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1

Experimental Study of Hypernuclei Electroproduction by High Precision Spectroscopy  

SciTech Connect

Jlab experiment E01-011, carried out in 2005 in JLab Hall C, is the second generation of the hypernuclear spectroscopy experiments by the (e,e{prime}K{sup +}) reaction. The (e,e{prime}K{sup +}) reaction is complimentary to the associated production reactions (K{sup -},{pi}{sup -}), ({pi}{sup +},K{sup +}) since, due to a larger momentum transfer to a hyperon, excitations of both spin-non-flip and spin-flip states are possible. The experiment uses high quality and continuous primary electron beam to produce neutron rich hypernuclei on various targets by the electroproduction. The experimental setup consists of splitter magnet, high resolution kaon spectrometer (HKS) and electron spectrometer (Enge) implemented in new configuration, the so called 'Tilt Method'. Production data was taken on multiple targets: CH{sub 2}, {sup 6}Li, {sup 7}Li, {sup 9}Be, {sup 10}B, {sup 12}C and {sup 28}Si. In present study the analysis of CH{sub 2}, {sup 12}C and {sup 28}Si is presented. The elementary processes of p(e,e{prime}K{sup +}){Lambda}/{Sigma} from CH{sup 2} data were used for calibration of the spectrometer optics and kinematics. The hypernuclear spectra of {sup 12}{sub {Lambda}}B was obtained with ground state resolution of 0.47 {+-} 0.07 MeV (FWHM), the best ever achieved. Feasibility of the electroproduction reaction to study medium to heavy targets has been proven with the first high resolution beyond p-shell hypernuclear spectra from {sup 28}{sub {Lambda}}Al hypernuclei. The obtained results of the E01-011 experiment confirmed that hypernuclear spectroscopy by the (e,e{prime}K{sup +}) reaction is a very useful technique.

Tomislav Seva

2009-12-01

2

Highly precise experimental device for determining the heat capacity of liquids under pressure  

NASA Astrophysics Data System (ADS)

An experimental device for making isobaric heat capacity measurements of liquids under pressure is presented. The device is an adaptation of the Setaram micro-DSC II atmospheric-pressure microcalorimeter, including modifications of vessels and a pressure line allowing the pressure in the measurement system to be set, controlled, and stabilized. The high sensitivity of the apparatus combined with a suitable calibration procedure allows very accurate heat capacity measurements under pressure to be made. The relative uncertainty in the isobaric molar heat capacity measurements provided by the new device is estimated to be 0.08% at atmospheric pressure and 0.2% at higher levels. The device was validated from isobaric molar heat capacity measurements for hexane, nonane, decane, undecane, dodecane, and tridecane, all of which were highly consistent with reported data. It also possesses a high sensitivity as reflected in its response to changes in excess isobaric molar heat capacity with pressure, which were examined in this work for the first time by making heat capacity measurements throughout the composition range of the 1-hexanol+n-hexane system. Finally, preliminary measurements at several pressures near the critical conditions for the nitromethane+2-butanol binary system were made that testify to the usefulness of the proposed device for studying critical phenomena in liquids under pressure.

González-Salgado, D.; Valencia, J. L.; Troncoso, J.; Carballo, E.; Peleteiro, J.; Romaní, L.; Bessières, D.

2007-05-01

3

Highly precise experimental device for determining the heat capacity of liquids under pressure.  

PubMed

An experimental device for making isobaric heat capacity measurements of liquids under pressure is presented. The device is an adaptation of the Setaram micro-DSC II atmospheric-pressure microcalorimeter, including modifications of vessels and a pressure line allowing the pressure in the measurement system to be set, controlled, and stabilized. The high sensitivity of the apparatus combined with a suitable calibration procedure allows very accurate heat capacity measurements under pressure to be made. The relative uncertainty in the isobaric molar heat capacity measurements provided by the new device is estimated to be 0.08% at atmospheric pressure and 0.2% at higher levels. The device was validated from isobaric molar heat capacity measurements for hexane, nonane, decane, undecane, dodecane, and tridecane, all of which were highly consistent with reported data. It also possesses a high sensitivity as reflected in its response to changes in excess isobaric molar heat capacity with pressure, which were examined in this work for the first time by making heat capacity measurements throughout the composition range of the 1-hexanol+n-hexane system. Finally, preliminary measurements at several pressures near the critical conditions for the nitromethane+2-butanol binary system were made that testify to the usefulness of the proposed device for studying critical phenomena in liquids under pressure. PMID:17552856

González-Salgado, D; Valencia, J L; Troncoso, J; Carballo, E; Peleteiro, J; Romaní, L; Bessières, D

2007-05-01

4

Experimental access to higher-order Zeeman effects by precision spectroscopy of highly charged ions in a Penning trap  

NASA Astrophysics Data System (ADS)

We present an experimental concept and setup for laser-microwave double-resonance spectroscopy of highly charged ions in a Penning trap. Such spectroscopy allows a highly precise measurement of the Zeeman splittings of fine- and hyperfine-structure levels due the magnetic field of the trap. We have performed detailed calculations of the Zeeman effect in the framework of quantum electrodynamics of bound states as present in such highly charged ions. We find that apart from the linear Zeeman effect, second- and third-order Zeeman effects also contribute to the splittings on a level of 10-4 and 10-8, respectively, and hence are accessible to a determination within the achievable spectroscopic resolution of the ARTEMIS experiment currently in preparation.

von Lindenfels, D.; Wiesel, M.; Glazov, D. A.; Volotka, A. V.; Sokolov, M. M.; Shabaev, V. M.; Plunien, G.; Quint, W.; Birkl, G.; Martin, A.; Vogel, M.

2013-02-01

5

Experimental access to higher-order Zeeman effects by precision spectroscopy of highly charged ions in a Penning trap  

E-print Network

We present an experimental concept and setup for laser-microwave double-resonance spectroscopy of highly charged ions in a Penning trap. Such spectroscopy allows a highly precise measurement of the Zeeman splittings of fine- and hyperfine-structure levels due the magnetic field of the trap. We have performed detailed calculations of the Zeeman effect in the framework of quantum electrodynamics of bound states as present in such highly charged ions. We find that apart from the linear Zeeman effect, second- and third-order Zeeman effects also contribute to the splittings on a level of 10^-4 and 10^-8, respectively, and hence are accessible to a determination within the achievable spectroscopic resolution of the ARTEMIS experiment currently in preparation.

von Lindenfels, D; Glazov, D A; Volotka, A V; Sokolov, M M; Shabaev, V M; Plunien, G; Quint, W; Birkl, G; Martin, A; Vogel, M

2013-01-01

6

EDITORIAL: High precision atomic physics High precision atomic physics  

NASA Astrophysics Data System (ADS)

Accurate atomic collision and structure data are an essential ingredient for a wide range of research fields as well as for major technological applications. Areas from laboratory physics to quantum processing, from plasma research applications in nuclear fusion to lighting research, as well as astrophysics and cosmology, depend critically on such data. But many data still exhibit inconsistencies and inaccuracies, so that significant efforts are continuing to improve the data quality. Additionally, a substantial body of much-needed data is absent from the published literature and from databases. Appreciable progress is being made, aided by greatly improved, or even entirely new, laboratory equipment and by vastly expanded computer power, which has made possible the development of greatly refined atomic structure codes. Thus in recent years, atomic data have not only become more accurate, but the body of data has also greatly increased, highly ionized species and complex heavy atoms have been addressed, fully relativistic treatments have been developed, and new energy and frequency ranges have been explored. This special issue focuses on many of these new sophisticated theoretical and experimental approaches that have made high precision atomic physics a reality. On the experimental side, several contributions cover the area of highly charged ions, where accurate measurements have become possible mainly due to the availability of electron beam ion traps (EBITs) and the utilization of storage rings. Studies of QED effects in Li-like ions, determinations of atomic lifetimes and precision wavelength measurements of highly charged ions are discussed. Furthermore, two contributions illustrate the extremely high precision of spectroscopic measurements for heavy ions and atoms, and two fundamental investigations address a new search for the electric dipole moment of the electron and measurements of the anapole moment in Fr and Rb. On the theoretical side, the contributions demonstrate that new, expanded and refined atomic structure and electron-impact collision codes are successfully applied to complex atomic systems, such as highly charged ions and heavy atoms, using increasingly full relativistic treatments.

Hibbert, Alan; Johnson, Walter; Wiese, Wolfgang

2010-04-01

7

High Precision Astrometry  

NASA Astrophysics Data System (ADS)

This |*|program |*|uses |*|the |*|enhanced |*|astrometric |*|precision |*|enabled |*|by |*|spatial |*|scanning |*|to |*|calibrate |*|remaining |*|obstacles |*|toreaching |*|<<40 |*|microarc|*|second |*|astrometry |*|{<1 |*|millipixel} |*|with |*|WFC3/UVIS |*|by |*|1} |*|improving |*|geometric |*|distor-on |*|2} |*|calibratingthe |*|e|*|ect |*|of |*|breathing |*|on |*|astrometry|*|3} |*|calibrating |*|the |*|e|*|ect |*|of |*|CTE |*|on |*|astrometry, |*|4} |*|characterizing |*|the |*|boundaries |*|andorientations |*|of |*|the |*|WFC3 |*|lithograph |*|cells.

Riess, Adam

2012-10-01

8

Highly Parallel, High-Precision Numerical Integration  

SciTech Connect

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

Bailey, David H.; Borwein, Jonathan M.

2005-04-22

9

High Precision Pressure Measurement with a Funnel  

ERIC Educational Resources Information Center

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

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

2008-01-01

10

High precision laser forming for microactuation  

NASA Astrophysics Data System (ADS)

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

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

2014-03-01

11

High-Precision Computation and Mathematical Physics  

SciTech Connect

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

Bailey, David H.; Borwein, Jonathan M.

2008-11-03

12

High precision redundant robotic manipulator  

DOEpatents

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

Young, Kar-Keung David (Mountain View, CA)

1998-01-01

13

Precision Experimental Verification of Special Relativity  

Microsoft Academic Search

We compare the results of precision electron g-factor experiments at low energy and at 110 keV. The agreement between these measurements constitutes the most precise laboratory confirmation to date of the predictions of special relativity. Relativistic electromagnetic theory and Thomas precession are verified in this test. We also consider limits on possible effects of acceleration.

D. Newman; G. W. Ford; A. Rich; E. Sweetman

1978-01-01

14

Towards High Precision Deuteron Polarimetry  

SciTech Connect

A finite electric dipole moment (EDM) in any fundamental system would constitute a signal for new physics. The deuteron presents itself as an optimal candidate both experimentally and theoretically. A new storage ring technique is being developed for which a small change in the vertical polarization would be a signal of a non-zero EDM. A novel polarimeter concept is under investigation. Besides being highly efficient, this polarimeter should continuously monitor the beam polarization, guaranteeing optimal sensitivity. Detailed studies on systematic error control, in addition to the measurement of cross sections and analyzing powers, were carried out at KVI-Groningen in The Netherlands. Measurements were conducted at COSY-Juelich in Germany yielding high efficiencies. The (statistics limited) ability to track changes in polarization at the level of a few hundred parts-per-million has been demonstrated. Further studies and developments to meet the final goal of sub-part-per-million sensitivity are in progress.

Silva e Silva, M. da [KVI, University of Groningen, Groningen (Netherlands)

2009-08-04

15

High precision anatomy for MEG.  

PubMed

Precise MEG estimates of neuronal current flow are undermined by uncertain knowledge of the head location with respect to the MEG sensors. This is either due to head movements within the scanning session or systematic errors in co-registration to anatomy. Here we show how such errors can be minimized using subject-specific head-casts produced using 3D printing technology. The casts fit the scalp of the subject internally and the inside of the MEG dewar externally, reducing within session and between session head movements. Systematic errors in matching to MRI coordinate system are also reduced through the use of MRI-visible fiducial markers placed on the same cast. Bootstrap estimates of absolute co-registration error were of the order of 1mm. Estimates of relative co-registration error were <1.5mm between sessions. We corroborated these scalp based estimates by looking at the MEG data recorded over a 6month period. We found that the between session sensor variability of the subject's evoked response was of the order of the within session noise, showing no appreciable noise due to between-session movement. Simulations suggest that the between-session sensor level amplitude SNR improved by a factor of 5 over conventional strategies. We show that at this level of coregistration accuracy there is strong evidence for anatomical models based on the individual rather than canonical anatomy; but that this advantage disappears for errors of greater than 5mm. This work paves the way for source reconstruction methods which can exploit very high SNR signals and accurate anatomical models; and also significantly increases the sensitivity of longitudinal studies with MEG. PMID:23911673

Troebinger, Luzia; López, José David; Lutti, Antoine; Bradbury, David; Bestmann, Sven; Barnes, Gareth

2014-02-01

16

High precision triangular waveform generator  

Microsoft Academic Search

An ultra-linear ramp generator having separately programmable ascending and descending ramp rates and voltages is provided. Two constant current sources provide the ramp through an integrator. Switching of the current at current source inputs rather than at the integrator input eliminates switching transients and contributes to the waveform precision. The triangular waveforms produced by the waveform generator are characterized by

1983-01-01

17

High precision triangular waveform generator  

DOEpatents

An ultra-linear ramp generator having separately programmable ascending and descending ramp rates and voltages is provided. Two constant current sources provide the ramp through an integrator. Switching of the current at current source inputs rather than at the integrator input eliminates switching transients and contributes to the waveform precision. The triangular waveforms produced by the waveform generator are characterized by accurate reproduction and low drift over periods of several hours. The ascending and descending slopes are independently selectable.

Mueller, Theodore R. (Oak Ridge, TN)

1983-01-01

18

New High Precision Linelist of H_3^+  

NASA Astrophysics Data System (ADS)

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

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

2014-06-01

19

Experimental Study of a Precision, Hydrodynamic Wheel Spindle for Submicron Cylindrical Grinding  

Microsoft Academic Search

Hydrodynamic journal bearings have been widely used in various types of rotating machinery, ranging from heavy duty, high-impact applications, such as the crank shaft of an internal combustion engine and turbine rotor, to high-precision, light load applications, such as precision spindles in cylindrical grinding machines. Although extensive theoretical and experimental results have been presented for hydrodynamic bearings, the available literature

J. F. Tu; M. Corless; M. J. Gehrich; A. J. Shih

1998-01-01

20

High precision thermal neutron detectors  

SciTech Connect

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

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

1994-10-01

21

High precision thermal neutron detectors  

SciTech Connect

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

Radeka, V.; Schaknowski, N.A.; Smith, G.C.; Yu, B. [Brookhaven National Laboratory, Upton, NY (United States)

1994-12-31

22

Development of precision measurement network of experimental advanced superconducting tokamak  

NASA Astrophysics Data System (ADS)

In order to obtain accurate position of the inner key components in the experimental advanced superconducting tokamak (EAST), a combined optical measurement method which is comprised of a laser tracker (LT) and articulated coordinate measuring machine (CMM) has been brought forward. LT, which is an optical measurement instrument and has a large measurement range and high accuracy, is employed for establishing the precision measurement network of EAST, and the articulated CMM is also employed for measuring the inner key components of EAST. The measurement uncertainty analyzed by the Unified Spatial Metrology Network (USMN) is 0.20 mm at a confidence probability of 95.44%. The proposed technology is appropriate for the inspection of the reconstruction of the EAST.

Yu, Liandong; Zhao, Huining; Zhang, Wei; Li, Weishi; Deng, Huaxia; Song, Yuntao; Gu, Yongqi

2014-12-01

23

Precision Crystal Calorimeters in High Energy Physics  

ScienceCinema

Precision crystal calorimeters traditionally play an important role in high energy physics experiments. In the last two decades, it faces a challenge to maintain its precision in a hostile radiation environment. This paper reviews the performance of crystal calorimeters constructed for high energy physics experiments and the progress achieved in understanding crystal?s radiation damage as well as in developing high quality scintillating crystals for particle physics. Potential applications of new generation scintillating crystals of high density and high light yield, such as LSO and LYSO, in particle physics experiments is also discussed.

Ren-Yuan Zhu

2010-01-08

24

High precision, rapid laser hole drilling  

DOEpatents

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

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

2013-04-02

25

High precision, rapid laser hole drilling  

DOEpatents

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

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

2005-03-08

26

High precision measurements in crustal dynamic studies  

NASA Technical Reports Server (NTRS)

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

Wyatt, F.; Berger, J.

1984-01-01

27

Design of a high precision current source  

Microsoft Academic Search

Current source is one of the key components in electrical measurement and control systems. However, the noise introduced by temperature drift and other interference makes it a significant source of systematic errors. To develop a high precision and stable current source, a Howland-based voltage to current conversion (V\\/I) circuit is presented in this paper. The current source is fully programmable

Yu Peng; Yanchao Xia; Shaojun Wang

2009-01-01

28

High precision, rapid laser hole drilling  

DOEpatents

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

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

2007-03-20

29

Verification of results obtained in the project on Theoretical and experimental basic investigations on high-precision optoelectronic measurement of the fixed star sky by satellite-borne instruments  

NASA Astrophysics Data System (ADS)

Main subject of the project was the verification of basic findings of the preceeding study 'Theoretical and experimental basic investigations on high-precision optoelectronic measurement of the fixed star sky by satellite-borne instruments', aimed at the improvement of the accuracy of star sensors which employ CCDs (charge coupled devices) as optoelectronic receivers. As a central tool for improving measurement accuracy, a model based algorithm for precise subpixel interpolation was investigated. The model algorithm was verified in single CCD matrices (employing the Modular Measurement System MMS) and in an ASTRO 1 M star sensor. Additional approaches for improving measurement accuracy of star sensors were investigated quantitatively by mathematical estimates. Another subject of this project was the extension and modification of Jena-Optronik's Modular Measurement System MMS for the measurement of the pixel weighting function of CCDs and the point spread function of lens systems, as necessary for the aforementioned measurements. In the concluding phase of the project, approaches to the implementation of accuracy improving methods in star sensors were investigated and a proposal for realization of a high precision star sensor in a succeeding project was worked out.

Elstner, C. F.; Schmidt, U.

1993-12-01

30

High-precision hydraulic Stewart platform  

NASA Astrophysics Data System (ADS)

We present a novel design for a Stewart platform (or hexapod), an apparatus which performs positioning tasks with high accuracy. The platform, which is supported by six hydraulic telescopic struts, provides six degrees of freedom with 1 ?m resolution. Rotations about user defined pivot points can be specified for any axis of rotation with microradian accuracy. Motion of the platform is performed by changing the strut lengths. Servo systems set and maintain the length of the struts to high precision using proportional hydraulic valves and incremental encoders. The combination of hydraulic actuators and a design which is optimized in terms of mechanical stiffness enables the platform to manipulate loads of up to 20 kN. Sophisticated software allows direct six-axis positioning including true path control. Our platform is an ideal support structure for a large variety of scientific instruments that require a stable alignment base with high-precision motion.

van Silfhout, Roelof G.

1999-08-01

31

Portable high precision pressure transducer system  

DOEpatents

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

Piper, Thomas C. (Idaho Falls, ID); Morgan, John P. (Idaho Falls, ID); Marchant, Norman J. (Idaho Falls, ID); Bolton, Steven M. (Pocatello, ID)

1994-01-01

32

Measurement and Precision: High School Activity  

NSDL National Science Digital Library

This activity from the Florida Advanced Technological Education (FL-ATE) Center asks students to use the concepts of measurement and precision in the context of designing and manufacturing surgical instruments. The interdisciplinary lesson plan involves science, computer technology, math and technical education. Students will have the opportunity to develop their understanding of number systems and their application in the context of a practical industrial situation. This version of the lesson is appropriate for high school aged students.

33

Note: High precision measurements using high frequency gigahertz signals  

NASA Astrophysics Data System (ADS)

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

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

2014-12-01

34

Adventures in High Precision Laser Spectroscopy  

SciTech Connect

Optical frequency comb techniques are revolutionizing the art of measuring the frequency of light. The complex and highly specialized harmonic laser frequency chains of the past can now be replaced by a universal optical frequency comb synthesizer using just a single mode-locked femtosecond laser. After spectral broadening in a nonlinear optical fiber, such a laser emits a regular comb of hundred of thousands of evenly spaced sharp laser lines, extending throughout the visible and near infrared spectrum. The frequency of each line can be determined by radio frequency methods with extreme precision. Such frequency comb synthesizers are already revolutionizing precision laser spectroscopy, they provide the clock work for novel ultraprecise atomic clocks, based on optical transitions in atoms, ions or molecules, and they open new frontiers for stringent tests of fundamental physics laws.

Theodor Haensch

2009-01-29

35

Precision mass measurements of highly charged ions  

NASA Astrophysics Data System (ADS)

The reputation of Penning trap mass spectrometry for accuracy and precision was established with singly charged ions (SCI); however, the achievable precision and resolving power can be extended by using highly charged ions (HCI). The TITAN facility has demonstrated these enhancements for long-lived (T1/2>=50 ms) isobars and low-lying isomers, including ^71Ge^21+, ^74Rb^8+, ^78Rb^8+, and ^98Rb^15+. The Q-value of ^71Ge enters into the neutrino cross section, and the use of HCI reduced the resolving power required to distinguish the isobars from 3 x 10^5 to 20. The precision achieved in the measurement of ^74Rb^8+, a superallowed ?-emitter and candidate to test the CVC hypothesis, rivaled earlier measurements with SCI in a fraction of the time. The 111.19(22) keV isomeric state in ^78Rb was resolved from the ground state. Mass measurements of neutron-rich Rb and Sr isotopes near A = 100 aid in determining the r-process pathway. Advanced ion manipulation techniques and recent results will be presented.

Kwiatkowski, A. A.; Bale, J. C.; Brunner, T.; Chaudhuri, A.; Chowdhury, U.; Ettenauer, S.; Frekers, D.; Gallant, A. T.; Grossheim, A.; Lennarz, A.; Mane, E.; MacDonald, T. D.; Schultz, B. E.; Simon, M. C.; Simon, V. V.; Dilling, J.

2012-10-01

36

Experimental evaluation of active-member control of precision structures  

NASA Technical Reports Server (NTRS)

The results of closed loop experiments that use piezoelectric active-members to control the flexible motion of a precision truss structure are described. These experiments are directed toward the development of high-performance structural systems as part of the Control/Structure Interaction (CSI) program at JPL. The focus of CSI activity at JPL is to develop the technology necessary to accurately control both the shape and vibration levels in the precision structures from which proposed large space-based observatories will be built. Structural error budgets for these types of structures will likely be in the sub-micron regime; optical tolerances will be even tighter. In order to achieve system level stability and local positioning at this level, it is generally expected that some form of active control will be required.

Fanson, James; Blackwood, Gary; Chu, Cheng-Chih

1989-01-01

37

High precision innovative micropump for artificial pancreas  

NASA Astrophysics Data System (ADS)

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

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

2014-03-01

38

A Double Precision High Speed Convolution Processor  

NASA Astrophysics Data System (ADS)

There exist several convolution processors on the market that can process images at video rate. However, none of these processors operates in floating point arithmetic. Unfortunately, many image processing algorithms presently under development are inoperable in integer arithmetic, forcing the researchers to use regular computers. To solve this problem, we designed a specialized convolution processor that operates in double precision floating point arithmetic with a throughput several thousand times faster than the one obtained on regular computer. Its high performance is attributed to a VLSI double precision convolution systolic cell designed in our laboratories. A 9X9 systolic array carries out, in a pipeline manner, every arithmetic operation. The processor is designed to interface directly with the VME Bus. A DMA chip is responsible for bringing the original pixel intensities from the memory of the computer to the systolic array and to return the convolved pixels back to memory. A special use of 8K RAMs allows an inexpensive and efficient way of delaying the pixel intensities in order to supply the right sequence to the systolic array. On board circuitry converts pixel values into floating point representation when the image is originally represented with integer values. An additional systolic cell, used as a pipeline adder at the output of the systolic array, offers the possibility of combining images together which allows a variable convolution window size and color image processing.

Larochelle, F.; Coté, J. F.; Malowany, A. S.

1989-11-01

39

Highly damped kinematic coupling for precision instruments  

DOEpatents

A highly damped kinematic coupling for precision instruments. The kinematic coupling provides support while causing essentially no influence to its nature shape, with such influences coming, for example, from manufacturing tolerances, temperature changes, or ground motion. The coupling uses three ball-cone constraints, each combined with a released flexural degree of freedom. This arrangement enables a gain of higher load capacity and stiffness, but can also significantly reduce the friction level in proportion to the ball radius divided by the distance between the ball and the hinge axis. The blade flexures reduces somewhat the stiffness of the coupling and provides an ideal location to apply constrained-layer damping which is accomplished by attaching a viscoelastic layer and a constraining layer on opposite sides of each of the blade flexures. The three identical ball-cone flexures provide a damped coupling mechanism to kinematically support the projection optics system of the extreme ultraviolet lithography (EUVL) system, or other load-sensitive apparatus.

Hale, Layton C. (Livermore, CA); Jensen, Steven A. (Livermore, CA)

2001-01-01

40

High precision droplet based new form manufacturing  

SciTech Connect

In collaboration with the University of California at Irvine (UCI), we are working on a new technology that relies on the precise deposition of nanoliter molten-metal droplets that are targeted onto a substrate by electrostatic charging and deflection. By this way, three-dimensional (3D) structural materials can be manufactured microlayer by microlayer. Because the volume of the droplets are small, they rapidly solidify on impact, bringing forth a material component with fine grain structures which lead to enhanced material properties (e.g., strength). UCI is responsible for an experimental investigation of the manufacturing feasibility of this process. LLNL has unique expertise in the computational modeling of 3D heat transfer and solid mechanics and has the large-scale computer resources necessary to model this large system. Process modeling will help move this technology from the bench-top to an industrial process. Applications at LLNL include rapid prototyping of metal parts and manufacturing new alloys by co-jetting different metals.

Aceves,S; Hadjiconstantinou, N; Miller, W O; Orme, M; Sahai, V; Shapiro, A B

1999-09-16

41

Trapped Positrons for High-Precision Magnetic Moment Measurements  

E-print Network

Trapped Positrons for High-Precision Magnetic Moment Measurements (Article begins on next page Positrons for High-Precision Magnetic Moment Measurements A thesis presented by Shannon Michelle Fogwell Shannon Michelle Fogwell Hoogerheide Trapped Positrons for High-Precision Magnetic Moment Measurements

Gabrielse, Gerald

42

High precision photon flux determination for photon tagging experiments  

NASA Astrophysics Data System (ADS)

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

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

2014-12-01

43

High precision photon flux determination for photon tagging experiments  

SciTech Connect

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

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

2014-07-01

44

High precision beam alignment of electromagnetic wigglers  

SciTech Connect

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

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

1993-01-01

45

Compact trimming design of a high-precision reference  

NASA Astrophysics Data System (ADS)

To design a high-precision reference, the various error sources have been analyzed and compensated with a compact 111 mV resistor-trim scheme and the upper and lower extremes of the reference precision are also temperature-compensated. At room temperature, the yield of ±0.5% precision is 96% and ±0.2% is 78%.

Guodong, Ren; Shifang, Zhao; Zhongshen, Pu; Zhiqiang, Wei

2014-04-01

46

Optimal dynamic performance for high-precision actuators/stages.  

SciTech Connect

System dynamic performance of actuator/stage groups, such as those found in optical instrument positioning systems and other high-precision applications, is dependent upon both individual component behavior and the system configuration. Experimental modal analysis techniques were implemented to determine the six degree of freedom stiffnesses and damping for individual actuator components. These experimental data were then used in a multibody dynamic computer model to investigate the effect of stage group configuration. Running the computer model through the possible stage configurations and observing the predicted vibratory response determined the optimal stage group configuration. Configuration optimization can be performed for any group of stages, provided there is stiffness and damping data available for the constituent pieces.

Preissner, C.; Lee, S.-H.; Royston, T. J.; Shu, D.

2002-07-03

47

High precision numerical accuracy in physics research  

NASA Astrophysics Data System (ADS)

Concerns arise that the current standard of double-precision floating-point may no longer be sufficient for today's large-scale numerical simulations. One approach to solve this problem will be to switch to a wider floating-point format: the upcoming quadruple-precision standard is introduced and compared to currently available software-based approaches. Another complimentary approach is to use mathematical and algorithmic techniques to improve the accuracy of large floating-point programs and the confidence in the quality of the result.

de Dinechin, Florent; Villard, Gilles

2006-04-01

48

An Experimental Study of Precision Deployment using an Autonomous Helicopter  

Microsoft Academic Search

We present a methodology for precision deployment of objects using an autonomous helicopter. We first describe the problem of precision deployment and then describe the methodology used for such a deployment mechanism. The main sensor used for deployment is GPS. The helicopter is given a either a single pre-surveyed location or a set of way-points on which to deploy. It

Srikanth Saripalli; Gaurav S. Sukhatme

49

High-precision triangular-waveform generator  

Microsoft Academic Search

An ultra-linear ramp generator having separately programmable ascending and decending ramp rates and voltages is provided. Two constant current sources provide the ramp through an integrator. Switching of the current at current source inputs rather than at the integrator input eliminates switching transients and contributes to the waveform precision. The triangular waveforms produced by the waveform generator are characterized by

1981-01-01

50

High Performance Computing Meets Experimental Mathematics  

E-print Network

High Performance Computing Meets Experimental Mathematics David H. Bailey Lawrence Berkeley on conventional systems. We also describe a new software package for performing arbitrary precision arithmetic been relatively slow to adopt computing as a serious tool for the practicing researcher, compared

Bailey, David H.

51

High Performance Computing Meets Experimental Mathematics #  

E-print Network

High Performance Computing Meets Experimental Mathematics # David H. Bailey Lawrence Berkeley on conventional systems. We also describe a new software package for performing arbitrary precision arithmetic been relatively slow to adopt computing as a serious tool for the practicing researcher, compared

Li, Xiaoye Sherry

52

High-precision triangular-waveform generator  

DOEpatents

An ultra-linear ramp generator having separately programmable ascending and decending ramp rates and voltages is provided. Two constant current sources provide the ramp through an integrator. Switching of the current at current source inputs rather than at the integrator input eliminates switching transients and contributes to the waveform precision. The triangular waveforms produced by the waveform generator are characterized by accurate reproduction and low drift over periods of several hours. The ascending and descending slopes are independently selectable.

Mueller, T.R.

1981-11-14

53

Advanced gravitational reference sensor for high precision space interferometers  

NASA Astrophysics Data System (ADS)

LISA and the next generation of space-based laser interferometers require gravitational reference sensors (GRS) to provide distance measurements to picometre precision for LISA, and femtometre precision for the proposed Big Bang Observatory (BBO). We describe a stand-alone GRS structure that has the benefits of higher sensitivity and ease of fabrication. The proposed GRS structure enables high precision interferometric links in three-dimensional directions. The GRS housing provides the optical reference surface onto which the transmitted laser beam, and the independent received laser beam are referenced. The stand-alone GRS allows balanced optical probing of the distance of the proof mass relative to the housing at a power and wavelength that differ from the transmitted and received wavelengths and with picometre sensitivity without radiation pressure imbalance. The single parameter that reduces proof mass disturbance forces is the gap spacing. Optical readout allows the use of a large gap between the GRS housing and proof mass. We propose using rf-modulated optical interferometry to measure both relative displacement and absolute distance. Further we propose to use a reflective grating beamsplitter within the GRS and on the external optical bench. The reflective grating design eliminates the in-path transmissive optical components and the dn/dT related optical path effects, and simplifies the optical bench structure. Inside the GRS, a near-Littrow mounted grating enables picometre precision measurement at microwatts of optical power. Preliminary experimental results using a grating beamsplitter interferometer are presented, which demonstrate an optical sensing sensitivity of 30 pm Hz-1/2.

Sun, Ke-Xun; Allen, Graham; Buchman, Sasha; DeBra, Dan; Byer, Robert

2005-05-01

54

High precision phase measurement technique for cell impedance spectroscopy  

NASA Astrophysics Data System (ADS)

This paper presents a new approach for high precision phase measurement. The new system is developed for biomedical applications such as complex cell impedance measurement and dielectric tissue analysis. In many of the named applications it is necessary to measure the complex dielectric constant of a sample as a function of frequency. Therefore the developed system is capable of measuring amplitude and especially high precision phase of the measurement signal over a wide frequency range from 10 Hz to 10 MHz. The experimental result of the new method shows a phase resolution of up to 0.01 degree at 1 MHz and 0.1 degree at 10 MHz. The excellent phase measurement resolution is achieved by a time transformation of the signal using a digital sampling circuitry. The functional principle of the digital sampling circuitry is based on Delta - Modulation and is implemented inside a cheap standard FPGA. The new system is successfully used in blood analysis applications and allows for a practical implementation of cost efficient capacitive hematocrit sensors for the first time.

Trebbels, Dennis; Woelki, Daniel; Zengerle, Roland

2010-04-01

55

High precision measurement system based on coplanar XY-stage  

NASA Astrophysics Data System (ADS)

A coplanar XY-stage, together with a high precise measurement system, is presented in this paper. The proposed coplanar XY-stage fully conforms to the Abbe principle. The symmetric structural design is considered to eliminate the structure deformation due to force and temperature changes. For consisting of a high precise measurement system, a linear diffraction grating interferometer(LDGI) is employed as the position feedback sensor with the resolution to 1 nm after the waveform interpolation, an ultrasonic motor HR4 is used to generate both the long stroke motion and the nano positioning on the same stage. Three modes of HR4 are used for positioning control: the AC mode in continuous motion control for the long stroke; the gate mode to drive the motor in low velocity for the short stroke; and the DC mode in which the motor works as a piezo actuator, enabling accurate positioning of a few nanometers. The stage calibration is carried out by comparing the readings of LDGI with a Renishaw laser interferometer and repeated 5 times. Experimental results show the XY-stage has achieved positioning accuracy in less than 20nm after the compensation of systematic errors, and standard deviation is within 20 nm for travels up to 20 mm.

Fan, Kuang-Chao; Miao, Jin-Wei; Gong, Wei; Zhang, You-Liang; Cheng, Fang

2011-12-01

56

High precision applications of the global positioning system  

NASA Technical Reports Server (NTRS)

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

Lichten, Stephen M.

1991-01-01

57

High precision fiber SINS with spin technology  

NASA Astrophysics Data System (ADS)

Fiber strapdown inertial navigation system (FSINS) is presently used in several applications related to marine navigation. However, the absolute position from FSINS contains the error that increases with time, which prevents its long-term use for the ship cruise. In order to improve the performance of FSINS based on our present inertial sensors, the spin technology was proposed in the system to mitigate the navigation errors and a prototype of the proposed system was developed in Navigation Lab. The prototype contains the IMU, temperature controller, rotating configuration, navigation and I/O electronics group, control and display, power supply subsystem and other modules. In the proposed spin technology, the IMU is rotated back and forth in azimuth through four orthogonal positions relative to the ship's longitudinal axis. Experimental testing was conducted for the prototype in the laboratory and the results showed that the RFSINS's navigation performance is improved 10 times.

Sun, Wei; Sun, Feng; Wang, Da-xue

2013-10-01

58

High-precision optical and microwave signal synthesis and distribution  

E-print Network

In this thesis, techniques for high-precision synthesis of optical and microwave signals and their distribution to remote locations are presented. The first topic is ultrafast optical pulse synthesis by coherent superposition ...

Kim, Jung-Won, 1976-

2007-01-01

59

High precision defocused observations of planetary transits  

NASA Astrophysics Data System (ADS)

It is only possible to measure physical properties of extrasolar planets, if they transit their host stars. One can determine the masses and the radii of this kind of objects, and hence, have constraints on their chemical composition, internal structure, formation and evolution. The availability of high quality light curves of planetary transits is essential in determining these properties within a few percent. In order to obtain high-quality transit light curves, we apply the well-established defocus technique on meter and sub-meter class telescopes in our project. This technique allows longer integration times, and hence collecting more photons to build up a higher S/N ratio. In this study, we present our first photometric results with the 1m Turkish telescope (T100) located at TÜB?TAK National Observatory (TUG) of Turkey, which proved to be a well suited instrument to these observations with its large field of view. %

Ba?türk, Ö.; Hinse, T. C.; Özavc?, ?.; Tezcan, C. T.; ?enavc?, H. V.; Burdanov, A.; Y&örüko?lu, O.; Orhan, R.; Selam, S. O.

2014-03-01

60

System and method for high precision isotope ratio destructive analysis  

DOEpatents

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

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

2013-07-02

61

High precision mass measurements for wine metabolomics  

NASA Astrophysics Data System (ADS)

An overview of the critical steps for the non-targeted Ultra-High Performance Liquid Chromatography coupled with Quadrupole Time-of-Flight Mass Spectrometry (UPLC-Q-ToF-MS) analysis of wine chemistry is given, ranging from the study design, data preprocessing and statistical analyses, to markers identification. UPLC-Q-ToF-MS data was enhanced by the alignment of exact mass data from FTICR-MS, and marker peaks were identified using UPLC-Q-ToF-MS². In combination with multivariate statistical tools and the annotation of peaks with metabolites from relevant databases, this analytical process provides a fine description of the chemical complexity of wines, as exemplified in the case of red (Pinot noir) and white (Chardonnay) wines from various geographic origins in Burgundy.

Roullier-Gall, Chloé; Witting, Michael; Gougeon, Régis; Schmitt-Kopplin, Philippe

2014-11-01

62

A Comparison of three high-precision quadrature schemes  

SciTech Connect

The authors have implemented three numerical quadrature schemes, using the new Arbitrary Precision (ARPREC) software package, with the objective of seeking a completely ''automatic'' arbitrary precision quadrature facility, namely one that does not rely on a priori information of the function to be integrated. Such a facility is required, for example, to permit the experimental identification of definite integrals based on their numerical values. The performance and accuracy of these three quadrature schemes are compared using a suite of 15 integrals, ranging from continuous, well-behaved functions on finite intervals to functions with vertical derivatives and integrable singularities at endpoints, as well as several integrals on an infinite interval.

Bailey, David H.; Li, Xiaoye S.

2003-07-01

63

Scalable knowledge harvesting with high precision and high recall  

Microsoft Academic Search

Harvesting relational facts from Web sources has received great attention for automatically constructing large knowledge bases. Stateof-the-art approaches combine pattern-based gathering of fact candidates with constraint-based reasoning. However, they still face major challenges regarding the trade-offs between precision, recall, and scalability. Techniques that scale well are susceptible to noisy patterns that degrade precision, while techniques that employ deep reasoning for

Ndapandula Nakashole; Martin Theobald; Gerhard Weikum

2011-01-01

64

High precision spectroscopy and imaging in THz frequency range  

NASA Astrophysics Data System (ADS)

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

Vaks, Vladimir L.

2014-03-01

65

Computer-controlled high-precision Michelson wavemeter  

NASA Astrophysics Data System (ADS)

The Michelson wavemeter is a popular instrument in many experiments where the high-precision measurement of a cw laser wavelength is required. In this paper, we describe a simple and inexpensive way to obtain high-precision measurements with this classical physicist's tool. We exploit the time stamp provided by the high-frequency clock present in modern data acquisition cards to measure the fractional uncertainty of the interference signal. The resulting relative uncertainty value for our current set-up is of the order of 10-8 and can be potentially improved by a factor of 100.

Pedregosa-Gutierrez, J.; Guyomarc'h, D.; Vedel, M.; Champenois, C.; Knoop, M.

2014-09-01

66

An experimental assembly for precise measurement of thermal accommodation coefficients  

NASA Astrophysics Data System (ADS)

An experimental apparatus has been developed to determine thermal accommodation coefficients for a variety of gas-surface combinations. Results are obtained primarily through measurement of the pressure dependence of the conductive heat flux between parallel plates separated by a gas-filled gap. Measured heat-flux data are used in a formula based on Direct Simulation Monte Carlo (DSMC) simulations to determine the coefficients. The assembly also features a complementary capability for measuring the variation in gas density between the plates using electron-beam fluorescence. Surface materials examined include 304 stainless steel, gold, aluminum, platinum, silicon, silicon nitride, and polysilicon. Effects of gas composition, surface roughness, and surface contamination have been investigated with this system; the behavior of gas mixtures has also been explored. Without special cleaning procedures, thermal accommodation coefficients for most materials and surface finishes were determined to be near 0.95, 0.85, and 0.45 for argon, nitrogen, and helium, respectively. Surface cleaning by in situ argon-plasma treatment reduced coefficient values by up to 0.10 for helium and by ˜0.05 for nitrogen and argon. Results for both single-species and gas-mixture experiments compare favorably to DSMC simulations.

Trott, Wayne M.; Castañeda, Jaime N.; Torczynski, John R.; Gallis, Michael A.; Rader, Daniel J.

2011-03-01

67

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

NASA Astrophysics Data System (ADS)

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

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

2014-09-01

68

High-precision thermal and electrical characterization of thermoelectric modules  

SciTech Connect

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

Kolodner, Paul [Bell Laboratories, Alcatel-Lucent, Inc., Murray Hill, New Jersey 07974 (United States)] [Bell Laboratories, Alcatel-Lucent, Inc., Murray Hill, New Jersey 07974 (United States)

2014-05-15

69

Faculty Position in Ultra High Precision Robotics & Manufacturing  

E-print Network

, actuators, transmission systems, sensors and methods targeting ultra-high precision additive manufacturing links to the diverse and well-established local high-technology industry. As a faculty member a curriculum vitae with a list of publications, a concise statement of research and teaching interests

Candea, George

70

Testing a collision avoidance display with high-precision navigation  

NASA Astrophysics Data System (ADS)

Recent years have seen a rise in sophisticated navigational positioning techniques. Starting from classical GPS, differential GPS, ground-based augmentation, and raw data submission have opened possibilities for high precision lateral positioning for beyond what was thinkable before. This yields new perspectives for technologies like ACAS/TCAS, by enabling last-minute lateral avoidance as a supplement to the established vertical avoidance maneuvers. Working together with Ohio University's Avionics Department, DLR has developed and tested a set of displays for situational awareness and lateral last-minute avoidance in a collision situation, implementing some state-of-the art ideas in collision avoidance. The displays include the possibility to foresee the hazard zone of a possible intruder and thus avoid that zone early. The displays were integrated into Ohio University's experimental airplane, and a flight experiment was conducted to make a first evaluation of the applicability. The tests were carried out in fall 2012. We will present the principal architecture of the displays and detail the implementation into the flight carrier. Furthermore, we will give first results of the displays' performance.

Peinecke, Niklas; Uijt de Haag, Maarten; Meysel, Frederik; Duan, Pengfei; Küppers, Rene; Beernink, Bram

2013-06-01

71

High precision patterning of ITO using femtosecond laser annealing process  

NASA Astrophysics Data System (ADS)

High precision patterning of crystalline indium tin oxide (c-ITO) patterns on amorphous ITO (a-ITO) thin films by femtosecond laser-induced crystallization with a Gaussian beam profile followed by chemical etching is demonstrated. In the proposed approach, the a-ITO thin film is selectively transformed into a c-ITO structure via a low heat affect zone and the well-defined thresholds (ablation and crystallization) supplied by the femtosecond laser pulse. The experimental results show that by careful control of the laser fluence above the crystallization threshold, c-ITO patterns with controllable line widths and ridge-free characteristics can be accomplished. By careful control of the laser fluence above the ablation threshold, fast fabrication of the two parallel sub-micro c-ITO line patterns using a single femtosecond laser beam and single scanning path can be achieved. Along-length sub-micro c-ITO line pattern is fabricated, and the feasibility of fabricating c-ITO patterns is confirmed, which are expected to be used in micro-electronics devices.

Cheng, Chung-Wei; Lin, Cen-Ying

2014-09-01

72

High precision framework for Chaos Many-Body Engine  

E-print Network

In this paper we present a C# 4.0 high precision framework for simulation of relativistic many-body systems. In order to benefit from, previously developed, chaos analysis instruments, all new modules were designed to be integrated with Chaos Many-Body Engine [1,3]. As a direct application, we used 46 digits precision for analyzing the Butterfly Effect of the gravitational force in a specific relativistic nuclear collision toy-model. Trying to investigate the average Lyapunov Exponent dependency on the incident momentum, an interesting case of intermittency was noticed. Based on the same framework, other high-precision simulations are currently in progress (e.g. study on the possibility of considering, hard to detect, extremely low frequency photons as one of the dark matter components).

I. V. Grossu; C. Besliu; D. Felea; Al. Jipa

2013-12-15

73

Method of high precision interval measurement in pulse laser ranging system  

NASA Astrophysics Data System (ADS)

Laser ranging is suitable for laser system, for it has the advantage of high measuring precision, fast measuring speed,no cooperative targets and strong resistance to electromagnetic interference,the measuremen of laser ranging is the key paremeters affecting the performance of the whole system.The precision of the pulsed laser ranging system was decided by the precision of the time interval measurement, the principle structure of laser ranging system was introduced, and a method of high precision time interval measurement in pulse laser ranging system was established in this paper.Based on the analysis of the factors which affected the precision of range measure,the pulse rising edges discriminator was adopted to produce timing mark for the start-stop time discrimination,and the TDC-GP2 high precision interval measurement system based on TMS320F2812 DSP was designed to improve the measurement precision.Experimental results indicate that the time interval measurement method in this paper can obtain higher range accuracy. Compared with the traditional time interval measurement system,the method simplifies the system design and reduce the influence of bad weather conditions,furthermore,it satisfies the requirements of low costs and miniaturization.

Wang, Zhen; Lv, Xin-yuan; Mao, Jin-jin; Liu, Wei; Yang, Dong

2013-09-01

74

A High-Precision NDIR Gas Sensor for Automotive Applications  

Microsoft Academic Search

A new high-precision spectroscopic gas sensor measuring carbon dioxide (CO2) for harsh environmental conditions of automotive applications is presented. The carbon dioxide concentration is the primary parameter for sensing in cabin air quality, as well as an important safety parameter when R744 (carbon dioxide) is used as the refrigerant in the air conditioning system. The automotive environment challenges the potential

Robert Frodl; Thomas Tille

2006-01-01

75

An NIR laser frequency comb for high precision Doppler  

E-print Network

An NIR laser frequency comb for high precision Doppler planet surveys Steve Osterman Center (CU) Jian Ge (UF) UF Steve Osterman NIR laser frequency comb BDEP 20 July 2009 + #12;Overview Why look/NIST/UF LFC Program Where can we go with this? Steve Osterman NIR laser frequency comb BDEP 20 July 2009 #12

Colorado at Boulder, University of

76

A Cooperative Metabolic Syndrome Estimation With High Precision Sensing Unit  

Microsoft Academic Search

In this letter, we discuss a sensor-integrated system model for metabolic syndrome prediction with workflow system. This model measures not only a cell temperature variation using invasive method but also controlling simulation for metabolic syn- drome prediction. To identify the system realization, we discuss the schemes for predicting metabolic syndrome from measure- ment of mitochondrial activity by using high precision

Chan-Hyun Youn; Eun Bo Shim; Soo Lim; Young Min Cho; Hyuck Ki Hong; Yeon Shik Choi; Hyo-Derk Park; Hong Kyu Lee

2011-01-01

77

High precision module for Chaos Many-Body Engine  

E-print Network

In this paper we present a C# high precision relativistic many-body module integrated with Chaos Many-Body Engine. As a direct application, we used it for estimating the butterfly effect involved by the gravitational force in a specific nuclear relativistic collision toy-model.

Grossu, I V; Felea, D; Jipa, Al

2014-01-01

78

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

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

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

79

High Precision Differential Photometry with CCDs: A Brief History  

Microsoft Academic Search

I present a brief history of the hunt for high photometric precision using CCDs in astronomy. CCDs were invented in 1969 and only 7 years later they started to appear at the major observatories of the time. The next 10 years constituted a steep learning curve for astronomers as they developed an understanding of CCDs as instruments and analysis techniques

Steve B. Howell

2011-01-01

80

PRECISION CONTROL OF LINEAR MOTOR DRIVEN HIGH-SPEED/ACCELERATION  

E-print Network

PRECISION CONTROL OF LINEAR MOTOR DRIVEN HIGH-SPEED/ACCELERATION ELECTRO-MECHANICAL SYSTEMS Bin Yao, IN47907 byao@purdue.edu http://widget.ecn.purdue.edu/~byao #12;LINEAR MOTOR POSITIONING STAGE #12 resolution, measurement noise, calculation time, and frame stiffness LINEAR MOTOR DRIVE SYSTEMSLINEAR MOTOR

Yao, Bin

81

Calibration of the TWIST high-precision drift chambers  

E-print Network

A method for the precise measurement of drift times for the high-precision drift chambers used in the TWIST detector is described. It is based on the iterative correction of the space-time relationships by the time residuals of the track fit, resulting in a measurement of the effective drift times. The corrected drift time maps are parametrised individually for each chamber using spline functions. Biases introduced by the reconstruction itself are taken into account as well, making it necessary to apply the procedure to both data and simulation. The described calibration is shown to improve the reconstruction performance and to extend significantly the physics reach of the experiment.

A. Grossheim; J. Hu; A. Olin

2010-08-30

82

Yale High Energy Physics Research: Precision Studies of Reactor Antineutrinos  

SciTech Connect

This reports presents experimental research at the intensity frontier of particle physics with particular focus on the study of reactor antineutrinos and the precision measurement of neutrino oscillations. The experimental neutrino physics group of Professor Heeger and Senior Scientist Band at Yale University has had leading responsibilities in the construction and operation of the Daya Bay Reactor Antineutrino Experiment and made critical contributions to the discovery of non-zero$\\theta_{13}$. Heeger and Band led the Daya Bay detector management team and are now overseeing the operations of the antineutrino detectors. Postdoctoral researchers and students in this group have made leading contributions to the Daya Bay analysis including the prediction of the reactor antineutrino flux and spectrum, the analysis of the oscillation signal, and the precision determination of the target mass yielding unprecedented precision in the relative detector uncertainty. Heeger's group is now leading an R\\&D effort towards a short-baseline oscillation experiment, called PROSPECT, at a US research reactor and the development of antineutrino detectors with advanced background discrimination.

