse discharge life of prototype high-power lithium-ion cells as part of the Advanced Technology Development (ATD) Program. One of the goals of ATD is to establish validated accelerated life test protocols for lithium-ion cells in the hybrid electric vehicle application. In order to accomplish this, aging experiments have been conducted on 18650-size cells containing a chemistry representative of these high-power designs. Loss of power and capacity are accompanied by increasing interfacial impedance at the cathode. These relationships are consistent within a given state-of-charge (SOC) over the range of storage temperatures and times. Inductive models have been used to construct detailed descriptions of the relationships between power fade and aging time and to relate power fade, capacity loss and impedance rise. These models can interpolate among the different experimental conditions and can also describe the error surface when fitting life prediction models to the data.

  6. Measurement of quality of life in men with prostate cancer.

    PubMed

    Albaugh, Jeffrey; Hacker, Eileen Danaher

    2008-02-01

    Prostate cancer continues to be one of the most common cancers diagnosed in men. In light of the excellent survival rates for prostate cancer, quality of life is a primary concern during and following prostate cancer treatment. Quality of life is defined and determined in multiple ways. This article explores quality of life in men with prostate cancer. Quality-of-life dimensions, measurement tools, and implications of quality of life with prostate cancer on clinical practice for oncology nurses will be presented. PMID:18258577

  7. Failure modes and effects criticality analysis and accelerated life testing of LEDs for medical applications

    NASA Astrophysics Data System (ADS)

    Sawant, M.; Christou, A.

    2012-12-01

    While use of LEDs in Fiber Optics and lighting applications is common, their use in medical diagnostic applications is not very extensive. Since the precise value of light intensity will be used to interpret patient results, understanding failure modes [1-4] is very important. We used the Failure Modes and Effects Criticality Analysis (FMECA) tool to identify the critical failure modes of the LEDs. FMECA involves identification of various failure modes, their effects on the system (LED optical output in this context), their frequency of occurrence, severity and the criticality of the failure modes. The competing failure modes/mechanisms were degradation of: active layer (where electron-hole recombination occurs to emit light), electrodes (provides electrical contact to the semiconductor chip), Indium Tin Oxide (ITO) surface layer (used to improve current spreading and light extraction), plastic encapsulation (protective polymer layer) and packaging failures (bond wires, heat sink separation). A FMECA table is constructed and the criticality is calculated by estimating the failure effect probability (β), failure mode ratio (α), failure rate (λ) and the operating time. Once the critical failure modes were identified, the next steps were generation of prior time to failure distribution and comparing with our accelerated life test data. To generate the prior distributions, data and results from previous investigations were utilized [5-33] where reliability test results of similar LEDs were reported. From the graphs or tabular data, we extracted the time required for the optical power output to reach 80% of its initial value. This is our failure criterion for the medical diagnostic application. Analysis of published data for different LED materials (AlGaInP, GaN, AlGaAs), the Semiconductor Structures (DH, MQW) and the mode of testing (DC, Pulsed) was carried out. The data was categorized according to the materials system and LED structure such as AlGaInP-DH-DC, Al

  8. Accelerated life test of sputtering and anode deposit spalling in a small mercury ion thruster

    NASA Technical Reports Server (NTRS)

    Power, J. L.

    1975-01-01

    Tantalum and molybdenum sputtered from discharge chamber components during operation of a 5 centimeter diameter mercury ion thruster adhered much more strongly to coarsely grit blasted anode surfaces than to standard surfaces. Spalling of the sputtered coating did occur from a coarse screen anode surface but only in flakes less than a mesh unit long. The results were obtained in a 200 hour accelerated life test conducted at an elevated discharge potential of 64.6 volts. The test approximately reproduced the major sputter erosion and deposition effects that occur under normal operation but at approximately 75 times the normal rate. No discharge chamber component suffered sufficient erosion in the test to threaten its structural integrity or further serviceability. The test indicated that the use of tantalum-surfaced discharge chamber components in conjunction with a fine wire screen anode surface should cure the problems of sputter erosion and sputtered deposits spalling in long term operation of small mercury ion thrusters.

  9. Methodology to Improve Design of Accelerated Life Tests in Civil Engineering Projects

    PubMed Central

    Lin, Jing; Yuan, Yongbo; Zhou, Jilai; Gao, Jie

    2014-01-01

    For reliability testing an Energy Expansion Tree (EET) and a companion Energy Function Model (EFM) are proposed and described in this paper. Different from conventional approaches, the EET provides a more comprehensive and objective way to systematically identify external energy factors affecting reliability. The EFM introduces energy loss into a traditional Function Model to identify internal energy sources affecting reliability. The combination creates a sound way to enumerate the energies to which a system may be exposed during its lifetime. We input these energies into planning an accelerated life test, a Multi Environment Over Stress Test. The test objective is to discover weak links and interactions among the system and the energies to which it is exposed, and design them out. As an example, the methods are applied to the pipe in subsea pipeline. However, they can be widely used in other civil engineering industries as well. The proposed method is compared with current methods. PMID:25111800

  10. Optical system for measurement of pyrotechnic test accelerations

    NASA Astrophysics Data System (ADS)

    Lieberman, Paul; Czajkowski, John; Rehard, John

    1992-12-01

    This effort was directed at comparing the response of several different accelerometer and amplifier combinations to the pyrotechnic pulse simulating the ordnance separation of stages of multistage missiles. These pyrotechnic events can contain peak accelerations in excess of 100,000 G and a frequency content exceeding 100,000 Hz. The main thrust of this work was to compare the several accelerometer systems with each other and with a very accurate laser Doppler displacement meter in order to establish the frequency bands and acceleration amplitudes where the accelerometer systems are in error. The comparisons were made in simple sine-wave and low-acceleration amplitude environments, as well as in very severe pyroshock environments. An optical laser Doppler displacement meter (LDDM) was used to obtain the displacement velocity and acceleration histories, as well as the corresponding shock spectrum.

  11. Effects of acceleration on gait measures in three horse gaits.

    PubMed

    Nauwelaerts, Sandra; Zarski, Lila; Aerts, Peter; Clayton, Hilary

    2015-05-01

    Animals switch gaits according to locomotor speed. In terrestrial locomotion, gaits have been defined according to footfall patterns or differences in center of mass (COM) motion, which characterizes mechanisms that are more general and more predictive than footfall patterns. This has generated different variables designed primarily to evaluate steady-speed locomotion, which is easier to standardize in laboratory conditions. However, in the ecology of an animal, steady-state conditions are rare and the ability to accelerate, decelerate and turn is essential. Currently, there are no data available that have tested whether COM variables can be used in accelerative or decelerative conditions. This study used a data set of kinematics and kinetics of horses using three gaits (walk, trot, canter) to evaluate the effects of acceleration (both positive and negative) on commonly used gait descriptors. The goal was to identify variables that distinguish between gaits both at steady state and during acceleration/deceleration. These variables will either be unaffected by acceleration or affected by it in a predictable way. Congruity, phase shift and COM velocity angle did not distinguish between gaits when the dataset included trials in unsteady conditions. Work (positive and negative) and energy recovery distinguished between gaits and showed a clear relationship with acceleration. Hodographs are interesting graphical representations to study COM mechanics, but they are descriptive rather than quantitative. Force angle, collision angle and collision fraction showed a U-shaped relationship with acceleration and seem promising tools for future research in unsteady conditions. PMID:25767145

  12. Measurements of Cl-36 in Antarctic meteorites and Antarctic ice using a Van de Graaff accelerator

    NASA Technical Reports Server (NTRS)

    Nishiizumi, K.; Arnold, J. R.; Finkel, R. C.; Elmore, D.; Ferraro, R. D.; Gove, H. E.; Beukens, R. P.; Chang, K. H.; Kilius, L. R.

    1979-01-01

    The paper presents measurements of cosmic-ray produced (Cl-36) in Antarctic meteorites and ice using a Van de Graaff accelerator as an ultrasensitive mass spectrometer. Results from this ion counting technique are used to support a two-stage irradiation model for the Yamato-7301 and Allan Hills-76008 meteorites and to show a long terrestrial age for Allan Hills-77002. Yamato-7304 has a terrestrial age of less than 0.1 m.y., and the (Cl-36) content of the Antarctic ice sample from the Yamato mountain is consistent with levels expected in currently depositing snow implying that the age of the ice cap at this site is less than on (Cl-36) half-life.

  13. ASSESSMENT OF THE PCFBC-EXPOSED AND ACCELERATED LIFE-TESTED CANDLE FILTERS

    SciTech Connect

    M.A. Alvin

    1999-09-30

    Development of the hot gas filtration technology has been the focus of DOE/FETC and Siemens Westinghouse Power Corporation during the past twenty years. Systems development during this time has successfully lead to the generation and implementation of high temperature Siemens Westinghouse particulate filtration systems that are currently installed and are operational at Demonstration Plant sites, and which are ready for installation at commercial plant sites. Concurrently, materials development has advanced the use of commercially available oxide- and nonoxide-based monoliths, and has fostered the manufacture and use of second generation, oxide-based, continuous fiber reinforced ceramic composites and filament wound materials. This report summarizes the material characterization results for commercially available and second generation filter materials tested in Siemens Westinghouse's advanced, high temperature, particulate removal system at the Foster Wheeler, pressurized circulating fluidized-bed combustion, pilot-scale test facility in Karhula, Finland, and subsequent extended accelerated life testing of aged elements in Siemens Westinghouse pressurized fluidized-bed combustion simulator test facility in Pittsburgh, PA. The viability of operating candle filters successfully for over 1 year of service life has been shown in these efforts. Continued testing to demonstrate the feasibility of acquiring three years of service operation on aged filter elements is recommended.

  14. Biomedical applications of accelerator mass spectrometry-isotope measurements at the level of the atom.

    PubMed

    Barker, J; Garner, R C

    1999-01-01

    Accelerator mass spectrometry (AMS) is a nuclear physics technique developed about twenty years ago, that uses the high energy (several MeV) of a tandem Van de Graaff accelerator to measure very small quantities of rare and long-lived isotopes. Elements that are of interest in biomedicine and environmental sciences can be measured, often to parts per quadrillion sensitivity, i.e. zeptomole to attomole levels (10(-21)-10(-18) mole) from milligram samples. This is several orders of magnitude lower than that achievable by conventional decay counting techniques, such as liquid scintillation counting (LSC). AMS was first applied to geochemical, climatological and archaeological areas, such as for radiocarbon dating (Shroud of Turin), but more recently this technology has been used for bioanalytical applications. In this sphere, most work has been conducted using aluminium, calcium and carbon isotopes. The latter is of special interest in drug metabolism studies, where a Phase 1 adsorption, distribution, metabolism and excretion (ADME) study can be conducted using only 10 nanoCurie (37 Bq or ca. 0.9 microSv) amounts or less of 14C-labelled drugs. In the UK, these amounts of radioactivity are below those necessary to request specific regulatory approval from the Department of Health's Administration of Radioactive Substances Advisory Committee (ARSAC), thus saving on valuable development time and resources. In addition, the disposal of these amounts is much less an environmental issue than that associated with microCurie quantities, which are currently used. Also, AMS should bring an opportunity to conduct "first into man" studies without the need for widespread use of animals. Centre for Biomedical Accelerator Mass Spectrometry (CBAMS) Ltd. is the first fully commercial company in the world to offer analytical services using AMS. With its high throughput and relatively low costs per sample analysis, AMS should be of great benefit to the pharmaceutical and biotechnology

  15. Life Cycle Thinking, Measurement and Management for Food System Sustainability.

    PubMed

    Pelletier, Nathan

    2015-07-01

    Food systems critically contribute to our collective sustainability outcomes. Improving food system sustainability requires life cycle thinking, measurement and management strategies. This article reviews the status quo and future prospects for bringing life cycle approaches to food system sustainability to the fore. PMID:25910060

  16. Multidimensional Quality of Life: A New Measure of Quality of Life in Adults

    ERIC Educational Resources Information Center

    Kreitler, Shulamith; Kreitler, Michal M.

    2006-01-01

    This paper presents a new measure for assessing quality of life (QOL)--the Multidimensional Quality of Life (MQOL)--and describes its derivation, characteristics, structure and several applications. Reasons for developing the MQOL include the restricted range of assessed domains and the heavy emphasis on health in many standard assessment tools.…

  17. Measurement of Electro-Optic Shock and Electron Acceleration in a Strongly Cavitated Laser Wakefield Accelerator

    SciTech Connect

    Helle, M. H.; Kaganovich, D.; Gordon, D. F.; Ting, A.

    2010-09-03

    Conically emitted second harmonic radiation was observed when a relativistically intense, ultrashort laser pulse was focused into a jet of gas. This second harmonic electro-optic shock is the result of frequency mixing within the sheath of electrons surrounding a highly cavitated plasma region created by the ponderomotive force of the laser. Strong correlation between the second harmonic characteristics and electron acceleration has been observed.

  18. Measurement of electro-optic shock and electron acceleration in a strongly cavitated laser wakefield accelerator.

    PubMed

    Helle, M H; Kaganovich, D; Gordon, D F; Ting, A

    2010-09-01

    Conically emitted second harmonic radiation was observed when a relativistically intense, ultrashort laser pulse was focused into a jet of gas. This second harmonic electro-optic shock is the result of frequency mixing within the sheath of electrons surrounding a highly cavitated plasma region created by the ponderomotive force of the laser. Strong correlation between the second harmonic characteristics and electron acceleration has been observed. PMID:20867524

  19. A Fine-Tooth Comb to Measure the Accelerating Universe

    NASA Astrophysics Data System (ADS)

    2008-09-01

    worth recalling that the kind of precision required, 1 cm/s, corresponds, on the focal plane of a typical high-resolution spectrograph, to a shift of a few tenths of a nanometre, that is, the size of some molecules," explains PhD student and team member Constanza Araujo-Hauck from ESO. The new calibration technique comes from the combination of astronomy and quantum optics, in a collaboration between researchers at ESO and the Max Planck Institute for Quantum Optics. It uses ultra-short pulses of laser light to create a 'frequency comb' - light at many frequencies separated by a constant interval - to create just the kind of precise 'ruler' needed to calibrate a spectrograph. After successful tests in the MPQ laboratory in 2007, the team have successfully tested a prototype device using the laser comb at the VTT (Vacuum Tower Telescope) solar telescope in Tenerife, on 8 March 2008, measuring the spectrum of the Sun in infrared light. The results are already impressive, and the technique promises to achieve the accuracy needed to study these big astronomical questions. "In our tests in Tenerife, we have already achieved beyond state-of-the-art accuracy. Now we are going to make the system more versatile, and develop it even further," says team member Tilo Steinmetz, from Menlo Systems GmbH, a spin-off company from the Max Planck Institute, which was founded to commercialise the frequency comb technique. Having tested the technique on a solar telescope, a new version of the system is now being built for the HARPS planet-finder instrument on ESO's 3.6-metre telescope at La Silla in Chile, before being considered for future generations of instruments. One of the ambitious project to be realised with the E-ELT, called CODEX, aims to measure the recently discovered acceleration of the universe directly, by following the velocities of distant galaxies and quasars over a 20-year period. This would let astronomers test Einstein's general relativity and the nature of the recently

  20. A Fine-Tooth Comb to Measure the Accelerating Universe

    NASA Astrophysics Data System (ADS)

    2008-09-01

    worth recalling that the kind of precision required, 1 cm/s, corresponds, on the focal plane of a typical high-resolution spectrograph, to a shift of a few tenths of a nanometre, that is, the size of some molecules," explains PhD student and team member Constanza Araujo-Hauck from ESO. The new calibration technique comes from the combination of astronomy and quantum optics, in a collaboration between researchers at ESO and the Max Planck Institute for Quantum Optics. It uses ultra-short pulses of laser light to create a 'frequency comb' - light at many frequencies separated by a constant interval - to create just the kind of precise 'ruler' needed to calibrate a spectrograph. After successful tests in the MPQ laboratory in 2007, the team have successfully tested a prototype device using the laser comb at the VTT (Vacuum Tower Telescope) solar telescope in Tenerife, on 8 March 2008, measuring the spectrum of the Sun in infrared light. The results are already impressive, and the technique promises to achieve the accuracy needed to study these big astronomical questions. "In our tests in Tenerife, we have already achieved beyond state-of-the-art accuracy. Now we are going to make the system more versatile, and develop it even further," says team member Tilo Steinmetz, from Menlo Systems GmbH, a spin-off company from the Max Planck Institute, which was founded to commercialise the frequency comb technique. Having tested the technique on a solar telescope, a new version of the system is now being built for the HARPS planet-finder instrument on ESO's 3.6-metre telescope at La Silla in Chile, before being considered for future generations of instruments. One of the ambitious project to be realised with the E-ELT, called CODEX, aims to measure the recently discovered acceleration of the universe directly, by following the velocities of distant galaxies and quasars over a 20-year period. This would let astronomers test Einstein's general relativity and the nature of the recently

  1. Thrust Stand Measurements of the Microwave Assisted Discharge Inductive Plasma Accelerator

    NASA Technical Reports Server (NTRS)

    Hallock, Ashley K.; Polzin, Kurt A.; Emsellem, Gregory D.

    2011-01-01

    Pulsed inductive plasma thrusters [1-3] are spacecraft propulsion devices in which electrical energy is capacitively stored and then discharged through an inductive coil. This type of pulsed thruster is electrodeless, with a time-varying current in the coil interacting with a plasma covering the face of the coil to induce a plasma current. Propellant is accelerated and expelled at a high exhaust velocity (O(10-100 km/s)) by the Lorentz body force arising from the interaction of the magnetic field and the induced plasma current. While this class of thruster mitigates the life-limiting issues associated with electrode erosion, pulsed inductive plasma thrusters require high pulse energies to inductively ionize propellant. The Microwave Assisted Dis- charge Inductive Plasma Accelerator (MAD-IPA), shown in Fig. 1, is a pulsed inductive plasma thruster that addressees this issue by partially ionizing propellant inside a conical inductive coil before the main current pulse via an electron cyclotron resonance (ECR) discharge. The ECR plasma is produced using microwaves and a static magnetic field from a set of permanent magnets arranged to create a thin resonance region along the inner surface of the coil, restricting plasma formation, and in turn current sheet formation, to a region where the magnetic coupling between the plasma and the theta-pinch coil is high. The use of a conical theta-pinch coil also serves to provide neutral propellant containment and plasma plume focusing that is improved relative to the more common planar geometry of the Pulsed Inductive Thruster (PIT) [1, 2]. In this paper, we describe thrust stand measurements performed to characterize the performance (specific impulse, thrust efficiency) of the MAD-IPA thruster. Impulse data are obtained at various pulse energies, mass flow rates and inductive coil geometries. Dependencies on these experimental parameters are discussed in the context of the current sheet formation and electromagnetic plasma

  2. Measuring quality of life in thai women with breast cancer.

    PubMed

    Glangkarn, Sumattana; Promasatayaprot, Vorapoj; Porock, Davina; Edgley, Alison

    2011-01-01

    Breast cancer has become a commonly diagnosed disease among Thai women in the last decade, despite the fact that Thai women generally have a lower rates than their Western counterparts. With the rising incidence and survival rates, it is crucial for nurses to look at the long term quality of life of these patients. A broad range of instruments have been used in clinical trials among breast cancer patients in oncology, like the EORTC questionnaire including the general quality of life questions (QLQ-C30) and the breast cancer module (QLQ-BR23), and the FACT-B questionnaire consisting of both a generic part (FACT-G) and a breast cancer specific module. They have been shown to have good validity and reliability properties both for the English original and translations into various languages including Thai. A few studies on quality of life in Thai context exist, covering quality of life in women with breast cancer. Therefore, the purpose of this study was to find which standard measure of common Western quality of life scales is appropriate to assess quality of life in Thai women with breast cancer. Results revealed the Thai version of EORTC QLQ-C30 and FACT-G questionnaires to be reliable and valid to assess quality of life in general. The best fit for measuring quality of life in Thai women with breast cancer during adjuvant treatment should be the EORTC QLQ-C30/-BR23. PMID:21627357

  3. Estimation of pressure gradients in pulsatile flow from magnetic resonance acceleration measurements.

    PubMed

    Tasu, J P; Mousseaux, E; Delouche, A; Oddou, C; Jolivet, O; Bittoun, J

    2000-07-01

    A method for estimating pressure gradients from MR images is demonstrated. Making the usual assumption that the flowing medium is a Newtonian fluid, and with appropriate boundary conditions, the inertial forces (or acceleration components of the flow) are proportional to the pressure gradients. The technique shown here is based on an evaluation of the inertial forces from Fourier acceleration encoding. This method provides a direct measurement of the total acceleration defined as the sum of the velocity derivative vs. time and the convective acceleration. The technique was experimentally validated by comparing MR and manometer pressure gradient measurements obtained in a pulsatile flow phantom. The results indicate that the MR determination of pressure gradients from an acceleration measurement is feasible with a good correlation with the true measurements (r = 0.97). The feasibility of the method is demonstrated in the aorta of a normal volunteer. Magn Reson Med 44:66-72, 2000. PMID:10893523

  4. Effects of measurement error on estimating biological half-life

    SciTech Connect

    Caudill, S.P.; Pirkle, J.L.; Michalek, J.E. )

    1992-10-01

    Direct computation of the observed biological half-life of a toxic compound in a person can lead to an undefined estimate when subsequent concentration measurements are greater than or equal to previous measurements. The likelihood of such an occurrence depends upon the length of time between measurements and the variance (intra-subject biological and inter-sample analytical) associated with the measurements. If the compound is lipophilic the subject's percentage of body fat at the times of measurement can also affect this likelihood. We present formulas for computing a model-predicted half-life estimate and its variance; and we derive expressions for the effect of sample size, measurement error, time between measurements, and any relevant covariates on the variability in model-predicted half-life estimates. We also use statistical modeling to estimate the probability of obtaining an undefined half-life estimate and to compute the expected number of undefined half-life estimates for a sample from a study population. Finally, we illustrate our methods using data from a study of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) exposure among 36 members of Operation Ranch Hand, the Air Force unit responsible for the aerial spraying of Agent Orange in Vietnam.

  5. Energy Measurements of Trapped Electrons from a Plasma Wakefield Accelerator

    SciTech Connect

    Kirby, Neal; Auerbach, David; Berry, Melissa; Blumenfeld, Ian; Clayton, Christopher E.; Decer, Franz-Josef; Hogan, Mark J.; Huang, Chengkun; Ischebeck, Rasmus; Iverson, Richard; Johnson, Devon; Joshi, Chadrashekhar; Katsouleas, Thomas; Lu, Wei; Marsh, Kenneth A.; Mori, Warren B.; Muggli, Patric; Oz, Erdem; Siemann, Robert H.; Walz, Dieter; Zhou, Miaomiao; /SLAC /UCLA /Southern California U.

    2007-01-03

    Recent electron beam driven plasma wakefield accelerator experiments carried out at SLAC indicate trapping of plasma electrons. More charge came out of than went into the plasma. Most of this extra charge had energies at or below the 10 MeV level. In addition, there were trapped electron streaks that extended from a few GeV to tens of GeV, and there were mono-energetic trapped electron bunches with tens of GeV in energy.

  6. Measuring health related quality of life in juvenile rheumatoid arthritis

    PubMed Central

    Carle, Adam C.; Dewitt, E. Morgan; Seid, M.

    2011-01-01

    Pediatric researchers and clinicians increasingly recognize the importance of measuring the impact of childhood disease across many aspects of a child’s life. In this review, we describe four measures of health related quality of life (HRQOL) designed specifically for children with Juvenile Idiopathic Arthritis (JIA). HRQOL generally refers to how an individual feels about aspects of their life in relation to their health. The World Health Organization originally described HRQOL as minimally including: physical, mental, and social health dimensions.1 Subsequent HRQOL definitions, while varied, have incorporated the notion that individuals have an important and distinct viewpoint regarding their disease and the quality of their life.2 They have also often emphasized HRQOL’s subjective nature.2 These features present unique challenges when measuring HRQOL in children. Cognizant of these issues, we review the development and psychometric properties of the Pediatric Quality of Life Inventory (PedsQL) Rheumatology Module 3.0, the Juvenile Arthritis Quality of Life Questionnaire (JAQQ), the Paediatric Rheumatology Quality of Life Scale (PRQL), and the Childhood Arthritis Health Profile (CAHP). PMID:22588764

  7. Quantum accelerometer: Distinguishing inertial Bob from his accelerated twin Rob by a local measurement

    SciTech Connect

    Dragan, Andrzej; Fuentes, Ivette; Louko, Jorma

    2011-04-15

    A single quantum system, such as the Unruh-DeWitt detector, can be used to determine absolute acceleration by local measurements on a quantum field. To show this, we consider two kinematically indistinguishable scenarios: an inertial observer, Bob, measuring the field of a uniformly accelerated cavity, and his noninertial twin, Rob, accelerating and making measurements in a stationary cavity. We find that these scenarios can be distinguished in the nonrelativistic regime only by measurements on highly excited massive fields, allowing one to detect the noninertialness of the reference frame.

  8. Quantum accelerometer: Distinguishing inertial Bob from his accelerated twin Rob by a local measurement

    NASA Astrophysics Data System (ADS)

    Dragan, Andrzej; Fuentes, Ivette; Louko, Jorma

    2011-04-01

    A single quantum system, such as the Unruh-DeWitt detector, can be used to determine absolute acceleration by local measurements on a quantum field. To show this, we consider two kinematically indistinguishable scenarios: an inertial observer, Bob, measuring the field of a uniformly accelerated cavity, and his noninertial twin, Rob, accelerating and making measurements in a stationary cavity. We find that these scenarios can be distinguished in the nonrelativistic regime only by measurements on highly excited massive fields, allowing one to detect the noninertialness of the reference frame.

  9. Accelerated Life Structural Benchmark Testing for a Stirling Convertor Heater Head

    NASA Astrophysics Data System (ADS)

    Krause, David L.; Kantzos, Pete T.

    2006-01-01

    For proposed long-duration NASA Space Science missions, the Department of Energy, Lockheed Martin, Infinia Corporation, and NASA Glenn Research Center are developing a high-efficiency, 110-watt Stirling Radioisotope Generator (SRG110). A structurally significant limit state for the SRG110 heater head component is creep deformation induced at high material temperature and low stress level. Conventional investigations of creep behavior adequately rely on experimental results from uniaxial creep specimens, and a wealth of creep data is available for the Inconel 718 material of construction. However, the specified atypical thin heater head material is fine-grained with a heat treatment that limits precipitate growth, and little creep property data for this microstructure is available in the literature. In addition, the geometry and loading conditions apply a multiaxial stress state on the component, far from the conditions of uniaxial testing. For these reasons, an extensive experimental investigation is ongoing to aid in accurately assessing the durability of the SRG110 heater head. This investigation supplements uniaxial creep testing with pneumatic testing of heater head-like pressure vessels at design temperature with stress levels ranging from approximately the design stress to several times that. This paper presents experimental results, post-test microstructural analyses, and conclusions for four higher-stress, accelerated life tests. Analysts are using these results to calibrate deterministic and probabilistic analytical creep models of the SRG110 heater head.

  10. Accelerated Life Structural Benchmark Testing for a Stirling Convertor Heater Head

    SciTech Connect

    Krause, David L.; Kantzos, Pete T.

    2006-01-20

    For proposed long-duration NASA Space Science missions, the Department of Energy, Lockheed Martin, Infinia Corporation, and NASA Glenn Research Center are developing a high-efficiency, 110-watt Stirling Radioisotope Generator (SRG110). A structurally significant limit state for the SRG110 heater head component is creep deformation induced at high material temperature and low stress level. Conventional investigations of creep behavior adequately rely on experimental results from uniaxial creep specimens, and a wealth of creep data is available for the Inconel 718 material of construction. However, the specified atypical thin heater head material is fine-grained with a heat treatment that limits precipitate growth, and little creep property data for this microstructure is available in the literature. In addition, the geometry and loading conditions apply a multiaxial stress state on the component, far from the conditions of uniaxial testing. For these reasons, an extensive experimental investigation is ongoing to aid in accurately assessing the durability of the SRG110 heater head. This investigation supplements uniaxial creep testing with pneumatic testing of heater head-like pressure vessels at design temperature with stress levels ranging from approximately the design stress to several times that. This paper presents experimental results, post-test microstructural analyses, and conclusions for four higher-stress, accelerated life tests. Analysts are using these results to calibrate deterministic and probabilistic analytical creep models of the SRG110 heater head.

  11. Accelerated Life Structural Benchmark Testing for a Stirling Convertor Heater Head

    NASA Technical Reports Server (NTRS)

    Krause, David L.; Kantzos, Pete T.

    2006-01-01

    For proposed long-duration NASA Space Science missions, the Department of Energy, Lockheed Martin, Infinia Corporation, and NASA Glenn Research Center are developing a high-efficiency, 110 W Stirling Radioisotope Generator (SRG110). A structurally significant limit state for the SRG110 heater head component is creep deformation induced at high material temperature and low stress level. Conventional investigations of creep behavior adequately rely on experimental results from uniaxial creep specimens, and a wealth of creep data is available for the Inconel 718 material of construction. However, the specified atypical thin heater head material is fine-grained with a heat treatment that limits precipitate growth, and little creep property data for this microstructure is available in the literature. In addition, the geometry and loading conditions apply a multiaxial stress state on the component, far from the conditions of uniaxial testing. For these reasons, an extensive experimental investigation is ongoing to aid in accurately assessing the durability of the SRG110 heater head. This investigation supplements uniaxial creep testing with pneumatic testing of heater head-like pressure vessels at design temperature with stress levels ranging from approximately the design stress to several times that. This paper presents experimental results, post-test microstructural analyses, and conclusions for four higher-stress, accelerated life tests. Analysts are using these results to calibrate deterministic and probabilistic analytical creep models of the SRG110 heater head.

  12. The Adaptive Basis of Psychosocial Acceleration: Comment on beyond Mental Health, Life History Strategies Articles

    ERIC Educational Resources Information Center

    Nettle, Daniel; Frankenhuis, Willem E.; Rickard, Ian J.

    2012-01-01

    Four of the articles published in this special section of "Developmental Psychology" build on and refine psychosocial acceleration theory. In this short commentary, we discuss some of the adaptive assumptions of psychosocial acceleration theory that have not received much attention. Psychosocial acceleration theory relies on the behavior of…

  13. Issues in Evaluating Importance Weighting in Quality of Life Measures

    ERIC Educational Resources Information Center

    Hsieh, Chang-ming

    2013-01-01

    For most empirical research investigating the topic of importance weighting in quality of life (QoL) measures, the prevailing approach has been to use (1) a limited choice of global QoL measures as criterion variables (often a single one) to determine the performance of importance weighting, (2) a limited option of weighting methods to develop…

  14. Measuring End-of-Life Care Processes in Nursing Homes

    ERIC Educational Resources Information Center

    Temkin-Greener, Helena; Zheng, Nan; Norton, Sally A.; Quill, Timothy; Ladwig, Susan; Veazie, Peter

    2009-01-01

    Purpose: The objectives of this study were to develop measures of end-of-life (EOL) care processes in nursing homes and to validate the instrument for measuring them. Design and Methods: A survey of directors of nursing was conducted in 608 eligible nursing homes in New York State. Responses were obtained from 313 (51.5% response rate) facilities.…

  15. Precise measurement of the {sup 19}Ne half-life

    SciTech Connect

    Triambak, S.

    2011-11-30

    We describe a high-precision measurement of the half-life of the T = 1/2 nucleus {sup 19}Ne, performed at TRIUMF, Canada's National Laboratory for Nuclear and Particle Physics, Vancouver, Canada. Some implications of this measurement related to tests of the Standard Model are discussed.

  16. Measurement and Data Distribution for Microgravity Accelerations on the International Space Station

    NASA Technical Reports Server (NTRS)

    McPherson, Kevin; Hrovat, Kenneth

    1999-01-01

    Two accelerometer systems will be available on the International Space Station to support microgravity payloads with information about the quasi-steady and vibratory acceleration environment of the research facilities. The Microgravity Acceleration Measurement System will record contributions to the quasi-steady microgravity environment, including the influences of aerodynamic drag, vehicle rotation, and venting effects. The Space Acceleration Measurement System-II will measure vibratory disturbances on-board due to vehicle, crew, and equipment disturbances. Due to the dynamic nature of the microgravity environment and its potential to influence sensitive experiments, NASA's Principal Investigator Microgravity Services project has initiated a plan through which the data from these instruments will be distributed to researchers in a timely and meaningful fashion. Beyond the obvious benefit of correlation between accelerations and the scientific phenomena being studied, such information is also useful for hardware developers who can gain qualitative and quantitative feedback about their facility acceleration output to station.

  17. Measuring the quality of life: why, how and what?

    PubMed

    Häyry, M

    1991-06-01

    In this paper three questions concerning quality of life in medicine and health care are analysed and discussed: the motives for measuring the quality of life, the methods used in assessing it, and the definition of the concept. The purposes of the study are to find an ethically acceptable motive for measuring the quality of life; to identify the methodological advantages and disadvantages of the most prevalent current methods of measurement; and to present an approach towards measuring and defining the quality of life which evades the difficulties encountered and discussed. The analysis comprises measurements both in the clinical situation concerning individual patients and in research concerning whole populations. Three motives are found for evaluating the quality of human life: allocation of scarce medical resources, facilitating clinical decision making, and assisting patients towards autonomous decision making. It is argued that the third alternative is the only one which does not evoke ethical problems. As for the methods of evaluation, several prevalent alternatives are presented, ranging from scales of physical performance to more subtle psychological questionnaires. Clinical questionnaires are found to fail to provide a scientific foundation for universally measuring the quality of life. Finally, the question of definition is tackled. The classical distinction between need-based and want-based theories of human happiness is presented and discussed. The view is introduced and defended that neither of these approaches can be universally preferred to the other. The difficulty with the need approach is that it denies the subjective aspects of human life; whereas the problem of the want approach is that it tends to ignore some of the objective realities of the human existence. In conclusion, it is argued that the choice of methods as well as definitions should be left to the competent patients themselves--who are entitled, if they so wish, to surrender the

  18. Simultaneous measurement of gravity acceleration and gravity gradient with an atom interferometer

    SciTech Connect

    Sorrentino, F.; Lien, Y.-H.; Rosi, G.; Tino, G. M.; Bertoldi, A.; Bodart, Q.; Cacciapuoti, L.; Angelis, M. de; Prevedelli, M.

    2012-09-10

    We demonstrate a method to measure the gravitational acceleration with a dual cloud atom interferometer; the use of simultaneous atom interferometers reduces the effect of seismic noise on the gravity measurement. At the same time, the apparatus is capable of accurate measurements of the vertical gravity gradient. The ability to determine the gravity acceleration and gravity gradient simultaneously and with the same instrument opens interesting perspectives in geophysical applications.

  19. Microwave measurements of azimuthal asymmetries in accelerating fields of disk-loaded waveguides

    SciTech Connect

    Loew, G.A.; Deruyter, H.; Defa, W.

    1983-03-01

    This paper presents microwave measurements of azimuthal asymmetries in the accelerating fields of the SLAC disk-loaded waveguide. These field asymmetries lead to rf phase-dependent beam steering which can be detrimental to operation of linear accelerators in general and of the SLAC Linear Collider in particular.

  20. Improved VLBI measurement of the solar system acceleration

    NASA Astrophysics Data System (ADS)

    Titov, O.; Lambert, S.

    2013-11-01

    Aims: We propose new estimates of the secular aberration drift, which is mainly caused by the rotation of the solar system about the Galactic center, based on up-to-date VLBI observations and improved method of outlier elimination. Methods: We fitted degree-2 vector spherical harmonics to the extragalactic radio source proper motion field derived from geodetic VLBI observations during 1979-2013. We paid particular attention to the outlier elimination procedure that removes outliers from (i) radio source coordinate time series and (ii) the proper motion sample. Results: We obtain more accurate values of the Solar system acceleration than in our previous paper. The acceleration vector is oriented towards the Galactic center within ~7°. The component perpendicular to the Galactic plane is statistically insignificant. We show that an insufficient cleaning of the data set can lead to strong variations in the dipole amplitude and orientation, and hence to statistically biased results. Proper motion data used for the DR solution is only available in electronic form at the CDS via anonymous ftp to http://cdsarc.u-strasbg.fr (ftp://130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/559/A95

  1. MEASUREMENTS OF THE CORONAL ACCELERATION REGION OF A SOLAR FLARE

    SciTech Connect

    Krucker, Saem; Hudson, H. S.; Glesener, L.; Lin, R. P.; White, S. M.; Masuda, S.; Wuelser, J.-P.

    2010-05-10

    The Reuven Ramaty High Energy Solar Spectroscopic Imager (RHESSI) and the Nobeyama Radioheliograph (NoRH) are used to investigate coronal hard X-ray and microwave emissions in the partially disk-occulted solar flare of 2007 December 31. The STEREO mission provides EUV images of the flare site at different viewing angles, establishing a two-ribbon flare geometry and occultation heights of the RHESSI and NoRH observations of {approx}16 Mm and {approx}25 Mm, respectively. Despite the occultation, intense hard X-ray emission up to {approx}80 keV occurs during the impulsive phase from a coronal source that is also seen in microwaves. The hard X-ray and microwave source during the impulsive phase is located {approx}6 Mm above thermal flare loops seen later at the soft X-ray peak time, similar in location to the above-the-loop-top source in the Masuda flare. A single non-thermal electron population with a power-law distribution (with spectral index of {approx}3.7 from {approx}16 keV up to the MeV range) radiating in both bremsstrahlung and gyrosynchrotron emission can explain the observed hard X-ray and microwave spectrum, respectively. This clearly establishes the non-thermal nature of the above-the-loop-top source. The large hard X-ray intensity requires a very large number (>5 x 10{sup 35} above 16 keV for the derived upper limit of the ambient density of {approx}8 x 10{sup 9} cm{sup -3}) of suprathermal electrons to be present in this above-the-loop-top source. This is of the same order of magnitude as the number of ambient thermal electrons. We show that collisional losses of these accelerated electrons would heat all ambient electrons to superhot temperatures (tens of keV) within seconds. Hence, the standard scenario, with hard X-rays produced by a beam comprising the tail of a dominant thermal core plasma, does not work. Instead, all electrons in the above-the-loop-top source seem to be accelerated, suggesting that the above-the-loop-top source is itself the

  2. Longitudinal impedance measurement of an RK-TBA induction accelerating gap

    SciTech Connect

    Eylon, S.; Henestroza, E.; Kim, J.-S.; Houck, T.L.; Westenskow, G.A.; Yu, S.S.

    1997-05-01

    Induction accelerating gap designs are being studied for Relativistic Klystron Two-Beam Accelerator (RK-TBA) applications. The accelerating gap has to satisfy the following major requirements: hold-off of the applied accelerating voltage pulse, low transverse impedance to limit beam breakup, low longitudinal impedance at the beam-modulation frequency to minimize power loss. Various gap geometries, materials and novel insulating techniques were explored to optimize the gap design. We report on the experimental effort to evaluate the rf properties of the accelerating gaps in a simple pillbox cavity structure. The experimental cavity setup was designed using the AMOS, MAFIA and URMEL numerical codes. Longitudinal impedance measurements above beam-tube cut-off frequency using a single-wire measuring system are presented.

  3. Method for direct measurement of cosmic acceleration by 21-cm absorption systems.

    PubMed

    Yu, Hao-Ran; Zhang, Tong-Jie; Pen, Ue-Li

    2014-07-25

    So far there is only indirect evidence that the Universe is undergoing an accelerated expansion. The evidence for cosmic acceleration is based on the observation of different objects at different distances and requires invoking the Copernican cosmological principle and Einstein's equations of motion. We examine the direct observability using recession velocity drifts (Sandage-Loeb effect) of 21-cm hydrogen absorption systems in upcoming radio surveys. This measures the change in velocity of the same objects separated by a time interval and is a model-independent measure of acceleration. We forecast that for a CHIME-like survey with a decade time span, we can detect the acceleration of a ΛCDM universe with 5σ confidence. This acceleration test requires modest data analysis and storage changes from the normal processing and cannot be recovered retroactively. PMID:25105607

  4. Measurement Techniques and Instruments Suitable for Life-prediction Testing of Photovoltaic Arrays

    NASA Technical Reports Server (NTRS)

    Noel, G. T.; Wood, V. E.; Mcginniss, V. D.; Hassell, J. A.; Richard, N. A.; Gaines, G. B.; Carmichael, D. C.

    1979-01-01

    The validation of a 20-year service life for low-cost photovoltaic arrays is a critical requirement in the Low-Cost Solar Array (LSA) Project. The validation is accomplished through accelerated life-prediction tests. A two-phase study was conducted to address the needs before such tests are carried out. The results and recommended techniques from the Phase 1 investigation are summarized in the appendix. Phase 2 of the study is covered in this report and consisted of experimental evaluations of three techniques selected from these recommended as a results of the Phase 1 findings. The three techniques evaluated were specular and nonspecular optical reflectometry, chemiluminescence measurements, and electric current noise measurements.

  5. First measurements of laser-accelerated proton induced luminescence

    SciTech Connect

    Floquet, V.; Ceccotti, T.; Dobosz Dufrenoy, S.; Bonnaud, G.; Monot, P.; Martin, Ph.; Gremillet, L.

    2012-09-15

    We present our first results about laser-accelerated proton induced luminescence in solids. In the first part, we describe the optimization of the proton source as a function of the target thickness as well as the laser pulse duration and energy. Due to the ultra high contrast ratio of our laser beam, we succeeded in using targets ranging from the micron scale down to nanometers thickness. The two optimal thicknesses we put in evidence are in good agreement with numerical simulations. Laser pulse duration shows a small influence on proton maximum energy, whereas the latter turns out to vary almost linearly as a function of laser energy. Thanks to this optimisation work, we have been able to acquire images of the proton energy deposition in a solid scintillator.

  6. Using Second Life to enhance ACCEL an online accelerated nursing BSN program.

    PubMed

    Stewart, Stephanie; Pope, Dawn; Duncan, Debra

    2009-01-01

    To create a presence in Second Life (SL) the university college of nursing (CON) purchased four virtual islands in December 2007. The intent was to enhance distance education with immersion learning experiences for nursing students in SL. The Pollock Alumni House, classrooms, faculty offices, a library, a student welcome center, a public health office, a disaster scenario, a clinic, a hospital, and several patient avatars were created. Houses are being built for nursing students to experience different patient care scenarios during home visits. At least 20 nursing faculty and academic staff and three cohorts of accelerated nursing students (77) have avatars and have experienced class sessions. Faculty and students schedule office hours, engage in synchronous chats, and utilize the public health department and SL support groups for class exercises. Current exercises in the public health department include a module in which the student learns the role of the sanitarian. Students use a checklist to inspect restaurants and bars in SL. They are also able to view a video of an interview with a sanitarian. Another module introduces them to the WIC (Women, Infants, and Children) program. Future student activities related to public health include disaster planning, bioterrorism, evacuations, community assessment, windshield surveys, fund raising, and health education as well as other activities suggested by public health nurses and students. The possibilities are limitless because of the resources that exist in the virtual world, SL. The purchase of the first two islands, the initial buildings, and the creation of the public health department was funded by a research grant. Virtual environments offer many advantages for nursing education. Many nursing students say they learn best when they actually "do something," which indicates that they often prefer experiential learning. Rare but life-threatening patient situations can be experienced since the clinical environment can

  7. An integrated fingerprinting and kinetic approach to accelerated shelf-life testing of chemical changes in thermally treated carrot puree.

    PubMed

    Kebede, Biniam T; Grauwet, Tara; Magpusao, Johannes; Palmers, Stijn; Michiels, Chris; Hendrickx, Marc; Loey, Ann Van

    2015-07-15

    To have a better understanding of chemical reactions during shelf-life, an integrated analytical and engineering toolbox: "fingerprinting-kinetics" was used. As a case study, a thermally sterilised carrot puree was selected. Sterilised purees were stored at four storage temperatures as a function of time. Fingerprinting enabled selection of volatiles clearly changing during shelf-life. Only these volatiles were identified and studied further. Next, kinetic modelling was performed to investigate the suitability of these volatiles as quality indices (markers) for accelerated shelf-life testing (ASLT). Fingerprinting enabled selection of terpenoids, phenylpropanoids, fatty acid derivatives, Strecker aldehydes and sulphur compounds as volatiles clearly changing during shelf-life. The amount of Strecker aldehydes increased during storage, whereas the rest of the volatiles decreased. Out of the volatiles, based on the applied kinetic modelling, myristicin, α-terpinolene, β-pinene, α-terpineol and octanal were identified as potential markers for ASLT. PMID:25722143

  8. An accelerated life test model for solid lubricated bearings based on dependence analysis and proportional hazard effect

    NASA Astrophysics Data System (ADS)

    Zhang, Chao; Wang, Shaoping; Bai, Guanghan

    2014-02-01

    Solid lubricated bearings are important mechanical components in space, and accelerated life tests (ALT) of them are widely conducted. ALT model is needed to give the lifetime of solid lubricated bearings with ALT data, and former accelerated life test models of solid lubricated models are mainly statistical models, while physical models can imply an understanding of the failure mechanism and are preferred whenever possible. This paper proposes a physical model, which is called copula dependent proportional hazards model. A solid lubricated bearing is considered as a system consisting of several dependent items and Clayton copula function is used to describe the dependence. Proportional hazard effect is also considered to build the model. An ALT of solid lubricated bearing is carried out and the results show that this model is effective.

  9. Gadolinium-148 and other spallation production cross section measurements for accelerator target facilities

    NASA Astrophysics Data System (ADS)

    Kelley, Karen Corzine

    At the Los Alamos Neutron Science Center accelerator complex, protons are accelerated to 800 MeV and directed to two tungsten targets, Target 4 at the Weapons Neutron Research facility and the 1L target at the Lujan Center. The Department of Energy requires hazard classification analyses to be performed on these targets and places limits on certain radionuclide inventories in the targets to avoid characterizing the facilities as "nuclear facilities." Gadolinium-148 is a radionuclide created from the spallation of tungsten. Allowed isotopic inventories are particularly low for this isotope because it is an alpha-particle emitter with a 75-year half-life. The activity level of Gadolinium-148 is low, but it encompasses almost two-thirds of the total dose burden for the two tungsten targets based on present yield estimates. From a hazard classification standpoint, this severely limits the lifetime of these tungsten targets. The cross section is not well-established experimentally and this is the motivation for measuring the Gadolinium-148 production cross section from tungsten. In a series of experiments at the Weapons Neutron Research facility, Gadolinium-148 production was measured for 600- and 800-MeV protons on tungsten, tantalum, and gold. These experiments used 3 mum thin tungsten, tantalum, and gold foils and 10 mum thin aluminum activation foils. In addition, spallation yields were determined for many short-lived and long-lived spallation products with these foils using gamma and alpha spectroscopy and compared with predictions of the Los Alamos National Laboratory codes CEM2k+GEM2 and MCNPX. The cumulative Gadolinium-148 production cross section measured from tantalum, tungsten, and gold for incident 600-MeV protons were 15.2 +/- 4.0, 8.31 +/- 0.92, and 0.591 +/- 0.155, respectively. The average production cross sections measured at 800 MeV were 28.6 +/- 3.5, 19.4 +/- 1.8, and 3.69 +/- 0.50 for tantalum, tungsten, and gold, respectively. These cumulative

  10. Precision half-life measurement of 17F

    NASA Astrophysics Data System (ADS)

    Brodeur, M.; Nicoloff, C.; Ahn, T.; Allen, J.; Bardayan, D. W.; Becchetti, F. D.; Gupta, Y. K.; Hall, M. R.; Hall, O.; Hu, J.; Kelly, J. M.; Kolata, J. J.; Long, J.; O'Malley, P.; Schultz, B. E.

    2016-02-01

    Background: The precise determination of f t values for superallowed mixed transitions between mirror nuclide are gaining attention as they could provide an avenue to test the theoretical corrections used to extract the Vu d matrix element from superallowed pure Fermi transitions. The 17F decay is particularly interesting as it proceeds completely to the ground state of 17O, removing the need for branching ratio measurements. The dominant uncertainty on the f t value of the 17F mirror transition stems from a number of conflicting half-life measurements. Purpose: A precision half-life measurement of 17F was performed and compared to previous results. Methods: The life-time was determined from the β counting of implanted 17F on a Ta foil that was removed from the beam for counting. The 17F beam was produced by transfers reaction and separated by the TwinSol facility of the Nuclear Science Laboratory of the University of Notre Dame. Results: The measured value of t1/2 new=64.402 (42) s is in agreement with several past measurements and represents one of the most precise measurements to date. In anticipation of future measurements of the correlation parameters for the decay and using the new world average t1/2 world=64.398 (61) s, we present a new estimate of the mixing ratio ρ for the mixed transition as well as the correlation parameters based on assuming Standard Model validity. Conclusions: The relative uncertainty on the new world average for the half-life is dominated by the large χ2=31 of the existing measurements. More precision measurements with different systematics are needed to remedy to the situation.

