Precision of Four Acoustic Bone Measurement Devices

NASA Technical Reports Server (NTRS)

Miller, Christopher; Feiveson, Alan H.; Shackelford, Linda; Rianon, Nahida; LeBlanc, Adrian

2000-01-01

Though many studies have quantified the precision of various acoustic bone measurement devices, it is difficult to directly compare the results among the studies, because they used disparate subject pools, did not specify the estimation methodology, or did not use consistent definitions for various precision characteristics. In this study, we used a repeated measures design protocol to directly determine the precision characteristics of four acoustic bone measurement devices: the Mechanical Response Tissue Analyzer (MRTA), the UBA-575+, the SoundScan 2000 (S2000), and the Sahara Ultrasound Done Analyzer. Ten men and ten women were scanned on all four devices by two different operators at five discrete time points: Week 1, Week 2, Week 3, Month 3 and Month 6. The percent coefficient of variation (%CV) and standardized coefficient of variation were computed for the following precision characteristics: interoperator effect, operator-subject interaction, short-term error variance, and long-term drift, The MRTA had high interoperator errors for its ulnar and tibial stiffness measures and a large long-term drift in its tibial stiffness measurement. The UBA-575+ exhibited large short-term error variances and long-term drift for all three of its measurements. The S2000's tibial speed of sound measurement showed a high short-term error variance and a significant operator-subject interaction but very good values ( < 1%) for the other precision characteristics. The Sahara seemed to have the best overall performance, but was hampered by a large %CV for short-term error variance in its broadband ultrasound attenuation measure.

Precision of Four Acoustic Bone Measurement Devices

NASA Technical Reports Server (NTRS)

Miller, Christopher; Rianon, Nahid; Feiveson, Alan; Shackelford, Linda; LeBlanc, Adrian

2000-01-01

Though many studies have quantified the precision of various acoustic bone measurement devices, it is difficult to directly compare the results among the studies, because they used disparate subject pools, did not specify the estimation methodology, or did not use consistent definitions for various precision characteristics. In this study, we used a repeated measures design protocol to directly determine the precision characteristics of four acoustic bone measurement devices: the Mechanical Response Tissue Analyzer (MRTA), the UBA-575+, the SoundScan 2000 (S2000), and the Sahara Ultrasound Bone Analyzer. Ten men and ten women were scanned on all four devices by two different operators at five discrete time points: Week 1, Week 2, Week 3, Month 3 and Month 6. The percent coefficient of variation (%CV) and standardized coefficient of variation were computed for the following precision characteristics: interoperator effect, operator-subject interaction, short-term error variance, and long-term drift. The MRTA had high interoperator errors for its ulnar and tibial stiffness measures and a large long-term drift in its tibial stiffness measurement. The UBA-575+ exhibited large short-term error variances and long-term drift for all three of its measurements. The S2000's tibial speed of sound measurement showed a high short-term error variance and a significant operator-subject interaction but very good values (less than 1%) for the other precision characteristics. The Sahara seemed to have the best overall performance, but was hampered by a large %CV for short-term error variance in its broadband ultrasound attenuation measure.

Precision of measurement and body size in whole-body air-displacement plethysmography.

PubMed

Wells, J C; Fuller, N J

2001-08-01

To investigate methodological and biological precision for air-displacement plethysmography (ADP) across a wide range of body size. Repeated measurements of body volume (BV) and body weight (WT), and derived estimates of density (BD) and indices of fat mass (FM) and fat-free mass (FFM). Sixteen men, aged 22--48 y; 12 women, aged 24--42 y; 13 boys, aged 5--14 y; 17 girls, aged 5--16 y. BV and WT were measured using the Bodpod ADP system from which estimates of BD, FM and FFM were derived. FM and FFM were further adjusted for height to give fat mass index (FMI) and fat-free mass index (FFMI). ADP is very precise for measuring both BV and BD (between 0.16 and 0.44% of the mean). After removing two outliers from the database, and converting BD to body composition, precision of FMI was <6% in adults and within 8% in children, while precision of FFMI was within 1.5% for both age groups. ADP shows good precision for BV and BD across a wide range of body size, subject to biological artefacts. If aberrant values can be identified and rejected, precision of body composition is also good. Aberrant values can be identified by using pairs of ADP procedures, allowing the rejection of data where successive BD values differed by >0.007 kg/l. Precision of FMI obtained using pairs of procedures improves to <4.5% in adults and <5.5% in children.

Precision measurement of the nuclear polarization in laser-cooled, optically pumped 37 K

DOE Office of Scientific and Technical Information (OSTI.GOV)

Fenker, B.; Behr, J. A.; Melconian, D.

We report a measurement of the nuclear polarization of laser-cooled, optically pumped 37K atoms which will allow us to precisely measure angular correlation parameters in themore » $${\\beta }^{+}$$-decay of the same atoms. These results will be used to test the V ₋ A framework of the weak interaction at high precision. At the Triumf neutral atom trap (Trinat), a magneto-optical trap confines and cools neutral 37K atoms and optical pumping spin-polarizes them. We monitor the nuclear polarization of the same atoms that are decaying in situ by photoionizing a small fraction of the partially polarized atoms and then use the standard optical Bloch equations to model their population distribution. We obtain an average nuclear polarization of $$\\bar{P}=0.9913\\pm 0.0009$$, which is significantly more precise than previous measurements with this technique. Since our current measurement of the β-asymmetry has $$0.2 \\% $$ statistical uncertainty, the polarization measurement reported here will not limit its overall uncertainty. This result also demonstrates the capability to measure the polarization to $$\\lt 0.1 \\% $$, allowing for a measurement of angular correlation parameters to this level of precision, which would be competitive in searches for new physics.« less

Precision measurement of the nuclear polarization in laser-cooled, optically pumped 37 K

DOE PAGES

Fenker, B.; Behr, J. A.; Melconian, D.; ...

2016-07-13

We report a measurement of the nuclear polarization of laser-cooled, optically pumped 37K atoms which will allow us to precisely measure angular correlation parameters in themore » $${\\beta }^{+}$$-decay of the same atoms. These results will be used to test the V ₋ A framework of the weak interaction at high precision. At the Triumf neutral atom trap (Trinat), a magneto-optical trap confines and cools neutral 37K atoms and optical pumping spin-polarizes them. We monitor the nuclear polarization of the same atoms that are decaying in situ by photoionizing a small fraction of the partially polarized atoms and then use the standard optical Bloch equations to model their population distribution. We obtain an average nuclear polarization of $$\\bar{P}=0.9913\\pm 0.0009$$, which is significantly more precise than previous measurements with this technique. Since our current measurement of the β-asymmetry has $$0.2 \\% $$ statistical uncertainty, the polarization measurement reported here will not limit its overall uncertainty. This result also demonstrates the capability to measure the polarization to $$\\lt 0.1 \\% $$, allowing for a measurement of angular correlation parameters to this level of precision, which would be competitive in searches for new physics.« less

Precision ESR measurements of transverse anisotropy in the single-molecule magnet Ni4

NASA Astrophysics Data System (ADS)

Collett, Charles A.; Allão Cassaro, Rafael A.; Friedman, Jonathan R.

2016-12-01

We present a method for precisely measuring the tunnel splitting in single-molecule magnets (SMMs) using electron-spin resonance, and use these measurements to precisely and independently determine the underlying transverse anisotropy parameter, given a certain class of transitions. By diluting samples of the SMM Ni4 via cocrystallization in a diamagnetic isostructural analog we obtain markedly narrower resonance peaks than are observed in undiluted samples. Using custom loop-gap resonators we measure the transitions at several frequencies, allowing a precise determination of the tunnel splitting. Because the transition under investigation occurs at zero field, and arises due to a first-order perturbation from the transverse anisotropy, we can determine the magnitude of this anisotropy independent of any other Hamiltonian parameters. This method can be applied to other SMMs with tunnel splittings arising from first-order transverse anisotropy perturbations.

Precision measures of the primordial deuterium abundance.

NASA Astrophysics Data System (ADS)

Cooke, R. J.; Pettini, M.; Jorgenson, R. A.; Murphy, M. T.; Steidel, C. C.

Near-pristine damped Lyman-alpha systems (DLAs) are the ideal environments to measure the primordial abundance of deuterium. In this conference report, I summarise our ongoing research programme to obtain the most precise determination of the primordial deuterium abundance from five high redshift DLAs. From this sample, we derive (D/H)_p = (2.53±0.04)×105, corresponding to a baryon density 100 Omega_b ,0 h2 = 2.202±0.046 assuming the standard model of Big Bang Nucleosynthesis. This value is in striking agreement with that measured from the temperature fluctuations imprinted on the cosmic microwave background. Although we find no strong evidence for new physics beyond the standard model, this line of research shows great promise in the near-future, when the next generation 30+ m telescopes equipped with echelle spectrographs come online.

Navigation Doppler lidar sensor for precision altitude and vector velocity measurements: flight test results

NASA Astrophysics Data System (ADS)

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

2011-06-01

An all fiber Navigation Doppler Lidar (NDL) system is under development at NASA Langley Research Center (LaRC) for precision descent and landing applications on planetary bodies. The sensor produces high-resolution line of sight range, altitude above ground, ground relative attitude, and high precision velocity vector measurements. Previous helicopter flight test results demonstrated the NDL measurement concepts, including measurement precision, accuracies, and operational range. This paper discusses the results obtained from a recent campaign to test the improved sensor hardware, and various signal processing algorithms applicable to real-time processing. The NDL was mounted in an instrumentation pod aboard an Erickson Air-Crane helicopter and flown over various terrains. The sensor was one of several sensors tested in this field test by NASA's Autonomous Landing and Hazard Avoidance Technology (ALHAT) project.

Navigation Doppler Lidar Sensor for Precision Altitude and Vector Velocity Measurements Flight Test Results

NASA Technical Reports Server (NTRS)

Pierrottet, Diego F.; Lockhard, George; Amzajerdian, Farzin; Petway, Larry B.; Barnes, Bruce; Hines, Glenn D.

2011-01-01

An all fiber Navigation Doppler Lidar (NDL) system is under development at NASA Langley Research Center (LaRC) for precision descent and landing applications on planetary bodies. The sensor produces high resolution line of sight range, altitude above ground, ground relative attitude, and high precision velocity vector measurements. Previous helicopter flight test results demonstrated the NDL measurement concepts, including measurement precision, accuracies, and operational range. This paper discusses the results obtained from a recent campaign to test the improved sensor hardware, and various signal processing algorithms applicable to real-time processing. The NDL was mounted in an instrumentation pod aboard an Erickson Air-Crane helicopter and flown over vegetation free terrain. The sensor was one of several sensors tested in this field test by NASA?s Autonomous Landing and Hazard Avoidance Technology (ALHAT) project.

Note: High precision measurements using high frequency gigahertz signals

NASA Astrophysics Data System (ADS)

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

2014-12-01

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

On precise phase difference measurement approach using border stability of detection resolution.

PubMed

Bai, Lina; Su, Xin; Zhou, Wei; Ou, Xiaojuan

2015-01-01

For the precise phase difference measurement, this paper develops an improved dual phase coincidence detection method. The measurement resolution of the digital phase coincidence detection circuits is always limited, for example, only at the nanosecond level. This paper reveals a new way to improve the phase difference measurement precision by using the border stability of the circuit detection fuzzy areas. When a common oscillator signal is used to detect the phase coincidence with the two comparison signals, there will be two detection fuzzy areas for the reason of finite detection resolution surrounding the strict phase coincidence. Border stability of fuzzy areas and the fluctuation difference of the two fuzzy areas can be even finer than the picoseconds level. It is shown that the system resolution obtained only depends on the stability of the circuit measurement resolution which is much better than the measurement device resolution itself.

Towards a Precision Measurement of the Lamb Shift in Hydrogen-Like Nitrogen

NASA Astrophysics Data System (ADS)

Myers, E. G.; Tarbutt, M. R.

Measurements of the 2S1/2-2P1/2 and 2S1/2 -2P3/2 transitions in moderate Z hydrogen-like ions can test Quantum-Electrodynamic calculations relevant to the interpretation of high-precision spectroscopy of atomic hydrogen. There is now particular interest in testing calculations of the two-loop self-energy. Experimental conditions are favorable for a measurement of the 2S1/2 - 2P3/2 transition in N6+ using a carbon dioxide laser. As a preliminary experiment, we have observed the 2S1/2 -2P3/2 transition in 14N6+ using a 2.5 MeV2 laser operating on the hot band of 12C16O2. The measured value of the transition centroid, 834.94(7) cm-1, agrees with, but is less precise than theory. However, the counting rate and signal-to-background ratio obtained indicate, that with careful control of systematics, a precision test of the theory is practical. Work towards constructing such a set-up is in pro gress.

Precision half-life measurement of 17F

NASA Astrophysics Data System (ADS)

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

2016-02-01

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

Superallowed nuclear beta decay: Precision measurements for basic physics

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hardy, J. C.

2012-11-20

For 60 years, superallowed 0{sup +}{yields}0{sup +} nuclear beta decay has been used to probe the weak interaction, currently verifying the conservation of the vector current (CVC) to high precision ({+-}0.01%) and anchoring the most demanding available test of the unitarity of the Cabibbo-Kobayashi-Maskawa (CKM) matrix ({+-}0.06%), a fundamental pillar of the electroweak standard model. Each superallowed transition is characterized by its ft-value, a result obtained from three measured quantities: the total decay energy of the transition, its branching ratio, and the half-life of the parent state. Today's data set is composed of some 150 independent measurements of 13 separatemore » superallowed transitions covering a wide range of parent nuclei from {sup 10}C to {sup 74}Rb. Excellent consistency among the average results for all 13 transitions - a prediction of CVC - also confirms the validity of the small transition-dependent theoretical corrections that have been applied to account for isospin symmetry breaking. With CVC consistency established, the value of the vector coupling constant, G{sub V}, has been extracted from the data and used to determine the top left element of the CKM matrix, V{sub ud}. With this result the top-row unitarity test of the CKM matrix yields the value 0.99995(61), a result that sets a tight limit on possible new physics beyond the standard model. To have any impact on these fundamental weak-interaction tests, any measurement must be made with a precision of 0.1% or better - a substantial experimental challenge well beyond the requirements of most nuclear physics measurements. I overview the current state of the field and outline some of the requirements that need to be met by experimentalists if they aim to make measurements with this high level of precision.« less

Precision Measures of the Primordial Abundance of Deuterium

NASA Astrophysics Data System (ADS)

Cooke, Ryan J.; Pettini, Max; Jorgenson, Regina A.; Murphy, Michael T.; Steidel, Charles C.

2014-01-01

We report the discovery of deuterium absorption in the very metal-poor ([Fe/H] = -2.88) damped Lyα system at z abs = 3.06726 toward the QSO SDSS J1358+6522. On the basis of 13 resolved D I absorption lines and the damping wings of the H I Lyα transition, we have obtained a new, precise measure of the primordial abundance of deuterium. Furthermore, to bolster the present statistics of precision D/H measures, we have reanalyzed all of the known deuterium absorption-line systems that satisfy a set of strict criteria. We have adopted a blind analysis strategy (to remove human bias) and developed a software package that is specifically designed for precision D/H abundance measurements. For this reanalyzed sample of systems, we obtain a weighted mean of (D/H)p = (2.53 ± 0.04) × 10-5, corresponding to a universal baryon density 100 Ωb, 0 h 2 = 2.202 ± 0.046 for the standard model of big bang nucleosynthesis (BBN). By combining our measure of (D/H)p with observations of the cosmic microwave background (CMB), we derive the effective number of light fermion species, N eff = 3.28 ± 0.28. We therefore rule out the existence of an additional (sterile) neutrino (i.e., N eff = 4.046) at 99.3% confidence (2.7σ), provided that the values of N eff and of the baryon-to-photon ratio (η10) did not change between BBN and recombination. We also place a strong bound on the neutrino degeneracy parameter, independent of the 4He primordial mass fraction, Y P: ξD = +0.05 ± 0.13 based only on the CMB+(D/H)p observations. Combining this value of ξD with the current best literature measure of Y P, we find a 2σ upper bound on the neutrino degeneracy parameter, |ξ| <= +0.062. Based on observations collected at the European Organisation for Astronomical Research in the Southern Hemisphere, Chile (VLT program IDs: 68.B-0115(A), 70.A-0425(C), 078.A-0185(A), 085.A-0109(A)), and at the W. M. Keck Observatory, which is operated as a scientific partnership among the California Institute of

Study on high-precision measurement of long radius of curvature

NASA Astrophysics Data System (ADS)

Wu, Dongcheng; Peng, Shijun; Gao, Songtao

2016-09-01

It is hard to get high-precision measurement of the radius of curvature (ROC), because of many factors that affect the measurement accuracy. For the measurement of long radius of curvature, some factors take more important position than others'. So, at first this paper makes some research about which factor is related to the long measurement distance, and also analyse the uncertain of the measurement accuracy. At second this article also study the influence about the support status and the adjust error about the cat's eye and confocal position. At last, a 1055micrometer radius of curvature convex is measured in high-precision laboratory. Experimental results show that the proper steady support (three-point support) can guarantee the high-precision measurement of radius of curvature. Through calibrating the gain of cat's eye and confocal position, is useful to ensure the precise position in order to increase the measurement accuracy. After finish all the above process, the high-precision long ROC measurement is realized.

Effectiveness of Spectral Similarity Measures to Develop Precise Crop Spectra for Hyperspectral Data Analysis

NASA Astrophysics Data System (ADS)

Chauhan, H.; Krishna Mohan, B.

2014-11-01

The present study was undertaken with the objective to check effectiveness of spectral similarity measures to develop precise crop spectra from the collected hyperspectral field spectra. In Multispectral and Hyperspectral remote sensing, classification of pixels is obtained by statistical comparison (by means of spectral similarity) of known field or library spectra to unknown image spectra. Though these algorithms are readily used, little emphasis has been placed on use of various spectral similarity measures to select precise crop spectra from the set of field spectra. Conventionally crop spectra are developed after rejecting outliers based only on broad-spectrum analysis. Here a successful attempt has been made to develop precise crop spectra based on spectral similarity. As unevaluated data usage leads to uncertainty in the image classification, it is very crucial to evaluate the data. Hence, notwithstanding the conventional method, the data precision has been performed effectively to serve the purpose of the present research work. The effectiveness of developed precise field spectra was evaluated by spectral discrimination measures and found higher discrimination values compared to spectra developed conventionally. Overall classification accuracy for the image classified by field spectra selected conventionally is 51.89% and 75.47% for the image classified by field spectra selected precisely based on spectral similarity. KHAT values are 0.37, 0.62 and Z values are 2.77, 9.59 for image classified using conventional and precise field spectra respectively. Reasonable higher classification accuracy, KHAT and Z values shows the possibility of a new approach for field spectra selection based on spectral similarity measure.

Constraining Saturn's interior density profile from precision gravity field measurement obtained during Grand Finale

NASA Astrophysics Data System (ADS)

Movshovitz, N.; Fortney, J. J.; Helled, R.; Hubbard, W. B.; Mankovich, C.; Thorngren, D.; Wahl, S. M.; Militzer, B.; Durante, D.

2017-12-01

The external gravity field of a planetary body is determined by the distribution of mass in its interior. Therefore, a measurement of the external field, properlyinterpreted, tells us about the interior density profile, ρ(r), which in turn can be used to constrain the composition in the interior and thereby learn about theformation mechanism of the planet. Recently, very high precision measurements of the gravity coefficients for Saturn have been made by the radio science instrument on the Cassini spacecraft during its Grand Finale orbits. The resulting coefficients come with an associated uncertainty. The task of matching a given density profile to a given set of gravity coefficients is relatively straightforward, but the question of how to best account for the uncertainty is not. In essentially all prior work on matching models to gravity field data inferences about planetary structure have rested on assumptions regarding the imperfectly known H/He equation of state and the assumption of an adiabatic interior. Here we wish to vastly expand the phase space of such calculations. We present a framework for describing all the possible interior density structures of a Jovian planet constrained by a given set of gravity coefficients and their associated uncertainties. Our approach is statistical. We produce a random sample of ρ(a) curves drawn from the underlying (and unknown) probability distribution of all curves, where ρ is the density on an interior level surface with equatorial radius a. Since the resulting set of density curves is a random sample, that is, curves appear with frequency proportional to the likelihood of their being consistent with the measured gravity, we can compute probability distributions for any quantity that is a function of ρ, such as central pressure, oblateness, core mass and radius, etc. Our approach is also Bayesian, in that it can utilize any prior assumptions about the planet's interior, as necessary, without being overly

Precision Measurements with a Molecular Clock

NASA Astrophysics Data System (ADS)

Grier, Andrew; McDonald, Mickey; McGuyer, Bart; Iwata, Geoffrey; Apfelbeck, Florian; Tarallo, Marco; Zelevinsky, Tanya

2015-05-01

We report on recent results obtained with photoassociated Sr2 molecules confined in a lattice. Sr2 has a range of electronically excited bound states which are readily accessible with optical wavelengths using the narrow 1S0->3P1 intercombination line. As in Nat. Phys. 11, 32, we measure the lifetimes of the narrow, deeply-bound subradiant states in the 1g (1S0+3P1 dissociative limit) potential, allowing for coherent control of molecules and a comparison with theoretical predictions of the lifetimes and transition strengths of these states. Next, we study ultracold photodissociation of Sr2 molecules through abortion of one and two photons near the atomic intercombination line. This allows us to observe the vector character of transition elements through the angular dissociation pattern and to directly measure barrier heights in the excited state potentials. Finally, as shown in PRL 114, 023001, we demonstrate that in a non-magic lattice, a narrow transition can be used to measure the trapped gas temperature through the linewidth of the spectral feature corresponding to the carrier transitions. We use this technique to measure the temperature of Sr2 molecules to 10x higher precision than with standard techniques. We discuss future prospects with this molecular lattice clock. Funding from NIST, ARO, and NSF IGERT.

Precision and repeatability of the Optotrak 3020 motion measurement system.

PubMed

States, R A; Pappas, E

2006-01-01

Several motion analysis systems are used by researchers to quantify human motion and to perform accurate surgical procedures. The Optotrak 3020 is one of these systems and despite its widespread use there is not any published information on its precision and repeatability. We used a repeated measures design study to evaluate the precision and repeatability of the Optotrak 3020 by measuring distance and angle in three sessions, four distances and three conditions (motion, static vertical, and static tilted). Precision and repeatability were found to be excellent for both angle and distance although they decreased with increasing distance from the sensors and with tilt from the plane of the sensors. Motion did not have a significant effect on the precision of the measurements. In conclusion, the measurement error of the Optotrak is minimal. Further studies are needed to evaluate its precision and repeatability under human motion conditions.

Predicting Document Retrieval System Performance: An Expected Precision Measure.

ERIC Educational Resources Information Center

Losee, Robert M., Jr.

1987-01-01

Describes an expected precision (EP) measure designed to predict document retrieval performance. Highlights include decision theoretic models; precision and recall as measures of system performance; EP graphs; relevance feedback; and computing the retrieval status value of a document for two models, the Binary Independent Model and the Two Poisson…

Precise attitude rate estimation using star images obtained by mission telescope for satellite missions

NASA Astrophysics Data System (ADS)

Inamori, Takaya; Hosonuma, Takayuki; Ikari, Satoshi; Saisutjarit, Phongsatorn; Sako, Nobutada; Nakasuka, Shinichi

2015-02-01

Recently, small satellites have been employed in various satellite missions such as astronomical observation and remote sensing. During these missions, the attitudes of small satellites should be stabilized to a higher accuracy to obtain accurate science data and images. To achieve precise attitude stabilization, these small satellites should estimate their attitude rate under the strict constraints of mass, space, and cost. This research presents a new method for small satellites to precisely estimate angular rate using star blurred images by employing a mission telescope to achieve precise attitude stabilization. In this method, the angular velocity is estimated by assessing the quality of a star image, based on how blurred it appears to be. Because the proposed method utilizes existing mission devices, a satellite does not require additional precise rate sensors, which makes it easier to achieve precise stabilization given the strict constraints possessed by small satellites. The research studied the relationship between estimation accuracy and parameters used to achieve an attitude rate estimation, which has a precision greater than 1 × 10-6 rad/s. The method can be applied to all attitude sensors, which use optics systems such as sun sensors and star trackers (STTs). Finally, the method is applied to the nano astrometry satellite Nano-JASMINE, and we investigate the problems that are expected to arise with real small satellites by performing numerical simulations.

Precision measurements on trapped antihydrogen in the ALPHA experiment.

PubMed

Eriksson, S

2018-03-28

Both the 1S-2S transition and the ground state hyperfine spectrum have been observed in trapped antihydrogen. The former constitutes the first observation of resonant interaction of light with an anti-atom, and the latter is the first detailed measurement of a spectral feature in antihydrogen. Owing to the narrow intrinsic linewidth of the 1S-2S transition and use of two-photon laser excitation, the transition energy can be precisely determined in both hydrogen and antihydrogen, allowing a direct comparison as a test of fundamental symmetry. The result is consistent with CPT invariance at a relative precision of around 2×10 -10 This constitutes the most precise measurement of a property of antihydrogen. The hyperfine spectrum of antihydrogen is determined to a relative uncertainty of 4×10 -4 The excited state and the hyperfine spectroscopy techniques currently both show sensitivity at the few 100 kHz level on the absolute scale. Here, the most recent work of the ALPHA collaboration on precision spectroscopy of antihydrogen is presented together with an outlook on improving the precision of measurements involving lasers and microwave radiation. Prospects of measuring the Lamb shift and determining the antiproton charge radius in trapped antihydrogen in the ALPHA apparatus are presented. Future perspectives of precision measurements of trapped antihydrogen in the ALPHA apparatus when the ELENA facility becomes available to experiments at CERN are discussed.This article is part of the Theo Murphy meeting issue 'Antiproton physics in the ELENA era'. © 2018 The Author(s).

Precision measurements on trapped antihydrogen in the ALPHA experiment

NASA Astrophysics Data System (ADS)

Eriksson, S.

2018-03-01

Both the 1S-2S transition and the ground state hyperfine spectrum have been observed in trapped antihydrogen. The former constitutes the first observation of resonant interaction of light with an anti-atom, and the latter is the first detailed measurement of a spectral feature in antihydrogen. Owing to the narrow intrinsic linewidth of the 1S-2S transition and use of two-photon laser excitation, the transition energy can be precisely determined in both hydrogen and antihydrogen, allowing a direct comparison as a test of fundamental symmetry. The result is consistent with CPT invariance at a relative precision of around 2×10-10. This constitutes the most precise measurement of a property of antihydrogen. The hyperfine spectrum of antihydrogen is determined to a relative uncertainty of 4×10-4. The excited state and the hyperfine spectroscopy techniques currently both show sensitivity at the few 100 kHz level on the absolute scale. Here, the most recent work of the ALPHA collaboration on precision spectroscopy of antihydrogen is presented together with an outlook on improving the precision of measurements involving lasers and microwave radiation. Prospects of measuring the Lamb shift and determining the antiproton charge radius in trapped antihydrogen in the ALPHA apparatus are presented. Future perspectives of precision measurements of trapped antihydrogen in the ALPHA apparatus when the ELENA facility becomes available to experiments at CERN are discussed. This article is part of the Theo Murphy meeting issue `Antiproton physics in the ELENA era'.

Expected precision of Europa Clipper gravity measurements

NASA Astrophysics Data System (ADS)

Verma, Ashok K.; Margot, Jean-Luc

2018-11-01

The primary gravity science objective of NASA's Clipper mission to Europa is to confirm the presence or absence of a global subsurface ocean beneath Europa's Icy crust. Gravity field measurements obtained with a radio science investigation can reveal much about Europa's interior structure. Here, we conduct extensive simulations of the radio science measurements with the anticipated spacecraft trajectory and attitude (17F12v2) and assets on the spacecraft and the ground, including antenna orientations and beam patterns, transmitter characteristics, and receiver noise figures. In addition to two-way Doppler measurements, we also include radar altimeter crossover range measurements. We concentrate on ± 2 h intervals centered on the closest approach of each of the 46 flybys. Our covariance analyses reveal the precision with which the tidal Love number k2, second-degree gravity coefficients Cbar20 and Cbar22 , and higher-order gravity coefficients can be determined. The results depend on the Deep Space Network (DSN) assets that are deployed to track the spacecraft. We find that some DSN allocations are sufficient to conclusively confirm the presence or absence of a global ocean. Given adequate crossover range performance, it is also possible to evaluate whether the ice shell is hydrostatic.

Linear FMCW Laser Radar for Precision Range and Vector Velocity Measurements

NASA Technical Reports Server (NTRS)

Pierrottet, Diego; Amzajerdian, Farzin; Petway, Larry; Barnes, Bruce; Lockhard, George; Rubio, Manuel

2008-01-01

An all fiber linear frequency modulated continuous wave (FMCW) coherent laser radar system is under development with a goal to aide NASA s new Space Exploration initiative for manned and robotic missions to the Moon and Mars. By employing a combination of optical heterodyne and linear frequency modulation techniques and utilizing state-of-the-art fiber optic technologies, highly efficient, compact and reliable laser radar suitable for operation in a space environment is being developed. Linear FMCW lidar has the capability of high-resolution range measurements, and when configured into a multi-channel receiver system it has the capability of obtaining high precision horizontal and vertical velocity measurements. Precision range and vector velocity data are beneficial to navigating planetary landing pods to the preselected site and achieving autonomous, safe soft-landing. The all-fiber coherent laser radar has several important advantages over more conventional pulsed laser altimeters or range finders. One of the advantages of the coherent laser radar is its ability to measure directly the platform velocity by extracting the Doppler shift generated from the motion, as opposed to time of flight range finders where terrain features such as hills, cliffs, or slopes add error to the velocity measurement. Doppler measurements are about two orders of magnitude more accurate than the velocity estimates obtained by pulsed laser altimeters. In addition, most of the components of the device are efficient and reliable commercial off-the-shelf fiber optic telecommunication components. This paper discusses the design and performance of a second-generation brassboard system under development at NASA Langley Research Center as part of the Autonomous Landing and Hazard Avoidance (ALHAT) project.

Research on the precision measurement of super-low reflectivity

NASA Astrophysics Data System (ADS)

Yuan, Hao-yu; Lu, Zong-gui; Xia, Yan-wen; Peng, Zhi-tao; Liu, Hua; Xu, Long-bo; Sun, Zhi-hong; Tang, Jun

2010-10-01

Introduced a high-precision measurement of measured the super-low reflectivity and small sampling angle. Using single reflect way measured, and compare with re-swatch. Testing the reflectance of the sampling mirror which be used on TIL, and analyze the error. Research results indicate, the main factor which affect result is energy detector error and energy detector linearity. This methods is easy and have high-precision, it can be used to measure the super-low reflectivity sampling mirror reflectance.

Covariate Imbalance and Precision in Measuring Treatment Effects

ERIC Educational Resources Information Center

Liu, Xiaofeng Steven

2011-01-01

Covariate adjustment can increase the precision of estimates by removing unexplained variance from the error in randomized experiments, although chance covariate imbalance tends to counteract the improvement in precision. The author develops an easy measure to examine chance covariate imbalance in randomization by standardizing the average…

Nucleon measurements at the precision frontier

DOE Office of Scientific and Technical Information (OSTI.GOV)

Carlson, Carl E.

We comment on nucleon measurements at the precision frontier. As examples of what can be learned, we concentrate on three topics, which are parity violating scattering experiments, the proton radius puzzle, and the symbiosis between nuclear and atomic physics.

High-precision relative position and attitude measurement for on-orbit maintenance of spacecraft

NASA Astrophysics Data System (ADS)

Zhu, Bing; Chen, Feng; Li, Dongdong; Wang, Ying

2018-02-01

In order to realize long-term on-orbit running of satellites, space stations, etc spacecrafts, in addition to the long life design of devices, The life of the spacecraft can also be extended by the on-orbit servicing and maintenance. Therefore, it is necessary to keep precise and detailed maintenance of key components. In this paper, a high-precision relative position and attitude measurement method used in the maintenance of key components is given. This method mainly considers the design of the passive cooperative marker, light-emitting device and high resolution camera in the presence of spatial stray light and noise. By using a series of algorithms, such as background elimination, feature extraction, position and attitude calculation, and so on, the high precision relative pose parameters as the input to the control system between key operation parts and maintenance equipment are obtained. The simulation results show that the algorithm is accurate and effective, satisfying the requirements of the precision operation technique.

A precise few-nucleon size difference by isotope shift measurements of helium

NASA Astrophysics Data System (ADS)

Rezaeian, Nima Hassan

We perform high precision measurements of an isotope shift between the two stable isotopes of helium. We use laser excitation of the 23 S1 -- 23P0 transition at 1083 .... in a metastable beam of 3He and 4He atoms. A newly developed tunable laser frequency selector along with our previous electro-optic frequency modulation technique provides extremely reliable, adaptable, and precise frequency and intensity control. The intensity control contributes negligibly to overall experimental uncertainty by selecting (t selection < 50 ) and stabilizing the intensity of the required sideband and eliminating (˜10-5) the unwanted frequencies generated during the modulation of 1083 nm laser carrier frequency. The selection technique uses a MEMS based fiber switch (tswitch ≈ 10 ms) and several temperature stabilized narrow band (˜3 GHz) fiber gratings. A fiber based optical circulator and an inline fiber amplifier provide the desired isolation and the net gain for the selected frequency. Also rapid (˜2 sec.) alternating measurements of the 23 S1 -- 23P0 interval for both species of helium is achieved with a custom fiber laser for simultaneous optical pumping. A servo-controlled retro-reflected laser beam eliminates residual Doppler effects during the isotope shift measurement. An improved detection design and software control makes negligible subtle potential biases in the data collection. With these advances, combined with new internal and external consistency checks, we are able to obtain results consistent with the best previous measurements, but with substantially improved precision. Our measurement of the 23S 1 -- 23P0 isotope shift between 3He and 4He is 31 097 535.2 (5)kHz. The most recent theoretic calculation combined with this measuremen. yields a new determination for nuclear size differences between 3He and 4He: Deltarc = 0.292 6 (1)exp (8)th(52)expfm, with a precision of less than a part in 104 coming from the experimental uncertainty (first parenthesis), and a

Precise measurement of scleral radius using anterior eye profilometry.

PubMed

Jesus, Danilo A; Kedzia, Renata; Iskander, D Robert

2017-02-01

To develop a new and precise methodology to measure the scleral radius based on anterior eye surface. Eye Surface Profiler (ESP, Eaglet-Eye, Netherlands) was used to acquire the anterior eye surface of 23 emmetropic subjects aged 28.1±6.6years (mean±standard deviation) ranging from 20 to 45. Scleral radius was obtained based on the approximation of the topographical scleral data to a sphere using least squares fitting and considering the axial length as a reference point. To better understand the role of scleral radius in ocular biometry, measurements of corneal radius, central corneal thickness, anterior chamber depth and white-to-white corneal diameter were acquired with IOLMaster 700 (Carl Zeiss Meditec AG, Jena, Germany). The estimated scleral radius (11.2±0.3mm) was shown to be highly precise with a coefficient of variation of 0.4%. A statistically significant correlation between axial length and scleral radius (R 2 =0.957, p<0.001) was observed. Moreover, corneal radius (R 2 =0.420, p<0.001), anterior chamber depth (R 2 =0.141, p=0.039) and white-to-white corneal diameter (R 2 =0.146, p=0.036) have also shown statistically significant correlations with the scleral radius. Lastly, no correlation was observed comparing scleral radius to the central corneal thickness (R 2 =0.047, p=0.161). Three-dimensional topography of anterior eye acquired with Eye Surface Profiler together with a given estimate of the axial length, can be used to calculate the scleral radius with high precision. Copyright © 2016 British Contact Lens Association. Published by Elsevier Ltd. All rights reserved.

Precision of higher-order aberration measurements with a new Placido-disk topographer and Hartmann-Shack wavefront sensor.

PubMed

López-Miguel, Alberto; Martínez-Almeida, Loreto; González-García, María J; Coco-Martín, María B; Sobrado-Calvo, Paloma; Maldonado, Miguel J

2013-02-01

To assess the intrasession and intersession precision of ocular, corneal, and internal higher-order aberrations (HOAs) measured using an integrated topographer and Hartmann-Shack wavefront sensor (Topcon KR-1W) in refractive surgery candidates. IOBA-Eye Institute, Valladolid, Spain. Evaluation of diagnostic technology. To analyze intrasession repeatability, 1 experienced examiner measured eyes 9 times successively. To study intersession reproducibility, the same clinician obtained measurements from another set of eyes in 2 consecutive sessions 1 week apart. Ocular, corneal, and internal HOAs were obtained. Coma and spherical aberrations, 3rd- and 4th-order aberrations, and total HOAs were calculated for a 6.0 mm pupil diameter. For intrasession repeatability (75 eyes), excellent intraclass correlation coefficients (ICCs) were obtained (ICC >0.87), except for internal primary coma (ICC = 0.75) and 3rd-order (ICC = 0.72) HOAs. Repeatability precision (1.96 × S(w)) values ranged from 0.03 μm (corneal primary spherical) to 0.08 μm (ocular primary coma). For intersession reproducibility (50 eyes), ICCs were good (>0.8) for ocular primary spherical, 3rd-order, and total higher-order aberrations; reproducibility precision values ranged from 0.06 μm (corneal primary spherical) to 0.21 μm (internal 3rd order), with internal HOAs having the lowest precision (≥0.12 μm). No systematic bias was found between examinations on different days. The intrasession repeatability was high; therefore, the device's ability to measure HOAs in a reliable way was excellent. Under intersession reproducibility conditions, dependable corneal primary spherical aberrations were provided. No author has a financial or proprietary interest in any material or method mentioned. Copyright © 2012 ASCRS and ESCRS. Published by Elsevier Inc. All rights reserved.

Precision Mass Property Measurements Using a Five-Wire Torsion Pendulum

NASA Technical Reports Server (NTRS)

Swank, Aaron J.

2012-01-01

A method for measuring the moment of inertia of an object using a five-wire torsion pendulum design is described here. Typical moment of inertia measurement devices are capable of 1 part in 10(exp 3) accuracy and current state of the art techniques have capabilities of about one part in 10(exp 4). The five-wire apparatus design shows the prospect of improving on current state of the art. Current measurements using a laboratory prototype indicate a moment of inertia measurement precision better than a part in 10(exp 4). In addition, the apparatus is shown to be capable of measuring the mass center offset from the geometric center. Typical mass center measurement devices exhibit a measurement precision up to approximately 1 micrometer. Although the five-wire pendulum was not originally designed for mass center measurements, preliminary results indicate an apparatus with a similar design may have the potential of achieving state of the art precision.

High Precision Pressure Measurement with a Funnel

ERIC Educational Resources Information Center

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

2008-01-01

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

Precision timing measurements of PSR J1012+5307

NASA Astrophysics Data System (ADS)

Lange, Ch.; Camilo, F.; Wex, N.; Kramer, M.; Backer, D. C.; Lyne, A. G.; Doroshenko, O.

2001-09-01

We present results and applications of high-precision timing measurements of the binary millisecond pulsar J1012+5307. Combining our radio timing measurements with results based on optical observations, we derive complete 3D velocity information for this system. Correcting for Doppler effects, we derive the intrinsic spin parameters of this pulsar and a characteristic age of 8.6+/-1.9Gyr. Our upper limit for the orbital eccentricity of only 8×10-7 (68 per cent confidence level) is the smallest ever measured for a binary system. We demonstrate that this makes the pulsar an ideal laboratory in which to test certain aspects of alternative theories of gravitation. Our precision measurements suggest deviations from a simple pulsar spin-down timing model, which are consistent with timing noise and the extrapolation of the known behaviour of slowly rotating pulsars.

Three-D multilateration: A precision geodetic measurement system

NASA Technical Reports Server (NTRS)

Escobal, P. R.; Ong, K. M.; Vonroos, O. H.; Shumate, M. S.; Jaffe, R. M.; Fliegel, H. F.; Muller, P. M.

1973-01-01

A technique of satellite geodesy for determining the relative three dimensional coordinates of ground stations within one centimeter over baselines of 20 to 10,000 kilometers is discussed. The system is referred to as 3-D Multilateration and has applications in earthquake hazard assessment, precision surveying, plate tectonics, and orbital mechanics. The accuracy is obtained by using pulsed lasers to obtain simultaneous slant ranges between several ground stations and a moving retroreflector with known trajectory for aiming the lasers.

High-precision mass measurements for the rp-process at JYFLTRAP

NASA Astrophysics Data System (ADS)

Canete, Laetitia; Eronen, Tommi; Jokinen, Ari; Kankainen, Anu; Moore, Ian D.; Nesterenko, Dimitry; Rinta-Antila, Sami

2018-01-01

The double Penning trap JYFLTRAP at the University of Jyväskylä has been successfully used to achieve high-precision mass measurements of nuclei involved in the rapid proton-capture (rp) process. A precise mass measurement of 31Cl is essential to estimate the waiting point condition of 30S in the rp-process occurring in type I x-ray bursts (XRBs). The mass-excess of 31C1 measured at JYFLTRAP, -7034.7(3.4) keV, is 15 more precise than the value given in the Atomic Mass Evaluation 2012. The proton separation energy Sp determined from the new mass-excess value confirmed that 30S is a waiting point, with a lower-temperature limit of 0.44 GK. The mass of 52Co effects both 51Fe(p,γ)52Co and 52Co(p,γ)53Ni reactions. The mass-excess value measured, - 34 331.6(6.6) keV is 30 times more precise than the value given in AME2012. The Q values for the 51Fe(p,γ)52Co and 52Co(p,γ)53Ni reactions are now known with a high precision, 1418(11) keV and 2588(26) keV respectively. The results show that 52Co is more proton bound and 53Ni less proton bound than what was expected from the extrapolated value.

Metering gun for dispensing precisely measured charges of fluid

NASA Technical Reports Server (NTRS)

Cook, T. A.; Scheibe, H. (Inventor)

1974-01-01

A cyclically operable fluid dispenser for use in dispensing precisely measured charges of potable water aboard spacecraft is described. The dispenser is characterized by (1) a sealed housing adapted to be held within a crewman's palm and coupled with a pressurized source of potable water; (2) a dispensing jet projected from the housing and configured to be received within a crewman's lips; (3) an expansible measuring chamber for measuring charges of drinking water received from the source; (4) and a dispenser actuator including a lever extended from the housing to be digitated for initiating operational cycles, whereby precisely measured charges of potable water selectively are delivered for drinking purposes in a weightless environment.

High Precision Measurement of the Neutron Polarizabilities via Compton Scattering on Deuterium at Eγ=65 MeV

NASA Astrophysics Data System (ADS)

Sikora, Mark; Compton@HIGS Team

2017-01-01

The electric (αn) and magnetic (βn) polarizabilities of the neutron are fundamental properties arising from its internal structure which describe the nucleon's response to applied electromagnetic fields. Precise measurements of the polarizabilities provide crucial constraints on models of Quantum Chromodynamics (QCD) in the low energy regime such as Chiral Effective Field Theories as well as emerging ab initio calculations from lattice-QCD. These values also contribute the most uncertainty to theoretical determinations of the proton-neutron mass difference. Historically, the experimental challenges to measuring αn and βn have been due to the difficulty in obtaining suitable targets and sufficiently intense beams, leading to significant statistical uncertainties. To address these issues, a program of Compton scattering experiments on the deuteron is underway at the High Intensity Gamma Source (HI γS) at Duke University with the aim of providing the world's most precise measurement of αn and βn. We report measurements of the Compton scattering differential cross section obtained at an incident photon energy of 65 MeV and discuss the sensitivity of these data to the polarizabilities.

Probabilistic metrology or how some measurement outcomes render ultra-precise estimates

NASA Astrophysics Data System (ADS)

Calsamiglia, J.; Gendra, B.; Muñoz-Tapia, R.; Bagan, E.

2016-10-01

We show on theoretical grounds that, even in the presence of noise, probabilistic measurement strategies (which have a certain probability of failure or abstention) can provide, upon a heralded successful outcome, estimates with a precision that exceeds the deterministic bounds for the average precision. This establishes a new ultimate bound on the phase estimation precision of particular measurement outcomes (or sequence of outcomes). For probe systems subject to local dephasing, we quantify such precision limit as a function of the probability of failure that can be tolerated. Our results show that the possibility of abstaining can set back the detrimental effects of noise.

High Precision Measurement of the Neutron Polarizabilities via Compton Scattering on Deuterium at HI γS

NASA Astrophysics Data System (ADS)

Sikora, Mark

2016-09-01

The electric (αn) and magnetic (βn) polarizabilities of the neutron are fundamental properties arising from its internal structure which describe the nucleon's response to applied electromagnetic fields. Precise measurements of the polarizabilities provide crucial constraints on models of Quantum Chromodynamics (QCD) in the low energy regime such as Chiral Effective Field Theories as well as emerging ab initio calculations from lattice-QCD. These values also contribute the most uncertainty to theoretical determinations of the proton-neutron mass difference. Historically, the experimental challenges to measuring αn and βn have been due to the difficulty in obtaining suitable targets and sufficiently intense beams, leading to significant statistical uncertainties. To address these issues, a program of Compton scattering experiments on the deuteron is underway at the High Intensity Gamma Source (HI γS) at Duke University with the aim of providing the world's most precise measurement of αn and βn. We report measurements of the Compton scattering differential cross section obtained at incident photon energies of 65 and 85 MeV and discuss the sensitivity of these data to the polarizabilities.

Precise delay measurement through combinatorial logic

NASA Technical Reports Server (NTRS)

Burke, Gary R. (Inventor); Chen, Yuan (Inventor); Sheldon, Douglas J. (Inventor)

2010-01-01

A high resolution circuit and method for facilitating precise measurement of on-chip delays for FPGAs for reliability studies. The circuit embeds a pulse generator on an FPGA chip having one or more groups of LUTS (the "LUT delay chain"), also on-chip. The circuit also embeds a pulse width measurement circuit on-chip, and measures the duration of the generated pulse through the delay chain. The pulse width of the output pulse represents the delay through the delay chain without any I/O delay. The pulse width measurement circuit uses an additional asynchronous clock autonomous from the main clock and the FPGA propagation delay can be displayed on a hex display continuously for testing purposes.

Precision Half-life Measurement of 25Al

NASA Astrophysics Data System (ADS)

Long, Jacob; Ahn, Tan; Allen, Jacob; Bardayan, Daniel; Becchetti, Fredrich; Blankstein, Drew; Brodeur, Maxime; Burdette, Daniel; Frentz, Bryce; Hall, Matthew; Kelly, James; Kolata, James; O'Malley, Patrick; Schultz, Bradley; Strauss, Sabrina; Valverde, Adrian; TwinSol Collaboration

2017-09-01

In recent years, precision measurements have led to considerable advances in several areas of physics, including fundamental symmetry. Precise determination of ft values for superallowed mixed transitions between mirror nuclides could provide an avenue to test the theoretical corrections used to extract the Vud matrix element from superallowed pure Fermi transitions. Calculation of the ft value requires the half-life, branching ratio, and Q value. 25Al decay is of particular interest as its half-life is derived from a series of conflicting measurements, and the largest uncertainty on the ft value stems from the half-life uncertainty. The life-time was determined by the β counting of implanted 25Al on a Ta foil that was removed from the beam for counting. The 25Al beam was produced by a transfer reaction and separated by the TwinSol facility of the Nuclear Science Laboratory of the University of Notre Dame. The 25Al results will be presented with preliminary results of more recent half-life measurements. The National Science Foundation.

Diode laser spectroscopy: precise spectral line shape measurements

NASA Astrophysics Data System (ADS)

Nadezhdinskii, A. I.

1996-07-01

When one speaks about modern trends in tunable diode laser spectroscopy (TDLS) one should mention that precise line shape measurements have become one of the most promising applications of diode lasers in high resolution molecular spectroscopy. Accuracy limitations of TDL spectrometers are considered in this paper, proving the ability to measure spectral line profile with precision better than 1%. A four parameter Voigt profile is used to fit the experimental spectrum, and the possibility of line shift measurements with an accuracy of 2 × 10 -5 cm -1 is shown. Test experiments demonstrate the error line intensity ratios to be less than 0.3% for the proposed approach. Differences between "soft" and "hard" models of line shape have been observed experimentally for the first time. Some observed resonance effects are considered with respect to collision adiabacity.

Quantifying the Precision of Single-Molecule Torque and Twist Measurements Using Allan Variance.

PubMed

van Oene, Maarten M; Ha, Seungkyu; Jager, Tessa; Lee, Mina; Pedaci, Francesco; Lipfert, Jan; Dekker, Nynke H

2018-04-24

Single-molecule manipulation techniques have provided unprecedented insights into the structure, function, interactions, and mechanical properties of biological macromolecules. Recently, the single-molecule toolbox has been expanded by techniques that enable measurements of rotation and torque, such as the optical torque wrench (OTW) and several different implementations of magnetic (torque) tweezers. Although systematic analyses of the position and force precision of single-molecule techniques have attracted considerable attention, their angle and torque precision have been treated in much less detail. Here, we propose Allan deviation as a tool to systematically quantitate angle and torque precision in single-molecule measurements. We apply the Allan variance method to experimental data from our implementations of (electro)magnetic torque tweezers and an OTW and find that both approaches can achieve a torque precision better than 1 pN · nm. The OTW, capable of measuring torque on (sub)millisecond timescales, provides the best torque precision for measurement times ≲10 s, after which drift becomes a limiting factor. For longer measurement times, magnetic torque tweezers with their superior stability provide the best torque precision. Use of the Allan deviation enables critical assessments of the torque precision as a function of measurement time across different measurement modalities and provides a tool to optimize measurement protocols for a given instrument and application. Copyright © 2018 Biophysical Society. Published by Elsevier Inc. All rights reserved.