Heeger, Karsten M [Yale University

2014-09-13

83

High Precision Spectroscopy of CH_5^+ Using Nice-Ohvms  

NASA Astrophysics Data System (ADS)

The elusive methonium ion, CH_5^+, is of great interest due to its highly fluxional nature. The only published high-resolution infrared spectrum remains completely unassigned to this date. The primary challenge in understanding the CH_5^+ spectrum is that traditional spectroscopic approaches rely on a molecule having only small (or even large) amplitude motions about a well-defined reference geometry, and this is not the case with CH_5^+. We are in the process of re-scanning Oka's spectrum, in the original Black Widow discharge cell, using the new technique of Noise Immune Cavity Enhanced Optical Heterodyne Velocity Modulation Spectroscopy (NICE-OHVMS). The high precision afforded by optical saturation in conjunction with a frequency comb allows transition line centers to be determined with sub-MHz accuracy and precision -- a substantial improvement over the 90 MHz precision of Oka's work. With a high-precision linelist in hand, we plan to search for four line combination differences to directly determine the spacings between rotational energy levels. Such a search is currently infeasible due to the large number of false positives resulting from the relatively low precision and high spectral density of Oka's spectrum. The resulting combination differences, in conjunction with state-of-the-art theoretical calculations from Tucker Carrington, may provide the first insight into the rotational structure of this unique molecular system. E. T. White, J. Tang, T. Oka, Science (1999) 284, 135--137. B. M. Siller, et al. Opt. Express (2011), 19, 24822--24827. K. N. Crabtree, et al. Chem. Phys. Lett. (2012), 551, 1--6. X. Wang, T. Carrington, J. Chem. Phys., (2008), 129, 234102.

Hodges, James N.; Perry, Adam J.; McCall, Benjamin J.

2013-06-01

84

High-precision absolute coordinate measurement using frequency scanned interferometry  

NASA Astrophysics Data System (ADS)

We reported previously on measurements of absolute distance with frequency scanned interferometry (FSI) method [1, 2]. In this paper, we extend the FSI method into 2-dimensional and 3-dimensional high-precision absolute coordinate measurements using a single laser. Absolute position is determined by several related absolute distances measured simultaneously. The achieved precision on X and Y in 2- and in 3-dimensional measurements is confirmed to be below 1 ?m, while the precision in Z (in 3D case) is found to be about 2 ?m. The last one is limited by the accuracy of the available translational stage used in the tests. A much more powerful laser and a better real-time data acquirement system will be required in case of measurements of larger absolute distances.

Tian-Xiang, C.; Hai-Jun, Y.; Cheng, L.

2014-03-01

85

High precision calibration for 2D optical standard  

NASA Astrophysics Data System (ADS)

Photomask is a kind of 2-D optical standard with etched orthogonal coordinates made of a glass substrate chrominged or filmed with other metal. In order to solve the problems of measurement and traceability of ultra precision photomasks used in advanced manufacturing industry, 2-D photomask optical standard was calibrated in high precision laser two coordinate standard device. A high precision differential laser interferometer system was used for a length standard, a high magnification optical micro vision system was used for precision optical positioning feedback. In this paper, a image measurement model was purposed; A sampling window auto identification algorithm was designed. Grid stripe image could be identified and aimed at automatically by this algorithm. An edge detection method based on bidirection progressive scanning and 3-sigma rule for eliminating outliers in sampling window was found. Dirty point could be removed with effect. Edge detection error could be lowered. By this means, the measurement uncertainty of 2-D optical standard's ruling span was less than 0.3 micrometer (k=2).

Sun, Shuanghua; Gan, Xiaochuan; Xue, Zi; Ye, Xiaoyou; Wang, Heyan; Gao, Hongtang

2012-10-01

86

High Efficiency Positron Accumulation for High-Precision Measurements  

E-print Network

Positrons are accumulated within a Penning trap designed to make more precise measurements of the positron and electron magnetic moments. The retractable radioactive source used is weak enough to require no license for handling radioactive material and the radiation dosage one meter from the source gives an exposure several times smaller than the average radiation dose on the earth's surface. The 100 mK trap is mechanically aligned with the 4.2 K superconducting solenoid that produces a 6 tesla magnetic trapping field with a direct mechanical coupling.

Hoogerheide, S Fogwell; Novitski, E; Gabrielse, G

2015-01-01

87

Recent Precision Experiments with Exotic Nuclei Produced with Uranium Projectiles and Experimental Prospects at Fair  

NASA Astrophysics Data System (ADS)

Precision experiments with relativistic fragments separated in-flight require special experimentalmethods to overcome the inherent large emittance from the creation in nuclear reactions and atomic interactions in matter. At GSI relativistic exotic nuclei have been produced via uranium projectile fragmentation and fission and investigated with the inflight separator FRS directly, or in combination with either the storage-cooler ring ESR or the FRS Ion Catcher. 1000 A·MeV 238U ions were used to create 60 new neutron-rich isotopes separated and identified with the FRS to measure their production cross sections. In another experimental campaign the fragments were separated in flight and injected into the storage-cooler ring ESR for accurate mass and lifetime measurements. In these experimentswe have obtained accurate new mass values analyzed via a novel method which has reduced the systematic errors for both Schottky Mass Spectrometry (SMS) and for Isochronous Mass Spectrometry (IMS). Pioneering experiments have been carried out with the FRS Ion Catcher consisting of three experimental components, the dispersive magnetic system of the FRS with a monoenergetic and a homogeneous degrader, a cryogenic stopping cell filled with pure helium and a multiple-reflection time-of flight mass separator. The FRS Ion Catcher enables high precision spectroscopy experiments with eV to keV exotic nuclides. Results from these different FRS experiments are presented in this overview together with prospects for the next-generation facility Super-FRS. The novel features of the Super-FRS compared with the present FRS will be discussed in addition.

Geissel, H.; Chen, L.; Dickel, T.; Farinon, F.; Dillmann, I.; Knöbel, R.; Kurcewicz, J.; Mukha, I.; Münzenberg, G.; Nociforo, C.; Patyk, Z.; Pietri, S.; Plass, W. R.; Prochazka, A.; Scheidenberger, C.; Takechi, M.; Weick, H.; Winfield, J. S.; Winkler, M.

2014-03-01

88

Calorimeters for Precision Timing Measurements in High Energy Physics  

NASA Astrophysics Data System (ADS)

Current and future high energy physics particle colliders are capable to provide instantaneous luminosities of 1034 cm-2s-1 and above. The high center of mass energy, the large number of simultaneous collision of beam particles in the experiments and the very high repetition rates of the collision events pose huge challenges. They result in extremely high particle fluxes, causing very high occupancies in the particle physics detectors operating at these machines. To reconstruct the physics events, the detectors have to make as much information as possible available on the final state particles. We discuss how timing information with a precision of around 10 ps and below can aid the reconstruction of the physics events under such challenging conditions. High energy photons play a crucial role in this context. About one third of the particle flux originating from high energy hadron collisions is detected as photons, stemming from the decays of neutral mesons. In addition, many key physics signatures under study are identified by high energy photons in the final state. They pose a particular challenge in that they can only be detected once they convert in the detector material. The particular challenge in measuring the time of arrival of a high energy photon lies in the stochastic component of the distance to the initial conversion and the size of the electromagnetic shower. They extend spatially over distances which propagation times of the initial photon and the subsequent electromagnetic shower which are large compared to the desired precision. We present studies and measurements from test beams and a cosmic muon test stand for calorimeter based timing measurements to explore the ultimate timing precision achievable for high energy photons of 10 GeV and above. We put particular focus on techniques to measure the timing with a precision of about 10 ps in association with the energy of the photon. For calorimeters utilizing scintillating materials and light guiding components, the propagation speed of the scintillation light in the calorimeter is important. We present studies and measurements of the propagation speed on a range of detector geometries. Finally, possible applications of precision timing in future high energy physics experiments are discussed.

Bornheim, Adolf; Apresyan, Artur; Duarte, Javier; Pena, Cristian; Ronzhin, Anatoly; Spiropulu, Maria; Xie, Si

2015-02-01

89

Highly Precise Measurements of Oxygen and Carbon Dioxide  

NASA Astrophysics Data System (ADS)

Highly-precise oxygen measurements have been used to constrain the carbon budget, study terrestrial photosynthesis and respiration, and estimate marine productivity. Measurements of the O2/N2 ratio have become more routine and have been recently used to detect strong increases in phytoplankton abundance (spring bloom), track seasonal changes in atmospheric potential oxygen, and prescribe individual pollution events to their point of origin. In most of these studies, O2/N2 ratios were measured with a 1? precision of ± 1.4 to ± 14 per meg (~ 0.3 - 3 ppm) in a measurement time of 10 - 20 minutes, and such high precision was required to discern typical oxygen concentrations changes of 20 ppm that occurred over several hours. In this work, we utilize near-infrared cavity-enhanced laser absorption spectroscopy (Off-Axis ICOS) to quantify ambient oxygen with a precision (1?, 100s) of ±7 ppm. By periodically calibrating the instrument, the analyzer is capable of making oxygen measurements to better than ±1 ppm (1?). The analyzer is highly linear (R2 > 0.9999) over a wide dynamic range (0 - 100 % oxygen). The sensor was combined with a commercial CO2/CH4/H2O Analyzer, and used to make measurements of respiration and fossil fuel pollution events with oxidative ratios ranging from 1.15 - 1.60. Future improvements will increase the analyzer precision to better than ±1.4 ppm (1?, 100s), and decrease the periodic referencing interval to > 1 hour. Measurements of ?(O2/N2 ) versus CO2 for a constant gas source, laboratory air, and outdoor air in an urban environment during two different time periods. The slope of these lines can be used to determine the oxidative ratio and help identify CO2 sources.

Gupta, M.

2012-12-01

90

Dynamic evaluation system for interpolation errors in the encoder of high precision  

NASA Astrophysics Data System (ADS)

In order to measure dynamic interpolation errors of photoelectric encoder of high precision, the dynamic evaluation system of interpolation errors is introduced. Firstly, the fine Moiré signal of encoder which is collected with the high-speed data gathering card into the computer is treated to equiangular data with the method of linear interpolation. Then, the analysis of harmonic wave with the FFT is processed. Compared with the standard signal, the dynamic interpolation errors of the encoder are calculated. Experimental results show that the precision of the dynamic evaluation system of interpolation errors is +/-0.1 %( pitch). The evaluation system is simple, fast, high precision, and can be used in the working field of the encoder.

Wan, Qiu-hua; Wu, Yong-zhi; Zhao, Chang-hai; Liang, Li-hui; Sun, Ying; Jiang, Yong

2009-05-01

91

Laser processing system development of large area and high precision  

NASA Astrophysics Data System (ADS)

As industry of PCB (Printed Circuit Board) and display growing, this industry requires an increasingly high-precision quality so current cutting process in industry is preferred laser machining than mechanical machining. Now, laser machining is used almost "step and repeat" method in large area, but this method has a problem such as cutting quality in the continuity of edge parts, cutting speed and low productivity. To solve these problems in large area, on-the-fly (stagescanner synchronized system) is gradually increasing. On-the-fly technology is able to process large area with high speed because of stage-scanner synchronized moving. We designed laser-based high precision system with on-the-fly. In this system, we used UV nano-second pulse laser, power controller and scanner with telecentric f-theta lens. The power controller is consisted of HWP(Half Wave Plate), thin film plate polarizer, photo diode, micro step motor and control board. Laser power is possible to monitor real-time and adjust precision power by using power controller. Using this machine, we tested cutting of large area coverlay and sheet type large area PCB by applying on-the-fly. As a result, our developed machine is possible to process large area without the problem of the continuity of edge parts and by high cutting speed than competitor about coverlay.

Park, Hyeongchan; Ryu, Kwanghyun; Hwang, Taesang

2013-03-01

92

A Network of Extremely High Precision Extrasolar Planet Tracker Instruments  

NASA Astrophysics Data System (ADS)

We present a plan to build a network of extremely high precision Doppler instruments based on a dispersed fixed-delay interferometer to hunt for super-Earth mass planets around nearby solar type stars. This kind of instrument is called EXtremely Precision ExtrasolaR planet Tracker (EXPERT). It consists of a thermally compensated monolithic interferometer and a high throughput cross-dispersed echelle spectrograph with a spectral resolution of R=18,000. The wavelength range is between 0.39-0.7 µm and is completely covered by a 4Kx4K CCD detector. This allows us to reach 0.5-1 m/s Doppler precision for a V=8 solar type star in a 15 min exposure with a 2m class telescope. The plan is to build three identical instruments and place one in the US, one in China and one in Spain to form an initial EXPERT network. The first one will be ready for commissioning at a 2m telescope in the US in the spring of 2009. The second one will be ready for commissioning on a Chinese 2.4m telescope in the summer of 2009. The third one may be ready for commissioning at a Spanish telescope in late 2009 or 2010 depending on funding availability. In the lab, we have reached 0.4 m/s Doppler precision with a monolithic interferometer and a bright light source. The same kind of interferometer has been installed in the Multi-object APO Radial Velocity Exoplanet Large-area Survey (MARVELS) instrument and has provided 2 m/s precision with bright calibration sources using only 600 Angstroms wavelength coverage and R=10,000. Project progress will be presented.

Chang, Liang; Ge, J.; Wan, X.; Zhao, B.; Groot, J.; Jiang, P.; Fleming, S.; Lee, B.; Mahadevan, S.; Hanna, K.; Hearty, F.

2009-01-01

93

Flight Test Performance of a High Precision Navigation Doppler Lidar  

NASA Technical Reports Server (NTRS)

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

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

2009-01-01

94

Strategy for Realizing High-Precision VUV Spectro-Polarimeter  

NASA Astrophysics Data System (ADS)

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

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

2014-12-01

95

A high precision micropositioner based on magnetostriction principle  

NASA Astrophysics Data System (ADS)

A novel two degree-of-freedom precision micro-positioner has been designed and built using Terfenol-D magnetostrictive material. The device consists of a group of Terfenol-D rods which have been linked together to form a rigid, prism-shaped body. When the coils wrapped around the Terfenol-D rods are supplied with electrical current, the magnetic fields produced will cause the rods to strain, inducing a displacement at the end point. Controlling the electrical currents supplied to the coils allows very precise movements to be obtained. Another degree of freedom can easily be added to make the device capable of precise motions anywhere within a volume. The device discussed here fits into a 3 in. by 3 in. by 1.5 in. space, and is capable of addressing a 100 ?m by 100 ?m workspace with a maximum current of 1.5 A applied. The open-loop repeatability of the device is 50 nm over the workspace. With the implementation of a simple closed-loop controller, the accuracy of the device is limited by that of the sensing system, and the resolutions of the 12 bit A/D and D/A boards used. Much higher resolution can be expected if 14 bits or 16 bits A/D and D/A boards are used. Potentially the device can be used for high precision microprobing, cellular biology, microsurgery, and industrial work in the micromechanical area.

Wang, Wanjun; Busch-Vishniac, Ilene

1992-01-01

96

Highly precise and compact ultrahigh vacuum rotary feedthrough  

NASA Astrophysics Data System (ADS)

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

Aiura, Y.; Kitano, K.

2012-03-01

97

Highly precise and compact ultrahigh vacuum rotary feedthrough.  

PubMed

The precision and rigidity of compact ultrahigh vacuum (UHV) rotary feedthroughs were substantially improved by preparing and installing an optimal crossed roller bearing with mounting holes. Since there are mounting holes on both the outer and inner races, the bearing can be mounted directly to rotary and stationary stages without any fixing plates and housing. As a result, it is possible to increase the thickness of the bearing or the size of the rolling elements in the bearing without increasing the distance between the rotating and fixing International Conflat flanges of the UHV rotary feedthrough. Larger rolling elements enhance the rigidity of the UHV rotary feedthrough. Moreover, owing to the structure having integrated inner and outer races and mounting holes, the performance is almost entirely unaffected by the installation of the bearing, allowing for a precise optical encoder to be installed in the compact UHV rotary feedthrough. Using position feedback via a worm gear system driven by a stepper motor and a precise rotary encoder, the actual angle of the compact UHV rotary feedthrough can be controlled with extremely high precision. PMID:22462959

Aiura, Y; Kitano, K

2012-03-01

98

High Precision Differential Photometry with CCDs: A Brief History  

Microsoft Academic Search

\\u000a I present a brief history of the hunt for high photometric precision using CCDs in astronomy. CCDs were invented in 1969 and\\u000a only 7?years later they started to appear at the major observatories of the time. The next 10?years constituted a steep learning\\u000a curve for astronomers as they developed an understanding of CCDs as instruments and analysis techniques for use

Steve B. Howell

99

Calibrated Precision Matrix Estimation for High-Dimensional Elliptical Distributions  

PubMed Central

We propose a semiparametric method for estimating a precision matrix of high-dimensional elliptical distributions. Unlike most existing methods, our method naturally handles heavy tailness and conducts parameter estimation under a calibration framework, thus achieves improved theoretical rates of convergence and finite sample performance on heavy-tail applications. We further demonstrate the performance of the proposed method using thorough numerical experiments. PMID:25632164

Zhao, Tuo; Liu, Han

2014-01-01

100

High-Precision Direct Method for the Radiative Transfer Problems  

NASA Astrophysics Data System (ADS)

It is the main aim of this paper to investigate the numerical methods of the radiative transfer equation. Using the five-point formula to approximate the differential part and the Simpson formula to substitute for integral part respectively, a new high-precision numerical scheme, which has 4-order local truncation error, is obtained. Subsequently, a numerical example for radiative transfer equation is carried out, and the calculation results show that the new numerical scheme is more accurate.

Zhang, Yan; Hou, Su-Qing; Yang, Ping; Wu, Kai-Su

2013-06-01

101

High-Precision Floating-Point Arithmetic in ScientificComputation  

SciTech Connect

At the present time, IEEE 64-bit floating-point arithmetic is sufficiently accurate for most scientific applications. However, for a rapidly growing body of important scientific computing applications, a higher level of numeric precision is required: some of these applications require roughly twice this level; others require four times; while still others require hundreds or more digits to obtain numerically meaningful results. Such calculations have been facilitated by new high-precision software packages that include high-level language translation modules to minimize the conversion effort. These activities have yielded a number of interesting new scientific results in fields as diverse as quantum theory, climate modeling and experimental mathematics, a few of which are described in this article. Such developments suggest that in the future, the numeric precision used for a scientific computation may be as important to the program design as are the algorithms and data structures.

Bailey, David H.

2004-12-31

102

Testing of a high performance, precision-bore railgun  

NASA Astrophysics Data System (ADS)

Design features and diagnostic data are presented for a high pressure railgun, with emphasis on the effects of using high precision rails. The device featured a hoop-wound fiberglass/epoxy barrel with the rail held in place by the pressure exerted by a four-piece bolted steel sleave on the exterior of the barrel. A relatively large rail cross section was employed which tended to shear off at the interface with the barrel as the test firing continued and rail deflection occurred. Test firing showed that a finely-honed rail assembly consistently yielded higher muzzle velocities of the projectile and inhibited the occurrence of restrikes behind the projectile.

Peterson, D. R.; Weeks, D. A.; Zowarka, R. C., Jr.; Cook, R. W.; Weldon, W. F.

1986-11-01

103

Modular Gravitational Reference Sensor for High Precision Astronomical Space Missions  

NASA Astrophysics Data System (ADS)

We review the progress in developing the Modular Gravitational Reference Sensor (modular GRS) [1], which was first proposed as a simplified core sensor for space gravitational wave detection missions. In a modular GRS, laser beam from the remote the sensor does not illuminate the proof mass directly. The internal measurement from housing to proof mass is separated from the external interferometry. A double side grating may further simplify the structure and may better preserve the measurement precision. We review the recent progress in developing modular GRS at Stanford. We have further studied optical sensing design that combines advantage of high precision interferometric measurement and robust optical shadow sensing scheme. We have made critical progress in optical measurement of the center of mass position of a spherical proof mass at a precision without costing the dynamic range while spinning. We have successfully demonstrated the feasibility of fabricating localized grating pattern onto the dielectric and gold materials. We have conducted an initial experiment of rf heterodyne of cavity reflection and thus lowered optical power than that in the direct detection. We have further studied UV LED that will be used for AC charge management experiment. The modular GRS will be an in-time, cost effective product for the advanced Laser Interferometric Space Antenna (LISA) and the Big Bang Observatory (BBO). [1] K. Sun, G. Allen, S. Buchman, D. DeBra, and R. L. Byer, “Advanced Architecture for High Precision Space Laser Interferometers”, 5th International LISA Symposium, ESTEC, Noordwijk, The Netherlands, 12-16 July 2004. Class. Quantum Grav. 22 (2005) S287-S296.

Sun, Ke-Xun; Allen, G.; Buchman, S.; Byer, R. L.; Conklin, J. W.; DeBra, D. B.; Gill, D.; Goh, A.; Higuchi, S.; Lu, P.; Robertson, N.; Swank, A.

2006-12-01

104

High Precision Oxygen Measurements as a Tool for CCS Monitoring  

NASA Astrophysics Data System (ADS)

CO2 emissions from below ground carbon storage reservoirs can be difficult to discriminate from CO2 produced via natural plant and microbial respiration. However, because respiration produces CO2 and consumes O2 in an approximately 1:1 ratio, it is possible to characterize leakage sources by measurement of simultaneous changes of both O2 and CO2. This approach is complicated by the fact that O2 comprises approximately 21% of the atmosphere, while CO2 is only present in the background atmosphere at ~400 parts per million, making it necessary to accurately measure changes in O2 concentration to six significant figures. Here we describe a portable high precision oxygen measurement system that employs a modified commercial fuel cell analyzer to quantify small changes in O2 concentration. High precision is achieved through precise control of flow and pressure, allowing near part per million precision of O2 and CO2 concentrations. This system has been incorporated into a mobile laboratory and has been deployed to the ZERT controlled release site in Bozeman, Montana and to a natural analog CO2 leak at Soda Springs, Idaho. Samples were collected at ground level, 1 meter, and 3 meters above the CO2 source and are displayed as the ratio of the O2 difference relative to a reference to the CO2 difference in concentration relative to the same reference (?O2/?CO2). It was observed that at wind speeds ? 2 m/s, the ?O2/?CO2 anomaly decreased with height and was still significantly different from background at 3 m. With increasing wind speed, ?O2/?CO2 anomalies decreased to background levels at 1 and 3 m but remained detectable at the ground surface. We will discuss attempts to quantify the CO2 release rate utilizing the measured ?O2/?CO2 elevation profiles and will present complementary eddy covariance data for comparison.

Trugman, A. T.; Dvonch, C.; Clegg, S. M.; Rahn, T.

2011-12-01

105

High Precision U/Th Dating of First Polynesian Settlement  

PubMed Central

Previous studies document Nukuleka in the Kingdom of Tonga as a founder colony for first settlement of Polynesia by Lapita peoples. A limited number of radiocarbon dates are one line of evidence supporting this claim, but they cannot precisely establish when this event occurred, nor can they afford a detailed chronology for sequent occupation. High precision U/Th dates of Acropora coral files (abraders) from Nukuleka give unprecedented resolution, identifying the founder event by 2838±8 BP and documenting site development over the ensuing 250 years. The potential for dating error due to post depositional diagenetic alteration of ancient corals at Nukuleka also is addressed through sample preparation protocols and paired dates on spatially separated samples for individual specimens. Acropora coral files are widely distributed in Lapita sites across Oceania. U/Th dating of these artifacts provides unparalleled opportunities for greater precision and insight into the speed and timing of this final chapter in human settlement of the globe. PMID:23144962

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

2012-01-01

106

Nonlinear control design for a high-precision contactless positioning system using magnetic levitation  

Microsoft Academic Search

This paper presents the implementation of a two degree-of-freedom, high-precision, magnetic-levitation-based positioning system. The apparatus employs one permanent magnet linear synchronous motor and is constructed by Quanser Inc. The paper focuses on the design and testing of a nonlinear controller required for actuating the positioning system. The controller is based on feedback linearization and output regulation. Experimental results show that

Robert Brydon Owen; Manfredi Maggiore; Jacob Apkarian

2005-01-01

107

Precise thermodynamic control of high pressure jet expansions.  

PubMed

We describe an experimental setup for supersonic jet expansions of supercritical fluids. It is characterized by well-defined thermodynamic values to allow systematic investigations of pressure and temperature effects on molecular beam parameters. The design permits stagnation temperatures T(0)=225-425 K with a thermal stability DeltaT(0)<30 mK and stagnation pressures p(0)=0.2-12 MPa that are measured with 0.05% precision. For optimum stability, gas reservoir, pressure transducer, and gauge amplifier are temperature-controlled, and a feedback loop permits active pressure stabilization using a pulseless syringe pump. With this approach stagnation pressures can be reproduced and kept constant to Deltap(0)<2.9 kPa. As a result, flow velocity and kinetic energy of molecular beams can be controlled with maximum accuracy. PMID:17672754

Christen, Wolfgang; Krause, Tim; Rademann, Klaus

2007-07-01

108

Test results of high-precision large cryogenic lens holders  

NASA Astrophysics Data System (ADS)

For the Euclid mission a Pre-Development phase is implemented to prove feasibility of individual components of the system [1]. The Near Infrared Spectrometer and Photometer (NISP) of EUCLID requires high precision large lens holders (?170 mm) at cryogenic temperatures (150K). The four lenses of the optical system are made of different materials: fused silica, CaF2, and LF5G15 that are mounted in a separate lens barrel design. Each lens has its separate mechanical interface to the lens barrel, the so called adaption ring. The performance of the lens holder design is verified by adapted test equipment and test facility including an optical metrology system. The characterization of the lens deformation and displacement (decenter, tilt) due to mechanical loads of the holder itself as well as thermally induced loads are driven by the required submicron precision range and the operational thermal condition. The surface deformation of the lens and its holder is verified by interferometric measurements, while tilt and position accuracy are measured by in-situ fibre based distance sensors. The selected distance measurement sensors have the capability to measure in a few mm range with submicron resolution in ultra high vacuum, in vibration environments and at liquid nitrogen temperatures and below. The calibration of the measurement system is of crucial importance: impacts such as temperature fluctuation, surface roughness, surface reflectivity, straylight effects, etc. on the measured distance are carefully calibrated. Inbuilt thermal expansion effects of the fibre sensors are characterized and proven with lens dummy with quasi zero CTE. The paper presents the test results and measured performance of the high precision large cryogenic lens holders attained by the metrology system. These results are presented on behalf of the EUCLID consortium.

Gal, C.; Reutlinger, A.; Boesz, A.; Leberle, T.; Mottaghibonab, A.; Eckert, P.; Dubowy, M.; Gebler, H.; Grupp, F.; Geis, N.; Bode, A.; Katterloher, R.; Bender, R.

2012-09-01

109

High Precision Measurement of Electrical Resistivity of Nickel Near the Ferromagnetic Phase Transition at High Pressure.  

NASA Astrophysics Data System (ADS)

High precision measurement of the resistance of nickel near its ferromagnetic phase transition at high pressure was done in a large volume hydrostatic cubic multi -anvil pressure cell and critical parameters were determined. A computer real time controlled measurement system was developed to measure the resistance vs temperature and pressure. A non-linear least-squares method was used to analyze the data. Experimental methods for the creation of a uniform temperature distribution in the cubic cell were developed. The optimal geometry of the thermal system under high pressure was determined by solving partial integral-differential equations. A new type of experiment for measuring pressure dependence of thermal conductivity was performed for baked and unbaked pyrophyllite. An analytical formula with a mathematical model for calculating the temperature distribution as a function of power delivered to a line source and the thermal conductivity of the surrounding medium in the cubic anvil pressure cell was derived. A mathematical model for the computer simulation of the dynamic process of a proportional-integral-differential temperature control system was created and a method was presented to determine the variable parameters in the differential equation using non-linear least-squares on experimental data.

Chen, Wei

110

Simulation of Thermal Behavior in High-Precision Measurement Instruments  

NASA Astrophysics Data System (ADS)

In this paper, a way to modularize complex finite-element models is described. The modularization is done with temperature fields that appear in high-precision measurement instruments. There, the temperature negatively impacts the achievable uncertainty of measurement. To correct for this uncertainty, the temperature must be known at every point. This cannot be achieved just by measuring temperatures at specific locations. Therefore, a numerical treatment is necessary. As the system of interest is very complex, modularization is unavoidable to obtain good numerical results.

Weis, Hanna Sophie; Augustin, Silke

2008-06-01

111

Precise measurement of magnetization characteristics in high pulsed field  

NASA Astrophysics Data System (ADS)

Permanent magnets, especially Nd-Fe-B magnets, are very important engineering elements that are widely used in many applications. The detailed design of electrical and electronic equipment using permanent magnets requires the precise measurement of magnetization characteristics. High pulsed magnetic fields can be used to measure the magnetization characteristics of permanent magnets in the easy and hard magnetization directions. Errors influencing the measurements stem from the relationship between the tested material, pick-up sensor configuration, and excitation coil. We present an analysis of the effect of the sensor construction on the accuracy of the measurements of the material's magnetic properties. We investigated the coaxial and series types sensor configurations.

Nakahata, Y.; Borkowski, B.; Shimoji, H.; Yamada, K.; Todaka, T.; Enokizono, M.

2012-04-01

112

High-precision micro/nano-scale machining system  

DOEpatents

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

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

2014-08-19

113

High-precision measurements of global stellar magnetic fields  

NASA Astrophysics Data System (ADS)

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

Plachinda, S. I.

2014-06-01

114

An Innovative Image Reconstruction Method for High-Precision Astrometry  

NASA Astrophysics Data System (ADS)

An automatic image-reconstruction method is presented, based on the use of a mathematical morphology operator. Variable structural elements along multiple directions are adopted for image convolution, and then all of the corresponding convolved images are stacked to obtain a final result. To investigate its efficiency, both simulated images and raw CCD images, produced by a trial observation using a 45-cm telescope, are tested. With this method, the influence of degradation in astrometric CCD images is reduced, and the position accuracy of background stars is distinctly improved. This method will contribute significantly to optical data reduction and high-order precision astrometry.

Sun, Rong-Yu; Zhao, Chang-Yin; Zhang, Yi-Ping

2013-10-01

115

Experimental study on the precise orbit determination of the BeiDou navigation satellite system.  

PubMed

The regional service of the Chinese BeiDou satellite navigation system is now in operation with a constellation including five Geostationary Earth Orbit satellites (GEO), five Inclined Geosynchronous Orbit (IGSO) satellites and four Medium Earth Orbit (MEO) satellites. Besides the standard positioning service with positioning accuracy of about 10 m, both precise relative positioning and precise point positioning are already demonstrated. As is well known, precise orbit and clock determination is essential in enhancing precise positioning services. To improve the satellite orbits of the BeiDou regional system, we concentrate on the impact of the tracking geometry and the involvement of MEOs, and on the effect of integer ambiguity resolution as well. About seven weeks of data collected at the BeiDou Experimental Test Service (BETS) network is employed in this experimental study. Several tracking scenarios are defined, various processing schemata are designed and carried out; and then, the estimates are compared and analyzed in detail. The results show that GEO orbits, especially the along-track component, can be significantly improved by extending the tracking network in China along longitude direction, whereas IGSOs gain more improvement if the tracking network extends in latitude. The involvement of MEOs and ambiguity-fixing also make the orbits better. PMID:23529116

He, Lina; Ge, Maorong; Wang, Jiexian; Wickert, Jens; Schuh, Harald

2013-01-01

116

Experimental demonstration of phase measurement precision beating standard quantum limit by projection measurement  

NASA Astrophysics Data System (ADS)

We propose and demonstrate experimentally a projection scheme to measure the quantum phase with a precision beating the standard quantum limit. The initial input state is a twin Fock state |N,Nrang proposed by Holland and Burnett (Phys. Rev. Lett., 71 (1993) 1355) but the phase information is extracted by a quantum state projection measurement. The phase precision is about 1.4/N for large photon number N, which approaches the Heisenberg limit of 1/N. Experimentally, we employ a four-photon state from type-II parametric down-conversion and achieve a phase uncertainty of 0.291±0.001 beating the standard quantum limit of 1/\\sqrt{N}=1/2 for four photons.

Sun, F. W.; Liu, B. H.; Gong, Y. X.; Huang, Y. F.; Ou, Z. Y.; Guo, G. C.

2008-04-01

117

High Precision Signal Processing Algorithm for White Light Interferometry  

PubMed Central

A new signal processing algorithm for absolute temperature measurement using white light interferometry has been proposed and investigated theoretically. The proposed algorithm determines the phase delay of an interferometer with very high precision (? one fringe) by identifying the zero order fringe peak of cross-correlation of two fringe scans of white light interferometer. The algorithm features cross-correlation of interferometer fringe scans, hypothesis testing and fine tuning. The hypothesis test looks for a zero order fringe peak candidate about which the cross-correlation is symmetric minimizing the uncertainty of mis-identification. Fine tuning provides the proposed algorithm with high precision sub-sample resolution phase delay estimation capability. The shot noise limited performance of the proposed algorithm has been analyzed using computer simulations. Root-mean-square (RMS) phase error of the estimated zero order fringe peak has been calculated for the changes of three different parameters (SNR, fringe scan sample rate, coherence length of light source). Computer simulations showed that the proposed signal processing algorithm identified the zero order fringe peak with a miss rate of 3 × 10-4 at 31 dB SNR and the extrapolated miss rate at 35 dB was 3 × 10-8. Also, at 35 dB SNR, RMS phase error less than 10-3 fringe was obtained. The proposed signal processing algorithm uses a software approach that is potentially inexpensive, simple and fast.

Kim, Jeonggon Harrison

2008-01-01

118

High Precision Assembly Line Synthesis for Molecules with Tailored Shapes  

PubMed Central

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

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

2014-01-01

119

High-precision time-interval measurement technique and methods  

NASA Astrophysics Data System (ADS)

This is a review of time-interval measurement methods and techniques. The paper begins with the definition of TDC or Time to Digit Converter. The interpolating principle, which modern TDC with high resolution and large dynamic range bases on, is introduced in the following. The mainstream time-interval measurement methods, including the direct counter method, TI stretching method, time-to-amplitude method, Vernier method, tapped delay line method and differential delay line method are described in detail. Detrimental factors, such as nonlinearity and metasability, which undermine the high precision, are also presented. To minimize these effects, the nonlinearity correction method, PLL and DLL technique are given. In addition, the future for time-interval measurement is proposed.

Zhang, Yan; Huang, Pei-Cheng

2006-03-01

120

Observing exoplanet populations with high-precision astrometry  

NASA Astrophysics Data System (ADS)

This thesis deals with the application of the astrometry technique, consisting in measuring the position of a star in the plane of the sky, for the discovery and characterisation of extra-solar planets. It is feasible only with a very high measurement precision, which motivates the use of space observatories, the development of new ground-based astronomical instrumentation and of innovative data analysis methods: The study of Sun-like stars with substellar companions using CORALIE radial velocities and HIPPARCOS astrometry leads to the determination of the frequency of close brown dwarf companions and to the discovery of a dividing line between massive planets and brown dwarf companions; An observation campaign employing optical imaging with a very large telescope demonstrates sufficient astrometric precision to detect planets around ultra-cool dwarf stars and the first results of the survey are presented; Finally, the design and initial astrometric performance of PRIMA, ! a new dual-feed near-infrared interferometric observing facility for relative astrometry is presented.

Sahlmann, Johannes

2012-06-01

121

Precision judgment criteria and supplement data processing method in high-precision ranging with dual-comb lasers  

NASA Astrophysics Data System (ADS)

A method using a pair of femtosecond frequency combs can realize ranging at a high precision of 1?m by Fourier Processing. In simulation of this system based on Matlab/Simulink, it is found that the choosing of repeating frequencies has great impact on frequency of the sampled signals, which influences the ranging precision a lot. The sampled signals are analyzed and classified into three types, which can be judgment criteria in system setting. Filter at Nyquist frequency is advised to decrease the edge effect of FFT, and a supplement means of cutting in data processing is proposed to improve precision.

Zhou, Qian; Li, Yang; Ni, Kai; Xu, Mingfei; Dong, Hao; Wu, Guanhao

2014-11-01

122

Developing and implementing a high precision setup system  

NASA Astrophysics Data System (ADS)

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

Peng, Lee-Cheng

123

High-precision efficiency calibration of a high-purity co-axial germanium detector  

E-print Network

A high-purity co-axial germanium detector has been calibrated in efficiency to a precision of about 0.15% over a wide energy range. High-precision scans of the detector crystal and gamma-ray source measurements have been compared to Monte-Carlo simulations to adjust the dimensions of a detector model. For this purpose, standard calibration sources and short-lived on-line sources have been used. The resulting efficiency calibration reaches the precision needed e.g. for branching ratio measurements of super-allowed beta decays for tests of the weak-interaction standard model.

B. Blank; J. Souin; P. Ascher; L. Audirac; G. Canchel; M. Gerbaux; S. Grevy; J. Giovinazzo; H. Guerin; T. Kurtukian Nieto; I. Matea; H. Bouzomita; P. Delahaye; G. F. Grinyer; J. C. Thomas

2014-04-04

124

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

USGS Publications Warehouse

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

Elder, W.P.

1989-01-01

125

High-Precision Photometry of Extreme KBO 2003 EL61  

NASA Astrophysics Data System (ADS)

We present high-precision, time-resolved, visible and near-infrared photometry of the large (diameter ~ 2500 km) Kuiper belt object (136108) 2003 EL61. The new data confirm rapid rotation at period P = 3.9155 ± 0.0001 h with a peak-to-peak photometric range of ?mR = 0.29 ± 0.02 mag and further show subtle but reproducible color variations with rotation. Rotational deformation of 2003 EL61 alone would give rise to a symmetric light curve free of color variations. The observed photometric deviations from the best-fit equilibrium model show the existence of a large surface region with an albedo and color different from the mean surface of 2003 EL61. We explore constraints on the nature of this anomalous region set by the existing data.

Lacerda, Pedro; Jewitt, David; Peixinho, Nuno

2008-05-01

126

Fast, High-Precision Readout Circuit for Detector Arrays  

NASA Technical Reports Server (NTRS)

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

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

2013-01-01

127

Manufacturing of high-precision aspherical and freeform optics  

NASA Astrophysics Data System (ADS)

Aspherical and freeform optical elements have a large potential in reducing optical aberrations and to reduce the number of elements in complex high performance optical systems. However, manufacturing a single piece or a small series of aspherical and freeform optics has for long been limited by the lack of flexible metrology tools. With the cooperative development of the NANOMEFOS metrology tool by TNO, TU/e and VSL, we are able to measure the form of aspheres and freeforms up to 500 mm in diameter with an accuracy better than 10 nm rms. This development opened the possibility to exploit a number of iterative, corrective manufacturing chains in which manufacturing technologies such as Single Point Diamond Turning, freeform grinding, deterministic polishing and classical polishing are combined in an iterative loop with metrology tools to measure form deviation (like CMM, LVDT contact measurement, interferometry and NANOMEFOS). This paper discusses the potentials, limitations and differences of iterative manufacturing chains used by TNO in the manufacturing of high performance optics for astronomical purposes such as the anufacturing of the L2 of the Optical Tube Assembly of the four laser-guide star facility of the ESO VLT, Manufacturing of Aluminium freeforms mirrors for the SCUBA-2 instrument. Based on these results we will give an outlook into the new challenges and solutions in manufacturing high-precision optics.

Hoogstrate, André M.; van Drunen, Casper; van Venrooy, Bart; Henselmans, Rens

2012-09-01

128

Design of a new high precision computer numerical control  

SciTech Connect

The purpose of this project is to produce a generic high precision computer numerical controller (CNC) for use on microinch- and sub-microinch-resolution machine tools at the Lawrence Livermore National Laboratory. In order to fully utilize the potential of these machine tools, the CNC must include the ability to use multiple feedback sensors on each machine axis, incorporate corrections for quasistatic geometric errors (such as straightness, and squareness), be able to function over a relatively large range of motion (in excess of 60 inches per axis), and be able to produce motion updates at a rate sufficient to take advantage of the high bandwidth of the servo systems. At present, no commercially available CNC can presently meet all of the resolution, feed rate, and length of travel requirements of these machines. In order to minimize the complexity of the system, and thereby increase its reliability and maintainability, the programming was done in a high level language. The number of processors was kept as small as possible while still maintaining the performance requirements. We also used commercially available hardware in preference to building, in order to increase both reliability and maintainability. Special emphasis was given to making the CNC's operator interface as friendly as possible. We have completed a prototype control. We plan to install and test it in 1988. 4 figs.

Sweeney, D.J.; Weinert, G.F.

1988-06-23

129

Precision, high dose radiotherapy: helium ion treatment of uveal melanoma  

SciTech Connect

The authors report on 75 patients with uveal melanoma who were treated by placing the Bragg peak of a helium ion beam over the tumor volume. The technique localizes the high dose region very tightly around the tumor volume. This allows critical structures, such as the optic disc and the macula, to be excluded from the high dose region as long as they are 3 to 4 mm away from the edge of the tumor. Careful attention to tumor localization, treatment planning, patient immobilization and treatment verification is required. With a mean follow-up of 22 months (3 to 60 months) the authors have had only five patients with a local recurrence, all of whom were salvaged with another treatment. Pretreatment visual acuity has generally been preserved as long as the tumor edge is at least 4 mm away from the macula and optic disc. The only serious complication to date has been an 18% incidence of neovascular glaucoma in the patients treated at our highest dose level. Clinical results and details of the technique are presented to illustrate potential clinical precision in administering high dose radiotherapy with charged particles such as helium ions or protons.

Saunders, W.M.; Char, D.H.; Quivey, J.M.; Castro, J.R.; Chen, G.T.Y.; Collier, J.M.; Cartigny, A.; Blakely, E.A.; Lyman, J.T.; Zink, S.R.

1985-02-01

130

Evaluation of high-precision sensors in structural monitoring.  

PubMed

One of the most intricate branches of metrology involves the monitoring of displacements and deformations of natural and anthropogenic structures under environmental forces, such as tidal or tectonic phenomena, or ground water level changes. Technological progress has changed the measurement process, and steadily increasing accuracy requirements have led to the continued development of new measuring instruments. The adoption of an appropriate measurement strategy, with proper instruments suited for the characteristics of the observed structure and its environmental conditions, is of high priority in the planning of deformation monitoring processes. This paper describes the use of precise digital inclination sensors in continuous monitoring of structural deformations. The topic is treated from two viewpoints: (i) evaluation of the performance of inclination sensors by comparing them to static and continuous GPS observations in deformation monitoring and (ii) providing a strategy for analyzing the structural deformations. The movements of two case study objects, a tall building and a geodetic monument in Istanbul, were separately monitored using dual-axes micro-radian precision inclination sensors (inclinometers) and GPS. The time series of continuous deformation observations were analyzed using the Least Squares Spectral Analysis Technique (LSSA). Overall, the inclinometers showed good performance for continuous monitoring of structural displacements, even at the sub-millimeter level. Static GPS observations remained insufficient for resolving the deformations to the sub-centimeter level due to the errors that affect GPS signals. With the accuracy advantage of inclination sensors, their use with GPS provides more detailed investigation of deformation phenomena. Using inclinometers and GPS is helpful to be able to identify the components of structural responses to the natural forces as static, quasi-static, or resonant. PMID:22163499

Erol, Bihter

2010-01-01

131

Evaluation of High-Precision Sensors in Structural Monitoring  

PubMed Central

One of the most intricate branches of metrology involves the monitoring of displacements and deformations of natural and anthropogenic structures under environmental forces, such as tidal or tectonic phenomena, or ground water level changes. Technological progress has changed the measurement process, and steadily increasing accuracy requirements have led to the continued development of new measuring instruments. The adoption of an appropriate measurement strategy, with proper instruments suited for the characteristics of the observed structure and its environmental conditions, is of high priority in the planning of deformation monitoring processes. This paper describes the use of precise digital inclination sensors in continuous monitoring of structural deformations. The topic is treated from two viewpoints: (i) evaluation of the performance of inclination sensors by comparing them to static and continuous GPS observations in deformation monitoring and (ii) providing a strategy for analyzing the structural deformations. The movements of two case study objects, a tall building and a geodetic monument in Istanbul, were separately monitored using dual-axes micro-radian precision inclination sensors (inclinometers) and GPS. The time series of continuous deformation observations were analyzed using the Least Squares Spectral Analysis Technique (LSSA). Overall, the inclinometers showed good performance for continuous monitoring of structural displacements, even at the sub-millimeter level. Static GPS observations remained insufficient for resolving the deformations to the sub-centimeter level due to the errors that affect GPS signals. With the accuracy advantage of inclination sensors, their use with GPS provides more detailed investigation of deformation phenomena. Using inclinometers and GPS is helpful to be able to identify the components of structural responses to the natural forces as static, quasi-static, or resonant. PMID:22163499

Erol, Bihter

2010-01-01

132

Ultra-High Precision, Ultra-Wide-Field Optical Photometry  

NASA Astrophysics Data System (ADS)

The low scintillation noise and the long continuous darkness are among the unique properties of the Dome-C site on the east Antarctic plateau. Ultra-high precision optical photometry is therefore among the techniques best suited for this particular site. We propose a telescope (ICE-T) optimized for ultra-high and ultra wide field photometry for Dome C. It consists of two 60cm optical ultra-wide-field Wynne-Schmidt telescopes and one 18cm narrow-field Maksutov spectrophotometric telescope on a single mount. ICE-T is currently a team effort of the German Alfred-Wegener-Institute for Polar Research, the Italian Universities of Padova and Perugia, the INAF Observatory Catania, and the Catalonian IEEC in Barcelona, Spain, and the AIP, with collaboration from the University of New South Wales, Australia and the University of St. Andrews, UK. In this paper, I discuss some of the many problems associated with sub-milli-mag photometry.

Strassmeier, K. G.

133

Silicon avalanche pixel sensor for high precision tracking  

NASA Astrophysics Data System (ADS)

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

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

2014-03-01

134

High-Precision Studies of Compact Variable Stars  

NASA Astrophysics Data System (ADS)

This book, which is a reworked and updated version of Steven Bloemen's original PhD thesis, reports on several high-precision studies of compact variable stars. Its strength lies in the large variety of observational, theoretical and instrumentation techniques that are presented and used and paves the way towards new and detailed asteroseismic applications of single and binary subdwarf stars. Close binary stars are studied using high cadence spectroscopic datasets collected with state of the art electron multiplying CCDs and analysed using Doppler tomography visualization techniques. The work touches upon instrumentation, presenting the calibration of a new fast, multi-colour camera installed at the Mercator Telescope on La Palma. The thesis also includes theoretical work on the computation of the temperature range in which stellar oscillations can be driven in subdwarf B-stars. Finally, the highlight of the thesis is the measurement of velocities of stars using only photometric data from NASA's Kepler satellite. Doppler beaming causes stars to appear slightly brighter when they move towards us in their orbits, and this subtle effect can be seen in Kepler's brightness measurements. The thesis presents the first validation of such velocity measurements using independent spectroscopic measurements. Since the detection and validation of this Doppler beaming effect, it has been used in tens of studies to detect and characterize binary star systems, which are key calibrators in stellar astronomy.

Bloemen, Steven

2014-10-01

135

A proposed experimental method for interpreting Doppler effect measurements and determining their precision  

NASA Technical Reports Server (NTRS)

The principal problem in the measurement of the Doppler reactivity effect is separating it from the thermal reactivity effects of the expansion of the heated sample. It is shown in this proposal that the thermal effects of sample expansion can be experimentally determined by making additional measurements with porous samples having the same mass and/or volume as the primary sample. By combining these results with independent measurements of the linear temperature coefficient and the computed temperature dependence of the Doppler coefficient the magnitude of the Doppler coefficient may be extracted from the data. These addiational measurements are also useful to experimentally determine the precision of the reactivity oscillator technique used to measure the reactivity effects of the heated sample.

Klann, P. G.

1973-01-01

136

Rigorous high-precision enclosures of fixed points and their invariant manifolds  

NASA Astrophysics Data System (ADS)

The well established concept of Taylor Models is introduced, which offer highly accurate C0 enclosures of functional dependencies, combining high-order polynomial approximation of functions and rigorous estimates of the truncation error, performed using verified arithmetic. The focus of this work is on the application of Taylor Models in algorithms for strongly non-linear dynamical systems. A method is proposed to extend the existing implementation of Taylor Models in COSY INFINITY from double precision coefficients to arbitrary precision coefficients. Great care is taken to maintain the highest efficiency possible by adaptively adjusting the precision of higher order coefficients in the polynomial expansion. High precision operations are based on clever combinations of elementary floating point operations yielding exact values for round-off errors. An experimental high precision interval data type is developed and implemented. Algorithms for the verified computation of intrinsic functions based on the High Precision Interval datatype are developed and described in detail. The application of these operations in the implementation of High Precision Taylor Models is discussed. An application of Taylor Model methods to the verification of fixed points is presented by verifying the existence of a period 15 fixed point in a near standard Henon map. Verification is performed using different verified methods such as double precision Taylor Models, High Precision intervals and High Precision Taylor Models. Results and performance of each method are compared. An automated rigorous fixed point finder is implemented, allowing the fully automated search for all fixed points of a function within a given domain. It returns a list of verified enclosures of each fixed point, optionally verifying uniqueness within these enclosures. An application of the fixed point finder to the rigorous analysis of beam transfer maps in accelerator physics is presented. Previous work done by Johannes Grote is extended to compute very accurate polynomial approximations to invariant manifolds of discrete maps of arbitrary dimension around hyperbolic fixed points. The algorithm presented allows for automatic removal of resonances occurring during construction. A method for the rigorous enclosure of invariant manifolds of continuous systems is introduced. Using methods developed for discrete maps, polynomial approximations of invariant manifolds of hyperbolic fixed points of ODEs are obtained. These approximations are outfit with a sharp error bound which is verified to rigorously contain the manifolds. While we focus on the three dimensional case, verification in higher dimensions is possible using similar techniques. Integrating the resulting enclosures using the verified COSY VI integrator, the initial manifold enclosures are expanded to yield sharp enclosures of large parts of the stable and unstable manifolds. To demonstrate the effectiveness of this method, we construct enclosures of the invariant manifolds of the Lorenz system and show pictures of the resulting manifold enclosures. To the best of our knowledge, these enclosures are the largest verified enclosures of manifolds in the Lorenz system in existence.

Wittig, Alexander N.

137

Closed loop high precision position control system with optical scale  

NASA Astrophysics Data System (ADS)

With the developments of science of art, there are more and more demands on the high resolution control of position of object to be controlled, such as lathe, product line, elements in the optical resonant cavity, telescope, and so on. As one device with high resolution, the optical scale has more and more utility within the industrial and civil applications. With one optical scale and small DC servo motor, one closed loop high resolution position control system is constructed. This apparatus is used to control the position of the elements of optical system. The optical scale is attached on the object or reference guide way. The object position is sampled by a readhead of non-contact optical encoder. Control system processes the position information and control the position of object through the motion control of servo DC motor. The DC motor is controlled by one controller which is connected to an industrial computer. And the micro frictionless slide table does support the smooth motion of object to be controlled. The control algorithm of system is PID (Proportional-Integral-Differential) methods. The PID control methods have well ROBUST. The needed data to control are position, velocity and acceleration of the object. These three parameters correspond to the PID characters respectively. After the accomplishments of hardware, GUI (Graphical user interface), that is, the software of control system is also programmed. The whole system is assembled by specialized worker. Through calibration experiments, the coefficients of PID are obtained respectively. And then the precision of position control of the system is about 0.1?m.