  11. Measuring the returns to NASA life sciences research and development

    NASA Astrophysics Data System (ADS)

    Hertzfeld, Henry R.

    1998-01-01

    The National Aeronautics and Space Administration has invested in R&D in the life sciences for forty years. The thrust of this investment has been directed toward the support of human beings in space flight and in space activities. There are many documented examples of beneficial services and products now used in everyday life and medical practice that can be traced to origins in the R&D of the space program. However, a framework for quantitatively documenting, characterizing, and analyzing these public benefits has eluded researchers. This paper will present the results of a pilot project that includes the development of a methodology for assessing the economic benefits from NASA life sciences R&D and for realistically evaluating the financial leverage that private companies which are either involved in NASA R&D or which have ``bootstrapped'' NASA R&D into commercial products have realized. The results will show that the NASA life sciences investments are more engineering oriented, and more typically show results in the fields of instrumentation and medical devices. This is substantially different in nature from the focus of the National Institutes of Health, which is organized around the diagnosis and treatment of diseases. The appropriate measures of benefits for engineering-oriented products are economic parameters that focus on capital equipment. NIH benefits are more typically measured by human labor parameters, including the much more difficult to quantify measures of the quality and delivery of medical services. Although there is tremendous overlap in the goals and outputs of NASA life sciences and NIH investments, and NASA R&D is also very concerned with human beings and the quality of life, NIH is the overwhelming large source of life sciences R&D funds in the US. NASA has a special niche in life sciences R&D that supports the NASA mission as well as overall research issues in the life sciences. This paper evaluates the economic benefits of NASA's life

  12. FERTILITY INTENTIONS AND EARLY LIFE HEALTH STRESS AMONG WOMEN IN EIGHT INDIAN CITIES: TESTING THE REPRODUCTIVE ACCELERATION HYPOTHESIS.

    PubMed

    Kulathinal, Sangita; Säävälä, Minna

    2015-09-01

    In life history theory, early life adversity is associated with an accelerated reproductive tempo. In harsh and unpredictable conditions in developing societies fertility is generally higher and the reproductive tempo faster than in more secure environments. This paper examines whether differences in female anthropometry, particularly adult height, are associated with fertility intentions of women in urban environments in India. The study population consists of women aged 15-29 (N=4485) in slums and non-slums of eight Indian cities in the National Family Health Survey (NFHS) of 2005-2006. Adult height is taken as a proxy for early childhood health and nutritional condition. Fertility intentions are examined by using two variables: the desire to have a child or another child, and to have it relatively soon, as indicative of accelerated reproductive scheduling. Evidence supporting the acceleration hypothesis is found in two urban frames out of 26 examined in a two-staged multinomial logistic model. In three cases, the relationship between fertility intentions and height is the opposite than expected by the acceleration hypothesis: taller women have a higher predictive probability of desiring a(nother) child and/or narrower birth spacing. Potential explanations for the partly contradictory relationship between the childhood health indicator and fertility intentions are discussed. PMID:25115228

  13. Standardisation and half-life measurements of (111)In.

    PubMed

    Dziel, Tomasz; Listkowska, Anna; Tymiński, Zbigniew

    2016-03-01

    The standardisation of (111)In by 4π(LS)-γ coincidence and anticoincidence counting is presented. Absolute measurements were performed for samples with different concentrations of carrier solution and for different window settings in the gamma channel. The radioactive concentration of the master solution determined on the same reference date was consistent for all measurements performed. The evaluated typical uncertainty was 0.43%. The half-life of (111)In was determined using a time series of measurements performed with an ionisation chamber. A least squares fit of the measured data resulted in a half-life of 2.8067 (34) days consistent with Decay Data Evaluation Project recommended value (0.064% higher than the DDEP value). PMID:26651174

  14. Measuring Students' Metacognition in Real-Life Situations

    ERIC Educational Resources Information Center

    Al-Hilawani, Yasser A.

    2003-01-01

    Metacognitive Performance of four groups of students (hearing high-achieving, hearing average-achieving, hearing underachieving, and deaf and hard of hearing) in first through third grade in the United Arab Emirates was examined and compared. Metacognition was measured using analyses of pictures depicting real-life problematic events, situations,…

  15. Optical Measurements of Dense Hypervelocity Plasmoids from Coaxial and Railgun Plasma Accelerators

    NASA Astrophysics Data System (ADS)

    Case, Andrew; Messer, Sarah; Bomgardner, Richard; Brockington, Samuel; Witherspoon, Douglas; Elton, Ray

    2009-11-01

    High velocity dense plasma jets are under continued experimental development for fusion applications including refueling, disruption mitigation, momentum injection/rotation drive, and magnetized target fusion. We present measurements taken on the plasmoids produced by a half-scale coaxial plasmoid accelerator, a full scale coaxial plasmoid accelerator, and a novel minirailgun accelerator. The data presented includes spectroscopic measurements of velocity and density, two point interferometric measurements of line integrated density and velocity, and fast framing camera imaging. Results from these measurements are in agreement with each other and with time of flight measurements taken using photodiodes, as well as total plasmoid momentum measurements taken using a ballistic pendulum technique. Plasma density is greater than 5 x10^15 cm-3, and velocities range up to 100 km/s, with a small component in some cases exceeding 120 km/s.

  16. Measuring Replicative Life Span in the Budding Yeast

    PubMed Central

    Steffen, Kristan K.; Kennedy, Brian K.; Kaeberlein, Matt

    2009-01-01

    Aging is a degenerative process characterized by a progressive deterioration of cellular components and organelles resulting in mortality. The budding yeast Saccharomyces cerevisiae has been used extensively to study the biology of aging, and several determinants of yeast longevity have been shown to be conserved in multicellular eukaryotes, including worms, flies, and mice 1. Due to the lack of easily quantified age-associated phenotypes, aging in yeast has been assayed almost exclusively by measuring the life span of cells in different contexts, with two different life span paradigms in common usage 2. Chronological life span refers to the length of time that a mother cell can survive in a non-dividing, quiescence-like state, and is proposed to serve as a model for aging of post-mitotic cells in multicellular eukaryotes. Replicative life span, in contrast, refers the number of daughter cells produced by a mother cell prior to senescence, and is thought to provide a model of aging in mitotically active cells. Here we present a generalized protocol for measuring the replicative life span of budding yeast mother cells. The goal of the replicative life span assay is to determine how many times each mother cell buds. The mother and daughter cells can be easily differentiated by an experienced researcher using a standard light microscope (total magnification 160X), such as the Zeiss Axioscope 40 or another comparable model. Physical separation of daughter cells from mother cells is achieved using a manual micromanipulator equipped with a fiber-optic needle. Typical laboratory yeast strains produce 20-30 daughter cells per mother and one life span experiment requires 2-3 weeks. PMID:19556967

  17. ACCELERATORS: A GUI tool for beta function measurement using MATLAB

    NASA Astrophysics Data System (ADS)

    Chen, Guang-Ling; Tian, Shun-Qiang; Jiang, Bo-Cheng; Liu, Gui-Min

    2009-04-01

    The beta function measurement is used to detect the shift in the betatron tune as the strength of an individual quadrupole magnet is varied. A GUI (graphic user interface) tool for the beta function measurement is developed using the MATLAB program language in the Linux environment, which facilitates the commissioning of the Shanghai Synchrotron Radiation Facility (SSRF) storage ring. In this paper, we describe the design of the application and give some measuring results and discussions about the definition of the measurement. The program has been optimized to solve some restrictions of the AT tracking code. After the correction with LOCO (linear optics from closed orbits), the horizontal and the vertical root mean square values (rms values) can be reduced to 0.12 and 0.10.

  18. Thrust Stand Measurements Using Alternative Propellants in the Microwave Assisted Discharge Inductive Plasma Accelerator

    NASA Technical Reports Server (NTRS)

    Hallock, Ashley K.; Polzin, Kurt A.

    2011-01-01

    Storable propellants (for example water, ammonia, and hydrazine) are attractive for deep space propulsion due to their naturally high density at ambient interplanetary conditions, which obviates the need for a cryogenic/venting system. Water in particular is attractive due to its ease of handling and availability both terrestrially and extra-terrestrially. While many storable propellants are reactive and corrosive, a propulsion scheme where the propellant is insulated from vulnerable (e.g. metallic) sections of the assembly would be well-suited to process these otherwise incompatible propellants. Pulsed inductive plasma thrusters meet this criterion because they can be operated without direct propellant-electrode interaction. During operation of these devices, electrical energy is capacitively stored and then discharged through an inductive coil creating a time-varying current in the coil that interacts with a plasma covering the face of the coil to induce a plasma current. Propellant is accelerated and expelled at a high exhaust velocity (O(10-100 km/s)) by the Lorentz body force arising from the interaction of the magnetic field and the induced plasma current. While this class of thruster mitigates the life-limiting issues associated with electrode erosion, many pulsed inductive plasma thrusters require high pulse energies to inductively ionize propellant. The Microwave Assisted Discharge Inductive Plasma Accelerator (MAD-IPA) is a pulsed inductive plasma thruster that addressees this issue by partially ionizing propellant inside a conical inductive coil before the main current pulse via an electron cyclotron resonance (ECR) discharge. The ECR plasma is produced using microwaves and a static magnetic field from a set of permanent magnets arranged to create a thin resonance region along the inner surface of the coil, restricting plasma formation, and in turn current sheet formation, to a region where the magnetic coupling between the plasma and the theta

  19. Measuring the angular dependence of betatron x-ray spectra in a laser-wakefield accelerator

    SciTech Connect

    Albert, F.; Pollock, B. B.; Shaw, J. L.; Marsh, K. A.; Ralph, J. E.; Chen, Y. -H.; Alessi, D.; Pak, A.; Clayton, C. E.; Glenzer, S. H.; Joshi, C.

    2014-07-22

    This paper presents a new technique to measure the angular dependence of betatron x-ray spectra in a laser-wakefield accelerator. Measurements are performed with a stacked image plates spectrometer, capable of detecting broadband x-ray radiation up to 1 MeV. It can provide measurements of the betatron x-ray spectrum at any angle of observation (within a 40 mrad cone) and of the beam profile. A detailed description of our data analysis is given, along with comparison for several shots. As a result, these measurements provide useful information on the dynamics of the electrons are they are accelerated and wiggled by the wakefield.

  20. Kaonic atoms measurements at the DAFNE accelerator: the SIDDHARTA experiment

    NASA Astrophysics Data System (ADS)

    Rizzo, A.; Bazzi, M.; Beer, G.; Berucci, C.; Bombelli, L.; Bragadireanu, A. M.; Cargnelli, M.; Curceanu (Petrascu, C.; Corradi, G.; dUffizi, A.; Fiorini, C.; Frizzi, T.; Ghio, F.; Guaraldo, C.; Hayano, R. S.; Iliescu, M.; Ishiwatari, T.; Iwasaki, M.; Kienle, P.; Levi Sandri, P.; Longoni, A.; Lucherini, V.; Marton, J.; Okada, S.; Pietreanu, D.; Ponta, T.; Romero Vidal, A.; Sbardella, E.; Scordo, A.; Shi, H.; Sirghi, D. L.; Sirghi, F.; Tatsuno, H.; Tudorache, A.; Tudorache, V.; Vazquez Doce, O.; Widmann, E.; Wunschek, B.; Zmeskal, J.

    2012-03-01

    Kaonic Hydrogen and Helium X-ray measurements play nowadays a fundamental role in testing the reliability of the Chiral Perturbation Theory as a realisation of the Quantum Chromodynamics at low energies. Dictated by both electromagnetic and strong interaction, X-ray transitions at lower energy levels of these complex bound systems offer indeed the unique opportunity to perform a threshold measurements of zero-energy meson-nucleon scattering. Nowadays the SIDDHARTA experiment at DAFNE collider is the only apparatus which can provide such kind of measurements with the high precision needed to disentangle different theoretical calculation scenarios. In this work we present the SIDDHARTA experiment performances and results, with a focus on the main topics of light kaonic atom physics.

  1. Systems approach to measuring short-duration acceleration transients

    NASA Astrophysics Data System (ADS)

    Schelby, F.

    A shock measurement system was developed in which the quartz seismic system, two poole active filter and an FET source follower are incorporated in a transducer housing. It is shown that the system will survive + or 100,000g without damage. The PCB can supply different ranges as required. The PCB Model 305M23, can obtain data comparable to those of standard piezoelectric and piezoresistive accelerometers when high frequencies are absent. In the presence of high frequency stimuli, the accelerometer has obtained data without over ranging its data channel and without introducing error signals from excitation of the resonant frequency of its seismic system. It is useful for impact and pyrotechnic measurements. The development effort and test program have enhanced the probability of acquiring successful structural measurements in harsh mechanical loading environments.

  2. Vacuum measurements of the K500 cyclotron accelerator chamber

    SciTech Connect

    Mallory, M.L.; Miller, P.S.; Kuchar, J.; Hudson, E.D.

    1986-01-01

    To evaluate the effectiveness of the unique internal cryopumping system, the pressure in the K500 superconducting cyclotron was measured as a function of radius for various gas flow rates emanating from the internal PIG source. For the test, a nude ion gauge with vertical dimension less than 2.3 cm was built and mounted on the internal beam probe. The effect of magnetic field on the ion gauge reading was determined and a method of degaussing the cyclotron was devised. Data from the normal shielded ion gauge located approximately 6 m away from the median plane was correlated with the internal vacuum measurements.

  3. Accelerator mass spectrometry measurements of natural and anthropogenic Cl-36

    SciTech Connect

    Sharma, P.; Gove, H.E.; Fehn, U.

    1993-04-01

    Radioactive chlorine-36 (half-life = 301,000 years) is produced by cosmic-ray induced spallation reactions in the Earth`s atmosphere and in surface rocks and through thermal neutron activation of stable chlorine-35 in the Earth`s crust. A large amount of chlorine-36 was introduced into the atmosphere and hydrosphere during nuclear weapon tests in the 1950`s and 1960`s (the so called {open_quotes}bomb pulse{close_quotes}). Additional sources of anthropogenic Cl-36 in the environment are activities associated with the nuclear power cycle. Results of three recent applications of chlorine-36 will be presented and discussed: (1) study of the dynamics of water movement and radioactive contaminants from nuclear fuel reprocessing plants at Savannah River Site, South Carolina and Idaho National Engineering Laboratory, Idaho Falls, Idaho, (2) investigation of potential water movement through the unsaturated zone at Yucca Mountain (a possible site for high level radioactive waste disposal), and (3) deciphering past variations in cosmic radiation using ancient packrat urine from Nevada.

  4. New Measurement of the 60Fe Half-Life.

    PubMed

    Rugel, G; Faestermann, T; Knie, K; Korschinek, G; Poutivtsev, M; Schumann, D; Kivel, N; Günther-Leopold, I; Weinreich, R; Wohlmuther, M

    2009-08-14

    We have made a new determination of the half-life of the radioactive isotope 60Fe using high precision measurements of the number of 60Fe atoms and their activity in a sample containing over 10(15) 60Fe atoms. Our new value for the half-life of 60Fe is (2.62+/-0.04) x 10(6) yr, significantly above the previously reported value of (1.49+/-0.27) x 10(6) yr. Our new measurement for the lifetime of 60Fe has significant implications for interpretations of galactic nucleosynthesis, for determinations of formation time scales of solids in the early Solar System, and for the interpretation of live 60Fe measurements from supernova-ejecta deposits on Earth. PMID:19792637

  5. Measurement of Gravitational Acceleration Using a Computer Microphone Port

    ERIC Educational Resources Information Center

    Khairurrijal; Eko Widiatmoko; Srigutomo, Wahyu; Kurniasih, Neny

    2012-01-01

    A method has been developed to measure the swing period of a simple pendulum automatically. The pendulum position is converted into a signal frequency by employing a simple electronic circuit that detects the intensity of infrared light reflected by the pendulum. The signal produced by the electronic circuit is sent to the microphone port and…

  6. Systems approach to measuring short-duration acceleration transients

    SciTech Connect

    Schelby, F.

    1983-01-01

    A shock measurement system has been developed in which the quartz seismic system, two-poole active filter and an FET source follower are incorporated in a transducer housing measuring 5/16'' hex.x 5/8''. Tests have shown that the system will survive +- 100,000g without damage. Although the results reported here are for accelerometers ranged to +- 20,000g, there is no reason to limit the accelerometers to that range and PCB can supply different ranges as required. The PCB Model 305M23, developed to Sandia's specifications, has proved capable of obtaining data comparable to that of standard piezoelectric and piezoresistive accelerometers when high frequencies are absent. In the presence of high frequency stimuli, the accelerometer has obtained data without over-ranging its data channel and without introducing error signals from excitation of the resonant frequency of its seismic system. It should, therefore, be especially useful for impact and pyrotechnic measurements. These shock accelerometers are in the process of being fielded in earth penetrator vehicles; in shale rubblization experiments will soon be available. It appears this joint development effort and test program has greatly enhanced the probability of acquiring successful structural measurements in harsh mechanical loading environments.

  7. Optics measurement and correction during acceleration with beta-squeeze in RHIC

    SciTech Connect

    Liu, C.; Marusic, A.; Minty, M.

    2015-05-03

    In the past, beam optics correction at RHIC has only taken place at injection and at final energy, with interpolation of corrections partially into the acceleration cycle. Recent measurements of the beam optics during acceleration and squeeze have evidenced significant beta-beats that, if corrected, could minimize undesirable emittance dilutions and maximize the spin polarization of polarized proton beams by avoiding the high-order multipole fields sampled by particles within the bunch. We recently demonstrated successful beam optics corrections during acceleration at RHIC. We verified conclusively the superior control of the beam realized via these corrections

  8. 2D electron density profile measurement in tokamak by laser-accelerated ion-beam probe

    SciTech Connect

    Chen, Y. H.; Yang, X. Y.; Lin, C. E-mail: cjxiao@pku.edu.cn; Wang, X. G.; Xiao, C. J. E-mail: cjxiao@pku.edu.cn; Wang, L.; Xu, M.

    2014-11-15

    A new concept of Heavy Ion Beam Probe (HIBP) diagnostic has been proposed, of which the key is to replace the electrostatic accelerator of traditional HIBP by a laser-driven ion accelerator. Due to the large energy spread of ions, the laser-accelerated HIBP can measure the two-dimensional (2D) electron density profile of tokamak plasma. In a preliminary simulation, a 2D density profile was reconstructed with a spatial resolution of about 2 cm, and with the error below 15% in the core region. Diagnostics of 2D density fluctuation is also discussed.

  9. Unsupervised classification of Space Acceleration Measurement System (SAMS) data using ART2-A

    NASA Technical Reports Server (NTRS)

    Smith, A. D.; Sinha, A.

    1999-01-01

    The Space Acceleration Measurement System (SAMS) has been developed by NASA to monitor the microgravity acceleration environment aboard the space shuttle. The amount of data collected by a SAMS unit during a shuttle mission is in the several gigabytes range. Adaptive Resonance Theory 2-A (ART2-A), an unsupervised neural network, has been used to cluster these data and to develop cause and effect relationships among disturbances and the acceleration environment. Using input patterns formed on the basis of power spectral densities (psd), data collected from two missions, STS-050 and STS-057, have been clustered.

  10. Numerical design and model measurements for a 1.3 GHz microtron accelerating cavity

    NASA Astrophysics Data System (ADS)

    Kleeven, W. J. G. M.; Theeuwen, M. E. H. J.; Knoben, M. H. M.; Moerdijk, A. J.; Botman, J. I. M.; van der Heide, J. A.; Timmermans, C. J.; Hagedoorn, H. L.

    1992-05-01

    As part of the free electron laser project TEUFEL, a 25 MeV racetrack microtron is under construction at the Eindhoven University. The accelerating cavity of this microtron is a standing wave on axis coupled structure. It consists of three accelerating cells and two coupling cells. Numerical field calculations for this cavity were done with the computer codes SUPERFISH, URMEL-T and MAFIA. Not only the accelerating modes but also the dangerous beam breakup modes were calculated with MAFIA. An aluminium, scale 1:1 model of the structure was made in order to measure various cavity properties. Field profiles were measured with the perturbation ball method. An equivalent LC-circuit simulation of the accelerating structure was made, which serves as a model for the interpretation of the results.

  11. Accelerated measurement of perikymata by an optical instrument

    PubMed Central

    Elhechmi, Imen; Braga, José; Dasgupta, Gautam; Gharbi, Tijani

    2013-01-01

    The proposed device considerably reduces the measuring time of important microscopic features of tooth crown surfaces. The instrumentation is accompanied by a computer program to analyse the results. Tooth enamel is formed by ameloblasts, which demonstrate daily secretory rhythms developing tissue-specific structures known as cross striations, and longer period markings that are referred as striae of Retzius. These striae correspond to linear structures on the enamel surface. This newly developed optical measuring instrument can automatically, precisely and accurately record the number and periodicity of perikymata on the dental crown. Furthermore it can characterize the variability in periodicity of perikymata in hominids. The depth of field can be extended as desired by taking several images with different focus positions and combining them into a single composite image that contains all regions fully focused. PMID:24156069

  12. Acceleration of matrix element computations for precision measurements

    SciTech Connect

    Brandt, Oleg; Gutierrez, Gaston; Wang, M. H.L.S.; Ye, Zhenyu

    2014-11-25

    The matrix element technique provides a superior statistical sensitivity for precision measurements of important parameters at hadron colliders, such as the mass of the top quark or the cross-section for the production of Higgs bosons. The main practical limitation of the technique is its high computational demand. Using the example of the top quark mass, we present two approaches to reduce the computation time of the technique by a factor of 90. First, we utilize low-discrepancy sequences for numerical Monte Carlo integration in conjunction with a dedicated estimator of numerical uncertainty, a novelty in the context of the matrix element technique. We then utilize a new approach that factorizes the overall jet energy scale from the matrix element computation, a novelty in the context of top quark mass measurements. The utilization of low-discrepancy sequences is of particular general interest, as it is universally applicable to Monte Carlo integration, and independent of the computing environment.

  13. PRECISION MEASUREMENT OF MUON G-2 AND ACCELERATOR RELATED ISSUES

    SciTech Connect

    BROWN,H.N.; BUNCE,G.; CAREY,R.M.; CUSHMAN,P.; DANBY,G.T.; DEBEVEC,P.T.; DEILE,M.; DENG,H.; DENINGER,W.; DHAWAN,S.K.; ET AL; MENG,W.

    2001-09-21

    A precision measurement of the anomalous g value, a{sub {mu}}=(g-2)/2, for the positive muon has been made using high intensity protons available at the Brookhaven AGS. The result based on the 1999 data a{sub {mu}}=11659202(14)(6) x 10{sup 10} (1.3ppm) is in good agreement with previous measurements and has an error one third that of the combined previous data. The current theoretical value from the standard model is a{sub {mu}} (SM)=11659159.6(6.7) x 10{sup 10} (0.57 ppm) and differ by over 2.5 standard deviation with experiment. Issues with reducing systematic errors and enhancing the injection and storage efficiencies are discussed.

  14. Shelf life of Crescenza cheese as measured by electronic nose.

    PubMed

    Benedetti, S; Sinelli, N; Buratti, S; Riva, M

    2005-09-01

    The shelf life of Crescenza, a traditional Italian soft cheese, was measured using classical analysis and a commercial electronic nose. Two lots of samples directly supplied by a manufacturer at the beginning of their commercial life were stored at 2 constant temperatures (8 and 15 degrees C) and analyzed until their respective expiration dates. Among the physicochemical parameters, pH, acidity, hue, and apparent yield rheological index appeared to be the best predictors of the quality decay. Changes in these indices were described with a sigmoidal transition function allowing definition of a loose and a severe shelf-life protocol, based on the trend of first and second time derivatives. A time range of 1 to 3 d at 15 degrees C and 4 to 8 d at 8 degrees C was accordingly assessed to maintain the freshness of Crescenza cheese. The quality decay of cheese aroma was evaluated by inspecting the headspace fingerprint of the same set of samples using the electronic nose. Sample classification through the aroma fingerprint confirmed the predicted shelf-life time ranges. A clear discrimination between "fresh," "aged," and "very aged" samples was obtained using principal components analysis, cluster analysis, and linear discriminant analysis statistical techniques. The predictive ability of the linear discriminant analysis classification model was confirmed by considering a new set of cheese samples purchased at the beginning of their commercial life from a local market and analyzed until their expiration date. PMID:16107392

  15. Summary Report of Mission Acceleration Measurements for STS-73, Launched October 20, 1995

    NASA Technical Reports Server (NTRS)

    Rogers, Melissa J. B.; DeLombard, Richard

    1996-01-01

    The microgravity environment of the Space Shuttle Columbia was measured during the STS-73 mission using accelerometers from five different instruments: the Orbital Acceleration Research Experiment, the Space Acceleration Measurement System, the Three-dimensional Microgravity Accelerometer, the Microgravity Measuring Device, and Suppression of Transient Accelerations by Levitation Evaluation System. The Microgravity Analysis Workstation quasi-steady environment calculation and comparison of this calculation with Orbital Acceleration Research Experiment data was used to assess how appropriate a planned attitude was expected to be for one Crystal Growth Facility experiment sample. The microgravity environment related to several different Orbiter, crew, and experiment operations is presented and interpreted in this report. Data are examined to show the effects of vernier reaction control system jet firings for Orbiter attitude control. This is compared to examples of data when no thrusters were firing, when the primary reaction control system jets were used for attitude control, and when single vernier jets were fired for test purposes. In general, vernier jets, when used for attitude control, cause accelerations in the 3 x 10(exp -4) g to 7 x 10(exp -4) g range. Primary jets used in this manner cause accelerations in the 0.01 to 0.025 g range. Other significant disturbance sources characterized are water dump operations, with Y(sub b) axis acceleration deviations of about 1 x 10(exp -6) g; payload bay door opening motion, with Y(sub o) and Z(sub o) axis accelerations of frequency 0.4 Hz; and probable Glovebox fan operations with notable frequency components at 20, 38, 43, 48, and 53 Hz. The STS-73 microgravity environment is comparable to the environments measured on earlier microgravity science missions.

  16. 148-Gd cross section measurements for accelerator target facilities

    SciTech Connect

    Corzine, R. K.; Pitcher, E. J.; Devlin, M. J.; Hertel, N. E.

    2002-01-01

    In a series of experiments at LANSCE's WNR facility, 148Gdp roduction was measured for 600- and 800-MeV protons on tungsten, tantalum, and gold. These experiments used 3 pm thin W, Ta, and Au foils and 10 pm thin A1 activation foils, Spallation yields were determined for many short-lived and long-lived spallation products with these foils using gamma and alpha spectroscopy.

  17. Summary Report of Mission Acceleration Measurements for STS-89: Launched January 22, 1998

    NASA Technical Reports Server (NTRS)

    Hrovat, Kenneth; McPherson, Kevin

    1999-01-01

    Support of microgravity research on the 89th flight of the Space Transportation System (STS-89) and a continued effort to characterize the acceleration environment of the Space Shuttle Orbiter and the Mir Space Station form the basis for this report. For the STS-89 mission, the Space Shuttle Endeavour was equipped with a Space Acceleration Measurement System (SAMS) unit, which collected more than a week's worth of data. During docked operations with Mir, a second SAMS unit collected approximately a day's worth of data yielding the only set of acceleration measurements recorded simultaneously on the two spacecraft. Based on the data acquired by these SAMS units, this report serves to characterize a number of acceleration events and quantify their impact on the local nature of the accelerations experienced at the Mechanics of Granular Materials (MGM) experiment location. Crew activity was shown to nearly double the median root-mean-square (RMS) acceleration level calculated below 10 Hz, while the Enhanced Orbiter Refrigerator/Freezer operating at about 22 Hz was a strong acceleration source in the vicinity of the MGM location. The MGM science requirement that the acceleration not exceed q I mg was violated numerous times during their experiment runs; however, no correlation with sample instability has been found to this point. Synchronization between the SAMS data from Endeavour and from Mir was shown to be close much of the time, but caution with respect to exact timing should be exercised when comparing these data. When orbiting as a separate vehicle prior to docking, Endeavour had prominent structural modes above 3 Hz, while Mir exhibited a cluster of modes around 1 Hz. When mated, a transition to common modes was apparent in the two SAMS data sets. This report is not a comprehensive analysis of the acceleration data, so those interested in further details should contact the Principal Investigator Microgravity Services team at the National Aeronautics and Space

  18. Orbiter Aerodynamic Acceleration Flight Measurements in the Rarefied-Flow Transition Regime

    NASA Technical Reports Server (NTRS)

    Blanchard, Robert C.; Wilmoth, Richard G.; LeBeau, Gerald J.

    1996-01-01

    Acceleration data taken from the Orbital Acceleration Research Experiment (OARE) during reentry on STS-62 have been analyzed using calibration factors taken on orbit. This is the first Orbiter mission which collected OARE data during the Orbiter reentry phase. The data examined include the flight regime from orbital altitudes down to about 90 km which covers the free-molecule-flow regime and the upper altitude fringes of the rarefied-flow transition into the hypersonic continuum. Ancillary flight data on Orbiter position, orientation, velocity, and rotation rates have been used in models to transform the measured accelerations to the Orbiter center-of-gravity, from which aerodynamic accelerations along the Orbiter body axes have been calculated. Residual offsets introduced in the measurements by unmodeled Orbiter forces are identified and discussed. Direct comparisons are made between the OARE flight data and an independent micro-gravity accelerometer experiment, the High Resolution Accelerometer Package (HiRAP), which also obtained flight data on reentry during the mission down to about 95 km. The resulting OARE aerodynamic acceleration measurements along the Orbiter's body axis, aid the normal to axial acceleration ratio in the free-molecule-flow and transition-flow regimes are presented and compared with numerical simulations from three direct simulation Monte Carlo codes.

  19. Optics measurement and correction during beam acceleration in the Relativistic Heavy Ion Collider

    SciTech Connect

    Liu, C.; Marusic, A.; Minty, M.

    2014-09-09

    To minimize operational complexities, setup of collisions in high energy circular colliders typically involves acceleration with near constant β-functions followed by application of strong focusing quadrupoles at the interaction points (IPs) for the final beta-squeeze. At the Relativistic Heavy Ion Collider (RHIC) beam acceleration and optics squeeze are performed simultaneously. In the past, beam optics correction at RHIC has taken place at injection and at final energy with some interpolation of corrections into the acceleration cycle. Recent measurements of the beam optics during acceleration and squeeze have evidenced significant beta-beats which if corrected could minimize undesirable emittance dilutions and maximize the spin polarization of polarized proton beams by avoidance of higher-order multipole fields sampled by particles within the bunch. In this report the methodology now operational at RHIC for beam optics corrections during acceleration with simultaneous beta-squeeze will be presented together with measurements which conclusively demonstrate the superior beam control. As a valuable by-product, the corrections have minimized the beta-beat at the profile monitors so reducing the dominant error in and providing more precise measurements of the evolution of the beam emittances during acceleration.

  20. ACCELERATORS: RF system design and measurement of HIRF-CSRe

    NASA Astrophysics Data System (ADS)

    Xu, Zhe; Zhao, Hong-Wei; Wang, Chun-Xiao; Xia, Jia-Wen; Zhan, Wen-Long; Bian, Zhi-Bin

    2009-05-01

    An RF system for the CSRe (cooling storage experimental ring) is designed and manufactured domestically. The present paper mainly describes the RF system design in five main sections: ferrite ring, RF cavity, RF generator, low level system and cavity cooling. The cavity is based on a type of coaxial resonator which is shorted at the end with one gap and loaded with domestic ferrite rings. The RF generator is designed in the push-pull mode and the low level control system is based on a DSP+FGPA+DDS+USB interface and has three feedback loops. Finally we give the results of the measurement on our system.

  1. Wavefront-sensor-based electron density measurements for laser-plasma accelerators

    SciTech Connect

    Plateau, Guillaume; Matlis, Nicholas; Geddes, Cameron; Gonsalves, Anthony; Shiraishi, Satomi; Lin, Chen; van Mourik, Reinier; Leemans, Wim

    2010-02-20

    Characterization of the electron density in laser produced plasmas is presented using direct wavefront analysis of a probe laser beam. The performance of a laser-driven plasma-wakefield accelerator depends on the plasma wavelength, hence on the electron density. Density measurements using a conventional folded-wave interferometer and using a commercial wavefront sensor are compared for different regimes of the laser-plasma accelerator. It is shown that direct wavefront measurements agree with interferometric measurements and, because of the robustness of the compact commercial device, have greater phase sensitivity, straightforward analysis, improving shot-to-shot plasma-density diagnostics.

  2. Acceleration of matrix element computations for precision measurements

    DOE PAGESBeta

    Brandt, Oleg; Gutierrez, Gaston; Wang, M. H.L.S.; Ye, Zhenyu

    2014-11-25

    The matrix element technique provides a superior statistical sensitivity for precision measurements of important parameters at hadron colliders, such as the mass of the top quark or the cross-section for the production of Higgs bosons. The main practical limitation of the technique is its high computational demand. Using the example of the top quark mass, we present two approaches to reduce the computation time of the technique by a factor of 90. First, we utilize low-discrepancy sequences for numerical Monte Carlo integration in conjunction with a dedicated estimator of numerical uncertainty, a novelty in the context of the matrix elementmore » technique. We then utilize a new approach that factorizes the overall jet energy scale from the matrix element computation, a novelty in the context of top quark mass measurements. The utilization of low-discrepancy sequences is of particular general interest, as it is universally applicable to Monte Carlo integration, and independent of the computing environment.« less

  3. Towards a Measurement of the Half-Life of {sup 60}Fe for Stellar and Early Solar System Models

    SciTech Connect

    Ostdiek, K.; Anderson, T.; Bauder, W.; Bowers, M.; Collon, P.; Dressler, R.; Greene, J.; Kutschera, W.; Lu, W.; Paul, M.

    2015-10-15

    Radioisotopes, produced in stars and ejected into the Interstellar Medium, are important for constraining stellar and early Solar System (ESS) models. In particular, the half-life of the radioisotope, Fe-60, can have an impact on calculations for the timing for ESS events, the distance to nearby Supernovae, and the brightness of individual, non-steady-state Fe gamma ray sources in the Galaxy. A half-life measurement has been undertaken at the University of Notre Dame and measurements of the Fe-60/Fe-56 concentration of our samples using Accelerator Mass Spectrometry has begun. This result will be coupled with an activity measurement of the isomeric decay in Co-60, which is the decay product of Fe. Preliminary half-life estimates of (2.53 +/- 0.24) x 10(6) years seem to confirm the recent measurement by Rugel et al. (2009). (C) 2015 Elsevier B.V. All rights reserved.

  4. Measuring students' metacognition in real-life situations.

    PubMed

    al-Hilawani, Yasser A

    2003-01-01

    Metacognitive performance of four groups of students (hearing high-achieving, hearing average-achieving, hearing under achieving, and deaf and hard of hearing) in first through third grade in the United Arab Emirates was examined and compared. Metacognition was measured using analyses of pictures depicting real-life problematic events, situations, and behaviors. Participants drew on their ability to apply problem solving and logical reasoning through visual analysis and discrimination of test materials rather than through verbal analysis. Results revealed that metacognition is influenced by students' age. Older students scored significantly higher on the metacognitive measure than younger students. Further analysis indicated that hearing high-achieving students scored significantly higher on the test than the other three groups when the age variable was controlled for. Deaf and hard of hearing students performed similarly to age-matched hearing students in applying reasoning skills to real-life situations. PMID:14574795

  5. Cross-Section Measurements with the Radioactive Isotope Accelerator (RIA)

    SciTech Connect

    Stoyer, M A; Moody, K J; Wild, J F; Patin, J B; Shaughnessy, D A; Stoyer, N J; Harris, L J

    2002-11-19

    RIA will produce beams of exotic nuclei of unprecedented luminosity. Preliminary studies of the feasibility of measuring cross-sections of interest to the science based stockpile stewardship (SBSS) program will be presented, and several experimental techniques will be discussed. Cross-section modeling attempts for the A = 95 mass region will be shown. In addition, several radioactive isotopes could be collected for target production or medical isotope purposes while the main in-beam experiments are running. The inclusion of a broad range mass analyzer (BRAMA) capability at RIA will enable more effective utilization of the facility, enabling the performance of multiple experiments at the same time. This option will be briefly discussed.

  6. Cross-Section Measurements with the Radioactive Isotope Accelerator (ria)

    NASA Astrophysics Data System (ADS)

    Stoyer, M. A.; Moody, K. J.; Wild, J. F.; Patin, J. B.; Shaughnessy, D. A.; Stoyer, N. J.; Harris, L. J.

    2003-10-01

    RIA will produce beams of exotic nuclei of unprecedented luminosity. Preliminary studies of the feasibility of measuring cross-sections of interest to the science based stockpile stewardship (SBSS) program will be presented, and several experimental techniques will be discussed. Cross-section modeling attempts for the A = 95 mass region will be shown. In addition, several radioactive isotopes could be collected for target production or medical isotope purposes while the main in-beam experiments are running. The inclusion of a broad range mass analyzer (BRAMA) capability at RIA will enable more effective utilization of the facility, enabling the performance of multiple experiments at the same time. This option will be briefly discussed.

  7. Accelerated testing of space batteries

    NASA Technical Reports Server (NTRS)

    Mccallum, J.; Thomas, R. E.; Waite, J. H.

    1973-01-01

    An accelerated life test program for space batteries is presented that fully satisfies empirical, statistical, and physical criteria for validity. The program includes thermal and other nonmechanical stress analyses as well as mechanical stress, strain, and rate of strain measurements.

  8. Quality of life measures in irritable bowel syndrome.

    PubMed

    Wong, Reuben K M; Drossman, Douglas A

    2010-06-01

    Irritable bowel syndrome (IBS) is a functional gastrointestinal disorder with significant morbidity, resulting from the interaction of physiologic, psychological, social, cultural and behavioral factors. In view of this complex interaction, and in the absence of a measurable biological index of disease, health-related quality of life (HRQoL) has emerged as an ideal measure for use in clinical trials and outcome studies. This article discusses the relevance of HRQoL measurement in IBS and its definition. It then explores the research methodology in HRQoL and describes how global measures and generic HRQoL instruments have been used in IBS. Finally, the IBS-specific HRQoL measures are described in detail, with an emphasis on their development, content and validation. PMID:20528115

  9. Measurement of the 225Ac half-life.

    PubMed

    Pommé, S; Marouli, M; Suliman, G; Dikmen, H; Van Ammel, R; Jobbágy, V; Dirican, A; Stroh, H; Paepen, J; Bruchertseifer, F; Apostolidis, C; Morgenstern, A

    2012-11-01

    The (225)Ac half-life was determined by measuring the activity of (225)Ac sources as a function of time, using various detection techniques: α-particle counting with a planar silicon detector at a defined small solid angle and in a nearly-2π geometry, 4πα+β counting with a windowless CsI sandwich spectrometer and with a pressurised proportional counter, gamma-ray spectrometry with a HPGe detector and with a NaI(Tl) well detector. Depending on the technique, the decay was followed for 59-141 d, which is about 6-14 times the (225)Ac half-life. The six measurement results were in good mutual agreement and their mean value is T(1/2)((225)Ac)=9.920 (3)d. This half-life value is more precise and better documented than the currently recommended value of 10.0 d, based on two old measurements lacking uncertainty evaluations. PMID:22940415

  10. Summary Report of Mission Acceleration Measurement for STS-87: Launched November 19, 1997

    NASA Technical Reports Server (NTRS)

    Rogers, Melissa J. B.; Hrovat, Kenneth; McPherson, Kevin; DeLombard, Richard; Reckart, Timothy

    1999-01-01

    Two accelerometer systems, the Orbital Acceleration Research Experiment and the Space Acceleration Measurement System, were used to measure and record the microgravity environment of the Orbiter Columbia during the STS-87 mission in November-December 1997. Data from two separate Space Acceleration Measurement System units were telemetered to the ground during the mission and data plots were displayed for investigators of the Fourth United States Microgravity Payload experiments in near real-time using the World Wide Web. Plots generated using Orbital Acceleration Research Experiment data (telemetered to the ground using a tape delay) were provided to the investigators using the World Wide Web approximately twelve hours after data recording. Disturbances in the microgravity environment as recorded by these instruments are grouped by source type: Orbiter systems, on-board activities, payload operations, and unknown sources. The environment related to the Ku-band antenna dither, Orbiter structural modes, attitude deadband collapses, water dump operations, crew sleep, and crew exercise was comparable to the effects of these sources on previous Orbiter missions. Disturbances related to operations of the Isothermal Dendritic Growth Experiment and Space Acceleration Measurement Systems that were not observed on previous missions are detailed. The effects of Orbiter cabin and airlock depressurization and extravehicular activities are also reported for the first time. A set of data plots representing the entire mission is included in the CD-ROM version of this report.

  11. A wireless accelerometer node for reliable and valid measurement of lumbar accelerations during treadmill running.

    PubMed

    Lindsay, Timothy R; Yaggie, James A; McGregor, Stephen J

    2016-01-01

    This study investigated the reliability of a wireless accelerometer and its agreement with optical motion capture for the measurement of root mean square (RMS) acceleration during running. RMS acceleration provides a whole-body metric of movement mechanics and economy. Fifteen healthy college-age participants performed treadmill running for two 60-s trials at 2.22, 2.78, and 3.33 m/s and one trial of 150 s (five 30-s epochs) at 2.78 m/s. We assessed between-trial and within-trial reliability, and agreement in each axis between a trunk-mounted wireless accelerometer and a reflective marker on the accelerometer measured by optical motion capture. Intraclass correlations assessing between-trial repeatability were 0.89-0.97, depending on the axis, and intraclass correlations assessing within-trial repeatability were 0.99-1.00. Bland-Altman analyses assessing agreement indicated mean difference values between -0.03 and 0.03 g, depending on the axis. Anterio-posterior acceleration had the greatest limits of agreement (LOA) (±0.12 g) and vertical acceleration had the smallest LOA (±0.03 g). For measuring RMS acceleration of the trunk, this wireless accelerometer node provides repeatable and valid measurement compared with the standard laboratory method of optical motion capture. PMID:26836779

  12. Summary Report of Mission Acceleration Measurement for STS-87, Launched November 19, 1997

    NASA Technical Reports Server (NTRS)

    Rogers, Melissa J. B.; Hrovat, Kenneth; McPherson, Kevin; DeLombard, Richard; Reckart, Timothy

    1999-01-01

    Two accelerometer systems, the Orbital Acceleration Research Experiment and the Space Acceleration Measurement System, were used to measure and record the microgravity environment of the Orbiter Columbia during the STS-87 mission in November-December 1997. Data from two separate Space Acceleration Measurement System units were telemetered to the ground during the mission and data plots were displayed for investigators of the Fourth United States Microgravity Payload experiments in near real-time using the World Wide Web. Plots generated using Orbital Acceleration Research Experiment data (telemetered to the ground using a tape delay) were provided to the investigators using the World Wide Web approximately twelve hours after data recording. Disturbances in the microgravity environment as recorded by these instruments are grouped by source type: Orbiter systems, on-board activities, payload operations, and unknown sources. The environment related to the Ku-band antenna dither, Orbiter structural modes, attitude deadband collapses, water dump operations, crew sleep, and crew exercise was comparable to the effects of these sources on previous Orbiter missions. Disturbances related to operations of the Isothermal Dendritic Growth Experiment and Space Acceleration Measurement Systems that were not observed on previous missions are detailed. The effects of Orbiter cabin and airlock depressurization and extravehicular activities are also reported for the first time. A set of data plots representing the entire mission is included in the CD-ROM version of this report.

  13. Accelerated life time testing of fused silica upon ArF laser irradiation

    NASA Astrophysics Data System (ADS)

    Mühlig, Ch.; Triebel, W.; Kufert, S.; Natura, U.

    2008-10-01

    We report on two approaches to strongly shorten life time testing of fused silica's absoption degradation upon 193 nm laser irradiation. Both approaches are based on enhancing the two photon absorption (TPA) induced generation of E' and NBOH defects centers in fused silica compared to common marathon test irradiation parameters. For the first approach the irradiation fluence is increased from typical values H<1 mJ/cm2 to H=10 mJ/cm2, therefore increasing the peak laser power for a more efficient TPA process. To avoid microchannel formation in the samples, being a common break-down criterion in marathon tests based on transmission measurements, a small sample of 10 mm length is irradiated and the absorption is measured directly by the laser induced deflection (LID) technique. For comparing the experimental results with a real marathon test at H=1.3 mJ/cm2, an experimental grade sample with very low hydrogen content, i.e. fast absorption changes due to reduced defect annealing, is choosen. During the fluence dependent absorption measurements after the prolonged irradiation at H=10 mJ/cm2 it is found, that both experiments reveal very comparable absorption data for H=1.3 mJ/cm2. For investigating standard material with high hydrogen content, i.e. slow absorption increase due to effective defect annealing, a sample is cooled down to -180 °C in a special designed experimental setup and irradiated at a laser fluence H=10 mJ/cm2. To control the increase of the defect density and to determine the end of the TPA induced defect generation, the fluorescence at 650 nm of the generated NBOH centers is monitored. Before and after the low temperature experiment, the absorption coefficient is measured directly by LID technique. By applying both, elevated laser fluence and low temperature, the ArF laser induced generation of E' and NBOH centers in the investigated sample is terminated after about 1.2*107 laser pulses. Therefore, a strong reduction of irradiation time is achieved

  14. Recent developments of ion sources for life-science studies at the Heavy Ion Medical Accelerator in Chiba (invited).

    PubMed

    Kitagawa, A; Drentje, A G; Fujita, T; Muramatsu, M; Fukushima, K; Shiraishi, N; Suzuki, T; Takahashi, K; Takasugi, W; Biri, S; Rácz, R; Kato, Y; Uchida, T; Yoshida, Y

    2016-02-01

    With about 1000-h of relativistic high-energy ion beams provided by Heavy Ion Medical Accelerator in Chiba, about 70 users are performing various biology experiments every year. A rich variety of ion species from hydrogen to xenon ions with a dose rate of several Gy/min is available. Carbon, iron, silicon, helium, neon, argon, hydrogen, and oxygen ions were utilized between 2012 and 2014. Presently, three electron cyclotron resonance ion sources (ECRISs) and one Penning ion source are available. Especially, the two frequency heating techniques have improved the performance of an 18 GHz ECRIS. The results have satisfied most requirements for life-science studies. In addition, this improved performance has realized a feasible solution for similar biology experiments with a hospital-specified accelerator complex. PMID:26932117

  15. Recent developments of ion sources for life-science studies at the Heavy Ion Medical Accelerator in Chiba (invited)

    NASA Astrophysics Data System (ADS)

    Kitagawa, A.; Drentje, A. G.; Fujita, T.; Muramatsu, M.; Fukushima, K.; Shiraishi, N.; Suzuki, T.; Takahashi, K.; Takasugi, W.; Biri, S.; Rácz, R.; Kato, Y.; Uchida, T.; Yoshida, Y.

    2016-02-01

    With about 1000-h of relativistic high-energy ion beams provided by Heavy Ion Medical Accelerator in Chiba, about 70 users are performing various biology experiments every year. A rich variety of ion species from hydrogen to xenon ions with a dose rate of several Gy/min is available. Carbon, iron, silicon, helium, neon, argon, hydrogen, and oxygen ions were utilized between 2012 and 2014. Presently, three electron cyclotron resonance ion sources (ECRISs) and one Penning ion source are available. Especially, the two frequency heating techniques have improved the performance of an 18 GHz ECRIS. The results have satisfied most requirements for life-science studies. In addition, this improved performance has realized a feasible solution for similar biology experiments with a hospital-specified accelerator complex.

  16. Summary Report of Mission Acceleration Measurements for STS-65, Launched 8 July 1994

    NASA Technical Reports Server (NTRS)

    Rogers, Melissa J. B.; Delombard, Richard

    1995-01-01

    The second flight of the International Microgravity Laboratory (IML-2) payload on board the STS-65 mission was supported by three accelerometer instruments: The Orbital Acceleration Research Experiment (OARE) located close to the orbiter center of mass; the Quasi-Steady Acceleration Measurement experiment, and the Space Acceleration Measurement System (SAMS), both in the Spacelab module. A fourth accelerometer, the Microgravity Measuring Device recorded data in the middeck in support of exercise isolation tests.Data collected by OARE and SAMS during IML-2 are displayed in this report. The OARE data represent the microgravity environment below 1 Hz. The SAMS data represent the environment in the 0.01 Hz to 100 Hz range. Variations in the environment caused by unique activities are presented. Specific events addressed are: crew activity, crew exercise, experiment component mixing activities, experiment centrifuge operations, refrigerator/freezer operations and circulation pump operations. The analyses included in this report complement analyses presented in other mission summary reports.

  17. Accelerated test techniques for micro-circuits: Evaluation of high temperature (473 k - 573 K) accelerated life test techniques as effective microcircuit screening methods

    NASA Technical Reports Server (NTRS)

    Johnson, G. M.