Fast and precise dense grid size measurement method based on coaxial dual optical imaging system

NASA Astrophysics Data System (ADS)

Guo, Jiping; Peng, Xiang; Yu, Jiping; Hao, Jian; Diao, Yan; Song, Tao; Li, Ameng; Lu, Xiaowei

2015-10-01

Test sieves with dense grid structure are widely used in many fields, accurate gird size calibration is rather critical for success of grading analysis and test sieving. But traditional calibration methods suffer from the disadvantages of low measurement efficiency and shortage of sampling number of grids which could lead to quality judgment risk. Here, a fast and precise test sieve inspection method is presented. Firstly, a coaxial imaging system with low and high optical magnification probe is designed to capture the grid images of the test sieve. Then, a scaling ratio between low and high magnification probes can be obtained by the corresponding grids in captured images. With this, all grid dimensions in low magnification image can be obtained by measuring few corresponding grids in high magnification image with high accuracy. Finally, by scanning the stage of the tri-axis platform of the measuring apparatus, whole surface of the test sieve can be quickly inspected. Experiment results show that the proposed method can measure the test sieves with higher efficiency compare to traditional methods, which can measure 0.15 million grids (gird size 0.1mm) within only 60 seconds, and it can measure grid size range from 20μm to 5mm precisely. In a word, the presented method can calibrate the grid size of test sieve automatically with high efficiency and accuracy. By which, surface evaluation based on statistical method can be effectively implemented, and the quality judgment will be more reasonable.

A novel design of the high-precision magnetic locator with three-dimension measurement capability applying dynamically sensing mechanism

NASA Astrophysics Data System (ADS)

Huang, Wen-Nan; Chen, Po-Shen; Chen, Mu-Ping; Teng, Ching-Cheng

2006-09-01

A novel design of the magnetic locator, for obtaining the high-precision measurement information of variety of the buried metal pipes, is presented in this paper. The concept of dynamically sensing mechanism, including the vibrating and moving devices, proposed herein is a simple and effective way to improve the precision of three-dimension location sensing for the underground utilities. Based on the primary magnetism of Lenz's law and Faraday's law, the functions of the amplifying effect for the sensing magnetic signals, as well as the distinguishing effect by the simple filtering algorithms embedded in processing programs, are achieved while the relatively strong noise exists. The verification results of these integration designs demonstrate the effectiveness both by precise locating for the buried utility, and accurate measurement for the depth.

Research about the high precision temperature measurement

NASA Astrophysics Data System (ADS)

Lin, J.; Yu, J.; Zhu, X.; Zeng, Z.; Deng, Y.

2012-12-01

High precision temperature control system is one of most important support conditions for tunable birefringent filter.As the first step,we researched some high precision temperature measurement methods for it. Firstly, circuits with a 24 bit ADC as the sensor's reader were carefully designed; Secondly, an ARM porcessor is used as the centrol processing unit, it provides sufficient reading and procesing ability; Thirdly, three kinds of sensors, PT100, Dale 01T1002-5 thermistor, Wheatstone bridge(constructed by pure copper and manganin) as the senor of the temperature were tested respectively. The resolution of the measurement with these three kinds of sensors are all better than 0.001 that's enough for 0.01 stability temperature control. Comparatively, Dale 01T1002-5 thermistor could get the most accurate temperature of the key point, Wheatstone bridge could get the most accurate mean temperature of the whole layer, both of them will be used in our futrue temperature controll system.

High-precision reflectivity measurements: improvements in the calibration procedure

NASA Astrophysics Data System (ADS)

Jupe, Marco; Grossmann, Florian; Starke, Kai; Ristau, Detlev

2003-05-01

The development of high quality optical components is heavily depending on precise characterization procedures. The reflectance and transmittance of laser components are the most important parameters for advanced laser applications. In the industrial fabrication of optical coatings, quality management is generally insured by spectral photometric methods according to ISO/DIS 15386 on a medium level of accuracy. Especially for high reflecting mirrors, a severe discrepancy in the determination of the absolute reflectivity can be found for spectral photometric procedures. In the first part of the CHOCLAB project, a method for measuring reflectance and transmittance with an enhanced precision was developed, which is described in ISO/WD 13697. In the second part of the CHOCLAB project, the evaluation and optimization for the presented method is scheduled. Within this framework international Round-Robin experiment is currently in progress. During this Round-Robin experiment, distinct deviations could be observed between the results of high precision measurement facilities of different partners. Based on the extended experiments, the inhomogeneity of the sample reflectivity was identified as one important origin for the deviation. Consequently, this inhomogeneity is also influencing the calibration procedure. Therefore, a method was developed that allows the calibration of the chopper blade using always the same position on the reference mirror. During the investigations, the homogeneity of several samples was characterized by a surface mapping procedure for 1064 nm. The measurement facility was extended to the additional wavelength 532 nm and a similar set-up was assembled at 10.6 μm. The high precision reflectivity procedure at the mentioned wavelengths is demonstrated for exemplary measurements.

EDITORIAL: Precision Measurement Technology at the 56th International Scientific Colloquium in Ilmenau Precision Measurement Technology at the 56th International Scientific Colloquium in Ilmenau

NASA Astrophysics Data System (ADS)

Manske, E.; Froehlich, T.

2012-07-01

The 56th International Scientific Colloquium was held from 12th to 16th September 2011 at the Ilmenau University of Technology in Germany. This event was organized by the Faculty of Mechanical Engineering under the title: 'Innovation in Mechanical Engineering—Shaping the Future' and was intended to reflect the entire scope of modern mechanical engineering. In three main topics many research areas, all involving innovative mechanical engineering, were addressed, especially in the fields of Precision Engineering and Precision Measurement Technology, Mechatronics and Ambient-Assisted Living and Systems Technology. The participants were scientists from 21 countries, and 166 presentations were given. This special issue of Measurement Science and Technology presents selected contributions on 'Precision Engineering and Precision Measurement Technology'. Over three days the conference participants discussed novel scientific results in two sessions. The main topics of these sessions were: Measurement and Sensor Technology Process measurement Laser measurement Force measurement Weighing technology Temperature measurement Measurement dynamics and Nanopositioning and Nanomeasuring Technology Nanopositioning and nanomeasuring machines Nanometrology Probes and tools Mechanical design Signal processing Control and visualization in NPM devices Significant research results from the Collaborative Research Centre SFB 622 'Nanopositioning and Nanomeasuring Machines' funded by the German Research Foundation (DFG) were presented as part of this topic. As the Chairmen, our special thanks are due to the International Programme Committee, the Organization Committee and the conference speakers as well as colleagues from the Institute of Process Measurement and Sensor Technology who helped make the conference a success. We would like to thank all the authors for their contributions, the referees for their time spent reviewing the contributions and their valuable comments, and the whole

Validating precision estimates in horizontal wind measurements from a Doppler lidar

DOE PAGES

Newsom, Rob K.; Brewer, W. Alan; Wilczak, James M.; ...

2017-03-30

Results from a recent field campaign are used to assess the accuracy of wind speed and direction precision estimates produced by a Doppler lidar wind retrieval algorithm. The algorithm, which is based on the traditional velocity-azimuth-display (VAD) technique, estimates the wind speed and direction measurement precision using standard error propagation techniques, assuming the input data (i.e., radial velocities) to be contaminated by random, zero-mean, errors. For this study, the lidar was configured to execute an 8-beam plan-position-indicator (PPI) scan once every 12 min during the 6-week deployment period. Several wind retrieval trials were conducted using different schemes for estimating themore » precision in the radial velocity measurements. Here, the resulting wind speed and direction precision estimates were compared to differences in wind speed and direction between the VAD algorithm and sonic anemometer measurements taken on a nearby 300 m tower.« less

Precise fiber length measurement using harmonic detection of phase-locked cavity modes

NASA Astrophysics Data System (ADS)

Terra, Osama

2018-06-01

In this paper, precise length measurements of optical fibers are performed by employing harmonic detection of the pulse-train frequency of a passively mode-locked fiber laser. This frequency is proportional to the length of the laser cavity in which the measured fiber is installed. Our proposed technique enables length measurement of long fibers from 1 to 40 km with precision from 0.4 to 8 mm and short fibers of few meters with precision as low as 26 μm. Such superior precision is achieved not only by the selection of higher harmonics of up to 1410, but also by the careful control of the wavelength at which the passive mode-locking occur, because of the broadband nature of the used gain medium.

One novel type of miniaturization FBG rotation angle sensor with high measurement precision and temperature self-compensation

NASA Astrophysics Data System (ADS)

Jiang, Shanchao; Wang, Jing; Sui, Qingmei

2018-03-01

In order to achieve rotation angle measurement, one novel type of miniaturization fiber Bragg grating (FBG) rotation angle sensor with high measurement precision and temperature self-compensation is proposed and studied in this paper. The FBG rotation angle sensor mainly contains two core sensitivity elements (FBG1 and FBG2), triangular cantilever beam, and rotation angle transfer element. In theory, the proposed sensor can achieve temperature self-compensation by complementation of the two core sensitivity elements (FBG1 and FBG2), and it has a boundless angel measurement range with 2π rad period duo to the function of the rotation angle transfer element. Based on introducing the joint working processes, the theory calculation model of the FBG rotation angel sensor is established, and the calibration experiment on one prototype is also carried out to obtain its measurement performance. After experimental data analyses, the measurement precision of the FBG rotation angle sensor prototype is 0.2 ° with excellent linearity, and the temperature sensitivities of FBG1 and FBG2 are 10 pm/° and 10.1 pm/°, correspondingly. All these experimental results confirm that the FBG rotation angle sensor can achieve large-range angle measurement with high precision and temperature self-compensation.

1998 Conference on Precision Electromagnetic Measurements Digest. Proceedings.

NASA Astrophysics Data System (ADS)

Nelson, T. L.

The following topics were dealt with: fundamental constants; caesium standards; AC-DC transfer; impedance measurement; length measurement; units; statistics; cryogenic resonators; time transfer; QED; resistance scaling and bridges; mass measurement; atomic fountains and clocks; single electron transport; Newtonian constant of gravitation; stabilised lasers and frequency measurements; cryogenic current comparators; optical frequency standards; high voltage devices and systems; international compatibility; magnetic measurement; precision power measurement; high resolution spectroscopy; DC transport standards; waveform acquisition and analysis; ion trap standards; optical metrology; quantised Hall effect; Josephson array comparisons; signal generation and measurement; Avogadro constant; microwave networks; wideband power standards; antennas, fields and EMC; quantum-based standards.

Precision Muonium Spectroscopy

NASA Astrophysics Data System (ADS)

Jungmann, Klaus P.

2016-09-01

The muonium atom is the purely leptonic bound state of a positive muon and an electron. It has a lifetime of 2.2 µs. The absence of any known internal structure provides for precision experiments to test fundamental physics theories and to determine accurate values of fundamental constants. In particular ground state hyperfine structure transitions can be measured by microwave spectroscopy to deliver the muon magnetic moment. The frequency of the 1s-2s transition in the hydrogen-like atom can be determined with laser spectroscopy to obtain the muon mass. With such measurements fundamental physical interactions, in particular quantum electrodynamics, can also be tested at highest precision. The results are important input parameters for experiments on the muon magnetic anomaly. The simplicity of the atom enables further precise experiments, such as a search for muonium-antimuonium conversion for testing charged lepton number conservation and searches for possible antigravity of muons and dark matter.

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

DOE Office of Scientific and Technical Information (OSTI.GOV)

Triambak, S.; TRIUMF, 4004 Wesbrook Mall, Vancouver, BC V6T 2A3

2011-11-30

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

Measurement device for high-precision spectral transmittance of solar blind filter

NASA Astrophysics Data System (ADS)

Wang, Yan; Qian, Yunsheng; Lv, Yang; Feng, Cheng; Liu, Jian

2017-02-01

In order to measure spectral transmittance of solar-blind filter ranging from ultraviolet to visible light accurately, a high-precision filter transmittance measuring system based on the ultraviolet photomultiplier is developed. The calibration method is mainly used to measure transmittance in this system, which mainly consists of an ultraviolet photomultiplier as core of the system and a lock-in amplifier combined with an optical modulator as the aided measurement for the system. The ultraviolet photomultiplier can amplify the current signal through the filter and have the characteristics of low dark current and high luminance gain. The optical modulator and the lock-in amplifier can obtain the signal from the photomultiplier and inhibit dark noise and spurious signal effectively. Through these two parts, the low light passing through the filters can be detected and we can calculate the transmittance by the optical power detected. Based on the proposed system, the limit detection of the transmittance can reach 10-12, while the result of the conventional approach is merely 10-6. Therefore, the system can make an effective assessment of solar blind ultraviolet filters.

Measurement Model and Precision Analysis of Accelerometers for Maglev Vibration Isolation Platforms.

PubMed

Wu, Qianqian; Yue, Honghao; Liu, Rongqiang; Zhang, Xiaoyou; Ding, Liang; Liang, Tian; Deng, Zongquan

2015-08-14

High precision measurement of acceleration levels is required to allow active control for vibration isolation platforms. It is necessary to propose an accelerometer configuration measurement model that yields such a high measuring precision. In this paper, an accelerometer configuration to improve measurement accuracy is proposed. The corresponding calculation formulas of the angular acceleration were derived through theoretical analysis. A method is presented to minimize angular acceleration noise based on analysis of the root mean square noise of the angular acceleration. Moreover, the influence of installation position errors and accelerometer orientation errors on the calculation precision of the angular acceleration is studied. Comparisons of the output differences between the proposed configuration and the previous planar triangle configuration under the same installation errors are conducted by simulation. The simulation results show that installation errors have a relatively small impact on the calculation accuracy of the proposed configuration. To further verify the high calculation precision of the proposed configuration, experiments are carried out for both the proposed configuration and the planar triangle configuration. On the basis of the results of simulations and experiments, it can be concluded that the proposed configuration has higher angular acceleration calculation precision and can be applied to different platforms.

Measurement Model and Precision Analysis of Accelerometers for Maglev Vibration Isolation Platforms

PubMed Central

Wu, Qianqian; Yue, Honghao; Liu, Rongqiang; Zhang, Xiaoyou; Ding, Liang; Liang, Tian; Deng, Zongquan

2015-01-01

High precision measurement of acceleration levels is required to allow active control for vibration isolation platforms. It is necessary to propose an accelerometer configuration measurement model that yields such a high measuring precision. In this paper, an accelerometer configuration to improve measurement accuracy is proposed. The corresponding calculation formulas of the angular acceleration were derived through theoretical analysis. A method is presented to minimize angular acceleration noise based on analysis of the root mean square noise of the angular acceleration. Moreover, the influence of installation position errors and accelerometer orientation errors on the calculation precision of the angular acceleration is studied. Comparisons of the output differences between the proposed configuration and the previous planar triangle configuration under the same installation errors are conducted by simulation. The simulation results show that installation errors have a relatively small impact on the calculation accuracy of the proposed configuration. To further verify the high calculation precision of the proposed configuration, experiments are carried out for both the proposed configuration and the planar triangle configuration. On the basis of the results of simulations and experiments, it can be concluded that the proposed configuration has higher angular acceleration calculation precision and can be applied to different platforms. PMID:26287203

Precision measurement of the weak charge of the proton

DOE Office of Scientific and Technical Information (OSTI.GOV)

None

The weak charge of the proton Q_W^p sets the strength of the proton's interaction with other particles via the neutral electroweak force, just as the electric charge sets the strength of the purely electromagnetic (EM) interaction. The standard model (SM) of electroweak particle physics predicts that Q_W^p is suppressed, due to a near-cancellation between the weak charges of the proton's three constituent quarks. This small SM "background" makes Q_W^p especially sensitive to potential new parity-violating (PV) interactions beyond those of the SM. Parity symmetry (invariance under spatial inversion (x,y,z) --> (-x,-y,-z)) is violated in the weak interaction, but not inmore » the other three forces of nature. Therefore PV provides a unique tool to isolate the weak interaction in order to observe the proton's weak charge1. Earlier experiments2 have measured parity-violating electron-scattering (PVES) asymmetries in kinematic regimes that are more sensitive to the proton's extended structure than to its weak charge. Here we report the most precise measurement of the PV electron-proton scattering asymmetry (A_ep = -226.5 ± 9.3 ppb, 1 ppb=10-9), in a kinematic regime where the theoretical uncertainties involved in determining Q_W^p are small. We use this measurement of A_ep to determine Q_W^p, obtaining consistent results using several methods which vary the degree of experimental and theoretical input. Our result for Q_W^p (0.0719 ± 0.0045) is in excellent agreement with the SM3. We employ energy-scale-dependent quantum corrections to relate Q_W^p to the electroweak mixing angle sin^2 theta_W, a fundamental SM parameter with which we are also in good agreement. In addition, we use our precise Q_W^p result to set TeV-scale constraints on potential new semi-leptonic PV physics not described by the SM.« less

Precision measurements from very-large scale aerial digital imagery.

PubMed

Booth, D Terrance; Cox, Samuel E; Berryman, Robert D

2006-01-01

Managers need measurements and resource managers need the length/width of a variety of items including that of animals, logs, streams, plant canopies, man-made objects, riparian habitat, vegetation patches and other things important in resource monitoring and land inspection. These types of measurements can now be easily and accurately obtained from very large scale aerial (VLSA) imagery having spatial resolutions as fine as 1 millimeter per pixel by using the three new software programs described here. VLSA images have small fields of view and are used for intermittent sampling across extensive landscapes. Pixel-coverage among images is influenced by small changes in airplane altitude above ground level (AGL) and orientation relative to the ground, as well as by changes in topography. These factors affect the object-to-camera distance used for image-resolution calculations. 'ImageMeasurement' offers a user-friendly interface for accounting for pixel-coverage variation among images by utilizing a database. 'LaserLOG' records and displays airplane altitude AGL measured from a high frequency laser rangefinder, and displays the vertical velocity. 'Merge' sorts through large amounts of data generated by LaserLOG and matches precise airplane altitudes with camera trigger times for input to the ImageMeasurement database. We discuss application of these tools, including error estimates. We found measurements from aerial images (collection resolution: 5-26 mm/pixel as projected on the ground) using ImageMeasurement, LaserLOG, and Merge, were accurate to centimeters with an error less than 10%. We recommend these software packages as a means for expanding the utility of aerial image data.

Precision Column CO2 Measurement from Space Using Broad Band LIDAR

NASA Technical Reports Server (NTRS)

Heaps, William S.

2009-01-01

In order to better understand the budget of carbon dioxide in the Earth's atmosphere it is necessary to develop a global high precision understanding of the carbon dioxide column. To uncover the missing sink" that is responsible for the large discrepancies in the budget as we presently understand it, calculation has indicated that measurement accuracy of 1 ppm is necessary. Because typical column average CO2 has now reached 380 ppm this represents a precision on the order of 0.25% for these column measurements. No species has ever been measured from space at such a precision. In recognition of the importance of understanding the CO2 budget to evaluate its impact on global warming the National Research Council in its decadal survey report to NASA recommended planning for a laser based total CO2 mapping mission in the near future. The extreme measurement accuracy requirements on this mission places very strong constraints on the laser system used for the measurement. This work presents an overview of the characteristics necessary in a laser system used to make this measurement. Consideration is given to the temperature dependence, pressure broadening, and pressure shift of the CO2 lines themselves and how these impact the laser system characteristics. We are examining the possibility of making precise measurements of atmospheric carbon dioxide using a broad band source of radiation. This means that many of the difficulties in wavelength control can be treated in the detector portion of the system rather than the laser source. It also greatly reduces the number of individual lasers required to make a measurement. Simplifications such as these are extremely desirable for systems designed to operate from space.

Border effect-based precise measurement of any frequency signal

NASA Astrophysics Data System (ADS)

Bai, Li-Na; Ye, Bo; Xuan, Mei-Na; Jin, Yu-Zhen; Zhou, Wei

2015-12-01

Limited detection resolution leads to fuzzy areas during the measurement, and the discrimination of the border of a fuzzy area helps to use the resolution stability. In this way, measurement precision is greatly improved, hence this phenomenon is named the border effect. The resolution fuzzy area and its application should be studied to realize high-resolution measurement. During the measurement of any frequency signal, the fuzzy areas of phase-coincidence detection are always discrete and irregular. In this paper the difficulty in capturing the border information of discrete fuzzy areas is overcome and extra-high resolution measurement is implemented. Measurement precision of any frequency-signal can easily reach better than 1 × 10-11/s in a wide range of frequencies, showing the great importance of the border effect. An in-depth study of this issue has great significance for frequency standard comparison, signal processing, telecommunication, and fundamental subjects. Project supported by the National Natural Science Foundation of China (Grant Nos. 10978017 and 61201288), the Natural Science Foundation of Research Plan Projects of Shaanxi Province, China (Grant No. 2014JM2-6128), and the Sino-Poland Science and Technology Cooperation Projects (Grant No. 36-33).

High-precision Ru isotopic measurements by multi-collector ICP-MS.

PubMed

Becker, Harry; Dalpe, Claude; Walker, Richard J

2002-06-01

Ruthenium isotopic data for a pure Aldrich ruthenium nitrate solution obtained using a Nu Plasma multi collector inductively coupled plasma-mass spectrometer (MC-ICP-MS) shows excellent agreement (better than 1 epsilon unit = 1 part in 10(4)) with data obtained by other techniques for the mass range between 96 and 101 amu. External precisions are at the 0.5-1.7 epsilon level (2sigma). Higher sensitivity for MC ICP-MS compared to negative thermal ionization mass spectrometry (N-TIMS) is offset by the uncertainties introduced by relatively large mass discrimination and instabilities in the plasma source-ion extraction region that affect the long-term reproducibility. Large mass bias correction in ICP mass spectrometry demands particular attention to be paid to the choice of normalizing isotopes. Because of its position in the mass spectrum and the large mass bias correction, obtaining precise and accurate abundance data for 104Ru by MC-ICP-MS remains difficult. Internal and external mass bias correction schemes in this mass range may show similar shortcomings if the isotope of interest does not lie within the mass range covered by the masses used for normalization. Analyses of meteorite samples show that if isobaric interferences from Mo are sufficiently large (Ru/Mo < 10(4)), uncertainties on the Mo interference correction propagate through the mass bias correction and yield inaccurate results for Ru isotopic compositions. Second-order linear corrections may be used to correct for these inaccuracies, but such results are generally less precise than N-TIMS data.

Precise Lamb Shift Measurements in Hydrogen-Like Heavy Ions—Status and Perspectives

NASA Astrophysics Data System (ADS)

Andrianov, V.; Beckert, K.; Bleile, A.; Chatterjee, Ch.; Echler, A.; Egelhof, P.; Gumberidze, A.; Ilieva, S.; Kiselev, O.; Kilbourne, C.; Kluge, H.-J.; Kraft-Bermuth, S.; McCammon, D.; Meier, J. P.; Reuschl, R.; Stöhlker, T.; Trassinelli, M.

2009-12-01

The precise determination of the energy of the Lyman α1 and α2 lines in hydrogen-like heavy ions provides a sensitive test of quantum electrodynamics in very strong Coulomb fields. For the first time, a calorimetric low-temperature detector was applied in an experiment to precisely determine the transition energy of the Lyman lines of lead ions 207Pb81+ at the Experimental Storage Ring (ESR) at GSI. The detectors consist of silicon thermistors, provided by the NASA/Goddard Space Flight Center, and Pb or Sn absorbers to obtain high quantum efficiency in the energy range of 40-80 keV, where the Doppler-shifted Lyman lines are located. The measured energy of the Lyman α1 line, E(Ly-α1, 207Pb81+) = (77937±12stat±23syst) eV, agrees within errors with theoretical predictions. The systematic error is mainly due to uncertainties in the non-linear energy calibration of the detectors as well as the relative position of detector and gas-jet target.

Concordance of macular pigment measurements obtained using customized heterochromatic flicker photometry, dual-wavelength autofluorescence, and single-wavelength reflectance.

PubMed

Dennison, Jessica L; Stack, Jim; Beatty, Stephen; Nolan, John M

2013-11-01

This study compares in vivo measurements of macular pigment (MP) obtained using customized heterochromatic flicker photometry (cHFP; Macular Metrics Densitometer(™)), dual-wavelength fundus autofluorescence (Heidelberg Spectralis(®) HRA + OCT MultiColor) and single-wavelength fundus reflectance (Zeiss Visucam(®) 200). MP was measured in one eye of 62 subjects on each device. Data from 49 subjects (79%) was suitable for analysis. Agreement between the Densitometer and Spectralis was investigated at various eccentricities using a variety of quantitative and graphical methods, including: Pearson correlation coefficient to measure degree of scatter (precision), accuracy coefficient, concordance correlation coefficient (ccc), paired t-test, scatter and Bland-Altman plots. The relationship between max MP from the Visucam and central MP from the Spectralis and Densitometer was investigated using regression methods. Agreement was strong between the Densitometer and Spectralis at all central eccentricities (e.g. at 0.25° eccentricity: accuracy = 0.97, precision = 0.90, ccc = 0.87). Regression analysis showed a very weak relationship between the Visucam and Densitometer (e.g. Visucam max on Densitometer central MP: R(2) = 0.008, p = 0.843). Regression analysis also demonstrated a weak relationship between MP measured by the Spectralis and Visucam (e.g. Visucam max on Spectralis central MP: R(2) = 0.047, p = 0.348). MP values obtained using the Heidelberg Spectralis are comparable to MP values obtained using the Densitometer. In contrast, MP values obtained using the Zeiss Visucam are not comparable with either the Densitometer or the Spectralis MP measuring devices. Taking cHFP as the current standard to which other MP measuring devices should be compared, the Spectralis is suitable for use in a clinical and research setting, whereas the Visucam is not. Copyright © 2013 Elsevier Ltd. All rights reserved.

Attaining the Photometric Precision Required by Future Dark Energy Projects

DOE Office of Scientific and Technical Information (OSTI.GOV)

Stubbs, Christopher

2013-01-21

This report outlines our progress towards achieving the high-precision astronomical measurements needed to derive improved constraints on the nature of the Dark Energy. Our approach to obtaining higher precision flux measurements has two basic components: 1) determination of the optical transmission of the atmosphere, and 2) mapping out the instrumental photon sensitivity function vs. wavelength, calibrated by referencing the measurements to the known sensitivity curve of a high precision silicon photodiode, and 3) using the self-consistency of the spectrum of stars to achieve precise color calibrations.

High Precision 2-D Grating Groove Density Measurement

NASA Astrophysics Data System (ADS)

Zhang, Ningxiao; McEntaffer, Randall; Tedesco, Ross

2017-08-01

Our research group at Penn State University is working on producing X-ray reflection gratings with high spectral resolving power and high diffraction efficiency. To estimate our fabrication accuracy, we apply a precise 2-D grating groove density measurement to plot groove density distributions of gratings on 6-inch wafers. In addition to plotting a fixed groove density distribution, this method is also sensitive to measuring the variation of the groove density simultaneously. This system can reach a measuring accuracy (ΔN/N) of 10-3. Here we present this groove density measurement and some applications.

Precision Measurement of The Most Distant Spectroscopically Confirmed

Science.gov Websites

Supernova SAO/NASA ADS Astronomy Abstract Service Title: Precision Measurement of The Most Space Astronomy, 389 UCB, University of Colorado, Boulder, CO 80309, USA), AI(Hamilton College Astronomy, Vanderbilt University, Nashville, TN 37240, USA), AO(E. O. Lawrence Berkeley National Lab, 1

Precision of natural satellite ephemerides from observations of different types

NASA Astrophysics Data System (ADS)

Emelyanov, N. V.

2017-08-01

Currently, various types of observations of natural planetary satellites are used to refine their ephemerides. A new type of measurement - determining the instants of apparent satellite encounters - has recently been proposed by Morgado and co-workers. The problem that arises is which type of measurement to choose in order to obtain an ephemeris precision that is as high as possible. The answer can be obtained only by modelling the entire process: observations, obtaining the measured values, refining the satellite motion parameters, and generating the ephemeris. The explicit dependence of the ephemeris precision on observational accuracy as well as on the type of observations is unknown. In this paper, such a dependence is investigated using the Monte Carlo statistical method. The relationship between the ephemeris precision for different types of observations is then assessed. The possibility of using the instants of apparent satellite encounters to obtain an ephemeris is investigated. A method is proposed that can be used to fit the satellite orbital parameters to this type of measurement. It is shown that, in the absence of systematic scale errors in the CCD frame, the use of the instants of apparent encounters leads to less precise ephemerides. However, in the presence of significant scale errors, which is often the case, this type of measurement becomes effective because the instants of apparent satellite encounters do not depend on scale errors.

The Accuracy and Precision of Flow Measurements Using Phase Contrast Techniques

NASA Astrophysics Data System (ADS)

Tang, Chao

Quantitative volume flow rate measurements using the magnetic resonance imaging technique are studied in this dissertation because the volume flow rates have a special interest in the blood supply of the human body. The method of quantitative volume flow rate measurements is based on the phase contrast technique, which assumes a linear relationship between the phase and flow velocity of spins. By measuring the phase shift of nuclear spins and integrating velocity across the lumen of the vessel, we can determine the volume flow rate. The accuracy and precision of volume flow rate measurements obtained using the phase contrast technique are studied by computer simulations and experiments. The various factors studied include (1) the partial volume effect due to voxel dimensions and slice thickness relative to the vessel dimensions; (2) vessel angulation relative to the imaging plane; (3) intravoxel phase dispersion; (4) flow velocity relative to the magnitude of the flow encoding gradient. The partial volume effect is demonstrated to be the major obstacle to obtaining accurate flow measurements for both laminar and plug flow. Laminar flow can be measured more accurately than plug flow in the same condition. Both the experiment and simulation results for laminar flow show that, to obtain the accuracy of volume flow rate measurements to within 10%, at least 16 voxels are needed to cover the vessel lumen. The accuracy of flow measurements depends strongly on the relative intensity of signal from stationary tissues. A correction method is proposed to compensate for the partial volume effect. The correction method is based on a small phase shift approximation. After the correction, the errors due to the partial volume effect are compensated, allowing more accurate results to be obtained. An automatic program based on the correction method is developed and implemented on a Sun workstation. The correction method is applied to the simulation and experiment results. The

Research on precise pneumatic-electric displacement sensor with large measurement range

NASA Astrophysics Data System (ADS)

Yin, Zhehao; Yuan, Yibao; Liu, Baoshuai

2017-10-01

This research mainly focuses on precise pneumatic-electric displacement sensor which has large measurement range. Under the high precision, measurement range can be expanded so that the need of high precision as well as large range can be satisfied in the field of machining inspection technology. This research was started by the analysis of pneumatic-measuring theory. Then, an gas circuit measuring system which is based on differential pressure was designed. This designed system can reach two aims: Firstly, to convert displacement signal into gas signal; Secondly, to reduce the measurement error which caused by pressure and environmental turbulence. Furthermore, in consideration of the high requirement for linearity, sensitivity and stability, the project studied the pneumatic-electric transducer which puts the SCX series pressure sensor as a key part. The main purpose of this pneumatic-electric transducer is to convert gas signal to suitable electrical signal. Lastly, a broken line subsection linearization circuit was designed, which can nonlinear correct the output characteristic curve so as to enlarge the linear measurement range. The final result could be briefly described like this: under the condition that measuring error is less than 1μm, measurement range could be extended to approximately 200μm which is much higher than the measurement range of traditional pneumatic measuring instrument. Meanwhile, it can reach higher exchangeability and stability in order to become more suitable to engineering application.

A new Ultra Precision Interferometer for absolute length measurements down to cryogenic temperatures

NASA Astrophysics Data System (ADS)

Schödel, R.; Walkov, A.; Zenker, M.; Bartl, G.; Meeß, R.; Hagedorn, D.; Gaiser, C.; Thummes, G.; Heltzel, S.

2012-09-01

A new Ultra Precision Interferometer (UPI) was built at Physikalisch-Technische Bundesanstalt. As its precursor, the precision interferometer, it was designed for highly precise absolute length measurements of prismatic bodies, e.g. gauge blocks, under well-defined temperature conditions and pressure, making use of phase stepping imaging interferometry. The UPI enables a number of enhanced features, e.g. it is designed for a much better lateral resolution and better temperature stability. In addition to the original concept, the UPI is equipped with an external measurement pathway (EMP) in which a prismatic body can be placed alternatively. The temperature of the EMP can be controlled in a much wider range compared to the temperature of the interferometer's main chamber. An appropriate cryostat system, a precision temperature measurement system and improved imaging interferometry were established to permit absolute length measurements down to cryogenic temperature, demonstrated for the first time ever. Results of such measurements are important for studying thermal expansion of materials from room temperature towards less than 10 K.

Precision saturated absorption spectroscopy of H3+

NASA Astrophysics Data System (ADS)

Guan, Yu-Chan; Chang, Yung-Hsiang; Liao, Yi-Chieh; Peng, Jin-Long; Wang, Li-Bang; Shy, Jow-Tsong

2018-03-01

In our previous work on the Lamb-dips of the ν2 fundamental band transitions of H3+, the saturated absorption spectrum was obtained by third-derivative spectroscopy using frequency modulation with an optical parametric oscillator (OPO). However, frequency modulation also caused errors in the absolute frequency determination. To solve this problem, we built a tunable offset locking system to lock the pump frequency of the OPO to an iodine-stabilized Nd:YAG laser. With this improvement, we were able to scan the OPO idler frequency precisely and obtain the saturated absorption profile using intensity modulation. Furthermore, ion concentration modulation was employed to subtract the background noise and increase the signal-to-noise ratio. To determine the absolute frequency of the idler wave, the OPO signal frequency was locked to an optical frequency comb. The absolute frequency accuracy of our spectrometer was better than 7 kHz, demonstrated by measuring the wavelength standard transition of methane at 3.39 μm. Finally, we measured 16 transitions of H3+ and our results agree very well with other precision measurements. This work successfully resolved the discrepancies between our previous measurements and other precision measurements.

Precise measurement of a magnetic field generated by the electromagnetic flux compression technique.

PubMed

Nakamura, D; Sawabe, H; Matsuda, Y H; Takeyama, S

2013-04-01

The precision of the values of a magnetic field generated by electromagnetic flux compression was investigated in ultra-high magnetic fields of up to 700 T. In an attempt to calibrate the magnetic field measured by pickup coils, precise Faraday rotation (FR) measurements were conducted on optical (quartz and crown) glasses. A discernible "turn-around" phenomenon was observed in the FR signal as well as the pickup coils before the end of a liner implosion. We found that the magnetic field measured by pickup coils should be corrected by taking into account the high-frequency response of the signal transmission line. Near the peak magnetic field, however, the pickup coils failed to provide reliable values, leaving the FR measurement as the only method to precisely measure extremely high magnetic fields.

A Reassessment of the Precision of Carbonate Clumped Isotope Measurements: Implications for Calibrations and Paleoclimate Reconstructions

NASA Astrophysics Data System (ADS)

Fernandez, Alvaro; Müller, Inigo A.; Rodríguez-Sanz, Laura; van Dijk, Joep; Looser, Nathan; Bernasconi, Stefano M.

2017-12-01

Carbonate clumped isotopes offer a potentially transformational tool to interpret Earth's history, but the proxy is still limited by poor interlaboratory reproducibility. Here, we focus on the uncertainties that result from the analysis of only a few replicate measurements to understand the extent to which unconstrained errors affect calibration relationships and paleoclimate reconstructions. We find that highly precise data can be routinely obtained with multiple replicate analyses, but this is not always done in many laboratories. For instance, using published estimates of external reproducibilities we find that typical clumped isotope measurements (three replicate analyses) have margins of error at the 95% confidence level (CL) that are too large for many applications. These errors, however, can be systematically reduced with more replicate measurements. Second, using a Monte Carlo-type simulation we demonstrate that the degree of disagreement on published calibration slopes is about what we should expect considering the precision of Δ47 data, the number of samples and replicate analyses, and the temperature range covered in published calibrations. Finally, we show that the way errors are typically reported in clumped isotope data can be problematic and lead to the impression that data are more precise than warranted. We recommend that uncertainties in Δ47 data should no longer be reported as the standard error of a few replicate measurements. Instead, uncertainties should be reported as margins of error at a specified confidence level (e.g., 68% or 95% CL). These error bars are a more realistic indication of the reliability of a measurement.

Broadband Lidar Technique for Precision CO2 Measurement

NASA Technical Reports Server (NTRS)

Heaps, William S.

2008-01-01

Presented are preliminary experimental results, sensitivity measurements and discuss our new CO2 lidar system under development. The system is employing an erbium-doped fiber amplifier (EDFA), superluminescent light emitting diode (SLED) as a source and our previously developed Fabry-Perot interferometer subsystem as a detector part. Global measurement of carbon dioxide column with the aim of discovering and quantifying unknown sources and sinks has been a high priority for the last decade. The goal of Active Sensing of CO2 Emissions over Nights, Days, and Seasons (ASCENDS) mission is to significantly enhance the understanding of the role of CO2 in the global carbon cycle. The National Academy of Sciences recommended in its decadal survey that NASA put in orbit a CO2 lidar to satisfy this long standing need. Existing passive sensors suffer from two shortcomings. Their measurement precision can be compromised by the path length uncertainties arising from scattering within the atmosphere. Also passive sensors using sunlight cannot observe the column at night. Both of these difficulties can be ameliorated by lidar techniques. Lidar systems present their own set of problems however. Temperature changes in the atmosphere alter the cross section for individual CO2 absorption features while the different atmospheric pressures encountered passing through the atmosphere broaden the absorption lines. Currently proposed lidars require multiple lasers operating at multiple wavelengths simultaneously in order to untangle these effects. The current goal is to develop an ultra precise, inexpensive new lidar system for precise column measurements of CO2 changes in the lower atmosphere that uses a Fabry-Perot interferometer based system as the detector portion of the instrument and replaces the narrow band laser commonly used in lidars with the newly available high power SLED as the source. This approach reduces the number of individual lasers used in the system from three or more

High precision measurements on fission-fragment de-excitation

NASA Astrophysics Data System (ADS)

Oberstedt, Stephan; Gatera, Angélique; Geerts, Wouter; Göök, Alf; Hambsch, Franz-Josef; Vidali, Marzio; Oberstedt, Andreas

2017-11-01

In recent years nuclear fission has gained renewed interest both from the nuclear energy community and in basic science. The first, represented by the OECD Nuclear Energy Agency, expressed the need for more accurate fission cross-section and fragment yield data for safety assessments of Generation IV reactor systems. In basic science modelling made much progress in describing the de-excitation mechanism of neutron-rich isotopes, e.g. produced in nuclear fission. Benchmarking the different models require a precise experimental data on prompt fission neutron and γ-ray emission, e.g. multiplicity, average energy per particle and total dissipated energy per fission, preferably as function of fission-fragment mass and total kinetic energy. A collaboration of scientists from JRC Geel (formerly known as JRC IRMM) and other institutes took the lead in establishing a dedicated measurement programme on prompt fission neutron and γ-ray characteristics, which has triggered even more measurement activities around the world. This contribution presents new advanced instrumentation and methodology we use to generate high-precision spectral data and will give a flavour of future data needs and opportunities.

A precise measurement of the $B^0$ meson oscillation frequency

DOE PAGES

Aaij, R.; Abellán Beteta, C.; Adeva, B.; ...

2016-07-21

The oscillation frequency, Δm d, of B 0 mesons is measured using semileptonic decays with a D – or D* – meson in the final state. The data sample corresponds to 3.0fb –1 of pp collisions, collected by the LHCb experiment at centre-of-mass energies √s = 7 and 8TeV. A combination of the two decay modes gives Δm d=(505.0±2.1±1.0)ns –1, where the first uncertainty is statistical and the second is systematic. This is the most precise single measurement of this parameter. It is consistent with the current world average and has similar precision.

Precision and accuracy of 3D lower extremity residua measurement systems

NASA Astrophysics Data System (ADS)

Commean, Paul K.; Smith, Kirk E.; Vannier, Michael W.; Hildebolt, Charles F.; Pilgram, Thomas K.

1996-04-01

Accurate and reproducible geometric measurement of lower extremity residua is required for custom prosthetic socket design. We compared spiral x-ray computed tomography (SXCT) and 3D optical surface scanning (OSS) with caliper measurements and evaluated the precision and accuracy of each system. Spiral volumetric CT scanned surface and subsurface information was used to make external and internal measurements, and finite element models (FEMs). SXCT and OSS were used to measure lower limb residuum geometry of 13 below knee (BK) adult amputees. Six markers were placed on each subject's BK residuum and corresponding plaster casts and distance measurements were taken to determine precision and accuracy for each system. Solid models were created from spiral CT scan data sets with the prosthesis in situ under different loads using p-version finite element analysis (FEA). Tissue properties of the residuum were estimated iteratively and compared with values taken from the biomechanics literature. The OSS and SXCT measurements were precise within 1% in vivo and 0.5% on plaster casts, and accuracy was within 3.5% in vivo and 1% on plaster casts compared with caliper measures. Three-dimensional optical surface and SXCT imaging systems are feasible for capturing the comprehensive 3D surface geometry of BK residua, and provide distance measurements statistically equivalent to calipers. In addition, SXCT can readily distinguish internal soft tissue and bony structure of the residuum. FEM can be applied to determine tissue material properties interactively using inverse methods.

Demonstration of a Fast, Precise Propane Measurement Using Infrared Spectroscopy

NASA Astrophysics Data System (ADS)

Zahniser, M. S.; Roscioli, J. R.; Nelson, D. D.; Herndon, S. C.

2016-12-01

Propane is one of the primary components of emissions from natural gas extraction and processing activities. In addition to being an air pollutant, its ratio to other hydrocarbons such as methane and ethane can serve as a "fingerprint" of a particular facility or process, aiding in identifying emission sources. Quantifying propane has typically required laboratory analysis of flask samples, resulting in low temporal resolution and making plume-based measurements infeasible. Here we demonstrate fast (1-second), high precision (<300 ppt) measurements of propane using high resolution mid-infrared spectroscopy at 2967 wavenumbers. In addition, we explore the impact of nearby water and ethane absorption lines on the accuracy and precision of the propane measurement. Finally, we discuss development of a dual-laser instrument capable of simultaneous measurements of methane, ethane, and propane (the C1-C3 compounds), all within a small spatial package that can be easily deployed aboard a mobile platform.

Segmentation quality evaluation using region-based precision and recall measures for remote sensing images

NASA Astrophysics Data System (ADS)

Zhang, Xueliang; Feng, Xuezhi; Xiao, Pengfeng; He, Guangjun; Zhu, Liujun

2015-04-01

Segmentation of remote sensing images is a critical step in geographic object-based image analysis. Evaluating the performance of segmentation algorithms is essential to identify effective segmentation methods and optimize their parameters. In this study, we propose region-based precision and recall measures and use them to compare two image partitions for the purpose of evaluating segmentation quality. The two measures are calculated based on region overlapping and presented as a point or a curve in a precision-recall space, which can indicate segmentation quality in both geometric and arithmetic respects. Furthermore, the precision and recall measures are combined by using four different methods. We examine and compare the effectiveness of the combined indicators through geometric illustration, in an effort to reveal segmentation quality clearly and capture the trade-off between the two measures. In the experiments, we adopted the multiresolution segmentation (MRS) method for evaluation. The proposed measures are compared with four existing discrepancy measures to further confirm their capabilities. Finally, we suggest using a combination of the region-based precision-recall curve and the F-measure for supervised segmentation evaluation.

High-precision measurement of magnetic penetration depth in superconducting films

DOE PAGES

He, X.; Gozar, A.; Sundling, R.; ...

2016-11-01

We report that the magnetic penetration depth (λ) in thin superconducting films is usually measured by the mutual inductance technique. The accuracy of this method has been limited by uncertainties in the geometry of the solenoids and in the film position and thickness, by parasitic coupling between the coils, etc. Here, we present several improvements in the apparatus and the method. To ensure the precise thickness of the superconducting layer, we engineer the films at atomic level using atomic-layer-by-layer molecular beam epitaxy. In this way, we also eliminate secondary-phase precipitates, grain boundaries, and pinholes that are common with other depositionmore » methods and that artificially increase the field transmission and thus the apparent λ. For better reproducibility, the thermal stability of our closed-cycle cryocooler used to control the temperature of the mutual inductance measurement has been significantly improved by inserting a custom-built thermal conductivity damper. Next, to minimize the uncertainties in the geometry, we fused a pair of small yet precisely wound coils into a single sapphire block machined to a high precision. Lastly, the sample is spring-loaded to exactly the same position with respect to the solenoids. Altogether, we can measure the absolute value of λ with the accuracy better than ±1%.« less

Precision measurement with an optical Josephson junction

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ng, H. T.; Burnett, K.; Dunningham, J. A.

2007-06-15

We present a theoretical study of a type of Josephson device, the so-called 'optical Josephson junction' [Y. Shin et al. Phys. Rev. Lett. 95, 170402 (2005).]. In this device, two condensates are optically coupled through a waveguide by a pair of Bragg beams. This optical Josephson junction differs from the usual Josephson junction where condensates are weakly coupled by tunneling through a barrier. We discuss the use of this optical Josephson junction, for making precision measurements.

CONFERENCE NOTE: Conference on Precision Electromagnetic Measurements

NASA Astrophysics Data System (ADS)

1991-01-01

The next Conference on Precision Electromagnetic Measurements (CPEM), will be held from 9 to 12 June 1992 at the Centre des Nouvelles Industries et Technologies (CNIT), La Défense, Paris, France. This conference, which is held every two years and whose importance and high level, confirmed by thirty years' experience, are recognized throughout the world, can be considered as a forum in which scientists, metrologists and professionals will have the opportunity to present and compare their research results on fundamental constants, standards and new techniques of precision measurement in the electromagnetic domain. Topics The following topics are regarded as the most appropriate for this conference: realization of units and fundamental constants d.c. a.c. and high voltage time and frequency radio-frequency and microwaves dielectrics, antennas, fields lasers, fibre optics advanced instrumentation, cryoelectronics. There will also be a session on international cooperation. Conference Language The conference language will be English. No translation will be provided. Organizers Société des Electriciens et des Electroniciens (SEE). Bureau National de Métrologie (BNM) Sponsors Institute of Electrical and Electronics Engineers (IEEE) Instrumentation & Measurement Society Union Radio Scientifique Internationale United States National Institute of Standards and Technology Centre National d'Etudes des Télécommunications Mouvement Français pour la Qualité, Section Métrologie Comité National Français de Radioélectricité Scientifique Contact Jean Zara, CPEM 92 publicity, Bureau National de Métrologie, 22, rue Monge, 75005 Paris Tel.: (33) 1 46 34 48 16, Fax: (33) 1 46 34 48 63

[Assessment of precision and accuracy of digital surface photogrammetry with the DSP 400 system].

PubMed

Krimmel, M; Kluba, S; Dietz, K; Reinert, S

2005-03-01

The objective of the present study was to evaluate the precision and accuracy of facial anthropometric measurements obtained through digital 3-D surface photogrammetry with the DSP 400 system in comparison to traditional 2-D photogrammetry. Fifty plaster casts of cleft infants were imaged and 21 standard anthropometric measurements were obtained. For precision assessment the measurements were performed twice in a subsample. Accuracy was determined by comparison of direct measurements and indirect 2-D and 3-D image measurements. Precision of digital surface photogrammetry was almost as good as direct anthropometry and clearly better than 2-D photogrammetry. Measurements derived from 3-D images showed better congruence to direct measurements than from 2-D photos. Digital surface photogrammetry with the DSP 400 system is sufficiently precise and accurate for craniofacial anthropometric examinations.

High-Precision Half-Life Measurement for the Superallowed β+ Emitter 22Mg

NASA Astrophysics Data System (ADS)

Dunlop, Michelle

2017-09-01

High precision measurements of the Ft values for superallowed Fermi beta transitions between 0+ isobaric analogue states allow for stringent tests of the electroweak interaction. These transitions provide an experimental probe of the Conserved-Vector-Current hypothesis, the most precise determination of the up-down element of the Cabibbo-Kobayashi-Maskawa matrix, and set stringent limits on the existence of scalar currents in the weak interaction. To calculate the Ft values several theoretical corrections must be applied to the experimental data, some of which have large model dependent variations. Precise experimental determinations of the ft values can be used to help constrain the different models. The uncertainty in the 22Mg superallowed Ft value is dominated by the uncertainty in the experimental ft value. The adopted half-life of 22Mg is determined from two measurements which disagree with one another, resulting in the inflation of the weighted-average half-life uncertainty by a factor of 2. The 22Mg half-life was measured with a precision of 0.02% via direct β counting at TRIUMF's ISAC facility, leading to an improvement in the world-average half-life by more than a factor of 3.

Precision PEP-II optics measurement with an SVD-enhanced Least-Square fitting

NASA Astrophysics Data System (ADS)

Yan, Y. T.; Cai, Y.

2006-03-01

A singular value decomposition (SVD)-enhanced Least-Square fitting technique is discussed. By automatic identifying, ordering, and selecting dominant SVD modes of the derivative matrix that responds to the variations of the variables, the converging process of the Least-Square fitting is significantly enhanced. Thus the fitting speed can be fast enough for a fairly large system. This technique has been successfully applied to precision PEP-II optics measurement in which we determine all quadrupole strengths (both normal and skew components) and sextupole feed-downs as well as all BPM gains and BPM cross-plane couplings through Least-Square fitting of the phase advances and the Local Green's functions as well as the coupling ellipses among BPMs. The local Green's functions are specified by 4 local transfer matrix components R12, R34, R32, R14. These measurable quantities (the Green's functions, the phase advances and the coupling ellipse tilt angles and axis ratios) are obtained by analyzing turn-by-turn Beam Position Monitor (BPM) data with a high-resolution model-independent analysis (MIA). Once all of the quadrupoles and sextupole feed-downs are determined, we obtain a computer virtual accelerator which matches the real accelerator in linear optics. Thus, beta functions, linear coupling parameters, and interaction point (IP) optics characteristics can be measured and displayed.

Study of multi-functional precision optical measuring system for large scale equipment

NASA Astrophysics Data System (ADS)

Jiang, Wei; Lao, Dabao; Zhou, Weihu; Zhang, Wenying; Jiang, Xingjian; Wang, Yongxi

2017-10-01

The effective application of high performance measurement technology can greatly improve the large-scale equipment manufacturing ability. Therefore, the geometric parameters measurement, such as size, attitude and position, requires the measurement system with high precision, multi-function, portability and other characteristics. However, the existing measuring instruments, such as laser tracker, total station, photogrammetry system, mostly has single function, station moving and other shortcomings. Laser tracker needs to work with cooperative target, but it can hardly meet the requirement of measurement in extreme environment. Total station is mainly used for outdoor surveying and mapping, it is hard to achieve the demand of accuracy in industrial measurement. Photogrammetry system can achieve a wide range of multi-point measurement, but the measuring range is limited and need to repeatedly move station. The paper presents a non-contact opto-electronic measuring instrument, not only it can work by scanning the measurement path but also measuring the cooperative target by tracking measurement. The system is based on some key technologies, such as absolute distance measurement, two-dimensional angle measurement, automatically target recognition and accurate aiming, precision control, assembly of complex mechanical system and multi-functional 3D visualization software. Among them, the absolute distance measurement module ensures measurement with high accuracy, and the twodimensional angle measuring module provides precision angle measurement. The system is suitable for the case of noncontact measurement of large-scale equipment, it can ensure the quality and performance of large-scale equipment throughout the process of manufacturing and improve the manufacturing ability of large-scale and high-end equipment.