Ge, Cheng-liang; Liao, Yuan; He, Zhong-wu; Luo, Zhong-xiang; Huang, Zhi-wei; Wan, Min; Hu, Xiao-yang; Fan, Guo-bin; Liang, Zheng

2008-03-01

138

Precision optical slit for high heat load or ultra high vacuum  

DOEpatents

This invention relates generally to slits used in optics that must be precisely aligned and adjusted. The optical slits of the present invention are useful in x-ray optics, x-ray beam lines, optical systems in which the entrance slit is critical for high wavelength resolution. The invention is particularly useful in ultra high vacuum systems where lubricants are difficult to use and designs which avoid the movement of metal parts against one another are important, such as monochrometers for high wavelength resolution with ultra high vacuum systems. The invention further relates to optical systems in which temperature characteristics of the slit materials is important. The present invention yet additionally relates to precision slits wherein the opposing edges of the slit must be precisely moved relative to a center line between the edges with each edge retaining its parallel orientation with respect to the other edge and/or the center line.

Andresen, Nord C. (Hayward, CA); DiGennaro, Richard S. (Albany, CA); Swain, Thomas L. (Richmond, CA)

1995-01-01

139

Precision optical slit for high heat load or ultra high vacuum  

DOEpatents

This invention relates generally to slits used in optics that must be precisely aligned and adjusted. The optical slits of the present invention are useful in x-ray optics, x-ray beam lines, optical systems in which the entrance slit is critical for high wavelength resolution. The invention is particularly useful in ultra high vacuum systems where lubricants are difficult to use and designs which avoid the movement of metal parts against one another are important, such as monochromators for high wavelength resolution with ultra high vacuum systems. The invention further relates to optical systems in which temperature characteristics of the slit materials is important. The present invention yet additionally relates to precision slits wherein the opposing edges of the slit must be precisely moved relative to a center line between the edges with each edge retaining its parallel orientation with respect to the other edge and/or the center line. 21 figures.

Andresen, N.C.; DiGennaro, R.S.; Swain, T.L.

1995-01-24

140

High precision and continuous optical transport using a standing wave optical  

E-print Network

High precision and continuous optical transport using a standing wave optical line trap Vassili://chaos.utexas.edu/ Abstract: We introduce the Standing Wave Optical Line Trap (SWOLT) as a novel tool for precise optical

Texas at Austin. University of

141

Highly precise digital image stabilization scheme for a hybrid stabilizing system  

NASA Astrophysics Data System (ADS)

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

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

2010-07-01

142

A Design of High-precision High-Voltage Fiber-Optic Analog Signal Isolation Converter  

Microsoft Academic Search

This paper introduces a design of high-precision high-voltage fiber-optic analog signal isolation converter based on the technology of Voltage-to-Frequency (V\\/F) and Frequency-to-Voltage (F\\/V) conversion. It describes the principle, system configuration and hardware design.

Jian-wei Li; Liu-wei Xu; Xiao-ning Liu; Lei Yang

2002-01-01

143

High Precision Measurement of Electrical Resistivity of Nickel Near the Ferromagnetic Phase Transition at High Pressure  

Microsoft Academic Search

High precision measurement of the resistance of nickel near its ferromagnetic phase transition at high pressure was done in a large volume hydrostatic cubic multi -anvil pressure cell and critical parameters were determined. A computer real time controlled measurement system was developed to measure the resistance vs temperature and pressure. A non-linear least-squares method was used to analyze the data.

Wei Chen

1991-01-01

144

High precision metrology based microwave effective linewidth measurement technique  

SciTech Connect

A precision microwave effective linewidth measurement technique for magnetic samples has been developed. The measurement utilizes a high-Q cylindrical cavity that contains the sample of interest, a highly stable and programable static magnetic field source, a computer controlled network analyzer for cavity center frequency {omega}{sub c} and quality factor Q{sub c} determinations, and the standard metrological substitution ABA method for accurate relative {omega}{sub c} and Q{sub c} measurements. Sequential long term ABA measurements show that the time and temperature drifts and random errors are the dominant sources of error, with uncertainties in {omega}{sub c}/2{pi} and Q{sub c} in the range of 50 kHz and 25, respectively. The ABA method is applied to eliminate these drifts and minimize the random errors. For measurements over 25 ABA cycles, accuracy is improved to 0.14 kHz for {omega}{sub c}/2{pi} and 3 for Q{sub c}. The temperature variation over a single ABA cycle is generally on the order of 10{sup -3}-10{sup -5} deg. C and there is no need for any further temperature stabilization or correction measures. The overall uncertainty in the 10 GHz effective linewidth determinations for a 3 mm diam, 0.5 mm thick polycrystalline yttrium iron garnet (YIG) disk is 0.15 Oe or less, well below the intrinsic single crystal YIG linewidth. This represents a factor of 10 improvement in measurement accuracy over previous work.

Mo, Nan; Green, Jerome J.; Beitscher, Bailey A.; Patton, Carl E. [Department of Physics, Colorado State University, Fort Collins, Colorado 80523 (United States)

2007-11-15

145

High-precision timeline for Earth's most severe extinction  

E-print Network

The end-Permian mass extinction was the most severe loss of marine and terrestrial biota in the last 542 My. Understanding its cause and the controls on extinction/recovery dynamics depends on an accurate and precise age ...

Burgess, Seth D.

146

Experimental Hypersonic Aerodynamic Characteristics of the 2001 Mars Surveyor Precision Lander with Flap  

NASA Technical Reports Server (NTRS)

Aerodynamic wind-tunnel screening tests were conducted on a 0.029 scale model of a proposed Mars Surveyor 2001 Precision Lander (70 deg half angle spherically blunted cone with a conical afterbody). The primary experimental objective was to determine the effectiveness of a single flap to trim the vehicle at incidence during a lifting hypersonic planetary entry. The laminar force and moment data, presented in the form of coefficients, and shock patterns from schlieren photography were obtained in the NASA Langley Aerothermodynamic Laboratory for post-normal shock Reynolds numbers (based on forebody diameter) ranging from 2,637 to 92,350, angles of attack ranging from 0 tip to 23 degrees at 0 and 2 degree sideslip, and normal-shock density ratios of 5 and 12. Based upon the proposed entry trajectory of the 2001 Lander, the blunt body heavy gas tests in CF, simulate a Mach number of approximately 12 based upon a normal shock density ratio of 12 in flight at Mars. The results from this experimental study suggest that when traditional means of providing aerodynamic trim for this class of planetary entry vehicle are not possible (e.g. offset c.g.), a single flap can provide similar aerodynamic performance. An assessment of blunt body aerodynamic effects attributed to a real gas were obtained by synergistic testing in Mach 6 ideal-air at a comparable Reynolds number. From an aerodynamic perspective, an appropriately sized flap was found to provide sufficient trim capability at the desired L/D for precision landing. Inviscid hypersonic flow computations using an unstructured grid were made to provide a quick assessment of the Lander aerodynamics. Navier-Stokes computational predictions were found to be in very good agreement with experimental measurement.

Horvath, Thomas J.; OConnell, Tod F.; Cheatwood, F. McNeil; Prabhu, Ramadas K.; Alter, Stephen J.

2002-01-01

147

The Mainz high-precision proton form factor measurement  

NASA Astrophysics Data System (ADS)

Form factors offer a direct approach to fundamental properties of the nucleons like the radius and charge distribution. Renewed interest was stirred up by the 5 sigma discrepancy between a recent determination of the proton radius from the Lamb shift in muonic hydrogen and preceding electron scattering results. The low-q shape of the form factors might also contain a direct signal of a pion cloud around the nucleus and is a strong test of hadron models. In my talk, I will discuss the electron scattering experiment performed with the 3-spectrometer-facility of the A1 collaboration at MAMI in Mainz, Germany. The data set covers the Q^2-range from 0.004 to 1,(GeV/c)^2 and includes about 1400 separate cross section measurements, spanning the range of scattering angles from below 20^o to above 120^o at six beam energies between 180 and 855,eV, with statistical uncertainties below 0.4%. The 3-spectrometer-setup allowed for a simultaneous monitoring of the luminosity and overlapping and redundant measurements of the cross section to achieve stringent control over systematic uncertainties. Beam stabilization systems and redundant current measurements further limit systematic effects. The measured cross sections were analyzed with the standard Rosenbluth separation technique and by employing direct fits of a large set of form factor models. The high redundancy of the data set allowed us to extract the form factors up to 0.6,(GeV/c)^2 with very small uncertainties and to give a new, precise value for the proton radius from electron scattering. From the form factors, the charge distribution and Zemach moments were calculated. The latter constitute important input for the theoretical corrections of the muonic Lamb shift experiment. However, the revised values can not explain the discrepancy. Further possible explanations include higher order QED-corrections, vacuum effects or even physics beyond the standard model.

Bernauer, Jan

2011-04-01

148

High Precision Prediction of Functional Sites in Protein Structures  

PubMed Central

We address the problem of assigning biological function to solved protein structures. Computational tools play a critical role in identifying potential active sites and informing screening decisions for further lab analysis. A critical parameter in the practical application of computational methods is the precision, or positive predictive value. Precision measures the level of confidence the user should have in a particular computed functional assignment. Low precision annotations lead to futile laboratory investigations and waste scarce research resources. In this paper we describe an advanced version of the protein function annotation system FEATURE, which achieved 99% precision and average recall of 95% across 20 representative functional sites. The system uses a Support Vector Machine classifier operating on the microenvironment of physicochemical features around an amino acid. We also compared performance of our method with state-of-the-art sequence-level annotator Pfam in terms of precision, recall and localization. To our knowledge, no other functional site annotator has been rigorously evaluated against these key criteria. The software and predictive models are incorporated into the WebFEATURE service at http://feature.stanford.edu/wf4.0-beta. PMID:24632601

Buturovic, Ljubomir; Wong, Mike; Tang, Grace W.; Altman, Russ B.; Petkovic, Dragutin

2014-01-01

149

Experimental method for determination of a suitable temperature range for glasses used in precision molding  

NASA Astrophysics Data System (ADS)

Viscosity of glass is one of its important technological properties. It is usually adopted as a mark in controlling and evaluating the workability of glass. The viscous features in a glass forming process are strongly relevant to the temperature distribution. Appropriate procedure setting and controlling of temperature is an essential issue for precision glass molding. But the characteristic viscosity of glass is difficult to be observed directly in a practical lens molding. It's not convenient to set up the molding conditions caused by the differences between theoretical data and actual system. The purpose of this experimental study is intended to provide a simple and reliable method for determination of suitable temperature intervals of glasses used in the precision molding fabrication which meets the requirements of process tolerances in the industrial productions. The average glass deforming force and center thickness of molded lens are taken as the two conditions of determination principle for molding temperature ranges. The average force should not less than the minimum value of measurement accuracy and the lens thickness should reach the design target in these temperature ranges. These two conditions are easy to be measured and fit for application in the engineering. The molding temperature ranges of several kinds of glass were obtained in this project. One of them is Schott optical glass P-LASF51 which is selected for evaluating and validating this method. Its suitable molding temperature range is from 590 to 614 . The results of molding experiments demonstrate the method is effective and feasible.

Ma, Tao; Chen, Fan; Yu, Jingchi

2010-10-01

150

Animal Experimentation in High Schools  

ERIC Educational Resources Information Center

Recommends that teacher and student be provided with the broadest possible spectrum of meaningful and feasible experiments in which the comfort of the experimental animal is protected by the design of the experiment. (BR)

Ansevin, Kystyna D.

1970-01-01

151

High-Precision Spectroscopy of Molecular Iodine: From Optical Frequency Standards to Global  

E-print Network

High-Precision Spectroscopy of Molecular Iodine: From Optical Frequency Standards to Global-Precision Spectroscopy of Molecular Iodine: From Optical Frequency Standards to Global Descriptions of Hyper-Precision Spectroscopy of Molecular Iodine: From Optical Frequency Standards to Global Descriptions of Hyper

Jin, Deborah

152

High precision quantum control of single donor spins in silicon  

E-print Network

The Stark shift of the hyperfine coupling constant is investigated for a P donor in Si far below the ionization regime in the presence of interfaces using Tight-binding and Band Minima Basis approaches and compared to the recent precision measurements. The TB electronic structure calculations included over 3 million atoms. In contrast to previous effective mass based results, the quadratic Stark coefficient obtained from both theories agrees closely with the experiments. This work represents the most sensitive and precise comparison between theory and experiment for single donor spin control. It is also shown that there is a significant linear Stark effect for an impurity near the interface, whereas, far from the interface, the quadratic Stark effect dominates. Such precise control of single donor spin states is required particularly in quantum computing applications of single donor electronics, which forms the driving motivation of this work.

Rajib Rahman; Cameron J. Wellard; Forrest R. Bradbury; Marta Prada; Jared H. Cole; Gerhard Klimeck; Lloyd C. L. Hollenberg

2007-05-15

153

The Art of High Precision Timing of Pulsars  

NASA Astrophysics Data System (ADS)

Nature's most stable clocks are the millisecond pulsars, astonishing objects which permit tests of General Relativity and the establishment of reference frames. Since their discovery in 1981, astronomers have developed more and more accurate means of timing them. In this lecture I will discuss techniques that optimise precision timing and contrast various efforts around the world and recent highlights. I will also examine the minimum specifications required to conduct precision timing campaigns, and the prospects for future instruments such as the eVLA, ASKAP, MeerKAT and the SKA, and how to beat radio frequency interference.

Bailes, Matthew

2009-05-01

154

Research on the structure of high-speed large-scale ultra-precision positioning system  

Microsoft Academic Search

According to the needs in such fields as IC manufacturing and ultra-precision machining, a precision positioning system based on macro-micro dual-drive was developed. The macro positioning system is a two dimensional high-speed large-scale precision positioning system based on linear motor drive. The micro positioning system is a low speed ultra-precision positioning system based on the PZT and flexure hinge. The

Chuan Yang; Guang L. Wang; Bi S. Yang; Hai R. Wang

2008-01-01

155

Two-dimensional, high flow, precisely controlled monodisperse drop source  

Microsoft Academic Search

A versatile acoustically-driven fluid atomizer was designed and operated that creates precise monodisperse sprays by Rayleigh breakup or polydisperse sprays by the acoustic driving of amplitude dependent instabilities. The atomizer forms a cylindrical, conical, or flat (sheet) liquid jet by means of a photofabricated nozzle. The spray pattern and spray volume are altered by changing the nozzle. A piezoelectric driver,

John L. Dressler

1993-01-01

156

High-precision isotopic analysis of nanogram quantities of plutonium  

SciTech Connect

A surface ionization-diffusion-type ionization source that uses a rhenium filament overplated with platinum has been developed and optimized for 0.5- to 2-ng plutonium samples. This source is capable of measuring the /sup 240/Pu//sup 239/Pu atom ratio in nuclear-test-debris samples to 0.15% precision and accuracy at the 95% confidence level.

Perrin, R.E.; Knobeloch, G.W.; Armijo, V.M.; Efurd, D.W.

1984-06-01

157

Preliminary design approach for large high precision segmented reflectors  

NASA Technical Reports Server (NTRS)

A simplified preliminary design capability for erectable precision segmented reflectors is presented. This design capability permits a rapid assessment of a wide range of reflector parameters as well as new structural concepts and materials. The preliminary design approach was applied to a range of precision reflectors from 10 meters to 100 meters in diameter while considering standard design drivers. The design drivers considered were: weight, fundamental frequency, launch packaging volume, part count, and on-orbit assembly time. For the range of parameters considered, on-orbit assembly time was identified as the major design driver. A family of modular panels is introduced which can significantly reduce the number of reflector parts and the on-orbit assembly time.

Mikulas, Martin M., Jr.; Collins, Timothy J.; Hedgepeth, John M.

1990-01-01

158

Ion source for high-precision mass spectrometry  

DOEpatents

The invention is directed to a method for increasing the precision of positive-ion relative abundance measurements conducted in a sector mass spectrometer having an ion source for directing a beam of positive ions onto a collimating slit. The method comprises incorporating in the source an electrostatic lens assembly for providing a positive-ion beam of circular cross section for collimation by the slit. 2 figures, 3 tables.

Todd, P.J.; McKown, H.S.; Smith, D.H.

1982-04-26

159

Ion source for high-precision mass spectrometry  

DOEpatents

The invention is directed to a method for increasing the precision of positive-ion relative abundance measurements conducted in a sector mass spectrometer having an ion source for directing a beam of positive ions onto a collimating slit. The method comprises incorporating in the source an electrostatic lens assembly for providing a positive-ion beam of circular cross section for collimation by the slit.

Todd, Peter J. (Oak Ridge, TN); McKown, Henry S. (Oak Ridge, TN); Smith, David H. (Oak Ridge, TN)

1984-01-01

160

Calculated thermal behavior of ventilated high precision radio telescopes  

Microsoft Academic Search

Radio telescopes that operate at millimeter and sub-millimeter wavelengths need a reflector-surface precision of a few tens of microns and a pointing accuracy of a few arcseconds. When built in a conventional way from steel and aluminum, as in the case of larger-diameter telescopes, thermal control must be applied to reduce temperature-induced deformations, in particular of the reflector backup structure.

A. Greve; M. Bremer

2006-01-01

161

High-Precision Determination of the Helium Abundance on Mars  

Microsoft Academic Search

We propose to use EUVE to observe Mars in late March 1999 in order to determine a precise value for the Martian helium abundance. An earlier measurement by EUVE yielded a marginal detection of the 58.4 nm line of neutral helium which led to an estimate of 4+\\/-2 ppm for the He mixing ratio. A new measurement at higher S\\/N

G. Randall Gladstone

1997-01-01

162

Gauges for Highly Precise Metrology of a Compound Mirror  

NASA Technical Reports Server (NTRS)

Three optical gauges have been developed for guiding the assembly and measuring precisely the reflecting surfaces of a compound mirror that comprises a corner-cube retroreflector glued in a hole on a flat mirror. In the specific application for which the gauges were developed, the compound mirror is part of a siderostat in a stellar interferometer. The flat-mirror portion of the compound mirror is the siderostat mirror; the retroreflector portion of the compound mirror is to be used, during operation of the interferometer, to monitor the location of the siderostat mirror surface relative to other optical surfaces of the interferometer. Nominally, the optical corner of the retroreflector should lie precisely on the siderostat mirror surface, but this precision cannot be achieved in fabrication: in practice, there remains some distance between the optical corner and the siderostat mirror surface. For proper operation of the interferometer, it is required to make this distance as small as possible and to know this distance within 1 nm. The three gauges make it possible to satisfy these requirements.

Gursel, Yekta

2005-01-01

163

Experimental High Energy Neutrino Astrophysics  

SciTech Connect

Neutrinos are considered promising probes for high energy astrophysics. More than four decades after deep water Cerenkov technique was proposed to detect high energy neutrinos. Two detectors of this type are successfully taking data: BAIKAL and AMANDA. They have demonstrated the feasibility of the high energy neutrino detection and have set first constraints on TeV neutrino production astrophysical models. The quest for the construction of km3 size detectors have already started: in the South Pole, the IceCube neutrino telescope is under construction; the ANTARES, NEMO and NESTOR Collaborations are working towards the installation of a neutrino telescope in the Mediterranean Sea.

Distefano, Carla [Laboratori Nazionali del Sud, Catania (Italy)

2005-10-12

164

High-precision radiocarbon dating and historical biblical archaeology in southern Jordan  

E-print Network

High-precision radiocarbon dating and historical biblical archaeology in southern Jordan Thomas E for review June 11, 2008) Recent excavations and high-precision radiocarbon dating from the largest Iron Age data with innovative visualization tools. The new radiocarbon dates push back by 2 centuries

Schulze, Jürgen P.

165

Figures deduction method for mast valuating interpolation errors of encoder with high precision  

Microsoft Academic Search

With the development of technology, especially the need of fast accurately running after and orientating the aim of horizon and air, the photoelectrical rotary encoder with high precision has become the research hotspot in the fields of international spaceflight and avigation, the errors evaluation of encoder with high precision is the one of the key technology that must to be

Jie Yi; Li-Min An; Chun-Xia Liu

2011-01-01

166

Pulsed Power Hydrodynamics: A Discipline Offering High Precision Data for Motivating and Validating Physics Models  

Microsoft Academic Search

The discipline of pulsed power hydrodynamics is a new application of low-impedance, pulsed power technology, developed to study implosion hydrodynamics, instabilities, turbulence, and material properties in a highly precise, controllable environment at the extremes of pressure and material velocity. The discipline of pulsed power hydrodynamics arose in response to the need for economical, high-precision data to validate sophisticated numerical models

R. E. Reinovsky

2005-01-01

167

High-precision analysis of SF6 at ambient level  

NASA Astrophysics Data System (ADS)

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

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

2013-09-01

168

Study on mechanism and process of ion beam machining on high-precision large optical surfaces  

NASA Astrophysics Data System (ADS)

Ion beam machining has become an important means adopted to high-precision large optical mirror processing. This study has conducted a bitmap-style model, calculation and analysis on low-energy Ar+ ion beam sputtering optical surface, based on Sigmund Theory and the CCOS principle. We have obtained the relationship of the removal function and the removal rate with major technological parameters of ion beam machining (e.g. dwell time, work distance, ion energy, etc.) also via orthogonal experiments of single point removal. Results indicated that the removal rate of amorphous SiO2 (fused silica) by Ar+ ions with 600~1200 electron volts increases with the increase of ion energy and dwell time at different extents, decreases exponentially with the increase in work distance. On the basis of computational analysis and experimental investigations, we optimized process conditions and further figured the plane mirror with the clear aperture of 130 millimeters, utilizing technologically optimized low-energy Ar+ ion beam machining. Eventually we obtained the high-precision figure shape with the post-machined surface roughness of 0.43~0.44 nm rms and the post-machined figure error of 1 nm rms.

Liang, Xiao; Gu, Yongqiang; Wang, Xiang; Ma, Zhanlong; Sui, Yongxin; Zheng, Jinjin

2014-08-01

169

Design of High-Efficiency Bidirectional DC–DC Converter and High-Precision Efficiency Measurement  

Microsoft Academic Search

This paper first introduces the design of an ultrahigh efficiency 50-kW bidirectional dc-dc converter at zero-voltage-switching operation, and then, a high-precision efficiency measurement method using a regenerative approach. The ultrahigh efficiency bidirectional dc-dc converter is achieved with 1) the use of CoolMOS as the main switch under zero-voltage soft switching condition; 2) multiple-phase legs for current sharing to reduce the

Wensong Yu; Hao Qian

2010-01-01

170

Application of high-temperature superconductors to high-precision accelerometers  

NASA Astrophysics Data System (ADS)

Superconducting materials offer unique capabilities to high-precision acceleration sensing. Two specific aspects are shielding of magnetic fields and magnetic levitation due to the Meissner Effect. The basic configuration and operation of accelerometers using superconducting materials are reviewed. Physical properties such as conductivity, permeability, trapped magnetic flux, and material uniformity are correlated to shielding and levitation performance. Measurements of these properties for the YBaCuO superconductors are included.

Lenz, James; Chen, Quark; McArdle, James; Werner, Tom; Castleman, Wayne

1990-10-01

171

A high precision, compact electromechanical ground rotation sensor.  

PubMed

We present a mechanical rotation sensor consisting of a balance pivoting on a tungsten carbide knife edge. These sensors are important for precision seismic isolation systems, as employed in land-based gravitational wave interferometers and for the new field of rotational seismology. The position sensor used is an air-core linear variable differential transformer with a demonstrated noise floor of 1 × 10?¹¹ m/?Hz. We describe the instrument construction and demonstrate low noise operation with a noise floor upper bound of 5.7 × 10?? rad/?Hz at 10 mHz and 6.4 × 10?¹? rad/?Hz at 0.1 Hz. The performance of the knife edge hinge is compatible with a behaviorur free of noise from dislocation self-organized criticality. PMID:24880388

Dergachev, V; DeSalvo, R; Asadoor, M; Bhawal, A; Gong, P; Kim, C; Lottarini, A; Minenkov, Y; Murphy, C; O'Toole, A; Peña Arellano, F E; Rodionov, A V; Shaner, M; Sobacchi, E

2014-05-01

172

A high precision, compact electromechanical ground rotation sensor  

NASA Astrophysics Data System (ADS)

We present a mechanical rotation sensor consisting of a balance pivoting on a tungsten carbide knife edge. These sensors are important for precision seismic isolation systems, as employed in land-based gravitational wave interferometers and for the new field of rotational seismology. The position sensor used is an air-core linear variable differential transformer with a demonstrated noise floor of {1}{ × 10^{-11}}textrm { m}/sqrt{textrm {Hz}}. We describe the instrument construction and demonstrate low noise operation with a noise floor upper bound of {5.7}{ × 10^{-9}}textrm { rad}/sqrt{textrm {Hz}} at 10 mHz and {6.4}{ × 10^{-10}}textrm { rad}/sqrt{textrm {Hz}} at 0.1 Hz. The performance of the knife edge hinge is compatible with a behaviorur free of noise from dislocation self-organized criticality.

Dergachev, V.; DeSalvo, R.; Asadoor, M.; Bhawal, A.; Gong, P.; Kim, C.; Lottarini, A.; Minenkov, Y.; Murphy, C.; O'Toole, A.; Peña Arellano, F. E.; Rodionov, A. V.; Shaner, M.; Sobacchi, E.

2014-05-01

173

High-precision positioning stage for microassembly purposes  

NASA Astrophysics Data System (ADS)

In this paper, a LC-SEM will be presented as observation device for micro assembly purposes. Compared to other means of magnification it offers several advantages like, for instance, a large depth of field. A gripper which can be operated inside this LC-SEM has been developed and tested. It can be equipped with an endoscope for additional process observation. Its gripping arms can be changed according to the assembly task. For precise and flexible positioning of the griper a complex 7-axes positioning system has been designed. It can be operated in the LC-SEM too, and offers a tool-center-point movement of the gripper in order to keep all assembly operations in the focus of the SEM. With these devices further study of micro assembly will be possible.

Weck, Manfred; Petersen, Bernd

1999-03-01

174

Two Pathfinder Tests of High Precision Astrometry On-Sky  

NASA Astrophysics Data System (ADS)

MCAO systems on ELTs should deliver the best available relative astrometric precision from the ground, which may be sufficient to detect exo-earths orbiting nearby brown and red dwarfs (< 0.03 mas). Yet despite the success of AO astrometry on large telescopes, we still do not understand the systematic errors that may dominate long-term astrometric stability with MCAO, such as dynamic optical distortion and differential atmospheric refraction (DAR). We present results from two on-sky pathfinders intended to characterize long-term systematic errors in MCAO systems and discuss implications for MCAO on ELTs. The first is an astrometric monitoring program of bright stars in 2013A on the GEMS LGS MCAO system. We isolate the effects of dynamic optical distortion by using narrow filters to counter atmospheric refraction and observing sparse fields to avoid crowding errors. We characterize the magnitude of long-term optical drift in GEMs as well as the dependency on the number of NGSs used. The second pathfinder is an on-sky test of the diffractive pupil concept on a 1-meter telescope at Lick Observatory, theorized to calibrate changing optical distortion with diffracted light from the target star (Guyon et al. 2012). These data indicate PSF modeling systematics of one thousandth of the star FWHM (1 mas) for individual stars, but we show that averaging the many diffracted PSFs reduces this error and other flat-fielding errors to the ~0.5 mas level. We show that the diffractive pupil stabilizes the instrumental distortion to at least the precision of the experiment (~1 mas over 3'). We simulate the astrometric performance of a hybrid MCAO + diffractive pupil system on ELTs. The diffracted PSFs include an anisoplanatic term, increasing PSF modeling errors, but the sum of all random errors (CDAR, DAR, DTTJ, S/N) can be better than 0.01 mas for 5 minute exposures for K < 15 stars.

Ammons, S. Mark; Bendek, Eduardo; Guyon, Olivier; Macintosh, Bruce; Marois, Christian; Neichel, Benoit; Galicher, Raphael; Savransky, Dimitri

2013-12-01

175

High precision Monte Carlo event generation for particle colliders  

NASA Astrophysics Data System (ADS)

Matrix-element calculations and parton shower programs are both crucial tools in the analysis of data at modern particle physics experiments at colliders. Finding the most effective ways to combine these complementary, but sometimes conflicting, approaches to simulating physical events has been the subject of much work in the recent decade. This thesis investigates state-of-the-art ways in which the precision of the matrix elements can be extended in combination with the parton shower. We identify three dimensions along which precision can be improved and describe how progress can be made along each one. First, we present a general method to match fully differential next-to-next-to-leading-order (NNLO) calculations to parton shower (PS) programs, which represents an extension of the successful LO+PS (leading order) and NLO+PS (next-to-leading order) frameworks to NNLO+PS. We discuss in detail the perturbative accuracy criteria a complete NNLO+PS matching has to satisfy, and we give an explicit and general construction of the input "Monte Carlo cross sections" satisfying all required criteria. Next, we describe how augmenting an NLO calculation with higher-order resummation of large Sudakov logarithms allows one to extend the lowest-order matching of tree-level matrix elements with parton showers to give a complete description at the next higher perturbative accuracy in alphas, at both small and large jet resolutions. As a byproduct, this combination naturally leads to a smooth connection of the NLO calculations for different jet multiplicities. We focus on the general construction of our method and present results of an implementation in the GENEVA Monte Carlo framework. For leptonic collisions, we apply our construction to e+e - ? jets and obtain good agreement with LEP data for a variety of 2-jet observables. For hadronic collisions, we look at Drell-Yan production.

Berggren, Calvin James

176

Virtual structures for high-precision cooperative mobile robotic control  

Microsoft Academic Search

A key problem in cooperative robotics is the maintenance of a geometric configuration during movement. To address this problem, the concept of a virtual structure is introduced. Control methods are developed to force an ensemble of robots to behave as if they were particles embedded in a rigid structure. The method was tested both using simulation and experimentation with a

Kar-Han Tan; M. Anthony Lewis

1996-01-01

177

High-precision control of LSRM based X-Y table for industrial applications.  

PubMed

The design of an X-Y table applying direct-drive linear switched reluctance motor (LSRM) principle is proposed in this paper. The proposed X-Y table has the characteristics of low cost, simple and stable mechanical structure. After the design procedure is introduced, an adaptive position control method based on online parameter identification and pole-placement regulation scheme is developed for the X-Y table. Experimental results prove the feasibility and its priority over a traditional PID controller with better dynamic response, static performance and robustness to disturbances. It is expected that the novel two-dimensional direct-drive system find its applications in high-precision manufacture area. PMID:22981303

Pan, J F; Cheung, Norbert C; Zou, Yu

2013-01-01

178

High precision predictions for exclusive V H production at the LHC  

NASA Astrophysics Data System (ADS)

We present a resummation-improved prediction for pp ? V H + 0 jets at the Large Hadron Collider. We focus on highly-boosted final states in the presence of jet veto to suppress the background. In this case, conventional fixed-order calculations are plagued by the existence of large Sudakov logarithms for Q ~ m V + m H which lead to unreliable predictions as well as large theoretical uncertainties, and thus limit the accuracy when comparing experimental measurements to the Standard Model. In this work, we show that the resummation of Sudakov logarithms beyond the next-to-next-to-leading-log accuracy, combined with the next-to-next-to-leading order calculation, reduces the scale uncertainty and stabilizes the perturbative expansion in the region where the vector bosons carry large transverse momentum. Our result improves the precision with which Higgs properties can be determined from LHC measurements using boosted Higgs techniques.

Li, Ye; Liu, Xiaohui

2014-06-01

179

A High Precision Feature Based on LBP and Gabor Theory for Face Recognition  

PubMed Central

How to describe an image accurately with the most useful information but at the same time the least useless information is a basic problem in the recognition field. In this paper, a novel and high precision feature called BG2D2LRP is proposed, accompanied with a corresponding face recognition system. The feature contains both static texture differences and dynamic contour trends. It is based on Gabor and LBP theory, operated by various kinds of transformations such as block, second derivative, direct orientation, layer and finally fusion in a particular way. Seven well-known face databases such as FRGC, AR, FERET and so on are used to evaluate the veracity and robustness of the proposed feature. A maximum improvement of 29.41% is achieved comparing with other methods. Besides, the ROC curve provides a satisfactory figure. Those experimental results strongly demonstrate the feasibility and superiority of the new feature and method. PMID:23552103

Xia, Wei; Yin, Shouyi; Ouyang, Peng

2013-01-01

180

Design and development of a high-precision, high-payload telescope dual-drive system  

NASA Astrophysics Data System (ADS)

A high precision, dual drive system has been designed and developed for the Wide Field Upgrade to the Hobby-Eberly Telescope* at McDonald Observatory in support of the Hobby-Eberly Telescope Dark Energy Experiment?. Analysis, design and controls details will be of interest to designers of large scale, high precision robotic motion devices. The drive system positions the 19,000 kg star tracker to a precision of less than 5 microns along its 4-meter travel. While positioning requirements remain essentially equal to the existing HET, tracker mass increases by a factor greater than 5. The 10.5-meter long tracker is driven at each end by planetary roller screws, each having two distinct drive sources dictated by the desired operation: one slowly rotates the screw when tracking celestial objects and the second rotates the nut for rapid displacements. Key results of the roller screw rotordynamics analysis are presented. A description of the complex bearing arrangement providing required degrees of freedom as well as the impact of a detailed Failure Modes and Effects Analysis addressing necessary safety systems is also presented. Finite element analysis results demonstrate how mechanical springs increase the telescope's natural frequency response by 22 percent. The critical analysis and resulting design is provided.

Worthington, Michael S.; Beets, Timothy A.; Beno, Joseph H.; Mock, Jason R.; Murphy, Brian T.; South, Brian J.; Good, John M.

2010-07-01

181

Mold, flow, and economic considerations in high temperature precision casting  

E-print Network

Casting high temperature alloys that solidify through a noticeable two phase region, specifically platinum-ruthenium alloys, is a particularly challenging task due to their high melting temperature and this necessitates ...

Humbert, Matthew S

2013-01-01

182

The accuracy and precision of the experimental ?-determination in the 1\\/E 1+? epithermal reactor-neutron spectrum  

Microsoft Academic Search

Some methods for the experimental ?-determination in the 1\\/E1+? epithermal reactorneutron spetrum are critically compared with respect to their accuracy and precision. The analysis is based\\u000a on the error propagation theory. Besides the general formulae numerical examples are elaborated for specific conditions in\\u000a the Thetis reactor (Gent) and the WWR-M reactor (Budapest).

F. De Corte; K. Sordo-El Hammami; L. Moens; A. Simonits; A. De Wispelaere; J. Hoste

1981-01-01

183

High-precision covariant one-boson-exchange potentials for np scattering below 350 MeV  

SciTech Connect

Using the Covariant Spectator Theory (CST), we have found One-Boson-Exchange (OBE) potentials that fit the 2006 world np data below 350 MeV with a chi2/Ndata very close to 1, for a total of 3788 data. Our potentials have significantly fewer adjustable parameters than previous high-precision potentials, and they also reproduce the experimental triton binding energy without introducing additional irreducible three-nucleon forces.

Franz Gross; Alfred Stadler

2007-09-10

184

New Insights into Stellar Astrophysics from High-Precision Photometry  

NASA Astrophysics Data System (ADS)

The rich harvest of information on the occurrence and nature of planets around solar-type stars is why Kepler was built, but equally profound from this mission are the insights and quantitative physical studies of stars. The Kepler sample is dominated by the ~100,000 stars that are like the Sun, yet the Kepler field includes examples of nearly every stellar type. Kepler's exquisite photometry - continuously over an extended time - has enabled the detection of new phenomena and has provided critical tests of stellar models. In this brief review I will summarize some of the exciting new findings that Kepler has made possible, including: Stellar surface granulation in late-type stars; Evidence for rapid rotation of the cores of some evolved stars; Flares on G, K and M stars; Precise ages for older solar-type stars; Evidence for "mixed" modes in evolved stars that couple p-modes to interior g-modes; Stellar differential rotation; Detection of stellar activity cycles from asteroseismology; Mixing processes in stars; Detailed studies of eclipsing binaries; A comparison of the Sun to similar stars; Pulsating stars; Stellar surface features revealed by planet transits.

Soderblom, David R.

2013-01-01

185

High-precision timeline for Earth's most severe extinction.  

PubMed

The end-Permian mass extinction was the most severe loss of marine and terrestrial biota in the last 542 My. Understanding its cause and the controls on extinction/recovery dynamics depends on an accurate and precise age model. U-Pb zircon dates for five volcanic ash beds from the Global Stratotype Section and Point for the Permian-Triassic boundary at Meishan, China, define an age model for the extinction and allow exploration of the links between global environmental perturbation, carbon cycle disruption, mass extinction, and recovery at millennial timescales. The extinction occurred between 251.941 ± 0.037 and 251.880 ± 0.031 Mya, an interval of 60 ± 48 ka. Onset of a major reorganization of the carbon cycle immediately precedes the initiation of extinction and is punctuated by a sharp (3‰), short-lived negative spike in the isotopic composition of carbonate carbon. Carbon cycle volatility persists for ?500 ka before a return to near preextinction values. Decamillenial to millennial level resolution of the mass extinction and its aftermath will permit a refined evaluation of the relative roles of rate-dependent processes contributing to the extinction, allowing insight into postextinction ecosystem expansion, and establish an accurate time point for evaluating the plausibility of trigger and kill mechanisms. PMID:24516148

Burgess, Seth D; Bowring, Samuel; Shen, Shu-zhong

2014-03-01

186

High precision determination of the terrestrial 40K abundance  

NASA Astrophysics Data System (ADS)

Recent improvements in the precision of mass spectrometric measurements have reduced the uncertainty of K-Ar and 39Ar-40Ar ages measured on geological materials. Now the major sources of uncertainty are the uncertainties on the 40K decay constant and the absolute abundance of 40K. In order to improve on this situation we determined the abundance of the 40K isotope in terrestrial standards. A ThermoFischer Triton+ thermal ionization mass spectrometer was used for K isotope ratio measurements of the NIST K standard reference materials SRM 918b and SRM 985. Ion beams were measured in Faraday cups with amplifiers equipped with 1010, 1011 and 1012 ? resistors. Three measurement protocols were used: (A) dynamic measurement with in-run fractionation correction by normalization to the IUPAC recommended isotope ratio 41K/39K = 0.072 1677; (B) total evaporation; (C) a modified total evaporation with interblock baseline measurements. Different measurement protocols were combined with different loading procedures. The best results were obtained by loading samples on single oxidized tantalum filaments with 0.1 M H3PO4. The total ion yields (ionization + transmission) were tested for the evaporation procedures (B) and (C) and ranged up to 48%. The resulting best estimate for the 40K/39K ratio is 0.000 125 116 ± 57 (2?), corresponding to an isotopic abundance 40K/K = (1.1668 ± 8) × 10-4.

Naumenko, Maria O.; Mezger, Klaus; Nägler, Thomas F.; Villa, Igor M.

2013-12-01

187

HIGH PRECISION MG ISOTOPE MEASUREMENTS OF METEORITIC SAMPLES BY SECONDARY ION MASS SPECTROMETRY  

E-print Network

1 HIGH PRECISION MG ISOTOPE MEASUREMENTS OF METEORITIC SAMPLES BY SECONDARY ION MASS SPECTROMETRY of isotopic ratios, typically of ± 5 ppm. In this study, we report for the first time a very detailed accuracy and precision of the final isotopic results, factors such as the Faraday cup (FC) background drift

188

A high precision pulsed quantum cascade laser spectrometer for measurements of stable isotopes of carbon dioxide  

E-print Network

A high precision pulsed quantum cascade laser spectrometer for measurements of stable isotopes for precise measurement of stable carbon (13 C/12 C) isotopologue ratios in atmospheric CO2. Using novel of analysis time. The standard deviation of 0.18ø for individual 30 s measurements shows that this prototype

Saleska, Scott

189

High-temperature precision forming of titanium blades  

SciTech Connect

Based on the experimental study of superplastic deformation parameters, a technology was developed for producing near-net-shape compressor blade forgings for gas turbine units from Ti-6.2Al-2.5Mo-1.5Cr-0.2Si-0.5Fe. The mechanical properties of these blades are higher than those of blades produced by conventional methods, and the anisotropy coefficient is reduced. The improved properties of the blades can be attributed to the isotropy of mechanical properties resulting from the homogeneous fine-grained equiaxed structure produced throughout the blade volume.

Ermachenko, A.G.; Karavayeva, M.V. [Russian Academy of Sciences, Ufa (Russian Federation). Inst. for Metals Superplasticity Problems

1996-10-01

190

Adaptive sliding mode control of a high-precision ball-screw-driven stage  

Microsoft Academic Search

High-precision position control has been widely used in scientific instruments and semiconductor fabrication equipment. Traditionally, controllable displacements with sub-micron and nano-level resolution are usually achieved by piezoelectric actuators because of their high bandwidth and ease of control. However, the travel range of piezoelectric actuator is usually small. In this paper, the ball-screw-driven system is studied to provide long-range and high-precision

Her-Terng Yau; Jun-Juh Yan

2009-01-01

191

A design of a low cost high precision data acquisition system  

Microsoft Academic Search

The paper presents a high precision data acquisition system with the LM231 V\\/F transform chip and a low cost single chip microcomputer. The V\\/F transformer features high precision, high linearity and with a simple peripheral circuit. The single chip microcomputer is connected directly to an interface with the LM231 chip that has a lower-power coupling circuit, to improve the system

Li Dongsheng

2002-01-01

192

Very-high-precision solutions of a class of Schrödinger type equations  

NASA Astrophysics Data System (ADS)

We investigate a method to solve a class of Schrödinger type equation eigenvalue problems numerically to very high precision P (from thousands to a million of decimals). The memory requirement, and the number of high-precision algebraic operations, of the method scale essentially linearly with P when only eigenvalues are computed. However, since the algorithms for multiplying high-precision numbers scale at a rate between P and PlogPloglogP, the time requirement of our method increases somewhat faster than P.

Mushtaq, Asif; Noreen, Amna; Olaussen, Kåre; Øverbø, Ingjald

2011-09-01

193

High speed, precision motion strategies for lightweight structures  

NASA Technical Reports Server (NTRS)

Abstracts of published papers and dissertations generated during the reporting period are compiled. Work on fine motion control was completed. Specifically, real time control of flexible manipulator vibrations were experimentally investigated. A linear model based on the application of Lagrangian dynamics to a rigid body mode and a series of separable flexible modes was examined with respect to model order requirements, and modal candidate selection. State feedback control laws were implemented based upon linear quadratic regulator design. Specification of the closed loop poles in the regulator design process was obtained by inclusion of a prescribed degree of stability in the manipulator model. Work on gross motion planning and control is also summarized. A systematic method to symbolically derive the full nonlinear dynamic equations of motion of multi-link flexible manipulators was developed.

Book, Wayne J.

1987-01-01

194

High precision speed measurement by using interferometric techniques  

NASA Astrophysics Data System (ADS)

In this work we present the experimental realization of speed measurement by the use of a two wave interferometer and digital signal processing techniques. We built an automated Michelson interferometer and using an He-Ne laser and with the use of the Fast Fourier Transform (FFT) and computer algorithms we derived a method for finding the speed of displacement. We report uncertainties in the order of 2-3 ?m/s. with the use of this procedure. This brings the potential of another physical variable measurement like distance or pressure by this indirect measurement method. This approach is compared with an ultrasonic Logger Pro ® speed measurement system, and the results are compared between systems.

Rodríguez Ávila, M. A.; Ochoa Valiente, R.; García Trujillo, L. A.

2015-01-01

195

Creating high-stability high-precision bipolar trim power supply  

SciTech Connect

Thomas Jefferson National Accelerator Facility (TJNAF) is founded by the US Department of Energy (DOE) office of science for the technology advancement and physics research in electron beam accelerator. This facility has the state of the art technology to carry out world-class cutting-edge experiments for the nucleus composition and atomic characteristics identification and exploration for the nature of the matter in the universe. A continuous wave electron beam is featured for such experiments, thus precise and stable trim power supply is required to meet such purpose. This paper demonstrates the challenges and solutions to design, assemble, fabrication and test such high-precision high-stability power supplies. This paper presents the novel design and first article test of the ±20A ±75V bipolar, 100ppm stability level current-regulated high-power trim power supplies for the beam manipulation. This special design can provide valuable documentation and reference values for future designs and special applications in particle accelerator power supply creation.

Chen, Zhe [JLAB; Merz, William A. [JLAB

2012-07-01

196

Development of a facility for high-precision irradiation of cells with carbon ions  

SciTech Connect

Purpose: Compared to photons, using particle radiation in radiotherapy reduces the dose and irradiated volume of normal tissues, potentially reducing side effects. The biological effect of dose deposited by particles such as carbon ions, however, differs from that of dose deposited by photons. The inaccuracy in models to estimate the biological effects of particle radiation remains the most important source of uncertainties in particle therapy. Improving this requires high-precision studies on biological effects of particle radiation. Therefore, the authors aimed to develop a facility for reproducible and high-precision carbon-ion irradiation of cells in culture. The combined dose nonuniformity in the lateral and longitudinal direction should not exceed {+-}1.5%. Dose to the cells from particles than other carbon ions should not exceed 5%. Methods: A uniform lateral dose distribution was realized using a single scatter foil and quadrupole magnets. A modulator wheel was used to create a uniform longitudinal dose distribution. The choice of beam energy and the optimal design of these components was determined using GEANT4 and SRIM Monte Carlo simulations. Verification of the uniformity of the dose distribution was performed using a scintillating screen (lateral) and a water phantom (longitudinal). The reproducibility of dose delivery between experiments was assessed by repeated measurements of the spatial dose distribution. Moreover, the reproducibility of dose-response measurements was tested by measuring the survival of irradiated HEK293 cells in three independent experiments. Results: The relative contribution of dose from nuclear reaction fragments to the sample was found to be <5% when using 90 MeV/u carbon ions. This energy still allows accurate dosimetry conforming to the IAEA Report TRS-398, facilitating comparison to dose-effect data obtained with other radiation qualities. A 1.3 mm long spread-out Bragg peak with a diameter of 30 mm was created, allowing the irradiation of cell samples with the specified accuracy. Measurements of the transverse and longitudinal dose distribution showed that the dose variation over the sample volume was {+-}0.8% and {+-}0.7% in the lateral and longitudinal directions, respectively. The track-averaged LET of 132{+-}10 keV/{mu}m and dose-averaged LET of 189{+-}15 keV/{mu}m at the position of the sample were obtained from a GEANT4 simulation, which was validated experimentally. Three separately measured cell-survival curves yielded nearly identical results. Conclusions: With the new facility, high-precision carbon-ion irradiations of biological samples can be performed with highly reproducible results.

Goethem, Marc-Jan van; Niemantsverdriet, Maarten; Brandenburg, Sytze; Langendijk, Johannes A.; Coppes, Robert P.; Luijk, Peter van [Department of Cell Biology, Section of Radiation and Stress Cell Biology, University Medical Center Groningen, University of Groningen, A. Deusinglaan 1, 9713AV Groningen (Netherlands); Department of Radiation Oncology, University Medical Center Groningen, University of Groningen, P.O. Box 30001, 9700RB Groningen (Netherlands); Kernfysisch Versneller Instituut, University of Groningen, Zernikelaan 25, 9747AA Groningen (Netherlands); Department of Radiation Oncology, University Medical Center Groningen, University of Groningen, P.O. Box 30001, 9700RB Groningen (Netherlands); Department of Cell Biology, Section of Radiation and Stress Cell Biology, University Medical Center Groningen, University of Groningen, A. Deusinglaan 1, 9713AV Groningen (Netherlands); Department of Radiation Oncology, University Medical Center Groningen, University of Groningen, P.O. Box 30001, 9700RB Groningen (Netherlands)

2011-01-15

197

Pointing Control System for a High Precision Flight Telescope  

SciTech Connect

A pointing control system is developed and tested for a flying gimbaled telescope. The two-axis pointing system is capable of sub-microradian pointing stability and high accuracy in the presence of large host vehicle jitter. The telescope also has high agility--it is capable of a 50-degree retarget (in both axes simultaneously) in less than 2 seconds. To achieve the design specifications, high-accuracy, high-resolution, two-speed resolvers were used, resulting in gimbal-angle measurements stable to 1.5 microradians. In addition, on-axis inertial angle displacement sensors were mounted on the telescope to provide host-vehicle jitter cancellation. The inertial angle sensors are accurate to about 100 nanoradians, but do not measure low frequency displacements below 2 Hz. The gimbal command signal includes host-vehicle attitude information, which is band-limited. This provides jitter data below 20 Hz, but includes a variable latency between 15 and 25 milliseconds. One of the most challenging aspects of this design was to combine the inertial-angle-sensor data with the less perfect information in the command signal to achieve maximum jitter reduction. The optimum blending of these two signals, along with the feedback compensation were designed using Quantitative Feedback Theory.

BENTLEY,ANTHONY E.; WILCOXEN,JEFFREY LEE

2000-12-01

198

High-precision position control of a heavy-lift manipulator in a dynamic environment  

E-print Network

This thesis considers the control of a heavy-lift serial manipulator operating on the deck of a large ocean vessel. This application presents a unique challenge for high- precision control because the system must contend ...

Garretson, Justin R. (Justin Richard)

2005-01-01

199

Isotope-ratio-monitoring gas chromatography methods for high-precision isotopic analysis of nanomole  

E-print Network

Isotope-ratio-monitoring gas chromatography methods for high-precision isotopic analysis and a commercially available continuous-flow, gas chromatography interface (the Finnigan Gas Bench II). This work

Bebout, Gray E.

200

High-precision pointing and attitude estimation and control algorithms for hardware-constrained spacecraft  

E-print Network

The overarching objective of this thesis is to develop algorithms for high-precision pointing and attitude estimation and control on hardware-constrained spacecraft. This includes small spacecraft, where tight mass, volume, ...

Pong, Christopher Masaru

2014-01-01

201

Assessing the precision of strain measurements using electron backscatter diffraction--part 2: experimental demonstration.  

