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1

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

2

Experimental setup to demonstrate low-frequency high-precision frequency stabilization of 1550 nm ECL Lasers  

NASA Astrophysics Data System (ADS)

Advances in fiber and waveguide technologies have brought about a new type of laser: the Planar Waveguide External Cavity Laser (PW-ECL) that shows a great potential for precision interferometric measurements. We show an experimental setup based on a 1550nm PW-ECL which was designed to achieve a frequency stabilization of 30 Hz/sqrt(Hz) or less at 10 mHz. The presented design makes use of thermal shielding to suppress temperature fluctuations at low frequencies as well as a vacuum system, high finesse cavity and low-noise electronics to reduce the frequency noise. A description of the components used in the design is given and initial results are presented.

Shoen, Steven; Téllez, Gregorio; Quetschke, Volker

2012-02-01

3

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

4

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

5

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

6

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

Young, K.K.D.

1998-09-22

7

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

8

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

9

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

10

Pitch evaluation of high-precision gratings  

NASA Astrophysics Data System (ADS)

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

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

2014-11-01

11

High Precision Laser Range Sensor  

NASA Technical Reports Server (NTRS)

The present invention is an improved distance measuring interferometer that includes high speed phase modulators and additional phase meters to generate and analyze multiple heterodyne signal pairs with distinct frequencies. Modulation sidebands with large frequency separation are generated by the high speed electro-optic phase modulators, requiring only a single frequency stable laser source and eliminating the need for a fist laser to be tuned or stabilized relative to a second laser. The combination of signals produced by the modulated sidebands is separated and processed to give the target distance. The resulting metrology apparatus enables a sensor with submicron accuracy or better over a multi- kilometer ambiguity range.

Dubovitsky, Serge (Inventor); Lay, Oliver P. (Inventor)

2003-01-01

12

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

13

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

14

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

15

High Precision Dating of Holocene Peat Deposits  

Microsoft Academic Search

Environmental change during the Holocene has often occurred on decadal to centennial time scales. Therefore, there is a need for high precision dating of the peat and sediment deposits which archive environmental change. This presentation is an overview of the state of the art in dating Holocene ombrotrophic peat deposits, and compares the age estimates produced by different methods in

D. Yeloff; K. Bennett; M. Blaauw; F. Chambers; B. van Geel; M. van der Linden; D. Mauquoy; J. van der Plicht; Ü. Sillasoo; P. Toms; J. Newberry; S. Brain

2006-01-01

16

Fiber Scrambling for High Precision Spectrographs  

NASA Astrophysics Data System (ADS)

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

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

2011-05-01

17

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

18

Note: High precision measurements using high frequency gigahertz signals.  

PubMed

Generalized lock-in amplifiers use digital cavities with Q-factors as high as 5 × 10(8) to measure signals with very high precision. In this Note, we show that generalized lock-in amplifiers can be used to analyze microwave (giga-hertz) signals with a precision of few tens of hertz. We propose that the physical changes in the medium of propagation can be measured precisely by the ultra-high precision measurement of the signal. We provide evidence to our proposition by verifying the Newton's law of cooling by measuring the effect of change in temperature on the phase and amplitude of the signals propagating through two calibrated cables. The technique could be used to precisely measure different physical properties of the propagation medium, for example, the change in length, resistance, etc. Real time implementation of the technique can open up new methodologies of in situ virtual metrology in material design. PMID:25554338

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

2014-12-01

19

Adaptive adjustment of a precision truss structure - Experimental validation  

NASA Technical Reports Server (NTRS)

Previous analytical studies have shown the feasibility of using a limited number of active members to adaptively alter the structural shape or behavior to other desired states. As a demonstration of this concept, this paper describes the results of a sequence of validation tests, their correlation with the analytical results, and the problems encountered. An existing full scale, space-erectable, high precision truss structure was used. For the most part, the results showed good agreement with the analysis. However, micron level nonlinearities in the structural behavior were discovered. The significance of the presence of these nonlinearities in precision structures and their impact on the basic premise of adaptivity are discussed.

Salama, M.; Umland, J.; Bruno, R.; Garba, J.

1993-01-01

20

High-precision IR molded lenses  

NASA Astrophysics Data System (ADS)

Umicore IR Glass is a company specialising in the production of chalcogenide glasses and moulded optics. The standard glass compositions are GASIR1 (Ge22As20Se58) and GASIR2 (Ge20Sb15Se65). These materials are transparent in the 3-5 ?m and 8-12 ?m bands. An industrial process has been developed to produce these two glasses with well controlled properties. The reproducibility of refractive index is for example better than 2.0 x 10-4 at 10 ?m. A unique and high precision moulding technology has been developed to produce low cost chalcogenide glass lenses with high performance levels. Spherical, aspherical and asphero-diffractive lenses are manufactured with very accurate surface precision. The form defect of the moulded surfaces can be less than 0.4 ?m with a typical roughness of 10 nm. When depositing an antireflection coating onto the moulded lenses, the reflection losses are reduced, raising the transmission to 98%, compared to 70% for uncoated lenses. A durable coating has also been developed as a protection for exposed lenses. Coated asphero-diffractive GASIR optics, used in infrared cameras give good quality images. The performance is comparable to that of an optical system with aspherical germanium. GASIR offers a cost-effective alternative to germanium for thermal imaging, especially for medium to high volume applications, both commercial and military.

Guimond, Yann M.; Bellec, Yann

2004-02-01

21

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

22

Experimental study on lawn sprinkler for energy-saving and variable range of the precision spraying  

Microsoft Academic Search

For solving the problem of high energy consumption of variable nozzle, the experimental study on lawn sprinkler for energy-saving and variable range of the precision spraying were carried out. In the case of square spraying, the functions of control period between nozzle inlet pressure, converter frequency and time were determined by tests. The motor frequency was regulated by the converter;

Yue Tang; Junping Liu; Yin Luo; Shouqi Yuan

2010-01-01

23

Faculty Position in Ultra High Precision Robotics & Manufacturing  

E-print Network

, manipulation and metrology systems targeting additive manufacturing; · New kinematics, quasi-perfect guidings, actuators, transmission systems, sensors and methods targeting ultra-high precision additive manufacturingFaculty Position in Ultra High Precision Robotics & Manufacturing at the Ecole Polytechnique

Candea, George

24

Scalable Knowledge Harvesting with High Precision and High Recall  

E-print Network

Scalable Knowledge Harvesting with High Precision and High Recall Ndapandula Nakashole, Martin,mtb,weikum}@mpi-inf.mpg.de ABSTRACT Harvesting relational facts from Web sources has received great at- tention for automatically constructing large knowledge bases. State- of-the-art approaches combine pattern-based gathering of fact can

25

Experimental Violation of Heisenberg's Precision Limit by Weak Measurements  

NASA Astrophysics Data System (ADS)

Along with the uncertainty principle, Heisenberg postulated another set of relations, which set a lower limit on the disturbance caused by a measurement [1]. These relations were shown by Ozawa to be inaccurate [2], shedding doubt on widely accepted bounds on the information left in a system after a measurement, and offering new insights into the foundations of quantum physics and quantum information. A theoretical scheme for testing Ozawa's precision-disturbance relations was proposed [3]. In this proposal the hurdle of destructive measurements is addressed by the weak value approach [4]. This scheme is based on a 3-qubit quantum circuit that requires two CNOT gates of variable strength with a common control qubit. Here, we present an experimental realization of Heisenberg's precision limit violation based on weak value measurements. We implement a technique inspired by the one-way quantum computing using entanglement as the substrate for quantum gates. In this way, we demonstrate a violation of Heisenberg's relation for measurement disturbance, confirming the revised bound due to Ozawa. [4pt] [1] Z. Phys. 43 172(1927); [2] Ann. Phys. NY 311 350(2004); [3] New J. Phys. 12 093011(2010); [4] Phys. Rev. Lett. 60 1351(1988)

Darabi, Ardavan; Rozema, Lee A.; Mahler, Dylan H.; Hayat, Alex; Soudagar, Yasaman; Steinberg, Aephraim M.

2012-02-01

26

High Precision Isotopic Reference Material Program  

NASA Astrophysics Data System (ADS)

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

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

2007-12-01

27

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

28

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

29

Precision axial translator with high stability.  

PubMed

We describe a new type of translator which is inherently stable against torsion and twisting. This concentric translator is also ideally suited for precise axial motion with clearance of the center line. PMID:18699660

Bösch, M A

1979-08-01

30

Precision measurements with highly charged ions at rest  

NASA Astrophysics Data System (ADS)

A decelerator will be installed at GSI in order to provide and study bare heavy nuclei or heavy nuclei with only few electrons at very low energies or almost at rest. Stripping at relativistic energies will produce highly charged ions. After electron cooling and deceleration in the experimental storage ring the ions are extracted from the storage ring at 4[thin space]MeV/u and further decelerated in a combination of an IH and four-rod RFQ structure. Finally, they are injected into a Penning trap where the ions are cooled to 4[thin space]K. From this cooler trap, the ions can be transferred in a quasi-continuous or pulsed mode to different experimental setups. High-precision measurements of electronic and nuclear binding energies will be performed in a Penning trap exploring the high charge states. Other key experiments focus on g-factor measurements of the bound electron, precision laser and X-ray spectroscopy, studies of ionic structure, hollow atoms, and ion-surface interaction at very low impact energies.

Herfurth, F.; Beier, Th.; Dahl, L.; Eliseev, S.; Heinz, S.; Kester, O.; Kozhuharov, C.; Maero, G.; Quint, W.

2006-04-01

31

Trapped positrons for high-precision magnetic moment measurements  

NASA Astrophysics Data System (ADS)

A single electron in a quantum cyclotron provides the most precise measurement of the electron magnetic moment, given in units of the Bohr magneton by g/2 = 1.001 159 652 180 73 (28) [0.28 ppt]. The most precise determination of the fine structure constant comes from combining this measurement with Standard Model theory, yielding alpha-1 = 137.035 999 173 (34) [0.25 ppb], limited by the experimental uncertainty of the electron g-value. The most stringent test of CPT symmetry in leptons comes from comparing the electron and positron magnetic moments, limited by the positron uncertainty at 4.2 ppt. A new high-stability apparatus has been built and commissioned for improved measurements of the electron and positron magnetic moments, a greatly improved test of lepton CPT symmetry, and an improved determination of the fine structure constant. These new measurements require robust positron loading from a retractable radioactive source that is small enough to avoid compromising the high-precision environment of our experiment. The design and implementation of such a scheme is a central focus of this work. Robust positron loading at a rate of 1-2 e+/min from a 6.5 muCi 22Na source has been demonstrated.

Hoogerheide, Shannon Michelle Fogwell

32

Experimental High Energy Physics  

E-print Network

Experimental High Energy Physics at the University of Toronto Faculty Members David Bailey Peter-energy physics research today is the culmination of centuries of searching for an understanding of the ultimate nature of matter. Over the last 30 years, the standard model of particle physics has gradually taken

33

High precision attitude determination for Magsat  

NASA Technical Reports Server (NTRS)

A two phase approach to attitude determination software development is introduced. The prelaunch planning and software activities connected with the development and testing of the baseline system for processing nominal attitude data for MAGSAT are described and postlaunch analysis and modifications are outlined. Attitude data processing began 5 months after launch so that postlaunch anomalies could be accounted for. Another advantage of the two phase approach is that costs are reduced because the system is not burdened with software dealing with all possible contingencies. A definitive, continuous, time history of the three axis attitude of the spacecraft was generated to a precision of 20 arc sec (one standard deviation), in each axis. Sensor alignment determinations were done continuously because of the deletrious effects of changing alignments on attitude precision.

Abshire, G.; Mccutcheon, R.; Summers, G.; Vanlandingham, F.; Meyers, G.

1981-01-01

34

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

35

High Precision Noise Measurements at Microwave Frequencies  

SciTech Connect

We describe microwave noise measurement system capable of detecting the phase fluctuations of rms amplitude of 2{center_dot}10{sup -11} rad/{radical}(Hz). Such resolution allows the study of intrinsic fluctuations in various microwave components and materials, as well as precise tests of fundamental physics. Employing this system we discovered a previously unknown phenomenon of down-conversion of pump oscillator phase noise into the low-frequency voltage fluctuations.

Ivanov, Eugene; Tobar, Michael [School of Physics, University of Western Australia, 35 Stirling Hwy., Crawley, 6009, WA (Australia)

2009-04-23

36

Zliding: Fluid Zooming and Sliding for High Precision Parameter Manipulation  

E-print Network

Zliding: Fluid Zooming and Sliding for High Precision Parameter Manipulation Gonzalo Ramos, Ravin precision parameter manipulation tasks typically require adjustment of the scale of manipulation in addition manipulation of scale (zooming) via pressure input while parameter manipulation within that scale is achieved

Balakrishnan, Ravin

37

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

38

High-Precision Spectroscopy of Pulsating Stars  

NASA Astrophysics Data System (ADS)

We review methodologies currently available to interprete time series of high-resolution high-S/N spectroscopic data of pulsating stars in terms of the kind of (non-radial) modes that are excited. We illustrate the drastic improvement of the detection treshold of line-profile variability thanks to the advancement of the instrumentation over the past two decades. This has led to the opportunity to interprete line-profile variations with amplitudes of order m/s, which is a factor 1000 lower than the earliest line-profile time series studies allowed for.

Aerts, C.; Hekker, S.; Desmet, M.; Carrier, F.; Zima, W.; Briquet, M.; De Ridder, J.

39

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

40

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

41

PACKAGE DESIGN FOR HIGH PRECISION MACHINE VISION Wai Hwa Fong  

E-print Network

.............................................................................. 14 Figure 8. Shape of compressive stress-strain curvePACKAGE DESIGN FOR HIGH PRECISION MACHINE VISION SYSTEMS By Wai Hwa Fong A Thesis Submitted........................................................................................... 10 3. RESULTS OF FOAM COMPRESSION TEST........................................................... 15

Shih, Albert J.

42

Galvanometer deflection: a precision high-speed system.  

PubMed

An X-Y galvanometer deflection system capable of high precision in a random access mode of operation is described. Beam positional information in digitized form is obtained by employing a Ronchi grating with a sophisticated optical detection scheme. This information is used in a control interface to locate the beam to the required precision. The system is characterized by high accuracy at maximum speed and is designed for operation in a variable environment, with particular attention placed on thermal insensitivity. PMID:20165203

Jablonowski, D P; Raamot, J

1976-06-01

43

High precision mass measurements for wine metabolomics  

PubMed Central

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. PMID:25431760

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

2014-01-01

44

High-precision camera distortion measurements with a "calibration harp".  

PubMed

This paper addresses the high-precision measurement of the distortion of a digital camera from photographs. Traditionally, this distortion is measured from photographs of a flat pattern that contains aligned elements. Nevertheless, it is nearly impossible to fabricate a very flat pattern and to validate its flatness. This fact limits the attainable measurable precisions. In contrast, it is much easier to obtain physically very precise straight lines by tightly stretching good quality strings on a frame. Taking literally "plumb-line methods," we built a "calibration harp" instead of the classic flat patterns to obtain a high-precision measurement tool, demonstrably reaching 2/100 pixel precisions. The harp is complemented with the algorithms computing automatically from harp photographs two different and complementary lens distortion measurements. The precision of the method is evaluated on images corrected by state-of-the-art distortion correction algorithms, and by popular software. Three applications are shown: first an objective and reliable measurement of the result of any distortion correction. Second, the harp permits us to control state-of-the art global camera calibration algorithms: it permits us to select the right distortion model, thus avoiding internal compensation errors inherent to these methods. Third, the method replaces manual procedures in other distortion correction methods, makes them fully automatic, and increases their reliability and precision. PMID:23201661

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

2012-10-01

45

High precision framework for chaos many-body engine  

NASA Astrophysics Data System (ADS)

In this paper we present a C# 4.0 high precision framework for simulation of relativistic many-body systems. In order to benefit from the, previously developed, chaos analysis instruments, all new modules were integrated with Chaos Many-Body Engine (Grossu et al. 2010, 2013). 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.

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

2014-04-01

46

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

47

The experimental study of a precision parallel manipulator with binary actuation: With application to MRI cancer treatment  

Microsoft Academic Search

In this paper the performance of a high-precision parallel robot manipulator with bistable actuation is experimentally evaluated. The manipulator is for performing prostate cancer biopsy and treatment within the bore of a magnetic resonance imaging (MRI) system. The analysis and simulations have shown that this bistable manipulator is able to perform well with dielectric elastomer actuators that have been shown

Kenjiro Tadakuma; Lauren M. Devita; Jean-sebastien Plante; Yan Shaoze; Steven Dubowsky

2008-01-01

48

Experimental Dynamic Characterization of a Reconfigurable Adaptive Precision Truss  

NASA Technical Reports Server (NTRS)

The dynamic behavior of a reconfigurable adaptive truss structure with non-linear joints is investigated. The objective is to experimentally examine the effects of the local non-linearities on the global dynamics of the structure. Amplitude changes in the frequency response functions are measured at micron levels of motion. The amplitude and frequency variations of a number of modes indicate a non-linear Coulomb friction response. Hysteretic bifurcation behavior is also measured at an amplitude approximately equal to the specified free-play in the joint. Under the 1 g pre-load, however, the non-linearity was dominantly characteristic of Coulomb friction with little evidence of free-play stiffening.

Hinkle, J. D.; Peterson, L. D.

1994-01-01

49

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

50

High-precision thermal and electrical characterization of thermoelectric modules  

NASA Astrophysics Data System (ADS)

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

2014-05-01

51

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

52

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

53

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

54

High channel count and high precision channel spacing multi-wavelength laser array for future PICs  

PubMed Central

Multi-wavelength semiconductor laser arrays (MLAs) have wide applications in wavelength multiplexing division (WDM) networks. In spite of their tremendous potential, adoption of the MLA has been hampered by a number of issues, particularly wavelength precision and fabrication cost. In this paper, we report high channel count MLAs in which the wavelengths of each channel can be determined precisely through low-cost standard ?m-level photolithography/holographic lithography and the reconstruction-equivalent-chirp (REC) technique. 60-wavelength MLAs with good wavelength spacing uniformity have been demonstrated experimentally, in which nearly 83% lasers are within a wavelength deviation of ±0.20?nm, corresponding to a tolerance of ±0.032?nm in the period pitch. As a result of employing the equivalent phase shift technique, the single longitudinal mode (SLM) yield is nearly 100%, while the theoretical yield of standard DFB lasers is only around 33.3%. PMID:25488111

Shi, Yuechun; Li, Simin; Chen, Xiangfei; Li, Lianyan; Li, Jingsi; Zhang, Tingting; Zheng, Jilin; Zhang, Yunshan; Tang, Song; Hou, Lianping; Marsh, John H.; Qiu, Bocang

2014-01-01

55

High channel count and high precision channel spacing multi-wavelength laser array for future PICs  

NASA Astrophysics Data System (ADS)

Multi-wavelength semiconductor laser arrays (MLAs) have wide applications in wavelength multiplexing division (WDM) networks. In spite of their tremendous potential, adoption of the MLA has been hampered by a number of issues, particularly wavelength precision and fabrication cost. In this paper, we report high channel count MLAs in which the wavelengths of each channel can be determined precisely through low-cost standard ?m-level photolithography/holographic lithography and the reconstruction-equivalent-chirp (REC) technique. 60-wavelength MLAs with good wavelength spacing uniformity have been demonstrated experimentally, in which nearly 83% lasers are within a wavelength deviation of +/-0.20 nm, corresponding to a tolerance of +/-0.032 nm in the period pitch. As a result of employing the equivalent phase shift technique, the single longitudinal mode (SLM) yield is nearly 100%, while the theoretical yield of standard DFB lasers is only around 33.3%.

Shi, Yuechun; Li, Simin; Chen, Xiangfei; Li, Lianyan; Li, Jingsi; Zhang, Tingting; Zheng, Jilin; Zhang, Yunshan; Tang, Song; Hou, Lianping; Marsh, John H.; Qiu, Bocang

2014-12-01

56

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

57

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

58

Bounding the Probability of Error for High Precision Recognition  

Microsoft Academic Search

We consider models for which it is important, early in processing, to estimate some variables with high precision, but perhaps at relatively low rates of recall. If some variables can be identified with near certainty, then th ey can be conditioned upon, allowing further inference to be done efficiently. Spe cifically, we consider optical character recognition (OCR) systems that can

Andrew Kae; Gary B. Huang; Erik G. Learned-miller

2009-01-01

59

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

60

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

61

Fiber optic synchronisation architecture for high precision GPS applications  

E-print Network

Fiber optic synchronisation architecture for high precision GPS applications Daniel Macias and the receiver is monitored at the millimetre level [2]. These issues can be solved using optical fiber links), Université Laval, Québec, QC, G1V 0A6, Canada sophie.larochelle@gel.ulaval.ca Abstract: We propose a GPS-over-fiber

Santerre, Rock

62

Low cost robotic imaging system for high precision photometry  

E-print Network

Low cost robotic imaging system for high precision photometry Olivier Guyon (Subaru Telescope (etendue = 1m telescope, 1deg diam FOV) 10" per pixel photon-noise limited on sky background Low cost, use, observe, choose target) Easy to duplicate and upgrade, low cost ­ scalable to multiple units, higher

Guyon, Olivier

63

High-Precision Stellar Photometry with the K2 Mission  

NASA Astrophysics Data System (ADS)

The K2 mission is a repurposed use of the Kepler spacecraft to perform high-precision photometry of selected fields in the ecliptic. We have developed an aperture photometry pipeline for K2 data which performs dynamic automated aperture mask selection, background estimation and subtraction, and positional decorrelation to minimize the effects of spacecraft pointing jitter. Here we describe that pipeline and the photometric precision we are capable of achieving with K2, illustrated by application to Campaign 0 data, and suggest future improvements in our algorithm.

Carboneau, Lindsey; Buzasi, Derek L.; Hessler, Carly; Lezcano, Andy; Preston, Heather L.

2015-01-01

64

GENERATION AND CONTROL OF HIGH PRECISION BEAMS AT LEPTON ACCELERATORS  

SciTech Connect

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

Yu-Chiu Chao

2007-06-25

65

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

66

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

67

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

68

High-precision DEM reconstruction based on airborne LiDAR point clouds  

NASA Astrophysics Data System (ADS)

Airborne LiDAR point clouds have become important data sources for DEM generation recently; however the problem of low precision and low efficiency in DEM production still exists. This paper proposes a new technical scheme for high-precision DEM production based on airborne LiDAR point clouds systematically. Firstly, an elevation and density analysis method is applied to filter out outliers. Secondly, ground points are detected by an improved filter algorithm based on the hierarchical smoothing method. Finally, feature lines are extracted by the planar surface fitting and intersecting method, and a simple data structure of feature lines preserved DEM is proposed to achieve reconstructing high accuracy DEM, combing feature lines with ground points. Experimental results show that the proposed scheme is able to compensate for deficiencies of existing DEM reconstruction techniques and can meet the needs of high precision DEM production based on LiDAR data.

Xu, Jingzhong; Kou, Yuan; Wang, Jun

2014-05-01

69

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

70

High-resolution accelerator-based mass spectrometry: precision, accuracy and background.  

PubMed

Radiocarbon accelerator mass spectrometry (AMS) is a high-sensitivity analysis technique which is nowadays widely used in many research fields such as archaeology, geology, environmental and earth sciences. We report on the features of the new high throughput accelerator mass spectrometer at the University of Lecce, Italy. The experimental apparatus is described and its general characteristics are reported in terms of measurement precision, accuracy and achievable background. PMID:15701419

Calcagnile, L; Quarta, G; D'Elia, M

2005-04-01

71

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

72

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

73

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

74

High precision depolarisation measurements with an opaque test bench  

Microsoft Academic Search

We present a tool to investigate neutron depolarisation effects with 10?4 precision. The test bench consists of two opaque 3He cells with in-situ adiabatic fast passage flipping of the helium spin. The cells polarise a neutron beam to more than 99.99 % and analyse its polarisation with high accuracy. For depolarisation studies, a sample can be inserted between the two

C Klauser; J Chastagnier; D Jullien; A Petoukhov; T Soldner

2012-01-01

75

High-precision mechanical profilometer for grazing incidence optics  

Microsoft Academic Search

A high precision mechanical profilometer (MPROS) has been designed and utilized for metrology on the Advances X-Ray Astrophysics Facility (AXAF) optic program. The instrument serves both as a measure of axial figure during the grinding phase of mirror fabrication and as the AXAF program crosscheck for axial sag error. MPROS has demonstrated an accuracy of 0.25 micrometers P-P over nominally

Joseph R. Cerino; Kristin L. Lewotsky; Robert P. Bourgeois; Thomas E. Gordon

1994-01-01

76

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

77

High-precision temperature control system based on PID algorithm  

Microsoft Academic Search

This system uses 8bit AT89C51 CPU as a core for building a electronic oven temperature control system with high precision, the temperature was changed to voltage signals by the thermal resistor PT1000 and amplified by LM358, then the analog voltage signal is converted to digital data by the AD0809. The PID algorithm was adopted as the software for power and

Jun-hong Yang; Xi-yan Bi

2010-01-01

78

Advanced imaging system for high-precision, high-resolution CCD imaging  

Microsoft Academic Search

The Advanced Imaging System is a slow scan, high precision CCD camera system designed specifically for low noise image acquisition and precise, highly flexible CCD testing and characterization. In addition, the system is designed to allow CCD mosaics to be supported with separate, programmable clock voltages and output amplifier operating points for each device. A high speed digital signal processor

Peter E. Doherty; Gary R. Sims

1991-01-01

79

High precision electrostatic potential calculations for cylindrically symmetric lenses  

SciTech Connect

A method is developed for a potential calculation within cylindrically symmetric electrostatic lenses using mesh relaxation techniques, and it is capable of considerably higher accuracies than currently available. The method involves (i) creating very high order algorithms (orders of 6, 8, and 10) for determining the potentials at points in the net using surrounding point values, (ii) eliminating the effect of the large errors caused by singular points, and (iii) reducing gradients in the high gradient regions of the geometry, thereby allowing the algorithms used in these regions to achieve greater precisions--(ii) and (iii) achieved by the use of telescopic multiregions. In addition, an algorithm for points one unit from a metal surface is developed, allowing general mesh point algorithms to be used in these situations, thereby taking advantage of the enhanced precision of the latter. A maximum error function dependent on a sixth order gradient of the potential is defined. With this the single point algorithmic errors are able to be viewed over the entire net. Finally, it is demonstrated that by utilizing the above concepts and procedures, the potential of a point in a reasonably high gradient region of a test geometry can realize a precision of less than 10{sup -10}.

Edwards, David Jr. [238 Marylyn Lane, Newark, Vermont 05871 (United States)

2007-02-15

80

High-precision spectroscopy of ultracold molecules in an optical lattice  

E-print Network

The study of ultracold molecules tightly trapped in an optical lattice can expand the frontier of precision measurement and spectroscopy, and provide a deeper insight into molecular and fundamental physics. Here we create, image, and probe microkelvin $^{88}$Sr$_2$ molecules in a lattice, and demonstrate precise measurements of molecular parameters as well as coherent control of molecular quantum states using optical fields. We discuss the sensitivity of the system to dimensional effects, a new bound-to-continuum spectroscopy technique for highly accurate binding energy measurements, and prospects for new physics with this rich experimental system.

McGuyer, B H; Iwata, G Z; Tarallo, M G; Grier, A T; Apfelbeck, F; Zelevinsky, T

2015-01-01

81

OPTIMIZING THE PRECISION OF TOXICITY THRESHOLD ESTIMATION USING A TWO-STAGE EXPERIMENTAL DESIGN  

EPA Science Inventory

An important consideration for risk assessment is the existence of a threshold, i.e., the highest toxicant dose where the response is not distinguishable from background. We have developed methodology for finding an experimental design that optimizes the precision of threshold mo...

82

Research into the advanced experimental methods for precision ion stopping range measurements in matter  

Microsoft Academic Search

The article presents the results of the experimental research on precision measurement of total stopping range and energy deposition function of intermediate and heavy ion beams in cold solid matter. The ``thick target'' method proves to be appropriate for this purpose. Two types of detectors were developed which provide an error of the total stopping range measurement of less than

I. E. Bakhmetjev; A. D. Fertman; A. A. Golubev; A. V. Kantsyrev; V. E. Luckjashin; B. Yu. Sharkov; V. I. Turtikov; A. V. Kunin; V. V. Vatulin; N. V. Zhidkov; E. G. Baldina; U. Neuner; J. Wieser; J. Jacoby; D. H. H. Hoffmann

2003-01-01

83

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

84

Automated high precision secondary pH measurements  

NASA Astrophysics Data System (ADS)

A new setup for high precision, automated secondary pH measurements together with a reference measurement procedure has been developed and tested in interlaboratory comparisons using buffers pH 4.005, pH 7.000, and pH 10.012 at 25 °C and 37 °C. Using primary buffers as standards, a standard uncertainty in pH better than 0.005 can be reached. The central measuring device is a one piece, thermostatted cell of PFA (perfluoroalkoxy) with a built-in Hamilton® Single Pore™ Glass electrode. Due to its flow-through principle this device allows pH measurements with low consumption of measurement solutions. The very hydrophobic and smooth PFA as construction material facilitates complete emptying of the cell. Furthermore, the tempering unit affords very precise temperature control and hence contributes to the low target uncertainty of the produced secondary buffer solutions. Use of a symmetric measurement sequence and the two point calibration was sufficient to reach high precision and accuracy.

Bastkowski, F.; Jakobsen, P. T.; Stefan, F.; Kristensen, H. B.; Jensen, H. D.; Kawiecki, R.; Wied, C. E.; Kauert, A.; Seidl, B.; Spitzer, P.; Eberhardt, R.; Adel, B.

2013-04-01

85

Automated high precision secondary pH measurements.  

PubMed

A new setup for high precision, automated secondary pH measurements together with a reference measurement procedure has been developed and tested in interlaboratory comparisons using buffers pH 4.005, pH 7.000, and pH 10.012 at 25?°C and 37?°C. Using primary buffers as standards, a standard uncertainty in pH better than 0.005 can be reached. The central measuring device is a one piece, thermostatted cell of PFA (perfluoroalkoxy) with a built-in Hamilton(®) Single Pore™ Glass electrode. Due to its flow-through principle this device allows pH measurements with low consumption of measurement solutions. The very hydrophobic and smooth PFA as construction material facilitates complete emptying of the cell. Furthermore, the tempering unit affords very precise temperature control and hence contributes to the low target uncertainty of the produced secondary buffer solutions. Use of a symmetric measurement sequence and the two point calibration was sufficient to reach high precision and accuracy. PMID:23635230

Bastkowski, F; Jakobsen, P T; Stefan, F; Kristensen, H B; Jensen, H D; Kawiecki, R; Wied, C E; Kauert, A; Seidl, B; Spitzer, P; Eberhardt, R; Adel, B

2013-04-01

86

Finite element simulation in fabrication of high-precision reflector panels  

NASA Astrophysics Data System (ADS)

Millimeter and sub-millimeter wave observations, however, which largely depend on the instrumentation techniques, provide vital experimental verifications for the theoretical studies of stars formation. To obtain the stronger and more precise radio spectrum signals, high precision reflector panels that are demanded in great amount especially for the large-aperture antenna and antenna-array. Many years, experts have put emphasis on the precise forming of reflector panels. This paper presents the high-precision panels with a sandwich-type construction of one skin-plate and one aluminum backup structural combined with structural adhesive, with high precision modules as the fundamental condition. The skin-plate fit the module well due to its flexible. The structural adhesive, with good flow-ability, automatically compensate the deviations between the skin-plate and the backup structural. In the end, individually shaped sandwich-like panels assemble up the high surface-accuracy reflectors. The internal stress analysis of skin-plate and structural adhesive are of utmost importance. Therefore, several kinds of skin-plate and structural adhesive in different material properties are listed and simulated with finite element method (ANSYS). Based on the simulation results, processing parameters to panel fabrication are determined more efficient and accurate.

Yan, Lei; Chen, Yi

2012-09-01

87

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

88

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

89

Multiple-sensor integration for rapid and high-precision coordinate metrology  

Microsoft Academic Search

The development of a multiple-sensor coordinate measuring system (CMM) is introduced and its applications to automated part localization and rapid surface digitization are experimentally demonstrated. The developed multiple-sensor CMM is characterized by an integrated use of a high-precision CMM equipped with a motorized touch probe, and a 3D active vision system, advanced computational software, and the associated electronics. The 3D

Tzung-Sz Shen; Jianbing Huang; Chia-Hsiang Menq

2000-01-01

90

High precision fundamental constants at the TeV scale  

E-print Network

This report summarizes the proceedings of the 2014 Mainz Institute for Theoretical Physics (MITP) scientific program on "High precision fundamental constants at the TeV scale". The two outstanding parameters in the Standard Model dealt with during the MITP scientific program are the strong coupling constant $\\alpha_s$ and the top-quark mass $m_t$. Lacking knowledge on the value of those fundamental constants is often the limiting factor in the accuracy of theoretical predictions. The current status on $\\alpha_s$ and $m_t$ has been reviewed and directions for future research have been identified.

S. Moch; S. Weinzierl; S. Alekhin; J. Blumlein; L. de la Cruz; S. Dittmaier; M. Dowling; J. Erler; J. R. Espinosa; J. Fuster; X. Garcia i Tormo; A. H. Hoang; A. Huss; S. Kluth; M. Mulders; A. S. Papanastasiou; J. Piclum; K. Rabbertz; C. Schwinn; M. Schulze; E. Shintani; P. Uwer; N. Zerf

2014-05-19

91

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

92

High-precision wide-dynamic-range WCE wavefront sensor  

NASA Astrophysics Data System (ADS)

A temporal carrier frequency shearing interferometer was designed and fabricated for Kaman Aerospace to support the Space Shuttle based Wavefront Control Experiment (WCE). This platform and the intended experiments placed many constraints (weight, size, power, sensitivity, etc.) on the sensor design process. The sensor resulting from this design meets all requirements by using a rotating crossed log spiral grating and PMT detectors to achieve both a large tilt range and high precision. A measurement dynamic range of 1340:1 is obtained at 3875 wavefronts per second and the sensor is shot noise limited over 5 decades of signal.

Horwitz, Bruce A.

1992-01-01

93

The Texas High-Precision Radial-Velocity Program  

NASA Astrophysics Data System (ADS)

The University of Texas program for the measurement of high precision stellar radial velocity variations has expanded considerably during the past few years, and now comprises four separate efforts: 1) The McDonald Observatory Planet Search (MOPS) program, using the coude spectrograph of the 2.7m Harlan Smith Telescope, now has eleven years of data. In addition to the companion to 16 Cygni B, several of the program stars are showing interesting variations, and may eventually be shown to have substellar companions. 2) The ESO Planet Search (ESOPS), using an I2 collaboration with Martin Kurster, Konrad Dennerl and Stefan Dobereiner, was the first high precision Southern Hemisphere radial velocity survey. This program now has accumulated five years of data on 37 target stars. Results on interesting objects, such as Proxima Centauri, will be shown. 3) In 1996 we started a search for substellar companions to Hyades dwarfs, using the Keck 1 HIRES spectrograph and I2 cell. The Hyades provide a homogeneous sample of stars formed at the same time with the same composition. The goal of this program is to determine the dependence of planet formation on the one remaining independent variable in the sample, the stellar mass. 4) The Hobby Eberly Telescope is now in the middle of its scientific commissioning. Its high resolution spectrograph will be installed in the fall of 1998. This queue scheduled telescope is an ideal facility to use for a detailed survey of a broad sample of stars in the solar neighborhood.

Cochran, W. D.; Hatzes, A. P.

94

Experimental Study on the Precise Orbit Determination of the BeiDou Navigation Satellite System  

PubMed Central

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

95

High precision depolarisation measurements with an opaque test bench  

NASA Astrophysics Data System (ADS)

We present a tool to investigate neutron depolarisation effects with 10-4 precision. The test bench consists of two opaque 3He cells with in-situ adiabatic fast passage flipping of the helium spin. The cells polarise a neutron beam to more than 99.99 % and analyse its polarisation with high accuracy. For depolarisation studies, a sample can be inserted between the two cells and its effect on a primarily highly polarised beam is analysed. The test bench has been validated at the cold neutron beam PF1B at Institut Laue-Langevin, France. We present here preliminary results for the wavelength range from 5Å to 7Å. Polarisation with super mirrors is limited to about 99.7%. Direct evidence of depolarisation in the order of 10-3 in polarising super mirrors was found by the test bench.

Klauser, C.; Chastagnier, J.; Jullien, D.; Petoukhov, A.; Soldner, T.