High-precision measurement of (186)Os/(188)Os and (187)Os/(188)Os: isobaric oxide corrections with in-run measured oxygen isotope ratios.

PubMed

Chu, Zhu-Yin; Li, Chao-Feng; Chen, Zhi; Xu, Jun-Jie; Di, Yan-Kun; Guo, Jing-Hui

2015-09-01

We present a novel method for high precision measurement of (186)Os/(188)Os and (187)Os/(188)Os ratios, applying isobaric oxide interference correction based on in-run measurements of oxygen isotopic ratios. For this purpose, we set up a static data collection routine to measure the main Os(16)O3(-) ion beams with Faraday cups connected to conventional 10(11) amplifiers, and (192)Os(16)O2(17)O(-) and (192)Os(16)O2(18)O(-) ion beams with Faraday cups connected to 10(12) amplifiers. Because of the limited number of Faraday cups, we did not measure (184)Os(16)O3(-) and (189)Os(16)O3(-) simultaneously in-run, but the analytical setup had no significant influence on final (186)Os/(188)Os and (187)Os/(188)Os data. By analyzing UMd, DROsS, an in-house Os solution standard, and several rock reference materials, including WPR-1, WMS-1a, and Gpt-5, the in-run measured oxygen isotopic ratios were proven to present accurate Os isotopic data. However, (186)Os/(188)Os and (187)Os/(188)Os data obtained with in-run O isotopic compositions for the solution standards and rock reference materials show minimal improvement in internal and external precision, compared to the conventional oxygen correction method. We concluded that, the small variations of oxygen isotopes during OsO3(-) analytical sessions are probably not the main source of error for high precision Os isotopic analysis. Nevertheless, use of run-specific O isotopic compositions is still a better choice for Os isotopic data reduction and eliminates the requirement of extra measurements of the oxygen isotopic ratios.

Upgrade of the SPIRAL identification station for high-precision measurements of nuclear β decay

NASA Astrophysics Data System (ADS)

Grinyer, G. F.; Thomas, J. C.; Blank, B.; Bouzomita, H.; Austin, R. A. E.; Ball, G. C.; Bucaille, F.; Delahaye, P.; Finlay, P.; Frémont, G.; Gibelin, J.; Giovinazzo, J.; Grinyer, J.; Kurtukian-Nieto, T.; Laffoley, A. T.; Leach, K. G.; Lefèvre, A.; Legruel, F.; Lescalié, G.; Perez-Loureiro, D.

2014-03-01

The low-energy identification station at SPIRAL (Système de Production d'Ions Radioactifs Accélérés en Ligne) has been upgraded for studying the β decays of short-lived radioactive isotopes and to perform high-precision half-life and branching-ratio measurements for superallowed Fermi and isospin T=1/2 mirror β decays. These new capabilities, combined with an existing Paul trap setup for measurements of β-ν angular-correlation coefficients, provide a powerful facility for investigating fundamental properties of the electroweak interaction through nuclear β decays. A detailed description of the design study, construction, and first results obtained from an in-beam commissioning experiment on the β+ decays 14 O and 17F are presented.

Laser-based measurements of δ13 C and δ2 H methane isotope signatures: precisions competitive with mass spectrometry methods

NASA Astrophysics Data System (ADS)

Yacovitch, Tara; Shorter, Joanne; Nelson, David; Herndon, Scott; Agnese, Mike; McManus, Barry; Zahniser, Mark

2017-04-01

In order to understand how and why methane (CH4 ) concentrations change over time, it is necessary to understand their sources and sinks. Stable isotope measurements of 13 CH4 :12 CH4 and CH3 D:12 CH4 ratios constrain the inventory of these sinks and sources. Current measurements often depend on Isotope Ratio Mass Spectrometry (IRMS), which requires extensive sample preparation including cryogenic separation of methane from air and subsequent conversion to either CO2 or H2 . Here, we detail improvements to a direct-absorption laser spectrometer that enable fast and precise measurements of methane isotope ratios (δ13 C and δ2 H ) of ambient air samples, without such sample preparation. The measurement system consists of a laser-based direct absorption spectrometer configured with a sample manifold for measurement of discrete samples (as opposed to flow-through measurements). Samples are trapped in the instrument using a rapid sample switching technique that compares each flask sample against a monitor tank sample. This approach reduces instrument drift and results in excellent precision. Precisions of 0.054 o/oo for δ13 C and 1.4 o/oo for δ2 H have been achieved (Allan-Werle deviations). These results are obtained in 20 minutes using 4 replicate comparisons to a monitor tank.

Plasmonic micropillars for precision cell force measurement across a large field-of-view

NASA Astrophysics Data System (ADS)

Xiao, Fan; Wen, Ximiao; Tan, Xing Haw Marvin; Chiou, Pei-Yu

2018-01-01

A plasmonic micropillar platform with self-organized gold nanospheres is reported for the precision cell traction force measurement across a large field-of-view (FOV). Gold nanospheres were implanted into the tips of polymer micropillars by annealing gold microdisks with nanosecond laser pulses. Each gold nanosphere is physically anchored in the center of a pillar tip and serves as a strong, point-source-like light scattering center for each micropillar. This allows a micropillar to be clearly observed and precisely tracked even under a low magnification objective lens for the concurrent and precision measurement across a large FOV. A spatial resolution of 30 nm for the pillar deflection measurement has been accomplished on this platform with a 20× objective lens.

Trueness and precision of digital impressions obtained using an intraoral scanner with different head size in the partially edentulous mandible.

PubMed

Hayama, Hironari; Fueki, Kenji; Wadachi, Juro; Wakabayashi, Noriyuki

2018-03-01

It remains unclear whether digital impressions obtained using an intraoral scanner are sufficiently accurate for use in fabrication of removable partial dentures. We therefore compared the trueness and precision between conventional and digital impressions in the partially edentulous mandible. Mandibular Kennedy Class I and III models with soft silicone simulated-mucosa placed on the residual edentulous ridge were used. The reference models were converted to standard triangulated language (STL) file format using an extraoral scanner. Digital impressions were obtained using an intraoral scanner with a large or small scanning head, and converted to STL files. For conventional impressions, pressure impressions of the reference models were made and working casts fabricated using modified dental stone; these were converted to STL file format using an extraoral scanner. Conversion to STL file format was performed 5 times for each method. Trueness and precision were evaluated by deviation analysis using three-dimensional image processing software. Digital impressions had superior trueness (54-108μm), but inferior precision (100-121μm) compared to conventional impressions (trueness 122-157μm, precision 52-119μm). The larger intraoral scanning head showed better trueness and precision than the smaller head, and on average required fewer scanned images of digital impressions than the smaller head (p<0.05). On the color map, the deviation distribution tended to differ between the conventional and digital impressions. Digital impressions are partially comparable to conventional impressions in terms of accuracy; the use of a larger scanning head may improve the accuracy for removable partial denture fabrication. Copyright © 2018 Japan Prosthodontic Society. Published by Elsevier Ltd. All rights reserved.

Interlaboratory comparison of autoradiographic DNA profiling measurements: precision and concordance.

PubMed

Duewer, D L; Lalonde, S A; Aubin, R A; Fourney, R M; Reeder, D J

1998-05-01

Knowledge of the expected uncertainty in restriction fragment length polymorphism (RFLP) measurements is required for confident exchange of such data among different laboratories. The total measurement uncertainty among all Technical Working Group for DNA Analysis Methods laboratories has previously been characterized and found to be acceptably small. Casework cell line control measurements provided by six Royal Canadian Mounted Police (RCMP) and 30 U.S. commercial, local, state, and Federal forensic laboratories enable quantitative determination of the within-laboratory precision and among-laboratory concordance components of measurement uncertainty typical of both sets of laboratories. Measurement precision is the same in the two countries for DNA fragments of size 1000 base pairs (bp) to 10,000 bp. However, the measurement concordance among the RCMP laboratories is clearly superior to that within the U.S. forensic community. This result is attributable to the use of a single analytical protocol in all RCMP laboratories. Concordance among U.S. laboratories cannot be improved through simple mathematical adjustments. Community-wide efforts focused on improved concordance may be the most efficient mechanism for further reduction of among-laboratory RFLP measurement uncertainty, should the resources required to fully evaluate potential cross-jurisdictional matches become burdensome as the number of RFLP profiles on record increases.

A precise measurement of the [Formula: see text] meson oscillation frequency.

PubMed

Aaij, R; Abellán Beteta, C; Adeva, B; Adinolfi, M; Affolder, A; Ajaltouni, Z; Akar, S; Albrecht, J; Alessio, F; Alexander, M; Ali, S; Alkhazov, G; Alvarez Cartelle, P; Alves, A A; Amato, S; Amerio, S; Amhis, Y; An, L; Anderlini, L; Anderson, J; Andreassi, G; Andreotti, M; Andrews, J E; Appleby, R B; Aquines Gutierrez, O; Archilli, F; d'Argent, P; Artamonov, A; Artuso, M; Aslanides, E; Auriemma, G; Baalouch, M; Bachmann, S; Back, J J; Badalov, A; Baesso, C; Baldini, W; Barlow, R J; Barschel, C; Barsuk, S; Barter, W; Batozskaya, V; Battista, V; Bay, A; Beaucourt, L; Beddow, J; Bedeschi, F; Bediaga, I; Bel, L J; Bellee, V; Belloli, N; Belyaev, I; Ben-Haim, E; Bencivenni, G; Benson, S; Benton, J; Berezhnoy, A; Bernet, R; Bertolin, A; Bettler, M-O; van Beuzekom, M; Bien, A; Bifani, S; Billoir, P; Bird, T; Birnkraut, A; Bizzeti, A; Blake, T; Blanc, F; Blouw, J; Blusk, S; Bocci, V; Bondar, A; Bondar, N; Bonivento, W; Borghi, S; Borsato, M; Bowcock, T J V; Bowen, E; Bozzi, C; Braun, S; Britsch, M; Britton, T; Brodzicka, J; Brook, N H; Buchanan, E; Bursche, A; Buytaert, J; Cadeddu, S; Calabrese, R; Calvi, M; Calvo Gomez, M; Campana, P; Campora Perez, D; Capriotti, L; Carbone, A; Carboni, G; Cardinale, R; Cardini, A; Carniti, P; Carson, L; Carvalho Akiba, K; Casse, G; Cassina, L; Castillo Garcia, L; Cattaneo, M; Cauet, Ch; Cavallero, G; Cenci, R; Charles, M; Charpentier, Ph; Chefdeville, M; Chen, S; Cheung, S-F; Chiapolini, N; Chrzaszcz, M; Cid Vidal, X; Ciezarek, G; Clarke, P E L; Clemencic, M; Cliff, H V; Closier, J; Coco, V; Cogan, J; Cogneras, E; Cogoni, V; Cojocariu, L; Collazuol, G; Collins, P; Comerma-Montells, A; Contu, A; Cook, A; Coombes, M; Coquereau, S; Corti, G; Corvo, M; Couturier, B; Cowan, G A; Craik, D C; Crocombe, A; Cruz Torres, M; Cunliffe, S; Currie, R; D'Ambrosio, C; Dall'Occo, E; Dalseno, J; David, P N Y; Davis, A; De Aguiar Francisco, O; De Bruyn, K; De Capua, S; De Cian, M; De Miranda, J M; De Paula, L; De Simone, P; Dean, C-T; Decamp, D; Deckenhoff, M; Del Buono, L; Déléage, N; Demmer, M; Derkach, D; Deschamps, O; Dettori, F; Dey, B; Di Canto, A; Di Ruscio, F; Dijkstra, H; Donleavy, S; Dordei, F; Dorigo, M; Dosil Suárez, A; Dossett, D; Dovbnya, A; Dreimanis, K; Dufour, L; Dujany, G; Dupertuis, F; Durante, P; Dzhelyadin, R; Dziurda, A; Dzyuba, A; Easo, S; Egede, U; Egorychev, V; Eidelman, S; Eisenhardt, S; Eitschberger, U; Ekelhof, R; Eklund, L; El Rifai, I; Elsasser, Ch; Ely, S; Esen, S; Evans, H M; Evans, T; Falabella, A; Färber, C; Farley, N; Farry, S; Fay, R; Ferguson, D; Fernandez Albor, V; Ferrari, F; Ferreira Rodrigues, F; Ferro-Luzzi, M; Filippov, S; Fiore, M; Fiorini, M; Firlej, M; Fitzpatrick, C; Fiutowski, T; Fohl, K; Fol, P; Fontana, M; Fontanelli, F; C Forshaw, D; Forty, R; Frank, M; Frei, C; Frosini, M; Fu, J; Furfaro, E; Gallas Torreira, A; Galli, D; Gallorini, S; Gambetta, S; Gandelman, M; Gandini, P; Gao, Y; García Pardiñas, J; Garra Tico, J; Garrido, L; Gascon, D; Gaspar, C; Gauld, R; Gavardi, L; Gazzoni, G; Gerick, D; Gersabeck, E; Gersabeck, M; Gershon, T; Ghez, Ph; Gianì, S; Gibson, V; Girard, O G; Giubega, L; Gligorov, V V; Göbel, C; Golubkov, D; Golutvin, A; Gomes, A; Gotti, C; Grabalosa Gándara, M; Graciani Diaz, R; Granado Cardoso, L A; Graugés, E; Graverini, E; Graziani, G; Grecu, A; Greening, E; Gregson, S; Griffith, P; Grillo, L; Grünberg, O; Gui, B; Gushchin, E; Guz, Yu; Gys, T; Hadavizadeh, T; Hadjivasiliou, C; Haefeli, G; Haen, C; Haines, S C; Hall, S; Hamilton, B; Han, X; Hansmann-Menzemer, S; Harnew, N; Harnew, S T; Harrison, J; He, J; Head, T; Heijne, V; Heister, A; Hennessy, K; Henrard, P; Henry, L; Hernando Morata, J A; van Herwijnen, E; Heß, M; Hicheur, A; Hill, D; Hoballah, M; Hombach, C; Hulsbergen, W; Humair, T; Hussain, N; Hutchcroft, D; Hynds, D; Idzik, M; Ilten, P; Jacobsson, R; Jaeger, A; Jalocha, J; Jans, E; Jawahery, A; Jing, F; John, M; Johnson, D; Jones, C R; Joram, C; Jost, B; Jurik, N; Kandybei, S; Kanso, W; Karacson, M; Karbach, T M; Karodia, S; Kecke, M; Kelsey, M; Kenyon, I R; Kenzie, M; Ketel, T; Khanji, B; Khurewathanakul, C; Kirn, T; Klaver, S; Klimaszewski, K; Kochebina, O; Kolpin, M; Komarov, I; Koopman, R F; Koppenburg, P; Kozeiha, M; Kravchuk, L; Kreplin, K; Kreps, M; Krocker, G; Krokovny, P; Kruse, F; Krzemien, W; Kucewicz, W; Kucharczyk, M; Kudryavtsev, V; K Kuonen, A; Kurek, K; Kvaratskheliya, T; Lacarrere, D; Lafferty, G; Lai, A; Lambert, D; Lanfranchi, G; Langenbruch, C; Langhans, B; Latham, T; Lazzeroni, C; Le Gac, R; van Leerdam, J; Lees, J-P; Lefèvre, R; Leflat, A; Lefrançois, J; Lemos Cid, E; Leroy, O; Lesiak, T; Leverington, B; Li, Y; Likhomanenko, T; Liles, M; Lindner, R; Linn, C; Lionetto, F; Liu, B; Liu, X; Loh, D; Longstaff, I; Lopes, J H; Lucchesi, D; Lucio Martinez, M; Luo, H; Lupato, A; Luppi, E; Lupton, O; Lusardi, N; Lusiani, A; Machefert, F; Maciuc, F; Maev, O; Maguire, K; Malde, S; Malinin, A; Manca, G; Mancinelli, G; Manning, P; Mapelli, A; Maratas, J; Marchand, J F; Marconi, U; Marin Benito, C; Marino, P; Marks, J; Martellotti, G; Martin, M; Martinelli, M; Martinez Santos, D; Martinez Vidal, F; Martins Tostes, D; Massafferri, A; Matev, R; Mathad, A; Mathe, Z; Matteuzzi, C; Mauri, A; Maurin, B; Mazurov, A; McCann, M; McCarthy, J; McNab, A; McNulty, R; Meadows, B; Meier, F; Meissner, M; Melnychuk, D; Merk, M; Michielin, E; Milanes, D A; Minard, M-N; Mitzel, D S; Molina Rodriguez, J; Monroy, I A; Monteil, S; Morandin, M; Morawski, P; Mordà, A; Morello, M J; Moron, J; Morris, A B; Mountain, R; Muheim, F; Müller, D; Müller, J; Müller, K; Müller, V; Mussini, M; Muster, B; Naik, P; Nakada, T; Nandakumar, R; Nandi, A; Nasteva, I; Needham, M; Neri, N; Neubert, S; Neufeld, N; Neuner, M; Nguyen, A D; Nguyen, T D; Nguyen-Mau, C; Niess, V; Niet, R; Nikitin, N; Nikodem, T; Novoselov, A; O'Hanlon, D P; Oblakowska-Mucha, A; Obraztsov, V; Ogilvy, S; Okhrimenko, O; Oldeman, R; Onderwater, C J G; Osorio Rodrigues, B; Otalora Goicochea, J M; Otto, A; Owen, P; Oyanguren, A; Palano, A; Palombo, F; Palutan, M; Panman, J; Papanestis, A; Pappagallo, M; Pappalardo, L L; Pappenheimer, C; Parkes, C; Passaleva, G; Patel, G D; Patel, M; Patrignani, C; Pearce, A; Pellegrino, A; Penso, G; Pepe Altarelli, M; Perazzini, S; Perret, P; Pescatore, L; Petridis, K; Petrolini, A; Petruzzo, M; Picatoste Olloqui, E; Pietrzyk, B; Pilař, T; Pinci, D; Pistone, A; Piucci, A; Playfer, S; Plo Casasus, M; Poikela, T; Polci, F; Poluektov, A; Polyakov, I; Polycarpo, E; Popov, A; Popov, D; Popovici, B; Potterat, C; Price, E; Price, J D; Prisciandaro, J; Pritchard, A; Prouve, C; Pugatch, V; Puig Navarro, A; Punzi, G; Qian, W; Quagliani, R; Rachwal, B; Rademacker, J H; Rama, M; Rangel, M S; Raniuk, I; Rauschmayr, N; Raven, G; Redi, F; Reichert, S; Reid, M M; Dos Reis, A C; Ricciardi, S; Richards, S; Rihl, M; Rinnert, K; Rives Molina, V; Robbe, P; Rodrigues, A B; Rodrigues, E; Rodriguez Lopez, J A; Rodriguez Perez, P; Roiser, S; Romanovsky, V; Romero Vidal, A; W Ronayne, J; Rotondo, M; Rouvinet, J; Ruf, T; Ruiz Valls, P; Saborido Silva, J J; Sagidova, N; Sail, P; Saitta, B; Salustino Guimaraes, V; Sanchez Mayordomo, C; Sanmartin Sedes, B; Santacesaria, R; Santamarina Rios, C; Santimaria, M; Santovetti, E; Sarti, A; Satriano, C; Satta, A; Saunders, D M; Savrina, D; Schael, S; Schiller, M; Schindler, H; Schlupp, M; Schmelling, M; Schmelzer, T; Schmidt, B; Schneider, O; Schopper, A; Schubiger, M; Schune, M-H; Schwemmer, R; Sciascia, B; Sciubba, A; Semennikov, A; Sergi, A; Serra, N; Serrano, J; Sestini, L; Seyfert, P; Shapkin, M; Shapoval, I; Shcheglov, Y; Shears, T; Shekhtman, L; Shevchenko, V; Shires, A; Siddi, B G; Silva Coutinho, R; Silva de Oliveira, L; Simi, G; Sirendi, M; Skidmore, N; Skwarnicki, T; Smith, E; Smith, E; Smith, I T; Smith, J; Smith, M; Snoek, H; Sokoloff, M D; Soler, F J P; Soomro, F; Souza, D; Souza De Paula, B; Spaan, B; Spradlin, P; Sridharan, S; Stagni, F; Stahl, M; Stahl, S; Stefkova, S; Steinkamp, O; Stenyakin, O; Stevenson, S; Stoica, S; Stone, S; Storaci, B; Stracka, S; Straticiuc, M; Straumann, U; Sun, L; Sutcliffe, W; Swientek, K; Swientek, S; Syropoulos, V; Szczekowski, M; Szczypka, P; Szumlak, T; T'Jampens, S; Tayduganov, A; Tekampe, T; Teklishyn, M; Tellarini, G; Teubert, F; Thomas, C; Thomas, E; van Tilburg, J; Tisserand, V; Tobin, M; Todd, J; Tolk, S; Tomassetti, L; Tonelli, D; Topp-Joergensen, S; Torr, N; Tournefier, E; Tourneur, S; Trabelsi, K; Tran, M T; Tresch, M; Trisovic, A; Tsaregorodtsev, A; Tsopelas, P; Tuning, N; Ukleja, A; Ustyuzhanin, A; Uwer, U; Vacca, C; Vagnoni, V; Valenti, G; Vallier, A; Vazquez Gomez, R; Vazquez Regueiro, P; Vázquez Sierra, C; Vecchi, S; van Veghel, M; Velthuis, J J; Veltri, M; Veneziano, G; Vesterinen, M; Viaud, B; Vieira, D; Vieites Diaz, M; Vilasis-Cardona, X; Vollhardt, A; Volyanskyy, D; Voong, D; Vorobyev, A; Vorobyev, V; Voß, C; de Vries, J A; Waldi, R; Wallace, C; Wallace, R; Walsh, J; Wandernoth, S; Wang, J; Ward, D R; Watson, N K; Websdale, D; Weiden, A; Whitehead, M; Wilkinson, G; Wilkinson, M; Williams, M; Williams, M P; Williams, M; Williams, T; Wilson, F F; Wimberley, J; Wishahi, J; Wislicki, W; Witek, M; Wormser, G; Wotton, S A; Wright, S; Wyllie, K; Xie, Y; Xu, Z; Yang, Z; Yu, J; Yuan, X; Yushchenko, O; Zangoli, M; Zavertyaev, M; Zhang, L; Zhang, Y; Zhelezov, A; Zhokhov, A; Zhong, L; Zhukov, V; Zucchelli, S

2016-01-01

The oscillation frequency, [Formula: see text], of [Formula: see text] mesons is measured using semileptonic decays with a [Formula: see text] or [Formula: see text] meson in the final state. The data sample corresponds to 3.0[Formula: see text] of pp collisions, collected by the LHCb experiment at centre-of-mass energies [Formula: see text] = 7 and 8[Formula: see text]. A combination of the two decay modes gives [Formula: see text], where the first uncertainty is statistical and the second is systematic. This is the most precise single measurement of this parameter. It is consistent with the current world average and has similar precision.

Precise measurement of dielectric anisotropy in ice Ih at 39 GHz

NASA Astrophysics Data System (ADS)

Matsuoka, Takeshi; Fujita, Shuji; Morishima, Shigenori; Mae, Shinji

1997-03-01

The dielectric permittivities parallel and perpendicular to the c axis (optic axis) of ice Ih were measured using an open resonator at 39 GHz in the temperature range 194-262 K. The dielectric anisotropy in ice at microwave frequencies is important for understanding remote sensing data in polar regions, obtained by ice radar and satellite-born microwave radar and radiometer. The measured samples were natural single-crystal ice collected from Mendenhall Glacier, Alaska. A very precise measurement was achieved by detecting two resonant peaks, one from the ordinary component and the other from the extraordinary component, simultaneously, from one sample. The real part of dielectric anisotropy, Δɛ'=ɛ∥c'-ɛ⊥c', at 39 GHz was 0.0339±0.0007 (1.07%±0.02%) at 252 K and slightly depended on temperature. Reference measurements at 1 MHz using parallel plate electrodes were also carried out. The measured dielectric anisotropy at microwave frequencies agrees very well with the value at 1 MHz. The absolute values of ɛ∥c' and ɛ⊥c' at 39 GHz were, respectively, smaller than those at 1 MHz and the difference was about 0.044 at 252 K. The results suggest that a small dispersion exists between GHz and MHz frequencies, but there is no frequency dependence in the value of anisotropy.

High precision isotope ratio measurements of mercury isotopes in cinnabar ores using multi-collector inductively coupled plasma mass spectrometry.

PubMed

Hintelmann, Holger; Lu, ShengYong

2003-06-01

Variations in Hg isotope ratios in cinnabar ores obtained from different countries were detected by high precision isotope ratio measurements using multi-collector inductively coupled mass spectrometry (MC-ICP-MS). Values of delta198/202Hg varied from 0.0-1.3 percent per thousand relative to a NIST SRM 1641d Hg solution. The typical external uncertainty of the delta values was 0.06 to 0.26 percent per thousand. Hg was introduced into the plasma as elemental Hg after reduction by sodium borohydride. A significant fractionation of lead isotopes was observed during the simultaneous generation of lead hydride, preventing normalization of the Hg isotope ratios using the measured 208/206Pb ratio. Hg ratios were instead corrected employing the simultaneously measured 205/203T1 ratio. Using a 10 ng ml(-1) Hg solution and 10 min of sampling, introducing 60 ng of Hg, the internal precision of the isotope ratio measurements was as low as 14 ppm. Absolute Hg ratios deviated from the representative IUPAC values by approximately 0.2% per u. This observation is explained by the inadequacy of the exponential law to correct for mass bias in MC-ICP-MS measurements. In the absence of a precisely characterized Hg isotope ratio standard, we were not able to determine unambiguously the absolute Hg ratios of the ore samples, highlighting the urgent need for certified standard materials.

Precision half-life measurement of 11C: The most precise mirror transition F t value

NASA Astrophysics Data System (ADS)

Valverde, A. A.; Brodeur, M.; Ahn, T.; Allen, J.; Bardayan, D. W.; Becchetti, F. D.; Blankstein, D.; Brown, G.; Burdette, D. P.; Frentz, B.; Gilardy, G.; Hall, M. R.; King, S.; Kolata, J. J.; Long, J.; Macon, K. T.; Nelson, A.; O'Malley, P. D.; Skulski, M.; Strauss, S. Y.; Vande Kolk, B.

2018-03-01

Background: The precise determination of the F t value in T =1 /2 mixed mirror decays is an important avenue for testing the standard model of the electroweak interaction through the determination of Vu d in nuclear β decays. 11C is an interesting case, as its low mass and small QE C value make it particularly sensitive to violations of the conserved vector current hypothesis. The present dominant source of uncertainty in the 11CF t value is the half-life. Purpose: A high-precision measurement of the 11C half-life was performed, and a new world average half-life was calculated. Method: 11C was created by transfer reactions and separated using the TwinSol facility at the Nuclear Science Laboratory at the University of Notre Dame. It was then implanted into a tantalum foil, and β counting was used to determine the half-life. Results: The new half-life, t1 /2=1220.27 (26 ) s, is consistent with the previous values but significantly more precise. A new world average was calculated, t1/2 world=1220.41 (32 ) s, and a new estimate for the Gamow-Teller to Fermi mixing ratio ρ is presented along with standard model correlation parameters. Conclusions: The new 11C world average half-life allows the calculation of a F tmirror value that is now the most precise value for all superallowed mixed mirror transitions. This gives a strong impetus for an experimental determination of ρ , to allow for the determination of Vu d from this decay.

Precision Measurement of Distribution of Film Thickness on Pendulum for Experiment of G

NASA Astrophysics Data System (ADS)

Liu, Lin-Xia; Guan, Sheng-Guo; Liu, Qi; Zhang, Ya-Ting; Shao, Cheng-Gang; Luo, Jun

2009-09-01

Distribution of film thickness coated on the pendulum of measuring the Newton gravitational constant G is determined with a weighing method by means of a precision mass comparator. The experimental result shows that the gold film on the pendulum will contribute a correction of -24.3 ppm to our G measurement with an uncertainty of 4.3 ppm, which is significant for improving the G value with high precision.

Precise measurement of energy of the first excited state of 115Sn (Eexc ≃ 497.3 keV)

NASA Astrophysics Data System (ADS)

Zheltonozhsky, V. A.; Savrasov, A. M.; Strilchuk, N. V.; Tretyak, V. I.

2018-01-01

Single beta decay of 115In to the first excited level of 115Sn (E\\text{exc}≃ 497.3 \\text{keV} ) is known as β-decay with the lowest Qβ value. To determine the Qβ precisely, one has to measure very accurately the E\\text{exc} value. A sample of tin enriched in 115Sn to 50.7% was irradiated by a proton beam at the U-120 accelerator of INR, Kyiv. The 115Sb radioactive isotope, created in the 115Sn(p,n)115Sb reaction, decays with T1/2 = 32 \\text{min} to 115Sn populating the 497 keV level with ≃ 96{%} probability. The total statistics of ˜105 counts collected in the 497 keV peak in a series of measurements, the exact description of the peak shape and the precisely known calibration points around the 497 keV peak allowed to obtain the value E\\text{exc}= 497.342(3) \\text{keV} , which is the most precise to-date. This leads to the following Qβ\\ast value for the decay 115In → 115Sn*: Qβ\\ast= 147 +/- 10 \\text{eV} .

Precision analysis for standard deviation measurements of immobile single fluorescent molecule images.

PubMed

DeSantis, Michael C; DeCenzo, Shawn H; Li, Je-Luen; Wang, Y M

2010-03-29

Standard deviation measurements of intensity profiles of stationary single fluorescent molecules are useful for studying axial localization, molecular orientation, and a fluorescence imaging system's spatial resolution. Here we report on the analysis of the precision of standard deviation measurements of intensity profiles of single fluorescent molecules imaged using an EMCCD camera.We have developed an analytical expression for the standard deviation measurement error of a single image which is a function of the total number of detected photons, the background photon noise, and the camera pixel size. The theoretical results agree well with the experimental, simulation, and numerical integration results. Using this expression, we show that single-molecule standard deviation measurements offer nanometer precision for a large range of experimental parameters.

Precise measurement of the top quark mass in the dilepton channel at D0.

PubMed

Abazov, V M; Abbott, B; Acharya, B S; Adams, M; Adams, T; Alexeev, G D; Alkhazov, G; Alton, A; Alverson, G; Alves, G A; Ancu, L S; Aoki, M; Arov, M; Askew, A; Åsman, B; Atramentov, O; Avila, C; BackusMayes, J; Badaud, F; Bagby, L; Baldin, B; Bandurin, D V; Banerjee, S; Barberis, E; Baringer, P; Barreto, J; Bartlett, J F; Bassler, U; Bazterra, V; Beale, S; Bean, A; Begalli, M; Begel, M; Belanger-Champagne, C; Bellantoni, L; Beri, S B; Bernardi, G; Bernhard, R; Bertram, I; Besançon, M; Beuselinck, R; Bezzubov, V A; Bhat, P C; Bhatnagar, V; Blazey, G; Blessing, S; Bloom, K; Boehnlein, A; Boline, D; Boos, E E; Borissov, G; Bose, T; Brandt, A; Brandt, O; Brock, R; Brooijmans, G; Bross, A; Brown, D; Brown, J; Bu, X B; Buehler, M; Buescher, V; Bunichev, V; Burdin, S; Burnett, T H; Buszello, C P; Calpas, B; Camacho-Pérez, E; Carrasco-Lizarraga, M A; Casey, B C K; Castilla-Valdez, H; Chakrabarti, S; Chakraborty, D; Chan, K M; Chandra, A; Chen, G; Chevalier-Théry, S; Cho, D K; Cho, S W; Choi, S; Choudhary, B; Cihangir, S; Claes, D; Clutter, J; Cooke, M; Cooper, W E; Corcoran, M; Couderc, F; Cousinou, M-C; Croc, A; Cutts, D; Das, A; Davies, G; De, K; de Jong, S J; De la Cruz-Burelo, E; Déliot, F; Demarteau, M; Demina, R; Denisov, D; Denisov, S P; Desai, S; Deterre, C; DeVaughan, K; Diehl, H T; Diesburg, M; Dominguez, A; Dorland, T; Dubey, A; Dudko, L V; Duggan, D; Duperrin, A; Dutt, S; Dyshkant, A; Eads, M; Edmunds, D; Ellison, J; Elvira, V D; Enari, Y; Evans, H; Evdokimov, A; Evdokimov, V N; Facini, G; Ferbel, T; Fiedler, F; Filthaut, F; Fisher, W; Fisk, H E; Fortner, M; Fox, H; Fuess, S; Garcia-Bellido, A; Gavrilov, V; Gay, P; Geng, W; Gerbaudo, D; Gerber, C E; Gershtein, Y; Ginther, G; Golovanov, G; Goussiou, A; Grannis, P D; Greder, S; Greenlee, H; Greenwood, Z D; Gregores, E M; Grenier, G; Gris, Ph; Grivaz, J-F; Grohsjean, A; Grünendahl, S; Grünewald, M W; Guillemin, T; Guo, F; Gutierrez, G; Gutierrez, P; Haas, A; Hagopian, S; Haley, J; Han, L; Harder, K; Harel, A; Hauptman, J M; Hays, J; Head, T; Hebbeker, T; Hedin, D; Hegab, H; Heinson, A P; Heintz, U; Hensel, C; Heredia-De la Cruz, I; Herner, K; Hesketh, G; Hildreth, M D; Hirosky, R; Hoang, T; Hobbs, J D; Hoeneisen, B; Hohlfeld, M; Hubacek, Z; Huske, N; Hynek, V; Iashvili, I; Illingworth, R; Ito, A S; Jabeen, S; Jaffré, M; Jamin, D; Jayasinghe, A; Jesik, R; Johns, K; Johnson, M; Johnston, D; Jonckheere, A; Jonsson, P; Joshi, J; Jung, A W; Juste, A; Kaadze, K; Kajfasz, E; Karmanov, D; Kasper, P A; Katsanos, I; Kehoe, R; Kermiche, S; Khalatyan, N; Khanov, A; Kharchilava, A; Kharzheev, Y N; Khatidze, D; Kirby, M H; Kohli, J M; Kozelov, A V; Kraus, J; Kulikov, S; Kumar, A; Kupco, A; Kurča, T; Kuzmin, V A; Kvita, J; Lammers, S; Landsberg, G; Lebrun, P; Lee, H S; Lee, S W; Lee, W M; Lellouch, J; Li, L; Li, Q Z; Lietti, S M; Lim, J K; Lincoln, D; Linnemann, J; Lipaev, V V; Lipton, R; Liu, Y; Liu, Z; Lobodenko, A; Lokajicek, M; Lopes de Sa, R; Lubatti, H J; Luna-Garcia, R; Lyon, A L; Maciel, A K A; Mackin, D; Madar, R; Magaña-Villalba, R; Malik, S; Malyshev, V L; Maravin, Y; Martínez-Ortega, J; McCarthy, R; McGivern, C L; Meijer, M M; Melnitchouk, A; Menezes, D; Mercadante, P G; Merkin, M; Meyer, A; Meyer, J; Miconi, F; Mondal, N K; Muanza, G S; Mulhearn, M; Nagy, E; Naimuddin, M; Narain, M; Nayyar, R; Neal, H A; Negret, J P; Neustroev, P; Novaes, S F; Nunnemann, T; Obrant, G; Orduna, J; Osman, N; Osta, J; Otero y Garzón, G J; Padilla, M; Pal, A; Parashar, N; Parihar, V; Park, S K; Parsons, J; Partridge, R; Parua, N; Patwa, A; Penning, B; Perfilov, M; Peters, K; Peters, Y; Petridis, K; Petrillo, G; Pétroff, P; Piegaia, R; Piper, J; Pleier, M-A; Podesta-Lerma, P L M; Podstavkov, V M; Polozov, P; Popov, A V; Prewitt, M; Price, D; Prokopenko, N; Protopopescu, S; Qian, J; Quadt, A; Quinn, B; Rangel, M S; Ranjan, K; Ratoff, P N; Razumov, I; Renkel, P; Rijssenbeek, M; Ripp-Baudot, I; Rizatdinova, F; Rominsky, M; Ross, A; Royon, C; Rubinov, P; Ruchti, R; Safronov, G; Sajot, G; Salcido, P; Sánchez-Hernández, A; Sanders, M P; Sanghi, B; Santos, A S; Savage, G; Sawyer, L; Scanlon, T; Schamberger, R D; Scheglov, Y; Schellman, H; Schliephake, T; Schlobohm, S; Schwanenberger, C; Schwienhorst, R; Sekaric, J; Severini, H; Shabalina, E; Shary, V; Shchukin, A A; Shivpuri, R K; Simak, V; Sirotenko, V; Skubic, P; Slattery, P; Smirnov, D; Smith, K J; Snow, G R; Snow, J; Snyder, S; Söldner-Rembold, S; Sonnenschein, L; Soustruznik, K; Stark, J; Stolin, V; Stoyanova, D A; Strauss, M; Strom, D; Stutte, L; Suter, L; Svoisky, P; Takahashi, M; Tanasijczuk, A; Taylor, W; Titov, M; Tokmenin, V V; Tsai, Y-T; Tsybychev, D; Tuchming, B; Tully, C; Uvarov, L; Uvarov, S; Uzunyan, S; Van Kooten, R; van Leeuwen, W M; Varelas, N; Varnes, E W; Vasilyev, I A; Verdier, P; Vertogradov, L S; Verzocchi, M; Vesterinen, M; Vilanova, D; Vokac, P; Wahl, H D; Wang, M H L S; Warchol, J; Watts, G; Wayne, M; Weber, M; Welty-Rieger, L; White, A; Wicke, D; Williams, M R J; Wilson, G W; Wobisch, M; Wood, D R; Wyatt, T R; Xie, Y; Xu, C; Yacoob, S; Yamada, R; Yang, W-C; Yasuda, T; Yatsunenko, Y A; Ye, Z; Yin, H; Yip, K; Youn, S W; Yu, J; Zelitch, S; Zhao, T; Zhou, B; Zhu, J; Zielinski, M; Zieminska, D; Zivkovic, L

2011-08-19

We measure the top quark mass (m(t)) in p ̄p collisions at a center of mass energy √s = 1.96 TeV using dilepton t ̄t→W(+)bW(-) ̄b→ℓ(+)ν(ℓ)bℓ(-) ̄ν(ℓ) ̄b events, where ℓ denotes an electron, a muon, or a tau that decays leptonically. The data correspond to an integrated luminosity of 5.4 fb(-1) collected with the D0 detector at the Fermilab Tevatron Collider. We obtain m(t)=174.0±1.8(stat)±2.4(syst) GeV, which is in agreement with the current world average m(t)=173.3±1.1 GeV. This is currently the most precise measurement of m(t) in the dilepton channel. © 2011 American Physical Society

Performance of Planar-Waveguide External Cavity Laser for Precision Measurements

NASA Technical Reports Server (NTRS)

Numata, Kenji; Camp, Jordan; Krainak, Michael A.; Stolpner, Lew

2010-01-01

A 1542-nm planar-waveguide external cavity laser (PW-ECL) is shown to have a sufficiently low level of frequency and intensity noise to be suitable for precision measurement applications. The frequency noise and intensity noise of the PW-ECL was comparable or better than the nonplanar ring oscillator (NPRO) and fiber laser between 0.1 mHz to 100 kHz. Controllability of the PW-ECL was demonstrated by stabilizing its frequency to acetylene (13C2H2) at 10(exp -13) level of Allan deviation. The PW-ECL also has the advantage of the compactness of a standard butterfly package, low cost, and a simple design consisting of a semiconductor gain media coupled to a planar-waveguide Bragg reflector. These features would make the PW-ECL suitable for precision measurements, including compact optical frequency standards, space lidar, and space interferometry

Precision Spectroscopy, Diode Lasers, and Optical Frequency Measurement Technology

NASA Technical Reports Server (NTRS)

Hollberg, Leo (Editor); Fox, Richard (Editor); Waltman, Steve (Editor); Robinson, Hugh

1998-01-01

This compilation is a selected set of reprints from the Optical Frequency Measurement Group of the Time and Frequency Division of the National Institute of Standards and Technology, and consists of work published between 1987 and 1997. The two main programs represented here are (1) development of tunable diode-laser technology for scientific applications and precision measurements, and (2) research toward the goal of realizing optical-frequency measurements and synthesis. The papers are organized chronologically in five, somewhat arbitrarily chosen categories: Diode Laser Technology, Tunable Laser Systems, Laser Spectroscopy, Optical Synthesis and Extended Wavelength Coverage, and Multi-Photon Interactions and Optical Coherences.

Inferring the gravitational potential of the Milky Way with a few precisely measured stars

DOE Office of Scientific and Technical Information (OSTI.GOV)

Price-Whelan, Adrian M.; Johnston, Kathryn V.; Hendel, David

2014-10-10

The dark matter halo of the Milky Way is expected to be triaxial and filled with substructure. It is hoped that streams or shells of stars produced by tidal disruption of stellar systems will provide precise measures of the gravitational potential to test these predictions. We develop a method for inferring the Galactic potential with tidal streams based on the idea that the stream stars were once close in phase space. Our method can flexibly adapt to any form for the Galactic potential: it works in phase-space rather than action-space and hence relies neither on our ability to derive actionsmore » nor on the integrability of the potential. Our model is probabilistic, with a likelihood function and priors on the parameters. The method can properly account for finite observational uncertainties and missing data dimensions. We test our method on synthetic data sets generated from N-body simulations of satellite disruption in a static, multi-component Milky Way, including a triaxial dark matter halo with observational uncertainties chosen to mimic current and near-future surveys of various stars. We find that with just eight well-measured stream stars, we can infer properties of a triaxial potential with precisions of the order of 5%-7%. Without proper motions, we obtain 10% constraints on most potential parameters and precisions around 5%-10% for recovering missing phase-space coordinates. These results are encouraging for the goal of using flexible, time-dependent potential models combined with larger data sets to unravel the detailed shape of the dark matter distribution around the Milky Way.« less

KamLAND's precision neutrino oscillation measurements

DOE PAGES

Decowski, M. P.

2016-04-13

The KamLAND experiment started operation in the Spring of 2002 and is operational to this day. The experiment observes signals from electron antineutrinos from distant nuclear reactors. The program, spanning more than a decade, allowed the determination of LMA-MSW as the solution to the solar neutrino transformation results (under the assumption of CPT invariance) and the measurement of various neutrino oscillation parameters. In particular, the solar mass-splitting Δm 2 21 was determined to high precision. Besides the study of neutrino oscillation, KamLAND started the investigation of geologically produced antineutrinos (geo- ν¯ e). As a result, the collaboration also reported onmore » a variety of other topics related to particle and astroparticle physics.« less

Applications of an automated stem measurer for precision forestry

Treesearch

N. Clark

2001-01-01

Accurate stem measurements are required for the determination of many silvicultural prescriptions, i.e., what are we going to do with a stand of trees. This would only be amplified in a precision forestry context. Many methods have been proposed for optimal ways to evaluate stems for a variety of characteristics. These methods usually involve the acquisition of total...

High-precision measurement of variations in calcium isotope ratios in urine by multiple collector inductively coupled plasma mass spectrometry

USGS Publications Warehouse

Morgan, J.L.L.; Gordon, G.W.; Arrua, R.C.; Skulan, J.L.; Anbar, A.D.; Bullen, T.D.

2011-01-01

We describe a new chemical separation method to isolate Ca from other matrix elements in biological samples, developed with the long-term goal of making high-precision measurement of natural stable Ca isotope variations a clinically applicable tool to assess bone mineral balance. A new two-column procedure utilizing HBr achieves the purity required to accurately and precisely measure two Ca isotope ratios (44Ca/42Ca and 44Ca/43Ca) on a Neptune multiple collector inductively coupled plasma mass spectrometer (MC-ICPMS) in urine. Purification requirements for Sr, Ti, and K (Ca/Sr > 10000; Ca/Ti > 10000000; and Ca/K > 10) were determined by addition of these elements to Ca standards of known isotopic composition. Accuracy was determined by (1) comparing Ca isotope results for samples and standards to published data obtained using thermal ionization mass spectrometry (TIMS), (2) adding a Ca standard of known isotopic composition to a urine sample purified of Ca, and (3) analyzing mixtures of urine samples and standards in varying proportions. The accuracy and precision of δ44/42Ca measurements of purified samples containing 25 μg of Ca can be determined with typical errors less than ±0.2‰ (2σ).

New instrumentation for precise (n,γ) measurements at ILL Grenoble

NASA Astrophysics Data System (ADS)

Urban, W.; Jentschel, M.; Märkisch, B.; Materna, Th; Bernards, Ch; Drescher, C.; Fransen, Ch; Jolie, J.; Köster, U.; Mutti, P.; Rzaca-Urban, T.; Simpson, G. S.

2013-03-01

An array of eight Ge detectors for coincidence measurements of γ rays from neutron-capture reactions has been constructed at the PF1B cold-neutron facility of the Institut Laue-Langevin. The detectors arranged in one plane every 45° can be used for angular correlation measurements. The neutron collimation line of the setup provides a neutron beam of 12 mm in diameter and the capture flux of about 108/(s × cm2) at the target position, with a negligible neutron halo. With the setup up to 109 γγ and up to 108 triple-γ coincidence events have been collected in a day measurement. Precise energy and efficiency calibrations up to 10 MeV are easily performed with 27Al(n,γ)28Al and 35Cl(n,γ)36Cl reactions. Test measurements have shown that neutron binding energies can be determined with an accuracy down to a few eV and angular correlation coefficients measured with a precision down to a percent level. The triggerless data collected with a digital electronics and acquisition allows to determine half-lives of excited levels in the nano- to microsecond range. The high resolving power of double- and triple-γ time coincidences allows significant improvements of excitation schemes reported in previous (n,γ) works and complements high-resolution γ-energy measurements at the double-crystal Bragg spectrometer GAMS of ILL.

Precise measurement of ultra-narrow laser linewidths using the strong coherent envelope

NASA Astrophysics Data System (ADS)

Huang, Shihong; Zhu, Tao; Liu, Min; Huang, Wei

2017-02-01

Laser linewidth narrowing down to kHz or even Hz is an important topic in areas like clock synchronization technology, laser radars, quantum optics, and high-precision detection. Conventional decoherence measurement methods like delayed self-heterodyne/homodyne interferometry cannot measure such narrow linewidths accurately. This is because a broadening of the Gaussian spectrum, which hides the laser’s intrinsic Lorentzian linewidth, cannot be avoided. Here, we introduce a new method using the strong coherent envelope to characterize the laser’s intrinsic linewidth through self-coherent detection. This method can eliminate the effect of the broadened Gaussian spectrum induced by the 1/f frequency noise. We analyze, in detail, the relationship between intrinsic laser linewidth, contrast difference with the second peak and the second trough (CDSPST) of the strong coherent envelope, and the length of the delaying fiber. The correct length for the delaying fiber can be chosen by combining the estimated laser linewidth (Δfest) with a specific CDSPST (ΔS) to obtain the accurate laser linewidth (Δf). Our results indicate that this method can be used as an accurate detection tool for measurements of narrow or super-narrow linewidths.

Possibility of New Precise Measurements of Muonic Helium Atom HFS at J-PARC MUSE

NASA Astrophysics Data System (ADS)

Strasser, P.; Shimomura, K.; Torii, H. A.

We propose the next generation of precision microwave spectroscopy measurements of the ground state hyperfine structure (HFS) of the muonic helium atom. The HFS interval is a sensitive tool to test three-body atomic system and bound-state QED theory as well as precise direct determination of the negative muon magnetic moment and hence its mass. Previous measurements performed in 1980s at PSI and LAMPF had uncertainties dominated by statistical errors. The new high-intensity pulsed negative muon beam at J-PARC MUSE give an opportunity to improve these measurements by nearly two orders of magnitude for the HFS interval, and almost tenfold for the negative muon mass, thus providing a more precise test of CPT invariance and determination of the negative counterpart of the anomalous g-factor for the existing BNL muon g-2 experiment. Both measurements at zero field and at high magnetic field are considered. An overview of the different aspects of these new muonic helium HFS measurements is presented.

High precision measurements of 26Naβ- decay

NASA Astrophysics Data System (ADS)

Grinyer, G. F.; Svensson, C. E.; Andreoiu, C.; Andreyev, A. N.; Austin, R. A.; Ball, G. C.; Chakrawarthy, R. S.; Finlay, P.; Garrett, P. E.; Hackman, G.; Hardy, J. C.; Hyland, B.; Iacob, V. E.; Koopmans, K. A.; Kulp, W. D.; Leslie, J. R.; MacDonald, J. A.; Morton, A. C.; Ormand, W. E.; Osborne, C. J.; Pearson, C. J.; Phillips, A. A.; Sarazin, F.; Schumaker, M. A.; Scraggs, H. C.; Schwarzenberg, J.; Smith, M. B.; Valiente-Dobón, J. J.; Waddington, J. C.; Wood, J. L.; Zganjar, E. F.

2005-04-01

High-precision measurements of the half-life and β-branching ratios for the β- decay of 26Na to 26Mg have been measured in β-counting and γ-decay experiments, respectively. A 4π proportional counter and fast tape transport system were employed for the half-life measurement, whereas the γ rays emitted by the daughter nucleus 26Mg were detected with the 8π γ-ray spectrometer, both located at TRIUMF's isotope separator and accelerator radioactive beam facility. The half-life of 26Na was determined to be T1/2=1.07128±0.00013±0.00021s, where the first error is statistical and the second systematic. The logft values derived from these experiments are compared with theoretical values from a full sd-shell model calculation.