PubMed

The residual impression after performing a microhardness indent in silicon has been mapped with high resolution EBSD to reveal residual elastic strain and lattice rotation fields. Mapping of the same area has been performed with variable pattern binning and exposure times to reveal the qualitative and quantitative differences resulting from reducing the pattern size and exposure time. Two dimension 'image' plots of these fields indicate that qualitative assessment of the shape and size of the fields can be performed with as much as 4×4 binning. However, quantitative assessment using line scans reveals that the smoothest profile can be obtained using minimal pattern binning and long exposure times. To compare and contrast with these experimental maps, finite element analysis has been performed using a continuum damage-plasticity material law which has been independently calibrated to Si [9]. The constitutive law incorporates isotropic hardening in compression, and isotropic hardening and damage in tension. To accurately capture the localised damage which develops during indentation via the nucleation and propagation of cracks around the indentation site cohesive elements were assigned along the interfaces between the planes which experience the maximum traction. The residual strain state around the indenter and the size of the cracks agree very well with the experimentally measured value. PMID:24034981

Britton, T B; Jiang, J; Clough, R; Tarleton, E; Kirkland, A I; Wilkinson, A J

2013-12-01

202

Modeling and high-precision control of a ball-screw-driven stage  

Microsoft Academic Search

The demand for high-precision stages has received great attention due to the progress of nano-technology in recent years. Systems to provide long-range and high-precision performance for positioning, tracking and contouring actions have become stringent issues. Among these systems, the ball-screw-driven systems have been widely used in industrial applications and academic researches. In such systems, the friction behavior dominates the resulting

C. L. Chen; M. J. Jang; K. C. Lin

2004-01-01

203

Design of high precision motor driving system for circular scanning ultrasonic endoscopic imaging equipment  

NASA Astrophysics Data System (ADS)

This paper describes the development of a motor driving system for circular scanning ultrasonic endoscopic imaging equipment. It was designed to guarantee the motor rotating at a relatively constant speed in load fluctuation conditions, which result from the bending and twisting of the flexible shaft which connects the probe to the motor. A hardware feedback circuit based on Frequency-To-Voltage Converter LM331 and Step-Down Voltage Regulator LM2576-ADJ was designed to ensure steady rotation of motor in load fluctuation conditions, and a D/A module offered by MCU was used to regulate the real-time rotary speed. The feedback response cycle is about 20 ?s according to theoretical analysis. Experimental results show that the maximum error is +/-1 r/min under the normal running environment (300 ~1500 r/min) and load fluctuation conditions, which means the average instability is reduced to 0.11% as compared with that of the motor drive simply based on MCU which is 0.94%. Both theoretical analysis and experimental results indicate that the motor driving system has high accuracy, fast response, excellent reliability and good versatility and portability, and can precisely guarantee the smooth movement of load-changing PMW (Pulse Width Modulation) motor, so as to ensure the imaging quality, and can effectively improve the efficiency and accuracy of the diagnosis.

Deng, Haoran; Bai, Baoping; Chen, Xiaodong; Zhao, Qiang; Li, Yanan; Wang, Yi; Yu, Daoyin

2013-12-01

204

High speed precision motion strategies for lightweight structures  

NASA Technical Reports Server (NTRS)

Work during the recording period proceeded along the lines of the proposal, i.e., three aspects of high speed motion planning and control of flexible structures were explored: fine motion control, gross motion planning and control, and automation using light weight arms. In addition, modeling the large manipulator arm to be used in experiments and theory has lead to some contributions in that area. These aspects are reported below. Conference, workshop and journal submissions, and presentations related to this work were seven in number, and are listed. Copies of written papers and abstracts are included.

Book, Wayne J.

1987-01-01

205

High precision moving magnet chopper for variable operation conditions  

NASA Technical Reports Server (NTRS)

In the context of an ESTEC technology contract, a Chopping Mechanism was developed and built with the Far Infrared and Submillimeter Telescope (FIRST) astronomy mission as a reference. The task of the mechanism is to tilt the subreflector of the telescope with an assumed mass of 2.5 kg about one chopping axis at nominal frequencies of up to 5 Hz and chopping angles of up to +/- 11.25 mrad with high efficiency (minimum time for position change). The chopping axis is required to run through the subreflector vertex. After performing a concept trade-off also considering the low operational temperatures in the 130 K range, a design using moving magnet actuators was found to be the favorite one. In addition, a bearing concept using flexible pivots was chosen to meet the high chopping accuracy required. With this approach, a very reliable design could be realized, since the actuators work without any mechanical contact between its moving and fixed parts, and the only bearings used are two flexible pivots supporting the subreflector mounting interface. The mechanism was completely built in titanium in a lightweight and stiff design. The moving magnet actuators were designed to meet the stringent requirements for minimum risetime (time necessary to move from one angular position to a new one) in the 20 msec range. The angular position and the corresponding chopping frequency as well can be arbitrarily selected by the user.

Aicher, Winfried; Schmid, Manfred

1994-01-01

206

A high-precision mechanical absolute-rotation sensor.  

PubMed

We have developed a mechanical absolute-rotation sensor capable of resolving ground rotation angle of less than 1 nrad/?Hz above 30 mHz and 0.2 nrad/?Hz above 100 mHz about a single horizontal axis. The device consists of a meter-scale beam balance, suspended by a pair of flexures, with a resonance frequency of 10.8 mHz. The center of mass is located 3 ?m above the pivot, giving an excellent horizontal displacement rejection of better than 3 × 10(-5) rad/m. The angle of the beam is read out optically using a high-sensitivity autocollimator. We have also built a tiltmeter with better than 1 nrad/?Hz sensitivity above 30 mHz. Co-located measurements using the two instruments allowed us to distinguish between background rotation signal at low frequencies and intrinsic instrument noise. The rotation sensor is useful for rotational seismology and for rejecting background rotation signal from seismometers in experiments demanding high levels of seismic isolation, such as Advanced Laser Interferometer Gravitational-wave Observatory. PMID:24517804

Venkateswara, Krishna; Hagedorn, Charles A; Turner, Matthew D; Arp, Trevor; Gundlach, Jens H

2014-01-01

207

A high-precision mechanical absolute-rotation sensor  

NASA Astrophysics Data System (ADS)

We have developed a mechanical absolute-rotation sensor capable of resolving ground rotation angle of less than 1 nrad/sqrt{Hz} above 30 mHz and 0.2 nrad/sqrt{Hz} above 100 mHz about a single horizontal axis. The device consists of a meter-scale beam balance, suspended by a pair of flexures, with a resonance frequency of 10.8 mHz. The center of mass is located 3 ?m above the pivot, giving an excellent horizontal displacement rejection of better than 3 × 10-5 rad/m. The angle of the beam is read out optically using a high-sensitivity autocollimator. We have also built a tiltmeter with better than 1 nrad/sqrt{Hz} sensitivity above 30 mHz. Co-located measurements using the two instruments allowed us to distinguish between background rotation signal at low frequencies and intrinsic instrument noise. The rotation sensor is useful for rotational seismology and for rejecting background rotation signal from seismometers in experiments demanding high levels of seismic isolation, such as Advanced Laser Interferometer Gravitational-wave Observatory.

Venkateswara, Krishna; Hagedorn, Charles A.; Turner, Matthew D.; Arp, Trevor; Gundlach, Jens H.

2014-01-01

208

A study of the high-precision displacement laser probe  

NASA Astrophysics Data System (ADS)

On the basis of the measuring principle of the dynamic active optical confocal probe based on time difference measurement that has a reference path, a dynamic active optical confocal probe based on time difference measurement but has no reference path is developed. In this paper, the working principle of this optical confocal probe is dissertated. A large-scale integrated measuring system is designed to simplify the structure of the probe and to enhance the stability of the probe. Single-chip microcomputer system with a high-speed ADC is selected in the measurement and control system of the probe. At the end of the paper, experiments on the performance of the optical confocal probe based on time difference measurement with no reference path are carried out. Experiment results show that the probe has a measuring resolution of 0.05?m, a measuring range of 0.2mm and a linearity of 0.4?m.

Fan, Yuming; Zhang, Guoxiong

2006-06-01

209

Precision high energy liner implosion experiments PHELIX [1  

SciTech Connect

This paper describes the hardware design of a small megajoule sized transformer coupled pulse power system utilized to drive hydrodynamic liner experiments with a nominal current capability of 10 megAmperes. The resulting liner velocities and characteristics provide properties of physics interest. The capacitor banks utilize the ''Atlas'' plastic cased 60 kV, 60 kJ capacitors [2] and railgaps [3]. The air insulated marx'S are configured to dive a multi-filar toroidal transformer. The 4:1 multi-filar toroidal transformer is mechanically part of a circular disc line and this feature results in an attractive inductance budget. Because of the compact size, re-usable transformer, and resulting low maintenance cost, shot rates can be high compared to other ''large'' machines or explosively driven hydrodynamic methods. The PHELIX modeling, construction status, and test results will also be provided.

Reass, William A [Los Alamos National Laboratory; Baca, David M [Los Alamos National Laboratory; Griego, Jeffrey R [Los Alamos National Laboratory; Reinovsky, Robert E [Los Alamos National Laboratory; Rousculp, Christopher L [Los Alamos National Laboratory; Turchi, Peter J [Los Alamos National Laboratory

2009-01-01

210

High Precision Superconducting Cavity Diagnostics With Higher Order Mode Measurements  

SciTech Connect

Experiments at the FLASH facility at DESY have demonstrated that the higher order modes induced in superconducting cavities can be used to provide a variety of beam and cavity diagnostics. The axes of the modes can be determined from the beam orbit that produces minimum power in the dipole HOM modes. The phase and amplitude of the dipole modes can be used to obtain high resolution beam position information, and the phase of the monopole modes to measure the beam phase relative to the accelerator rf. For most superconducting accelerators, the existing higher order mode couplers provide the necessary signals, and the downmix and digitizing electronics are straightforward, similar to those for a conventional beam position monitor.

Molloy, S.; Frisch, J.; McCormick, D.; May, J.; Ross, M.; Smith, T.; /SLAC; Baboi, N.; Hensler, O.; Petrosian, L.; /DESY; Napoly, O.; Paparella, R.C.; Simon, C.; /Saclay; Eddy, N.; Nagaitsev, S.; Wendt, M.; /Fermilab

2007-02-12

211

High precision pointing with a multiline spectrometer at the VTT  

NASA Astrophysics Data System (ADS)

We are investigating the pointing quality of the VTT, Tenerife under the aspect of suitability for long-term heliosesimological observations. Tests have shown that thermal and mechanical loads within the telescope may create spurious image drifts with shift rates of up to 5 arcsec per hour. During daylong recordings this will reduce significantly the effective size of the field-of-view and may infer artificial lateral movements into the data. The underlying problem that not all image position offsets developing during a measurement may be compensated for is common to most high-resolution solar telescopes independently of the type of pointing system used. We are developing new approaches to address this problem which are to be tested in the near future at the VTT. The simulations established so far show that the problem may be reduced by more than 90 %.

Staiger, J.

2012-12-01

212

Atomic Hydrogen as High-Precision Field Standard for High-Field EPR  

PubMed Central

We introduce atomic hydrogen trapped in an octaisobutylsilsesquioxane nanocage (H@iBuT8) as a new molecular high-precision magnetic field standard for high-field EPR spectroscopy of organic radicals and other systems with signals around g = 2. Its solid-state EPR spectrum consists of two narrow lines separated by about 51 mT and centered at g ? 2. The isotropic g factor is 2.00294(3) and essentially temperature independent. The isotopic 1H hyperfine coupling constant is 1416.8(2) MHz below 70 K and decreases slightly with increasing temperature to 1413.7(1) MHz at room temperature. The spectrum of the standard does not overlap with those of most organic radicals, and it can be easily prepared and is stable at room temperature. PMID:20813570

Stoll, Stefan; Ozarowski, Andrew; Britt, R. David; Angerhofer, Alexander

2010-01-01

213

A high precision ultrasonic system for vibration measurements  

NASA Astrophysics Data System (ADS)

A microcomputer-aided ultrasonic system that can be used to measure the vibratory displacements of an object is presented. A pair of low cost 40-kHz ultrasonic transducers is used to transmit ultrasound toward an object and receive the ultrasound reflected from the object. The relative motion of the object modulates the phase angle difference between the transmitted and received ultrasound signals. A single-chip microcomputer-based phase detector was designed to record and analyze the phase shift information which is then sent to a PC-AT microcomputer for processing. We have developed an ingenious method to reconstruct the relative motion of an object from the acquired data of the phase difference changes. A digital plotter based experiment was also designed for testing the performance of the whole system. The measured accuracy of the system in the reported experiments is within +/- 0.4 mm and the theoretical maximal measurable speed of the object is 89.6 cm/s. The main advantages of this ultrasonic vibration measurement system are high resolution, low cost, noncontact measurement, and easy installation.

Young, M. S.; Li, Y. C.

1992-11-01

214

A research of a high precision multichannel data acquisition system  

NASA Astrophysics Data System (ADS)

The output signals of the focusing system in lithography are analog. To convert the analog signals into digital ones which are more flexible and stable to process, a desirable data acquisition system is required. The resolution of data acquisition, to some extent, affects the accuracy of focusing. In this article, we first compared performance between the various kinds of analog-to-digital converters (ADC) available on the market at the moment. Combined with the specific requirements (sampling frequency, converting accuracy, numbers of channels etc) and the characteristics (polarization, amplitude range etc) of the analog signals, the model of the ADC to be used as the core chip in our hardware design was determined. On this basis, we chose other chips needed in the hardware circuit that would well match with ADC, then the overall hardware design was obtained. Validation of our data acquisition system was verified through experiments and it can be demonstrated that the system can effectively realize the high resolution conversion of the multi-channel analog signals and give the accurate focusing information in lithography.

Zhong, Ling-na; Tang, Xiao-ping; Yan, Wei

2013-08-01

215

High Resolution Airborne Digital Imagery for Precision Agriculture  

NASA Technical Reports Server (NTRS)

The Environmental Research Aircraft and Sensor Technology (ERAST) program is a NASA initiative that seeks to demonstrate the application of cost-effective aircraft and sensor technology to private commercial ventures. In 1997-98, a series of flight-demonstrations and image acquisition efforts were conducted over the Hawaiian Islands using a remotely-piloted solar- powered platform (Pathfinder) and a fixed-wing piloted aircraft (Navajo) equipped with a Kodak DCS450 CIR (color infrared) digital camera. As an ERAST Science Team Member, I defined a set of flight lines over the largest coffee plantation in Hawaii: the Kauai Coffee Company's 4,000 acre Koloa Estate. Past studies have demonstrated the applications of airborne digital imaging to agricultural management. Few studies have examined the usefulness of high resolution airborne multispectral imagery with 10 cm pixel sizes. The Kodak digital camera integrated with ERAST's Airborne Real Time Imaging System (ARTIS) which generated multiband CCD images consisting of 6 x 106 pixel elements. At the designated flight altitude of 1,000 feet over the coffee plantation, pixel size was 10 cm. The study involved the analysis of imagery acquired on 5 March 1998 for the detection of anomalous reflectance values and for the definition of spectral signatures as indicators of tree vigor and treatment effectiveness (e.g., drip irrigation; fertilizer application).

Herwitz, Stanley R.

1998-01-01

216

High precision fabrication and positioning of nanoelectrodes in a nanopore.  

PubMed

A simple and versatile method for the direct fabrication of tunneling electrodes with controllable gap distance by using electron-beam-induced deposition (EBID) is presented. We show that tunneling nanogaps smaller than the minimum feature size realizable by conventional EBID can be achieved with a standard scanning electron microscope. These gaps can easily be embedded in nanopores with high accuracy. The controllability of this fabrication method and the nanogap geometry was verified by SEM and TEM imaging. Furthermore, tunneling spectroscopy in a group of solvents with different barrier heights was used to determine the nanogap functionality. Ultimately, the presented fabrication method can be further applied for the fabrication of arrays of nanogap/nanopores or nanogap electrodes with tunable electrode materials. Additionally, this method can also offer direct fabrication of nanoscale electrode systems with tunable spacing for redox cycling and plasmonic applications, which represents an important step in the development of tunneling nanopore structures and in enhancing the capabilities of nanopore sensors. PMID:24446951

Ivanov, Aleksandar P; Freedman, Kevin J; Kim, Min Jun; Albrecht, Tim; Edel, Joshua B

2014-02-25

217

In-plane laser forming for high precision alignment  

NASA Astrophysics Data System (ADS)

Laser microforming is extensively used to align components with submicrometer accuracy, often after assembly. While laser-bending sheet metal is the most common laser-forming mechanism, the in-plane upsetting mechanism is preferred when a high actuator stiffness is required. A three-bridge planar actuator made out of Invar 36 sheet was used to characterize this mechanism by experiments, finite element method modeling, and a fast-reduced model. The predictions of the thermal models agree well with the temperature measurements, while the final simulated displacement after 15 pulses deviates up to a factor of 2 from the measurement, using standard isotropic hardening models. Furthermore, it was found from the experiments and models that a small bridge width and a large bridge thickness are beneficial to decrease the sensitivity to disturbances in the process. The experiments have shown a step size as small as 0.1 ?m, but with a spread of 20%. This spread is attributed to scattering in surface morphology, which affects the absorbed laser power. To decrease the spread and increase the positioning accuracy, an adapted closed-loop learning algorithm is proposed. Simulations using the reduced model showed that 78% of the alignment trials were within the required accuracy of ±0.1 ?m.

Folkersma, Ger; Römer, Gert-Willem; Brouwer, Dannis; Veld, Bert Huis in't.

2014-12-01

218

High-precision and high-accuracy rovibrational spectroscopy of molecular ions  

NASA Astrophysics Data System (ADS)

We present a versatile new instrument capable of measuring rovibrational transition frequencies of molecular ions with sub-MHz accuracy and precision. A liquid-nitrogen cooled positive column discharge cell, which can produce large column densities of a wide variety of molecular ions, is probed with sub-Doppler spectroscopy enabled by a high-power optical parametric oscillator locked to a moderate finesse external cavity. Frequency modulation (heterodyne) spectroscopy is employed to reduce intensity fluctuations due to the cavity lock, and velocity modulation spectroscopy permits ion-neutral discrimination. The relatively narrow Lamb dips are precisely and accurately calibrated using an optical frequency comb. This method is completely general as it relies on the direct measurement of absorption or dispersion of rovibrational transitions. We expect that this new approach will open up many new possibilities: from providing new benchmarks for state-of-the-art ab initio calculations to supporting astronomical observations to helping assign congested spectra by combination differences. Herein, we describe the instrument in detail and demonstrate its performance by measuring ten R-branch transitions in the ?2 band of H_3^+, two transitions in the ?1 band of HCO+, and the first sub-Doppler transition of CH_5^+.

Hodges, James N.; Perry, Adam J.; Jenkins, Paul A.; Siller, Brian M.; McCall, Benjamin J.

2013-10-01

219

High-Precision Noble Gas Analysis of Allende Diamond  

NASA Astrophysics Data System (ADS)

We have performed a high-resolution step-wise pyrolysis experiment (29 temperature steps from 600 degrees C to 2100 degrees C) on a 1.625 mg sample of diamond (is identical to C delta) residue from Allende (CV3) prepared at Washington University. Our initial motivation for this work was to determine, by utilizing a relatively large number of release fractions, whether any of the Xe components previously observed in meteoritic C delta residues (e.g., Xe-P3, Xe-HL is identical to Xe-Ex, Xe-Y [1-4]) could be better resolved. In particular, we wanted to determine whether any temperature-dependent separation of Xe-H from Xe-L could be observed (as has been noted by [2]). However, as expected on a priori grounds [e.g. 4], such a separation was not observed, and the Ne, Ar, Kr, and Xe analyses of this work are consistent, within error, with previous noble gas analyses of meteoritic diamond [1-4]. The Xe data (Fig. 1) show the three-component mixing seen in earlier works [1-4]. The inferred Xe-Ex endmember composition is in good agreement with the results of [4], which utilized a larger suite of meteorites. The inferred limits on the possible endmember compositions of the Xe-Y component, however, are somewhat different from those derived in [4] (See Fig. 1). The Ar data show a similar three-component mixing (Ar-P3, Ar-Ex, Ar-Y; cf. [4]), and we obtain the following limits for ^38Ar/^36Ar in the latter two components: (^38Ar/^36Ar)(sub)Ex > 0.2220 and (^38Ar/^36Ar)(sub)Y < 0.2088. In addition, our data indicate that (Ar/Xe)(sub)P3>(Ar/Xe)(sub)Y>(Ar/Xe)(sub)Ex, consistent with the results of [4]. The Ne data clearly indicate the presence of at least two components: Ne-P3 and Ne-A2. On a standard Ne three- isotope plot the Ne data lie within ~2 sigma of a line connecting the points (20:21:22) = (8.45:0.032:1.00) and = (7.65:0.41:1.00). Although Ne-A2 may possibly represent a mix between a Ne-Ex and a Ne-Y component [4], we cannot resolve Ne-Ex from Ne-Y, neither on the basis of the Ne isotopes alone nor by relying on the elemental abundances of these components for Ar and Xe. Contributions from a Ne-E-like component and spallogenic Ne may be required to explain the data. However, such contributions are probably not indigenous to the diamonds, but may be due to minor contaminant phases or to gases inherited from phases dissolved during processing. We also observe clear excesses of spallogenic and halogen-derived (from neutron captures) Ar, Kr, and Xe in the lower temperature fractions. Again, these components are probably not indigenous to the diamonds, but were presumably acquired by the diamonds from other phases during processing or via implantation from spallation recoils during Allende's recent cosmic ray exposure. Similar neutron effects occurring during Allende's recent exposure have been observed by [5] and larger neutron effects were observed in an Inman residue of lesser purity [2]. References. [1] Lewis R. S. and Anders E. (1988) LPS XIX, 679- 680. [2] Nichols R. H. Jr. et al. (1991) GCA, 55, 2921-2936. [3] Verchovsky et al. (1993) LPS XXIII, 1467-1468. [4] Huss G. R. and Lewis R. S. (1993) Meteoritics, submitted. [5] Gobel R. et al. (1992) GCA 46, 1777-1792.

Brazzle, R. H.; Gao, X.; Hohenberg, C. M.; Nichols, R. H., Jr.

1993-07-01

220

HIGH PRECISION K-SHELL PHOTOABSORPTION CROSS SECTIONS FOR ATOMIC OXYGEN: EXPERIMENT AND THEORY  

SciTech Connect

Photoabsorption of atomic oxygen in the energy region below the 1s {sup -1} threshold in X-ray spectroscopy from Chandra and XMM-Newton is observed in a variety of X-ray binary spectra. Photoabsorption cross sections determined from an R-matrix method with pseudo-states and new, high precision measurements from the Advanced Light Source (ALS) are presented. High-resolution spectroscopy with E/{Delta}E Almost-Equal-To 4250 {+-} 400 was obtained for photon energies from 520 eV to 555 eV at an energy resolution of 124 {+-} 12 meV FWHM. K-shell photoabsorption cross section measurements were made with a re-analysis of previous experimental data on atomic oxygen at the ALS. Natural line widths {Gamma} are extracted for the 1s {sup -1}2s {sup 2}2p {sup 4}({sup 4} P)np {sup 3} P Degree-Sign and 1s {sup -1}2s {sup 2}2p {sup 4}({sup 2} P)np {sup 3} P Degree-Sign Rydberg resonances series and compared with theoretical predictions. Accurate cross sections and line widths are obtained for applications in X-ray astronomy. Excellent agreement between theory and the ALS measurements is shown which will have profound implications for the modeling of X-ray spectra and spectral diagnostics.

McLaughlin, B. M. [Centre for Theoretical Atomic, Molecular and Optical Physics (CTAMOP), School of Mathematics and Physics, Queen's University Belfast, Belfast BT7 1NN (United Kingdom); Ballance, C. P. [Department of Physics, 206 Allison Laboratory, Auburn University, Auburn, AL 36849-5311 (United States); Bowen, K. P.; Gardenghi, D. J.; Stolte, W. C., E-mail: b.mclaughlin@qub.ac.uk, E-mail: ballance@physics.auburn.edu, E-mail: bowenk4@gmail.com, E-mail: dgardenghi@gmail.com, E-mail: wcstolte@lbl.gov [Department of Chemistry, University of Nevada, Las Vegas, NV 89154-4003 (United States)

2013-07-01

221

High Precision K-shell Photoabsorption Cross Sections for Atomic Oxygen: Experiment and Theory  

NASA Astrophysics Data System (ADS)

Photoabsorption of atomic oxygen in the energy region below the 1s -1 threshold in X-ray spectroscopy from Chandra and XMM-Newton is observed in a variety of X-ray binary spectra. Photoabsorption cross sections determined from an R-matrix method with pseudo-states and new, high precision measurements from the Advanced Light Source (ALS) are presented. High-resolution spectroscopy with E/?E ? 4250 ± 400 was obtained for photon energies from 520 eV to 555 eV at an energy resolution of 124 ± 12 meV FWHM. K-shell photoabsorption cross section measurements were made with a re-analysis of previous experimental data on atomic oxygen at the ALS. Natural line widths ? are extracted for the 1s -12s 22p 4(4 P)np 3 P° and 1s -12s 22p 4(2 P)np 3 P° Rydberg resonances series and compared with theoretical predictions. Accurate cross sections and line widths are obtained for applications in X-ray astronomy. Excellent agreement between theory and the ALS measurements is shown which will have profound implications for the modeling of X-ray spectra and spectral diagnostics.

McLaughlin, B. M.; Ballance, C. P.; Bowen, K. P.; Gardenghi, D. J.; Stolte, W. C.

2013-07-01

222

Use of Terrestrial Laser Scanning Technology for Long Term High Precision Deformation Monitoring  

PubMed Central

The paper presents a new methodology for high precision monitoring of deformations with a long term perspective using terrestrial laser scanning technology. In order to solve the problem of a stable reference system and to assure the high quality of possible position changes of point clouds, scanning is integrated with two complementary surveying techniques, i.e., high quality static GNSS positioning and precise tacheometry. The case study object where the proposed methodology was tested is a high pressure underground pipeline situated in an area which is geologically unstable. PMID:22303152

Vezo?nik, Rok; Ambroži?, Tomaž; Sterle, Oskar; Bilban, Gregor; Pfeifer, Norbert; Stopar, Bojan

2009-01-01

223

High-precision half-life measurement for the superallowed ?+ emitter ²?Al(m).  

PubMed

A high-precision half-life measurement for the superallowed ?+ emitter 26Al(m) was performed at the TRIUMF-ISAC radioactive ion beam facility yielding T 1/2 6346.54 ± 0.46(stat) ± 0.60 (syst) ms, consistent with, but 2.5 times more precise than, the previous world average. The 26Al(m) half-life and ft value, 3037.53(61) s, are now the most precisely determined for any superallowed ? decay. Combined with recent theoretical corrections for isospin-symmetry-breaking and radiative effects, the corrected Ft value for (26)Al(m), 3073.0(12) s, sets a new benchmark for the high-precision superallowed Fermi ?-decay studies used to test the conserved vector current hypothesis and determine the V(ud) element of the Cabibbo-Kobayashi-Maskawa quark mixing matrix. PMID:21405268

Finlay, P; Ettenauer, S; Ball, G C; Leslie, J R; Svensson, C E; Andreoiu, C; Austin, R A E; Bandyopadhyay, D; Cross, D S; Demand, G; Djongolov, M; Garrett, P E; Green, K L; Grinyer, G F; Hackman, G; Leach, K G; Pearson, C J; Phillips, A A; Sumithrarachchi, C S; Triambak, S; Williams, S J

2011-01-21

224

High-precision wavelength calibration of astronomical spectrographs with laser frequency combs  

Microsoft Academic Search

We describe a possible new technique for precise wavelength calibration of high-resolution astronomical spectrographs using femtosecond-pulsed mode-locked lasers controlled by stable oscillators such as atomic clocks. Such `frequency combs' provide a series of narrow modes which are uniformly spaced according to the laser's pulse repetition rate and whose absolute frequencies are known a priori with relative precision better than 10-12.

M. T. Murphy; Th. Udem; R. Holzwarth; A. Sizmann; L. Pasquini; C. Araujo-Hauck; H. Dekker; S. D'Odorico; M. Fischer; T. W. Hänsch; A. Manescau

2007-01-01

225

Design and testing of a highly stable and precise resistivity-meter  

E-print Network

sensitive to resistivity variations. The method claims sensitivity approaching 10 s over a, period of years. To date, no resistivity changes conclusively correlated with earthquakes have been reported. Park and Fitterman (1990) installed at Parkfield... a highly stable and precise resistivity-meter. A stability and precision of 1 part in 10 to 10 will allow the monitoring of small resistivity changes associated with earthquakes, strain due to earth tides and some forms of chemical contamination...

Chauvelier, Chantal Martine

1991-01-01

226

High-speed and Precise Geometric Correction for GMS S-VISSR Data  

Microsoft Academic Search

In this paper, high-speed and precise geometric correction for GMS S-VISSR data is described. Bi-linear interpolation is used for speeding up the geometric correction. The precise correction is carried out by using the ground control points. Moreover, the geometric correction considering the elevation is applied in land area. In the case of the correction on infrared channels, visible and infrared

Masaki YASUKAWA; Mikio TAKAGI; Masaru KITSUREGAWA

2002-01-01

227

High-speed and precise geometric correction for GMS S-VISSR data  

Microsoft Academic Search

In this paper, high-speed and precise geometric correction for GIMS S-VISSR data is described. Bi-linear interpolation is used for speeding up the geometric correction. The precise correction is carried out by using the ground control points. Moreover, the geometric correction considering the elevation is applied in land area. In the case of the correction on infrared channels, visible and infrared

Masaki YASUKAWA; Mikio TAKAGI; Masaru KITSUREGAWA

2004-01-01

228

High-precision measurements of ? p elastic differential cross sections in the second resonance region  

NASA Astrophysics Data System (ADS)

Cross sections for ?±p elastic scattering have been measured to high precision by the EPECUR Collaboration for beam momenta between 800 and 1240 MeV/c using the ITEP proton synchrotron. The data precision allows comparisons of the existing partial-wave analyses on a level not possible previously. These comparisons imply that over the covered energy range, the Carnegie-Mellon-Berkeley analysis is significantly more predictive when compared to versions of the Karlsruhe-Helsinki analyses.

Alekseev, I. G.; Andreev, V. A.; Bordyuzhin, I. G.; Briscoe, W. J.; Filimonov, Ye. A.; Golubev, V. V.; Gridnev, A. B.; Kalinkin, D. V.; Koroleva, L. I.; Kozlenko, N. G.; Kozlov, V. S.; Krivshich, A. G.; Morozov, B. V.; Nesterov, V. M.; Novinsky, D. V.; Ryltsov, V. V.; Sadler, M.; Shurygin, B. M.; Strakovsky, I. I.; Sulimov, A. D.; Sumachev, V. V.; Svirida, D. N.; Tarakanov, V. I.; Trautman, V. Yu.; Workman, R. L.; Epecur Collaboration; Gw Ins Data Analysis Center

2015-02-01

229

Initial Development of High Precision, High Resolution Ion Beam Spectrometer in the Near-Infrared  

NASA Astrophysics Data System (ADS)

Interest in molecular ions stretches across many fields, from combustion to astrochemistry. These ions can be difficult to study spectroscopically in the laboratory, however. Obstacles include the relatively small density of ions produced in samples compared to neutral molecules and high rotational temperatures of the ions (which lead to dilution of the energy levels). To overcome some of these challenges of molecular ion spectroscopy, we are developing a fast ion beam spectrometer system we call Sensitive, Cooled, Resolved Ion BEam Spectroscopy (SCRIBES). This setup will enable the sensitive study of a supersonically cooled ion beam, taking advantage of narrow linewidths, a mass-dependent Doppler shift for mass identification of each spectral line, and on-line mass spectrometry for beam composition studies. Presently, the spectrometer contains an ion beam source that produces ions at high rotational temperature. We have characterized the spectrometer using the near-infrared rovibronic transitions of N_2^+, optimizing the sensitivity of the instrument. Furthermore, we have used an optical frequency comb for highly accurate frequency calibration, measuring a N_2^+ transition to within an accuracy of 8 MHz. This work in the near-infrared has laid the foundation for mid-infrared and indirect THz ion beam spectroscopy of many interesting molecular ions at a high level of precision, accuracy, and resolution.

Porambo, Michael; Siller, Brian; Mills, Andrew; Perera, Manori; Kreckel, Holger; McCall, Benjamin

2012-06-01

230

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

NASA Astrophysics Data System (ADS)

Due to its highly favorable physical and chemical properties, titanium and titanium alloy are widely used in a variety of industries. Because of the low output of a single batch, plate cold rolling without tension is the most common rolling production method for titanium alloy. This method is lack of on-line thickness closed-loop control, with carefully thickness setting models for precision. A set of high-precision thickness setting models are proposed to suit the production method. Because of frequent variations in rolling specification, a model structural for the combination of analytical models and statistical models is adopted to replace the traditional self-learning method. The deformation resistance and friction factor, the primary factors which affect model precision, are considered as the objectives of statistical modeling. Firstly, the coefficient fitting of deformation resistance analytical model based on over-determined equations set is adopted. Additionally, a support vector machine(SVM) is applied to the modeling of the deformation resistance and friction factor. The setting models are applied to a 1450 plate-coiling mill for titanium alloy plate rolling, and then thickness precision is found consistently to be within 3%, exceeding the precision of traditional setting models with a self-learning method based on a large number of stable rolling data. Excellent application performance is obtained. The proposed research provides a set of high-precision thickness setting models which are well adapted to the characteristics of titanium alloy plate cold rolling without tension.

Wang, Xiaochen; Yang, Quan; He, Fei; Sun, Youzhao; Xiao, Huifang

2015-03-01

231

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

NASA Astrophysics Data System (ADS)

Due to its highly favorable physical and chemical properties, titanium and titanium alloy are widely used in a variety of industries. Because of the low output of a single batch, plate cold rolling without tension is the most common rolling production method for titanium alloy. This method is lack of on-line thickness closed-loop control, with carefully thickness setting models for precision. A set of high-precision thickness setting models are proposed to suit the production method. Because of frequent variations in rolling specification, a model structural for the combination of analytical models and statistical models is adopted to replace the traditional self-learning method. The deformation resistance and friction factor, the primary factors which affect model precision, are considered as the objectives of statistical modeling. Firstly, the coefficient fitting of deformation resistance analytical model based on over-determined equations set is adopted. Additionally, a support vector machine(SVM) is applied to the modeling of the deformation resistance and friction factor. The setting models are applied to a 1450 plate-coiling mill for titanium alloy plate rolling, and then thickness precision is found consistently to be within 3%, exceeding the precision of traditional setting models with a self-learning method based on a large number of stable rolling data. Excellent application performance is obtained. The proposed research provides a set of high-precision thickness setting models which are well adapted to the characteristics of titanium alloy plate cold rolling without tension.

Wang, Xiaochen; Yang, Quan; He, Fei; Sun, Youzhao; Xiao, Huifang

2014-10-01

232

A theoretical and experimental investigation of surface roughness formation in ultra-precision diamond turning  

Microsoft Academic Search

In this paper, a model-based simulation system is presented for the analysis of surface roughness generation in ultra-precision diamond turning. The system is based on a surface roughness model which takes into account the effect of tool geometry, process parameters and relative tool-work vibration. It is evaluated through a series of cutting experiments. The results indicate that the system can

C. F Cheung; W. B Lee

2000-01-01

233

A Collaborative Research in Experimental Study and Numerical Simulation of Compression Molding of Precision Glass Optical Elements  

Microsoft Academic Search

Compression molding process can potentially be used to make high precision glass lenses. In a lens molding process, glass raw material is heated above its transition temperature and is subsequently pressed between the two mold halves into a lens shape. Controlled cooling (annealing) of the formed lens is then carried out with the molds in a closed position in order

A. Jain; L. Li; A. Y. Yi; F. Klocke; G. Pongs; F. Wang

234

Natural Vs. Precise Concise Languages for Human Operation of Computers: Research Issues and Experimental Approaches  

Microsoft Academic Search

This paper raises concerns that natural language front ends for computer systems can limit a researcher's scope of thinking, yield inappropriately complex systems, and exaggerate public fear of computers. Alternative modes of computer use are suggested and the role of psychologically oriented controlled experimentation is emphasized. Research methods and recent experimental results are briefly reviewed.

Ben Shneiderman

1980-01-01

235

High Precision HalfWave Rectifier Circuit In Dual Phase Output Mode  

E-print Network

This paper present high precision halfwave rectifier circuit in dual phase output mode by 0.5 micrometer CMOS technology, plus or minus 1.5 V low voltage, it has received input signal and sent output current signal, respond in high frequency. The main structure compound with CMOS inverter circuit, common source circuit, and current mirror circuit. Simulation and confirmation quality of working by PSpice program, then it able to operating at maximum frequency about 100 MHz, maximum input current range about 400 \\mu Ap p, high precision output signal, low power dissipation, and uses a little transistor.

Jamjaem, Theerayut

2010-01-01

236

High precision X-ray stereo for automated 3D CAD-based inspection  

Microsoft Academic Search

An important challenge in industrial metrology is to provide rapid measurement of critical 3D internal object geometry for either inspecting high volume parts or controlling a machining process. Existing metrological techniques are typically too slow to meet this need or can not measure small features with high precision. In this paper, we present a new method that achieves fast, accurate,

J. Alison Noble; Rajiv Gupta; Joe Mundy; Andrea Schmitz; Richard I. Hartley

1998-01-01

237

A gas chromatography/combustion/isotope ratio mass spectrometry system for high-precision  

E-print Network

A gas chromatography/combustion/isotope ratio mass spectrometry system for high-precision d13 C methane cycle in the past. We developed a highly automated (continuous-flow) gas chromatography in the infrared spectrum. Today methane is recognised as an important greenhouse gas that affects the earth

Fischer, Hubertus

238

Dynamic evaluation system for interpolation errors in the encoder of high precision  

Microsoft Academic Search

In order to measure dynamic interpolation errors of photoelectric encoder of high precision, the dynamic evaluation system of interpolation errors is introduced. Firstly, the fine Moiré signal of encoder which is collected with the high-speed data gathering card into the computer is treated to equiangular data with the method of linear interpolation. Then, the analysis of harmonic wave with the

Qiu-Hua Wan; Yong-Zhi Wu; Chang-Hai Zhao; Li-Hui Liang; Ying Sun; Yong Jiang

2009-01-01

239

Precision Measurements of the Ionization Energy and Its Temperature Variation in High Purity Silicon Radiation Detectors  

Microsoft Academic Search

High precision absolute measurements of the ionization energy (¿) for alpha particles and electrons have been made in two thick high purity silicon guard ring detectors between 100 K and 250 K. At a fixed energy (E) both ¿¿ and ¿e- were found to vary linearly (r = 0.999) with the band gap (WG). ¿¿ and ¿e- also increased with

R. D. Ryan

1973-01-01

240

FPC: A High-Speed Compressor for Double-Precision Floating-Point Data  

E-print Network

FPC: A High-Speed Compressor for Double-Precision Floating-Point Data Martin Burtscher Paruj the throughput demands of high-performance systems. A comparison with five lossless compression schemes, BZIP2-mean compression ratio. Moreover, FPC provides a guaranteed throughput as long as the prediction tables fit

Burtscher, Martin

241

Development of a new lapping method for high precision ball screw (2nd report)  

Microsoft Academic Search

This paper presents a new approach in lapping process in making appropriate condition to improve the manufacturing operations for ball screw. After grinding, high precision ball screw is lapped by highly skilled operators. These operators have the ability to control and maintain the lapping conditions by sensing the lapping torque manually. Prior to lapping process, the effective diameter must be

Dominic S. Guevarra; Akira Kyusojin; Hiromi Isobe; Yoshiaki Kaneko

2002-01-01

242

Highly Accurate Fan Rib Type Mesh Deployable Reflector with Precise Surface Adjuster and Link Deployment System  

Microsoft Academic Search

This paper describes the techniques that realize a highly accurate and reproducible fan rib type deployable mesh reflector. A surface adjuster using a precision screw mechanism and large pads is developed to accurately form the mesh surface with very small amounts of mesh pillowing. A newly developed link deployment system characterized by its high deployment torque and low rib deployment

T. Itanami; M. Misawa; H. Kumazawa

1992-01-01

243

A high precision TDC based on a multi-phase clock  

E-print Network

The design of a high-precision time-to-digital converter (TDC) based on a multiphase clock implemented using a single field-programmable gate array is discussed in this paper. The TDC can increase the resolution of the measurement by using time interpolation. A phase-locked loop is used to generate four multiphase clocks whose frequencies are the same and whose phases are 0{\\deg}, 45{\\deg}, 90{\\deg}, and 135{\\deg}. In addition, the duty ratios of the four clocks are 50%. By utilizing four multiphase clocks to make up the interpolation clock, one clock period can be divided into eight uniform parts. The resolution of the TDC can be improved to 1/8 of a clock period. Furthermore, we have also designed a discriminator circuit for identifying the start and stop signals. On the basis of this circuit, the TDC can still measure the time interval of two signals when the start and stop signals are uncertain. The experimental results indicate that the time resolution of the TDC can achieve the theoretical value, and th...

Qi, Zhong; Li, Deyuan; Yang, Lei; Yao, Zeen; Li, Dongcang

2015-01-01

244

A high precision TDC based on a multi-phase clock  

E-print Network

The design of a high-precision time-to-digital converter (TDC) based on a multiphase clock implemented using a single field-programmable gate array is discussed in this paper. The TDC can increase the resolution of the measurement by using time interpolation. A phase-locked loop is used to generate four multiphase clocks whose frequencies are the same and whose phases are 0{\\deg}, 45{\\deg}, 90{\\deg}, and 135{\\deg}. In addition, the duty ratios of the four clocks are 50%. By utilizing four multiphase clocks to make up the interpolation clock, one clock period can be divided into eight uniform parts. The resolution of the TDC can be improved to 1/8 of a clock period. Furthermore, we have also designed a discriminator circuit for identifying the start and stop signals. On the basis of this circuit, the TDC can still measure the time interval of two signals when the start and stop signals are uncertain. The experimental results indicate that the time resolution of the TDC can achieve the theoretical value, and the linearity is very good. The architecture consumes fewer logic cells and is more stable.

Zhong Qi; Xiangting Meng; Deyuan Li; Lei Yang; Zeen Yao; Dongcang Li

2015-02-04

245

High precision double-interferometry displacement measurement by waveform transforming based on FFT  

NASA Astrophysics Data System (ADS)

The paper researches on a high precision displacement measurement system mixing double-wavelength interferometry and single-wavelength interferometry by waveform transforming based on Fast Fourier Transform (FFT) technology. The signal of double-wavelength interferometry is used for determining the amplitude of the measurand which makes the measurement range be as large as half a synthetic-wavelength, while that of single-wavelength interferometry is for measuring the value of the measurand precisely which endows the measurement resolution to be as high as less than 1nm, for the amount of the interference fringes of the signal of single-wavelength interferometry during the shifting range of the peak of the signal of double-wavelength interferometry demonstrates the value of the measurand. However, as the signal of double-wavelength interferometry is cosine amplitude modulated, the peak area of it is flatten and the peak position is difficult to be determined, which will influence the measurement precision directly. In order to address the peak position of the double-wavelength interferometric signal accurately, we transform using FFT technology the cosine amplitude modulated signal of double-wavelength interferometry into a triangle-wave amplitude modulated signal to make the peak position prominent. It is very easy to determine the peak position accurately and the amount of the interference fringes of the signal of single-wavelength interferometry during the shifting range of the peak will also be determined precisely. High precision displacement measurement with large range and high resolution could be realized.

Wang, Yunzhi; Xie, Fang; Ma, Sen

2013-12-01

246

High-precision covariant one-boson-exchange potentials for np scattering below 350 MeV  

SciTech Connect

All realistic potential models for the two-nucleon interaction are to some extent based on boson exchange. However, in order to achieve an essentially perfect fit to the scattering data, characterized by a chi2/Ndata~ 1, previous potentials have abandoned a pure one boson-exchange mechanism (OBE). Using a covariant theory, we have found a true OBE potential that fits the 2006 world np data below 350 MeV with a chi2/Ndata = 1.00 for 3612 data. Our potential has fewer adjustable parameters than previous high precision potentials, and also reproduces the experimental triton binding energy without introducing additional irreducible three-nucleon forces.

Franz Gross; Alfred Stadler

2007-12-01

247

A high precision attitude determination and control system for the UYS-1 nanosatellite  

NASA Astrophysics Data System (ADS)

This paper presents the design of a high precision attitude determination and control system for the UYS-1 Ukrainian nanosatellite. Its main task is the 3-axis stabilization with less than 0.5° angle errors, so the satellite may take high precision photos of Earth's surface. To accomplish this task, this system comprises a star tracker and three reaction wheels. To avoid external disturbances and actuators faults, a PD-type and a PID-type robust controllers are simulated and the results are compared to an empirically adjusted PD controller.

Chaurais, J. R.; Ferreira, H. C.; Ishihara, J. Y.; Borges, R. A.; Kulabukhov, A. M.; Larin, V. A.; Belikov, V. V.

248

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

SciTech Connect

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

Meziane, Mehdi [DUKE

2013-11-01

249

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

SciTech Connect

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

Meziane, Mehdi [Duke University, Durham, NC 27708 (United States); Collaboration: PRad Collaboration

2013-11-07

250

A high-precision calculation method for interface normal and curvature on an unstructured grid  

NASA Astrophysics Data System (ADS)

In the volume-of-fluid algorithm, the calculations of the interface normal and curvature are crucially important for accurately simulating interfacial flows. However, few methods have been proposed for the high-precision interface calculation on an unstructured grid. In this paper, the authors develop a height function method that works appropriately on an unstructured grid. In the process, the definition of the height function is discussed, and the high-precision calculation method of the interface normal is developed to meet the necessary condition for a second-order method. This new method has highly reduced computational cost compared with a conventional high-precision method because the interface normal calculation is completed by solving relatively simple algebraic equations. The curvature calculation method is also discussed and the approximated quadric curve of an interface is employed to calculate the curvature. Following a basic verification, the developed height function method is shown to successfully provide superior calculation accuracy and highly reduced computational cost compared with conventional calculation methods in terms of the interface normal and curvature. In addition, the height function method succeeds in calculating accurately the slotted-disk revolution problem and the oscillating drop on unstructured grids. Therefore, the developed height function method is confirmed to be an efficient technique for the high-precision numerical simulation of interfacial flows on an unstructured grid.

Ito, Kei; Kunugi, Tomoaki; Ohno, Shuji; Kamide, Hideki; Ohshima, Hiroyuki

2014-09-01

251

Experimental studies of high pressure RF discharges  

Microsoft Academic Search

Summary form only given, as follows. Experimental studies on RF discharges at 13.56 MHz have been performed at very high gas pressures between 1 Torr to atmospheric pressure. Plasma parameters, comparable to low pressure discharges, are estimated in He discharges by optical emission spectroscopy and Langmuir probe measurements. The estimated electron density of 1-10×1011 cm-3 and electron temperature of 1-2

H. W. Herrmann; I. Henius; G. S. Selwyn

1998-01-01

252

Investigation of high-precision {Lambda} hypernuclear spectroscopy via the (e,e'K{sup +}) reaction  

SciTech Connect

The study of {Lambda} hypernuclear structure is very interesting in point of the understanding of the interaction between {Lambda} and nucleon ({Lambda}-N interaction) and its ?strange? structure itself due to the containment of a {Lambda} hyperon which has a strangeness as a new degree of freedom. In the several way to study the Lamda hypernuclei, the (e,e'K{sup +}) reaction spectroscopy is a powerful tool for the precise investigation of {Lamda} hypernuclear structure. The purpose of the preset thesis is the establishment of the experimental design with the efficient data analysis method for the (e,e'K{sup +}) hypernuclear spectroscopic experiment in the wide mass region (from A=7 to A=52). It is very challenging to perform the (e,e'K{sup +}) spectroscopic experiment with such a heavy target, because of the huge electron background due to the bremsstrahlung process. In the experiment, it is required to obtain the necessary hypernuclear yield, suppressing the background event ratio. We achieved these requirements by newly constructing the high resolution electron spectrometer (HES) and splitter magnet (SPL) dedicated to the (e,e'K{sup +}) spectroscopic experiment. The HES consists of two quadrupole magnets and a dipole magnets (Q-Q-D) with a momentum resolution of dp/p = 3x10^-4 at p = 0.84 GeV/c. It was used being vertically tilted by 6.5 degree so as to optimize signal to noise ratio and hypernuclear yield. The SPL is a dipole magnet. The experimental target was placed at the entrance of this magnet. The role of the SPL is to separate four kind of particles; scattered kaons, photons created by the bremsstrahlung, the post beam and scattered electrons. In addition, since the SPL is a part of the kaon and electron spectrometers. We designed the magnet shape carefully considering these points. The experiment was performed with 2.344 GeV/c electron beam from CEBAF at Jefferson Lab. The experimental setup consists of the HES, SPL and HKS (high momentum resolution kaon spectrometer). The HKS is also a Q-Q-D type spectrometer with the momentum resolution of dp/p = 2x10^-4 at p = 1.2 GeV/c. In the data analysis, the particle momentum calibration was the most important procedure. At the initial point, the particle momentum was obtained from the calculated magnetic field map of the spectrometer whose accuracy is an order of 10^-2. The initial momentum was calibrated by two step, the the magnetic field map improvement and the calibration with known masses of {Lambda}/{Sigma}{sup 0} which were observed by the CH{sub 2} target data. As a result of the calibration, the momentum resolutions of HKS and HES were estimated as 4x10^-4 and 6x10^-4, respectively. Though these values are the double of the designed value, it was achieved to obtain the {Lambda}/{Sigma}{sup 0} peaks with the same order of the designed energy from the original calculated magnetic field. The cross section was calculated with the several estimated factors. The averaged p({gamma}*, K{sup +}){Lamda} cross section in the HKS acceptance, (0.90 < cos({theta}^CM_K{sup +}) < 1.0) was calculated as 227 ± 12 ±26 [nb/sr], which is consistent within the error bar with the other experiment results of p({gamma}, K{sup +}){Lamda}. The obtained yield of the peak was almost same as the designed value with the considered detector efficiencies. The observed hypernuclear spectrum of ^12_{Lambda} B was also consistent with the other experimental results. These analysis result represents that the experimental setup including the newly constructed HES and SPL worked and the calibration procedure of this unique experimental setup is basically established.