2012-02-01

96

Highly Precise Measurement of HIV DNA by Droplet Digital PCR  

PubMed Central

Deoxyribonucleic acid (DNA) of the human immunodeficiency virus (HIV) provides the most sensitive measurement of residual infection in patients on effective combination antiretroviral therapy (cART). Droplet digital PCR (ddPCR) has recently been shown to provide highly accurate quantification of DNA copy number, but its application to quantification of HIV DNA, or other equally rare targets, has not been reported. This paper demonstrates and analyzes the application of ddPCR to measure the frequency of total HIV DNA (pol copies per million cells), and episomal 2-LTR (long terminal repeat) circles in cells isolated from infected patients. Analysis of over 300 clinical samples, including over 150 clinical samples assayed in triplicate by ddPCR and by real-time PCR (qPCR), demonstrates a significant increase in precision, with an average 5-fold decrease in the coefficient of variation of pol copy numbers and a >20-fold accuracy improvement for 2-LTR circles. Additional benefits of the ddPCR assay over qPCR include absolute quantification without reliance on an external standard and relative insensitivity to mismatches in primer and probe sequences. These features make digital PCR an attractive alternative for measurement of HIV DNA in clinical specimens. The improved sensitivity and precision of measurement of these rare events should facilitate measurements to characterize the latent HIV reservoir and interventions to eradicate it. PMID:23573183

Strain, Matthew C.; Lada, Steven M.; Luong, Tiffany; Rought, Steffney E.; Gianella, Sara; Terry, Valeri H.; Spina, Celsa A.; Woelk, Christopher H.; Richman, Douglas D.

2013-01-01

97

Highly precise measurement of HIV DNA by droplet digital PCR.  

PubMed

Deoxyribonucleic acid (DNA) of the human immunodeficiency virus (HIV) provides the most sensitive measurement of residual infection in patients on effective combination antiretroviral therapy (cART). Droplet digital PCR (ddPCR) has recently been shown to provide highly accurate quantification of DNA copy number, but its application to quantification of HIV DNA, or other equally rare targets, has not been reported. This paper demonstrates and analyzes the application of ddPCR to measure the frequency of total HIV DNA (pol copies per million cells), and episomal 2-LTR (long terminal repeat) circles in cells isolated from infected patients. Analysis of over 300 clinical samples, including over 150 clinical samples assayed in triplicate by ddPCR and by real-time PCR (qPCR), demonstrates a significant increase in precision, with an average 5-fold decrease in the coefficient of variation of pol copy numbers and a >20-fold accuracy improvement for 2-LTR circles. Additional benefits of the ddPCR assay over qPCR include absolute quantification without reliance on an external standard and relative insensitivity to mismatches in primer and probe sequences. These features make digital PCR an attractive alternative for measurement of HIV DNA in clinical specimens. The improved sensitivity and precision of measurement of these rare events should facilitate measurements to characterize the latent HIV reservoir and interventions to eradicate it. PMID:23573183

Strain, Matthew C; Lada, Steven M; Luong, Tiffany; Rought, Steffney E; Gianella, Sara; Terry, Valeri H; Spina, Celsa A; Woelk, Christopher H; Richman, Douglas D

2013-01-01

98

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

99

High-precision x-ray spectroscopy in few-electron ions  

NASA Astrophysics Data System (ADS)

The experimental and spectrum analysis procedures that led to about 15 new, high-precision, relative x-ray line energy measurements are presented. The measured lines may be used as x-ray reference lines in the 2.4-3.1 keV range. Applications also include tests of the atomic theory, and in particular of quantum electrodynamics and of relativistic many-body theory calculations. The lines originate from 2- to 4-electron ions of sulfur (Z=16), chlorine (Z=17) and argon (Z=18). The precision reached for their energy ranges from a few parts per million (ppm) to about 50 ppm. This places the new measurements among the most precise performed in mid-Z highly charged ions (Z is the nuclear charge number). The elements of the experimental setup are described: the ion source (an electron cyclotron resonance ion trap), the spectrometer (a single, spherically bent crystal spectrometer), as well as the spectrum acquisition camera (low-noise, high-efficiency CCD). The spectrum analysis procedure, which is based on a full simulation of the spectrometer response function, is also presented.

LeBigot, E. O.; Boucard, S.; Covita, D. S.; Gotta, D.; Gruber, A.; Hirtl, A.; Fuhrmann, H.; Indelicato, P.; dos Santos, J. M. F.; Schlesser, S.; Simons, L. M.; Stingelin, L.; Trassinelli, M.; Veloso, J. F. C. A.; Wasser, A.; Zmeskal, J.

2009-05-01

100

High-Precision Mass Measurements of Radionuclides with Penning Traps  

NASA Astrophysics Data System (ADS)

The mass of an atom is directly related to the binding energy of all its constituents. Thus, it provides information about all the interactions inside the atom. High-precision mass measurements hence allow studies of fundamental interactions and are of great importance in many different fields in physics. The masses of radionuclides provide information on their stability and their structure and are therefore of particular interest for nuclear structure investigations and as input for nucleosynthesis models in nuclear astrophysics. Penning trap mass spectrometry provides masses of radionuclides with unprecedented accuracies on the order of 10^{-8} and can nowadays be applied even to nuclides with short half-lives and low production rates. Utilizing advanced ion manipulation techniques radionuclides from essentially all elements produced in a broad range of nuclear reactions can be accessed. In this chapter the standard procedures of on-line Penning trap mass spectrometry are introduced and some representative examples of recent mass measurements are given.

Block, Michael

101

High-precision mechanical profilometer for grazing incidence optics  

NASA Astrophysics Data System (ADS)

A high precision mechanical profilometer (MPROS) has been designed and utilized for metrology on the Advances X-Ray Astrophysics Facility (AXAF) optic program. The instrument serves both as a measure of axial figure during the grinding phase of mirror fabrication and as the AXAF program crosscheck for axial sag error. MPROS has demonstrated an accuracy of 0.25 micrometers P-P over nominally 1 meter of travel. The design is relatively simple, employing Hewlett Packard distance measuring interferometers, an air bearing slide, and coated Zerodur reference surface. This paper will present the AXAF axial metrology requirements, MPROS design, and reference surface calibration. System performance and results will be presented and discussed.

Cerino, Joseph R.; Lewotsky, Kristin L.; Bourgeois, Robert P.; Gordon, Thomas E.

1994-09-01

102

Thermal-mechanical behavior of high precision composite mirrors  

NASA Technical Reports Server (NTRS)

Composite mirror panels were designed, constructed, analyzed, and tested in the framework of a NASA precision segmented reflector task. The deformations of the reflector surface during the exposure to space enviroments were predicted using a finite element model. The composite mirror panels have graphite-epoxy or graphite-cyanate facesheets, separated by an aluminum or a composite honeycomb core. It is pointed out that in order to carry out detailed modeling of composite mirrors with high accuracy, it is necessary to have temperature dependent properties of the materials involved and the type and magnitude of manufacturing errors and material nonuniformities. The structural modeling and analysis efforts addressed the impact of key design and materials parameters on the performance of mirrors.

Kuo, C. P.; Lou, M. C.; Rapp, D.

1993-01-01

103

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

104

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

105

DEVELOPMENT AND TESTING OF A NOVEL HIGH-PRECISION STEADY FLOW INSTRUMENT FOR UNSATURATED SOILS  

Microsoft Academic Search

This study is concerned with the development of a novel high-precision steady flow instrument applicable to common unsaturated soils such as clay, silt, sand, gravel soil and soft soil. The instrument consists of three parts: high-precision water pressure control system, high-precision air pressure control system and high-precision measurement system. Stepping motor was chosen as the source of water pressure power

Yong Sang; Longtan Shao; Xiaoxia Guo

2011-01-01

106

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

107

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

108

Silicon Avalanche Pixel Sensor for High Precision Tracking  

E-print Network

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 a large 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 ...

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

2013-01-01

109

A Computer Controlled Precision High Pressure Measuring System  

NASA Astrophysics Data System (ADS)

A microcontroller (AT89C51) based electronics has been designed and developed for high precision calibrator based on Digiquartz pressure transducer (DQPT) for the measurement of high hydrostatic pressure up to 275 MPa. The input signal from DQPT is converted into a square wave form and multiplied through frequency multiplier circuit over 10 times to input frequency. This input frequency is multiplied by a factor of ten using phased lock loop. Octal buffer is used to store the calculated frequency, which in turn is fed to microcontroller AT89C51 interfaced with a liquid crystal display for the display of frequency as well as corresponding pressure in user friendly units. The electronics developed is interfaced with a computer using RS232 for automatic data acquisition, computation and storage. The data is acquired by programming in Visual Basic 6.0. This system is interfaced with the PC to make it a computer controlled system. The system is capable of measuring the frequency up to 4 MHz with a resolution of 0.01 Hz and the pressure up to 275 MPa with a resolution of 0.001 MPa within measurement uncertainty of 0.025%. The details on the hardware of the pressure measuring system, associated electronics, software and calibration are discussed in this paper.

Sadana, S.; Yadav, S.; Jha, N.; Gupta, V. K.; Agarwal, R.; Bandyopadhyay, A. K.; Saxena, T. K.

2011-01-01

110

A High-Speed and High-Precision Position Control Using Sliding Mode Compensator  

NASA Astrophysics Data System (ADS)

To achieve high-speed and high-precision position control for semiconductor product machines and industrial robots, the full-closed feedback control is applied. Many control methods have been proposed for such a system. In general, P,PI/I-PI control which is one of PID control is applied to a lot of industrial applications. However, in case of changing mechanical characters of control target, the parameters of P,PI/I-PI control have to be changed for keeping a good motion performance. In this paper, we propose a new P,PI/I-P control method which is with nonlinear compensator. The algorithm of nonlinear compensator is based on sliding mode control with chattering compensation. The effectiveness of proposed control method is evaluated by using full-closed single axis slider system via point to point control and contour control in the case of changing load. From the experimental results, the proposed control method has robustness in the case of changing acceleration/deceleration of control reference, changing load and low velocity contouring motion.

Tsuruta, Kazuhiro; Sato, Kazuya; Ushimi, Nobuhiro; Fujimoto, Takashi

111

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

112

Interferometric apparatus for ultra-high precision displacement measurement  

NASA Technical Reports Server (NTRS)

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

Zhao, Feng (Inventor)

2004-01-01

113

The Belle II pixel detector: High precision with low material  

NASA Astrophysics Data System (ADS)

An upgrade of the existing Japanese flavor factory (KEKB in Tsukuba, Japan) is under construction, and foreseen for commissioning by the end of 2014. This new e+e- machine (“SuperKEKB”) will deliver an instantaneous luminosity of 8×1035 cm-2 s-1, which is 40 times higher than the world record set by KEKB. In order to be able to fully exploit the increased number of events and provide high precision measurements of the decay vertex of the B meson systems in such a harsh environment, the Belle detector will be upgraded (“Belle II”) and a new silicon vertex detector, based on the DEPFET technology, will be designed and constructed. The new pixel detector, close to the interaction point, will consist on two layers of DEPFET active pixel sensors. This technology combines the detection together with the in-pixel amplification by the integration, on every pixel, of a field effect transistor into a fully depleted silicon bulk. In Belle II, DEPFET sensors thinned down to 75 ?m with low power consumption and low intrinsic noise will be used.

Marinas, C.

2013-12-01

114

[High-precision wavelength calibration of wide-band monochromator].  

PubMed

Usually the monochromator is used to output monochromatic light to calibrate the space remote sensing spectrometer. In the present paper, the confidence of space remote sensing spectrometer is used as a standard to evaluate the precision of wide-band monochromator wavelength calibration. Through analysis of the accuracy of the instrument, the monochromator wavelength repeatability error and deviations was obtained respectively. And the intrinsic spectrum of the high pressure mercury lamp and the grating diffraction was used as calibration lines to avoid the error caused by replacing the light source. Through the special method of wavelength calibration to shorten the scan time, the Gaussian fitting was used to look for peaks of wavelength to reduce error. Finally, the relationship derived from polynomial fitting to measure the exact wavelengths' accuracy of the monochromator and calculate the calibration confidence of the space remote sensing spectrometer. Using this method, we can make wavelength accuracy of the 1.5 M monochromator with wavelength band from 200 to 840 nm to reach to +/- 0.016 nm, then the confidence of the space remote sensing spectrometer can reach to 99.82%. PMID:23285905

Zhang, Zi-Hui; Wang, Shu-Rong; Huang, Yu; Li, Bo; Yu, Xiang-Yang; Lin, Guan-Yu

2012-10-01

115

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

116

High-precision VLBI astrometry of radio-emitting stars  

NASA Astrophysics Data System (ADS)

Multiple-epoch phase-referenced VLBI observations of 11 radio-emitting stars have been conducted as part of an astrometric program to link the Hipparcos optical reference frame to the radio extragalactic reference frame. We present the VLBI positions, proper motions and trigonometric parallaxes from this program in the ICRF (International Celestial Reference Frame). These astrometric parameters are absolute because they are directly measured relative to the distant quasars used as VLBI phase reference calibrators. The mean astrometric precision achieved relative to the calibrators is 0.36 milliarcsecond and the highest precision is for the RS CVn close binary sigma (2) CrB with formal uncertainties of 0.12 milliarcsecond for its relative position, 0.05 milliarcsecond for its annual proper motion and 0.10 milliarcsecond for its trigonometric parallax. In addition to the Hipparcos link, these observations have provided several new results. The distance to the nearby Tau-Auriga star forming region is 148 +/- 5 pc, determined directly through the VLBI trigonometric parallax of the Pre-Main-Sequence star HD283447 of this region. The orthogonality of the 2 orbital planes in the ternary system Algol is supported by new astrometric evidences. The proper motions of HR5110, HR1099 and IM Peg, regarded as possible guide stars for the NASA Gravity Probe B space mission, have formal precisions of 0.16, 0.31 and 0.40 milliarcsecond per year, respectively, and the mission requirement is 0.15 milliarcsecond per year. The close binary UX Ari is the only star that exhibits an acceleration larger than 3sigma and the most plausible cause is the gravitational interaction of a third body. The distances of the stars HD199178, IM Peg and AR Lac were uncertain by as much as 50% before our observations and are now 116 +/- 4, 97 +/- 6, 41.7 +/- 0.6 pc, respectively. The two X-ray binaries in our program, LSI61303 and Cyg X1, exhibit larger than expected post-fit position residuals. The linear scale of the rms of these residuals is > 10(13) cm, more than 10 times the stellar separations in these systems. For LSI 61303, this scale is consistent with the size of the free-free absorption region of the enshrouding material beyond which radio radiation can escape. This would argue for in situ acceleration of the energetic electrons responsible for the synchrotron emission detected by VLBI as proposed by Vestrand (1983). The space velocities of LSI 61303 and Cyg X1 determined with our VLBI proper motions, radial velocities and distances, are 58 +/- 6 and 70 +/- 3 km s(-1) , respectively, and are relatively high. This is expected if a neutron star or a black hole lurk in these systems.

Lestrade, J.-F.; Preston, R. A.; Jones, D. L.; Phillips, R. B.; Rogers, A. E. E.; Titus, M. A.; Rioja, M. J.; Gabuzda, D. C.

1999-04-01

117

High Precision 40K/39K Ratio Determination  

NASA Astrophysics Data System (ADS)

Potassium is one of the eight most abundant chemical elements in the Earth's crust and a major element in many rock-forming minerals. The isotope 40K is radioactive and undergoes ?- decay to 40Ca (ca. 89.3%) and electron capture to 40Ar (ca. 10.7%). Both decays can potentially be used as dating systems. The most commonly used branch is the decay of 40K to 40Ar because it can yield highly precise ages. Both decay schemes rely on the knowledge of the 40K branching ratio and the natural 40K abundance. A 40K abundance of 0.011672±41 % was measured on terrestrial material [1]. The relative uncertainty of 0.35 % has not been improved since. Recent improvements in the precision of mass spectrometric measurements have led to the situation that the uncertainties on the K decay constant and the abundance of 40K are a major source of uncertainty on the measured ages. A more precise definition of the 40K decay constant was attempted by different research groups within the last decade [2-9] but the goal of obtaining 0.1 % relative uncertainty on K-Ar ages for geological materials, as requested by the EARTHtime initiative, has not been achieved yet. In order to improve on this situation we studied the abundances of the K isotopes in terrestrial standards. A ThermoFischer Triton+ thermal ionisation mass spectrometer was used for K isotope ratio measurements of the NIST SRM 918b K standard loaded on Ta filaments with 0.1M phosphoric acid. Three techniques were applied: (A) dynamic measurement with in-run normalisation to the IUPAC value 41K/39K=0.072168; (B) a simple total evaporation procedure; (C) the "NBL-modified" total evaporation [10]. The 40K ion beam was measured in a Faraday cup with a 1E12 ? resistor; 39K and 41K were collected in Faraday cups with 1E11 ? resistors. Amplifier gains were intercalibrated by supplying fixed voltages off-line. Different measurement techniques were combined with different loading procedures. We also tested ionisation yields for the evaporation procedures (B) and (C). Our measured 40K/39K ratios are statistically indistinguishable from those reported by [1] but have lower uncertainties. Techniques A, B and C gave 1 standard error of 0.07 %, 0.2 %, and 0.14 %, respectively. 1. Garner E.L. et al. (1975) J.Res.Natl.Bur.Stand.79A, 713-725. 2. Grau Malonda A., Grau Carles A. (2002) Appl. Radiat. Isot. 56, 153-156. 3. Kossert K., Günter E. (2004) Appl.Radiat.Isot.60, 459-464. 4. Krumrei T.V. et al. (2006) Chem.Geol. 227, 258-273. 5. Kwon J. et al. (2002) Math.Geol. 34, 457-475. 6. Min K. et al. (2000) Geochim. Cosmochim. Acta 64, 73-98. 7. Nägler T.F., Villa I.M. (2000) Chem. Geol. 169, 5-16. 8. Renne P.R. et al. (2010) Geochim. Cosmochim. Acta 74, 5349-5367. 9. Schwarz W.H. et al. (2011) Geochim. Cosmochim. Acta 75, 5094-5096. 10. Richter S., Goldberg S.A. (2003) Int. J. Mass Spect. 229, 181-197.

Naumenko, M. O.; Mezger, K.; Nagler, T. F.; Villa, I. M.

2012-12-01

118

HIGH-PRECISION ASTROMETRY WITH A DIFFRACTIVE PUPIL TELESCOPE  

SciTech Connect

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

Guyon, Olivier; Eisner, Josh A.; Angel, Roger; Woolf, Neville J. [Steward Observatory, University of Arizona, Tucson, AZ 85721 (United States); Bendek, Eduardo A.; Milster, Thomas D. [College of Optical Sciences, University of Arizona, Tucson, AZ 85721 (United States); Mark Ammons, S. [Lawrence Livermore National Laboratory, Physics Division L-210, 7000 East Ave., Livermore, CA 94550 (United States); Shao, Michael; Shaklan, Stuart; Levine, Marie; Nemati, Bijan [Jet Propulsion Laboratory, 4800 Oak Grove Drive, Pasadena, CA 91109 (United States); Pitman, Joe [Exploration Sciences, P.O. Box 24, Pine, CO 80470 (United States); Woodruff, Robert A. [2081 Evergreen Avenue, Boulder, CO 80304 (United States); Belikov, Ruslan, E-mail: guyon@naoj.org [NASA Ames Research Center, Moffett Field, CA 94035 (United States)

2012-06-01

119

J. metamorphic Geol., 2000, 18, 665681 High-precision geothermobarometry across the High Himalayan  

E-print Network

J. metamorphic Geol., 2000, 18, 665­681 High-precision geothermobarometry across the High Himalayan metamorphic sequence, Langtang Valley, Nepal G. FRASER,1* B. WORLEY2 AND M. SANDIFORD2 1Department of Geology recognized features of Himalayan geology is the apparent inversion of metamorphic sequences, as evidenced

Sandiford, Mike

120

Design and characteristics of a high-precision chopper wheel motor driver Xi Bin Gu and Ying Guo  

E-print Network

-stability chopper wheel motor driver are presented. Experimental results show that this unit can be interfaced a 75A1004-2 Globe Motor in the frequency range from 50 to 400 Hz--a typical unit operated in variousDesign and characteristics of a high-precision chopper wheel motor driver Xi Bin Gu and Ying Guo

Kaiser, Ralf I.

121

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

122

High precision measurements for the rp-process  

NASA Astrophysics Data System (ADS)

The explosive nuclear burning of hydrogen at high temperatures and densities on the surface of accreting neutron stars, known as the rp-process, gives rise to a number of observable phenomena related to X-ray bursts. Recent astronomical observations provide unprecedented information, e.g. on atomic abundances in ejecta and time structure in X-ray bursts. To interpret these data requires an understanding of the nuclear processes during the explosive events and, therefore, information on the structure of unstable, proton-rich nuclei. Network model calculations show that the dominant burning processes, after breakout from the hot CNO cycles at sufficiently high temperatures, proceed via proton- and ?-induced reactions. Since the reaction rates are very sensitive to the nuclear structure, shell- and statistical-model calculations are often insufficient in predicting exact reaction paths. Therefore, we have been conducting experiments using high-resolution spectrometers to search for resonances that play a role in the rp-process and determine the nuclear-structure, most importantly excitation energies, accurately above the particle thresholds. The techniques and examples of experimental results will be presented and discussed. The status and outlook of direct measurements of stellar reactions rates in inverse kinematics using planned recoil separators will be outlined.

Berg, G. P. A.; Fujita, Y.; Görres, J.; Harakeh, M. N.; Hatanaka, K.; Long, A.; Neveling, R.; Smit, F. D.; Talwar, R.; Tamii, A.; Wiescher, M.

2012-09-01

123

Precision Experiments With Stored And Cooled Highly Charged Ions  

NASA Astrophysics Data System (ADS)

Accumulation, storing and cooling techniques play an increasingly important role in many areas of science. These procedures can be applied in Penning traps and storage rings to ions. In this way, quantum electrodynamics can be tested in extreme electromagnetic fields by measuring hyperfine structure splittings. Lamb shifts, or g-factors in hydrogen-like heavy systems such as U91+ or Pb81+. In addition, fundamental constants or nuclear properties like the atomic mass can be determined. In the case of a radioactive ion, the fate of an individual ion, undergoing a nuclear decay, can be studied in detail by observing the disappearance of the signal of the mother and the appearance of that of the daughter isotope. Presently, the Highly-charged Ion TRAP (HITRAP) facility is being built up at GSI. Stable or radioactive highly charged ions are produced by colliding relativistic ions with a target. After electron cooling and deceleration in the storage ring ESR at GSI, these ions are ejected, decelerated further, and injected into a Penning trap where cooling to 4 K takes place. From there, the cooled highly charged ions such as hydrogen-like uranium are transferred at low energy to different experimental set-ups which are being built up by the international HITRAP Collaboration.

Kluge, H.-Jürgen

2006-11-01

124

Derivative properties from high-precision equations of state.  

PubMed

In this study, the behavior of derivative properties estimated by equations of state, including isochoric heat capacity, isobaric heat capacity, speed of sound, and the Joule-Thomson coefficient for pure compounds and a mixture, has been investigated. The Schmidt-Wagner and Jacobsen-Stewart equations of state were used for predictions of derivative properties of 10 different pure compounds from various nonpolar hydrocarbons, nonpolar cyclic hydrocarbons, polar compounds, and refrigerants. The estimations were compared to experimental data. To evaluate the behavior of mixtures, the extended corresponding states principle (ECS) was studied. Analytical relationships were derived for isochoric heat capacity, isobaric heat capacity, the Joule-Thomson coefficient, and the speed of sound. The ECS calculations were compared to the reference surface data of methane + ethane. The ECS principle was found to generate data of high quality. PMID:25347617

Haghbakhsh, Reza; Konttorp, Morten; Raeissi, Sona; Peters, Cor J; O'Connell, John P

2014-12-11

125

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

126

High-precision measurement of chlorine stable isotope ratios  

USGS Publications Warehouse

We present an analysis procedure that allows stable isotopes of chlorine to be analyzed with precision sufficient for geological and hydrological studies. The total analytical precision is ?????0.09%., and the present known range of chloride in the surface and near-surface environment is 3.5???. As Cl- is essentially nonreactive in natural aquatic environments, it is a conservative tracer and its ??37Cl is also conservative. Thus, the ??37Cl parameter is valuable for quantitative evaluation of mixing of different sources of chloride in brines and aquifers. ?? 1993.

Long, A.; Eastoe, C.J.; Kaufmann, R.S.; Martin, J.G.; Wirt, L.; Finley, J.B.

1993-01-01

127

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

128

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

129

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

130

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

131

Precision measurements of spin interactions with high density atomic vapors  

NASA Astrophysics Data System (ADS)

Polarized atomic vapors can be used to detect fields interacting with a spin. Recent advances have extended the sensitivity of atomic magnetometers to a level favorable for fundamental physics research, and in many cases the sensitivity approaches quantum metrology limits. In this thesis, we present a high density atomic K-3He comagnetometer, which features suppressed sensitivity to magnetic fields, but retains sensitivity to anomalous fields that couple differently than a magnetic field to electron and nuclear spins. The comagnetometer was used to measure interactions with a separate optically pumped 3He nuclear spin source. The 3He spin precession frequency in the comagnetometer was measured with a resolution of 18 pHz over the course of approximately one month, enabling us to constrain the anomalous spin-spin interaction between neutrons to be less than 2.5 x 10-8 of their magnetic or less than 2 x 10-3 of their gravitational interaction at a length scale of 50 cm. We set new laboratory bounds on the coupling strength of light pseudoscalar, vector and pseudovector particles to neutrons, and we consider the implications of our measurement to recently proposed models for unparticles and Goldstone bosons from spontaneous breaking of Lorentz symmetry. We also describe theoretically and experimentally a quantum non-demolition (QND) measurement of atomic spin in the context of radio frequency magnetometer with hot alkali-metal vapors. Using stroboscopic probe light we demonstrate suppression of the probe back-action on the measured observable, which depends on the probe duty cycle and on the detuning of the probe modulation frequency from twice the alkali Larmor frequency. We study the dependence of spin-projection noise on the polarization for atoms with spin greater than 1/2 and develop a theoretical model that agrees well with the data. Finally, it is shown theoretically that QND measurements can improve the long-term sensitivity of atomic magnetometers with non-linear relaxation.

Vasilakis, Georgios

2011-12-01

132

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

133

High Precision PSD Guided Robot Localization: Design, Mapping, and Position Control  

E-print Network

that need to be fulfilled (e.g. assembly in the semiconductor indus- try or robot assisted medical surgeryHigh Precision PSD Guided Robot Localization: Design, Mapping, and Position Control Sebastian Blank developed high precision robot localization system employing position sensitive detectors (PSD). A lateral

Berns, Karsten

134

High-precision control of piezoelectric nanopositioning stages using hysteresis compensator and disturbance observer  

NASA Astrophysics Data System (ADS)

This paper proposes a novel high-performance control scheme with hysteresis compensator and disturbance observer for high-precision motion control of a nanopositioning stage driven by a piezoelectric stack actuator (PSA). In the developed control scheme, a real-time inverse hysteresis compensator (IHC) with the modified Prandtl-Ishlinskii model is firstly designed to compensate for the asymmetric hysteresis nonlinearity of the PSA. Due to the imperfect compensation, the dynamics behaviors of the PSA-actuated stage with the IHC can be treated as a linear dynamic system plus a lumped disturbance term. Owing to the unknown nature of this lumped disturbance term, a disturbance observer (DOB) is used as a means for disturbance rejection. With the DOB, a tracking controller is finally designed and implemented to stabilize the position error. To verify the proposed control scheme, a real-time experimental platform with a PSA-actuated nanopositioning stage is built, and extensive experimental tests are performed. The comparative experimental results demonstrate the effectiveness and improved performance of the developed control approach in terms of the maximum-value errors, root-mean-square-value errors and hysteresis compensation.

Gu, Guo-Ying; Zhu, Li-Min; Su, Chun-Yi

2014-10-01

135

Applied high resolution digital control for universal precision systems  

E-print Network

This thesis describes the design and characterization of a high-resolution analog interface for dSPACE digital control systems and a high-resolution, high-speed data acquisition and control system. These designs are intended ...

Gawlik, Aaron John

2008-01-01

136

Rotor crack detection based on high-precision modal parameter identification method and wavelet finite element model  

NASA Astrophysics Data System (ADS)

In this paper, a new method based on high-precision modal parameter identification method and wavelet finite element (WFE) model is presented to determine the depth and location of a transverse surface crack in a rotor system. The rotor system is modeled using finite element method of B-spline wavelet on the interval (FEM BSWI), while the crack is equivalent as a weightless rotational spring. Additionally, a novel method based on empirical mode decomposition (EMD) and Laplace wavelet is proposed to acquire modal parameters with high precision, which is implemented to improve the precision of crack identification. By providing the first three natural frequencies, contours for the specified natural frequency are plotted in the same coordinate, and the intersection of the three curves predicts the crack location and size. The experimental results indicate that the proposed method can accurately identify the position and depth of different cracks. The effectiveness and reliability of the proposed method is verified.

Dong, H. B.; Chen, X. F.; Li, B.; Qi, K. Y.; He, Z. J.

2009-04-01

137

Precision compression molding of glass microlenses and microlens arrays--an experimental study.  

PubMed

An innovative manufacturing process utilizing high-temperature compression molding to fabricate aspherical microlenses by using optical glasses, such as BK7, K-PG325, and soda-lime glass, is investigated. In a departure from conventional approaches, a unique hollow contactless mold design is adopted. Polished glass substrates and the mold assembly are heated above the glass transition temperature first, followed by initial forming, then annealing. The forming rate is controlled in real time to ensure mold position accuracy. Mold materials used include tungsten carbides, 316 stainless steel, 715 copper nickel, and aluminum alloys. The geometric control of the microlenses or microlens arrays can be precisely controlled by the forming temperature, forming speed, mold design, and annealing time. PMID:16237925

Firestone, G C; Yi, A Y

2005-10-10

138

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

139

BAM: A metrology device for a high precision astrometric mission  

NASA Astrophysics Data System (ADS)

Gaia is ESA next-generation astrometric space mission, that will be launched in December 2013. The main objective of Gaia is to produce an astrometric census of one billion objects down to the 20th magnitude. The level of astrometric precision will be around the 10 microarcseconds. In order to achieve such demanding performances, the complexity of the satellite is huge, and a proper fully automated operation must be adopted. One of the essential parts of the satellite is the BAM instrument, an interferometric device with the task of monitoring the variation of the Basic Angle between the two telescope that compose the payload. In this paper we describe the main features of this sub-instrument and its performances.

Riva, A.; Gai, M.; Lattanzi, M. G.; Russo, F.; Buzzi, R.

2014-12-01

140

A high precision, compact electromechanical ground rotation sensor  

SciTech Connect

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{sup ?11}m/?( Hz ). We describe the instrument construction and demonstrate low noise operation with a noise floor upper bound of 5.7 × 10{sup ?9} rad /?( Hz ) at 10 mHz and 6.4 × 10{sup ?10} 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.

Dergachev, V., E-mail: volodya@caltech.edu [LIGO Laboratory, California Institute of Technology, MS 100-36, Pasadena, California 91125 (United States); DeSalvo, R. [LIGO Laboratory, California Institute of Technology, MS 100-36, Pasadena, California 91125 (United States) [LIGO Laboratory, California Institute of Technology, MS 100-36, Pasadena, California 91125 (United States); University of Sannio, C.so Garibaldi 107, Benevento 82100 (Italy); Asadoor, M. [Mayfield Senior School, 500 Bellefontaine Street, Pasadena, California 91105 (United States) [Mayfield Senior School, 500 Bellefontaine Street, Pasadena, California 91105 (United States); Oklahoma State University, 219 Student Union, Stillwater, Oklahoma 74074 (United States); Bhawal, A. [Arcadia High School, 180 Campus Drive, Arcadia, California 91007 (United States) [Arcadia High School, 180 Campus Drive, Arcadia, California 91007 (United States); Carnegie Mellon University, 5000 Forbes Ave, Pittsburgh, Pennsylvania 15213 (United States); Gong, P. [Department of Precision Instrument, Tsinghua University, Beijing 100084 (China) [Department of Precision Instrument, Tsinghua University, Beijing 100084 (China); School of Industrial and System Engineering, Georgia Institute of Technology, Atlanta, Georgia 30332-0205 (United States); Kim, C. [California Institute of Technology, Pasadena, California 91125 (United States)] [California Institute of Technology, Pasadena, California 91125 (United States); Lottarini, A. [Department of Computer Science, University of Pisa, Largo B. Pontecorvo 3, 56127 Pisa (Italy) [Department of Computer Science, University of Pisa, Largo B. Pontecorvo 3, 56127 Pisa (Italy); Department of Computer Science, Columbia University, 1214 Amsterdam Avenue, New York, New York 10027 (United States); Minenkov, Y. [Sezione INFN Tor Vergata, via della Ricerca Scientifica  1, 00133 Roma (Italy)] [Sezione INFN Tor Vergata, via della Ricerca Scientifica  1, 00133 Roma (Italy); Murphy, C. [School of Physics, The University of Western Australia, 35 Stirling Highway, Crawley, Perth, Western Australia 6009 (Australia) [School of Physics, The University of Western Australia, 35 Stirling Highway, Crawley, Perth, Western Australia 6009 (Australia); University of Melbourne Grattan Street, Parkville VIC 3010 (Australia); O'Toole, A. [University of California, Los Angeles, 405 Hilgard Ave, Los Angeles, California 90095 (United States) [University of California, Los Angeles, 405 Hilgard Ave, Los Angeles, California 90095 (United States); Michigan Technological University, 1400 Townsend Dr, Houghton, Michigan 49931 (United States); Peña Arellano, F. E. [National Astronomical Observatory of Japan, 2-21-1 Osawa, Mitaka, Tokyo 181-8588 (Japan)] [National Astronomical Observatory of Japan, 2-21-1 Osawa, Mitaka, Tokyo 181-8588 (Japan); and others

2014-05-15

141

Research into the advanced experimental methods for precision ion stopping range measurements in matter  

NASA Astrophysics Data System (ADS)

The article presents the results of the experimental research on precision measurement of total stopping range and energy deposition function of intermediate and heavy ion beams in cold solid matter. The “thick target” method proves to be appropriate for this purpose. Two types of detectors were developed which provide an error of the total stopping range measurement of less than 3% and of the beam energy deposition function of about 7%. The experiments with 58Ni+26, 197Au+65, and 238U+72 ion beams in the energy range 100 300 MeV/u were performed on SIS-18 (Gesellschaft für Schwerionenforschung, Darmstadt) in 1999 2001. The measured data on the total stopping ranges for the above ion species in bulk and foiled Al and Cu targets are presented. The investigation showed that there is a noticeable discrepancy between the measured stopping ranges and the theoretically predicted ones. Also, it was shown that realistic ion energy deposition depends on the type of target (bulk or foiled). Further investigation is necessary to clarify the latter.

Bakhmetjev, I. E.; Fertman, A. D.; Golubev, A. A.; Kantsyrev, A. V.; Luckjashin, V. E.; Sharkov, B. Yu.; Turtikov, V. I.; Kunin, A. V.; Vatulin, V. V.; Zhidkov, N. V.; Baldina, E. G.; Neuner, U.; Wieser, J.; Jacoby, J.; Hoffmann, D. H. H.

2003-01-01

142

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

143

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

144

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

145

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

146

High-precision atomic structure measurements in thallium  

NASA Astrophysics Data System (ADS)

Using a thallium atomic beam apparatus, we are undertaking a series of laser spectroscopy measurements with the goal of providing precise, independent cross-checks on the accuracy of new calculations of parity nonconservation in thallium(M. Kozlov et al.), Phys Rev. A64, 053107 (2001). In our apparatus, a laser beam interacts transversely with a dense, 2-cm-wide thallium beam and reveals roughly tenfold Doppler narrowing of the absorption profile. Having completed a new 0.4% measurement of the Stark shift within the 378 nm 6P_1/2-7S_1/2 E1 transition, we have now begun to study the weak 1283 nm 6P_1/2-6P_3/2 transition in the atomic beam. We seek to determine both Stark shift components, as well as the various components of the Stark-induced amplitude within this mixed M1/E2 transition. Using these existing laser systems, we have also begun a vapor cell spectroscopy study of the 1301 nm 7S_1/2-7P_1/2 E1 transition by means of a two-step excitation from the ground state. To enhance the visibility of these weak absorption signals, we are employing an FM spectroscopy technique. The demodulated laser transmission spectrum provides a low-noise, zero-background signal, and includes replicas of the absorption spectrum separated by the well-known RF sideband frequency, offering built-in frequency scale calibration.

Burkhardt, M. H.; Holmes, C. D.; Uhl, R.; Majumder, P. K.

2004-05-01

147

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

148

New approach to high-precision Fourier transform spectrometer design.  