    1976-01-01

    The application of high temperature accelerated test techniques was shown to be an effective method of microcircuit defect screening. Comprehensive microcircuit evaluations and a series of high temperature (473 K to 573 K) life tests demonstrated that a freak or early failure population of surface contaminated devices could be completely screened in thirty two hours of test at an ambient temperature of 523 K. Equivalent screening at 398 K, as prescribed by current Military and NASA specifications, would have required in excess of 1,500 hours of test. All testing was accomplished with a Texas Instruments' 54L10, low power triple-3 input NAND gate manufactured with a titanium- tungsten (Ti-W), Gold (Au) metallization system. A number of design and/or manufacturing anomalies were also noted with the Ti-W, Au metallization system. Further study of the exact nature and cause(s) of these anomalies is recommended prior to the use of microcircuits with Ti-W, Au metallization in long life/high reliability applications. Photomicrographs of tested circuits are included.

  18. Experimental measurements of rf breakdowns and deflecting gradients in mm-wave metallic accelerating structures

    NASA Astrophysics Data System (ADS)

    Dal Forno, Massimo; Dolgashev, Valery; Bowden, Gordon; Clarke, Christine; Hogan, Mark; McCormick, Doug; Novokhatski, Alexander; Spataro, Bruno; Weathersby, Stephen; Tantawi, Sami G.

    2016-05-01

    We present an experimental study of a high gradient metallic accelerating structure at sub-THz frequencies, where we investigated the physics of rf breakdowns. Wakefields in the structure were excited by an ultrarelativistic electron beam. We present the first quantitative measurements of gradients and metal vacuum rf breakdowns in sub-THz accelerating cavities. When the beam travels off axis, a deflecting field is induced in addition to the longitudinal field. We measured the deflecting forces by observing the displacement and changes in the shape of the electron bunch. This behavior can be exploited for subfemtosecond beam diagnostics.

  19. Radionuclides in man and his environment measured by accelerator mass spectrometry

    SciTech Connect

    Hellborg, Ragnar; Erlandsson, Bengt; Kiisk, Madis; Persson, Per; Skog, Goeran; Stenstroem, Kristina; Mattsson, Soeren; Leide-Svegborn, Sigrid; Olofsson, Mikael

    1999-06-10

    Accelerator mass spectrometry (AMS) is a highly sensitive analytical method for measuring very low concentrations of both radionuclides and stable nuclides. For radioanalytical purposes, the main advantages of AMS compared to conventional radiometric methods are the use of smaller samples (mg size) and shorter measuring times (less than one hour). In this report some current applications of the AMS technique at the Lund Pelletron accelerator are presented, in particular studies of {sup 14}C-labeled pharmaceuticals used in clinical nuclear medicine and biomedical research.

  20. Life in the Fast Lane: Effects of Early Grade Acceleration on High School and College Outcomes

    ERIC Educational Resources Information Center

    McClarty, Katie Larsen

    2015-01-01

    Research has repeatedly demonstrated the positive effects of acceleration for gifted and talented students. This study expands the literature by not only evaluating the impact of early grade skipping on high school and college outcomes but also examining the role of postacceleration opportunities on subsequent performance. Using a representative…

  1. Theoretical analysis of acceleration measurements in a model of an operating wind turbine.

    SciTech Connect

    Adams, Douglas E.; Rumsey, Mark Allen; White, Jonathan Randall

    2010-04-01

    Wind loading from turbulence and gusts can cause damage in horizontal axis wind turbines. These unsteady loads and the resulting damage initiation and propagation are difficult to predict. Unsteady loads enter at the rotor and are transmitted to the drivetrain. The current generation of wind turbine has drivetrain-mounted vibration and bearing temperature sensors, a nacelle-mounted inertial measurement unit, and a nacelle-mounted anemometer and wind vane. Some advanced wind turbines are also equipped with strain measurements at the root of the rotor. This paper analyzes additional measurements in a rotor blade to investigate the complexity of these unsteady loads. By identifying the spatial distribution, amplitude, and frequency bandwidth of these loads, design improvements could be facilitated to reduce uncertainties in reliability predictions. In addition, dynamic load estimates could be used in the future to control high-bandwidth aerodynamic actuators distributed along the rotor blade to reduce the saturation of slower pitch actuators currently used for wind turbine blades. Local acceleration measurements are made along a rotor blade to infer operational rotor states including deflection and dynamic modal contributions. Previous work has demonstrated that acceleration measurements can be experimentally acquired on an operating wind turbine. Simulations on simplified rotor blades have also been used to demonstrate that mean blade loading can be estimated based on deflection estimates. To successfully apply accelerometers in wind turbine applications for load identification, the spectral and spatial characteristics of each excitation source must be understood so that the total acceleration measurement can be decomposed into contributions from each source. To demonstrate the decomposition of acceleration measurements in conjunction with load estimation methods, a flexible body model has been created with MSC.ADAMS{copyright} The benefit of using a simulation model

  2. Life Satisfaction in Persons with Lacunar Infarction--A Comparative Analysis of Two Measures of Life Satisfaction.

    ERIC Educational Resources Information Center

    Olsson, G-B.; And Others

    1996-01-01

    A study of 76 Swedish patients (ages 40-86) with lacunar infarctions used a life satisfaction questionnaire to investigate whether the patients were satisfied and how their life situation was affected by the infarction. Results found that the questionnaire was not an effective instrument for measuring life satisfaction in this population. (CR)

  3. Development of and flight results from the Space Acceleration Measurement System (SAMS)

    NASA Technical Reports Server (NTRS)

    Delombard, Richard; Finley, Brian D.; Baugher, Charles R.

    1992-01-01

    Described here is the development of and the flight results from the Space Acceleration Measurement System (SAMS) flight units used in the Orbiter middeck, Spacelab module, and the Orbitercargo bay. The SAMS units are general purpose microgravity accelerometers designed to support a variety of science experiments with microgravity acceleration measurements. A total of six flight units have been fabricated; four for use in the Orbiter middeck and Spacelab module, and two for use in the Orbiter cargo bay. The design of the units is briefly described. The initial two flights of SAMS units on STS-40 (June 1991) and STS-43 (August 1991) resulted in 371 megabytes and 2.6 gigabytes of data respectively. Analytical techniques developed to examine this quantity of acceleration data are described and sample plots of analyzed data are illustrated. Future missions for the SAMS units are listed.

  4. A first attempt to measure 92Nb/93Nb ratios with Accelerator Mass Spectrometry

    NASA Astrophysics Data System (ADS)

    Guozhu, He; Ming, He; Zuying, Zhou; Zhenyu, Li; Kejun, Dong; Shaoyong, Wu; Shilong, Liu; Xiongjun, Chen; Qiwen, Fan; Chaoli, Li; Xianwen, He; Heng, Li; Shan, Jiang

    2013-01-01

    An Accelerator Mass Spectrometry (AMS) method for the measurement of the long-lived radionuclide 92Nb has been established at the HI-13 Tandem Accelerator of the China Institute of Atomic Energy (CIAE). Niobium powder mixed with PbF2 by a ratio of 1:2 (in mass) was used as the cathode material. Atomic anions of Nb- were extracted from a Cs-beam sputter source. The terminal voltage of the tandem accelerator was 8.5 MV. Nb13+ ions were selected after terminal foil stripping. A multi-anode gas ionization chamber was used for the particle detection. The total suppression factor of the two major interfering isobars, 92Zr and 92Mo, was about 103. A detection limit of about 10-11 was achieved for 92Nb/93Nb ratio measurements on a blank sample.

  5. Determination of Shelf Life for Butter and Cheese Products in Actual and Accelerated Conditions

    PubMed Central

    Lim, Kwang-Sei; Yang, Cheul-Young

    2014-01-01

    The aim of this study was to estimate the shelf life of butter and cheese products, with shelf life being a guide used to determine the storage period of food before deterioration. Butter and cheese samples stored at 10℃ and 15℃ had a shelf life of 221 d, while those stored at 25℃ and 35℃ had a shelf life of 109 d. Quality changes, including total cell count, coliform counts, Listeria monocytogenes counts, acid value, moisture content, pH, acidity and overall sensory evaluation, were monitored. In order to pass the overall sensory evaluation, a quality score of 5 points on a 9-point scale was required. For other quality criteria, legal quality limits were established based on the “Process Criteria and Ingredient Standard of Livestock Products” by the Animal, Plant and Fisheries Quarantine and Inspection Agency (Republic of Korea). The nonlegal quality limit was estimated by regression analysis between non-quality criteria (y) and overall sensory evaluation (x). The shelf life was estimated based on the number of days that the product passed the quality limit of the quality criteria. The shelf life of samples stored at 10℃, 15℃, 25℃ and 35℃ was 21.94, 17.18, 6.10 and 0.58 mon, respectively, for butter and 10.81, 9.47, 4.64 and 0.20 mon, respectively, for cheese. PMID:26760945

  6. Measuring test mass acceleration noise in space-based gravitational wave astronomy

    NASA Astrophysics Data System (ADS)

    Congedo, Giuseppe

    2015-03-01

    The basic constituent of interferometric gravitational wave detectors—the test-mass-to-test-mass interferometric link—behaves as a differential dynamometer measuring effective differential forces, comprising an integrated measure of gravity curvature, inertial effects, as well as nongravitational spurious forces. This last contribution is going to be characterized by the LISA Pathfinder mission, a technology precursor of future space-borne detectors like eLISA. Changing the perspective from displacement to acceleration can benefit the data analysis of LISA Pathfinder and future detectors. The response in differential acceleration to gravitational waves is derived for a space-based detector's interferometric link. The acceleration formalism can also be integrated into time delay interferometry by building up the unequal-arm Michelson differential acceleration combination. The differential acceleration is nominally insensitive to the system's free evolution dominating the slow displacement dynamics of low-frequency detectors. Working with acceleration also provides an effective way to subtract measured signals acting as systematics, including the actuation forces. Because of the strong similarity with the equations of motion, the optimal subtraction of systematic signals, known within some amplitude and time shift, with the focus on measuring the noise provides an effective way to solve the problem and marginalize over nuisance parameters. The F statistic, in widespread use throughout the gravitation waves community, is included in the method and suitably generalized to marginalize over linear parameters and noise at the same time. The method is applied to LPF simulator data and, thanks to its generality, can also be applied to the data reduction and analysis of future gravitational wave detectors.

  7. Measuring the Resilience of Advanced Life Support Systems

    NASA Technical Reports Server (NTRS)

    Bell, Ann Maria; Dearden, Richard; Levri, Julie A.

    2002-01-01

    Despite the central importance of crew safety in designing and operating a life support system, the metric commonly used to evaluate alternative Advanced Life Support (ALS) technologies does not currently provide explicit techniques for measuring safety. The resilience of a system, or the system s ability to meet performance requirements and recover from component-level faults, is fundamentally a dynamic property. This paper motivates the use of computer models as a tool to understand and improve system resilience throughout the design process. Extensive simulation of a hybrid computational model of a water revitalization subsystem (WRS) with probabilistic, component-level faults provides data about off-nominal behavior of the system. The data can then be used to test alternative measures of resilience as predictors of the system s ability to recover from component-level faults. A novel approach to measuring system resilience using a Markov chain model of performance data is also developed. Results emphasize that resilience depends on the complex interaction of faults, controls, and system dynamics, rather than on simple fault probabilities.

  8. Accelerated multiscale space-time finite element simulation and application to high cycle fatigue life prediction

    NASA Astrophysics Data System (ADS)

    Zhang, Rui; Wen, Lihua; Naboulsi, Sam; Eason, Thomas; Vasudevan, Vijay K.; Qian, Dong

    2016-05-01

    A multiscale space-time finite element method based on time-discontinuous Galerkin and enrichment approach is presented in this work with a focus on improving the computational efficiencies for high cycle fatigue simulations. While the robustness of the TDG-based space-time method has been extensively demonstrated, a critical barrier for the extensive application is the large computational cost due to the additional temporal dimension and enrichment that are introduced. The present implementation focuses on two aspects: firstly, a preconditioned iterative solver is developed along with techniques for optimizing the matrix storage and operations. Secondly, parallel algorithms based on multi-core graphics processing unit are established to accelerate the progressive damage model implementation. It is shown that the computing time and memory from the accelerated space-time implementation scale with the number of degree of freedom N through {˜ }{O}(N^{1.6}) and {˜ }{O}(N) , respectively. Finally, we demonstrate the accelerated space-time FEM simulation through benchmark problems.

  9. Accelerated multiscale space-time finite element simulation and application to high cycle fatigue life prediction

    NASA Astrophysics Data System (ADS)

    Zhang, Rui; Wen, Lihua; Naboulsi, Sam; Eason, Thomas; Vasudevan, Vijay K.; Qian, Dong

    2016-08-01

    A multiscale space-time finite element method based on time-discontinuous Galerkin and enrichment approach is presented in this work with a focus on improving the computational efficiencies for high cycle fatigue simulations. While the robustness of the TDG-based space-time method has been extensively demonstrated, a critical barrier for the extensive application is the large computational cost due to the additional temporal dimension and enrichment that are introduced. The present implementation focuses on two aspects: firstly, a preconditioned iterative solver is developed along with techniques for optimizing the matrix storage and operations. Secondly, parallel algorithms based on multi-core graphics processing unit are established to accelerate the progressive damage model implementation. It is shown that the computing time and memory from the accelerated space-time implementation scale with the number of degree of freedom N through ˜ O(N^{1.6}) and ˜ O(N), respectively. Finally, we demonstrate the accelerated space-time FEM simulation through benchmark problems.

  10. Measurement of acceleration while walking as an automated method for gait assessment in dairy cattle.

    PubMed

    Chapinal, N; de Passillé, A M; Pastell, M; Hänninen, L; Munksgaard, L; Rushen, J

    2011-06-01

    The aims were to determine whether measures of acceleration of the legs and back of dairy cows while they walk could help detect changes in gait or locomotion associated with lameness and differences in the walking surface. In 2 experiments, 12 or 24 multiparous dairy cows were fitted with five 3-dimensional accelerometers, 1 attached to each leg and 1 to the back, and acceleration data were collected while cows walked in a straight line on concrete (experiment 1) or on both concrete and rubber (experiment 2). Cows were video-recorded while walking to assess overall gait, asymmetry of the steps, and walking speed. In experiment 1, cows were selected to maximize the range of gait scores, whereas no clinically lame cows were enrolled in experiment 2. For each accelerometer location, overall acceleration was calculated as the magnitude of the 3-dimensional acceleration vector and the variance of overall acceleration, as well as the asymmetry of variance of acceleration within the front and rear pair of legs. In experiment 1, the asymmetry of variance of acceleration in the front and rear legs was positively correlated with overall gait and the visually assessed asymmetry of the steps (r ≥ 0.6). Walking speed was negatively correlated with the asymmetry of variance of the rear legs (r=-0.8) and positively correlated with the acceleration and the variance of acceleration of each leg and back (r ≥ 0.7). In experiment 2, cows had lower gait scores [2.3 vs. 2.6; standard error of the difference (SED)=0.1, measured on a 5-point scale] and lower scores for asymmetry of the steps (18.0 vs. 23.1; SED=2.2, measured on a continuous 100-unit scale) when they walked on rubber compared with concrete, and their walking speed increased (1.28 vs. 1.22 m/s; SED=0.02). The acceleration of the front (1.67 vs. 1.72 g; SED=0.02) and rear (1.62 vs. 1.67 g; SED=0.02) legs and the variance of acceleration of the rear legs (0.88 vs. 0.94 g; SED=0.03) were lower when cows walked on rubber

  11. Acceleration and Rotation in a Pendulum Ride, Measured Using an iPhone 4

    ERIC Educational Resources Information Center

    Pendrill, Ann-Marie; Rohlen, Johan

    2011-01-01

    Many modern cell phones have built-in sensors that may be used as a resource for physics education. Amusement rides offer examples of many different types of motion, where the acceleration leads to forces experienced throughout the body. A comoving 3D-accelerometer gives an electronic measurement of the varying forces acting on the rider, but a…

  12. SU-E-T-543: Measurement of Neutron Activation From Different High Energy Varian Linear Accelerators

    SciTech Connect

    Thatcher, T; Madsen, S; Sudowe, R; Meigooni, A Soleimani

    2015-06-15

    Purpose: Linear accelerators producing photons above 10 MeV may induce photonuclear reactions in high Z components of the accelerator. These liberated neutrons can then activate the structural components of the accelerator and other materials in the beam path through neutron capture reactions. The induced activity within the accelerator may contribute to additional dose to both patients and personnel. This project seeks to determine the total activity and activity per activated isotope following irradiation in different Varian accelerators at energies above 10 MeV. Methods: A Varian 21IX accelerator was used to irradiate a 30 cm × 30 cm × 20 cm solid water phantom with 15 MV x-rays. The phantom was placed at an SSD of 100 cm and at the center of a 20 cm × 20 cm field. Activation induced gamma spectra were acquired over a 5 minute interval after 1 and 15 minutes from completion of the irradiation. All measurements were made using a CANBERRA Falcon 5000 Portable HPGe detector. The majority of measurements were made in scattering geometry with the detector situated at 90° to the incident beam, 30 cm from the side of the phantom and approximately 10 cm from the top. A 5 minute background count was acquired and automatically subtracted from all subsequent measurements. Photon spectra were acquired for both open and MLC fields. Results: Based on spectral signatures, nuclides have been identified and their activities calculated for both open and MLC fields. Preliminary analyses suggest that activities from the activation products in the microcurie range. Conclusion: Activation isotopes have been identified and their relative activities determined. These activities are only gross estimates since efficiencies have not been determined for this source-detector geometry. Current efforts are focused on accurate determination of detector efficiencies using Monte Carlo calculations.

  13. Development of a Trauma-Specific Quality of Life Measurement

    PubMed Central

    Wanner, John Paul; deRoon-Cassini, Terri; Kodadek, Lisa; Brasel, Karen

    2016-01-01

    Background Complex, disease-specific factors help to determine post-traumatic quality of life, but current practice utilizes outcome measures generated from the general population. Trauma survivorship has grown rapidly while defining the factors that influence post-traumatic quality of life has lagged. This study sought to develop a valid and reliable trauma-specific quality of life measure to help guide future post-traumatic research and clinical care. Methods Qualitative data were collected from adult trauma patients and their caregivers (Phase 1). Subsequent analysis of these data resulted in the development of a 59-item quality of life (QoL) questionnaire. The 59-item trauma-specific QoL questionnaire (T-QoL) was then administered to adult trauma patients (n=394) and a factor analysis was conducted. The validity of the final TQoL measurement tool was assessed (n=111) using the Medical Outcomes Study 36-Item Short Form Health Survey version 2 and the PTSD Checklist-Civilian Version (Phase 2). Results A 5-component structure using 43 items appeared to best represent the data. The 5 components included: Emotional Well-Being, Functional Engagement, Recovery/Resilience, Peri-Traumatic Experience, Physical Well-Being. Four of the five components were found to have strong Cronbach's alpha scores (>0.7), demonstrating consistent inter-item reliability. All subscales of the T-QoL correlated negatively with the PCL-C (p<.01), demonstrating that as the T-QoL increases, the likelihood of PTSD decreases. The physical well-being subscale of the T-QoL correlated significantly with the SF-36v2 PCS as did the emotional well-being subscale with the SF-36v2 MCS (p<.05). Conclusions This study utilized the experiences of trauma victims and their informal caregivers to develop a five-component, 43-item questionnaire with domains that are unique to trauma populations. Its accuracy and validity was confirmed using the PCL-C and the SF-36v2. We believe that the TQoL represents a novel

  14. Design and RF Measurements of AN X-Band Accelerating Structure for the Sparc Project

    NASA Astrophysics Data System (ADS)

    Alesini, D.; Bacci, A.; Falone, A.; Migliorati, M.; Mostacci, A.; Palpini, F.; Palumbo, L.; Spataro, B.

    The paper presents the design of an X-band accelerating section for linearizing the longitudinal phase space in the Frascati Linac Coherent Light Source (SPARC). The nine cells structure, operating on the π standing wave mode, is fed by a central coupler and has been designed to obtain a 42 MV/m accelerating gradient. The 2D profile has been obtained using the electromagnetic codes Superfish and Oscar2D while the coupler has been designed using HFSS. Bead-pull measurements made on a copper prototype have been performed and the results are illustrated and compared with the numerical predictions.

  15. Design and RF Measurements of AN X-Band Accelerating Structure for the Sparc Project

    NASA Astrophysics Data System (ADS)

    Alesini, D.; Bacci, A.; Falone, A.; Migliorati, M.; Mostacci, A.; Palpini, F.; Palumbo, L.; Spataro, B.

    2007-09-01

    The paper presents the design of an X-band accelerating section for linearizing the longitudinal phase space in the Frascati Linac Coherent Light Source (SPARC). The nine cells structure, operating on the π standing wave mode, is fed by a central coupler and has been designed to obtain a 42 MV/m accelerating gradient. The 2D profile has been obtained using the electromagnetic codes Superfish and Oscar2D while the coupler has been designed using HFSS. Bead-pull measurements made on a copper prototype have been performed and the results are illustrated and compared with the numerical predictions.

  16. Laser Induced Fluorescence Measurements of Ion Velocity in Magnetic Cusped Plasma Accelerators

    NASA Astrophysics Data System (ADS)

    MacDonald, Natalia; Cappelli, Mark; Hargus, William, Jr.

    2012-10-01

    Cusped Field Thrusters (CFTs) are magnetized plasma accelerators that use strong cusps to shape the magnetic field and hence the electrostatic potential. The cusped magnetic field lines meter the electron transport to the anode and reduce the energetic ion flux towards the dielectric channel walls, thereby reducing the effects of erosion. This work presents time averaged laser induced fluorescence velocity measurements of the ions in the plumes of three CFT variants. These include the Cylindrical Hall Thruster (CHT), Cylindrical Cusped Field Thruster (CCFT), and Diverging Cusped Field Thruster (DCFT). Results indicate that magnetic cusps form equipotential surfaces, and that the majority of ion acceleration occurs outside of the thruster channels.

  17. APS linac klystron and accelerating structure gain measurements and klystron PFN voltage regulation requirements

    SciTech Connect

    Sereno, N.S.

    1997-07-01

    This note details measurements of the APS positron linac klystron and accelerating structure gain and presents an analysis of the data using fits to simple mathematical models. The models are used to investigate the sensitivity of the energy dependence of the output positron beam to klystron parameters. The gain measurements are separated into two parts: first, the energy gains of the accelerating structures of the positron linac are measured as a function of output power of the klystron; second, the klystron output power is measured as a function of input drive power and pulse forming network (PFN) voltage. This note concentrates on the positron linac rf and its performance as it directly affects the energy stability of the positron beam injected into the positron accumulator ring (PAR). Ultimately it is important to be able to minimize beam energy variations to maximize the PAR accumulation efficiency.

  18. Scientific life should be measured in seven year units.

    PubMed

    Charlton, Bruce G

    2006-01-01

    Traditional wisdom and empirical observation unite in recommending a 7 year unit for measuring human life - including individual and institutional science. But, because of astronomy and the decimal system, things tend to be measured either in years, five years or in decades. A year is too short while a decade is too long to measure the trends and transitions of individual or institutional life. And the half decade, such as the 'five year plan' beloved by politicians and bureaucrats seems too short. Therefore, seven years should become the standard unit for tracking trends and measuring attainment. Precedents for using a seven year unit include the notorious Jesuit saying: 'Give me the child until he is seven, and I will show you the man'; and the 'ninth commandment' of Leo Szilard: 'Do your work for six years; but in the seventh, go into solitude or among strangers, so that the memory of your friends does not prevent you from being what you have become'. In a scientific career, seven years is approximately the time spent at high school, the time taken for a traditional basic scientific training of first degree and doctorate, and the period after the doctorate building the knowledge to become an expert specialist. There seems to be enough anecdotal evidence to support the idea that we should reconsider the universal but un-reflective use of decimal units in planning and evaluation. For instance, seven year fellowships and program grants might replace the current five year versions. A new - and previously unconsidered - field of research beckons. PMID:16524670

  19. A small 1 MeV electron accelerator for measuring heavy metal concentrations in smokestack gases

    NASA Astrophysics Data System (ADS)

    Reppond, A.; Redden, D. P.; Meitzler, C. R.; Swenson, D. A.

    1997-05-01

    A low-current electron beam may be used as a diagnostic tool to measure the concentrations of heavy metals (Cd, Pb, Hg) present in the flue gas particulates produced by smelters or cement kilns. A small electron accelerator is being constructed as part of a prototype emissions monitoring system. The electron beam energy has a design energy of 1 MeV, a peak current of 5 mA, and a duty factor of 0.1 percent. In this paper, we discuss the results of a set of EGS4 calculations used to model the transport properties of a 1 MeV electron beam passing through a thin vacuum window and the flue gas. Since the accelerator will be mounted in a harsh environment, we have investigated the effects of temperature variations on the linac structure and RF power source. The present status of the accelerator construction project is presented.

  20. First Direct Measurement of Acceleration in the Outflow of a Nova: U Scorpii (1999)

    NASA Astrophysics Data System (ADS)

    Lépine, Sébastien; Shara, Michael M.; Livio, Mario; Zurek, David

    1999-09-01

    We report the first direct measurement of acceleration in the outflow of a nova, U Sco, observed 5 days after the start of an outburst. Spectroscopic time series of the intense Hα emission line, obtained with the Space Telescope Imaging Spectrograph camera on board the Hubble Space Telescope, shows a bright emission component moving across the spectrum at a rate of +0.16+/-0.02 Å in 30 minutes. This is consistent with a clump of emitting material having a line-of-sight acceleration ar=+4.1+/-0.5 m s-2. The data suggest that this clump resides within a moderately collimated bipolar outflow. Due to projection effects, this implies an actual acceleration of the clump relative to the star of a>~+25 m s-2. Based on observations with the NASA/ESA Hubble Space Telescope, obtained at the Space Telescope Science Institute, which is operated by AURA, Inc., under NASA contract NAS5-26555.

  1. Methodology for designing accelerated aging tests for predicting life of photovoltaic arrays

    NASA Technical Reports Server (NTRS)

    Gaines, G. B.; Thomas, R. E.; Derringer, G. C.; Kistler, C. W.; Bigg, D. M.; Carmichael, D. C.

    1977-01-01

    A methodology for designing aging tests in which life prediction was paramount was developed. The methodology builds upon experience with regard to aging behavior in those material classes which are expected to be utilized as encapsulant elements, viz., glasses and polymers, and upon experience with the design of aging tests. The experiences were reviewed, and results are discussed in detail.

  2. Summary Report of Mission Acceleration Measurements for STS-75, Launched February 22, 1996

    NASA Technical Reports Server (NTRS)

    Rogers, Melissa J. B.; Hrovat, Kenneth; Moskowitz, Milton E.; McPherson, Kevin M.; DeLombard, Richard

    1996-01-01

    Two accelerometers provided acceleration data during the STS-75 mission in support of the third United States Microgravity Payload (USMP-3) experiments. The Orbital Acceleration Research Experiment (OARE) and the Space Acceleration Measurement System (SAMS) provided a measure of the microgravity environment of the Space Shuttle Columbia. The OARE provided investigators with quasi-steady acceleration measurements after about a six hour time lag dictated by downlink constraints. SAMS data were downlinked in near-real-time and recorded on-board for post-mission analysis. An overview of the mission is provided as are brief discussions of these two accelerometer systems. Data analysis techniques used to process SAMS and OARE data are discussed Using a combination of these techniques, the microgravity environment related to several different Orbiter, crew, and experiment operations is presented and interpreted. The microgravity environment represented by SAMS and OARE data is comparable to the environments measured by the instruments on earlier microgravity science missions. The OARE data compared well with predictions of the quasi-steady environment. The SAMS data show the influence of thruster firings and crew motion (transient events) and of crew exercise, Orbiter systems, and experiment operations (oscillatory events). Thruster activity on this mission appears to be somewhat more frequent than on other microgravity missions with the combined firings of the F5L and F5R jets producing significant acceleration transients. The specific crew activities performed in the middeck and flight deck, the SPREE table rotations, the waste collection system compaction, and the fuel cell purge had negligible effects on the microgravity environment of the USMP-3 carriers. The Ku band antenna repositioning activity resulted in a brief interruption of the ubiquitous 17 Hz signal in the SAMS data. In addition, the auxiliary power unit operations during the Flight Control System checkout

  3. Measurement of the velocities in the transient acceleration process using all-fiber photonic Doppler velocimetry

    NASA Astrophysics Data System (ADS)

    Wang, Jian; Wu, Chong-qing; Song, Hong-wei; Yu, Tao; Xu, Jing-jing

    2011-05-01

    Based on analysis of basic photonic Doppler velocimetry (PDV), a formula to measure velocity variation in a single cycle is put forward. PDV has been improved in three aspects, namely, the laser, the detector and the data processing. A measurement system for velocity of the initial stage of a shock motion has been demonstrated. Instantaneous velocity measurements have been performed. The experimental results have a good agreement with the values obtained from the accelerometer. Compared with the traditional fringe method, the proposed method in this paper can identify instantaneous velocity variation. So it is particularly suitable for measuring the velocity in the transient acceleration process of shock waves and detonation waves.

  4. Buildup region and skin-dose measurements for the Therac 6 linear accelerator for radiation therapy.

    PubMed

    Tannous, N B; Gagnon, W F; Almond, P R

    1981-01-01

    Buildup and surface-dose measurements were taken for the 6 MV photon beam from a Therac 6 linear accelerator manufactured by Atomic Energy of Canada Limited (AECL) with and without a lucite blocking tray in place. Further measurements were made with a copper filter designed to reduce secondary electrons emitted by photon interactions with the Lucite tray. The results are discussed in relation to skin-sparing for radiation therapy patients. The measurements were made with a fixed volume PTW parallel-plate ionization chamber and corrected to zero-chamber volume. The results were found to be consistent with similar measurements taken with a variable volume extrapolation chamber. PMID:6798394

  5. C-14 content of ten meteorites measured by tandem accelerator mass spectrometry

    NASA Technical Reports Server (NTRS)

    Brown, R. M.; Andrews, H. R.; Ball, G. C.; Burn, N.; Imahori, Y.; Milton, J. C. D.; Fireman, E. L.

    1984-01-01

    Measurements of C-14 in three North American and seven Antarctic meteorites show in most cases that this cosmogenic isotope, which is tightly bound, was separated from absorbed atmospheric radiocarbon by stepwise heating extractions. The present upper limit to age determination by the accelerator method varies from 50,000 to 70,000 years, depending on the mass and carbon content of the sample. The natural limit caused by cosmic ray production of C-14 in silicate rocks at 2000 m elevation is estimated to be 55,000 + or - 5000 years. An estimation is also made of the 'weathering ages' of the Antarctic meteorites from the specific activity of loosely bound CO2 which is thought to be absorbed from the terrestrial atmosphere. Accelerator measurements are found to agree with previous low level counting measurements, but are more sensitive and precise.

  6. The LLNL Accelerator Mass Spectrometry System for Biochemical 14C-Measurements

    SciTech Connect

    Ognibene, T J; Bench, G; Brown, T A; Vogel, J S

    2002-10-31

    We report on recent improvements made to our 1 MV accelerator mass spectrometry system that is dedicated to {sup 14}C quantification of biochemical samples. Increased vacuum pumping capacity near the high voltage terminal has resulted in a 2-fold reduction of system backgrounds to 0.04 amol {sup 14}C/mg carbon. Carbon ion transmission through the accelerator has also improved a few percent. We have also developed tritium measurement capability on this spectrometer. The {sup 3}H/{sup 1}H isotopic ratio of a milligram-sized processed tap water sample has been measured at 4 {+-} 1 x 10{sup -16} (430 {+-} 110 {micro}Bq/mg H). Measurement throughput for a typical biochemical {sup 3}H sample is estimated to be {approx}10 minutes/sample.

  7. HUBBLE PARAMETER MEASUREMENT CONSTRAINTS ON THE COSMOLOGICAL DECELERATION-ACCELERATION TRANSITION REDSHIFT

    SciTech Connect

    Farooq, Omer; Ratra, Bharat E-mail: ratra@phys.ksu.edu

    2013-03-20

    We compile a list of 28 independent measurements of the Hubble parameter between redshifts 0.07 {<=} z {<=} 2.3 and use this to place constraints on model parameters of constant and time-evolving dark energy cosmologies. These H(z) measurements by themselves require a currently accelerating cosmological expansion at about, or better than, 3{sigma} confidence. The mean and standard deviation of the six best-fit model deceleration-acceleration transition redshifts (for the three cosmological models and two Hubble constant priors we consider) are z{sub da} = 0.74 {+-} 0.05, in good agreement with the recent Busca et al. determination of z{sub da} = 0.82 {+-} 0.08 based on 11 H(z) measurements between redshifts 0.2 {<=} z {<=} 2.3, almost entirely from baryon-acoustic-oscillation-like data.

  8. Application of real-time digitization techniques in beam measurement for accelerators

    NASA Astrophysics Data System (ADS)

    Zhao, Lei; Zhan, Lin-Song; Gao, Xing-Shun; Liu, Shu-Bin; An, Qi

    2016-04-01

    Beam measurement is very important for accelerators. In this paper, modern digital beam measurement techniques based on IQ (In-phase & Quadrature-phase) analysis are discussed. Based on this method and high-speed high-resolution analog-to-digital conversion, we have completed three beam measurement electronics systems designed for the China Spallation Neutron Source (CSNS), Shanghai Synchrotron Radiation Facility (SSRF), and Accelerator Driven Sub-critical system (ADS). Core techniques of hardware design and real-time system calibration are discussed, and performance test results of these three instruments are also presented. Supported by National Natural Science Foundation of China (11205153, 10875119), Knowledge Innovation Program of the Chinese Academy of Sciences (KJCX2-YW-N27), and the Fundamental Research Funds for the Central Universities (WK2030040029),and the CAS Center for Excellence in Particle Physics (CCEPP).

  9. In-situ measurements of the secondary electron yield in an accelerator environment: Instrumentation and methods

    NASA Astrophysics Data System (ADS)

    Hartung, W. H.; Asner, D. M.; Conway, J. V.; Dennett, C. A.; Greenwald, S.; Kim, J.-S.; Li, Y.; Moore, T. P.; Omanovic, V.; Palmer, M. A.; Strohman, C. R.

    2015-05-01

    The performance of a particle accelerator can be limited by the build-up of an electron cloud (EC) in the vacuum chamber. Secondary electron emission from the chamber walls can contribute to EC growth. An apparatus for in-situ measurements of the secondary electron yield (SEY) in the Cornell Electron Storage Ring (CESR) was developed in connection with EC studies for the CESR Test Accelerator program. The CESR in-situ system, in operation since 2010, allows for SEY measurements as a function of incident electron energy and angle on samples that are exposed to the accelerator environment, typically 5.3 GeV counter-rotating beams of electrons and positrons. The system was designed for periodic measurements to observe beam conditioning of the SEY with discrimination between exposure to direct photons from synchrotron radiation versus scattered photons and cloud electrons. The samples can be exchanged without venting the CESR vacuum chamber. Measurements have been done on metal surfaces and EC-mitigation coatings. The in-situ SEY apparatus and improvements to the measurement tools and techniques are described.

  10. Valuing vaccines using value of statistical life measures.

    PubMed

    Laxminarayan, Ramanan; Jamison, Dean T; Krupnick, Alan J; Norheim, Ole F

    2014-09-01

    Vaccines are effective tools to improve human health, but resources to pursue all vaccine-related investments are lacking. Benefit-cost and cost-effectiveness analysis are the two major methodological approaches used to assess the impact, efficiency, and distributional consequences of disease interventions, including those related to vaccinations. Childhood vaccinations can have important non-health consequences for productivity and economic well-being through multiple channels, including school attendance, physical growth, and cognitive ability. Benefit-cost analysis would capture such non-health benefits; cost-effectiveness analysis does not. Standard cost-effectiveness analysis may grossly underestimate the benefits of vaccines. A specific willingness-to-pay measure is based on the notion of the value of a statistical life (VSL), derived from trade-offs people are willing to make between fatality risk and wealth. Such methods have been used widely in the environmental and health literature to capture the broader economic benefits of improving health, but reservations remain about their acceptability. These reservations remain mainly because the methods may reflect ability to pay, and hence be discriminatory against the poor. However, willingness-to-pay methods can be made sensitive to income distribution by using appropriate income-sensitive distributional weights. Here, we describe the pros and cons of these methods and how they compare against standard cost-effectiveness analysis using pure health metrics, such as quality-adjusted life years (QALYs) and disability-adjusted life years (DALYs), in the context of vaccine priorities. We conclude that if appropriately used, willingness-to-pay methods will not discriminate against the poor, and they can capture important non-health benefits such as financial risk protection, productivity gains, and economic wellbeing. PMID:25045822

  11. Surface composition and barium evaporation rate of ``pedigreed'' impregnated tungsten dispenser cathodes during accelerated life testing

    NASA Astrophysics Data System (ADS)

    Tomich, D. H.; Mescher, J. A.; Grant, J. T.

    1987-03-01

    A study has been made of the surface composition and barium evaporation rate of "pedigreed" impregnated tungsten dispenser cathodes. The effect of air exposure on coated cathodes was examined and was found to have no significant effect on barium evaporation rate although in some cases longer reactivation times were required. No changes in surface topography were apparent following air exposure and reactivation. Life testing was done at 100°C above the typical operating temperature for the cathode, where the typical operating temperature was taken to be 950°C for coated cathodes and 1050°C for uncoated cathodes. The cathodes were examined at different stages of life testing, up to 1200 h. Significant decreases in barium evaporation rates were found after as few as 500 h of life testing. After 1000 h the evaporation rate had decreased more than an order of magnitude. Changes in surface composition were also found. The effects of tungsten particle size, used in manufacture of the billet, on barium evaporation rate were also studied but no correlation was found.

  12. Accelerated discovery of cathode materials with prolonged cycle life for lithium-ion battery

    NASA Astrophysics Data System (ADS)

    Nishijima, Motoaki; Ootani, Takuya; Kamimura, Yuichi; Sueki, Toshitsugu; Esaki, Shogo; Murai, Shunsuke; Fujita, Koji; Tanaka, Katsuhisa; Ohira, Koji; Koyama, Yukinori; Tanaka, Isao

    2014-08-01

    Large-scale battery systems are essential for efficiently utilizing renewable energy power sources from solar and wind, which can generate electricity only intermittently. The use of lithium-ion batteries to store the generated energy is one solution. A long cycle life is critical for lithium-ion battery when used in these applications; this is different from portable devices which require 1,000 cycles at most. Here we demonstrate a novel co-substituted lithium iron phosphate cathode with estimated 70%-capacity retention of 25,000 cycles. This is found by exploring a wide chemical compositional space using density functional theory calculations. Relative volume change of a compound between fully lithiated and delithiated conditions is used as the descriptor for the cycle life. On the basis of the results of the screening, synthesis of selected materials is targeted. Single-phase samples with the required chemical composition are successfully made by an epoxide-mediated sol-gel method. The optimized materials show excellent cycle-life performance as lithium-ion battery cathodes.

  13. Accelerated discovery of cathode materials with prolonged cycle life for lithium-ion battery.

    PubMed

    Nishijima, Motoaki; Ootani, Takuya; Kamimura, Yuichi; Sueki, Toshitsugu; Esaki, Shogo; Murai, Shunsuke; Fujita, Koji; Tanaka, Katsuhisa; Ohira, Koji; Koyama, Yukinori; Tanaka, Isao

    2014-01-01

    Large-scale battery systems are essential for efficiently utilizing renewable energy power sources from solar and wind, which can generate electricity only intermittently. The use of lithium-ion batteries to store the generated energy is one solution. A long cycle life is critical for lithium-ion battery when used in these applications; this is different from portable devices which require 1,000 cycles at most. Here we demonstrate a novel co-substituted lithium iron phosphate cathode with estimated 70%-capacity retention of 25,000 cycles. This is found by exploring a wide chemical compositional space using density functional theory calculations. Relative volume change of a compound between fully lithiated and delithiated conditions is used as the descriptor for the cycle life. On the basis of the results of the screening, synthesis of selected materials is targeted. Single-phase samples with the required chemical composition are successfully made by an epoxide-mediated sol-gel method. The optimized materials show excellent cycle-life performance as lithium-ion battery cathodes. PMID:25080933

  14. Neural Network Models of Simple Mechanical Systems Illustrating the Feasibility of Accelerated Life Testing

    NASA Technical Reports Server (NTRS)

    Fusaro, Robert L.; Jones, Steven P.; Jansen, Ralph

    1996-01-01

    A complete evaluation of the tribological characteristics of a given material/mechanical system is a time-consuming operation since the friction and wear process is extremely systems sensitive. As a result, experimental designs (i.e., Latin Square, Taguchi) have been implemented in an attempt to not only reduce the total number of experimental combinations needed to fully characterize a material/mechanical system, but also to acquire life data for a system without having to perform an actual life test. Unfortunately, these experimental designs still require a great deal of experimental testing and the output does not always produce meaningful information. In order to further reduce the amount of experimental testing required, this study employs a computer neural network model to investigate different material/mechanical systems. The work focuses on the modeling of the wear behavior, while showing the feasibility of using neural networks to predict life data. The model is capable of defining which input variables will influence the tribological behavior of the particular material/mechanical system being studied based on the specifications of the overall system.

  15. Initial measurements of beam breakup instability in the advanced test accelerator

    SciTech Connect

    Chong, Y.P.; Caporaso, G.J.; Struve, K.W.

    1985-05-13

    This paper reports the measurements of beam breakup (BBU) instability performed on the Advanced Test Accelerator (ATA) up to the end of February, 1984. The main objective was to produce a high current usable electron beam at the ATA output. A well-known instability is BBU which arises from the accelerator cavity modes interacting with the electron beam. The dominant mode is TM/sub 130/ at a frequency of approximately 785 MHz. It couples most strongly to the beam motion and has been observed to grow in the Experimental Test Accelerator (ETA) which has only eight accelerator cavities. ATA has one hundred and seventy cavities and, therefore, the growth of BBU is expected to be more severe. In this paper, BBU measurements are reported for ATA with beam currents of 4 to 7 kA. Analysis showed that the growth of the instability with propagation distance was as expected for the lower currents. However, the high-current data showed an apparent higher growth rate than expected. An explanation for this anomaly is given in terms of a ''corkscrew'' excitation. The injector BBU noise level for a field emission brush cathode was found to be an order of magnitude lower than for a cold plasma discharge cathode. These injector rf amplitudes agree very well with values obtained using the method of differenced B sub solar loops.

  16. Intrinsic beam emittance of laser-accelerated electrons measured by x-ray spectroscopic imaging.

    PubMed

    Golovin, G; Banerjee, S; Liu, C; Chen, S; Zhang, J; Zhao, B; Zhang, P; Veale, M; Wilson, M; Seller, P; Umstadter, D

    2016-01-01

    The recent combination of ultra-intense lasers and laser-accelerated electron beams is enabling the development of a new generation of compact x-ray light sources, the coherence of which depends directly on electron beam emittance. Although the emittance of accelerated electron beams can be low, it can grow due to the effects of space charge during free-space propagation. Direct experimental measurement of this important property is complicated by micron-scale beam sizes, and the presence of intense fields at the location where space charge acts. Reported here is a novel, non-destructive, single-shot method that overcame this problem. It employed an intense laser probe pulse, and spectroscopic imaging of the inverse-Compton scattered x-rays, allowing measurement of an ultra-low value for the normalized transverse emittance, 0.15 (±0.06) π mm mrad, as well as study of its subsequent growth upon exiting the accelerator. The technique and results are critical for designing multi-stage laser-wakefield accelerators, and generating high-brightness, spatially coherent x-rays. PMID:27090440

  17. Intrinsic beam emittance of laser-accelerated electrons measured by x-ray spectroscopic imaging

    DOE PAGESBeta

    Golovin, G.; Banerjee, S.; Liu, C.; Chen, S.; Zhang, J.; Zhao, B.; Zhang, P.; Veale, M.; Wilson, M.; Seller, P.; et al

    2016-04-19

    Here, the recent combination of ultra-intense lasers and laser-accelerated electron beams is enabling the development of a new generation of compact x-ray light sources, the coherence of which depends directly on electron beam emittance. Although the emittance of accelerated electron beams can be low, it can grow due to the effects of space charge during free-space propagation. Direct experimental measurement of this important property is complicated by micron-scale beam sizes, and the presence of intense fields at the location where space charge acts. Reported here is a novel, non-destructive, single-shot method that overcame this problem. It employed an intense lasermore » probe pulse, and spectroscopic imaging of the inverse-Compton scattered x-rays, allowing measurement of an ultra-low value for the normalized transverse emittance, 0.15 (±0.06) π mm mrad, as well as study of its subsequent growth upon exiting the accelerator. The technique and results are critical for designing multi-stage laser-wakefield accelerators, and generating high-brightness, spatially coherent x-rays.« less

  18. Intrinsic beam emittance of laser-accelerated electrons measured by x-ray spectroscopic imaging

    PubMed Central

    Golovin, G.; Banerjee, S.; Liu, C.; Chen, S.; Zhang, J.; Zhao, B.; Zhang, P.; Veale, M.; Wilson, M.; Seller, P.; Umstadter, D.

    2016-01-01

    The recent combination of ultra-intense lasers and laser-accelerated electron beams is enabling the development of a new generation of compact x-ray light sources, the coherence of which depends directly on electron beam emittance. Although the emittance of accelerated electron beams can be low, it can grow due to the effects of space charge during free-space propagation. Direct experimental measurement of this important property is complicated by micron-scale beam sizes, and the presence of intense fields at the location where space charge acts. Reported here is a novel, non-destructive, single-shot method that overcame this problem. It employed an intense laser probe pulse, and spectroscopic imaging of the inverse-Compton scattered x-rays, allowing measurement of an ultra-low value for the normalized transverse emittance, 0.15 (±0.06) π mm mrad, as well as study of its subsequent growth upon exiting the accelerator. The technique and results are critical for designing multi-stage laser-wakefield accelerators, and generating high-brightness, spatially coherent x-rays. PMID:27090440

  19. Intrinsic beam emittance of laser-accelerated electrons measured by x-ray spectroscopic imaging

    NASA Astrophysics Data System (ADS)

    Golovin, G.; Banerjee, S.; Liu, C.; Chen, S.; Zhang, J.; Zhao, B.; Zhang, P.; Veale, M.; Wilson, M.; Seller, P.; Umstadter, D.

    2016-04-01

    The recent combination of ultra-intense lasers and laser-accelerated electron beams is enabling the development of a new generation of compact x-ray light sources, the coherence of which depends directly on electron beam emittance. Although the emittance of accelerated electron beams can be low, it can grow due to the effects of space charge during free-space propagation. Direct experimental measurement of this important property is complicated by micron-scale beam sizes, and the presence of intense fields at the location where space charge acts. Reported here is a novel, non-destructive, single-shot method that overcame this problem. It employed an intense laser probe pulse, and spectroscopic imaging of the inverse-Compton scattered x-rays, allowing measurement of an ultra-low value for the normalized transverse emittance, 0.15 (±0.06) π mm mrad, as well as study of its subsequent growth upon exiting the accelerator. The technique and results are critical for designing multi-stage laser-wakefield accelerators, and generating high-brightness, spatially coherent x-rays.

  20. Automatic detection of lameness in gestating group-housed sows using positioning and acceleration measurements.

    PubMed

    Traulsen, I; Breitenberger, S; Auer, W; Stamer, E; Müller, K; Krieter, J

    2016-06-01

    Lameness is an important issue in group-housed sows. Automatic detection systems are a beneficial diagnostic tool to support management. The aim of the present study was to evaluate data of a positioning system including acceleration measurements to detect lameness in group-housed sows. Data were acquired at the Futterkamp research farm from May 2012 until April 2013. In the gestation unit, 212 group-housed sows were equipped with an ear sensor to sample position and acceleration per sow and second. Three activity indices were calculated per sow and day: path length walked by a sow during the day (Path), number of squares (25×25 cm) visited during the day (Square) and variance of the acceleration measurement during the day (Acc). In addition, data on lameness treatments of the sows and a weekly lameness score were used as reference systems. To determine the influence of a lameness event, all indices were analysed in a linear random regression model. Test day, parity class and day before treatment had a significant influence on all activity indices (P<0.05). In healthy sows, indices Path and Square increased with increasing parity, whereas variance slightly decreased. The indices Path and Square showed a decreasing trend in a 14-day period before a lameness treatment and to a smaller extent before a lameness score of 2 (severe lameness). For the index acceleration, there was no obvious difference between the lame and non-lame periods. In conclusion, positioning and acceleration measurements with ear sensors can be used to describe the activity pattern of sows. However, improvements in sampling rate and analysis techniques should be made for a practical application as an automatic lameness detection system. PMID:27074864

  1. A new method of accelerated life testing based on the Grey System Theory for a model-based lithium-ion battery life evaluation system

    NASA Astrophysics Data System (ADS)

    Gu, Weijun; Sun, Zechang; Wei, Xuezhe; Dai, Haifeng

    2014-12-01

    The lack of data samples is the main difficulty for the lifetime study of a lithium-ion battery, especially for a model-based evaluation system. To determine the mapping relationship between the battery fading law and the different external factors, the testing of batteries should be implemented to the greatest extent possible. As a result, performing a battery lifetime study has become a notably time-consuming undertaking. Without reducing the number of testing items pre-specified within the test matrices of an accelerated life testing schedule, a grey model that can be used to predict the cycle numbers that result in the specific life ending index is established in this paper. No aging mechanism is required for this model, which is exclusively a data-driven method obtained from a small quantity of actual testing data. For higher accuracy, a specific smoothing method is introduced, and the error between the predicted value and the actual value is also modeled using the same method. By the verification of a phosphate iron lithium-ion battery and a manganese oxide lithium-ion battery, this grey model demonstrated its ability to reduce the required number of cycles for the operational mode of various electric vehicles.