Kawama, Daisuke

2012-03-31

253

Experimental approaches for addressing fundamental biological questions in living, functioning cells with single molecule precision  

PubMed Central

In recent years, single molecule experimentation has allowed researchers to observe biological processes at the sensitivity level of single molecules in actual functioning, living cells, thereby allowing us to observe the molecular basis of the key mechanistic processes in question in a very direct way, rather than inferring these from ensemble average data gained from traditional molecular and biochemical techniques. In this short review, we demonstrate the impact that the application of single molecule bioscience experimentation has had on our understanding of various cellular systems and processes, and the potential that this approach has for the future to really address very challenging and fundamental questions in the life sciences. PMID:22773951

Lenn, Tchern; Leake, Mark C.

2012-01-01

254

High Precision And Miniaturized Mark Position Sensing Methods For 3-D Shape Measurement  

NASA Astrophysics Data System (ADS)

A high precision mark position sensing method for image position sensing detector (PSD) with kaleido scopic mirror tunnel (KM-PSM) is introduced. To increase the image position detecting precision of a sensor element itself, hybrid ( analogue and digital ) type position sensitive device (R-HPSD) is invented. In order to realize high precision and miniaturized 3-D position measuring system, 1-D mark direction sensing method (PM-DSM) which consist of a 1-D image position sensing element, a cylindrical lens and a parallel mirror tunnel is proposed. Furtheremore, an optical range sensing method (RORS) which is suitable to realize a miniaturized optical range sensing probe based on the triangulation, is proposed. In addition, an optical range sensing probe for advanced 3-D coordinates measuring machine is considered.

Idesawa, Masanori

1989-01-01

255

High-precision tracking with non-blinking quantum dots resolves nanoscale vertical displacement.  

PubMed

Novel non-blinking quantum dots (NBQDs) were utilized in three-dimensional super-localization, high-precision tracking applications under an automated scanning-angle total internal reflection fluorescence microscope (SA-TIRFM). NBQDs were randomly attached to stationary microtubules along the radial axis under gliding assay conditions. By automatically scanning through a wide range of incident angles with different evanescent-field layer thicknesses, the fluorescence intensity decay curves were obtained. Fit with theoretical decay functions, the absolute vertical positions were determined with sub-10-nm localization precision. The emission intensity profile of the NBQDs attached to kinesin-propelled microtubules was used to resolve the self-rotation of gliding microtubules within a small vertical distance of ~50 nm. We demonstrate the applicability of NBQDs in high-precision fluorescence imaging experiments. PMID:22458433

Marchuk, Kyle; Guo, Yijun; Sun, Wei; Vela, Javier; Fang, Ning

2012-04-11

256

High-Precision Positioning and Real-Time Data Processing of Uav-Systems  

NASA Astrophysics Data System (ADS)

Available micro-sized Unmanned Aerial Vehicles (UAVs) in the civilian domain currently make use of common GPS receivers and do not address scenarios where high-precision positioning of the UAV is an inevitable requirement. However, for use cases such as creating orthophotos using direct georeferencing, an improved positioning needs to be developed. This article analyses the requirements for integrating Real Time Kinematic positioning into micro-sized UAVs. Additionally, it describes the data processing and synchronisation of the high-precision position data for a workflow of orthorectification of aerial imagery. Preliminary results are described for the use case of precision farming. The described approach for positioning has the potential to achieve a positional accuracy of 1-3 cm, which can be considered as adequate for direct georeferencing of aerial imagery.

Rieke, M.; Foerster, T.; Geipel, J.; Prinz, T.

2011-09-01

257

A simple breathing circuit allowing precise control of inspiratory gases for experimental respiratory manipulations  

PubMed Central

Background Respiratory manipulations modulating blood flow and oxygenation levels have become an important component of modern functional MRI applications. Manipulations often consist of temporarily switching inspired fractions of CO2 and O2; and have typically been performed using simple oxygen masks intended for applications in respiratory therapy. However, precise control of inspired gas composition is difficult using this type of mask due to entrainment of room air and resultant dilution of inspired gases. We aimed at developing a gas delivery apparatus allowing improved control over the fractional concentration of inspired gases, to be used in brain fMRI studies. Findings The breathing circuit we have conceived allowed well controlled step changes in FiO2 and FiCO2, at moderate flow rates achievable on standard clinical flow regulators. In a two run test inside the scanner we demonstrate that tightly controlled simple gas switching manipulations can afford good intra-subject reproducibility of induced hyperoxia/hypercapnia responses. Although our approach requires a non-vented mask fitting closely to the subject’s face, the circuit ensures a continuous supply of breathable air even if the supply of medical gases is interrupted, and is easily removable in case of an emergency. The apparatus we propose is also compact and MRI compatible, allowing subject placement in confined spaces such as an MRI scanner for brain examinations. Conclusions We have reported a new approach for the controlled administration of medical gases, and describe an implementation of the breathing circuit that is MRI compatible and uses commercially available parts. The resultant apparatus allows simple, safe and precise manipulations of FiO2 and FiCO2. PMID:24725848

2014-01-01

258

Remote and high precision step height measurement with an optical fiber multiplexing interferometric system  

NASA Astrophysics Data System (ADS)

An optical fiber multiplexing low coherence and high coherence interferometric system, which includes a Fizeau interferometer as the sensing element and a Michelson interferometer as the demodulating element, is designed for remote and high precision step height measurement. The Fizeau interferometer is placed in the remote field for sensing the measurand, while the Michelson interferometer which works in both modes of low coherence interferometry and high coherence interferometry is employed for demodulating the measurand. The range of the step height is determined by the low coherence interferometry and the value of it is measured precisely by the high coherence interferometry. High precision has been obtained by searching precisely the peak of the low coherence interferogram symmetrically from two sides of the low coherence interferogram and stabilizing the Michelson interferometer with a feedback loop. The maximum step height that could be measured is 6 mm while the measurement resolution is less than 1 nm. The standard deviation of 10 times measurement results of a step height of 1 mm configurated with two gauge blocks is 0.5 nm.

Wang, Yunzhi; Xie, Fang; Ma, Sen; Chen, Liang

2015-03-01

259

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

NASA Astrophysics Data System (ADS)

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

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

2013-01-01

260

Figures deduction method for mast valuating interpolation errors of encoder with high precision  

NASA Astrophysics Data System (ADS)

With the development of technology, especially the need of fast accurately running after and orientating the aim of horizon and air, the photoelectrical rotary encoder with high precision has become the research hotspot in the fields of international spaceflight and avigation, the errors evaluation of encoder with high precision is the one of the key technology that must to be resolved. For the encoder with high precision, the interpolation errors is the main factor which affects its precision. Existing interpolation errors detection adopts accurate apparatus such as little angle measurement apparatus and optics polyhedron, requesting under the strict laboratory condition to carry on. The detection method is also time-consuming, hard to tackle and easy to introduce detect errors. This paper mainly studies the fast evaluation method of interpolation errors of encoder with high precision which is applied to the working field. Taking the Lissajou's figure produced by moiré fringe as foundation, the paper sets up the radius vector's mathematical model to represent figure's form deviation, analyses the implied parameters information of moiré fringe, the relation of the radius vector deviation and interpolation errors in the figures and puts forward the method of interpolation errors figures evaluation. Adopting figure deduction method, and directly from harmonic component of radius vector deviation toward harmonic component of interpolation errors, the interpolation errors can be gotten in the paper. Through data collecting card, the Moiré fringe signal is transmitted into the computer, then, the computer storages the data, using figures evaluation method to analyses the data, drawing the curve of interpolation errors. Comparing with interpolation errors drawing from traditional detect method, the change trend of the interpolation errors curve is similar, peak-peak value is almost equality. The result of experiment indicates: the method of the paper can be applied to evaluate interpolation errors of high precision encoder, which need simple equipment and the examination method is efficient and feasible; Apart from these, the data processing can be realized by valuation analysis software, and the time is short, the result manifestation is intuitionistic; the system can be used in the working field, avert the influence of the speed, and has important meaning to the research of high precision encoder's dynamic precision characteristics.

Yi, Jie; An, Li-min; Liu, Chun-xia

2011-08-01

261

Statics and Dynamics Performance Evaluation for a High Precision XYZ Compliant Parallel Micromanipulator  

E-print Network

Statics and Dynamics Performance Evaluation for a High Precision XYZ Compliant Parallel) in terms of statics and dynamics is carried out in this paper, which is quite necessary in designing paid on the statics and dynamics characterization especially in the early design stage mainly due

Li, Yangmin

262

Rapid, high-precision potentiometric titration of alkalinity in ocean and sediment pore waters  

Microsoft Academic Search

A system for rapid, high precision potentiometric determination of alkalinity in sea water and sediment pore water is presented. Two titration units were used: a 40 ml unit for seawater and a small volume unit for sediment pore water. Titration time was normally less than 10 minutes per sample, including sample exchange. With a 40 ml sample volume, the relative

Conny Haraldsson; Leif G. Anderson; Martin Hassellöv; Stefan Hulth; Kristina Olsson

1997-01-01

263

Micropropulsion Technologies for the European High-Precision Formation Flying Interferometer DARWIN  

Microsoft Academic Search

The ESA mission DARWIN is a formation flying interferometer with high demands on precise relative positioning between the spacecraft. Due to lack of alternatives, the micropropulsion system of choice has persistently been Field-Emission Electric Propulsion. In recent years many other micropropulsion technologies have started to emerge, and these were evaluated for their suitability to DARWIN. It was found that the

M. Kilter; A. Karlsson

2004-01-01

264

A Highly Accurate Stress Measurement System for Producing Precise X-Ray Masks  

Microsoft Academic Search

A new system that measures stress in film deposited on Si wafers has been developed to produce highly accurate X-ray masks. The system consists of very rigid air sliders, an electrostatic sensor, and a soft-handling wafer chuck. With the system, wafer warp is precisely measured before and after film deposition, and the stress distribution is calculated from those measurements. Wafer

Masatoshi Oda; Atsunobu Une; Ikuo Okada; Shinji Shinohara; Yasuo Nakayama; Hideo Yoshihara

1995-01-01

265

\\Precision Mining" of High-Dimensional Patterns with Self-Organizing Maps  

E-print Network

), where Sx y k is the data value in the kth image band (k = 1 ::: NB) at pixel location (x y), is called pixel (x y). NB denotes the number of im- age bands. x = 1 ::: Xmax and y = 1 ::: Ymax, where Xmax and Y\\Precision Mining" of High-Dimensional Patterns with Self-Organizing Maps: Interpretation

Merényi, Erzsébet

266

An appraisal method of dynamic interpolation error for high precision encoder  

Microsoft Academic Search

edu.cn Ahstract- This paper introduces an appraisal method of the dynamic interpolation error for the high precision encoder (Lissajou pattern calculation method). When the encoder is rolling, two groups of fine photoelectric signals whose phase difference are 1[\\/2 can be collected using data collected car. The shape and position deviation can be obtained through the comparison between Lissajou charts and

Jie Yi; Li-min An; Chun-xia Liu; Qiu-hua Wan

2011-01-01

267

EXPLORATION OF THE KUIPER BELT BY HIGH-PRECISION PHOTOMETRIC STELLAR OCCULTATIONS: FIRST RESULTS  

E-print Network

EXPLORATION OF THE KUIPER BELT BY HIGH-PRECISION PHOTOMETRIC STELLAR OCCULTATIONS: FIRST RESULTS F of serendipitous stellar occultation. This method consists of recording the diffraction shadow created when an object crosses the observer's line of sight and occults the disk of a background star. One of our

Roques, Françoise

268

High precision relocation of earthquakes at Iliamna Volcano, Alaska Patrick Statz-Boyer a  

E-print Network

High precision relocation of earthquakes at Iliamna Volcano, Alaska Patrick Statz Volcano Observatory, Anchorage, AK 99508, United States a b s t r a c ta r t i c l e i n f o Article history: Received 27 October 2008 Accepted 20 April 2009 Available online 7 May 2009 Keywords: volcano

269

Abstract--Gear hobbing is a common method of manufacturing high precision involute gears. The thorough  

E-print Network

Abstract-- Gear hobbing is a common method of manufacturing high precision involute gears importance in order to produce helical and spur gears as they influence the cost of the manufacturing process and the quality of the produced gear. HOB3D is a simulation code that enables users to simulate the process

Aristomenis, Antoniadis

270

A High-Precision Time Interval Measurement Method Using Phase-Estimation Algorithm  

Microsoft Academic Search

High-precision time interval measurement is widely used in time synchronization, satellite navigation, laser ranging, and nuclear electronics. The resolution and accuracy of the currently used time counter are about 25 and 100 ps, respectively. A new time interval measurement method, in which the signal under test is used to trigger a sampler and the phase of the reference sinusoid signal

Xiangwei Zhu; Guangfu Sun; Shaowei Yong; Zhaowen Zhuang

2008-01-01

271

Sensitivity of high precision Michelson-Morley experiments to tilting of their setups  

E-print Network

We describe the effects to be expected of unwanted or voluntary deviations from the vertical of the axis of the active rotation of modern high precision experiments of the Michelson-Morley type. The theoretical description that we use is a particular implementation of the Principle of free mobility.

Ll. Bel

2005-09-26

272

High-precision cylindrical and quasi-cylindrical aspherization of small surfaces by ion beam figuring  

Microsoft Academic Search

We have used a broad ion beam technique to generate cylindrical structures. Although limited to small dimensions, it produces potentially high precision smooth surfaces. As a first trial, four surfaces were produced for an industrial application, using a fairly simple mask; the 8 mm wide, 3 micrometers deep W profile cylinder was engraved on silicon substrates. Reproducibility was in the

Raymond Mercier; Michel Mullot; Michel Lamare; Gerard Tissot

1999-01-01

273

Learning High Precision Rules to Make Predictions of Morbidities in Discharge Summaries  

E-print Network

Learning High Precision Rules to Make Predictions of Morbidities in Discharge Summaries Ted Challenge used supervised machine learning techniques that re- lied on bag of words unigram features found. In the textual task, the prediction was based strictly on information found in the patient's discharge summary

Pedersen, Ted

274

J. Bouvier, A. Chalabaev, C. Charbonnel (eds) THE NEARBY SUPERNOVA FACTORY: TOWARD A HIGH-PRECISION  

E-print Network

SF2A 2007 J. Bouvier, A. Chalabaev, C. Charbonnel (eds) THE NEARBY SUPERNOVA FACTORY: TOWARD A HIGH-PRECISION SPECTRO-PHOTOMETRY Y. Copin1, on behalf of the Nearby Supernova Factory, C. Buton1, E. Gangler1, G. Smadja Supernova Factory (SNfactory) is an international project to discover and study a large sample of type Ia

Aragon, Cecilia R.

275

Study on high-precision inspection multi-vision cameras space layout  

Microsoft Academic Search

In the field of three dimension vision inspection, a stereo system full detection for an object surface is usually used the method of camera motion, fixed mosaic-type and rotating scanning. We presented that the object feature need be placed in the best clarity area of an optical axes intersected binocular system in high-precision full inspection. Based on a series of

Cai Yong; Qin Xiansheng; Liu Qiong; Zhang Shuangquan

2010-01-01

276

Experimental studies of high pressure RF discharges  

SciTech Connect

Experimental studies on RF discharges at 13.56 MHz have been performed at very high gas pressures between 1 Torr to atmospheric pressure. Plasma parameters, comparable to low pressure discharges, are estimated in He discharges by optical emission spectroscopy and Langmuir probe measurements. The estimated electron density of 1--10 {times} 1011 cm{sup {minus}3} and electron temperature of 1--2 eV is consistent with a 1-D model of plasma impedance and particle balance. The plasma conditions change substantially as oxygen is introduced into the discharge. A decrease in electron density is observed, which is attributed to the electronegativity of oxygen. In addition, formation of oxygen atoms and metastable oxygen molecules is observed by optical emission spectroscopy. A further increase in the oxygen flow results in the extinction of the discharge or arcing. A detailed analysis of the experimental results will be presented.

Herrmann, H.W.; Park, J.; Henins, I.; Selwyn, G.S. [Los Alamos National Lab., NM (United States)

1998-12-31

277

Continuous online field deployable high precision and high resolution water isotope analysis from ice cores  

NASA Astrophysics Data System (ADS)

One of the most important features of ice cores as climate and atmospheric paleoarchives is their potential for high temporal resolution. The measurement of chemical impurities in ice cores that fully exploits this high resolution has become standard with the advent of Continuous Flow Analysis (CFA) from continuously melted ice core segments, often performed in the field. Meanwhile, the measurement of water stable isotopic composition (deuterium and oxygen-18) continues, for the most part, to be performed offline via discrete sampling with traditional mass spectroscopy. These offline procedures are time consuming, expensive, and do not fully exploit the temporal resolution available in the ice core. Here we describe a new method and the first results for the determination of water isotopic content measured from a continuous melted rod with a commercially available near-infrared cavity ring down spectrometer (CRDS; http://www.picarro.com/) coupled to a CFA system both in the field on the Greenland ice sheet and in the laboratory. For the measurement of water isotopes a carefully controlled fraction of the CFA melt stream is evaporated directly into the laser cavity for simultaneous analysis of both deuterium and oxygen-18 content. The details of the system have been tested with a deployment to the North Greenland Eemian Ice Drilling (NEEM) coupled to the University of Bern CFA system and in the laboratory with NGRIP ice coupled to the University of Copenhagen CFA system. The results show that the system already produces the highest interpretable resolution records that are comparable or somewhat less precise than traditional mass spectroscopy discrete sample methods. The enormous potential of the system is being realized in the density and resolution of the produced records in connection with other highly resolved series (e.g. chemical impurities), and also in the efficiency by which the records can be produced. Among other things, time series from this type of analysis will benefit ice core dating via layer counting of deconvoluted isotopic series. High resolution paleo-temperature reconstructions based on the calculation of the differential diffusion rates of the two heavy isotopologues of water vapor in firn, via the study of their spectral properties, can also benefit from the enhanced resolution of the measured time series.

Gkinis, Vasileios; Popp, Trevor; Johnsen, Sigfus; Blunier, Thomas; Stowasser, Christopher; Kettner, Ernesto

2010-05-01

278

High-precision Penning trap mass measurements for tests of the Standard Model  

SciTech Connect

With the nowadays achievable accuracy in Penning trap mass spectrometry on short-lived exotic nuclides as well as stable atoms, precision fundamental tests can be performed, among them a test of the Standard Model, in particular with regard to the weak interaction, the CPT symmetry conservation, and the unitarity of the Cabibbo-Kobayashi-Maskawa quark mixing matrix. In addition, accurate mass values of specific nuclides are important for neutrino physics. The presently best tests of the Standard Model with high-precision Penning trap mass spectrometry will be reviewed.

Blaum, Klaus; Eliseev, Sergey [Max-Planck-Institut fuer Kernphysik, Saupfercheckweg 1, 69117 Heidelberg (Germany); Nagy, Szilard [Max-Planck-Institut fuer Kernphysik, Saupfercheckweg 1, 69117 Heidelberg (Germany); GSI Helmholtzzentrum fuer Schwerionenforschung, Planckstrasse 1, 64291 Darmstadt (Germany)

2010-08-04

279

Dual Wavelength Cavity Ringdown Spectroscopy for High Precision Methane Isotope Ratio Measurements  

NASA Astrophysics Data System (ADS)

We demonstrate a frequency stabilized cavity ringdown spectrometer capable of measuring simultaneous isotopes of methane (12CH_4, 13CH_4, 12CH_3D) of enriched samples to high precision (?D<0.03% and ?13C<0.01%). The spectrometer employs coupling of two orthogonally polarized CW lasers into a ringdown cavity for simultaneous spectral measurements over the full wavelength range of 1.45-1.65?m. In addition, we discuss the necessity of modeling methane lineshapes with the Galatry profile to achieve the highest precision.

Bui, Thinh Quoc; Shen, Linhan; Hogan, Daniel; Chen, Pin; Okumura, Mitchio

2014-06-01

280

High-precision and high-resolution speleothem Th-230 dating by MC-ICP-MS with SEM protocols  

NASA Astrophysics Data System (ADS)

To facilitate the measurement of femtogram-quantity U-Th isotopic compositions suitable for high-precision and high-resolution speleothem Th-230 dating, secondary electron multiplier (SEM) protocol techniques for multicollector inductively coupled plasma mass spectrometry (MC-ICP-MS) have been developed. The instrumental sensitivities are 1-2%, with a 2-sigma precision of 1-2 permil for abundance determinations of 50-200-fg U-234 (1-4-ng U-238) or Th-230. Measurement consistency of this MC-ICP-MS combined with previous mass spectrometric results on U-Th standards and a variety of carbonates demonstrates the validity of the SEM-protocol method. About 20-200-mg speleothem samples with sub-ppm-to-ppm U are required to earn a 5 permil precision on ages from 5-100 kyrs. Requirement of small sample size, 10s-100s mg carbonate, can permit high temporal resolution to date speleothems with slow growth rates, such as 1-10 mm/kyr. Single-lamina Th-230 dating techniques with precision of ±1 yr for annual stalagmite layers with an age of 300 years are achievable. This high-precision Th-230 chronology is critical to accurately establish age models, date events and splice geochemical proxy time series records from multiple samples in the fields of paleoclimatology.

Shen, Chuan-Chou; Wu, Chung-Che; Lin, Ke; Cheng, Hai; Edwards, R. Lawrence; Hsieh, Yu-Te; Li, Tingyong; Kano, Akihiro; Hori, Masako

2010-05-01

281

High-precision predictions for the light CP-even Higgs boson mass of the minimal supersymmetric standard model.  

PubMed

For the interpretation of the signal discovered in the Higgs searches at the LHC it will be crucial in particular to discriminate between the minimal Higgs sector realized in the standard model (SM) and its most commonly studied extension, the minimal supersymmetric standard model (MSSM). The measured mass value, having already reached the level of a precision observable with an experimental accuracy of about 500 MeV, plays an important role in this context. In the MSSM the mass of the light CP-even Higgs boson, Mh, can directly be predicted from the other parameters of the model. The accuracy of this prediction should at least match the one of the experimental result. The relatively high mass value of about 126 GeV has led to many investigations where the scalar top quarks are in the multi-TeV range. We improve the prediction for Mh in the MSSM by combining the existing fixed-order result, comprising the full one-loop and leading and subleading two-loop corrections, with a resummation of the leading and subleading logarithmic contributions from the scalar top sector to all orders. In this way for the first time a high-precision prediction for the mass of the light CP-even Higgs boson in the MSSM is possible all the way up to the multi-TeV region of the relevant supersymmetric particles. The results are included in the code FEYNHIGGS. PMID:24765944

Hahn, T; Heinemeyer, S; Hollik, W; Rzehak, H; Weiglein, G

2014-04-11

282

High precision measurements of the diamond Hugoniot in and above the melt region  

SciTech Connect

High precision laser-driven shock wave measurements of the diamond principal Hugoniot have been made at pressures between 6 and 19 Mbar. Shock velocities were determined with 0.3-1.1% precision using a velocity interferometer. Impedance matching analysis, incorporating systematic errors in the equation-of-state of the quartz standard, was used to determine the Hugoniot with 1.2-2.7% precision in density. The results are in good agreement with published ab initio calculations which predict a small negative melt slope along the Hugoniot, but disagree with previous laser-driven shock wave experiments which had observed a large density increase in the melt region. In the extensive solid-liquid coexistence regime between 6 and 10 Mbar these measurements indicate that the mixed phase may be slightly more dense than would be expected from a simple interpolation between liquid and solid Hugoniots.

Hicks, D; Boehly, T; Celliers, P; Bradley, D; Eggert, J; McWilliams, R S; Collins, G

2008-08-05

283

High-precision measurements of the diamond Hugoniot in and above the melt region  

SciTech Connect

High-precision measurements of the diamond principal Hugoniot have been made at pressures between 6 and 19 Mbar. Shock velocities were determined with 0.3%-1.1% precision using a velocity interferometer. Impedance-matching analysis, incorporating systematic uncertainties in the equation of state of the quartz standard, was used to determine the Hugoniot with 1.2%-2.7% precision in density. The results are in good agreement with published ab initio calculations, which predict a small negative melt slope along the Hugoniot, but disagree with previous laser-driven shock wave experiments, which had observed a large density increase in the melt region. In the extensive solid-liquid coexistence regime between 6 and 10 Mbar, the present measurements indicate that the mixed phase is a few percent more dense than what would be expected from a simple interpolation between liquid and solid Hugoniots.

Hicks, D. G.; Celliers, P. M.; Bradley, D. K.; Eggert, J. H.; Collins, G. W. [Lawrence Livermore National Laboratory, Livermore, California 94550 (United States); Boehly, T. R. [Laboratory for Laser Energetics, University of Rochester, New York 14623 (United States); McWilliams, R. S. [Lawrence Livermore National Laboratory, Livermore, California 94550 (United States); University of California, Berkeley, California 94720 (United States); Jeanloz, R. [University of California, Berkeley, California 94720 (United States)

2008-11-01

284

The FAST telescope and its possible contribution to high precision astrometry  

NASA Astrophysics Data System (ADS)

In this report we give a brief introduction to the Five hundred meter Apeture Spherical Telescope (FAST). Some possible contributions of FAST to high precision astrometry are discussed. The illuminated aperture of FAST in normal operation mode is 300m in diameter. With special feeding mechanism, the whole 500m aperture could be used. FAST will cover frequencies from 70MHz to 3GHz, and observe at zenith angle of up to 40 degrees without a notable gain loss. As the most sensitive single dish radio telescope, FAST would be able to discover more mega-masers and measure the radial velocities of masers with higher precision. This may yield more delicate dynamics of their maser spots. FAST will increase the precision of time of arrival (ToA) measurements for pulsars. This will help in detecting the stochastic gravitational wave background and in establishing an independent timing standard based on the long-term stability of the rotations of a group of millisecond pulsars. FAST might also work as a very powerful ground station for the future space missions. In a three-way communication mode, FAST should be able to provide precise ranging and Doppler measurements. Moreover, by joining the international VLBI network, FAST would help to improve the precision of the VLBI astrometry measurements.

Jin, C. J.; Nan, R. D.; Gan, H. Q.

2008-07-01

285

A new method to eliminate the noise of vacuum microelectronic high precision accelerometer  

NASA Astrophysics Data System (ADS)

The vacuum microelectronic high precision accelerometer was developed based on the vacuum field emission theory; it has many advantages such as high precision, good linearity in theory, but the inherent low frequency such as 1/f noise of the accelerometer decreases the signal-to-noise ratio greatly, and it is the main influencing factors to precision and linearity of accelerometer. In this paper a new method to eliminate noise of vacuum microelectronic high precision accelerometer was first bring forward by using modulation and demodulation and coherent detection technology. The system mainly includes AC signal generator, current obtain, phase shift, demodulator, differential amplification and feedback control. At last, the noise between 0 Hz and 200Hz contrast test experiment of the accelerometer was carried out by oscilloscope, the result shows the mean spectrum density of output signal is 29?V/?Hz between 0 Hz and 200Hz. Static gravitation field rolling experiment in +/-1 g is also performed to measure the linearity of the accelerometer; the least-square linear fitting curve shows the maximum nonlinear is 0.41%. Through the results we can draw conclusion that the noise and linear performs have been greatly improved through eliminated noise.

Liu, Hai-tao; Wen, Zhi-yu; Chen, Li; Wen, Zhong-quan; He, Xue-feng

2011-08-01

286

Structures Formed in Experimentally Sheared Artificial Fault Gouge: Precise Statistical Measurements  

NASA Astrophysics Data System (ADS)

The physical parameters governing earthquakes change with the ongoing formation and evolution of structures, formed in the course of a single or multiple earthquakes, within a particular fault zone or in a broad volume containing interacting tectonic faults. Our precise knowledge of these complex phenomena is still elusive. Especially, works considering geometrical evolution of shear structures under controlled conditions are rare. In order to gain some insights we accomplished a set of 12 laboratory experiments using a servo-controlled direct-shear apparatus, under room temperature and without controlling the air humidity. Two fault gouge layers (industrially produced quartz powder, average particle size of 5 ? m, and pre-shear thickness of 1.5, 2.0 and 3.0 mm,) were sandwiched between three granite blocks. The middle block was slid in order to create frictional structures within the simulated gouge. The total imposed shear strain varies between 0.14 and 11.80. The post-shear gouge layer thickness ranges from 0.99-2.11 mm. Each experiment was run under a constant normal stress (varying from 10-44 MPa through the experiments) and at a constant shear velocity (0.07, 0.7 and 7 ? m/s, through the experiments). Later, in cross-sections of solidified by epoxy glue gouge (parallel to the shear direction, normal to the gouge walls,) we quantified the numerous R-shears, according to their density distribution, fracture thickness (measured perpendicularly to the fracture walls), fracture angle and morphology, and fracture length. In gouge views parallel to the sliding blocks, we measured fracture length and along-strike R-shear morphology. Although the latter data are with lower quality, both observational sets provide precise statistical fracture data as well snapshots of evolving 3D structures. We observe shear localization with decreasing gouge layer thickness and with increasing normal stress. The average density of major fractures increases from 2.83 to 3.67 [fracture/cm] for decrease of the post-shear gouge layer thickness. This is at the expense of a considerable decrease of visible more diffusive minor fractures. On the other hand, the fractures formed at lower normal stress are more irregular and show average fracture density of 4.48 [fracture/cm]. The latter decreases down to 3.64 at higher normal stress, as the fracture morphology becomes more regular. The fracture density increases abruptly from zero, after a small total shear strain (0.15-0.50), and later the change is slower or none with the increase of the total shear strain; the fractures are already localized and they accommodate most of the brittle deformation. Also we observe weak polarity in fracture development in accordance to the sliding sense, especially in the subset of fractures starting from the gouge wall and dying out within the gouge layer. More such fractures are developed along the leading part of the sliding blocks. Our results throw new light over the formation and development of fault-related structures and their dependency on the earthquake-governing physical parameters.

Dilov, T.; Yoshida, S.; Kato, A.; Nakatani, M.; Mochizuki, H.; Otsuki, K.

2004-12-01

287

Experimental and theoretical high energy physics program  

NASA Astrophysics Data System (ADS)

Experimental and theoretical high-energy physics research at Purdue is summarized in a number of reports. Subjects treated include the following: the CLEO experiment for the study of heavy flavor physics; gas microstrip detectors; particle astrophysics; affine Kac-Moody algebra; nonperturbative mass bounds on scalar and fermion systems due to triviality and vacuum stability constraints; resonance neutrino oscillations; e(+)e(-) collisions at CERN; (bar p)-p collisions at FNAL; accelerator physics at Fermilab; development work for the SDC detector at SSC; TOPAZ; D-zero physics; physics beyond the standard model; and the Collider Detector at Fermilab.

Finley, J.; Gaidos, J. A.; Loeffler, F. J.; McIlwain, R. L.; Miller, D. H.; Palfrey, T. R.; Shibata, E. I.; Shipsey, I. P.

1993-04-01

288

[Experimental and theoretical high energy physics program  

SciTech Connect

Experimental and theoretical high-energy physics research at Purdue is summarized in a number of reports. Subjects treated include the following: the CLEO experiment for the study of heavy flavor physics; gas microstrip detectors; particle astrophysics; affine Kac{endash}Moody algebra; nonperturbative mass bounds on scalar and fermion systems due to triviality and vacuum stability constraints; resonance neutrino oscillations; e{sup +}e{sup {minus}} collisions at CERN; {bar p}{endash}p collisions at FNAL; accelerator physics at Fermilab; development work for the SDC detector at SSC; TOPAZ; D-zero physics; physics beyond the standard model; and the Collider Detector at Fermilab. (RWR)

Finley, J.; Gaidos, J.A.; Loeffler, F.J.; McIlwain, R.L.; Miller, D.H.; Palfrey, T.R.; Shibata, E.I.; Shipsey, I.P.

1993-04-01

289

High precision alignment of cryo-electron subtomograms through gradient-based parallel optimization  

PubMed Central

Background Cryo-electron tomography emerges as an important component for structural system biology. It not only allows the structural characterization of macromolecular complexes, but also the detection of their cellular localizations in near living conditions. However, the method is hampered by low resolution, missing data and low signal-to-noise ratio (SNR). To overcome some of these difficulties and enhance the nominal resolution one can align and average a large set of subtomograms. Existing methods for obtaining the optimal alignments are mostly based on an exhaustive scanning of all but discrete relative rigid transformations (i.e. rotations and translations) of one subtomogram with respect to the other. Results In this paper, we propose gradient-guided alignment methods based on two popular subtomogram similarity measures, a real space as well as a Fourier-space constrained score. We also propose a stochastic parallel refinement method that increases significantly the efficiency for the simultaneous refinement of a set of alignment candidates. We estimate that our stochastic parallel refinement is on average about 20 to 40 fold faster in comparison to the standard independent refinement approach. Results on simulated data of model complexes and experimental structures of protein complexes show that even for highly distorted subtomograms and with only a small number of very sparsely distributed initial alignment seeds, our combined methods can accurately recover true transformations with a substantially higher precision than the scanning based alignment methods. Conclusions Our methods increase significantly the efficiency and accuracy for subtomogram alignments, which is a key factor for the systematic classification of macromolecular complexes in cryo-electron tomograms of whole cells. PMID:23046491

2012-01-01

290

High-precision two-dimensional atom localization via quantum interference in a tripod-type system  

NASA Astrophysics Data System (ADS)

A scheme is proposed for high-precision two-dimensional atom localization in a four-level tripod-type atomic system via measurement of the excited state population. It is found that because of the position-dependent atom–field interaction, the precision of 2D atom localization can be significantly improved by appropriately adjusting the system parameters. Our scheme may be helpful in laser cooling or atom nanolithography via high-precision and high-resolution atom localization.

Wang, Zhiping; Yu, Benli

2014-03-01

291

High Precision Tracking Control based on Pseudo-Inverse Feedforward Control System for Next-Generation Optical Disks  

NASA Astrophysics Data System (ADS)

Optical disk drive systems must realize high-precision tracking control. For this purpose, we have already proposed a tracking control system that is composed of a high gain servo controller (HGSC) and a perfect tracking controller (PTC). The conventional feedforward tracking control system adequately suppresses the tracking error caused by track eccentricity. However, the PTC system in the conventional system is complicated. Therefore, the PTC system embedded on a digital signal processor (DSP) cannot realize fast sampling time and the conventional system has a speedup limitation in the optical disk tracking control system. Hence, in this paper, we propose a new high-speed and high-precision feedforward tracking control system that uses a pseudo-inverse matrix. The proposed system consists of the pseudo-inverse feedforward control (P-IFFC). The proposed system realizes simple and quick execution in a digital signal processor software servo. Our experimental results confirm that the proposed system effectively suppresses the tracking error under a condition of the 7200 rpm disk rotation speed of DVD+R. In addition, the conventional systems and the proposed system with a pseudo-inverse matrix are compared in terms of processing time and tracking error.

Ogata, Tokoku; Nakazaki, Tatsuya; Sakimura, Naohide; Ohishi, Kiyoshi; Miyazaki, Toshimasa; Koide, Daiichi; Tokumaru, Haruki; Takano, Yoshimichi

2012-08-01

292

High-precision and high-speed laser microjoining for electronics and microsystems  

NASA Astrophysics Data System (ADS)

The joining processes in electronic device manufacturing are today still dominated by conventional joining techniques like press fitting, crimping and resistance welding. Laser beam joining techniques have been under intensive investigations and subsequently new processes for mass manufacturing and high accuracy assembling were established. With the newly developed SHADOW (R) welding technology technical aspects such as tensile strength, geometry and precision of the weld could be improved. This technology provides highest flexibility in weld geometry with a minimum welding time as well as new possibilities in using application adapted materials. Different parts and even different metals can be joined by a non-contact process. The application of a relative movement between the laser beam and the part to be joined at feed rates of up to 60 m/min produces weld seams with a length from 0.6 mm to 15.7 mm using a pulsed Nd:YAG laser with a pulse duration of up to 50 ms. Due to the low energy input, typically 1 J to 6 J, a weld width as small as 50 ?m and a weld depth as small as 20 pm have been attained. This results in low distortion of the joined watch components. Within this paper this new welding process will be explained and several examples of joined components will be presented with respect to fundamentals and the sustainable implementation of the SHADOW (R) welding technique into watch manufacturing and electronic industry. For microsystem applications the laser joining technology is modified to join even silicon and glass parts without any melting based on the formation of a thermally induced oxygen bond. New fields of applications for joining different materials such as steel to brass or steel to copper for electrical interconnects will be discussed. Here the SHADOW (R) welding technique offers new possibilities for the combination of good electrical properties of copper with high mechanical stiffness of steel. The paper will give a closer look to microjoining applications especially using the SHADOW (R) welding technique. Basics of the process as well as its application on dedicated examples will be shown for small parts such as axis-wheel combinations and electrical connectors.

Gillner, Arnold; Olowinsky, Alexander; Klages, Kilian; Gedicke, Jens; Sari, Fahri

2006-02-01

293

Micromachined capillary cross-connector for high-precision fraction collection.  

PubMed

A new approach for high-precision fraction collection of double-stranded DNA fragments by capillary electrophoresis coupled to a micromachined plastic capillary cross-connector is presented. The system design integrates four fused-silica capillaries with an acrylic cross-channel connector. The cross-channel structure was introduced to enhance the efficiency of the fraction collection process by electrokinetic manipulations. Following the detection of the sample zone of interest at or slightly upstream of the cross during the separation mode, the potentials were reconfigured to collection mode to direct the selected analyte zone into the corresponding collection vial, while keeping the rest of the sample components virtually stopped within the separation capillary. In this way the spacing between consecutive bands of interest can be physically increased, allowing precise isolation of spatially close sample zones. After collection of the target fraction the separation mode is resumed, and the separation/collection cycle is repeated until all desired sample zones are separated and captured. The capillary cross-connector was fabricated of a transparent acrylic substrate by microdrilling flat end and through channels, matching precisely the O.D. and I.D. of the connected capillary tubing, respectively. This design provided a close to zero dead volume connection assembly for the separation and collection capillaries causing minimal extra band broadening during high-precision micropreparative DNA fractionation. PMID:12498238

Khandurina, Julia; Guttman, András

2002-12-01

294

High precision mobile location framework and its service based on virtual reference station of GPS  

NASA Astrophysics Data System (ADS)

The wireless communication technology and space technology are synchronously developed in recent years, which bring up the development of location based service (LBS). At present, many location technology methods were developed. However, all these methods can only provide a relative poor location precision and depend on high cost. The technology of Virtual Reference Station (VRS) of GPS is then involved in this paper. One of the objective in this paper is aim to give the LBS position structure to improve the mobile location position when a mobile position instrument is connected with VRS network. The cheaper GPS built-in Personal Designer Aid (PDA) is then used to achieve a higher precision by using RTCM data from existing VRS network. In order to obtain a high precision position when using the low-cost GPS receiver as a rover, the infrusture of the mobile differential correction system is then put forward. According to network transportation of RTCM via internet protocol (NTRIP), the message is communicated through wireless network, such as GPRS, CDMA and so on. The rough coordinate information is sent to VRS control center continuously, and then the VRS correction information is replied to rover in the data format of RTCM3.1. So the position will be updated based on mathematic solution after the decoding of RTCM3.1 data. The thought of LBS position can improve the precision, and can speed the LBS.

Liu, Chun; Sun, Liangyu; Yao, Lianbi

2008-10-01

295

Studies on fast triggering and high precision tracking with Resistive Plate Chambers  

NASA Astrophysics Data System (ADS)

We report on studies of fast triggering and high precision tracking using Resistive Plate Chambers (RPCs). Two beam tests were carried out with the 180 GeV/c muon beam at CERN using glass RPCs with gas gaps of 1.15 mm and equipped with readout strips with 1.27 mm pitch. This is the first beam test of RPCs with fine-pitch readout strips that explores precision tracking and triggering capabilities. RPC signals were acquired with precision timing and charge integrating readout electronics at both ends of the strips. The time resolution was measured to be better than 600 ps and the average spatial resolution was found to be 220 ?m using charge information and 287 ?m only using signal arrival time information. The dual-ended readout allows the determination of the average and the difference of the signal arrival times. The average time was found to be independent of the incident particle position along the strip and is useful for triggering purposes. The time difference yielded a determination of the hit position with a precision of 7.5 mm along the strip. These results demonstrate the feasibility using RPCs for fast and high-resolution triggering and tracking.

Aielli, G.; Ball, R.; Bilki, B.; Chapman, J. W.; Cardarelli, R.; Dai, T.; Diehl, E.; Dubbert, J.; Ferretti, C.; Feng, H.; Francis, K.; Guan, L.; Han, L.; Hou, S.; Levin, D.; Li, B.; Liu, L.; Paolozzi, L.; Repond, J.; Roloff, J.; Santonico, R.; Song, H. Y.; Wang, X. L.; Wu, Y.; Xia, L.; Xu, L.; Zhao, T.; Zhao, Z.; Zhou, B.; Zhu, J.

2013-06-01

296

A gas chromatography/pyrolysis/isotope ratio mass spectrometry system for high-precision dD measurements  

E-print Network

A gas chromatography/pyrolysis/isotope ratio mass spectrometry system for high-precision d we present a highly automated, high-precision online gas chromatography/pyrolysis/isotope ratio monitoring mass spectrometry (GC/P/irmMS) technique for the analysis of dD(CH4). It includes gas extraction

Fischer, Hubertus

297

High Precision Isotope Analyses Using Multi-Collector SIMS: Applications to Earth and Planetary Science.  

NASA Astrophysics Data System (ADS)

The CAMECA IMS-1280 large radius, multicollector ion microprobe at the Wisc-SIMS National Facility is capable of high accuracy and precision for in situ analysis of isotope ratios. With improved hardware stability and software capability, high precision isotope analyses are routinely performed, typically 5 min per spot. We have developed analytical protocols for stable isotope analyses of oxygen, carbon, Mg, Si and Sulfur using multi-collector Faraday Cups (MCFC) and achieved precision of 0.1-0.2 ‰ (1SD) from a typically 10?m spot analyses. A number of isotopically homogeneous mineral standards have been prepared and calibrated in order to certify the accuracy of analyses in the same level. When spatial resolution is critical, spot size is reduced down to sub- ?m for ? 18O to obtain better than 0.5‰ (1SD) precision by using electron multiplier (EM) on multi-collection system. Multi-collection EM analysis is also applied at 10 ppm level to Li isotope ratios in zircon with precision better than 2‰ (1SD). A few applications will be presented. (1) Oxygen three isotope analyses of chondrules in ordinary chondrites revealed both mass dependent and mass independent oxygen isotope fractionations among chondrules as well as within individual chondrules. The results give constraints on the process of chondrule formation and origin of isotope reservoirs in the early solar system. (2) High precision 26Al-26Mg (half life of 0.73 Ma) chronology is applied to zoned melilite and anorthite from Ca, Al-rich inclusions (CAI) in Leoville meteorite, and a well-defined internal isochron is obtained. The results indicate the Al- Mg system was remained closed within 40ky of the crystallization of melilite and anorthite in this CAI. (3) Sub- ?m spot analyses of ?18O in isotopically zoned zircon from high-grade metamorphism reveals a diffusion profile of ~6‰ over 2?m, indicating slow diffusion of oxygen in zircon. This result also implies that old Archean detrital zircons (> 4Ga) might preserve their primary oxygen isotopic records, which allows us to trace the geological processes of the early earth [1]. Lithium isotope analyses of pre- 4Ga zircon from Jack Hills show high Li abundance and low ? 7Li, indicating existence of highly weathered crustal material as early as 4.3Ga. In conclusion, these new techniques allow us to study small natural variations of stable isotopes at ?m-scale that permit exciting and fundamental research where samples are small, precious, or zoned. [1] Page FZ et al. (2007) Am Min 92, 1772-1775.

Kita, N. T.; Ushikubo, T.; Valley, J. W.

2008-05-01

298

High-precision and high-resolution carbonate 230Th dating by MC-ICP-MS with SEM protocols  

NASA Astrophysics Data System (ADS)

To facilitate the measurement of U-Th isotopic compositions suitable for high-precision and high-resolution 230Th dating of coral and speleothem carbonates, secondary electron multiplier (SEM) protocol techniques for multicollector inductively coupled plasma mass spectrometry (MC-ICP-MS) have been developed. The instrumental sensitivities are 1-2%, with a precision of ±1-2‰ (2?) for abundance determination of 50-200 fg 234U (1-4 ng 238U) or 230Th. This method features chemistry refinements, improvements to procedural and instrumental blanks, spectral inference reductions, and careful consideration of non-linear SEM behavior. Measurement consistency of this MC-ICP-MS combined with previous mass spectrometric results on U-Th standards and a variety of carbonates demonstrates the validity of the SEM protocol method. For fossil corals, a routine U-Th isotopic determination at permil-level precision requires only 10-50 mg of carbonate. As little as 200 mg of young coral with an age of less than 20 yr can be dated with a precision of ±0.3-0.8 yr. About 20-200 mg speleothem samples with sub-ppm-to-ppm U are required to earn a 5‰ precision on ages from 5 to 100 kyr. Requirement of small sample size, 10-100s mg carbonate, can permit high temporal resolution to date speleothems with slow growth rates, i.e., 1-10 mm/kyr. This high-precision 230Th chronology is critical to accurately establish age models, date events and splice geochemical proxy time series records from multiple samples in the fields of paleoclimatology and paleoceanography. The U-Th isotopic determination techniques described here can also be applied to different environmental samples, such as waters, rocks, and sediments.

Shen, Chuan-Chou; Wu, Chung-Che; Cheng, Hai; Lawrence Edwards, R.; Hsieh, Yu-Te; Gallet, Sylvain; Chang, Ching-Chih; Li, Ting-Yong; Lam, Doan Dinh; Kano, Akihiro; Hori, Masako; Spötl, Christoph

2012-12-01

299

Experimental Sensitivity Table Method for Precision Alignment of Amon-Ra Instrument  

NASA Astrophysics Data System (ADS)

The Amon-Ra instrument is the main optical payload of the proposed EARTHSHINE satellite. It consists of a visible wavelength instrument and an IR energy channel instrument to measure a global Earth albedo. We report a new sensitivity technique for efficient alignment of the visible channel instrument. Whilst the sensitivity table method has been widely used in the alignment process, the straightforward application of the method tends to produce slow process convergence because of shop floor alignment practice uncertainties. We investigated the error sources commonly associated with alignment practices and used them when estimating the Zernike polynomial coefficients. Aided with single center field wavefront error (WFE) measurements and their corresponding Zernike polynomial coefficients, the method involves the construction and use of an experimental, instead of simulated, sensitivity table to be used for alignment state estimations. A trial alignment experiment for the Amon Ra optical system was performed and the results show that 71.28 nm in rms WFE was achieved only after two alignment iterations. This tends to demonstrate its superior performance to the conventional method.

Oh, Eunsong; Ahn, Ki-Beom; Kim, Sug-Whan

2014-09-01

300

Electromagnetic controlled cortical impact device for precise, graded experimental traumatic brain injury.  

PubMed

Genetically modified mice represent useful tools for traumatic brain injury (TBI) research and attractive preclinical models for the development of novel therapeutics. Experimental methods that minimize the number of mice needed may increase the pace of discovery. With this in mind, we developed and characterized a prototype electromagnetic (EM) controlled cortical impact device along with refined surgical and behavioral testing techniques. By varying the depth of impact between 1.0 and 3.0 mm, we found that the EM device was capable of producing a broad range of injury severities. Histologically, 2.0-mm impact depth injuries produced by the EM device were similar to 1.0-mm impact depth injuries produced by a commercially available pneumatic device. Behaviorally, 2.0-, 2.5-, and 3.0-mm impacts impaired hidden platform and probe trial water maze performance, whereas 1.5-mm impacts did not. Rotorod and visible platform water maze deficits were also found following 2.5- and 3.0-mm impacts. No impairment of conditioned fear performance was detected. No differences were found between sexes of mice. Inter-operator reliability was very good. Behaviorally, we found that we could statistically distinguish between injury depths differing by 0.5 mm using 12 mice per group and between injury depths differing by 1.0 mm with 7-8 mice per group. Thus, the EM impactor and refined surgical and behavioral testing techniques may offer a reliable and convenient framework for preclinical TBI research involving mice. PMID:17439349

Brody, David L; Mac Donald, Christine; Kessens, Chad C; Yuede, Carla; Parsadanian, Maia; Spinner, Mike; Kim, Eddie; Schwetye, Katherine E; Holtzman, David M; Bayly, Philip V

2007-04-01

301

Theoretical and experimental research on machine tool servo system for ultra-precision position compensation on CNC lathe  

NASA Astrophysics Data System (ADS)

The theories and techniques for improving machining accuracy via position control of diamond tool's tip and raising resolution of cutting depth on precise CNC lathes have been extremely focused on. A new piezo-driven ultra-precision machine tool servo system is designed and tested to improve manufacturing accuracy of workpiece. The mathematical model of machine tool servo system is established and the finite element analysis is carried out on parallel plate flexure hinges. The output position of diamond tool's tip driven by the machine tool servo system is tested via a contact capacitive displacement sensor. Proportional, integral, derivative (PID) feedback is also implemented to accommodate and compensate dynamical change owing cutting forces as well as the inherent non-linearity factors of the piezoelectric stack during cutting process. By closed loop feedback controlling strategy, the tracking error is limited to 0.8 ?m. Experimental results have shown the proposed machine tool servo system could provide a tool positioning resolution of 12 nm, which is much accurate than the inherent CNC resolution magnitude. The stepped shaft of aluminum specimen with a step increment of cutting depth of 1 ?m is tested, and the obtained contour illustrates the displacement command output from controller is accurately and real-time reflected on the machined part.

Ma, Zhichao; Hu, Leilei; Zhao, Hongwei; Wu, Boda; Peng, Zhenxing; Zhou, Xiaoqin; Zhang, Hongguo; Zhu, Shuai; Xing, Lifeng; Hu, Huang

2010-08-01

302

High-precision molecular dynamics simulation of UO 2-PuO 2: Pair potentials comparison in UO 2  

NASA Astrophysics Data System (ADS)

Our series of articles is devoted to high-precision molecular dynamics simulation of mixed actinide-oxide (MOX) fuel in the approximation of rigid ions and pair interactions (RIPI) using high-performance graphics processors (GPU). In this first article ten most recent and widely used interatomic sets of pair potentials (SPP) are assessed by reproduction of solid phase properties of uranium dioxide (UO 2) - temperature dependences of the lattice constant, bulk modulus, enthalpy and heat capacity. Measurements were performed with 1 K accuracy in a wide temperature range from 300 K up to melting points. The best results are demonstrated by two recent SPPs MOX-07 and Yakub-09, which both had been fitted to the recommended thermal expansion in the range of temperatures 300-3100 K. They reproduce the experimental data better than the widely used SPPs Basak-03 and Morelon-03 at temperatures above 2500 K.