PubMed

Laser fringes have long been used to establish the x axis in interferometric spectrometry, but solutions for the intensity axis have been less satisfactory. Now we are seeing the rapid commercial development of low-cost, medium-speed, sigma-delta analog-to-digital converters developed for stereo audio applications. A single chip provides two channels of 20-bit precision at 50 kHz, a significant improvement over many current systems of much greater cost and complexity. But while the laser works in the spatial domain, this converter operates strictly in the time domain; it cannot be triggered. I have developed a bridge between these two domains, the adaptive digital filter, which not only permits us to use this converter to obtain measurements at arbitrary times but as a bonus shows us how to move much of the complexity of an interferometric-control and data-acquisition system from hardware to software. For example, flexible fringe subdivision (to increase the free spectral range) is easily obtained with a simple and efficient algorithm, completely free of laser ghosts. Compensation for drive velocity variation is also possible, requiring only a modest increase in computer memory. PMID:21085438

Brault, J W

1996-06-01

149

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

150

High-precision automatic online measurement system of engine block top surface holes  

NASA Astrophysics Data System (ADS)

The measurement of holes in the engine block top surface determines the general coupling effect of the engine. All of these holes are strictly restricted by the requirements of the dimensional tolerance and the geometrical tolerance, which determines the final engine quality. At present, these holes are measured mostly by the coordinate measuring machine (CMM) in the production line, and meeting the industry demands of automation, rapidity, and online testing with the method is difficult. A new rapid solution measuring the holes in the engine block top surface is proposed, which is based on the combination of multiple visual sensors. The flexible location method of the block is designed, and the global data fusion model based on multiple visual sensors is studied. Finally, the unified correction model of the lens distortion and the system inclination is proposed, and a revised system model with more precision is researched. The CMM measures the holes sizes and the spatial relationship between holes, and the data obtained are substituted into the global data fusion model to complete the system on-site rapid calibration. The experimental results show that the scheme is feasible. The measurement system can meet the production line needs of intelligence, rapidity, and high precision.

Yongqiang, Shi; Changku, Sun; Yukun, Ma; Hongxu, Duan; Peng, Wang

2012-05-01

151

Precision mass spectrometry of highly charged ions with TITAN. Status and outlook  

NASA Astrophysics Data System (ADS)

High-precision and accurate atomic mass measurements are vital for the description of nuclear structure, investigations of nuclear astrophysical processes, and tests of fundamental symmetries. We report on mass measurements of short-lived highly charged ions using the TITAN Penning-trap mass spectrometer at TRIUMF. To increase the overall efficiency and precision of the mass measurement of highly charged ions, an addition to the TITAN system, the novel cooler Penning trap CPET is discussed.

Simon, V. V.; Chaudhuri, A.; Chowdhury, U.; Gallant, A. T.; Kwiatkowski, A. A.; Lennarz, A.; Macdonald, T. D.; Schultz, B. E.; Simon, M. C.; Andreoiu, C.; Gwinner, G.; Dilling, J.

2014-06-01

152

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

153

Design of a high precision falling-ball viscometer  

SciTech Connect

The increase in uncertainty throughout the viscosity scale being the principal disadvantage of capillary viscometry, an absolute falling-ball viscometer has been developed, making it possible to cover a wide range of viscosities while keeping a weak uncertainty. The measurement of viscosity of a liquid then rests on the terminal velocity measurement of a falling ball, corrected by the principal identified effects (edge effects, inertial effects, etc.). An experimental bench was developed in order to reach a relative uncertainty of the order of 10{sup -3} to the measure of viscosity. The bench, by the use of a linear camera, allows us to observe the trajectory and to obtain the variations in velocity of the ball inside a cylindrical tube filled with liquid whose viscosity is to be measured.

Brizard, M.; Megharfi, M.; Mahe, E.; Verdier, C. [Laboratoire National d'Essais (BNM-LNE), 1 Rue Gaston Boissier, 75015 Paris Cedex 15 (France); Laboratoire de Spectrometrie Physique (UMR5588, UJF-CNRS), 140 Avenue de la Physique BP 87, 38402 St Martin d'Heres Cedex (France)

2005-02-01

154

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

155

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

156

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

157

High precision automatic voltage regulator using the series transformer  

Microsoft Academic Search

This paper presents the design and analysis of a PWM inverter type automatic voltage regulator (A.V.R). The proposed A.V.R consists of a DC\\/AC inverter with reversible voltage control and a transformer for voltage compensation. The designed A.V.R can be used to deal with both directions of voltage regulation with high efficiency and reliability. This A.V.R has the function as the

Se-Na Lee; Zang Lei; Min-Jung Lee; Sung-Geun Song; Sung-Jun Park

2009-01-01

158

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

159

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.

160

Optimal mould design for the manufacture by compression moulding of high-precision lenses  

Microsoft Academic Search

The increasing need for low-cost, high-precision optical devices requires innovative manufacturing techniques or the optimization of existing ones. The present study focuses on the latter alternative and proposes a computer-aided, mould optimization algorithm for the manufacturing of high-precision glass lenses by compression moulding. The intuitive, yet very efficient, algorithm computes at each optimization loop the mismatch between the desired and

M. Sellier; C. Breitbach; H. Loch; N. Siedow

161

Three precision differential pressure indicators for operation at high temperatures and pressures  

E-print Network

THREE PRECISION DIFFERENTIAL PRESSURE INDICATORS FOR OPERATION AT HIGH TEMPERATURES AND PRESSURES A Thesis by DOUGLAS CLAYTON OSBURN III Submitted to the Graduate College of Texas ASM University in partial fulfillment of the requirement... for the degree of MASTER OF SCIENCE May 1981 Major Subject: Chemical Engineering THREE PRECISION DIFFERENTIAL PRESSURE INDICATORS FOR OPERATION AT HIGH TEMPERATURES AND PRESSURES A Thesis by DOUGLAS CLAYTON OSBURN III Approved as to style and content by...

Osburn, Douglas Clayton

2012-06-07

162

Phenomenological High Precision Neutron-Proton Delta-Shell Potential  

E-print Network

We provide a successful fit for proton-neutron scattering below pion production threshold up to LAB energies of 350 MeV. We use seven high-quality fits based on potentials with different forms as a measure of the systematic uncertainty. We represent the interaction as a sum of delta-shells in configuration space below the 3fm and a charge dependent one pion exchange potential above 3fm together with magnetic and vacuum polarization effects. Special attention is paid to estimate the errors of the phenomenological interaction.

R. Navarro Perez; J. E. Amaro; E. Ruiz Arriola

2012-02-13

163

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

164

Algorithm for high-precision georeference and rectification of high-resolution space images  

NASA Astrophysics Data System (ADS)

The current state-of-the-art of high-resolution space images enables the performance of large scale mapping, map updating, monitoring of the Earth cover and the environment, and other practical, scientific, and defence-related tasks requiring to determine with great accuracy the mutual position of individual discrete points [2, 3, 4, 5, 6, 7, 8, 9]. Based on a number of studies conducted at home and abroad [4, 7, 9], it was proven that the space images obtained upon their processing by the supplier and accordingly, upon their high-precision georeference and rectification by the user, differ substantially in their precision. This happens when the user determines the coordinates of the ground-based CPs using GPS measurements and dedicated software, accounting for the recommendations made during processing. Based on the designed mathematical model [1, 3, 5], an algorithm is suggested that may be used to prepare software for processing and assessment of collected observational material after the Least Square Method (LSM).

Georgiev, Nikola

165

High integrity GPS/INS filter for precise relative navigation  

NASA Astrophysics Data System (ADS)

A GPS/INS filter design for absolute and relative state estimation is discussed. The GPS code and Doppler measurements are used for absolute state estimation while the GPS carrier phase and Doppler measurements are used for relative state estimation. Real-time results obtained from a Hardware-in-the-Loop Simulation and actual F-18 flight tests are presented. To ensure accurate state estimation, the observability of the GPS/INS system is analyzed analytically when the system is at rest and during maneuvers. The system observability enhancement during two different maneuvers is discussed. Simulation results illustrating the observability of the system during the different stages of the GPS/INS system operation are also presented. To allow successful use of the high-accuracy carrier phase measurements, two methods for resolving GPS integer ambiguity are introduced. The first combines an efficient method for obtaining the admissible integer ambiguity hypotheses within a probabilistic volume with an integer hypothesis testing method to reduce the convergence time with high probability to the GPS carrier phase integers. The second GPS integer ambiguity resolution method is based on a log-formulation of the Multiple Hypothesis Wald Sequential Probability Test (MHWSPT). The computational time requirement of the latter method is shown to be smaller than the former method. Real-time results are presented to show the performance of the two methods introduced.

Abdel-Hafez, Mamoun F.

166

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

167

A high precision radiation-tolerant LVDT conditioning module  

NASA Astrophysics Data System (ADS)

Linear variable differential transformer (LVDT) position sensors are widely used in particle accelerators and nuclear plants, thanks to their properties of contact-less sensing, radiation tolerance, infinite resolution, good linearity and cost efficiency. Many applications require high reading accuracy, even in environments with high radiation levels, where the conditioning electronics must be located several hundred meters away from the sensor. Sometimes even at long distances the conditioning module is still exposed to ionizing radiation. Standard off-the-shelf electronic conditioning modules offer limited performances in terms of reading accuracy and long term stability already with short cables. A radiation tolerant stand-alone LVDT conditioning module has been developed using Commercial Off-The-Shelf (COTS) components. The reading of the sensor output voltages is based on a sine-fit algorithm digitally implemented on an FPGA ensuring few micrometers reading accuracy even with low signal-to-noise ratios. The algorithm validation and board architecture are described. A full metrological characterization of the module is reported and radiation tests results are discussed.

Masi, A.; Danzeca, S.; Losito, R.; Peronnard, P.; Secondo, R.; Spiezia, G.

2014-05-01

168

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

169

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

170

Development of Large Current High Precision Pulse Power Supply  

NASA Astrophysics Data System (ADS)

JAEA and KEK are jointly constructing a high intensity proton accelerator project J-PARC. Its main accelerator is 3GeV synchrotron. Its injection bump magnets, especially horizontal paint bump magnets, are excited by large pulse currents. Their rated currents are over 10kA and pulse widths are about 1ms. Tracking errors are required to be less than 1%. Multiple connected two-quadrant IGBT choppers are adopted for their power supplies. Their output currents are controlled by feedback control with minor loop voltage control (m-AVR). When output current of a chopper intermits at small current, its output voltage rises up and current control becomes difficult. In this paper response of m-AVR and output voltage characteristics at current intermittent region are studied and an improved control scheme is proposed. The performance is confirmed by a test.

Takayanagi, Tomohiro; Koseki, Shoichiro; Kubo, Hiroshi; Katoh, Shuji; Ogawa, Shinichi

171

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

172

Conditional DNA repair mutants enable highly precise genome engineering  

PubMed Central

Oligonucleotide-mediated multiplex genome engineering is an important tool for bacterial genome editing. The efficient application of this technique requires the inactivation of the endogenous methyl-directed mismatch repair system that in turn leads to a drastically elevated genomic mutation rate and the consequent accumulation of undesired off-target mutations. Here, we present a novel strategy for mismatch repair evasion using temperature-sensitive DNA repair mutants and temporal inactivation of the mismatch repair protein complex in Escherichia coli. Our method relies on the transient suppression of DNA repair during mismatch carrying oligonucleotide integration. Using temperature-sensitive control of methyl-directed mismatch repair protein activity during multiplex genome engineering, we reduced the number of off-target mutations by 85%, concurrently maintaining highly efficient and unbiased allelic replacement. PMID:24500200

Nyerges, Ákos; Csörg?, Bálint; Nagy, István; Latinovics, Dóra; Szamecz, Béla; Pósfai, György; Pál, Csaba

2014-01-01

173

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

174

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

175

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

176

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

PubMed

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 H3(+), two transitions in the ?1 band of HCO(+), and the first sub-Doppler transition of CH5(+). PMID:24182022

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

2013-10-28

177

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

178

High-precision B (E2) measurements of semi-magic Ni58,60,62,64 by Coulomb excitation  

NASA Astrophysics Data System (ADS)

High-precision reduced electric-quadrupole transition probabilities B (E2;01+?21+) have been measured from single-step Coulomb excitation of semi-magic Ni58,60,62,64 (Z=28) beams at 1.8 MeV per nucleon on a natural carbon target. The energy loss of the nickel beams through the carbon target were directly measured with a zero-degree Bragg detector and the absolute B (E2) values were normalized by Rutherford scattering. The B (E2) values disagree with recent lifetime studies that employed the Doppler-shift attenuation method. The present high-precision B (E2) values reveal an asymmetry about Ni62, midshell between N =28 and 40, with larger values towards Ni56 (Z =N=28). The experimental B (E2) values are compared with shell-model calculations in the full pf model space and the results indicate a soft Ni56 core.

Allmond, J. M.; Brown, B. A.; Stuchbery, A. E.; Galindo-Uribarri, A.; Padilla-Rodal, E.; Radford, D. C.; Batchelder, J. C.; Howard, M. E.; Liang, J. F.; Manning, B.; Varner, R. L.; Yu, C.-H.

2014-09-01

179

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

180

Precision dosing of powders by vibratory and screw feeders: an experimental study  

Microsoft Academic Search

The addition of small amounts of very precisely dosed powdery ingredients into bulk powders and\\/or liquid mixtures is important in such industrial operations as mixing, granulation and crystallization. The general practice is to use a screw, vibration or belt feeder combined with a loss by weight device and an appropriate controller. The present work concentrates on two vibratory feeders, one

Gabriel I. Tardos; Quingyang Lu

1996-01-01

181

Study on Continuous-Casting Slab High-Precision Length Measurement and Cutting Control Technique  

Microsoft Academic Search

Directed at the precision-decreasing problems like abrasion and slippage which occur in the roller for measuring continuous-casting slab length, a technology of edge detection for CCD (charge coupled device) digital image was adopted that fulfilled fixed-length cutting control at the first stage and dynamic tracing of casting speed. With hydraulic pressure cushioning and back-pushing technology, the second stage high-precision fixed-length

Huiyi Zhang; Tao Tao; Xingli Jiao

2006-01-01

182

High-Precision Visual Long-Term Memory in Children With High-Functioning Autism.  

PubMed

Domain-general theories of autism rest on evidence that the disorder impacts not only social communication skills but also nonsocial functions such as memory. Yet recognition memory deficits have been inconsistently documented, especially for stimuli other than faces and sentences. Here we tested school-age children with high-functioning autism (ASD) and IQ, and age-matched comparison children on a visual long-term memory task involving more than 100 photographs of objects, faces, cats, houses, and abstract stimuli. Children viewed each photograph for 2 s. After a 10-min filled delay, we assessed recognition memory for object category as well as for specific exemplars. Data supported the presence of a high-capacity and high-precision visual memory in children with ASD. Both category memory and exemplar memory accuracies were above 90% for categories for which a single exemplar had been encoded. When more exemplars per category were encoded, category memory improved, but exemplar memory declined. An exception was face memory, which remained highly accurate even after many faces had been encoded. Our study provided no evidence that visual memory in general, and face memory in particular, is impaired in children with ASD. (PsycINFO Database Record (c) 2014 APA, all rights reserved). PMID:25436998

Jiang, Yuhong V; Palm, Bryce E; DeBolt, Michaela C; Goh, Yi Shuen

2014-12-01

183

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

184

MATS and LaSpec: High-precision experiments using ion traps and lasers at FAIR  

NASA Astrophysics Data System (ADS)

Nuclear ground state properties including mass, charge radii, spins and moments can be determined by applying atomic physics techniques such as Penning-trap based mass spectrometry and laser spectroscopy. The MATS and LaSpec setups at the low-energy beamline at FAIR will allow us to extend the knowledge of these properties further into the region far from stability. The mass and its inherent connection with the nuclear binding energy is a fundamental property of a nuclide, a unique “fingerprint”. Thus, precise mass values are important for a variety of applications, ranging from nuclear-structure studies like the investigation of shell closures and the onset of deformation, tests of nuclear mass models and mass formulas, to tests of the weak interaction and of the Standard Model. The required relative accuracy ranges from 10-5 to below 10-8 for radionuclides, which most often have half-lives well below 1 s. Substantial progress in Penning trap mass spectrometry has made this method a prime choice for precision measurements on rare isotopes. The technique has the potential to provide high accuracy and sensitivity even for very short-lived nuclides. Furthermore, ion traps can be used for precision decay studies and offer advantages over existing methods. With MATS (Precision Measurements of very short-lived nuclei using an A_dvanced Trapping System for highly-charged ions) at FAIR we aim to apply several techniques to very short-lived radionuclides: High-accuracy mass measurements, in-trap conversion electron and alpha spectroscopy, and trap-assisted spectroscopy. The experimental setup of MATS is a unique combination of an electron beam ion trap for charge breeding, ion traps for beam preparation, and a high-precision Penning trap system for mass measurements and decay studies. For the mass measurements, MATS offers both a high accuracy and a high sensitivity. A relative mass uncertainty of 10-9 can be reached by employing highly-charged ions and a non-destructive Fourier-Transform Ion-Cyclotron-Resonance (FT-ICR) detection technique on single stored ions. This accuracy limit is important for fundamental interaction tests, but also allows for the study of the fine structure of the nuclear mass surface with unprecedented accuracy, whenever required. The use of the FT-ICR technique provides true single ion sensitivity. This is essential to access isotopes that are produced with minimum rates which are very often the most interesting ones. Instead of pushing for highest accuracy, the high charge state of the ions can also be used to reduce the storage time of the ions, hence making measurements on even shorter-lived isotopes possible. Decay studies in ion traps will become possible with MATS. Novel spectroscopic tools for in-trap high-resolution conversion-electron and charged-particle spectroscopy from carrier-free sources will be developed, aiming e.g. at the measurements of quadrupole moments and E0 strengths. With the possibility of both high-accuracy mass measurements of the shortest-lived isotopes and decay studies, the high sensitivity and accuracy potential of MATS is ideally suited for the study of very exotic nuclides that will only be produced at the FAIR facility.Laser spectroscopy of radioactive isotopes and isomers is an efficient and model-independent approach for the determination of nuclear ground and isomeric state properties. Hyperfine structures and isotope shifts in electronic transitions exhibit readily accessible information on the nuclear spin, magnetic dipole and electric quadrupole moments as well as root-mean-square charge radii. The dependencies of the hyperfine splitting and isotope shift on the nuclear moments and mean square nuclear charge radii are well known and the theoretical framework for the extraction of nuclear parameters is well established. These extracted parameters provide fundamental information on the structure of nuclei at the limits of stability. Vital information on both bulk and valence nuclear properties are derived and an exceptional sensitivity to changes in nuclear def

Rodríguez, D.; Blaum, K.; Nörtershäuser, W.; Ahammed, M.; Algora, A.; Audi, G.; Äystö, J.; Beck, D.; Bender, M.; Billowes, J.; Block, M.; Böhm, C.; Bollen, G.; Brodeur, M.; Brunner, T.; Bushaw, B. A.; Cakirli, R. B.; Campbell, P.; Cano-Ott, D.; Cortés, G.; Crespo López-Urrutia, J. R.; Das, P.; Dax, A.; de, A.; Delheij, P.; Dickel, T.; Dilling, J.; Eberhardt, K.; Eliseev, S.; Ettenauer, S.; Flanagan, K. T.; Ferrer, R.; García-Ramos, J.-E.; Gartzke, E.; Geissel, H.; George, S.; Geppert, C.; Gómez-Hornillos, M. B.; Gusev, Y.; Habs, D.; Heenen, P.-H.; Heinz, S.; Herfurth, F.; Herlert, A.; Hobein, M.; Huber, G.; Huyse, M.; Jesch, C.; Jokinen, A.; Kester, O.; Ketelaer, J.; Kolhinen, V.; Koudriavtsev, I.; Kowalska, M.; Krämer, J.; Kreim, S.; Krieger, A.; Kühl, T.; Lallena, A. M.; Lapierre, A.; Le Blanc, F.; Litvinov, Y. A.; Lunney, D.; Martínez, T.; Marx, G.; Matos, M.; Minaya-Ramirez, E.; Moore, I.; Nagy, S.; Naimi, S.; Neidherr, D.; Nesterenko, D.; Neyens, G.; Novikov, Y. N.; Petrick, M.; Plaß, W. R.; Popov, A.; Quint, W.; Ray, A.; Reinhard, P.-G.; Repp, J.; Roux, C.; Rubio, B.; Sánchez, R.; Schabinger, B.; Scheidenberger, C.; Schneider, D.; Schuch, R.; Schwarz, S.; Schweikhard, L.; Seliverstov, M.; Solders, A.; Suhonen, M.; Szerypo, J.; Taín, J. L.; Thirolf, P. G.; Ullrich, J.; van Duppen, P.; Vasiliev, A.; Vorobjev, G.; Weber, C.; Wendt, K.; Winkler, M.; Yordanov, D.; Ziegler, F.

2010-05-01

185

High-precision laser beam shaping using a binary-amplitude spatial light modulator.  

PubMed

We have achieved high-precision laser beam shaping by using a binary-amplitude spatial light modulator, a digital micromirror device (DMD), followed by an imaging telescope that contains a pinhole low-pass filter (LPF). An error diffusion algorithm was used to design the initial DMD pixel pattern based on the measured input beam profile. This pattern was iteratively refined by simulating the optically low-pass filtered DMD image and changing DMD pixels to lift valleys and suppress peaks. We noted the gap between the experimental result of 1.4% root-mean-square (RMS) error and the simulated result for the same DMD pattern of 0.3% RMS error. Therefore, we deemed it necessary to introduce iterative refinement based on actual measurements of the output image to further improve the uniformity of the beam. Using this method, we have demonstrated the ability to shape raw, non-spatially filtered laser beams (quasi-Gaussian beams) into beams with precisely controlled profiles that have an unprecedented level of RMS error with respect to the target profile. We have shown that our iterative refinement process is able to improve the light intensity uniformity to around 1% RMS error in a raw camera image for both 633 and 1064 nm laser beams. The use of a digital LPF on the camera image is justified in that it matches the performance of the pinhole filter in the experimental setup. The digital low-pass filtered results reveal that the actual optical beam profiles have RMS error down to 0.23%. Our approach has also demonstrated the ability to produce a range of target profiles as long as they have similar spatial-frequency content (i.e., a slowly varying beam profile). Circular and square cross-section flat-top beams and beams with a linear intensity variation within a circular and square cross section were produced with similarly low RMS errors. The measured errors were about twice the ultimate limit of 0.1% RMS error based on the number of binary DMD pixels that participate in the beam-formation process. PMID:20220887

Liang, Jinyang; Kohn, Rudolph N; Becker, Michael F; Heinzen, Daniel J

2010-03-10

186

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

187

Laser ablation and high precision patterning of biomaterials and intraocular lenses  

NASA Astrophysics Data System (ADS)

The use of intraocular lenses (IOL) is the most promising method for restoring excellent vision in cataract surgery. In addition, multifocal intraocular lenses for good distant and near vision are investigated. Several new materials, techniques and patterns are studied for the formation and etching of intraocular lenses in order to improve their optical properties and reduce the diffractive aberrations. As pulsed laser ablation is well established as a universal tool for surface processing of organic polymer materials, this study was focused in using laser ablation with short and ultra short laser pulses for surface modification of PMMA and intraocular lenses, instead of using other conventional techniques. The main advantage of using very short laser pulses, e.g. of ns, ps or fs duration, is that heat diffusion into the polymer material is negligible. As a result high precision patterning of the sample, without thermal damage of the surroundings, becomes possible. In this study, laser ablation was performed using commercially available hydrophobic acrylic IOLs, hydrophilic acrylic IOLs, and PMMA IOLs, with various diopters. We investigated the ablation efficiency and the phenomenology of the etched patterns by testing the ablation rate, versus laser energy fluence, at several wavelengths and the surface modification with atomic force microscopy (AFM), or scanning electron microscopy (SEM). The irradiated polymers have different optical properties, at the applied wavelengths, and therefore, present different ablation behaviour and morphology of the laser ablated crater walls and surrounding surfaces. The experimental results, some theoretical assumptions for mathematical modeling of the relevant ablation mechanisms are discussed.

Serafetinides, A. A.; Spyratou, E.; Makropoulou, M.

2010-10-01

188

High-precision two-way optic-fiber time transfer using an improved time code  

NASA Astrophysics Data System (ADS)

We present a novel high-precision two-way optic-fiber time transfer scheme. The Inter-Range Instrumentation Group (IRIG-B) time code is modified by increasing bit rate and defining new fields. The modified time code can be transmitted directly using commercial optical transceivers and is able to efficiently suppress the effect of the Rayleigh backscattering in the optical fiber. A dedicated codec (encoder and decoder) with low delay fluctuation is developed. The synchronization issue is addressed by adopting a mask technique and combinational logic circuit. Its delay fluctuation is less than 27 ps in terms of the standard deviation. The two-way optic-fiber time transfer using the improved codec scheme is verified experimentally over 2 m to100 km fiber links. The results show that the stability over 100 km fiber link is always less than 35 ps with the minimum value of about 2 ps at the averaging time around 1000 s. The uncertainty of time difference induced by the chromatic dispersion over 100 km is less than 22 ps.

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

2014-11-01

189

A modified highly precise direct integration method for a class of linear time-varying systems  

NASA Astrophysics Data System (ADS)

It is always a bottleneck to design an effective algorithm for linear time-varying systems in engineering applications. For a class of systems, whose coefficients matrix is based on time-varying polynomial, a modified highly precise direct integration (VHPD-T method) was presented. Through introducing new variables and expanding dimensions, the system can be transformed into a time-invariant system, in which the transfer matrix can be computed for once and used forever with a highly precise direct integration method. The method attains higher precision than the common methods (e.g. RK4 and power series) and high efficiency in computation. Some numerical examples demonstrate the validity and efficiency of the method proposed.

Liu, XiaoMei; Zhou, Gang; Zhu, Shuai; Wang, YongHong; Sun, WeiRong; Weng, ShiLie

2014-07-01

190

High-Precision Radiosurgical Dose Delivery by Interlaced Microbeam Arrays of High-Flux Low-Energy Synchrotron  

E-print Network

that synchrotron photons can be used for human radiosurgical applications. Our data show that interlaced microbeam Microbeam Arrays of High-Flux Low-Energy Synchrotron X-Rays. PLoS ONE 5(2): e9028. doi:10.1371/journalHigh-Precision Radiosurgical Dose Delivery by Interlaced Microbeam Arrays of High-Flux Low

Paris-Sud XI, Université de

191

Fabrication and Assembly of High-Precision Hinge and Latch Joints for Deployable Optical Instruments  

NASA Technical Reports Server (NTRS)

Descriptions are presented of high-precision hinge and latch joints that have been co-developed, for application to deployable optical instruments, by NASA Langley Research Center and Nyma/ADF. Page-sized versions of engineering drawings are included in two appendices to describe all mechanical components of both joints. Procedures for assembling the mechanical components of both joints are also presented. The information herein is intended to facilitate the fabrication and assembly of the high-precision hinge and latch joints, and enable the incorporation of these joints into the design of deployable optical instrument systems.

Phelps, James E.

1999-01-01

192

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

193

Adjusting for High-dimensional Covariates in Sparse Precision Matrix Estimation by ?1-Penalization.  

PubMed

Motivated by the analysis of genetical genomic data, we consider the problem of estimating high-dimensional sparse precision matrix adjusting for possibly a large number of covariates, where the covariates can affect the mean value of the random vector. We develop a two-stage estimation procedure to first identify the relevant covariates that affect the means by a joint ?1 penalization. The estimated regression coefficients are then used to estimate the mean values in a multivariate sub-Gaussian model in order to estimate the sparse precision matrix through a ?1-penalized log-determinant Bregman divergence. Under the multivariate normal assumption, the precision matrix has the interpretation of a conditional Gaussian graphical model. We show that under some regularity conditions, the estimates of the regression coefficients are consistent in element-wise ?? norm, Frobenius norm and also spectral norm even when p ? n and q ? n. We also show that with probability converging to one, the estimate of the precision matrix correctly specifies the zero pattern of the true precision matrix. We illustrate our theoretical results via simulations and demonstrate that the method can lead to improved estimate of the precision matrix. We apply the method to an analysis of a yeast genetical genomic data. PMID:23687392

Yin, Jianxin; Li, Hongzhe

2013-04-01

194

High precision metrology method for unobscured Three Mirror Anastigmatic (TMA) mapping camera boresight  

NASA Astrophysics Data System (ADS)

High precision of mapping camera boresight directly affects the positioning accuracy of geographical location and photogrammetry. Although it can fulfill the request of good performance for unobscured TMA optical system, which adopted computer aided alignment method, single lens was unobscured which unable ascertain boresight by using lens centering technology, and boresight is randomicity as a result of compensating relation of multivariables. A novel method using the measurement of theodolite space intersection was proposed to rapidly and high accurately complete establish the relation between boresight and a cube in precision alignment stage, simultaneously, the relation of component deflexion and boresight have been simulated by computer model reverse optimization. Thus, the image quality and precision of boresight was effective operated according to the request of satellite assembly.

Zhao, Xi-ting; Jiao, Wen-chun; Liao, Zhi-bo

2012-10-01

195

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

196

Acoustic grating fringe projector for high-speed and high-precision three-dimensional shape measurements  

SciTech Connect

A new acoustic grating fringe projector (AGFP) was developed for high-speed and high-precision 3D measurement. A new acoustic grating fringe projection theory is also proposed to describe the optical system. The AGFP instrument can adjust the spatial phase and period of fringes with unprecedented speed and accuracy. Using rf power proportional-integral-derivative (PID) control and CCD synchronous control, we obtain fringes with fine sinusoidal characteristics and realize high-speed acquisition of image data. Using the device, we obtained a precise phase map for a 3D profile. In addition, the AGFP can work in running fringe mode, which could be applied in other measurement fields.

Yin Xuebing; Zhao Huijie; Zeng Junyu; Qu Yufu

2007-05-20

197

High-Precision Measurements of the Superallowed Beta+ Decays of 38Ca and 46V  

E-print Network

depended on beta-delayed gamma-ray intensities being measured with a high-purity germanium detector calibrated for absolute efficiency to 0.2% precision. This branching-ratio result represents our first step in bringing the ft value for the superallowed ³?...

Park, Hyo-In

2012-10-19

198

High-precision control of a maglev linear actuator with nanopositioning capability  

Microsoft Academic Search

Presents high-precision control of a magnetically levitated (maglev) linear actuator with novel geometric configuration. The linear actuator is used as a unit actuator in the development of a maglev instrument with six-axis nanopositioning capability. The novel configuration in this design concept leads to a lightweight and compact size. The objective of development of this maglev linear actuator is to verify

Won-jong Kim; Himanshu Maheshwari

2002-01-01

199

High-Precision Fuzzy Control Strategy in Continuous Casting Mold Servo Control System  

Microsoft Academic Search

Caster vibration waveform with variable, non-sinusoidal vibration characteristics, the device uses electro-hydraulic servo drive control algorithm using variable universe fuzzy control, robustness, high control precision, fast response. The paper focuses on variable universe fuzzy controller of rigor the flex-factors that ensure its applicability, and integration testing to determine model parameters, and through computer simulation validity and accuracy.

Yong Tian; Ling-hua Wang

2010-01-01

200

High Precision Spectroscopy of Strontium in an Optical Lattice: Towards a New Standard for  

E-print Network

High Precision Spectroscopy of Strontium in an Optical Lattice: Towards a New Standard Spectroscopy of Strontium in an Optical Lattice: Towards a New Standard for Frequency and Time Thesis directed atomic clock states equally, such that the transition frequency is unchanged. Strontium is a natural

Jin, Deborah

201

High-precision two-colour spaceborne laser ranging system for monitoring of geodynamic processes  

Microsoft Academic Search

The design concept of a spaceborne two-color picosecond-pulse laser ranging system operating at a pulse rate of about 20 Hz from a 1600 km circular orbit is presented. The system is designed to estimate distances to ground-based passive arrays of retroreflector targets, which are deployed in tectonically highly active zones, with a precision within + or - 1 cm. Since

H. P. Lutz; W. Krause; G. Barthel

1982-01-01

202

Maintaining high precision of isotope ratio analysis over extended periods of time  

Microsoft Academic Search

Stable isotope ratios are reliable and long lasting process tracers. In order to compare data from different locations or different sampling times at a high level of precision, a measurement strategy must include reliable traceability to an international stable isotope scale via a reference material (RM). Since these international RMs are available in low quantities only, we have developed our

Willi A. Brand

2009-01-01

203

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, Research Laboratory for Archaeology and the History of Art, University of Oxford, Dyson Perrins Building¨nggassstrasse 51, CH-3000 Bern 9, Switzerland; and **Friends of Archaeology, P.O. Box 2440, Amman 11181, Jordan

Schulze, Jürgen P.

204

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 form 2 July 2005) We describe a prototype instrument using a Peltier cooled quantum cascade laser diode lasers. The application of pulsed near room-temperature quantum cascade lasers to this demanding

Saleska, Scott

205

Research papers High precision microsampling and preparation of zoned garnet porphyroblasts for  

E-print Network

Research papers High precision microsampling and preparation of zoned garnet porphyroblasts for Sm December 2010 Editor: R.L. Rudnick Keywords: Garnet Geochronology Microsampling Sm/Nd Zoned garnet, and geochronologic analysis of zoned garnets, which have limited the progress and application of this potentially

Baxter, Ethan F.

206

Methodology for developing a high-precision ultrasound flow meter and fluid velocity profile reconstruction  

Microsoft Academic Search

This article reports the methodology used to develop a high-precision ultrasound transit time flow meter dedicated to liquid hydrocarbons. This kind of flow meter is designed for custody transfer applications requiring accuracy better than 0.15% of reading. We focus here on certain specific points to achieve this accuracy. The transit time method needs to estimate accurately the time delay between

Emmanuelle Mandard; Denis Kouame; Rodolphe Battault; Jean-Pierre Remenieras; F. Patat

2008-01-01

207

Microplasma patterning of bonded microchannels using high-precision "injected" electrodes.  

PubMed

A rapid, high-precision method for localised plasma-treatment of bonded PDMS microchannels is demonstrated. Patterned electrodes were prepared by injection of molten gallium into preformed microchannel guides. The electrode guides were prepared without any additional fabrication steps compared to conventional microchannel fabrication. Alignment of the "injected" electrodes is precisely controlled by the photomask design, rather than positioning accuracy of alignment tools. Surface modification is detected using a fluorescent dye (Rhodamine B), revealing a well-defined micropattern with regions less than 100 µm along the length of the microchannel. PMID:21031179

Priest, Craig; Gruner, Philipp J; Szili, Endre J; Al-Bataineh, Sameer A; Bradley, James W; Ralston, John; Steele, David A; Short, Robert D

2011-02-01

208

A High Precision Ranging Scheme for IEEE802.15.4a Chirp Spread Spectrum System  

NASA Astrophysics Data System (ADS)

This letter proposes a high precision ranging scheme based on the time of arrival estimation technique for the IEEE 802.15.4a chirp spread spectrum system. The proposed scheme consists of a linear channel impulse response estimation process with the zero forcing or minimum mean square error technique and the multipath delay estimation process with matrix pencil algorithm. The performance of the proposed scheme is compared with that of a well known MUSIC algorithm in terms of computational complexity and ranging precision. Simulation results demonstrate that the proposed scheme outperforms the MUSIC algorithm even though it has comparatively lower computational complexity.

Kim, Na Young; Kim, Sujin; Kim, Youngok; Kang, Joonhyuk

209

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

210

On-line low flow high-precision gas metering systems  

Microsoft Academic Search

The paper describes a high precision gas meter suitable for low rates of flow (< 5 cm3 min?1) which can be interfaced with data acquisition software for continuous on-line measurement. The meter used the highly sensitive pressure transducers currently available, operated with a very small back pressure, and had an accuracy around 0.5%. A frequency to voltage converter was developed

A. J. Guwy; D. L. Hawkes; F. R. Hawkes

1995-01-01

211

Development of the Portable Synchrotron MIRRORCLE-CV for High Precision Non-Destructive Testing  

SciTech Connect

We started the development of the portable synchrotron MIRRORCLE-CV series, which provides a high quality x-ray beam for high precision non-destructive testing (NDT). Computer simulations for the magnetic field design and electron dynamics reveal that the outer diameter of the synchrotron magnet can be as small as 30 cm. This synchrotron size approaches that of a conventional x-ray tube.