  2. Requirements and Development of an Acceleration Measurement System for International Space Station Microgravity Science Payloads

    NASA Technical Reports Server (NTRS)

    Sutliff, Thomas J.

    1997-01-01

    The International Space Station is being developed by NASA and international partners as a versatile user platform to allow long term on-orbit investigations of a variety of scientific and technology arenas. In particular, scientific studies are planned within a research class known as microgravity science in areas such as biotechnology, combustion, fluid physics, and materials sciences. An acceleration measurement system is in development to aid such research conducted in the on-orbit conditions of apparent weightlessness. This system provides a general purpose acceleration measurement capability in support of these payloads and investigators. Such capability allows for systematic study of scientific phenomena by obtaining information regarding the local accelerations present during experiment operations. Preparations for implementing this flight measurement system involves two distinct stages: requirements development prior to initiating the design activity, and the design activity itself. This paper defines the requirements definition approach taken, provides an overview of the results of the requirements phase, and outlines the initial design considerations being addressed for this measurement system. Some preliminary engineering approaches are also described.

  3. Space Acceleration Measurement System-II: Microgravity Instrumentation for the International Space Station Research Community

    NASA Technical Reports Server (NTRS)

    Sutliff, Thomas J.

    1999-01-01

    The International Space Station opens for business in the year 2000, and with the opening, science investigations will take advantage of the unique conditions it provides as an on-orbit laboratory for research. With initiation of scientific studies comes a need to understand the environment present during research. The Space Acceleration Measurement System-II provides researchers a consistent means to understand the vibratory conditions present during experimentation on the International Space Station. The Space Acceleration Measurement System-II, or SAMS-II, detects vibrations present while the space station is operating. SAMS-II on-orbit hardware is comprised of two basic building block elements: a centralized control unit and multiple Remote Triaxial Sensors deployed to measure the acceleration environment at the point of scientific research, generally within a research rack. Ground Operations Equipment is deployed to complete the command, control and data telemetry elements of the SAMS-II implementation. Initially, operations consist of user requirements development, measurement sensor deployment and use, and data recovery on the ground. Future system enhancements will provide additional user functionality and support more simultaneous users.

  4. Measurement of Neutrons Produced by Beam-Target Interactions via a Coaxial Plasma Accelerator

    NASA Astrophysics Data System (ADS)

    Cauble, Scott; Poehlmann, Flavio; Rieker, Gregory; Cappelli, Mark

    2011-10-01

    This poster presents a method to measure neutron yield from a coaxial plasma accelerator. Stored electrical energies between 1 and 19 kJ are discharged within a few microseconds across the electrodes of the coaxial gun, accelerating deuterium gas samples to plasma beam energies well beyond the keV energy range. The focus of this study is to examine the interaction of the plasma beam with a deuterated target by designing and fabricating a detector to measure neutron yield. Given the strong electromagnetic pulse associated with our accelerator, indirect measurement of neutrons via threshold-dependent nuclear activation serves as both a reliable and definitive indicator of high-energy particles for our application. Upon bombardment with neutrons, discs or stacks of metal foils placed near the deuterated target undergo nuclear activation reactions, yielding gamma-emitting isotopes whose decay is measured by a scintillation detector system. By collecting gamma ray spectra over time and considering nuclear cross sections, the magnitude of the original neutron pulse is inferred.

  5. Quality of life measurement and outcome in aphasia

    PubMed Central

    Spaccavento, Simona; Craca, Angela; Del Prete, Marina; Falcone, Rosanna; Colucci, Antonia; Di Palma, Angela; Loverre, Anna

    2014-01-01

    Background Quality of life (QL) can be defined as the individual’s perception of their own well-being. Aphasia is the most important potential consequence of stroke and has a profound effect on a patient’s life, causing emotional distress, depression, and social isolation, due to loss of language functions. Aims To draw up a QL questionnaire for aphasics (QLQA) focusing particularly on difficulties in interpersonal relationships and on the loss of independence as a result of language disorders. We reported the results of a psychometric evaluation of this measure. Moreover, we experimentally focused on the differences in QLQA between patients affected only by neurological motor impairment and hemiparetic patients with aphasia (PWA) in order to verify the specific role of aphasia on QL. We also explored if the QLQA is sensitive to the severity of aphasia and to the time elapsing from the stroke. Methods A total of 146 consecutive PWA and 37 control subjects were enrolled to evaluate the reliability (internal consistency and test–retest reliability) and validity of the QLQA, using standard psychometric methods. Patients were divided into acute (within 3 months since stroke) and chronic (beyond 3 months) groups, and into mild and severe according to the severity of aphasia. The experimental group of only acute PWA was compared to control subjects, with right hemispherical lesion and without aphasia in QLQA total and partial scores. Results The QLQA had good internal consistency and test–retest reliability. Acute and chronic PWA and mild and severe ones differed in QLQA total, communication, and autonomy subscales. No differences were found in psychological condition. Between aphasic and control patients, significant differences were found in all QLQA subscales. Conclusion The QLQA is a valid measure of QL in PWA, contributing to a better distinction between severe and mild aphasia, and it is sensitive also to the variations in QL depending on the time interval

  6. Online beam energy measurement of Beijing electron positron collider II linear accelerator.

    PubMed

    Wang, S; Iqbal, M; Liu, R; Chi, Y

    2016-02-01

    This paper describes online beam energy measurement of Beijing Electron Positron Collider upgraded version II linear accelerator (linac) adequately. It presents the calculation formula, gives the error analysis in detail, discusses the realization in practice, and makes some verification. The method mentioned here measures the beam energy by acquiring the horizontal beam position with three beam position monitors (BPMs), which eliminates the effect of orbit fluctuation, and is much better than the one using the single BPM. The error analysis indicates that this online measurement has further potential usage such as a part of beam energy feedback system. The reliability of this method is also discussed and demonstrated in this paper. PMID:26931839

  7. Online beam energy measurement of Beijing electron positron collider II linear accelerator

    NASA Astrophysics Data System (ADS)

    Wang, S.; Iqbal, M.; Liu, R.; Chi, Y.

    2016-02-01

    This paper describes online beam energy measurement of Beijing Electron Positron Collider upgraded version II linear accelerator (linac) adequately. It presents the calculation formula, gives the error analysis in detail, discusses the realization in practice, and makes some verification. The method mentioned here measures the beam energy by acquiring the horizontal beam position with three beam position monitors (BPMs), which eliminates the effect of orbit fluctuation, and is much better than the one using the single BPM. The error analysis indicates that this online measurement has further potential usage such as a part of beam energy feedback system. The reliability of this method is also discussed and demonstrated in this paper.

  8. Long life nickel electrodes for a nickel-hydrogen cell. III - Results of an accelerated test and failure analyses

    NASA Technical Reports Server (NTRS)

    Lim, H. S.; Verzwyvelt, S. A.

    1984-01-01

    Nineteen different designs of nickel electrodes were tested in Ni/H2 boiler plate cells in an accelerated low earth orbit cycle regime to the end of their life. The failure analyses of these cells showed that the major performance changes due to the cycling was a severe reduction of their high rate discharge capability rather than an absolute capacity reduction. Many physical changes of the nickel electrodes were observed after the cycling test. These changes include dimensional expansion, sinter rupture, loose black powdering of the active material, morphology changes, active material migration, increase of pore volume, change of pore distribution, and increase of surface area. All of these were caused by active material expansion with cycling. Among these changes, the morphology change which involves migration of active material away from the current collecting nickel sinter appears to be that most responsible for the reduction of the rate capability.

  9. In vitro evaluation of the bonding durability of self-adhesive resin cement to titanium using highly accelerated life test.

    PubMed

    Lin, Jie; Shinya, Akikazu; Gomi, Harunori; Matinlinna, Jukka Pekka; Shinya, Akiyoshi

    2011-01-01

    The purpose of this in vitro study was to evaluate the bonding durability of three self-adhesive resin cements to titanium using the Highly Accelerated Life Test (HALT). The following self-adhesive resin cements were used to bond pairs of titanium blocks together according to manufacturers' instructions: RelyX Unicem, Breeze, and Clearfil SA Luting. After storage in water at 37°C for 24 h, bonded specimens (n=15) immersed in 37°C water were subjected to cyclic shear load testing regimes of 20, 30, or 40 kg using a fatigue testing machine. Cyclic loading continued until failure occurred, and the number of cycles taken to reach failure was recorded. The bonding durability of a self-adhesive resin cement to titanium was largely influenced by the weight of impact load. HALT showed that Clearfil SA Luting, which contained MDP monomer, yielded the highest median bonding lifetime to titanium. PMID:22123007

  10. Summary Report of Mission Acceleration Measurements for STS-62, Launched 4 March 1994

    NASA Technical Reports Server (NTRS)

    Rogers, Melissa J. B.; Delombard, Richard

    1994-01-01

    The second mission of the United States Microgravity Payload on-board the STS-62 mission was supported with three accelerometer instruments: the Orbital Acceleration Research Experiment (OARE) and two units of the Space Acceleration Measurements System (SAMS). The March 4, 1994 launch was the fourth successful mission for OARE and the ninth successful mission for SAMS. The OARE instrument utilizes a sensor for very low frequency measurements below one Hertz. The accelerations in this frequency range are typically referred to as quasisteady accelerations. One of the SAMS units had two remote triaxial sensor heads mounted on the forward MPESS structure between two furnance experiments, MEPHISTO and AADSF. These triaxial heads had low-pass filter cut-off frequencies at 10 and 25 Hz. The other SAMS unit utilized three remote triaxial sensor heads. Two of the sensor heads were mounted on the aft MPESS structure between the two experiments IDGE and ZENO. These triaxial heads had low-pass filter cut-off frequencies at 10 and 25 Hz. The third sensor head was mounted on the thermostat housing inside the IDGE experiment container. This triaxial head had a low-pass filter cut-off frequency at 5 Hz. This report is prepared to furnish interested experiment investigators with a guide to evaluating the acceleration environment during STS-62 and as a means of identifying areas which require further study. To achieve this purpose, various pieces of information are included, such as an overview of the STS-62 mission, a description of the accelerometer system flown on STS-62, some specific analysis of the accelerometer data in relation to the various mission activities, and an overview of the low-gravity environment during the entire mission. An evaluation form is included at the end of the report to solicit users' comments about the usefulness of this series of reports.

  11. Method and apparatus for measuring gravitational acceleration utilizing a high temperature superconducting bearing

    DOEpatents

    Hull, John R.

    2000-01-01

    Gravitational acceleration is measured in all spatial dimensions with improved sensitivity by utilizing a high temperature superconducting (HTS) gravimeter. The HTS gravimeter is comprised of a permanent magnet suspended in a spaced relationship from a high temperature superconductor, and a cantilever having a mass at its free end is connected to the permanent magnet at its fixed end. The permanent magnet and superconductor combine to form a bearing platform with extremely low frictional losses, and the rotational displacement of the mass is measured to determine gravitational acceleration. Employing a high temperature superconductor component has the significant advantage of having an operating temperature at or below 77K, whereby cooling may be accomplished with liquid nitrogen.

  12. Rayleigh-Taylor Growth Measurements in the Acceleration Phase of Spherical Implosions on OMEGA

    SciTech Connect

    Smalyuk, V. A.; Hu, S. X.; Hager, J. D.; Delettrez, J. A.; Meyerhofer, D. D.; Sangster, T. C.; Shvarts, D.

    2009-09-04

    The Rayleigh-Taylor (RT) growth of 3D broadband nonuniformities was measured using x-ray radiography in spherical plastic shells accelerated by laser light at an intensity of approx2x10{sup 14} W/cm{sup 2}. The 20- and 24-mum-thick spherical shells were imploded with 54 beams on the OMEGA laser system. The shells contained diagnostic openings for backlighter x rays used to image shell modulations. The measured shell trajectories and modulation RT growth were in fair agreement with 2D hydro simulations during the acceleration phase of the implosions with convergence ratios of up to approx2.2. Since the ignition designs rely on these simulations, improvements in the numerical codes will be implemented to achieve better agreement with experiments.

  13. Rayleigh-Taylor Growth Measurements in the Acceleration Phase of Spherical Implosions on OMEGA

    SciTech Connect

    Smalyuk, V.A.; Hu, S.X.; Hager, J.D.; Delettrez, J.A.; Meyerhofer, D.D.; Sangster, T.C.; Shvarts, D.

    2009-09-10

    The Rayleigh-Taylor (RT) growth of 3D broadband nonuniformities was measured using x-ray radiography in spherical plastic shells accelerated by laser light at an intensity of ~2 x 10^14 W/cm^2. The 20- and 24-um-thick spherical shells were imploded with 54 beams on the OMEGA laser system. The shells contained diagnostic openings for backlighter x rays used to image shell modulations. The measured shell trajectories and modulation RT growth were in fair agreement with 2D hydro simulations during the acceleration phase of the implosions with convergence ratios of up to ~2:2. Since the ignition designs rely on these simulations, improvements in the numerical codes will be implemented to achieve better agreement with experiments.

  14. A fiber optic strain measurement and quench localization system for use in superconducting accelerator dipole magnets

    SciTech Connect

    van Oort, J.M.; Scanlan, R.M.; ten Kate, H.H.J.

    1994-10-17

    A novel fiber-optic measurement system for superconducting accelerator magnets is described. The principal component is an extrinsic Fabry-Perot Interferometer to determine localized strain and stress in coil windings. The system can be used either as a sensitive relative strain measurement system or as an absolute strain detector. Combined, one can monitor the mechanical behaviour of the magnet system over time during construction, long time storage and operation. The sensing mechanism is described, together with various tests in laboratory environments. The test results of a multichannel test matrix to be incorporated first in the dummy coils and then in the final version of a 13T Nb{sub 3}Sn accelerator dipole magnet are presented. Finally, the possible use of this system as a quench localization system is proposed.

  15. Method and Apparatus for measuring Gravitational Acceleration Utilizing a high Temperature Superconducting Bearing

    SciTech Connect

    Hull, John R.

    1998-11-06

    Gravitational acceleration is measured in all spatial dimensions with improved sensitivity by utilizing a high temperature superconducting (HTS) gravimeter. The HTS gravimeter is comprised of a permanent magnet suspended in a spaced relationship from a high temperature superconductor, and a cantilever having a mass at its free end is connected to the permanent magnet at its fixed end. The permanent magnet and superconductor combine to form a bearing platform with extremely low frictional losses, and the rotational displacement of the mass is measured to determine gravitational acceleration. Employing a high temperature superconductor component has the significant advantage of having an operative temperature at or below 77K, whereby cooling maybe accomplished with liquid nitrogen.

  16. A fiber optic strain measurement and quench localization for use in superconducting accelerator dipole magnets

    NASA Astrophysics Data System (ADS)

    Vanoort, Johannes M.; Scanlan, Ronald M.; Tenkate, Herman H. J.

    1994-10-01

    A novel fiber-optic measurement system for superconducting accelerator magnets is described. The principal component is an extrinsic Fabry-Perot Interferometer to determine localized strain and stress in coil windings. The system can be used either as a sensitive relative strain measurement system or as an absolute strain detector. Combined, one can monitor the mechanical behaviour of the magnet system over time during construction, long time storage and operation. The sensing mechanism is described, together with various tests in laboratory environments. The test results of a multichannel test matrix to be incorporated first in the dummy coils and then in the final version of a 13T Nb3Sn accelerator dipole magnet are presented. Finally, the possible use of this system as a quench localization system is proposed.

  17. Quality of Life in South Africa: Measurement and Analysis.

    ERIC Educational Resources Information Center

    Moller, V.; And Others

    Research on the quality of life in South Africa is increasing as a result of a growing concern to improve the living conditions and overall quality of life for many underprivileged South Africans. Perceptions of well-being and basic needs were investigated in a nationwide study conducted in 1982-83. Components of the variable "quality of life"…

  18. Laser damage threshold measurements of optical materials for direct laser accelerators

    SciTech Connect

    Soong, Ken; Byer, R. L.; Colby, E. R.; England, R. J.; Peralta, E. A.

    2012-12-21

    The laser-damage threshold is a fundamental limit for any dielectric laser-driven accelerator and is set by the material of the structure. In this paper, we present a theoretical model of the laser damage mechanism, in comparison with experimental data on the damage threshold of silicon. Additionally, we present damage threshold measurement data of various optical materials, most of which have not been previously characterized in the picosecond-regime.

  19. Repeatable electrical measurement instrumentation for use in the accelerated stress testing of thin film solar cells

    NASA Technical Reports Server (NTRS)

    Davis, C. W.; Lathrop, J. W.

    1985-01-01

    Attention is given to the construction, calibration, and performance of a repeatable measurement system for use in conjunction with the accelerated stress testing of a-Si:H cells. A filtered diode array is utilized to approximate the spectral response of any type of solar cell in discrete portions of the spectrum. It is noted that in order to achieve the necessary degree of overall repeatability, it is necessary to pay particular attention to methods of contacting and positioning the cells.

  20. Measurement and Characterization of the Acceleration Environment on Board the Space Station

    NASA Technical Reports Server (NTRS)

    Baugher, Charles R. (Editor)

    1990-01-01

    This workshop provides a comprehensive overview of the work and status of each of these areas to provide a basis for establishing a systematic approach to the challenge of avoiding these difficulties during the Space Station era of materials experimentation. The discussions were arranged in the order of: the scientific understanding of the requirements for a micro-gravity environment, a history of acceleration measurements on spacecraft, the state of accelerometer technology, and the current understanding of the predicted Space Station environment.

  1. Summary report of mission acceleration measurements for STS-60, SPACEHAB2, launched 11 February 1994

    NASA Technical Reports Server (NTRS)

    Rogers, Melissa J. B.; Delombard, Richard

    1994-01-01

    The STS-60 mission, which launched on 11 February 1994, carried seven accelerometer systems. This report describes the configuration of each of these systems, where they were located on the Orbiter and the name of a contact person for each system. The Space Acceleration Measurement System (SAMS) was one of the accelerometer systems on-board and this mission marked its eighth successful flight. Acceleration data are provided here for SAMS which flew under an agreement between the NASA Microgravity Science and Applications division and the NASA office of Advanced Concepts and Technology. Acceleration data for the other accelerometer systems are not presented here. SAMS was located in the commercial SPACEHAB laboratory, on its second flight. The SAMS system was configured with three triaxial sensor heads with filter cut-offs of 5, 10, and 50 Hz. The acceleration environment related to an experiment centrifuge, an experiment refrigerator freezer unit, a SAMS sensor head rotation, an Orbiter shudder, and payload deploy activities are discussed. In the Appendices, all of the data from SAMS Head B (10 Hz) are plotted to provide an overview of the environment during the majority of the STS-60 mission. An evaluation form is included at the end of the report to solicit users' comments about the usefulness of this series of reports.

  2. Thermal performance analysis and measurements of the prototype cryomodules of European XFEL accelerator - part I

    NASA Astrophysics Data System (ADS)

    Wang, X. L.; Barbanotti, S.; Eschke, J.; Jensch, K.; Klos, R.; Maschmann, W.; Petersen, B.; Sawlanski, O.

    2014-11-01

    The European X-Ray Free Electron Laser (XFEL), the research facility currently under construction in the Hamburg area, Germany, is based on a superconducting linear accelerator that brings electrons to almost the speed of light. The linear accelerator consists of 100 accelerating cryomodules (CMs) operating at the temperature of 2 K. The thermal performances of the accelerator CMs are a key element to determine the heat load budget, the required capacity and the cost of the XFEL refrigerating system and to guarantee its efficient operation. The measurement of the thermal performances of the CMs is also an important step in the qualification of the CMs during the series production. This paper describes the thermal performance analysis of the European XFEL prototype cryomodules. The analysis takes into account all the main contributors (multilayer insulation, current leads, power couplers, support posts, and cavities) to the static and dynamic heat loads at various cryogenic temperature levels. Existing empirical databases are reviewed and used to evaluate the heat transfer through the multilayer insulation and numerical simulations are developed to investigate the heat loads generated from the different CM components.

  3. SAMS Acceleration Measurements on Mir from November 1995 to March 1996

    NASA Technical Reports Server (NTRS)

    DeLombard, Richard

    1997-01-01

    The NASA Microgravity Science and Applications Division (MSAD) sponsors science experiments on a variety of microgravity carriers, including Orbiter missions and Russia's Mir space station. The MSAD sponsors the Space Acceleration Measurement System (SAMS) at the NASA Lewis Research Center (LERC) to support these science experiments by providing acceleration measurements to characterize the microgravity environment to which the experiments were exposed. The LeRC Principal Investigator Microgravity Services (PIMS) project supports principal investigations of microgravity science experiments as they evaluate the effects of varying acceleration levels on their experiments. In 1994, a SAMS unit was installed on the Mir space station. In a manner similar to Orbiter mission support, the SAMS unit supports science experiments from the U.S. and Russia by measuring the microgravity environment during experiment operations. Previous reports have summarized the SAMS data acquired during the period from September 1994 to November 1995. During the time period from November 1995 to March 1996, the primary SAMS-supported experiment was a Protein Crystal Growth (PCG) experiment. SAMS data were obtained during the PCG operations on Mir in accordance with the requirements specified by the PCG Principal Investigator. Also included in this data are mission events of interest, such as the undocking of STS-74 from Mir (November 1995) and the docking of Atlantis (STS-76) to Mir in March 1996. This report presents an overview of the SAMS data recorded in the interval from November 1995 to March 1996.

  4. Ambient dose and dose rate measurements in the vicinity of Elekta Precise accelerators for radiation therapy.

    PubMed

    Zutz, H; Hupe, O

    2014-12-01

    In radiation therapy, commercially available medical linear accelerators (LINACs) are used. At high primary beam energies in the 10-MeV range, the leakage dose of the accelerator head and the backscatter from the room walls, the air and the patient become more important. Therefore, radiation protection measurements of photon dose rates in the treatment room and in the maze are performed to quantify the radiation field. Since the radiation of the LINACs is usually pulsed with short radiation pulse durations in the microsecond range, there are problems with electronic dose (rate) meters commonly used in radiation protection. In this paper measurements with ionisation chambers are presented and electronic dosemeters are used for testing at selected positions. The measured time-averaged dose rate ranges from a few microsieverts per hour in the maze to some millisieverts per hour in the vicinity of the accelerator head and up to some sieverts per hour in the blanked primary beam and several hundred sieverts per hour in the direct primary beam. PMID:24379437

  5. Quality of life measurement in gastrointestinal and liver disorders

    PubMed Central

    BORGAONKAR, M; IRVINE, E

    2000-01-01

    Modern medicine has had a considerable impact on mortality rates for serious illness. Many chronic diseases which have previously been associated with an increased mortality now have survival rates approaching those of the background population. However, chronic diseases such as cancer, chronic pain syndromes, and chronic inflammatory conditions impose a considerable burden on families, the health care system, and society. Health related quality of life (HRQOL) is a concept that has developed from the need to estimate the impact of such chronic diseases. HRQOL measurement is a conceptual framework which attempts to predict daily function and well being based on subjective attitudes and experiences of physical, social, and emotional health. It has been evaluated predominantly from the patient's viewpoint as proxy respondents appear to underestimate the full effect of chronic illness on functional status. Measuring HRQOL in clinical research is most frequently undertaken using multi-item questionnaires to estimate daily function. Factors which affect HRQOL can be broadly classed as disease related and disease independent. The use of different assessment techniques permits comparisons between and within disorders. Generic and disease specific instruments used together enhance the ability to direct treatment for individuals and patient populations. Psychometrically sound questionnaires must be used. However, the type of instrument and research methods adopted depend on the question of interest. We have attempted to catalogue and critically assess the disease specific instruments used in the assessment of chronic gastrointestinal disease.

 PMID:10940286

  6. Accelerated and real-time geosynchronous life cycling test performance of nickel-hydrogen batteries

    NASA Technical Reports Server (NTRS)

    Green, R. S.

    1985-01-01

    RCA Astro-Electronics currently has four nickel-hydrogen storage battery modules (11 cells each) on test in simulated geosynchronous life cycle regimes. These battery modules are of identical design to those used on the GSTAR (GTE Satellite Corp.) and Spacenet (GTE Spacenet Corp.) communications satellites. The batteries are being tested using an automated test station equipped with computer-controlled environmental chambers and recording equipment. The two battery types, 30 ampere-hours and 40 ampere-hours (GSTAR and Spacenet, respectively), are being electrically cycled using identical 44-day eclipse sequences at 5 C and vary with respect to depth of discharge, recharge ratio, duration of accumulated suntime, and the use of a reconditioning sequence. The test parameters are outlined and the preliminary test data and results are presented.

  7. Quality of Life Assessment for Physical Activity and Health Promotion: Further Psychometrics and Comparison of Measures

    ERIC Educational Resources Information Center

    Gill, Diane L.; Reifsteck, Erin J.; Adams, Melanie M.; Shang, Ya-Ting

    2015-01-01

    Despite the clear relationship between physical activity and quality of life, few sound, relevant quality of life measures exist. Gill and colleagues developed a 32-item quality of life survey, and provided initial psychometric evidence. This study further examined that quality of life survey in comparison with the widely used short form (SF-36)…

  8. Comparison of measured Varian Clinac 21EX and TrueBeam accelerator electron field characteristics.

    PubMed

    Lloyd, Samantha A M; Zavgorodni, Sergei; Gagne, Isabelle M

    2015-01-01

    Dosimetric comparisons of radiation fields produced by Varian's newest linear accelerator, the TrueBeam, with those produced by older Varian accelerators are of interest from both practical and research standpoints. While photon fields have been compared in the literature, similar comparisons of electron fields have not yet been reported. In this work, electron fields produced by the TrueBeam are compared with those produced by Varian's Clinac 21EX accelerator. Diode measurements were taken of fields shaped with electron applicators and delivered at 100 cm SSD, as well as those shaped with photon MLCs without applicators and delivered at 70 cm SSD for field sizes ranging from 5 × 5 to 25 × 25 cm² at energies between 6 and 20 MeV. Additionally, EBT2 and EBT3 radio-chromic film measurements were taken of an MLC-shaped aperture with closed leaf pairs delivered at 70 cm SSD using 6 and 20 MeV electrons. The 6 MeV fields produced by the TrueBeam and Clinac 21EX were found to be almost indistinguishable. At higher energies, TrueBeam fields shaped by electron applicators were generally flatter and had less photon contamination compared to the Clinac 21EX. Differences in PDDs and profiles fell within 3% and 3 mm for the majority of measurements. The most notable differences for open fields occurred in the profile shoulders for the largest applicator field sizes. In these cases, the TrueBeam and Clinac 21EX data differed by as much as 8%. Our data indicate that an accurate electron beam model of the Clinac 21EX could be used as a starting point to simulate electron fields that are dosimetrically equivalent to those produced by the TrueBeam. Given that the Clinac 21EX shares head geometry with Varian's iX, Trilogy, and Novalis TX accelerators, our findings should also be applicable to these machines. PMID:26219015

  9. Measurements of the Influence of Acceleration and Temperature of Bodies on their Weight

    SciTech Connect

    Dmitriev, Alexander L.

    2008-01-21

    A brief review of experimental research of the influence of acceleration and temperatures of test mass upon gravitation force, executed between the 1990s and the beginning of 2000 at the St.-Petersburg State University of Information Technologies, Mechanics and Optics in cooperation with D. I. Mendeleev's Institute of Metrology is provided. According to a phenomenological notion, the acceleration of a test mass caused by external action, for example electromagnetic forces, results in changes of the gravitational properties of this mass. Consequences are a dependence upon gravity on the size and sign of test mass acceleration, and also on its absolute temperature. Results of weighing a rotor of a mechanical gyroscope with a horizontal axis, an anisotropic crystal with the big difference of the speed of longitudinal acoustic waves, measurements of temperature dependence of weight of metal bars of nonmagnetic materials, and also measurement of restitution coefficients at quasi-elastic impact of a steel ball about a massive plate are given. In particular, a reduction of apparent mass of a horizontal rotor with relative size 3.10{sup -6} at a speed of rotation of 18.6 thousand rev/min was observed. A negative temperature dependence of the weight of a brass core with relative size near 5.10{sup -4} K{sup -1} at room temperature was measured; this temperature factor was found to be a maximum for light and elastic metals. All observably experimental effects, have probably a general physical reason connected with the weight change dependent upon acceleration of a body or at thermal movement of its microparticles. The reduction of mass at high temperatures is of particular interest for propulsion applications.

  10. Measurements of the Influence of Acceleration and Temperature of Bodies on their Weight

    NASA Astrophysics Data System (ADS)

    Dmitriev, Alexander L.

    2008-01-01

    A brief review of experimental research of the influence of acceleration and temperatures of test mass upon gravitation force, executed between the 1990s and the beginning of 2000 at the St.-Petersburg State University of Information Technologies, Mechanics and Optics in cooperation with D. I. Mendeleev's Institute of Metrology is provided. According to a phenomenological notion, the acceleration of a test mass caused by external action, for example electromagnetic forces, results in changes of the gravitational properties of this mass. Consequences are a dependence upon gravity on the size and sign of test mass acceleration, and also on its absolute temperature. Results of weighing a rotor of a mechanical gyroscope with a horizontal axis, an anisotropic crystal with the big difference of the speed of longitudinal acoustic waves, measurements of temperature dependence of weight of metal bars of nonmagnetic materials, and also measurement of restitution coefficients at quasi-elastic impact of a steel ball about a massive plate are given. In particular, a reduction of apparent mass of a horizontal rotor with relative size 3.10-6 at a speed of rotation of 18.6 thousand rev/min was observed. A negative temperature dependence of the weight of a brass core with relative size near 5.10-4 K-1 at room temperature was measured; this temperature factor was found to be a maximum for light and elastic metals. All observably experimental effects, have probably a general physical reason connected with the weight change dependent upon acceleration of a body or at thermal movement of its microparticles. The reduction of mass at high temperatures is of particular interest for propulsion applications.

  11. Diffusive Shock Acceleration Simulations: Comparison with Particle Methods and Bow Shock Measurements

    NASA Astrophysics Data System (ADS)

    Kang, Hyesung; Jones, T. W.

    1995-07-01

    Direct comparisons of diffusive particle acceleration numerical simulations have been made against Monte Carlo and hybrid plasma simulations by Ellison et al. (1993) and against observations at the Earth's bow shock presented by Ellison et al. (1990). Toward this end we have introduced a new numerical scheme for injection of cosmic-ray particles out of the thermal plasma, modeled by way of the diffusive scattering process itself; that is, the diffusion and acceleration across the shock front of particles out of the suprathermal tail of the Maxwellian distribution. Our simulations take two forms. First, we have solved numerically the timedependent diffusion-advection equation for the high-energy (cosmic-ray) protons in one-dimensional quasiparallel shocks. Dynamical feedback between the particles and thermal plasma is included. The proton fluxes on both sides of the shock derived from our method are consistent with those calculated by Ellison et al. (1993). A similar test has compared our methods to published measurements at the Earth's bow shock when the interplanetary magnetic field was almost parallel to the solar wind velocity (Ellison et al. 1990). Again our results are in good agreement. Second, the same shock conditions have been simulated with the two-fluid version of diffusive shock acceleration theory by adopting injection rates and the closure parameters inferred from the diffusion-advection equation calculations. The acceleration efficiency and the shock structure calculated with the two-fluid method are in good agreement with those computed with the diffusion-advection method. Thus, we find that all of these computational methods (diffusion-advection, two-fluid, Monte Carlo, and hybrid) are in substantial agreement on the issues they can simultaneously address, so that the essential physics of diffusive particle acceleration is adequately contained within each. This is despite the fact that each makes what appear to be very different assumptions or

  12. Summary Report of Mission Acceleration Measurements for STS-79. Launched 16 Sep. 1996

    NASA Technical Reports Server (NTRS)

    Rogers, Melissa J. B.; Moskowitz, Milton E.; Hrovat, Kenneth; Reckart, Timothy A.

    1997-01-01

    The Space Acceleration Measurement System (SAMS) collected acceleration data in support of the Mechanics of Granular Materials experiment during the STS-79 Mir docking mission, September 1996. STS-79 was the first opportunity to record SAMS data on an Orbiter while it was docked to Mir. Crew exercise activities in the Atlantis middeck and the Mir base module are apparent in the data. The acceleration signals related to the Enhanced Orbiter Refrigerator Freezer had different characteristics when comparing the data recorded on Atlantis on STS-79 with the data recorded on Mir during STS-74. This is probably due, at least in part, to different transmission paths and SAMS sensor head mounting mechanisms. Data collected on Atlantis during the STS-79 docking indicate that accelerations due to vehicle and solar array structural modes from Mir transfer to Atlantis and that the structural modes of the Atlantis-Mir complex are different from those of either vehicle independently. A 0.18 Hz component of the SAMS data, present while the two vehicles were docked, was probably caused by the Mir solar arrays. Compared to Atlantis structural modes of about 3.9 and 4.9 Hz, the Atlantis-Mir complex has structural components of about 4.5 and 5.1 Hz. After docking, apparent structural modes appeared in the data at about 0.8 and 1.8 Hz. The appearance, disappearance, and change in the structural modes during the docking and undocking phases of the joint Atlantis-Mir operations indicates that the structural modes of the two spacecraft have an effect on the microgravity environment of each other. The transfer of structural and equipment related accelerations between vehicles is something that should be considered in the International Space Station era.

  13. An Acceleration Measurement Capability on International Space Station Supporting Microgravity Science Payloads

    NASA Technical Reports Server (NTRS)

    Sutliff, Thomas J.

    1997-01-01

    The conditions present in low-earth-orbit have enabled various scientific investigations to be conducted. A fundamental reason that space is a useful environment for science is the presence of a decreased effect of gravity while in orbital free-fall. Science investigations are conducted to study phenomena occurring as a result of reductions in buoyancy forces and phenomena enabled as a result of the apparent lack of gravity. The science community requires knowledge of the environment in which their experiments are being conducted. A general purpose measurement system was developed in the 1980's to supply scientific investigators with data of the residual acceleration environment. The Space Acceleration Measurement System, or SAMS, has flown aboard the NASA shuttle fleet over fourteen times, successfully acquiring acceleration measurement data in support of microgravity science experiments. As NASA continues its development of the International Space Station and its associated research payloads, it once again becomes necessary to address the requirement to measure the residual acceleration in support of the planned scientific investigations. As a follow-on to the SAMS project, SAMS-2 was initiated to investigate the requirements and develop the measurement system to support the microgravity science payloads aboard the International Space Station. The characteristics of the payload complement to be supported by SAMS-2 and the different capabilities provided by the station requires a fresh look at the design implementation of a general purpose measurement system. Not only is there a requirement for measurements in support of numerous, potentially simultaneous experiments, but this support is required to be provided for at least ten years of on-orbit operation as compared to a ten to fourteen day mission on shuttle. These differences in fundamental requirements result in the design configuration of the space station-based SAMS-2 being significantly different than that

  14. Measurements of Neutron Induced Cross Sections at the Oak Ridge Electron Linear Accelerator

    SciTech Connect

    Guber, K.H.; Harvey, J.A.; Hill, N.W.; Koehler, P.E.; Leal, L.C.; Sayer, R.O.; Spencer, R.R.

    1999-09-20

    We have used the Oak Ridge Electron Linear Accelerator (ORELA) to measure neutron total and the fission cross sections of 233U in the energy range from 0.36 eV to ~700 keV. We report average fission and total cross sections. Also, we measured the neutron total cross sections of 27Al and Natural chlorine as well as the capture cross section of Al over an energy range from 100 eV up to about 400 keV.

  15. Acceleration and rotation in a pendulum ride, measured using an iPhone 4

    NASA Astrophysics Data System (ADS)

    Pendrill, Ann-Marie; Rohlén, Johan

    2011-11-01

    Many modern cell phones have built-in sensors that may be used as a resource for physics education. Amusement rides offer examples of many different types of motion, where the acceleration leads to forces experienced throughout the body. A comoving 3D-accelerometer gives an electronic measurement of the varying forces acting on the rider, but a complete description of a motion also requires measurement of the rotation around the three axes, as provided, for example, by the iPhone 4. Here we present and interpret accelerometer and gyroscope data that were collected on a rotary pendulum ride.

  16. Measurements of the Argonne Wakefield Accelerator's low charge, 4 MeV RF photocathode witness beam.

    SciTech Connect

    Power, J.

    1998-04-01

    The Argonne Wakefield Accelerator's (AWA) witness RF photocathode gun produced its first electron beam in April of 1996. We have characterized the charge, energy, emittance and bunch length of the witness beam over the last several months. The emittance Was measured by both a quad scan that fitted for space charge using an in house developed Mathematica routine and a pepper pot technique. The bunch length was measured by imaging Cherenkov light from a quartz plate to a Hamamatsu streak camera with 2 psec resolution. A beam energy of 3.9 Mev was measured with a 6 inch round pole spectrometer while a beam charge was measured with both an ICT and a Faraday Cup. Although the gun will normally be run at 100 pC it has produced charges from 10 pC to 4 nc. All results of the measurements to date are presented here.

  17. Neutron field measurements for alara purposes around a Van de Graaff accelerator building.

    PubMed

    Kockerols, P; Lebacq, A L; Gasparro, J; Hult, M; Janssens, H; Lövestam, G; Vanhavere, F

    2004-01-01

    The Institute for Reference Materials and Measurements operates a 7.0 MV Van de Graaff accelerator to generate monoenergetic neutron radiation for experimental applications. Owing to increased intensities of generated neutron fields and the more stringent regulation related to the maximum dose for the public, a concrete shielding wall surrounding the experimental building was constructed. This paper presents a study aiming at evaluating the effect of the shielding on the neutron field outside the wall. For this purpose, the following measurements were carried out around the building: (1) cartography of the neutron field for different experimental conditions; (2) measurement of neutron spectra using multiple Bonner spheres; (3) activation measurements using gold discs followed by low-level gamma spectrometry. From the measurements, it can be concluded that the wall fulfils its purpose to reduce the neutron dose rate to the surrounding area to an acceptable level. PMID:15353736

  18. Fusion-neutron measurements for magnetized liner inertial fusion experiments on the Z accelerator

    NASA Astrophysics Data System (ADS)

    Hahn, K. D.; Chandler, G. A.; Ruiz, C. L.; Cooper, G. W.; Gomez, M. R.; Slutz, S.; Sefkow, A. B.; Sinars, D. B.; Hansen, S. B.; Knapp, P. F.; Schmit, P. F.; Harding, E.; Jennings, C. A.; Awe, T. J.; Geissel, M.; Rovang, D. C.; Torres, J. A.; Bur, J. A.; Cuneo, M. E.; Glebov, V. Yu; Harvey-Thompson, A. J.; Herrman, M. C.; Hess, M. H.; Johns, O.; Jones, B.; Lamppa, D. C.; Lash, J. S.; Martin, M. R.; McBride, R. D.; Peterson, K. J.; Porter, J. L.; Reneker, J.; Robertson, G. K.; Rochau, G. A.; Savage, M. E.; Smith, I. C.; Styron, J. D.; Vesey, R. A.

    2016-05-01

    Several magnetized liner inertial fusion (MagLIF) experiments have been conducted on the Z accelerator at Sandia National Laboratories since late 2013. Measurements of the primary DD (2.45 MeV) neutrons for these experiments suggest that the neutron production is thermonuclear. Primary DD yields up to 3e12 with ion temperatures ∼2-3 keV have been achieved. Measurements of the secondary DT (14 MeV) neutrons indicate that the fuel is significantly magnetized. Measurements of down-scattered neutrons from the beryllium liner suggest ρRliner∼1g/cm2. Neutron bang times, estimated from neutron time-of-flight (nTOF) measurements, coincide with peak x-ray production. Plans to improve and expand the Z neutron diagnostic suite include neutron burn-history diagnostics, increased sensitivity and higher precision nTOF detectors, and neutron recoil-based yield and spectral measurements.

  19. SAMS Acceleration Measurements on Mir From January to May 1997 (NASA Increment 4)

    NASA Technical Reports Server (NTRS)

    DeLombard, Richard

    1998-01-01

    During NASA Increment 4 (January to May 1997), about 5 gigabytes of acceleration data were collected by the Space Acceleration Measurements System (SAMS) onboard the Russian Space Station, Mir. The data were recorded on 28 optical disks which were returned to Earth on STS-84. During this increment, SAMS data were collected in the Priroda module to support the Mir Structural Dynamics Experiment (MiSDE), the Binary Colloidal Alloy Tests (BCAT), Angular Liquid Bridge (ALB), Candle Flames in Microgravity (CFM), Diffusion Controlled Apparatus Module (DCAM), Enhanced Dynamic Load Sensors (EDLS), Forced Flow Flame Spreading Test (FFFT), Liquid Metal Diffusion (LMD), Protein Crystal Growth in Dewar (PCG/Dewar), Queen's University Experiments in Liquid Diffusion (QUELD), and Technical Evaluation of MIM (TEM). This report points out some of the salient features of the microgravity environment to which these experiments were exposed. Also documented are mission events of interest such as the docked phase of STS-84 operations, a Progress engine burn, Soyuz vehicle docking and undocking, and Progress vehicle docking. This report presents an overview of the SAMS acceleration measurements recorded by 10 Hz and 100 Hz sensor heads. The analyses included herein complement those presented in previous summary reports prepared by the Principal Investigator Microgravity Services (PIMS) group.

  20. Development of backsheet tests and measurements to improve correlation of accelerated exposures to fielded modules

    NASA Astrophysics Data System (ADS)

    Felder, Thomas C.; Gambogi, William J.; Kopchick, James G.; Amspacher, Lucas; Peacock, R. Scott; Foltz, Benjamin; Stika, Katherine M.; Bradley, Alexander Z.; Hamzavy, Babak; Yu, Bao-Ling; Garreau-iles, Lucie; Fu, Oakland; Hu, Hongjie; Trout, T. John

    2015-09-01

    Matching accelerated test results to field observations is an important objective in the photovoltaic industry. We continue to develop test methods to strengthen correlations. We have previously reported good correlation of FTIR spectra between accelerated tests and field measurements. The availability of portable FTIR spectrometers has made measurement in the field convenient and reliable. Recently, nano-indentation has shown promise to correlate changes in backsheet mechanical properties. A precisely shaped stylus is pressed into a sample, load vs displacement recorded and mechanical properties of interest calculated in a nondestructive test. This test can be done on full size modules, allowing area variations in mechanical properties to be recorded. Finally, we will discuss optical profilometry. In this technique a white light interferogram of a surface is Fourier transformed to produce a three-dimensional image. Height differences from 1 nm to 5 mm can be detected over an area of a few cm. This technique can be used on minimodules, and is useful to determine crack and defect dimensions. Results will be presented correlating accelerated tests with fielded modules covering spectroscopic, mechanical, and morphological changes.

  1. First particle acceleration measurements for a shocked multiphase flow at a new horizontal shock tube facility

    NASA Astrophysics Data System (ADS)

    Orlicz, Greg; Martinez, Adam; Prestridge, Kathy; Extreme Fluids Team

    2013-11-01

    The horizontal shock tube at Los Alamos, used for over 20 years to study shock-driven mixing between different density gases, has been retrofitted with a new particle seeding system, test section, and diaphragmless driver to investigate the unsteady forces on particles as they are accelerated by a shock wave. Current experiments are performed to measure the acceleration of dispersed glycol droplets, with nominal 0.5 μm diameter, carried in ambient air. Measurements at this facility will be used to develop and validate empirical models implemented in numerical codes. A Particle Image Velocimetry/Accelerometry (PIVA) system is implemented at the facility using eight laser pulses and an eight-frame high speed camera. The lasers are 532 nm Nd:YAGs with pulse widths of 20 ns, and the camera is a Specialised Imaging SIMD with 1280 × 960 resolution at up to 7 million frames per second. With this PIVA arrangement, eight particle fields are collected by independently varying the interframe times. Seven velocity and six acceleration fields are used to study the unsteady drag on the particles. Initial data sets are with a size distribution of known particle diameters. Plans are to vary the particle/gas density ratio, particle diameters, and particle phase (liquid/solid).

  2. Cantilever-based FBG sensor for temperature-independent acceleration measurement

    NASA Astrophysics Data System (ADS)

    Zhou, Wenjun; Dong, Xinyong; Jin, Yongxing; Zhao, Chun-Liu

    2009-11-01

    A novel accelerometer based on a strain-chirped optical fiber Bragg grating (FBG) is proposed. The FBG is glued in a slanted direction onto the lateral side of a right-angled triangle cantilever beam with a mass bonded on its free end. Vertical acceleration applied to the cantilever beam leads to a uniform bending along the beam length. As a result, the FBG is chirped and its reflection bandwidth changes linearly with the applied acceleration. A high sensitivity of 0.679 nm/g has been achieved in the experiment. The experimental results of the sensor are compared with the results of a conventional accelerometer for the dynamic measurements. This sensor is temperature insensitive, owning to the temperature-independence nature of reflection bandwidth of the FBG.

  3. Influence of tungsten fiber's slow drift on the measurement of G with angular acceleration method

    NASA Astrophysics Data System (ADS)

    Luo, Jie; Wu, Wei-Huang; Xue, Chao; Shao, Cheng-Gang; Zhan, Wen-Ze; Wu, Jun-Fei; Milyukov, Vadim

    2016-08-01

    In the measurement of the gravitational constant G with angular acceleration method, the equilibrium position of torsion pendulum with tungsten fiber undergoes a linear slow drift, which results in a quadratic slow drift on the angular velocity of the torsion balance turntable under feedback control unit. The accurate amplitude determination of the useful angular acceleration signal with known frequency is biased by the linear slow drift and the coupling effect of the drifting equilibrium position and the room fixed gravitational background signal. We calculate the influences of the linear slow drift and the complex coupling effect on the value of G, respectively. The result shows that the bias of the linear slow drift on G is 7 ppm, and the influence of the coupling effect is less than 1 ppm.

  4. Influence of tungsten fiber's slow drift on the measurement of G with angular acceleration method.

    PubMed

    Luo, Jie; Wu, Wei-Huang; Xue, Chao; Shao, Cheng-Gang; Zhan, Wen-Ze; Wu, Jun-Fei; Milyukov, Vadim

    2016-08-01

    In the measurement of the gravitational constant G with angular acceleration method, the equilibrium position of torsion pendulum with tungsten fiber undergoes a linear slow drift, which results in a quadratic slow drift on the angular velocity of the torsion balance turntable under feedback control unit. The accurate amplitude determination of the useful angular acceleration signal with known frequency is biased by the linear slow drift and the coupling effect of the drifting equilibrium position and the room fixed gravitational background signal. We calculate the influences of the linear slow drift and the complex coupling effect on the value of G, respectively. The result shows that the bias of the linear slow drift on G is 7 ppm, and the influence of the coupling effect is less than 1 ppm. PMID:27587137

  5. Raman distributed temperature measurement at CERN high energy accelerator mixed field radiation test facility (CHARM)

    NASA Astrophysics Data System (ADS)

    Toccafondo, Iacopo; Nannipieri, Tiziano; Signorini, Alessandro; Guillermain, Elisa; Kuhnhenn, Jochen; Brugger, Markus; Di Pasquale, Fabrizio

    2015-09-01

    In this paper we present a validation of distributed Raman temperature sensing (RDTS) at the CERN high energy accelerator mixed field radiation test facility (CHARM), newly developed in order to qualify electronics for the challenging radiation environment of accelerators and connected high energy physics experiments. By investigating the effect of wavelength dependent radiation induced absorption (RIA) on the Raman Stokes and anti-Stokes light components in radiation tolerant Ge-doped multi-mode (MM) graded-index optical fibers, we demonstrate that Raman DTS used in loop configuration is robust to harsh environments in which the fiber is exposed to a mixed radiation field. The temperature profiles measured on commercial Ge-doped optical fibers is fully reliable and therefore, can be used to correct the RIA temperature dependence in distributed radiation sensing systems based on P-doped optical fibers.