Potashnikov, S. I.; Boyarchenkov, A. S.; Nekrasov, K. A.; Kupryazhkin, A. Ya.

2011-12-01

303

High-precision image aided inertial navigation with known features: observability analysis and performance evaluation.  

PubMed

A high-precision image-aided inertial navigation system (INS) is proposed as an alternative to the carrier-phase-based differential Global Navigation Satellite Systems (CDGNSSs) when satellite-based navigation systems are unavailable. In this paper, the image/INS integrated algorithm is modeled by a tightly-coupled iterative extended Kalman filter (IEKF). Tightly-coupled integration ensures that the integrated system is reliable, even if few known feature points (i.e., less than three) are observed in the images. A new global observability analysis of this tightly-coupled integration is presented to guarantee that the system is observable under the necessary conditions. The analysis conclusions were verified by simulations and field tests. The field tests also indicate that high-precision position (centimeter-level) and attitude (half-degree-level)-integrated solutions can be achieved in a global reference. PMID:25330046

Jiang, Weiping; Wang, Li; Niu, Xiaoji; Zhang, Quan; Zhang, Hui; Tang, Min; Hu, Xiangyun

2014-01-01

304

High-precision image position sensing methods suitable for 3-D measurement  

NASA Astrophysics Data System (ADS)

A high-precision image position sensing method for a position sensitive detector (PSD) with a kaleidoscopic mirror tunnel (KM-PSM) is introduced. In order to increase the relative resolution of the image position detecting element itself, a hybrid type position sensitive device (R-HPSD) has been invented. A 1-D mark direction sensing method (PM-DSM) which consists of a 1-D image position sensing element, a cylindrical lens and a parallel mirror tunnel is proposed for the realization of a high-precision and miniaturized 3-D position measuring system. Furthermore, an optical range sensing method (RORS), which is suitable for realizing a miniaturized optical range sensing probe based on the triangulation, is proposed.

Idesawa, Masanori

305

High-precision measurement of pixel positions in a charge-coupled device.  

PubMed

The high level of spatial uniformity in modern CCD's makes them excellent devices for astrometric instruments. However, at the level of accuracy envisioned by the more ambitious projects such as the Astrometric Imaging Telescope, current technology produces CCD's with significant pixel registration errors. We describe a technique for making high-precision measurements of relative pixel positions. We measured CCD's manufactured for the Wide Field Planetary Camera II installed in the Hubble Space Telescope. These CCD's are shown to have significant step-and-repeat errors of 0.033 pixel along every 34th row, as well as a 0.003-pixel curvature along 34-pixel stripes. The source of these errors is described. Our experiments achieved a per-pixel accuracy of 0.011 pixel. The ultimate shot-noise limited precision of the method is less than 0.001 pixel. PMID:21060522

Shaklan, S; Sharman, M C; Pravdo, S H

1995-10-10

306

All low voltage lateral junction scanning tunneling microscope with very high precision and stability  

NASA Astrophysics Data System (ADS)

We describe the first lateral junction and fully low voltage scanning tunneling microscope, featuring very high precision, stability, compactness, and image quality (highly oriented pyrolytic graphite atomic resolution images). In its core, the tip and sample each sit on one of two parallel-mounted piezoelectric tube scanners so that the tip-sample gap is regulated along the scanners' pairing direction. The scanner's large lateral deflection provides a large gap regulation range even under low voltages, allowing exclusively using only low voltage (less than ±15 V) operational amplifiers to precisely implement the coarse (inertial slider) and fine approach, feedback control, and hence the entire electronics. Because the scanners are identical and adjacent, thermal drifts are minimal.

Hou, Yubin; Wang, Jihui; Lu, Qingyou

2008-11-01

307

All low voltage lateral junction scanning tunneling microscope with very high precision and stability.  

PubMed

We describe the first lateral junction and fully low voltage scanning tunneling microscope, featuring very high precision, stability, compactness, and image quality (highly oriented pyrolytic graphite atomic resolution images). In its core, the tip and sample each sit on one of two parallel-mounted piezoelectric tube scanners so that the tip-sample gap is regulated along the scanners' pairing direction. The scanner's large lateral deflection provides a large gap regulation range even under low voltages, allowing exclusively using only low voltage (less than +/-15 V) operational amplifiers to precisely implement the coarse (inertial slider) and fine approach, feedback control, and hence the entire electronics. Because the scanners are identical and adjacent, thermal drifts are minimal. PMID:19045895

Hou, Yubin; Wang, Jihui; Lu, Qingyou

2008-11-01

308

Optical timing receiver for the NASA laser ranging system. Part 2: High precision time interval digitizer  

NASA Technical Reports Server (NTRS)

The development of a high precision time interval digitizer is described. The time digitizer is a 10 psec resolution stop watch covering a range of up to 340 msec. The measured time interval is determined as a separation between leading edges of a pair of pulses applied externally to the start input and the stop input of the digitizer. Employing an interpolation techniques and a 50 MHz high precision master oscillator, the equivalent of a 100 GHz clock frequency standard is achieved. Absolute accuracy and stability of the digitizer are determined by the external 50 MHz master oscillator, which serves as a standard time marker. The start and stop pulses are fast 1 nsec rise time signals, according to the Nuclear Instrument means of tunnel diode discriminators. Firing level of the discriminator define start and stop points between which the time interval is digitized.

Leskovar, B.; Turko, B.

1977-01-01

309

Direct high-precision measurement of the magnetic moment of the proton.  

PubMed

One of the fundamental properties of the proton is its magnetic moment, µp. So far µp has been measured only indirectly, by analysing the spectrum of an atomic hydrogen maser in a magnetic field. Here we report the direct high-precision measurement of the magnetic moment of a single proton using the double Penning-trap technique. We drive proton-spin quantum jumps by a magnetic radio-frequency field in a Penning trap with a homogeneous magnetic field. The induced spin transitions are detected in a second trap with a strong superimposed magnetic inhomogeneity. This enables the measurement of the spin-flip probability as a function of the drive frequency. In each measurement the proton's cyclotron frequency is used to determine the magnetic field of the trap. From the normalized resonance curve, we extract the particle's magnetic moment in terms of the nuclear magneton: ?p = 2.792847350(9)?N. This measurement outperforms previous Penning-trap measurements in terms of precision by a factor of about 760. It improves the precision of the forty-year-old indirect measurement, in which significant theoretical bound state corrections were required to obtain µp, by a factor of 3. By application of this method to the antiproton magnetic moment, the fractional precision of the recently reported value can be improved by a factor of at least 1,000. Combined with the present result, this will provide a stringent test of matter/antimatter symmetry with baryons. PMID:24870545

Mooser, A; Ulmer, S; Blaum, K; Franke, K; Kracke, H; Leiteritz, C; Quint, W; Rodegheri, C C; Smorra, C; Walz, J

2014-05-29

310

High-efficiency piezoelectric motor combining continuous rotation with precise control over angular positioning  

NASA Astrophysics Data System (ADS)

The letter describes a piezoelectric motor that combines the merits of piezoelectric materials, such as high power density generated at electromechanical resonance, and a precise control of displacement. The motor utilizes a direct coupling mechanism between the stator and rotor, where a clutch drives the rotor via locking it. The direct coupling makes it possible to transmit the whole power generated in the piezoelectric element to the rotor, and thus achieve the high efficiency of the motor. It also allows the combining of two regimes of operation: continuous rotation and a stepwise motion within a 360° interval with a high resolution of angular displacement.

Glazounov, A. E.; Wang, S.; Zhang, Q. M.; Kim, C.

1999-08-01

311

High precision micro-displacement fiber sensor through a suspended-core Sagnac interferometer.  

PubMed

A sensing system for micro-displacement measurement based in a suspended-core fiber Sagnac interferometer is presented. The suspended-core fiber characterization was made through the use of an optical backscatter reflectometer, screening its multimodal and birefringent behavior. Its sensitivity to displacement measurements is shown to be due only to birefringence, being that core-cladding mode coupling is negligible. High precision (~0.45 ?m) was obtained using three different measurement instruments, showing an extremely high stability and high insensitivity to temperature, demonstrating that the sensing system has the ability for low cost applications. PMID:22854467

Bravo, M; Pinto, A M R; Lopez-Amo, M; Kobelke, J; Schuster, K

2012-01-15

312

Comment on "High-Precision Determination of the Electric and Magnetic Form Factors of the Proton"  

E-print Network

In a recent Letter, Bernauer, et al. present fits to the proton electromagnetic form factors, GEp(Q^2) and GMp(Q^2), along with extracted proton charge and magnetization radii based on large set of new, high statistical precision (<0.2%) cross section measurements. The Coulomb corrections they apply differ dramatically from more modern and complete calculations, implying significant error in their final results.

J. Arrington

2011-08-15

313

The digital and high-precision error detection of complex freeform surface  

Microsoft Academic Search

The exploitation and modification of automobile die attach great importance to the automobile exploitation. It should be realized in the process of modifying mould-obtaining 3D model by reverse engineering-testing errors-confirming model. This thesis applies the method of ATOS Optical Scanner and CMM (Three-Coordinate Measuring Machine) to obtain the complete high-precision point cloud data because of the complicated free form surface

Hongsheng Fu; Luyue Ju; Xuexia Li

2008-01-01

314

MEMS - Frequency Agile High Precision Ranging under the Dual Use Applications Program (DUAP)  

Microsoft Academic Search

The objective of this program was laboratory demonstration of a low cost, jamming resistant, precision ranging system (radar) for proximity fuze and short-range measurement systems. Two approaches were envisioned: (1) The baseline-a baseband system directly radiating and detecting a random sequence of short pulses and (2) A higher risk design based on a transmitter using high-speed modulation of a micro-electromechanical

Paul Bauhahn

2001-01-01

315

Development of high-precision temperature measurement system based on ARM  

Microsoft Academic Search

The high-precision temperature measurement system which adopts ARM processor LM3S1138 as controlling core was introduced in this paper. In the temperature measuring circuits, the current driving circuit of sensor Pt100A and A\\/D converting circuit adopt the same reference voltage, which makes A\\/D conversion results are only dependent on the changing value of platinum resistance with the temperature change DeltaRT, and

Yi Xianjun; Liu Cuimei

2009-01-01

316

High-precision neutron spectrometer for study of spontaneous and ion induced fission  

SciTech Connect

A high-precision neutron spectrometer system to study the dependences of the fission process is presented. One advantage of the spectrometer is the possibility to investigate both spontaneous fission and fission induced by light or heavy ions of intermediate energies. Systematic errors can thereby be reduced and {sup 252}Cf can be used for calibration purposes. The time evolution in the process is studied by measuring the energy and angular distributions of the emitted neutrons. Some preliminary data is also presented.

Batenkov, O.; Blinov, M.; Majorov, M.; Mogaev, A.; Smirnov, S.; Veshikov, A. [V.G. Khlopin Radium Institute, St. Petersburg (Russian Federation); Conde, H.; Elmgren, K.; Hultqvist, S.; Nilsson, J. [Uppsala Univ. (Sweden)] [and others

1994-12-31

317

Detuned Twin-Signal-Recycling for ultra-high precision interferometers  

E-print Network

We propose a new interferometer technique for high precision phase measurements such as those in gravitational wave detection. The technique utilizes a pair of optically coupled resonators that provides identical resonance conditions for the upper as well the lower phase modulation signal sidebands. This symmetry significantly reduces the noise spectral density in a wide frequency band compared with single sideband recycling topologies of current and planned gravitational wave detectors. Furthermore the application of squeezed states of light becomes less demanding.

Andre Thuering; Roman Schnabel; Harald Lueck; Karsten Danzmann

2007-07-03

318

[2-component technic for the production of positioning supports for highly precise radiotherapy].  

PubMed

In many small institutes exact positioning supports could not yet be manufactured for cost and personal reasons. This problem is solved in a simple manner by the use of the described modern synthetics which allow the application of high-precision techniques such as small-field pendulum therapy and isocentric multifield therapy. This system serves the safety of patients and therapists and is meant to prevent recurrences and late damages especially in children. PMID:2799629

Hawliczek, R; Theil, E; Schmidt, W

1989-09-01

319

High Precision Measurement of the Muonium Ground State Hyperfine Interval and the Muon Magnetic Moment  

Microsoft Academic Search

The hfs interval of ground state muonium, (DELTA)(nu), and the ratio of the muon magnetic moment to that of the proton, (mu)(,(mu))\\/(mu)(,p), have been measured with high precision by means of microwave magnetic resonance techniques at the Los Alamos Meson Physics Facility (LAMPF). Muonium was formed by stopping low momentum polarized positive muons in a resonant cavity containing Kr gas

Fesseha Gebre Mariam

1981-01-01

320

High-precision calculations of atomic properties and parity nonconservation in systems with one valence electron  

Microsoft Academic Search

High-precision calculations of atomic properties of systems with one valence electron outside of a closed core are carried out using a relativistic all-order method. The method used here is a linearized version of coupled-cluster method which sums infinite sets of many- body perturbation theory terms. Energy levels are calculated for the ground state and five excited states of sodium and

Marianna Suyatoslavna Safronova

2001-01-01

321

Development of a high precision tabletop versatile CNC wire-EDM for making intricate micro parts  

Microsoft Academic Search

The micro-electrical discharge machining (micro-EDM) process has been proved to be appropriate for making 3D micro parts that are difficult and even impossible to manufacture by other processes. In this paper a high precision tabletop CNC wire electrical discharge machine (wire EDM) designed specifically for machining complex shape micro parts or structures is developed. In the machine developed, a novel

Yunn-Shiuan Liao; Shun-Tong Chen; Chang-Sheng Lin

2005-01-01

322

High precision angle calibration of robotic total stations and laser trackers  

NASA Astrophysics Data System (ADS)

This paper presents the recent development of two angle standards, referred to as the Horizontal Circle Comparator (HCC) and the Vertical Circle Comparator (VCC), used in the calibration of high precision spherical measurement systems; a family of instruments consisting of robotic total stations (RTSs), and laser trackers (LTs). The paper discusses these standards and their utilization and then presents the first results of instrument calibrations with them.

Martin, D.; Chetwynd, D. G.

2008-10-01

323

A micro-computer based system for high precision temperature measurement using Platinum RTD's  

Microsoft Academic Search

A micro-computer controlled system for 10 channel high precision temperature data acquisition has been developed. The temperature sensing elements are Platinum Resistance Thermometer Devices (RTD's). Probe construction, using standard, commercially available RTD elements is described and wiring and switching requirements for the 4-wire resistance measurements are noted. The system consists of a Digital Equipment Corp. MINC-11 Computer linked, via IEEE-488

W. T. Matthew

1982-01-01

324

Experimental study of the fabrication of chalcogenide glass lenses by using precision glass molding  

NASA Astrophysics Data System (ADS)

Although the development of small formats (640 × 480 pixel arrays) and amorphous silicon microbolometers has greatly decreased detector cost, another important component of a thermal camera, the optics, still prohibit a breakthrough for high-volume commercial systems. The aspheric lenses used in thermal imaging are typically made using the costly single-point diamond turning (SPDT) process with expensive single-crystal materials (Ge, ZnS, etc.). As a potential solution to reduce cost, the compression molding method using chalcogenide glass has become attractive for fabricating IR optics. The present paper reports the fabrication of a mold and a molded chalcogenide glass lens for a thermal security camera. In addition, the molded chalcogenide glass lens was evaluated using the form error, roughness and decentration for each surface of the molded lens. From the evaluation results, we verified that the molded lens was capable of being used for thermal imaging applications.

Cha, Du Hwan; Kim, Jeong-Ho; Kim, Hye-Jeong

2014-11-01

325

Next generation KATRIN high precision voltage divider for voltages up to 65kV  

E-print Network

The KATRIN (KArlsruhe TRItium Neutrino) experiment aims to determine the mass of the electron antineutrino with a sensitivity of 200meV by precisely measuring the electron spectrum of the tritium beta decay. This will be done by the use of a retarding spectrometer of the MAC-E-Filter type. To achieve the desired sensitivity the stability of the retarding potential of -18.6kV has to be monitored with a precision of 3ppm over at least two months. Since this is not feasible with commercial devices, two ppm-class high voltage dividers were developed, following the concept of the standard divider for DC voltages of up to 100kV of the Physikalisch-Technische Bundesanstalt (PTB). In order to reach such high accuracies different effects have to be considered. The two most important ones are the temperature dependence of resistance and leakage currents, caused by insulators or corona discharges. For the second divider improvements were made concerning the high-precision resistors and the thermal design of the divider....

Bauer, S; Hochschulz, F; Ortjohann, H -W; Rosendahl, S; Thümmler, T; Schmidt, M; Weinheimer, C

2013-01-01

326

Next generation KATRIN high precision voltage divider for voltages up to 65kV  

NASA Astrophysics Data System (ADS)

The KATRIN (KArlsruhe TRItium Neutrino) experiment aims to determine the mass of the electron antineutrino with a sensitivity of 200 meV by precisely measuring the electron spectrum of the tritium beta decay. This will be done by the use of a retarding spectrometer of the MAC-E-Filter type. To achieve the desired sensitivity the stability of the retarding potential of -18.6 kV has to be monitored with a precision of 3 ppm over at least two months. Since this is not feasible with commercial devices, two ppm-class high voltage dividers were developed, following the concept of the standard divider for DC voltages of up to 100 kV of the Physikalisch-Technische Bundesanstalt (PTB). In order to reach such high accuracies different effects have to be considered. The two most important ones are the temperature dependence of resistance and leakage currents, caused by insulators or corona discharges. For the second divider improvements were made concerning the high-precision resistors and the thermal design of the divider. The improved resistors are the result of a cooperation with the manufacturer. The design improvements, the investigation and the selection of the resistors, the built-in ripple probe and the calibrations at PTB will be reported here. The latter demonstrated a stability of about 0.1 ppm/month over a period of two years.

Bauer, S.; Berendes, R.; Hochschulz, F.; Ortjohann, H.-W.; Rosendahl, S.; Thümmler, T.; Schmidt, M.; Weinheimer, C.

2013-10-01

327

Precision of high-resolution multibeam echo sounding coupled with high-accuracy positioning in a shallow water coastal environment  

NASA Astrophysics Data System (ADS)

Over 4 years, repetitive bathymetric measurements of a shipwreck in the Grådyb tidal inlet channel in the Danish Wadden Sea were carried out using a state-of-the-art high-resolution multibeam echosounder (MBES) coupled with a real-time long range kinematic (LRK™) global positioning system. Seven measurements during a single survey in 2003 ( n=7) revealed a horizontal and vertical precision of the MBES system of ±20 and ±2 cm, respectively, at a 95% confidence level. By contrast, four annual surveys from 2002 to 2005 ( n=4) yielded a horizontal and vertical precision (at 95% confidence level) of only ±30 and ±8 cm, respectively. This difference in precision can be explained by three main factors: (1) the dismounting of the system between the annual surveys, (2) rougher sea conditions during the survey in 2004 and (3) the limited number of annual surveys. In general, the precision achieved here did not correspond to the full potential of the MBES system, as this could certainly have been improved by an increase in coverage density (soundings/m2), achievable by reducing the survey speed of the vessel. Nevertheless, precision was higher than that reported to date for earlier offshore test surveys using comparable equipment.

Ernstsen, Verner B.; Noormets, Riko; Hebbeln, Dierk; Bartholomä, Alex; Flemming, Burg W.

2006-09-01

328

Recent Operational Improvements To High Precision Photometric Observations With Warm IRAC  

NASA Astrophysics Data System (ADS)

We present recent improvements to the data taking for high precision photometric observations with warm IRAC. The IRAC 3.6 and 4.5 ?m observations have significant photometric systematics due to a coupling of telescope motions with intra-pixel gain variations. These systematics are being trended with increasingly sophisticated techniques by the community (e.g. Ballard et al. 2010). A significant systematic due to a pointing wobble was reduced by 50% permitting observers to achieve precisions of 60 ppm (Demory et al. 2011). Most recently, use of the optical peakup instrument aboard Spitzer has been tested to place all IRAC staring mode observations on the same portion of a pixel. These tests have been effective in placing repeated epochs in the same 0.24 by 0.24 arcsec region of a pixel which has a minimal gain variation (sweet-spot). Preliminary high precision ( 10-4) gain maps of the sweet-spots will be presented. Coupled with science data taken at these sweet-spots, the gain maps will improve the ability to remove systematics from photometry. Results from demonstration observations of KOI-069 will be presented. The peakup mode has been tested for targets with V magnitude between 7 and 12.5. In limited testing, peakups using guide stars have been shown effective for stars outside this magnitude range. Full commissioning of the mode is ongoing with the expectation that all high-precision photometric observations will use peakups by the beginning of 2012. Use of the mode can continue as long as Spitzer is operating and should permit photon-limited follow-up and characteriztion of all Kepler discoveries. This work is based on observations made with the Spitzer Space Telescope, which is operated by the Jet Propulsion Laboratory, California Institute of Technology under a contract with NASA. Support for this work was provided by NASA through an award issued by JPL/Caltech.

Carey, Sean J.; Krick, J.; Ingalls, J.; von Braun, K.; Stauffer, J.; Charbonneau, D.; Ballard, S.; Fisher, M.; Olds, R.

2012-01-01

329

Early Results from A Global Network of Extremely High Precision Extrasolar Planet Tracker Instruments  

NASA Astrophysics Data System (ADS)

We report early results from two of the Extremely High Precision Extrasolar Planet Tracker Instruments (EXPERT) as part of a global network for hunting for low mass planets in the next decade. The first EXPERT was commissioned at the Kitt Peak 2.1m in September 2009 and the second one is to be commissioned at the LiJiang 2.4m telescope in December 2009. EXPERT is a combination of a thermally compensated monolithic interferometer and a high throughput cross-dispersed echelle spectrograph with a spectral resolution of R=18,000. It covers 0.39-0.7 ?m in a single exposure. The commissioning data shows that we have reached a Doppler precision of about 1 m/s for a solar type star with S/N 100 per pixel using an early version of data pipeline with iodine absorption calibration (0.5-0.6 ?m only), which is consistent with our original design. We also achieved slightly better than R=18,000 spectral resolution, about 10 mK temperature stability over a few days, a total detection efficiency of 18.8% from the telescope fiber tip to the detector at 0.55 ?m. The final predicted Doppler precision based on ThAr calibration being developed to cover the entire operating wavelengths is about 0.5 m/s. Our goal is to populate six 2 meter class telescopes with the EXPERT instruments across the globe to have more than 90% duty cycle for time sensitive extremely high precision Doppler measurements such as hunting for Earth like rocky planets and studying stellar oscillations. The network will also be used for following up planet candidates from the on-going SDSS-III Multi-object APO Radial Velocity Exoplanet Large-area Survey (MARVELS) and space missions. We acknowledge support from W.M. Keck Foundation, NSF, Chinese NSF, UF and the LiJET consortium.

Ge, Jian; Chang, L.; Groot, J.; Wan, X.; Zhao, B.; Varosi, F.; Hanna, K.; Jiang, P.; Fleming, S.; Lee, B.; Pais, R.; Wang, J.; Dou, L.; Liu, J.; Costello, E.; Delgado-Navarro, A.; Bollampally, S.; Bosman, T.; Powell, S.; Wang, T.; Wang, T.; Yuan, W.; Zhou, J.; Zhou, H.

2010-01-01

330

Mechanisms of Archean crust formation inferred from high-precision HFSE systematics in TTGs  

NASA Astrophysics Data System (ADS)

It has been proposed that Archean tonalitic-trondhjemitic-granodioritic magmas (TTGs) formed by melting of mafic crust at high pressures. The residual mineralogy of the TTGs (either (garnet)-amphibolite or rutile-bearing eclogite) is believed to control the trace element budget of TTGs. In particular, ratios of high-field-strength elements (HFSE) can help to discriminate between the different residual lithologies. In order to place constraints on the source mineralogy of TTGs, we performed high-precision HFSE measurements by isotope dilution (Nb, Ta, Zr, Hf) together with Lu-Hf and Sm-Nd measurements on representative, ca. 3.85-2.8 Ga TTGs and related rock types from southern West Greenland, W-India and from the Superior Province. These measurements are complemented by major and trace element data for the TTGs. Texturally homogeneous early Archean (3.85-3.60 Ga old) and Mesoarchean (ca. 3.1-2.8 Ga old) TTGs have both low Ni (<11 ppm) and Cr contents (<20 ppm), indicating that there was little or no interaction with mantle peridotite during ascent. Ratios of Nb/Ta in juvenile Eoarchean TTGs range from ca. 7 to ca. 24, and in juvenile Mesoarchean TTGs from ca. 14 to ca. 27. Even higher Nb/Ta (14-42) were obtained for migmatitic TTGs and intra-crustal differentiates, most likely mirroring further fractionation of Nb from Ta as a consequence of partial melting, fluid infiltration and migmatisation. In the juvenile TTGs, positive correlations between Nb/Ta and Gd/Yb, La/Yb, Sr/Y, Zr/Sm and Zr/Nb are observed. These compositional arrays are best explained by melting of typical Isua tholeiites in both, the rutile-bearing eclogite stability field (>15 kbar, high Nb/Ta) and the garnet-amphibolite stability field (10-15 kbar, low Nb/Ta). With respect to the low end of Nb/Ta found for TTGs, there is currently some uncertainty between the available experimental datasets for amphibole. Independent of these uncertainties, the TTG compositions found here still require the presence of both endmember residues. A successful geological model for the TTGs therefore has to account for the co-occurrence of both low- and high-Nb/Ta TTGs within the same geologic terrane. An additional feature observed in the Eoarchean samples from Greenland is a systematic co-variation between Nb/Ta and initial ?Hf(t), which is best explained by a model where TTG-melting occured at progressively increasing pressures in a pile of tectonically thickened mafic crust. The elevated Nb/Ta in migmatitic TTGs and intra-crustal differentiates can shed further light on the role of intra-crustal differentiation processes in the global Nb/Ta cycle. Lower crustal melting processes at granulite facies conditions may generate high-Nb/Ta domains in the middle crust, whereas mid-crustal melting at amphibolite facies conditions may account for the low Nb/Ta generally observed in upper crustal rocks.

Hoffmann, J. Elis; Münker, Carsten; Næraa, Tomas; Rosing, Minik T.; Herwartz, Daniel; Garbe-Schönberg, Dieter; Svahnberg, Henrik

2011-08-01

331

A Flexile and High Precision Calibration Method for Binocular Structured Light Scanning System  

PubMed Central

3D (three-dimensional) structured light scanning system is widely used in the field of reverse engineering, quality inspection, and so forth. Camera calibration is the key for scanning precision. Currently, 2D (two-dimensional) or 3D fine processed calibration reference object is usually applied for high calibration precision, which is difficult to operate and the cost is high. In this paper, a novel calibration method is proposed with a scale bar and some artificial coded targets placed randomly in the measuring volume. The principle of the proposed method is based on hierarchical self-calibration and bundle adjustment. We get initial intrinsic parameters from images. Initial extrinsic parameters in projective space are estimated with the method of factorization and then upgraded to Euclidean space with orthogonality of rotation matrix and rank 3 of the absolute quadric as constraint. Last, all camera parameters are refined through bundle adjustment. Real experiments show that the proposed method is robust, and has the same precision level as the result using delicate artificial reference object, but the hardware cost is very low compared with the current calibration method used in 3D structured light scanning system. PMID:25202736

Yuan, Jianying; Wang, Qiong; Li, Bailin

2014-01-01

332

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

NASA Technical Reports Server (NTRS)

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

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

2011-01-01

333

A flexile and high precision calibration method for binocular structured light scanning system.  

PubMed

3D (three-dimensional) structured light scanning system is widely used in the field of reverse engineering, quality inspection, and so forth. Camera calibration is the key for scanning precision. Currently, 2D (two-dimensional) or 3D fine processed calibration reference object is usually applied for high calibration precision, which is difficult to operate and the cost is high. In this paper, a novel calibration method is proposed with a scale bar and some artificial coded targets placed randomly in the measuring volume. The principle of the proposed method is based on hierarchical self-calibration and bundle adjustment. We get initial intrinsic parameters from images. Initial extrinsic parameters in projective space are estimated with the method of factorization and then upgraded to Euclidean space with orthogonality of rotation matrix and rank 3 of the absolute quadric as constraint. Last, all camera parameters are refined through bundle adjustment. Real experiments show that the proposed method is robust, and has the same precision level as the result using delicate artificial reference object, but the hardware cost is very low compared with the current calibration method used in 3D structured light scanning system. PMID:25202736

Yuan, Jianying; Wang, Qiong; Li, Bailin

2014-01-01

334

Design, performance, and early results from extremely high Doppler precision instruments in a global network  

NASA Astrophysics Data System (ADS)

We report design, performance and early results from two of the Extremely High Precision Extrasolar Planet Tracker Instruments (EXPERT) as part of a global network for hunting for low mass planets in the next decade. EXPERT is a combination of a thermally compensated monolithic Michelson interferometer and a cross-dispersed echelle spectrograph for extremely high precision Doppler measurements for nearby bright stars (e.g., 1m/s for a V=8 solar type star in 15 min exposure). It has R=18,000 with a 72 micron slit and a simultaneous coverage of 390-694 nm. The commissioning results show that the instrument has already produced a Doppler precision of about 1 m/s for a solar type star with S/N~100 per pixel. The instrument has reached ~4 mK (P-V) temperature stability, ~1 mpsi pressure stability over a week and a total instrument throughput of ~30% at 550 nm from the fiber input to the detector. EXPERT also has a direct cross-dispersed echelle spectroscopy mode fed with 50 micron fibers. It has spectral resolution of R=27,000 and a simultaneous wavelength coverage of 390-1000 nm.

Ge, Jian; Zhao, Bo; Groot, John; Chang, Liang; Varosi, Frank; Wan, Xiaoke; Powell, Scott; Jiang, Peng; Hanna, Kevin; Wang, Ji; Pais, Rohan; Liu, Jian; Dou, Liming; Schofield, Sidney; McDowell, Shaun; Costello, Erin; Delgado-Navarro, Adriana; Fleming, Scott; Lee, Brian; Bollampally, Sandeep R.; Bosman, Troy; Jakeman, Hali; Fletcher, Adam; Marquez, Gabriel

2010-07-01

335

The instrument of high-precision photoelectric autocollimator based on PSD  

NASA Astrophysics Data System (ADS)

In response to the accuracy of most autocollimator measurement is not high, and limited to one-dimensional static measurement., we designed a kind of high-precision photoelectric self-collimation measurement system which based on position sensitive detector(PSD). The system uses a return-type optical path to reduce equipment size, and the use of neural network based on the PSD for the non-linear correction. When the distance is 10m, it can achieve the measurement range +/- 4', full-range measurement error of less than 0.1", measurement resolution of less than 0.01" and other technical indicators.

Zhang, Xinting; An, Zhiyong

2011-11-01

336

Precision blood-leak detector with high long-time stability  

NASA Astrophysics Data System (ADS)

With this publication a precision blood-leak-detector is presented. The blood-leak-detector is used for recognition of fractures in the dialyzer of a kidney-machine. It has to detect safely a blood flow of ml/min to exclude any risk for the patient. A lot of systems exist for blood-leak-detection. All of them use the same principle. They detect the light absorption in the dialyze fluid. The actual used detectors are inferior to the new developed sensor in resolution and long-time stability. Regular test of the existing systems and high failure rates are responsible for the high maintenance.

Georgiadis, Christos; Kleuver, Wolfram

1999-11-01

337

High-precision microcutting of ceramics with short-pulsed solid state lasers  

NASA Astrophysics Data System (ADS)

This contribution will present results for high-precision cutting of technical ceramics with short-pulsed solid-state lasers in fundamental and frequency-doubled wavelength. On the basis of ample experiments, a surprising absorption behavior of some ceramics in the case of irradiation with high intensity will be discussed. Furthermore, the influence of wavelength and process gas on cutting speed and quality is demonstrated. The investigations resulted in a process strategy with multiple passing over of the kerf suited for remarkably improving process velocity and quality. Finally, structures applicable for nozzles and spinnerets are shown.

Radtke, Joachim; Abeln, Tobias; Weikert, Michael; Dausinger, Friedrich

2000-11-01

338

The design of a stepper motor control-based high-precision varifocal imaging optical system  

NASA Astrophysics Data System (ADS)

This study, while introducing the theories and makeup of conventional cam varifocal system, indicates the two faults stemming from their inherent mechanism and potentiometer-based focal-length measurement: 1) inability to stop optic axis vibration and 2) considerable error in real-time output of focal-length value. As a result, a stepper motor, instead of cam mechanism, was employed to control mirrors of variofocus and mirrors of compensation in moving accurately along straight-ling rails so that continuous focal-length variation and surface image positioning were accomplished; a linear encoder was substituted for potentiometer in realizing real-time output of focal-length value and also in closed-loop control of stepper motor. Compared with the cam mechanism, this system provides 90% less vibration and 80% more positioning precision, thereby basically solving the problems of the cam system and enabling the high-precision angular measurement.

Xiang, Bai

2012-11-01

339

Communication: High precision sub-Doppler infrared spectroscopy of the HeH{sup +} ion  

SciTech Connect

The hydrohelium cation, HeH{sup +}, serves as an important benchmark for ab initio calculations that take into account non-adiabatic, relativistic, and quantum electrodynamic effects. Such calculations are capable of predicting molecular transitions to an accuracy of ?300 MHz or less. However, in order to continue to push the boundaries on these calculations, new measurements of these transitions are required. Here we measure seven rovibrational transitions in the fundamental vibrational band to a precision of ?1 MHz using the technique of Noise Immune Cavity Enhanced Optical Heterodyne Velocity Modulation Spectroscopy. These newly measured transitions are included in a fit to the rotation-vibration term values to derive refined spectroscopic constants in the v = 0 and v = 1 vibrational states, as well as to calculate rotation-vibration energy levels with high precision.

Perry, Adam J.; Hodges, James N.; Markus, Charles R.; Kocheril, G. Stephen [Department of Chemistry, University of Illinois, Urbana, Illinois 61801 (United States); McCall, Benjamin J., E-mail: bjmccall@illinois.edu [Department of Chemistry, University of Illinois, Urbana, Illinois 61801 (United States); Departments of Astronomy and Physics, University of Illinois, Urbana, Illinois 61801 (United States)

2014-09-14

340

Communication: High precision sub-Doppler infrared spectroscopy of the HeH+ ion  

NASA Astrophysics Data System (ADS)

The hydrohelium cation, HeH+, serves as an important benchmark for ab initio calculations that take into account non-adiabatic, relativistic, and quantum electrodynamic effects. Such calculations are capable of predicting molecular transitions to an accuracy of ˜300 MHz or less. However, in order to continue to push the boundaries on these calculations, new measurements of these transitions are required. Here we measure seven rovibrational transitions in the fundamental vibrational band to a precision of ˜1 MHz using the technique of Noise Immune Cavity Enhanced Optical Heterodyne Velocity Modulation Spectroscopy. These newly measured transitions are included in a fit to the rotation-vibration term values to derive refined spectroscopic constants in the v = 0 and v = 1 vibrational states, as well as to calculate rotation-vibration energy levels with high precision.

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

2014-09-01

341

Communication: High precision sub-Doppler infrared spectroscopy of the HeH? ion.  

PubMed

The hydrohelium cation, HeH(+), serves as an important benchmark for ab initio calculations that take into account non-adiabatic, relativistic, and quantum electrodynamic effects. Such calculations are capable of predicting molecular transitions to an accuracy of ~300 MHz or less. However, in order to continue to push the boundaries on these calculations, new measurements of these transitions are required. Here we measure seven rovibrational transitions in the fundamental vibrational band to a precision of ~1 MHz using the technique of Noise Immune Cavity Enhanced Optical Heterodyne Velocity Modulation Spectroscopy. These newly measured transitions are included in a fit to the rotation-vibration term values to derive refined spectroscopic constants in the v = 0 and v = 1 vibrational states, as well as to calculate rotation-vibration energy levels with high precision. PMID:25217893

Perry, Adam J; Hodges, James N; Markus, Charles R; Kocheril, G Stephen; McCall, Benjamin J

2014-09-14

342

Measuring instrument for radial composite deviations of high-precision master gear  

NASA Astrophysics Data System (ADS)

During double flank rolling composite detection, the radial composite deviations of master gears has been existed and transferred to the measured gear by the primary harmonic curve. In order to improve measurement accuracy, a measuring instrument is developed for radial composite deviations of high-precision master gear in the paper. This instrument uses the structure of spring-suspend swing span to overcome the shortcomings of large rotation errors, low sensitivity, low resolution and large measuring force appearing in the traditional combination-type gear inspection instrument. Artificial intelligence technology is used to improve the efficiency and accuracy of this instrument. The result is that the measuring apparatus is able to meet the requirement and improve efficiency through the measuring experiments on master gears of precision grade 2 with modulus 2 mm and 3 mm, respectively.

Ma, Yong; Wang, Tongxiang; Lou, Zhifeng; Wang, Liding; Zhang, Yuling

2010-08-01

343

High-precision cylindrical and quasi-cylindrical aspherization of small surfaces by ion beam figuring  

NASA Astrophysics Data System (ADS)

We have used a broad ion beam technique to generate cylindrical structures. Although limited to small dimensions, it produces potentially high precision smooth surfaces. As a first trial, four surfaces were produced for an industrial application, using a fairly simple mask; the 8 mm wide, 3 micrometers deep W profile cylinder was engraved on silicon substrates. Reproducibility was in the range of 1 percent when working in reproducible conditions, allowing refinement of the mask. We shall discuss the limitations of the method and improvement of the mask. We shall discuss a project extending the method to quasi-cylindrical figuring: the fabrication of a diffraction-limited off-axis ellipsoidal mirror at a 21 nm wavelength, with, as a first trial, the fabrication of a toroidal surface to a nanometric precision.

Mercier, Raymond; Mullot, Michel; Lamare, Michel; Tissot, Gerard

1999-09-01

344

Fabrication of high precision metallic freeform mirrors with magnetorheological finishing (MRF)  

NASA Astrophysics Data System (ADS)

The fabrication of complex shaped metal mirrors for optical imaging is a classical application area of diamond machining techniques. Aspherical and freeform shaped optical components up to several 100 mm in diameter can be manufactured with high precision in an acceptable amount of time. However, applications are naturally limited to the infrared spectral region due to scatter losses for shorter wavelengths as a result of the remaining periodic diamond turning structure. Achieving diffraction limited performance in the visible spectrum demands for the application of additional polishing steps. Magnetorheological Finishing (MRF) is a powerful tool to improve figure and finish of complex shaped optics at the same time in a single processing step. The application of MRF as a figuring tool for precise metal mirrors is a nontrivial task since the technology was primarily developed for figuring and finishing a variety of other optical materials, such as glasses or glass ceramics. In the presented work, MRF is used as a figuring tool for diamond turned aluminum lightweight mirrors with electroless nickel plating. It is applied as a direct follow-up process after diamond machining of the mirrors. A high precision measurement setup, composed of an interferometer and an advanced Computer Generated Hologram with additional alignment features, allows for precise metrology of the freeform shaped optics in short measuring cycles. Shape deviations less than 150 nm PV / 20 nm rms are achieved reliably for freeform mirrors with apertures of more than 300 mm. Characterization of removable and induced spatial frequencies is carried out by investigating the Power Spectral Density.

Beier, Matthias; Scheiding, Sebastian; Gebhardt, Andreas; Loose, Roman; Risse, Stefan; Eberhardt, Ramona; Tünnermann, Andreas

2013-09-01

345

Highly precise micro-retroreflector array fabricated by the LIGA process and its application as tapped delay line filter.  

PubMed

We report on the fabrication of a one-dimensional micro-retroreflector array with a pitch of 100 ?m. The array was fabricated by x-ray lithography and the lithographie, galvanik und abformung (LIGA) process in a 1 mm thick poly(methyl methacrylate) (PMMA) layer and subsequently covered with Au. The area of the array is 1 mm×10 mm. The high precision of the LIGA-based fabrication process allows one to use the element in spectrometers. Here, it is suggested to apply it to the implementation of a transversal filter for femtosecond pulses. We present a theoretical description of the performance of the retroreflector array as a filtering device and show experimental results. PMID:22945143

Bohling, Michael; Seiler, Thomas; Wdowiak, Boguslaw; Jahns, Jürgen; Mohr, Jürgen; Börner, Martin

2012-09-01

346

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

PubMed Central

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

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

2014-01-01

347

High precision regions of phase sensitivity for the superposition of coherent fields  

NASA Astrophysics Data System (ADS)

We investigate the problem of parameter estimation for the superposition of coherent fields under perfect and lossy regimes. We show the optimal range for higher precision of phase estimation by exactly solving a model consisting of a Schrödinger-cat state (SCS) subject to zero-temperature under a decoherence effect due to a dissipative interaction with an environment. We find the phenomenon that the quantum Fisher information (QFI), namely, the precision of estimation, is slowly reduced with the environment effect and affected by the photon number effects. We find that revivals and retardation of the QFI loss may occur by adjusting the mean photon number, and increasing the photons strongly enhances the coherence and hence augments the resolution of the parameter estimation. Due to the significance of how a system is quantum correlated with its environment in the construction of a scalable quantum computer, the entanglement between the coherent field and its environment is investigated during the dissipation. We show that partial entanglement trapping occurs during the dynamics depending on the mean photon number. These features make the SCS with a larger average number of photons a good candidate for implementation of schemes of quantum optics and information with high precision.

Berrada, K.

2014-09-01

348

A micro-computer based system for high precision temperature measurement using Platinum RTD's  

NASA Astrophysics Data System (ADS)

A micro-computer controlled system for 10 channel high precision temperature data acquisition has been developed. The temperature sensing elements are Platinum Resistance Thermometer Devices (RTD's). Probe construction, using standard, commercially available RTD elements is described and wiring and switching requirements for the 4-wire resistance measurements are noted. The system consists of a Digital Equipment Corp. MINC-11 Computer linked, via IEEE-488 interface bus cables, to a HP (Hewlett-Packard) 34555A Digital Volt/Ohm Meter, an HP-3495A Scanner/Multiplexer, and, during calibration, a HP 2804A Quartz Thermometer. Two programs are employed: one for probe calibration and the other for the temperature measurement application. In the calibration program, the ten probes are individually calibrated against the Quartz Thermometer which has an absolute accuracy specification of + or 0.04 C. A proportional control water bath having a thermal stability specification of + or - 0.004 C provided the common thermal medium during calibration. Currently a three point calibration spanning 6 C (37 to 43 C) is employed. The individual probe constants are computed and recorded on a computer file for access via the temperature measurement program. An initial evaluation of the precision of the calibrated RTD system against the Quartz Thermometer reading yielded an overall precision of + or - 0.0004 C and worst case error of less than + or - 0.01 C.

Matthew, W. T.

1982-07-01

349

Optical vortex beam based optical fan for high-precision optical measurements and optical switching.  

PubMed

The polarization and orbital angular momentum properties of light are of great importance in optical science and technology in the fields of high-precision optical measurements and high-capacity and high-speed optical communications. Here we show a method for the construction of a simple and robust scheme to rotate a light beam such as a fan, which is based on a combination of these two properties and using the thermal-dispersion and electro-optical effect of birefringent crystals. Using a computer-based digital image-processing technique, we determine the temperature and thermal-dispersion difference of the crystal with high resolution. We also use the rotation phenomenon to realize thermo-optic and electro-optic switches. The basic operating principles for measurement and switching processes are presented in detail. The methods developed here will have wide practical applicability in various fields, including remote sensing, materials science, and optical communication networks. PMID:25166083

Zhou, Zhi-Yuan; Li, Yan; Ding, Dong-Sheng; Zhang, Wei; Shi, Shuai; Shi, Bao-Sen

2014-09-01

350

Piezoelectric stepper motor with direct coupling mechanism to achieve high efficiency and precise control of motion.  

PubMed

The paper describes a piezoelectric motor that combines the merits of piezoelectric materials, such as high power density generated at electromechanical resonance, and a precise control of displacement. In the motor, a standing shear wave is excited at the resonance in the piezoelectric tube, and it produces high-frequency torsional vibrations of the stator. The vibrations are converted into unidirectional rotation of a rotor by using a direct coupling mechanism between the stator and the rotor in which a clutch drives the rotor via locking it. The direct coupling makes it possible to transmit the whole power generated in the piezoelectric tube to the rotor, and thus achieve the high efficiency of the motor. It also allows combining two regimes of operation: continuous rotation and a stepwise motion within a 360 degrees interval with a high resolution of angular displacement. PMID:18238641

Glazounov, A E; Wang, S; Zhang, Q M; Kim, C

2000-01-01

351

High precision pulsar timing: Nancay and the european pulsar timing array  

NASA Astrophysics Data System (ADS)

Pulsars are highly stable celestial rotators used in many different applications, from tests of the theories describing the gravitation to the search for a Gravitational Waves background. They could even play a role in time scales definition and those point sources are also used to link the different reference frames. Nancay radiotelescope is involved in high precision timing since 20 years. Since 2004, a coherent dedispersion instrumentation enables numerous routine observations on more than 200 pulsars using half of the time of this 100-meters class radiotelescope. Two main programs are currently conducted. A large set of young and old pulsars is timed for a multi-wavelength approach, complementary to the very successful high energy observations of pulsars done by the instrument FERMI/LAT (Abdo et al., 2009). A set of highly stable millisecond pulsars is monitored as our contribution to the European Pulsar Timing Array in order to probe any kind of Gravitational Waves background.

Cognard, I.; Desvignes, G.; Theureau, G.

2011-10-01

352

Direct high-precision measurement of the magnetic moment of the proton  

E-print Network

The spin-magnetic moment of the proton $\\mu_p$ is a fundamental property of this particle. So far $\\mu_p$ has only been measured indirectly, analysing the spectrum of an atomic hydrogen maser in a magnetic field. Here, we report the direct high-precision measurement of the magnetic moment of a single proton using the double Penning-trap technique. We drive proton-spin quantum jumps by a magnetic radio-frequency field in a Penning trap with a homogeneous magnetic field. The induced spin-transitions are detected in a second trap with a strong superimposed magnetic inhomogeneity. This enables the measurement of the spin-flip probability as a function of the drive frequency. In each measurement the proton's cyclotron frequency is used to determine the magnetic field of the trap. From the normalized resonance curve, we extract the particle's magnetic moment in units of the nuclear magneton $\\mu_p=2.792847350(9)\\mu_N$. This measurement outperforms previous Penning trap measurements in terms of precision by a factor of about 760. It improves the precision of the forty year old indirect measurement, in which significant theoretical bound state corrections were required to obtain $\\mu_p$, by a factor of 3. By application of this method to the antiproton magnetic moment $\\mu_{\\bar{p}}$ the fractional precision of the recently reported value can be improved by a factor of at least 1000. Combined with the present result, this will provide a stringent test of matter/antimatter symmetry with baryons.

A. Mooser; S. Ulmer; K. Blaum; K. Franke; H. Kracke; C. Leiteritz; W. Quint; C. C. Rodegheri; C. Smorra; J. Walz

2014-06-18

353

A High Precision Method for Quantitative Measurements of Reactive Oxygen Species in Frozen Biopsies  

PubMed Central

Objective An electron paramagnetic resonance (EPR) technique using the spin probe cyclic hydroxylamine 1-hydroxy-3-methoxycarbonyl-2,2,5,5-tetramethylpyrrolidine (CMH) was introduced as a versatile method for high precision quantification of reactive oxygen species, including the superoxide radical in frozen biological samples such as cell suspensions, blood or biopsies. Materials and Methods Loss of measurement precision and accuracy due to variations in sample size and shape were minimized by assembling the sample in a well-defined volume. Measurement was carried out at low temperature (150 K) using a nitrogen flow Dewar. The signal intensity was measured from the EPR 1st derivative amplitude, and related to a sample, 3-carboxy-proxyl (CP•) with known spin concentration. Results The absolute spin concentration could be quantified with a precision and accuracy better than ±10 µM (k?=?1). The spin concentration of samples stored at ?80°C could be reproduced after 6 months of storage well within the same error estimate. Conclusion The absolute spin concentration in wet biological samples such as biopsies, water solutions and cell cultures could be quantified with higher precision and accuracy than normally achievable using common techniques such as flat cells, tissue cells and various capillary tubes. In addition; biological samples could be collected and stored for future incubation with spin probe, and also further stored up to at least six months before EPR analysis, without loss of signal intensity. This opens for the possibility to store and transport incubated biological samples with known accuracy of the spin concentration over time. PMID:24603936

Lindgren, Mikael; Gustafsson, Håkan

2014-01-01

354

High-Precision Marine Sr Isotope Geochronology in Deep Time: Permian Tuffs and Conodonts  

NASA Astrophysics Data System (ADS)

Stratigraphic sections of the Southern Urals containing abundant and well-preserved fauna for precise biostratigraphic correlation and common instratified volcanic ash beds dated by U-Pb zircon geochronology offer a unique opportunity to constrain a temporally accurate Late Pennsylvanian-Early Permian seawater Sr curve. The 87Sr/86Sr compositions of conodonts (biogenic apatite) were measured by high-precision thermal ionization mass spectrometry following rigorous pretreatment protocols, and plotted within an age model calibrated by 13 high-precision U-Pb zircon ash bed ages. The resulting seawater Sr curve shows a significant reduction in data scatter by comparison to earlier curves (Denison et al., 1994; Veizer et al., 1999; Bruckschen et al., 1999; Korte et al., 2006), suggesting that our conodont pre-dissolution treatment was highly effective for retrieving the original seawater Sr signal. The relatively flat Late Moscovian through mid-Ghzelian seawater Sr curve of this study is generally consistent with that of Bruckschen et al. (1999). Beginning in the mid-Ghzelian, our data define a decreasing trend in 87Sr/86Sr through the mid-Sakmarian, consistent with the data of Korte et al. (2006). By combining our high precision 87Sr/86Sr measurements and U-Pb age calibration, the resolution of Sr isotope geochronology approaches 0.5 Ma in this interval. This highly resolved seawater 87Sr/86Sr record obtained for the Late Moscovian through mid-Sakmarian will aid in global carbonate chemostratigraphic correlation and contribute to our understanding of the timing of Late Paleozoic glacial and tectonic events. References: Bruckschen, P., Oesmann, S., Veizer, J., 1999. Isotope stratigraphy of the European Carboniferous: proxy signals for ocean chemistry, climate and tectonics. Chemical Geology 161, p. 127-163. Denison, R.E., Koepnick, R.B., Burke, W.H., Hetherington, E.A., Fletcher, A., 1994. Construction of the Mississippian, Pennsylvanian and Permian seawater 87Sr/86Sr curve. Chemical Geology 112, p.145-167. Veizer, J., Ala, D., Azmy, K., Bruckschen, P., Buhl, D., Bruhn, J., Carden, G.A.F., Diener, A., Ebneth, S., Godderis, Y., Jasper, T., Korte, C., Pawellek, F., Podlaha, O.G., Strauss, H., 1999. 87Sr/86Sr, ´13C and ?18O evolution of Phanerozoic seawater. Chemical Geology 161, p. 59-88. Korte, C., Jasper, T., Kozur, H.W., Veizer, J., 2006. 87Sr/86Sr record of Permian seawater. Palaeogeography, Pala3eoclimatology, Palaeoecology 240, p. 89-107.