Hasegawa, Daisuke; Toyosugi, Norio; Noh, Young Deok; Yamada, Takanori; Morita, Masaki; Mantey, Edward; Masaoka, Sei [Photon Production Laboratory, Ltd., 4-2-1 (808) Takagai-cho Minami, Ohmihachiman-city 523-0898, Shiga (Japan); Yamada, Hironari [Synchrotron Light Life Science Center, Ritsumeikan University, 1-1-1 Nojihigashi, Kusatsu-city 525-8577, Shiga (Japan)

2007-01-19

212

Experimental Characterization of Hysteresis in a Revolute Joint for Precision Deployable Structures  

NASA Technical Reports Server (NTRS)

Recent studies of the micro-dynamic behavior of a deployable telescope metering truss have identified instabilities in the equilibrium shape of the truss in response to low-energy dynamic loading. Analyses indicate that these micro-dynamic instabilities arise from stick-slip friction within the truss joints (e.g., hinges and latches). The present study characterizes the low-magnitude quasi-static load cycle response of the precision revolute joints incorporated in the deployable telescope metering truss, and specifically, the hysteretic response of these joints caused by stick-slip friction within the joint. Detailed descriptions are presented of the test setup and data reduction algorithms, including discussions of data-error sources and data-filtering techniques. Test results are presented from thirteen specimens, and the effects of joint preload and manufacturing tolerances are investigated. Using a simplified model of stick-slip friction, a relationship is made between joint load-cycle behavior and micro-dynamic dimensional instabilities in the deployable telescope metering truss.

Lake, Mark S.; Fung, Jimmy; Gloss, Kevin; Liechty, Derek S.

1997-01-01

213

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

214

High-precision optical systems with inexpensive hardware: a unified alignment and structural design approach  

NASA Astrophysics Data System (ADS)

High-precision opto-mechanical structures have historically been plagued by high costs for both hardware and the associated alignment and assembly process. This problem is especially true for space applications where only a few production units are produced. A methodology for optical alignment and optical structure design is presented which shifts the mechanism of maintaining precision from tightly toleranced, machined flight hardware to reusable, modular tooling. Using the proposed methodology, optical alignment error sources are reduced by the direct alignment of optics through their surface retroreflections (pips) as seen through a theodolite. Optical alignment adjustments are actualized through motorized, sub-micron precision actuators in 5 degrees of freedom. Optical structure hardware costs are reduced through the use of simple shapes (tubes, plates) and repeated components. This approach produces significantly cheaper hardware and more efficient assembly without sacrificing alignment precision or optical structure stability. The design, alignment plan and assembly of a 4" aperture, carbon fiber composite, Schmidt-Cassegrain concept telescope is presented.

Winrow, Edward G.; Chavez, Victor H.

2011-09-01

215

A New High-precision Correction Method of Temperature Distribution in Model Stellar Atmospheres  

NASA Astrophysics Data System (ADS)

The main features of the temperature correction methods, suggested and used in modeling of plane-parallel stellar atmospheres, are discussed. The main features of the new method are described. Derivation of the formulae for a version of the Unsöld-Lucy method, used by us in the SMART (Stellar Model Atmospheres and Radiative Transport) software for modeling stellar atmospheres, is presented. The method is based on a correction of the model temperature distribution based on minimizing differences of flux from its accepted constant value and on the requirement of the lack of its gradient, meaning that local source and sink terms of radiation must be equal. The final relative flux constancy obtainable by the method with the SMART code turned out to have the precision of the order of 0.5 %. Some of the rapidly converging iteration steps can be useful before starting the high-precision model correction. The corrections of both the flux value and of its gradient, like in Unsöld-Lucy method, are unavoidably needed to obtain high-precision flux constancy. A new temperature correction method to obtain high-precision flux constancy for plane-parallel LTE model stellar atmospheres is proposed and studied. The non-linear optimization is carried out by the least squares, in which the Levenberg-Marquardt correction method and thereafter additional correction by the Broyden iteration loop were applied. Small finite differences of temperature (? T/T=10-3) are used in the computations. A single Jacobian step appears to be mostly sufficient to get flux constancy of the order 10-2 %. The dual numbers and their generalization -- the dual complex numbers (the duplex numbers) -- enable automatically to get the derivatives in the nilpotent part of the dual numbers. A version of the SMART software is in the stage of refactorization to dual and duplex numbers, what enables to get rid of the finite differences, as an additional source of lowering precision of the computed results.

Sapar, A.; Poolamäe, R.; Sapar, L.

216

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

217

High precision titanium isotope measurements on geological samples by high resolution MC-ICPMS  

NASA Astrophysics Data System (ADS)

A method has been developed for the precise and reproducible measurement of Ti isotopes in natural materials using high resolution MC-ICPMS. Instrumental mass fractionation is internally corrected using 49Ti/47Ti. Replicate measurements of synthetic standard solutions, terrestrial rocks, and the carbonaceous chondrite Allende yield a long-term reproducibility (2[sigma]) of 0.28[var epsilon], 0.34[var epsilon], and 0.28[var epsilon] for 50Ti/47Ti, 48Ti/47Ti, and 46Ti/47Ti, respectively. Isobaric interferences from 46,48Ca+, 50V+, 50Cr+, and doubly charged Zr can be corrected for reliably in separated Ti solutions with Ca/Ti < 5, V/Ti < 0.3, Cr/Ti < 0.2, and Zr/Ti < 1, respectively. Such elemental ratios are achieved easily in most samples using the anion-exchange procedure presented. Single and double charged polyatomic ions can either be resolved, e.g., 14N36Ar+, or do not compromise the measurements. The method has been successfully applied to terrestrial rocks, meteorites, and various mineral separates. Terrestrial samples and standards agree within analytical uncertainties but are consistently different from the recommended values of Niederer et al. [F.R. Niederer, D.A. Papanastassiou, G.J. Wasserburg, Geochim. Cosmochim. Acta 45 (1981) 1017] with the largest effect on 50Ti/47Ti. The new results provide evidence that the recommended terrestrial 50Ti/47Ti is not well constrained; our data are higher by ~13[var epsilon] than the recommended value. Better agreement is found with the values recommended by Heydegger et al. [H.R. Heydegger, J.J. Foster, W. Compston, Earth Planet. Sci. Lett. 58 (1982) 406]. Our best estimate for the isotopic composition of terrestrial Ti (relative to 49Ti/47Ti = 0.749766) is: 50Ti/47Ti = 0.73010, 48Ti/47Ti = 10.06884, and 46Ti/47Ti = 1.09325. This corresponds to an atomic weight of 47.877, significantly different from the value of 47.867 recommended by IUPAC. A 50Ti/47Ti anomaly for bulk Allende of 3.37 ± 0.51[var epsilon] is found, while for 48Ti/47Ti and 46Ti/47Ti the data are identical to the terrestrial value within the uncertainties. This is consistent with other recently reported differences between the bulk Earth and chondrites in neutron-rich nuclides.

Leya, Ingo; Schönbächler, Maria; Wiechert, Uwe; Krähenbühl, Urs; Halliday, Alex N.

2007-05-01

218

[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

219

High-precision measurements in few-electron highly charged ions at the Heidelberg Electron Beam Ion Trap (EBIT)  

Microsoft Academic Search

The research program at the Heidelberg Electron Beam Ion Trap (EBIT) has concentrated mainly on precision measurements relevant to quantum electrodynamics (QED) and nuclear physics. Spectroscopic measurements in the optical region have delivered the most accurate wavelengths ever reported for highly charged ions, extracting even isotopic shifts. The forbidden transitions of B-like Ar XIV and Be-like Ar XV ions were

J. R. C. Lopez-Urrutia; J. Braun; G. Brenner; H. Bruhns; N. Dragani; A. J. G. Martinez; A. Lapierre; V. Mironov; C. Osborne; G. Sikler; R. Soria Orts; H. Tawara; J. Ullrich; I. I. Tupitsyn; V. M. Shabaev

2005-01-01

220

Using femtosecond laser to fabricate highly precise interior three-dimensional microstructures in polymeric flow chip  

PubMed Central

This paper reports using femtosecond laser marker to fabricate the three-dimensional interior microstructures in one closed flow channel of plastic substrate. Strip-like slots in the dimensions of 800 ?m×400 ?m×65 ?m were ablated with pulse Ti:sapphire laser at 800 nm (pulse duration of ?120 fs with 1 kHz repetition rate) on acrylic slide. After ablation, defocused beams were used to finish the surface of microstructures. Having finally polished with sonication, the laser fabricated structures are highly precise with the arithmetic roughness of 1.5 and 4.5 nm. Fabricating such highly precise microstructures cannot be accomplished with nanosecond laser marking or other mechanical drilling methods. In addition, since laser ablation can directly engrave interior microstructures in one closed chip, glue smearing problems to damage molded microstructures possibly to occur during the chip sealing procedures can be avoided too. PMID:21079695

Lee, Chia-Yu; Chang, Ting-Chou; Wang, Shau-Chun; Chien, Chih-Wei; Cheng, Chung-Wei

2010-01-01

221

Geometrical aspects of laser-drilled high precision holes for flow control applications  

NASA Astrophysics Data System (ADS)

Laser drilling has become a valuable tool for the manufacture of high precision micro holes in a variety of materials. Laser drilled precision holes have applications in the automotive, aerospace, medical and sensor industry for flow control applications. The technology is competing with conventional machining micro electro-discharge machining in the field of fuel injection nozzle for combustion engines. Depending on the application, laser and optics have to be chosen which suits the requirements. In this paper, the results achieved with different lasers and drilling techniques will be compared to the hole specifications in flow control applications. The issue of geometry control of high aspect ratio laser drilled holes in metals will be investigated. The comparison of flow measurement results to microscopic hole dimension measurement show that flow characteristics strongly depend on cavitation number during flow.

Giedl, Roswitha; Helml, H.-J.; Wagner, F. X.; Wild, Michael J.

2003-11-01

222

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

223

Scientific results from high-precision astrometry at the Palomar Testbed Interferometer  

NASA Astrophysics Data System (ADS)

A new observing mode for the Palomar Testbed Interferometer was developed in 2002-2003 which enables differential astrometry at the level of 20 micro-arcseconds (?as) for binary systems with separations of several hundred milli-arcseconds (mas). This phase-referenced mode is the basis of the Palomar High-precision Astrometric Search for Exoplanet Systems (PHASES), a search for giant planets orbiting either the primary or secondary star in fifty binary systems. We present the first science results from the PHASES search. The properties of the stars comprising binary systems are determined to high precision. The mutual inclinations of several hierarchical triple star systems have been determined. We will present upper limits constraining the the existence of giant planets in a few of the target systems.

Muterspaugh, Matthew W.; Lane, Benjamin F.; Konacki, Maciej; Burke, B. F.; Colavita, M. M.; Kulkarni, S. R.; Shao, M.

2006-06-01

224

Determination of the half-life of 213Fr with high precision  

NASA Astrophysics Data System (ADS)

High-precision measurement of half-life and Q? value of neutral and highly charged ? emitters is a major subject of investigation currently. In this framework, we recently pushed half-life measurements of neutral emitters to a precision of a few per mil. This result was achieved by using different techniques and apparatuses at Istituto Nazionale di Fisica Nucleare Laboratori Nazionali del Sud (INFN-LNS) and GSI Darmstadt. Here we report on 213Fr half-life determination [T1/2(213Fr) = 34.14±0.06 s] at INFN-LNS, detailing the measurement protocol used. Direct comparison with the accepted value in the literature shows a discrepancy of more than three sigma. We propose this new value as a reference, discussing previous experiments.

Fisichella, M.; Musumarra, A.; Farinon, F.; Nociforo, C.; Del Zoppo, A.; Figuera, P.; La Cognata, M.; Pellegriti, M. G.; Scuderi, V.; Torresi, D.; Strano, E.

2013-07-01

225

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

226

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

227

Verification program for a high-precision large cryogenic lens holder  

Microsoft Academic Search

For the Euclid mission a Pre-Development phase is implemented to prove feasibility of individual components of the system. The Near Infrared Spectrometer and Photometer (NISP) of EUCLID requires high precision and large lens holders (Ø170 mm) at cryogenic temperatures (120K - 150K). The four lenses of the optical system are made of different materials: fused silica, CaF2, and LF5G15 that

A. Boesz; F. Grupp; T. Leberle; A. Mottaghibonab; N. Geis; R. Bender

2011-01-01

228

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

229

High-precision infrared pulse laser ranging for active vehicle anti-collision application  

Microsoft Academic Search

In this work, a high-precision infrared pulse laser ranging system based on FPGA and microcontroller Atmel16 is proposed for active vehicle anti-collision application, and the key technologies of this system including optical device, laser receiver component, and time-of-flight stretching component are studied deeply based on the principle of the pulse laser time-of-flight measurement. The light energy transmission is analyzed in

Yandong Chen; Zhiqiang Meng; Jinglin Liu; Heping Jiang

2011-01-01

230

A comparative study of integrators for constructing ephemerides with high precision.  

NASA Astrophysics Data System (ADS)

There are four indexes for evaluating various integrators. They are the local truncation error, the numerical stability, the complexity of computation and the quality of adaptation. A review and a comparative study of several numerical integration methods, such as Adams, Cowell, Runge-Kutta-Fehlberg, Gragg-Bulirsch-Stoer extrapolation, Everhart, Taylor series and Krogh, which are popular for constructing ephemerides with high precision, has been worked out.

Huang, Tian-Yi

1990-09-01

231

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

PubMed Central

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

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

2010-01-01

232

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

233

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

SciTech Connect

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

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

1988-12-31

234

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

235

Electromagnetic Controlled Cortical Impact Device for Precise, Graded Experimental Traumatic Brain Injury  

PubMed Central

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.; DONALD, CHRISTINE Mac; KESSENS, CHAD C.; YUEDE, CARLA; PARSADANIAN, MAIA; SPINNER, MIKE; KIM, EDDIE; SCHWETYE, KATHERINE E.; HOLTZMAN, DAVID M.; BAYLY, PHILIP V.

2008-01-01

236

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

237

Mathematical model for chemically induced lipid peroxidation in precision-cut liver slices: computer simulation and experimental calibration.  

PubMed

A biologically based pharmacodynamic (BBPD) model was developed in order to describe and simulate chemically induced lipid peroxidation in precision cut mouse liver slices. The model was written in Advanced Continuous Simulation Language (ACSL) and simulations were performed using SIMUSOLV software on a VAX/VMS mainframe computer. The BBPD model simulated formation of lipid hydroperoxides and thiobarbituric acid reactive substances (TBARS) over time as a function of the amounts of cytochrome P450 (CYP)-activated chemical inducer and active antioxidants. The rate of peroxidation was controlled by lipid peroxidizability, destruction of CYP, autooxidation, and activity of glutathione peroxidase. The BBPD model was initially parameterized with the literature data for TBARS formation during lipid peroxidation, reported for rat liver slices induced with bromotrichloromethane and tert-butyl hydroperoxide (TBOOH). Then, the biochemical parameters were adjusted to reflect the physiology of the mouse liver, and the BBPD model was used to simulate TBARS formation during lipid peroxidation in precision cut mouse liver slices induced with TBOOH. The BBPD model predictions were in agreement with the experimental data. PMID:8835842

Byczkowski, J Z; Channel, S R; Pravecek, T L; Miller, C R

1996-06-01

238

Optical phasing of a segmented mirror with sub-nanometer precision: experimental results of the APE Internal Metrology  

NASA Astrophysics Data System (ADS)

This paper presents a non-contact optical metrology measuring the pistons and tip/tilt angles of the 61 hexagonal segments of a compact-sized segmented mirror. The instrument has been developed within the scope of a design study for a European Extremely Large Telescope (E-ELT). It is used as reference sensor for cophasing of the mirror segments in closed loop control. The mirror shape is also measured by different types of stellar light-based phasing cameras whose performances will be evaluated with regard to a future E-ELT. Following a description of the system architecture, the second part of the paper presents experimental results demonstrating the level of precision: 0.48nm RMS in piston and 0.074 ?rad RMS in tip and tilt.

Wilhelm, Rainer; Luong, Bruno; Courteville, Alain; Estival, Sébastien; Gonté, Frédéric

2008-07-01

239

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

240

Radiography of a normal fault system by 64,000 high-precision earthquake locations: The 2009 L'Aquila  

E-print Network

Radiography of a normal fault system by 64,000 high-precision earthquake locations: The 2009 L of a rheological (i.e., creeping) discontinuity explaining how normal faults detach at depth. Citation: Valoroso, L of a normal fault system by 64,000 high-precision earthquake locations: The 2009 L'Aquila (central Italy) case

Cerveny, Vlastislav

241

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

242

Interisotope determination of ultracold rubidium interactions from three high-precision experiments.  

PubMed

Combining the measured binding energies of four of the most weakly bound rovibrational levels of the 87Rb2 molecule with results of two other recent high-precision experiments, we obtain exceptionally strong constraints on the atomic interaction parameters in a highly model independent analysis. The comparison of (85)Rb and (87)Rb data, where the two isotopes are related by a mass scaling procedure, plays a crucial role. We predict scattering lengths, clock shifts, and Feshbach resonances with an unprecedented level of accuracy. Two of the Feshbach resonances occur at easily accessible magnetic fields in mixed-spin channels. One is related to a d-wave shape resonance. PMID:11864003

van Kempen, E G M; Kokkelmans, S J J M F; Heinzen, D J; Verhaar, B J

2002-03-01

243

High precision atomic data for halo nuclei and related nuclear structure  

SciTech Connect

Nuclear charge radii of the lightest neutron-halo isotopes {sup 6,8}He, {sup 11}Li, and {sup 11}Be have been measured during the last decade using tailored laser-spectroscopic techniques for the needs of high-accuracy isotope shift measurements on millisecond-isotopes with very low production yields. Nuclear charge radii can be extracted using high-precision calculations of the mass-shift contribution and the electronic factor of the finite-nuclear-size effect. These results are important benchmarks for nuclear structure theory and give access to the correlations between halo neutrons and average distances of the halo neutrons from the core nucleus.

Noertershaeuser, Wilfried [Technische Universitaet Darmstadt (Germany); Johannes Gutenberg-Universitaet Mainz (Germany); GSI Helmholtzzentrum fuer Schwerionenforschung, Darmstadt (Germany)

2013-07-11

244

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

245

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

246

High precision Faraday collector MC-ICPMS thorium isotope ratio determination  

NASA Astrophysics Data System (ADS)

Uranium-series dating of carbonate materials requires precise determination of the spike sample thorium isotope ratio, 230Th/229Th. This ratio is commonly measured using ion counting techniques, however the precision of analyses using ion counting devices suffers from beam intensity limitations, drift in multiplier gain and non-linearities in electron multiplier response. Here, we describe the application of multiple-collector inductively coupled plasma mass spectrometry (MC-ICPMS) to determine thorium isotope ratios at hitherto unattained precision. For the first time, thorium isotope analyses were performed using only Faraday collectors coupled to 1011 [Omega] feedback resistors in the amplifier system. Spiked thorium solutions were concentrated to produce 230Th and 229Th signal intensities of around 50 mV and 100 mV, respectively (across a 1011 [Omega] resistor) and are run at high intensity for a short period of time (~1 min). These analyses yield a 230Th/229Th external reproducibility of better than 0.3[per mille sign] for ~25-30 pg of consumed 230Th. This is a factor of two better than the best published thermal ionisation mass spectrometry (TIMS) and MC-ICPMS techniques for similar sample sizes, and represents up to an order of magnitude improvement over many other established protocols. Combined with new techniques for high precision Faraday measurement of uranium isotopic composition [1], this permits improvements in the uncertainty of U-series ages to better than 0.1 thousand years (ka) at 100 ka and 1 ka at 300 ka. It should also be possible to resolve events to ~14 ka at 600 ka. Using these techniques, the U-series dating limit can be extended from 500-600 ka to 800 ka enabling a more detailed study of the frequency of late Pleistocene climate events.

Potter, Emma-Kate; Stirling, Claudine H.; Andersen, Morten B.; Halliday, Alex N.

2005-12-01

247

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

248

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

NASA Astrophysics Data System (ADS)

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.

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

2014-05-01

249

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

250

Maintaining high precision of isotope ratio analysis over extended periods of time.  

PubMed

Stable isotope ratios are reliable and long lasting process tracers. In order to compare data from different locations or different sampling times at a high level of precision, a measurement strategy must include reliable traceability to an international stable isotope scale via a reference material (RM). Since these international RMs are available in low quantities only, we have developed our own analysis schemes involving laboratory working RM. In addition, quality assurance RMs are used to control the long-term performance of the delta-value assignments. The analysis schemes allow the construction of quality assurance performance charts over years of operation. In this contribution, the performance of three typical techniques established in IsoLab at the MPI-BGC in Jena is discussed. The techniques are (1) isotope ratio mass spectrometry with an elemental analyser for delta(15)N and delta(13)C analysis of bulk (organic) material, (2) high precision delta(13)C and delta(18)O analysis of CO(2) in clean-air samples, and (3) stable isotope analysis of water samples using a high-temperature reaction with carbon. In addition, reference strategies on a laser ablation system for high spatial resolution delta(13)C analysis in tree rings is exemplified briefly. PMID:20183227

Brand, Willi A

2009-06-01

251

High precision differential abundance measurements in globular clusters: chemical inhomogeneities in NGC 6752  

NASA Astrophysics Data System (ADS)

We report on a strictly differential line-by-line analysis of high-quality UVES spectra of bright giants in the metal-poor globular cluster NGC 6752. We achieved high precision differential chemical abundance measurements for Fe, Na, Si, Ca, Ti, Cr, Ni, Zn, Y, Zr, Ba, La, Ce, Pr, Nd, Sm, Eu and Dy with uncertainties as low as ˜0.01 dex (˜2 per cent). We obtained the following main results. (1) The observed abundance dispersions are a factor of ˜2 larger than the average measurement uncertainty. (2) There are positive correlations, of high statistical significance, between all elements and Na. (3) For any pair of elements, there are positive correlations of high statistical significance, although the amplitudes of the abundance variations are small. Removing abundance trends with effective temperature and/or using a different pair of reference stars does not alter these results. These abundance variations and correlations may reflect a combination of (a) He abundance variations and (b) inhomogeneous chemical evolution in the pre- or protocluster environment. Regarding the former, the current constraints on ?Y from photometry likely preclude He as being the sole explanation. Regarding the latter, the nucleosynthetic source(s) must have synthesized Na, ?, Fe-peak and neutron-capture elements and in constant amounts for species heavier than Si; no individual object can achieve such nucleosynthesis. We speculate that other, if not all, globular clusters may exhibit comparable abundance variations and correlations to NGC 6752 if subjected to a similarly precise analysis.

Yong, David; Meléndez, Jorge; Grundahl, Frank; Roederer, Ian U.; Norris, John E.; Milone, A. P.; Marino, A. F.; Coelho, P.; McArthur, Barbara E.; Lind, K.; Collet, R.; Asplund, Martin

2013-10-01

252

An optical fan for light beams for high-precision optical measurements and optical switching  

E-print Network

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 totally new method, based on a combination of these two properties and using the thermal dispersion and electro-optical effect of birefringent crystals, the construction of a simple and robust scheme to rotate a light beam like a fan. Using a computer-based digital image processing technique, we determine the temperature and the 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.

Zhou, Zhi-Yuan; Ding, Dong-Sheng; Jiang, Yun-Kun; Zhang, Wei; Shi, Shuai; Shi, Bao-Sen; Guo, Guang-Can

2014-01-01

253

An optical fan for light beams for high-precision optical measurements and optical switching  

E-print Network

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 totally new method, based on a combination of these two properties and using the thermal dispersion and electro-optical effect of birefringent crystals, the construction of a simple and robust scheme to rotate a light beam like a fan. Using a computer-based digital image processing technique, we determine the temperature and the 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.

Zhi-Yuan Zhou; Yan Li; Dong-Sheng Ding; Yun-Kun Jiang; Wei Zhang; Shuai Shi; Bao-Sen Shi; Guang-Can Guo

2014-05-08

254

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

255

Experimental Summary: Very High Energy Cosmic Rays and their Interactions  

NASA Astrophysics Data System (ADS)

The XVII International Symposium on Very High Energy Cosmic Ray Interactions, held in August of 2012 in Berlin, was the first one in the history of the Symposium,where a plethora of high precision LHC data with relevance for cosmic ray physics was presented. This report aims at giving a brief summary of those measurements andit discusses their relevance for observations of high energy cosmic rays. Enormous progress has been made also in air shower observations and in direct measurements of cosmic rays, exhibiting many more structure in the cosmic ray energy spectrum than just a simple power law with a knee and an ankle. At the highest energy, the flux suppression may not be dominated by the GZK-effect but by the limiting energy of a nearby source or source population. New projects and application of new technologies promise further advances also in the near future. We shall discuss the experimental and theoretical progress in the field and its prospects for coming years.

Kampert, Karl-Heinz

2013-06-01

256

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

257

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

258

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

259

High-precision resistance measurements on amorphous CuTi down to 15 mK  

NASA Astrophysics Data System (ADS)

We have developed a new method for making high-precision resistance measurements on amorphous-metal ribbons with very reliable thermometry down to 15 mK. In our technique the measuring current flows perpendicular to the plane of the metal ribbon and potassium metal is used to thermally anchor the ribbon to the thermometers and refrigerator. We have been able to obtain very good fits of the weak-localization and enhanced electron-electron interaction theories to the CuTi data in zero field.

Fan, R.; Pratt, W. P., Jr.; Greig, D.

1992-11-01

260

High school driver education using peer tutors, direct instruction, and precision teaching.  

PubMed Central

The authors investigated the combined effects of direct instruction and precision teaching by peer tutors in a high school driver education curriculum. Learners (N = 4) included students with intellectual and learning disabilities and students without disabilities. Peer tutoring was associated with immediate increases in correct responding and a simultaneous and rapid deceleration of errors. Three learners passed the written tests in the driver education classroom, obtained driver's licenses, and produced similar or better driving records than students who did not require assistance. This program is being continued and expanded by school personnel without assistance from the authors. PMID:2055802

Bell, K E; Young, K R; Salzberg, C L; West, R P

1991-01-01

261

Characterization of an INVS Model IV Neutron Counter for High Precision ($?,n$) Cross-Section Measurements  

E-print Network

A neutron counter designed for assay of radioactive materials has been adapted for beam experiments at TUNL. The cylindrical geometry and 60% maximum efficiency make it well suited for ($\\gamma,n$) cross-section measurements near the neutron emission threshold. A high precision characterization of the counter has been made using neutrons from several sources. Using a combination of measurements and simulations, the absolute detection efficiency of the neutron counter was determined to an accuracy of $\\pm$ 3% in the neutron energy range between 0.1 and 1 MeV. It is shown that this efficiency characterization is generally valid for a wide range of targets.

C. W. Arnold; T. B. Clegg; H. J Karwowski; G. C. Rich; J. R. Tompkins; C. R. Howell

2011-01-17

262

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

263

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

264

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

265

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

266

Fabrication of micro-optical components by high-precision embossing  

NASA Astrophysics Data System (ADS)

Optical components, such as miniature spectrometer gratings working in the infrared range for environmental monitoring or physical analytics, contribute appeciably to the price of Micro Electro Opto Mechanical Systems (MOEMS). These optical components could be a part of a miniature functional package produced with an alternative fabrication technology based on cold forming metals. The cost-efficient fabrication of these components, for example by implementation of forming technology, appears promising. With this technology, high quality embossing of optical structures for high precision requirements in a batch process is possible. In this way the system costs can be reduced. In this paper aluminum forming by cold embossed grating for the fabrication of gratings was investigated. Experiments with different geometries of the embossed grating were carried out. The quality of the embossed structures is primarily determined by the precision and surface quality of the die. Therefore we used a single crystalline silicon tool made by etching as a die. Quality criteria for the review of the formed optical grating were the geometry of surfaces and the surface roughness as well as optical properties of the total structure.

Otto, Thomas; Schubert, Andreas; Boehm, Juliana; Gessner, Thomas

2000-08-01

267

A High Precision Position Sensor Design and Its Signal Processing Algorithm for a Maglev Train  

PubMed Central

High precision positioning technology for a kind of high speed maglev train with an electromagnetic suspension (EMS) system is studied. At first, the basic structure and functions of the position sensor are introduced and some key techniques to enhance the positioning precision are designed. Then, in order to further improve the positioning signal quality and the fault-tolerant ability of the sensor, a new kind of discrete-time tracking differentiator (TD) is proposed based on nonlinear optimal control theory. This new TD has good filtering and differentiating performances and a small calculation load. It is suitable for real-time signal processing. The stability, convergence property and frequency characteristics of the TD are studied and analyzed thoroughly. The delay constant of the TD is figured out and an effective time delay compensation algorithm is proposed. Based on the TD technology, a filtering process is introduced in to improve the positioning signal waveform when the sensor is under bad working conditions, and a two-sensor switching algorithm is designed to eliminate the positioning errors caused by the joint gaps of the long stator. The effectiveness and stability of the sensor and its signal processing algorithms are proved by the experiments on a test train during a long-term test run. PMID:22778582

Xue, Song; Long, Zhiqiang; He, Ning; Chang, Wensen

2012-01-01

268

A high precision position sensor design and its signal processing algorithm for a maglev train.  

PubMed

High precision positioning technology for a kind of high speed maglev train with an electromagnetic suspension (EMS) system is studied. At first, the basic structure and functions of the position sensor are introduced and some key techniques to enhance the positioning precision are designed. Then, in order to further improve the positioning signal quality and the fault-tolerant ability of the sensor, a new kind of discrete-time tracking differentiator (TD) is proposed based on nonlinear optimal control theory. This new TD has good filtering and differentiating performances and a small calculation load. It is suitable for real-time signal processing. The stability, convergence property and frequency characteristics of the TD are studied and analyzed thoroughly. The delay constant of the TD is figured out and an effective time delay compensation algorithm is proposed. Based on the TD technology, a filtering process is introduced in to improve the positioning signal waveform when the sensor is under bad working conditions, and a two-sensor switching algorithm is designed to eliminate the positioning errors caused by the joint gaps of the long stator. The effectiveness and stability of the sensor and its signal processing algorithms are proved by the experiments on a test train during a long-term test run. PMID:22778582

Xue, Song; Long, Zhiqiang; He, Ning; Chang, Wensen

2012-01-01

269

Velocity and abundance precisions for future high-resolution spectroscopic surveys: a study for 4MOST  

E-print Network

In preparation for future, large-scale, multi-object, high-resolution spectroscopic surveys of the Galaxy, we present a series of tests of the precision in radial velocity and chemical abundances that any such project can achieve at a 4m class telescope. We briefly discuss a number of science cases that aim at studying the chemo-dynamical history of the major Galactic components (bulge, thin and thick disks, and halo) - either as a follow-up to the Gaia mission or on their own merits. Based on a large grid of synthetic spectra that cover the full range in stellar parameters of typical survey targets, we devise an optimal wavelength range and argue for a moderately high-resolution spectrograph. As a result, the kinematic precision is not limited by any of these factors, but will practically only suffer from systematic effects, easily reaching uncertainties <1 km/s. Under realistic survey conditions (namely, considering stars brighter than r=16 mag with reasonable exposure times) we prefer an ideal resolving...

Caffau, E; Sbordone, L; Sartoretti, P; Hansen, C J; Royer, F; Leclerc, N; Bonifacio, P; Christlieb, N; Ludwig, H G; Grebel, E K; de Jong, R S; Chiappini, C; Walcher, J; Mignot, S; Feltzing, S; Cohen, M; Minchev, I; Helmi, A; Piffl, T; Depagne, E; Schnurr, O

2012-01-01

270

Non-contact profiling for high precision fast asphere topology measurement  

NASA Astrophysics Data System (ADS)

Quality control in the fabrication of high precision optics these days needs nanometer accuracy. However, the fast growing number of optics with complex aspheric shapes demands an adapted measurement method as existing metrology systems more and more reach their limits. In this contribution the authors present a unique and highly flexible approach for measuring spheric and aspheric optics with diameters from 2mm up to 420mm and with almost unlimited spheric departures. Based on a scanning point interferometer the system combines the high precision and the speed of an optical interferometer with the high form flexibility of a classical tactile scanning system. This enables the measurement of objects with steep or strongly changing slopes such as "pancake" or "gull wing" objects. The high accuracy of ±50nm over the whole surface is achieved by using a full reference concept ensuring the position control even over long scanning paths. The core of the technology is a multiwavelength interferometer (MWLI); by use of several wavelengths this sensor system allows for the measurement of objects with polished as well as with ground surfaces. Furthermore, a large absolute measurement range facilitates measuring surfaces with steps or discontinuities like diffractive structures or even segmented objects. As all the measurements can be done using one and the same system, a direct comparison is possible during production and after finishing an object. The contribution gives an insight into the functionality of the MWLI-sensor as well as into the concept of the reference system of the scanning metrology system. Furthermore, samples of application are discussed.

Petter, Jürgen; Berger, Gernot

2013-04-01

271

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

272

Precision high-value resistance scaling with a two-terminal cryogenic current comparator.  

PubMed

We describe a cryogenic two-terminal high-resistance bridge and its application in precision resistance scaling from the quantized Hall resistance (QHR) at RH = RK/2 = 12?906.4035 ? to decade resistance standards with values between 1 M? and 1 G?. The design minimizes lead resistance errors with multiterminal connections to the QHR device. A single variable voltage source and resistive ratio windings are utilized to achieve excellent dynamic stability, which is not readily obtained in low-current measurements with conventional cryogenic current comparators (CCCs). Prototypes of this bridge have been verified by a successful international comparison of high-resistance scaling using two-terminal CCCs in the national metrology institutes of Argentina, Mexico, and the United States. PMID:24784632

Hernandez-Marquez, F L; Bierzychudek, M E; Jones, G R; Elmquist, R E

2014-04-01

273

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

274

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

275

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

276

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

277

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

278

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

279

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

280

Highly Precise and Developmentally Programmed Genome Assembly in Paramecium Requires Ligase IV–Dependent End Joining  

PubMed Central

During the sexual cycle of the ciliate Paramecium, assembly of the somatic genome includes the precise excision of tens of thousands of short, non-coding germline sequences (Internal Eliminated Sequences or IESs), each one flanked by two TA dinucleotides. It has been reported previously that these genome rearrangements are initiated by the introduction of developmentally programmed DNA double-strand breaks (DSBs), which depend on the domesticated transposase PiggyMac. These DSBs all exhibit a characteristic geometry, with 4-base 5? overhangs centered on the conserved TA, and may readily align and undergo ligation with minimal processing. However, the molecular steps and actors involved in the final and precise assembly of somatic genes have remained unknown. We demonstrate here that Ligase IV and Xrcc4p, core components of the non-homologous end-joining pathway (NHEJ), are required both for the repair of IES excision sites and for the circularization of excised IESs. The transcription of LIG4 and XRCC4 is induced early during the sexual cycle and a Lig4p-GFP fusion protein accumulates in the developing somatic nucleus by the time IES excision takes place. RNAi–mediated silencing of either gene results in the persistence of free broken DNA ends, apparently protected against extensive resection. At the nucleotide level, controlled removal of the 5?-terminal nucleotide occurs normally in LIG4-silenced cells, while nucleotide addition to the 3? ends of the breaks is blocked, together with the final joining step, indicative of a coupling between NHEJ polymerase and ligase activities. Taken together, our data indicate that IES excision is a “cut-and-close” mechanism, which involves the introduction of initiating double-strand cleavages at both ends of each IES, followed by DSB repair via highly precise end joining. This work broadens our current view on how the cellular NHEJ pathway has cooperated with domesticated transposases for the emergence of new mechanisms involved in genome dynamics. PMID:21533177

Marmignon, Antoine; Ku, Michael; Silve, Aude; Meyer, Eric; Forney, James D.; Malinsky, Sophie; Bétermier, Mireille

2011-01-01

281

Highly precise and developmentally programmed genome assembly in Paramecium requires ligase IV-dependent end joining.  