  6. Voltage measurements at the vacuum post-hole convolute of the Z pulsed-power accelerator

    NASA Astrophysics Data System (ADS)

    Waisman, E. M.; McBride, R. D.; Cuneo, M. E.; Wenger, D. F.; Fowler, W. E.; Johnson, W. A.; Basilio, L. I.; Coats, R. S.; Jennings, C. A.; Sinars, D. B.; Vesey, R. A.; Jones, B.; Ampleford, D. J.; Lemke, R. W.; Martin, M. R.; Schrafel, P. C.; Lewis, S. A.; Moore, J. K.; Savage, M. E.; Stygar, W. A.

    2014-12-01

    Presented are voltage measurements taken near the load region on the Z pulsed-power accelerator using an inductive voltage monitor (IVM). Specifically, the IVM was connected to, and thus monitored the voltage at, the bottom level of the accelerator's vacuum double post-hole convolute. Additional voltage and current measurements were taken at the accelerator's vacuum-insulator stack (at a radius of 1.6 m) by using standard D -dot and B -dot probes, respectively. During postprocessing, the measurements taken at the stack were translated to the location of the IVM measurements by using a lossless propagation model of the Z accelerator's magnetically insulated transmission lines (MITLs) and a lumped inductor model of the vacuum post-hole convolute. Across a wide variety of experiments conducted on the Z accelerator, the voltage histories obtained from the IVM and the lossless propagation technique agree well in overall shape and magnitude. However, large-amplitude, high-frequency oscillations are more pronounced in the IVM records. It is unclear whether these larger oscillations represent true voltage oscillations at the convolute or if they are due to noise pickup and/or transit-time effects and other resonant modes in the IVM. Results using a transit-time-correction technique and Fourier analysis support the latter. Regardless of which interpretation is correct, both true voltage oscillations and the excitement of resonant modes could be the result of transient electrical breakdowns in the post-hole convolute, though more information is required to determine definitively if such breakdowns occurred. Despite the larger oscillations in the IVM records, the general agreement found between the lossless propagation results and the results of the IVM shows that large voltages are transmitted efficiently through the MITLs on Z . These results are complementary to previous studies [R. D. McBride et al., Phys. Rev. ST Accel. Beams 13, 120401 (2010)] that showed efficient

  7. Quality of Life Scale: A Measure of Function for People with Pain

    MedlinePlus

    Quality Of Life Scale A Measure Of Function For People With Pain 0 Non-functioning 1 2 3 4 5 6 7 8 Stay in bed all ... in family life Quality Of Life Scale A Measure Of Function For People With Pain ain is ...

  8. MANTRA: Measuring Neutron Capture Cross Sections in Actinides with Accelerator Mass Spectrometry

    NASA Astrophysics Data System (ADS)

    Bauder, W.; Pardo, R. C.; Collon, P.; Palchan, T.; Scott, R.; Vondrasek, R.; Nusair, O.; Nair, C.; Paul, M.; Kondev, F.; Chen, J.; Youinou, G.; Salvatores, M.; Palmotti, G.; Berg, J.; Maddock, T.; Imel, G.

    2013-10-01

    With rising global energy needs, there is substantial interest in nuclear energy research. To explore possibilities for advanced fuel cycles, better neutron cross section data are needed for the minor actinides. The MANTRA (Measurement of Actinide Neutron TRAsmutation) project will improve these data by measuring integral (n, γ) cross sections. The cross sections will be extracted by measuring isotopic ratios in pure actinide samples, irradiated in the Advanced Test Reactor at Idaho National Lab, using Accelerator Mass Spectrometry(AMS) at the Argonne Tandem Linac Accelerator System (ATLAS). MANTRA presents a unique AMS challenge because of the goal to measure multiple isotopic ratios on a large number of samples. To meet these challenges, we have modified the AMS setup at ATLAS to include a laser ablation system for solid material injection into our ECR ion source. I will present work on the laser ablation system and modified source geometry, as well as preliminary measurements of unirradiated actinide samples at ATLAS. This work was supported by the U.S. Department of Energy, Office of Nuclear Physics, under Contract No. DE-AC02-06CH11357.

  9. A procedure for combining rotating-coil measurements of large-aperture accelerator magnets

    NASA Astrophysics Data System (ADS)

    Köster, Oliver; Fiscarelli, Lucio; Russenschuck, Stephan

    2016-05-01

    The rotating search coil is a precise and widely used tool for measuring the magnetic field harmonics of accelerator magnets. This paper deals with combining several such multipole measurements, in order to cover magnet apertures largely exceeding the diameter of the available search coil. The method relies on the scaling laws for multipole coefficients and on the method of analytic continuation along zero-homotopic paths. By acquiring several measurements of the integrated magnetic flux density at different transverse positions within the bore of the accelerator magnet, the uncertainty on the field harmonics can be reduced at the expense of tight tolerances on the positioning. These positioning tolerances can be kept under control by mounting the rotating coil and its motor-drive unit on precision alignment stages. Therefore, the proposed technique is able to yield even more precise results for the higher-order field components than a dedicated rotating search coil of larger diameter. Moreover, the versatility of the measurement bench is enhanced by avoiding the construction of rotating search coils of different measurement radii.

  10. Laboratory Measurements of Linear Electron Acceleration by Inertial Alfvén Waves

    NASA Astrophysics Data System (ADS)

    Schroeder, J. W. R.

    2015-11-01

    Alfvén waves occur in conjunction with a significant fraction of auroral electron acceleration. Inertial mode Alfvén waves (vA >vte) in the auroral magnetosphere (2 - 4RE) with perpendicular scales on the order of the electron skin depth (c /ωpe) have a parallel electric field that, according to theory, is capable of nonlinearly accelerating suprathermal electrons to auroral energies. Unfortunately, due to space-time ambiguities of rocket and satellite measurements, it has not yet been possible to fully verify how Alfvén waves contribute to the production of accelerated electrons. To overcome the limitations of in situ spacecraft data, laboratory experiments have been carried out using the Large Plasma Device (LaPD), an NSF/DOE user facility at UCLA. An Electron Cyclotron Absorption (ECA) diagnostic has been developed to record the suprathermal parallel electron distribution function with 0.1% precision. The diagnostic records the electron distribution while inertial Alfvén waves simultaneously propagate through the plasma. Recent measurements have isolated oscillations of suprathermal electrons at the Alfvén wave frequency. Despite complications from boundary effects and the finite size of the experiment, a linear kinetic model has been produced that describes the experimental results. To our knowledge this is the first quantitative agreement between the measured and modeled linear response of suprathermal electrons to an inertial Alfvén wave. This verification of the linear physics is a necessary step before the nonlinear acceleration process can be isolated in future experiments. Presently, nonlinear effects cannot be detected because of limited Alfvén wave amplitudes. Ongoing work is focused on designing a higher-power antenna capable of efficiently launching larger-amplitude Alfvén waves with tunable perpendicular wavenumber and developing a theoretical understanding of the nonlinear acceleration process in LaPD plasma conditions. This material is

  11. On the effect of accelerated winds on the wave growth through detailed laboratory measurements.

    NASA Astrophysics Data System (ADS)

    Ocampo-Torres, Francisco J.; Branger, Hubert; Osuna, Pedro; Hernández, Aldo

    2013-04-01

    The possible influence of accelerated winds on air-water momentum fluxes is being studied through detailed laboratory measurements in a large wind-wave flume. Wind stress over the water surface, waves and surface drift are measured in the 40m long wind-wave tank at IRPHE, Marseille. While momentum fluxes are estimated directly through the eddy correlation method in a station about the middle of the tank, they provide information corresponding to rather short non-dimensional fetch not previously reported. Wave evolution along the tank is determined through a series of wave gauges, and the wind-induced surface drift is obtained at one of the first measuring stations at the beginning of the tank. At each experimental run very low wind was on (about 1m/s) for a certain period and suddenly it was constantly accelerated to reach about 13 m/s (as well as 8 and 5 m/s during different runs) in about 15 sec to as long as 600 sec. The wind was kept constant at that high speed for 2 to 10 min, and then suddenly and constantly decelerate to 0. Data from the constant high winds provided us with reference equilibrium conditions for at least 3 different wind speed. We, nevertheless, focus in the recordings while wind was being constantly accelerated expecting some contribution to the understanding of gustiness, the implied wind wave growth and the onset of surface drift. Wind-wave growth is observed to lag behind the wind stress signal, and furthermore, a two regime wind stress is noticed, apparently well correlated with a) the incipient growth and appearance of the first waves and b) the arrival of waves from the up-wind section of the tank. Results of non-dimensional wave energy as a function of non-dimensional fetch represent an extension of at least 2 decades shorter non-dimensional fetch to the wave growth curves typically found in the literature. The linear tendency of wave growth compares very well only when wind is reaching its maximum, while during the accelerated wind

  12. Transverse Beam Emittance Measurements of a 16 MeV Linac at the Idaho Accelerator Center

    SciTech Connect

    S. Setiniyaz, T.A. Forest, K. Chouffani, Y. Kim, A. Freyberger

    2012-07-01

    A beam emittance measurement of the 16 MeV S-band High Repetition Rate Linac (HRRL) was performed at Idaho State University's Idaho Accelerator Center (IAC). The HRRL linac structure was upgraded beyond the capabilities of a typical medical linac so it can achieve a repetition rate of 1 kHz. Measurements of the HRRL transverse beam emittance are underway that will be used to optimize the production of positrons using HRRL's intense electron beam on a tungsten converter. In this paper, we describe a beam imaging system using on an OTR screen and a digital CCD camera, a MATLAB tool to extract beamsize and emittance, detailed measurement procedures, and the measured transverse emittances for an arbitrary beam energy of 15 MeV.

  13. A hybrid data acquisition system for magnetic measurements of accelerator magnets

    SciTech Connect

    Wang, X.; Hafalia, R.; Joseph, J.; Lizarazo, J.; Martchevsky, M.; Sabbi, G. L.

    2011-06-03

    A hybrid data acquisition system was developed for magnetic measurement of superconducting accelerator magnets at LBNL. It consists of a National Instruments dynamic signal acquisition (DSA) card and two Metrolab fast digital integrator (FDI) cards. The DSA card records the induced voltage signals from the rotating probe while the FDI cards records the flux increment integrated over a certain angular step. This allows the comparison of the measurements performed with two cards. In this note, the setup and test of the system is summarized. With a probe rotating at a speed of 0.5 Hz, the multipole coefficients of two magnets were measured with the hybrid system. The coefficients from the DSA and FDI cards agree with each other, indicating that the numerical integration of the raw voltage acquired by the DSA card is comparable to the performance of the FDI card in the current measurement setup.

  14. Fuel retention measurements in Alcator C-Mod using accelerator-based in situ materials surveillance

    NASA Astrophysics Data System (ADS)

    Hartwig, Zachary S.; Barnard, Harold S.; Sorbom, Brandon N.; Lanza, Richard C.; Lipschultz, Bruce; Stahle, Peter W.; Whyte, Dennis G.

    2015-08-01

    This paper presents the first in situ time- and space-resolved measurements of deuterium (D) fuel retention in plasma-facing component (PFC) surfaces using Accelerator-based In-situ Materials Surveillance (AIMS) on the Alcator C-Mod tokamak. AIMS is a novel in situ materials diagnostic technique based on the spectroscopic analysis of nuclear reaction products induced in PFC surfaces using an ∼MeV beam of deuterons from a compact linear accelerator in between plasma shots. AIMS measurements of D retention on inner wall PFCs were acquired during diverted and limited plasma operations and during wall conditioning experiments. Intershot measurements demonstrate the local erosion and codeposition of boron films on PFC surfaces with a constant D / B ratio. This is consistent with previous results suggesting that D codeposition with boron is insufficient to account for the net retention observed in Alcator C-Mod. Changes in deuterium concentration during boronization, electron cyclotron and glow cleanings were also measured.

  15. Waveband Analysis of Track Irregularities in High-Speed Railway from On-Board Acceleration Measurement

    NASA Astrophysics Data System (ADS)

    Lee, Jun Seok; Choi, Sunghoon; Kim, Sang-Soo; Kim, Young Guk; Kim, Seog Won; Park, Choonsoo

    This paper is focused on waveband analysis of the lateral and vertical track irregularities from the on-board acceleration measurement of in-service high-speed trains. The track irregularities play important roles to determine dynamic stability of vehicles and ride quality of passengers, so that their amplitude and wavelength should be monitored continuously and carefully. Measuring acceleration at the axle-box or bogie of the trains has been under consideration for low-cost implementation and robust to a harsh railway environment. To estimate the track irregularities, lateral and vertical vibration caused by the wheel/track interaction is measured by the axle-box and bogie mounted accelerometers of an in-service high-speed train. A Kalman filter is used to prevent unrealistic drifts in the estimation. By applying the waveband-pass and compensation filters to the estimated displacement, it is possible to estimate the track irregularities. A distance-wavelength representation is used to identify their waveband in an intuitive way. It is verified by comparing with a commercial track geometry measurement system. From their comparison, it confirms that the representation can produce a satisfactory result.

  16. Summary Report of Mission Acceleration Measurements for STS-95: Launched October 19, 1998

    NASA Technical Reports Server (NTRS)

    McPherson, Kevin; Hrovat, Kevin

    2000-01-01

    John H. Glenn's historic return to space was a primary focus of the STS-95 mission. The Hubble Space Telescope (HST) orbital Systems Test (HOST), an STS-95 payload, was an in-flight demonstration of HST components to be installed during the next HST servicing mission. One of the components under evaluation was the cryocooler for the Near Infrared Camera and Multi-Object Spectrometer (NICMOS). Based on concerns about vibrations from the operation of the NICMOS cryocooler affecting the overall HST line-of-sight requirements, the Space Acceleration Measurement System for Free-Flyers (SAMS-FF) was employed to measure the vibratory environment of the STS-95 mission, including any effects introduced by the NICMOS cryocooler. The STS-95 mission represents the first STS mission supported by SAMS-FF. Utilizing a Control and Data Acquisition Unit (CDU) and two triaxial sensor heads (TSH) mounted on the HOST support structure in Discovery's cargo bay, the SAMS-FF and the HOST project were able to make vibratory measurements both on-board the vibration-isolated NICMOS cryocooler and off-board the cryocooler mounting plate. By comparing the SAMS-FF measured vibrations on-board and off-board the NICMOS cryocooler, HST engineers could assess the cryocooler g-jitter effects on the HST line-of-sight requirements. The acceleration records from both SAMS-FF accelerometers were analyzed and significant features of the microgravity environment are detailed in this report.

  17. Continuous Wavelet Transform Analysis of Acceleration Signals Measured from a Wave Buoy

    PubMed Central

    Chuang, Laurence Zsu-Hsin; Wu, Li-Chung; Wang, Jong-Hao

    2013-01-01

    Accelerometers, which can be installed inside a floating platform on the sea, are among the most commonly used sensors for operational ocean wave measurements. To examine the non-stationary features of ocean waves, this study was conducted to derive a wavelet spectrum of ocean waves and to synthesize sea surface elevations from vertical acceleration signals of a wave buoy through the continuous wavelet transform theory. The short-time wave features can be revealed by simultaneously examining the wavelet spectrum and the synthetic sea surface elevations. The in situ wave signals were applied to verify the practicality of the wavelet-based algorithm. We confirm that the spectral leakage and the noise at very-low-frequency bins influenced the accuracies of the estimated wavelet spectrum and the synthetic sea surface elevations. The appropriate thresholds of these two factors were explored. To study the short-time wave features from the wave records, the acceleration signals recorded from an accelerometer inside a discus wave buoy are analysed. The results from the wavelet spectrum show the evidence of short-time nonlinear wave events. Our study also reveals that more surface profiles with higher vertical asymmetry can be found from short-time nonlinear wave with stronger harmonic spectral peak. Finally, we conclude that the algorithms of continuous wavelet transform are practical for revealing the short-time wave features of the buoy acceleration signals. PMID:23966188

  18. Measurement of performance using acceleration control and pulse control in simulated spacecraft docking operations

    NASA Technical Reports Server (NTRS)

    Brody, Adam R.; Ellis, Stephen R.

    1992-01-01

    Nine commercial airline pilots served as test subjects in a study to compare acceleration control with pulse control in simulated spacecraft maneuvers. Simulated remote dockings of an orbital maneuvering vehicle (OMV) to a space station were initiated from 50, 100, and 150 meters along the station's -V-bar (minus velocity vector). All unsuccessful missions were reflown. Five way mixed analysis of variance (ANOVA) with one between factor, first mode, and four within factors (mode, bloch, range, and trial) were performed on the data. Recorded performance measures included mission duration and fuel consumption along each of the three coordinate axes. Mission duration was lower with pulse mode, while delta V (fuel consumption) was lower with acceleration mode. Subjects used more fuel to travel faster with pulse mode than with acceleration mode. Mission duration, delta V, X delta V, Y delta V., and Z delta V all increased with range. Subjects commanded the OMV to 'fly' at faster rates from further distances. These higher average velocities were paid for with increased fuel consumption. Asymmetrical transfer was found in that the mode transitions could not be predicted solely from the mission duration main effect. More testing is advised to understand the manual control aspects of spaceflight maneuvers better.

  19. Small scale particle acceleration processes in the auroral region: Remote sensing and "in situ" measurements

    NASA Astrophysics Data System (ADS)

    Pottelette, R.; Berthomier, M.; Pickett, J.

    2012-04-01

    Among the many problems in auroral physics that are barely understood the microphysical problems occupy a majority position. Thanks to high sampling and telemetry rates implemented on spacecraft devoted to the study of the auroral regions such as POLAR, FAST, CLUSTER 2…, it has become possible to determine the role of transient nonlinear structures in the basic microscopic processes regulating the Magnetosphere-Ionosphere interactions. Great progress has been achieved in probing the nonlinear turbulent plasma processes which accelerate energetic particles and generate radiation such as the Auroral Kilometric Radiation (AKR) in the auroral upward current region. Narrow-in-altitude acceleration layers (double layers) can be identified by using both particles and waves measurements. Double layers once immersed in the plasma necessarily accelerate particles along the magnetic field, thereby generating locally strong turbulent processes leading to the formation of phase-space holes. As predicted by numerical simulations, we will emphasize the asymmetric character of the turbulence generated in the regions located upstream (low-potential side) or downstream (high-potential side) of a double layer. We will also point out that monitoring the time variation of the frequency drift of the elementary AKR radiators allows to qualitatively infer about the dynamics and the spatial extension of the field-aligned potential drops.

  20. Continuous wavelet transform analysis of acceleration signals measured from a wave buoy.

    PubMed

    Chuang, Laurence Zsu-Hsin; Wu, Li-Chung; Wang, Jong-Hao

    2013-01-01

    Accelerometers, which can be installed inside a floating platform on the sea, are among the most commonly used sensors for operational ocean wave measurements. To examine the non-stationary features of ocean waves, this study was conducted to derive a wavelet spectrum of ocean waves and to synthesize sea surface elevations from vertical acceleration signals of a wave buoy through the continuous wavelet transform theory. The short-time wave features can be revealed by simultaneously examining the wavelet spectrum and the synthetic sea surface elevations. The in situ wave signals were applied to verify the practicality of the wavelet-based algorithm. We confirm that the spectral leakage and the noise at very-low-frequency bins influenced the accuracies of the estimated wavelet spectrum and the synthetic sea surface elevations. The appropriate thresholds of these two factors were explored. To study the short-time wave features from the wave records, the acceleration signals recorded from an accelerometer inside a discus wave buoy are analysed. The results from the wavelet spectrum show the evidence of short-time nonlinear wave events. Our study also reveals that more surface profiles with higher vertical asymmetry can be found from short-time nonlinear wave with stronger harmonic spectral peak. Finally, we conclude that the algorithms of continuous wavelet transform are practical for revealing the short-time wave features of the buoy acceleration signals. PMID:23966188

  1. Results of Measurements of Accelerations of Technological Devices onboard the FotonSpacecraft

    NASA Astrophysics Data System (ADS)

    Barmin, I. V.; Volkov, M. V.; Egorov, A. V.; Reut, E. F.; Senchenkov, A. S.

    2001-07-01

    This paper generalizes the results of measuring the residual accelerations arising when investigations in space materials science are carried out onboard the unmanned Fotonspacecraft. The levels of vibroaccelerations are analyzed in the frequency band of 1 500 Hz for the technological devices UZ01, UZ04, and POLIZON, developed by the Federal Unitary State Enterprise “Barmin Design Bureau of General Machine Building” (V.P. Barmin KBOM). The levels of accelerations are estimated in the frequency band of 0 1 Hz in the zone of technological operations of these facilities. The basic sources of vibroaccelerations acting upon the frames of devices are determined in the capsule zone, where technological processes of producing new materials take place. In the frequency band of 1 500 Hz the vibroaccelerations are shown to be generated by the operation of Fotonspacecraft units and a drive of capsule translation during the technological process. On the capsule frame they reach the values of (1 3) × 10 3 g. The level of linear accelerations in the infralow-frequency band is determined by rotational motions of the Fotonspacecraft. It depends on the device location with respect to the spacecraft center of mass and does not exceed (1 7) × 10 6 gin the steady-state regime in the zone of technological activity.

  2. Temporal evolution and electric potential structure of the auroral acceleration region from multispacecraft measurements

    NASA Astrophysics Data System (ADS)

    Forsyth, C.; Fazakerley, A. N.; Walsh, A. P.; Watt, C. E.; Garza, K.; Owen, C. J.; Constantinescu, D. O.; Dandouras, I. S.; Fornacon, K.; Lucek, E. A.; Marklund, G. T.; Sadeghi, S. S.; Khotyaintsev, Y. V.; Masson, A.; Doss, N.

    2013-12-01

    Bright aurorae can be excited by the acceleration of electrons into the atmosphere in violation of ideal magnetohydrodynamics. Modelling studies predict that the accelerating electric potential consists of electric double layers at the boundaries of an acceleration region but observations suggest that particle acceleration occurs throughout this region. Using multispacecraft observations from Cluster, we have examined two upward current regions on 14 December 2009. Our observations show that the potential difference below C4 and C3 changed by up to 1.7 kV between their respective crossings, which were separated by 150 s. The field-aligned current density observed by C3 was also larger than that observed by C4. The potential drop above C3 and C4 was approximately the same in both crossings. Using a novel technique of quantitively comparing the electron spectra measured by Cluster 1 and 3, which were separated in altitude, we determine when these spacecraft made effectively magnetically conjugate observations, and we use these conjugate observations to determine the instantaneous distribution of the potential drop in the AAR. Our observations show that an average of 15% of the potential drop in the AAR was located between C1 at 6235 km and C3 at 4685 km altitude, with a maximum potential drop between the spacecraft of 500 V, and that the majority of the potential drop was below C3. Assuming a spatial invariance along the length of the upward current region, we discuss these observations in terms of temporal changes and the vertical structure of the electrostatic potential drop and in the context of existing models and previous single- and multispacecraft observations.

  3. Temporal evolution and electric potential structure of the auroral acceleration region from multispacecraft measurements

    NASA Astrophysics Data System (ADS)

    Forsyth, C.; Fazakerley, A. N.; Walsh, A. P.; Watt, C. E. J.; Garza, K. J.; Owen, C. J.; Constantinescu, D.; Dandouras, I.; FornaçOn, K.-H.; Lucek, E.; Marklund, G. T.; Sadeghi, S. S.; Khotyaintsev, Y.; Masson, A.; Doss, N.

    2012-12-01

    Bright aurorae can be excited by the acceleration of electrons into the atmosphere in violation of ideal magnetohydrodynamics. Modeling studies predict that the accelerating electric potential consists of electric double layers at the boundaries of an acceleration region but observations suggest that particle acceleration occurs throughout this region. Using multispacecraft observations from Cluster, we have examined two upward current regions on 14 December 2009. Our observations show that the potential difference below C4 and C3 changed by up to 1.7 kV between their respective crossings, which were separated by 150 s. The field-aligned current density observed by C3 was also larger than that observed by C4. The potential drop above C3 and C4 was approximately the same in both crossings. Using a novel technique of quantitively comparing the electron spectra measured by Cluster 1 and 3, which were separated in altitude, we determine when these spacecraft made effectively magnetically conjugate observations, and we use these conjugate observations to determine the instantaneous distribution of the potential drop in the AAR. Our observations show that an average of 15% of the potential drop in the AAR was located between C1 at 6235 km and C3 at 4685 km altitude, with a maximum potential drop between the spacecraft of 500 V, and that the majority of the potential drop was below C3. Assuming a spatial invariance along the length of the upward current region, we discuss these observations in terms of temporal changes and the vertical structure of the electrostatic potential drop and in the context of existing models and previous single- and multispacecraft observations.

  4. Analytical Validation of Accelerator Mass Spectrometry for Pharmaceutical Development: the Measurement of Carbon-14 Isotope Ratio.

    SciTech Connect

    Keck, B D; Ognibene, T; Vogel, J S

    2010-02-05

    Accelerator mass spectrometry (AMS) is an isotope based measurement technology that utilizes carbon-14 labeled compounds in the pharmaceutical development process to measure compounds at very low concentrations, empowers microdosing as an investigational tool, and extends the utility of {sup 14}C labeled compounds to dramatically lower levels. It is a form of isotope ratio mass spectrometry that can provide either measurements of total compound equivalents or, when coupled to separation technology such as chromatography, quantitation of specific compounds. The properties of AMS as a measurement technique are investigated here, and the parameters of method validation are shown. AMS, independent of any separation technique to which it may be coupled, is shown to be accurate, linear, precise, and robust. As the sensitivity and universality of AMS is constantly being explored and expanded, this work underpins many areas of pharmaceutical development including drug metabolism as well as absorption, distribution and excretion of pharmaceutical compounds as a fundamental step in drug development. The validation parameters for pharmaceutical analyses were examined for the accelerator mass spectrometry measurement of {sup 14}C/C ratio, independent of chemical separation procedures. The isotope ratio measurement was specific (owing to the {sup 14}C label), stable across samples storage conditions for at least one year, linear over 4 orders of magnitude with an analytical range from one tenth Modern to at least 2000 Modern (instrument specific). Further, accuracy was excellent between 1 and 3 percent while precision expressed as coefficient of variation is between 1 and 6% determined primarily by radiocarbon content and the time spent analyzing a sample. Sensitivity, expressed as LOD and LLOQ was 1 and 10 attomoles of carbon-14 (which can be expressed as compound equivalents) and for a typical small molecule labeled at 10% incorporated with {sup 14}C corresponds to 30 fg

  5. Quick Look Report of Acceleration Measurements on Mir Space Station During Mir-16

    NASA Technical Reports Server (NTRS)

    Delombard, Richard; Rogers, Melissa J. B.

    1995-01-01

    The NASA Microgravity Science and Applications Division (MSAD) sponsors the Space Acceleration Measurement System (SAMS) to support microgravity science experiments with microgravity acceleration measurements. In the past, SAMS was flown exclusively on the NASA Orbiters. MSAD is currently sponsoring science experiments participating in the Shuttle-Mir Science Program in cooperation with the Russians on the Mir space station. Included in the complement of MSAD experiments and equipment is a SAMS unit installed on the Mir space station. On 25 August 1994, the SAMS unit was launched on a Russia Progress vehicle to the Mir space station. The SAMS unit will support science experiments from the U.S. and Russia in a manner similar to the Orbiter missions by measuring the microgravity environments during the experiment operations. In October 1994, the SAMS unit recorded data on Mir for over fifty-three hours in seven different time periods to survey possible locations for future experiments. This report presents a quick look at the data and the microgravity environment during the time periods in which SAMS data were acquired. The Mir acceleration data were examined to ascertain gross attributes of the data. This report does not present an exhaustive examination of all possible activities due to the short time available to prepare this quick look report and due to the absence of complete timeline information during the SAMS recording time periods. Appendices A, B and C provide plots of the SAMS data for an overview of the microgravity environment at the times that data were recorded. Appendix D describes the procedures to access SAMS data by file transfer protocol (ftp) utilizing the internet. Appendix E contains a user comment sheet.

  6. The use of radiochromic films to measure and analyze the beam profile of charged particle accelerators.

    PubMed

    Avila-Rodriguez, M A; Wilson, J S; McQuarrie, S A

    2009-11-01

    The use of radiochromic films as a simple and inexpensive tool to accurately measure and analyze the beam profile of charged particle accelerators is described. In this study, metallic foils of different materials and thicknesses were irradiated with 17.8MeV protons and autoradiographic images of the beam strike were acquired by exposing pieces of RCF in direct contact with the irradiated foils. The films were digitalized using a conventional scanner and images were analyzed using DoseLab. Beam intensity distributions, isodose curves and linear beam profiles of the digitalized images were acquired. PMID:19054679

  7. Time-resolved energy spectrum measurement of a linear induction accelerator with the magnetic analyzer

    NASA Astrophysics Data System (ADS)

    Wang, Yuan; Jiang, Xiao-Guo; Yang, Guo-Jun; Chen, Si-Fu; Zhang, Zhuo; Wei, Tao; Li, Jin

    2015-01-01

    We recently set up a time-resolved optical beam diagnostic system. Using this system, we measured the high current electron beam energy in the accelerator under construction. This paper introduces the principle of the diagnostic system, describes the setup, and shows the results. A bending beam line was designed using an existing magnetic analyzer with a 300 mm-bending radius and a 60° bending angle at hard-edge approximation. Calculations show that the magnitude of the beam energy is about 18 MeV, and the energy spread is within 2%. Our results agree well with the initial estimates deduced from the diode voltage approach.

  8. Measurement of Asymmetric Optical Pumping of Ions Accelerating in a Magnetic-field Gradient

    SciTech Connect

    Xuan Sun; Earl Scime; Mahmood Miah; Samuel Cohen; Frederick Skiff

    2004-10-28

    We report observations of asymmetric optical pumping of argon ions accelerating in a magnetic field gradient. The signature is a difference in the laser-induced-fluorescence (LIF) emission amplitude from a pair of Zeeman-split states. A model that reproduces the dependence of the asymmetry on magnetic-field and ion-velocity gradients is described. With the model, the fluorescence intensity ratio provides a new method of measuring ion collisionality. This phenomenon has implications for interpreting stellar plasma spectroscopy data which often exhibit unequal Zeeman state intensities.

  9. Proposed method for high-speed plasma density measurement in proton-driven plasma wakefield acceleration

    SciTech Connect

    Tarkeshian, R.; Reimann, O.; Muggli, P.

    2012-12-21

    Recently a proton-bunch-driven plasma wakefield acceleration experiment using the CERN-SPS beam was proposed. Different types of plasma cells are under study, especially laser ionization, plasma discharge, and helicon sources. One of the key parameters is the spatial uniformity of the plasma density profile along the cell that has to be within < 1% of the nominal density (6 Multiplication-Sign 10{sup 14} cm{sup -3}). Here a setup based on a photomixing concept is proposed to measure the plasma cut-off frequency and determine the plasma density.

  10. Montblanc: GPU accelerated Radio Interferometer Measurement Equations in support of Bayesian Inference for Radio Observations

    NASA Astrophysics Data System (ADS)

    Perkins, Simon; Marais, Patrick; Zwart, Jonathan; Natarajan, Iniyan; Tasse, Cyril; Smirnov, Oleg

    2015-02-01

    Montblanc, written in Python, is a GPU implementation of the Radio interferometer measurement equation (RIME) in support of the Bayesian inference for radio observations (BIRO) technique. The parameter space that BIRO explores results in tens of thousands of computationally expensive RIME evaluations before reduction to a single X2 value. The RIME is calculated over four dimensions, time, baseline, channel and source and the values in this 4D space can be independently calculated; therefore, the RIME is particularly amenable to a parallel implementation accelerated by Graphics Programming Units (GPUs). Montblanc is implemented for NVIDIA's CUDA architecture and outperforms MeqTrees (ascl:1209.010) and OSKAR.

  11. Fabrication and Measurement of 12 GeV Prototype Quadrupoles at Thomas Jefferson National Accelerator Facility

    SciTech Connect

    Tommy Hiatt, Mark Wiseman, Kenneth Baggett, J. Beck, Leigh Harwood, Joseph Meyers, Jeffrey Dail

    2009-05-01

    Jefferson Lab's Continuous Electron Beam Accelerator Facility (CEBAF) currently has a maximum beam energy of 6 GeV. The 12 GeV Upgrade Project will double the existing energy and is currently scheduled for completion in 2014. This doubling of energy requires modifications to the beam transport system which includes the addition of several new magnet designs and modifications to many existing designs. Prototyping efforts have been concluded for two different designs of quadrupole magnets required for the upgrade. The design, fabrication and measurement will be discussed.

  12. Feedback control of torsion balance in measurement of gravitational constant G with angular acceleration method

    SciTech Connect

    Quan, Li-Di; Xue, Chao; Shao, Cheng-Gang; Yang, Shan-Qing; Tu, Liang-Cheng; Luo, Jun; Wang, Yong-Ji

    2014-01-15

    The performance of the feedback control system is of central importance in the measurement of the Newton's gravitational constant G with angular acceleration method. In this paper, a PID (Proportion-Integration-Differentiation) feedback loop is discussed in detail. Experimental results show that, with the feedback control activated, the twist angle of the torsion balance is limited to 7.3×10{sup −7} rad /√( Hz ) at the signal frequency of 2 mHz, which contributes a 0.4 ppm uncertainty to the G value.

  13. Lessons from two field tests on pipeline damage detection using acceleration measurement

    NASA Astrophysics Data System (ADS)

    Shinozuka, Masanobu; Lee, Sungchil; Kim, Sehwan; Chou, Pai H.

    2011-04-01

    Early detection of pipeline damages has been highlighted in water supply industry. Water pressure change in pipeline due to a sudden rupture causes pipe to vibrate and the pressure change propagates through the pipeline. From the measurement of pipe vibration the rupture can be detected. In this paper, the field test results and observations are provided for implementing next generation of SCADA system for pipeline rupture detection. Two field tests were performed on real buried plastic and metal pipelines for rupture detection. The rupture was simulated by introducing sudden water pressure drop caused by water blow-off and valve control. The measured acceleration data at the pipe surfaces were analyzed in both time and frequency domain. In time domain, the sudden narrow increase of acceleration amplitude was used as an indication of rupture event. For the frequency domain analysis, correlation function and the short time Fourier Transform technique were adopted to trace the dominant frequency shift. The success of rupture detection was found to be dependent on several factors. From the frequency analysis, the dominant frequency of metal water pipe was shifted by the water pressure drop, however, it was hard to identify from the plastic pipeline. Also the influence of existing facility such as airvac on pipe vibrations was observed. Finally, several critical lessons learned in the viewpoint of field measurement are discussed in this paper.

  14. Measurement of time-dependent external moments and forces by the sum of weighted accelerations technique

    SciTech Connect

    Priddy, T.G.; Gregory, D.L.; Coleman, R.G.

    1989-01-01

    Force identification using a sum of weighted accelerations technique (SWAT) is developed for measurement of externally applied force and moment which dynamically excite a structural system. Mode shape coefficients, from a free-body modal characterization, are used to determine two sets of weighting factors which, when used in the SWAT, eliminate the free-body vibrational response. One set of weighting factors, having the units of mass, are used in the SWAT measurement of the resultant force vector. The second set of weighting factors, having the units of first-moment-of-mass, are calculated to measure the moment acting at the center of mass of the external force with a similar sum of weighted accelerations. The theory for determining the force and moment vectors is developed in this paper. We illustrate the technique through the analysis of a simple beam and a rectangular plate. We then demonstrate the analytical predictions with the laboratory testing of softly suspended structures. 8 refs., 16 figs., 1 tab.

  15. The microphysics of particle acceleration in the auroral ionosphere: Why sounding rocket measurements are essential

    NASA Technical Reports Server (NTRS)

    Arnoldy, Roger L.

    1994-01-01

    Through the combination of attitude controlled, high altitude rockets (altitudes greater than 600 km), high telemetry rates (several megabits/sec), pitch angle imaging particle sensors and interferometric wave measurements giving wavelength in addition to frequency data, the series of TOPAZ flights have uncovered a low altitude acceleration mechanism by which ionospheric ions receive their initial energy transverse to B in order to leave the ionosphere and populate the trapped radiation. The transverse acceleration of oxygen and hydrogen ionospheric ions is the result of Landau resonance of these ions with intense (up to 400 mv/m) lower hybrid waves on the resonance cone within caviton structures. Future work is directed toward trying to measure the size of the solitary wave structures. From a statistical argument, they appear to be the order of 100 m across B and much longer in dimension along B. Important questions remain: are there other low altitude heating mechanisms acting as well; is the dayside ion outflow driven differently. To answer these questions, it is intended to make sounding rocket measurements in the cusp/cleft region. The proposed Norwegian rocket launch facility at Svalbard could play a very important role by providing easy access to the cusp/cleft region.

  16. Anode power deposition in quasi-steady MPD arcs. [accelerator anode heat flux measurement

    NASA Technical Reports Server (NTRS)

    Saber, A. J.; Jahn, R. G.

    1973-01-01

    The power deposited in the anode of a quasi-steady MPD accelerator has been measured directly by thermocouples attached to the inside surface of a shell anode which provide a local measurement of anode heat flux. The results over a range of arc currents from 5.5 to 44 kiloamperes and argon mass flows from 1 g/sec to 48 g/sec show that the fraction of the total input power deposited in the anode decreases drastically from 50% at an arc power of 200 kW to 10% at 20 MW, and that anode power is not uniformly deposited in the anode. A theoretical model of the anode heat transfer, including effects of anode work function, electron thermal energy, and anode sheath, can be brought into reasonable agreement with the measurements, provided the effective range of the conduction electrons from within the discharge plasma to the anode surface is properly acknowledged.

  17. Measurement of 59Ni and 63Ni by accelerator mass spectrometry at CIAE

    NASA Astrophysics Data System (ADS)

    Wang, Xiaoming; He, Ming; Ruan, Xiangdong; Xu, Yongning; Shen, Hongtao; Du, Liang; Xiao, Caijin; Dong, Kejun; Jiang, Shan; Yang, Xuran; Lan, Xiaoxi; Wu, Shaoyong; Zhao, Qingzhang; Cai, Li; Pang, Fangfang

    2015-10-01

    The long lived isotopes 59Ni and 63Ni can be used in many areas such as radioactive waste management, neutron dosimetry, cosmic radiation study, and so on. Based on the large accelerator and a big Q3D magnetic spectrometer, the measurement method for 59Ni and 63Ni is under development at the AMS facility at China Institute of Atomic Energy (CIAE). By using the ΔE-Q3D technique with the Q3D magnetic spectrometer, the isobaric interferences were greatly reduced in the measurements of 59Ni and 63Ni. A four anode gas ionization chamber was then used to further identify isobars. With these techniques, the abundance sensitivities of 59Ni and 63Ni measurements are determined as 59Ni/Ni = 1 × 10-13 and 63Ni/Ni = 2 × 10-12, respectively.

  18. Describing and Measuring the Chemical Signatures of Life

    NASA Technical Reports Server (NTRS)

    Crawford, R. L.; Paszczynski, A.; Lang, Q.; Cheng, I. F.; Barnes, B.; Anderson, T. J.; Wells, R.; Wai, C.; Corti, G.; Allenbach, L.

    2000-01-01

    Here we discuss an approach to remotely detecting extraterrestrial life forms on other planets or their moons by detection of specific types of organic molecules. The life entities to be detected would be presently active life forms, or those that are only recently dormant. The only place beside Earth's moon where humans have actually examined surface soils for the presence of organic molecules is Mars. This was accomplished using mass-spectrometry during the Viking mission, and results were negative. The lack of organic moieties, if they ever were present, probably resulted form their destruction over geologic time frames by the extraordinarily reactive surface soils found there. Thus, on Mars, detection of organic signatures of life probably would be possible only in subsurface soils, or perhaps in polar regions.

  19. Shelf-life and colour change kinetics of Aloe vera gel powder under accelerated storage in three different packaging materials.

    PubMed

    Ramachandra, C T; Rao, P Srinivasa

    2013-08-01

    Aloe vera gel powder was produced through dehumidified air drying of Aloe vere gel at optimized conditions of temperature, relative humidity and air velocity of 64 °C, 18% and 0.8 m.s(-1), respectively. The powder was packed in three different packaging materials viz., laminated aluminum foil (AF), biaxially oriented polypropylene (BOPP) and polypropylene (PP). The shelf-life of the powder was predicted on the basis of free flowness of product under accelerated storage condition (38 ± 1 °C, 90 ± 1% relative humidity) and was calculated to be 33.87, 42.58 and 51.05 days in BOPP, PP and AF, respectively. The storage stability of powder in terms of colour change was studied. The magnitude of colour change of Aloe vera gel powder during storage suggests that AF was better than BOPP and PP. The colour change of powder during storage followed first order reaction kinetics with a rate constant of 0.0444 per day for AF, 0.075 per day for BOPP and 0.0498 per day for PP. PMID:24425977

  20. Measurements of Accelerator-Produced Leakage Neutron and Photon Transmission through Concrete

    SciTech Connect

    Nelson, Walter R

    2002-07-04

    Optimum shielding of the radiation from particle accelerators requires knowledge of the attenuation characteristics of the shielding material. The most common material for shielding this radiation is concrete, which can be made using various materials of different densities as aggregates. These different concrete mixes can have very different attenuation characteristics. Information about the attenuation of leakage photons and neutrons in ordinary and heavy concrete is, however, very limited. To increase our knowledge and understanding of the radiation attenuation in concrete of various compositions, we have performed measurements of the transmission of leakage radiation, photons and neutrons, from a Varian Clinac 2100C medical linear accelerator operating at maximum electron energies of 6 and 18 MeV. We also calculated, using Monte Carlo techniques, the leakage neutron spectra and its transmission through concrete. The results of these measurements and calculations extend the information currently available for designing shielding for medical electron accelerators. Photon transmission characteristics depend more on the manufacturer of the concrete than on the atomic composition. A possible cause for this effect is a non-uniform distribution of the high density aggregate, typically iron, in the concrete matrix. Errors in estimated transmission of photons can exceed a factor of three, depending on barrier thickness, if attenuation in high-density concrete is simply scaled from that of normal density concrete. We found that neutron transmission through the high-density concretes can be estimated most reasonably and conservatively by using the linear tenth-value layer of normal concrete if specific values of the tenth-value layer of the high-density concrete are not known. The reason for this is that the neutron transmission depends primarily on the hydrogen content of the concrete, which does not significantly depend on concrete density. Errors of factors of two to

  1. Measurement of Actinides in Environmental Samples at Micro-Becquerel Levels by Accelerator Mass Spectrometry

    SciTech Connect

    Brown, T A; Knezovich, J P; Marchetti, A A; Hamilton, T F

    2002-09-03

    The need for ultra-sensitive actinide measurements continues to expand in the fields of environmental stewardship, nuclear isotope forensics, radiobioassay and environmental research. We have developed a heavy isotope accelerator mass spectrometry (AMS) system at Lawrence Livermore National Laboratory's Center for Accelerator Mass Spectrometry (CAMS). The system was designed particularly for the measurement of actinide concentrations and isotopic ratios. A fast isotope switching capability has been incorporated in the system, allowing flexibility in isotope selection and for the quasi-continuous normalization to a reference isotope spike. Initially, our utilization of the system has concentrated on the measurement of Pu isotopes. Under current operating conditions, background levels equivalent to <10{sup 6} atoms are observed during routine {sup 239}Pu and {sup 240}Pu measurements. Measurements of samples containing 10{sup 13} {sup 238}U atoms demonstrate that the system provides a {sup 238}U rejection factor of >10{sup 7}. Recently, we have utilized the high dynamic range of the AMS system in measuring samples whose Pu contents ranged from <10{sup 6} (background) to >10{sup 11} Pu atoms. Measurements of known materials, combined with results from an externally organized intercomparison program, indicate that our {sup 239}Pu measurements are accurate and precise down to the {mu}Bq level ({approx}10{sup 6} atoms). The development of the heavy isotope system was undertaken with particular interest in the measurement of environmental samples, including soils, sediments, waters, air filters, tissue samples, and human urine. The high rejection of interferences, including molecular interferences, and low susceptibility to matrix components, provided by the AMS technique are of particular relevance for such complex samples. These two factors significantly reduce demands on sample preparation chemistry for Pu analyses, allowing relatively simple, cost-effective procedures

  2. Feasibility of a Computerized Method to Measure Quality of "Everyday" Life in Children with Neuromuscular Disorders

    ERIC Educational Resources Information Center

    Bray, Paula; Bundy, Anita C.; Ryan, Monique M.; North, Kathryn N.

    2010-01-01

    Measurement of quality of life is becoming increasingly important in health care. Self-reported quality of life is the preferred method of gathering this information, but children are often excluded from this process, their input being replaced by parent-proxy report. This feasibility study tested assessment of "daily" quality-of-life by a…

  3. Assessing the Need for the Development of Standardized Life Skills Measures

    ERIC Educational Resources Information Center

    Duerden, Mat D.; Witt, Peter A.

    2011-01-01

    Youth practitioners often select life skills as intentionally targeted program outcomes. While research findings suggest the efficacy of program experiences to positively influence a variety of life skills, it remains difficult to compare these findings due to measurement incongruities. Individual life skills (e.g., leadership, decision making,…

  4. Assessing College Student-Athletes' Life Stress: Initial Measurement Development and Validation

    ERIC Educational Resources Information Center

    Lu, Frank Jing-Horng; Hsu, Ya-Wen; Chan, Yuan-Shuo; Cheen, Jang-Rong; Kao, Kuei-Tsu

    2012-01-01

    College student-athletes have unique life stress that warrants close attention. The purpose of this study was to develop a reliable and valid measurement assessing college student-athletes' life stress. In Study 1, a focus group discussion and Delphi method produced a questionnaire draft, termed the College Student-Athletes' Life Stress Scale. In…

  5. Equation Of State Measurements of Warm Dense Copper Heated By Laser Accelerated Proton Beams

    NASA Astrophysics Data System (ADS)

    Dyer, Gilliss; Feldman, Samuel; Kuk, Donghoon; Wagner, Craig; Gaul, Erhard; Donovan, Michael; Martinez, Mikael; Borger, Teddy; Spinks, Michael; Jiang, Sheng; Aymond, Franki; Akli, Kramer; Ditmire, Todd

    2014-10-01

    We report equation of state (EOS) measurements of solid density transition metals heated to temperatures of 1 to 50 eV by laser accelerated pulsed proton beams. Matter at these densities and temperatures, referred to as warm dense matter (WDM), will exhibit long-range coupling, partial ionization and thermal energies comparable to the Fermi energy, making theoretical predictions of state properties very challenging. Mbar pressures likewise make such states difficult to study in the lab. In this work we use a terawatt or petawatt laser to accelerate MeV protons from a source foil, which then heat an adjacent sample foil. We probe the sample foil on a picosecond timescale using streaked optical pyrometery, time resolved interferometry, and XUV imaging. Previously we and various other groups have applied these techniques to the study of aluminum, one of the best-understood metals from the standpoint of high energy density equations of state. Here we present measurements of Cu, Cr, and Ag. Transition metals such as these are of particular interest because of modeling challenges posed by a partially filled d - orbital.

  6. Counting calories in cormorants: dynamic body acceleration predicts daily energy expenditure measured in pelagic cormorants.

    PubMed

    Stothart, Mason R; Elliott, Kyle H; Wood, Thomas; Hatch, Scott A; Speakman, John R

    2016-07-15

    The integral of the dynamic component of acceleration over time has been proposed as a measure of energy expenditure in wild animals. We tested that idea by attaching accelerometers to the tails of free-ranging pelagic cormorants (Phalacrocorax pelagicus) and simultaneously estimating energy expenditure using doubly labelled water. Two different formulations of dynamic body acceleration, [vectorial and overall DBA (VeDBA and ODBA)], correlated with mass-specific energy expenditure (both R(2)=0.91). VeDBA models combining and separately parameterizing flying, diving, activity on land and surface swimming were consistently considered more parsimonious than time budget models and showed less variability in model fit. Additionally, we observed evidence for the presence of hypometabolic processes (i.e. reduced heart rate and body temperature; shunting of blood away from non-essential organs) that suppressed metabolism in cormorants while diving, which was the most metabolically important activity. We concluded that a combination of VeDBA and physiological processes accurately measured energy expenditure for cormorants. PMID:27207639

  7. High gradient dielectric wakefield device measurements at the Argonne wakefield accelerator

    SciTech Connect

    Schoessow, P.; Conde, M.; Gai, W.; Konecny, R.; Power, J.; Simpson, J.

    1997-10-01

    The Argonne Wakefield Accelerator (AWA) is a facility designed to investigate high gradient wakefield acceleration techniques. Wakefields are excited using a drive beam produced by a 14 MeV high current photoinjector-based linac. A second photocathode gun generates a 4 MeV witness beam which is used as a probe of the wakefields in the device under test. The delay of the witness bunch with respect to the drive bunch can be continuously varied from -100 ps to >1 ns. The drive and witness bunches propagate along collinear or parallel trajectories through the test section. A dipole spectrometer is then used to measure the energy change of the witness beam. The complete wakefield measurement system has been commissioned and wakefield experiments using dielectric structures are underway. Initial experiments have focused on collinear wakefield device geometries where the drive and witness bunches traverse the same structure. For attaining very high gradients we will construct and study step-up transformer structures in which the rf pulse generated by the drive beam is compressed transversely and longitudinally.