High-Precision Half-Life Measurement for the Superallowed β+ Emitter Alm26

NASA Astrophysics Data System (ADS)

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

2011-01-01

A high-precision half-life measurement for the superallowed β+ emitter Alm26 was performed at the TRIUMF-ISAC radioactive ion beam facility yielding T1/2=6346.54±0.46stat±0.60systms, consistent with, but 2.5 times more precise than, the previous world average. The Alm26 half-life and ft value, 3037.53(61) s, are now the most precisely determined for any superallowed β decay. Combined with recent theoretical corrections for isospin-symmetry-breaking and radiative effects, the corrected Ft value for Alm26, 3073.0(12) s, sets a new benchmark for the high-precision superallowed Fermi β-decay studies used to test the conserved vector current hypothesis and determine the Vud element of the Cabibbo-Kobayashi-Maskawa quark mixing matrix.

A GPS measurement system for precise satellite tracking and geodesy

NASA Technical Reports Server (NTRS)

Yunck, T. P.; Wu, S.-C.; Lichten, S. M.

1985-01-01

NASA is pursuing two key applications of differential positioning with the Global Positioning System (GPS): sub-decimeter tracking of earth satellites and few-centimeter determination of ground-fixed baselines. Key requirements of the two applications include the use of dual-frequency carrier phase data, multiple ground receivers to serve as reference points, simultaneous solution for use position and GPS orbits, and calibration of atmospheric delays using water vapor radiometers. Sub-decimeter tracking will be first demonstrated on the TOPEX oceanographic satellite to be launched in 1991. A GPS flight receiver together with at least six ground receivers will acquire delta range data from the GPS carriers for non-real-time analysis. Altitude accuracies of 5 to 10 cm are expected. For baseline measurements, efforts will be made to obtain precise differential pseudorange by resolving the cycle ambiguity in differential carrier phase. This could lead to accuracies of 2 or 3 cm over a few thousand kilometers. To achieve this, a high-performance receiver is being developed, along with improved calibration and data processing techniques. Demonstrations may begin in 1986.

Precision flux density measurements of the giant planets at 8420 MHz

NASA Technical Reports Server (NTRS)

Turegano, J. A.; Klein, M. J.

1981-01-01

Precision measurements of the 3.56 cm flux densities of Jupiter, Saturn, Uranus, and Neptune are reported. The results are compared with previously published measurements as a means of: (1) remotely sensing long-term changes in the microwave emission from the atmospheres of these planets; (2) measuring the effects of Saturn's rings on the disk temperature as observed from earth at different ring inclination angles.

Precision flux density measurements of the giant planets at 8420 MHz

NASA Technical Reports Server (NTRS)

Turegano, J. A.; Klein, M. J.

1981-01-01

Precision measurements of the 3.56 cm flux densities of Jupiter, Saturn, Uranus, and Neptune are reported. The results are compared with previously published measurements as a means of: remotely sensing long-term changes in the microwave emission from the atmospheres of these planets and measuring the effects of Saturn's rings on the disk temperature as observed from earth at different ring inclination angles.

Precision Measurements of Long-Baseline Neutrino Oscillation at LBNF

DOE PAGES

Worcester, Elizabeth

2015-08-06

In a long-baseline neutrino oscillation experiment, the primary physics objectives are to determine the neutrino mass hierarchy, to determine the octant of the neutrino mixing angle θ 23, to search for CP violation in neutrino oscillation, and to precisely measure the size of any CP-violating effect that is discovered. This presentation provides a brief introduction to these measurements and reports on efforts to optimize the design of a long-baseline neutrino oscillation experiment, the status of LBNE, and the transition to an international collaboration at LBNF.

Precise orbit determination based on raw GPS measurements

NASA Astrophysics Data System (ADS)

Zehentner, Norbert; Mayer-Gürr, Torsten

2016-03-01

Precise orbit determination is an essential part of the most scientific satellite missions. Highly accurate knowledge of the satellite position is used to geolocate measurements of the onboard sensors. For applications in the field of gravity field research, the position itself can be used as observation. In this context, kinematic orbits of low earth orbiters (LEO) are widely used, because they do not include a priori information about the gravity field. The limiting factor for the achievable accuracy of the gravity field through LEO positions is the orbit accuracy. We make use of raw global positioning system (GPS) observations to estimate the kinematic satellite positions. The method is based on the principles of precise point positioning. Systematic influences are reduced by modeling and correcting for all known error sources. Remaining effects such as the ionospheric influence on the signal propagation are either unknown or not known to a sufficient level of accuracy. These effects are modeled as unknown parameters in the estimation process. The redundancy in the adjustment is reduced; however, an improvement in orbit accuracy leads to a better gravity field estimation. This paper describes our orbit determination approach and its mathematical background. Some examples of real data applications highlight the feasibility of the orbit determination method based on raw GPS measurements. Its suitability for gravity field estimation is presented in a second step.

High-Precision Measurement of the Ne19 Half-Life and Implications for Right-Handed Weak Currents

NASA Astrophysics Data System (ADS)

Triambak, S.; Finlay, P.; Sumithrarachchi, C. S.; Hackman, G.; Ball, G. C.; Garrett, P. E.; Svensson, C. E.; Cross, D. S.; Garnsworthy, A. B.; Kshetri, R.; Orce, J. N.; Pearson, M. R.; Tardiff, E. R.; Al-Falou, H.; Austin, R. A. E.; Churchman, R.; Djongolov, M. K.; D'Entremont, R.; Kierans, C.; Milovanovic, L.; O'Hagan, S.; Reeve, S.; Sjue, S. K. L.; Williams, S. J.

2012-07-01

We report a precise determination of the Ne19 half-life to be T1/2=17.262±0.007s. This result disagrees with the most recent precision measurements and is important for placing bounds on predicted right-handed interactions that are absent in the current standard model. We are able to identify and disentangle two competing systematic effects that influence the accuracy of such measurements. Our findings prompt a reassessment of results from previous high-precision lifetime measurements that used similar equipment and methods.

High-precision measurement of the 19Ne half-life and implications for right-handed weak currents.

PubMed

Triambak, S; Finlay, P; Sumithrarachchi, C S; Hackman, G; Ball, G C; Garrett, P E; Svensson, C E; Cross, D S; Garnsworthy, A B; Kshetri, R; Orce, J N; Pearson, M R; Tardiff, E R; Al-Falou, H; Austin, R A E; Churchman, R; Djongolov, M K; D'Entremont, R; Kierans, C; Milovanovic, L; O'Hagan, S; Reeve, S; Sjue, S K L; Williams, S J

2012-07-27

We report a precise determination of the (19)Ne half-life to be T(1/2)=17.262±0.007 s. This result disagrees with the most recent precision measurements and is important for placing bounds on predicted right-handed interactions that are absent in the current standard model. We are able to identify and disentangle two competing systematic effects that influence the accuracy of such measurements. Our findings prompt a reassessment of results from previous high-precision lifetime measurements that used similar equipment and methods.

Precision Measurement of the Electron's Electric Dipole Moment Using Trapped Molecular Ions

NASA Astrophysics Data System (ADS)

Cairncross, William B.; Gresh, Daniel N.; Grau, Matt; Cossel, Kevin C.; Roussy, Tanya S.; Ni, Yiqi; Zhou, Yan; Ye, Jun; Cornell, Eric A.

2017-10-01

We describe the first precision measurement of the electron's electric dipole moment (de) using trapped molecular ions, demonstrating the application of spin interrogation times over 700 ms to achieve high sensitivity and stringent rejection of systematic errors. Through electron spin resonance spectroscopy on 180Hf 19F+ in its metastable 3Δ1 electronic state, we obtain de=(0.9 ±7. 7stat±1. 7syst)×10-29 e cm , resulting in an upper bound of |de|<1.3 ×10-28 e cm (90% confidence). Our result provides independent confirmation of the current upper bound of |de|<9.4 ×10-29 e cm [J. Baron et al., New J. Phys. 19, 073029 (2017), 10.1088/1367-2630/aa708e], and offers the potential to improve on this limit in the near future.

Preliminary results for a higher-precision measurement of the helium n=2 triplet P fine structure

NASA Astrophysics Data System (ADS)

Kato, K.; Skinner, T. D. G.; George, M. C.; Fitzakerley, D. W.; Vutha, A. C.; Storry, C. H.; Bezginov, N.; Valdez, T.; Hessels, E. A.

2017-04-01

Preliminary results for a higher-precision measurement of the n=2 triplet P J=1 to J=2 fine-structure interval in atomic helium are presented. A beam of metastable helium atoms is created in a liquid-nitrogen-cooled dc-discharge source, and is intensified using a 2D-MOT. These atoms are excited to the 2 triplet P state, and undergo a frequency-offset separated-oscillatory-field (FOSOF) microwave experiment. Only atoms which undergo a microwave transition, in the time-separated microwave fields are laser-excited to a Rydberg state and then Stark ionized and counted. Our new experimental design has eliminated the major systematic effects of previous experiments, and has led to a substantial improvement in the signal-to-noise ratio of the collected data. Our final improved measurement (with an expected uncertainty of less than 100 Hz) will allow for a test of 2-electron QED-theory in the helium n=2 triplet P system, and will be an important step towards obtaining a precise determination of the fine-structure constant. This research is supported by NSERC, CRC, CFI and NIST.

Reliability of Pressure Ulcer Rates: How Precisely Can We Differentiate Among Hospital Units, and Does the Standard Signal-Noise Reliability Measure Reflect This Precision?

PubMed

Staggs, Vincent S; Cramer, Emily

2016-08-01

Hospital performance reports often include rankings of unit pressure ulcer rates. Differentiating among units on the basis of quality requires reliable measurement. Our objectives were to describe and apply methods for assessing reliability of hospital-acquired pressure ulcer rates and evaluate a standard signal-noise reliability measure as an indicator of precision of differentiation among units. Quarterly pressure ulcer data from 8,199 critical care, step-down, medical, surgical, and medical-surgical nursing units from 1,299 US hospitals were analyzed. Using beta-binomial models, we estimated between-unit variability (signal) and within-unit variability (noise) in annual unit pressure ulcer rates. Signal-noise reliability was computed as the ratio of between-unit variability to the total of between- and within-unit variability. To assess precision of differentiation among units based on ranked pressure ulcer rates, we simulated data to estimate the probabilities of a unit's observed pressure ulcer rate rank in a given sample falling within five and ten percentiles of its true rank, and the probabilities of units with ulcer rates in the highest quartile and highest decile being identified as such. We assessed the signal-noise measure as an indicator of differentiation precision by computing its correlations with these probabilities. Pressure ulcer rates based on a single year of quarterly or weekly prevalence surveys were too susceptible to noise to allow for precise differentiation among units, and signal-noise reliability was a poor indicator of precision of differentiation. To ensure precise differentiation on the basis of true differences, alternative methods of assessing reliability should be applied to measures purported to differentiate among providers or units based on quality. © 2016 The Authors. Research in Nursing & Health published by Wiley Periodicals, Inc. © 2016 The Authors. Research in Nursing & Health published by Wiley Periodicals, Inc.

Reliability of Pressure Ulcer Rates: How Precisely Can We Differentiate Among Hospital Units, and Does the Standard Signal‐Noise Reliability Measure Reflect This Precision?

PubMed Central

Cramer, Emily

2016-01-01

Abstract Hospital performance reports often include rankings of unit pressure ulcer rates. Differentiating among units on the basis of quality requires reliable measurement. Our objectives were to describe and apply methods for assessing reliability of hospital‐acquired pressure ulcer rates and evaluate a standard signal‐noise reliability measure as an indicator of precision of differentiation among units. Quarterly pressure ulcer data from 8,199 critical care, step‐down, medical, surgical, and medical‐surgical nursing units from 1,299 US hospitals were analyzed. Using beta‐binomial models, we estimated between‐unit variability (signal) and within‐unit variability (noise) in annual unit pressure ulcer rates. Signal‐noise reliability was computed as the ratio of between‐unit variability to the total of between‐ and within‐unit variability. To assess precision of differentiation among units based on ranked pressure ulcer rates, we simulated data to estimate the probabilities of a unit's observed pressure ulcer rate rank in a given sample falling within five and ten percentiles of its true rank, and the probabilities of units with ulcer rates in the highest quartile and highest decile being identified as such. We assessed the signal‐noise measure as an indicator of differentiation precision by computing its correlations with these probabilities. Pressure ulcer rates based on a single year of quarterly or weekly prevalence surveys were too susceptible to noise to allow for precise differentiation among units, and signal‐noise reliability was a poor indicator of precision of differentiation. To ensure precise differentiation on the basis of true differences, alternative methods of assessing reliability should be applied to measures purported to differentiate among providers or units based on quality. © 2016 The Authors. Research in Nursing & Health published by Wiley Periodicals, Inc. PMID:27223598

Precise half-life measurement of the superallowed emitter 30S

NASA Astrophysics Data System (ADS)

Iacob, V. E.; Hardy, J. C.; Chen, L.; Horvat, V.; Bencomo, M.; Nica, N.; Park, H. I.; Roeder, B. T.; Saastamoinen, A.

2018-03-01

We have measured the half-life of 30S, the parent of a superallowed 0+→0+β transition, to a high precision using very pure sources and a 4 π proportional gas counter to detect the decay positrons. Our result for the half-life is 1.179 92(34) s. As a by-product of this measurement, we determine the half-life of its daughter, 30P, to be 2.501(2) min.

Double-trap measurement of the proton magnetic moment at 0.3 parts per billion precision.

PubMed

Schneider, Georg; Mooser, Andreas; Bohman, Matthew; Schön, Natalie; Harrington, James; Higuchi, Takashi; Nagahama, Hiroki; Sellner, Stefan; Smorra, Christian; Blaum, Klaus; Matsuda, Yasuyuki; Quint, Wolfgang; Walz, Jochen; Ulmer, Stefan

2017-11-24

Precise knowledge of the fundamental properties of the proton is essential for our understanding of atomic structure as well as for precise tests of fundamental symmetries. We report on a direct high-precision measurement of the magnetic moment μ p of the proton in units of the nuclear magneton μ N The result, μ p = 2.79284734462 (±0.00000000082) μ N , has a fractional precision of 0.3 parts per billion, improves the previous best measurement by a factor of 11, and is consistent with the currently accepted value. This was achieved with the use of an optimized double-Penning trap technique. Provided a similar measurement of the antiproton magnetic moment can be performed, this result will enable a test of the fundamental symmetry between matter and antimatter in the baryonic sector at the 10 -10 level. Copyright © 2017, American Association for the Advancement of Science.

High-precision branching ratio measurement for the superallowed β+ emitter Ga62

NASA Astrophysics Data System (ADS)

Finlay, P.; Ball, G. C.; Leslie, J. R.; Svensson, C. E.; Towner, I. S.; Austin, R. A. E.; Bandyopadhyay, D.; Chaffey, A.; Chakrawarthy, R. S.; Garrett, P. E.; Grinyer, G. F.; Hackman, G.; Hyland, B.; Kanungo, R.; Leach, K. G.; Mattoon, C. M.; Morton, A. C.; Pearson, C. J.; Phillips, A. A.; Ressler, J. J.; Sarazin, F.; Savajols, H.; Schumaker, M. A.; Wong, J.

2008-08-01

A high-precision branching ratio measurement for the superallowed β+ decay of Ga62 was performed at the Isotope Separator and Accelerator (ISAC) radioactive ion beam facility. The 8π spectrometer, an array of 20 high-purity germanium detectors, was employed to detect the γ rays emitted following Gamow-Teller and nonanalog Fermi β+ decays of Ga62, and the SCEPTAR plastic scintillator array was used to detect the emitted β particles. Thirty γ rays were identified following Ga62 decay, establishing the superallowed branching ratio to be 99.858(8)%. Combined with the world-average half-life and a recent high-precision Q-value measurement for Ga62, this branching ratio yields an ft value of 3074.3±1.1 s, making Ga62 among the most precisely determined superallowed ft values. Comparison between the superallowed ft value determined in this work and the world-average corrected F tmacr value allows the large nuclear-structure-dependent correction for Ga62 decay to be experimentally determined from the CVC hypothesis to better than 7% of its own value, the most precise experimental determination for any superallowed emitter. These results provide a benchmark for the refinement of the theoretical description of isospin-symmetry breaking in A⩾62 superallowed decays.

Measuring the universe with high-precision large-scale structure

NASA Astrophysics Data System (ADS)

Mehta, Kushal Tushar

Baryon acoustic oscillations (BAOs) are used to obtain precision measurements of cosmological parameters from large-scale surveys. While robust against most systematics, there are certain theoretical uncertainties that can affect BAO and galaxy clustering measurements. In this thesis I use data from the Sloan Digital Sky Survey (SDSS) to measure cosmological parameters and use N-body and smoothed-particle hydrodynamic (SPH) simulations to measure the effect of theoretical uncertainties by using halo occupation distributions (HODs). I investigate the effect of galaxy bias on BAO measurements by creating mock galaxy catalogs from large N-body simulations at z = 1. I find that there is no additional shift in the acoustic scale (0.10% +/- 0.10%) for the less biased HODs (b 3). I present the methodology and implementation of the simple one-step reconstruction technique introduced by Eisenstein et al. (2007) to biased tracers in N-body simulation. Reconstruction reduces the errorbars on the acoustic scale measurement by a factor of 1.5 - 2, and removes any additional shift due to galaxy bias for all HODs (0.07% +/- 0.15%) . Padmanabhan et al. (2012) and Xu et al. (2012) use this reconstruction technique in the SDSS DR7 data to measure DV (z = 0.35) (rsfidr s) = 1356 +/- 25 Mpc. Here I use this measurement in combination with measurements from the cosmic microwave background and the supernovae legacy survey to measure various cosmological parameters. I find the data consistent with the LambdaCDM Universe with a flat geometry. In particular, I measure H0 = 69.8 +/- 1.2 km/s/Mpc, w = 0.97 +/- 0.17, OK= -0.004 +/- 0.005 in the LambdaCDM, wCDM, and oCDM models respectively. Next, I measure the effect of large-scale (5 Mpc) halo environment density on the HOD by using an SPH simulation at z = 0, 0.35, 0.5, 0.75, 1.0$. I do not find any significant dependence of the HOD on the halo environment density for different galaxy mass thresholds, red and blue galaxies, and at different

Generating high precision ionospheric ground-truth measurements

NASA Technical Reports Server (NTRS)

Komjathy, Attila (Inventor); Sparks, Lawrence (Inventor); Mannucci, Anthony J. (Inventor)

2007-01-01

A method, apparatus and article of manufacture provide ionospheric ground-truth measurements for use in a wide-area augmentation system (WAAS). Ionospheric pseudorange/code and carrier phase data as primary observables is received by a WAAS receiver. A polynomial fit is performed on the phase data that is examined to identify any cycle slips in the phase data. The phase data is then leveled. Satellite and receiver biases are obtained and applied to the leveled phase data to obtain unbiased phase-leveled ionospheric measurements that are used in a WAAS system. In addition, one of several measurements may be selected and data is output that provides information on the quality of the measurements that are used to determine corrective messages as part of the WAAS system.

High-Precision Half-Life Measurements for the Superallowed Fermi β+ Emitters 14O and 18Ne

NASA Astrophysics Data System (ADS)

Laffoley, A. T.; Andreoiu, C.; Austin, R. A. E.; Ball, G. C.; Bender, P. C.; Bidaman, H.; Bildstein, V.; Blank, B.; Bouzomita, H.; Cross, D. S.; Deng, G.; Diaz Varela, A.; Dunlop, M. R.; Dunlop, R.; Finlay, P.; Garnsworthy, A. B.; Garrett, P.; Giovinazzo, J.; Grinyer, G. F.; Grinyer, J.; Hadinia, B.; Jamieson, D. S.; Jigmeddorj, B.; Ketelhut, S.; Kisliuk, D.; Leach, K. G.; Leslie, J. R.; MacLean, A.; Miller, D.; Mills, B.; Moukaddam, M.; Radich, A. J.; Rajabali, M. M.; Rand, E. T.; Svensson, C. E.; Tardiff, E.; Thomas, J. C.; Turko, J.; Voss, P.; Unsworth, C.

High-precision half-life measurements, at the level of ±0.04%, for the superallowed Fermi emitters 14O and 18Ne have been performed at TRIUMF's Isotope Separator and Accelerator facility. Using 3 independent detector systems, a gas-proportional counter, a fast plastic scintillator, and a high-purity germanium array, a series of direct β and γ counting measurements were performed for each of the isotopes. In the case of 14O, these measurements were made to help resolve an existing discrepancy between detection methods, whereas for 18Ne the half-life precision has been improved in anticipation of forthcoming high-precision branching ratio measurements.

Digital PCR Modeling for Maximal Sensitivity, Dynamic Range and Measurement Precision

PubMed Central

Majumdar, Nivedita; Wessel, Thomas; Marks, Jeffrey

2015-01-01

The great promise of digital PCR is the potential for unparalleled precision enabling accurate measurements for genetic quantification. A challenge associated with digital PCR experiments, when testing unknown samples, is to perform experiments at dilutions allowing the detection of one or more targets of interest at a desired level of precision. While theory states that optimal precision (Po) is achieved by targeting ~1.59 mean copies per partition (λ), and that dynamic range (R) includes the space spanning one positive (λL) to one negative (λU) result from the total number of partitions (n), these results are tempered for the practitioner seeking to construct digital PCR experiments in the laboratory. A mathematical framework is presented elucidating the relationships between precision, dynamic range, number of partitions, interrogated volume, and sensitivity in digital PCR. The impact that false reaction calls and volumetric variation have on sensitivity and precision is next considered. The resultant effects on sensitivity and precision are established via Monte Carlo simulations reflecting the real-world likelihood of encountering such scenarios in the laboratory. The simulations provide insight to the practitioner on how to adapt experimental loading concentrations to counteract any one of these conditions. The framework is augmented with a method of extending the dynamic range of digital PCR, with and without increasing n, via the use of dilutions. An example experiment demonstrating the capabilities of the framework is presented enabling detection across 3.33 logs of starting copy concentration. PMID:25806524

Error analysis of high-rate GNSS precise point positioning for seismic wave measurement

NASA Astrophysics Data System (ADS)

Shu, Yuanming; Shi, Yun; Xu, Peiliang; Niu, Xiaoji; Liu, Jingnan

2017-06-01

High-rate GNSS precise point positioning (PPP) has been playing a more and more important role in providing precise positioning information in fast time-varying environments. Although kinematic PPP is commonly known to have a precision of a few centimeters, the precision of high-rate PPP within a short period of time has been reported recently with experiments to reach a few millimeters in the horizontal components and sub-centimeters in the vertical component to measure seismic motion, which is several times better than the conventional kinematic PPP practice. To fully understand the mechanism of mystified excellent performance of high-rate PPP within a short period of time, we have carried out a theoretical error analysis of PPP and conducted the corresponding simulations within a short period of time. The theoretical analysis has clearly indicated that the high-rate PPP errors consist of two types: the residual systematic errors at the starting epoch, which affect high-rate PPP through the change of satellite geometry, and the time-varying systematic errors between the starting epoch and the current epoch. Both the theoretical error analysis and simulated results are fully consistent with and thus have unambiguously confirmed the reported high precision of high-rate PPP, which has been further affirmed here by the real data experiments, indicating that high-rate PPP can indeed achieve the millimeter level of precision in the horizontal components and the sub-centimeter level of precision in the vertical component to measure motion within a short period of time. The simulation results have clearly shown that the random noise of carrier phases and higher order ionospheric errors are two major factors to affect the precision of high-rate PPP within a short period of time. The experiments with real data have also indicated that the precision of PPP solutions can degrade to the cm level in both the horizontal and vertical components, if the geometry of satellites is

Towards an unbiased filter routine to determine precipitation and evapotranspiration from high precision lysimeter measurements

NASA Astrophysics Data System (ADS)

Peters, Andre; Groh, Jannis; Schrader, Frederik; Durner, Wolfgang; Vereecken, Harry; Pütz, Thomas

2017-06-01

Weighing lysimeters are considered to be the best means for a precise measurement of water fluxes at the interface between the soil-plant system and the atmosphere. Any decrease of the net mass of the lysimeter can be interpreted as evapotranspiration (ET), any increase as precipitation (P). However, the measured raw data need to be filtered to separate real mass changes from noise. Such filter routines typically apply two steps: (i) a low pass filter, like moving average, which smooths noisy data, and (ii) a threshold filter that separates significant from insignificant mass changes. Recent developments of these filters have identified and solved some problems regarding bias in the data processing. A remaining problem is that each change in flow direction is accompanied with a systematic flow underestimation due to the threshold scheme. In this contribution, we analyze this systematic effect and show that the absolute underestimation is independent of the magnitude of a flux event. Thus, for small events, like dew or rime formation, the relative error is high and can reach the same magnitude as the flux itself. We develop a heuristic solution to the problem by introducing a so-called "snap routine". The routine is calibrated and tested with synthetic flux data and applied to real measurements obtained with a precision lysimeter for a 10-month period. The heuristic snap routine effectively overcomes these problems and yields an almost unbiased representation of the real signal.

Few-Nucleon Charge Radii and a Precision Isotope Shift Measurement in Helium

NASA Astrophysics Data System (ADS)

Hassan Rezaeian, Nima; Shiner, David

2015-05-01

Precision atomic theory and experiment provide a valuable method to determine few nucleon charge radii, complementing the more direct scattering approaches, and providing sensitive tests of few-body nuclear theory. Some puzzles with respect to this method exist, particularly in the muonic and electronic measurements of the proton radius, and as well with respect to measurements of nuclear size in helium. We perform precision measurements of the isotope shift of the 23S -23P transitions in 3He and 4He. A tunable laser frequency discriminator and electro-optic modulation technique give precise frequency and intensity control. We select (ts <50 ms) and stabilize the intensity of the required sideband and eliminate the unused sidebands (<= 10¬5) . The technique uses a MEMS fiber switch (ts = 10 ms) and several temperature stabilized narrow band (3 GHz) fiber gratings. A fiber based optical circulator and amplifier provide the desired isolation and net gain for the selected frequency. A beam with both species of helium is achieved using a custom fiber laser for simultaneous optical pumping. A servo-controlled retro-reflected laser beam eliminates Doppler effects. Careful detection design and software control allows for unbiased data collection. Current results will be discussed. This work is supported by NSF PHY-1068868 and PHY-1404498.

Ultra-High Precision Half-Life Measurement for the Superallowed &+circ; Emitter ^26Al^m

NASA Astrophysics Data System (ADS)

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

2009-10-01

The calculated nuclear structure dependent correction for ^26Al^m (δC-δNS= 0.305(27)% [1]) is smaller by nearly a factor of two than the other twelve precision superallowed cases, making it an ideal case to pursue a reduction in the experimental errors contributing to the Ft value. An ultra-high precision half-life measurement for the superallowed &+circ; emitter ^26Al^m has been made at the Isotope Separator and Accelerator (ISAC) facility at TRIUMF in Vancouver, Canada. A beam of ˜10^5 ^26Al^m/s was delivered in October 2007 and its decay was observed using a 4π continuous gas flow proportional counter as part of an ongoing experimental program in superallowed Fermi β decay studies. With a statistical precision of ˜0.008%, the present work represents the single most precise measurement of any superallowed half-life to date. [4pt] [1] I.S. Towner and J.C. Hardy, Phys. Rev. C 79, 055502 (2009).

Ultra-High Precision Half-Life Measurement for the Superallowed &+circ; Emitter ^26Al^m

NASA Astrophysics Data System (ADS)

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

2008-10-01

The calculated nuclear structure dependent correction for ^26Al^m (δC-δNS= 0.305(27)% [1]) is smaller by nearly a factor of two than the other twelve precision superallowed cases, making it an ideal case to pursue a reduction in the experimental errors contributing to the Ft value. An ultra-high precision half-life measurement for the superallowed &+circ; emitter ^26Al^m has been made using a 4π continuous gas flow proportional counter as part of an ongoing experimental program in superallowed Fermi β decay studies at the Isotope Separator and Accelerator (ISAC) facility at TRIUMF in Vancouver, Canada, which delivered a beam of ˜10^5 ^26Al^m/s in October 2007. With a statistical precision of ˜0.008%, the present work represents the single most precise measurement of any superallowed half-life to date. [1] I.S. Towner and J.C. Hardy, Phys. Rev. C 77, 025501 (2008).

Digital encoding of cellular mRNAs enabling precise and absolute gene expression measurement by single-molecule counting.

PubMed

Fu, Glenn K; Wilhelmy, Julie; Stern, David; Fan, H Christina; Fodor, Stephen P A

2014-03-18

We present a new approach for the sensitive detection and accurate quantitation of messenger ribonucleic acid (mRNA) gene transcripts in single cells. First, the entire population of mRNAs is encoded with molecular barcodes during reverse transcription. After amplification of the gene targets of interest, molecular barcodes are counted by sequencing or scored on a simple hybridization detector to reveal the number of molecules in the starting sample. Since absolute quantities are measured, calibration to standards is unnecessary, and many of the relative quantitation challenges such as polymerase chain reaction (PCR) bias are avoided. We apply the method to gene expression analysis of minute sample quantities and demonstrate precise measurements with sensitivity down to sub single-cell levels. The method is an easy, single-tube, end point assay utilizing standard thermal cyclers and PCR reagents. Accurate and precise measurements are obtained without any need for cycle-to-cycle intensity-based real-time monitoring or physical partitioning into multiple reactions (e.g., digital PCR). Further, since all mRNA molecules are encoded with molecular barcodes, amplification can be used to generate more material for multiple measurements and technical replicates can be carried out on limited samples. The method is particularly useful for small sample quantities, such as single-cell experiments. Digital encoding of cellular content preserves true abundance levels and overcomes distortions introduced by amplification.

Estimating maneuvers for precise relative orbit determination using GPS

NASA Astrophysics Data System (ADS)

Allende-Alba, Gerardo; Montenbruck, Oliver; Ardaens, Jean-Sébastien; Wermuth, Martin; Hugentobler, Urs

2017-01-01

Precise relative orbit determination is an essential element for the generation of science products from distributed instrumentation of formation flying satellites in low Earth orbit. According to the mission profile, the required formation is typically maintained and/or controlled by executing maneuvers. In order to generate consistent and precise orbit products, a strategy for maneuver handling is mandatory in order to avoid discontinuities or precision degradation before, after and during maneuver execution. Precise orbit determination offers the possibility of maneuver estimation in an adjustment of single-satellite trajectories using GPS measurements. However, a consistent formulation of a precise relative orbit determination scheme requires the implementation of a maneuver estimation strategy which can be used, in addition, to improve the precision of maneuver estimates by drawing upon the use of differential GPS measurements. The present study introduces a method for precise relative orbit determination based on a reduced-dynamic batch processing of differential GPS pseudorange and carrier phase measurements, which includes maneuver estimation as part of the relative orbit adjustment. The proposed method has been validated using flight data from space missions with different rates of maneuvering activity, including the GRACE, TanDEM-X and PRISMA missions. The results show the feasibility of obtaining precise relative orbits without degradation in the vicinity of maneuvers as well as improved maneuver estimates that can be used for better maneuver planning in flight dynamics operations.

A Linear Variable-[theta] Model for Measuring Individual Differences in Response Precision

ERIC Educational Resources Information Center

Ferrando, Pere J.

2011-01-01

Models for measuring individual response precision have been proposed for binary and graded responses. However, more continuous formats are quite common in personality measurement and are usually analyzed with the linear factor analysis model. This study extends the general Gaussian person-fluctuation model to the continuous-response case and…

Optical Frequency Stabilization and Optical Phase Locked Loops: Golden Threads of Precision Measurement

DOE Office of Scientific and Technical Information (OSTI.GOV)

Taubman, Matthew S.

Stabilization of lasers through locking to optical cavities, atomic transitions, and molecular transitions has enabled the field of precision optical measurement since shortly after the invention of the laser. Recent advances in the field have produced an optical clock that is orders of magnitude more stable than those of just a few years prior. Phase locking of one laser to another, or to a frequency offset from another, formed the basis for linking stable lasers across the optical spectrum, such frequency chains exhibiting progressively finer precision through the years. Phase locking between the modes within a femtosecond pulsed laser hasmore » yielded the optical frequency comb, one of the most beautiful and useful instruments of our time. This talk gives an overview of these topics, from early work through to the latest 1E-16 thermal noise-limited precision recently attained for a stable laser, and the ongoing quest for ever finer precision and accuracy. The issues of understanding and measuring line widths and shapes are also studied in some depth, highlighting implications for servo design for sub-Hz line widths.« less

High Precision Continuous and Real-Time Measurement of Atmospheric Oxygen Using Cavity Ring-Down Spectroscopy.

NASA Astrophysics Data System (ADS)

Kim-Hak, D.; Hoffnagle, J.; Rella, C.; Sun, M.

2016-12-01

Oxygen is a major and vital component of the Earth atmosphere representing about 21% of its composition. It is consumed or produced through biochemical processes such as combustion, respiration, and photosynthesis. Although atmospheric oxygen is not a greenhouse gas, it can be used as a top-down constraint on the carbon cycle. The variation observations of oxygen in the atmosphere are very small, in the order of the few ppm's. This presents the main technical challenge for measurement as a very high level of precision is required and only few methods including mass spectrometry, fuel cell, and paramagnetic are capable of overcoming it. Here we present new developments of a high-precision gas analyzer that utilizes the technique of Cavity Ring-Down Spectroscopy to measure oxygen concentration and oxygen isotope. Its compact and ruggedness design combined with high precision and long-term stability allows the user to deploy the instrument in the field for continuous monitoring of atmospheric oxygen level. Measurements have a 1-σ 5-minute averaging precision of 1-2 ppm for O2 over a dynamic range of 0-20%. We will present supplemental data acquired from our 10m tower measurements in Santa Clara, CA.

Precision Mechanical Measurement Using the Levitation Mass Method (LMM)

NASA Astrophysics Data System (ADS)

Fujii, Yusaku; Jin, Tao; Maru, Koichi

2010-12-01

The present status and the future prospects of a method for precision mass and force measurement, the levitation mass method (LMM), are reviewed. The LMM has been proposed and improved by the authors. In the LMM, the inertial force of a mass levitated using a pneumatic linear bearing is used as the reference force applied to the objects under test, such as force transducers, materials or structures. The inertial force of the levitated mass is measured using an optical interferometer. The three typical applications of the LMM, i.e. the dynamic force calibration, the micro force material tester and the space scale, are reviewed in this paper.

Precision measurements of thermodynamic parameters of heavy alkali metals

NASA Astrophysics Data System (ADS)

Blagonravov, L. A.; Modenov, A. A.

2017-11-01

On the temperature dependences of a number of one-component liquids, regions of anomalous behavior in the form of kinks and also in the form of limited areas of forced growth have been previously observed (LA Blagonravov, LA Orlov, et al., TVT 2000, vol. 38, No. 4, p.566-572). However, the interpretation of these anomalies is complicated by the small magnitude of the effects themselves (the magnitude of the observed effect was 5%, a random error of 2-3%). An increase in the accuracy of measurements is required for a more confident determination of the detailed shape of the anomalies. In the proposed work, thermodynamic parameters are studied using a technique that uses the elastic-thermal effect. The adiabatic thermal coefficient of pressure (a.t.p.c.) is measured: χ = (1/T)(∂T/∂p)S. An installation in which the pressure change is carried out in a periodic mode is used for measurements. The software allows simultaneous averaging of the values of the amplitude of pressure oscillations and the amplitude of temperature response oscillations with the subsequent determination of their ratio. The facility uses an advanced pressure modulator, which allows creating pressure oscillations of the shape close to sinusoidal (the value of the second harmonic is not more than 10%) and a precision SR-810 nanovoltmeter with a synchronous digital detector. The currently used technique provides an acceptable measurement accuracy (error in the region of 0.5-1%). However, to further increase the accuracy, it was decided to make changes in the measuring path. Namely, by developing and applying a scheme of a precision low-noise preamplifier based on the instrument amplifier INA333, a circuit allowing simultaneous measurement of not only the two above parameters but also the current temperature of the sample (to exclude the effect of temperature drift.) Preliminary results of measurements of the temperature dependence of the a.t.p.c. of liquid cesium in the temperature range up to

Imaging subtle microstructural variations in ceramics with precision ultrasonic velocity and attenuation measurements

NASA Technical Reports Server (NTRS)

Generazio, Edward R.; Roth, Don J.; Baaklini, George Y.

1987-01-01

Acoustic images of a silicon carbide ceramic disk were obtained using a precision scanning contact pulse echo technique. Phase and cross-correlation velocity, and attenuation maps were used to form color images of microstructural variations. These acoustic images reveal microstructural variations not observable with X-ray radiography.

Proceedings of the Fourth Precise Time and Time Interval Planning Meeting

NASA Technical Reports Server (NTRS)

Acrivos, H. N. (Compiler); Wardrip, S. C. (Compiler)

1972-01-01

The proceedings of a conference on Precise Time and Time Interval Planning are presented. The subjects discussed include the following: (1) satellite timing techniques, precision frequency sources, and very long baseline interferometry, (2) frequency stabilities and communications, and (3) very low frequency and ultrahigh frequency propagation and use. Emphasis is placed on the accuracy of time discrimination obtained with time measuring equipment and specific applications of time measurement to military operations and civilian research projects.

Precision Measurement of the Mass of the hc(P11) State of Charmonium

NASA Astrophysics Data System (ADS)

Dobbs, S.; Metreveli, Z.; Seth, K. K.; Tomaradze, A.; Libby, J.; Powell, A.; Wilkinson, G.; Ecklund, K. M.; Love, W.; Savinov, V.; Lopez, A.; Mendez, H.; Ramirez, J.; Ge, J. Y.; Miller, D. H.; Shipsey, I. P. J.; Xin, B.; Adams, G. S.; Anderson, M.; Cummings, J. P.; Danko, I.; Hu, D.; Moziak, B.; Napolitano, J.; He, Q.; Insler, J.; Muramatsu, H.; Park, C. S.; Thorndike, E. H.; Yang, F.; Artuso, M.; Blusk, S.; Khalil, S.; Li, J.; Mountain, R.; Nisar, S.; Randrianarivony, K.; Sultana, N.; Skwarnicki, T.; Stone, S.; Wang, J. C.; Zhang, L. M.; Bonvicini, G.; Cinabro, D.; Dubrovin, M.; Lincoln, A.; Naik, P.; Rademacker, J.; Asner, D. M.; Edwards, K. W.; Reed, J.; Briere, R. A.; Ferguson, T.; Tatishvili, G.; Vogel, H.; Watkins, M. E.; Rosner, J. L.; Alexander, J. P.; Cassel, D. G.; Duboscq, J. E.; Ehrlich, R.; Fields, L.; Galik, R. S.; Gibbons, L.; Gray, R.; Gray, S. W.; Hartill, D. L.; Heltsley, B. K.; Hertz, D.; Hunt, J. M.; Kandaswamy, J.; Kreinick, D. L.; Kuznetsov, V. E.; Ledoux, J.; Mahlke-Krüger, H.; Mohapatra, D.; Onyisi, P. U. E.; Patterson, J. R.; Peterson, D.; Riley, D.; Ryd, A.; Sadoff, A. J.; Shi, X.; Stroiney, S.; Sun, W. M.; Wilksen, T.; Athar, S. B.; Patel, R.; Yelton, J.; Rubin, P.; Eisenstein, B. I.; Karliner, I.; Mehrabyan, S.; Lowrey, N.; Selen, M.; White, E. J.; Wiss, J.; Mitchell, R. E.; Shepherd, M. R.; Besson, D.; Pedlar, T. K.; Cronin-Hennessy, D.; Gao, K. Y.; Hietala, J.; Kubota, Y.; Klein, T.; Lang, B. W.; Poling, R.; Scott, A. W.; Zweber, P.

2008-10-01

A precision measurement of the mass of the hc(P11) state of charmonium has been made using a sample of 24.5×106 ψ(2S) events produced in e+e- annihilation at the Cornell Electron Storage Ring (CESR). The reaction used was ψ(2S)→π0hc, π0→γγ, hc→γηc, and the reaction products were detected in the CLEO-c detector. Data have been analyzed both for the inclusive reaction and for the exclusive reactions in which ηc decays are reconstructed in 15 hadronic decay channels. Consistent results are obtained in the two analyses. The averaged results of the present measurements are M(hc)=3525.28±0.19(stat.)±0.12(syst.)MeV, and B(ψ(2S)→π0hc)×B(hc→γηc)=(4.19±0.32±0.45)×10-4. Using the PJ3 centroid mass, ΔMhf(1P)≡⟨M(χcJ)⟩-M(hc)=+0.02±0.19±0.13MeV.

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

PubMed

Ender, Andreas; Mehl, Albert

2013-02-01

A new approach to both 3-dimensional (3D) trueness and precision is necessary to assess the accuracy of intraoral digital impressions and compare them to conventionally acquired impressions. The purpose of this in vitro study was to evaluate whether a new reference scanner is capable of measuring conventional and digital intraoral complete-arch impressions for 3D accuracy. A steel reference dentate model was fabricated and measured with a reference scanner (digital reference model). Conventional impressions were made from the reference model, poured with Type IV dental stone, scanned with the reference scanner, and exported as digital models. Additionally, digital impressions of the reference model were made and the digital models were exported. Precision was measured by superimposing the digital models within each group. Superimposing the digital models on the digital reference model assessed the trueness of each impression method. Statistical significance was assessed with an independent sample t test (α=.05). The reference scanner delivered high accuracy over the entire dental arch with a precision of 1.6 ±0.6 µm and a trueness of 5.3 ±1.1 µm. Conventional impressions showed significantly higher precision (12.5 ±2.5 µm) and trueness values (20.4 ±2.2 µm) with small deviations in the second molar region (P<.001). Digital impressions were significantly less accurate with a precision of 32.4 ±9.6 µm and a trueness of 58.6 ±15.8µm (P<.001). More systematic deviations of the digital models were visible across the entire dental arch. The new reference scanner is capable of measuring the precision and trueness of both digital and conventional complete-arch impressions. The digital impression is less accurate and shows a different pattern of deviation than the conventional impression. Copyright © 2013 The Editorial Council of the Journal of Prosthetic Dentistry. Published by Mosby, Inc. All rights reserved.

Smart and precise alignment of optical systems

NASA Astrophysics Data System (ADS)

Langehanenberg, Patrik; Heinisch, Josef; Stickler, Daniel

2013-09-01

For the assembly of any kind of optical systems the precise centration of every single element is of particular importance. Classically the precise alignment of optical components is based on the precise centering of all components to an external axis (usually a high-precision rotary spindle axis). Main drawback of this timeconsuming process is that it is significantly sensitive to misalignments of the reference (e.g. the housing) axis. In order to facilitate process in this contribution we present a novel alignment strategy for the TRIOPTICS OptiCentric® instrument family that directly aligns two elements with respect to each other by measuring the first element's axis and using this axis as alignment reference without the detour of considering an external reference. According to the optical design any axis in the system can be chosen as target axis. In case of the alignment to a barrel this axis is measured by using a distance sensor (e.g., the classically used dial indicator). Instead of fine alignment the obtained data is used for the calculation of its orientation within the setup. Alternatively, the axis of an optical element (single lens or group of lenses) whose orientation is measured with the standard OptiCentric MultiLens concept can be used as a reference. In the instrument's software the decentering of the adjusting element to the calculated axis is displayed in realtime and indicated by a target mark that can be used for the manual alignment. In addition, the obtained information can also be applied for active and fully automated alignment of lens assemblies with the help of motorized actuators.

Precise Penning trap measurements of double β-decay Q-values

NASA Astrophysics Data System (ADS)

Redshaw, M.; Brodeur, M.; Bollen, G.; Bustabad, S.; Eibach, M.; Gulyuz, K.; Izzo, C.; Lincoln, D. L.; Novario, S. J.; Ringle, R.; Sandler, R.; Schwarz, S.; Valverde, A. A.

2015-10-01

The double β-decay (ββ -decay) Q-value, defined as the mass difference between parent and daughter atoms, is an important parameter for both two-neutrino ββ -decay (2 νββ) and neutrinoless ββ -decay (0 νββ) experiments. The Q-value enters into the calculation of the phase space factors, which relate the measured ββ -decay half-life to the nuclear matrix element and, in the case of 0 νββ , the effective Majorana mass of the neutrino. In addition, the Q-value defines the total kinetic energy of the two electrons emitted in 0 νββ , corresponding to the location of the single peak that is the sought after signature of 0 νββ . Hence, it is essential to have a precise and accurate Q-value determination. Over the last decade, the Penning trap mass spectrometry community has made a significant effort to provide precise ββ -decay Q-value determinations. Here we report on recent measurements with the Low Energy Beam and Ion Trap (LEBIT) facility at the National Superconducting Cyclotron Laboratory (NSCL) of the 48Ca, 82Se, and 96Zr Q-values. These measurements complete the determination of ββ -decay Q-values for the 11 ``best'' candidates (those with Q >2 MeV). We also report on a measurement of the 78Kr double electron capture (2EC) Q-value and discuss ongoing Penning trap measurements relating to ββ -decay and 2EC. Support from NSF Contract No. PHY-1102511, and DOE Grant No. 03ER-41268.

Precise measurement of cosmic ray fluxes with the AMS-02 experiment

DOE Office of Scientific and Technical Information (OSTI.GOV)

Vecchi, Manuela, E-mail: manuela.vecchi@ifsc.usp.br

2015-12-17

The AMS-02 detector is a large acceptance magnetic spectrometer operating onboard the International Space Station since May 2011. The main goals of the detector are the search for antimatter and dark matter in space, as well as the measurement of cosmic ray composition and flux. In this document we present precise measurements of cosmic ray positrons, electrons and protons, collected during the first 30 months of operations.

New precision measurements of free neutron beta decay with cold neutrons

DOE PAGES

Baeßler, Stefan; Bowman, James David; Penttilä, Seppo I.; ...

2014-10-14

Precision measurements in free neutron beta decay serve to determine the coupling constants of beta decay, and offer several stringent tests of the standard model. This study describes the free neutron beta decay program planned for the Fundamental Physics Beamline at the Spallation Neutron Source at Oak Ridge National Laboratory, and finally puts it into the context of other recent and planned measurements of neutron beta decay observables.

Precision Measurement of the Electron's Electric Dipole Moment Using Trapped Molecular Ions.

PubMed

Cairncross, William B; Gresh, Daniel N; Grau, Matt; Cossel, Kevin C; Roussy, Tanya S; Ni, Yiqi; Zhou, Yan; Ye, Jun; Cornell, Eric A

2017-10-13

We describe the first precision measurement of the electron's electric dipole moment (d_{e}) using trapped molecular ions, demonstrating the application of spin interrogation times over 700 ms to achieve high sensitivity and stringent rejection of systematic errors. Through electron spin resonance spectroscopy on ^{180}Hf^{19}F^{+} in its metastable ^{3}Δ_{1} electronic state, we obtain d_{e}=(0.9±7.7_{stat}±1.7_{syst})×10^{-29}  e cm, resulting in an upper bound of |d_{e}|<1.3×10^{-28}  e cm (90% confidence). Our result provides independent confirmation of the current upper bound of |d_{e}|<9.4×10^{-29}  e cm [J. Baron et al., New J. Phys. 19, 073029 (2017)NJOPFM1367-263010.1088/1367-2630/aa708e], and offers the potential to improve on this limit in the near future.

Peak Measurement for Vancomycin AUC Estimation in Obese Adults Improves Precision and Lowers Bias.

PubMed

Pai, Manjunath P; Hong, Joseph; Krop, Lynne

2017-04-01

Vancomycin area under the curve (AUC) estimates may be skewed in obese adults due to weight-dependent pharmacokinetic parameters. We demonstrate that peak and trough measurements reduce bias and improve the precision of vancomycin AUC estimates in obese adults ( n = 75) and validate this in an independent cohort ( n = 31). The precision and mean percent bias of Bayesian vancomycin AUC estimates are comparable between covariate-dependent ( R 2 = 0.774, 3.55%) and covariate-independent ( R 2 = 0.804, 3.28%) models when peaks and troughs are measured but not when measurements are restricted to troughs only ( R 2 = 0.557, 15.5%). Copyright © 2017 American Society for Microbiology.

A Precise Measurement of the Deuteron Elastic Structure Function A(Q 2)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Honegger, Andrian

1999-12-07

During summer 1997 experiment 394-018 measured the deuteron tensor polarization in D(e,e'more » $$vec\\{d}$$) scattering in Hall C at Jefferson Laboratory. In a momentum transfer range between 0.66 and 1.8 (GeV=c) 2, with slight changes in the experimental setup, the collaboration performed six precision measurements of the deuteron structure function A(Q 2) in elastic D(e,e'd) scattering . Scattered electrons and recoil deuterons were detected in coincidence in the High Momentum Spectrometer and the recoil polarimeter POLDER, respectively. At every kinematics H(e,e') data were taken to study systematic effects of the measurement. These new precise measurements resolve discrepancies between older data sets and put significant constraints on existing models of the deuteron electromagnetic structure. This work was supported by the Swiss National Science Foundation, the French Centre National de la Recherche Scientifique and the Commissariat 'a l'Energie Atomique, the U.S. Department of Energy and the National Science Foundation and the K.C. Wong Foundation.« less

Frequency scanning interferometry in ATLAS: remote, multiple, simultaneous and precise distance measurements in a hostile environment

NASA Astrophysics Data System (ADS)

Coe, P. A.; Howell, D. F.; Nickerson, R. B.

2004-11-01

ATLAS is the largest particle detector under construction at CERN Geneva. Frequency scanning interferometry (FSI), also known as absolute distance interferometry, will be used to monitor shape changes of the SCT (semiconductor tracker), a particle tracker in the inaccessible, high radiation environment at the centre of ATLAS. Geodetic grids with several hundred fibre-coupled interferometers (30 mm to 1.5 m long) will be measured simultaneously. These lengths will be measured by tuning two lasers and comparing the resulting phase shifts in grid line interferometers (GLIs) with phase shifts in a reference interferometer. The novel inexpensive GLI design uses diverging beams to reduce sensitivity to misalignment, albeit with weaker signals. One micrometre precision length measurements of grid lines will allow 10 µm precision tracker shape corrections to be fed into ATLAS particle tracking analysis. The technique was demonstrated by measuring a 400 mm interferometer to better than 400 nm and a 1195 mm interferometer to better than 250 nm. Precise measurements were possible, even with poor quality signals, using numerical analysis of thousands of intensity samples. Errors due to drifts in interferometer length were substantially reduced using two lasers tuned in opposite directions and the precision was further improved by linking measurements made at widely separated laser frequencies.