PubMed

During the sexual cycle of the ciliate Paramecium, assembly of the somatic genome includes the precise excision of tens of thousands of short, non-coding germline sequences (Internal Eliminated Sequences or IESs), each one flanked by two TA dinucleotides. It has been reported previously that these genome rearrangements are initiated by the introduction of developmentally programmed DNA double-strand breaks (DSBs), which depend on the domesticated transposase PiggyMac. These DSBs all exhibit a characteristic geometry, with 4-base 5' overhangs centered on the conserved TA, and may readily align and undergo ligation with minimal processing. However, the molecular steps and actors involved in the final and precise assembly of somatic genes have remained unknown. We demonstrate here that Ligase IV and Xrcc4p, core components of the non-homologous end-joining pathway (NHEJ), are required both for the repair of IES excision sites and for the circularization of excised IESs. The transcription of LIG4 and XRCC4 is induced early during the sexual cycle and a Lig4p-GFP fusion protein accumulates in the developing somatic nucleus by the time IES excision takes place. RNAi-mediated silencing of either gene results in the persistence of free broken DNA ends, apparently protected against extensive resection. At the nucleotide level, controlled removal of the 5'-terminal nucleotide occurs normally in LIG4-silenced cells, while nucleotide addition to the 3' ends of the breaks is blocked, together with the final joining step, indicative of a coupling between NHEJ polymerase and ligase activities. Taken together, our data indicate that IES excision is a "cut-and-close" mechanism, which involves the introduction of initiating double-strand cleavages at both ends of each IES, followed by DSB repair via highly precise end joining. This work broadens our current view on how the cellular NHEJ pathway has cooperated with domesticated transposases for the emergence of new mechanisms involved in genome dynamics. PMID:21533177

Kapusta, Aurélie; Matsuda, Atsushi; Marmignon, Antoine; Ku, Michael; Silve, Aude; Meyer, Eric; Forney, James D; Malinsky, Sophie; Bétermier, Mireille

2011-04-01

282

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

283

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

284

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

285

High-precision test of collective versus single-particle motion of protons and neutrons in the  

E-print Network

sources: DOE Office of Science, Office of Nuclear Physics Resources: Holifield Radioactive Beam Facility for the nuclear shell model (basic microscopic model of all nuclear theory). · These high-precision results

286

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

287

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

PubMed Central

Recent excavations and high-precision radiocarbon dating from the largest Iron Age (IA, ca. 1200–500 BCE) copper production center in the southern Levant demonstrate major smelting activities in the region of biblical Edom (southern Jordan) during the 10th and 9th centuries BCE. Stratified radiocarbon samples and artifacts were recorded with precise digital surveying tools linked to a geographic information system developed to control on-site spatial analyses of archaeological finds and model data with innovative visualization tools. The new radiocarbon dates push back by 2 centuries the accepted IA chronology of Edom. Data from Khirbat en-Nahas, and the nearby site of Rujm Hamra Ifdan, demonstrate the centrality of industrial-scale metal production during those centuries traditionally linked closely to political events in Edom's 10th century BCE neighbor ancient Israel. Consequently, the rise of IA Edom is linked to the power vacuum created by the collapse of Late Bronze Age (LB, ca. 1300 BCE) civilizations and the disintegration of the LB Cypriot copper monopoly that dominated the eastern Mediterranean. The methodologies applied to the historical IA archaeology of the Levant have implications for other parts of the world where sacred and historical texts interface with the material record. PMID:18955702

Levy, Thomas E.; Higham, Thomas; Bronk Ramsey, Christopher; Smith, Neil G.; Ben-Yosef, Erez; Robinson, Mark; Münger, Stefan; Knabb, Kyle; Schulze, Jürgen P.; Najjar, Mohammad; Tauxe, Lisa

2008-01-01

288

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

289

High precision study of muon catalyzed fusion in D2 and HD gas  

NASA Astrophysics Data System (ADS)

Muon catalyzed dd fusion in D2 and HD gases in the temperature range from 28 to 350 K was investigated in a series of experiments based on a time-projection ionization chamber operating with pure hydrogen. All main observables in this reaction chain were measured with high absolute precision including the resonant and non-resonant dd? formation rates, the rate for hyperfine transitions in d? atoms, the branching ratio of the two charge symmetric fusion channels 3He + n and t + p and the muon sticking probability. The report presents the final analysis of the data together with a comprehensive comparison with calculations based on recent ?CF theories. The energy of the loosely bound dd? state with quantum numbers J = 1, ? = 1, which is central to the mechanism of resonant molecule formation, is extracted with precision ?11(fit) = -1.9651(7) eV. in impressive agreement with the latest theoretical results ?11(theory) = -1.9646 eV.

Balin, D. V.; Ganzha, V. A.; Kozlov, S. M.; Maev, E. M.; Petrov, G. E.; Soroka, M. A.; Schapkin, G. N.; Semenchuk, G. G.; Trofimov, V. A.; Vasiliev, A. A.; Vorobyov, A. A.; Voropaev, N. I.; Petitjean, C.; Gartner, B.; Lauss, B.; Marton, J.; Zmeskal, J.; Case, T.; Crowe, K. M.; Kammel, P.; Hartmann, F. J.; Faifman, M. P.

2011-03-01

290

High Precision CTE-Measurement of SiC-100 for Cryogenic Space-Telescopes  

E-print Network

We present the results of high precision measurements of the thermal expansion of the sintered SiC, SiC-100, intended for use in cryogenic space-telescopes, in which minimization of thermal deformation of the mirror is critical and precise information of the thermal expansion is needed for the telescope design. The temperature range of the measurements extends from room temperature down to $\\sim$ 10 K. Three samples, #1, #2, and #3 were manufactured from blocks of SiC produced in different lots. The thermal expansion of the samples was measured with a cryogenic dilatometer, consisting of a laser interferometer, a cryostat, and a mechanical cooler. The typical thermal expansion curve is presented using the 8th order polynomial of the temperature. For the three samples, the coefficients of thermal expansion (CTE), $\\bar{\\alpha}_{#1}$, $\\bar{\\alpha}_{#2}$, and $\\bar{\\alpha}_{#3}$ were derived for temperatures between 293 K and 10 K. The average and the dispersion (1 $\\sigma$ rms) of these three CTEs are 0.816 an...

Enya, K; Onaka, T; Nakagawa, T; Kaneda, H; Hirabayashi, M; Toulemont, Y; Castel, D; Kanai, Y; Fujishiro, N

2007-01-01

291

Surface-enhanced resonance Raman scattering nanostars for high-precision cancer imaging.  

PubMed

The inability to visualize the true extent of cancers represents a significant challenge in many areas of oncology. The margins of most cancer types are not well demarcated because the cancer diffusely infiltrates the surrounding tissues. Furthermore, cancers may be multifocal and characterized by the presence of microscopic satellite lesions. Such microscopic foci represent a major reason for persistence of cancer, local recurrences, and metastatic spread, and are usually impossible to visualize with currently available imaging technologies. An imaging method to reveal the true extent of tumors is desired clinically and surgically. We show the precise visualization of tumor margins, microscopic tumor invasion, and multifocal locoregional tumor spread using a new generation of surface-enhanced resonance Raman scattering (SERRS) nanoparticles, which are termed SERRS nanostars. The SERRS nanostars feature a star-shaped gold core, a Raman reporter resonant in the near-infrared spectrum, and a primer-free silication method. In genetically engineered mouse models of pancreatic cancer, breast cancer, prostate cancer, and sarcoma, and in one human sarcoma xenograft model, SERRS nanostars enabled accurate detection of macroscopic malignant lesions, as well as microscopic disease, without the need for a targeting moiety. Moreover, the sensitivity (1.5 fM limit of detection) of SERRS nanostars allowed imaging of premalignant lesions of pancreatic and prostatic neoplasias. High sensitivity and broad applicability, in conjunction with their inert gold-silica composition, render SERRS nanostars a promising imaging agent for more precise cancer imaging and resection. PMID:25609167

Harmsen, Stefan; Huang, Ruimin; Wall, Matthew A; Karabeber, Hazem; Samii, Jason M; Spaliviero, Massimiliano; White, Julie R; Monette, Sébastien; O'Connor, Rachael; Pitter, Kenneth L; Sastra, Stephen A; Saborowski, Michael; Holland, Eric C; Singer, Samuel; Olive, Kenneth P; Lowe, Scott W; Blasberg, Ronald G; Kircher, Moritz F

2015-01-21

292

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

293

High-resolution estimation of the water balance of high-precision lysimeters  

NASA Astrophysics Data System (ADS)

Lysimeters offer the opportunity to determine precipitation, evapotranspiration and groundwater recharge with high accuracy. In comparison to other techniques, like Eddy-flux-systems or evaporation pans, lysimeters provide a direct measurement of evapotranspiration via the built-in weighing system. The measurement of precipitation can benefit of the much higher surface area compared to typical rain gauge systems. Nevertheless, lysimeters are exposed to several external influences that could falsify the calculated fluxes. Therefore, the estimation of the relevant fluxes requires an adequate data processing, while accounting for the various possible error sources. Most lysimeter studies correct noise in the data by applying a smoothing of the data using a time window of about one hour. These high averaging times can lead to a falsification of the water balance and a loss of information on the dynamics of the processes. In the present study, we present a processing scheme which is based on five filter components that refer to different possible error sources and allow a simple implementation. We further use a set of 12 crop lysimeters and 6 grass lysimeters of the TERENO SoilCan research site Bad Lauchstädt to show that a temporally highly resolved data processing of lysimeter data with a high temporal resolution and good accuracy is possible.

Hannes, Matthias; Wollschläger, Ute; Vogel, Hans-Jörg; Fank, Johann; Pütz, Thomas; Durner, Wolfgang; Schrader, Frederik; Gebler, Sebastian

2014-05-01

294

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

295

Glacial rebound of the British Isles?II. A high-resolution, high-precision model  

Microsoft Academic Search

SUMMARY Observations of ice movements across the British Isles and of sea-level changes around the shorelines during Late Devensian time (after about 25 000 yr BP) have been used to establish a high spatial and temporal resolution model for the rebound of Great Britain and associated sea-level change. The sea-level observations include sites within the margins of the former ice

Kurt Lambeck

1993-01-01

296

High precision electric gate for time-of-flight ion mass spectrometers  

NASA Technical Reports Server (NTRS)

A time-of-flight mass spectrometer having a chamber with electrodes to generate an electric field in the chamber and electric gating for allowing ions with a predetermined mass and velocity into the electric field. The design uses a row of very thin parallel aligned wires that are pulsed in sequence so the ion can pass through the gap of two parallel plates, which are biased to prevent passage of the ion. This design by itself can provide a high mass resolution capability and a very precise start pulse for an ion mass spectrometer. Furthermore, the ion will only pass through the chamber if it is within a wire diameter of the first wire when it is pulsed and has the right speed so it is near all other wires when they are pulsed.

Sittler, Edward C. (Inventor)

2011-01-01

297

Highly precise distributed Brillouin scattering sensor for structural health monitoring of optical ground wire cable  

NASA Astrophysics Data System (ADS)

A distributed Brillouin scattering sensor with high special precision has been developed for the measurement of small damages/cracks of 1.5 cm. The out-layer damaged regions in an optical ground wire (OPGW) cable have been identified successfully by measuring the strain distributions every 5 cm using this technology. The stress increased to 127 kN which corresponds to more than 7500 micro-strain in the fibers. The locations of structural indentations comprising repaired and undamaged regions are found and distinguished using their corresponding strain data. The elongation of repaired region increases with time on 127 kN. These results are quantified in terms of the fiber orientation, stress, and behavior relative to undamaged sections.

Zou, Lufan; Ravet, Fabien; Bao, Xiaoyi; Chen, Liang

2004-07-01

298

Frequency-comb-referenced mid-infrared source for high-precision spectroscopy.  

PubMed

We report on a tunable continuous-wave mid-infrared optical parametric oscillator (OPO), which is locked to a fully stabilized near-infrared optical frequency comb using a frequency doubling scheme. The OPO is used for 40 GHz mode-hop-free, frequency-comb-locked scans in the wavelength region between 2.7 and 3.4 ?m. We demonstrate the applicability of the method to high-precision cavity-ring-down spectroscopy of nitrous oxide (N2O) and water (H2O) at 2.85 µm and of methane (CH4) at 3.2 ?m. PMID:25607205

Peltola, Jari; Vainio, Markku; Fordell, Thomas; Hieta, Tuomas; Merimaa, Mikko; Halonen, Lauri

2014-12-29

299

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

300

Design of a high precision microwave reflector. [for earth upper atmosphere study  

NASA Technical Reports Server (NTRS)

Development of a high accuracy spherical microwave reflector to support contour RMS and pointing requirements for a new series of space instruments is reported. The reflector system is composed of precision machined aluminum tile reflectors supported from a eutectic coated graphite epoxy structure by flexures. Several basic technologies have been integrated into a manufacturing process that accommodates fabrication techniques of both optical and composite constraints. The optical figure and its change due to thermal gradient was measured in a thermal vacuum environment with a Ronchi system. The radiometer system is in support of the Microwave Limb Sounder, an experiment to measure emissions from earth's atmospheric limb thus obtaining wind, temperature, pressure and chemical composition measurements.

Noller, E. W.; Bauer, J. L.

1980-01-01

301

High precision isotopic analyses of uranium and plutonium by total sample volatilization and signal integration  

SciTech Connect

Techniques have been developed which permit rapid, high-precision analyses of uranium and plutonium by multiple-filament thermal ionization mass spectrometry utilizing a commercial multicollector instrument. The salient feature of the method is volatilization of the entire sample while simultaneously integrating the signal from each isotope, thus virtually eliminating the effects of isotope fractionation in the evaporation process. The method permits the analysis of samples much smaller than required for conventional techniques using Faraday collectors and is expected to have application in the analysis of many elements in addition to uranium and plutonium. Run-to-run reproducibilities of <0.02% (RSD) have been obtained for isotope ratios of uranium and plutonium. 7 refs., 5 figs., 4 tabs.

Callis, E.L.; Abernathey, R.M.

1989-01-01

302

TITAN-EBIT — charge breeding of radioactive isotopes for high precision mass measurements  

NASA Astrophysics Data System (ADS)

TRIUMF's Ion Trap for Atomic and Nuclear science (TITAN) is a multi-ion trap facility with the goal of high precision mass measurements of radio-nuclides. TITAN is coupled to the ISAC on-line facility at TRIUMF, Vancouver, Canada, and consists of a Radio-Frequency Quadrupole (RFQ) buncher and cooler, an Electron Beam Ion Trap (EBIT), a Cooler Penning Trap (CPET), presently under construction and installation planned for 2011, and the Measurement Penning Trap (MPET). To date the TITAN EBIT has been used for charge breeding of stable and radioactive isotopes. In this paper we report the successful injection and extraction of stable Na and radioactive 25Na. Preliminary emittance measurements have been completed and the emittance in the vertical direction was found to be epsilonrms = 15.7±0.5?mm-mrad at a beam energy of 1.95 keV.

Gallant, A. T.; Brodeur, M.; Brunner, T.; Ettenauer, S.; Good, M.; Lapierre, A.; Ringle, R.; Simon, V. V.; Delheij, P.; Dilling, J.

2010-08-01

303

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

304

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

305

High-dimensional Sparse Precision Matrix Estimation via Sparse Column Inverse Operator  

E-print Network

This paper proposes a new method for estimating sparse precision matrices in the high dimensional setting. This procedure applies a novel Sparse Column-wise Inverse Operator (SCIO) to modified sample covariance matrices. We establish the convergence rates of this procedure under various matrix norms. Under the Frobenius norm loss, we prove theoretical guarantees on using cross validation to pick data-driven tunning parameters. Another important advantage of this estimator is its efficient computation for large-scale problems, using a path-following coordinate descent algorithm we provide. Numerical merits of our estimator are also illustrated using simulated and real datasets. In particular, this method is found to perform favorably on analyzing an HIV brain tissue dataset and an ADHD resting fMRI dataset.

Liu, Weidong

2012-01-01

306

The high precision gamma-ray spectrometer for lunar polar orbiter SELENE  

NASA Astrophysics Data System (ADS)

The high precision gamma-ray spectrometer (GRS) is scheduled to be launched on the lunar polar orbiter of the SELENE mission in 2007. The GRS consists of a large Ge crystal as a main detector and massive bismuth germanate crystals as an anticoincidence detector. A Stirling cryocooler was adopted in cooling the Ge detector. The flight model of SELENE GRS has been completed and an energy resolution of 3.0 keV (FWHM) at 1.332 MeV has been achieved. The spectrometer aims to observe nuclear line gamma rays emitted from the lunar surface in a wide energy range from 100 keV to 12 MeV for one year and more to obtain chemical composition on the entire lunar surface. The gamma-ray data enable us to study lunar geoscience problems including crust and mantle composition, and volatile reservoirs at polar regions.

Hasebe, N.; Yamashita, N.; Okudaira, O.; Kobayashi, S.; Yamamoto, H.; Ishizaki, T.; Hirano, K.; Sakurai, K.; Miyachi, T.; Miyajima, M.; Fujii, M.; Kobayashi, M.-N.; Takashima, T.; Shibamura, E.; Gasnault, O.; Maurice, S.; D'Uston, C.; Reedy, R.; Grande, M.

2008-07-01

307

Challenges and opportunities in high-precision Be-10 measurements at CAMS  

NASA Astrophysics Data System (ADS)

We determined the overall efficiency for 10Be of the high-intensity LLNL modified Middleton cesium sputter source in combination with the CAMS FN mass spectrometer. BeO - ionization efficiency is >3%. Charge exchange efficiency including transmission through the tandem for 7.5 MeV Be +3 is ˜34%, resulting in a total system efficiency of just over 1%. At this efficiency and with very low backgrounds, we estimate our detection limit to be ˜1000 10Be atoms. Cathodes prepared with only ˜80 ?g of 9Be show only an ˜33% reduction in 9Be beam current compared to a sample with ˜200 ?g. These same samples, prepared from 07KNSTD1032 standard material, contained 1 × 10 7 and 5 × 10 610Be atoms and exhibited similar ionization and total system efficiency. These results demonstrate the feasibility of pursuing applications that require precise measurement of samples with low 10Be concentrations and/or small sample size.

Rood, Dylan H.; Hall, Sarah; Guilderson, Thomas P.; Finkel, Robert C.; Brown, Thomas A.

2010-04-01

308

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

309

Correlated cryo-fluorescence and cryo-electron microscopy with high spatial precision and improved sensitivity.  

PubMed

Performing fluorescence microscopy and electron microscopy on the same sample allows fluorescent signals to be used to identify and locate features of interest for subsequent imaging by electron microscopy. To carry out such correlative microscopy on vitrified samples appropriate for structural cryo-electron microscopy it is necessary to perform fluorescence microscopy at liquid-nitrogen temperatures. Here we describe an adaptation of a cryo-light microscopy stage to permit use of high-numerical aperture objectives. This allows high-sensitivity and high-resolution fluorescence microscopy of vitrified samples. We describe and apply a correlative cryo-fluorescence and cryo-electron microscopy workflow together with a fiducial bead-based image correlation procedure. This procedure allows us to locate fluorescent bacteriophages in cryo-electron microscopy images with an accuracy on the order of 50 nm, based on their fluorescent signal. It will allow the user to precisely and unambiguously identify and locate objects and events for subsequent high-resolution structural study, based on fluorescent signals. PMID:24275379

Schorb, Martin; Briggs, John A G

2014-08-01

310

Verification program for a high-precision large cryogenic lens holder  

NASA Astrophysics Data System (ADS)

For the Euclid mission a Pre-Development phase is implemented to prove feasibility of individual components of the system. The Near Infrared Spectrometer and Photometer (NISP) of EUCLID requires high precision and large lens holders (Ø170 mm) at cryogenic temperatures (120K - 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 shall be verified by an adapted test facility including an optical metrology system. The characterization of the lens deformation and displacement due to thermally induced loads are driven by the required micrometer precision range and by 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 fiber based distance sensors. The applied distance measurement sensors have the capability to measure in a few mm range with submicron resolution at ultra high vacuum, in vibration environments and at liquid nitrogen temperatures and below. The calibration of the measurement system is of crucial importance; therefore the sensors shall be mounted on a stiff and well characterized reference structure made of nearly zero-CTE ceramic material. The verification program is currently under development at Kayser-Threde in the context of a contract with Max-Planck-Institute for Extraterrestrial Physics. The paper presents the vacuum chamber design, the metrology system, the used Ground Support Equipment, and the detailed verification program.

Boesz, A.; Grupp, F.; Leberle, T.; Mottaghibonab, A.; Geis, N.; Bender, R.

2011-09-01

311

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

312

Double Penning trap technique for precise g factor determinations in highly charged ions  

Microsoft Academic Search

:   We present a detailed description of an experiment to determine the magnetic moment of an electron bound in hydrogen-like\\u000a carbon. This forms a high-accuracy test of bound-state quantum electrodynamics. Special emphasis is given to the discussion\\u000a of systematic uncertainties which limit our present accuracy. The described experimental setup may also be used for the determination\\u000a of g factors in

H. Häffner; T. Beier; S. Djekic; N. Hermanspahn; H.-J. Kluge; W. Quint; S. Stahl; J. Verdú; T. Valenzuela; G. Werth

2003-01-01

313

The ASTROID Simulator Software Package: Realistic Modelling of High-Precision High-Cadence Space-Based Imaging  

E-print Network

The preparation of a space-mission that carries out any kind of imaging to detect high-precision low-amplitude variability of its targets requires a robust model for the expected performance of its instruments. This model cannot be derived from simple addition of noise properties due to the complex interaction between the various noise sources. While it is not feasible to build and test a prototype of the imaging device on-ground, realistic numerical simulations in the form of an end-to-end simulator can be used to model the noise propagation in the observations. These simulations not only allow studying the performance of the instrument, its noise source response and its data quality, but also the instrument design verification for different types of configurations, the observing strategy and the scientific feasibility of an observing proposal. In this way, a complete description and assessment of the objectives to expect from the mission can be derived. We present a high-precision simulation software packag...

Marcos-Arenal, P; De Ridder, J; Huygen, R; Aerts, C

2014-01-01

314

Theoretical and experimental research on error analysis and optimization of tool path in fabricating aspheric compound eyes by precision micro milling  

NASA Astrophysics Data System (ADS)

Structure design and fabricating methods of three-dimensional (3D) artificial spherical compound eyes have been researched by many scholars. Micro-nano optical manufacturing is mostly used to process 3D artificial compound eyes. However, spherical optical compound eyes are less at optical performance than the eyes of insects, and it is difficult to further improve the imaging quality of compound eyes by means of micro-nano optical manufacturing. In this research, nonhomogeneous aspheric compound eyes (ACEs) are designed and fabricated. The nonhomogeneous aspheric structure is applied to calibrate the spherical aberration. Micro milling with advantages in processing three-dimensional micro structures is adopted to manufacture ACEs. In order to obtain ACEs with high imaging quality, the tool paths are optimized by analyzing the influence factors consisting of interpolation allowable error, scallop height and tool path pattern. In the experiments, two kinds of ACEs are manufactured by micro-milling with different too path patterns and cutting parameter on the miniature precision five-axis milling machine tool. The experimental results indicate that the ACEs of high surface quality can be achieved by circularly milling small micro-lens individually with changeable cutting depth. A prototype of the aspheric compound eye (ACE) with surface roughness ( R a) below 0.12 ?m is obtained with good imaging performance. This research ameliorates the imaging quality of 3D artificial compound eyes, and the proposed method of micro-milling can improve surface processing quality of compound eyes.

Chen, Mingjun; Xiao, Yong; Tian, Wenlan; Wu, Chunya; Chu, Xin

2014-05-01

315

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

316

Autoionizing high-Rydberg states of very heavy Belike ions: A tool for precision spectroscopy  

Microsoft Academic Search

Autoionizing high-Rydberg states formed during the initial electron capture phase of dielectronic recombination (DR) provide a unique access to spectroscopic information of highly charged heavy ions. This paper summarizes recent experimental and theoretical studies on the low energy 1s22pjnlj? (j=1\\/2, 3\\/2) Be-like DR resonances associated with the 2s1\\/2?2pj core excitations of the Li-like ions 19779Au76+, 20892Pb79+ and 23892U89+. An extrapolation

C. Brandau; T. Bartsch; S. Böhm; C. Böhme; A. Hoffknecht; H. Knopp; S. Schippers; W. Shi; A. Müller; N. Grün; W. Scheid; T. Steih; F. Bosch; B. Franzke; C. Kozhuharov; P. H Mokler; F. Nolden; M. Steck; T. Stöhlker; Z. Stachura

2003-01-01

317

High-precision (143)Nd/(144)Nd ratios from NdO(+) data corrected with in-run measured oxygen isotope ratios.  

PubMed

The NdO(+) technique has been considerably refined in recent years for high-precision measurement of Nd isotope ratios in low-level samples (1-5 ng Nd). As oxygen isotopic compositions may vary significantly with experimental conditions such as filament material, ionization enhancer and the ambient oxygen in the ion source, great "care" should be taken for using correct oxygen isotopic compositions to do the isobaric oxide corrections for the "conventional" NdO(+) method. Our method presented here for NdO(+) data reduction and PrO(+) interference corrections uses the oxygen isotope composition determined in each cycle of the NdO(+) measurements. For that purpose, we measured the small ion signals of (150)Nd(17)O(+) and (150)Nd(18)O(+) with amplifiers equipped with 10(12) ? feedback resistors, and those of Nd(16)O(+) ion beams with 10(11) ? amplifiers. Using 10(12) ? amplifiers facilitates a precise measurement of the very small (150)Nd(17)O(+) and (150)Nd(18)O(+) ion signals and calculation of highly accurate and precise (143)Nd/(144)Nd isotope ratios. The (143)Nd/(144)Nd ratios for JNdi-1 standards and several whole-rock reference materials determined with the method on 4 ng of Nd loads are consistent with previously reported values within analytical error, with internal and external precision (2 RSE and 2 RSD) of better than 20 and 30 ppm, respectively. PMID:25301302

Chu, Zhu-Yin; Li, Chao-Feng; Hegner, Ernst; Chen, Zhi; Yan, Yan; Guo, Jing-Hui

2014-11-18

318

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

319

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

320

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

321

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

322

New technology enables high precision multislit collimators for microbeam radiation therapy  

NASA Astrophysics Data System (ADS)

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 ?m full width at half maximum (FWHM) values and 100-400 ?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 ?m FWHM and 400 ?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 ?m to less than 1 ?m for a nominal FWHM value of 25 ?m. The specifications of both devices, the methods used to measure these characteristics, and the results are presented.

Bräuer-Krisch, E.; Requardt, H.; Brochard, T.; Berruyer, G.; Renier, M.; Laissue, J. A.; Bravin, A.

2009-07-01

323

A rapid high-precision flow cytometry based technique for total white blood cell counting in chickens.  

PubMed

The automated analysis of total white blood cell count and white blood cell differentials is routine in research and clinical diagnosis in mammalian species. In contrast, in avian haematology these parameters are still estimated by conventional microscopic procedures due to technical difficulties associated with the morphological peculiarities of avian erythrocytes and thrombocytes. Both cell types are nucleated and fairly resistant to cell lysis, a prerequisite for automated leukocyte quantification and differentiation by commercial instruments. By using an anti-CD45 monoclonal antibody in combination with selected subset specific markers we have established a simple (no-lyse no-wash single-step one-tube) flow cytometry based technique for high precision chicken blood cell quantification. EDTA-blood samples are diluted, spiked with fluorescence beads and incubated with a mixture of fluorochrome conjugated chicken leukocyte specific antibodies. We demonstrate that total leukocyte numbers as well as thrombocyte, monocyte, T-cell, B-cell and heterophilic granulocyte numbers can be determined by flow cytometry in a single step without prior cell lysis, cell separation or cell washing steps. Importantly, we also show that blood samples can be fixed prior to cell staining which enables shipping of samples making the technology widely available. Comparison of this technique with conventional microscopy revealed superior precision. By comparing leukocyte differentials of two chicken populations and during immune system development after hatch we demonstrate that large sample numbers can be analysed within hours. This technique will help to overcome previous restrictions in immune status analysis in chickens in experimental systems, during vaccine testing and health status monitoring in chicken flocks. Advances in avian genomics should facilitate the development of appropriate tools for other avian species in the future which will make this technique broadly applicable. PMID:22088676

Seliger, Christian; Schaerer, Beatrice; Kohn, Marina; Pendl, Helene; Weigend, Steffen; Kaspers, Bernd; Härtle, Sonja

2012-01-15

324

The geochemical behaviour of W in subduction zones: constraints from high precision isotope dilution measurements  

NASA Astrophysics Data System (ADS)

Assessing the behaviour of W during silicate Earth's differentiation is hampered by low abundances of W in terrestrial reservoirs, making sufficiently precise and accurate measurements difficult. Previous results (e.g., Newsom et al. 1996) indicate a lower W/Th of the mantle (ca. 0.19) compared to the Earth's crust, (ca. 0.26), suggesting that W appears to be more incompatible than Th. New data for MORB (Munker et al. 2007), however, demonstrate that W/Th is not significantly fractionated during dry peridotite melting, tentatively suggesting a fractionation of the two elements during crust formation by subduction related processes. We present high precision W and Nb-Ta, Zr-Hf data obtained by isotope dilution, using a mixed 183W-180Ta- 94Zr-180Hf-176Lu tracer and multiple collector inductively coupled plasma mass spectrometry (MC-ICPMS). This enables the direct determination of W and HFSE from one sample digestion. For some samples, a "nugget effect" as previously reported for PGE was observed, reflecting sample heterogeneity. Measured Ta and W abundances determined in basaltic glasses and whole rock powders from various island arc settings yield Ta/W ratios of 0.6 to 1.7, significantly lower than the values reported for MORB (4-6). In contrast, Nb/Ta for the samples overlap with MORB values, suggesting that Nb and Ta were not mobile in the magma sources. These systematic differences indicate that W does not behave as other HFSE (Nb-Ta, Zr-Hf) in subduction zones but rather displays a higher mobility in slab components. Intra-oceanic arc suites involving subducted pelagic sediment in their sources generally display higher W/Th compared to magmas without sediment-derived components in their sources, reflecting the higher initial W abundances in subducted pelagic sediments. A fractionation of W/Th during crust formation could consequently be explained by a selective W enrichment relative to Th during subduction processes.

Konig, S.; Munker, C.; Schuth, S.

2007-12-01

325

On-sky Tests of High-Precision Astrometry Using a Diffractive Mask  

NASA Astrophysics Data System (ADS)

We present a new ground-based technique to detect or follow-up long-period, potentially habitable exoplanets via precise relative astrometry of host stars using Multi-Conjugate Adaptive Optics (MCAO) on 8 meter telescopes equipped with diffractive masks. MCAO improves relative astrometry both by cancellation of high-altitude atmospheric layers, which induce dynamic focal-plane distortions, and the improvement of centroiding precision with sharper PSFs. However, mass determination of habitable exoplanets requires multi-year reference grid stability of ~1-10 uas or nanometer-level stability on the long-term average of out-of-pupil phase errors, which is difficult to achieve with MCAO (e.g., Meyer et al. 2011). The diffractive pupil technique calibrates dynamic distortion via extended diffraction spikes generated by a dotted primary mirror, which are referenced against a grid of background stars (Guyon et al. 2012). We show that the diffractive pupil improves MCAO's long-term astrometric stability to the microarcsecond level. The diffractive grid provides four benefits to relative astrometry: (1) increased dynamic range, permitting observation of V < 10 stars without saturation; (2) calibration of dynamic distortion; and (3) a spectrum of the target star, which can be used to calibrate the magnitude of differential atmospheric refraction to the microarcsecond level. A diffractive 8-meter telescope with diffraction-limited MCAO in K-band reaches < 3-5 µas relative astrometric error per coordinate in one hour on a bright target star in fields of moderate stellar density 10-40 stars arcmin-2). We present results of an on-sky test of the diffractive pupil on the Nickel 1-meter telescope at Lick Observatory, obtained in Fall 2012.

Ammons, Stephen; Bendek, E.; Macintosh, B.; Guyon, O.

2013-01-01

326

Small-scale, high-precision and high-accuracy determination of Poisson's ratios in cohesive marine sediments  

NASA Astrophysics Data System (ADS)

Poisson's ratio (static) appears as a parameter in models of soft-sediment geomechanical processes such as gas bubble formation and bioturbation, and in a number of practical applications, including acoustic imaging, but is rarely measured in soft near-surface (upper 20 cm) marine sediments. A new uniaxial apparatus was developed to assess Poisson's ratios of cylindrical samples of soft cohesive sediments under finite-strain, unconfined, undrained conditions. No constraining membrane around the sample is necessary in the instrument. By monitoring the fluid level in a capillary, changes in sample volume can be determined to high precision (reproducibility). Measurements on reference materials, i.e., gelatine and polyurethane, also indicate high accuracy (veracity). For natural sediments from Nova Scotia, Canada, Poisson's ratios range from 0.4951 to 0.5 with no indication of anisotropy; therefore, such sediments act as incompressible solids to short-term/small-magnitude stresses, as occur during bubble formation and infaunal movement.

L'Esperance, J. Christopher; Boudreau, Bernard P.; Barry, Mark A.; Johnson, Bruce D.

2013-02-01

327

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

328

High Precision and High Sensitivity Measurements of Osmium Isotopes in Natural Waters  

NASA Astrophysics Data System (ADS)

Direct measurements of Os in water are critical in understanding the geochemical cycle of Os in the environment. However, measurements of Os isotopes in natural waters are challenging due to a) low concentrations (~10 fg/g or less; 1 fg/g = 10-15 g/g) and b) the differences in oxidation states of naturally occurring and tracer Os that prevent accurate determination of Os concentration by isotope dilution [Sharma et al., GCA 61:5411, 1997]. It has been recognized for more than a decade that the best way to chemically separate and purify Os and at the same time achieve tracer-sample equilibration is to oxidize Os in sample-tracer mixture to OsO4. Three techniques have been developed: 1) heating of sample-tracer mixture with Br2 and Cr6+ in Teflon bombs at 90°C and solvent-extraction of OsO4 with Br2 [Levasseur et al., Science 282:272, 1998]; 2) heating to 180°C with Cr6+ in sealed glass (carius) tubes and its extraction by distillation [Sharma et al., GCA 63:4005, 1999]; 3) heating of water in the presence of H2O2 and H2SO4 and distillation of OsO4 [Woodhouse et al., EPSL 173:223, 1999]. The blanks for these techniques are [Os] = 22 fg 187Os/188Os = 0.47, [Os] = 19 fg 187Os/188Os = 0.27, and [Os] = 120 fg 187Os/188Os = 0.31, respectively. We have modified the carius tube technique by using a High Pressure Asher at 300°C and a confining pressure of 100 bars. This method is an improvement over previous techniques because the time required to achieve complete oxidation is much shorter due to the increased temperature of reaction and the blanks are significantly lower ([Os] = 2.2 fg, 187Os/188Os = 0.18) due to smaller amounts of reagents used. Additionally, we have modified the mass spectrometry associated with measuring low level Os samples. Typically, Os is measured on a single Pt filament as OsO3-, but we have modified the technique to include a double filament geometry. We use Ta for the ionization filament and Pt for the evaporation filament. The double filament geometry allows us to run samples at a lower temperature, thus reducing the blank contribution from the Pt filament. Not only do we find total Re counts to be reduced, but organic interferences on mass 233 (185Re.16O4-) are no longer present, allowing for more accurate Re correction. Repeated measurements of a 200 fg standard gives 2? uncertainty of 1.38% for 187Os/188Os and 0.32% for 190Os/188Os. The improvements in chemistry and mass spectrometry allow the analysis of low level water samples such as snow from Antarctica and to understand the transport of Os from atmosphere to the oceans. We have applied this technique to surface and deep seawater samples collected from the Atlantic Ocean through GEOTRACES (Summer '08) and find that the surface seawater has been impacted by inputs of anthropogenic Os.

Chen, C.; Sharma, M.

2008-12-01

329

Towards establishing high-precision 40Ar/39Ar chronologies for distal tephra archives  

NASA Astrophysics Data System (ADS)

To develop further understanding of palaeoclimate change in a context of, for example, the expansion of hominin out of Africa and abrupt climate change, correlation between high-resolution terrestrial, marine and ice core archives from around the globe is key. Whereas there can be significant uncertainties in the tuning of palaeoclimate proxy records (i.e., wiggle matching) between regions, direct tephra correlations have essentially zero uncertainty, providing the correlations are robust. Tephrochronology has demonstrated tremendous potential for correlation of records across regions and construction of relative chronological tephra matrices. However absolute dating is often required for: (1) pinning of events to the geological timescale; and (2) to confirm the validity of correlations if geochemical fingerprints do not prove to be definitive. 14C dating can be used for radiocarbon-bearing sediments within which volcanic tephra are intercalated. However, the technique only extends over the last 50 ka and precision suffers dramatically with increasing age. The technique is reliant on the availability of radiocarbon-bearing material within sediments and direct comparison of 14C chronologies from marine and terrestrial settings is problematic owing to marine reservoir offset. OSL dating can also be used to date sediments above and below tephra units but uncertainties are typically too large for development of high-precision chronologies. Volcanic K-bearing distal tephra can theoretically be dated using the 40Ar/39Ar technique thereby placing direct temporal constraints on palaeoclimate records. However, in reality, distal tephra are usually fine-grained and crystal-poor, lacking mineral phases amenable to 40Ar/39Ar dating of young rocks, e.g., sanidine. Although the distal samples contain abundant K-bearing glass shards, they have been shown to provide unreliable 40Ar/39Ar ages likely due to a combination of post eruption K-loss (during glass hydration?) and 37Ar and 39Ar recoil effects. These effects are amplified by a high surface area to volume ratio of glass shards and thus short effective diffusion dimensions (radii of glass shards). I will discuss the application of 40Ar/39Ar geochronology to distal tephra and present two methodologies for establishing absolute 40Ar/39Ar age constraints for distal tephra archives. Two case studies will be presented: [1] dating of distal tephra in Lake Suigetsu, Japan by establishing robust correlations between proximal (crystal-rich) and distal (crystal-poor) volcanic deposits, and [2] dating of distal Toba tephra throughout peninsular of India by targeting of sub-100 ?m shards of biotite. A look at future development in 40Ar/39Ar geochronology and noble gas mass spectrometry with implications for tephrochronology studies will conclude the presentation.