  8. Motor recovery monitoring using acceleration measurements in post acute stroke patients

    PubMed Central

    2013-01-01

    Background Stroke is one of the major causes of morbidity and mortality. Its recovery and treatment depends on close clinical monitoring by a clinician especially during the first few hours after the onset of stroke. Patients who do not exhibit early motor recovery post thrombolysis may benefit from more aggressive treatment. Method A novel approach for monitoring stroke during the first few hours after the onset of stroke using a wireless accelerometer based motor activity monitoring system is developed. It monitors the motor activity by measuring the acceleration of the arms in three axes. In the presented proof of concept study, the measured acceleration data is transferred wirelessly using iMote2 platform to the base station that is equipped with an online algorithm capable of calculating an index equivalent to the National Institute of Health Stroke Score (NIHSS) motor index. The system is developed by collecting data from 15 patients. Results We have successfully demonstrated an end-to-end stroke monitoring system reporting an accuracy of calculating stroke index of more than 80%, highest Cohen’s overall agreement of 0.91 (with excellent κ coefficient of 0.76). Conclusion A wireless accelerometer based ‘hot stroke’ monitoring system is developed to monitor the motor recovery in acute-stroke patients. It has been shown to monitor stroke patients continuously, which has not been possible so far with high reliability. PMID:23590690

  9. Measurements of fusion neutrons from Magnetized Liner Inertial Fusion Experiments on the Z accelerator

    NASA Astrophysics Data System (ADS)

    Hahn, K. D.; Chandler, G. A.; Ruiz, C. L.; Gomez, M. R.; Slutz, S. A.; Sefkow, A. B.; Sinars, D. B.; Hansen, S. B.; Knapp, P. F.; Schmit, P. F.; Harding, E. C.; Awe, T. J.; Torres, J. A.; Jones, B.; Bur, J. A.; Cooper, G. W.; Styron, J. D.; Glebov, V. Yu.

    2015-11-01

    Strong evidence of thermonuclear neutron production has been observed during Magnetized Liner Inertial Fusion (MagLIF) experiments on the Z accelerator. So far, these experiments have utilized deuterium fuel and produced primary DD fusion neutron yields up to 2e12 with electron and ion stagnation temperatures in the 2-3 keV range. We present MagLIF neutron measurements and compare to other data and implosion simulations. In addition to primary DD and secondary DT yields and ion temperatures, other complex physics regarding the degree of fuel magnetization and liner density are elucidated by the neutron measurements. Neutron diagnostic development for deuterium and future deuterium-tritium fuel experiments are also discussed. Sandia is sponsored by the U.S. DOE's NNSA under contract DE-AC04-94AL85000.

  10. Measurements of the critical power for self-injection of electrons in a laser wakefield accelerator

    SciTech Connect

    Froula, D H; Clayton, C E; Doppner, T; Fonseca, R A; Marsh, K A; Barty, C J; Divol, L; Glenzer, S H; Joshi, C; Lu, W; Martins, S F; Michel, P; Mori, W; Palastro, J P; Pollock, B B; Pak, A; Ralph, J E; Ross, J S; Siders, C; Silva, L O; Wang, T

    2009-06-02

    A laser wakefield acceleration study has been performed in the matched, self-guided, blow-out regime where a 10 J, 60 fs laser produced 720 {+-} 50 MeV quasi-monoenergetic electrons with a divergence of {Delta}{theta} = 2.85 {+-} 0.15 mRad. While maintaining a nearly constant plasma density (3 x 10{sup 18} cm{sup -3}), a linear electron energy gain was measured from 100 MeV to 700 MeV when the plasma length was scaled from 3 mm to 8 mm. Absolute charge measurements indicate that self-injection occurs when P/P{sub cr} > 4 and saturates around 100 pC for P/P{sub cr} > 12. The results are compared with both analytical scalings and full 3D particle-in-cell simulations.

  11. Generation and measurement of ultrashort pulses from the Stanford Superconducting Accelerator free-electron laser

    SciTech Connect

    Richman, B.A.; DeLong, K.W.; Trebino, R.

    1995-11-01

    The authors present results of frequency resolved optical gating (FROG) measurements on the Superconducting Accelerator (SCA) mid-IR free-electron laser (FEL) at Stanford. FROG retrieves complete amplitude and phase content of an optical pulse. First, they review the properties of FELs including the ability to tune wavelength and pulse length. In addition, the electron beam driving the FEL often affects the optical pulse shape. The SCA mid-IR FEL currently operates at wavelengths between 4 {micro}m and 10 {micro}m and its pulse length can be varied from 700 fs to 2 ps. They then describe details of the experimental layout and procedures particular to FELs and to the mid-IR. Finally, they show FROG measurements on the FEL including examples of nearly transform limited pulses, frequency chirped pulses, and pulses distorted by atmospheric water vapor absorption.

  12. The radiation field measurement and analysis outside the shielding of A 10 MeV electron irradiation accelerator

    NASA Astrophysics Data System (ADS)

    Shang, Jing; Li, Juexin; Xu, Bing; Li, Yuxiong

    2011-10-01

    Electron accelerators are employed widely for diverse purposes in the irradiation-processing industry, from sterilizing medical products to treating gemstones. Because accelerators offer high efficiency, high power, and require little preventative maintenance, they are becoming more and more popular than using the 60Co isotope approach. However, the electron accelerator exposes potential radiation hazards. To protect workers and the public from exposure to radiation, the radiation field around the electronic accelerator must be assessed, especially that outside the shielding. Thus, we measured the radiation dose at different positions outside the shielding of a 10-MeV electron accelerator using a new data-acquisition unit named Mini-DDL (Mini-Digital Data Logging). The measurements accurately reflect the accelerator's radiation status. In this paper, we present our findings, results and compare them with our theoretical calculations. We conclude that the measurements taken outside the irradiation hall are consistent with the findings from our calculations, except in the maze outside the door of the accelerator room. We discuss the reason for this discrepancy.

  13. Yeast dynamic metabolic flux measurement in nutrient-rich media by HPLC and accelerator mass spectrometry.

    PubMed

    Stewart, Benjamin J; Navid, Ali; Turteltaub, Kenneth W; Bench, Graham

    2010-12-01

    Metabolic flux, the flow of metabolites through networks of enzymes, represents the dynamic productive output of cells. Improved understanding of intracellular metabolic fluxes will enable targeted manipulation of metabolic pathways of medical and industrial importance to a greater degree than is currently possible. Flux balance analysis (FBA) is a constraint-based approach to modeling metabolic fluxes, but its utility is limited by a lack of experimental measurements. Incorporation of experimentally measured fluxes as system constraints will significantly improve the overall accuracy of FBA. We applied a novel, two-tiered approach in the yeast Saccharomyces cerevisiae to measure nutrient consumption rates (extracellular fluxes) and a targeted intracellular flux using a (14)C-labeled precursor with HPLC separation and flux quantitation by accelerator mass spectrometry (AMS). The use of AMS to trace the intracellular fate of (14)C-glutamine allowed the calculation of intracellular metabolic flux through this pathway, with glutathione as the metabolic end point. Measured flux values provided global constraints for the yeast FBA model which reduced model uncertainty by more than 20%, proving the importance of additional constraints in improving the accuracy of model predictions and demonstrating the use of AMS to measure intracellular metabolic fluxes. Our results highlight the need to use intracellular fluxes to constrain the models. We show that inclusion of just one such measurement alone can reduce the average variability of model predicted fluxes by 10%. PMID:21062031

  14. Calorimetric measurement of afterheat in target materials for the accelerator production of tritium

    SciTech Connect

    Perry, R.B.; Zucker, M.S.

    1994-06-01

    The estimate of afterheat in a spallation target of lead (Pb) or tungsten (W), by calorimetry, is the purpose of this experiment in support of the Accelerator Production of Tritium (APT). Such measurements are needed to confirm code calculations, these being the only practical way of gaining this type of information in a form suitable to aid the design of the APT machine. Knowledge of the magnitude and duration of afterheat resulting from decay of activation products produced by proton bombardment of the target is necessary to quantify APT safety assumptions, to design target cooling and safety systems, and to reduce technical risk. Direct calorimetric measurement of the afterheat for the appropriate incident proton energies is more reliable than the available alternative, which is indirect, based on data from gamma-ray spectroscopy measurements. The basic concept, a direct measurement of decay afterheat which bypasses the laborious classical way of determining this quantity, has been demonstrated to work. The gamma-ray energy given off by the decay products produced in the activation of lead or tungsten with high-energy protons apparently does represent a significant fraction of the total decay energy. A calorimeter designed for measurement of isotopes decaying by alpha emission must be modified to reduce energy lost with escaping gamma rays. Replacement of the aluminum liner with a tungsten liner in the SSC measurement chamber resulted in a 270% increase in measured heat, proving that the energy loss in the earlier (1992) measurements was significant. Gamma-ray measurements are needed to confirm the gamma-ray absorption calculations for the calorimeter to determine the correction for loss of heat due to transmission of high-energy gamma rays through the calorimeter walls. The experiments at BLIP have shown that calorimetry can be a useful tool in measuring the afterheat in APT target materials.

  15. Family Quality of Life: Moving from Measurement to Application

    ERIC Educational Resources Information Center

    Zuna, Nina I.; Turnbull, Ann; Summers, Jean Ann

    2009-01-01

    Noting the absence of sound theoretical underpinnings for family quality of life (FQoL) research and work, the authors note that, to guide FQoL practice, research findings must be schematically organized so as to enable practitioners to implement empirical findings effectively. One way to meet this goal is to introduce a theoretical model that…

  16. Measuring Quality of Life in Informal Settlements in South Africa

    ERIC Educational Resources Information Center

    Richards, Robin; O'Leary, Brian; Mutsonziwa, Kingstone

    2007-01-01

    South African cities attract thousands of new residents every year in search of work and a better life. The housing backlog coupled with a shortage of housing subsidies means that for many South Africans there is no alternative but to live in informal housing and shack settlements. Informal settlements are therefore here to stay for the next…

  17. Measuring the Child Quality of Life: Issues and Options.

    ERIC Educational Resources Information Center

    Arboleda, Jairo; Levinger, Beryl

    A Child Quality of Life Index (CQLI) should be developed in order to realize three objectives: (1) to raise the consciousness of decision makers, prospective donors, field workers, and community members concerning the needs of children; (2) to assist field workers and community members in planning specific programs to meet the priority needs of…

  18. CASAS: An Effective Measurement System for Life Skills.

    ERIC Educational Resources Information Center

    Stiles, Richard L.; And Others

    The California Adult Student Assessment System (CASAS) is a comprehensive educational system designed to enable adult educators to develop and evaluate a life skills curriculum for competency based educational programs. The system comprises the CASAS Competency List, the CASAS Item Bank, the User's Manual, the Curriculum Index and Matrix, and…

  19. Output trends, characteristics, and measurements of three megavoltage radiotherapy linear accelerators.

    PubMed

    Hossain, Murshed

    2014-01-01

    The purpose of this study is to characterize and understand the long-term behavior of the output from megavoltage radiotherapy linear accelerators. Output trends of nine beams from three linear accelerators over a period of more than three years are reported and analyzed. Output, taken during daily warm-up, forms the basis of this study. The output is measured using devices having ion chambers. These are not calibrated by accredited dosimetry laboratory, but are baseline-compared against monthly output which is measured using calibrated ion chambers. We consider the output from the daily check devices as it is, and sometimes normalized it by the actual output measured during the monthly calibration of the linacs. The data show noisy quasi-periodic behavior. The output variation, if normalized by monthly measured "real' output, is bounded between ± 3%. Beams of different energies from the same linac are correlated with a correlation coefficient as high as 0.97, for one particular linac, and as low as 0.44 for another. These maximum and minimum correlations drop to 0.78 and 0.25 when daily output is normalized by the monthly measurements. These results suggest that the origin of these correlations is both the linacs and the daily output check devices. Beams from different linacs, independent of their energies, have lower correlation coefficient, with a maximum of about 0.50 and a minimum of almost zero. The maximum correlation drops to almost zero if the output is normalized by the monthly measured output. Some scatter plots of pairs of beam output from the same linac show band-like structures. These structures are blurred when the output is normalized by the monthly calibrated output. Fourier decomposition of the quasi-periodic output is consistent with a 1/f power law. The output variation appears to come from a distorted normal distribution with a mean of slightly greater than unity. The quasi-periodic behavior is manifested in the seasonally averaged output

  20. Output trends, characteristics, and measurements of three mega-voltage radiotherapy linear accelerators

    PubMed Central

    Hossain, Murshed

    2015-01-01

    The purpose of this study is to characterize and understand the long term behavior of the output from megavoltage radiotherapy linear accelerators. Output trends of nine beams from three linear accelerators over a period of more than three years are reported and analyzed. Output taken during daily warm-up forms the basis of this study. The output is measured using devices having ion-chambers. These are not calibrated by accredited dosimetry laboratory but are baseline compared against monthly output which are measured using calibrated ion-chambers. We consider the output from the daily check devices as it is and sometimes normalized them by the actual output measured during the monthly calibration of the Linacs. The data shows noisy quasi-periodic behavior. The output variation if normalized by monthly measured “real’ output, is bounded between ±3%. Beams of different energies from the same Linac are correlated with a correlation coefficient as high as 0.97 for one particular Linac and as low as 0.44 for another. These maximum and minimum correlations drop to 0.78 and 0.25 when daily output is normalized by the monthly measurements. These results suggest that the origin of these correlations are both the Linacs and the daily output check devices. Beams from different Linacs, independent of their energies, have lower correlation coefficient with a maximum of about 0.50 and a minimum of almost zero. The maximum correlation drops to almost zero if the output is normalized by the monthly measured output. Some scatter plots of pairs of beam-output from the same Linac show band-like structures. These structures are blurred when the output is normalized by the monthly calibrated output. Fourier decomposition of the quasi periodic output is consistent with a 1/f power law. The output variation appears to come from a distorted normal distribution with a mean of slightly greater than unity. The quasi-periodic behavior is manifested in the seasonally averaged output

  1. Fusion-neutron measurements for magnetized liner inertial fusion experiments on the Z accelerator

    DOE PAGESBeta

    Hahn, K. D.; Chandler, G. A.; Ruiz, C. L.; Cooper, G. W.; Gomez, M. R.; Slutz, S.; Sefkow, A. B.; Sinars, D. B.; Hansen, S. B.; Knapp, P. F.; et al

    2016-05-01

    Several magnetized liner inertial fusion (MagLIF) experiments have been conducted on the Z accelerator at Sandia National Laboratories since late 2013. Measurements of the primary DD (2.45 MeV) neutrons for these experiments suggest that the neutron production is thermonuclear. Primary DD yields up to 3e12 with ion temperatures ~2-3 keV have been achieved. Measurements of the secondary DT (14 MeV) neutrons indicate that the fuel is significantly magnetized. Measurements of down-scattered neutrons from the beryllium liner suggest ρRliner ~ 1g/cm2. Neutron bang times, estimated from neutron time-of-flight (nTOF) measurements, coincide with peak x-ray production. Furthermore, plans to improve and expandmore » the Z neutron diagnostic suite include neutron burn-history diagnostics, increased sensitivity and higher precision nTOF detectors, and neutron recoil-based yield and spectral measurements.« less

  2. Evo-SETI SCALE to measure Life on Exoplanets

    NASA Astrophysics Data System (ADS)

    Maccone, Claudio

    2016-04-01

    that the GBM exponential may be regarded as the geometric locus of all the peaks of a one-parameter (i.e. the peak time p) family of b-lognormals. Since b-lognormals are pdf-s, the area under each of them always equals 1 (normalization condition) and so, going from left to right on the time axis, the b-lognormals become more and more "peaky", and so they last less and less in time. This is precisely what happened in human history: civilizations that lasted millennia (like Ancient Greece and Rome) lasted just centuries (like the Italian Renaissance and Portuguese, Spanish, French, British and USA Empires) but they were more and more advanced in the "level of civilization". This "level of civilization" is what physicists call ENTROPY. Also, in refs. Maccone [3] and [4], this author proved that, for all GBMs, the (Shannon) Entropy of the b-lognormals in his Peak-Locus Theorem grows LINEARLY in time. The Molecular Clock, well known to geneticists since 50 years, shows that the DNA base-substitutions occur LINEARLY in time since they are neutral with respect to Darwinian selection. In simple words: DNA evolved by obeying the laws of quantum physics only (microscopic laws) and not by obeying assumed "Darwinian selection laws" (macroscopic laws). This is Kimura's neutral theory of molecular evolution. The conclusion is that the Molecular Clock and the b-lognormal Entropy are the same thing. At last, we reach the new, original result justifying the publication of this paper. On exoplanets, molecular evolution is proceeding at about the same rate as it did proceed on Earth: rather independently of the physical conditions of the exoplanet, if the DNA had the possibility to evolve in water initially. Thus, Evo-Entropy, i.e. the (Shannon) Entropy of the generic b-lognormal of the Peak-Locus Theorem, provides the Evo-SETI SCALE to measure the evolution of life on exoplanets.

  3. A Systematic Review of Measures of End-of-Life Care and Its Outcomes

    PubMed Central

    Mularski, Richard A; Dy, Sydney M; Shugarman, Lisa R; Wilkinson, Anne M; Lynn, Joanne; Shekelle, Paul G; Morton, Sally C; Sun, Virginia C; Hughes, Ronda G; Hilton, Lara K; Maglione, Margaret; Rhodes, Shannon L; Rolon, Cony; Lorenz, Karl A

    2007-01-01

    Objective To identify psychometrically sound measures of outcomes in end-of-life care and to characterize their use in intervention studies. Data Sources English language articles from 1990 to November 2005 describing measures with published psychometric data and intervention studies of end-of-life care. Study Design Systematic review of end-of-life care literature. Extraction Methods Two reviewers organized identified measures into 10 major domains. Eight reviewers extracted and characterized measures from intervention studies. Principal Findings Of 24,423 citations, we extracted 200 articles that described 261 measures, accepting 99 measures. In addition to 35 measures recommended in a prior systematic review, we identified an additional 64 measures of the end-of-life experience. The most robust measures were in the areas of symptoms, quality of life, and satisfaction; significant gaps existed in continuity of care, advance care planning, spirituality, and caregiver well-being. We also reviewed 84 intervention studies in which 135 patient-centered outcomes were assessed by 97 separate measures. Of these, 80 were used only once and only eight measures were used in more than two studies. Conclusions In general, most measures have not undergone rigorous development and testing. Measure development in end-of-life care should focus on areas with identified gaps, and testing should be done to facilitate comparability across the care settings, populations, and clinical conditions. Intervention research should use robust measures that adhere to these standards. PMID:17850523

  4. Acceleration Measurement and Characterization in Support of the USMP-4 Payloads

    NASA Technical Reports Server (NTRS)

    Rogers, M. J. B.; Hrovat, K.; McPherson, K.; DeLombard, R.; Reckart, T.

    1999-01-01

    One common characteristic of the USMP-4 experiments is that various effects of gravity make it difficult, if not impossible, to achieve usable results when performing the experiments on Earth's surface. Therefore, the investigators took advantage of the microgravity environment afforded by being in low-Earth orbit to perform their research. Interpretation of the experiment results both during the mission and upon post-mission analyses of data and samples required an understanding of the microgravity environment in which the experiments were conducted. To achieve that understanding, data were collected using the Orbital Acceleration Research Experiment (OARE) and two Space Acceleration Measurement Systems (SAMS). Data from those systems, combined with an assessment of mission and experiment activities, were used to characterize the microgravity environment that existed on Columbia during the mission. The text herein gives details about some characteristics of the environment that were noted during the mission and during post-mission data analysis. The disturbances studied include the Ku-band antenna 17 Hz dither; the effect of changing the Orbiter attitude deadband limits; the effects of different bicycle ergometer configurations; and the effect of IDGE (Isothermal Dendritic Growth Experiment) experiment fans and SAMS computer hard drives. Additional information about the microgravity environment is provided. Supplementary data plots representing the environment throughout the majority of the mission are available at the Uniform Resource Locator (URL). Data files for both SAMS and OARE are accessible via anonymous file transfer protocol from the file server.

  5. From "Work-Family" to "Work-Life": Broadening Our Conceptualization and Measurement

    ERIC Educational Resources Information Center

    Keeney, Jessica; Boyd, Elizabeth M.; Sinha, Ruchi; Westring, Alyssa F.; Ryan, Ann Marie

    2013-01-01

    Despite frequent reference to "work-life" issues in the organizational literature, little theoretical or empirical attention has been paid to nonwork areas beyond family. The purpose of the research described here is to move beyond work-family conflict to a broader conceptualization and measurement of work interference with life. A measure of work…

  6. Sample Heterogeneity and the Measurement Structure of the Multidimensional Students' Life Satisfaction Scale

    ERIC Educational Resources Information Center

    Sawatzky, Richard; Ratner, Pamela A.; Johnson, Joy L.; Kopec, Jacek A.; Zumbo, Bruno D.

    2009-01-01

    Several measurement assumptions were examined with the goal of assessing the validity of the Multidimensional Students' Life Satisfaction Scale (MSLSS), a measure of adolescents' satisfaction with their family, friends, living environment, school, self, and general quality of life. The data were obtained via a cross-sectional survey of 8,225…

  7. Improvement in quality of life measures after laparoscopic antireflux surgery.

    PubMed Central

    Trus, T L; Laycock, W S; Waring, J P; Branum, G D; Hunter, J G

    1999-01-01

    OBJECTIVE: To determine if patients with gastroesophageal reflux "well controlled medically" had a different quality of life from those with residual symptoms receiving aggressive medical therapy, and to determine whether laparoscopic antireflux surgery significantly altered quality of life in patients with gastroesophageal reflux. SUMMARY BACKGROUND DATA: Clinical determinants of outcome may not adequately reflect the full impact of therapy. The medical outcomes study short form (SF-36) is a well-validated questionnaire that assays eight specific health concepts in three general fields. It may provide a more sensitive tool for judging the success of antireflux therapy. METHODS: A total of 345 patients undergoing laparoscopic antireflux surgery completed at least one questionnaire during the study period. Preoperative questionnaires were completed by 290 patients, 223 completed a questionnaire 6 weeks after surgery, and 50 completed the same questionnaire 1 year after surgery. A subgroup of 70 patients was divided before surgery into two groups on the basis of their response to standard medical therapy. RESULTS: Preoperative scores were extremely low. All eight SF-36 health categories improved significantly 6 weeks and 1 year after surgery. In the 70-patient subgroup, 53 patients (76%) underwent laparoscopic antireflux surgery because of symptoms refractory to medical therapy and 17 patients (24%) reported that their symptoms were well controlled but elected to have surgery because they wished to be medication-free. The preoperative quality of life scores of these two patient groups were equivalent in all but one category. Postoperative scores were significantly improved in all categories and indistinguishable between the two groups. CONCLUSIONS: Laparoscopic antireflux surgery is an effective therapy for patients with gastroesophageal reflux and may be more effective than medical therapy at improving quality of life. PMID:10077044

  8. SAMS Acceleration Measurements on Mir from May 1997 to June 1998 (NASA Increments 5, 6, and 7)

    NASA Technical Reports Server (NTRS)

    DeLombard, Richard

    1999-01-01

    During NASA Increments 5, 6, and 7 (May 1997 to June 1998), about eight gigabytes of acceleration data were collected by the Space Acceleration Measurement System (SAMS) onboard the Russian Space Station Mir. The data were recorded on twenty-seven optical disks which were returned to Earth on Orbiter missions STS-86, STS-89, and STS-91. During these increments, SAMS data were collected in the Priroda module to support various microgravity experiments. This report points out some of the salient features of the microgravity acceleration environment to which the experiments were exposed. This report presents an overview of the SAMS acceleration measurements recorded by 10 Hz and 100 Hz sensor heads. The analyses included herein complement those presented in previous Mir increment summary reports prepared by the Principal Investigator Microgravity Services project.

  9. The association between objectively measured physical activity and life-space mobility among older people.

    PubMed

    Tsai, L-T; Portegijs, E; Rantakokko, M; Viljanen, A; Saajanaho, M; Eronen, J; Rantanen, T

    2015-08-01

    The purpose of this cross-sectional study was to investigate the association between objectively measured physical activity and life-space mobility in community-dwelling older people. Life-space refers to the spatial area a person purposefully moves through in daily life (bedroom, home, yard, neighborhood, town, and beyond) and life-space mobility to the frequency of travel and the help needed when moving through different life-space areas. The study population comprised community-living 75- to 90-year-old people {n = 174; median age 79.7 [interquartile range (IQR) 7.1]}, participating in the accelerometer substudy of Life-Space Mobility in Old Age (LISPE) project. Step counts and activity time were measured by an accelerometer (Hookie "AM20 Activity Meter") for 7 days. Life-space mobility was assessed with Life-Space Assessment (LSA) questionnaire. Altogether, 16% had a life-space area restricted to the neighborhood when moving independently. Participants with a restricted life space were less physically active and about 70% of them had exceptionally low values in daily step counts (≤ 615 steps) and moderate activity time (≤ 6.8 min). Higher step counts and activity time correlated positively with life-space mobility. Prospective studies are needed to clarify the temporal order of low physical activity level and restriction in life-space mobility. PMID:26152855

  10. The measurement of photoneutrons in the vicinity of a Siemens Primus linear accelerator.

    PubMed

    Lin, J P; Chu, T C; Lin, S Y; Liu, M T

    2001-09-01

    This study involves the measurement of photoneutron contamination emitted from a Siemens Primus medical linear accelerator by using BD-PND bubble detectors. Various bubble detectors were arranged around the linac head with the interval of I m and at the same height as the isocenter to measure the dose equivalent distribution in the treatment room. The measurements were performed for 15 MV X-rays with 40 x 40cm2 and 0 x 0cm2 fields and for 15,18, and 21 MeV electrons with 25 x 25 cm2 electron cone. Neutron dose equivalent rate at the points of measurement in the treatment room decreased with increasing distance to the isocenter. The maximum neutron dose equivalents were at the isocenter, and the values for 15MV 40 x 40 and 0 x 0 cm2 were 1843+/-90 and 169.9+/-59.9 microSv per Gy X-ray, respectively. The values for 15, 18 and 21 MeV electrons with 25 x 25 cm2 cones were 100.0+/-20.4, 262.7+/-61.2 and 349.0+/-29.6 microSv per Gy electron, respectively. The neutron contamination of electrons less than 12 MeV was below the detection limit. PMID:11515653

  11. Self-organizing map (SOM) of space acceleration measurement system (SAMS) data.

    PubMed

    Sinha, A; Smith, A D

    1999-01-01

    In this paper, space acceleration measurement system (SAMS) data have been classified using self-organizing map (SOM) networks without any supervision; i.e., no a priori knowledge is assumed regarding input patterns belonging to a certain class. Input patterns are created on the basis of power spectral densities of SAMS data. Results for SAMS data from STS-50 and STS-57 missions are presented. Following issues are discussed in details: impact of number of neurons, global ordering of SOM weight vectors, effectiveness of a SOM in data classification, and effects of shifting time windows in the generation of input patterns. The concept of 'cascade of SOM networks' is also developed and tested. It has been found that a SOM network can successfully classify SAMS data obtained during STS-50 and STS-57 missions. PMID:11543426

  12. Self-organizing map (SOM) of space acceleration measurement system (SAMS) data

    NASA Technical Reports Server (NTRS)

    Sinha, A.; Smith, A. D.

    1999-01-01

    In this paper, space acceleration measurement system (SAMS) data have been classified using self-organizing map (SOM) networks without any supervision; i.e., no a priori knowledge is assumed regarding input patterns belonging to a certain class. Input patterns are created on the basis of power spectral densities of SAMS data. Results for SAMS data from STS-50 and STS-57 missions are presented. Following issues are discussed in details: impact of number of neurons, global ordering of SOM weight vectors, effectiveness of a SOM in data classification, and effects of shifting time windows in the generation of input patterns. The concept of 'cascade of SOM networks' is also developed and tested. It has been found that a SOM network can successfully classify SAMS data obtained during STS-50 and STS-57 missions.

  13. Light scattering microscopy measurements of single nuclei compared with GPU-accelerated FDTD simulations

    NASA Astrophysics Data System (ADS)

    Stark, Julian; Rothe, Thomas; Kieß, Steffen; Simon, Sven; Kienle, Alwin

    2016-04-01

    Single cell nuclei were investigated using two-dimensional angularly and spectrally resolved scattering microscopy. We show that even for a qualitative comparison of experimental and theoretical data, the standard Mie model of a homogeneous sphere proves to be insufficient. Hence, an accelerated finite-difference time-domain method using a graphics processor unit and domain decomposition was implemented to analyze the experimental scattering patterns. The measured cell nuclei were modeled as single spheres with randomly distributed spherical inclusions of different size and refractive index representing the nucleoli and clumps of chromatin. Taking into account the nuclear heterogeneity of a large number of inclusions yields a qualitative agreement between experimental and theoretical spectra and illustrates the impact of the nuclear micro- and nanostructure on the scattering patterns.

  14. E-beam dynamics calculations and comparison with measurements of a high duty accelerator at Boeing

    SciTech Connect

    Parazzoli, C.G.; Dowell, D.H.

    1995-12-31

    The electron dynamics in the photoinjector cavities and through the beamline for a high duty factor electron accelerator are computed. The particle in a cell code ARGUS, is first used in the low energy (< 2 MeV) region of the photoinjector, then the ARGUS-generated phase space at the photoinjector exit is used as input in the standard particle pusher code PARMELA, and the electron beam properties at the end of the beamline computed. Comparisons between the calculated and measured electron bea mradial profiles and emittances are presented for different values of the electron pulse charge. A discussion of the methodology used and on the accuracy of PARMELA in the low energy region of the photoinjector is given.

  15. Summary Report of mission acceleration measurements for STS-66. Launched November 3, 1994

    NASA Technical Reports Server (NTRS)

    Rogers, Melissa J. B.; Delombard, Richard

    1995-01-01

    Experiments flown in the middeck of Atlantis during the STS-66 mission were supported by the Space Acceleration Measurement System (SAMS). In particular, the three triaxial SAMS sensor heads collected data in support of protein crystal growth experiments. Data collected during STS-66 are reviewed in this report. The STS-66 SAMS data represent the microgravity environment in the 0.01 Hz to 10 Hz range. Variations in the environment related to differing levels of crew activity are discussed in the report. A comparison is made among times when the crew was quiet during a public affairs conference, working quietly, and exercising. These levels of activity are also compared to levels recorded by a SAMS unit in the Spacelab on Columbia during the STS-65 mission.

  16. Light scattering microscopy measurements of single nuclei compared with GPU-accelerated FDTD simulations.

    PubMed

    Stark, Julian; Rothe, Thomas; Kieß, Steffen; Simon, Sven; Kienle, Alwin

    2016-04-01

    Single cell nuclei were investigated using two-dimensional angularly and spectrally resolved scattering microscopy. We show that even for a qualitative comparison of experimental and theoretical data, the standard Mie model of a homogeneous sphere proves to be insufficient. Hence, an accelerated finite-difference time-domain method using a graphics processor unit and domain decomposition was implemented to analyze the experimental scattering patterns. The measured cell nuclei were modeled as single spheres with randomly distributed spherical inclusions of different size and refractive index representing the nucleoli and clumps of chromatin. Taking into account the nuclear heterogeneity of a large number of inclusions yields a qualitative agreement between experimental and theoretical spectra and illustrates the impact of the nuclear micro- and nanostructure on the scattering patterns. PMID:26976736

  17. Measurements of reduced corkscrew motion on the ETA-II linear induction accelerator

    SciTech Connect

    Allen, S.L.; Brand, H.R.; Chambers, F.W.; Chen, Y.J.; Coffield, F.E.; Deadrick, F.J.; Griffith, L.V.; Lager, D.L.; Mauer, W.J.; Nexsen, W.E.; Paul, A.C.; Sampayan, S.; Turner, W.C.

    1991-05-01

    The ETA-II linear induction accelerator is used to drive a microwave free electron laser (FEL). Corkscrew motion, which previously limited performance, has been reduced by: (1) an improved pulse distribution system which reduces energy sweep, (2) improved magnetic alignment achieved with a stretched wire alignment technique (SWAT) and (3) a unique magnetic tuning algorithm. Experiments have been carried out on a 20-cell version of ETA-II operating at 1500 A and 2.7 MeV. The measured transverse beam motion is less than 0.5 mm for 40 ns of the pulse, an improvement of a factor of 2 to 3 over previous results. Details of the computerized tuning procedure, estimates of the corkscrew phase, and relevance of these results to future FEL experiments are presented. 11 refs.

  18. Measurements of the critical power for self-injection of electrons in a laser wakefield accelerator.

    PubMed

    Froula, D H; Clayton, C E; Döppner, T; Marsh, K A; Barty, C P J; Divol, L; Fonseca, R A; Glenzer, S H; Joshi, C; Lu, W; Martins, S F; Michel, P; Mori, W B; Palastro, J P; Pollock, B B; Pak, A; Ralph, J E; Ross, J S; Siders, C W; Silva, L O; Wang, T

    2009-11-20

    A laser wakefield acceleration study has been performed in the matched, self-guided, blowout regime producing 720 +/- 50 MeV quasimonoenergetic electrons with a divergence Deltatheta_{FWHM} of 2.85 +/- 0.15 mrad using a 10 J, 60 fs 0.8 microm laser. While maintaining a nearly constant plasma density (3 x 10{18} cm{-3}), the energy gain increased from 75 to 720 MeV when the plasma length was increased from 3 to 8 mm. Absolute charge measurements indicate that self-injection of electrons occurs when the laser power P exceeds 3 times the critical power P{cr} for relativistic self-focusing and saturates around 100 pC for P/P{cr} > 5. The results are compared with both analytical scalings and full 3D particle-in-cell simulations. PMID:20366048

  19. Measurements of the Critical Power for Self-Injection of Electrons in a Laser Wakefield Accelerator

    NASA Astrophysics Data System (ADS)

    Froula, D. H.; Clayton, C. E.; Döppner, T.; Marsh, K. A.; Barty, C. P. J.; Divol, L.; Fonseca, R. A.; Glenzer, S. H.; Joshi, C.; Lu, W.; Martins, S. F.; Michel, P.; Mori, W. B.; Palastro, J. P.; Pollock, B. B.; Pak, A.; Ralph, J. E.; Ross, J. S.; Siders, C. W.; Silva, L. O.; Wang, T.

    2009-11-01

    A laser wakefield acceleration study has been performed in the matched, self-guided, blowout regime producing 720±50MeV quasimonoenergetic electrons with a divergence ΔθFWHM of 2.85±0.15mrad using a 10 J, 60 fs 0.8μm laser. While maintaining a nearly constant plasma density (3×1018cm-3), the energy gain increased from 75 to 720 MeV when the plasma length was increased from 3 to 8 mm. Absolute charge measurements indicate that self-injection of electrons occurs when the laser power P exceeds 3 times the critical power Pcr for relativistic self-focusing and saturates around 100 pC for P/Pcr>5. The results are compared with both analytical scalings and full 3D particle-in-cell simulations.

  20. Purpose in life is associated with physical activity measured by accelerometer.

    PubMed

    Hooker, Stephanie A; Masters, Kevin S

    2016-06-01

    Previous research has shown that purpose in life, the belief that one's life is meaningful and goal-directed, is associated with greater engagement in self-reported physical activity. The purpose of this study was to examine the relationship between purpose in life and accelerometer-measured physical activity. Community volunteers (N = 104) completed measures of purpose in life and potential confounds and wore accelerometers for three consecutive days. Purpose in life was positively associated with objectively measured movement, moderate to vigorous physical activity, and with self-reported activity. These relationships were largely unchanged after controlling for potential confounds. These results suggest that purpose in life is a reliable correlate of physical activity. PMID:25104777

  1. Accelerated test methods for life prediction of hermetic motor insulation systems exposed to alternative refrigerant/lubricant mixtures. Phase 3: Reproducibility and discrimination testing. Final report

    SciTech Connect

    Ellis, P.F. II; Ferguson, A.F.; Fuentes, K.T.

    1996-05-06

    In 1992, the Air-Conditioning and Refrigeration Technology Institute, Inc. (ARTI) contracted Radian Corporation to ascertain whether an improved accelerated test method or procedure could be developed that would allow prediction of the life of motor insulation materials used in hermetic motors for air-conditioning and refrigeration equipment operated with alternative refrigerant/lubricant mixtures. This report presents the results of phase three concerning the reproducibility and discrimination testing.

  2. Accelerator Mass Spectrometry Measurements of Plutonium in Sediment and Seawater from the Marshall Islands

    SciTech Connect

    Leisvik, M; Hamilton, T

    2001-08-01

    During the summer 2000, I was given the opportunity to work for about three months as a technical trainee at Lawrence Livermore National Laboratory, or LLNL as I will refer to it hereafter. University of California runs this Department of Energy laboratory, which is located 70 km east of San Francisco, in the small city of Livermore. This master thesis in Radioecology is based on the work I did here. LLNL, as a second U.S.-facility for development of nuclear weapons, was built in Livermore in the beginning of the 1950's (Los Alamos in New Mexico was the other one). It has since then also become a 'science center' for a number of areas like magnetic and laser fusion energy, non-nuclear energy, biomedicine, and environmental science. The Laboratory's mission has changed over the years to meet new national needs. The following two statements were found on the homepage of LLNL (http://www.llnl.gov), at 2001-03-05, where also information about the laboratory and the scientific projects that takes place there, can be found. 'Our primary mission is to ensure that the nation's nuclear weapons remain safe, secure, and reliable and to prevent the spread and use of nuclear weapons worldwide'. 'Our goal is to apply the best science and technology to enhance the security and well-being of the nation and to make the world a safer place.' The Marshall Islands Dose Assessment and Radioecology group at the Health and Ecological Assessments division employed me, and I also worked to some extent with the Centre for Accelerator Mass Spectrometry (CAMS) group. The work I did at LLNL can be divided into two parts. In the first part Plutonium (Pu) measurements in sediments from the Rongelap atoll in Marshall Islands, using Accelerator Mass Spectrometry (AMS) were done. The method for measuring these kinds of samples is well understood at LLNL since soil samples have been measured with AMS for Pu in the past. Therefore it was the results that were of main interest and not the technique

  3. Measurements in Transitional Boundary Layers Under High Free-Stream Turbulence and Strong Acceleration Conditions

    NASA Technical Reports Server (NTRS)

    Volino, Ralph J.; Simon, Terrence W.

    1995-01-01

    Measurements from transitional, heated boundary layers along a concave-curved test wall are presented and discussed. A boundary layer subject to low free-stream turbulence intensity (FSTI), which contains stationary streamwise (Gortler) vortices, is documented. The low FSTI measurements are followed by measurements in boundary layers subject to high (initially 8%) free-stream turbulence intensity and moderate to strong streamwise acceleration. Conditions were chosen to simulate those present on the downstream half of the pressure side of a gas turbine airfoil. Mean flow characteristics as well as turbulence statistics, including the turbulent shear stress, turbulent heat flux, and turbulent Prandtl number, are documented. A technique called "octant analysis" is introduced and applied to several cases from the literature as well as to data from the present study. Spectral analysis was applied to describe the effects of turbulence scales of different sizes during transition. To the authors'knowledge, this is the first detailed documentation of boundary layer transition under such high free-stream turbulence conditions.

  4. The impact of nausea and vomiting upon quality of life measures.

    PubMed Central

    Bliss, J. M.; Robertson, B.; Selby, P. J.

    1992-01-01

    The measurement of quality of life in cancer patients has achieved prominence in recent years. This results from recognition of the limitations of available therapies and a clearer view of the goals of treatment in patients whose diseases may not be curable. Many different approaches to the measurement of quality of life have been proposed and these will be reviewed. In a recent survey of available methods, the Medical Research Council's Working Party on Quality of Life Measurement systematically analysed available instruments for measuring quality of life specifically in cancer patients and commented on a number of instruments of general purpose that may be used in oncology. It was concluded that no instrument is entirely satisfactory for all purposes and that available instruments have to be selected carefully for a particular study or a particular aspect of clinical practice. However, among the existing instruments, the Rotterdam Symptom Checklist for a general assessment of many facets of quality of life and the Hospital Anxiety and Depression Scale, for detecting psychosocial morbidity quickly and easily, were useful. In our own studies we have used a multiple linear analogue scale system to measure aspects of quality of life in breast cancer patients and have recently addressed the determinants of overall quality of life. Our studies identify the importance of evaluating the psychometric properties of measurement instruments in quality of life. Reliability and validity and the ability to discriminate changes with time and between clinically distinct groups have to be carefully assessed.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:1467195

  5. The assessment and measurement of adult life stress: Basic premises, operational principles, and design requirements.

    PubMed

    Harkness, Kate L; Monroe, Scott M

    2016-07-01

    Life stress is a central factor in the onset and course of a wide range of medical and psychiatric conditions. Determining the precise etiological and pathological consequences of stress, though, has been hindered by weaknesses in prevailing definitional and measurement practices. The purpose of the current paper is to evaluate the primary strategies for defining and measuring major and minor acute life events, chronic stressors, and daily hassles as informed by 3 basic scientific premises. The first premise concerns the manner in which stress is conceptualized and operationally defined, and specifically we assert that stress measures must not conflate the stress exposure with the stress response. The second premise concerns how stress exposures are measured, and we provide guidelines for optimizing standardized and sensitive indicators of life stress. The third premise addresses the consequences of variations in the procedures for life event measurement with regard to the validity of the research designs employed. We show that life stress measures are susceptible to several sources of bias, and if these potential sources of bias are not controlled in the design of the research, spurious findings may result. Our goal is to provide a useful guide for researchers who consider life stress to be an important factor in their theoretical models of disease, wish to incorporate measures of life stress in their research, and seek to avoid the common pitfalls of past measurement practices. (PsycINFO Database Record PMID:27254487

  6. Voltage measurements at the vacuum post-hole convolute of the Z pulsed-power accelerator

    SciTech Connect

    Waisman, E. M.; McBride, R. D.; Cuneo, M. E.; Wenger, D. F.; Fowler, W. E.; Johnson, W. A.; Basilio, L. I.; Coats, R. S.; Jennings, C. A.; Sinars, D. B.; Vesey, R. A.; Jones, B.; Ampleford, D. J.; Lemke, R. W.; Martin, M. R.; Schrafel, P. C.; Lewis, S. A.; Moore, J. K.; Savage, M. E.; Stygar, W. A.

    2014-12-08

    Presented are voltage measurements taken near the load region on the Z pulsed-power accelerator using an inductive voltage monitor (IVM). Specifically, the IVM was connected to, and thus monitored the voltage at, the bottom level of the accelerator’s vacuum double post-hole convolute. Additional voltage and current measurements were taken at the accelerator’s vacuum-insulator stack (at a radius of 1.6 m) by using standard D-dot and B-dot probes, respectively. During postprocessing, the measurements taken at the stack were translated to the location of the IVM measurements by using a lossless propagation model of the Z accelerator’s magnetically insulated transmission lines (MITLs) and a lumped inductor model of the vacuum post-hole convolute. Across a wide variety of experiments conducted on the Z accelerator, the voltage histories obtained from the IVM and the lossless propagation technique agree well in overall shape and magnitude. However, large-amplitude, high-frequency oscillations are more pronounced in the IVM records. It is unclear whether these larger oscillations represent true voltage oscillations at the convolute or if they are due to noise pickup and/or transit-time effects and other resonant modes in the IVM. Results using a transit-time-correction technique and Fourier analysis support the latter. Regardless of which interpretation is correct, both true voltage oscillations and the excitement of resonant modes could be the result of transient electrical breakdowns in the post-hole convolute, though more information is required to determine definitively if such breakdowns occurred. Despite the larger oscillations in the IVM records, the general agreement found between the lossless propagation results and the results of the IVM shows that large voltages are transmitted efficiently through the MITLs on Z. These results are complementary to previous studies [R. D. McBride et al., Phys. Rev. ST Accel. Beams 13, 120401 (2010)] that

  7. Voltage measurements at the vacuum post-hole convolute of the Z pulsed-power accelerator

    DOE PAGESBeta

    Waisman, E. M.; McBride, R. D.; Cuneo, M. E.; Wenger, D. F.; Fowler, W. E.; Johnson, W. A.; Basilio, L. I.; Coats, R. S.; Jennings, C. A.; Sinars, D. B.; et al

    2014-12-08

    Presented are voltage measurements taken near the load region on the Z pulsed-power accelerator using an inductive voltage monitor (IVM). Specifically, the IVM was connected to, and thus monitored the voltage at, the bottom level of the accelerator’s vacuum double post-hole convolute. Additional voltage and current measurements were taken at the accelerator’s vacuum-insulator stack (at a radius of 1.6 m) by using standard D-dot and B-dot probes, respectively. During postprocessing, the measurements taken at the stack were translated to the location of the IVM measurements by using a lossless propagation model of the Z accelerator’s magnetically insulated transmission lines (MITLs)more » and a lumped inductor model of the vacuum post-hole convolute. Across a wide variety of experiments conducted on the Z accelerator, the voltage histories obtained from the IVM and the lossless propagation technique agree well in overall shape and magnitude. However, large-amplitude, high-frequency oscillations are more pronounced in the IVM records. It is unclear whether these larger oscillations represent true voltage oscillations at the convolute or if they are due to noise pickup and/or transit-time effects and other resonant modes in the IVM. Results using a transit-time-correction technique and Fourier analysis support the latter. Regardless of which interpretation is correct, both true voltage oscillations and the excitement of resonant modes could be the result of transient electrical breakdowns in the post-hole convolute, though more information is required to determine definitively if such breakdowns occurred. Despite the larger oscillations in the IVM records, the general agreement found between the lossless propagation results and the results of the IVM shows that large voltages are transmitted efficiently through the MITLs on Z. These results are complementary to previous studies [R. D. McBride et al., Phys. Rev. ST Accel. Beams 13, 120401 (2010)] that showed

  8. Concurrent validity of accelerations measured using a tri-axial inertial measurement unit while walking on firm, compliant and uneven surfaces.

    PubMed

    Cole, Michael H; van den Hoorn, Wolbert; Kavanagh, Justin K; Morrison, Steven; Hodges, Paul W; Smeathers, James E; Kerr, Graham K

    2014-01-01

    Although accelerometers are extensively used for assessing gait, limited research has evaluated the concurrent validity of these devices on less predictable walking surfaces or the comparability of different methods used for gravitational acceleration compensation. This study evaluated the concurrent validity of trunk accelerations derived from a tri-axial inertial measurement unit while walking on firm, compliant and uneven surfaces and contrasted two methods used to remove gravitational accelerations; i) subtraction of the best linear fit from the data (detrending); and ii) use of orientation information (quaternions) from the inertial measurement unit. Twelve older and twelve younger adults walked at their preferred speed along firm, compliant and uneven walkways. Accelerations were evaluated for the thoracic spine (T12) using a tri-axial inertial measurement unit and an eleven-camera Vicon system. The findings demonstrated excellent agreement between accelerations derived from the inertial measurement unit and motion analysis system, including while walking on uneven surfaces that better approximate a real-world setting (all differences <0.16 m.s(-2)). Detrending produced slightly better agreement between the inertial measurement unit and Vicon system on firm surfaces (delta range: -0.05 to 0.06 vs. 0.00 to 0.14 m.s(-2)), whereas the quaternion method performed better when walking on compliant and uneven walkways (delta range: -0.16 to -0.02 vs. -0.07 to 0.07 m.s(-2)). The technique used to compensate for gravitational accelerations requires consideration in future research, particularly when walking on compliant and uneven surfaces. These findings demonstrate trunk accelerations can be accurately measured using a wireless inertial measurement unit and are appropriate for research that evaluates healthy populations in complex environments. PMID:24866262

  9. Concurrent Validity of Accelerations Measured Using a Tri-Axial Inertial Measurement Unit while Walking on Firm, Compliant and Uneven Surfaces

    PubMed Central

    Cole, Michael H.; van den Hoorn, Wolbert; Kavanagh, Justin K.; Morrison, Steven; Hodges, Paul W.; Smeathers, James E.; Kerr, Graham K.