Precision measurement of refractive index of air based on laser synthetic wavelength interferometry with Edlén equation estimation.

PubMed

Yan, Liping; Chen, Benyong; Zhang, Enzheng; Zhang, Shihua; Yang, Ye

2015-08-01

A novel method for the precision measurement of refractive index of air (n(air)) based on the combining of the laser synthetic wavelength interferometry with the Edlén equation estimation is proposed. First, a n(air_e) is calculated from the modified Edlén equation according to environmental parameters measured by low precision sensors with an uncertainty of 10(-6). Second, a unique integral fringe number N corresponding to n(air) is determined based on the calculated n(air_e). Then, a fractional fringe ε corresponding to n(air) with high accuracy can be obtained according to the principle of fringe subdivision of laser synthetic wavelength interferometry. Finally, high accurate measurement of n(air) is achieved according to the determined fringes N and ε. The merit of the proposed method is that it not only solves the problem of the measurement accuracy of n(air) being limited by the accuracies of environmental sensors, but also avoids adopting complicated vacuum pumping to measure the integral fringe N in the method of conventional laser interferometry. To verify the feasibility of the proposed method, comparison experiments with Edlén equations in short time and in long time were performed. Experimental results show that the measurement accuracy of n(air) is better than 2.5 × 10(-8) in short time tests and 6.2 × 10(-8) in long time tests.

High-Precision Half-Life and Branching Ratio Measurements for the Superallowed β+ Emitter 26Alm

NASA Astrophysics Data System (ADS)

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

2013-03-01

High-precision half-life and branching-ratio measurements for the superallowed β+ emitter 26Alm were performed at the TRIUMF-ISAC radioactive ion beam facility. An upper limit of ≤ 15 ppm at 90% C.L. was determined for the sum of all possible non-analogue β+/EC decay branches of 26Alm, yielding a superallowed branching ratio of 100.0000+0-0.0015%. A value of T1/2 = 6:34654(76) s was determined for the 26Alm half-life which is consistent with, but 2.5 times more precise than, the previous world average. Combining these results with world-average measurements yields an ft value of 3037.58(60) s, the most precisely determined for any superallowed emitting nucleus to date. This high-precision ft value for 26Alm provides a new benchmark to refine theoretical models of isospin-symmetry-breaking effects in superallowed β decays.

Centroiding Experiment for Determining the Positions of Stars with High Precision

NASA Astrophysics Data System (ADS)

Yano, T.; Araki, H.; Hanada, H.; Tazawa, S.; Gouda, N.; Kobayashi, Y.; Yamada, Y.; Niwa, Y.

2010-12-01

We have experimented with the determination of the positions of star images on a detector with high precision such as 10 microarcseconds, required by a space astrometry satellite, JASMINE. In order to accomplish such a precision, we take the following two procedures. (1) We determine the positions of star images on the detector with the precision of about 0.01 pixel for one measurement, using an algorithm for estimating them from photon weighted means of the star images. (2) We determine the positions of star images with the precision of about 0.0001-0.00001 pixel, which corresponds to that of 10 microarcseconds, using a large amount of data over 10000 measurements, that is, the error of the positions decreases according to the amount of data. Here, we note that the procedure 2 is not accomplished when the systematic error in our data is not excluded adequately even if we use a large amount of data. We first show the method to determine the positions of star images on the detector using photon weighted means of star images. This algorithm, used in this experiment, is very useful because it is easy to calculate the photon weighted mean from the data. This is very important in treating a large amount of data. Furthermore, we need not assume the shape of the point spread function in deriving the centroid of star images. Second, we show the results in the laboratory experiment for precision of determining the positions of star images. We obtain that the precision of estimation of positions of star images on the detector is under a variance of 0.01 pixel for one measurement (procedure 1). We also obtain that the precision of the positions of star images becomes a variance of about 0.0001 pixel using about 10000 measurements (procedure 2).

Precision, accuracy, and efficiency of four tools for measuring soil bulk density or strength.

Treesearch

Richard E. Miller; John Hazard; Steven Howes

2001-01-01

Monitoring soil compaction is time consuming. A desire for speed and lower costs, however, must be balanced with the appropriate precision and accuracy required of the monitoring task. We compared three core samplers and a cone penetrometer for measuring soil compaction after clearcut harvest on a stone-free and a stony soil. Precision (i.e., consistency) of each tool...

Microcomputer-based Peltier thermostat for precision optical radiation measurements

NASA Astrophysics Data System (ADS)

Zhu, Xiaosong; Krochmann, Eike; Chen, Jiashu

1992-03-01

We have developed a microcomputer-based thermostat for a light measuring head in precision optical radiation measurements. This thermostat consists of a single-chip microcomputer, a digital-to-analog converter, a liquid crystal display, a power operational amplifier, and a Peltier element (thermoelectric cooler). The Peltier element keeps the temperature of the photometer head at 20±0.1 °C in the ambient temperature range from -20 to 60 °C. A control algorithm which combines the ``Bang-Bang'' mode and proportional-plus-integral-plus-derivative mode is used to achieve fast and smooth thermostatic performance. This thermostat is effective, inexpensive, and easy to adjust. Several applications of the Peltier thermostat are mentioned.

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

NASA Technical Reports Server (NTRS)

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

1992-01-01

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.

Is digital photography an accurate and precise method for measuring range of motion of the shoulder and elbow?

PubMed

Russo, Russell R; Burn, Matthew B; Ismaily, Sabir K; Gerrie, Brayden J; Han, Shuyang; Alexander, Jerry; Lenherr, Christopher; Noble, Philip C; Harris, Joshua D; McCulloch, Patrick C

2018-03-01

Accurate measurements of shoulder and elbow motion are required for the management of musculoskeletal pathology. The purpose of this investigation was to compare three techniques for measuring motion. The authors hypothesized that digital photography would be equivalent in accuracy and show higher precision compared to the other two techniques. Using infrared motion capture analysis as the reference standard, shoulder flexion/abduction/internal rotation/external rotation and elbow flexion/extension were measured using visual estimation, goniometry, and digital photography on 10 fresh frozen cadavers. These measurements were performed by three physical therapists and three orthopaedic surgeons. Accuracy was defined by the difference from the reference standard (motion capture analysis), while precision was defined by the proportion of measurements within the authors' definition of clinical significance (10° for all motions except for elbow extension where 5° was used). Analysis of variance (ANOVA), t-tests, and chi-squared tests were used. Although statistically significant differences were found in measurement accuracy between the three techniques, none of these differences met the authors' definition of clinical significance. Precision of the measurements was significantly higher for both digital photography (shoulder abduction [93% vs. 74%, p < 0.001], shoulder internal rotation [97% vs. 83%, p = 0.001], and elbow flexion [93% vs. 65%, p < 0.001]) and goniometry (shoulder abduction [92% vs. 74%, p < 0.001] and shoulder internal rotation [94% vs. 83%, p = 0.008]) than visual estimation. Digital photography was more precise than goniometry for measurements of elbow flexion only [93% vs. 76%, p < 0.001]. There was no clinically significant difference in measurement accuracy between the three techniques for shoulder and elbow motion. Digital photography showed higher measurement precision compared to visual estimation for shoulder abduction, shoulder

Taking the Measure of the Universe : Precision Astrometry with SIM PlanetQuest

NASA Technical Reports Server (NTRS)

Unwin, Stephen C.; Shao, Michael; Tanner, Angelle M.; Allen, Ronald J.; Beichman, Charles A.; Boboltz, David; Catanzarite, Joseph H.; Chaboyer, Brian C.; Ciardi, David R.; Edberg, Stephen J.;

A new fitting method for measurement of the curvature radius of a short arc with high precision

NASA Astrophysics Data System (ADS)

Tao, Wei; Zhong, Hong; Chen, Xiao; Selami, Yassine; Zhao, Hui

2018-07-01

The measurement of an object with a short arc is widely encountered in scientific research and industrial production. As the most classic method of arc fitting, the least squares fitting method suffers from low precision when it is used for measurement of arcs with smaller central angles and fewer sampling points. The shorter the arc, the lower is the measurement accuracy. In order to improve the measurement precision of short arcs, a parameter constrained fitting method based on a four-parameter circle equation is proposed in this paper. The generalized Lagrange function was introduced together with the optimization by gradient descent method to reduce the influence from noise. The simulation and experimental results showed that the proposed method has high precision even when the central angle drops below 4° and it has good robustness when the noise standard deviation rises to 0.4 mm. This new fitting method is suitable for the high precision measurement of short arcs with smaller central angles without any prior information.

Using High-Precision Specific Gravity Measurements to Study Minerals in Undergraduate Geoscience Courses

ERIC Educational Resources Information Center

Brandriss, Mark E.

2010-01-01

This article describes ways to incorporate high-precision measurements of the specific gravities of minerals into undergraduate courses in mineralogy and physical geology. Most traditional undergraduate laboratory methods of measuring specific gravity are suitable only for unusually large samples, which severely limits their usefulness for student…

Assessing the precision of a time-sampling-based study among GPs: balancing sample size and measurement frequency.

PubMed

van Hassel, Daniël; van der Velden, Lud; de Bakker, Dinny; van der Hoek, Lucas; Batenburg, Ronald

2017-12-04

Our research is based on a technique for time sampling, an innovative method for measuring the working hours of Dutch general practitioners (GPs), which was deployed in an earlier study. In this study, 1051 GPs were questioned about their activities in real time by sending them one SMS text message every 3 h during 1 week. The required sample size for this study is important for health workforce planners to know if they want to apply this method to target groups who are hard to reach or if fewer resources are available. In this time-sampling method, however, standard power analyses is not sufficient for calculating the required sample size as this accounts only for sample fluctuation and not for the fluctuation of measurements taken from every participant. We investigated the impact of the number of participants and frequency of measurements per participant upon the confidence intervals (CIs) for the hours worked per week. Statistical analyses of the time-use data we obtained from GPs were performed. Ninety-five percent CIs were calculated, using equations and simulation techniques, for various different numbers of GPs included in the dataset and for various frequencies of measurements per participant. Our results showed that the one-tailed CI, including sample and measurement fluctuation, decreased from 21 until 3 h between one and 50 GPs. As a result of the formulas to calculate CIs, the increase of the precision continued and was lower with the same additional number of GPs. Likewise, the analyses showed how the number of participants required decreased if more measurements per participant were taken. For example, one measurement per 3-h time slot during the week requires 300 GPs to achieve a CI of 1 h, while one measurement per hour requires 100 GPs to obtain the same result. The sample size needed for time-use research based on a time-sampling technique depends on the design and aim of the study. In this paper, we showed how the precision of the

Measurement of whole tire profile

NASA Astrophysics Data System (ADS)

Yang, Yongyue; Jiao, Wenguang

2010-08-01

In this paper, a precision measuring device is developed for obtaining characteristic curve of tire profile and its geometric parameters. It consists of a laser displacement measurement unit, a closed-loop precision two-dimensional coordinate table, a step motor control system and a fast data acquisition and analysis system. Based on the laser trigonometry, a data map of tire profile and coordinate values of all points can be obtained through corresponding data transformation. This device has a compact structure, a convenient control, a simple hardware circuit design and a high measurement precision. Experimental results indicate that measurement precision can meet the customer accuracy requirement of +/-0.02 mm.

A neural measure of precision in visual working memory.

PubMed

Ester, Edward F; Anderson, David E; Serences, John T; Awh, Edward

2013-05-01

Recent studies suggest that the temporary storage of visual detail in working memory is mediated by sensory recruitment or sustained patterns of stimulus-specific activation within feature-selective regions of visual cortex. According to a strong version of this hypothesis, the relative "quality" of these patterns should determine the clarity of an individual's memory. Here, we provide a direct test of this claim. We used fMRI and a forward encoding model to characterize population-level orientation-selective responses in visual cortex while human participants held an oriented grating in memory. This analysis, which enables a precise quantitative description of multivoxel, population-level activity measured during working memory storage, revealed graded response profiles whose amplitudes were greatest for the remembered orientation and fell monotonically as the angular distance from this orientation increased. Moreover, interparticipant differences in the dispersion-but not the amplitude-of these response profiles were strongly correlated with performance on a concurrent memory recall task. These findings provide important new evidence linking the precision of sustained population-level responses in visual cortex and memory acuity.

Precise method for the measurement of catalase activity in honey.

PubMed

Huidobro, José F; Sánchez, M Pilar; Muniategui, Soledad; Sancho, M Teresa

2005-01-01

An improved method is reported for the determination of catalase activity in honey. We tested different dialysis membranes, dialysis fluid compositions and amounts, dialysis temperatures, sample amounts, and dialysis times. The best results were obtained by dialysis of 7.50 g sample in a cellulose dialysis sack, using two 3 L portions of 0.015 M sodium phosphate buffer (pH 7.0) as the dialysis fluid at 4 degrees C for 22 h. As in previous methods, catalase activity was determined on the basis of the rate of disappearance of the substrate, H202, with the H202 determined spectrophotometrically at 400 nm in an assay system containing o-dianisidine and peroxidase. Trials indicated that the best solvent for the o-dianisidine was 0.2 M sodium phosphate buffer, pH 6.1; the best starting H202 concentration was 3 mM; the best HCl concentration for stopping the reaction was 6 N; and the best sample volume for catalase measurement was 7.0 mL. Precision values (relative standard deviations for analyses of 10 subsamples of each of 3 samples) were high, ranging from 0.48% for samples with high catalase activity to 1.98% for samples with low catalase activity.

Pb and Sr isotope measurements by inductively coupled plasma mass spectrometer: efficient time management for precision improvement

NASA Astrophysics Data System (ADS)

Monna, F.; Loizeau, J.-L.; Thomas, B. A.; Guéguen, C.; Favarger, P.-Y.

1998-08-01

One of the factors limiting the precision of inductively coupled plasma mass spectrometry is the counting statistics, which depend upon acquisition time and ion fluxes. In the present study, the precision of the isotopic measurements of Pb and Sr is examined. The time of measurement is optimally shared for each isotope, using a mathematical simulation, to provide the lowest theoretical analytical error. Different algorithms of mass bias correction are also taken into account and evaluated in term of improvement of overall precision. Several experiments allow a comparison of real conditions with theory. The present method significantly improves the precision, regardless of the instrument used. However, this benefit is more important for equipment which originally yields a precision close to that predicted by counting statistics. Additionally, the procedure is flexible enough to be easily adapted to other problems, such as isotopic dilution.

Implementation of a high precision multi-measurement time-to-digital convertor on a Kintex-7 FPGA

NASA Astrophysics Data System (ADS)

Kuang, Jie; Wang, Yonggang; Cao, Qiang; Liu, Chong

2018-05-01

Time-to-digital convertors (TDCs) based on field programmable gate array (FPGA) are becoming more and more popular. Multi-measurement is an effective method to improve TDC precision beyond the cell delay limitation. However, the implementation of TDC with multi-measurement on FPGAs manufactured with 28 nm and more advanced process is facing new challenges. Benefiting from the ones-counter encoding scheme, which was developed in our previous work, we implement a ring oscillator multi-measurement TDC on a Xilinx Kintex-7 FPGA. Using the two TDC channels to measure time-intervals in the range (0 ns-30 ns), the average RMS precision can be improved to 5.76 ps, meanwhile the logic resource usage remains the same with the one-measurement TDC, and the TDC dead time is only 22 ns. The investigation demonstrates that the multi-measurement methods are still available for current main-stream FPGAs. Furthermore, the new implementation in this paper could make the trade-off among the time precision, resource usage and TDC dead time better than ever before.

Measurements of experimental precision for trials with cowpea (Vigna unguiculata L. Walp.) genotypes.

PubMed

Teodoro, P E; Torres, F E; Santos, A D; Corrêa, A M; Nascimento, M; Barroso, L M A; Ceccon, G

2016-05-09

The aim of this study was to evaluate the suitability of statistics as experimental precision degree measures for trials with cowpea (Vigna unguiculata L. Walp.) genotypes. Cowpea genotype yields were evaluated in 29 trials conducted in Brazil between 2005 and 2012. The genotypes were evaluated with a randomized block design with four replications. Ten statistics that were estimated for each trial were compared using descriptive statistics, Pearson correlations, and path analysis. According to the class limits established, selective accuracy and F-test values for genotype, heritability, and the coefficient of determination adequately estimated the degree of experimental precision. Using these statistics, 86.21% of the trials had adequate experimental precision. Selective accuracy and the F-test values for genotype, heritability, and the coefficient of determination were directly related to each other, and were more suitable than the coefficient of variation and the least significant difference (by the Tukey test) to evaluate experimental precision in trials with cowpea genotypes.

Development of ultra-precision micro-cavity measurement technique in HIT-UOI

NASA Astrophysics Data System (ADS)

Cui, Jiwen; Li, Lei; Tan, Jiubin

2010-08-01

Micro cavities with high aspect ratio are widely used in different fields including aerospace and defense industries with the development of manufacturing technology. So how to measure the dimension of these cavities has become one of the major research subjects in the field of measurement and instrument. This paper describes some activities of the precision micro cavity measurement technique in Center of Ultra-precision Optoelectronic Instrument (UOI), Harbin Institute of Technology (HIT). The key issue of micro cavity measurement in UOI is called touch-trigger measurement method. The first scheme is double optical fiber coupling, in which light coming from the incident optical fiber is transmitted in the reversal direction via the optical fiber coupling into the effluent optical fiber, the lateral displacement of the touch-trigger sensor is transformed into the deflexion of light coming out from the effluent optical fiber, and the deflexion is transformed into an image signal by the object lens and CCD capturing system. And the second scheme is micro focal-length collimation, in which a fiber stem with a ball mounted on its end is used as a probe and a small segment of it is used as a cylindrical lens to collimate a point light source and image it to a camera, the deflection of the fiber stem can be inferred from the change in image acquired by the camera with ultrahigh displacement sensitivity. Experiments for these activities will be given with a focus on the measurement results and repeatability uncertainty.

Pressure measurements with a precision of 0.001 ppm in magnetic fields at low temperatures

NASA Astrophysics Data System (ADS)

Miura, Y.; Matsushima, N.; Ando, T.; Kuno, S.; Inoue, S.; Ito, K.; Mamiya, T.

1993-11-01

Pressure measurements made by an ac bridge technique with a precision of 0.001 ppm in magnetic fields at low temperatures using a Straty-Adams type gauge are described. In order to improve the sensitivity and the long-term stability of the bridge system, coaxial cables without dielectric insulator were developed, with a small cable capacitance temperature coefficient of the impedance. This pressure measurement system has a sensitivity of dP/P˜5×10-10 and a long-term stability of dP/P˜2.4×10-9 over 18 h. This is especially useful for measurements such as electric and magnetic susceptibility measurements in magnetic fields at low temperatures requiring a high precision.

Precision Branching Ratio Measurement for the Superallowed &+circ; Emitter ^62Ga

NASA Astrophysics Data System (ADS)

Finlay, Paul; Svensson, C. E.; Austin, R. A. E.; Ball, G. C.; Bandyopadhyay, D.; Chaffey, A.; Chakrawarthy, R. S.; Garrett, P. E.; Grinyer, G. F.; Hackman, G.; Hyland, B.; Kanungo, R.; Leslie, J. R.; Mattoon, C.; Morton, A. C.; Pearson, C. J.; Ressler, J. J.; Sarazin, F.; Savajols, H.

2007-10-01

A high-precision branching ratio measurement for the superallowed &+circ; emitter ^62Ga has been made using the 8π γ-ray spectrometer in conjunction with the SCintillating Electron-Positron Tagging ARray (SCEPTAR) as part of an ongoing experimental program in superallowed Fermi beta decay studies at the Isotope Separator and Accelerator (ISAC) facility at TRIUMF in Vancouver, Canada, which delivered a high-purity beam of ˜10^4 ^62Ga/s in December 2005. The present work represents the highest statistics measurement of the ^62Ga superallowed branching ratio to date. 25 γ rays emitted following non-superallowed decay branches of ^62Ga have been identified and their intensities determined. These data yield a superallowed branching ratio with 10-4 precision, and our observed branch to the first nonanalogue 0^+ state sets a new upper limit on the isospin-mixing correction δC1^1. By comparing our ft value with the world average Ft, we make stringent tests of the different calculations for the isospin-symmetry-breaking correction δC, which is predicted to be large for ^62Ga.

U-238-U-234-Th-230-Th-232 systematics and the precise measurement of time over the past 500,000 years

NASA Technical Reports Server (NTRS)

Edwards, R. Lawrence; Chen, J. H.; Wasserburg, G. J.

1987-01-01

A method is presented for the high-precision measurement of the Th-230 abundance in corals by isotope-dilution mass spectrometry using techniques developed by Chen and Wasserburg (1980, 1981) and Chen et al. (1986). It is shown that 6 x 10 to the 8th atoms of Th-230 can be measured to + or - 30 percent (2 sigma) and 2 x 10 to the 10th atoms of Th-230 to + or - 2 percent. The time over which useful age data on corals can be obtained ranges from a few years to about 500 ky, with the uncertainty in age ranging from 5 y for a 180-y-old coral, to 44 y for a 8294-y-old coral, to 1.1 ky for a 123.1-ky-old coral. Ages were determined with high analytical precision for several corals that grew during high sea-level stands about 120 ky ago, supporting the view that the dominant cause of Pleistocene climate change was Milankovitch forcing.

Precision measurements with atom interferometry

NASA Astrophysics Data System (ADS)

Schubert, Christian; Abend, Sven; Schlippert, Dennis; Ertmer, Wolfgang; Rasel, Ernst M.

2017-04-01

Interferometry with matter waves enables precise measurements of rotations, accelerations, and differential accelerations [1-5]. This is exploited for determining fundamental constants [2], in fundamental science as e.g. testing the universality of free fall [3], and is applied for gravimetry [4], and gravity gradiometry [2,5]. At the Institut für Quantenoptik in Hannover, different approaches are pursued. A large scale device is designed and currently being set up to investigate the gain in precision for gravimetry, gradiometry, and fundamental tests on large baselines [6]. For field applications, a compact and transportable device is being developed. Its key feature is an atom chip source providing a collimated high flux of atoms which is expected to mitigate systematic uncertainties [7,8]. The atom chip technology and miniaturization benefits from microgravity experiments in the drop tower in Bremen and sounding rocket experiments [8,9] which act as pathfinders for space borne operation [10]. This contribution will report about our recent results. The presented work is supported by the CRC 1227 DQ-mat, the CRC 1128 geo-Q, the RTG 1729, the QUEST-LFS, and by the German Space Agency (DLR) with funds provided by the Federal Ministry of Economic Affairs and Energy (BMWi) due to an enactment of the German Bundestag under Grant No. DLR 50WM1552-1557. [1] P. Berg et al., Phys. Rev. Lett., 114, 063002, 2015; I. Dutta et al., Phys. Rev. Lett., 116, 183003, 2016. [2] J. B. Fixler et al., Science 315, 74 (2007); G. Rosi et al., Nature 510, 518, 2014. [3] D. Schlippert et al., Phys. Rev. Lett., 112, 203002, 2014. [4] A. Peters et al., Nature 400, 849, 1999; A. Louchet-Chauvet et al., New J. Phys. 13, 065026, 2011; C. Freier et al., J. of Phys.: Conf. Series 723, 012050, 2016. [5] J. M. McGuirk et al., Phys. Rev. A 65, 033608, 2002; P. Asenbaum et al., arXiv:1610.03832. [6] J. Hartwig et al., New J. Phys. 17, 035011, 2015. [7] H. Ahlers et al., Phys. Rev. Lett. 116, 173601

Design of Measure and Control System for Precision Pesticide Deploying Dynamic Simulating Device

NASA Astrophysics Data System (ADS)

Liang, Yong; Liu, Pingzeng; Wang, Lu; Liu, Jiping; Wang, Lang; Han, Lei; Yang, Xinxin

A measure and control system for precision deploying pesticide simulating equipment is designed in order to study pesticide deployment technology. The system can simulate every state of practical pesticide deployment, and carry through precise, simultaneous measure to every factor affecting pesticide deployment effects. The hardware and software incorporates a structural design of modularization. The system is divided into many different function modules of hardware and software, and exploder corresponding modules. The modules’ interfaces are uniformly defined, which is convenient for module connection, enhancement of system’s universality, explodes efficiency and systemic reliability, and make the program’s characteristics easily extended and easy maintained. Some relevant hardware and software modules can be adapted to other measures and control systems easily. The paper introduces the design of special numeric control system, the main module of information acquisition system and the speed acquisition module in order to explain the design process of the module.

Precision measurement of the mass of the hc(1P1) state of charmonium.

PubMed

Dobbs, S; Metreveli, Z; Seth, K K; Tomaradze, A; Libby, J; Powell, A; Wilkinson, G; Ecklund, K M; Love, W; Savinov, V; Lopez, A; Mendez, H; Ramirez, J; Ge, J Y; Miller, D H; Shipsey, I P J; Xin, B; Adams, G S; Anderson, M; Cummings, J P; Danko, I; Hu, D; Moziak, B; Napolitano, J; He, Q; Insler, J; Muramatsu, H; Park, C S; Thorndike, E H; Yang, F; Artuso, M; Blusk, S; Khalil, S; Li, J; Mountain, R; Nisar, S; Randrianarivony, K; Sultana, N; Skwarnicki, T; Stone, S; Wang, J C; Zhang, L M; Bonvicini, G; Cinabro, D; Dubrovin, M; Lincoln, A; Naik, P; Rademacker, J; Asner, D M; Edwards, K W; Reed, J; Briere, R A; Ferguson, T; Tatishvili, G; Vogel, H; Watkins, M E; Rosner, J L; Alexander, J P; Cassel, D G; Duboscq, J E; Ehrlich, R; Fields, L; Galik, R S; Gibbons, L; Gray, R; Gray, S W; Hartill, D L; Heltsley, B K; Hertz, D; Hunt, J M; Kandaswamy, J; Kreinick, D L; Kuznetsov, V E; Ledoux, J; Mahlke-Krüger, H; Mohapatra, D; Onyisi, P U E; Patterson, J R; Peterson, D; Riley, D; Ryd, A; Sadoff, A J; Shi, X; Stroiney, S; Sun, W M; Wilksen, T; Athar, S B; Patel, R; Yelton, J; Rubin, P; Eisenstein, B I; Karliner, I; Mehrabyan, S; Lowrey, N; Selen, M; White, E J; Wiss, J; Mitchell, R E; Shepherd, M R; Besson, D; Pedlar, T K; Cronin-Hennessy, D; Gao, K Y; Hietala, J; Kubota, Y; Klein, T; Lang, B W; Poling, R; Scott, A W; Zweber, P

2008-10-31

A precision measurement of the mass of the h_{c}(1P1) state of charmonium has been made using a sample of 24.5x10;{6} psi(2S) events produced in e;{+}e;{-} annihilation at the Cornell Electron Storage Ring (CESR). The reaction used was psi(2S)-->pi;{0}h_{c}, pi;{0}-->gammagamma, h_{c}-->gammaeta_{c}, and the reaction products were detected in the CLEO-c detector. Data have been analyzed both for the inclusive reaction and for the exclusive reactions in which eta_{c} decays are reconstructed in 15 hadronic decay channels. Consistent results are obtained in the two analyses. The averaged results of the present measurements are M(h_{c})=3525.28+/-0.19(stat.)+/-0.12(syst.) MeV, and B(psi(2S)-->pi;{0}h_{c})xB(h_{c}-->gammaeta_{c})=(4.19+/-0.32+/-0.45)x10;{-4}. Using the ;{3}P_{J} centroid mass, DeltaM_{hf}(1P) identical withM(chi_{cJ})-M(h_{c})=+0.02+/-0.19+/-0.13 MeV.

Is digital photography an accurate and precise method for measuring range of motion of the hip and knee?

PubMed

Russo, Russell R; Burn, Matthew B; Ismaily, Sabir K; Gerrie, Brayden J; Han, Shuyang; Alexander, Jerry; Lenherr, Christopher; Noble, Philip C; Harris, Joshua D; McCulloch, Patrick C

2017-09-07

Accurate measurements of knee and hip motion are required for management of musculoskeletal pathology. The purpose of this investigation was to compare three techniques for measuring motion at the hip and knee. The authors hypothesized that digital photography would be equivalent in accuracy and show higher precision compared to the other two techniques. Using infrared motion capture analysis as the reference standard, hip flexion/abduction/internal rotation/external rotation and knee flexion/extension were measured using visual estimation, goniometry, and photography on 10 fresh frozen cadavers. These measurements were performed by three physical therapists and three orthopaedic surgeons. Accuracy was defined by the difference from the reference standard, while precision was defined by the proportion of measurements within either 5° or 10°. Analysis of variance (ANOVA), t-tests, and chi-squared tests were used. Although two statistically significant differences were found in measurement accuracy between the three techniques, neither of these differences met clinical significance (difference of 1.4° for hip abduction and 1.7° for the knee extension). Precision of measurements was significantly higher for digital photography than: (i) visual estimation for hip abduction and knee extension, and (ii) goniometry for knee extension only. There was no clinically significant difference in measurement accuracy between the three techniques for hip and knee motion. Digital photography only showed higher precision for two joint motions (hip abduction and knee extension). Overall digital photography shows equivalent accuracy and near-equivalent precision to visual estimation and goniometry.

Vacuum ultraviolet spectropolarimeter design for precise polarization measurements.

PubMed

Narukage, Noriyuki; Auchère, Frédéric; Ishikawa, Ryohko; Kano, Ryouhei; Tsuneta, Saku; Winebarger, Amy R; Kobayashi, Ken

2015-03-10

Precise polarization measurements in the vacuum ultraviolet (VUV) region provide a new means for inferring weak magnetic fields in the upper atmosphere of the Sun and stars. We propose a VUV spectropolarimeter design ideally suited for this purpose. This design is proposed and adopted for the NASA-JAXA chromospheric lyman-alpha spectropolarimeter (CLASP), which will record the linear polarization (Stokes Q and U) of the hydrogen Lyman-α line (121.567 nm) profile. The expected degree of polarization is on the order of 0.1%. Our spectropolarimeter has two optically symmetric channels to simultaneously measure orthogonal linear polarization states with a single concave diffraction grating that serves both as the spectral dispersion element and beam splitter. This design has a minimal number of reflective components with a high VUV throughput. Consequently, these design features allow us to minimize the polarization errors caused by possible time variation of the VUV flux during the polarization modulation and by statistical photon noise.

Precision positioning device

DOEpatents

McInroy, John E.

2005-01-18

A precision positioning device is provided. The precision positioning device comprises a precision measuring/vibration isolation mechanism. A first plate is provided with the precision measuring mean secured to the first plate. A second plate is secured to the first plate. A third plate is secured to the second plate with the first plate being positioned between the second plate and the third plate. A fourth plate is secured to the third plate with the second plate being positioned between the third plate and the fourth plate. An adjusting mechanism for adjusting the position of the first plate, the second plate, the third plate, and the fourth plate relative to each other.

Precision Measurement of the Beryllium-7 Solar Neutrino Interaction Rate in Borexino

NASA Astrophysics Data System (ADS)

Saldanha, Richard Nigel

Solar neutrinos, since their first detection nearly forty years ago, have revealed valuable information regarding the source of energy production in the Sun, and have demonstrated that neutrino oscillations are well described by the Large Mixing Angle (LMA) oscillation parameters with matter interactions due to the Mikheyev-Smirnov-Wolfenstein (MSW) effect. This thesis presents a precision measurement of the 7Be solar neutrino interaction rate within Borexino, an underground liquid scintillator detector that is designed to measure solar neutrino interactions through neutrino-electron elastic scattering. The thesis includes a detailed description of the analysis techniques developed and used for this measurement as well as an evaluation of the relevant systematic uncertainties that affect the precision of the result. The rate of neutrino-electron elastic scattering from 0.862 MeV 7Be neutrinos is determined to be 45.4 +/- 1.6 (stat) +/- 1.5 (sys) counts/day/100 ton. Due to extensive detector calibrations and improved analysis methods, the systematic uncertainty in the interaction rate has been reduced by more than a factor of two from the previous evaluation. In the no-oscillation hypothesis, the interaction rate corresponds to a 0.862 MeV 7Be electron neutrino flux of (2.75 +/- 0.13) x 10 9 cm-2 sec-1. Including the predicted neutrino flux from the Standard Solar Model yields an electron neutrino survival probability of Pee 0.51 +/- 0.07 and rules out the no-oscillation hypothesis at 5.1sigma The LMA-MSW neutrino oscillation model predicts a transition in the solar Pee value between low (< 1 MeV) and high (> 10 MeV) energies which has not yet been experimentally confirmed. This result, in conjunction with the Standard Solar Model, represents the most precise measurement of the electron neutrino survival probability for solar neutrinos at sub-MeV energies.

Impact of beam-beam effects on precision luminosity measurements at the ILC

NASA Astrophysics Data System (ADS)

Rimbault, C.; Bambade, P.; Mönig, K.; Schulte, D.

2007-09-01

In this paper, the impact of beam-beam effects on the precision luminosity measurement at the International Linear Collider is investigated quantitatively for the first time. GUINEA-PIG, a beam-beam interaction simulation tool, is adapted to treat the space charge effects affecting the Bhabha events used in this measurement. The biases due to the resulting changes in kinematics are evaluated for different center-of-mass energies and beam parameters.

Pico-coulomb charge measured at BELLA to percent-level precision using a Turbo-ICT

NASA Astrophysics Data System (ADS)

Nakamura, K.; Mittelberger, D. E.; Gonsalves, A. J.; Daniels, J.; Mao, H.-S.; Stulle, F.; Bergoz, J.; Leemans, W. P.

2016-03-01

Precise diagnostics of picocoulomb level particle bunches produced by laser plasma accelerators (LPAs) can be a significant challenge. Without proper care, the small signals associated with such bunches can be dominated by a background generated by laser, target, laser-plasma interaction and particle induced radiation. In this paper, we report on first charge measurements using the newly developed Turbo-ICT for LPAs. We outline the Turbo-ICT working principle, which allows precise sub-picocoulomb measurements even in the presence of significant background signals. A comparison of the Turbo-ICT, a conventional integrating current transformer (ICT) and a scintillating screen (Lanex) was carried out at the Berkeley Lab Laser Accelerator. Results show that the Turbo-ICT can measure sub-picocoulomb charge accurately and has significantly improved noise immunity compared to the ICT.

Technical Report on the Modification of 3-Dimensional Non-contact Human Body Laser Scanner for the Measurement of Anthropometric Dimensions: Verification of its Accuracy and Precision.

PubMed

Jafari Roodbandi, Akram Sadat; Naderi, Hamid; Hashenmi-Nejad, Naser; Choobineh, Alireza; Baneshi, Mohammad Reza; Feyzi, Vafa

2017-01-01

Introduction: Three-dimensional (3D) scanners are widely used in medicine. One of the applications of 3D scanners is the acquisition of anthropometric dimensions for ergonomics and the creation of an anthropometry data bank. The aim of this study was to evaluate the precision and accuracy of a modified 3D scanner fabricated in this study. Methods: In this work, a 3D scan of the human body was obtained using DAVID Laser Scanner software and its calibration background, a linear low-power laser, and one advanced webcam. After the 3D scans were imported to the Geomagic software, 10 anthropometric dimensions of 10 subjects were obtained. The measurements of the 3D scanner were compared to the measurements of the same dimensions by a direct anthropometric method. The precision and accuracy of the measurements of the 3D scanner were then evaluated. The obtained data were analyzed using an independent sample t test with the SPSS software. Results: The minimum and maximum measurement differences from three consecutive scans by the 3D scanner were 0.03 mm and 18 mm, respectively. The differences between the measurements by the direct anthropometry method and the 3D scanner were not statistically significant. Therefore, the accuracy of the 3D scanner is acceptable. Conclusion: Future studies will need to focus on the improvement of the scanning speed and the quality of the scanned image.

Technical Report on the Modification of 3-Dimensional Non-contact Human Body Laser Scanner for the Measurement of Anthropometric Dimensions: Verification of its Accuracy and Precision

PubMed Central

Jafari Roodbandi, Akram Sadat; Naderi, Hamid; Hashenmi-Nejad, Naser; Choobineh, Alireza; Baneshi, Mohammad Reza; Feyzi, Vafa

2017-01-01

Introduction: Three-dimensional (3D) scanners are widely used in medicine. One of the applications of 3D scanners is the acquisition of anthropometric dimensions for ergonomics and the creation of an anthropometry data bank. The aim of this study was to evaluate the precision and accuracy of a modified 3D scanner fabricated in this study. Methods: In this work, a 3D scan of the human body was obtained using DAVID Laser Scanner software and its calibration background, a linear low-power laser, and one advanced webcam. After the 3D scans were imported to the Geomagic software, 10 anthropometric dimensions of 10 subjects were obtained. The measurements of the 3D scanner were compared to the measurements of the same dimensions by a direct anthropometric method. The precision and accuracy of the measurements of the 3D scanner were then evaluated. The obtained data were analyzed using an independent sample t test with the SPSS software. Results: The minimum and maximum measurement differences from three consecutive scans by the 3D scanner were 0.03 mm and 18 mm, respectively. The differences between the measurements by the direct anthropometry method and the 3D scanner were not statistically significant. Therefore, the accuracy of the 3D scanner is acceptable. Conclusion: Future studies will need to focus on the improvement of the scanning speed and the quality of the scanned image. PMID:28912940

Precision Laser Spectroscopic Measurement of Helium -4(1S2S S(3) to 1S2P P(3)) Lamb Shift and Fine Structure

NASA Astrophysics Data System (ADS)

Dixson, Ronald Gene

This thesis is a presentation of the results of a precise measurement of the absolute wavelength and fine structure splitting of the 1s2s ^3S to 1s2p ^3P transition of the ^4He atom. The experiment described in this thesis is the first one in which laser spectroscopy has been done on the 2 ^3S to 2^3 P transition in a metastable atomic beam. The energy interval between the 2^3S and the 2^3P state is precisely determined by comparison of the absolute wavelength of the transition with our standard laser (an iodine stabilized He-Ne laser with an accuracy of 1.6 parts in 10^{10 }) in a Fabry-Perot interferometer. The experimental Lamb shift of the transition is determined by subtracting from the measured frequency the precisely known non-quantum electrodynamic contributions to the theoretical value of the interval. From our measurements of the absolute wavelength, the following weighted (2J + 1) average for the 2^3S to 2^3P transition frequency and experimental Lamb Shift are obtained:eqalign{& rm f_{2S{-}2P} = 276 736 495.59 (5) rm MHz.cr& {bf L}[ 2^3Sto2 ^3P] = 5311.26 (5) rm MHz.cr} Our value for the Lamb Shift is in agreement with the best previous measurement but a factor of 60 more precise. It is also two orders of magnitude more precise than the present theoretical calculation, presenting quite a challenge to theorists. Nevertheless, this work is very timely since it is anticipated (DRA94) (MOR94) that the theory will reach this level in the near future. The measured fine structure splittings of the 2^3P level are: eqalign{rm 2^3P_0to rm2^3P_2 &: 31908.135 (3) rm MHzcrrm 2^3P_1to rm2^3P_2 &: sk{5}2291.173 (3) rm MHz}These results are more precise than previous microwave measurements and in significant disagreement with them, a situation which is especially timely and interesting since new theoretical calculations of these fine structure intervals (DRA94) at this level of precision are nearing completion.

Precision measurement of the mass difference between light nuclei and anti-nuclei

NASA Astrophysics Data System (ADS)

Alice Collaboration; Adam, J.; Adamová, D.; Aggarwal, M. M.; Aglieri Rinella, G.; Agnello, M.; Agrawal, N.; Ahammed, Z.; Ahmed, I.; Ahn, S. U.; Aimo, I.; Aiola, S.; Ajaz, M.; Akindinov, A.; Alam, S. N.; Aleksandrov, D.; Alessandro, B.; Alexandre, D.; Alfaro Molina, R.; Alici, A.; Alkin, A.; Alme, J.; Alt, T.; Altinpinar, S.; Altsybeev, I.; Alves Garcia Prado, C.; Andrei, C.; Andronic, A.; Anguelov, V.; Anielski, J.; Antičić, T.; Antinori, F.; Antonioli, P.; Aphecetche, L.; Appelshäuser, H.; Arcelli, S.; Armesto, N.; Arnaldi, R.; Aronsson, T.; Arsene, I. C.; Arslandok, M.; Augustinus, A.; Averbeck, R.; Azmi, M. D.; Bach, M.; Badalà, A.; Baek, Y. W.; Bagnasco, S.; Bailhache, R.; Bala, R.; Baldisseri, A.; Ball, M.; Baltasar Dos Santos Pedrosa, F.; Baral, R. C.; Barbano, A. M.; Barbera, R.; Barile, F.; Barnaföldi, G. G.; Barnby, L. S.; Barret, V.; Bartalini, P.; Bartke, J.; Bartsch, E.; Basile, M.; Bastid, N.; Basu, S.; Bathen, B.; Batigne, G.; Batista Camejo, A.; Batyunya, B.; Batzing, P. C.; Bearden, I. G.; Beck, H.; Bedda, C.; Behera, N. K.; Belikov, I.; Bellini, F.; Bello Martinez, H.; Bellwied, R.; Belmont, R.; Belmont-Moreno, E.; Belyaev, V.; Bencedi, G.; Beole, S.; Berceanu, I.; Bercuci, A.; Berdnikov, Y.; Berenyi, D.; Bertens, R. A.; Berzano, D.; Betev, L.; Bhasin, A.; Bhat, I. R.; Bhati, A. K.; Bhattacharjee, B.; Bhom, J.; Bianchi, L.; Bianchi, N.; Bianchin, C.; Bielčík, J.; Bielčíková, J.; Bilandzic, A.; Biswas, S.; Bjelogrlic, S.; Blanco, F.; Blau, D.; Blume, C.; Bock, F.; Bogdanov, A.; Bøggild, H.; Boldizsár, L.; Bombara, M.; Book, J.; Borel, H.; Borissov, A.; Borri, M.; Bossú, F.; Botje, M.; Botta, E.; Böttger, S.; Braun-Munzinger, P.; Bregant, M.; Breitner, T.; Broker, T. A.; Browning, T. A.; Broz, M.; Brucken, E. J.; Bruna, E.; Bruno, G. E.; Budnikov, D.; Buesching, H.; Bufalino, S.; Buncic, P.; Busch, O.; Buthelezi, Z.; Buxton, J. T.; Caffarri, D.; Cai, X.; Caines, H.; Calero Diaz, L.; Caliva, A.; Calvo Villar, E.; Camerini, P.; Carena, F.; Carena, W.; Castillo Castellanos, J.; Castro, A. J.; Casula, E. A. R.; Cavicchioli, C.; Ceballos Sanchez, C.; Cepila, J.; Cerello, P.; Chang, B.; Chapeland, S.; Chartier, M.; Charvet, J. L.; Chattopadhyay, Subhasis; Chattopadhyay, Sukalyan; Chelnokov, V.; Cherney, M.; Cheshkov, C.; Cheynis, B.; Chibante Barroso, V.; Chinellato, D. D.; Chochula, P.; Choi, K.; Chojnacki, M.; Choudhury, S.; Christakoglou, P.; Christensen, C. H.; Christiansen, P.; Chujo, T.; Chung, S. U.; Cicalo, C.; Cifarelli, L.; Cindolo, F.; Cleymans, J.; Colamaria, F.; Colella, D.; Collu, A.; Colocci, M.; Conesa Balbastre, G.; Conesa Del Valle, Z.; Connors, M. E.; Contreras, J. G.; Cormier, T. M.; Corrales Morales, Y.; Cortés Maldonado, I.; Cortese, P.; Cosentino, M. R.; Costa, F.; Crochet, P.; Cruz Albino, R.; Cuautle, E.; Cunqueiro, L.; Dahms, T.; Dainese, A.; Danu, A.; Das, D.; Das, I.; Das, S.; Dash, A.; Dash, S.; de, S.; de Caro, A.; de Cataldo, G.; de Cuveland, J.; de Falco, A.; de Gruttola, D.; De Marco, N.; de Pasquale, S.; Deisting, A.; Deloff, A.; Dénes, E.; D'Erasmo, G.; di Bari, D.; di Mauro, A.; di Nezza, P.; Diaz Corchero, M. A.; Dietel, T.; Dillenseger, P.; Divià, R.; Djuvsland, Ø.; Dobrin, A.; Dobrowolski, T.; Domenicis Gimenez, D.; Dönigus, B.; Dordic, O.; Dubey, A. K.; Dubla, A.; Ducroux, L.; Dupieux, P.; Ehlers, R. J.; Elia, D.; Engel, H.; Erazmus, B.; Erhardt, F.; Eschweiler, D.; Espagnon, B.; Estienne, M.; Esumi, S.; Evans, D.; Evdokimov, S.; Eyyubova, G.; Fabbietti, L.; Fabris, D.; Faivre, J.; Fantoni, A.; Fasel, M.; Feldkamp, L.; Felea, D.; Feliciello, A.; Feofilov, G.; Ferencei, J.; Fernández Téllez, A.; Ferreiro, E. G.; Ferretti, A.; Festanti, A.; Figiel, J.; Figueredo, M. A. S.; Filchagin, S.; Finogeev, D.; Fionda, F. M.; Fiore, E. M.; Fleck, M. G.; Floris, M.; Foertsch, S.; Foka, P.; Fokin, S.; Fragiacomo, E.; Francescon, A.; Frankenfeld, U.; Fuchs, U.; Furget, C.; Furs, A.; Fusco Girard, M.; Gaardhøje, J. J.; Gagliardi, M.; Gago, A. M.; Gallio, M.; Gangadharan, D. R.; Ganoti, P.; Gao, C.; Garabatos, C.; Garcia-Solis, E.; Gargiulo, C.; Gasik, P.; Germain, M.; Gheata, A.; Gheata, M.; Ghosh, P.; Ghosh, S. K.; Gianotti, P.; Giubellino, P.; Giubilato, P.; Gladysz-Dziadus, E.; Glässel, P.; Goméz Coral, D. M.; Gomez Ramirez, A.; González-Zamora, P.; Gorbunov, S.; Görlich, L.; Gotovac, S.; Grabski, V.; Graczykowski, L. K.; Grelli, A.; Grigoras, A.; Grigoras, C.; Grigoriev, V.; Grigoryan, A.; Grigoryan, S.; Grinyov, B.; Grion, N.; Grosse-Oetringhaus, J. F.; Grossiord, J.-Y.; Grosso, R.; Guber, F.; Guernane, R.; Guerzoni, B.; Gulbrandsen, K.; Gulkanyan, H.; Gunji, T.; Gupta, A.; Gupta, R.; Haake, R.; Haaland, Ø.; Hadjidakis, C.; Haiduc, M.; Hamagaki, H.; Hamar, G.; Hanratty, L. D.; Hansen, A.; Harris, J. W.; Hartmann, H.; Harton, A.; Hatzifotiadou, D.; Hayashi, S.; Heckel, S. T.; Heide, M.; Helstrup, H.; Herghelegiu, A.; Herrera Corral, G.; Hess, B. A.; Hetland, K. F.; Hilden, T. E.; Hillemanns, H.; Hippolyte, B.; Hristov, P.; Huang, M.; Humanic, T. J.; Hussain, N.; Hussain, T.; Hutter, D.; Hwang, D. S.; Ilkaev, R.; Ilkiv, I.; Inaba, M.; Ionita, C.; Ippolitov, M.; Irfan, M.; Ivanov, M.; Ivanov, V.; Izucheev, V.; Jacobs, P. M.; Jahnke, C.; Jang, H. J.; Janik, M. A.; Jayarathna, P. H. S. Y.; Jena, C.; Jena, S.; Jimenez Bustamante, R. T.; Jones, P. G.; Jung, H.; Jusko, A.; Kalinak, P.; Kalweit, A.; Kamin, J.; Kang, J. H.; Kaplin, V.; Kar, S.; Karasu Uysal, A.; Karavichev, O.; Karavicheva, T.; Karpechev, E.; Kebschull, U.; Keidel, R.; Keijdener, D. L. D.; Keil, M.; Khan, K. H.; Khan, M. Mohisin; Khan, P.; Khan, S. A.; Khanzadeev, A.; Kharlov, Y.; Kileng, B.; Kim, B.; Kim, D. W.; Kim, D. J.; Kim, H.; Kim, J. S.; Kim, Mimae.; Kim, Minwoo; Kim, S.; Kim, T.; Kirsch, S.; Kisel, I.; Kiselev, S.; Kisiel, A.; Kiss, G.; Klay, J. L.; Klein, C.; Klein, J.; Klein-Bösing, C.; Kluge, A.; Knichel, M. L.; Knospe, A. G.; Kobayashi, T.; Kobdaj, C.; Kofarago, M.; Köhler, M. K.; Kollegger, T.; Kolojvari, A.; Kondratiev, V.; Kondratyeva, N.; Kondratyuk, E.; Konevskikh, A.; Kour, M.; Kouzinopoulos, C.; Kovalenko, V.; Kowalski, M.; Kox, S.; Koyithatta Meethaleveedu, G.; Kral, J.; Králik, I.; Kravčáková, A.; Krelina, M.; Kretz, M.; Krivda, M.; Krizek, F.; Kryshen, E.; Krzewicki, M.; Kubera, A. M.; Kučera, V.; Kucheriaev, Y.; Kugathasan, T.; Kuhn, C.; Kuijer, P. G.; Kulakov, I.; Kumar, A.; Kumar, J.; Kumar, L.; Kurashvili, P.; Kurepin, A.; Kurepin, A. B.; Kuryakin, A.; Kushpil, S.; Kweon, M. J.; Kwon, Y.; La Pointe, S. L.; La Rocca, P.; Lagana Fernandes, C.; Lakomov, I.; Langoy, R.; Lara, C.; Lardeux, A.; Lattuca, A.; Laudi, E.; Lea, R.; Leardini, L.; Lee, G. R.; Lee, S.; Legrand, I.; Lehnert, J.; Lemmon, R. C.; Lenti, V.; Leogrande, E.; León Monzón, I.; Leoncino, M.; Lévai, P.; Li, S.; Li, X.; Lien, J.; Lietava, R.; Lindal, S.; Lindenstruth, V.; Lippmann, C.; Lisa, M. A.; Ljunggren, H. M.; Lodato, D. F.; Loenne, P. I.; Loggins, V. R.; Loginov, V.; Loizides, C.; Lopez, X.; López Torres, E.; Lowe, A.; Lu, X.-G.; Luettig, P.; Lunardon, M.; Luparello, G.; Maevskaya, A.; Mager, M.; Mahajan, S.; Mahmood, S. M.; Maire, A.; Majka, R. D.; Malaev, M.; Maldonado Cervantes, I.; Malinina, L.; Mal'Kevich, D.; Malzacher, P.; Mamonov, A.; Manceau, L.; Manko, V.; Manso, F.; Manzari, V.; Marchisone, M.; Mareš, J.; Margagliotti, G. V.; Margotti, A.; Margutti, J.; Marín, A.; Markert, C.; Marquard, M.; Martashvili, I.; Martin, N. A.; Martin Blanco, J.; Martinengo, P.; Martínez, M. I.; Martínez García, G.; Martinez Pedreira, M.; Martynov, Y.; Mas, A.; Masciocchi, S.; Masera, M.; Masoni, A.; Massacrier, L.; Mastroserio, A.; Matyja, A.; Mayer, C.; Mazer, J.; Mazzoni, M. A.; McDonald, D.; Meddi, F.; Menchaca-Rocha, A.; Meninno, E.; Mercado Pérez, J.; Meres, M.; Miake, Y.; Mieskolainen, M. M.; Mikhaylov, K.; Milano, L.; Milosevic, J.; Minervini, L. M.; Mischke, A.; Mishra, A. N.; Miśkowiec, D.; Mitra, J.; Mitu, C. M.; Mohammadi, N.; Mohanty, B.; Molnar, L.; Montaño Zetina, L.; Montes, E.; Morando, M.; Moreira de Godoy, D. A.; Moreno, L. A. P.; Moretto, S.; Morreale, A.; Morsch, A.; Muccifora, V.; Mudnic, E.; Mühlheim, D.; Muhuri, S.; Mukherjee, M.; Müller, H.; Mulligan, J. D.; Munhoz, M. G.; Murray, S.; Musa, L.; Musinsky, J.; Nandi, B. K.; Nania, R.; Nappi, E.; Naru, M. U.; Nattrass, C.; Nayak, K.; Nayak, T. K.; Nazarenko, S.; Nedosekin, A.; Nellen, L.; Ng, F.; Nicassio, M.; Niculescu, M.; Niedziela, J.; Nielsen, B. S.; Nikolaev, S.; Nikulin, S.; Nikulin, V.; Noferini, F.; Nomokonov, P.; Nooren, G.; Norman, J.; Nyanin, A.; Nystrand, J.; Oeschler, H.; Oh, S.; Oh, S. K.; Ohlson, A.; Okatan, A.; Okubo, T.; Olah, L.; Oleniacz, J.; Oliveira da Silva, A. C.; Oliver, M. H.; Onderwaater, J.; Oppedisano, C.; Ortiz Velasquez, A.; Oskarsson, A.; Otwinowski, J.; Oyama, K.; Ozdemir, M.; Pachmayer, Y.; Pagano, P.; Paić, G.; Pajares, C.; Pal, S. K.; Pan, J.; Pandey, A. K.; Pant, D.; Papikyan, V.; Pappalardo, G. S.; Pareek, P.; Park, W. J.; Parmar, S.; Passfeld, A.; Paticchio, V.; Paul, B.; Pawlak, T.; Peitzmann, T.; Pereira da Costa, H.; Pereira de Oliveira Filho, E.; Peresunko, D.; Pérez Lara, C. E.; Peskov, V.; Pestov, Y.; Petráček, V.; Petrov, V.; Petrovici, M.; Petta, C.; Piano, S.; Pikna, M.; Pillot, P.; Pinazza, O.; Pinsky, L.; Piyarathna, D. B.; Płoskoń, M.; Planinic, M.; Pluta, J.; Pochybova, S.; Podesta-Lerma, P. L. M.; Poghosyan, M. G.; Polichtchouk, B.; Poljak, N.; Poonsawat, W.; Pop, A.; Porteboeuf-Houssais, S.; Porter, J.; Pospisil, J.; Prasad, S. K.; Preghenella, R.; Prino, F.; Pruneau, C. A.; Pshenichnov, I.; Puccio, M.; Puddu, G.; Pujahari, P.; Punin, V.; Putschke, J.; Qvigstad, H.; Rachevski, A.; Raha, S.; Rajput, S.; Rak, J.; Rakotozafindrabe, A.; Ramello, L.; Raniwala, R.; Raniwala, S.; Räsänen, S. S.; Rascanu, B. T.; Rathee, D.; Razazi, V.; Read, K. F.; Real, J. S.; Redlich, K.; Reed, R. J.; Rehman, A.; Reichelt, P.; Reicher, M.; Reidt, F.; Ren, X.; Renfordt, R.; Reolon, A. R.; Reshetin, A.; Rettig, F.; Revol, J.-P.; Reygers, K.; Riabov, V.; Ricci, R. A.; Richert, T.; Richter, M.; Riedler, P.; Riegler, W.; Riggi, F.; Ristea, C.; Rivetti, A.; Rocco, E.; Rodríguez Cahuantzi, M.; Rodriguez Manso, A.; Røed, K.; Rogochaya, E.; Rohr, D.; Röhrich, D.; Romita, R.; Ronchetti, F.; Ronflette, L.; Rosnet, P.; Rossi, A.; Roukoutakis, F.; Roy, A.; Roy, C.; Roy, P.; Rubio Montero, A. J.; Rui, R.; Russo, R.; Ryabinkin, E.; Ryabov, Y.; Rybicki, A.; Sadovsky, S.; Šafařík, K.; Sahlmuller, B.; Sahoo, P.; Sahoo, R.; Sahoo, S.; Sahu, P. K.; Saini, J.; Sakai, S.; Saleh, M. A.; Salgado, C. A.; Salzwedel, J.; Sambyal, S.; Samsonov, V.; Sanchez Castro, X.; Šándor, L.; Sandoval, A.; Sano, M.; Santagati, G.; Sarkar, D.; Scapparone, E.; Scarlassara, F.; Scharenberg, R. P.; Schiaua, C.; Schicker, R.; Schmidt, C.; Schmidt, H. R.; Schuchmann, S.; Schukraft, J.; Schulc, M.; Schuster, T.; Schutz, Y.; Schwarz, K.; Schweda, K.; Scioli, G.; Scomparin, E.; Scott, R.; Seeder, K. S.; Seger, J. E.; Sekiguchi, Y.; Selyuzhenkov, I.; Senosi, K.; Seo, J.; Serradilla, E.; Sevcenco, A.; Shabanov, A.; Shabetai, A.; Shadura, O.; Shahoyan, R.; Shangaraev, A.; Sharma, A.; Sharma, M.; Sharma, N.; Shigaki, K.; Shtejer, K.; Sibiriak, Y.; Siddhanta, S.; Sielewicz, K. M.; Siemiarczuk, T.; Silvermyr, D.; Silvestre, C.; Simatovic, G.; Simonetti, G.; Singaraju, R.; Singh, R.; Singha, S.; Singhal, V.; Sinha, B. C.; Sinha, T.; Sitar, B.; Sitta, M.; Skaali, T. B.; Slupecki, M.; Smirnov, N.; Snellings, R. J. M.; Snellman, T. W.; Søgaard, C.; Soltz, R.; Song, J.; Song, M.; Song, Z.; Soramel, F.; Sorensen, S.; Spacek, M.; Spiriti, E.; Sputowska, I.; Spyropoulou-Stassinaki, M.; Srivastava, B. K.; Stachel, J.; Stan, I.; Stefanek, G.; Steinpreis, M.; Stenlund, E.; Steyn, G.; Stiller, J. H.; Stocco, D.; Strmen, P.; Suaide, A. A. P.; Sugitate, T.; Suire, C.; Suleymanov, M.; Sultanov, R.; Šumbera, M.; Symons, T. J. M.; Szabo, A.; Szanto de Toledo, A.; Szarka, I.; Szczepankiewicz, A.; Szymanski, M.; Takahashi, J.; Tanaka, N.; Tangaro, M. A.; Tapia Takaki, J. D.; Tarantola Peloni, A.; Tariq, M.; Tarzila, M. G.; Tauro, A.; Tejeda Muñoz, G.; Telesca, A.; Terasaki, K.; Terrevoli, C.; Teyssier, B.; Thäder, J.; Thomas, D.; Tieulent, R.; Timmins, A. R.; Toia, A.; Trogolo, S.; Trubnikov, V.; Trzaska, W. H.; Tsuji, T.; Tumkin, A.; Turrisi, R.; Tveter, T. S.; Ullaland, K.; Uras, A.; Usai, G. L.; Utrobicic, A.; Vajzer, M.; Vala, M.; Valencia Palomo, L.; Vallero, S.; van der Maarel, J.; van Hoorne, J. W.; van Leeuwen, M.; Vanat, T.; Vande Vyvre, P.; Varga, D.; Vargas, A.; Vargyas, M.; Varma, R.; Vasileiou, M.; Vasiliev, A.; Vauthier, A.; Vechernin, V.; Veen, A. M.; Veldhoen, M.; Velure, A.; Venaruzzo, M.; Vercellin, E.; Vergara Limón, S.; Vernet, R.; Verweij, M.; Vickovic, L.; Viesti, G.; Viinikainen, J.; Vilakazi, Z.; Villalobos Baillie, O.; Villatoro Tello, A.; Vinogradov, A.; Vinogradov, L.; Vinogradov, Y.; Virgili, T.; Vislavicius, V.; Viyogi, Y. P.; Vodopyanov, A.; Völkl, M. A.; Voloshin, K.; Voloshin, S. A.; Volpe, G.; von Haller, B.; Vorobyev, I.; Vranic, D.; Vrláková, J.; Vulpescu, B.; Vyushin, A.; Wagner, B.; Wagner, J.; Wang, H.; Wang, M.; Wang, Y.; Watanabe, D.; Weber, M.; Weber, S. G.; Wessels, J. P.; Westerhoff, U.; Wiechula, J.; Wikne, J.; Wilde, M.; Wilk, G.; Wilkinson, J.; Williams, M. C. S.; Windelband, B.; Winn, M.; Yaldo, C. G.; Yamaguchi, Y.; Yang, H.; Yang, P.; Yano, S.; Yasnopolskiy, S.; Yin, Z.; Yokoyama, H.; Yoo, I.-K.; Yurchenko, V.; Yushmanov, I.; Zaborowska, A.; Zaccolo, V.; Zaman, A.; Zampolli, C.; Zanoli, H. J. C.; Zaporozhets, S.; Zarochentsev, A.; Závada, P.; Zaviyalov, N.; Zbroszczyk, H.; Zgura, I. S.; Zhalov, M.; Zhang, H.; Zhang, X.; Zhang, Y.; Zhao, C.; Zhigareva, N.; Zhou, D.; Zhou, Y.; Zhou, Z.; Zhu, H.; Zhu, J.; Zhu, X.; Zichichi, A.; Zimmermann, A.; Zimmermann, M. B.; Zinovjev, G.; Zyzak, M.