Mark, D. F.

2012-12-01

330

High precision materials processing using a novel Q-switched CO2 laser  

NASA Astrophysics Data System (ADS)

Holes with diameters of about 400 ?m have been laser trepanned in Ti6Al4V and carbon fibre reinforced polymer (CFRP) thin sheets with a thickness of 0.5 mm. A commercial CO2 laser (SM1500E, FEHA LaserTec, Germany) and a novel Q-switched CO2 laser (?-storm, IAI, Netherlands) were used as radiation sources. Optical microscopy, scanning electron microscopy and replicas of the processed holes were used to investigate the influence of the CO2 laser pulse parameters (e.g. pulse energy, duration and peak power) on the processing quality. It was shown that melt formation and high temperature oxidation reactions of Ti6Al4V during thermal laser processing were reduced significantly by using short and high intense Q-switched CO2 laser pulses. During trepanning of CFRP heat affected zones resulting from the extremely different thermal properties (melting and vaporisation temperature, heat conduction) of the reinforcing carbon fibres and the polymer matrix were reduced significantly by using the Q-switched CO2 laser. The results demonstrate that Ti6Al4V and CFRP can be processed very precisely with CO2 laser radiation and air as processing gas without melt formation and thermal damage.

Gräf, Stephan; Staupendahl, Gisbert; Krämer, André; Müller, Frank A.

2015-03-01

331

The Spring 1985 high precision baseline test of the JPL GPS-based geodetic system  

NASA Technical Reports Server (NTRS)

The Spring 1985 High Precision Baseline Test (HPBT) was conducted. The HPBT was designed to meet a number of objectives. Foremost among these was the demonstration of a level of accuracy of 1 to 2:10 to the 7th power, or better, for baselines ranging in length up to several hundred kilometers. These objectives were all met with a high degree of success, with respect to the demonstration of system accuracy in particular. The results from six baselines ranging in length from 70 to 729 km were examined for repeatability and, in the case of three baselines, were compared to results from colocated VLBI systems. Repeatability was found to be 5:10 to the 8th power (RMS) for the north baseline coordinate, independent of baseline length, while for the east coordinate RMS repeatability was found to be larger than this by factors of 2 to 4. The GPS-based results were found to be in agreement with those from colocated VLBI measurements, when corrected for the physical separations of the VLBI and CPG antennas, at the level of 1 to 2:10 to the 7th power in all coordinates, independent of baseline length. The results for baseline repeatability are consistent with the current GPA error budget, but the GPS-VLBI intercomparisons disagree at a somewhat larger level than expected. It is hypothesized that these differences may result from errors in the local survey measurements used to correct for the separations of the GPS and VLBI antenna reference centers.

Davidson, John M.; Thornton, Catherine L.; Stephens, Scott A.; Blewitt, Geoffrey; Lichten, Stephen M.; Sovers, Ojars J.; Kroger, Peter M.; Skrumeda, Lisa L.; Border, James S.; Neilan, Ruth E.

1987-01-01

332

High precision landing site mapping and rover localization for Chang'e-3 mission  

NASA Astrophysics Data System (ADS)

This paper presents the comprehensive results of landing site topographic mapping and rover localization in Chang'e-3 mission. High-precision topographic products of the landing site with extremely high resolutions (up to 0.05 m) were generated from descent images and registered to CE-2 DOM. Local DEM and DOM with 0.02 m resolution were produced routinely at each waypoint along the rover traverse. The lander location was determined to be (19.51256°W, 44.11884°N, -2615.451 m) using a method of DOM matching. In order to reduce error accumulation caused by wheel slippage and IMU drift in dead reckoning, cross-site visual localization and DOM matching localization methods were developed to localize the rover at waypoints; the overall traveled distance from the lander is 114.8 m from cross-site visual localization and 111.2 m from DOM matching localization. The latter is of highest accuracy and has been verified using a LRO NAC image where the rover trajeactory is directly identifiable. During CE-3 mission operations, landing site mapping and rover localization products including DEMs and DOMs, traverse maps, vertical traverse profiles were generated timely to support teleoperation tasks such as obstacle avoidance and rover path planning.

Liu, ZhaoQin; Di, KaiChang; Peng, Man; Wan, WenHui; Liu, Bin; Li, LiChun; Yu, TianYi; Wang, BaoFeng; Zhou, JianLiang; Chen, HongMin

2015-01-01

333

Frontend electronics for high-precision single photo-electron timing using FPGA-TDCs  

NASA Astrophysics Data System (ADS)

The next generation of high-luminosity experiments requires excellent particle identification detectors which calls for Imaging Cherenkov counters with fast electronics to cope with the expected hit rates. A Barrel DIRC will be used in the central region of the Target Spectrometer of the planned PANDA experiment at FAIR. A single photo-electron timing resolution of better than 100 ps is required by the Barrel DIRC to disentangle the complicated patterns created on the image plane. R&D studies have been performed to provide a design based on the TRB3 readout using FPGA-TDCs with a precision better than 20 ps RMS and custom frontend electronics with high-bandwidth pre-amplifiers and fast discriminators. The discriminators also provide time-over-threshold information thus enabling walk corrections to improve the timing resolution. Two types of frontend electronics cards optimised for reading out 64-channel PHOTONIS Planacon MCP-PMTs were tested: one based on the NINO ASIC and the other, called PADIWA, on FPGA discriminators. Promising results were obtained in a full characterisation using a fast laser setup and in a test experiment at MAMI, Mainz, with a small scale DIRC prototype.

Cardinali, M.; Dzyhgadlo, R.; Gerhardt, A.; Götzen, K.; Hohler, R.; Kalicy, G.; Kumawat, H.; Lehmann, D.; Lewandowski, B.; Patsyuk, M.; Peters, K.; Schepers, G.; Schmitt, L.; Schwarz, C.; Schwiening, J.; Traxler, M.; Ugur, C.; Zühlsdorf, M.; Dodokhov, V. Kh.; Britting, A.; Eyrich, W.; Lehmann, A.; Uhlig, F.; Düren, M.; Föhl, K.; Hayrapetyan, A.; Kröck, B.; Merle, O.; Rieke, J.; Cowie, E.; Keri, T.; Montgomery, R.; Rosner, G.; Achenbach, P.; Corell, O.; Ferretti Bondy, M. I.; Hoek, M.; Lauth, W.; Rosner, C.; Sfienti, C.; Thiel, M.; Bühler, P.; Gruber, L.; Marton, J.; Suzuki, K.

2014-12-01

334

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

PubMed

In this Letter, we demonstrate a fully stabilized Er:fiber frequency comb by using a fiber-based, high-precision optical-microwave phase detector. To achieve high-precision and long-term phase locking of the repetition rate to a microwave reference, frequency control techniques (tuning pump power and cavity length) are combined together as its feedback. Since the pump power has been used for stabilization of the repetition rate, we introduce a pair of intracavity prisms as a regulator for carrier-envelope offset frequency, thereby phase locking one mode of the comb to the rubidium saturated absorption transition line. The stabilized comb performs the same high stability as the reference for the repetition rate and provides a residual frequency instability of 3.6×10-13 for each comb mode. The demonstrated stabilization scheme could provide a high-precision comb for optical communication, direct frequency comb spectroscopy. PMID:25490492

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

2014-11-15

335

High precision and high yield fabrication of dense nanoparticle arrays onto DNA origami at statistically independent binding sites  

NASA Astrophysics Data System (ADS)

High precision, high yield, and high density self-assembly of nanoparticles into arrays is essential for nanophotonics. Spatial deviations as small as a few nanometers can alter the properties of near-field coupled optical nanostructures. Several studies have reported assemblies of few nanoparticle structures with controlled spacing using DNA nanostructures with variable yield. Here, we report multi-tether design strategies and attachment yields for homo- and hetero-nanoparticle arrays templated by DNA origami nanotubes. Nanoparticle attachment yield via DNA hybridization is comparable with streptavidin-biotin binding. Independent of the number of binding sites, >97% site-occupation was achieved with four tethers and 99.2% site-occupation is theoretically possible with five tethers. The interparticle distance was within 2 nm of all design specifications and the nanoparticle spatial deviations decreased with interparticle spacing. Modified geometric, binomial, and trinomial distributions indicate that site-bridging, steric hindrance, and electrostatic repulsion were not dominant barriers to self-assembly and both tethers and binding sites were statistically independent at high particle densities.High precision, high yield, and high density self-assembly of nanoparticles into arrays is essential for nanophotonics. Spatial deviations as small as a few nanometers can alter the properties of near-field coupled optical nanostructures. Several studies have reported assemblies of few nanoparticle structures with controlled spacing using DNA nanostructures with variable yield. Here, we report multi-tether design strategies and attachment yields for homo- and hetero-nanoparticle arrays templated by DNA origami nanotubes. Nanoparticle attachment yield via DNA hybridization is comparable with streptavidin-biotin binding. Independent of the number of binding sites, >97% site-occupation was achieved with four tethers and 99.2% site-occupation is theoretically possible with five tethers. The interparticle distance was within 2 nm of all design specifications and the nanoparticle spatial deviations decreased with interparticle spacing. Modified geometric, binomial, and trinomial distributions indicate that site-bridging, steric hindrance, and electrostatic repulsion were not dominant barriers to self-assembly and both tethers and binding sites were statistically independent at high particle densities. Electronic supplementary information (ESI) available. See DOI: 10.1039/c4nr03069a

Takabayashi, Sadao; Klein, William P.; Onodera, Craig; Rapp, Blake; Flores-Estrada, Juan; Lindau, Elias; Snowball, Lejmarc; Sam, Joseph T.; Padilla, Jennifer E.; Lee, Jeunghoon; Knowlton, William B.; Graugnard, Elton; Yurke, Bernard; Kuang, Wan; Hughes, William L.

2014-10-01

336

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

337

High precision multi-genome scale reannotation of enzyme function by EFICAz  

PubMed Central

Background The functional annotation of most genes in newly sequenced genomes is inferred from similarity to previously characterized sequences, an annotation strategy that often leads to erroneous assignments. We have performed a reannotation of 245 genomes using an updated version of EFICAz, a highly precise method for enzyme function prediction. Results Based on our three-field EC number predictions, we have obtained lower-bound estimates for the average enzyme content in Archaea (29%), Bacteria (30%) and Eukarya (18%). Most annotations added in KEGG from 2005 to 2006 agree with EFICAz predictions made in 2005. The coverage of EFICAz predictions is significantly higher than that of KEGG, especially for eukaryotes. Thousands of our novel predictions correspond to hypothetical proteins. We have identified a subset of 64 hypothetical proteins with low sequence identity to EFICAz training enzymes, whose biochemical functions have been recently characterized and find that in 96% (84%) of the cases we correctly identified their three-field (four-field) EC numbers. For two of the 64 hypothetical proteins: PA1167 from Pseudomonas aeruginosa, an alginate lyase (EC 4.2.2.3) and Rv1700 of Mycobacterium tuberculosis H37Rv, an ADP-ribose diphosphatase (EC 3.6.1.13), we have detected annotation lag of more than two years in databases. Two examples are presented where EFICAz predictions act as hypothesis generators for understanding the functional roles of hypothetical proteins: FLJ11151, a human protein overexpressed in cancer that EFICAz identifies as an endopolyphosphatase (EC 3.6.1.10), and MW0119, a protein of Staphylococcus aureus strain MW2 that we propose as candidate virulence factor based on its EFICAz predicted activity, sphingomyelin phosphodiesterase (EC 3.1.4.12). Conclusion Our results suggest that we have generated enzyme function annotations of high precision and recall. These predictions can be mined and correlated with other information sources to generate biologically significant hypotheses and can be useful for comparative genome analysis and automated metabolic pathway reconstruction. PMID:17166279

Arakaki, Adrian K; Tian, Weidong; Skolnick, Jeffrey

2006-01-01

338

High-Precision Isotope Analysis Of Uranium And Thorium By Tims  

SciTech Connect

The U.S. Geological Survey (USGS) Yucca Mountain Project Branch laboratory in Denver, Colorado, conducts routine high-precision isotope analyses of uranium (U) and thorium (Th) using thermal ionization mass-spectrometry (TIMS). The measurements are conducted by a solid-source mass-spectrometer equipped with a Faraday multi-collector system and an energy filter in front of an active-film-type secondary electron multiplier (SEM). The abundance sensitivity of the instrument (signal at mass 237 over {sup 238}U in natural U) with the energy filter is {approx} 15 x 10{sup -9} and peak tails are reduced by a factor of {approx}100 relative to the Faraday cup measurements. Since instrument installation in April 2004, more than 500 rock and water samples have been analyzed in support of isotope-geochemical studies for the U.S. Department of Energy's Yucca Mountain Project. Isotope ratios of sub-nanogram to microgram U and Th samples are measured on graphite-coated single-filament and double-filament assemblies using zone-refined rhenium filaments. Ion beams less than 5 millivolt (mV) are measured with the SEM, which is corrected for non-linearity on the basis of measurements of National Institute of Standards and Technology (NIST) U-500 and 4321 B standards with ion beams ranging from 0.01 to 8 mV. Inter-calibration between the SEM and the Faraday multi-collector is performed for every mass cycle using a {approx}5 mV beam switched between Faraday cup and SEM ('bridging' technique), because SEM-Faraday inter-calibrations prior to the measurement failed to produce acceptable results. Either natural ({sup 235}U) or artificial ({sup 236}U, {sup 229}Th) isotopes were used for the bridging. Separate runs are conducted for minor isotopes using SEM only. These techniques result in high within-run precisions of <0.1 to 0.2 percent for {sup 234}U/{sup 238}U and 0.2 to 0.5 percent for {sup 230}Th/{sup 238}U.

L.A. Neymark

2006-08-31

339

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 and excellent laboratories for stellar astrophysics. This thesis addresses both research domains via three primary topics: (1) the behavior of Cepheid pulsations via highly precise multi-epoch Doppler measurements (velocimetry); (2) open cluster membership via a newly-developed 8-dimensional astro-statistical method; (3) the effect of rotation on populations of classical Cepheids based on predictions by Geneva stellar evolution models.Using highly-precise velocimetry (1), I revealed additional complexity (modulation) present in Cepheid radial velocity curves that can bias distance estimates based on the Baade-Wesselink (BW) method by up to 15%. Two types of modulation were found: a) steady long-term amplitude variations over the timescale of the observing program (3 years) for short-period Cepheids; b) stochastic cycle-to-cycle variations for long-period Cepheids. It is thus crucial to obtain contemporaneous measurements of angular and linear radius variations to ensure accuracy of BW distances.The eight-dimensional census of Cepheids belonging to Galactic open clusters (2) established a bona-fide sample of cluster Cepheids useful for calibrating the Cepheid period-luminosity relation. Several new cluster Cepheid candidates were identified, one of which has been recently confirmed by independent investigators. The method's quantitative nature and fast computation renders it particularly interesting for large data sets such as those expected from ESA's Gaia space mission.Finally, this thesis presents the first detailed investigation of the effect of rotation on populations of Cepheids (3). Using Geneva stellar evolution models, we show that a) rotation provides a suitable explanation for the long-standing Cepheid mass discrepancy and that b) rotation can lead to an intrinsic dispersion in the period-luminosity relation. Rotation should no longer be neglected in Cepheid-related studies, since the rotational history of Cepheid progenitors significantly affects their present-day luminosity.Further research is in progress to exploit these findings with the goal of improving the accuracy of Cepheid-based distances.

Irving Anderson, Richard

2015-01-01

340

Guidance characteristics of some displacement devices used in a high-precision He-Ne laser displacement measurement system  

Microsoft Academic Search

The guidance characteristics of three different translation stages for application as the driver in a high precision displacement transducer calibration instrument (measuring laser) were assessed. A high voltage PZT tube, a low voltage three-segment PZT, and a corrugated diaphragm displacement device with a magnetic coil drive were investigated. The maximum yaw and pitch angles of the PZT tube were 8

U. Brand; K. Miyashita; J. Hannemann

1997-01-01

341

Large stroke and high precision pneumatic–piezoelectric hybrid positioning control using adaptive discrete variable structure control  

Microsoft Academic Search

This paper investigates a novel large stroke and high precision pneumatic–piezoelectric hybrid positioning control system that contains a pneumatic servo cylinder and a piezoelectric servo actuator combined in cascade. The pneumatic servo cylinder serves to positioning with high speed and large stroke; the piezoelectric actuator positions in fine stroke for compensating the influence of friction force so as to achieve

Mao-Hsiung Chiang; Chung-Chieh Chen; Tan-Ni Tsou

2005-01-01

342

Evidence of 11-year solar cycles in tree rings from 1010 to 1110 AD - Progress on high precision AMS measurements  

NASA Astrophysics Data System (ADS)

Oak tree rings from Southern Germany covering the AD 1010-1110 years have been analyzed for radiocarbon with accelerator mass spectrometry (AMS) at the laboratory at ETH Zurich. High-precision measurements with a precision down to 12 years radiocarbon age and a time resolution of 2 years aimed to identify modulations of the 14C concentration in tree ring samples caused by the 11 years solar cycles, a feature that so far is not visible in the IntCal calibration curve. Our results are in good agreement with the current calibration curve IntCal09. However, we observed an offset in radiocarbon age of 25-40 years towards older values. An evaluation of our sample preparation, that included variations of e.g.: chemicals, test glasses and processing steps did not explain this offset. The numerous measurements using the AMS-MICADAS system validated its suitability for high precision measurements with high repeatability.

Güttler, D.; Wacker, L.; Kromer, B.; Friedrich, M.; Synal, H.-A.

2013-01-01

343

Tunable diode laser spectrometer for high-precision concentration and ratio measurements of long-lived atmospheric gases  

NASA Astrophysics Data System (ADS)

The ambient fluctuations of long-lived atmospheric gases such as carbon dioxide, methane, and carbonyl sulfide, to name a few, contain important information about sources, sinks and potential secular trends. Since such fluctuations can be quite small, typically less than a few percent, high precision instruments are required. In the present study, we describe a versatile tunable diode laser system for this purpose. This system employs a number of novel features for increased system control and versatility. In addition to high precision, such versatility enables us to acquire the ratio of 2 spectral features with high precision, even when the signal amplitudes are a factor of 26 different and when the spectral features are separated by as much as 0.424 cm-1. This capability can be used to address many important applications in atmospheric studies.

Fried, Alan; Drummond, James R.; Henry, Bruce E.; Fox, Jack

1991-05-01

344

Design of a novel high-precision opto-electronic levelmeter  

NASA Astrophysics Data System (ADS)

For currently market available levelmeter can not meet the requirement for measuring the azimuth mounting of the LAMOST, this paper presents a novel design scheme of an opto-electronic levelmeter with needed high precision. The levelmeter is essentially a combination of an optical front end and a computer aided measuring back end. The light from a point source is firstly turned to be parallel and reflected by a tip-tilt mirror which keeps pointing to the zenith and then imaged onto a CCD target through optical system, afterwards, the position of the image spot is processed by computer software to give measurement results. By rotating the LAMOST mounting about azimuth axis with the levelmeter on it, the axis system is measured, and if the measured azimuth axis is not perpendicular enough, the image spot on CCD target is to offset some distance by which the tilt angle of the axis can be evaluated. The design principle and data processing of the levelmeter are detailed systematically in this paper. Experiment results confirmed that the accuracy of the levermeter is up to 0.043" beyond that required by the technical specification of the LAMOST. Also, the novel levermeter is applicable to measuring azimuth axes of other telescopes.

Li, Guoping; He, Qiuhui; Li, Xinnan

2004-09-01

345

Quantitative Design of Regulatory Elements Based on High-Precision Strength Prediction Using Artificial Neural Network  

PubMed Central

Accurate and controllable regulatory elements such as promoters and ribosome binding sites (RBSs) are indispensable tools to quantitatively regulate gene expression for rational pathway engineering. Therefore, de novo designing regulatory elements is brought back to the forefront of synthetic biology research. Here we developed a quantitative design method for regulatory elements based on strength prediction using artificial neural network (ANN). One hundred mutated Trc promoter & RBS sequences, which were finely characterized with a strength distribution from 0 to 3.559 (relative to the strength of the original sequence which was defined as 1), were used for model training and test. A precise strength prediction model, NET90_19_576, was finally constructed with high regression correlation coefficients of 0.98 for both model training and test. Sixteen artificial elements were in silico designed using this model. All of them were proved to have good consistency between the measured strength and our desired strength. The functional reliability of the designed elements was validated in two different genetic contexts. The designed parts were successfully utilized to improve the expression of BmK1 peptide toxin and fine-tune deoxy-xylulose phosphate pathway in Escherichia coli. Our results demonstrate that the methodology based on ANN model can de novo and quantitatively design regulatory elements with desired strengths, which are of great importance for synthetic biology applications. PMID:23560087

Xiong, Zhiqiang; Xu, Feng; Zhao, Guoping; Wang, Yong

2013-01-01

346

High-Precision Thermodynamic and Critical Properties from Tensor Renormalization-Group Flows  

NASA Astrophysics Data System (ADS)

The recently developed tensor renormalization-group (TRG) method [1] provides a highly precise technique for deriving thermodynamic and critical properties of lattice Hamiltonians. The TRG is a local coarse-graining transformation, with the elements of the tensor at each lattice site playing the part of the interactions that undergo the renormalization-group flows. These tensor flows are directly related [2] to the phase diagram structure of the infinite system, with each phase flowing to a distinct surface of fixed points. Fixed-point analysis and summation along the flows give the critical exponents, as well as thermodynamic functions along the entire temperature range. Thus, for the ferromagnetic triangular lattice Ising model, the free energy is calculated to better than 10-5 along the entire temperature range. Unlike previous position-space renormalization-group methods, the truncation (of the tensor index range D) in this general method converges under straightforward and systematic improvements. Our best results are easily obtained with D=24, corresponding to 4624-dimensional renormalization-group flows. [1] M. Levin and C.P. Nave, Phys. Rev. Lett. 99, 120601 (2007). [2] M. Hinczewski and A.N. Berker, arXiv:0709.2803v1 [cond-mat.stat-mech], Phys. Rev. E, in press.

Hinczewski, Michael; Berker, A. Nihat

2008-03-01

347

High-precision estimate of the critical exponents for the directed Ising universality class  

NASA Astrophysics Data System (ADS)

With extensive Monte Carlo simulations, we present high-precision estimates of the critical exponents of branching annihilating random walks with two offspring, a prototypical model of the directed Ising universality class in one dimension. To estimate the exponents accurately, we propose a systematic method to find corrections to scaling whose leading behavior is supposed to take the form t -? in the long-time limit at the critical point. Our study shows that ? ? 0.75 for the number of particles in defect simulations and ? ? 0.5 for other measured quantities, which should be compared with the widely used value of ? = 1. Using ? so obtained, we analyze the effective exponents to find that ?/? ? = 0.2872(2), z = 1.7415(5), ? = 0.0000(2), and accordingly, ?/? ? = 0.5000(6). Our numerical results for ?/? ? and z are clearly different from the conjectured rational numbers ?/? ? = tfrac{2} {7} ? 0.2857, z = tfrac{7} {4} = 1.75 by Jensen [Phys. Rev. E, 50, 3623 (1994)]. Our result for ?/? ?, however, is consistent with tfrac{1} {2} , which is believed to be exact.

Park, Su-Chan

2013-02-01

348

Research on the polishing technology of high-precision aspherical cylindrical lens  

NASA Astrophysics Data System (ADS)

Aspherical cylindrical lens compared with the cylindrical lens, they improved image quality and optical properties, simplified the system architecture. They applied in many fields, such as high power laser system, fax machines and typographical scan imaging system, as well as bar code scanning, lighting and other aspects of holography. Aspherical cylindrical lens are centrosymmetric. It is difficult to process. Parallel with the side line and bus bar line is difficult to ensure. Machining accuracy is low. It is usually about 15 ?m, that not sufficient to meet the needs of modern highprecision laser systems. These have become a major problem restricting its development. Combining traditional and modern polishing techniques, a new technique for polishing aspherical cylindrical lens is proposed-- longitudinal feedback compensation technology. With dimensions of 15 × 5 × 5 mm quartz aspherical cylindrical lens as an example, the surface profilometer results of detection of the workpiece usually, modify the shape of the polishing surface of the mold, to control the size of the area of the polishing, the surface of the workpiece to achieve the effect of the type of compensation. After repeated testing and feedback compensation, gradually improve the accuracy of the workpiece surface type. The results show that this technique can effectively improve the precision aspherical cylindrical lens. After detection the workpiece surface accuracy is 0.8?m, the surface finish is Class II. It has the actual production of a certain application value.

Fu, Xiu-hua; Wang, Zhe; Jia, Zong-he; Dong, Huan; Liu, Dan; Zhang, Chuan-xin

2014-08-01

349

PRECISE HIGH-CADENCE TIME SERIES OBSERVATIONS OF FIVE VARIABLE YOUNG STARS IN AURIGA WITH MOST  

SciTech Connect

To explore young star variability on a large range of timescales, we have used the MOST satellite to obtain 24 days of continuous, sub-minute cadence, high-precision optical photometry on a field of classical and weak-lined T Tauri stars (TTSs) in the Taurus-Auriga star formation complex. Observations of AB Aurigae, SU Aurigae, V396 Aurigae, V397 Aurigae, and HD 31305 reveal brightness fluctuations at the 1%-10% level on timescales of hours to weeks. We have further assessed the variability properties with Fourier, wavelet, and autocorrelation techniques, identifying one significant period per star. We present spot models in an attempt to fit the periodicities, but find that we cannot fully account for the observed variability. Rather, all stars exhibit a mixture of periodic and aperiodic behavior, with the latter dominating stochastically on timescales less than several days. After removal of the main periodicity, periodograms for each light curve display power-law trends consistent with those seen for other young accreting stars. Several of our targets exhibited unusual variability patterns not anticipated by prior studies, and we propose that this behavior originates with the circumstellar disks. The MOST observations underscore the need for investigation of TTS light variations on a wide range of timescales in order to elucidate the physical processes responsible; we provide guidelines for future time series observations.

Cody, Ann Marie; Tayar, Jamie; Hillenbrand, Lynne A. [Department of Astrophysics, California Institute of Technology, MC 249-17, Pasadena, CA 91125 (United States); Matthews, Jaymie M. [Department of Physics and Astronomy, University of British Columbia, 6224 Agricultural Road, Vancouver, British Columbia V6T 1Z1 (Canada); Kallinger, Thomas, E-mail: amc@ipac.caltech.edu [Institut fuer Astronomie, Universitaet Wien, Tuerkenschanzstrasse 17, A-1180 Vienna (Austria)

2013-03-15

350

Influence of material removal programming on ion beam figuring of high-precision optical surfaces  

NASA Astrophysics Data System (ADS)

Ion beam figuring (IBF) provides a nanometer/subnanometer precision fabrication technology for optical components, where the surface materials on highlands are gradually removed by the physical sputtering effect. In this deterministic method, the figuring process is usually divided into several iterations and the sum of the removed material in each iteration is expected to approach the ideally removed material as nearly as possible. However, we find that the material removal programming in each iteration would influence the surface error convergence of the figuring process. The influence of material removal programming on the surface error evolution is investigated through the comparative study of the contour removal method (CRM) and the geometric proportion removal method (PRM). The research results indicate that the PRM can maintenance the smoothness of the surface topography during the whole figuring process, which would benefit the stable operation of the machine tool and avoid the production of mid-to-high spatial frequency surface errors. Additionally, the CRM only has the corrective effect on the area above the contour line in each iteration, which would result in the nonuniform convergence of the surface errors in various areas. All these advantages distinguish PRM as an appropriate material removal method for ultraprecision optical surfaces.

Liao, Wenlin; Dai, Yifan; Xie, Xuhui

2014-09-01

351

High precision measurements of carbon disulfide negative ion mobility and diffusion  

NASA Astrophysics Data System (ADS)

High precision measurements were made of reduced mobility, lateral and longitudinal diffusion of CS2- ions in 40 Torr CS2 and a 30-10 Torr CS2-CF4 gas mixture. The reduced mobility was found to be 0.4645 ± 0.0006 cm2 atm/s V in CS2 and 0.523 ± 0.001 cm2 atm/s V in the CS2-CF4 gas mixture at STP. The lateral diffusion temperatures for these two gases (295 ± 15 K and 297 ± 6 K) were found to be in good agreement with room temperature. By contrast longitudinal diffusion temperature was found to be slightly elevated (319 ± 10 (stat) ± 8 (sys) K and 310 ± 20 (stat) ± 6 (sys) K) though given the errors, room temperature diffusion cannot be ruled out. For lateral diffusion, significant capture distances (0.21 ± 0.07 mm and 0.15 ± 0.03 mm) were measured while for longitudinal diffusion the results were not conclusive.

Snowden-Ifft, D. P.; Gauvreau, J.-L.

2013-05-01

352

High-precision prompt-?-ray spectral data from the reaction Pu241(nth, f)  

NASA Astrophysics Data System (ADS)

In this paper we present results from the first high-precision prompt-?-ray spectral measurements from the reaction Pu241(nth, f). Apart from one recent experiment, no data are reported in the literature for this fissioning system, which motivated a new dedicated experiment. We have measured prompt-fission ? rays with three cerium-doped LaBr3 (two 5.08cm×5.08 cm and one 7.62cm×7.62 cm) and one CeBr3 (5.08cm×5.08 cm) scintillation detectors, which all exhibit excellent timing and good energy resolution. The average ?-ray multiplicity was determined to be ?¯?=(8.21±0.09) per fission, the average energy to be ??=(0.78±0.01) MeV, and the total energy to be E? ,tot=(6.41±0.06) MeV as the weighted average from all detectors. Since the results from all detectors are in excellent agreement, and the total released ? energy is modestly higher than the one in the present evaluated nuclear data files, we suspect that the underestimation of the prompt-? heating in nuclear reactors is due to fast-neutron-induced fission on U238 or rather from fission induced by ? rays from neutron capture in the construction material.

Oberstedt, S.; Billnert, R.; Belgya, T.; Bry?, T.; Geerts, W.; Guerrero, C.; Hambsch, F.-J.; Kis, Z.; Moens, A.; Oberstedt, A.; Sibbens, G.; Szentmiklosi, L.; Vanleeuw, D.; Vidali, M.

2014-08-01

353

Recent developments for high-precision mass measurements of the heaviest elements at SHIPTRAP  

NASA Astrophysics Data System (ADS)

Atomic nuclei far from stability continue to challenge our understanding. For example, theoretical models have predicted an “island of stability” in the region of the superheavy elements due to the closure of spherical proton and neutron shells. Depending on the model, these are expected at Z = 114, 120 or even 126 and N = 172 or 184. Valuable information on the road to the island of stability is derived from high-precision mass measurements, which give direct access to binding energies of short-lived trans-uranium nuclei. Recently, direct mass measurements at SHIPTRAP have been extended to nobelium and lawrencium isotopes around the deformed shell gap N = 152. In order to further extend mass measurements to the region of superheavy elements, new technical developments are required to increase the performance of our setup. The sensitivity will increase through the implementation of a new detection method, where observation of one single ion is sufficient. Together with the use of a more efficient gas stopping cell, this will us allow to significantly enhance the overall efficiency of SHIPTRAP.

Minaya Ramirez, E.; Ackermann, D.; Blaum, K.; Block, M.; Droese, C.; Düllmann, Ch. E.; Eibach, M.; Eliseev, S.; Haettner, E.; Herfurth, F.; Heßberger, F. P.; Hofmann, S.; Marx, G.; Nesterenko, D.; Novikov, Yu. N.; Plaß, W. R.; Rodríguez, D.; Scheidenberger, C.; Schweikhard, L.; Thirolf, P. G.; Weber, C.

2013-12-01

354

High-precision, longitudinal, disc-averaged magnetic field measurements of ? Canis Minoris and ? Leporis.  

NASA Astrophysics Data System (ADS)

High-precision longitudinal, disc-averaged magnetic field measurements have been made on two late-type stars, ? CMi (HR 2943) and ? Lep (HR 1829). A magneto-optical filter has been used to measure the degree of circular polarization in the wings of a line of neutral potassium (7699 A) formed in the atmosphere of the target star. From 10 nights of data taken on ? CMi on the 1.9-m reflector at the South African Astronomical Observatory (SAAO) in 1993 January, an upper limit to any net longitudinal field component present - assuming the field to be constant over the period of observation - of -0.40+/-0.26G was established. Similarly, upper limits for ? Lep of -4.3+/-6.4G and -0.7+/-1.6G were established, from 4 and 10 nights of data taken in 1992 and 1993 January respectively. No significant, periodic, day-to-day variations were seen in the three time series of data.

Bedford, D. K.; Chaplin, W. J.; Davies, A. R.; Innis, J. L.; Isaak, G. R.; Speake, C. C.

1995-01-01

355

A method to discriminate solar and antisolar differential rotation in high-precision light curves  

E-print Network

Surface differential rotation (DR) is one major ingredient of the magnetic field generation process in the Sun and likely in other stars. The term solar-like differential rotation describes the observation that solar equatorial regions rotate faster than polar ones. The opposite effect of polar regions rotating faster than equatorial ones (termed as antisolar DR) has only been observed in a few stars, although there is evidence from theoretical dynamo models. We present a new method to detect the sign of DR (i.e. solar-like or antisolar DR) by analyzing long-term high-precision light curves with the Lomb-Scargle periodogram.We compute the Lomb-Scargle periodogram and identify a set of significant periods $P_k$, which we associate with active regions located at different latitudes on the the stellar surface. If detectable, the first harmonics ($P_k'$) of these periods were identified to compute their peak-height-ratios $r_k:=h(P_k')/h(P_k)$. Spots rotating at lower latitudes generate less sine-shaped light cur...

Reinhold, T

2015-01-01

356

High precision predictions for near-Earth asteroids: the strange case of (3908) Nyx  

NASA Astrophysics Data System (ADS)

In November 2004 radar delay measurements of near-Earth asteroid (3908) Nyx obtained at the Arecibo radio telescope turned out to be away from the orbital prediction. We prove that this discrepancy was caused by a poor astrometric treatment and an incomplete dynamical model, which did not account for nongravitational perturbations. To improve the astrometric treatment, we remove known star catalog biases, apply suitable weights to the observations, and use an aggressive outlier rejection scheme. The main issue related to the dynamical model is having not accounted for the Yarkovsky effect. Including the Yarkovsky perturbation in the model makes the orbital prediction and the radar measurements statistically consistent by both reducing the offset and increasing the prediction uncertainty to a more realistic level. This analysis shows the sensitivity of high precision predictions to the astrometric treatment and the Yarkovsky effect. By using the full observational dataset we obtain a detection of the Yarkovsky effect acting on Nyx corresponding to an orbital drift m/year. In turn, we derive constraints on thermal inertia and bulk density. In particular, we find that the bulk density of Nyx is around 1 g/cm, possibly less. To make sure that our results are not corrupted by an asteroid impact or a close approach with a perturbing asteroid not included in our dynamical model, we show that the astrometry provides no convincing evidence of an impulsive variation of Nyx's velocity while crossing the main belt region.

Farnocchia, D.; Chesley, S. R.; Tholen, D. J.; Micheli, M.

2014-08-01

357

High precision cell slicing by harmonically actuated ultra-sharp SixNy blades  

NASA Astrophysics Data System (ADS)

We describe a micro-knife system with an ultra-sharp blade that is harmonically actuated by lead zirconate titanate (PZT). In particular, harmonic actuation along its cutting direction is demonstrated to provide clean and sharp cut lines for hepatocytes. Such performance is not provided by ordinary ultrasonic actuation. The blade is 500?nm-thick silicon nitride (SixNy); it can cut a single cell. Finite element analysis and measurements of displacement around resonant frequencies were used to optimize the dimensions, driving frequency and voltage. To evaluate the cutting precision, commercial scalpels and the SixNy blade without and with harmonic actuation were compared. When used to cut primary hepatocytes in a mono-layer, a commercial stainless scalpel burst cells, and the SixNy blade without harmonic actuation cut cells with a wide and ragged line. However, due to the controlled ultrasonic mode shape, operating frequency, high frequency and low applied power, the SixNy blade with harmonic actuation at 1Vpp and 70.1?kHz provided a clean and sharp cut line which was as narrow as 2?µm. The SixNy blade with harmonic actuation has potential applications as a tool for minimally invasive surgery.