    2014-01-01

    Although accelerometers are extensively used for assessing gait, limited research has evaluated the concurrent validity of these devices on less predictable walking surfaces or the comparability of different methods used for gravitational acceleration compensation. This study evaluated the concurrent validity of trunk accelerations derived from a tri-axial inertial measurement unit while walking on firm, compliant and uneven surfaces and contrasted two methods used to remove gravitational accelerations; i) subtraction of the best linear fit from the data (detrending); and ii) use of orientation information (quaternions) from the inertial measurement unit. Twelve older and twelve younger adults walked at their preferred speed along firm, compliant and uneven walkways. Accelerations were evaluated for the thoracic spine (T12) using a tri-axial inertial measurement unit and an eleven-camera Vicon system. The findings demonstrated excellent agreement between accelerations derived from the inertial measurement unit and motion analysis system, including while walking on uneven surfaces that better approximate a real-world setting (all differences <0.16 m.s−2). Detrending produced slightly better agreement between the inertial measurement unit and Vicon system on firm surfaces (delta range: −0.05 to 0.06 vs. 0.00 to 0.14 m.s−2), whereas the quaternion method performed better when walking on compliant and uneven walkways (delta range: −0.16 to −0.02 vs. −0.07 to 0.07 m.s−2). The technique used to compensate for gravitational accelerations requires consideration in future research, particularly when walking on compliant and uneven surfaces. These findings demonstrate trunk accelerations can be accurately measured using a wireless inertial measurement unit and are appropriate for research that evaluates healthy populations in complex environments. PMID:24866262

  10. APT: An Autonomous Tool for Measuring Acceleration, Pressure, and Temperature with Large Dynamic Range and Bandwidth

    NASA Astrophysics Data System (ADS)

    Heesemann, M.; Davis, E. E.

    2015-12-01

    We describe a new tool developed to facilitate the study of inter-related geodetic, geodynamic, seismic, and oceanographic phenomena. It incorporates a novel tri-axial accelerometer developed by Quartz Seismic Sensors, Inc, a pressure sensor developed by Paroscientific Inc., and a low-power, high-precision frequency counter and data logger built by RBR, Ltd. The sensors, counters, and loggers are housed in a 7 cm o.d., 70 cm long pressure case designed for use in up to 12 km of water. Sampling intervals are programmable from 0.1 s to 1 hr; standard memory can store up to 30 million samples; total power consumption is roughly 115 mW when operating continuously (1 s.p.s. or higher) and proportionately lower when operating intermittently (e.g., 2 mW at 1 sample per min.). Serial and USB communications protocols allow a variety of download and cable-connection options. Measurement precision of the order of 10-8 of full scale (e.g., 4000 m water depth, 1 g) allows observations of pressure and acceleration variations of 0.4 Pa and 0.1 μm s-2. Long-term variations in vertical acceleration are sensitive to displacement through the gravity gradient at a level of roughly 2 cm; long-term variations in horizontal acceleration are sensitive to tilt at a level of 0.01 μRad. With these sensitivities and the broad bandwidth (5 Hz to DC), ground motion associated with microseisms and seismic waves, tidal loading, and slow and rapid geodynamic deformation normally studied by disparate instruments can be observed with a single tool. The first c. 1-year deployment with the instrument connected to the Ocean Networks Canada NEPTUNE observatory cable is underway to study interseismic deformation of the Cascadia subduction zone. It will then be deployed at the Hikurangi subduction zone to study episodic slow slip. Deployment of the tool for the initial test was accomplished by pushing the tool vertically below the seafloor with the remotely operated vehicle Jason, with no profile

  11. The fluid-dynamic disturbances induced on the ISS, based on the first acceleration measurements on board the space station.

    PubMed

    Monti, R; Savino, R; Paterna, D

    2005-07-01

    The different acceleration components on the ISS that are responsible for the generation of convective motions in a fluid cell either in the presence of density gradients or in quasi-isodense processes, are analyzed. The NASA measurements of the quasi-steady and periodic acceleration on the ISS are considered and their effects on fluid-dynamic experiments are computed and discussed under different assumptions. In particular, numerical simulations are carried out to identify the relative importance of linear and pendular accelerations, due to possible rotations of the P/L around its center of mass. The effects caused by variable accelerations created by an isolation mount that exhibits an attenuation factor not constant within the payload volume, caused by the reaction forces of the umbilicals, are computed and analyzed. PMID:15900644

  12. Accelerated vs. unaccelerated serial MRI based TBM-SyN measurements for Clinical Trials in Alzheimer’s disease

    PubMed Central

    Vemuri, Prashanthi; Senjem, Matthew L.; Gunter, Jeffrey L.; Lundt, Emily S.; Tosakulwong, Nirubol; Weigand, Stephen D.; Borowski, Bret J.; Bernstein, Matt A.; Zuk, Samantha M.; Lowe, Val J.; Knopman, David S.; Petersen, Ronald C.; Fox, Nick C.; Thompson, Paul M.; Weiner, Michael W.; Jack, Clifford R.

    2015-01-01

    Objective Our primary objective was to compare the performance of unaccelerated vs. accelerated structural MRI for measuring disease progression using serial scans in Alzheimer’s disease (AD). Methods We identified cognitively normal (CN), early mild cognitive impairment (EMCI), late mild cognitive impairment (LMCI) and AD subjects from all available Alzheimer’s Disease Neuroimaging Initiative (ADNI) subjects with usable pairs of accelerated and unaccelerated scans. There were a total of 696 subjects with baseline and 3 month scans, 628 subjects with baseline and 6 month scans and 464 subjects with baseline and 12 month scans available. We employed the Symmetric Diffeomorphic Image Normalization method (SyN) for normalization of the serial scans to obtain Tensor Based Morphometry (TBM) maps which indicate the structural changes between pairs of scans. We computed a TBM-SyN summary score of annualized structural changes over 31 regions of interest (ROIs) that are characteristically affected in AD. TBM-SyN scores were computed using accelerated and unaccelerated scan pairs and compared in terms of agreement, group-wise discrimination, and sample size estimates for a hypothetical therapeutic trial. Results We observed a number of systematic differences between TBM-SyN scores computed from accelerated and unaccelerated pairs of scans. TBM-SyN scores computed from accelerated scans tended to have overall higher estimated values than those from unaccelerated scans. However, the performance of accelerated scans was comparable to unaccelerated scans in terms of discrimination between clinical groups and sample sizes required in each clinical group for a therapeutic trial. We also found that the quality of both accelerated vs. unaccelerated scans were similar. Conclusions Accelerated scanning protocols reduce scan time considerably. Their group-wise discrimination and sample size estimates were comparable to those obtained with unaccelerated scans. The two protocols did

  13. Measurements in Transitional Boundary Layers Under High Free-Stream Turbulence and Strong Acceleration Conditions.

    NASA Astrophysics Data System (ADS)

    Volino, Ralph John

    1995-01-01

    Measurements from transitional, heated boundary layers along a concave-curved test wall are presented and discussed. A boundary layer subject to low free-stream turbulence intensity (FSTI), which contains stationary streamwise (Gortler) vortices, is documented. The low FSTI measurements are followed by measurements in boundary layers subject to high (initially 8%) free-stream turbulence intensity and moderate to strong (K = {nuover U_sp{infty} {2}}{dUinftyover dx} as high as 9times 10^{ -6}) acceleration. The high FSTI experiments are the main focus of the work. Conditions were chosen to simulate those present on the downstream half of the pressure side of a gas turbine airfoil. The high FSTI boundary layers undergo transition from a strongly disturbed non-turbulent state to a fully-turbulent state. Due to the stabilizing effect of strong acceleration, the transition zones are of extended length in spite of the high FSTI. Transitional values of skin friction coefficients and Stanton numbers drop below flat-plate, low FSTI, turbulent flow correlations, but remain well above laminar flow values. Mean velocity and temperature profiles exhibit clear changes in shape as the flow passes through transition. Turbulence statistics, including the turbulent shear stress, turbulent heat flux, and turbulent Prandtl number, are documented. Turbulent transport is strongly suppressed below values in unaccelerated turbulent boundary layers. A technique called "octant analysis" is introduced and applied to several cases from the literature as well as to data from the present study. Octant analysis shows a fundamental difference between transitional and fully-turbulent boundary layers. Transitional boundary layers are characterized by incomplete mixing compared to fully-turbulent boundary layers. Similar octant analysis results are observed in both low and high FSTI cases. Spectral analysis suggests that the non-turbulent zone of the high FSTI flow is dominated by large scale

  14. Single-shot betatron source size measurement from a laser-wakefield accelerator

    NASA Astrophysics Data System (ADS)

    Köhler, A.; Couperus, J. P.; Zarini, O.; Jochmann, A.; Irman, A.; Schramm, U.

    2016-09-01

    Betatron radiation emitted by accelerated electrons in laser-wakefield accelerators can be used as a diagnostic tool to investigate electron dynamics during the acceleration process. We analyze the spectral characteristics of the emitted Betatron pattern utilizing a 2D x-ray imaging spectroscopy technique. Together with simultaneously recorded electron spectra and x-ray images, the betatron source size, thus the electron beam radius, can be deduced at every shot.

  15. Simultaneous Concentration and Velocity Field Measurements in a Shock-accelerated Mixing Layer

    NASA Astrophysics Data System (ADS)

    Reese, Daniel; Oakley, Jason; Weber, Chris; Rothamer, David; Navarro, Jose; Bonazza, Riccardo

    2013-11-01

    The Richtmyer-Meshkov instability (RMI) is experimentally investigated at the Wisconsin Shock Tube Laboratory. Simultaneous concentration and velocity field measurements from the mixing layer of experimental RMI images are obtained through the application of the Advection-Corrected Correlation Image Velocimetry (ACCIV) technique. A statistically repeatable broadband initial condition is created by first setting up a gravitationally stable stagnation plane of helium +acetone over argon and then injecting the gases horizontally at the interface to create a shear layer. The shear layer is then accelerated by a Mach 2.2 planar shock wave that causes the growth of any perturbations present at the interface, and time-separated image pair data of the mixing layer are obtained using planar laser induced fluorescence (PLIF). The image pair is corrected to show relative acetone concentration, and is then used as input to the ACCIV algorithm to obtain velocity field results. These velocity field measurements are compared with those obtained from numerical simulations. Turbulent kinetic energy spectra are compared with particle imaging velocimetry (PIV) and simulation results to validate regions of applicability. We wish to thank the Department of Energy National Nuclear Security Administration for supporting this work.

  16. Beam-wall interaction measurements in LLNL induction accelerator bend experiment

    NASA Astrophysics Data System (ADS)

    Molvik, A. W.; Friedman, A.; Kamin, G. W.; Sangster, T. C.; Eylon, S.; Hopkins, H. S.

    1997-11-01

    Ion-induced desorption coefficients are determined from measurements of pressure rises when an ion beam strikes a surface. These measurements are made after the first bend of 9^circ by deflecting the beam onto the stainless steel beam tube, and within a pill-box where the beam strikes a stainless steel target at an angle that can be varied from 90^circ to ~10^circ. The beam consists of 2 mA of singly-charged potassium ions at 80 keV with pulse lengths of several microsec. Data near 10^circ are relevant to near-term experiments where beam halo could strike the wall at angles of a few degrees. Data near 90^circ are relevant to ions resulting from charge exchange with a reactor driver class beam which has a space potential of the order of 100 kV. These data will aid in assessing the adequacy of the existing vacuum system when the bend experiment is upgraded to a recirculator induction accelerator.

  17. Low-level measurement of 63Ni by means of accelerator mass spectrometry

    NASA Astrophysics Data System (ADS)

    Rugel, G.; Arazi, A.; Carroll, K. L.; Faestermann, T.; Knie, K.; Korschinek, G.; Marchetti, A. A.; Martinelli, R. E.; McAninch, J. E.; Rühm, W.; Straume, T.; Wallner, A.; Wallner, C.

    2004-08-01

    The radionuclide 63Ni (T1/2=100.1 a) has been proposed as a fluence monitor for fast neutrons in copper samples from Hiroshima. Accelerator mass spectrometry (AMS) represents a powerful tool for the detection of this radionuclide, provided the isobaric interference of 63Cu can be sufficiently suppressed. In this paper, we report the first results from a study on the 63Cu background observed in different sets of control samples, and in a 127-year-old environmental copper sample which was directly exposed to cosmic radiation for about 80 years. The 63Ni/Ni ratios measured in the blank samples range up to about 2 × 10-13 corresponding to concentrations of a few times 10463Ni atoms/g Cu. These results provide information on the overall background of the applied methodology and, thus, on the possible sensitivity of 63Ni measurements in copper samples by means of AMS. In the environmental sample, a 63Ni concentration of (1.0 ± 0.3) × 10563Ni atoms/g Cu was observed which is not significantly different from the results obtained on commercially available copper material. A similar concentration would be expected in a copper sample located 1300 m from the hypocenter of the Hiroshima atomic bomb.

  18. An exploration of skin acceleration level as a measure of phonatory function in singing.

    PubMed

    Lamarche, Anick; Ternström, Sten

    2008-01-01

    Two kinds of fluctuations are observed in phonetogram recordings of singing. Sound pressure level (SPL) can vary due to vibrato and also due to the effect of open and closed vowels. Since vowel variation is mostly a consequence of vocal tract modification and is not directly related to phonatory function, it could be helpful to suppress such variation when studying phonation. Skin acceleration level (SAL), measured at the jugular notch and on the sternum, might be less influenced by effects of the vocal tract. It is explored in this study as an alternative measure to SPL. Five female singers sang vowel series on selected pitches and in different tasks. Recorded data were used to investigate two null hypotheses: (1) SPL and SAL are equally influenced by vowel variation and (2) SPL and SAL are equally correlated to subglottal pressure (P(S)). Interestingly, the vowel variation effect was small in both SPL and SAL. Furthermore, in comparison to SPL, SAL correlated weakly to P(S). SAL exhibited practically no dependence on fundamental frequency, rather, its major determinant was the musical dynamic. This results in a non-sloping, square-like phonetogram contour. These outcomes show that SAL potentially can facilitate phonetographic analysis of the singing voice. PMID:17059878

  19. X-ray beam size measurements on the Advanced Test Accelerator

    SciTech Connect

    Struve, K.W.; Chambers, F.W.; Lauer, E.J.; Slaughter, D.R.

    1986-01-01

    The electron beam size has been determined on the Advanced Test Accelerator (ATA) by intercepting the beam with a target and measuring the resulting x-ray intensity as a function of time as the target is moved through the beam. Several types of targets have been used. One is a tantalum rod which extends completely across the drift chamber. Another is a tungsten powder filled carbon crucible. Both of these probes are moved from shot to shot so that the x-ray signal intensity varies with probe position. A third is a larger tantalum disk which is inserted on beam axis to allow determining beam size on a one shot basis. The x-ray signals are detected with an MCP photomultiplier tube located at 90/sup 0/ to the beamline. It is sufficiently shielded to reject background x-rays and neutrons. The signals were digitized, recorded and later unfolded to produce plots of x-ray intensity versus probe position for several times during the pulse. The presumption that the x-ray intensity is proportional to beam current density is checked computationally. Details of the probe construction and PMT shielding, as well as sample measurements are given.

  20. RF impedance measurements on the DARHT-II accelerator intercell assembly

    SciTech Connect

    Fawley, William M.; Eylon, Shmuel; Briggs, Richard

    2003-05-05

    We report upon recent experimental measurements made of RF properties of the intercell assembly of the second axis accelerator[1] of Dual Axis Radiographic Hydrodynamic Test (DARHT) facility at LANL. The intercells provide both pumping and diagnostic access to the main DARHT-II beamline. Their design includes a pumping plenum separated from the main beam pipe by return current rods together with RF shielding provided by a copper-coated stainless steel mesh. Measurements using the twin lead technique (see Ref. [2]) at low frequencies (f < 200 MHz) suggest a constant value for the ratio h of the radial and azimuthal magnetic field components to which the transverse impedance is linearly related. We find that these results compare favorably to predictions from a simple analytic, lumped circuit model which includes the effects of the mesh and return current rods. We also present RF loop-to-loop frequency scans above beam pipe cutoff ({approx}600 MHz) showing the existence of many RF modes with relatively high Q's.

  1. Comparison between CARIBIC Aerosol Samples Analysed by Accelerator-Based Methods and Optical Particle Counter Measurements

    NASA Astrophysics Data System (ADS)

    Martinsson, B. G.; Friberg, J.; Andersson, S. M.; Weigelt, A.; Hermann, M.; Assmann, D.; Voigtländer, J.; Brenninkmeijer, C. A. M.; van Velthoven, P. J. F.; Zahn, A.

    2014-08-01

    Inter-comparison of results from two kinds of aerosol systems in the CARIBIC (Civil Aircraft for the Regular Investigation of the atmosphere Based on a Instrument Container) passenger aircraft based observatory, operating during intercontinental flights at 9-12 km altitude, is presented. Aerosol from the lowermost stratosphere (LMS), the extra-tropical upper troposphere (UT) and the tropical mid troposphere (MT) were investigated. Aerosol particle volume concentration measured with an optical particle counter (OPC) is compared with analytical results of the sum of masses of all major and several minor constituents from aerosol samples collected with an impactor. Analyses were undertaken with the following accelerator-based methods: particle-induced X-ray emission (PIXE) and particle elastic scattering analysis (PESA). Data from 48 flights during 1 year are used, leading to a total of 106 individual comparisons. The ratios of the particle volume from the OPC and the total mass from the analyses were in 84% within a relatively narrow interval. Data points outside this interval are connected with inlet-related effects in clouds, large variability in aerosol composition, particle size distribution effects and some cases of non-ideal sampling. Overall, the comparison of these two CARIBIC measurements based on vastly different methods show good agreement, implying that the chemical and size information can be combined in studies of the MT/UT/LMS aerosol.

  2. Comparison between CARIBIC aerosol samples analysed by accelerator-based methods and optical particle counter measurements

    NASA Astrophysics Data System (ADS)

    Martinsson, B. G.; Friberg, J.; Andersson, S. M.; Weigelt, A.; Hermann, M.; Assmann, D.; Voigtländer, J.; Brenninkmeijer, C. A. M.; van Velthoven, P. J. F.; Zahn, A.

    2014-04-01

    Inter-comparison of results from two kinds of aerosol systems in the CARIBIC (Civil Aircraft for the Regular Investigation of the atmosphere Based on an Instrument Container) passenger aircraft based observatory, operating during intercontinental flights at 9-12 km altitude, is presented. Aerosol from the lowermost stratosphere (LMS), the extra-tropical upper troposphere (UT) and the tropical mid troposphere (MT) were investigated. Aerosol particle volume concentration measured with an optical particle counter (OPC) is compared with analytical results of the sum of masses of all major and several minor constituents from aerosol samples collected with an impactor. Analyses were undertaken with accelerator-based methods particle-induced X-ray emission (PIXE) and particle elastic scattering analysis (PESA). Data from 48 flights during one year are used, leading to a total of 106 individual comparisons. The ratios of the particle volume from the OPC and the total mass from the analyses were in 84% within a relatively narrow interval. Data points outside this interval are connected with inlet-related effects in clouds, large variability in aerosol composition, particle size distribution effects and some cases of non-ideal sampling. Overall, the comparison of these two CARIBIC measurements based on vastly different methods show good agreement, implying that the chemical and size information can be combined in studies of the MT/UT/LMS aerosol.

  3. Low Frequency Vibration Characteristics of the Space Acceleration Measurement System 2 Tape Drive Assembly

    NASA Technical Reports Server (NTRS)

    Javeed, Mehzad; Russell, James W.

    1996-01-01

    This report summarizes results of force and moment measurements of the Space Acceleration Measurement System 2 (SAMS 2) Tape Drive Assembly (TDA) over the frequency range from 0.35 Hz to 256 Hz for steady state operations including write, read, rewind, and fast forward. Time domain force results are presented for transient TDA operations that include software eject, manual eject, and manual load. Three different mounting configurations were employed for attaching the inner box with the tape drive unit to the outer box. Two configurations employed grommet sets with spring rates of 42 and 62 pounds per inch respectively. The third configuration employed a set of metallic washers. For all four steady state operations the largest average forces were on the Y axis with the metallic washers and were less than 0.005 pounds. The largest average moments were on the X axes with the washers and were less than 0.030 pound inches. At the third octave centerband frequency of 31.5 Hz, the 42 pound per inch grommets showed the greatest forces and moments for read and write operations. At the third octave centerband frequency of 49.6 Hz, the 62 pound per inch grommets showed the greatest forces and moments for rewind operation. Transient operation forces ranged from 0.75 pounds for the software eject to greater than 1 pound for manual load and eject.

  4. Transvers Impedance Measurements of the Modified DARHT-2Accelerator Cell Design

    SciTech Connect

    Briggs, Dick; Waldron, Will

    2005-11-30

    The DARHT-2 accelerator cells have been redesigned to make their high voltage performance more robust. At the outset of the DARHT-2 development program about 8 years ago, an extensive campaign was mounted to minimize the transverse impedance of the original cell design. Since the initial spec on the machine was a beam current of 4 kA, the control of beam-breakup (BBU) amplification with a 2 microsecond pulse length was considered to be one the most critical issues in the design. Even after advances in detector technology allowed the beam current requirement to be lowered to 2 kA, the goal for the standard cell impedance was kept at {approx}300 ohms/meter to allow for the possibility of future beam current upgrades to 4 kA without any modifications in the cells. The results of this campaign to minimize the transverse impedance are described in detail in Reference 1. After several iterations in the design of ferrite dampers and the anode finger stock shape, the measured (peak) impedance of the original standard cell was determined to be about 280 ohms/meter. (As a reference point, the measured impedance of the DARHT-1 cell is about 880 ohms/meter). This impedance provided such a wide safety margin against BBU amplification at 2 kA that it was felt that the cell redesign could focus on voltage holding without any detailed considerations of impacts on the transverse impedance. Now that a baseline design for the DARHT-2 cell has been established and tested, however, it was felt that a measurement of its impedance would be prudent. The results of these impedance measurements are presented in this note. The objective was mainly to do a ''quick check'' to ensure that there were no surprises, and to provide an estimate of the BBU frequencies and growth rates to the experimental test program.

  5. Measuring Depression at the End of Life: Is the Hamilton Depression Rating Scale a Valid Instrument?

    ERIC Educational Resources Information Center

    Olden, Megan; Rosenfeld, Barry; Pessin, Hayley; Breitbart, William

    2009-01-01

    Depression at the end of life is a common mental health issue with serious implications for quality of life and decision making. This study investigated the reliability and validity of one of the most frequently used measures of depression, the Hamilton Depression Rating Scale (HAM-D) in 422 patients with terminal cancer admitted to a palliative…

  6. Do We Need to Weight Satisfaction Scores with Importance Ratings in Measuring Quality of Life?

    ERIC Educational Resources Information Center

    Wu, Chia-Huei; Yao, Grace

    2006-01-01

    Trauer and Mackinnon (2001; Quality of life research 10, pp. 579-585) recently proposed that weighting satisfaction scores by importance ratings in measuring quality of life is undesirable and unnecessary. However, they didn't use empirical data to support their claim. In this study, different weighting algorithms developed by Cummins (1997;…

  7. Measuring Outcomes of Family-Centered Intervention: Development of the Life Participation for Parents (LPP)

    ERIC Educational Resources Information Center

    Fingerhut, Patricia E.

    2009-01-01

    Raising a child with disabilities impacts the ability of parents to participate in life situations. This paper describes the development of a new instrument, Life Participation for Parents, to measure outcomes of pediatric therapy on parental participation. Items were reviewed by six occupational therapists with experience in pediatrics and…

  8. Measuring the quality of life of the elderly in health promotion intervention clinical trials.

    PubMed Central

    Kutner, N G; Ory, M G; Baker, D I; Schechtman, K B; Hornbrook, M C; Mulrow, C D

    1992-01-01

    The Multicenter Trials of Frailty and Injuries: Cooperative Studies of Intervention Techniques (FICSIT) is a series of clinical trials of biomedical, behavioral, and environmental interventions to reduce the risks of frailty and injury among the elderly. Reliable assessment of the quality of life reported by the subjects is a central issue in evaluating the interventions. An intervention may have a significant impact on an elderly person's sense of well-being, even though significant improvement is not observed in selected physical outcome measures. Elderly persons' compliance with particular intervention regimens may be influenced by the quality of life effects that they perceive in relation to the intervention. The researchers review the definition and measurement of quality of life in the trials, with particular attention to issues in determining common measures used at all study locations. Practical considerations in the selection and use of quality of life measures in both community and institutional populations are addressed. Topics discussed include the interrelation of aging, functional capacities, and quality of life; the multi-dimensionality of quality of life in relation to differential intervention effects; and age-related issues in the collection of quality of life data. Preliminary observations are reviewed, and potential contributions of FICSIT to intervention-sensitive quality of life assessments among the elderly are noted. PMID:1410233

  9. Assessing the Validity of Single-item Life Satisfaction Measures: Results from Three Large Samples

    PubMed Central

    Cheung, Felix; Lucas, Richard E.

    2014-01-01

    Purpose The present paper assessed the validity of single-item life satisfaction measures by comparing single-item measures to the Satisfaction with Life Scale (SWLS) - a more psychometrically established measure. Methods Two large samples from Washington (N=13,064) and Oregon (N=2,277) recruited by the Behavioral Risk Factor Surveillance System (BRFSS) and a representative German sample (N=1,312) recruited by the Germany Socio-Economic Panel (GSOEP) were included in the present analyses. Single-item life satisfaction measures and the SWLS were correlated with theoretically relevant variables, such as demographics, subjective health, domain satisfaction, and affect. The correlations between the two life satisfaction measures and these variables were examined to assess the construct validity of single-item life satisfaction measures. Results Consistent across three samples, single-item life satisfaction measures demonstrated substantial degree of criterion validity with the SWLS (zero-order r = 0.62 – 0.64; disattenuated r = 0.78 – 0.80). Patterns of statistical significance for correlations with theoretically relevant variables were the same across single-item measures and the SWLS. Single-item measures did not produce systematically different correlations compared to the SWLS (average difference = 0.001 – 0.005). The average absolute difference in the magnitudes of the correlations produced by single-item measures and the SWLS were very small (average absolute difference = 0.015 −0.042). Conclusions Single-item life satisfaction measures performed very similarly compared to the multiple-item SWLS. Social scientists would get virtually identical answer to substantive questions regardless of which measure they use. PMID:24890827

  10. Measuring the Impact of Diabetes on Life Expectancy and Disability-Free Life Expectancy Among Older Adults in Mexico

    PubMed Central

    2010-01-01

    Objectives. The aim of the present study is to investigate differences in total life expectancy (TLE), disability-free life expectancy (DFLE), disabled life expectancy (DLE), and personal care assistance between individuals with and without diabetes in Mexico. Methods. The sample was drawn from the nationally representative Mexican Health and Aging Study. Disability was assessed through a basic Activities of Daily Living (ADL) measure, the Instrumental Activities of Daily Living (IADL) scale, and the Nagi physical performance measure. The Interpolation of Markov Chains method was used to estimate the impact of diabetes on TLE and DFLE. Results. Results indicate that diabetes reduces TLE at ages 50 and 80 by about 10 and 4 years, respectively. Diabetes is also associated with fewer years in good health. DFLE (based on ADL measures) at age 50 is 20.8 years (95% confidence interval [CI]: 19.2–22.3) for those with diabetes, compared with 29.9 years (95% CI: 28.8–30.9) for those without diabetes. Regardless of diabetes status, Mexican women live longer but face a higher disability burden than men. Conclusion. Among older adults in Mexico, diabetes is associated with shorter TLE and DFLE. The negative effect of diabetes on the number of years lived, particularly in good health, creates significant economic, social, and individual costs for elderly Mexicans. PMID:20028950

  11. Measurement of Beryllium in Biological Samples by Accelerator Mass Spectrometry: Applications for Studying Chronic Beryllium Disease

    SciTech Connect

    Chiarappa-Zucca, M L; Finkel, R C; Martinelli, R E; McAninch, J E; Nelson, D O; Turtletaub, K W

    2004-04-15

    A method using accelerator mass spectrometry (AMS) has been developed for quantifying attomoles of beryllium (Be) in biological samples. This method provides the sensitivity to trace Be in biological samples at very low doses with the purpose of identifying the molecular targets involved in chronic beryllium disease. Proof of the method was tested by administering 0.001, 0.05, 0.5 and 5.0 {micro}g {sup 9}Be and {sup 10}Be by intraperitoneal injection to male mice and removing spleen, liver, femurs, blood, lung, and kidneys after 24 h exposure. These samples were prepared for AMS analysis by tissue digestion in nitric acid, followed by further organic oxidation with hydrogen peroxide and ammonium persulfate and lastly, precipitation of Be with ammonium hydroxide, and conversion to beryllium oxide at 800 C. The {sup 10}Be/{sup 9}Be ratio of the extracted beryllium oxide was measured by AMS and Be in the original sample was calculated. Results indicate that Be levels were dose-dependent in all tissues and the highest levels were measured in the spleen and liver. The measured {sup 10}Be/{sup 9}Be ratios spanned 4 orders of magnitude, from 10{sup -10} to 10{sup -14}, with a detection limit of 3.0 x 10{sup -14}, which is equivalent to 0.8 attomoles of {sup 10}Be. These results show that routine quantification of nanogram levels of Be in tissues is possible and that AMS is a sensitive method that can be used in biological studies to understand the molecular dosimetry of Be and mechanisms of toxicity.

  12. Measuring quality of life in mental health: Are we asking the right questions?

    PubMed Central

    Connell, Janice; O'Cathain, Alicia; Brazier, John

    2014-01-01

    Measuring quality-adjusted-life years using generic preference-based quality of life measures is common practice when evaluating health interventions. However, there are concerns that measures in common use, such as the EQ-5D and SF-6D, focus overly on physical health and therefore may not be appropriate for measuring quality of life for people with mental health problems. The aim of this research was to identify the domains of quality of life that are important to people with mental health problems in order to assess the content validity of these generic measures. Qualitative semi-structured interviews were conducted with 19 people, recruited from UK mental health services, with a broad range of mental health problems at varying levels of severity. This complemented a previous systematic review and thematic synthesis of qualitative studies on the same topic. Seven domains important to quality of life for people with mental health problems were identified: well-being and ill-being; relationships and a sense of belonging; activity; self-perception; autonomy, hope and hopelessness; and physical health. These were consistent with the systematic review, with the addition of physical health as a domain, and revealed a differing emphasis on the positive and negative aspects of quality of life according to the severity of the mental health problems. We conclude that the content of existing generic preference-based measures of health do not cover this domain space well. Additionally, because people may experience substantial improvements in their quality of life without registering on the positive end of a quality of life scale, it is important that the full spectrum of negative through to positive aspects of each domain are included in any quality of life measure. PMID:25194472

  13. Measuring quality of life in mental health: are we asking the right questions?

    PubMed

    Connell, Janice; O'Cathain, Alicia; Brazier, John

    2014-11-01

    Measuring quality-adjusted-life years using generic preference-based quality of life measures is common practice when evaluating health interventions. However, there are concerns that measures in common use, such as the EQ-5D and SF-6D, focus overly on physical health and therefore may not be appropriate for measuring quality of life for people with mental health problems. The aim of this research was to identify the domains of quality of life that are important to people with mental health problems in order to assess the content validity of these generic measures. Qualitative semi-structured interviews were conducted with 19 people, recruited from UK mental health services, with a broad range of mental health problems at varying levels of severity. This complemented a previous systematic review and thematic synthesis of qualitative studies on the same topic. Seven domains important to quality of life for people with mental health problems were identified: well-being and ill-being; relationships and a sense of belonging; activity; self-perception; autonomy, hope and hopelessness; and physical health. These were consistent with the systematic review, with the addition of physical health as a domain, and revealed a differing emphasis on the positive and negative aspects of quality of life according to the severity of the mental health problems. We conclude that the content of existing generic preference-based measures of health do not cover this domain space well. Additionally, because people may experience substantial improvements in their quality of life without registering on the positive end of a quality of life scale, it is important that the full spectrum of negative through to positive aspects of each domain are included in any quality of life measure. PMID:25194472

  14. Old dogs with new tricks: Detecting accelerated long-term forgetting by extending traditional measures.

    PubMed

    Miller, Laurie A; Flanagan, Emma; Mothakunnel, Annu; Mohamed, Armin; Thayer, Zoe

    2015-04-01

    Accelerated long-term forgetting (ALF) is a condition in which normal memory performance is displayed after short delays, but significant memory loss is detected when memory is tested after several days or weeks. This condition has been reported in patients with epilepsy, but there are few normative scores available for its detection in clinical practice. In the present study, we assessed 60 healthy control subjects 18-60years of age on three memory measures [Rey Auditory Verbal Learning (RAVLT), Logical Memory (LM), and Aggie Figures] at delays of 30min and 7days. With these normative values, we determined cutoff scores to look for ALF and then categorized the performance of 15 patients with focal epilepsy on the same tasks. Seven of the patients showed ALF, and, in four of these, no other memory deficits (i.e., deficits at 30min on at least one task) were detected. Of the several demographic and epilepsy factors examined, only higher estimated IQ and older age predicted ALF (and only on one task: RAVLT). The findings provide a useful set of data to be applied in the clinic and some insight into the factors that influence retention within the first week. PMID:25825369

  15. Fluoride sample matrices and reaction cells — new capabilities for isotope measurements in accelerator mass spectrometry

    NASA Astrophysics Data System (ADS)

    Kieser, W. E.; Zhao, X.-L.; Eliades, J.; Litherland, A. E.

    2012-04-01

    Two new techniques, which extend the range of elements that can be analyzed by Accelerator Mass Spectrometry (AMS), and which increase its isobar selection capabilities, have been recently introduced. The first consists of embedding the sample material in a fluoride matrix (e.g. PbF2), which facilitates the production, in the ion source, of fluoride molecular anions that include the isotope of interest. In addition to forming anions with large electron binding energies and thereby increasing the range of analysable elements, in many cases by selection of a molecular form with a particular number of fluorine atoms, some isobar discrimination can be obtained. The second technique, for the significant reduction of atomic isobar interferences, is used following mass selection of the rare isotope. It consists of the deceleration, cooling and reaction of the rare mass beam with a gas, selected so that unwanted isobars are greatly attenuated in comparison with the isotope of interest. Proof of principle measurements for the analysis of 36C1 and 41Ca have provided encouraging results and work is proceeding on the integration of these techniques in a new AMS system planned for installation in late 2012 at the University of Ottawa.

  16. Fusion-neutron-yield, activation measurements at the Z accelerator: design, analysis, and sensitivity.

    PubMed

    Hahn, K D; Cooper, G W; Ruiz, C L; Fehl, D L; Chandler, G A; Knapp, P F; Leeper, R J; Nelson, A J; Smelser, R M; Torres, J A

    2014-04-01

    We present a general methodology to determine the diagnostic sensitivity that is directly applicable to neutron-activation diagnostics fielded on a wide variety of neutron-producing experiments, which include inertial-confinement fusion (ICF), dense plasma focus, and ion beam-driven concepts. This approach includes a combination of several effects: (1) non-isotropic neutron emission; (2) the 1/r(2) decrease in neutron fluence in the activation material; (3) the spatially distributed neutron scattering, attenuation, and energy losses due to the fielding environment and activation material itself; and (4) temporally varying neutron emission. As an example, we describe the copper-activation diagnostic used to measure secondary deuterium-tritium fusion-neutron yields on ICF experiments conducted on the pulsed-power Z Accelerator at Sandia National Laboratories. Using this methodology along with results from absolute calibrations and Monte Carlo simulations, we find that for the diagnostic configuration on Z, the diagnostic sensitivity is 0.037% ± 17% counts/neutron per cm(2) and is ∼ 40% less sensitive than it would be in an ideal geometry due to neutron attenuation, scattering, and energy-loss effects. PMID:24784607

  17. Fusion-neutron-yield, activation measurements at the Z accelerator: Design, analysis, and sensitivity

    SciTech Connect

    Hahn, K. D. Ruiz, C. L.; Fehl, D. L.; Chandler, G. A.; Knapp, P. F.; Smelser, R. M.; Torres, J. A.; Cooper, G. W.; Nelson, A. J.; Leeper, R. J.

    2014-04-15

    We present a general methodology to determine the diagnostic sensitivity that is directly applicable to neutron-activation diagnostics fielded on a wide variety of neutron-producing experiments, which include inertial-confinement fusion (ICF), dense plasma focus, and ion beam-driven concepts. This approach includes a combination of several effects: (1) non-isotropic neutron emission; (2) the 1/r{sup 2} decrease in neutron fluence in the activation material; (3) the spatially distributed neutron scattering, attenuation, and energy losses due to the fielding environment and activation material itself; and (4) temporally varying neutron emission. As an example, we describe the copper-activation diagnostic used to measure secondary deuterium-tritium fusion-neutron yields on ICF experiments conducted on the pulsed-power Z Accelerator at Sandia National Laboratories. Using this methodology along with results from absolute calibrations and Monte Carlo simulations, we find that for the diagnostic configuration on Z, the diagnostic sensitivity is 0.037% ± 17% counts/neutron per cm{sup 2} and is ∼ 40% less sensitive than it would be in an ideal geometry due to neutron attenuation, scattering, and energy-loss effects.

  18. Fusion-neutron-yield, activation measurements at the Z accelerator: Design, analysis, and sensitivity

    NASA Astrophysics Data System (ADS)

    Hahn, K. D.; Cooper, G. W.; Ruiz, C. L.; Fehl, D. L.; Chandler, G. A.; Knapp, P. F.; Leeper, R. J.; Nelson, A. J.; Smelser, R. M.; Torres, J. A.

    2014-04-01

    We present a general methodology to determine the diagnostic sensitivity that is directly applicable to neutron-activation diagnostics fielded on a wide variety of neutron-producing experiments, which include inertial-confinement fusion (ICF), dense plasma focus, and ion beam-driven concepts. This approach includes a combination of several effects: (1) non-isotropic neutron emission; (2) the 1/r2 decrease in neutron fluence in the activation material; (3) the spatially distributed neutron scattering, attenuation, and energy losses due to the fielding environment and activation material itself; and (4) temporally varying neutron emission. As an example, we describe the copper-activation diagnostic used to measure secondary deuterium-tritium fusion-neutron yields on ICF experiments conducted on the pulsed-power Z Accelerator at Sandia National Laboratories. Using this methodology along with results from absolute calibrations and Monte Carlo simulations, we find that for the diagnostic configuration on Z, the diagnostic sensitivity is 0.037% ± 17% counts/neutron per cm2 and is ˜ 40% less sensitive than it would be in an ideal geometry due to neutron attenuation, scattering, and energy-loss effects.

  19. Purpose in Life in Emerging Adulthood: Development and Validation of a New Brief Measure

    PubMed Central

    Hill, Patrick L.; Edmonds, Grant W.; Peterson, Missy; Luyckx, Koen; Andrews, Judy A.

    2015-01-01

    Accruing evidence points to the value of studying purpose in life across adolescence and emerging adulthood. Research though is needed to understand the unique role of purpose in life in predicting well-being and developmentally relevant outcomes during emerging adulthood. The current studies (total n = 669) found support for the development of a new brief measure of purpose in life using data from American and Canadian samples, while demonstrating evidence for two important findings. First, purpose in life predicted well-being during emerging adulthood, even when controlling for the Big Five personality traits. Second, purpose in life was positively associated with self-image and negatively associated with delinquency, again controlling for personality traits. Findings are discussed with respect to how studying purpose in life can help understand which individuals are more likely to experience positive transitions into adulthood. PMID:26958072

  20. Measuring the Effect of Tourism Services on Travelers' Quality of Life: Further Validation.

    ERIC Educational Resources Information Center

    Neal, Janet D.; Sirgy, M. Joseph; Uysal, Muzaffer

    2004-01-01

    lication and extension study provided additional validational support of the original tourism services satisfaction measure in relation to QOL-related measures.Neal, Sirgy and Uysal (1999) developed a model and a measure to capture the effect of tourism services on travelers' quality of life (QOL). They hypothesized that travelers' overall life…

  1. The Skindex instruments to measure the effects of skin disease on quality of life.

    PubMed

    Chren, Mary-Margaret

    2012-04-01

    Skindex-29 and Skindex-16 are validated measures of the effects of skin diseases on patients' quality of life. This article reviews the development of both versions of Skindex, discusses their measurement properties and interpretability, and gives examples of how they have been used and adapted for dermatologic research internationally. Studies of quality of life in patients with nonmelanoma skin cancer are described to illustrate the use of Skindex to understand quality of life and to compare effectiveness of different treatments for this highly prevalent condition. PMID:22284137

  2. World Pendulum--A Distributed Remotely Controlled Laboratory (RCL) to Measure the Earth's Gravitational Acceleration Depending on Geographical Latitude

    ERIC Educational Resources Information Center

    Grober, S.; Vetter, M.; Eckert, B.; Jodl, H.-J.

    2007-01-01

    We suggest that different string pendulums are positioned at different locations on Earth and measure at each place the gravitational acceleration (accuracy [delta]g is approximately equal to 0.01 m s[superscript -2]). Each pendulum can be remotely controlled via the internet by a computer located somewhere on Earth. The theoretical part describes…

  3. Calculating Nozzle Side Loads using Acceleration Measurements of Test-Based Models

    NASA Technical Reports Server (NTRS)

    Brown, Andrew M.; Ruf, Joe

    2007-01-01

    As part of a NASA/MSFC research program to evaluate the effect of different nozzle contours on the well-known but poorly characterized "side load" phenomena, we attempt to back out the net force on a sub-scale nozzle during cold-flow testing using acceleration measurements. Because modeling the test facility dynamics is problematic, new techniques for creating a "pseudo-model" of the facility and nozzle directly from modal test results are applied. Extensive verification procedures were undertaken, resulting in a loading scale factor necessary for agreement between test and model based frequency response functions. Side loads are then obtained by applying a wide-band random load onto the system model, obtaining nozzle response PSD's, and iterating both the amplitude and frequency of the input until a good comparison of the response with the measured response PSD for a specific time point is obtained. The final calculated loading can be used to compare different nozzle profiles for assessment during rocket engine nozzle development and as a basis for accurate design of the nozzle and engine structure to withstand these loads. The techniques applied within this procedure have extensive applicability to timely and accurate characterization of all test fixtures used for modal test.A viewgraph presentation on a model-test based pseudo-model used to calculate side loads on rocket engine nozzles is included. The topics include: 1) Side Loads in Rocket Nozzles; 2) Present Side Loads Research at NASA/MSFC; 3) Structural Dynamic Model Generation; 4) Pseudo-Model Generation; 5) Implementation; 6) Calibration of Pseudo-Model Response; 7) Pseudo-Model Response Verification; 8) Inverse Force Determination; 9) Results; and 10) Recent Work.

  4. Investigation on target normal sheath acceleration through measurements of ions energy distribution

    NASA Astrophysics Data System (ADS)

    Tudisco, S.; Altana, C.; Lanzalone, G.; Muoio, A.; Cirrone, G. A. P.; Mascali, D.; Schillaci, F.; Brandi, F.; Cristoforetti, G.; Ferrara, P.; Fulgentini, L.; Koester, P.; Labate, L.; Palla, D.; Gizzi, L. A.

    2016-02-01

    An experimental campaign aiming at investigating the ion acceleration mechanisms through laser-matter interaction in femtosecond domain has been carried out at the Intense Laser Irradiation Laboratory facility with a laser intensity of up to 2 × 1019 W/cm2. A Thomson parabola spectrometer was used to obtain the spectra of the ions of the different species accelerated. Here, we show the energy spectra of light-ions and we discuss their dependence on structural characteristics of the target and the role of surface and target bulk in the acceleration process.

  5. Measurements of wave-breaking radiation from a laser-wakefield accelerator.

    PubMed

    Thomas, A G R; Mangles, S P D; Najmudin, Z; Kaluza, M C; Murphy, C D; Krushelnick, K

    2007-02-01

    Spectral analysis of radiation emitted transverse to laser propagation in laser-wakefield acceleration experiments shows broadband emission when electrons are accelerated to relativistic energies. The region over which emission occurs is short compared with the overall interaction length. The energy of the emission and location along the interaction length both vary with plasma density. A model for the radiation from self-trapped electrons indicates that the emission is a signature of the violent initial acceleration, and hence can be used as a diagnostic of the self-injection mechanism. PMID:17358867

  6. Latitudinal variation of speed and mass flux in the acceleration region of the solar wind inferred from spectral broadening measurements

    NASA Technical Reports Server (NTRS)

    Woo, Richard; Goldstein, Richard M.

    1994-01-01

    Spectral broadening measurements conducted at S-band (13-cm wavelength) during solar minimum conditions in the heliocentric distance range of 3-8 R(sub O) by Mariner 4, Pioneer 10, Mariner 10, Helios 1, Helios 2, and Viking have been combined to reveal a factor of 2.6 reduction in bandwidth from equator to pole. Since spectral broadening bandwidth depends on electron density fluctuation and solar wind speed, and latitudinal variation of the former is available from coherence bandwidth measurements, the remote sensing spectral broadening measurements provide the first determination of the latitudinal variation of solar wind speed in the acceleration region. When combined with electron density measurements deduced from white-light coronagraphs, this result also leads to the first determination of the latitudinal variation of mass flux in the acceleration region. From equator to pole, solar wind speed increases by a factor of 2.2, while mass flux decreases by a factor of 2.3. These results are consistent with measurements of solar wind speed by multi-station intensity scintillation measurements, as well as measurements of mass flux inferred from Lyman alpha observations, both of which pertain to the solar wind beyond 0.5 AU. The spectral broadening observations, therefore, strengthen earlier conclusions about the latitudinal variation of solar wind speed and mass flux, and reinforce current solar coronal models and their implications for solar wind acceleration and solar wind modeling.

  7. Stress Rupture Life Reliability Measures for Composite Overwrapped Pressure Vessels

    NASA Technical Reports Server (NTRS)

    Murthy, Pappu L. N.; Thesken, John C.; Phoenix, S. Leigh; Grimes-Ledesma, Lorie

    2007-01-01

    Composite Overwrapped Pressure Vessels (COPVs) are often used for storing pressurant gases onboard spacecraft. Kevlar (DuPont), glass, carbon and other more recent fibers have all been used as overwraps. Due to the fact that overwraps are subjected to sustained loads for an extended period during a mission, stress rupture failure is a major concern. It is therefore important to ascertain the reliability of these vessels by analysis, since the testing of each flight design cannot be completed on a practical time scale. The present paper examines specifically a Weibull statistics based stress rupture model and considers the various uncertainties associated with the model parameters. The paper also examines several reliability estimate measures that would be of use for the purpose of recertification and for qualifying flight worthiness of these vessels. Specifically, deterministic values for a point estimate, mean estimate and 90/95 percent confidence estimates of the reliability are all examined for a typical flight quality vessel under constant stress. The mean and the 90/95 percent confidence estimates are computed using Monte-Carlo simulation techniques by assuming distribution statistics of model parameters based also on simulation and on the available data, especially the sample sizes represented in the data. The data for the stress rupture model are obtained from the Lawrence Livermore National Laboratories (LLNL) stress rupture testing program, carried out for the past 35 years. Deterministic as well as probabilistic sensitivities are examined.

  8. Grip pressure measurements during activities of daily life

    NASA Astrophysics Data System (ADS)

    Sanford, Joe; Young, Carolyn; Popa, Dan; Bugnariu, Nicoleta; Patterson, Rita

    2014-06-01

    Research has expanded human-machine communication methods past direct programming and standard hand- held joystick control. Individual force sensors have been used as a simple means of providing environmental information to a robot and research has shown that more advanced sensitive skins can be viable input devices. These touch sensitive surfaces allow for additional modes of interaction between machines in open, undefined environments. These interactions include object detection for navigation and safety but can also be used for recognition of users command gestures by their machine partner. Key to successful implementation of these gestures is the understanding of varied strategies used for communication and interaction and the development of performance limits. Data of dominant hand grip forces was collected using a Tekscan Grip VersaTek Pressure Measurement System during opening of a door. Analysis of data from 10 male and female subjects is presented. The results of qualitative and quantitative analysis of these data show variability in hand configurations between users. Average data over the cohort is reported. These data will be used in future work to provide human metrology constraints and limits for use in simulation and design of new, physical human-robot interaction systems.

  9. Evaluation of the electrode performance for PAFC by using acid absorption, acceleration and ac-impedance measurement

    SciTech Connect

    Kim, Chang-Soo; Song, Rak-Hyun; Choi, Byung-Woo

    1996-12-31

    In PAFC, the degradation on cathode electrode caused by carbon corrosion, platinum dissolution and growth is especially severe. An acceleration test is a good technique for evaluating the degradation of electrode performance, because it does not need long time. Coleman et al used thermal cycling and on-off cycling as an acceleration test. Song et al showed that hydrogen shortage decreased the electrode performance more rapidly than that of air shortage in gas shortage test. Honji et al reported that the rate of coarsening of Pt particle is rapid in open circuit potential and this is one of major causes on the performance degradation of electrode. The cathode performance has been studied by using acid absorption, acceleration and ac-impedance measurements as functions of the polytetrafluoroethylene (PTFE) contents and sintering temperatures of the electrode.

  10. Beam-based measurements of long-range transverse wakefields in the Compact Linear Collider main-linac accelerating structure

    NASA Astrophysics Data System (ADS)

    Zha, Hao; Latina, Andrea; Grudiev, Alexej; De Michele, Giovanni; Solodko, Anastasiya; Wuensch, Walter; Schulte, Daniel; Adli, Erik; Lipkowitz, Nate; Yocky, Gerald S.