2015-10-01

The measurement of the mass differences for systems bound by the strong force has reached a very high precision with protons and anti-protons. The extension of such measurement from (anti-)baryons to (anti-)nuclei allows one to probe any difference in the interactions between nucleons and anti-nucleons encoded in the (anti-)nuclei masses. This force is a remnant of the underlying strong interaction among quarks and gluons and can be described by effective theories, but cannot yet be directly derived from quantum chromodynamics. Here we report a measurement of the difference between the ratios of the mass and charge of deuterons (d) and anti-deuterons (), and 3He and nuclei carried out with the ALICE (A Large Ion Collider Experiment) detector in Pb-Pb collisions at a centre-of-mass energy per nucleon pair of 2.76 TeV. Our direct measurement of the mass-over-charge differences confirms CPT invariance to an unprecedented precision in the sector of light nuclei. This fundamental symmetry of nature, which exchanges particles with anti-particles, implies that all physics laws are the same under the simultaneous reversal of charge(s) (charge conjugation C), reflection of spatial coordinates (parity transformation P) and time inversion (T).

Precision measurement of the mass difference between light nuclei and anti-nuclei

DOE Office of Scientific and Technical Information (OSTI.GOV)

Adam, J.

The measurement of the mass differences for systems bound by the strong force has reached a very high precision with protons and anti-protons. The extension of such measurement from (anti-)baryons to (anti-)nuclei allows one to probe any difference in the interactions between nucleons and anti-nucleons encoded in the (anti-)nuclei masses. Also, this force is a remnant of the underlying strong interaction among quarks and gluons and can be described by effective theories, but cannot yet be directly derived from quantum chromodynamics. Here we report a measurement of the difference between the ratios of the mass and charge of deuterons (d) and anti-deuterons (more » $$-\\atop{d}$$), and 3He and 3$$-\\atop{He}$$nuclei carried out with the ALICE (A Large Ion Collider Experiment) detector in Pb–Pb collisions at a centre-of-mass energy per nucleon pair of 2.76 TeV. Our direct measurement of the mass-over-charge differences confirms CPT invariance to an unprecedented precision in the sector of light nuclei. This fundamental symmetry of nature, which exchanges particles with anti-particles, implies that all physics laws are the same under the simultaneous reversal of charge(s) (charge conjugation C), reflection of spatial coordinates (parity transformation P) and time inversion (T).« less

Precision measurement of the mass difference between light nuclei and anti-nuclei

DOE PAGES

Adam, J.

2015-08-17

The measurement of the mass differences for systems bound by the strong force has reached a very high precision with protons and anti-protons. The extension of such measurement from (anti-)baryons to (anti-)nuclei allows one to probe any difference in the interactions between nucleons and anti-nucleons encoded in the (anti-)nuclei masses. Also, this force is a remnant of the underlying strong interaction among quarks and gluons and can be described by effective theories, but cannot yet be directly derived from quantum chromodynamics. Here we report a measurement of the difference between the ratios of the mass and charge of deuterons (d) and anti-deuterons (more » $$-\\atop{d}$$), and 3He and 3$$-\\atop{He}$$nuclei carried out with the ALICE (A Large Ion Collider Experiment) detector in Pb–Pb collisions at a centre-of-mass energy per nucleon pair of 2.76 TeV. Our direct measurement of the mass-over-charge differences confirms CPT invariance to an unprecedented precision in the sector of light nuclei. This fundamental symmetry of nature, which exchanges particles with anti-particles, implies that all physics laws are the same under the simultaneous reversal of charge(s) (charge conjugation C), reflection of spatial coordinates (parity transformation P) and time inversion (T).« less

Measurement precision and noise analysis of CCD cameras

NASA Astrophysics Data System (ADS)

Wu, ZhenSen; Li, Zhiyang; Zhang, Ping

1993-09-01

CHINA The lirait precision of CCD camera with 1O. bit analogue to digital conversion is estimated in this paper . The noise effect on ineasurenent precision and the noise characteristics are analyzed in details. The noise process means are also discussed and the diagram of noise properties is given in this paper.

Circumnuclear Molecular Disks in Early-type Galaxies: Physical Properties and Precision Black Hole Mass Measurements

NASA Astrophysics Data System (ADS)

Boizelle, Benjamin

2018-01-01

ALMA is now capable of providing the most precise determinations of the masses of supermassive black holes in early-type galaxies (ETGs). In ALMA Cycle 2 we began a program to map the molecular gas kinematics in nearby ETGs that host central dust disks as seen in Hubble Space Telescope imaging. These initial observations targeted CO(2-1) emission at ~0.3" resolution, corresponding roughly to the projected radii of influence of the central black holes. In all cases we detect significant (~108 M⊙) molecular gas reservoirs that are in dynamically cold rotation, providing the most sensitive probes of the inner gravitational potentials of luminous ETGs. Using these gas kinematics, we verify that these molecular disks are formally stable against gravitational fragmentation and collapse. In several galaxies we detect central high-velocity gas rotation that provides direct kinematic evidence for a black hole. For two of these targets, NGC 1332 and NGC 3258, we have obtained higher-resolution observations (0.044" and 0.09") in Cycles 3 and 4 that more fully map out the gas rotation within the gravitational sphere of influence. We present dynamical modeling results for these targets, demonstrating that ALMA observations can enable black hole mass measurements at a precision of 10% or better, with minimal susceptibility to the systematic uncertainties that affect other methods of black hole mass measurement in ETGs. We discuss the impact of future high-resolution ALMA observations on black hole demographics and their potential to refine the high-mass end of the black hole-host galaxy scaling relationships.

Breakthrough in current-in-plane tunneling measurement precision by application of multi-variable fitting algorithm.

PubMed

Cagliani, Alberto; Østerberg, Frederik W; Hansen, Ole; Shiv, Lior; Nielsen, Peter F; Petersen, Dirch H

2017-09-01

We present a breakthrough in micro-four-point probe (M4PP) metrology to substantially improve precision of transmission line (transfer length) type measurements by application of advanced electrode position correction. In particular, we demonstrate this methodology for the M4PP current-in-plane tunneling (CIPT) technique. The CIPT method has been a crucial tool in the development of magnetic tunnel junction (MTJ) stacks suitable for magnetic random-access memories for more than a decade. On two MTJ stacks, the measurement precision of resistance-area product and tunneling magnetoresistance was improved by up to a factor of 3.5 and the measurement reproducibility by up to a factor of 17, thanks to our improved position correction technique.

High Precision Continuous and Real-Time Measurement of Atmospheric Oxygen Using Cavity Ring-Down Spectroscopy

NASA Astrophysics Data System (ADS)

Kim-Hak, David; Leuenberger, Markus; Berhanu, Tesfaye; Nyfeler, Peter; Hoffnagle, John; Sun, Minghua

2017-04-01

Oxygen (O2) is a major and vital component of the Earth atmosphere representing about 21% of its composition. It is consumed or produced through biochemical processes such as combustion, respiration, and photosynthesis and can be used as a top-down constraint on the carbon cycle. The observed variations of oxygen in the atmosphere are relatively small, in the order of a few ppm's. This presents the main technical challenge for the measurement since a very high level of precision on a large background is required. Only few analytical methods including mass spectrometry, fuel, ultraviolet[1] and paramagnetic cells are capable of achieving it. Here we present new developments of a high-precision gas analyzer that utilizes the technique of Cavity Ring-Down Spectroscopy to measure oxygen concentration and its oxygen isotope ratio 18O/16O. Its compact and ruggedness design combined with high precision and long-term stability allows the user to deploy the instrument in the field for continuous monitoring of atmospheric oxygen level. Measurements have a 1-σ 5-minute averaging precision of 1-2 ppm for O2 over a dynamic range of 0-50%. We will present comparative test results of this instrument against the incumbent technologies such as the mass spectrometer and the paramagnetic cell. In addition, we will demonstrate its long-term stability from a field deployment in Switzerland.

Laser System for Precise, Unambiguous Range Measurements

NASA Technical Reports Server (NTRS)

Dubovitsky, Serge; Lay, Oliver

2005-01-01

The Modulation Sideband Technology for Absolute Range (MSTAR) architecture is the basis of design of a proposed laser-based heterodyne interferometer that could measure a range (distance) as great as 100 km with a precision and resolution of the order of 1 nm. Simple optical interferometers can measure changes in range with nanometer resolution, but cannot measure range itself because interference is subject to the well-known integer-multiple-of-2 -radians phase ambiguity, which amounts to a range ambiguity of the order of 1 m at typical laser wavelengths. Existing rangefinders have a resolution of the order of 10 m and are therefore unable to resolve the ambiguity. The proposed MSTAR architecture bridges the gap, enabling nanometer resolution with an ambiguity range that can be extended to arbitrarily large distances. The MSTAR architecture combines the principle of the heterodyne interferometer with the principle of extending the ambiguity range of an interferometer by using light of two wavelengths. The use of two wavelengths for this purpose is well established in optical metrology, radar, and sonar. However, unlike in traditional two-color laser interferometry, light of two wavelengths would not be generated by two lasers. Instead, multiple wavelengths would be generated as sidebands of phase modulation of the light from a single frequency- stabilized laser. The phase modulation would be effected by applying sinusoidal signals of suitable frequencies (typically tens of gigahertz) to high-speed electro-optical phase modulators. Intensity modulation can also be used

Examination about Influence for Precision of 3d Image Measurement from the Ground Control Point Measurement and Surface Matching

NASA Astrophysics Data System (ADS)

Anai, T.; Kochi, N.; Yamada, M.; Sasaki, T.; Otani, H.; Sasaki, D.; Nishimura, S.; Kimoto, K.; Yasui, N.

2015-05-01

As the 3D image measurement software is now widely used with the recent development of computer-vision technology, the 3D measurement from the image is now has acquired the application field from desktop objects as wide as the topography survey in large geographical areas. Especially, the orientation, which used to be a complicated process in the heretofore image measurement, can be now performed automatically by simply taking many pictures around the object. And in the case of fully textured object, the 3D measurement of surface features is now done all automatically from the orientated images, and greatly facilitated the acquisition of the dense 3D point cloud from images with high precision. With all this development in the background, in the case of small and the middle size objects, we are now furnishing the all-around 3D measurement by a single digital camera sold on the market. And we have also developed the technology of the topographical measurement with the air-borne images taken by a small UAV [1~5]. In this present study, in the case of the small size objects, we examine the accuracy of surface measurement (Matching) by the data of the experiments. And as to the topographic measurement, we examine the influence of GCP distribution on the accuracy by the data of the experiments. Besides, we examined the difference of the analytical results in each of the 3D image measurement software. This document reviews the processing flow of orientation and the 3D measurement of each software and explains the feature of the each software. And as to the verification of the precision of stereo-matching, we measured the test plane and the test sphere of the known form and assessed the result. As to the topography measurement, we used the air-borne image data photographed at the test field in Yadorigi of Matsuda City, Kanagawa Prefecture JAPAN. We have constructed Ground Control Point which measured by RTK-GPS and Total Station. And we show the results of analysis made

Precise measurement of surface plasmon forces at a metal-dielectric interface using a calibrated evanescent wave

NASA Astrophysics Data System (ADS)

Liu, Lulu; Woolf, Alex

2015-03-01

By observing the motion of an optically trapped microscopic colloid, sub-piconewton static and dynamical forces have been measured using a technique called photonic force microscopy. This technique, though potentially powerful, has in the past struggled to make precise measurements in the vicinity of a reflective or metallic interface, due to distortions of the optical field. We introduce a new in-situ, contact-free calibration method for particle tracking using an evanescent wave, and demonstrate its expanded capability by the precise measurement of forces of interaction between a single colloid and the optical field generated by a propagating surface plasmon polariton on gold.

High-Precision Isotope Ratio Measurements of Sub-Picogram Actinide Samples

NASA Astrophysics Data System (ADS)

Pollington, A. D.; Kinman, W.

2016-12-01

One of the most exciting trends in analytical geochemistry over the past decade is the push towards smaller and smaller sample sizes while simultaneously achieving high precision isotope ratio measurements. This trend has been driven by advances in clean chemistry protocols, and by significant breakthroughs in mass spectrometer ionization efficiency and detector quality (stability and noise for low signals). In this presentation I will focus on new techniques currently being developed at Los Alamos National Laboratory for the characterization of ultra-small samples (pg, fg, ag), with particular focus on actinide measurements by MC-ICP-MS. Analyses of U, Pu, Th and Am are routinely carried out in our facility using multi-ion counting techniques. I will describe some of the challenges associated with using exclusively ion counting methods (e.g., stability, detector cross calibration, etc.), and how we work to mitigate them. While the focus of much of the work currently being carried out is in the broad field of nuclear forensics and safeguards, the techniques that are being developed are directly applicable to many geologic questions that require analyses of small samples of U and Th, for example. In addition to the description of the technique development, I will present case studies demonstrating the precision and accuracy of the method as applied to real-world samples.

Improving the Rank Precision of Population Health Measures for Small Areas with Longitudinal and Joint Outcome Models

PubMed Central

Athens, Jessica K.; Remington, Patrick L.; Gangnon, Ronald E.

2015-01-01

Objectives The University of Wisconsin Population Health Institute has published the County Health Rankings since 2010. These rankings use population-based data to highlight health outcomes and the multiple determinants of these outcomes and to encourage in-depth health assessment for all United States counties. A significant methodological limitation, however, is the uncertainty of rank estimates, particularly for small counties. To address this challenge, we explore the use of longitudinal and pooled outcome data in hierarchical Bayesian models to generate county ranks with greater precision. Methods In our models we used pooled outcome data for three measure groups: (1) Poor physical and poor mental health days; (2) percent of births with low birth weight and fair or poor health prevalence; and (3) age-specific mortality rates for nine age groups. We used the fixed and random effects components of these models to generate posterior samples of rates for each measure. We also used time-series data in longitudinal random effects models for age-specific mortality. Based on the posterior samples from these models, we estimate ranks and rank quartiles for each measure, as well as the probability of a county ranking in its assigned quartile. Rank quartile probabilities for univariate, joint outcome, and/or longitudinal models were compared to assess improvements in rank precision. Results The joint outcome model for poor physical and poor mental health days resulted in improved rank precision, as did the longitudinal model for age-specific mortality rates. Rank precision for low birth weight births and fair/poor health prevalence based on the univariate and joint outcome models were equivalent. Conclusion Incorporating longitudinal or pooled outcome data may improve rank certainty, depending on characteristics of the measures selected. For measures with different determinants, joint modeling neither improved nor degraded rank precision. This approach suggests a simple

Measuring Constructs in Family Science: How Can Item Response Theory Improve Precision and Validity?

PubMed Central

Gordon, Rachel A.

2014-01-01

This article provides family scientists with an understanding of contemporary measurement perspectives and the ways in which item response theory (IRT) can be used to develop measures with desired evidence of precision and validity for research uses. The article offers a nontechnical introduction to some key features of IRT, including its orientation toward locating items along an underlying dimension and toward estimating precision of measurement for persons with different levels of that same construct. It also offers a didactic example of how the approach can be used to refine conceptualization and operationalization of constructs in the family sciences, using data from the National Longitudinal Survey of Youth 1979 (n = 2,732). Three basic models are considered: (a) the Rasch and (b) two-parameter logistic models for dichotomous items and (c) the Rating Scale Model for multicategory items. Throughout, the author highlights the potential for researchers to elevate measurement to a level on par with theorizing and testing about relationships among constructs. PMID:25663714

Reliability, precision, and gender differences in knee internal/external rotation proprioception measurements.

PubMed

Nagai, Takashi; Sell, Timothy C; Abt, John P; Lephart, Scott M

2012-11-01

To develop and assess the reliability and precision of knee internal/external rotation (IR/ER) threshold to detect passive motion (TTDPM) and determine if gender differences exist. Test-retest for the reliability/precision and cross-sectional for gender comparisons. University neuromuscular and human performance research laboratory. Ten subjects for the reliability and precision aim. Twenty subjects (10 males and 10 females) for gender comparisons. All TTDPM tests were performed using a multi-mode dynamometer. Subjects performed TTDPM at two knee positions (near IR or ER end-range). Intraclass correlation coefficient (ICC (3,k)) and standard error of measurement (SEM) were used to evaluate the reliability and precision. Independent t-tests were used to compare genders. TTDPM toward IR and ER at two knee positions. Intrasession and intersession reliability and precision were good (ICC=0.68-0.86; SEM=0.22°-0.37°). Females had significantly diminished TTDPM toward IR at IR-test position (males: 0.77°±0.14°, females: 1.18°±0.46°, p=0.021) and TTDPM toward IR at the ER-test position (males: 0.87°±0.13°, females: 1.36°±0.58°, p=0.026). No other significant gender differences were found (p>0.05). The current IR/ER TTDPM methods are reliable and accurate for the test-retest or cross-section research design. Gender differences were found toward IR where the ACL acts as the secondary restraint. Copyright © 2011 Elsevier Ltd. All rights reserved.

a High-Precision Branching-Ratio Measurement for the Superallowed β+ Emitter 74Rb

NASA Astrophysics Data System (ADS)

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

2013-03-01

Precision measurements of superallowed Fermi beta decay allow for tests of the Cabibbo-Kobayashi-Maskawa matrix (CKM) unitarity, the conserved vector current hypothesis, and the magnitude of isospin-symmetry-breaking effects in nuclei. A high-precision measurement of the branching ratio for the β+ decay of 74Rb has been performed at the Isotope Separator and ACcelerator (ISAC) facility at TRIUMF. The 8π spectrometer, an array of 20 close-packed HPGe detectors, was used to detect gamma rays emitted following the decay of 74Rb. PACES, an array of 5 Si(Li) detectors, was used to detect emitted conversion electrons, while SCEPTAR, an array of plastic scintillators, was used to detect emitted beta particles. A total of 51γ rays have been identified following the decay of 21 excited states in the daughter nucleus 74Kr.

Precision mass measurements of neutron-rich Co isotopes beyond N =40

NASA Astrophysics Data System (ADS)

Izzo, C.; Bollen, G.; Brodeur, M.; Eibach, M.; Gulyuz, K.; Holt, J. D.; Kelly, J. M.; Redshaw, M.; Ringle, R.; Sandler, R.; Schwarz, S.; Stroberg, S. R.; Sumithrarachchi, C. S.; Valverde, A. A.; Villari, A. C. C.

2018-01-01

The region near Z =28 and N =40 is a subject of great interest for nuclear structure studies due to spectroscopic signatures in 68Ni suggesting a subshell closure at N =40 . Trends in nuclear masses and their derivatives provide a complementary approach to shell structure investigations via separation energies. Penning trap mass spectrometry has provided precise measurements for a number of nuclei in this region; however, a complete picture of the mass surfaces has so far been limited by the large uncertainty remaining for nuclei with N >40 along the iron (Z =26 ) and cobalt (Z =27 ) chains because these species are not available from traditional isotope separator online rare isotope facilities. The Low-Energy Beam and Ion Trap Facility at the National Superconducting Cyclotron Laboratory is the first and only Penning trap mass spectrometer coupled to a fragmentation facility and therefore presents the unique opportunity to perform precise mass measurements of these elusive isotopes. Here we present the first Penning trap measurements of Co,6968, carried out at this facility. Some ambiguity remains as to whether the measured values are ground-state or isomeric-state masses. A detailed discussion is presented to evaluate this question and to motivate future work. In addition, we perform ab initio calculations of ground-state and two-neutron separation energies of cobalt isotopes with the valence-space in-medium similarity renormalization group approach based on a particular set of two- and three-nucleon forces that predict saturation in infinite matter. We discuss the importance of these measurements and calculations for understanding the evolution of nuclear structure near 68Ni.

Apparatus for Ultrahigh Precision Measurement of 13 S1 - 23S 1 Interval in Positronium

NASA Astrophysics Data System (ADS)

Goldman, Harris J.

Positronium (Ps) is a purely leptonic atom comprising an electron and its antimatter equivalent, the positron, in a quasi-stable bound state. Due to its fundamental nature, Ps is an ideal test bed for bound-state QED. Recent high-precision spectroscopic experiments reveal a discrepancy in the measurement of the proton charge radius rp, known as the Proton Charge Radius Puzzle. Spectroscopic measurments carried out on hydrogen and muonic hydrogen, the bound state of a muon and a proton, differ from other scattering and other spectroscopic experiments by 3.3sigma. The measurement of rp comes from fitting the resulting measurement of either the 1S-2S interval of hydrogen or the Lamb Shift in muonic hydrogen to theory. Neither of these atoms are governed purely by quantum electrodynamics (QED) alone as nuclear structure has a role to play. The ratio of the masses of the orbiting particle m to that of the nucleus M is a coefficient in a number of a QED corrections to the energy levels of hydrogen (m/M = 1/1836) and muonic hydrogen ( m/M = 207/1836) and reveals the importance of performing a complementary spectroscopic measurement in Ps, where m/M = 1. The last measurement of the 1S-2S interval was carried out by Fee, Chu, Mills, et al. in 1993 to a precision of 3.2 ppb. The state-of-the-art measurement on hydrogen is now at an uncertainty of 4.2 x 10-15. While the simplicity of Ps causes it to be appealing to test bound-state QED, its antiparticle-particle nature makes it difficult to work with: the ground state lifetime of the triplet state is 142 ns, and whereas the 2S lifetime in Ps is 1.14 micros, the 2S lifetime in hydrogen is 105x longer. We have designed and constructed an apparatus and experiment to measure the 1S-2S interval in Ps at precision levels that we expect to immediately improve upon the previous measurements by factor of 2x and pave the way for ultimate comparison to the hydrogenic measurements. The apparatus also opens the doors to a new frontier in

5 MeV Mott polarimeter for rapid precise electron beam polarization measurements

DOE Office of Scientific and Technical Information (OSTI.GOV)

Price, J.S.; Poelker, B.M.; Sinclair, C.K.

1997-11-01

Low energy (E{sub k} = 100 keV) Mott scattering polarimeters are ill-suited to support operations foreseen for the polarized electron injector at Jefferson Lab. One solution is to measure the polarization at 5 MeV where multiple and plural scattering are unimportant and precision beam monitoring is straightforward. The higher injector beam current offsets the lower cross-sections; measured rates scale to 1 kHz/{mu}A with a 1 {mu}m thick gold target foil.

Evaluating measurements of carbon dioxide emissions using a precision source--A natural gas burner.

PubMed

Bryant, Rodney; Bundy, Matthew; Zong, Ruowen

2015-07-01

A natural gas burner has been used as a precise and accurate source for generating large quantities of carbon dioxide (CO2) to evaluate emissions measurements at near-industrial scale. Two methods for determining carbon dioxide emissions from stationary sources are considered here: predicting emissions based on fuel consumption measurements-predicted emissions measurements, and direct measurement of emissions quantities in the flue gas-direct emissions measurements. Uncertainty for the predicted emissions measurement was estimated at less than 1%. Uncertainty estimates for the direct emissions measurement of carbon dioxide were on the order of ±4%. The relative difference between the direct emissions measurements and the predicted emissions measurements was within the range of the measurement uncertainty, therefore demonstrating good agreement. The study demonstrates how independent methods are used to validate source emissions measurements, while also demonstrating how a fire research facility can be used as a precision test-bed to evaluate and improve carbon dioxide emissions measurements from stationary sources. Fossil-fuel-consuming stationary sources such as electric power plants and industrial facilities account for more than half of the CO2 emissions in the United States. Therefore, accurate emissions measurements from these sources are critical for evaluating efforts to reduce greenhouse gas emissions. This study demonstrates how a surrogate for a stationary source, a fire research facility, can be used to evaluate the accuracy of measurements of CO2 emissions.

Ion current as a precise measure of the loading rate of a magneto-optical trap

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jiang, W.; Bailey, K.; Lu, Z. -T.

2014-01-01

We have demonstrated that the ion current resulting from collisions between metastable krypton atoms in a magneto-optical trap can be used to precisely measure the trap loading rate. We measured both the ion current of the abundant isotope Kr-83 (isotopic abundance = 11%) and the single-atom counting rate of the rare isotope Kr-85 (isotopic abundance similar to 1 x 10(-11)), and found the two quantities to be proportional at a precision level of 0.9%. This work results in a significant improvement in using the magneto-optical trap as an analytical tool for noble-gas isotope ratio measurements, and will benefit both atomicmore » physics studies and applications in the earth sciences. (C) 2014 Optical Society of America« less

Fully automated laboratory and field-portable goniometer used for performing accurate and precise multiangular reflectance measurements

NASA Astrophysics Data System (ADS)

Harms, Justin D.; Bachmann, Charles M.; Ambeau, Brittany L.; Faulring, Jason W.; Ruiz Torres, Andres J.; Badura, Gregory; Myers, Emily

2017-10-01

Field-portable goniometers are created for a wide variety of applications. Many of these applications require specific types of instruments and measurement schemes and must operate in challenging environments. Therefore, designs are based on the requirements that are specific to the application. We present a field-portable goniometer that was designed for measuring the hemispherical-conical reflectance factor (HCRF) of various soils and low-growing vegetation in austere coastal and desert environments and biconical reflectance factors in laboratory settings. Unlike some goniometers, this system features a requirement for "target-plane tracking" to ensure that measurements can be collected on sloped surfaces, without compromising angular accuracy. The system also features a second upward-looking spectrometer to measure the spatially dependent incoming illumination, an integrated software package to provide full automation, an automated leveling system to ensure a standard frame of reference, a design that minimizes the obscuration due to self-shading to measure the opposition effect, and the ability to record a digital elevation model of the target region. This fully automated and highly mobile system obtains accurate and precise measurements of HCRF in a wide variety of terrain and in less time than most other systems while not sacrificing consistency or repeatability in laboratory environments.

Precision of MRI-based body composition measurements of postmenopausal women

PubMed Central

Romu, Thobias; Thorell, Sofia; Lindblom, Hanna; Berin, Emilia; Holm, Anna-Clara Spetz; Åstrand, Lotta Lindh; Karlsson, Anette; Borga, Magnus; Hammar, Mats; Leinhard, Olof Dahlqvist

2018-01-01

Objectives To determine precision of magnetic resonance imaging (MRI) based fat and muscle quantification in a group of postmenopausal women. Furthermore, to extend the method to individual muscles relevant to upper-body exercise. Materials and methods This was a sub-study to a randomized control trial investigating effects of resistance training to decrease hot flushes in postmenopausal women. Thirty-six women were included, mean age 56 ± 6 years. Each subject was scanned twice with a 3.0T MR-scanner using a whole-body Dixon protocol. Water and fat images were calculated using a 6-peak lipid model including R2*-correction. Body composition analyses were performed to measure visceral and subcutaneous fat volumes, lean volumes and muscle fat infiltration (MFI) of the muscle groups’ thigh muscles, lower leg muscles, and abdominal muscles, as well as the three individual muscles pectoralis, latissimus, and rhomboideus. Analysis was performed using a multi-atlas, calibrated water-fat separated quantification method. Liver-fat was measured as average proton density fat-fraction (PDFF) of three regions-of-interest. Precision was determined with Bland-Altman analysis, repeatability, and coefficient of variation. Results All of the 36 included women were successfully scanned and analysed. The coefficient of variation was 1.1% to 1.5% for abdominal fat compartments (visceral and subcutaneous), 0.8% to 1.9% for volumes of muscle groups (thigh, lower leg, and abdomen), and 2.3% to 7.0% for individual muscle volumes (pectoralis, latissimus, and rhomboideus). Limits of agreement for MFI was within ± 2.06% for muscle groups and within ± 5.13% for individual muscles. The limits of agreement for liver PDFF was within ± 1.9%. Conclusion Whole-body Dixon MRI could characterize a range of different fat and muscle compartments with high precision, including individual muscles, in the study-group of postmenopausal women. The inclusion of individual muscles, calculated from the

Spectropolarimetry with PEPSI at the LBT: accuracy vs. precision in magnetic field measurements

NASA Astrophysics Data System (ADS)

Ilyin, Ilya; Strassmeier, Klaus G.; Woche, Manfred; Hofmann, Axel

2009-04-01

We present the design of the new PEPSI spectropolarimeter to be installed at the Large Binocular Telescope (LBT) in Arizona to measure the full set of Stokes parameters in spectral lines and outline its precision and the accuracy limiting factors.

High-precision mass measurements for the isobaric multiplet mass equation at A = 52

NASA Astrophysics Data System (ADS)

Nesterenko, D. A.; Kankainen, A.; Canete, L.; Block, M.; Cox, D.; Eronen, T.; Fahlander, C.; Forsberg, U.; Gerl, J.; Golubev, P.; Hakala, J.; Jokinen, A.; Kolhinen, V. S.; Koponen, J.; Lalović, N.; Lorenz, Ch; Moore, I. D.; Papadakis, P.; Reinikainen, J.; Rinta-Antila, S.; Rudolph, D.; Sarmiento, L. G.; Voss, A.; Äystö, J.

2017-06-01

Masses of 52Co, 52Co m , 52Fe, 52Fe m , and 52Mn have been measured with the JYFLTRAP double Penning trap mass spectrometer. The isobaric multiplet mass equation for the T = 2 quintet at A = 52 has been studied employing the new mass values. No significant breakdown (beyond the 3σ level) of the quadratic form of the IMME was observed ({χ }2/n=2.4). The cubic coefficient was 6.0(32) keV ({χ }2/n=1.1). The excitation energies for the isomer and the T = 2 isobaric analog state in 52Co have been determined to be 374(13) keV and 2922(13) keV, respectively. The measured mass values for 52Co and 52Co m are 29(10) keV and 16(15) keV higher, respectively, than obtained in a recent storage-ring experiment, and significantly lower than predicted by extrapolations. Consequently, this has an impact on the proton separation energies for 52Co and 53Ni relevant for the astrophysical rapid proton capture process. The Q value for the proton decay from the 19/{2}- isomer in 53Co has been determined with an unprecedented precision, {Q}p=1558.8(17) keV.

A precision analogue integrator system for heavy current measurement in MFDC resistance spot welding

NASA Astrophysics Data System (ADS)

Xia, Yu-Jun; Zhang, Zhong-Dian; Xia, Zhen-Xin; Zhu, Shi-Liang; Zhang, Rui

2016-02-01

In order to control and monitor the quality of middle frequency direct current (MFDC) resistance spot welding (RSW), precision measurement of the welding current up to 100 kA is required, for which Rogowski coils are the only viable current transducers at present. Thus, a highly accurate analogue integrator is the key to restoring the converted signals collected from the Rogowski coils. Previous studies emphasised that the integration drift is a major factor that influences the performance of analogue integrators, but capacitive leakage error also has a significant impact on the result, especially in long-time pulse integration. In this article, new methods of measuring and compensating capacitive leakage error are proposed to fabricate a precision analogue integrator system for MFDC RSW. A voltage holding test is carried out to measure the integration error caused by capacitive leakage, and an original integrator with a feedback adder is designed to compensate capacitive leakage error in real time. The experimental results and statistical analysis show that the new analogue integrator system could constrain both drift and capacitive leakage error, of which the effect is robust to different voltage levels of output signals. The total integration error is limited within  ±0.09 mV s-1 0.005% s-1 or full scale at a 95% confidence level, which makes it possible to achieve the precision measurement of the welding current of MFDC RSW with Rogowski coils of 0.1% accuracy class.

Optimetrics for Precise Navigation

NASA Technical Reports Server (NTRS)

Yang, Guangning; Heckler, Gregory; Gramling, Cheryl

2017-01-01

Optimetrics for Precise Navigation will be implemented on existing optical communication links. The ranging and Doppler measurements are conducted over communication data frame and clock. The measurement accuracy is two orders of magnitude better than TDRSS. It also has other advantages of: The high optical carrier frequency enables: (1) Immunity from ionosphere and interplanetary Plasma noise floor, which is a performance limitation for RF tracking; and (2) High antenna gain reduces terminal size and volume, enables high precision tracking in Cubesat, and in deep space smallsat. High Optical Pointing Precision provides: (a) spacecraft orientation, (b) Minimal additional hardware to implement Precise Optimetrics over optical comm link; and (c) Continuous optical carrier phase measurement will enable the system presented here to accept future optical frequency standard with much higher clock accuracy.

Prospects for Precision Measurement of CO2 Column from Space

NASA Technical Reports Server (NTRS)

Heaps, William S.; Kawa, S. Randolph; Burris, John F.; Wilson, Emily L.; Georgieva, Elena; Miodek, Marty

2005-01-01

In order to address the problem of sources and sinks of CO2 measurements are needed on a global scale. Clearly a satellite is a promising approach to meeting this requirement. Unfortunately, most methods for making a CO2 measurement from space involve the whole column. Since sources and sinks at the surface represent a small perturbation to the total column one is faced with the need to measure the column with a precision better than 1%. No species has ever been measured from space at this level. We have developed over the last 3 years a small instrument based upon a Fabry-Perot interferometer that is very sensitive to atmospheric CO2 and has a high signal to noise ratio. We have tested this instrument in a ground based configuration and from aircraft platforms simulating operation from a satellite. We will present results from these tests and discuss ways that this promising new instrument could be used to improve our understanding of the global carbon budget.

The Measurement of Little g: A Fertile Ground for Precision Measurement Science

PubMed Central

Faller, James E.

2005-01-01

The occasion of the 100th anniversary of Einstein’s “golden year” provides a wonderful opportunity to discuss some aspects of gravity—gravitation being an interest of Einstein’s that occurred a few years after 1905. I’ll do this by talking about the measurement of little g, the free-fall acceleration on the Earth’s surface that is mainly due to the Earth’s gravity but whose value is also affected by centrifugal forces that are a result of the Earth’s rotation. I will also describe two equivalence experiments and a test of the inverse-square law of gravitation. Finally, I will make some observations on the science of precision measurement—a subject that underpins much of scientific progress. PMID:27308179

Measuring Constructs in Family Science: How Can Item Response Theory Improve Precision and Validity?

ERIC Educational Resources Information Center

Gordon, Rachel A.

2015-01-01

This article provides family scientists with an understanding of contemporary measurement perspectives and the ways in which item response theory (IRT) can be used to develop measures with desired evidence of precision and validity for research uses. The article offers a nontechnical introduction to some key features of IRT, including its…

Progress on Passive Sensor for Ultra-Precise Measurement of Carbon Dioxide from Space

NASA Technical Reports Server (NTRS)

Heaps, William S.; Kawa, S. Randolph

2002-01-01

Global measurements of atmospheric carbon dioxides (CO2) are needed to resolve significant discrepancies that exist in our understanding of the global carbon budget and, therefore, man's role in global climate change. The science measurement requirements for CO2 are extremely demanding (precision c .3%) No atmospheric chemical species has ever been measured from space with this precision. We are developing a novel application of a Fabry-Perot interferometer to detect spectral absorption of reflected sunlight by CO2 and O2 in the atmosphere. Preliminary design studies indicate that the method will be able to achieve the sensitivity and signal-to-noise required to measure column CO2 at the target specification. We are presently engaged in the construction of a prototype instrument for deployment on an aircraft to test the instrument performance and our ability to retrieve the data in the real atmosphere. In the first 6 months we have assembled a laboratory bench system to begin testing the optical and electronic components. We are also undertaking some measurements of signal and noise levels for actual sunlight reflecting from the ground. We shall present results from some of these ground based studies and discuss their implications for a space based system.

Search for new physics in a precise 20F beta spectrum shape measurement

NASA Astrophysics Data System (ADS)

George, Elizabeth; Voytas, Paul; Chuna, Thomas; Naviliat-Cuncic, Oscar; Gade, Alexandra; Hughes, Max; Huyan, Xueying; Liddick, Sean; Minamisono, Kei; Paulauskas, Stanley; Weisshaar, Dirk; Ban, Gilles; Flechard, Xavier; Lienard, Etienne

2015-10-01

We are carrying out a measurement of the shape of the energy spectrum of β particles from 20F decay. We aim to achieve a relative precision below 3%, representing an order of magnitude improvement compared to previous experiments. This level of precision will enable a test of the so-called strong form of the conserved vector current (CVC) hypothesis, and should also enable us to place competitive limits on the contributions of exotic tensor couplings in beta decay. In order to control systematic effects, we are using a technique that takes advantage of high energy radioactive beams at the NSCL to implant the decaying nuclei in a scintillation detector deep enough that the emitted beta particles cannot escape. The β-particle energy is measured with the implantation detector after switching off the beam implantation. Ancillary detectors are used to tag the 1.633-MeV γ-rays following the β decay for coincidence measurements in order to reduce backgrounds. We will give an overview and report on the status of the experiment.

Precision half-life measurement of the 4-fold forbidden {beta} decay of {sup 50}V

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dombrowski, H.; Neumaier, S.; Zuber, K.

2011-05-15

A sensitive search of the 4-fold forbidden nonunique decay of {sup 50}V has been performed. A total mass measuring time product of 186 kg d has been accumulated. A reliable half-life value with the highest precision so far of (2.29{+-}0.25)x10{sup 17} years of the electron capture decay of {sup 50}V into the first excited state of {sup 50}Ti could be obtained. A photon emission line following the {beta} decay into the first excited state of {sup 50}Cr could not be observed, resulting in a lower limit on the half-life of the {beta}-decay branch of 1.7x10{sup 18} years. This is notmore » in good agreement with a claimed observation of this decay branch published in 1989.« less

High-Precision Measurement of 13C/12C Isotopic Ratio Using Gas Chromatography-Combustion-Cavity Ring-Down Spectroscopy

NASA Astrophysics Data System (ADS)

Saad, N.; Kuramoto, D. S.; Haase, C.; Crosson, E.; Tan, S.; Zare, R. N.

2009-12-01

combusted products were combined with dry nitrogen gas to provide sufficient gas flow for the CRDS analyzer, which measured the 13C/12C isotopic ratio of the separated methane, ethane, and propane, obtaining a precision of 0.95 permil or better. The calibration accuracy was within 3 permil of the values determined using IRMS. The current CRDS-based system is less expensive, does not require highly trained personnel to operate, and is portable, compared with IRMS. We anticipate that advances in spectroscopic analysis will improve the precision and accuracy of the CRDS isotopic measurement, making it comparable with IRMS.

Precision and accuracy of age estimates obtained from anal fin spines, dorsal fin spines, and sagittal otoliths for known-age largemouth bass

USGS Publications Warehouse

Klein, Zachary B.; Bonvechio, Timothy F.; Bowen, Bryant R.; Quist, Michael C.

2017-01-01

Sagittal otoliths are the preferred aging structure for Micropterus spp. (black basses) in North America because of the accurate and precise results produced. Typically, fisheries managers are hesitant to use lethal aging techniques (e.g., otoliths) to age rare species, trophy-size fish, or when sampling in small impoundments where populations are small. Therefore, we sought to evaluate the precision and accuracy of 2 non-lethal aging structures (i.e., anal fin spines, dorsal fin spines) in comparison to that of sagittal otoliths from known-age Micropterus salmoides (Largemouth Bass; n = 87) collected from the Ocmulgee Public Fishing Area, GA. Sagittal otoliths exhibited the highest concordance with true ages of all structures evaluated (coefficient of variation = 1.2; percent agreement = 91.9). Similarly, the low coefficient of variation (0.0) and high between-reader agreement (100%) indicate that age estimates obtained from sagittal otoliths were the most precise. Relatively high agreement between readers for anal fin spines (84%) and dorsal fin spines (81%) suggested the structures were relatively precise. However, age estimates from anal fin spines and dorsal fin spines exhibited low concordance with true ages. Although use of sagittal otoliths is a lethal technique, this method will likely remain the standard for aging Largemouth Bass and other similar black bass species.