Jeong, Hwapyeong; Li, Tao; Gianchandani, Yogesh B.; Park, Jaesung

2015-02-01

358

High-Precision Shape Control of In-Space Deployable Large Membrane/Thin-Shell Reflectors  

NASA Technical Reports Server (NTRS)

This innovation has been developed to improve the resolutions of future spacebased active and passive microwave antennas for earth-science remote sensing missions by maintaining surface figure precisions of large membrane/thin-shell reflectors during orbiting. The intention is for these sensing instruments to be deployable at orbit altitudes one or two orders of magnitude higher than Low Earth Orbit (LEO), but still being able to acquire measurements at spatial resolution and sensitivity similar to those of LEO. Because active and passive microwave remote sensors are able to penetrate through clouds to acquire vertical profile measurements of geophysical parameters, it is desirable to elevate them to the higher orbits to obtain orbital geometries that offer large spatial coverage and more frequent observations. This capability is essential for monitoring and for detailed understanding of the life cycles of natural hazards, such as hurricanes, tropical storms, flash floods, and tsunamis. Major components of this high-precision antenna-surface-control system include a membrane/thin shell reflector, a metrology sensor, a controller, actuators, and corresponding power amplifier and signal conditioning electronics (see figure). Actuators are attached to the back of the reflector to produce contraction/ expansion forces to adjust the shape of the thin-material reflector. The wavefront-sensing metrology system continuously measures the surface figure of the reflector, converts the surface figure to digital data and feeds the data to the controller. The controller determines the control parameters and generates commands to the actuator system. The flexible, piezoelectric polymer actuators are thus activated, providing the control forces needed to correct any distortions that exist in the reflector surface. Piezoelectric polymer actuators are very thin and flexible. They can be implemented on the back of the membrane/thin-shell reflector without introducing significant amounts of mass or stiffness to the reflector. They can be rolled up or folded to accommodate the packaging needed for launch. An analytical model of the system, which includes the membrane reflector, actuator, and controller has been developed to investigate the functionality of this control system on a 35-meter-diameter membrane reflector. The performance of this system under external disturbances such as in space thermal loads and W-error due to inflation has been investigated. A subscale breadboard has been developed, and the functionality of this control concept has been demonstrated by this breadboard.

Watkins, Ronald; Goebel, Dan; Hofer, Richard

2010-01-01

359

In Proc. of International Conference on Robotics and Automation, 1997 Experimental Evaluation of Uncalibrated Visual Servoing for Precision  

E-print Network

) without any prior information, while carrying out a 3 DOF manipulation task. For 6 and higher DOF prior information, while carrying out a 3 DOF manipulation task. 3. We were able to verify of Uncalibrated Visual Servoing for Precision Manipulation Martin J¨agersand, Olac Fuentes, Randal Nelson

Fuentes, Olac

360

In Proc. of International Conference on Robotics and Automation, 1997 Experimental Evaluation of Uncalibrated Visual Servoing for Precision  

E-print Network

) without any prior information, while carrying out a 3 DOF manipulation task. For 6 and higher DOF without any prior information, while carrying out a 3 DOF manipulation task. 3. We were able to verify of Uncalibrated Visual Servoing for Precision Manipulation \\Lambda Martin JË?agersand, Olac Fuentes, Randal Nelson

Nelson, Randal

361

HIGH-PRECISION TIMING OF FIVE MILLISECOND PULSARS: SPACE VELOCITIES, BINARY EVOLUTION, AND EQUIVALENCE PRINCIPLES  

SciTech Connect

We present high-precision timing of five millisecond pulsars (MSPs) carried out for more than seven years; four pulsars are in binary systems and one is isolated. We are able to measure the pulsars' proper motions and derive an estimate for their space velocities. The measured two-dimensional velocities are in the range 70-210 km s{sup -1}, consistent with those measured for other MSPs. We also use all the available proper motion information for isolated and binary MSPs to update the known velocity distribution for these populations. As found by earlier works, we find that the velocity distribution of binary and isolated MSPs are indistinguishable with the current data. Four of the pulsars in our observing program are highly recycled with low-mass white dwarf companions and we are able to derive accurate binary parameters for these systems. For three of these binary systems, we are able to place initial constraints on the pulsar masses with best-fit values in the range 1.0-1.6 M{sub Sun }. The implications of the results presented here to our understanding of binary pulsar evolution are discussed. The updated parameters for the binary systems studied here, together with recently discovered similar systems, allowed us to update previous limits on the violation of the strong equivalence principle through the parameter |{Delta}| to 4.6 Multiplication-Sign 10{sup -3} (95% confidence) and the violation of Lorentz invariance/momentum conservation through the parameter |{alpha}-hat3| to 5.5 Multiplication-Sign 10{sup -20} (95% confidence).

Gonzalez, M. E.; Stairs, I. H. [Department of Physics and Astronomy, University of British Columbia, Vancouver, BC, V6T 1Z1 (Canada); Ferdman, R. D.; Lyne, A. G. [Jodrell Bank Centre for Astrophysics, University of Manchester, Manchester, M13 9PL (United Kingdom); Freire, P. C. C.; Kramer, M. [Max-Planck-Institut fuer Radioastronomie, D-53121 Bonn (Germany); Nice, D. J. [Physics Department, Lafayette College, Easton, PA 18042 (United States); Demorest, P. B.; Ransom, S. M. [National Radio Astronomy Observatory, Charlottesville, VA 22903 (United States); Camilo, F. [Columbia Astrophysics Laboratory, Columbia University, New York, NY 10027 (United States); Hobbs, G.; Manchester, R. N., E-mail: gonzalez@phas.ubc.ca1 [Australia Telescope National Facility, CSIRO, Epping, NSW 1710 (Australia)

2011-12-20

362

HIGH-PRECISION PREDICTIONS FOR THE ACOUSTIC SCALE IN THE NONLINEAR REGIME  

SciTech Connect

We measure shifts of the acoustic scale due to nonlinear growth and redshift distortions to a high precision using a very large volume of high-force-resolution simulations. We compare results from various sets of simulations that differ in their force, volume, and mass resolution. We find a consistency within 1.5-sigma for shift values from different simulations and derive shift alpha(z) -1 = (0.300\\pm 0.015)% [D(z)/D(0)]^{2} using our fiducial set. We find a strong correlation with a non-unity slope between shifts in real space and in redshift space and a weak correlation between the initial redshift and low redshift. Density-field reconstruction not only removes the mean shifts and reduces errors on the mean, but also tightens the correlations: after reconstruction, we recover a slope of near unity for the correlation between the real and redshift space and restore a strong correlation between the low and the initial redshifts. We derive propagators and mode-coupling terms from our N-body simulations and compared with Zeldovich approximation and the shifts measured from the chi^2 fitting, respectively. We interpret the propagator and the mode-coupling term of a nonlinear density field in the context of an average and a dispersion of its complex Fourier coefficients relative to those of the linear density field; from these two terms, we derive a signal-to-noise ratio of the acoustic peak measurement. We attempt to improve our reconstruction method by implementing 2LPT and iterative operations: we obtain little improvement. The Fisher matrix estimates of uncertainty in the acoustic scale is tested using 5000 (Gpc/h)^3 of cosmological PM simulations from Takahashi et al. (2009). (abridged)

Seo, Hee-Jong; Eckel, Jonathan; Eisenstein, Daniel J.; Mehta, Kushal; Metchnik, Marc; Padmanabhan, Nikhil; Pinto, Phillip; Takahashi, Ryuichi; White, Martin; Xu, Xiaoying

2010-09-10

363

High Precision Mass Measurement for the Black Hole in Nova Muscae 1991  

NASA Astrophysics Data System (ADS)

Mass is the fundamental parameter for an astrophysical black hole, since the accurate value of mass is a prerequisite for measuring a black hole's spin via the continuum-fitting method. Previous dynamical analyses have established that the X-ray binary Nova Muscae 1991 (GRS 1124-683) harbors a black hole. In this work, we utilize 72 high resolution Magellan Echelle (MagE) spectra and 72 strictly simultaneous V-band photometry (obtained with 2.5-m DuPont Telescope) to significantly improve the precision of the mass measurement for the black hole in Nova Muscae 1991. The spectra were taken on two consecutive nights and cover the full 11.4-hour orbital cycle. The radial velocities of Nova Muscae 1991 are determined by cross-correlating the object spectra with the spectrum of a (K3 V) template star obtained with the same instrument configuration. Five orders of the echelle spectra deliver consistent, high-quality radial velocity curves, from which the radial velocity amplitude is measured to be 406.45+/-2.40 km/s, which is consistent with previous works while the uncertainty is reduced by a factor of 3. We have also obtained the first accurate measurement of the rotational broadening of the stellar absorption lines (v sini=82.9+/-1.1 km/s). From the MagE spectra we have determined the veiling of the stellar light by the disk emission (e.g., 61+/-1% of the total light at 5500 A). This will allow us to correct the simultaneous photometric observation for the disk veiling effect, which will be used to accurately constrain the systemic inclination.

Wu, Jianfeng; McClintock, Jeffrey E.; Steeghs, Danny; Longa, Penelope; Torres, Manuel; Ho, Luis C.; Callanan, Paul; Reynolds, Mark; Orosz, Jerome A.; Jonker, Peter G

2014-08-01

364

FAST TCP in High-Speed Networks: An Experimental Study  

E-print Network

1 FAST TCP in High-Speed Networks: An Experimental Study Sanjay Hegde, David Lapsley, Bartek experiments using FAST TCP on two high-speed networks and uncovered some of the hidden problems affecting high-speed such as FAST TCP will continue to improve with time, it is clear that in order to realize the vision of high-speed

Low, Steven H.

365

Towards the GEOSAT Follow-On Precise Orbit Determination Goals of High Accuracy and Near-Real-Time Processing  

NASA Technical Reports Server (NTRS)

The US Navy's GEOSAT Follow-On spacecraft (GFO) primary mission objective is to map the oceans using a radar altimeter. Satellite laser ranging data, especially in combination with altimeter crossover data, offer the only means of determining high-quality precise orbits. Two tuned gravity models, PGS7727 and PGS7777b, were created at NASA GSFC for GFO that reduce the predicted radial orbit through degree 70 to 13.7 and 10.0 mm. A macromodel was developed to model the nonconservative forces and the SLR spacecraft measurement offset was adjusted to remove a mean bias. Using these improved models, satellite-ranging data, altimeter crossover data, and Doppler data are used to compute both daily medium precision orbits with a latency of less than 24 hours. Final precise orbits are also computed using these tracking data and exported with a latency of three to four weeks to NOAA for use on the GFO Geophysical Data Records (GDR s). The estimated orbit precision of the daily orbits is between 10 and 20 cm, whereas the precise orbits have a precision of 5 cm.

Lemoine, Frank G.; Zelensky, Nikita P.; Chinn, Douglas S.; Beckley, Brian D.; Lillibridge, John L.

2006-01-01

366

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

Microsoft Academic Search

We describe a prototype instrument using a Peltier cooled quantum cascade laser for precise measurement of stable carbon (13C\\/12C) isotopologue ratios in atmospheric CO2. Using novel optics and signal processing techniques in a compact instrument, we are able to detect the difference between sample and reference with a precision of 0.10\\/00 (2sigma standard error of mean of 11 samples) in

J. B. McManus; D. D. Nelson; J. H. Shorter; R. Jimenez; S. Herndon; S. Saleska; M. Zahniser

2005-01-01

367

High-Precision Isotope Analysis of Uranium and Thorium by TIMS  

NASA Astrophysics Data System (ADS)

The U.S. Geological Survey (USGS) Yucca Mountain Project Branch laboratory in Denver, Colorado, conducts routine high-precision isotope analyses of uranium (U) and thorium (Th) using thermal ionization mass- spectrometry (TIMS). The measurements are conducted by a ThermoFinnigan Triton\\texttrademark equipped with a Faraday multi-collector system and an energy filter in front of an active-film-type secondary electron multiplier (SEM). The abundance sensitivity of the instrument (signal at mass 237 over 238U in natural U) with the energy filter is about 15 ppb and peak tails are reduced by a factor of about 100 relative to the Faraday cup measurements. Since instrument installation in April 2004, more than 500 rock and water samples have been analyzed in support of isotope-geochemical studies for the U.S. Department of Energy`s Yucca Mountain Project. Isotope ratios of sub-nanogram to microgram U and Th samples are measured on graphite-coated single- filament and double-filament assemblies using zone-refined rhenium filaments. Ion beams less than 5 mV are measured with the SEM, which is corrected for non-linearity on the basis of measurements of NIST U-500 and 4321B standards with ion beams ranging from 0.01 to 8 mV. Inter-calibration between the SEM and the Faraday multi-collector is performed for every mass cycle using a 5 mV beam switched between Faraday cup and SEM (bridging technique), because SEM-Faraday inter-calibrations prior to the measurement failed to produce acceptable results. Either natural (^{235}U) or artificial (^{236}U, ^{229}Th) isotopes were used for the bridging. Separate runs are conducted for minor isotopes using SEM only. These techniques result in high within-run precisions of less than 0.1 to 0.2 percent for 234U/238U and 0.2 to 0.5 percent for 230Th/238U. The performance of the instrument is monitored using several U and Th isotope standards. The mean measured 234U/238U in NIST SRM 4321B is (52.879±0.004)×10-6 (95 percent confidence, n=134).The mean fractionation factor in these analyses is 0.09±0.06 percent per mass unit. The ^{236}U/238U value of about 1.1×10-9 measured in this standard defines an upper limit for the ^{236}U background in the analyses. The mean atomic 234U/238U and activity 230Th/238U for 29 runs of an internal secular equilibrium uranium ore standard is (54.82±0.02) ×10-6 and 1.002±0.002, respectively. The Th isotopic composition in the IRMM-036 standard was obtained after addition of high-purity ^{229}Th tracer and measuring 232Th/^{229}Th and 230Th/^{229}Th ratios in separate lower- and higher-temperature runs, respectively. The resulting 230Th/232Th for 30 runs is 31.09±0.04 ×10-7, in excellent agreement with the certified value of 31.13±0.78 ×10-7. The USGS laboratory measured four samples of depleted to low-enriched uranium in the recent Regular European Inter-laboratory Measurement Evaluation Program (REIMEP-18). The results of these analyses are close to the certified values.

Neymark, L. A.; Paces, J. B.

2006-12-01

368

Progress on precision measurements of inner shell transitions in highly charged ions at an ECR ion source  

SciTech Connect

Inner shell transitions of highly charged ions produced in the plasma of an Electron Cyclotron Resonance Ion Source (ECRIS) were observed the first time by a Double Crystal Spectrometer (DCS). The DCS is a well-used tool in precision x-ray spectroscopy due to its ability of precision wavelength measurement traced back to a relative angle measurement. Because of its requirement for a bright x-ray source the DCS has not been used before in direct measurements of highly charged ions (HCI). Our new precision measurement of inner shell transitions in HCI is not just going to provide new x-ray standards for quantum metrology but can also give information about the plasma in which the ions reside. Ionic temperatures and with that the electron density can be determined by thorough examination of line widths measured with great accuracy.

Szabo, Csilla I.; Indelicato, Paul; LeBigot, Eric-Olivier; Vallette, Alexandre; Amaro, Pedro; Guerra, Mauro; Gumberidze, Alex [Laboratoire Kastler Brossel, Ecole Normale Superieure, CNRS, Universite Pierre et Marie Curie- Paris 6, Case 74, 4 place Jussieu, F-75005 Paris (France); Centro de Fisica Atomica, CFA, Departamento de Fisica (Portugal); Faculdade de Ciencias e Tecnologia, FCT, Universidade Nova de Lisboa, 2829-516 Caparica (Portugal); Laboratoire Kastler Brossel, Ecole Normale Superieure, CNRS, Universite Pierre et Marie Curie- Paris 6, Case 74, 4 place Jussieu, F-75005 Paris (France)

2012-05-25

369

Experimental study of highly viscous impinging jets  

SciTech Connect

The objective of this research is to study the behavior of highly viscous gravity-driven jets filling a container. Matters of interest are the formation of voids in the fluid pool during the filling process and the unstable behavior of the fluid in the landing region which manifests itself as an oscillating motion. The working fluids used in this research are intended to simulate the flow behavior of molten glass. Qualitative and quantitative results are obtained in a parametric study. The fraction of voids present in the fluid pool after the filling of the container is measured for different parameter values of viscosity and mass flow rate. Likewise, frequencies of the oscillating jet are measured. Results are inconclusive with regard to a correlation between parameter settings and void fractions. As for frequencies, power law correlations are established.

Gomon, M. [Univ. of Texas, Austin, TX (United States). Dept. of Mechanical Engineering

1998-12-01

370

Globular Cluster Streams as Galactic High-Precision Scales - The Poster Child Palomar 5  

NASA Astrophysics Data System (ADS)

We model the tidal stream of the Milky Way globular cluster Palomar 5 (Pal 5), and show that the unique geometry of the problem yields powerful constraints on the model parameters characterizing the Local Standard of Rest (LSR), the Milky Way and Pal 5 itself. Using only SDSS data and a few radial velocities from the literature, we find that the distance of the Sun from the Galactic Center is 8.30+/-0.25 kpc, and the LSR transverse velocity is 242+/-16 km/s. Assuming that the dark halo of the Galaxy follows a NFW density profile, we fit it with a virial mass of (1.6+/-0.4) 1012Msun, a virial radius of 195+/-19 kpc, and hence a rather low concentration of 5+/-2. Moreover, we find it with a flattening of qz = 0.95(+0.16)(-0.12) to be essentially spherical - at least within the inner 25 kpc, which are effectively probed by Pal 5. We also determine Pal 5's mass, distance and proper motions independently from other methods, which enables us to perform vital cross-checks for these methods. We conclude that finding more globular cluster streams is essential for mapping out the structure of the halo of our Galaxy to high precision. Finally, we point out that all our best-fit models yield similar substructure patterns as the ones observed in the Pal 5 stream within about 5 kpc of the cluster. The origin of these substructures is epicylic motion of stars along the stream. Such epicylic substructures have to be taken into account when searching tidal streams for signs of past encounters with dark-matter subhalos

Kupper, Andreas Hans Wilhelm; Balbinot, Eduardo; Bonaca, Ana; Johnston, Kathryn V.; Hogg, David W.; Kroupa, Pavel; Santiago, Basilio

2015-01-01

371

High precision methods for locating the celestial intermediate pole and origin  

NASA Astrophysics Data System (ADS)

Context: .The precession-nutation transformation describes the changing directions on the celestial sphere of the Earth's pole and an adopted origin of right ascension. The coordinate system for the celestial sphere is the geocentric celestial reference system, and the two directions are the celestial intermediate pole (CIP) and the celestial intermediate origin (CIO), the latter having supplanted the equinox for this purpose following IAU resolutions in 2000. The celestial coordinate triad based on the CIP and CIO is called the celestial intermediate reference system; the prediction of topocentric directions additionally requires the Earth rotation angle (ERA), the counterpart of Greenwich sidereal time (GST) in the former equinox based system. Aims: .The purpose of this paper is to review the different ways of calculating the CIP and CIO directions to precisions of a few microarcseconds over a time span of several centuries, meeting the requirements of high-accuracy applications. Methods: .Various implementations are described, their theoretical bases compared and the relationships between the expressions for the relevant parameters are provided. Semi-analytical and numerical comparisons have been made, based on the P03 precession and the IAU 2000A nutation, with slight modifications to the latter to make it consistent with P03. Results: .We have identified which transformations between celestial and terrestrial coordinates involve a minimum number of variables and coefficients for given accuracy objectives. The various methods are consistent at the level of a few microarcseconds over several centuries, and equal accuracy is achievable using both the equinox/GST paradigm and the CIO/ERA paradigm. Given existing nutation models, the most concise expressions for locating the CIP are based on the Fukushima-Williams bias-precession-nutation angles. The CIO can be located to a few microarcseconds using the CIO locator s. The equation of the origins (EO) is sensitive to the precession-nutation, but can locate the CIO to a few microarcseconds as long as consistent models are used for EO and precession-nutation.

Capitaine, N.; Wallace, P. T.

2006-05-01

372

Glue test results for high-precision large cryogenic lens holder  

NASA Astrophysics Data System (ADS)

The Near Infrared Spectrometer and Photometer (NISP) of EUCLID requires high precision large lens holders (Ø170 mm) at cryogenic temperatures (150 K). The lenses of the optical system are glued into separate lens holders, the so called adaption rings. For the selection and verification of a suitable adhesive extensive glue selection tests are performed and results presented in this paper. With potential glue candidates, handling, single lap shear, connection tension and shear tests are carried out at room temperature (RT) and 150 K (OPS). For the NISP optical system DP490 is selected as the most suitable adhesive. The test results have shown that an even distribution of the glue in the glue gap is of crucial importance for the functioning and performance of the bonded lens system. The different coefficients of thermal expansion (CTE) between lens and lens holder produce large local mechanical stress and might cause lens breakage or failure of bonding. The design of the injection channel and the gluing procedure are developed to meet the lens performance requirements. An example is shown that after thermal cycling the remaining 0.5 mm - 1 mm thick adhesive in the injection channel results in large local mechanical stresses, and hence, damage of the lens. For a successful performance of the glue interface not only an optimum glue gap of 80 - 150 ?m is important, also micro-cracks of the glass at the gluing area have to be avoided. The performed glue tests with DP490 for 3 different lens/ring material combinations show sufficient mechanical tension and shear strength for bonding of the lens system. Titanium/LF5G15 and Invar/Fused Silica combinations have reached the strength of 30 MPa at RT and 50 GPa at 150 K. These results are presented on behalf of the EUCLID consortium.

Reutlinger, A.; Mottaghibonab, A.; Gal, C.; Boesz, A.; Grupp, F.; Geis, N.; Bode, A.; Katterloher, R.; Bender, R.

2012-09-01

373

High-precision genetic mapping of behavioral traits in the diversity outbred mouse population  

PubMed Central

Historically our ability to identify genetic variants underlying complex behavioral traits in mice has been limited by low mapping resolution of conventional mouse crosses. The newly developed Diversity Outbred (DO) population promises to deliver improved resolution that will circumvent costly fine-mapping studies. The DO is derived from the same founder strains as the Collaborative Cross (CC), including three wild-derived strains. Thus the DO provides more allelic diversity and greater potential for discovery compared to crosses involving standard mouse strains. We have characterized 283 male and female DO mice using open-field, light–dark box, tail-suspension and visual-cliff avoidance tests to generate 38 behavioral measures. We identified several quantitative trait loci (QTL) for these traits with support intervals ranging from 1 to 3 Mb in size. These intervals contain relatively few genes (ranging from 5 to 96). For a majority of QTL, using the founder allelic effects together with whole genome sequence data, we could further narrow the positional candidates. Several QTL replicate previously published loci. Novel loci were also identified for anxiety- and activity-related traits. Half of the QTLs are associated with wild-derived alleles, confirming the value to behavioral genetics of added genetic diversity in the DO. In the presence of wild-alleles we sometimes observe behaviors that are qualitatively different from the expected response. Our results demonstrate that high-precision mapping of behavioral traits can be achieved with moderate numbers of DO animals, representing a significant advance in our ability to leverage the mouse as a tool for behavioral genetics PMID:23433259

Logan, R W; Robledo, R F; Recla, J M; Philip, V M; Bubier, J A; Jay, J J; Harwood, C; Wilcox, T; Gatti, D M; Bult, C J; Churchill, G A; Chesler, E J

2013-01-01

374

High-precision figure correction of x-ray telescope optics using ion implantation  

NASA Astrophysics Data System (ADS)

Achieving both high resolution and large collection area in the next generation of x-ray telescopes requires highly accurate shaping of thin mirrors, which is not achievable with current technology. Ion implantation offers a promising method of modifying the shape of mirrors by imparting internal stresses in a substrate, which are a function of the ion species and dose. This technique has the potential for highly deterministic substrate shape correction using a rapid, low cost process. Wafers of silicon and glass (D-263 and BK-7) have been implanted with Si+ ions at 150 keV, and the changes in shape have been measured using a Shack-Hartmann metrology system. We show that a uniform dose over the surface repeatably changes the spherical curvature of the substrates, and we show correction of spherical curvature in wafers. Modeling based on experiments with spherical curvature correction shows that ion implantation could be used to eliminate higher-order shape errors, such as astigmatism and coma, by using a spatially-varying implant dose. We will report on progress in modelling and experimental tests to eliminate higher-order shape errors. In addition, the results of experiments to determine the thermal and temporal stability of implanted substrates will be reported.

Chalifoux, Brandon; Sung, Edward; Heilmann, Ralf K.; Schattenburg, Mark L.

2013-09-01

375

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

E-print Network

of greenhouse gases; however, little is known about their isotopic composition. In particular, stable sources exhibit distinct carbon and hydrogen isotopic composition. However, CH4 isotope analysisA gas chromatography/pyrolysis/isotope ratio mass spectrometry system for high-precision d

Fischer, Hubertus

376

NORAD-ATOMIC-DATA NORAD-Atomic-Data contains ab initio high-precision fundamental data for radiative atomic  

E-print Network

requires several codes. In contrast to atomic structure codes, the R-matrix codes do not identify to results from atomic structure calculations, the R-matrix computations can consider and yield much largerNORAD-ATOMIC-DATA NORAD-Atomic-Data contains ab initio high-precision fundamental data

Nahar, Sultana Nurun

377

Practical experience with IEEE 1588 high Precision Time Synchronization in electrical substation based on IEC 61850 Process Bus  

Microsoft Academic Search

This paper describes the experience from the world first installation of High Voltage substation with IEC 61850 Process Bus where IEEE 1588 Time Synchronization and dynamic multicast filtering have been used. The authors provide brief introduction to the concept of digital substation and process bus, then provide overview of IEEE 1588 standard for precise time synchronization and finally describe the

R. Moore; R. Midence; M. Goraj

2010-01-01

378

Precision Irrigators Network: On-Farm Research Demonstration to Evaluate Irrigation Scheduling Tools in the Wintergarden and Texas High Plains  

E-print Network

Precision Irrigators Network: On-Farm Research Demonstration to Evaluate Irrigation Scheduling Tools in the Wintergarden and Texas High Plains Submitted by: Giovanni Piccinni, formerly with Texas AgriLife Research... ..................................................................................................................... 14 SUMMARY ........................................................................................................................................ 14 CHAPTER 1: Wintergarden Agronomic Demonstrations and Implementation .......15 Giovanni...

Piccinni, Giovanni; Leskovar, Daniel; Harman, Wyatte; Marek, Thomas; Harris, B.L.

379

High Temperature Experimental Characterization of Microscale Thermoelectric Effects.  

E-print Network

??AbstractHigh Temperature Experimental Characterization of Microscale Thermoelectric Effects By Tela FavaloroThermoelectric devices have been employed for many years as a reliable energy conversion technology for… (more)

Favaloro, Tela

2014-01-01

380

High-resolution frequency-modulated continuous-wave laser ranging for precision distance metrology applications  

NASA Astrophysics Data System (ADS)

Frequency-modulated continuous wave (FMCW) laser ranging is one of the most interesting techniques for precision distance metrology. In order to ensure the theoretical measurement range and precision, a narrow linewidth external cavity tunable laser with large tuning range is chosen. In practical situations, the tuning nonlinearity of the laser reduces the measurement precision, hence an auxiliary interferometer is used to measure the laser tuning rate and linearize the frequency ramp. Then, fast Fourier transform algorithm is applied to the resampled signal of the main interferometer, and the full-width at half maximum of the frequency spectrum is narrowed. In the end, the experiments are carried out using the FMCW laser ranging system and demonstrate 50-?m range resolution at 8.7 m.

Shi, Guang; Zhang, Fumin; Qu, Xinghua; Meng, Xiangsong

2014-12-01

381

Precise 3D dimensional metrology using high-resolution x-ray computed tomography (?CT)  

NASA Astrophysics Data System (ADS)

Over the past decade computed tomography (CT) with conventional x-ray sources has evolved from an imaging method in medicine to a well established technology for industrial applications in fields such as material science, light metals and plastics processing, microelectronics and geology. By using modern microfocus and nanofocus X-ray tubes, parts can be scanned with sub-micrometer resolutions. Currently, micro-CT is a technology increasingly used for metrology applications in the automotive industry. CT offers big advantages compared with conventional tactile or optical coordinate measuring machines (CMMs). This is of greater importance if complex parts with hidden or difficult accessible surfaces have to be measured. In these cases, CT offers the advantage of a high density of measurement points and a non-destructive and fast capturing of the sample's complete geometry. When using this growing technology the question arises how precise a ?CT based CMM can measure as compared to conventional and established methods for coordinate measurements. For characterizing the metrological capabilities of a tactile or optical CMM, internationally standardized parameters like length measurement error and probing error are defined and used. To increase the acceptance of CT as a metrological method, our work seeks to clarify the definition and usage of parameters used in the field of metrology as these apply to CT. In this paper, an overview of the process chain in CT based metrology will be given and metrological characteristics will be described. For the potential user of CT as 3D metrology tool it is important to show the measurement accuracy and repeatability on realistic samples. Following a discussion of CT metrology techniques, two samples are discussed. The first compares a measured CT Data set to CAD data using CMM data as a standard for comparison of results. The second data second realistic data set will compare the results of applying both the CMM method of measurement and the CT method of measurement within the same CT data set. A comparison of these results to the data obtained by means of CT shows that state of the art high resolution CT can provide measurement accuracy on the order of established coordinate measurement techniques.

Brunke, Oliver; Santillan, Javier; Suppes, Alexander

2010-09-01

382

Proposal of Single Metal\\/Dual High Devices for Aggressively Scaled CMISFETs With Precise Gate Profile Control  

Microsoft Academic Search

We have proposed a single metal\\/dual high-k gate stack for aggressively scaled complementary metal-insulator-semiconductor field-effect transistors (MISFETs). The threshold voltage is controlled by the dual high-k dielectrics, such as MgO- and Al2O3-containing HfSiON for n- and p-type MISFETs, respectively. The gate profile is precisely controlled by taking advantage of a common gate electrode, which will suppress the variation in device

Nobuyuki Mise; Tetsu Morooka; Takahisa Eimori; Tetsuo Ono; Motoyuki Sato; Satoshi Kamiyama; Yasuo Nara; Yuzuru Ohji

2009-01-01

383

Application of high-precision two-way ranging to Galileo Earth-1 encounter navigation  

NASA Technical Reports Server (NTRS)

The application of precision two-way ranging to orbit determination with relatively short data arcs is investigated for the Galileo spacecraft's approach to its first Earth encounter (December 8, 1990). Analysis of previous S-band (2.3-GHz) ranging data acquired from Galileo indicated that under good signal conditions submeter precision and 10-m ranging accuracy were achieved. It is shown that ranging data of sufficient accuracy, when acquired from multiple stations, can sense the geocentric angular position of a distant spacecraft. A range data filtering technique, in which explicit modeling of range measurement bias parameters for each station pass is utilized, is shown to largely remove the systematic ground system calibration errors and transmission media effects from the Galileo range measurements, which would otherwise corrupt the angle-finding capabilities of the data. The accuracy of the Galileo orbit solutions obtained with S-band Doppler and precision ranging were found to be consistent with simple theoretical calculations, which predicted that angular accuracies of 0.26-0.34 microrad were achievable. In addition, the navigation accuracy achieved with precision ranging was marginally better than that obtained using delta-differenced one-way range (delta DOR), the principal data type that was previously used to obtain spacecraft angular position measurements operationally.

Pollmeier, V. M.; Thurman, S. W.

1992-01-01

384

Evaluation of the precision agricultural landscape modeling system (PALMS) in the semiarid Texas southern high plains  

Technology Transfer Automated Retrieval System (TEKTRAN)

Accurate models to simulate the soil water balance in semiarid cropping systems are needed to evaluate management practices for soil and water conservation in both irrigated and dryland production systems. The objective of this study was to evaluate the application of the Precision Agricultural Land...

385

High-precision measurement of the atomic mass of the electron.  

PubMed

The quest for the value of the electron's atomic mass has been the subject of continuing efforts over the past few decades. Among the seemingly fundamental constants that parameterize the Standard Model of physics and which are thus responsible for its predictive power, the electron mass me is prominent, being responsible for the structure and properties of atoms and molecules. It is closely linked to other fundamental constants, such as the Rydberg constant R? and the fine-structure constant ? (ref. 6). However, the low mass of the electron considerably complicates its precise determination. Here we combine a very precise measurement of the magnetic moment of a single electron bound to a carbon nucleus with a state-of-the-art calculation in the framework of bound-state quantum electrodynamics. The precision of the resulting value for the atomic mass of the electron surpasses the current literature value of the Committee on Data for Science and Technology (CODATA) by a factor of 13. This result lays the foundation for future fundamental physics experiments and precision tests of the Standard Model. PMID:24553144

Sturm, S; Köhler, F; Zatorski, J; Wagner, A; Harman, Z; Werth, G; Quint, W; Keitel, C H; Blaum, K

2014-02-27

386

Quantifying Condition-Dependent Intracellular Protein Levels Enables High-Precision Fitness Estimates  

E-print Network

-precision growth estimates that allow extension of phenotypic growth-based assays closer to the limits the growth rate of microbial populations as a measure of fitness. However, an enormous gap separates growth advantage of the recent discovery that transcript and protein levels in budding yeast closely track growth

Needleman, Daniel

387

High-precision optical measurements of 13 isotope ratios in organic compounds at  

E-print Network

-precision isotope ratios are special-purpose isotope-ratio mass spectrometers (IRMS) (2, 3) that are fairly costly accuracy for methane, ethane, and propane is within 3 of the values determined using isotope ratio mass; however, it should be noted that the isotopes of hydrogen, nitrogen, oxygen, and sulfur have also been

Zare, Richard N.

388

High precision 13C and 18O isotope analysis of small carbonates with Dual Inlet and Kiel IV Carbonate Device  

NASA Astrophysics Data System (ADS)

The measurement of high precision isotope analysis in carbonates has been possible since the development of the dual inlet 50 years ago. The isotope ratios of the CO2 processed from a sample carbonate and of a CO2 reference gas are compared using a change over valve as gas inlet to the isotope ratio mass spectrometer. The low CO2 gas pressures evolved from the sample are equilibrated to the pressure of the standard gas. The analysis of small carbonates in the low microgram range became feasible with the introduction of a small micro volume incorporated into the preparation device. For climate research the analyst needs a device to be able to measure a large number of samples with stable high precision and without correction of raw data. To minimize the sample preparation and high precision analysis of data records a preparation device and mass spectrometer system is needed which is able to go to 10 micrograms of carbonate sample without loosing isotope ratio precision. The Kiel IV carbonate device has been developed for standard sample amount measurements of greater than 20 microgram and has been optimised to down to 10 microgram samples using a MAT 253 mass spectrometer. For the CO2 preparation inside the Kiel IV all physical/chemical properties are process controlled, i.e. acid temperature, CO2 freeze and release temperatures and evolved pCO2 from the carbonate. It will be presented what differences in high precision and accuracy of isotope ratios exist within different mass spectrometers and preparation devices (GasBench II, Kiel IV, MAT253, Delta V series). Additionally possible interfering aspects, i.e. content and evolution of water during carbonate-acid reaction, reference gas quality and sample-standard gas decrease, and their influence on data results will be explained.

Radke, J.; Hilkert, A.

2009-04-01

389

Measuring stellar differential rotation with high-precision space-borne photometry  

NASA Astrophysics Data System (ADS)

Context. Stellar differential rotation is important for understanding hydromagnetic stellar dynamos, instabilities, and transport processes in stellar interiors, as well as for a better treatment of tides in close binary and star-planet systems. Aims: We introduce a method of measuring a lower limit to the amplitude of surface differential rotation from high-precision, evenly sampled photometric time series, such as those obtained by space-borne telescopes. It is designed to be applied to main-sequence late-type stars whose optical flux modulation is dominated by starspots. Methods: An autocorrelation of the time series was used to select stars that allow an accurate determination of starspot rotation periods. A simple two-spot model was applied together with a Bayesian information criterion to preliminarily select intervals of the time series showing evidence of differential rotation with starspots of almost constant area. Finally, the significance of the differential rotation detection and a measurement of its amplitude and uncertainty were obtained by an a posteriori Bayesian analysis based on a Monte Carlo Markov chain approach. We applied our method to the Sun and eight other stars for which previous spot modelling had been performed to compare our results with previous ones. Results: We find that autocorrelation is a simple method for selecting stars with a coherent rotational signal that is a prerequisite for successfully measuring differential rotation through spot modelling. For a proper Monte Carlo Markov chain analysis, it is necessary to take the strong correlations among different parameters that exist in spot modelling into account. For the planet-hosting star Kepler-30, we derive a lower limit to the relative amplitude of the differential rotation of ?P/P = 0.0523 ± 0.0016. We confirm that the Sun as a star in the optical passband is not suitable for measuring differential rotation owing to the rapid evolution of its photospheric active regions. In general, our method performs well in comparison to more sophisticated and time-consuming approaches.