    2016-01-01

    The baseline design of CLIC (Compact Linear Collider) uses X-band accelerating structures for its main linacs. In order to maintain beam stability in multibunch operation, long-range transverse wakefields must be suppressed by 2 orders of magnitude between successive bunches, which are separated in time by 0.5 ns. Such strong wakefield suppression is achieved by equipping every accelerating structure cell with four damping waveguides terminated with individual rf loads. A beam-based experiment to directly measure the effectiveness of this long-range transverse wakefield and benchmark simulations was made in the FACET test facility at SLAC using a prototype CLIC accelerating structure. The experiment showed good agreement with the simulations and a strong suppression of the wakefields with an unprecedented minimum resolution of 0.1 V /(pC mm m ) .

  11. A measurement of actinide neutron transmutations with accelerator mass spectrometry in order to infer neutron capture cross sections

    NASA Astrophysics Data System (ADS)

    Bauder, William K.

    Improved neutron capture cross section data for transuranic and minor actinides are essential for assessing possibilities for next generation reactors and advanced fuel cycles. The Measurement of Actinide Neutron TRAnsmutation (MANTRA) project aims to make a comprehensive set of energy integrated neutron capture cross section measurements for all relevant isotopes from Th to Cf. The ability to extract these cross sections relies on the use of Accelerator Mass Spectrometry (AMS) to analyze isotopic concentrations in samples irradiated in the Advanced Test Reactor (ATR). The AMS measurements were performed at the Argonne Tandem Linear Accelerator System (ATLAS) and required a number of key technical developments to the ion source, accelerator, and detector setup. In particular, a laser ablation material injection system was developed at the electron cyclotron resonance ion source. This system provides a more effective method to produce ion beams from samples containing only 1% actinide material and offers some benefits for reducing cross talk in the source. A series of four actinide measurements are described in this dissertation. These measurements represent the most substantial AMS work attempted at ATLAS and the first results of the MANTRA project. Isotopic ratios for one and two neutron captures were measured in each sample with total uncertainties around 10%. These results can be combined with a MCNP model for the neutron fluence to infer actinide neutron capture cross sections.

  12. Accelerated life test of the USDOE OC-OTEC experimental system refurbished with magnetic bearings for the 3rd stage vacuum compressor. Final report

    SciTech Connect

    Vega, L.A.

    1997-04-01

    This report documents the accelerated life test (time-to-failure) performed, at the request of DOE, to evaluate the viability of the magnetic bearing system installed in the stage 3 vacuum pump. To this effect the plant was successfully operated for over 500 hours during the period September-November 1996. The first part of this report discusses system performance by deriving subsystem and system performance parameters from a typical record. This is followed by the discussion of the life tests. The instrumentation used to estimate the performance parameters given here is depicted. The third stage pump was operated for 535 hours without incident. It is concluded that magnetic bearings are the preferable choice for the OC-OTEC centrifugal vacuum pumps.

  13. Differential longitudinal changes in cortical thickness, surface area and volume across the adult life span: regions of accelerating and decelerating change.

    PubMed

    Storsve, Andreas B; Fjell, Anders M; Tamnes, Christian K; Westlye, Lars T; Overbye, Knut; Aasland, Hilde W; Walhovd, Kristine B

    2014-06-18

    Human cortical thickness and surface area are genetically independent, emerge through different neurobiological events during development, and are sensitive to different clinical conditions. However, the relationship between changes in the two over time is unknown. Additionally, longitudinal studies have almost invariably been restricted to older adults, precluding the delineation of adult life span trajectories of change in cortical structure. In this longitudinal study, we investigated changes in cortical thickness, surface area, and volume after an average interval of 3.6 years in 207 well screened healthy adults aged 23-87 years. We hypothesized that the relationships among metrics are dynamic across the life span, that the primary contributor to cortical volume reductions in aging is cortical thinning, and that magnitude of change varies with age and region. Changes over time were seen in cortical area (mean annual percentage change [APC], -0.19), thickness (APC, -0.35), and volume (APC, -0.51) in most regions. Volume changes were primarily explained by changes in thickness rather than area. A negative relationship between change in thickness and surface area was found across several regions, where more thinning was associated with less decrease in area, and vice versa. Accelerating changes with increasing age was seen in temporal and occipital cortices. In contrast, decelerating changes were seen in prefrontal and anterior cingulate cortices. In conclusion, a dynamic relationship between cortical thickness and surface area changes exists throughout the adult life span. The mixture of accelerating and decelerating changes further demonstrates the importance of studying these metrics across the entire adult life span. PMID:24948804

  14. Estimating the Reliability of Single-Item Life Satisfaction Measures: Results from Four National Panel Studies

    ERIC Educational Resources Information Center

    Lucas, Richard E.; Donnellan, M. Brent

    2012-01-01

    Life satisfaction is often assessed using single-item measures. However, estimating the reliability of these measures can be difficult because internal consistency coefficients cannot be calculated. Existing approaches use longitudinal data to isolate occasion-specific variance from variance that is either completely stable or variance that…

  15. Application of an IRT Polytomous Model for Measuring Health Related Quality of Life

    ERIC Educational Resources Information Center

    Tejada, Antonio J. Rojas; Rojas, Oscar M. Lozano

    2005-01-01

    Background: The Item Response Theory (IRT) has advantages for measuring Health Related Quality of Life (HRQOL) as opposed to the Classical Tests Theory (CTT). Objectives: To present the results of the application of a polytomous model based on IRT, specifically, the Rating Scale Model (RSM), to measure HRQOL with the EORTC QLQ-C30. Methods: 103…

  16. Panoptic Performativity and School Inspection Regimes: Disciplinary Mechanisms and Life under Special Measures

    ERIC Educational Resources Information Center

    Perryman, Jane

    2006-01-01

    This paper looks at Ofsted and particularly special measures regimes as part of a disciplinary mechanism. It examines issues such as school effectiveness theories, the increasing powers of Ofsted, and life under special measures and links it to performativity, discipline and surveillance using the metaphor of the panopticon. The change in…

  17. Measuring quality of life in heart failure: one versus multiple items

    PubMed Central

    Jaarsma, T.; Lesman-Leegte, G.A.T.; Cleuren, G.V.J.; Lucas, C.M.H.B.

    2005-01-01

    Background Symptoms of heart failure and consequences of treatment can have a great impact on patients' lives. Improving quality of life is generally recognised as one of the major goals of treatment. The purpose of this study was to determine the relationship between a one-item quality-of-life measure (Ladder of Life) and the Minnesota Living with Heart Failure Questionnaire and possible equality. Method 231 patients who were admitted with symptoms of chronic heart failure to a cardiology ward in a general hospital (53% male, age 75±11, LVEF 40±16) completed the Minnesota Living with Heart Failure Questionnaire (MLwHFQ) and were asked to rate their sense of well-being on the Ladder of Life (10= best possible life, 0= worst possible life). Demographic and clinical data were obtained by chart review. Results The overall well-being score on the Ladder of Life correlated significantly with the total MLwHFQ (r=-0.36, p<0.001). However, there is a large variation in MLwHFQ scores (12-83) in patients who score a relatively high overall well-being (>6, relatively good Q0L). A large variation in MLwHFQ scores (10-105) also exists in patients with a relatively low score on the Ladder of Life (<1, low QOL). Conclusion Assessment of quality of life with a simple and practical tool using the one-item Ladder of Life can give clinicians and researchers important information on the quality of life of patients. Whether such a single-item question is responsive enough to detect changes in treatment and predict readmission needs to be studied in more detail. Imagesp341-a PMID:25696416

  18. Measurements of I-129 in meteorites and lunar rock by tandem accelerator mass spectrometry

    NASA Technical Reports Server (NTRS)

    Nizhiizumi, K.; Arnold, J. R.; Elmore, D.; Gove, H. E.; Honda, M.

    1983-01-01

    Precise measurements of the half-life of I-129 in three different meteorites and one lunar surface rock are reported. The meteorite source of I-129 was produced by cosmic ray secondary neutron reactions on Te, while the source in lunar materials in spallation on barium and rare earth elements. The Abee, Allende, and Dhajala meteorites were examined, together with the lunar rock 14310. Details of the process used to extract the iodine are provided. The Abee and Allende samples exhibited a production of 0.5 atom/min per gm of Te from the (n,2n) reaction and 0.05 atom/min/gm for the (n,gamma) reaction. The I-129 is concluded to be a viable tool for long-lived cosmogenic nuclide studies. Further work to extend the data to include the constancy of the cosmic ray flux, the meteorite bombardment history, and the cosmic exposure age dating by means of the I-129 and Xe-129 method is indicated.

  19. Operation and reactivity measurements of an accelerator driven subcritical TRIGA reactor

    NASA Astrophysics Data System (ADS)

    O'Kelly, David Sean

    Experiments were performed at the Nuclear Engineering Teaching Laboratory (NETL) in 2005 and 2006 in which a 20 MeV linear electron accelerator operating as a photoneutron source was coupled to the TRIGA (Training, Research, Isotope production, General Atomics) Mark II research reactor at the University of Texas at Austin (UT) to simulate the operation and characteristics of a full-scale accelerator driven subcritical system (ADSS). The experimental program provided a relatively low-cost substitute for the higher power and complexity of internationally proposed systems utilizing proton accelerators and spallation neutron sources for an advanced ADSS that may be used for the burning of high-level radioactive waste. Various instrumentation methods that permitted ADSS neutron flux monitoring in high gamma radiation fields were successfully explored and the data was used to evaluate the Stochastic Pulsed Feynman method for reactivity monitoring.

  20. Assessment of two-dimensional induced accelerations from measured kinematic and kinetic data.

    PubMed

    Hof, A L; Otten, E

    2005-11-01

    A simple algorithm is presented to calculate the induced accelerations of body segments in human walking for the sagittal plane. The method essentially consists of setting up 2x4 force equations, 4 moment equations, 2x3 joint constraint equations and two constraints related to the foot-ground interaction. Data needed for the equations are, next to masses and moments of inertia, the positions of ankle, knee and hip. This set of equations is put in the form of an 18x18 matrix or 20x20 matrix, the solution of which can be found by inversion. By applying input vectors related to gravity, to centripetal accelerations or to muscle moments, the 'induced' accelerations and reaction forces related to these inputs can be found separately. The method was tested for walking in one subject. Good agreement was found with published results obtained by much more complicated three-dimensional forward dynamic models. PMID:16214657

  1. Improving highly accelerated fat fraction measurements for clinical trials in muscular dystrophy: origin and quantitative effect of R2* changes.

    PubMed

    Loughran, Thomas; Higgins, David M; McCallum, Michelle; Coombs, Anna; Straub, Volker; Hollingsworth, Kieren G

    2015-05-01

    Purpose To investigate the effect of R2* modeling in conventional and accelerated measurements of skeletal muscle fat fraction in control subjects and patients with muscular dystrophy. Materials and Methods Eight patients with Becker muscular dystrophy and eight matched control subjects were recruited with approval from the Newcastle and North Tyneside 2 Research Ethics Committee and with written consent. Chemical-shift images with six widely spaced echo times (in 3.5-msec increments) were acquired to correlate R2* and muscle fat fraction. The effect of incorporating or neglecting R2* modeling on fat fraction magnitude and variance was evaluated in a typical three-echo protocol (with 0.78-msec increments). Accelerated acquisitions with this protocol with 3.65×, 4.94×, and 6.42× undersampling were reconstructed by using combined compressed sensing and parallel imaging and fat fraction maps produced with R2* modeling. Results Muscle R2* at 3.0 T (33-125 sec(-1)) depended on the morphology of fat replacement, the highest values occurring with the greatest interdigitation of fat. The inclusion of R2* modeling removed bias, which was greatest at low fat fraction, but did not increase variance. The 95% limits of agreement of the accelerated acquisitions were tight and not degraded by R2* modeling (1.65%, 1.95%, and 2.22% for 3.65×, 4.94×, and 6.42× acceleration, respectively). Conclusion Incorporating R2* modeling prevents systematic errors in muscle fat fraction by up to 3.5% without loss of precision and should be incorporated into all muscular dystrophy studies. Fat fraction measurements can be accelerated fivefold by using combined compressed sensing and parallel imaging, modeling for R2* without loss of fidelity. PMID:25575118

  2. Going nuts: Measuring free-fall acceleration by analyzing the sound of falling metal pieces

    NASA Astrophysics Data System (ADS)

    Kuhn, Jochen; Vogt, Patrik; Theilmann, Florian

    2016-03-01

    Galilei presented the kinematics of a one-dimensional accelerated motion with ease and in terms of elegant geometry. Moreover, he believed, "Philosophy [i.e. physics] is written in this grand book—I mean the universe—which stands continually open to our gaze, but it cannot be understood unless one first learns to comprehend the language and interpret the characters in which it is written. It is written in the language of mathematics, and its characters are triangles, circles, and other geometrical figures, without which it is humanly impossible to understand a single word of it." In classroom practice, however, it can be difficult to reveal this mathematical heart of nature; free fall and other accelerated motions often get obscured by friction or other sources of errors. In this paper, we introduce a method of analyzing free-fall motion indirectly by evaluating the noise of freely falling metal pieces. The method connects a deeper understanding of the mathematical structure of accelerated motion with the possibility to derive a numerical value for the free-fall acceleration g.

  3. Methodology for the calibration of and data acquisition with a six-degree-of-freedom acceleration measurement device

    NASA Astrophysics Data System (ADS)

    Lee, Harvey; Plank, Gordon; Weinstock, Herbert; Coltman, Michael

    1989-06-01

    Described here is a methodology for calibrating and gathering data with a six-degree-of-freedom acceleration measurement device that is intended to measure head acceleration of anthropomorphic dummies and human volunteers in automotive crash testing and head impact trauma studies. Error models (system equations) were developed for systems using six accelerometers in a coplanar (3-2-1) configuration, nine accelerometers in a coplanar (3-3-3) configuration and nine accelerometers in a non-coplanar (3-2-2-2) configuration and the accuracy and stability of these systems were compared. The model was verified under various input and computational conditions. Results of parametric sensitivity analyses which included parameters such as system geometry, coordinate system location, data sample rate and accelerometer cross axis sensitivities are presented. Recommendations to optimize data collection and reduction are given. Complete source listings of all of the software developed are presented.

  4. A New Ground Motion Intensity Measure, Peak Filtered Acceleration (PFA), to Estimate Collapse Vulnerability of Buildings in Earthquakes

    NASA Astrophysics Data System (ADS)

    Song, Shiyan

    In this thesis, we develop an efficient collapse prediction model, the PFA (Peak Filtered Acceleration) model, for buildings subjected to different types of ground motions. For the structural system, the PFA model covers modern steel and reinforced concrete moment-resisting frame buildings (potentially reinforced concrete shear wall buildings). For ground motions, the PFA model covers ramp-pulse-like ground motions, long-period ground motions, and short-period ground motions. To predict whether a building will collapse in response to a given ground motion, we first extract long-period components from the ground motion using a Butterworth low-pass filter with suggested order and cutoff frequency. The order depends on the type of ground motion, and the cutoff frequency depends on the building's natural frequency and ductility. We then compare the filtered acceleration time history with the capacity of the building. The capacity of the building is a constant for 2-dimentional buildings and a limit domain for 3-dimentional buildings. If the filtered acceleration exceeds the building's capacity, the building is predicted to collapse. Otherwise, it is expected to survive the ground motion. The parameters used in PFA model, which include fundamental period, global ductility and lateral capacity, can be obtained either from numerical analysis or interpolation based on the reference building system proposed in this thesis. The PFA collapse prediction model greatly reduces computational complexity while archiving good accuracy. It is verified by FEM simulations of 13 frame building models and 150 ground motion records. Based on the developed collapse prediction model, we propose to use PFA (Peak Filtered Acceleration) as a new ground motion intensity measure for collapse prediction. We compare PFA with traditional intensity measures PGA, PGV, PGD, and Sa in collapse prediction and find that PFA has the best performance among all the intensity measures. We also provide a

  5. Measurement of the {sup 214}Po half-life by the DEVIS track setup

    SciTech Connect

    Belov, V. A.; Brakhman, E. V.; Zeldovich, O. Ya.; Karelin, A. K.; Kirichenko, V. V.; Kobyakin, A. S. Kozodaeva, O. M.; Kuchenkov, A. V.; Tsvetkova, T. N.

    2013-04-15

    Measurement of the {sup 214}Po half-life with the DEVIS track setup at the Institute of Theoretical and Experimental Physics (ITEP, Moscow) by means of a procedure based on determining lifetimes of individual nuclei is described. The value obtained for the {sup 214}Po half-life is 163.8 {+-} 3.0 Micro-Sign s. The possibility of reaching the accuracy of the measurements that is required for testing the statement that the decay of some nuclei has a nonexponential character and the source intensity necessary for this are discussed.

  6. The half-life of ²²⁷Th by direct and indirect measurements.

    PubMed

    Collins, S M; Pommé, S; Jerome, S M; Ferreira, K M; Regan, P H; Pearce, A K

    2015-10-01

    Utilising a chemically purified solution the radioactive half-life of (227)Th has been determined indirectly by observation of the ingrowth of (223)Ra using an ionisation chamber (IC) and for the first time by direct observation of the change in activity with time using a high-purity germanium (HPGe) γ-ray spectrometer. The radioactive decay was observed for ~104 days (~5.6 half-lives) by γ-ray spectrometry and approximately 63 days and 72 days (~3.4 and ~3.9 half-lives) using an ionisation chamber (IC). The resulting half-life values - 18.695 (4) days (IC) and 18.683 (20) days (HPGe) - are consistent and detailed uncertainty budgets are presented for the two measurement techniques. A weighted mean of our results of 18.695 (4) days is inconsistent with the most precise published half-life value of 18.7176 (52) days (Jordan and Blanke, 1967). A critical evaluation of literature data has been performed, indicating a paucity of reliable and independent measurements. Selected independent published values have been used to determine a recommended half-life of 18.697 (7) days. A method has been introduced in the course of this work so that the recommended half-life of (227)Th as determined by ingrowth can be modified if a different (223)Ra half-life has been determined, evaluated and adopted. PMID:26197020

  7. Accelerated Helium and Hydrogen Production in Fe-54 Doped Alloys - Measurements and Calculations for the FIST Experiment

    SciTech Connect

    Greenwood, Lawrence R.; Oliver, Brian M.; Ohnuki, S.; Shiba, K.; Kohno, Y.; Kohyama, A.; Robertson, J. P.; Meadows, J. W.; Gelles, David S.

    2000-09-01

    Helium and hydrogen measurements for F-82H alloys enriched up to 96% in 54Fe demonstrate accelerated gas production due to differences in the isotopic cross sections. The samples were irradiated in the JP-17 and JP-22 experiments in HFIR. Results are compared to calculations using isotopic helium production cross sections from ENDF/B-VI or the computer code, GNASH, for the radioactive isotope 55Fe. Helium measurements demonstrated an accelerated helium (appm)/dpa ratio of 2.3 after a 1.25-year irradiation, an increase of a factor of 4.3 over natural iron, due to higher helium production cross sections for 54Fe and 55Fe. Alloys doped with 55Fe could achieve helium/dpa ratios up to about 20, well above the fusion reactor ratio of 10. Calculations predict that hydrogen production is accelerated by about a factor of 13 over natural iron. However, measurements show that most of this hydrogen is not retained in the samples.

  8. Summary Report of Mission Acceleration Measurements for MSL-1: STS-83, Launched April 14, 1997; STS-94, Launched July 1, 1997

    NASA Technical Reports Server (NTRS)

    Moskowitz, Milton E.; Hrovat, Kenneth; Tschen, Peter; McPherson, Kevin; Nati, Maurizio; Reckart, Timothy A.

    1998-01-01

    The microgravity environment of the Space Shuttle Columbia was measured during the STS-83 and STS-94 flights of the Microgravity Science Laboratory (MSL-1) mission using four different accelerometer systems: the Orbital Acceleration Research Experiment (OARE), the Space Acceleration Measurement System (SAMS), the Microgravity Measurement Assembly (MMA), and the Quasi-Steady Acceleration Measurement (QSAM) system. All four accelerometer systems provided investigators with acceleration measurements downlinked in near-real-time. Data from each system was recorded for post-mission analysis. The OARE measured the Shuttle's acceleration with high resolution in the quasi-steady frequency regime below about 0.1 Hz. The SAMS provided investigators with higher frequency acceleration measurements up to 25 Hz. The QSAM and MMA systems provided investigators with quasi-steady and higher frequency (up to 100 Hz) acceleration measurements, respectively. The microgravity environment related to various Orbiter maneuvers, crew activities, and experiment operations as measured by the OARE and MMA is presented and interpreted in section 8 of this report.

  9. Accelerator mass spectrometry: from nuclear physics to dating

    SciTech Connect

    Kutschera, W.

    1983-01-01

    Several applications of accelerator-based mass spectroscopy are reviewed. Among these are the search for unknown species, determination of comogenic radioisotopes in natural materials and measurements of half-lifes, especially those of significance to dating. Accelerator parameters and techniques of importance for these applications are also considered.

  10. Displacement measurements in the cryogenically cooled dipoles of the new CERN-LHC particle accelerator

    NASA Astrophysics Data System (ADS)

    Inaudi, Daniele; Glisic, Branko; Scandale, Walter; Garcia Perez, Juan; Billan, Jaques; Radaelli, Stefano

    2001-08-01

    All evidence indicates that new physics, and answers to some of the most profound scientific questions of our time, lie at energies around 1 TeV. To look for this new physics, the next research instrument in Europe's particle physics armory is the Large Hadron Collider (LHC). This challenging machine will use the most advanced superconducting magnet and accelerator technologies ever employed. LHC experiments are being designed to look for theoretically predicted phenomena.

  11. Measurements of in-air output ratios for a linear accelerator with and without the flattening filter.

    PubMed

    Zhu, X R; Kang, Y; Gillin, M T

    2006-10-01

    The in-air output ratio (Sc) for photon beams from linear accelerators describes the change of in-air output as a function of the collimator settings. The physical origin of the Sc is mainly due to the change in scattered radiation that can reach the point of measurement as the geometry of the head changes. The flattening filter (FF) and primary collimator are the major sources of scattered radiation. The change in amount of backscattered radiation from the collimator into the beam-monitoring chamber also contributes to the variation of output. In this work, we measured the Sc and backscatter factors (Sb) into the beam-monitoring chamber for a linear accelerator with and without the FF. We measured the Sc with a Farmer-type chamber in a miniphantom at the depth of 10 g/cm2 for 6- and 18-MV x-ray beams from a Varian Clinac 2100EX linear accelerator. The Sb were measured with a universal pulse counter and a diode array with build-in counting hardware and software. The head scatter component (Sh) was then derived from the relationship Sc= Sh x Sb, where Sb was the linear fit of measured results. Significant differences were observed for Sc with and without the FF. Within the range of experimental uncertainty, the Sb was similar with and without the FF. The variations in Sh differed significantly over the range of field sizes of 3 X 3 to 40 X 40 cm2 with and without the FF; for the 6-MV beam, it was 8% vs 3%, and for the 18-MV beam, 7% vs 1%. By analyzing the contributions of backscatter factor and total in-air output ratios with and without the FF, we directly gained insight into the contributions of different components to the total variations in Sc of a linear accelerator. Sc, Sb, and Sh are basic and useful dosimetric quantities for delivery of intensity-modulated radiation therapy using a linear accelerator operating in a mode without the FF. PMID:17089838

  12. Measurement of the (211)Pb half-life using recoil atoms from (219)Rn decay.

    PubMed

    Aitken-Smith, P M; Collins, S M

    2016-04-01

    The radioactive half-life of (211)Pb was measured, by α-particle counting of samples of radiochemically pure (211)Pb in equilibrium with its α-emitting progeny, (211)Bi and (211)Po. The samples were prepared by the collection of (215)Po recoil atoms from the decay of the (219)Rn decay progeny produced from a (223)Ra sample onto stainless steel discs. The radioactive decay of the (211)Pb was measured utilising a 2π proportional counter operating on the α plateau. A half-life of 36.164 (13)min was determined, which is in agreement with currently available literature. A full uncertainty budget is presented. A recommended half-life of T1/2((211)Pb)=36.161 (17)min has been evaluated from the current literature values. PMID:26773817

  13. Acceleration performance of individual European sea bass Dicentrarchus labrax measured with a sprint performance chamber: comparison with high-speed cinematography and correlates with ecological performance.

    PubMed

    Vandamm, Joshua P; Marras, Stefano; Claireaux, Guy; Handelsman, Corey A; Nelson, Jay A

    2012-01-01

    Locomotor performance can influence the ecological and evolutionary success of a species. For fish, favorable outcomes of predator-prey encounters are often presumably due to robust acceleration ability. Although escape-response or "fast-start" studies utilizing high-speed cinematography are prevalent, little is known about the contribution of relative acceleration performance to ecological or evolutionary success in a species. This dearth of knowledge may be due to the time-consuming nature of analyzing film, which imposes a practical limit on sample sizes. Herein, we present a high-throughput potential alternative for measuring fish acceleration performance using a sprint performance chamber (SPC). The acceleration performance of a large number of juvenile European sea bass (Dicentrarchus labrax) from two populations was analyzed. Animals from both hatchery and natural ontogenies were assessed, and animals of known acceleration ability had their ecological performance measured in a mesocosm environment. Individuals from one population also had their acceleration performance assessed by both high-speed cinematography and an SPC. Acceleration performance measured in an SPC was lower than that measured by classical high-speed video techniques. However, short-term repeatability and interindividual variation of acceleration performance were similar between the two techniques, and the SPC recorded higher sprint swimming velocities. Wild fish were quicker to accelerate in an SPC and had significantly greater accelerations than all groups of hatchery-raised fish. Acceleration performance had no significant effect on ecological performance (as assessed through animal growth and survival in the mesocosms). However, it is worth noting that wild animals did survive predation in the mesocosm better than farmed ones. Moreover, the hatchery-originated fish that survived the mesocosm experiment, when no predators were present, displayed significantly increased acceleration

  14. Development of an Accelerated Test Design for Predicting the Service Life of the Solar Array at Mead, Nebraska

    NASA Technical Reports Server (NTRS)

    Gaines, G. B.; Thomas, R. E.; Noel, G. T.; Shilliday, T. S.; Wood, V. E.; Carmichael, D. C.

    1979-01-01

    Potential long-term degradation modes for the two types of modules in the Mead array were determined and judgments were made as to those environmental stresses and combinations of stresses which accelerate the degradation of the power output. Hierarchical trees representing the severity of effects of stresses (test conditions) on eleven individual degradation modes were constructed and were pruned of tests judged to be nonessential. Composites of those trees were developed so that there is now one pruned tree covering eight degradation modes, another covering two degradation modes, and a third covering one degradation mode. These three composite trees form the basis for selection of test conditions in the final test plan which is now being prepared.

  15. Vorticity, turbulence production, and turbulence induced accelerations in a rectangular jet as measured using 3-D LDA

    NASA Technical Reports Server (NTRS)

    Morrison, Gerald L.; Swan, David H.

    1990-01-01

    The flow field of a rectangular jet with a 4:1 aspect ratio (50.4 x 12.7 mm) was studied at a Reynolds number of 100,000 (Mach number 0.09) using a 3-D laser Doppler anemometer system. Measurements were performed along the major and minor axis planes and at various downstream cross-sections of the jet. The mean velocity vector and entire Reynolds stress tensor were measured and presented in a previous publication. The present work presents the vorticity vector, turbulence production, and turbulence induced acceleration vector distributions which were calculated from the previously presented data.

  16. The actual measurements at the tide gauges do not support strongly accelerating twentieth-century sea-level rise reconstructions

    NASA Astrophysics Data System (ADS)

    Parker, A.

    2016-03-01

    Contrary to what is claimed by reconstructions of the Global Mean Sea Level (GMSL) indicating accelerating sea level rates of rise over the twentieth-century, the actual measurements at the tide gauges show the sea levels have not risen nor accelerated that much. The most recent estimation by Hay et al [1] of the twentieth-century global mean sea level (GMSL) rise is the last attempt to give exact reconstructions without having enough information of the state of the world oceans over a century where unfortunately the good measurements were not that many. The information on relative rates of rise at the tide gauges and land subsidence of global positioning system (GPS) domes suggest the relative rate of rise is about 0.25mm/year, without any detectable acceleration. [The naïve average of all the world tide gauges of sufficient quality and length of the Permanent Service to Mean Sea Level (PSMSL) data base], Both the relative rates of rise at the tide gauges and the land vertical velocity of GPS domes of the Système d'Observation du Niveau des Eaux Littorales (SONEL) data base are strongly variable in space and time to make a nonsense the GMSL estimation.

  17. A resonant sensor composed of quartz double ended tuning fork and silicon substrate for digital acceleration measurement

    SciTech Connect

    Li, Cun; Zhao, Yulong Cheng, Rongjun; Yu, Zhongliang; Liu, Yan

    2014-03-15

    Presented in this paper is a micro-resonant acceleration sensor based on the frequency shift of quartz double ended tuning fork (DETF). The structure is silicon substrate having a proof mass supported by two parallel flexure hinges as doubly sustained cantilever, with a resonating DETF located between the hinges. The acceleration normal to the chip plane induces an axial stress in the DETF beam and, in turn, a proportional shift in the beam resonant frequency. Substrate is manufactured by single-crystal silicon for stable mechanical properties and batch-fabrication processes. Electrodes on the four surfaces of DETF beam excite anti-phase vibration model, to balance inner stress and torque and imply a high quality factor. The sensor is simply packaged and operates unsealed in atmosphere for measurements. The tested natural frequency is 36.9 kHz and the sensitivity is 21 Hz/g on a nominally ±100 g device, which is in good agreement with analytical calculation and finite element simulation. The output frequency drifting is less than 0.5 Hz (0.0014% of steady output) within 1 h. The nonlinearity is 0.0019%FS and hysteresis is 0.0026%FS. The testing results confirm the feasibility of combining quartz DETF and silicon substrate to achieve a micro-resonant sensor based on simple processing for digital acceleration measurements.

  18. The actual measurements at the tide gauges do not support strongly accelerating twentieth-century sea-level rise reconstructions

    NASA Astrophysics Data System (ADS)

    Parker, A.

    2016-03-01

    Contrary to what is claimed by reconstructions of the Global Mean Sea Level (GMSL) indicating accelerating sea level rates of rise over the twentieth-century, the actual measurements at the tide gauges show the sea levels have not risen nor accelerated that much. The most recent estimation by Hay et al of the twentieth-century global mean sea level (GMSL) rise is the last attempt to give exact reconstructions without having enough information of the state of the world oceans over a century where unfortunately the good measurements were not that many. The information on relative rates of rise at the tide gauges and land subsidence of global positioning system (GPS) domes suggest the relative rate of rise is about 0.25mm/year, without any detectable acceleration. [The naïve average of all the world tide gauges of sufficient quality and length of the Permanent Service to Mean Sea Level (PSMSL) data base], Both the relative rates of rise at the tide gauges and the land vertical velocity of GPS domes of the Système d'Observation du Niveau des Eaux Littorales (SONEL) data base are strongly variable in space and time to make a nonsense the GMSL estimation.

  19. A resonant sensor composed of quartz double ended tuning fork and silicon substrate for digital acceleration measurement.

    PubMed

    Li, Cun; Zhao, Yulong; Cheng, Rongjun; Yu, Zhongliang; Liu, Yan

    2014-03-01

    Presented in this paper is a micro-resonant acceleration sensor based on the frequency shift of quartz double ended tuning fork (DETF). The structure is silicon substrate having a proof mass supported by two parallel flexure hinges as doubly sustained cantilever, with a resonating DETF located between the hinges. The acceleration normal to the chip plane induces an axial stress in the DETF beam and, in turn, a proportional shift in the beam resonant frequency. Substrate is manufactured by single-crystal silicon for stable mechanical properties and batch-fabrication processes. Electrodes on the four surfaces of DETF beam excite anti-phase vibration model, to balance inner stress and torque and imply a high quality factor. The sensor is simply packaged and operates unsealed in atmosphere for measurements. The tested natural frequency is 36.9 kHz and the sensitivity is 21 Hz/g on a nominally ±100 g device, which is in good agreement with analytical calculation and finite element simulation. The output frequency drifting is less than 0.5 Hz (0.0014% of steady output) within 1 h. The nonlinearity is 0.0019%FS and hysteresis is 0.0026%FS. The testing results confirm the feasibility of combining quartz DETF and silicon substrate to achieve a micro-resonant sensor based on simple processing for digital acceleration measurements. PMID:24689613

  20. Life Span as the Measure of Performance and Learning in a Business Gaming Simulation

    ERIC Educational Resources Information Center

    Thavikulwat, Precha

    2012-01-01

    This study applies the learning curve method of measuring learning to participants of a computer-assisted business gaming simulation that includes a multiple-life-cycle feature. The study involved 249 participants. It verified the workability of the feature and estimated the participants' rate of learning at 17.4% for every doubling of experience.…

  1. 18F Half-life measurement using 2-γ coincidence method

    NASA Astrophysics Data System (ADS)

    Kang, Y. S.; Ahn, J. K.; Kim, S. H.; Byun, J. I.; Han, J. B.; Lee, K. B.

    2015-11-01

    The accuracy of the half-life measurement of short-lived radioisotopes such as positron-emitting 18F (τ1/2 ≈ 100 min) is limited mainly by inaccuracies in the detector counting statistics. Gamma-ray measurement with a high-activity 18F source requires counting-loss corrections to compensate for random summing effects and the detector's dead time. In this study, we measure the half-life of 18F with two 511-keV γ-rays using two high-purity germanium (HPGe) detectors. The counting-loss corrections are performed via two approaches to address the problems of random coincidence summing and dead time: a half-life measurement with a 22Na source and a Geant4 simulation of the detector response. Variations in the full-width at half maximum (FWHM) of the 511-keV peak are found to show good correlation with the random summing effect. The half-life of 18F is estimated as 109.73 ± 0.14 min.

  2. Translating Oral Health-Related Quality of Life Measures: Are There Alternative Methodologies?

    ERIC Educational Resources Information Center

    Brondani, Mario; He, Sarah

    2013-01-01

    Translating existing sociodental indicators to another language involves a rigorous methodology, which can be costly. Free-of-charge online translator tools are available, but have not been evaluated in the context of research involving quality of life measures. To explore the value of using online translator tools to develop oral health-related…

  3. Measuring Service-Mindedness and Its Relationship with Spirituality and Life Satisfaction

    ERIC Educational Resources Information Center

    Pashak, Travis J.; Laughter, Tim C.

    2012-01-01

    A self-report measure of service-mindedness was designed in order to fill in a gap in the literature and evaluate a potential link between spirituality and satisfaction with life. A sample of 133 undergraduate students at a Catholic university in the Mid-west completed the Service-Mindedness Scale (SMS), along with the Spiritual Involvement and…

  4. Using Preference-Based Measures to Assess Quality of Life in Stuttering

    ERIC Educational Resources Information Center

    Bramlett, Robin E.; Bothe, Anne K.; Franic, Duska M.

    2006-01-01

    Purpose: The purpose of this study was to determine whether standard pharmaco-economic preference methods can be used to assess perceived quality of life in stuttering. Method: Seventy-five nonstuttering adults completed a standardized face-to-face interview that included a rating scale, standard gamble, and time trade-off preference measures for…

  5. Art Appreciation, Farming, Measurement, Reading & Phonics, Renaissance: Daily Life, Sound & Light.

    ERIC Educational Resources Information Center

    Web Feet, 2002

    2002-01-01

    This annotated subject guide to Web sites for grades K-8 focuses on art appreciation, farming, measurement, reading and phonics, renaissance daily life, sound and light, and calendar connections for June observances. Specific grade levels are indicated for each annotation. (LRW)

  6. Measuring Longevity Achievements under Welfare Interdependencies: A Case for Joint Life Expectancy Indicators

    ERIC Educational Resources Information Center

    Ponthiere, Gregory

    2007-01-01

    Whereas period life expectancy constitutes an intuitive indicator of the survival conditions prevailing at a particular period, this paper argues that, given the existence of welfare interdependencies, that widespread indicator is nonetheless an incomplete measure of the longevity achievements relevant for human well-being. The central importance…

  7. Application of gamma-ray radiography and gravimetric measurements after accelerated corrosion tests of steel embedded in mortar

    SciTech Connect

    Duffó, Gustavo; Gaillard, Natalia; Mariscotti, Mario; Ruffolo, Marcelo

    2015-08-15

    The accelerated corrosion by the impressed current technique is widely used in studies of concrete durability since it has the advantage that tests can be carried out within reasonable periods of time. In the present work the relationship between the applied current density and the resulting damage on the reinforcing steel, by applying optical microscopy, scanning electron microscopy, gamma-ray radiography and gravimetric measurements, was studied by means of the implementation of accelerated corrosion tests on reinforced mortar. The results show that the efficiency of the applied current is between 1 and 77%, regardless of the applied current density, the water/cement ratio and the mortar cover depth of the specimens. The results show the applicability of the gamma-ray radiography technique to detect localized corrosion of steel rebars in laboratory specimens.

  8. Design and RF measurements of an X-band accelerating structure for linearizing the longitudinal emittance at SPARC

    NASA Astrophysics Data System (ADS)

    Alesini, D.; Falone, A.; Migliorati, M.; Mostacci, A.; Palpini, F.; Palumbo, L.; Spataro, B.

    2005-12-01

    The paper presents the design of an X-band accelerating section for linearizing the longitudinal phase space in the Frascati Linac Coherent Light Source (SPARC). The nine cells structure, operating on the π standing wave mode, is fed by a central coupler and has been designed to obtain a 42 MV/m accelerating gradient. The two-dimensional (2D) profile has been obtained using the electromagnetic codes Superfish and Oscar-2D while the coupler has been designed using HFSS. Bead-pull measurements made on a copper prototype have been performed and the results are illustrated and compared with the numerical predictions. Mechanical details of the realized prototype and RF properties of the structure as a function of the assembly characteristics are also discussed.

  9. Measurement of depth-dose of linear accelerator and simulation by use of Geant4 computer code

    PubMed Central

    Sardari, D.; Maleki, R.; Samavat, H.; Esmaeeli, A.

    2010-01-01

    Radiation therapy is an established method of cancer treatment. New technologies in cancer radiotherapy need a more accurate computation of the dose delivered in the radiotherapy treatment plan. This study presents some results of a Geant4-based application for simulation of the absorbed dose distribution given by a medical linear accelerator (LINAC). The LINAC geometry is accurately described in the Monte Carlo code with use of the accelerator manufacturer's specifications. The capability of the software for evaluating the dose distribution has been verified by comparisons with measurements in a water phantom; the comparisons were performed for percentage depth dose (PDD) and profiles for various field sizes and depths, for a 6-MV electron beam. Experimental and calculated dose values were in good agreement both in PDD and in transverse sections of the water phantom. PMID:24376926

  10. Measurement techniques and instruments suitable for life-prediction testing of photovoltaic arrays

    NASA Technical Reports Server (NTRS)

    Noel, G. T.; Sliemers, F. A.; Deringer, G. C.; Wood, V. E.; Wilkes, K. E.; Gaines, G. B.; Carmichael, D. C.

    1978-01-01

    Array failure modes, relevant materials property changes, and primary degradation mechanisms are discussed as a prerequisite to identifying suitable measurement techniques and instruments. Candidate techniques and instruments are identified on the basis of extensive reviews of published and unpublished information. These methods are organized in six measurement categories - chemical, electrical, optical, thermal, mechanical, and other physicals. Using specified evaluation criteria, the most promising techniques and instruments for use in life prediction tests of arrays were selected.

  11. RBC-/Cr-51/ half-life and albumin turnover in growing Beagle dogs during chronic radial acceleration

    NASA Technical Reports Server (NTRS)

    Beckman, D. A.; Evans, J. W.; Oyama, J.

    1979-01-01

    The effects of chronic centrifugation on growing Beagle dogs exposed to -2 or -2.6 Gx on albumin and RBC turnover rates, albumin concentration and space, and total blood volume were determined and compared with caged and run control of animals. Albumin-(I-125) and autologous RBC-(Cr-51) preparations were injected into all dogs at day 82 of the centrifugation periods, and the disappearance curves were determined by successive bleedings of the animals over the next 35 d, during which the centrifugation was continued. There were no differences in albumin turnover rates or space. Two populations of RBCs were found in both centrifugated groups, one with a normal half-life of 27 + or - 1 S.E.M. d, and one with a significantly (p less than 0.01) shorter half-life of 15 + or - 2 S.E.M. d. An absolute polycythemia was also observed in both centrifuged groups. The results suggest that chronic centrifugation acts through some as-yet unknown mechanism to affect RBC population kinetics.

  12. Neutron activation analyses and half-life measurements at the usgs triga reactor

    NASA Astrophysics Data System (ADS)

    Larson, Robert E.

    Neutron activation of materials followed by gamma spectroscopy using high-purity germanium detectors is an effective method for making measurements of nuclear beta decay half-lives and for detecting trace amounts of elements present in materials. This research explores applications of neutron activation analysis (NAA) in two parts. Part 1. High Precision Methods for Measuring Decay Half-Lives, Chapters 1 through 8 Part one develops research methods and data analysis techniques for making high precision measurements of nuclear beta decay half-lives. The change in the electron capture half-life of 51Cr in pure chromium versus chromium mixed in a gold lattice structure is explored, and the 97Ru electron capture decay half-life are compared for ruthenium in a pure crystal versus ruthenium in a rutile oxide state, RuO2. In addition, the beta-minus decay half-life of 71mZn is measured and compared with new high precision findings. Density Functional Theory is used to explain the measured magnitude of changes in electron capture half-life from changes in the surrounding lattice electron configuration. Part 2. Debris Collection Nuclear Diagnostic at the National Ignition Facility, Chapters 9 through 11 Part two explores the design and development of a solid debris collector for use as a diagnostic tool at the National Ignition Facility (NIF). NAA measurements are performed on NIF post-shot debris collected on witness plates in the NIF chamber. In this application NAA is used to detect and quantify the amount of trace amounts of gold from the hohlraum and germanium from the pellet present in the debris collected after a NIF shot. The design of a solid debris collector based on material x-ray ablation properties is given, and calculations are done to predict performance and results for the collection and measurements of trace amounts of gold and germanium from dissociated hohlraum debris.

  13. Filtered x-ray diode diagnostics fielded on the Z-accelerator for source power measurements

    SciTech Connect

    Chandler, G.A.; Deeney, C.; Cuneo, M.

    1998-06-02

    Filtered x-ray diode, (XRD), detectors are used as primary radiation flux diagnostics on Sandia`s Z-accelerator, which generates nominally a 200 TW, 2 MJ, x-ray pulse. Given such flux levels and XRD sensitivities the detectors are being fielded 23 meters from the source. The standard diagnostic setup and sensitivities are discussed. Vitreous carbon photocathodes are being used to reduce the effect of hydrocarbon contamination present in the Z-machine vacuum system. Nevertheless pre- and post-calibration data taken indicate spectrally dependent changes in the sensitivity of these detectors by up to factors up to 2 or 3.

  14. A life-course approach to measuring socioeconomic position in population health surveillance systems.

    PubMed

    Chittleborough, C R; Baum, F E; Taylor, A W; Hiller, J E

    2006-11-01

    Measuring socioeconomic position (SEP) in population chronic disease and risk factor surveillance systems is essential for monitoring socioeconomic inequalities in health over time. Life-course measures are an innovative way to supplement other SEP indicators in surveillance systems. A literature review examined the indicators of early-life SEP that could potentially be used in population health surveillance systems. The criteria of validity, relevance, reliability and deconstruction were used to determine the value of potential indicators. Early-life SEP indicators used in cross-sectional and longitudinal studies included education level, income, occupation, living conditions, family structure and residential mobility. Indicators of early-life SEP should be used in routine population health surveillance to monitor trends in the health and SEP of populations over time, and to analyse long-term effects of policies on the changing health of populations. However, these indicators need to be feasible to measure retrospectively, and relevant to the historical, geographical and sociocultural context in which the surveillance system is operating. PMID:17053288

  15. Measurements of photo-neutrons from a medical linear accelerator using CR-39 plastic nuclear track detectors

    NASA Astrophysics Data System (ADS)

    Monson, Jonathan Michael

    Photo-neutrons are produced when x-ray energies exceed 7 MeV. Photo-neutron production varies depending on x-ray beam energy. CR-39 PNTDs were used in this study to measure the neutron absorbed dose and dose equivalent produced by a Varian Clinac 23EX for x-ray beams of 6 and 18 MVp and with a Varian Trilogy using an x-ray beam of 10 MVp. Neutron absorbed dose and dose equivalent were measured at 100 cm SSD at 0, 20, and 40 cm off-axis from the primary beam in air. Using a polyethylene phantom the neutron absorbed dose and dose equivalent were measured at 100 cm SSD from the top of the phantom at 0, 5, and 10 cm from the surface, in the beam central axis and off-axis distances of 20 and 40 cm at a depth of 10 cm. The neutron absorbed dose and dose equivalent from medical linear accelerators have been measured from the LET spectrum of recoiled tracks produced in the CR-39 PNTDs for high energy neutrons (1-20 MeV) and the neutron dose equivalent for low energy (< 1 MeV) neutrons were measured using TRNDs. In this study, the experimentally measured absorbed dose and dose equivalent from photo-neutrons produced in a common medical linear accelerator operating at energies 10 and 18 MVp range from 0.2 microGy n/Gyx and 2 microSv n/Gyx to 495 microGy n/Gyx and 5500 microSv n/Gyx respectively. The neutron absorbed dose for the 6 MVp x-ray beam was measured to be 0 microGyn/Gyx. Low energy neutrons accounted for less than 1% of the neutron dose equivalent. Those detectors exposed inside of the phantom measured a higher contribution from high LET (> 100 keV/microm) particles than those detectors exposed in air.

  16. 38 CFR 9.14 - Accelerated Benefits.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ...' GROUP LIFE INSURANCE AND VETERANS' GROUP LIFE INSURANCE § 9.14 Accelerated Benefits. (a) What is an Accelerated Benefit? An Accelerated Benefit is a payment of a portion of your Servicemembers' Group Life Insurance or Veterans' Group Life Insurance to you before you die. (b) Who is eligible to receive...

  17. 38 CFR 9.14 - Accelerated Benefits.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...' GROUP LIFE INSURANCE AND VETERANS' GROUP LIFE INSURANCE § 9.14 Accelerated Benefits. (a) What is an Accelerated Benefit? An Accelerated Benefit is a payment of a portion of your Servicemembers' Group Life Insurance or Veterans' Group Life Insurance to you before you die. (b) Who is eligible to receive...

  18. 38 CFR 9.14 - Accelerated Benefits.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...' GROUP LIFE INSURANCE AND VETERANS' GROUP LIFE INSURANCE § 9.14 Accelerated Benefits. (a) What is an Accelerated Benefit? An Accelerated Benefit is a payment of a portion of your Servicemembers' Group Life Insurance or Veterans' Group Life Insurance to you before you die. (b) Who is eligible to receive...

  19. Personality Disorders in Later Life: Questions about the Measurement, Course, and Impact of Disorders

    PubMed Central

    Oltmanns, Thomas F.; Balsis, Steve

    2011-01-01

    Lifespan perspectives have played a crucial role in shaping our understanding of many forms of psychopathology. Unfortunately, little attention has been given to personality disorders in middle adulthood and later life. Several issues are responsible for this deficiency, including difficulty applying the diagnostic criteria for personality disorders to older people and challenges in identifying appropriate samples of older participants. The goal of this review is to explore the benefits of considering older adults in the study of personality disorders. Later life offers a unique opportunity for investigators to consider links between personality pathology and consequential outcomes in people’s lives. Many domains are relevant, including health, longevity, social adjustment, marital relationships, and the experience of major life events. We review each domain and consider ways in which the study of middle-aged and older adults challenges researchers to evaluate how personality disorders in general are defined and measured. PMID:21219195

  20. ‘Just give me the best quality of life questionnaire’: the Karnofsky scale and the history of quality of life measurements in cancer trials

    PubMed Central

    Timmermann, Carsten

    2013-01-01

    Objectives: To use the history of the Karnofsky Performance Scale as a case study illustrating the emergence of interest in the measurement and standardisation of quality of life; to understand the origins of current-day practices. Methods: Articles referring to the Karnofsky scale and quality of life measurements published from the 1940s to the 1990s were identified by searching databases and screening journals, and analysed using close-reading techniques. Secondary literature was consulted to understand the context in which articles were written. Results: The Karnofsky scale was devised for a different purpose than measuring quality of life: as a standardisation device that helped quantify effects of chemotherapeutic agents less easily measurable than survival time. Interest in measuring quality of life only emerged around 1970. Discussion: When quality of life measurements were increasingly widely discussed in the medical press from the late 1970s onwards, a consensus emerged that the Karnofsky scale was not a very good tool. More sophisticated approaches were developed, but Karnofsky continued to be used. I argue that the scale provided a quick and simple, approximate assessment of the ‘soft’ effects of treatment by physicians, overlapping but not identical with quality of life. PMID:23239756