High-precision half-life determination for the superallowed β+ emitter Ga62

NASA Astrophysics Data System (ADS)

Grinyer, G. F.; Finlay, P.; Svensson, C. E.; Ball, G. C.; Leslie, J. R.; Austin, R. A. E.; Bandyopadhyay, D.; Chaffey, A.; Chakrawarthy, R. S.; Garrett, P. E.; Hackman, G.; Hyland, B.; Kanungo, R.; Leach, K. G.; Mattoon, C. M.; Morton, A. C.; Pearson, C. J.; Phillips, A. A.; Ressler, J. J.; Sarazin, F.; Savajols, H.; Schumaker, M. A.; Wong, J.

2008-01-01

The half-life of the superallowed β+ emitter Ga62 has been measured at TRIUMF's Isotope Separator and Accelerator facility using a fast-tape-transport system and 4π continuous-flow gas proportional counter to detect the positrons from the decay of Ga62 to the daughter Zn62. The result, T1/2=116.100±0.025 ms, represents the most precise measurement to date (0.022%) for any superallowed β-decay half-life. When combined with six previous measurements of the Ga62 half-life, a new world average of T1/2=116.121±0.021 ms is obtained. This new half-life measurement results in a 20% improvement in the precision of the Ga62 superallowed ft value while reducing its mean by 0.9σ to ft=3074.3(12) s. The impact of this half-life measurement on precision tests of the CVC hypothesis and isospin symmetry breaking corrections for A⩾62 superallowed decays is discussed.

Precise Temperature Measurement for Increasing the Survival of Newborn Babies in Incubator Environments

PubMed Central

Frischer, Robert; Penhaker, Marek; Krejcar, Ondrej; Kacerovsky, Marian; Selamat, Ali

2014-01-01

Precise temperature measurement is essential in a wide range of applications in the medical environment, however the regarding the problem of temperature measurement inside a simple incubator, neither a simple nor a low cost solution have been proposed yet. Given that standard temperature sensors don't satisfy the necessary expectations, the problem is not measuring temperature, but rather achieving the desired sensitivity. In response, this paper introduces a novel hardware design as well as the implementation that increases measurement sensitivity in defined temperature intervals at low cost. PMID:25494352

Precision measurement of electric organ discharge timing from freely moving weakly electric fish.

PubMed

Jun, James J; Longtin, André; Maler, Leonard

2012-04-01

Physiological measurements from an unrestrained, untethered, and freely moving animal permit analyses of neural states correlated to naturalistic behaviors of interest. Precise and reliable remote measurements remain technically challenging due to animal movement, which perturbs the relative geometries between the animal and sensors. Pulse-type electric fish generate a train of discrete and stereotyped electric organ discharges (EOD) to sense their surroundings actively, and rapid modulation of the discharge rate occurs while free swimming in Gymnotus sp. The modulation of EOD rates is a useful indicator of the fish's central state such as resting, alertness, and learning associated with exploration. However, the EOD pulse waveforms remotely observed at a pair of dipole electrodes continuously vary as the fish swims relative to the electrodes, which biases the judgment of the actual pulse timing. To measure the EOD pulse timing more accurately, reliably, and noninvasively from a free-swimming fish, we propose a novel method based on the principles of waveform reshaping and spatial averaging. Our method is implemented using envelope extraction and multichannel summation, which is more precise and reliable compared with other widely used threshold- or peak-based methods according to the tests performed under various source-detector geometries. Using the same method, we constructed a real-time electronic pulse detector performing an additional online pulse discrimination routine to enhance further the detection reliability. Our stand-alone pulse detector performed with high temporal precision (<10 μs) and reliability (error <1 per 10(6) pulses) and permits longer recording duration by storing only event time stamps (4 bytes/pulse).

Precision measurements of the RSA method using a phantom model of hip prosthesis.

PubMed

Mäkinen, Tatu J; Koort, Jyri K; Mattila, Kimmo T; Aro, Hannu T

2004-04-01

Radiostereometric analysis (RSA) has become one of the recommended techniques for pre-market evaluation of new joint implant designs. In this study we evaluated the effect of repositioning of X-ray tubes and phantom model on the precision of the RSA method. In precision measurements, we utilized mean error of rigid body fitting (ME) values as an internal control for examinations. ME value characterizes relative motion among the markers within each rigid body and is conventionally used to detect loosening of a bone marker. Three experiments, each consisting of 10 double examinations, were performed. In the first experiment, the X-ray tubes and the phantom model were not repositioned between one double examination. In experiments two and three, the X-ray tubes were repositioned between one double examination. In addition, the position of the phantom model was changed in experiment three. Results showed that significant differences could be found in 2 of 12 comparisons when evaluating the translation and rotation of the prosthetic components. Repositioning procedures increased ME values mimicking deformation of rigid body segments. Thus, ME value seemed to be a more sensitive parameter than migration values in this study design. These results confirmed the importance of standardized radiographic technique and accurate patient positioning for RSA measurements. Standardization and calibration procedures should be performed with phantom models in order to avoid unnecessary radiation dose of the patients. The present model gives the means to establish and to follow the intra-laboratory precision of the RSA method. The model is easily applicable in any research unit and allows the comparison of the precision values in different laboratories of multi-center trials.

a New Value for the Rydberg Constant by Precision Measurement of the Hydrogen Balmer-Beta Transition.

NASA Astrophysics Data System (ADS)

Zhao, Ping

investigated. Hydrogen energy levels are calculated according to most recent values of physical constants. {rm R}_infty is obtained by comparing the measured and calculated hydrogen Balmer-beta transition. The result is in good agreement with the two most recent, but less precise experiments.

Precision Measurement of the p ( e , e ' p ) π 0 Reaction at Threshold

DOE PAGES

Chirapatpimol, K.; Shabestari, M. H.; Lindgren, R. A.; ...

2015-05-13

New results are reported from a measurement ofmore » $$\\pi^0$$ electroproduction near threshold using the p(e, e´p) π⁰ reaction. The experiment was designed to determine precisely the energy dependence of $s-$ and $p-$wave electromagnetic multipoles as a stringent test of the predictions of Chiral Perturbation Theory (ChPT). The data were taken with an electron beam energy of 1192 MeV using a two-spectrometer setup in Hall A at Jefferson Lab. For the first time, complete coverage of the $$\\phi^*_{\\pi}$$ and $$\\theta^*_{\\pi}$$ angles in the $$p \\pi^0$$ center-of-mass was obtained for invariant energies above threshold from 0.5 MeV up to 15 MeV. The 4-momentum transfer $Q^2$ coverage ranges from 0.05 to 0.155 (GeV/c)$^2$ in fine steps. A simple phenomenological analysis of our data shows strong disagreement with $p-$wave predictions from ChPT for $Q^2>0.07$ (GeV/c)$^2$, while the $s-$wave predictions are in reasonable agreement.« less

Precise and traceable carbon isotope ratio measurements by multicollector ICP-MS: what next?

PubMed

Santamaria-Fernandez, Rebeca

2010-06-01

This article reviews recent developments in the use of multicollector inductively coupled plasma mass spectrometry (MC-ICP-MS) to provide high-precision carbon isotope ratio measurements. MC-ICP-MS could become an alternative method to isotope ratio mass spectrometry (IRMS) for rapid carbon isotope ratio determinations in organic compounds and characterisation and certification of isotopic reference materials. In this overview, the advantages, drawbacks and potential of the method for future applications are critically discussed. Furthermore, suggestions for future improvements in terms of precision and sensitivity are made. No doubt, this is an exciting analytical challenge and, as such, hurdles will need to be cleared.

Precision ephemerides for gravitational-wave searches. I. Sco X-1

DOE Office of Scientific and Technical Information (OSTI.GOV)

Galloway, Duncan K.; Premachandra, Sammanani; Steeghs, Danny

2014-01-20

Rapidly rotating neutron stars are the only candidates for persistent high-frequency gravitational wave emission, for which a targeted search can be performed based on the spin period measured from electromagnetic (e.g., radio and X-ray) observations. The principal factor determining the sensitivity of such searches is the measurement precision of the physical parameters of the system. Neutron stars in X-ray binaries present additional computational demands for searches due to the uncertainty in the binary parameters. We present the results of a pilot study with the goal of improving the measurement precision of binary orbital parameters for candidate gravitational wave sources. Wemore » observed the optical counterpart of Sco X-1 in 2011 June with the William Herschel Telescope and also made use of Very Large Telescope observations in 2011 to provide an additional epoch of radial-velocity measurements to earlier measurements in 1999. From a circular orbit fit to the combined data set, we obtained an improvement of a factor of 2 in the orbital period precision and a factor of 2.5 in the epoch of inferior conjunction T {sub 0}. While the new orbital period is consistent with the previous value of Gottlieb et al., the new T {sub 0} (and the amplitude of variation of the Bowen line velocities) exhibited a significant shift, which we attribute to variations in the emission geometry with epoch. We propagate the uncertainties on these parameters through to the expected Advanced LIGO-Virgo detector network observation epochs and quantify the improvement obtained with additional optical observations.« less

Record-Breaking Radio Astronomy Project to Measure Sky with Extreme Precision

NASA Astrophysics Data System (ADS)

2009-11-01

Astronomers will tie together the largest collection of the world's radio telescopes ever assembled to work as a single observing tool in a project aimed at improving the precision of the reference frame scientists use to measure positions in the sky. The National Science Foundation's Very Long Baseline Array (VLBA) will be a key part of the project, which is coordinated by the International VLBI Service for Geodesy and Astrometry. For 24 hours, starting Wednesday, November 18, and ending Thursday, November 19, 35 radio telescopes located on seven continents will observe 243 distant quasars. The quasars, galaxies with supermassive black holes at their cores, are profuse emitters of radio waves, and also are so distant that, despite their actual motions in space, they appear stationary as seen from Earth. This lack of apparent motion makes them ideal celestial landmarks for anchoring a grid system, similar to earthly latitude and longitude, used to mark the positions of celestial objects. Data from all the radio telescopes will be combined to make them work together as a system capable of measuring celestial positions with extremely high precision. The technique used, called very long baseline interferometry (VLBI), has been used for decades for both astronomical and geodetic research. However, no previous position-measuring observation has used as many radio telescopes or observed as many objects in a single session. The previous record was a 23-telescope observation. At a meeting in Brazil last August, the International Astronomical Union adopted a new reference frame for celestial positions that will be used starting on January 1. This new reference frame uses a set of 295 quasars to define positions, much like surveyor's benchmarks in a surburban subdivision. Because even with 35 radio telescopes around the world, there are some gaps in sky coverage, the upcoming observation will observe 243 of the 295. By observing so many quasars in a single observing session

Selection and use of TLDS for high precision NERVA shielding measurements

NASA Technical Reports Server (NTRS)

Woodsum, H. C.

1972-01-01

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

Direct and precise measurement of displacement and velocity of flexible web in roll-to-roll manufacturing systems

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kang, Dongwoo; Lee, Eonseok; Choi, Young-Man

Interest in the production of printed electronics using a roll-to-roll system has gradually increased due to its low mass-production costs and compatibility with flexible substrate. To improve the accuracy of roll-to-roll manufacturing systems, the movement of the web needs to be measured precisely in advance. In this paper, a novel measurement method is developed to measure the displacement and velocity of the web precisely and directly. The proposed algorithm is based on the traditional single field encoder principle, and the scale grating has been replaced with a printed grating on the web. Because a printed grating cannot be as accuratemore » as a scale grating in a traditional encoder, there will inevitably be variations in pitch and line-width, and the motion of the web should be measured even though there are variations in pitch and line-width in the printed grating patterns. For this reason, the developed algorithm includes a precise method of estimating the variations in pitch. In addtion, a method of correcting the Lissajous curve is presented for precision phase interpolation to improve measurement accuracy by correcting Lissajous circle to unit circle. The performance of the developed method is evaluated by simulation and experiment. In the experiment, the displacement error was less than 2.5 μm and the velocity error of 1σ was about 0.25%, while the grating scale moved 30 mm.« less

Direct and precise measurement of displacement and velocity of flexible web in roll-to-roll manufacturing systems

NASA Astrophysics Data System (ADS)

Kang, Dongwoo; duk Kim, Young; Lee, Eonseok; Choi, Young-Man; Lee, Taik-Min; Kim, Dongmin

2013-12-01

Interest in the production of printed electronics using a roll-to-roll system has gradually increased due to its low mass-production costs and compatibility with flexible substrate. To improve the accuracy of roll-to-roll manufacturing systems, the movement of the web needs to be measured precisely in advance. In this paper, a novel measurement method is developed to measure the displacement and velocity of the web precisely and directly. The proposed algorithm is based on the traditional single field encoder principle, and the scale grating has been replaced with a printed grating on the web. Because a printed grating cannot be as accurate as a scale grating in a traditional encoder, there will inevitably be variations in pitch and line-width, and the motion of the web should be measured even though there are variations in pitch and line-width in the printed grating patterns. For this reason, the developed algorithm includes a precise method of estimating the variations in pitch. In addtion, a method of correcting the Lissajous curve is presented for precision phase interpolation to improve measurement accuracy by correcting Lissajous circle to unit circle. The performance of the developed method is evaluated by simulation and experiment. In the experiment, the displacement error was less than 2.5 μm and the velocity error of 1σ was about 0.25%, while the grating scale moved 30 mm.

High-precision measurements of wetland sediment elevation. I. Recent improvements to the sedimentation--erosion table

USGS Publications Warehouse

Cahoon, D.R.; Lynch, J.C.; Hensel, P.; Boumans, R.; Perez, B.C.; Segura, B.; Day, J.W.

2002-01-01

The sedimentation-erosion table (SET) developed by Boumans and Day (1993) is herein renamed the surface elevation table (SET) to better reflect the conceptual view of the processes being measured. The SET was designed for making high-resolution measurements of small-scale changes in elevation of loose, unconsolidated sediments in shallow water and mudflat habitats. The SET has undergone three major improvements to increase precision and so that it can be used to measure sediment elevation in vegetated wetlands as well as shallow water habitats. The remote-release 'sliding plate' mechanism has been replaced with a single plate, collars (first 2.5 cm then 7.5 cm in length) have been attached to the plate to reduce play in the placement of the measuring pins, and the brass measuring pins have been replaced with fiberglass pins to reduce bending and consequent loss of precision. Under ideal laboratory conditions, the 95% confidence limit for individual pin measurements averaged about A? 1.4 mm (range A? 0.7 to A? 1.9 mm). These modifications have resulted in a reduction of error by about 50%.

Potential for long-term, high-frequency, high-precision methane isotope measurements to improve UK emissions estimates

NASA Astrophysics Data System (ADS)

Rennick, Chris; Bausi, Francesco; Arnold, Tim

2017-04-01

On the global scale methane (CH4) concentrations have more than doubled over the last 150 years, and the contribution to the enhanced greenhouse effect is almost half of that due to the increase in carbon dioxide (CO2) over the same period. Microbial, fossil fuel, biomass burning and landfill are dominant methane sources with differing annual variabilities; however, in the UK for example, mixing ratio measurements from a tall tower network and regional scale inversion modelling have thus far been unable to disaggregate emissions from specific source categories with any significant certainty. Measurement of the methane isotopologue ratios will provide the additional information needed for more robust sector attribution, which will be important for directing policy action Here we explore the potential for isotope ratio measurements to improve the interpretation of atmospheric mixing ratios beyond calculation of total UK emissions, and describe current analytical work at the National Physical Laboratory that will realise deployment of such measurements. We simulate isotopic variations at the four UK greenhouse gas tall tower network sites to understand where deployment of the first isotope analyser would be best situated. We calculate the levels of precision needed in both δ-13C and δ-D in order to detect particular scenarios of emissions. Spectroscopic measurement in the infrared by quantum cascade laser (QCL) absorption is a well-established technique to quantify the mixing ratios of trace species in atmospheric samples and, as has been demonstrated in 2016, if coupled to a suitable preconcentrator then high-precision measurements are possible. The current preconcentration system under development at NPL is designed to make the highest precision measurements yet of the standard isotope ratios via a new large-volume cryogenic trap design and controlled thermal desorption into a QCL spectrometer. Finally we explore the potential for the measurement of clumped

A new, high-precision measurement of the X-ray Cu K α spectrum

NASA Astrophysics Data System (ADS)

Mendenhall, Marcus H.; Cline, James P.; Henins, Albert; Hudson, Lawrence T.; Szabo, Csilla I.; Windover, Donald

2016-03-01

One of the primary measurement issues addressed with NIST Standard Reference Materials (SRMs) for powder diffraction is that of line position. SRMs for this purpose are certified with respect to lattice parameter, traceable to the SI through precise measurement of the emission spectrum of the X-ray source. Therefore, accurate characterization of the emission spectrum is critical to a minimization of the error bounds on the certified parameters. The presently accepted sources for the SI traceable characterization of the Cu K α emission spectrum are those of Härtwig, Hölzer et al., published in the 1990s. The structure of the X-ray emission lines of the Cu K α complex has been remeasured on a newly commissioned double-crystal instrument, with six-bounce Si (440) optics, in a manner directly traceable to the SI definition of the meter. In this measurement, the entire region from 8020 eV to 8100 eV has been covered with a highly precise angular scale and well-defined system efficiency, providing accurate wavelengths and relative intensities. This measurement is in modest disagreement with reference values for the wavelength of the Kα1 line, and strong disagreement for the wavelength of the Kα2 line.

Precision ESR Measurements of Transverse Anisotropy in the Single-molecule Magnet Ni4

NASA Astrophysics Data System (ADS)

Friedman, Jonathan; Collett, Charles; Allao Cassaro, Rafael

We present a method to precisely determine the transverse anisotropy in a single-molecule magnet (SMM) through electron-spin resonance measurements of a tunnel splitting that arises from the anisotropy via first-order perturbation theory. We demonstrate the technique using the SMM Ni4 diluted via co-crystallization in a diamagnetic isostructural analogue. At 5% dilution, we find markedly narrower resonance peaks than are observed in undiluted samples. Ni4 has a zero-field tunnel splitting of 4 GHz, and we measure that transition at several nearby frequencies using custom loop-gap resonators, allowing a precise determination of the tunnel splitting. Because the transition under investigation arises due to a first-order perturbation from the transverse anisotropy, and lies at zero field, we can relate the splitting to the transverse anisotropy independent of any other Hamiltonian parameters. This method can be applied to other SMMs with zero-field tunnel splittings arising from first-order transverse anisotropy perturbations. NSF Grant No. DMR-1310135.

Mass spectrometry in Earth sciences: the precise and accurate measurement of time.

PubMed

Schaltegger, Urs; Wotzlaw, Jörn-Frederik; Ovtcharova, Maria; Chiaradia, Massimo; Spikings, Richard

2014-01-01

Precise determinations of the isotopic compositions of a variety of elements is a widely applied tool in Earth sciences. Isotope ratios are used to quantify rates of geological processes that occurred during the previous 4.5 billion years, and also at the present time. An outstanding application is geochronology, which utilizes the production of radiogenic daughter isotopes by the radioactive decay of parent isotopes. Geochronological tools, involving isotopic analysis of selected elements from smallest volumes of minerals by thermal ionization mass spectrometry, provide precise and accurate measurements of time throughout the geological history of our planet over nine orders of magnitude, from the accretion of the proto-planetary disk, to the timing of the last glaciation. This article summarizes the recent efforts of the Isotope Geochemistry, Geochronology and Thermochronology research group at the University of Geneva to advance the U-Pb geochronological tool to achieve unprecedented precision and accuracy, and presents two examples of its application to two significant open questions in Earth sciences: what are the triggers and timescales of volcanic supereruptions, and what were the causes of mass extinctions in the geological past, driven by global climatic and environmental deterioration?

Breaking Quantum and Thermal Limits on Precision Measurements

NASA Astrophysics Data System (ADS)

Thompson, James K.

2016-05-01

I will give an overview of our efforts to use correlations and entanglement between many atoms to overcome quantum and thermal limits on precision measurements. In the first portion of my talk, I will present a path toward a 10000 times reduced sensitivity to the thermal mirror motion that limits the linewidth of today's best lasers. By utilizing narrow atomic transitions, the laser's phase information is primarily stored in the atomic gain medium rather than in the vibration-sensitive cavity field. To this end, I will present the first observation of lasing based on the mHz linewidth optical-clock transition in a laser-cooled ensemble of strontium atoms. In the second portion of my talk, I will describe how we use collective measurements to surpass the standard quantum limit on phase estimation 1 /√{ N} for N unentangled atoms. We achieve a directly observed reduction in phase variance relative to the standard quantum limit of as much as 17.7(6) dB. Supported by DARPA QuASAR, NIST, ARO, and NSF PFC. This material is based upon work supported by the National Science Foundation under Grant Number 1125844 Physics Frontier Center.

Precise measurement of the performance of thermoelectric modules

NASA Astrophysics Data System (ADS)

Díaz-Chao, Pablo; Muñiz-Piniella, Andrés; Selezneva, Ekaterina; Cuenat, Alexandre

2016-08-01

The potential exploitation of thermoelectric modules into mass market applications such as exhaust gas heat recovery in combustion engines requires an accurate knowledge of their performance. Further expansion of the market will also require confidence on the results provided by suppliers to end-users. However, large variation in performance and maximum operating point is observed for identical modules when tested by different laboratories. Here, we present the first metrological study of the impact of mounting and testing procedures on the precision of thermoelectric modules measurement. Variability in the electrical output due to mechanical pressure or type of thermal interface materials is quantified for the first time. The respective contribution of the temperature difference and the mean temperature to the variation in the output performance is quantified. The contribution of these factors to the total uncertainties in module characterisation is detailed.

QCD Precision Measurements and Structure Function Extraction at a High Statistics, High Energy Neutrino Scattering Experiment:. NuSOnG

NASA Astrophysics Data System (ADS)

Adams, T.; Batra, P.; Bugel, L.; Camilleri, L.; Conrad, J. M.; de Gouvêa, A.; Fisher, P. H.; Formaggio, J. A.; Jenkins, J.; Karagiorgi, G.; Kobilarcik, T. R.; Kopp, S.; Kyle, G.; Loinaz, W. A.; Mason, D. A.; Milner, R.; Moore, R.; Morfín, J. G.; Nakamura, M.; Naples, D.; Nienaber, P.; Olness, F. I.; Owens, J. F.; Pate, S. F.; Pronin, A.; Seligman, W. G.; Shaevitz, M. H.; Schellman, H.; Schienbein, I.; Syphers, M. J.; Tait, T. M. P.; Takeuchi, T.; Tan, C. Y.; van de Water, R. G.; Yamamoto, R. K.; Yu, J. Y.

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 (PDF's). 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 parametrized 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.

Experimental setup for precise measurement of losses in high-temperature superconducting transformer

NASA Astrophysics Data System (ADS)

Janu, Z.; Wild, J.; Repa, P.; Jelinek, Z.; Zizek, F.; Peksa, L.; Soukup, F.; Tichy, R.

2006-10-01

A simple cryogenic system for testing of the superconducting power transformer was constructed. Thermal shielding is provided by additional liquid nitrogen bath instead of super-insulation. The system, together with use of a precise nitrogen liquid level meter, permitted calorimetric measurements of losses of the 8 kVA HTS transformer with a resolution of the order of 0.1 W.

Precision measurement of the top quark mass in lepton + jets final States.

PubMed

Abazov, V M; Abbott, B; Acharya, B S; Adams, M; Adams, T; Agnew, J P; Alexeev, G D; Alkhazov, G; Alton, A; Askew, A; Atkins, S; Augsten, K; Avila, C; Badaud, F; Bagby, L; Baldin, B; Bandurin, D V; Banerjee, S; Barberis, E; Baringer, P; Bartlett, J F; Bassler, U; Bazterra, V; Bean, A; Begalli, M; Bellantoni, L; Beri, S B; Bernardi, G; Bernhard, R; Bertram, I; Besançon, M; Beuselinck, R; Bhat, P C; Bhatia, S; Bhatnagar, V; Blazey, G; Blessing, S; Bloom, K; Boehnlein, A; Boline, D; Boos, E E; Borissov, G; Borysova, M; Brandt, A; Brandt, O; Brock, R; Bross, A; Brown, D; Bu, X B; Buehler, M; Buescher, V; Bunichev, V; Burdin, S; Buszello, C P; Camacho-Pérez, E; Casey, B C K; Castilla-Valdez, H; Caughron, S; Chakrabarti, S; Chan, K M; Chandra, A; Chapon, E; Chen, G; Cho, S W; Choi, S; Choudhary, B; Cihangir, S; Claes, D; Clutter, J; Cooke, M; Cooper, W E; Corcoran, M; Couderc, F; Cousinou, M-C; Cutts, D; Das, A; Davies, G; de Jong, S J; De La Cruz-Burelo, E; Déliot, F; Demina, R; Denisov, D; Denisov, S P; Desai, S; Deterre, C; DeVaughan, K; Diehl, H T; Diesburg, M; Ding, P F; Dominguez, A; Dubey, A; Dudko, L V; Duperrin, A; Dutt, S; Eads, M; Edmunds, D; Ellison, J; Elvira, V D; Enari, Y; Evans, H; Evdokimov, V N; Fauré, A; Feng, L; Ferbel, T; Fiedler, F; Filthaut, F; Fisher, W; Fisk, H E; Fortner, M; Fox, H; Fuess, S; Garbincius, P H; Garcia-Bellido, A; García-González, J A; Gavrilov, V; Geng, W; Gerber, C E; Gershtein, Y; Ginther, G; Gogota, O; Golovanov, G; Grannis, P D; Greder, S; Greenlee, H; Grenier, G; Gris, Ph; Grivaz, J-F; Grohsjean, A; Grünendahl, S; Grünewald, M W; Guillemin, T; Gutierrez, G; Gutierrez, P; Haley, J; Han, L; Harder, K; Harel, A; Hauptman, J M; Hays, J; Head, T; Hebbeker, T; Hedin, D; Hegab, H; Heinson, A P; Heintz, U; Hensel, C; Heredia-De La Cruz, I; Herner, K; Hesketh, G; Hildreth, M D; Hirosky, R; Hoang, T; Hobbs, J D; Hoeneisen, B; Hogan, J; Hohlfeld, M; Holzbauer, J L; Howley, I; Hubacek, Z; Hynek, V; Iashvili, I; Ilchenko, Y; Illingworth, R; Ito, A S; Jabeen, S; Jaffré, M; Jayasinghe, A; Jeong, M S; Jesik, R; Jiang, P; Johns, K; Johnson, E; Johnson, M; Jonckheere, A; Jonsson, P; Joshi, J; Jung, A W; Juste, A; Kajfasz, E; Karmanov, D; Katsanos, I; Kehoe, R; Kermiche, S; Khalatyan, N; Khanov, A; Kharchilava, A; Kharzheev, Y N; Kiselevich, I; Kohli, J M; Kozelov, A V; Kraus, J; Kumar, A; Kupco, A; Kurča, T; Kuzmin, V A; Lammers, S; Lebrun, P; Lee, H S; Lee, S W; Lee, W M; Lei, X; Lellouch, J; Li, D; Li, H; Li, L; Li, Q Z; Lim, J K; Lincoln, D; Linnemann, J; Lipaev, V V; Lipton, R; Liu, H; Liu, Y; Lobodenko, A; Lokajicek, M; Lopes de Sa, R; Luna-Garcia, R; Lyon, A L; Maciel, A K A; Madar, R; Magaña-Villalba, R; Malik, S; Malyshev, V L; Mansour, J; Martínez-Ortega, J; McCarthy, R; McGivern, C L; Meijer, M M; Melnitchouk, A; Menezes, D; Mercadante, P G; Merkin, M; Meyer, A; Meyer, J; Miconi, F; Mondal, N K; Mulhearn, M; Nagy, E; Narain, M; Nayyar, R; Neal, H A; Negret, J P; Neustroev, P; Nguyen, H T; Nunnemann, T; Orduna, J; Osman, N; Osta, J; Pal, A; Parashar, N; Parihar, V; Park, S K; Partridge, R; Parua, N; Patwa, A; Penning, B; Perfilov, M; Peters, Y; Petridis, K; Petrillo, G; Pétroff, P; Pleier, M-A; Podstavkov, V M; Popov, A V; Prewitt, M; Price, D; Prokopenko, N; Qian, J; Quadt, A; Quinn, B; Ratoff, P N; Razumov, I; Ripp-Baudot, I; Rizatdinova, F; Rominsky, M; Ross, A; Royon, C; Rubinov, P; Ruchti, R; Sajot, G; Sánchez-Hernández, A; Sanders, M P; Santos, A S; Savage, G; Savitskyi, M; Sawyer, L; Scanlon, T; Schamberger, R D; Scheglov, Y; Schellman, H; Schwanenberger, C; Schwienhorst, R; Sekaric, J; Severini, H; Shabalina, E; Shary, V; Shaw, S; Shchukin, A A; Simak, V; Skubic, P; Slattery, P; Smirnov, D; Snow, G R; Snow, J; Snyder, S; Söldner-Rembold, S; Sonnenschein, L; Soustruznik, K; Stark, J; Stoyanova, D A; Strauss, M; Suter, L; Svoisky, P; Titov, M; Tokmenin, V V; Tsai, Y-T; Tsybychev, D; Tuchming, B; Tully, C; Uvarov, L; Uvarov, S; Uzunyan, S; Van Kooten, R; van Leeuwen, W M; Varelas, N; Varnes, E W; Vasilyev, I A; Verkheev, A Y; Vertogradov, L S; Verzocchi, M; Vesterinen, M; Vilanova, D; Vokac, P; Wahl, H D; Wang, M H L S; Warchol, J; Watts, G; Wayne, M; Weichert, J; Welty-Rieger, L; Williams, M R J; Wilson, G W; Wobisch, M; Wood, D R; Wyatt, T R; Xie, Y; Yamada, R; Yang, S; Yasuda, T; Yatsunenko, Y A; Ye, W; Ye, Z; Yin, H; Yip, K; Youn, S W; Yu, J M; Zennamo, J; Zhao, T G; Zhou, B; Zhu, J; Zielinski, M; Zieminska, D; Zivkovic, L

2014-07-18

We measure the mass of the top quark in lepton+jets final states using the full sample of pp collision data collected by the D0 experiment in Run II of the Fermilab Tevatron Collider at sqrt[s] = 1.96 TeV, corresponding to 9.7 fb(-1) of integrated luminosity. We use a matrix element technique that calculates the probabilities for each event to result from tt production or background. The overall jet energy scale is constrained in situ by the mass of the W boson. We measure m(t) = 174.98 ± 0.76 GeV. This constitutes the most precise single measurement of the top-quark mass.

Optimized spectroscopic scheme for enhanced precision CO measurements with applications to urban source attribution

NASA Astrophysics Data System (ADS)

Nottrott, A.; Hoffnagle, J.; Farinas, A.; Rella, C.

2014-12-01

Carbon monoxide (CO) is an urban pollutant generated by internal combustion engines which contributes to the formation of ground level ozone (smog). CO is also an excellent tracer for emissions from mobile combustion sources. In this work we present an optimized spectroscopic sampling scheme that enables enhanced precision CO measurements. The scheme was implemented on the Picarro G2401 Cavity Ring-Down Spectroscopy (CRDS) analyzer which measures CO2, CO, CH4 and H2O at 0.2 Hz. The optimized scheme improved the raw precision of CO measurements by 40% from 5 ppb to 3 ppb. Correlations of measured CO2, CO, CH4 and H2O from an urban tower were partitioned by wind direction and combined with a concentration footprint model for source attribution. The application of a concentration footprint for source attribution has several advantages. The upwind extent of the concentration footprint for a given sensor is much larger than the flux footprint. Measurements of mean concentration at the sensor location can be used to estimate source strength from a concentration footprint, while measurements of the vertical concentration flux are necessary to determine source strength from the flux footprint. Direct measurement of vertical concentration flux requires high frequency temporal sampling and increases the cost and complexity of the measurement system.

Technical note: Aerosol light absorption measurements with a carbon analyser - Calibration and precision estimates

NASA Astrophysics Data System (ADS)

Ammerlaan, B. A. J.; Holzinger, R.; Jedynska, A. D.; Henzing, J. S.

2017-09-01

Equivalent Black Carbon (EBC) and Elemental Carbon (EC) are different mass metrics to quantify the amount of combustion aerosol. Both metrics have their own measurement technique. In state-of-the-art carbon analysers, optical measurements are used to correct for organic carbon that is not evolving because of pyrolysis. These optical measurements are sometimes used to apply the technique of absorption photometers. Here, we use the transmission measurements of our carbon analyser for simultaneous determination of the elemental carbon concentration and the absorption coefficient. We use MAAP data from the CESAR observatory, the Netherlands, to correct for aerosol-filter interactions by linking the attenuation coefficient from the carbon analyser to the absorption coefficient measured by the MAAP. Application of the calibration to an independent data set of MAAP and OC/EC observations for the same location shows that the calibration is applicable to other observation periods. Because of simultaneous measurements of light absorption properties of the aerosol and elemental carbon, variation in the mass absorption efficiency (MAE) can be studied. We further show that the absorption coefficients and MAE in this set-up are determined within a precision of 10% and 12%, respectively. The precisions could be improved to 4% and 8% when the light transmission signal in the carbon analyser is very stable.

Tests of a Fast Plastic Scintillator for High-Precision Half-Life Measurements

NASA Astrophysics Data System (ADS)

Laffoley, A. T.; Dunlop, R.; Finlay, P.; Leach, K. G.; Michetti-Wilson, J.; Rand, E. T.; Svensson, C. E.; Grinyer, G. F.; Thomas, J. C.; Ball, G.; Garnsworthy, A. B.; Hackman, G.; Orce, J. N.; Triambak, S.; Williams, S. J.; Andreoiu, C.; Cross, D.

2013-03-01

A fast plastic scintillator detector is evaluated for possible use in an ongoing program of high-precision half-life measurements of short lived β emitters. Using data taken at TRI-UMF's Isotope Separator and Accelerator Facility with a radioactive 26Na beam, a detailed investigation of potential systematic effects with this new detector setup is being performed. The technique will then be applied to other β-decay half-life measurements including the superallowed Fermi β emitters 10C, 14O, and T = 1/2 decay of 15O.

Precision measurement of the electromagnetic dipole strengths in Be11

NASA Astrophysics Data System (ADS)

Kwan, E.; Wu, C. Y.; Summers, N. C.; Hackman, G.; Drake, T. E.; Andreoiu, C.; Ashley, R.; Ball, G. C.; Bender, P. C.; Boston, A. J.; Boston, H. C.; Chester, A.; Close, A.; Cline, D.; Cross, D. S.; Dunlop, R.; Finlay, A.; Garnsworthy, A. B.; Hayes, A. B.; Laffoley, A. T.; Nano, T.; Navrátil, P.; Pearson, C. J.; Pore, J.; Quaglioni, S.; Svensson, C. E.; Starosta, K.; Thompson, I. J.; Voss, P.; Williams, S. J.; Wang, Z. M.

2014-05-01

The electromagnetic dipole strength in Be11 between the bound states has been measured using low-energy projectile Coulomb excitation at bombarding energies of 1.73 and 2.09 MeV/nucleon on a Pt196 target. An electric dipole transition probability B(E1;1/2-→1/2+)=0.102(2) e2fm was determined using the semi-classical code Gosia, and a value of 0.098(4) e2fm was determined using the Extended Continuum Discretized Coupled Channels method with the quantum mechanical code FRESCO. These extracted B(E1) values are consistent with the average value determined by a model-dependent analysis of intermediate energy Coulomb excitation measurements and are approximately 14% lower than that determined by a lifetime measurement. The much-improved precisions of 2% and 4% in the measured B(E1) values between the bound states deduced using Gosia and the Extended Continuum Discretized Coupled Channels method, respectively, compared to the previous accuracy of ˜10% will help in our understanding of and better improve the realistic inter-nucleon interactions.

High-precision double-frequency interferometric measurement of the cornea shape

NASA Astrophysics Data System (ADS)

Molebny, Vasyl V.; Pallikaris, Ioannis G.; Naoumidis, Leonidas P.; Smirnov, Eugene M.; Ilchenko, Leonid M.; Goncharov, Vadym O.

1996-11-01

To measure the shape of the cornea and its declinations from the necessary values before and after PRK operation, s well as the shape of other spherical objects like artificial pupil, a technique was used of double-frequency dual-beam interferometry. The technique is based on determination of the optical path difference between two neighboring laser beams, reflected from the cornea or other surface under investigation. Knowing the distance between the beams on the investigated shape. The shape itself is reconstructed by along-line integration. To adjust the wavefront orientation of the laser beam to the spherical shape of the cornea or artificial pupil in the course of scanning, additional lens is involved. Signal-to-noise ratio is ameliorated excluding losses in the acousto-optic deflectors. Polarization selection is realized for choosing the signal needed for measurement. 2D image presentation is accompanied by convenient PC accessories, permitting precise cross-section measurements along selected directions. Sensitivity of the order of 10-2 micrometers is achieved.

Precision measurement of transition matrix elements via light shift cancellation.

PubMed

Herold, C D; Vaidya, V D; Li, X; Rolston, S L; Porto, J V; Safronova, M S

2012-12-14

We present a method for accurate determination of atomic transition matrix elements at the 10(-3) level. Measurements of the ac Stark (light) shift around "magic-zero" wavelengths, where the light shift vanishes, provide precise constraints on the matrix elements. We make the first measurement of the 5s - 6p matrix elements in rubidium by measuring the light shift around the 421 and 423 nm zeros through diffraction of a condensate off a sequence of standing wave pulses. In conjunction with existing theoretical and experimental data, we find 0.3235(9)ea(0) and 0.5230(8)ea(0) for the 5s - 6p(1/2) and 5s - 6p(3/2) elements, respectively, an order of magnitude more accurate than the best theoretical values. This technique can provide needed, accurate matrix elements for many atoms, including those used in atomic clocks, tests of fundamental symmetries, and quantum information.

High precision Hugoniot measurements of D2 near maximum compression

NASA Astrophysics Data System (ADS)

Benage, John; Knudson, Marcus; Desjarlais, Michael

2015-11-01

The Hugoniot response of liquid deuterium has been widely studied due to its general importance and to the significant discrepancy in the inferred shock response obtained from early experiments. With improvements in dynamic compression platforms and experimental standards these results have converged and show general agreement with several equation of state (EOS) models, including quantum molecular dynamics (QMD) calculations within the Generalized Gradient Approximation (GGA). This approach to modeling the EOS has also proven quite successful for other materials and is rapidly becoming a standard approach. However, small differences remain among predictions obtained using different local and semi-local density functionals; these small differences show up in the deuterium Hugoniot at ~ 30-40 GPa near the region of maximum compression. Here we present experimental results focusing on that region of the Hugoniot and take advantage of advancements in the platform and standards, resulting in data with significantly higher precision than that obtained in previous studies. These new data may prove to distinguish between the subtle differences predicted by the various density functionals. Results of these experiments will be presented along with comparison to various QMD calculations. Sandia National Laboratories is a multi-program laboratory operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin company, for the U.S. Department of Energy's National Nuclear Security Administration under contract DE-AC04-94AL85000.

Improved measurement linearity and precision for AMCW time-of-flight range imaging cameras.

PubMed

Payne, Andrew D; Dorrington, Adrian A; Cree, Michael J; Carnegie, Dale A

2010-08-10

Time-of-flight range imaging systems utilizing the amplitude modulated continuous wave (AMCW) technique often suffer from measurement nonlinearity due to the presence of aliased harmonics within the amplitude modulation signals. Typically a calibration is performed to correct these errors. We demonstrate an alternative phase encoding approach that attenuates the harmonics during the sampling process, thereby improving measurement linearity in the raw measurements. This mitigates the need to measure the system's response or calibrate for environmental changes. In conjunction with improved linearity, we demonstrate that measurement precision can also be increased by reducing the duty cycle of the amplitude modulated illumination source (while maintaining overall illumination power).

High-precision optical measurement of the 2S hyperfine interval in atomic hydrogen.

PubMed

Kolachevsky, N; Fischer, M; Karshenboim, S G; Hänsch, T W

2004-01-23

We have applied an optical method to the measurement of the 2S hyperfine interval in atomic hydrogen. The interval has been measured by means of two-photon spectroscopy of the 1S-2S transition on a hydrogen atomic beam shielded from external magnetic fields. The measured value of the 2S hyperfine interval is equal to 177 556 860(16) Hz and represents the most precise measurement of this interval to date. The theoretical evaluation of the specific combination of 1S and 2S hyperfine intervals D21 is in fair agreement (within 1.4 sigma) with the value for D21 deduced from our measurement.

Precise Measurement of the Mass of the τ Lepton

NASA Astrophysics Data System (ADS)

Luo, Tao

2014-03-01

An optimized energy scan near the τ pair production threshold has been performed using the BESIII detector. About 24 pb-1 of data, distributed over four scan points, was collected. The τ mass is determined directly from the threshold behavior of the τ pair production cross section in the e+e- collisions. The key question in the measurement is how to determine the beam energy precisely. Here the beam energy measurement system (BEMS) for BEPC-II is used to determine the beam energy. The relative systematic uncertainty of the electron and positron beam energy determination in our experiment is estimated as 2 ×10-5 ; the relative uncertainty of the beam's energy spread is about 6 % . This analysis is based on the combined data from the ee , eμ , eh , μμ , μh , hh , eρ , μρ and πρ final states, where h denotes a charged π or K. The mass of the τ lepton is measured as mτ = 1776 . 91 +/- 0 . 12 +0. 09 - 0 . 12 MeV/c2 which is consistent with results from any other groups included by the Particle Data Group, but has the smallest uncertainty.

Precision measurement of the three 2(3)P(J) helium fine structure intervals.

PubMed

Zelevinsky, T; Farkas, D; Gabrielse, G

2005-11-11

The three 2(3)P fine structure intervals of 4H are measured at an improved accuracy that is sufficient to test two-electron QED theory and to determine the fine structure constant alpha to 14 parts in 10(9). The more accurate determination of alpha, to a precision higher than attained with the quantum Hall and Josephson effects, awaits the reconciliation of two inconsistent theoretical calculations now being compared term by term. A low pressure helium discharge presents experimental uncertainties quite different than for earlier measurements and allows direct measurements of light pressure shifts.

Within- and between-laboratory precision in the measurement of body volume using air displacement plethysmography and its effect on body composition assessment.

PubMed

Collins, A L; Saunders, S; McCarthy, H D; Williams, J E; Fuller, N J

2004-01-01

To determine and compare the extent of within- and between-laboratory precision in body volume (BV) measurements using air displacement plethysmography (ADP), the BOD POD body composition system, and to interpret any such variability in terms of body composition estimates. Repeated test procedures of BV assessment using the BOD POD ADP were reproduced at two laboratories for the estimation of precision, both within and between laboratories. In total, 30 healthy adult volunteers, 14 men (age, 19-48 y; body mass index (BMI), 19.7-30.3 kg/m2) and 16 women (age, 19-40 y; BMI, 16.3-35.7 kg/m2), were each subjected to two test procedures at both laboratories. Two additional volunteers were independently subjected to 10 repeated test procedures at both laboratories. Repeated measurements of BV, uncorrected for the effects of isothermal air in the lungs and the surface area artifact, were obtained using the BOD POD ADP, with the identical protocol being faithfully applied at both laboratories. Uncorrected BV measurements were adjusted to give estimates of actual BV that were used to calculate body density (body weight (BWt)/actual BV) from which estimates of body composition were derived. The differences between repeated BV measurements or body composition estimates were used to assess within-laboratory precision (repeatability), as standard deviation (SD) and coefficient of variation; the differences between measurements reproduced at each laboratory were used to determine between-laboratory precision (reproducibility), as bias and 95% limits of agreement (from SD of the differences between laboratories). The extent of within-laboratory methodological precision for BV (uncorrected and actual) was variable according to subject, sample group and laboratory conditions (range of SD, 0.04-0.13 l), and was mostly due to within-individual biological variability (typically 78-99%) rather than to technical imprecision. There was a significant (P<0.05) bias between laboratories for

A T-Type Capacitive Sensor Capable of Measuring 5-DOF Error Motions of Precision Spindles

PubMed Central

Xiang, Kui; Qiu, Rongbo; Mei, Deqing; Chen, Zichen

2017-01-01

The precision spindle is a core component of high-precision machine tools, and the accurate measurement of its error motions is important for improving its rotation accuracy as well as the work performance of the machine. This paper presents a T-type capacitive sensor (T-type CS) with an integrated structure. The proposed sensor can measure the 5-degree-of-freedom (5-DOF) error motions of a spindle in-situ and simultaneously by integrating electrode groups in the cylindrical bore of the stator and the outer end face of its flange, respectively. Simulation analysis and experimental results show that the sensing electrode groups with differential measurement configuration have near-linear output for the different types of rotor displacements. What’s more, the additional capacitance generated by fringe effects has been reduced about 90% with the sensing electrode groups fabricated based on flexible printed circuit board (FPCB) and related processing technologies. The improved signal processing circuit has also been increased one times in the measuring performance and makes the measured differential output capacitance up to 93% of the theoretical values. PMID:28846631

Precision measurement of the weak charge of the proton.

PubMed

2018-05-01

Large experimental programmes in the fields of nuclear and particle physics search for evidence of physics beyond that explained by current theories. The observation of the Higgs boson completed the set of particles predicted by the standard model, which currently provides the best description of fundamental particles and forces. However, this theory's limitations include a failure to predict fundamental parameters, such as the mass of the Higgs boson, and the inability to account for dark matter and energy, gravity, and the matter-antimatter asymmetry in the Universe, among other phenomena. These limitations have inspired searches for physics beyond the standard model in the post-Higgs era through the direct production of additional particles at high-energy accelerators, which have so far been unsuccessful. Examples include searches for supersymmetric particles, which connect bosons (integer-spin particles) with fermions (half-integer-spin particles), and for leptoquarks, which mix the fundamental quarks with leptons. Alternatively, indirect searches using precise measurements of well predicted standard-model observables allow highly targeted alternative tests for physics beyond the standard model because they can reach mass and energy scales beyond those directly accessible by today's high-energy accelerators. Such an indirect search aims to determine the weak charge of the proton, which defines the strength of the proton's interaction with other particles via the well known neutral electroweak force. Because parity symmetry (invariance under the spatial inversion (x, y, z) → (-x, -y, -z)) is violated only in the weak interaction, it provides a tool with which to isolate the weak interaction and thus to measure the proton's weak charge 1 . Here we report the value 0.0719 ± 0.0045, where the uncertainty is one standard deviation, derived from our measured parity-violating asymmetry in the scattering of polarized electrons on protons, which is -226.5�

Pulse oximeter accuracy and precision affected by sensor location in cyanotic children.

PubMed

Sedaghat-Yazdi, Farshad; Torres, Adalberto; Fortuna, Randall; Geiss, Dale M

2008-07-01

Children's digits are often too small for proper attachment of oximeter sensors, necessitating sensor placement on the sole of the foot or palm of the hand. No study has determined what effect these sensor locations have on the accuracy and precision of this technology. The objective of this study was to assess the effect of sensor location on pulse oximeter accuracy (i.e., bias) and precision in critically ill children. Prospective, observational study with consecutive sampling. Tertiary care, pediatric intensive care unit. Fifty critically ill children, newborn to 2 yrs of age, with an indwelling arterial catheter. Forty-seven of 50 (94%) patients were postcardiac surgery. None. Co-oximeter-measured arterial oxygen saturation (Sao2) was compared with simultaneously obtained pulse oximetry saturations (Spo2). A total of 98 measurements were obtained, 48 measurements in the upper extremities (finger and palm) and 50 measurements in the lower extremities (toe and sole). The median Sao2 was 92% (66% to 100%). There was a significant difference in bias (i.e., average Spo2 - Sao2) and precision (+/-1 sd) when the sole and toe were compared (sole, 2.9 +/- 3.9 vs. toe, 1.6 +/- 2.2, p = .02) but no significant difference in bias and precision between the palm and the finger (palm, 1.4 +/- 3.2 vs. finger, 1.2 +/- 2.3, p = .99). There was a significant difference in bias +/- precision when the Sao2 was <90% compared with when Sao2 was >or=90% in the sole (6.0 +/- 5.7 vs. 1.8 +/- 2.1, p = .002) and palm (4.5 +/- 4.5 vs. 0.7 +/- 2.4, p = .006) but no significant difference in the finger (1.8 +/- 3.8 vs. 1.1 +/- 1.8, p = .95) or toe (1.9 +/- 2.9 vs. 1.6 +/- 1.9, p = .65). The Philips M1020A pulse oximeter and Nellcor MAX-N sensors were less accurate and precise when used on the sole of the foot or palm of the hand of a child with an Sao2 <90%.

Quantum preservation of the measurements precision using ultra-short strong pulses in exact analytical solution

NASA Astrophysics Data System (ADS)

Berrada, K.; Eleuch, H.

2017-09-01

Various schemes have been proposed to improve the parameter-estimation precision. In the present work, we suggest an alternative method to preserve the estimation precision by considering a model that closely describes a realistic experimental scenario. We explore this active way to control and enhance the measurements precision for a two-level quantum system interacting with classical electromagnetic field using ultra-short strong pulses with an exact analytical solution, i.e. beyond the rotating wave approximation. In particular, we investigate the variation of the precision with a few cycles pulse and a smooth phase jump over a finite time interval. We show that by acting on the shape of the phase transient and other parameters of the considered system, the amount of information may be increased and has smaller decay rate in the long time. These features make two-level systems incorporated in ultra-short, of-resonant and gradually changing phase good candidates for implementation of schemes for the quantum computation and the coherent information processing.

[The search for a precise method of measurement in psychical experiments].

PubMed

Borck, Cornelius

2002-06-01

In a series of three brief case studies, it is reconstructed how cognition and psychic activity were explored as energetic and economic transformations in a variety of experimental settings. 1. In the 1870s, the German psychiatrist Emil Kraepelin started his search for an objective measurement of cognitive performance in which he engaged over several decades. His investigations resulted in a graphic representation of cognitive efficiency, the "arbeitscurve", delineating the numbers of additions per time interval in close resemblance to representations of machine efficiency. 2. At the turn of the century, the American nutrition scientist and agronomist Wilbur Olin Atwater convinced himself in a series of precision measurements that the human motor was a so perfectly closed input-output system that he rejected any mental surplus in the form of cognitive energy transformations as contradictions to the principle of the conservation of energy. 3. At the beginning of the twentieth century and on the basis of Atwater's results, the German psychiatrist Hans Berger stipulated a special form of psychic energy for mediating between the principle of the conservation of energy and mental causality. Berger attempted to quantify psychic energy as one factor of brain metabolism. In the three cases of precision investigations into psychic life presented here, the experimental space of psychophysiology turned mental activity into a form of machine-like behavior.