Schmitz, M. D.; Davydov, V. I.; Snyder, W. S.

2007-12-01

355

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

SciTech Connect

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

Cottrell, Elizabeth; Kelley, Katherine A.; Lanzirotti, Antonio; Fischer, Rebecca A.; (Rhode Island); (UC); (Smithsonian)

2009-11-04

356

ACT3: a high-speed, high-precision electrical impedance tomograph.  

PubMed

This paper presents the design, implementation, and performance of Rensselaer's third-generation Adaptive Current Tomograph, ACT3. This system uses 32 current sources and 32 phase-sensitive voltmeters to make a 32-electrode system that is capable of applying arbitrary spatial patterns of current. The instrumentation provides 16 b precision on both the current values and the real and reactive voltage readings and can collect the data for a single image in 133 ms. Additionally, the instrument is able to automatically calibrate its voltmeters and current sources and adjust the current source output impedance under computer control. The major system components are discussed in detail and performance results are given. Images obtained using stationary agar targets and a moving pendulum in a phantom as well as in vivo resistivity profiles showing human respiration are shown. PMID:7927393

Cook, R D; Saulnier, G J; Gisser, D G; Goble, J C; Newell, J C; Isaacson, D

1994-08-01

357

Separated Oscillatory Fields for High-Precision Penning Trap Mass Spectrometry  

E-print Network

Ramsey's method of separated oscillatory fields is applied to the excitation of the cyclotron motion of short-lived ions in a Penning trap to improve the precision of their measured mass. The theoretical description of the extracted ion-cyclotron-resonance line shape is derived out and its correctness demonstrated experimentally by measuring the mass of the short-lived $^{38}$Ca nuclide with an uncertainty of $1.6\\cdot 10^{-8}$ using the ISOLTRAP Penning trap mass spectrometer at CERN. The mass value of the superallowed beta-emitter $^{38}$Ca is an important contribution for testing the conserved-vector-current hypothesis of the electroweak interaction. It is shown that the Ramsey method applied to mass measurements yields a statistical uncertainty similar to that obtained by the conventional technique ten times faster.

S. George; S. Baruah; B. Blank; K. Blaum; M. Breitenfeldt; U. Hager; F. Herfurth; A. Herlert; A. Kellerbauer; H. J. Kluge; M. Kretzschmar; D. Lunney; R. Savreux; S. Schwarz; L. Schweikhard; C. Yazidjian

2007-01-19

358

A novel approach for high precision rapid potentiometric titrations: Application to hydrazine assay  

NASA Astrophysics Data System (ADS)

We propose a high precision rapid personal computer (PC) based potentiometric titration technique using a specially designed mini-cell to carry out redox titrations for assay of chemicals in quality control laboratories attached to industrial, R&D, and nuclear establishments. Using this technique a few microlitre of sample (50-100 ?l) in a total volume of ˜2 ml solution can be titrated and the waste generated after titration is extremely low comparing to that obtained from the conventional titration technique. The entire titration including online data acquisition followed by immediate offline analysis of data to get information about concentration of unknown sample is completed within a couple of minutes (about 2 min). This facility has been created using a new class of sensors, viz., pulsating sensors developed in-house. The basic concept in designing such instrument and the salient features of the titration device are presented in this paper. The performance of the titration facility was examined by conducting some of the high resolution redox titrations using dilute solutions--hydrazine against KIO3 in HCl medium, Fe(II) against Ce(IV) and uranium using Davies-Gray method. The precision of titrations using this innovative approach lies between 0.048% and 1.0% relative standard deviation in different redox titrations. With the evolution of this rapid PC based titrator it was possible to develop a simple but high precision potentiometric titration technique for quick determination of hydrazine in nuclear fuel dissolver solution in the context of reprocessing of spent nuclear fuel in fast breeder reactors.

Sahoo, P.; Malathi, N.; Ananthanarayanan, R.; Praveen, K.; Murali, N.

2011-11-01

359

Asynchronous RTK precise DGNSS positioning method for deriving a low-latency high-rate output  

NASA Astrophysics Data System (ADS)

Low-latency high-rate (> 1 Hz) precise real-time kinematic (RTK) can be applied in high-speed scenarios such as aircraft automatic landing, precise agriculture and intelligent vehicle. The classic synchronous RTK (SRTK) precise differential GNSS (DGNSS) positioning technology, however, is not able to obtain a low-latency high-rate output for the rover receiver because of long data link transmission time delays (DLTTD) from the reference receiver. To overcome the long DLTTD, this paper proposes an asynchronous real-time kinematic (ARTK) method using asynchronous observations from two receivers. The asynchronous observation model (AOM) is developed based on undifferenced carrier phase observation equations of the two receivers at different epochs with short baseline. The ephemeris error and atmosphere delay are the possible main error sources on positioning accuracy in this model, and they are analyzed theoretically. In a short DLTTD and during a period of quiet ionosphere activity, the main error sources decreasing positioning accuracy are satellite orbital errors: the "inverted ephemeris error" and the integration of satellite velocity error which increase linearly along with DLTTD. The cycle slip of asynchronous double-differencing carrier phase is detected by TurboEdit method and repaired by the additional ambiguity parameter method. The AOM can deal with synchronous observation model (SOM) and achieve precise positioning solution with synchronous observations as well, since the SOM is only a specific case of AOM. The proposed method not only can reduce the cost of data collection and transmission, but can also support the mobile phone network data link transfer mode for the data of the reference receiver. This method can avoid data synchronizing process besides ambiguity initialization step, which is very convenient for real-time navigation of vehicles. The static and kinematic experiment results show that this method achieves 20 Hz or even higher rate output in real time. The ARTK positioning accuracy is better and more robust than the combination of phase difference over time (PDOT) and SRTK method at a high rate. The ARTK positioning accuracy is equivalent to SRTK solution when the DLTTD is 0.5 s, and centimeter level accuracy can be achieved even when DLTTD is 15 s.

Liang, Zhang; Hanfeng, Lv; Dingjie, Wang; Yanqing, Hou; Jie, Wu

2015-03-01

360

Localization microscopy (SPDM) facilitates high precision control of lithographically produced nanostructures.  

PubMed

Nanoscale resolution in material sciences is usually restricted to scanning electron beam microscopes. Here we present a procedure that allows single molecule resolution of the sample surface with visible light. Highlighting the performance we used electron beam lithography to generate highly regular nanostructures consisting of interconnected cubes. The samples were labeled with Alexa 647 dyes. The spatial organization of the dyes on nanostructured surfaces was localized with single molecule resolution using localization microscopy. This succeeded also in an absolute spatial calibration of the localization method applied (spectral precision distance microscopy/SPDM). The findings will contribute to the field of product control for industrial applications and long-term fluorescence imaging. PMID:25212964

Grab, A L; Hagmann, M; Dahint, R; Cremer, C

2015-01-01

361

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

SciTech Connect

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

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

2012-04-01

362

High-precision gas gain and energy transfer measurements in Ar-CO2 mixtures  

NASA Astrophysics Data System (ADS)

Ar-CO2 is a Penning mixture since a fraction of the energy stored in Ar 3p5 3 d and higher excited states can be transferred to ionize CO2 molecules. In the present work, concentration and pressure dependence of Penning transfer rate and photon feedback parameter in Ar-CO2 mixtures have been investigated with recent systematic high-precision gas gain measurements which cover the range 1-50% CO2 at 400, 800, 1200, 1800 hPa and gas gain from 1 to 5×105.

?ahin, Özkan; Kowalski, Tadeusz Z.; Veenhof, Rob

2014-12-01

363

Precise control of the size and noise of solid-state nanopores using high electric fields.  

PubMed

We present a methodology for preparing silicon nitride nanopores that provides in situ control of size with sub-nanometer precision while simultaneously reducing electrical noise by up to three orders of magnitude through the cyclic application of high electric fields in an aqueous environment. Over 90% of nanopores treated with this technique display desirable noise characteristics and readily exhibit translocation of double-stranded DNA molecules. Furthermore, previously used nanopores with degraded electrical properties can be rejuvenated and used for further single-molecule experiments. PMID:22983670

Beamish, Eric; Kwok, Harold; Tabard-Cossa, Vincent; Godin, Michel

2012-10-12

364

High precision pointing system based on Risley prism: analysis and simulation  

NASA Astrophysics Data System (ADS)

This paper presents the key issues for high precision pointing system using Risley prism. An iterative optimization algorithm is proposed to solve the inverse problem of Risley Prism and anti-achromatic Risley Prism. Different error sources, particularly Risley prism's rotation errors and rotation axis jitters are considered. Error propagation formula between pointing accuracy and rotation position is deduced. Finally, a beam steering simulation system including target position creating module, Risley Prism inverse solution module, Risley Prism rotation control module and beam pointing module is established. The simulation results show that it can achieve better than 1 arcsec pointing accuracy.

Li, Jin-ying; Peng, Qi; Chen, Ke; Fu, Cheng-yu

2015-02-01

365

High-precision calculation of the parity-nonconserving amplitude in francium M. S. Safronova and W. R. Johnson  

E-print Network

High-precision calculation of the parity-nonconserving amplitude in francium M. S. Safronova and W-precision calculation of the 7s-8s parity-nonconserving PNC transition amplitude in francium, based on a relativistic-nonconserving PNC amplitudes in francium, the heaviest alkali-metal atom, have been pro- posed 1 , and considerable

Johnson, Walter R.

366

High-precision photometry by telescope defocusing - VII. The ultrashort period planet WASP-103  

NASA Astrophysics Data System (ADS)

We present 17 transit light curves of the ultrashort period planetary system WASP-103, a strong candidate for the detection of tidally-induced orbital decay. We use these to establish a high-precision reference epoch for transit timing studies. The time of the reference transit mid-point is now measured to an accuracy of 4.8 s, versus 67.4 s in the discovery paper, aiding future searches for orbital decay. With the help of published spectroscopic measurements and theoretical stellar models, we determine the physical properties of the system to high precision and present a detailed error budget for these calculations. The planet has a Roche lobe filling factor of 0.58, leading to a significant asphericity; we correct its measured mass and mean density for this phenomenon. A high-resolution Lucky Imaging observation shows no evidence for faint stars close enough to contaminate the point spread function of WASP-103. Our data were obtained in the Bessell RI and the SDSS griz passbands and yield a larger planet radius at bluer optical wavelengths, to a confidence level of 7.3?. Interpreting this as an effect of Rayleigh scattering in the planetary atmosphere leads to a measurement of the planetary mass which is too small by a factor of 5, implying that Rayleigh scattering is not the main cause of the variation of radius with wavelength.

Southworth, John; Mancini, L.; Ciceri, S.; Budaj, J.; Dominik, M.; Figuera Jaimes, R.; Haugbølle, T.; Jørgensen, U. G.; Popovas, A.; Rabus, M.; Rahvar, S.; von Essen, C.; Schmidt, R. W.; Wertz, O.; Alsubai, K. A.; Bozza, V.; Bramich, D. M.; Calchi Novati, S.; D'Ago, G.; Hinse, T. C.; Henning, Th.; Hundertmark, M.; Juncher, D.; Korhonen, H.; Skottfelt, J.; Snodgrass, C.; Starkey, D.; Surdej, J.

2015-02-01

367

High Sensitive Precise 3D Accelerometer for Solar System Exploration with Unmanned Spacecrafts  

NASA Astrophysics Data System (ADS)

Solutions of several space and geophysical tasks require creating high sensitive precise accelerometers with sensitivity in order of 10 -13 g. These several tasks are following: inertial navigation of the Earth and Space; gravimetry nearby the Earth and into Space; geology; geophysics; seismology etc. Accelerometers (gravimeters and gradientmeters) with required sensitivity are not available now. The best accelerometers in the world have sensitivity worth on 4-5 orders. It has been developed a new class of fiber-optical sensors (FOS) with light pulse modulation. These sensors have super high threshold sensitivity and wide (up to 10 orders) dynamic range, and can be used as a base for creating of measurement units of physical values as 3D superhigh sensitive precise accelerometers of linear accelerations that is suitable for highest requirements. The principle of operation of the FOS is organically combined with a digital signal processing. It allows decreasing hardware of the accelerometer due to using a usual air-borne or space-borne computer; correcting the influence of natural, design, technological drawbacks of FOS on measured results; neutralising the influence of extraordinary situations available during using of FOS; decreasing the influence of internal and external destabilising factors (as for FOS), such as oscillation of environment temperature, instability of pendulum cycle frequency of sensitive element of the accelerometer etc. We were conducted a quantitative estimation of precise opportunities of analogue FOS in structure of fiber optical measuring devices (FOMD) for elementary FOMD with analogue FOS built on modern element basis of fiber optics (FO), at following assumptions: absolute parameter stability of devices of FOS measuring path; single transmission band of registration path; maximum possible inserted in optical fiber (OF) a radiated power. Even at such idealized assumptions, a calculated value in limit reached minimum inaccuracy of measuring, by analogue FOS, has been ˜ 10-4 %. Substantially accessible values are yet worse on 2-3 order. The reason of poor precise performances of measurers on the basis of analogue FOS is metrologically poor quality of a stream of optical radiation carrying out role of the carrier and receptor of the information. It is a high level of photon noise and a small blanket intensity level. First reason reflects the fact of discreteness of flow of high-energy photons, and it is consequence of second one - smallness, on absolute value, of inserted power into OF from available radiation sources (RS). Works on improvement of FO elements are carrying out. Certainly, it will be created RS allow to insert enough of power into standard OF. But simple increasing of optical flow power in measuring path of FOS will not be able to decide radically the problem of increasing of measuring prices: with raising of power in proportion of square root of its value there is raising a power of photon noises - 1000-times increase of power promises only 30-times increase of measuring precise; insertion into OF more large power (˜ 1 W for standard silicon OF) causes an appearance of non-linear effects in it, which destroying an operating principle of analogue FOS. Thus, it is needed to constatate impossibility of building, at that time, measurers of analogue FOS, concurated with traditional (electrical) measurers on measuring precise. At that all, advantages of FO, as basis of building of FO MD requires to find ways for decision of these problems. Analysis of problem of sensitivity of usual (analogue) FOS has brought us to conclusion about necessity of reviewing of principles of information signal forming in FOS and principles its next electronic processing. For radical increasing of accuracy of measurements with using FOS it is necessary to refuse analogue modulation of optical flow and to transfer to discreet its modulations, entering thus in optical flow new, non-optical, parameters, which will serve as recipients of the information. It allows to save up all advantages of FOS (carrier of in

Savenko, Y. V.; Demyanenko, P. O.; Zinkovskiy, Y. F.

368

The research of the high precision universal stable reconnaissance platform in near space  

NASA Astrophysics Data System (ADS)

The appliance of military was recognized more and more ,It is important that pod can bear the weight of the availability payload achieve the observation to the earth in 20km-100km area and work in the all-weather. The stable platform can load high imaging spectrometer, the thermal infrared imager, the infrared radiometer, the millimeter waves radar, the laser weapon and so on,in order to realize reconnaissance and attacking integrative and warning the long-distant missile. The stabilization accuracy of platform is prior to 20?rad and burden heavy load to the best of one's abilities. It used high precision velocity and acceleration gyroscope to fulfill the stabilization of the platform. Light-weight design by using new composite material and optimizing design. It was adapt to the near space environment better by structure design and simulation analysis.Enhance its basic frequency and sure the rigid of the frame platform .In addition, the structure of platform apply the two-axis and four-frame and use the method of FEA to fulfill the optimum design in order to attain the object of light-weight.In consider to the precision of the platform I establish the math model and make use of the monte carlo method to appraise and analysis the error that affect the precision of the platform. After emulating by the software of the Matlab to verify the results. It is apply the method that link the platform and aerocraft by mounting the no angular displacement shock absorbers on the elevator mechanism. This kind of design insulate the angular vibration and minish the linear vibration to ensure the image quality.

Yang, Hong-tao; Cao, Jian-zhong; Fan, Zhe-yuan; Chen, Wei-ning

2011-08-01

369

Optical test bench for high precision metrology and alignment of zoom sub-assembly components  

NASA Astrophysics Data System (ADS)

Thales Angénieux (TAGX) designs and manufactures zoom lens assemblies for cinema applications. These objectives are made of mobile lens assemblies. These need to be precisely characterized to detect alignment, polishing or glass index homogeneity errors, which amplitude may range to a few hundreds of nanometers. However these assemblies are highly aberrated with mainly spherical aberration (>30 ?m PV). PHASICS and TAGX developed a solution based on the use of a PHASICS SID4HR wave front sensor. This is based on quadri-wave lateral shearing interferometry, a technology known for its high dynamic range. A 100-mm diameter He:Ne source illuminates the lens assembly entrance pupil. The transmitted wave front is then directly measured by the SID4- HR. The measured wave front (WFmeas) is then compared to a simulation from the lens sub-assembly optical design (WFdesign). We obtain a residual wave front error (WFmanufactured), which reveals lens imperfections due to its manufacturing. WFmeas=WFdesign+(WFEradius+WFEglass+WFEpolish)=WF design + WFmanufactured The optical test bench was designed so that this residual wave front is measured with a precision below 100 nm PV. The measurement of fast F-Number lenses (F/2) with aberrations up to 30 ?m, with a precision of 100 nm PV was demonstrated. This bench detects mismatches in sub-assemblies before the final integration step in the zoom. Pre-alignment is also performed in order to overpass the mechanical tolerances. This facilitates the completed zoom alignment. In final, productivity gains are expected due to alignment and mounting time savings.

Leprêtre, F.; Levillain, E.; Wattellier, B.; Delage, P.; Brahmi, D.; Gascon, A.

2013-09-01

370

Active Focal Zone Sharpening for High-Precision Treatment Using Histotripsy  

PubMed Central

The goal of this study is to develop a focal zone sharpening strategy that produces more precise lesions for pulsed cavitational ultrasound therapy, or histotripsy. Precise and well-confined lesions were produced by locally suppressing cavitation in the periphery of the treatment focus without affecting cavitation in the center. The local suppression of cavitation was achieved using cavitation nuclei preconditioning pulses to actively control cavitation in the periphery of the focus. A 1-MHz 513-element therapeutic array was used to generate both the therapy and the nuclei preconditioning pulses. For therapy, 10-cycle bursts at 100-Hz pulse repetition frequency with P?/P+ pressure of 21/76 MPa were delivered to the geometric focus of the therapeutic array. For nuclei preconditioning, a different pulse was delivered to an annular region immediately surrounding the focus before each therapy pulse. A parametric study on the effective pressure, pulse duration, and delivery time of the preconditioning pulse was conducted in red blood cell-gel phantoms, where cavitational damage was indicated by the color change resulting from local cell lysis. Results showed that a short-duration (20 µs) preconditioning pulse at a medium pressure (P?/P+ pressure of 7.2/13.6 MPa) delivered shortly before (30 µs) the therapy pulse substantially suppressed the peripheral damage by 77 ± 13% while complete fractionation in the focal center was maintained. High-speed imaging of the bubble cloud showed a substantial decrease in the maximum width of the bubble cloud by 48 ± 24% using focal zone sharpening. Experiments in ex vivo livers confirmed that highly confined lesions were produced in real tissues as well as in the phantoms. This study demonstrated the feasibility of active focal zone sharpening using cavitation nuclei preconditioning, allowing for increased treatment precision compared with the natural focal width of the therapy transducer. PMID:21342816

Wang, Tzu-Yin; Xu, Zhen; Hall, Timothy L.; Fowlkes, J. Brian; Roberts, William W.; Cain, Charles A.

2011-01-01

371

MEMS - Frequency Agile High Precision Ranging under the Dual Use Applications Program (DUAP)  

NASA Astrophysics Data System (ADS)

The objective of this program was laboratory demonstration of a low cost, jamming resistant, precision ranging system (radar) for proximity fuze and short-range measurement systems. Two approaches were envisioned: (1) The baseline-a baseband system directly radiating and detecting a random sequence of short pulses and (2) A higher risk design based on a transmitter using high-speed modulation of a micro-electromechanical (MEM) oscillator to avoid low frequency antenna radiation requirements. Size constraints drive the design toward small, single-chip monocycle pulse radar implemented in CMOS (Complementary Metal Oxide Semiconductors). This device with two external capacitors, a battery and a miniature antenna for the baseline approach is described in Figure 1-1. Triggering ranges from several inches to more than 6feet were demonstrated. Fabrication of MEM components on gallium arsenide for the second approach will require additional work. While CMOS technology is almost ideal for the long time-constant, multiple pulse integration circuits in the precision ranging receiver and most of the transmitter circuits, it is insufficient for submunition sensor final output amplifiers. The issue is the small size of the submunition antenna. Either step recovery diode circuit or higher performance output transistors are needed to generate the high frequency spectrum required for efficient radiation from these antennas. Using a 0.5-micron BiCMOS/Si(3e process, recently available for prototyping at MOSIS,' all of the required CMOS and faster output devices could be implemented with trivial modifications of the existing circuits.

Bauhahn, Paul

2001-12-01

372

Diode Laser-based Sensor for High Precision Measurements of Ambient CO2  

NASA Astrophysics Data System (ADS)

We report on the development of a new, high precision sensor for monitoring ambient CO2. This economical, robust, autonomous CO2 sensor is intended for widespread deployment in networks. We have developed a tunable diode laser-based absorption spectrometer, operating at a wavelength of 2 "Ým, which utilizes Integrated Cavity Output Spectroscopy (ICOS) to create an optical pathlength of 60 m in a physical pathlength of 20 cm. The sensor also uses Wavelength Modulation Spectroscopy for high sensitivity detection. We have achieved a precision of better than 1 part in 3000 for the dry air mixing ratio of CO2 for a 1 minute averaging period. The sensor design ensures a measurement cell having a small sample volume, which decreases the consumption of calibration gases. We also use an integrated dedicated microprocessor-based controller and signal processing electronics to achieve a small footprint. The sensor measures 20 x 43 x 56 cm and weighs 15 kg. The prototype was demonstrated at the University of New Hampshire's Atmospheric Observatory at Thompson Farm, in Durham, NH during June and July 2008. It was successfully intercompared with an NDIR sensor and operated automatically around the clock for 6 weeks. It was also intercompared with the NOAA NDIR sensor at the Boulder Atmospheric Observatory in Erie, CO in September 2008.

Sonnenfroh, D. M.; Parameswaran, K.; Varner, R.

2008-12-01

373

High-precision temporal constraints on intrusive magmatism of the Siberian Traps  

NASA Astrophysics Data System (ADS)

The broad temporal coincidence between large igneous province magmatism and some of the most severe biotic/environmental crises in Earth history has led many to infer a causal connection between the two. Notable examples include the end-Permian mass extinction and eruption/emplacement of the Siberian Traps large igneous province (LIP) and the end-Triassic mass extinction and the Central Atlantic Magmatic Province. In models proposing a causal connection between LIP magmatism and the environmental changes that lead to mass extinction, gases and particulates injected into the atmosphere are thought to cause abrupt changes in climate and ocean chemistry sufficient to drive mass extinction of marine and terrestrial biota. Magmatism has been proposed to cause voluminous volatile release via contact metamorphism of the sedimentary rocks. In the case of the Siberian Traps LIP, the compositions of sedimentary rocks (carbonates, evaporates, organic-rich shales) that host sills and dikes are ideal for greenhouse gas generation. When coupled with the enormous volume of Siberian LIP intrusive rocks, there is the potential for volatile generation on a scale necessary to drive environmental changes and mass extinction. This model must be tested by comparing the timing of intrusive magmatism with that of the mass extinction. Coupled high-precision geochronology and astrochronology have constrained the timing of biotic crisis and associated environmental perturbations from the deca-millennial to sub-millennial timescale, suggesting that the biotic crisis was abrupt, occurring over < 100 ka. Published geochronology on sills and dikes from the LIP are sparse and lack the necessary precision to resolve the relative timing of the two events outside of age uncertainty. We present new high-precision U-Pb zircon geochronology on seventeen gabbroic sills from throughout the magmatic province. This includes samples from the mineralized and differentiated intrusions in the Noril'sk region, from the central portion of the magmatic province and from the massive sills in the southern region of the LIP, where many intrusions are associated with eruptive pipes proposed to be the main mechanism by which volatiles are injected into the upper atmosphere. Weighted mean 206Pb/238U dates have uncertainties that range from ± 44 to 180 ka. Such precision allows resolution of the relative timing of sill emplacement and the extinction interval outside of analytical uncertainty, allows the timescale of changes in the global carbon cycle to be compared to that of the LIP, and permits evaluation of the role of intrusive magmatism in the mass extinction and during the post-extinction biotic recovery interval.

Burgess, Seth; Bowring, Sam; Pavlov, Volodia E.; Veselovsky, Roman V.

2014-05-01

374

Versatile, kinetically controlled, high precision electrohydrodynamic writing of micro/nanofibers  

PubMed Central

Direct writing of hierarchical micro/nanofibers have recently gained popularity in flexible/stretchable electronics due to its low cost, simple process and high throughput. A kinetically controlled mechanoelectrospinning (MES) is developed to directly write diversified hierarchical micro/nanofibers in a continuous and programmable manner. Unlike conventional near-field electrospinning, our MES method introduces a mechanical drawing force, to simultaneously enhance the positioning accuracy and morphology controllability. The MES is predominantly controlled by the substrate speed, the nozzle-to-substrate distance, and the applied voltage. As a demonstration, smooth straight, serpentine, self-similar, and bead-on-string structures are direct-written on silicon/elastomer substrates with a resolution of 200?nm. It is believed that MES can promote the low-cost, high precision fabrication of flexible/stretchable electronics or enable the direct writing of the sacrificial structures for nanoscale lithography. PMID:25091829

Huang, YongAn; Duan, Yongqing; Ding, Yajiang; Bu, Ningbin; Pan, Yanqiao; Lu, Nanshu; Yin, Zhouping

2014-01-01

375

Design and Calibration of a High-Precision Density Gauge for Firn and Ice Cores  

NASA Astrophysics Data System (ADS)

The Maine Automated Density Gauge Experiment (MADGE) is a field deployable gamma-ray density gauging instrument designed to provide high resolution (3.3 mm) and high precision (±0.004 g cm-3) density profiles of polar firn and ice cores at a typical throughput of 1.5 m h-1. The resulting density profiles are important in ice sheet mass balance and paleoclimate studies, as well as the modeling electromagnetic wave propagation in firn and ice for remote sensing and ground penetrating radar applications. This study describes the design (optimal gamma-ray energy selection, measurement uncertainty analysis, dead-time corrections) and calibration (mass-attenuation coefficient and absolute density calibrations) of the instrument, and discusses the results of additional experiments to verify the calculated measurement uncertainty. Data collected from firn cores drilled on the recent 2006-2007 U.S. Internation Trans-Antarctic Scientific Expedition are also shown and discussed.

Breton, Daniel; Hamilton, Gordon

2009-10-01

376

New high precision data on the differential cross sections of the pion-proton elastic scattering  

NASA Astrophysics Data System (ADS)

The EPECUR collaboration presents new high precision data on the pion-proton elastic scattering in the second resonance region. The experiment EPECUR is placed on the universal beam channel of the accelerator ITEP. The setup features 0.1% beam pion momentum tagging system, 25 cm long liquid hydrogen target, placed in mylar container and beryllium outer shell, low material wire drift chambers and high performance DAQ. More than 3 billions of triggers have been collected. The data cover pion beam momentum range 0.8 - 1.3 GeV/c and 40-120 degrees center-of-mass scattering angle range for both positive and negative pions. The measured differential cross section has 2% statistical accuracy in 2 degrees angle and 5 MeV/c momentum intervals.

Alekseev, I. G.; Andreev, V. A.; Bordyuzhin, I. G.; Filimonov, Ye. A.; Golubev, V. V.; Gridnev, A. B.; Kalinkin, D. V.; Koroleva, L. I.; Kozlenko, N. G.; Kozlov, V. S.; Krivshich, A. G.; Morozov, B. V.; Nesterov, V. M.; Novinsky, D. V.; Ryltsov, V. V.; Sadler, M.; Shurygin, B. M.; Sulimov, A. D.; Sumachev, V. V.; Svirida, D. N.; Tarakanov, V. I.; Trautman, V. Yu.

2014-11-01

377

Versatile, kinetically controlled, high precision electrohydrodynamic writing of micro/nanofibers  

NASA Astrophysics Data System (ADS)

Direct writing of hierarchical micro/nanofibers have recently gained popularity in flexible/stretchable electronics due to its low cost, simple process and high throughput. A kinetically controlled mechanoelectrospinning (MES) is developed to directly write diversified hierarchical micro/nanofibers in a continuous and programmable manner. Unlike conventional near-field electrospinning, our MES method introduces a mechanical drawing force, to simultaneously enhance the positioning accuracy and morphology controllability. The MES is predominantly controlled by the substrate speed, the nozzle-to-substrate distance, and the applied voltage. As a demonstration, smooth straight, serpentine, self-similar, and bead-on-string structures are direct-written on silicon/elastomer substrates with a resolution of 200 nm. It is believed that MES can promote the low-cost, high precision fabrication of flexible/stretchable electronics or enable the direct writing of the sacrificial structures for nanoscale lithography.

Huang, Yongan; Duan, Yongqing; Ding, Yajiang; Bu, Ningbin; Pan, Yanqiao; Lu, Nanshu; Yin, Zhouping

2014-08-01

378

Versatile, kinetically controlled, high precision electrohydrodynamic writing of micro/nanofibers.  

PubMed

Direct writing of hierarchical micro/nanofibers have recently gained popularity in flexible/stretchable electronics due to its low cost, simple process and high throughput. A kinetically controlled mechanoelectrospinning (MES) is developed to directly write diversified hierarchical micro/nanofibers in a continuous and programmable manner. Unlike conventional near-field electrospinning, our MES method introduces a mechanical drawing force, to simultaneously enhance the positioning accuracy and morphology controllability. The MES is predominantly controlled by the substrate speed, the nozzle-to-substrate distance, and the applied voltage. As a demonstration, smooth straight, serpentine, self-similar, and bead-on-string structures are direct-written on silicon/elastomer substrates with a resolution of 200 nm. It is believed that MES can promote the low-cost, high precision fabrication of flexible/stretchable electronics or enable the direct writing of the sacrificial structures for nanoscale lithography. PMID:25091829

Huang, YongAn; Duan, Yongqing; Ding, Yajiang; Bu, Ningbin; Pan, Yanqiao; Lu, Nanshu; Yin, Zhouping

2014-01-01

379

Note: High precision angle generator using multiple ultrasonic motors and a self-calibratable encoder  

NASA Astrophysics Data System (ADS)

We present an angle generator with high resolution and accuracy, which uses multiple ultrasonic motors and a self-calibratable encoder. A cylindrical air bearing guides a rotational motion, and the ultrasonic motors achieve high resolution over the full circle range with a simple configuration. The self-calibratable encoder can compensate the scale error of a divided circle (signal period: 20?) effectively by applying the equal-division-averaged method. The angle generator configures a position feedback control loop using the readout of the encoder. By combining the ac and dc operation mode, the angle generator produced stepwise angular motion with 0.005? resolution. We also evaluated the performance of the angle generator using a precision angle encoder and an autocollimator. The expanded uncertainty (k = 2) in the angle generation was estimated less than 0.03?, which included the calibrated scale error and the nonlinearity error.

Kim, Jong-Ahn; Kim, Jae Wan; Kang, Chu-Shik; Jin, Jonghan; Bong Eom, Tae

2011-11-01

380

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

PubMed Central

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

Hartwell, Supaporn Kradtap; Grudpan, Kate

2012-01-01

381

High-precision soft x-ray polarimeter at Diamond Light Source.  

PubMed

The development and performance of a high-precision polarimeter for the polarization analysis in the soft x-ray region is presented. This versatile, high-vacuum compatible instrument is supported on a hexapod to simplify the alignment with a resolution less than 5 ?rad, and can be moved with its own independent control system easily between different beamlines and synchrotron facilities. The polarimeter can also be used for the characterization of reflection and transmission properties of optical elements. A W/B(4)C multilayer phase retarder was used to characterize the polarization state up to 1200 eV. A fast and accurate alignment procedure was developed, and complete polarization analysis of the APPLE II undulator at 712 eV has been performed. PMID:22225209

Wang, H; Dhesi, S S; Maccherozzi, F; Cavill, S; Shepherd, E; Yuan, F; Deshmukh, R; Scott, S; van der Laan, G; Sawhney, K J S

2011-12-01

382

High-precision soft x-ray polarimeter at Diamond Light Source  

NASA Astrophysics Data System (ADS)

The development and performance of a high-precision polarimeter for the polarization analysis in the soft x-ray region is presented. This versatile, high-vacuum compatible instrument is supported on a hexapod to simplify the alignment with a resolution less than 5 ?rad, and can be moved with its own independent control system easily between different beamlines and synchrotron facilities. The polarimeter can also be used for the characterization of reflection and transmission properties of optical elements. A W/B4C multilayer phase retarder was used to characterize the polarization state up to 1200 eV. A fast and accurate alignment procedure was developed, and complete polarization analysis of the APPLE II undulator at 712 eV has been performed.

Wang, H.; Dhesi, S. S.; Maccherozzi, F.; Cavill, S.; Shepherd, E.; Yuan, F.; Deshmukh, R.; Scott, S.; van der Laan, G.; Sawhney, K. J. S.

2011-12-01

383

High-precision atom localization via controllable spontaneous emission in a cycle-configuration atomic system.  

PubMed

A scheme for realizing two-dimensional (2D) atom localization is proposed based on controllable spontaneous emission in a coherently driven cycle-configuration atomic system. As the spatial-position-dependent atom-field interaction, the frequency of the spontaneously emitted photon carries the information about the position of the atom. Therefore, by detecting the emitted photon one could obtain the position information available, and then we demonstrate high-precision and high-resolution 2D atom localization induced by the quantum interference between the multiple spontaneous decay channels. Moreover, we can achieve 100% probability of finding the atom at an expected position by choosing appropriate system parameters under certain conditions. PMID:22453461

Ding, Chunling; Li, Jiahua; Yu, Rong; Hao, Xiangying; Wu, Ying

2012-03-26

384

A high-precision cryogenically-cooled crystal monochromator for the APS diagnostics beamline  

SciTech Connect

A high-precision cryogenically-cooled crystal monochromator has been developed for the APS diagnostics beamline. The design permits simultaneous measurements of the particle beam size and divergence. It provides for a large rotation angle, {minus}15{degree} to 180{degree}, with a resolution of 0.0005{degree}. The roll angle of the crystal can be adjusted by up to {+-}3{degree} with a resolution of 0.0001{degree}. A vertical translational stage, with a stroke of {+-}25 mm and resolution of 8 {micro}m, is provided to enable using different parts of the same crystal or to retract the crystal from the beam path. The modular design will allow optimization of cooling schemes to minimize thermal distortions of the crystal under high heat loads.

Rotela, E.; Yang, B.; Sharma, s.; Barcikowski, A.

2000-07-24

385

A demonstration of high precision GPS orbit determination for geodetic applications  

NASA Technical Reports Server (NTRS)

High precision orbit determination of Global Positioning System (GPS) satellites is a key requirement for GPS-based precise geodetic measurements and precise low-earth orbiter tracking, currently under study at JPL. Different strategies for orbit determination have been explored at JPL with data from a 1985 GPS field experiment. The most successful strategy uses multi-day arcs for orbit determination and includes fine tuning of spacecraft solar pressure coefficients and station zenith tropospheric delays using the GPS data. Average rms orbit repeatability values for 5 of the GPS satellites are 1.0, 1.2, and 1.7 m in altitude, cross-track, and down-track componenets when two independent 5-day fits are compared. Orbit predictions up to 24 hours outside the multi-day arcs agree within 4 m of independent solutions obtained with well tracked satellites in the prediction interval. Baseline repeatability improves with multi-day as compared to single-day arc orbit solutions. When tropospheric delay fluctuations are modeled with process noise, significant additional improvement in baseline repeatability is achieved. For a 246-km baseline, with 6-day arc solutions for GPS orbits, baseline repeatability is 2 parts in 100 million (0.4-0.6 cm) for east, north, and length components and 8 parts in 100 million for the vertical component. For 1314 and 1509 km baselines with the same orbits, baseline repeatability is 2 parts in 100 million for the north components (2-3 cm) and 4 parts in 100 million or better for east, length, and vertical components.

Lichten, S. M.; Border, J. S.

1987-01-01

386

The Generation of Higher-order Laguerre-Gauss Optical Beams for High-precision Interferometry  

PubMed Central

Thermal noise in high-reflectivity mirrors is a major impediment for several types of high-precision interferometric experiments that aim to reach the standard quantum limit or to cool mechanical systems to their quantum ground state. This is for example the case of future gravitational wave observatories, whose sensitivity to gravitational wave signals is expected to be limited in the most sensitive frequency band, by atomic vibration of their mirror masses. One promising approach being pursued to overcome this limitation is to employ higher-order Laguerre-Gauss (LG) optical beams in place of the conventionally used fundamental mode. Owing to their more homogeneous light intensity distribution these beams average more effectively over the thermally driven fluctuations of the mirror surface, which in turn reduces the uncertainty in the mirror position sensed by the laser light. We demonstrate a promising method to generate higher-order LG beams by shaping a fundamental Gaussian beam with the help of diffractive optical elements. We show that with conventional sensing and control techniques that are known for stabilizing fundamental laser beams, higher-order LG modes can be purified and stabilized just as well at a comparably high level. A set of diagnostic tools allows us to control and tailor the properties of generated LG beams. This enabled us to produce an LG beam with the highest purity reported to date. The demonstrated compatibility of higher-order LG modes with standard interferometry techniques and with the use of standard spherical optics makes them an ideal candidate for application in a future generation of high-precision interferometry. PMID:23962813

Carbone, Ludovico; Fulda, Paul; Bond, Charlotte; Brueckner, Frank; Brown, Daniel; Wang, Mengyao; Lodhia, Deepali; Palmer, Rebecca; Freise, Andreas

2013-01-01

387

A Lightweight, Precision-Deployable, Optical Bench for High Energy Astrophysics Missions  

NASA Astrophysics Data System (ADS)

The small angle of total reflection for X-rays, forcing grazing incidence optics with large collecting areas to long focal lengths, has been a fundamental barrier to the advancement of high-energy astrophysics. Design teams around the world have long recognized that a significant increase in effective area beyond Chandra and XMM-Newton requires either a deployable optical bench or separate X-ray optics and instrument module on formation flying spacecraft. Here, we show that we have in hand the components for a lightweight, precision-deployable optical bench that, through its inherent design features, is the affordable path to the next generation of imaging high-energy astrophysics missions. We present our plans for a full-scale engineering model of a deployable optical bench for Explorer-class missions. We intend to use this test article to raise the technology readiness level (TRL) of the tensegrity truss for a lightweight, precision-deployable optical bench for high-energy astrophysics missions from TRL 3 to TRL 5 through a set of four well-defined technology milestones. The milestones cover the architecture's ability to deploy and control the focal point, characterize the deployed dynamics, determine long-term stability, and verify the stowed load capability. Our plan is based on detailed design and analysis work and the construction of a first prototype by our team. Building on our prior analysis and the high TRL of the architecture components we are ready to move on to the next step. The key elements to do this affordably are two existing, fully characterized, flight-quality, deployable booms. After integrating them into the test article, we will demonstrate that our architecture meets the deployment accuracy, adjustability, and stability requirements. The same test article can be used to further raise the TRL in the future.

Danner, Rolf; Dailey, D.; Lillie, C.

2011-09-01

388

The generation of higher-order Laguerre-Gauss optical beams for high-precision interferometry.  

PubMed

Thermal noise in high-reflectivity mirrors is a major impediment for several types of high-precision interferometric experiments that aim to reach the standard quantum limit or to cool mechanical systems to their quantum ground state. This is for example the case of future gravitational wave observatories, whose sensitivity to gravitational wave signals is expected to be limited in the most sensitive frequency band, by atomic vibration of their mirror masses. One promising approach being pursued to overcome this limitation is to employ higher-order Laguerre-Gauss (LG) optical beams in place of the conventionally used fundamental mode. Owing to their more homogeneous light intensity distribution these beams average more effectively over the thermally driven fluctuations of the mirror surface, which in turn reduces the uncertainty in the mirror position sensed by the laser light. We demonstrate a promising method to generate higher-order LG beams by shaping a fundamental Gaussian beam with the help of diffractive optical elements. We show that with conventional sensing and control techniques that are known for stabilizing fundamental laser beams, higher-order LG modes can be purified and stabilized just as well at a comparably high level. A set of diagnostic tools allows us to control and tailor the properties of generated LG beams. This enabled us to produce an LG beam with the highest purity reported to date. The demonstrated compatibility of higher-order LG modes with standard interferometry techniques and with the use of standard spherical optics makes them an ideal candidate for application in a future generation of high-precision interferometry. PMID:23962813

Carbone, Ludovico; Fulda, Paul; Bond, Charlotte; Brueckner, Frank; Brown, Daniel; Wang, Mengyao; Lodhia, Deepali; Palmer, Rebecca; Freise, Andreas

2013-01-01

389

Development of a high-precision ADS-B based conflict alerting system for operations in the airport environment  

E-print Network

The introduction of Automatic Dependent Surveillance - Broadcast (ADS-B) as the future source of aircraft surveillance worldwide provides an opportunity to introduce high-precision airborne conflict alerting systems for ...

Kunzi, Fabrice

2014-01-01

390

Operating a (87)Sr optical lattice clock with high precision and at high density.  

PubMed

We describe recent experimental progress with the JILA Sr optical frequency standard, which has a systematic uncertainty at the 10-(16) fractional frequency level. An upgraded laser system has recently been constructed in our lab which may allow the JILA Sr standard to reach the standard quantum measurement limit and achieve record levels of stability. To take full advantage of these improvements, it will be necessary to operate a lattice clock with a large number of atoms, and systematic frequency shifts resulting from atomic interactions will become increasingly important. We discuss how collisional frequency shifts can arise in an optical lattice clock employing fermionic atoms and describe a novel method by which such systematic effects can be suppressed. PMID:22481774

Swallows, Matthew; Martin, Michael; Bishof, Michael; Benko, Craig; Lin, Yige; Blatt, Sebastian; Rey, Ana Maria; Ye, Jun

2012-03-01

391

The value of high-frequency, high-precision methane isotopologue measurements for source and sink estimation  

NASA Astrophysics Data System (ADS)

We present an observing system simulation experiment examining the potential benefits of new methane isotopologues measurements for global- and national-scale source and sink inversions. New measurements are expected in the coming years, using quantum cascade laser spectroscopy with sample preconcentration, that will allow observations of?13C - CH4 and ?D - CH4at approximately hourly intervals and higher precision than previously possible. Using model-generated `pseudo-data', we predict the variability that these new systems should encounter in the atmosphere, and estimate the additional uncertainty reduction that should result from their use in source and sink inversions. We find that much of the?-value variability from seasonal to daily timescales should be resolvable at the target precision of the new observations. For global source estimation, we find additional uncertainty reductions of between 3-9 Tg/year for four major source categories (microbial, biomass burning, landfill and fossil fuel), compared to mole fraction-only inversions, if the higher end of the anticipated isotopologue-measurement precisions can be achieved. On national scales, we obtain average uncertainty reductions of ˜10% of the source strength for countries close to high-frequency monitoring sites, although the degree of uncertainty reduction on such small scales varies significantly (from close to 0% to almost 50%) for different sources and countries.

Rigby, M.; Manning, A. J.; Prinn, R. G.

2012-06-01

392

High precision 11B/10B analysis with a simplified MC-ICP-MS  

NASA Astrophysics Data System (ADS)

Boron isotope ratio is a powerful tracer in the fields of geochemistry, biochemistry, and environmental chemistry. One important application of 11B/10B isotope ratio in geochemistry is as an indicator for paleo pH of seawater recorded in marine carbonates in deep-sea sediments. Boron isotope ratios are determined by TIMS or MC-ICP-MS with precisions of better than 0.1 % RSD, but a large inter-lab discrepancy of 0.6 % is still observed for actual carbonate samples (Foster, 2008). Here, we tried to determine B isotope ratio by MC-ICP-MS with a simple and common analytical techniques using a quartz sample introduction system with a PFA nebulizer, and compared to recently developed precise B isotope ratio analysis techniques by TIMS in positive ion detection mode determined as Cs2BO2+ ions with sample amount of <100 ng (Ishikawa and Nagaishi, 2011) and by MC-ICP-MS (Foster, 2008, Louvat et al., 2011). 11B/10B isotope ratios of a 50 ppb B solution dissolved in a HNO3, mannitol, HF-mixed solution were determined against an isotopic reference NIST-SRM 951 with a standard sample bracketing technique in the wet plasma condition. Resultant analytical reproducibility (twice standard deviation) was +/-0.02 % with a consumption of 50 ng B, and the washout time was comparable to that of NH3 gas addition to the introduction system (Foster, 2008). 11B/10B isotope ratios of actual carbonate sample and seawater were determined after simple chemical purification with a common cation exchange resin instead of a boron selective resin. Their relative differences from the standard were consistent with those determined by the positive TIMS within analytical uncertainty. Current potential of MC-ICP-MS for precise B isotopic analysis will be discussed. Foster, G., 2008. Seawater pH, pCO2 and [CO32-] variations in the Caribbean Sea over the last 130kyr: A boron isotope and B/Ca study of planktic foraminifera, Earth Planet. Sci. Lett., 271, 254-266. Ishikawa, T. and Nagaishi, K., 2011. High-precision isotopic analysis of boron by positive thermal ionization mass spectrometry with sample preheating, J. Anal. At. Spectrom., 26, 359-365. Louvat, P., Bouchez, J, and Paris, G., 2011. MC-ICP-MS isotope measurements with direct injection nebulisation (d-DIHEN): Optimisation and application to boron in seawater and carbonate samples., Geostand. Geoanal. Res., 35, 75-88.

Tanimizu, M.; Nagaishi, K.

2012-04-01

393

High-precision percolation thresholds and Potts-model critical manifolds from graph polynomials  

NASA Astrophysics Data System (ADS)

The critical curves of the q-state Potts model can be determined exactly for regular two-dimensional lattices G that are of the three-terminal type. This comprises the square, triangular, hexagonal and bow-tie lattices. Jacobsen and Scullard have defined a graph polynomial PB(q, v) that gives access to the critical manifold for general lattices. It depends on a finite repeating part of the lattice, called the basis B, and its real roots in the temperature variable v = eK - 1 provide increasingly accurate approximations to the critical manifolds upon increasing the size of B. Using transfer matrix techniques, these authors computed PB(q, v) for large bases (up to 243 edges), obtaining determinations of the ferromagnetic critical point vc > 0 for the (4, 82), kagome, and (3, 122) lattices to a precision (of the order 10-8) slightly superior to that of the best available Monte Carlo simulations. In this paper we describe a more efficient transfer matrix approach to the computation of PB(q, v) that relies on a formulation within the periodic Temperley-Lieb algebra. This makes possible computations for substantially larger bases (up to 882 edges), and the precision on vc is hence taken to the range 10-13. We further show that a large variety of regular lattices can be cast in a form suitable for this approach. This includes all Archimedean lattices, their duals and their medials. For all these lattices we tabulate high-precision estimates of the bond percolation thresholds pc and Potts critical points vc. We also trace and discuss the full Potts critical manifold in the (q, v) plane, paying special attention to the antiferromagnetic region v < 0. Finally, we adapt the technique to site percolation as well, and compute the polynomials PB(p) for certain Archimedean and dual lattices (those having only cubic and quartic vertices), using very large bases (up to 243 vertices). This produces the site percolation thresholds pc to a precision of the order of 10-9.

>Jesper Lykke Jacobsen,

2014-04-01

394

Closed tubes preparation of graphite for high-precision AMS radiocarbon analysis  

NASA Astrophysics Data System (ADS)

Radiocarbon dating is an established tool applied in Geochronology. Technical developments of Accelerator Mass Spectrometry AMS, which allow measurements of samples containing less than 1 mg of carbon, opened opportunities for new applications. Moreover, high resolution records of the past changes require high-resolution chronologies i.e. sampling for 14C dating. In result, the field of applications is rapidly expanding and number of radiocarbon analysis is growing rapidly. Nowadays dedicated 14C AMS machines have great capacity for analysis but in order to keep up with the demand for analysis and provide the results as fast as possible a very efficient way of sample preparation is required. Sample preparation for 14C AMS analysis consists of two steps: separation of relevant carbon from the sample material (removing contamination) and preparation of graphite for AMS analysis. The last step usually involves reaction of CO2 with H2, in the presence of metal catalyst (Fe or Co) of specific mesh size heated to 550-625°C, as originally suggested by Vogel et al. (1984). Various graphitization systems have been built in order to fulfil the requirement of sample quality needed for high-precision radiocarbon data. In the early 90ties another method has been proposed (Vogel 1992) and applied by few laboratories mainly for environmental or biomedical samples. This method uses TiH2 as a source of H2 and can be easily and flexibly applied to produce graphite. Sample of CO2 is frozen in to the tube containing pre-conditioned Zn/TiH2 and Fe catalyst. Torch sealed tubes are then placed in the stepwise heated oven at 500/550°C and left to react for several hours. The greatest problem is the lack of control of the reaction completeness and considerable fractionation. However, recently reported results (Xu et al. 2007) suggest that high precision dating using graphite produced in closed tubes might be possible. We will present results of radiocarbon dating of the set of standards and secondary IAEA standards to demonstrate to what level this method can be used for high precision radiocarbon dating. References Vogel JS. 1992. Rapid Production of Graphite without Contamination for Biomedical Ams. Radiocarbon 34: 344-350. Vogel JS, Southon JR, Nelson DE, and Brown TA. 1984. Performance of Catalytically Condensed Carbon for Use in Accelerator Mass-Spectrometry. Nuclear Instruments & Methods in Physics Research Section B-Beam Interactions with Materials and Atoms 233: 289-293. Xu X, Trumbore SE, Zheng S, Southon JR, McDuffee KE, Luttgen M, and Liu JC. 2007. Modifying a sealed tube zinc reduction method for preparation of AMS graphite targets: Reducing background and attaining high precision. Nuclear Instruments and Methods in Physics Research Section B: Beam Interactions with Materials and Atoms Accelerator Mass Spectrometry - Proceedings of the Tenth International Conference on Accelerator Mass Spectrometry 259: 320-329.