Lanza, A. F.; Das Chagas, M. L.; De Medeiros, J. R.

2014-04-01

390

Cranio Spinal Irradiation of Medulloblastoma Using High Precision Techniques - A Dosimetric Comparison.  

PubMed

Radiotherapy planning, delivery and junction dose verification remain exigent for Cranio Spinal Irradiation (CSI) in medulloblastoma patients. This study aims to evaluate high precision techniques such as Intensity Modulated Radiation Therapy (IMRT), Rapid Arc Therapy (RA) with and without flattening filter (FF) on the basis of dosimetric analysis. Five patients treated with jagged junction Intensity Modulated RadioTherapy (IMRT) using dynamic Multi Leaf Collimators (MLC) were randomly selected for this retrospective study. IMRT, Rapid Arc (RA) plans were simulated in the same CT data set with and without flattening filter. Total dose prescribed was 28.80 Gy in 16 fractions. An evaluation criterion of 98% of PTV receiving 100% of the prescription dose was followed in all plans. Twenty treatment plans with 260 Dose Volume Histograms (DVHs) was created. Dosimetric parameters such as Dmax, Dmin, Dmean, V95%, V107%, CI for PTV and Dmax, Dmean, V80%, V50%, V30%, V10% for Organs At Risk (OAR) were extracted from DVHs. Treatment delivery efficiency was also evaluated for total Beam On Time (BOT). FFF Rapid Arc therapy (6F_RA) resulted in conformal doses throughout the cranio spinal axis. FF and FFF dynamic IMRT had minimal V107%, 1.23% and 2.88% compared to 49.15 and 66.36 of rapid arc therapy (with and without FF). 6F_IMRT resulted in lesser mean doses to eyes, liver, lungs and kidneys. Heart mean dose was less (3.08 Gy) with 6X_IMRT. Thyroid and esophagus doses could be reduced to about 41.2% and 10% respectively with 6F_RA. The BOT for the treatment techniques were 3.43 min (6X_IMRT), 1.59 min (6F_IMRT), 5min (6X_RA), 4.5 min (6F_RA). Removal of flattening filter in IMRT could improve dose coverage along the caniospinal axis and normal tissue sparing. A reduction of 46.3% BOT could increase treatment efficiency of 6F_IMRT compared to 6X_IMRT. CSI could be simpler since junction doses can be evaded in IMRT and RA techniques. PMID:24645747

Pichandi, A; Ganesh, K M; Jerrin, A; Balaji, K; Sridhar, P S; Surega, A

2014-03-17

391

Development of a mobile and high-precision atmospheric CO2 monitoring station  

NASA Astrophysics Data System (ADS)

Nowadays one of the most burning questions for the science is the rate and the reasons of the recent climate change. Greenhouse gases (GHG), mainly CO2 and CH4 in the atmosphere could affect the climate of our planet. However, the relation between the amount of atmospheric GHG and the climate is complex, full with interactions and feedbacks partly poorly known even by now. The only way to understand the processes, to trace the changes, to develop and validate mathematical models for forecasts is the extensive, high precision, continuous monitoring of the atmosphere. Fossil fuel CO2 emissions are a major component of the European carbon budget. Separation of the fossil fuel signal from the natural biogenic one in the atmosphere is, therefore, a crucial task for quantifying exchange flux of the continental biosphere through atmospheric observations and inverse modelling. An independent method to estimate trace gas emissions is the top-down approach, using atmospheric CO2 concentration measurements combined with simultaneous radiocarbon (14C) observations. As adding fossil fuel CO2 to the atmosphere, therefore, leads not only to an increase in the CO2 content of the atmosphere but also to a decrease in the 14C/12C ratio in atmospheric CO2. The ATOMKI has more than two decade long experience in atmospheric 14CO2 monitoring. As a part of an ongoing research project being carried out in Hungary to investigate the amount and temporal and spatial variations of fossil fuel CO2 in the near surface atmosphere we developed a mobile and high-precision atmospheric CO2 monitoring station. We describe the layout and the operation of the measuring system which is designed for the continuous, unattended monitoring of CO2 mixing ratio in the near surface atmosphere based on an Ultramat 6F (Siemens) infrared gas analyser. In the station one atmospheric 14CO2 sampling unit is also installed which is developed and widely used since more than one decade by ATOMKI. Mixing ratio of CO2 is measured at 2 m above the ground by the monitoring station. Air is pumped through a 9.5-mm-diameter plastic tube (PFA, Swagelok) to a CO2 analyser located in a container box. Container box (Containex) is 1.5 m wide, 1.2 m deep and 2.2 m high, designed as a mobile measuring room which is field deployable, only electric power is required. A 15 micron pore size stainless steel Tee-Type (Swagelok) particle filter is located at the inlet of the sampler tube. Diaphragm pump (KNF) is used to draw air continuously through the sampling tube from monitoring level at flow rate of ~ 2 L/min. After leaving the pump, the air at 5 psig overpressure enters a glass trap for liquid water that is cooled in a regular household refrigerator, to dry the air to a dew point of 3°-4°C. Liquid water is forced out through an orifice at the bottom of the trap. The air sample inlet tube and the standard gases (Linde Hungary) are connected to miniature solenoid valves (S Series, ASCO Numatics) in a manifold which are normally closed and controlled by the CO2 analyser, which selects which gas is sampled. The air leaving the manifold through its common outlet is further dried to a dew point of about -25°C by passage through a 360-cm-long Nafion drier (Permapure), so that the water vapour interference and dilution effect are <0.1 ppm equivalent CO2. The Nafion drier is purged in a counter flow (300 cm3/min) arrangement using waste sample air that has been further dried by passage through anhydrous CaSO4 (Drierite). Analysis is carried out using an infrared gas analyser Ultramat 6F which is a specialised model for field applications by Siemens. A constant sample flow rate of 300 cm3/min is maintained by a mass flow controller (Aalborg). The reference cell of the CO2 analyzer is continuously flushed with a compressed reference gas of 350 ppm CO2 in synthetic air (Messer Hungarogáz). The basic calibration cycle is 2 hours, consisting of a zero-point calibration and a span calibration. Each calibration is consisting of 2 min flushing and 20 sec signal integration. The usual change of the r

Molnár, M.; Haszpra, L.; Major, I.; Svingor, É.; Veres, M.

2009-04-01

392

X-Lase CoreScriber, Picosecond Fiber Laser Tool for High-Precision Scribing and Cutting of Transparent Materials  

NASA Astrophysics Data System (ADS)

We have developed various industrial transparent material scribing processes and a laser tool, picosecond MHz-range all- fiber laser X-Lase CoreScriber. The remarkably high peak power, exceptionally good beam quality, and integrability of the X-Lase CoreScriber combined with high achievable material processing speeds provide tempting solutions for high- precision glass processing. Here presented sapphire and Gorilla glass dicing processes are based on transparent material internal modification with short and intense high repetition rate ps-laser pulses. Increased processing speeds and cutting qualities in comparison to other conventional processing methods are presented.

Kivistö, S.; Amberla, T.; Konnunaho, T.; Kangastupa, J.; Sillanpää, J.

393

Franciscan subduction off to a slow start: evidence from high-precision LuHf garnet ages on high grade-blocks  

E-print Network

Franciscan subduction off to a slow start: evidence from high-precision Lu­Hf garnet ages on high Available online 21 July 2004 Editor: B. Wood Abstract Lu­Hf analyses of garnet from metabasic amphibolite us to place new constraints on the early thermal history of the Franciscan subduction zone. Garnets

Wang, Zhi "Luke"

394

High School Algebra Readiness Program: A Quasi-Experimental Study  

ERIC Educational Resources Information Center

This quasi-experimental study measured the effectiveness of a locally created summer Algebra readiness program in a large suburban high school district in New Jersey. Incoming ninth grade students who were not ready for high school algebra were invited to participate in the summer program. The program was designed to provide access to more…

Birnbohm, Carol L.

2010-01-01

395

Experimental mechanics at velocity extremes —Very high strain rates  

Microsoft Academic Search

The early experimental work of Clark and Wood with regard to von Kármán's theory on the effect of material flow and fracture at high strain rates has led to many controversial issues on these effects. Interest has been greatly revived in recent years because of the increased emphasis on such high-velocity forming processes as explosive and capacitor discharge. Considerable new

W. W. Wood

1967-01-01

396

Correlated fluorescence and 3D electron microscopy with high sensitivity and spatial precision.  

PubMed

Correlative electron and fluorescence microscopy has the potential to elucidate the ultrastructural details of dynamic and rare cellular events, but has been limited by low precision and sensitivity. Here we present a method for direct mapping of signals originating from ?20 fluorescent protein molecules to 3D electron tomograms with a precision of less than 100 nm. We demonstrate that this method can be used to identify individual HIV particles bound to mammalian cell surfaces. We also apply the method to image microtubule end structures bound to mal3p in fission yeast, and demonstrate that growing microtubule plus-ends are flared in vivo. We localize Rvs167 to endocytic sites in budding yeast, and show that scission takes place halfway through a 10-s time period during which amphiphysins are bound to the vesicle neck. This new technique opens the door for direct correlation of fluorescence and electron microscopy to visualize cellular processes at the ultrastructural scale. PMID:21200030

Kukulski, Wanda; Schorb, Martin; Welsch, Sonja; Picco, Andrea; Kaksonen, Marko; Briggs, John A G

2011-01-10

397

Correlated fluorescence and 3D electron microscopy with high sensitivity and spatial precision  

PubMed Central

Correlative electron and fluorescence microscopy has the potential to elucidate the ultrastructural details of dynamic and rare cellular events, but has been limited by low precision and sensitivity. Here we present a method for direct mapping of signals originating from ?20 fluorescent protein molecules to 3D electron tomograms with a precision of less than 100 nm. We demonstrate that this method can be used to identify individual HIV particles bound to mammalian cell surfaces. We also apply the method to image microtubule end structures bound to mal3p in fission yeast, and demonstrate that growing microtubule plus-ends are flared in vivo. We localize Rvs167 to endocytic sites in budding yeast, and show that scission takes place halfway through a 10-s time period during which amphiphysins are bound to the vesicle neck. This new technique opens the door for direct correlation of fluorescence and electron microscopy to visualize cellular processes at the ultrastructural scale. PMID:21200030

Kukulski, Wanda; Schorb, Martin; Welsch, Sonja; Picco, Andrea

2011-01-01

398

High precision measurement of the masses of the D0 and KS mesons  

NASA Astrophysics Data System (ADS)

Using 580 pb-1 of e+e- annihilation data taken with the CLEO-c detector at ?(3770), the decay D0(D¯0)?K±???+?- has been studied to make the highest precision measurement of D0 mass, M(D0)=1864.845±0.025±0.022±0.053 MeV, where the first error is statistical, the second error is systematic, and the third error is due to uncertainty in kaon masses. As an intermediate step of the present investigation, the mass of the KS meson has been measured to be M(KS)=497.607±0.007±0.015 MeV. Both M(D0) and M(KS) are the most precise single measurements of the masses of these mesons.

Tomaradze, A.; Dobbs, S.; Xiao, T.; Seth, Kamal K.; Bonvicini, G.

2014-02-01

399

High precision pick-up coils for pulsed field magnetization measurements  

Microsoft Academic Search

A pick-up system for precise magnetization measurements in pulsed field facilities is presented. Samples with diameters up to 5mm can be measured (diameter of the pick-up coil is 6.8mm, outer diameter of the pick-up system is 11.8mm). The optimized geometry of the concentric pick-up and compensation coils reduces the influence of a sample displacement on the measured signal. The measured

D. Eckert; R. Grössinger; M. Doerr; F. Fischer; A. Handstein; D. Hinz; H. Siegel; P. Verges; K.-H. Müller

2001-01-01

400

Noise-Robust Estimation of Planar Roto-Translations with High Precision  

Microsoft Academic Search

This article extends in three ways a frequency domain technique for estimating planar rotations introduced by Lucchese et al. (see Proc. of ISCAS'96, Atlanta, Georgia, vol.2, p.774-7, 1996). It refines the technique algorithmically, since it improves the precision by one or two orders of magnitude, depending upon the noise levels. It presents a stochastic version of that method and demonstrates

Luca Lucchese; Guido M. Cortelazzo

1997-01-01

401

HIGH-PRECISION MACLAURIN-BASED MODELS OF ROTATING LIQUID PLANETS  

SciTech Connect

We present an efficient numerical self-consistent field method for calculating a gravitational model of a rotating liquid planet to spherical harmonic degree {approx}30 and a precision {approx}10{sup -12} in the external gravity field. The method's accuracy is validated by comparing results, for Jupiter rotation parameters, with the exact Maclaurin constant-density solution. The method can be generalized to non-constant density.

Hubbard, W. B. [Lunar and Planetary Laboratory, University of Arizona, Tucson, AZ 85721 (United States)

2012-09-01

402

Retrieval of Precise Radial Velocities from High Resolution Near-Infrared Spectra of M Dwarfs  

NASA Astrophysics Data System (ADS)

We present a data analysis pipeline focused on obtaining precision radial velocities (RV) of M Dwarfs from spectra taken between 2.309 and 2.316 microns by the CSHELL spectrograph (R~46,000) at NASA's Infrared Telescope Facility with the aid of a methane isotopologue gas cell (see poster by Plavchan et al. at this meeting). The pipeline compares the observed spectra with a forward model defined by parameters that are optimized using a simplex amoeba algorithm. The stellar template is optimized simultaneously with the fit parameters in an iterative process. The pipeline accounts for temporal variations in the spectral wavelength solution, line spread function, and interference fringes due to instrumental effects. We apply our pipeline to the M Dwarfs GJ 15 A and GJ 876 and the M Giant SV Peg. For GJ 15 A, we are able to obtain 30 m/s RV precision. For the planet host GJ 876, the two most massive planets are easily retrievable from our RV curve. For SV Peg, the single night RV precision can be as low as 15 m/s, with < 5 m/s obtainable through data stacking.

Gao, Peter; Plavchan, Peter; Gagne, Jonathan; Furlan, Elise; Bottom, Michael; Anglada-Escudé, Guillem; White, Russel J.; Davison, Cassy; Mills, Sean; Beichman, Charles A.; Brinkworth, Carolyn; Johnson, John; Ciardi, David R.; Wallace, J. Kent; Mennesson, Bertrand; von Braun, Kaspar; Vasisht, Gautam; Prato, Lisa A.; Kane, Stephen R.; Tanner, Angelle M.; Walp, Bernie; Crawford, Sam; Lin, Sean

2015-01-01

403

Precise, highly female-biased sex ratios in a social spider.  

PubMed Central

It has been recognized for some time that the risk of producing maleless clutches should select for a lower than binomial variance in the sex ratio of organisms with female-biased sex ratios, small clutches and breeding groups containing the clutch of a single female. However, to date, precise sex ratios have only been reported for organisms with haplodiploid sex determination, a system which allows direct control of the sex of individual offspring. In contrast, under heterogametic sex determination chance is expected to play a crucial role in determining the sex composition of any one family, in particular when males are the heterogametic sex. Here, we present evidence of precise or underdispersed primary sex ratios in the Neotropical social spider Anelosimus domingo Levi. We show that this diplodiploid species with male heterogamety has not only beaten the odds of meiosis by producing mostly daughters, but has also attained relative precision in the proportion of sons and daughters produced in any one clutch. The latter finding suggests the existence of mechanisms that allow sorting of the two types of sperm in this spider species. PMID:10983829

Avilés, L; McCormack, J; Cutter, A; Bukowski, T

2000-01-01

404

A new high-precision measurement system used in the image calibration of a large-sized photographic instrument  

NASA Astrophysics Data System (ADS)

The purpose of characterizing the image of large-sized photographic instrument is to make the directionality of three coordinate axises in the three-dimensional coordinate of the image and the directionality of three axises of coordinate in the frame of axes of the instrument keep the same direction. This problem was solved by a high-precision measurement system composed of double-theodolite and a set of communication system. Two cube prisms will be respectively placed on the image surface and the instrument. Every cube prism will stand for a three-dimensional coordinate from the image surface or the instrument. As a result, the interdependence of both coordinates from the image surface and the instrument can be obtained by measuring the interdependence of the both cube prisms with autocollimation survey axiom. In the survey system, two high-precision stations TDA5005 from Leica Company will be selected as double-theodolite and the interdependence of both coordinates can be achieved by moving the station only at one time. Therefore, this measurement system is a high efficient and high-precision surveying method to the image calibration of the large-sized photographic instrument. Based on the experiment, its measuring accuracy can reach arc-second level.

Li, Yan; Liu, Zexun

2005-02-01

405

A new high-precision borehole-temperature logging system used at GISP2, Greenland, and Taylor Dome, Antarctica  

USGS Publications Warehouse

We describe a high-precision (0.1-1.0 mK) borehole-temperature (BT) logging system developed at the United States Geological Survey (USGS) for use in remote polar regions. We discuss calibration, operational and data-processing procedures, and present an analysis of the measurement errors. The system is modular to facilitate calibration procedures and field repairs. By interchanging logging cables and temperature sensors, measurements can be made in either shallow air-filled boreholes or liquid-filled holes up to 7 km deep. Data can be acquired in either incremental or continuous-logging modes. The precision of data collected by the new logging system is high enough to detect and quantify various thermal effects at the milli-Kelvin level. To illustrate this capability, we present sample data from the 3 km deep borehole at GISP2, Greenland, and from a 130m deep air-filled hole at Taylor Dome, Antarctica. The precision of the processed GTSP2 continuous temperature logs is 0.25-0.34 mK, while the accuracy is estimated to be 4.5 mK. The effects of fluid convection and the dissipation of the thermal disturbance caused by drilling the borehole are clearly visible in the data. The precision of the incremental Taylor Dome measurements varies from 0.11 to 0.32mK, depending on the wind strength during the experiments. With this precision, we found that temperature fluctuations and multi-hour trends in the BT measurements correlate well with atmospheric-pressure changes.

Clow, G.D.; Saltus, R.W.; Waddington, E.D.

1996-01-01

406

Early Science Results from Dharma Planet Survey (DPS), a Robotic, High Cadence and High Doppler Precision Survey of Close-in Super-Earths  

NASA Astrophysics Data System (ADS)

The Dharma Planet Survey (DPS) is ready to monitor ~150 nearby very bright FGKM dwarfs during 2014-2017 using the TOU optical high resolution spectrograph (R~100,000) at the AST 2m telescope (2014-2015) and the 50-inch Robotic Telescope (2015-2017). With ~1m/s RV precision and high cadence (~100 observations per target randomly spread over 300 days), a total of about 90 close-in sub-Neptune planets including about 50 super-Earths and Earth-size planets are expected to be detected, which will provide a unique RV low mass planet sample for studying the occurrence rate and properties of this recently identified dominant planet population. The survey also provides the largest single homogenous high precision RV sample of nearby stars for constraining various planet formation models. Early telescope commissioning results show that TOU achieves ~0.5 m/s RV precision over a month with simultaneous ThAr calibration and has reached about 1.3 m/s RV precision with a RV stable star, Tau Ceti, and ~2 m/s for two other RV stable stars (HD 109358 & HD 185144) over one month and confirmed the 70 Vir giant planet with RV precision of 3 m/s (RMS). Early results including low mass planet candidates from the DPS pilot survey of 20 GK dwarfs will be presented.

Ma, Bo; Ge, Jian; Muterspaugh, Matthew W.; Sithajan, Sirinrat; Thomas, Neil B.; Senan Seieroe Grieves, Nolan; Li, Rui; Singer, Michael; Powell, Scott; Varosi, Frank; Zhao, Bo; Liu, Jian; Schofield, Sidney; Jakeman, Hali; Yoder, William; Williamson, Michael W.; Maxwell, Ted; Avner, Louis; Gittelmacher, Jakob

2015-01-01

407

High-Precision Measurements of the Solar Diameter and Oblateness by the Solar Disk Sextant (SDS) Experiment  

Microsoft Academic Search

We reduce and analyze, in a uniform way, all of the data obtained by the Solar Disk Sextant (SDS) experiment, concerning high-precision\\u000a measurements of the solar radius and oblateness, in the bandwidth 590 {–} 670 nm, made onboard stratospheric balloons during\\u000a a series of flights carried out in 1992, 1994, 1995, and 1996. The measured radius value appears anti-correlated with

A. Egidi; B. Caccin; S. Sofia; W. Heaps; W. Hoegy; L. Twigg

2006-01-01

408

High precision measurements of atmospheric nitrous oxide and methane using thermoelectrically cooled mid-infrared quantum cascade lasers and detectors  

Microsoft Academic Search

A compact, fast response, mid-infrared absorption spectrometer using thermoelectrically (TE) cooled pulsed quantum cascade (QC) lasers and TE detectors has been developed to demonstrate the applicability of QC lasers for high precision measurements of nitrous oxide and methane in the earth’s atmosphere. Reduced pressure extractive sampling with a 56m path length, 0.5l volume, multiple pass absorption cell allows a time

David D. Nelson; Barry McManus; Shawn Urbanski; Scott Herndon; Mark S. Zahniser

2004-01-01

409

Simultaneous determination of highly precise Debye-Waller factors and multiple structure factors for chemically ordered tetragonal FePd  

NASA Astrophysics Data System (ADS)

Large sets of highly precise and accurate structure factors and anisotropic Debye-Waller factors for the tetragonal chemically ordered and ferromagnetic intermetallic phase FePd were simultaneously obtained using multi-beam convergent-beam electron diffraction (CBED). The CBED pattern sensitivity to structure and Debye-Waller factor changes is assessed and the potential for bonding charge measurements in FePd is discussed.

Sang, X. H.; Kulovits, A.; Wiezorek, J.

2011-05-01

410

A new high-precision measurement system used in the image calibration of a large-sized photographic instrument  

Microsoft Academic Search

The purpose of characterizing the image of large-sized photographic instrument is to make the directionality of three coordinate axises in the three-dimensional coordinate of the image and the directionality of three axises of coordinate in the frame of axes of the instrument keep the same direction. This problem was solved by a high-precision measurement system composed of double-theodolite and a

Yan Li; Zexun Liu

2005-01-01

411

A cryptic record of magma mixing in diorites revealed by high-precision SIMS oxygen isotope analysis of zircons  

Microsoft Academic Search

High-precision in-situ ion microprobe (SIMS) oxygen isotope analysis of zircons from two diorite intrusions associated with the late Caledonian Lochnagar pluton in Scotland has revealed large differences in the degree of heterogeneity in zircon ?18O between the diorites. Zircon crystals from the Cul nan Gad diorite (CnG) show a unimodal distribution of oxygen isotope values (?18O=6.0±0.6‰ (2?)) and no or

S. K. Appleby; C. M. Graham; M. R. Gillespie; R. W. Hinton; G. J. H. Oliver

2008-01-01

412

Experimental astrophysics with high power lasers and Z pinches  

SciTech Connect

With the advent of high energy density (HED) experimental facilities, such as high-energy lasers and fast Z-pinch, pulsed-power facilities, mm-scale quantities of matter can be placed in extreme states of density, temperature, and/or velocity. This has enabled the emergence of a new class of experimental science, HED laboratory astrophysics, wherein the properties of matter and the processes that occur under extreme astrophysical conditions can be examined in the laboratory. Areas particularly suitable to this class of experimental astrophysics include the study of opacities relevant to stellar interiors; equations of state relevant to planetary interiors; strong shock driven nonlinear hydrodynamics and radiative dynamics, relevant to supernova explosions and subsequent evolution; protostellar jets and high Mach-number flows; radiatively driven molecular clouds and nonlinear photoevaporation front dynamics; and photoionized plasmas relevant to accretion disks around compact objects, such as black holes and neutron stars.

Remington, B A; Drake, R P; Ryutov, D D

2004-12-10

413

Fabrication of replicated high-precision insert elements for micro-optical bench arrangements  

NASA Astrophysics Data System (ADS)

Transparent polymer elements, containing both 3D-positioning structures and planar optical elements made by surface structuring, open the way for the mutual passive alignment of optical elements with respect to fibers, detectors and light sources in micro-optical benches with sub-micron precision. A fabrication process is presented for polymer inserts in micro-optical benches, which combines the mechanical precision of the LIGA-process with the wide variety of optical functions offered by diffractive optical elements. For this purpose, metal masters with lens elements made by surface structuring, and frame structures made with deep X-ray lithography and electroplating were used in a combined molding tool, and precision micro-optical elements were replicated by injection molding. The fabrication of the different parts of the mold insert and the alignment and fixing schemes for metal plates forming the micro cavity is described in detail. Injection molding experiments have been carried out using polycarbonate, a polymer known for its good optical properties. We discuss the different designs of mold inserts and injection geometries used for the mold, which were chosen in order to control the shrinkage of the molded element, to restrict damages during demolding, and to avoid inhomogeneities in the area of the lenses due to flow anisotropies and seam lines. We report on the characterization of the molded lens components. Injection molded lens structures are compared with hot embossed replicas, and used for the purpose of collimation applications. The imaging properties of these optical elements from single mode fibers onto single mode fibers is discussed. The miniature optical elements are arranged in arrays with 250 micrometers pitch which make them well suited for applications with fiber ribbons. Various positioning schemes and bench arrangements are under development.

Schift, Helmut; Soechtig, Juergen; Glaus, Fredy; Vonlanthen, A.; Westenhoefer, S.

1998-09-01

414

Applications of inertial-sensor high-inheritance instruments to DSN precision antenna pointing  

NASA Technical Reports Server (NTRS)

Laboratory test results of the initialization and tracking performance of an existing inertial-sensor-based instrument are given. The instrument, although not primarily designed for precision antenna pointing applications, demonstrated an on-average 10-hour tracking error of several millidegrees. The system-level instrument performance is shown by analysis to be sensor limited. Simulated instrument improvements show a tracking error of less than 1 mdeg, which would provide acceptable performance, i.e., low pointing loss, for the Deep Space Network 70-m antenna subnetwork, operating at Ka-band (1-cm wavelength).

Goddard, R. E.

1992-01-01

415

Applications of inertial-sensor high-inheritance instruments to DSN precision antenna pointing  

NASA Technical Reports Server (NTRS)

Laboratory test results of the initialization and tracking performance of an existing inertial-sensor-based instrument are given. The instrument, although not primarily designed for precision antenna pointing applications, demonstrated an on-average 10-hour tracking error of several millidegrees. The system-level instrument performance is shown by analysis to be sensor limited. Simulated instrument improvements show a tracking error of less than 1 mdeg, which would provide acceptable performance, i.e., low pointing loss, for the DSN 70-m antenna sub network, operating at Ka-band (1-cm wavelength).

Goddard, R. E.

1992-01-01

416

Method of high-precision microsampled blood and plasma mass densitometry  

NASA Technical Reports Server (NTRS)

The reliability of the mechanical oscillator technique for blood and plasma density measurements on samples of volumes less than 0.1 ml is examined, and a precision of 0.001 g/l is found if plasma-isodensic heparin solution and siliconized densitometers are employed. Sources of measurement errors in the density determinations include storage of plasma samples, inhomogeneity of blood samples, and density reading before adequate temperature equilibration. In tests of plasma sample storage, the best reproducibility was obtained with samples kept at 4 C. Linear correlations were found between plasma density and plasma protein concentration, blood density and blood hemoglobin concentration, and erythrocyte density and MCHC.

Hinghofer-Szalkay, H.

1986-01-01

417

Experimental and theoretical research in high energy astrophysics  

NASA Technical Reports Server (NTRS)

NASA grants to MIT for investigations in experimental and theoretical high energy astrophysics have, over the years, nurtured the infrastructure development and experimental activities that have led to successful proposals for the OSO 7, SAS 3, HEAO 1, and HEAO 2 missions and to the achievements in high energy astrophysics of the MIT Group. This report consists of excerpts from the progress reports of 1988 through 1990 that have been submitted as a regular feature of the renewal requests. These excerpts convey the flavor of the grant-supported activities, and a sense of the progress that has been made in each of the areas investigations.

Clark, George W.

1990-01-01

418

High-precision semi-spherical meter of two degrees of freedom  

NASA Astrophysics Data System (ADS)

The semi-spherical meter uses a photo-detector mounted on a mobile rectangular arc, which by means of two stepper motors describes the semi-spherical trajectories required. For controlling motors and data acquisition, a Peripheral Interface Controller (PIC) is employed, which helps keeping the low cost of the overall system. One of the stepper motors is located on the lateral axis of the device; that displaces the sensor along a semi-circular trajectory of 170°, almost complete meridians. Another motor located at the base of the device enables 360° rotation of the illumination source under test. The precision is increased by the using of two angle sensors located on the opposite lateral axis and on the mobile base of the illumination source. Additionally, before the data obtained from the photo-detector arrive to the PIC, a stage of signal conditioning is used. This step allows us to increase not only the precision, but also the versatility of the meter to analyze illumination sources of different sizes and fluxes. The communication protocol between the data acquisition stage and the computer is USART. A graphical user interface (GUI) is employed on the base of the hyperterminal. The number of measurement points is determined by programming the two motors. The mechanical structure provides enough rigidity for supporting the accuracy required by the data acquisition circuitry based on a PIC. Measurement of illumination sources of different sizes is possible by using adjustable lengths of the mobile base and the ring.

Vera-Dimas, J. G.; Tecpoyotl-Torres, M.; Martínez-Fabián, S. E.; Escobedo-Alatorre, J.; Cisneros-Villalobos, L.; Ibarra Manzano, O. G.; Sanchez-Mondragon, J.

2012-10-01

419

High precision Ag isotope measurements in geologic materials by multiple-collector ICPMS  

NASA Astrophysics Data System (ADS)

This paper presents an improved technique for the precise and accurate determination of Ag isotopic composition in geologic samples. Following the separation of Ag from the rock matrix with a three-stage ion exchange procedure, the isotopic composition is measured by MC-ICPMS. Instrumental mass bias is corrected externally using a Pd standard, which was added to each sample, and sample-standard bracketing. The use of wet plasma significantly improves the analytical precision by eliminating variations in fractionation between Pd and Ag. A virtually identical behavior of the mass bias for Pd and Ag during the analyses is a prerequisite for the external correction method. Replicate dissolutions of the carbonaceous chondrite Allende with <100 ng Ag yield an external reproducibility (2 S.D.) of 53 ppm for 107Ag/109Ag. Since the ion exchange procedure provides a good separation from matrix elements such as Ti and Fe, the method is suitable for the analysis of stony and iron meteorites as well as sulfide minerals and terrestrial basalts. The technique thus can be applied to investigate Ag isotopic variations in a large variety of solar system materials.

Schönbächler, Maria; Carlson, Richard W.; Horan, Mary F.; Mock, Timothy D.; Hauri, Erik H.

2007-03-01

420

Z-boson as "the standard candle" for high precision W-boson physics at LHC  

E-print Network

In this paper we propose a strategy for measuring the inclusive W-boson production processes at LHC. This strategy exploits simultaneously the unique flexibility of the LHC collider in running variable beam particle species at variable beam energies, and the configuration flexibility of the LHC detectors. We propose their concrete settings for a precision measurement of the Standard Model parameters. These dedicated settings optimise the use of the Z boson and Drell-Yan pair production processes as ``the standard reference candles''. The presented strategy allows to factorise and to directly measure those of the QCD effects which affect differently the W and Z production processes. It reduces to a level of 10^{-4} the impact of uncertainties in the partonic distribution functions (PDFs) and in the transverse momentum of the quarks on the measurement precision. Last but not the least, it reduces by a factor of 10 an impact of systematic measurement errors, such as the energy scale and the measurement resolution, on the W-boson production observables.

M. W. Krasny; F. Fayette; W. Placzek; A. Siodmok

2007-03-09

421

Long-term, High Frequency, High Precision pH Measurements on the MBARI deep-water FOCE Experiment at the MARS Cabled Observatory in Monterey Bay, CA  

NASA Astrophysics Data System (ADS)

The MBARI deep-water FOCE experiment was deployed on the MARS cabled observatory in Monterey Bay on May 4th, 2011. It has been in continuous operation (excluding a few minor shore based power outages) ever since. During the fifteen months of deployment, we have been able to observe both the daily variation in pH in response to water mass movements associated with the semi-diurnal tides, internal waves and longer-term trends as a function of the seasonal variations in the water masses within the Monterey Bay Canyon. Our experimental site is located at 890 meters, just below the oxygen minimum for Monterey Bay, and we clearly see the anticipated inverse correlation between seawater temperature and pH. Daily variation in pH is on the order of 0.020-0.030 pH units with longer term trends adding an additional variation of similar magnitude. Instrumentation on this experiment included two CTDs with oxygen sensors (Sea-Bird 52). One CTD is mounted on the external FOCE framework to measure the background conditions, and one CTD is installed within the FOCE pH control area to monitor the experimentally manipulated conditions. In addition, 6 MBARI modified Sea-Bird 18 pH sensors were mounted on the FOCE apparatus. Four of these pH sensors monitored pH inside the experimental chamber and two monitored the external background seawater conditions. Although we originally intended to conduct several in situ CO2 enrichment experiments to study the impact of ocean acidification on the benthic biology and then recover the apparatus after one year, unanticipated changes in the ship schedule have left the FOCE experiment in place for nearly fifteen months at the time of this writing. Throughout this time period, all sensor data has been logged by the MBARI Shore-Side Data System (SSDS) resulting in the longest continuous record of high precision pH measurements in the intermediate water column. We present an analysis of the data obtained from this unique data set, and discuss our in-situ calibration techniques used to compensate for long term sensor drift associated with the reference electrode.

Peltzer, E. T.; Maughan, T.; Barry, J. P.; Brewer, P. G.; Headley, K. L.; Herlien, R.; Kirkwood, W. J.; Matsumoto, G. I.; O'Reilly, T. C.; Salamy, K. A.; Scholfield, J.; Shane, F. F.; Walz, P. M.

2012-12-01

422

A high precision method for mapping phase to amplitude in direct digital synthesis and its hardware implementation.  

PubMed

There exist a number of algorithms to map the phase to amplitude in direct digital synthesis (DDS). For DDS with more than 14 output bits, the Coordinate Rotation Digital Computer (CORDIC) algorithm is well known for its high precision. Also, it is effective in solutions where there is the need of in-phase and quadrature components simultaneously because the algorithm calculates both. In this paper, a Taylor expansion based method was proposed to calculate both in-phase and quadrature at the same time. Numerical simulations for different data format, e.g., double and finite bits, were carried out in Matlab and Quartus, which were followed by the hardware implementation in Field Programmable Gate Array. The results demonstrated that the proposed method possessed higher precision and exhausted less logic elements than the CORDIC algorithm. PMID:25430130

Cao, Zhang; Song, Wei; Peng, Zhicong; Xu, Lijun

2014-11-01

423

SPIRou: the near-infrared spectropolarimeter/high-precision velocimeter for the Canada-France-Hawaii telescope  

E-print Network

SPIRou is a near-IR \\'echelle spectropolarimeter and high-precision velocimeter under construction as a next-generation instrument for the Canada-France-Hawaii-Telescope. It is designed to cover a very wide simultaneous near-IR spectral range (0.98-2.35 {\\mu}m) at a resolving power of 73.5K, providing unpolarized and polarized spectra of low-mass stars at a radial velocity (RV) precision of 1m/s. The main science goals of SPIRou are the detection of habitable super-Earths around low-mass stars and the study of how critically magnetic fields impact star / planet formation. Following a successful final design review in Spring 2014, SPIRou is now under construction and is scheduled to see first light in late 2017. We present an overview of key aspects of SPIRou's optical and mechanical design.

Artigau, Étienne; Donati, Jean-François; Doyon, René; Delfosse, Xavier; Baratchart, Sébastien; Lacombe, Marielle; Moutou, Claire; Rabou, Patrick; Parès, Laurent P; Micheau, Yoan; Thibault, Simon; Reshetov, Vladimir A; Dubois, Bruno; Hernandez, Olivier; Vallée, Philippe; Wang, Shiang-Yu; Dolon, François; Pepe, Francesco A; Bouchy, François; Striebig, Nicolas; Hénault, François; Loop, David; Saddlemyer, Leslie; Barrick, Gregory; Vermeulen, Tom; Dupieux, Michel; Hébrard, Guillaume; Boisse, Isabelle; Martioli, Eder; Alencar, Silvia H P; Nascimento, José-Diaz do; Figueira, Pedro

2014-01-01

424

High precision AlGaAsSb ridge-waveguide etching by in situ reflectance monitored ICP-RIE  

NASA Astrophysics Data System (ADS)

GaSb-based semiconductor diode lasers are promising candidates for light sources working in the mid-infrared wavelength region of 2-5 ?m. Using edge emitti