Hajdas, I.; Michczynska, D.; Bonani, G.; Maurer, M.; Wacker, L.

2009-04-01

395

Two Fabry-Perot interferometers for high precision wavelength calibration in the near-infrared  

NASA Astrophysics Data System (ADS)

The most frequently used standard light sources for spectroscopic high precision wavelength calibration are hollow cathode lamps. These lamps, however, do not provide homogeneous line distribution and intensities. Particularly in the infrared, the number of useful lines is severely limited and the spectrum is contaminated by lines of the filler gas. With the goal of achieving sub m/s stability in the infrared, as required for detecting earthlike extra-solar planets, we are developing two passively stabilized Fabry-Perot interferometers for the red visible (600-1050nm) and near infrared wavelength regions (900-1350nm). Each of the two interferometers can produce ~15,000 lines of nearly constant brightness. The Fabry-Perot interferometers aim at a RV calibration precision of 10cm/s and are optimized in line shape and spacing for the infrared planet hunting CARMENES spectrograph that is currently being built for the Calar Alto 3.5m telescope. Here we present the first results of our work.

Schäfer, Sebastian; Reiners, Ansgar

2012-09-01

396

High-precision correlative fluorescence and electron cryo microscopy using two independent alignment markers?  

PubMed Central

Correlative light and electron microscopy (CLEM) is an emerging technique which combines functional information provided by fluorescence microscopy (FM) with the high-resolution structural information of electron microscopy (EM). So far, correlative cryo microscopy of frozen-hydrated samples has not reached better than micrometre range accuracy. Here, a method is presented that enables the correlation between fluorescently tagged proteins and electron cryo tomography (cryoET) data with nanometre range precision. Specifically, thin areas of vitrified whole cells are examined by correlative fluorescence cryo microscopy (cryoFM) and cryoET. Novel aspects of the presented cryoCLEM workflow not only include the implementation of two independent electron dense fluorescent markers to improve the precision of the alignment, but also the ability of obtaining an estimate of the correlation accuracy for each individual object of interest. The correlative workflow from plunge-freezing to cryoET is detailed step-by-step for the example of locating fluorescence-labelled adenovirus particles trafficking inside a cell. PMID:24262358

Schellenberger, Pascale; Kaufmann, Rainer; Siebert, C. Alistair; Hagen, Christoph; Wodrich, Harald; Grünewald, Kay

2014-01-01

397

Constraints on the acceleration of the solar system from high-precision timing  

E-print Network

Many astronomers have speculated that the solar system contains undiscovered massive planets or a distant stellar companion. The acceleration of the solar system barycenter can constrain the mass and position of the putative companion. In this paper we use the most recent timing data on accurate astronomical clocks (millisecond pulsars, pulsars in binary systems and pulsating white dwarfs) to constrain this acceleration. No evidence for non-zero acceleration has been found; the typical sensitivity achieved by our method is a/c=a few times 10^{-19} s^{-1}, comparable to the acceleration due to a Jupiter-mass planet at 200 AU. The acceleration method is limited by the uncertainties in the distances and by the timing precision for pulsars in binary systems, and by the intrinsic distribution of the period derivatives for millisecond pulsars. Timing data provide stronger constraints than residuals in the motions of comets or planets if the distance to the companion exceeds a few hundred AU. The acceleration method is also more sensitive to the presence of a distant companion (> 300-400 AU) than existing optical and infrared surveys. We outline the differences between the effects of the peculiar acceleration of the solar system and the background of gravitational waves on high-precision timing.

Nadia L. Zakamska; Scott Tremaine

2005-06-22

398

High-Precision Isothermal Titration Calorimetry with Automated Peak Shape Analysis  

PubMed Central

Isothermal titration calorimetry (ITC) is a powerful classical method that enables researchers in many fields to study the thermodynamics of molecular interactions. Primary ITC data comprise the temporal evolution of differential power reporting the heat of reaction during a series of injections of aliquots of a reactant into a sample cell. By integration of each injection peak, an isotherm can be constructed of total changes in enthalpy as a function of changes in solution composition, which is rich in thermodynamic information on the reaction. However, the signals from the injection peaks are superimposed by the stochastically varying time-course of the instrumental baseline power, limiting the precision of ITC isotherms. Here, we describe a method for automated peak assignment based on peak-shape analysis via singular value decomposition in combination with detailed least-squares modeling of local pre- and post-injection baselines. This approach can effectively filter out contributions of short-term noise and adventitious events in the power trace. This method also provides, for the first time, statistical error estimates for the individual isotherm data points. In turn, this results in improved detection limits for high-affinity or low-enthalpy binding reactions and significantly higher precision of the derived thermodynamic parameters. PMID:22530732

Keller, Sandro; Vargas, Carolyn; Zhao, Huaying; Piszczek, Grzegorz; Brautigam, Chad A.; Schuck, Peter

2012-01-01

399

High-precision molecular dynamics simulation of UO2-PuO2: Anion self-diffusion in UO2  

NASA Astrophysics Data System (ADS)

Our series of articles is devoted to high-precision molecular dynamics simulation of mixed actinide-oxide (MOX) fuel in the approximation of rigid ions and pair interactions (RIPI) using high-performance graphics processors (GPU). In this article we study self-diffusion mechanisms of oxygen anions in uranium dioxide (UO2) with the 10 recent and widely used sets of interatomic pair potentials (SPP) under periodic (PBC) and isolated (IBC) boundary conditions. Wide range of measured diffusion coefficients (from 10-3 cm2/s at melting point down to 10-12 cm2/s at 1400 K) made possible a direct comparison (without extrapolation) of the simulation results with the experimental data, which have been known only at low temperatures (T < 1500 K). A highly detailed (with the temperature step of 1 K) calculation of the diffusion coefficient allowed us to plot temperature dependences of the diffusion activation energy and its derivative, both of which show a wide (˜1000 K) superionic transition region confirming the broad ?-peaks of heat capacity obtained by us earlier. It is shown that regardless of SPP the anion self-diffusion in model crystals without surface or artificially embedded defects goes on via exchange mechanism, rather than interstitial or vacancy mechanisms suggested by the previous works. The activation energy of exchange diffusion turned out to coincide with the anti-Frenkel defect formation energy calculated by the lattice statics.

Potashnikov, S. I.; Boyarchenkov, A. S.; Nekrasov, K. A.; Kupryazhkin, A. Ya.

2013-02-01

400

MEMS profilometry by low coherence phase shifting interferometry: Effect of the light spectrum for high precision measurements  

Microsoft Academic Search

A white light interferometer can be used to measure profiles of a few nanometers and is therefore particularly well adapted for micro electro mechanical systems characterization. We present theoretical and experimental results on the profile precision as a function of the light source spectrum. We demonstrate that even if a broadband source is used in the phase shifting mode, the

S. Jorez; A. Cornet; J. P. Raskin

2006-01-01

401

High precision series solutions of differential equations: Ordinary and regular singular points of second order ODEs  

NASA Astrophysics Data System (ADS)

A subroutine for a very-high-precision numerical solution of a class of ordinary differential equations is provided. For a given evaluation point and equation parameters the memory requirement scales linearly with precision P, and the number of algebraic operations scales roughly linearly with P when P becomes sufficiently large. We discuss results from extensive tests of the code, and how one, for a given evaluation point and equation parameters, may estimate precision loss and computing time in advance. Program summary Program title: seriesSolveOde1 Catalogue identifier: AEMW_v1_0 Program summary URL: http://cpc.cs.qub.ac.uk/summaries/AEMW_v1_0.html Program obtainable from: CPC Program Library, Queen's University, Belfast, N. Ireland Licensing provisions: Standard CPC licence, http://cpc.cs.qub.ac.uk/licence/licence.html No. of lines in distributed program, including test data, etc.: 991 No. of bytes in distributed program, including test data, etc.: 488116 Distribution format: tar.gz Programming language: C++ Computer: PC's or higher performance computers. Operating system: Linux and MacOS RAM: Few to many megabytes (problem dependent). Classification: 2.7, 4.3 External routines: CLN — Class Library for Numbers [1] built with the GNU MP library [2], and GSL — GNU Scientific Library [3] (only for time measurements). Nature of problem: The differential equation -s2({d2}/{dz2}+{1-?+-?-}/{z}{d}/{dz}+{?+?-}/{z2})?(z)+{1}/{z} ?n=0N vnzn?(z)=0, is solved numerically to very high precision. The evaluation point z and some or all of the equation parameters may be complex numbers; some or all of them may be represented exactly in terms of rational numbers. Solution method: The solution ?(z), and optionally ?'(z), is evaluated at the point z by executing the recursion A(z)={s-2}/{(m+1+?-?+)(m+1+?-?-)} ?n=0N Vn(z)A(z), ?(z)=?(z)+A(z), to sufficiently large m. Here ? is either ?+ or ?-, and Vn(z)=vnz. The recursion is initialized by A(z)=?z?,for n=0,1,…,N ?(z)=A0(z). Restrictions: No solution is computed if z=0, or s=0, or if ?=?- (assuming Re?+?Re?-) with ?+-?- an integer, except when ?+-?-=1 and v =0 (i.e. when z is an ordinary point for z?(z)). Additional comments: The code of the main algorithm is in the file seriesSolveOde1.cc, which "#include" the file checkForBreakOde1.cc. These routines, and the programs using them, must "#include" the file seriesSolveOde1.cc. Running time: On a Linux PC that is a few years old, at y=?{10} to an accuracy of P=200 decimal digits, evaluating the ground state wavefunction of the anharmonic oscillator (with the eigenvalue known in advance); (cf. Eq. (6)) takes about 2 ms, and about 40 min at an accuracy of P=100000 decimal digits. References: [1] B. Haible and R.B. Kreckel, CLN — Class Library for Numbers, http://www.ginac.de/CLN/ [2] T. Granlund and collaborators, GMP — The GNU Multiple Precision Arithmetic Library, http://gmplib.org/ [3] M. Galassi et al., GNU Scientific Library Reference Manual (3rd Ed.), ISBN 0954612078., http://www.gnu.org/software/gsl/

Noreen, Amna; Olaussen, Kåre

2012-10-01

402

High precision chemical mechanical polishing of highly-boron-doped Si wafer used for epitaxial substrate  

Microsoft Academic Search

The surface waviness with concentric circular pattern is generated on highly-boron-doped Si wafer by chemical–mechanical polishing (CMP) with amine system polishing slurry. To investigate the generation mechanism of the waviness, the mechanical and chemical characteristics were clarified using the silicon crystal samples with various boron concentration level ranging from 2.9×1017cm?3 to 1.3×1020cm?3. The conventional silicon substrate used as epitaxial wafer

J. Watanabe; G. Yu; O. Eryu; I. Koshiyama; K. Izumi; K. Nakashima; M. Umeno; T. Jimbo; K. Kodama

2005-01-01

403

A high-precision multi-channel TAC and QAC module for the neutron detection wall  

NASA Astrophysics Data System (ADS)

A single width NIM module that includes eight channels of the time-to-amplitude converter (TAC) and the charge-to-amplitude converter (QAC) is introduced in the paper, which is designed for the large neutron wall detector to measure charge (energy) and time interval simultaneously. The module adopts a high precision gated integration circuit to realize TAC and QAC. The input range of TAC is from 30 ns to 1 ?s, and the input range of QAC is from 40 pC to 600 pC. The linearity error of TAC is lower than 1.28%, and the time resolution of TAC is less than 0.871%. The linearity error of QAC is lower than 0.81%, and the resolution of QAC is better than 0.936%. Supported by National Natural Science Foundation of China (11005135, 11079045) and National Instruments Special of China (2011YQ12009604)

She, Qian-Shun; Su, Hong; Qian, Yi; Yu, Yu-Hong

2015-02-01

404

Composite-Light-Pulse Technique for High-Precision Atom Interferometry  

NASA Astrophysics Data System (ADS)

We realize beam splitters and mirrors for atom waves by employing a sequence of light pulses rather than individual ones. In this way we can tailor atom interferometers with improved sensitivity and accuracy. We demonstrate our method of composite pulses by creating a symmetric matter-wave interferometer which combines the advantages of conventional Bragg- and Raman-type concepts. This feature leads to an interferometer with a high immunity to technical noise allowing us to devise a large-area Sagnac gyroscope yielding a phase shift of 6.5 rad due to the Earth's rotation. With this device we achieve a rotation rate precision of 120 nrad s-1 Hz-1 /2 and determine the Earth's rotation rate with a relative uncertainty of 1.2%.

Berg, P.; Abend, S.; Tackmann, G.; Schubert, C.; Giese, E.; Schleich, W. P.; Narducci, F. A.; Ertmer, W.; Rasel, E. M.

2015-02-01

405

Niphargus: A silicon band-gap sensor temperature logger for high-precision environmental monitoring  

NASA Astrophysics Data System (ADS)

A temperature logger, named 'Niphargus', was developed at the Geological Survey of Belgium to monitor temperature of local natural processes. It has a sensitivity of the order of a few hundredths of degrees on temperature variability in open air, caves, soils and river environment. The newly developed instrument uses a state-of-the-art band-gap silicon temperature sensor with integrated digital output. This sensor reduces the risk of drift associated with thermistor-based sensing devices, especially in humid environments. The Niphargus is designed to be highly reliable, low-cost and powered by a single lithium cell with up to several years autonomy, depending on the sampling rate and environmental conditions. A batch of Niphargus loggers was also compared to a precision thermistor to assess absolute temperature accuracy. Further characterization came from two field case studies in Belgium: monitoring of a mineralized water stream near the town of Spa and air temperature monitoring inside Han-sur-Lesse cave.

Burlet, C.; Vanbrabant, Y.; Piessens, K.; Welkenhuysen, K.; Verheyden, S.

2015-01-01

406

High precision and convenient extension simulation platform for satellite attitude and orbit system  

NASA Astrophysics Data System (ADS)

In this paper, a high precision and convenient extension simulation platform for satellite attitude and orbit system is developed, to demonstrate the satellite attitude and orbit system for given space mission, and test the new underdeveloped algorithms for attitude/orbit dynamics, attitude determination, orbit navigation, and attitude/orbit control. The simulation platform is based on Matlab/Simulink software, using the technique of Simulink modeling, importing C/Fortran code in Matlab/Simulink, and embedded Matlab function, with beautiful reusability, inheritability and expansibility. The paper orderly presents the background behind the development of the platform, the platform design architecture and capability, the validity of the platform, the inheritability and expansibility of the platform, the platform implementation example for Chinese weather satellite (FY-3), and the future development for the platform.

Cui, Hongzheng; Han, Chao; Chen, Pei; Luo, Qinqin

2012-01-01

407

Non-contact high precision measurement of surface form tolerances and central thickness for optical elements  

NASA Astrophysics Data System (ADS)

The traditional contact measuring methods could not satisfy the current optical elements measuring requirements. Noncontact high precision measuring theory, principle and instrument of the surface form tolerances and central thickness for optical elements were studied in the paper. In comparison with other types of interferometers, such as Twyman-Green and Mach-Zehnder, a Fizeau interferometer has the advantages of having fewer optical components, greater accuracy, and is easier to use. Some relations among the 3/A(B/C), POWER/PV and N/?N were studied. The PV with POWER removed can be the reference number of ?N. The chromatic longitudinal aberration of a special optical probe can be used for non-contanct central thickness measurement.

Lou, Ying

2010-10-01

408

Development of a high-precision slit for x-ray beamline at SPring-8  

NASA Astrophysics Data System (ADS)

A high-precision slit for monochromatic x-rays has been developed as one of the standardized components in the undulator beamline at SPring-8. Advanced experiments such as x-ray micro-beam diffraction and x-ray scanning microscope using nano-beam require small, variable and accurate apertures. The newly developed slit has an aperture size ranging from 1 ?m × 1 ?m to 20 mm × 20 mm with a resolution of 0.5 ?m in full step. Each blade is independently driven through bellows mounted on both sides of the vacuum chamber. A set of bellows prevents displacement of the blade by evacuation. Using this slit, we could improve the displacement from 20 ?m to 1 ?m. The positioning accuracy of the slit is 0.5 ?m. The slits have been installed in the three beamlines at SPring-8.

Takeuchi, T.; Tanaka, M.; Miura, T.; Senba, Y.; Shimada, Y.; Tajiri, H.; Sakata, O.; Sato, M.; Koganezawa, T.; Uesugi, K.; Ohashi, H.; Goto, S.

2009-08-01

409

Composite-light-pulse technique for high-precision atom interferometry.  

PubMed

We realize beam splitters and mirrors for atom waves by employing a sequence of light pulses rather than individual ones. In this way we can tailor atom interferometers with improved sensitivity and accuracy. We demonstrate our method of composite pulses by creating a symmetric matter-wave interferometer which combines the advantages of conventional Bragg- and Raman-type concepts. This feature leads to an interferometer with a high immunity to technical noise allowing us to devise a large-area Sagnac gyroscope yielding a phase shift of 6.5 rad due to the Earth's rotation. With this device we achieve a rotation rate precision of 120??nrad?s^{-1}?Hz^{-1/2} and determine the Earth's rotation rate with a relative uncertainty of 1.2%. PMID:25723216

Berg, P; Abend, S; Tackmann, G; Schubert, C; Giese, E; Schleich, W P; Narducci, F A; Ertmer, W; Rasel, E M

2015-02-13

410

Classical Cepheids: High-precision Velocimetry, Cluster Membership, and the Effect of Rotation  

NASA Astrophysics Data System (ADS)

Classical Cepheids are crucial calibrators of the extragalactic distance scale. Despite the adjective 'classical' and their use as 'standard candles', many open problems remain and ensure a steady scientific interest in these objects. This thesis has contributed to the understanding of Cepheids via three different topics: (1) an unprecedented observational program dedicated to studying highly precise Doppler measurements (velocimetry), which as has enabled several observational discoveries; (2) a newly-developed astro-statistical method for conducting an all-sky census of Cepheids belonging to Galactic open clusters, which is suitable for the era of large surveys (big data) such as the ESA's Gaia space mission; (3) the first detailed investigation of the effect of rotation on populations of classical Cepheids using Geneva stellar evolution models, which provides an explanation for the 45-year old Cepheid mass discrepancy problem. Last, but not least, I investigated the implications of my work for the extragalactic distance scale.

Anderson, Richard I.

2013-12-01

411

TRB3: a 264 channel high precision TDC platform and its applications  

NASA Astrophysics Data System (ADS)

The TRB3 features four FPGA-based TDCs with < 20 ps RMS time precision between two channels and 256+4+4 channels in total. One central FPGA provides flexible trigger functionality and GbE connectivity including powerful slow control. We present recent users' applications of this platform following the COME&KISS principle: successful test beamtimes at CERN (CBM), in Jülich and Mainz with an FPGA-based discriminator board (PaDiWa), a charge-to-width FEE board with high dynamic range, read-out of the n-XYTER ASIC and software for data unpacking and TDC calibration in ROOT. We conclude with an outlook on future developments.

Neiser, A.; Adamczewski-Musch, J.; Hoek, M.; Koenig, W.; Korcyl, G.; Linev, S.; Maier, L.; Michel, J.; Palka, M.; Penschuck, M.; Traxler, M.; U?ur, C.; Zink, A.

2013-12-01

412

QCD Precision Measurements and Structure Function Extraction at a High Statistics, High Energy Neutrino Scattering Experiment: NuSOnG  

E-print Network

We extend the physics case for a new high-energy, ultra-high statistics neutrino scattering experiment, NuSOnG (Neutrino Scattering On Glass) to address a variety of issues including precision QCD measurements, extraction of structure functions, and the derived Parton Distribution Functions (PDFs). This experiment uses a Tevatron-based neutrino beam to obtain a sample of Deep Inelastic Scattering (DIS) events which is over two orders of magnitude larger than past samples. We outline an innovative method for fitting the structure functions using a parameterized energy shift which yields reduced systematic uncertainties. High statistics measurements, in combination with improved systematics, will enable NuSOnG to perform discerning tests of fundamental Standard Model parameters as we search for deviations which may hint of "Beyond the Standard Model" physics.

T. Adams; P. Batra; L. Bugel; L. Camilleri; J. M. Conrad; A. de Gouvêa; P. H. Fisher; J. A. Formaggio; J. Jenkins; G. Karagiorgi; T. R. Kobilarcik; S. Kopp; G. Kyle; W. A. Loinaz; D. A. Mason; R. Milner; R. Moore; J. G. Morfín; M. Nakamura; D. Naples; P. Nienaber; F. I. Olness; J. F. Owens; S. F. Pate; A. Pronin; W. G. Seligman; M. H. Shaevitz; H. Schellman; I. Schienbein; M. J. Syphers; T. M. P. Tait; T. Takeuchi; C. Y. Tan; R. G. Van de Water; R. K. Yamamoto; J. Y. Yu

2009-06-19

413

QCD Precision Measurements and Structure Function Extraction at a High Statistics, High Energy Neutrino Scattering Experiment: NuSOnG  

SciTech Connect

We extend the physics case for a new high-energy, ultra-high statistics neutrino scattering experiment, NuSOnG (Neutrino Scattering On Glass) to address a variety of issues including precision QCD measurements, extraction of structure functions, and the derived Parton Distribution Functions (PDFs). This experiment uses a Tevatron-based neutrino beam to obtain a sample of Deep Inelastic Scattering (DIS) events which is over two orders of magnitude larger than past samples. We outline an innovative method for fitting the structure functions using a parameterized energy shift which yields reduced systematic uncertainties. High statistics measurements, in combination with improved systematics, will enable NuSOnG to perform discerning tests of fundamental Standard Model parameters as we search for deviations which may hint of 'Beyond the Standard Model' physics.

Adams, T.; /Florida State U.; Batra, P.; /Columbia U.; Bugel, Leonard G.; /Columbia U.; Camilleri, Leslie Loris; /Columbia U.; Conrad, Janet Marie; /MIT; de Gouvea, A.; /Northwestern U.; Fisher, Peter H.; /MIT; Formaggio, Joseph Angelo; /MIT; Jenkins, J.; /Northwestern U.; Karagiorgi, Georgia S.; /MIT; Kobilarcik, T.R.; /Fermilab /Texas U.

2009-06-01

414

Online high-precision delta(2)H and delta(18)O analysis in water by pyrolysis.  

PubMed

A method for online simultaneous delta(2)H and delta(18)O analysis in water by high-temperature conversion is presented. Water is injected by using a syringe into a high-temperature carbon reactor and converted into H(2) and CO, which are separated by gas chromatography (GC) and carried by helium to the isotope ratio mass spectrometer for hydrogen and oxygen isotope analysis. A series of experiments was conducted to evaluate several issues such as sample size, temperature and memory effects. The delta(2)H and delta(18)O values in multiple water standards changed consistently as the reactor temperature increased from 1150 to 1480 degrees C. The delta(18)O in water can be measured at a lower temperature (e.g. 1150 degrees C) although the precision was relatively poor at temperatures <1300 degrees C. Memory effects exist for delta(2)H and delta(18)O between two waters, and can be reduced (to <1%) with proper measures. The injection of different amounts of water may affect the isotope ratio results. For example, in contrast to small injections (100 nL or less) from small syringes (e.g. 1.2 microL), large injections (1 microL or more) from larger syringes (e.g. 10 microL) with dilution produced asymmetric peaks and shifts of isotope ratios, e.g. 4 per thousand for delta(2)H and 0.4 per thousand for delta(18)O, probably resulting from isotope fractionation during dilution via the ConFlo interface. This method can be used to analyze nanoliter samples of water (e.g. 30 nL) with good precision of 0.5 per thousand for delta(2)H and 0.1 per thousand for delta(18)O. This is important for geosciences; for instance, fluid inclusions in ancient minerals may be analyzed for delta(2)H and delta(18)O to help understand the formation environments. PMID:19714707

Lu, Feng H

2009-10-01

415

A high precision micropositioner with five degrees of freedom based on an electromagnetic driving principle  

NASA Astrophysics Data System (ADS)

A five degrees of freedom high precision micropositioner based on spring suspension and electromagnetic driving has been designed, constructed, and tested. The device consists of two parts: a moving part and a stationary part. The moving part, named as ``motor'', is formed with a rigid frame and three groups of coils fixed on it. The stationary part of the device, called ``stator'', includes a chassis and twelve U-shaped magnetic ``shoes''. The motor is attached to the stator with flat springs whose linear suspension allows it to move in all dimensions except the rotation around z axis. The coils have been laid out in such a way that fractions of them pass through the air gaps between the facing magnets in the magnetic shoes. When electrical currents are supplied to the coils, the resulting Lorenz forces drive the motor to move in the five degrees of freedom allowed by the spring suspension. Since the system is inherently stable and there is no mechanical friction, the open-loop resolutions of the device are found to be limited only by that of the 12-bit D/A board used. A closed-loop translation resolution of 0.3 ?m has been achieved over a working space of 180 ?m by 180 ?m by 680 ?m. A closed-loop rotation resolution of 2.73×10-6 rad has been achieved over a working space of 1.38×10-3 rad. Potentially the device can be used for high precision microprobing and testing, cellular biology, microsurgery, and testing of micromechanical devices in the fast developing MEMS area.

Wang, Wanjun; He, Tian

1996-01-01

416

Optomechanical design of a high-precision detector robot arm system for x-ray nano-diffraction with x-ray nanoprobe  

NASA Astrophysics Data System (ADS)

Collaboration between Argonne National Laboratory and Brookhaven National Laboratory has created a design for the high-precision detector robot arm system that will be used in the x-ray nano-diffraction experimental station at the Hard X-ray Nanoprobe (HXN) beamline for the NSLS-II project. The robot arm system is designed for positioning and manipulating an x-ray detector in three-dimensional space for nano-diffraction data acquisition with the HXN x-ray microscope. It consists of the following major component groups: a granite base with air-bearing support, a 2-D horizontal base stage, a vertical axis goniometer, a 2-D vertical plane robot arm, a 3-D fast scanning stages group, and a 2-D x-ray pixel detector. The design specifications and unique optomechanical structure of this novel high-precision detector robot arm system will be presented in this paper.

Shu, D.; Kalbfleisch, S.; Kearney, S.; Anton, J.; Chu, Y. S.

2014-03-01

417

Novel high-speed 3-DOF linear direct drive operating with submicron precision  

NASA Astrophysics Data System (ADS)

Developments in microelectronics, micromechanics and microelectromechanical systems require significant improvements in manufacturing tools for mass productions. Especially the assembling tools have to become feaster and more precise. Many assembly devices use XY stages driven by DC servomotors with ball screws or parallel structures; others use linear drives with traditional ball bearings. Only a few devices use linear drives together with air bearings, but always together with an angular guide for X and Y direction. The novel approach present in this paper is based on linear drives together with a planar air bearing. In contrast to other stages, it does not need any angular guide. This reduces the moved mass and leads to higher accelerations. It consists of an arrangement of four identical moving-coils attached to a slide, which is suspended by a planar air bearing. This new configuration allows a workspace of 60 X 60 mm2 and an acceleration exceeding 10 g1 with a resolution better than 100 nm. This paper gives an overview of the system, describes the design of the moving coils and shows first experimental result of the controller.

Sprenger, Bernhard; Siegwart, Roland Y.

1998-01-01

418

High-resolution estimation of the water balance components from high-precision lysimeters  

NASA Astrophysics Data System (ADS)

Lysimeters offer the opportunity to determine precipitation, evapotranspiration and groundwater-recharge with high accuracy. In contrast to other techniques, like Eddy-flux systems or evaporation pans, lysimeters provide a direct measurement of evapotranspiration from a clearly defined surface area at the scale of a soil profile via the built-in weighing system. In particular the estimation of precipitation can benefit from the much higher surface area compared to typical raingauge systems. Nevertheless, lysimeters are exposed to several external influences that could falsify the calculated fluxes. Therefore, the estimation of the relevant fluxes requires an appropriate data processing with respect to various error sources. Most lysimeter studies account for noise in the data by averaging. However, the effects of smoothing by averaging on the accuracy of the estimated water balance is rarely investigated. In this study, we present a filtering scheme, which is designed to deal with the various kinds of possible errors. We analyze the influence of averaging times and thresholds on the calculated water balance. We further investigate the ability of two adaptive filtering methods (the Adaptive Window and Adaptive Threshold filter (AWAT-filter) (Peters et al., 2014) and the consecutively described synchro-filter) in further reducing the filtering error. On the basis of the data sets of 18 simultanously running lysimeters of the TERENO SoilCan research site in Bad Lauchstädt, we show that the estimation of the water balance with high temporal resolution and good accuracy is possible.

Hannes, M.; Wollschläger, U.; Schrader, F.; Durner, W.; Gebler, S.; Pütz, T.; Fank, J.; von Unold, G.; Vogel, H.-J.

2015-01-01

419

HPMSS(High Precision Magnetic Survey System) and InterRidge  

NASA Astrophysics Data System (ADS)

From the beginning of 1990s to the beginning of 2000s, the Japanese group of IntreRidge conducted many cruises for three component magnetic survey using Shipboard Three Component Magnetometer (STCM) and Deep Towed Three Component Magnetometer (DTCM) in the world wide oceans. We have been developing HPMSS during this time with support of Dr.Tamaki(the late representative of InterRidge Japan) who understood the advantages of three component geomagnetic anomalies (TCGA). TCGA measured by STCM determines the direction of geomagnetic anomaly lineations precisely at every point where TCGA were observed, which playes the important role in magnetic anomaly lineation analysis. Even in the beginning of 2000s, almost all marine magnetic scientists believed that the total intensity anomly (TIA) is the better data than TCGA for analysis because the scalar magnetometers (e.g. proton precession magnetometer) have the better accuracy than any other magnetometers (e.g.flux gate magnetometer (FGM)). We employed the high accrate gyroscope (e.g.ring lase gyroscope (RLG)/optical fiber gyroscope (OFG)) to improve the accuracy of STCM/DTCM equipped with FGM. Moreover we employed accurate and precise FGM which was selected among the market. Finally we developed the new magnetic survey system with high precision usable as airborn, shipboard and dee-ptowed magnetometers which we call HPMSS(High Precision Magnetic Survey System). As an optional equipment, we use LAN to communicate between a data aquisiitin part and a data logging part, and GPS for a position fix. For the deep-towed survey, we use the acoustic position fix (super short base line method) and the acoustic communication to monitor the DTCM status. First we used HPMSS to obtain the magnetization structure of the volcanic island, Aogashima located 300km south of Tokyo using a hellcopter in 2006 and 2009. Next we used HPMSS installed in DTCM in 2010,2011 and 2012 using R/V Bosei-maru belonging to Tokai University. Also we used HPMSS installed in AUV (automonous undersea vehicle), belonging to JAMSTEC in 2009,2010 and 2011. We have been emphasizing the importnace of TCGA compared to TIA because TIA does not obey the Laplace equation which means TIA is not harmonic, then we cannot apply the Fourier analysis on TIA. We will show the structure of three component magnetization of the mineral deposit in the volcanic thermal area in Izu-Ogasawara island Arc, called Hakurei Deposit. TCGA of DTCM and AUV survey data were used and the depth section and the vertical section of three components of magnetization of Hakurei Deposit area will be presented. We emphasize that reliable 3D structure of three component of magnetization was obtained from TCGA using HPMSS as the result of deep support of InterRidge Japan, especially deep support of Dr. Tamaki.

Isezaki, N.; Sayanagi, K.

2012-12-01

420

Portable, high intensity isotopic neutron source provides increased experimental accuracy  

NASA Technical Reports Server (NTRS)

Small portable, high intensity isotopic neutron source combines twelve curium-americium beryllium sources. This high intensity of neutrons, with a flux which slowly decreases at a known rate, provides for increased experimental accuracy.

Mohr, W. C.; Stewart, D. C.; Wahlgren, M. A.

1968-01-01

421

Symposium on computing in experimental high energy physics  

NASA Astrophysics Data System (ADS)

This was the first symposium on computing in experimental high energy physics to be held during the ICCMSE conference. The symposium attracted 21 papers on a number of topics relevant for present day high energy physics experiments.

Bose, Tulika

2012-12-01

422

Sensitivity studies of high-precision methane column concentration inversion using a line-by-line radiative transfer model  

NASA Astrophysics Data System (ADS)

Hyper-spectral remote sensing may provide an effective solution to retrieve the methane (CH4) concentration in an atmospheric column. As a result of exploring the absorptive characteristics of CH4, an appropriate band is selected from hyperspectral data for the detection of its column concentration with high precision. Following the most recent inversion theory and methods, the line-by-line radiative transfer model (LBLRTM) is employed to forward model the impact of four sensitive factors on inversion precision, including CH4 initial profile, temperature, overlapping gases, and surface albedo. The results indicate that the four optimized factors could improve the inversion precision of atmospheric CH4 column concentration.

Song, Ci; Shu, Jiong; Zhou, Mandi; Gao, Wei

2013-12-01

423

Mid-infrared frequency comb for broadband high precision and sensitivity molecular spectroscopy.  

PubMed

We report on the experimental demonstration of the metrological and spectroscopic performances of a mid-infrared comb generated by a nonlinear downconversion process from a Ti:sapphire-based near-infrared comb. A quantum cascade laser at 4330 nm was phase-locked to a single tooth of this mid-infrared comb and its frequency-noise power spectral density was measured. The mid-infrared comb itself was also used as a multifrequency highly coherent source to perform ambient air direct comb spectroscopy with the Vernier technique, by demultiplexing it with a high-finesse Fabry-Perot cavity. PMID:25166071

Galli, I; Bartalini, S; Cancio, P; Cappelli, F; Giusfredi, G; Mazzotti, D; Akikusa, N; Yamanishi, M; De Natale, P

2014-09-01

424

New technology enables high precision multislit collimators for microbeam radiation therapy  

SciTech Connect

During the past decade microbeam radiation therapy has evolved from preclinical studies to a stage in which clinical trials can be planned, using spatially fractionated, highly collimated and high intensity beams like those generated at the x-ray ID17 beamline of the European Synchrotron Radiation Facility. The production of such microbeams typically between 25 and 100 {mu}m full width at half maximum (FWHM) values and 100-400 {mu}m center-to-center (c-t-c) spacings requires a multislit collimator either with fixed or adjustable microbeam width. The mechanical regularity of such devices is the most important property required to produce an array of identical microbeams. That ensures treatment reproducibility and reliable use of Monte Carlo-based treatment planning systems. New high precision wire cutting techniques allow the fabrication of these collimators made of tungsten carbide. We present a variable slit width collimator as well as a single slit device with a fixed setting of 50 {mu}m FWHM and 400 {mu}m c-t-c, both able to cover irradiation fields of 50 mm width, deemed to meet clinical requirements. Important improvements have reduced the standard deviation of 5.5 {mu}m to less than 1 {mu}m for a nominal FWHM value of 25 {mu}m. The specifications of both devices, the methods used to measure these characteristics, and the results are presented.

Braeuer-Krisch, E.; Requardt, H.; Brochard, T.; Berruyer, G.; Renier, M.; Bravin, A. [European Synchrotron Radiation Facility, B.P. 220, 38043 Grenoble (France); Laissue, J. A. [Institute of Pathology, University of Bern, Murtenstrasse 31, 3010 Bern (Switzerland)

2009-07-15

425

Fluorescence lifetime plate reader: Resolution and precision meet high-throughput  

NASA Astrophysics Data System (ADS)

We describe a nanosecond time-resolved fluorescence spectrometer that acquires fluorescence decay waveforms from each well of a 384-well microplate in 3 min with signal-to-noise exceeding 400 using direct waveform recording. The instrument combines high-energy pulsed laser sources (5-10 kHz repetition rate) with a photomultiplier and high-speed digitizer (1 GHz) to record a fluorescence decay waveform after each pulse. Waveforms acquired from rhodamine or 5-((2-aminoethyl)amino) naphthalene-1-sulfonic acid dyes in a 384-well plate gave lifetime measurements 5- to 25-fold more precise than the simultaneous intensity measurements. Lifetimes as short as 0.04 ns were acquired by interleaving with an effective sample rate of 5 GHz. Lifetime measurements resolved mixtures of single-exponential dyes with better than 1% accuracy. The fluorescence lifetime plate reader enables multiple-well fluorescence lifetime measurements with an acquisition time of 0.5 s per well, suitable for high-throughput fluorescence lifetime screening applications.

Petersen, Karl J.; Peterson, Kurt C.; Muretta, Joseph M.; Higgins, Sutton E.; Gillispie, Gregory D.; Thomas, David D.

2014-11-01

426

Fluorescence lifetime plate reader: resolution and precision meet high-throughput.  

PubMed

We describe a nanosecond time-resolved fluorescence spectrometer that acquires fluorescence decay waveforms from each well of a 384-well microplate in 3 min with signal-to-noise exceeding 400 using direct waveform recording. The instrument combines high-energy pulsed laser sources (5-10 kHz repetition rate) with a photomultiplier and high-speed digitizer (1 GHz) to record a fluorescence decay waveform after each pulse. Waveforms acquired from rhodamine or 5-((2-aminoethyl)amino) naphthalene-1-sulfonic acid dyes in a 384-well plate gave lifetime measurements 5- to 25-fold more precise than the simultaneous intensity measurements. Lifetimes as short as 0.04 ns were acquired by interleaving with an effective sample rate of 5 GHz. Lifetime measurements resolved mixtures of single-exponential dyes with better than 1% accuracy. The fluorescence lifetime plate reader enables multiple-well fluorescence lifetime measurements with an acquisition time of 0.5 s per well, suitable for high-throughput fluorescence lifetime screening applications. PMID:25430092

Petersen, Karl J; Peterson, Kurt C; Muretta, Joseph M; Higgins, Sutton E; Gillispie, Gregory D; Thomas, David D

2014-11-01

427

THE APPLICATION OF MULTIVIEW METHODS FOR HIGH-PRECISION ASTROMETRIC SPACE VLBI AT LOW FREQUENCIES  

SciTech Connect

High-precision astrometric space very long baseline interferometry (S-VLBI) at the low end of the conventional frequency range, i.e., 20 cm, is a requirement for a number of high-priority science goals. These are headlined by obtaining trigonometric parallax distances to pulsars in pulsar-black hole pairs and OH masers anywhere in the Milky Way and the Magellanic Clouds. We propose a solution for the most difficult technical problems in S-VLBI by the MultiView approach where multiple sources, separated by several degrees on the sky, are observed simultaneously. We simulated a number of challenging S-VLBI configurations, with orbit errors up to 8 m in size and with ionospheric atmospheres consistent with poor conditions. In these simulations we performed MultiView analysis to achieve the required science goals. This approach removes the need for beam switching requiring a Control Moment Gyro, and the space and ground infrastructure required for high-quality orbit reconstruction of a space-based radio telescope. This will dramatically reduce the complexity of S-VLBI missions which implement the phase-referencing technique.

Dodson, R.; Rioja, M.; Imai, H. [International Centre for Radio Astronomy Research, M468, University of Western Australia, 35 Stirling Hwy, Crawley, Western Australia 6009 (Australia); Asaki, Y. [Institute of Space and Astronautical Science, 3-1-1 Yoshinodai, Chuou, Sagamihara, Kanagawa 252-5210 (Japan); Hong, X.-Y.; Shen, Z., E-mail: richard.dodson@icrar.org [Shanghai Astronomical Observatory, CAS, 200030 Shanghai (China)

2013-06-15

428

High-precision timing observations of the millisecond pulsar PSR 1821-24 at Nancay.  

NASA Astrophysics Data System (ADS)

High-precision timing observations of the millisecond pulsar PSR 1821-24 have been conducted on 305 individual dates at the Nancay radiotelescope at 1.4GHz between March 2 1989 and July 21 1993. The Time Of Arrival residuals after the standard fit of the pulsar parameters are characterised by a rms of 2.78?s. This dense and precise timing series has allowed the first determination of the apparent second period derivative d^2^P/dt^2^ for PSR 1821-24 and of its proper motion. We find that the observed quasi-cubic variation (i.e. the apparent d^2^P/dt^2^) of the post-fit residuals matches the level of low-frequency noise predicted by the empirical relationship of Arzoumanian et al. (1994) for the rotation irregularities of classical pulsars. We conclude that the millisecond pulsar PSR 1821-24, similarly to PSR 1937+21, exhibits instrinsic rotation irregularities, unless d^2^P/dt^2^ is a jerk (?(a)) induced during a close encounter in the globular cluster M28. This pulsar is the youngest known millisecond pulsar according to a characteristic age (1/2P_0_/?(P)_0_) of 30x10^6^yr. Relatively young millisecond pulsars, like PSR 1821-24 and PSR 1937+21, might be prone to rotation irregularities while old millisecond pulsars like PSR 1855+09 are more stable. We find a discrepancy between the optical proper motion of M28 and our timing proper motion of PSR 1821-24 larger than the pulsar escape velocity in the cluster. Reconciling these two proper motions is important for the kinematics of M28 and the study of the gravitational potential of the Galactic disk and bulge. Finally, we present the daily timing observations of PSR 1821-24 conducted every year since 1989 when the solar corona intervenes between the pulsar and the Earth at Christmas time. We have used these timing observations along a single cut through the corona to fit a spherically symmetric model of its electron density n_e_=n_0_x(r/r_0_)^-?^. With a slightly more sophisticated model for the coronal electron density, precise timing observations of PSR 1821-24 during these periods over a complete solar cycle could monitor the global flattening expected for the coronal plasma at the solar minimum.

Cognard, I.; Bourgois, G.; Lestrade, J.-F.; Biraud, F.; Aubry, D.; Darchy, B.; Drouhin, J.-P.

1996-07-01

429

Correction method for high-precision CD measurements on electrostatically charged wafers  

NASA Astrophysics Data System (ADS)

A correction method for automatic, high-precision CD-measurements on electrostatically charged wafers has been developed and installed in the Hitachi CD-SEM S-9260 to evaluate its performance. There are two types of charging: global and local. Global charging is stable and spreads all over a wafer while the local charging area is limited within the beam scanning area. A conventional CD-SEM has two weak points with respect to those charged wafers: one is failure at the positioning and autofocusing procedure which interferes with the fully automatic measurement sequence, and the other is disturbance of optical magnification which degrades the precision of CD-measurement values. By probing the global charging voltage with an electrostatic voltmeter prior to the CD-measurements, we subtract the voltage from a retarding voltage and then apply it to the wafer holder. The beam-focusing condition can stay within the fully automatically tunable range. And by generating numerical functions to represent the relationship between the global charging voltage, wafer height, excitation current of the objective lens and optical magnification, with the help of electron optical simulations, we can calculate the true optical magnification and the correct CD-measurement values. The local charging voltage is derived from the voltage shift of S-curves of secondary electron yield between conductive and insulated wafers measured with an energy filter. We correct the CD-measurement values using the simulated proportional relationship between magnifications of the electrostatic micro-lens and the local charging voltage. The coefficient is almost constant when the charging area is smaller than an equivalent circle of 100mm radius. We demonstrate that the CD-measurement values are successfully corrected within 0.1 percent in deviation for both charging types.

Ose, Yoichi; Ezumi, Makoto; Ishijima, Tatsuaki; Todokoro, Hideo; Nagai, Kouichi

2002-07-01

430

High-Precision Sub-Doppler Infrared Spectroscopy of HeH^+  

NASA Astrophysics Data System (ADS)

The helium hydride ion, HeH^+, is the simplest heteronuclear diatomic, and is composed of the two most abundant elements in the universe. It is widely believed that this ion was among the first molecules to be formed; thus it has been of great interest to scientists studying the chemistry of the early universe. HeH^+ is also isoelectronic to H_2 which makes it a great target ion for theorists to include adiabatic and non-adiabatic corrections to its Born-Oppenheimer potential energy surface. The accuracy of such calculations is further improved by incorporating electron relativistic and quantum electrodynamic effects. Using the highly sensitive spectroscopic technique of Noise Immune Cavity Enhanced Optical Heterodyne Velocity Modulation Spectroscopy (NICE-OHVMS) we are able to perform sub-Doppler spectroscopy on ions of interest. When combined with frequency calibration from an optical frequency comb we fit line centers with sub-MHz precision as has previously been shown for the H3^+, HCO+, and CH5+ ions. Here we report a list of the most precisely measured rovibrational transitions of HeH^+ to date. These measurements should allow theorists to continue to push the boundaries of ab initio calculations in order to further study this important fundamental species. S. Lepp, P. C. Stancil, A. Dalgarno J. Phys. B (2002), 35, R57. S. Lepp, Astrophys. Space Sci. (2003), 285, 737. K. Pachucki, J. Komasa, J. Chem. Phys (2012), 137, 204314. J. N. Hodges, A. J. Perry, P. A. Jenkins II, B. M. Siller, B. J. McCall J. Chem. Phys. (2013), 139, 164201.

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

2014-06-01

431

High precision during food recruitment of experienced (reactivated) foragers in the stingless bee Scaptotrigona mexicana (Apidae, Meliponini)  

NASA Astrophysics Data System (ADS)

Several studies have examined the existence of recruitment communication mechanisms in stingless bees. However, the spatial accuracy of location-specific recruitment has not been examined. Moreover, the location-specific recruitment of reactivated foragers, i.e., foragers that have previously experienced the same food source at a different location and time, has not been explicitly examined. However, such foragers may also play a significant role in colony foraging, particularly in small colonies. Here we report that reactivated Scaptotrigona mexicana foragers can recruit with high precision to a specific food location. The recruitment precision of reactivated foragers was evaluated by placing control feeders to the left and the right of the training feeder (direction-precision tests) and between the nest and the training feeder and beyond it (distance-precision tests). Reactivated foragers arrived at the correct location with high precision: 98.44% arrived at the training feeder in the direction trials (five-feeder fan-shaped array, accuracy of at least +/-6° of azimuth at 50 m from the nest), and 88.62% arrived at the training feeder in the distance trials (five-feeder linear array, accuracy of at least +/-5 m or +/-10% at 50 m from the nest). Thus, S. mexicana reactivated foragers can find the indicated food source at a specific distance and direction with high precision, higher than that shown by honeybees, Apis mellifera, which do not communicate food location at such close distances to the nest.

Sánchez, Daniel; Nieh, James C.; Hénaut, Yann; Cruz, Leopoldo; Vandame, Rémy

432

A Lane-Level LBS System for Vehicle Network with High-Precision BDS/GPS Positioning  

PubMed Central

In recent years, research on vehicle network location service has begun to focus on its intelligence and precision. The accuracy of space-time information has become a core factor for vehicle network systems in a mobile environment. However, difficulties persist in vehicle satellite positioning since deficiencies in the provision of high-quality space-time references greatly limit the development and application of vehicle networks. In this paper, we propose a high-precision-based vehicle network location service to solve this problem. The major components of this study include the following: (1) application of wide-area precise positioning technology to the vehicle network system. An adaptive correction message broadcast protocol is designed to satisfy the requirements for large-scale target precise positioning in the mobile Internet environment; (2) development of a concurrence service system with a flexible virtual expansion architecture to guarantee reliable data interaction between vehicles and the background; (3) verification of the positioning precision and service quality in the urban environment. Based on this high-precision positioning service platform, a lane-level location service is designed to solve a typical traffic safety problem. PMID:25755665

Guo, Chi; Guo, Wenfei; Cao, Guangyi; Dong, Hongbo

2015-01-01

433

A lane-level LBS system for vehicle network with high-precision BDS/GPS positioning.  

PubMed

In recent years, research on vehicle network location service has begun to focus on its intelligence and precision. The accuracy of space-time information has become a core factor for vehicle network systems in a mobile environment. However, difficulties persist in vehicle satellite positioning since deficiencies in the provision of high-quality space-time references greatly limit the development and application of vehicle networks. In this paper, we propose a high-precision-based vehicle network location service to solve this problem. The major components of this study include the following: (1) application of wide-area precise positioning technology to the vehicle network system. An adaptive correction message broadcast protocol is designed to satisfy the requirements for large-scale target precise positioning in the mobile Internet environment; (2) development of a concurrence service system with a flexible virtual expansion architecture to guarantee reliable data interaction between vehicles and the background; (3) verification of the positioning precision and service quality in the urban environment. Based on this high-precision positioning service platform, a lane-level location service is designed to solve a typical traffic safety problem. PMID:25755665

Guo, Chi; Guo, Wenfei; Cao, Guangyi; Dong, Hongbo

2015-01-01

434

Advanced navigation and guidance for high-precision planetary landing on Mars  

NASA Astrophysics Data System (ADS)

Several international missions scheduled for years 2011--2013 have as objective a Mars surface sample return to Earth. In order to gather samples of high scientific quality, these missions require precise landing at preselected locations on Mars. Since the previous missions on Mars have flown unguided and highly inaccurate atmospheric entry, a new generation of landing systems must be developed. It was demonstrated by Wolf et al., [2004] that the most efficient way to increase the landing accuracy is achieved during the atmospheric entry by steering the vehicle trajectory in order to eliminate the dispersions caused at entry and accumulated during the hypersonic phase. Thus, the research project proposed here will investigate the problem and bring advances on atmospheric entry navigation, guidance and control techniques applied to atmospheric entry on Mars. The state-of-the-art revealed several limitations on the current techniques such as the lack of proper navigation system and the inability to guide the trajectory efficiently in presence of disturbances and entry conditions uncertainties. On the theoretical side, the nonlinear state estimators required for navigation use algorithms that are a heavy computational burden for the onboard processor. Following these limitations, the research presented in this document is conducted along three paths: estimation theory, entry navigation techniques and entry guidance techniques in order to investigate on advances to achieve high precision landing. After an in-depth investigation of the theoretical background required to understand the atmospheric entry dynamics, a number of issues are addressed and the following substantial contributions regarding Mars atmospheric entry navigation and guidance are achieved. (C1) A theoretical improvement of the unscented Kalman Filter by merging two variants in the literature. The resulting technique has the advantages of both former algorithms. (C2) Four navigation concepts using inertial measurement units and radio ranging from reference beacons (known and unknown) for complete state estimation, atmospheric density estimation and vehicle aerodynamics estimation. (C3) The successful application of the unscented Kalman filtering to atmospheric entry for both state and parameter estimation. (C4) The development of two analytical predictor-corrector guidance techniques for atmospheric entry. The first uses two constant flightpath angle segments in order to meet the terminal altitude, velocity and downrange requirements.