Critical Steps in Data Analysis for Precision Casimir Force Measurements with Semiconducting Films

NASA Astrophysics Data System (ADS)

Banishev, A. A.; Chang, Chia-Cheng; Mohideen, U.

2011-06-01

Some experimental procedures and corresponding results of the precision measurement of the Casimir force between low doped Indium Tin Oxide (ITO) film and gold sphere are described. Measurements were performed using an Atomic Force Microscope in high vacuum. It is shown that the magnitude of the Casimir force decreases after prolonged UV treatment of the ITO film. Some critical data analysis steps such as the correction for the mechanical drift of the sphere-plate system and photodiodes are discussed.

Critical Steps in Data Analysis for Precision Casimir Force Measurements with Semiconducting Films

NASA Astrophysics Data System (ADS)

Banishev, A. A.; Chang, Chia-Cheng; Mohideen, U.

Some experimental procedures and corresponding results of the precision measurement of the Casimir force between low doped Indium Tin Oxide (ITO) film and gold sphere are described. Measurements were performed using an Atomic Force Microscope in high vacuum. It is shown that the magnitude of the Casimir force decreases after prolonged UV treatment of the ITO film. Some critical data analysis steps such as the correction for the mechanical drift of the sphere-plate system and photodiodes are discussed.

Testing the Standard Model by precision measurement of the weak charges of quarks

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ross Young; Roger Carlini; Anthony Thomas

In a global analysis of the latest parity-violating electron scattering measurements on nuclear targets, we demonstrate a significant improvement in the experimental knowledge of the weak neutral-current lepton-quark interactions at low-energy. The precision of this new result, combined with earlier atomic parity-violation measurements, limits the magnitude of possible contributions from physics beyond the Standard Model - setting a model-independent, lower-bound on the scale of new physics at ~1 TeV.

High-precision measurement of chlorine stable isotope ratios

USGS Publications Warehouse

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

1993-01-01

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.

Validation of strain gauges as a method of measuring precision of fit of implant bars.

PubMed

Hegde, Rashmi; Lemons, Jack E; Broome, James C; McCracken, Michael S

2009-04-01

Multiple articles in the literature have used strain gauges to estimate the precision of fit of implant bars. However, the accuracy of these measurements has not been fully documented. The purpose of this study was to evaluate the response of strain gauges to known amounts of misfit in an implant bar. This is an important step in validation of this device. A steel block was manufactured with five 4.0-mm externally hexed implant platforms machined into the block 7-mm apart. A 1.4-cm long gold alloy bar was cast to fit 2 of the platforms. Brass shims of varying thickness (150, 300, and 500 microm) were placed under one side of the bar to create misfit. A strain gage was used to record strain readings on top of the bar, one reading at first contact of the bar and one at maximum screw torque. Microgaps between the bar and the steel platforms were measured using a high-precision optical measuring device at 4 points around the platform. The experiment was repeated 3 times. Two-way analysis of variance and linear regression were used for statistical analyses. Shim thickness had a significant effect on strain (P < 0.0001). There was a significant positive correlation between shim thickness and strain (R(2) = 0.93) for strain at maximum torque, and for strain measurements at first contact (R(2) = 0.91). Microgap measurements showed no correlation with increasing misfit. Strain in the bar increased significantly with increasing levels of misfit. Strain measurements induced at maximum torque are not necessarily indicative of the maximum strains experienced by the bar. The presence or absence of a microgap between the bar and the platform is not necessarily indicative of passivity. These data suggest that microgap may not be clinically reliable as a measure of precision of fit.

Precision and accuracy of manual water-level measurements taken in the Yucca Mountain area, Nye County, Nevada, 1988-90

USGS Publications Warehouse

Boucher, M.S.

1994-01-01

Water-level measurements have been made in deep boreholes in the Yucca Mountain area, Nye County, Nevada, since 1983 in support of the U.S. Department of Energy's Yucca Mountain Project, which is an evaluation of the area to determine its suitability as a potential storage area for high-level nuclear waste. Water-level measurements were taken either manually, using various water-level measuring equipment such as steel tapes, or they were taken continuously, using automated data recorders and pressure transducers. This report presents precision range and accuracy data established for manual water-level measurements taken in the Yucca Mountain area, 1988-90. Precision and accuracy ranges were determined for all phases of the water-level measuring process, and overall accuracy ranges are presented. Precision ranges were determined for three steel tapes using a total of 462 data points. Mean precision ranges of these three tapes ranged from 0.014 foot to 0.026 foot. A mean precision range of 0.093 foot was calculated for the multiconductor cable, using 72 data points. Mean accuracy values were calculated on the basis of calibrations of the steel tapes and the multiconductor cable against a reference steel tape. The mean accuracy values of the steel tapes ranged from 0.053 foot, based on three data points to 0.078, foot based on six data points. The mean accuracy of the multiconductor cable was O. 15 foot, based on six data points. Overall accuracy of the water-level measurements was calculated by taking the square root of the sum of the squares of the individual accuracy values. Overall accuracy was calculated to be 0.36 foot for water-level measurements taken with steel tapes, without accounting for the inaccuracy of borehole deviations from vertical. An overall accuracy of 0.36 foot for measurements made with steel tapes is considered satisfactory for this project.

Precision of pQCT-measured total, trabecular and cortical bone area, content, density and estimated bone strength in children

PubMed Central

Duff, W.R.D.; Björkman, K.M.; Kawalilak, C.E.; Kehrig, A.M.; Wiebe, S.; Kontulainen, S.

2017-01-01

Objectives: To define pQCT precision errors, least-significant-changes, and identify associated factors for bone outcomes at the radius and tibia in children. Methods: We obtained duplicate radius and tibia pQCT scans from 35 children (8-14yrs). We report root-mean-squared coefficient of variation (CV%RMS) and 95% limits-of-agreement to characterize repeatability across scan quality and least-significant-changes for bone outcomes at distal (total and trabecular area, content and density; and compressive bone strength) and shaft sites (total area and content; cortical area content, density and thickness; and torsional bone strength). We used Spearman’s rho to identify associations between CV% and time between measurements, child’s age or anthropometrics. Results: After excluding unanalyzable scans (6-10% of scans per bone site), CV%RMS ranged from 4% (total density) to 19% (trabecular content) at the distal radius, 4% (cortical content) to 8% (cortical thickness) at the radius shaft, 2% (total density) to 14% (trabecular content) at the distal tibia and from 2% (cortical content) to 6% (bone strength) at the tibia shaft. Precision errors were within 95% limits-of-agreement across scan quality. Age was associated (rho -0.4 to -0.5, p <0.05) with CV% at the tibia. Conclusion: Bone density outcomes and cortical bone properties appeared most precise (CV%RMS <5%) in children. PMID:28574412

Precision measurement of CP violation in B(S)(0)→J/ΨK+K- decays.

PubMed

Aaij, R; Adeva, B; Adinolfi, M; Affolder, A; Ajaltouni, Z; Akar, S; Albrecht, J; Alessio, F; Alexander, M; Ali, S; Alkhazov, G; Alvarez Cartelle, P; Alves, A A; Amato, S; Amerio, S; Amhis, Y; An, L; Anderlini, L; Anderson, J; Andreassen, R; Andreotti, M; Andrews, J E; Appleby, R B; Aquines Gutierrez, O; Archilli, F; Artamonov, A; Artuso, M; Aslanides, E; Auriemma, G; Baalouch, M; Bachmann, S; Back, J J; Badalov, A; Baesso, C; Baldini, W; Barlow, R J; Barschel, C; Barsuk, S; Barter, W; Batozskaya, V; Battista, V; Bay, A; Beaucourt, L; Beddow, J; Bedeschi, F; Bediaga, I; Belogurov, S; Belous, K; Belyaev, I; Ben-Haim, E; Bencivenni, G; Benson, S; Benton, J; Berezhnoy, A; Bernet, R; Bertolin, A; Bettler, M-O; van Beuzekom, M; Bien, A; Bifani, S; Bird, T; Bizzeti, A; Bjørnstad, P M; Blake, T; Blanc, F; Blouw, J; Blusk, S; Bocci, V; Bondar, A; Bondar, N; Bonivento, W; Borghi, S; Borgia, A; Borsato, M; Bowcock, T J V; Bowen, E; Bozzi, C; Brett, D; Britsch, M; Britton, T; Brodzicka, J; Brook, N H; 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Koopman, R F; Koppenburg, P; Korolev, M; Kravchuk, L; Kreplin, K; Kreps, M; Krocker, G; Krokovny, P; Kruse, F; Kucewicz, W; Kucharczyk, M; Kudryavtsev, V; Kurek, K; Kvaratskheliya, T; La Thi, V N; Lacarrere, D; Lafferty, G; Lai, A; Lambert, D; Lambert, R W; Lanfranchi, G; Langenbruch, C; Langhans, B; Latham, T; Lazzeroni, C; Le Gac, R; van Leerdam, J; Lees, J-P; Lefèvre, R; Leflat, A; Lefrançois, J; Leroy, O; Lesiak, T; Leverington, B; Li, Y; Likhomanenko, T; Liles, M; Lindner, R; Linn, C; Lionetto, F; Liu, B; Lohn, S; Longstaff, I; Lopes, J H; Lowdon, P; Lucchesi, D; Luo, H; Lupato, A; Luppi, E; Lupton, O; Machefert, F; Machikhiliyan, I V; Maciuc, F; Maev, O; Malde, S; Malinin, A; Manca, G; Mancinelli, G; Mapelli, A; Maratas, J; Marchand, J F; Marconi, U; Marin Benito, C; Marino, P; Märki, R; Marks, J; Martellotti, G; Martinelli, M; Martinez Santos, D; Martinez Vidal, F; Martins Tostes, D; Massafferri, A; Matev, R; Mathe, Z; Matteuzzi, C; Mazurov, A; McCann, M; McCarthy, J; McNab, A; 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2015-01-30

The time-dependent CP asymmetry in B(s)(0)→J/ψK+K- decays is measured using pp collision data, corresponding to an integrated luminosity of 3.0  fb-1, collected with the LHCb detector at center-of-mass energies of 7 and 8 TeV. In a sample of 96,000 B(s)(0)→J/ψK+K- decays, the CP-violating phase ϕs is measured, as well as the decay widths ΓL and ΓH of the light and heavy mass eigenstates of the B(s)(0)-B[over ¯]s0 system. The values obtained are ϕs=-0.058±0.049±0.006  rad, Γs≡(ΓL+ΓH)/2=0.6603±0.0027±0.0015  ps-1, and ΔΓs≡ΓL-ΓH=0.0805±0.0091±0.0032  ps-1, where the first uncertainty is statistical and the second, systematic. These are the most precise single measurements of those quantities to date. A combined analysis with Bs0→J/ψπ+π- decays gives ϕs=-0.010±0.039  rad. All measurements are in agreement with the standard model predictions. For the first time, the phase ϕs is measured independently for each polarization state of the K+K- system and shows no evidence for polarization dependence.

High-precision half-life measurements of the T =1 /2 mirror β decays 17F and 33Cl

NASA Astrophysics Data System (ADS)

Grinyer, J.; Grinyer, G. F.; Babo, M.; Bouzomita, H.; Chauveau, P.; Delahaye, P.; Dubois, M.; Frigot, R.; Jardin, P.; Leboucher, C.; Maunoury, L.; Seiffert, C.; Thomas, J. C.; Traykov, E.

2015-10-01

Background: Measurements of the f t values for T =1 /2 mirror β+ decays offer a method to test the conserved vector current hypothesis and to determine Vud, the up-down matrix element of the Cabibbo-Kobayashi-Maskawa matrix. In most mirror decays used for these tests, uncertainties in the f t values are dominated by the uncertainties in the half-lives. Purpose: Two precision half-life measurements were performed for the T =1 /2 β+ emitters, 17F and 33Cl, in order to eliminate the half-life as the leading source of uncertainty in their f t values. Method: Half-lives of 17F and 33Cl were determined using β counting of implanted radioactive ion beam samples on a moving tape transport system at the Système de Production d'Ions Radioactifs Accélérés en Ligne low-energy identification station at the Grand Accélérateur National d'Ions Lourds. Results: The 17F half-life result, 64.347 (35) s, precise to ±0.05 % , is a factor of 5 times more precise than the previous world average. The half-life of 33Cl was determined to be 2.5038 (22) s. The current precision of ±0.09 % is nearly 2 times more precise compared to the previous world average. Conclusions: The precision achieved during the present measurements implies that the half-life no longer dominates the uncertainty of the f t values for both T =1 /2 mirror decays 17F and 33Cl.

Precision Ephemerides for Gravitational-wave Searches. I. Sco X-1

NASA Astrophysics Data System (ADS)

Galloway, Duncan K.; Premachandra, Sammanani; Steeghs, Danny; Marsh, Tom; Casares, Jorge; Cornelisse, Rémon

2014-01-01

Rapidly rotating neutron stars are the only candidates for persistent high-frequency gravitational wave emission, for which a targeted search can be performed based on the spin period measured from electromagnetic (e.g., radio and X-ray) observations. The principal factor determining the sensitivity of such searches is the measurement precision of the physical parameters of the system. Neutron stars in X-ray binaries present additional computational demands for searches due to the uncertainty in the binary parameters. We present the results of a pilot study with the goal of improving the measurement precision of binary orbital parameters for candidate gravitational wave sources. We observed the optical counterpart of Sco X-1 in 2011 June with the William Herschel Telescope and also made use of Very Large Telescope observations in 2011 to provide an additional epoch of radial-velocity measurements to earlier measurements in 1999. From a circular orbit fit to the combined data set, we obtained an improvement of a factor of 2 in the orbital period precision and a factor of 2.5 in the epoch of inferior conjunction T 0. While the new orbital period is consistent with the previous value of Gottlieb et al., the new T 0 (and the amplitude of variation of the Bowen line velocities) exhibited a significant shift, which we attribute to variations in the emission geometry with epoch. We propagate the uncertainties on these parameters through to the expected Advanced LIGO-Virgo detector network observation epochs and quantify the improvement obtained with additional optical observations. Based on observations made with ESO Telescopes at the La Silla Paranal Observatory under programme ID 087.D-0278.

Precise Nuclear Data Measurements Possible with the NIFFTE fissionTPC for Advanced Reactor Designs

NASA Astrophysics Data System (ADS)

Towell, Rusty; Niffte Collaboration

2015-10-01

The Neutron Induced Fission Fragment Tracking Experiment (NIFFTE) Collaboration has applied the proven technology of Time Projection Chambers (TPC) to the task of precisely measuring fission cross sections. With the NIFFTE fission TPC, precise measurements have been made during the last year at the Los Alamos Neutron Science Center from both U-235 and Pu-239 targets. The exquisite tracking capabilities of this device allow the full reconstruction of charged particles produced by neutron beam induced fissions from a thin central target. The wealth of information gained from this approach will allow systematics to be controlled at the level of 1%. The fissionTPC performance will be presented. These results are critical to the development of advanced uranium-fueled reactors. However, there are clear advantages to developing thorium-fueled reactors such as Liquid Fluoride Thorium Reactors over uranium-fueled reactors. These advantages include improved reactor safety, minimizing radioactive waste, improved reactor efficiency, and enhanced proliferation resistance. The potential for using the fissionTPC to measure needed cross sections important to the development of thorium-fueled reactors will also be discussed.

J-GFT NMR for precise measurement of mutually correlated nuclear spin-spin couplings.

PubMed

Atreya, Hanudatta S; Garcia, Erwin; Shen, Yang; Szyperski, Thomas

2007-01-24

G-matrix Fourier transform (GFT) NMR spectroscopy is presented for accurate and precise measurement of chemical shifts and nuclear spin-spin couplings correlated according to spin system. The new approach, named "J-GFT NMR", is based on a largely extended GFT NMR formalism and promises to have a broad impact on projection NMR spectroscopy. Specifically, constant-time J-GFT (6,2)D (HA-CA-CO)-N-HN was implemented for simultaneous measurement of five mutually correlated NMR parameters, that is, 15N backbone chemical shifts and the four one-bond spin-spin couplings 13Calpha-1Halpha, 13Calpha-13C', 15N-13C', and 15N-1HNu. The experiment was applied for measuring residual dipolar couplings (RDCs) in an 8 kDa protein Z-domain aligned with Pf1 phages. Comparison with RDC values extracted from conventional NMR experiments reveals that RDCs are measured with high precision and accuracy, which is attributable to the facts that (i) the use of constant time evolution ensures that signals do not broaden whenever multiple RDCs are jointly measured in a single dimension and (ii) RDCs are multiply encoded in the multiplets arising from the joint sampling. This corresponds to measuring the couplings multiple times in a statistically independent manner. A key feature of J-GFT NMR, i.e., the correlation of couplings according to spin systems without reference to sequential resonance assignments, promises to be particularly valuable for rapid identification of backbone conformation and classification of protein fold families on the basis of statistical analysis of dipolar couplings.

Measuring changes in Plasmodium falciparum transmission: Precision, accuracy and costs of metrics

PubMed Central

Tusting, Lucy S.; Bousema, Teun; Smith, David L.; Drakeley, Chris

2016-01-01

As malaria declines in parts of Africa and elsewhere, and as more countries move towards elimination, it is necessary to robustly evaluate the effect of interventions and control programmes on malaria transmission. To help guide the appropriate design of trials to evaluate transmission-reducing interventions, we review eleven metrics of malaria transmission, discussing their accuracy, precision, collection methods and costs, and presenting an overall critique. We also review the non-linear scaling relationships between five metrics of malaria transmission; the entomological inoculation rate, force of infection, sporozoite rate, parasite rate and the basic reproductive number, R0. Our review highlights that while the entomological inoculation rate is widely considered the gold standard metric of malaria transmission and may be necessary for measuring changes in transmission in highly endemic areas, it has limited precision and accuracy and more standardised methods for its collection are required. In areas of low transmission, parasite rate, sero-conversion rates and molecular metrics including MOI and mFOI may be most appropriate. When assessing a specific intervention, the most relevant effects will be detected by examining the metrics most directly affected by that intervention. Future work should aim to better quantify the precision and accuracy of malaria metrics and to improve methods for their collection. PMID:24480314

Number-Density Measurements of CO2 in Real Time with an Optical Frequency Comb for High Accuracy and Precision

NASA Astrophysics Data System (ADS)

Scholten, Sarah K.; Perrella, Christopher; Anstie, James D.; White, Richard T.; Al-Ashwal, Waddah; Hébert, Nicolas Bourbeau; Genest, Jérôme; Luiten, Andre N.

2018-05-01

Real-time and accurate measurements of gas properties are highly desirable for numerous real-world applications. Here, we use an optical-frequency comb to demonstrate absolute number-density and temperature measurements of a sample gas with state-of-the-art precision and accuracy. The technique is demonstrated by measuring the number density of 12C16O2 with an accuracy of better than 1% and a precision of 0.04% in a measurement and analysis cycle of less than 1 s. This technique is transferable to numerous molecular species, thus offering an avenue for near-universal gas concentration measurements.

Linearity, Bias, and Precision of Hepatic Proton Density Fat Fraction Measurements by Using MR Imaging: A Meta-Analysis.

PubMed

Yokoo, Takeshi; Serai, Suraj D; Pirasteh, Ali; Bashir, Mustafa R; Hamilton, Gavin; Hernando, Diego; Hu, Houchun H; Hetterich, Holger; Kühn, Jens-Peter; Kukuk, Guido M; Loomba, Rohit; Middleton, Michael S; Obuchowski, Nancy A; Song, Ji Soo; Tang, An; Wu, Xinhuai; Reeder, Scott B; Sirlin, Claude B

2018-02-01

Purpose To determine the linearity, bias, and precision of hepatic proton density fat fraction (PDFF) measurements by using magnetic resonance (MR) imaging across different field strengths, imager manufacturers, and reconstruction methods. Materials and Methods This meta-analysis was performed in accordance with Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. A systematic literature search identified studies that evaluated the linearity and/or bias of hepatic PDFF measurements by using MR imaging (hereafter, MR imaging-PDFF) against PDFF measurements by using colocalized MR spectroscopy (hereafter, MR spectroscopy-PDFF) or the precision of MR imaging-PDFF. The quality of each study was evaluated by using the Quality Assessment of Studies of Diagnostic Accuracy 2 tool. De-identified original data sets from the selected studies were pooled. Linearity was evaluated by using linear regression between MR imaging-PDFF and MR spectroscopy-PDFF measurements. Bias, defined as the mean difference between MR imaging-PDFF and MR spectroscopy-PDFF measurements, was evaluated by using Bland-Altman analysis. Precision, defined as the agreement between repeated MR imaging-PDFF measurements, was evaluated by using a linear mixed-effects model, with field strength, imager manufacturer, reconstruction method, and region of interest as random effects. Results Twenty-three studies (1679 participants) were selected for linearity and bias analyses and 11 studies (425 participants) were selected for precision analyses. MR imaging-PDFF was linear with MR spectroscopy-PDFF (R 2 = 0.96). Regression slope (0.97; P < .001) and mean Bland-Altman bias (-0.13%; 95% limits of agreement: -3.95%, 3.40%) indicated minimal underestimation by using MR imaging-PDFF. MR imaging-PDFF was precise at the region-of-interest level, with repeatability and reproducibility coefficients of 2.99% and 4.12%, respectively. Field strength, imager manufacturer, and reconstruction method

Precision manometer gauge

DOEpatents

McPherson, Malcolm J.; Bellman, Robert A.

1984-01-01

A precision manometer gauge which locates a zero height and a measured height of liquid using an open tube in communication with a reservoir adapted to receive the pressure to be measured. The open tube has a reference section carried on a positioning plate which is moved vertically with machine tool precision. Double scales are provided to read the height of the positioning plate accurately, the reference section being inclined for accurate meniscus adjustment, and means being provided to accurately locate a zero or reference position.

Precision manometer gauge

DOEpatents

McPherson, M.J.; Bellman, R.A.

1982-09-27

A precision manometer gauge which locates a zero height and a measured height of liquid using an open tube in communication with a reservoir adapted to receive the pressure to be measured. The open tube has a reference section carried on a positioning plate which is moved vertically with machine tool precision. Double scales are provided to read the height of the positioning plate accurately, the reference section being inclined for accurate meniscus adjustment, and means being provided to accurately locate a zero or reference position.

Potential for noninvasive assessment of lung inhomogeneity using highly precise, highly time-resolved measurements of gas exchange

PubMed Central

Mountain, James E.; Santer, Peter; O’Neill, David P.; Smith, Nicholas M. J.; Ciaffoni, Luca; Couper, John H.; Ritchie, Grant A. D.; Hancock, Gus; Whiteley, Jonathan P.

2018-01-01

Inhomogeneity in the lung impairs gas exchange and can be an early marker of lung disease. We hypothesized that highly precise measurements of gas exchange contain sufficient information to quantify many aspects of the inhomogeneity noninvasively. Our aim was to explore whether one parameterization of lung inhomogeneity could both fit such data and provide reliable parameter estimates. A mathematical model of gas exchange in an inhomogeneous lung was developed, containing inhomogeneity parameters for compliance, vascular conductance, and dead space, all relative to lung volume. Inputs were respiratory flow, cardiac output, and the inspiratory and pulmonary arterial gas compositions. Outputs were expiratory and pulmonary venous gas compositions. All values were specified every 10 ms. Some parameters were set to physiologically plausible values. To estimate the remaining unknown parameters and inputs, the model was embedded within a nonlinear estimation routine to minimize the deviations between model and data for CO2, O2, and N2 flows during expiration. Three groups, each of six individuals, were studied: young (20–30 yr); old (70–80 yr); and patients with mild to moderate chronic obstructive pulmonary disease (COPD). Each participant undertook a 15-min measurement protocol six times. For all parameters reflecting inhomogeneity, highly significant differences were found between the three participant groups (P < 0.001, ANOVA). Intraclass correlation coefficients were 0.96, 0.99, and 0.94 for the parameters reflecting inhomogeneity in deadspace, compliance, and vascular conductance, respectively. We conclude that, for the particular participants selected, highly repeatable estimates for parameters reflecting inhomogeneity could be obtained from noninvasive measurements of respiratory gas exchange. NEW & NOTEWORTHY This study describes a new method, based on highly precise measures of gas exchange, that quantifies three distributions that are intrinsic to the lung

Testing the standard model by precision measurement of the weak charges of quarks.

PubMed

Young, R D; Carlini, R D; Thomas, A W; Roche, J

2007-09-21

In a global analysis of the latest parity-violating electron scattering measurements on nuclear targets, we demonstrate a significant improvement in the experimental knowledge of the weak neutral-current lepton-quark interactions at low energy. The precision of this new result, combined with earlier atomic parity-violation measurements, places tight constraints on the size of possible contributions from physics beyond the standard model. Consequently, this result improves the lower-bound on the scale of relevant new physics to approximately 1 TeV.

Novel linear piezoelectric motor for precision position stage

NASA Astrophysics Data System (ADS)

Chen, Chao; Shi, Yunlai; Zhang, Jun; Wang, Junshan

2016-03-01

Conventional servomotor and stepping motor face challenges in nanometer positioning stages due to the complex structure, motion transformation mechanism, and slow dynamic response, especially directly driven by linear motor. A new butterfly-shaped linear piezoelectric motor for linear motion is presented. A two-degree precision position stage driven by the proposed linear ultrasonic motor possesses a simple and compact configuration, which makes the system obtain shorter driving chain. Firstly, the working principle of the linear ultrasonic motor is analyzed. The oscillation orbits of two driving feet on the stator are produced successively by using the anti-symmetric and symmetric vibration modes of the piezoelectric composite structure, and the slider pressed on the driving feet can be propelled twice in only one vibration cycle. Then with the derivation of the dynamic equation of the piezoelectric actuator and transient response model, start-upstart-up and settling state characteristics of the proposed linear actuator is investigated theoretically and experimentally, and is applicable to evaluate step resolution of the precision platform driven by the actuator. Moreover the structure of the two-degree position stage system is described and a special precision displacement measurement system is built. Finally, the characteristics of the two-degree position stage are studied. In the closed-loop condition the positioning accuracy of plus or minus <0.5 μm is experimentally obtained for the stage propelled by the piezoelectric motor. A precision position stage based the proposed butterfly-shaped linear piezoelectric is theoretically and experimentally investigated.

Precision Measurements of $$A_1^n$$ in the Deep Inelastic Regime

DOE PAGES

Parno, Diana; Flay, David; Posik, Matthew; ...

2015-04-07

We have performed precision measurements of the double-spin virtual-photon asymmetry A₁ on the neutron in the deep inelastic scattering regime, using an open-geometry, large-acceptance spectrometer and a longitudinally and transversely polarized ³He target. Our data cover a wide kinematic range 0.277 ≤ x ≤ 0.5480 at an average Q² value of 3.078 (GeV/c)², doubling the available high-precision neutron data in this x range. We have combined our results with world data on proton targets to make a leading-order extraction of the ratio of polarized-to-unpolarized parton distribution functions for up quarks and for down quarks in the same kinematic range. Ourmore » data are consistent with a previous observation of an View the MathML source A 1 n zero crossing near x=0.5. We find no evidence of a transition to a positive slope in (Δd+Δd¯)/(d+d¯) up to x=0.548.« less

A new microscope optics for laser dark-field illumination applied to high precision two dimensional measurement of specimen displacement.

PubMed

Noda, Naoki; Kamimura, Shinji

2008-02-01

With conventional light microscopy, precision in the measurement of the displacement of a specimen depends on the signal-to-noise ratio when we measure the light intensity of magnified images. This implies that, for the improvement of precision, getting brighter images and reducing background light noise are both inevitably required. For this purpose, we developed a new optics for laser dark-field illumination. For the microscopy, we used a laser beam and a pair of axicons (conical lenses) to get an optimal condition for dark-field observations. The optics was applied to measuring two dimensional microbead displacements with subnanometer precision. The bandwidth of our detection system overall was 10 kHz. Over most of this bandwidth, the observed noise level was as small as 0.1 nm/radicalHz.

Interferometric apparatus for ultra-high precision displacement measurement

NASA Technical Reports Server (NTRS)

Zhao, Feng (Inventor)

2004-01-01

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

Precision Electron Density Measurements in the SSX MHD Wind Tunnel

NASA Astrophysics Data System (ADS)

Suen-Lewis, Emma M.; Barbano, Luke J.; Shrock, Jaron E.; Kaur, Manjit; Schaffner, David A.; Brown, Michael R.

2017-10-01

We characterize fluctuations of the line averaged electron density of Taylor states produced by the magnetized coaxial plasma gun of the SSX device using a 632.8 nm HeNe laser interferometer. The analysis method uses the electron density dependence of the refractive index of the plasma to determine the electron density of the Taylor states. Typical magnetic field and density values in the SSX device approach about B ≅ 0.3 T and n = 0 . 4 ×1016 cm-3 . Analysis is improved from previous density measurement methods by developing a post-processing method to remove relative phase error between interferometer outputs and to account for approximately linear phase drift due to low-frequency mechanical vibrations of the interferometer. Precision density measurements coupled with local measurements of the magnetic field will allow us to characterize the wave composition of SSX plasma via density vs. magnetic field correlation analysis, and compare the wave composition of SSX plasma with that of the solar wind. Preliminary results indicate that density and magnetic field appear negatively correlated. Work supported by DOE ARPA-E ALPHA program.

Detecting dark-matter waves with a network of precision-measurement tools

NASA Astrophysics Data System (ADS)

Derevianko, Andrei

2018-04-01

Virialized ultralight fields (VULFs) are viable cold dark-matter candidates and include scalar and pseudoscalar bosonic fields, such as axions and dilatons. Direct searches for VULFs rely on low-energy precision-measurement tools. While previous proposals have focused on detecting coherent oscillations of the VULF signals at the VULF Compton frequencies for individual devices, here I consider a network of such devices. Virialized ultralight fields are essentially dark-matter waves and as such they carry both temporal and spatial phase information. Thereby, the discovery reach can be improved by using networks of precision-measurement tools. To formalize this idea, I derive a spatiotemporal two-point correlation function for the ultralight dark-matter fields in the framework of the standard halo model. Due to VULFs being Gaussian random fields, the derived two-point correlation function fully determines N -point correlation functions. For a network of ND devices within the coherence length of the field, the sensitivity compared to a single device can be improved by a factor of √{ND}. Further, I derive a VULF dark-matter signal profile for an individual device. The resulting line shape is strongly asymmetric due to the parabolic dispersion relation for massive nonrelativistic bosons. I discuss the aliasing effect that extends the discovery reach to VULF frequencies higher than the experimental sampling rate. I present sensitivity estimates and develop a stochastic field signal-to-noise ratio statistic. Finally, I consider an application of the formalism developed to atomic clocks and their networks.

A comparison of technical replicate (cuts) effect on lamb Warner-Bratzler shear force measurement precision.

PubMed

Holman, B W B; Alvarenga, T I R C; van de Ven, R J; Hopkins, D L

2015-07-01

The Warner-Bratzler shear force (WBSF) of 335 lamb m. longissimus lumborum (LL) caudal and cranial ends was measured to examine and simulate the effect of replicate number (r: 1-8) on the precision of mean WBSF estimates and to compare LL caudal and cranial end WBSF means. All LL were sourced from two experimental flocks as part of the Information Nucleus slaughter programme (CRC for Sheep Industry Innovation) and analysed using a Lloyd Texture analyser with a Warner-Bratzler blade attachment. WBSF data were natural logarithm (ln) transformed before statistical analysis. Mean ln(WBSF) precision improved as r increased; however the practical implications support an r equal to 6, as precision improves only marginally with additional replicates. Increasing LL sample replication results in better ln(WBSF) precision compared with increasing r, provided that sample replicates are removed from the same LL end. Cranial end mean WBSF was 11.2 ± 1.3% higher than the caudal end. Crown Copyright © 2015. Published by Elsevier Ltd. All rights reserved.

High-Precision Half-Life Measurement for the Superallowed {beta}{sup +} Emitter {sup 26}Al{sup m}

DOE Office of Scientific and Technical Information (OSTI.GOV)

Finlay, P.; Svensson, C. E.; Green, K. L.

2011-01-21

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

Precision displacement reference system

DOEpatents

Bieg, Lothar F.; Dubois, Robert R.; Strother, Jerry D.

2000-02-22

A precision displacement reference system is described, which enables real time accountability over the applied displacement feedback system to precision machine tools, positioning mechanisms, motion devices, and related operations. As independent measurements of tool location is taken by a displacement feedback system, a rotating reference disk compares feedback counts with performed motion. These measurements are compared to characterize and analyze real time mechanical and control performance during operation.

Precision measurement of the top-quark mass in lepton$+$jets final states

DOE PAGES

Abazov, Victor Mukhamedovich

2015-06-04

We measure the mass of the top quark in lepton þ jets final states using the full sample of pp¯ collision data collected by the D0 experiment in Run II of the Fermilab Tevatron Collider at √s = 1.96 TeV, corresponding to 9.7 fb -1 of integrated luminosity. We also use a matrix element technique that calculates the probabilities for each event to result from tt¯ production or background. Furthermore, the overall jet energy scale is constrained in situ by the mass of the W boson. We measure m t = 174.98 ± 0.76 GeV. As a result, this constitutesmore » the most precise single measurement of the top-quark mass.« less

Precision measurement of the top-quark mass in lepton+jets final states

DOE PAGES

Abazov, Victor Mukhamedovich

2014-07-17

We measure the mass of the top quark in leptonmore » $+$jets final states using the full sample of $$p\\bar{p}$$ collision data collected by the D0 experiment in Run II of the Fermilab Tevatron Collider at $$\\sqrt s=1.96 $$TeV, corresponding to $$9.7 {\\rm fb}^{-1}$$ of integrated luminosity. We use a matrix element technique that calculates the probabilities for each event to result from $$t\\bar t$$ production or background. The overall jet energy scale is constrained in situ by the mass of the $W$ boson. We measure $$m_t=174.98\\pm0.76$$ GeV. In conclusion, this constitutes the most precise single measurement of the top-quark mass.« less

A double-spike method for K-Ar measurement: A technique for high precision in situ dating on Mars and other planetary surfaces

NASA Astrophysics Data System (ADS)

Farley, K. A.; Hurowitz, J. A.; Asimow, P. D.; Jacobson, N. S.; Cartwright, J. A.

2013-06-01

A new method for K-Ar dating using a double isotope dilution technique is proposed and demonstrated. The method is designed to eliminate known difficulties facing in situ dating on planetary surfaces, especially instrument complexity and power availability. It may also have applicability in some terrestrial dating applications. Key to the method is the use of a solid tracer spike enriched in both 39Ar and 41K. When mixed with lithium borate flux in a Knudsen effusion cell, this tracer spike and a sample to be dated can be successfully fused and degassed of Ar at <1000 °C. The evolved 40Ar∗/39Ar ratio can be measured to high precision using noble gas mass spectrometry. After argon measurement the sample melt is heated to a slightly higher temperature (˜1030 °C) to volatilize potassium, and the evolved 39K/41K ratio measured by Knudsen effusion mass spectrometry. Combined with the known composition of the tracer spike, these two ratios define the K-Ar age using a single sample aliquot and without the need for extreme temperature or a mass determination. In principle the method can be implemented using a single mass spectrometer. Experiments indicate that quantitative extraction of argon from a basalt sample occurs at a sufficiently low temperature that potassium loss in this step is unimportant. Similarly, potassium isotope ratios measured in the Knudsen apparatus indicate good sample-spike equilibration and acceptably small isotopic fractionation. When applied to a flood basalt from the Viluy Traps, Siberia, a K-Ar age of 351 ± 19 Ma was obtained, a result within 1% of the independently known age. For practical reasons this measurement was made on two separate mass spectrometers, but a scheme for combining the measurements in a single analytical instrument is described. Because both parent and daughter are determined by isotope dilution, the precision on K-Ar ages obtained by the double isotope dilution method should routinely approach that of a pair of

High precision measurements in crustal dynamic studies

NASA Technical Reports Server (NTRS)

Wyatt, F.; Berger, J.

1984-01-01

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

Surrogate biochemical markers: precise measurement for strategic drug and biologics development.

PubMed

Lee, J W; Hulse, J D; Colburn, W A

1995-05-01

More efficient drug and biologics development is necessary for future success of pharmaceutical and biotechnology companies. One way to achieve this objective is to use rationally selected surrogate markers to improve the early decision-making process. Using typical clinical chemistry methods to measure biochemical markers may not ensure adequate precision and reproducibility. In contrast, using analytical methods that meet good laboratory practices along with rational selection and validation of biochemical markers can give those who use them a competitive advantage over those who do not by providing meaningful data for earlier decision making.

Time interval measurement device based on surface acoustic wave filter excitation, providing 1 ps precision and stability.

PubMed

Panek, Petr; Prochazka, Ivan

2007-09-01

This article deals with the time interval measurement device, which is based on a surface acoustic wave (SAW) filter as a time interpolator. The operating principle is based on the fact that a transversal SAW filter excited by a short pulse can generate a finite signal with highly suppressed spectra outside a narrow frequency band. If the responses to two excitations are sampled at clock ticks, they can be precisely reconstructed from a finite number of samples and then compared so as to determine the time interval between the two excitations. We have designed and constructed a two-channel time interval measurement device which allows independent timing of two events and evaluation of the time interval between them. The device has been constructed using commercially available components. The experimental results proved the concept. We have assessed the single-shot time interval measurement precision of 1.3 ps rms that corresponds to the time of arrival precision of 0.9 ps rms in each channel. The temperature drift of the measured time interval on temperature is lower than 0.5 ps/K, and the long term stability is better than +/-0.2 ps/h. These are to our knowledge the best values reported for the time interval measurement device. The results are in good agreement with the error budget based on the theoretical analysis.

TEPC measurements obtained on the Mir space station.

PubMed

Bottollier-Depois, J F; Siegrist, M; Petrov, V M; Shurshakov, V V; Bengin, V; Koslova, S B

2002-10-01

Measurements of the radiation environment inside the Mir space station were performed with a tissue equivalent proportional counter (TEPC) during the Antares mission in 1992, and over a long period following it. Interesting results concerning radiation measurements show (a) the South Atlantic Anomaly crossing, (b) the increase of radiation near the poles, and (c) the effects of solar particle events (the most important one occurring in early November 1992). This data also provides information about the dose and the quality factor of the radiation to which the cosmonauts were exposed during different missions. These data are compared with measurements obtained using a solid state detector. c2002 Elsevier Science Ltd. All rights reserved.

Precise monitoring of global temperature trends from satellites

NASA Technical Reports Server (NTRS)

Spencer, Roy W.; Christy, John R.

1990-01-01

Passive microwave radiometry from satellites provides more precise atmospheric temperature information than that obtained from the relatively sparse distribution of thermometers over the earth's surface. Accurate global atmospheric temperature estimates are needed for detection of possible greenhouse warming, evaluation of computer models of climate change, and for understanding important factors in the climate system. Analysis of the first 10 years (1979 to 1988) of satellite measurements of lower atmospheric temperature changes reveals a monthly precision of 0.01 C, large temperature variability on time scales from weeks to several years, but no obvious trend for the 10-year period. The warmest years, in descending order, were 1987, 1988, 1983, and 1980. The years 1984, 1985, and 1986 were the coolest.

Artificial intelligence, physiological genomics, and precision medicine.

PubMed

Williams, Anna Marie; Liu, Yong; Regner, Kevin R; Jotterand, Fabrice; Liu, Pengyuan; Liang, Mingyu

2018-04-01

Big data are a major driver in the development of precision medicine. Efficient analysis methods are needed to transform big data into clinically-actionable knowledge. To accomplish this, many researchers are turning toward machine learning (ML), an approach of artificial intelligence (AI) that utilizes modern algorithms to give computers the ability to learn. Much of the effort to advance ML for precision medicine has been focused on the development and implementation of algorithms and the generation of ever larger quantities of genomic sequence data and electronic health records. However, relevance and accuracy of the data are as important as quantity of data in the advancement of ML for precision medicine. For common diseases, physiological genomic readouts in disease-applicable tissues may be an effective surrogate to measure the effect of genetic and environmental factors and their interactions that underlie disease development and progression. Disease-applicable tissue may be difficult to obtain, but there are important exceptions such as kidney needle biopsy specimens. As AI continues to advance, new analytical approaches, including those that go beyond data correlation, need to be developed and ethical issues of AI need to be addressed. Physiological genomic readouts in disease-relevant tissues, combined with advanced AI, can be a powerful approach for precision medicine for common diseases.

Precision and Error of Three-dimensional Phenotypic Measures Acquired from 3dMD Photogrammetric Images

PubMed Central

Aldridge, Kristina; Boyadjiev, Simeon A.; Capone, George T.; DeLeon, Valerie B.; Richtsmeier, Joan T.

2015-01-01

The genetic basis for complex phenotypes is currently of great interest for both clinical investigators and basic scientists. In order to acquire a thorough understanding of the translation from genotype to phenotype, highly precise measures of phenotypic variation are required. New technologies, such as 3D photogrammetry are being implemented in phenotypic studies due to their ability to collect data rapidly and non-invasively. Before these systems can be broadly implemented the error associated with data collected from images acquired using these technologies must be assessed. This study investigates the precision, error, and repeatability associated with anthropometric landmark coordinate data collected from 3D digital photogrammetric images acquired with the 3dMDface System. Precision, error due to the imaging system, error due to digitization of the images, and repeatability are assessed in a sample of children and adults (N=15). Results show that data collected from images with the 3dMDface System are highly repeatable and precise. The average error associated with the placement of landmarks is sub-millimeter; both the error due to digitization and to the imaging system are very low. The few measures showing a higher degree of error include those crossing the labial fissure, which are influenced by even subtle movement of the mandible. These results suggest that 3D anthropometric data collected using the 3dMDface System are highly reliable and therefore useful for evaluation of clinical dysmorphology and surgery, analyses of genotype-phenotype correlations, and inheritance of complex phenotypes. PMID:16158436

Obtaining identical results with double precision global accuracy on different numbers of processors in parallel particle Monte Carlo simulations

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cleveland, Mathew A., E-mail: cleveland7@llnl.gov; Brunner, Thomas A.; Gentile, Nicholas A.

2013-10-15

We describe and compare different approaches for achieving numerical reproducibility in photon Monte Carlo simulations. Reproducibility is desirable for code verification, testing, and debugging. Parallelism creates a unique problem for achieving reproducibility in Monte Carlo simulations because it changes the order in which values are summed. This is a numerical problem because double precision arithmetic is not associative. Parallel Monte Carlo, both domain replicated and decomposed simulations, will run their particles in a different order during different runs of the same simulation because the non-reproducibility of communication between processors. In addition, runs of the same simulation using different domain decompositionsmore » will also result in particles being simulated in a different order. In [1], a way of eliminating non-associative accumulations using integer tallies was described. This approach successfully achieves reproducibility at the cost of lost accuracy by rounding double precision numbers to fewer significant digits. This integer approach, and other extended and reduced precision reproducibility techniques, are described and compared in this work. Increased precision alone is not enough to ensure reproducibility of photon Monte Carlo simulations. Non-arbitrary precision approaches require a varying degree of rounding to achieve reproducibility. For the problems investigated in this work double precision global accuracy was achievable by using 100 bits of precision or greater on all unordered sums which where subsequently rounded to double precision at the end of every time-step.« less

Precise Ionosphere Monitoring via a DSFH Satellite TT&C Link

NASA Astrophysics Data System (ADS)

Chen, Xiao; Li, Guangxia; Li, Zhiqiang; Yue, Chao

2014-11-01

A phase-coherent and frequency-hopped PN ranging system was developed, originally for the purpose of anti-jamming TT&C (tracking, telemetry and telecommand) of military satellites of China, including the Beidou-2 navigation satellites. The key innovation in the synchronization of this system is the unambiguous phase recovery of direct sequence and frequency hopping (DSFH) spread spectrum signal and the correction of frequency-dependent phase rotation caused by ionosphere. With synchronization achieved, a TEC monitoring algorithm based on maximum likelihood (ML) principle is proposed and its measuring precision is analyzed through ground simulation, onboard confirmation tests will be performed when transionosphere DSFH links are established in 2014. The measuring precision of TEC exceeds that obtained from GPS receiver data because the measurement is derived from unambiguous carrier phase estimates, not pseudorange estimates. The observation results from TT&C stations can provide real time regional ionosphere TEC estimation.

Precision measurement of neutrino oscillation parameters with KamLAND.

PubMed

Abe, S; Ebihara, T; Enomoto, S; Furuno, K; Gando, Y; Ichimura, K; Ikeda, H; Inoue, K; Kibe, Y; Kishimoto, Y; Koga, M; Kozlov, A; Minekawa, Y; Mitsui, T; Nakajima, K; Nakajima, K; Nakamura, K; Nakamura, M; Owada, K; Shimizu, I; Shimizu, Y; Shirai, J; Suekane, F; Suzuki, A; Takemoto, Y; Tamae, K; Terashima, A; Watanabe, H; Yonezawa, E; Yoshida, S; Busenitz, J; Classen, T; Grant, C; Keefer, G; Leonard, D S; McKee, D; Piepke, A; Decowski, M P; Detwiler, J A; Freedman, S J; Fujikawa, B K; Gray, F; Guardincerri, E; Hsu, L; Kadel, R; Lendvai, C; Luk, K-B; Murayama, H; O'Donnell, T; Steiner, H M; Winslow, L A; Dwyer, D A; Jillings, C; Mauger, C; McKeown, R D; Vogel, P; Zhang, C; Berger, B E; Lane, C E; Maricic, J; Miletic, T; Batygov, M; Learned, J G; Matsuno, S; Pakvasa, S; Foster, J; Horton-Smith, G A; Tang, A; Dazeley, S; Downum, K E; Gratta, G; Tolich, K; Bugg, W; Efremenko, Y; Kamyshkov, Y; Perevozchikov, O; Karwowski, H J; Markoff, D M; Tornow, W; Heeger, K M; Piquemal, F; Ricol, J-S

2008-06-06

The KamLAND experiment has determined a precise value for the neutrino oscillation parameter Deltam21(2) and stringent constraints on theta12. The exposure to nuclear reactor antineutrinos is increased almost fourfold over previous results to 2.44 x 10(32) proton yr due to longer livetime and an enlarged fiducial volume. An undistorted reactor nu[over]e energy spectrum is now rejected at >5sigma. Analysis of the reactor spectrum above the inverse beta decay energy threshold, and including geoneutrinos, gives a best fit at Deltam21(2)=7.58(-0.13)(+0.14)(stat) -0.15+0.15(syst) x 10(-5) eV2 and tan2theta12=0.56(-0.07)+0.10(stat) -0.06+0.10(syst). Local Deltachi2 minima at higher and lower Deltam21(2) are disfavored at >4sigma. Combining with solar neutrino data, we obtain Deltam21(2)=7.59(-0.21)+0.21 x 10(-5) eV2 and tan2theta12=0.47(-0.05)+0.06.

Accuracy and Precision in Measurements of Biomass Oxidative Ratio and Carbon Oxidation State

NASA Astrophysics Data System (ADS)

Gallagher, M. E.; Masiello, C. A.; Randerson, J. T.; Chadwick, O. A.; Robertson, G. P.

2007-12-01

Ecosystem oxidative ratio (OR) is a critical parameter in the apportionment of anthropogenic CO2 between the terrestrial biosphere and ocean carbon reservoirs. OR is the ratio of O2 to CO2 in gas exchange fluxes between the terrestrial biosphere and atmosphere. Ecosystem OR is linearly related to biomass carbon oxidation state (Cox), a fundamental property of the earth system describing the bonding environment of carbon in molecules. Cox can range from -4 to +4 (CH4 to CO2). Variations in both Cox and OR are driven by photosynthesis, respiration, and decomposition. We are developing several techniques to accurately measure variations in ecosystem Cox and OR; these include elemental analysis, bomb calorimetry, and 13C nuclear magnetic resonance spectroscopy. A previous study, comparing the accuracy and precision of elemental analysis versus bomb calorimetry for pure chemicals, showed that elemental analysis-based measurements are more accurate, while calorimetry- based measurements yield more precise data. However, the limited biochemical range of natural samples makes it possible that calorimetry may ultimately prove most accurate, as well as most cost-effective. Here we examine more closely the accuracy of Cox and OR values generated by calorimetry on a large set of natural biomass samples collected from the Kellogg Biological Station-Long Term Ecological Research (KBS-LTER) site in Michigan.

The MOLLER Experiment: ``An Ultra-precise Measurement of the Weak Charge of the Electron using moller Scattering''

NASA Astrophysics Data System (ADS)

Beminiwattha, Rakitha; Moller Collaboration

2017-09-01

Parity Violating Electron Scattering (PVES) is an extremely successful precision frontier tool that has been used for testing the Standard Model (SM) and understanding nucleon structure. Several generations of highly successful PVES programs at SLAC, MIT-Bates, MAMI-Mainz, and Jefferson Lab have contributed to the understanding of nucleon structure and testing the SM. But missing phenomena like matter-antimatter asymmetry, neutrino flavor oscillations, and dark matter and energy suggest that the SM is only a `low energy' effective theory. The MOLLER experiment at Jefferson Lab will measure the weak charge of the electron, QWe = 1 - 4sin2θW , with a precision of 2.4 % by measuring the parity violating asymmetry in electron-electron () scattering and will be sensitive to subtle but measurable deviations from precisely calculable predictions from the SM. The MOLLER experiment will provide the best contact interaction search for leptons at low OR high energy makes it a probe of physics beyond the Standard Model with sensitivities to mass-scales of new PV physics up to 7.5 TeV. Overview of the experiment and recent pre-R&D progress will be reported.

Towards high-precision measurement of the Tritium - He-3 mass difference

NASA Astrophysics Data System (ADS)

Shi, Wei; Redshaw, Matthew; Victoria, Juliette; Myers, Edmund

2004-05-01

An independent measurement of the mass difference of ^3He-^3T provides an important check of systematic errors in tritium beta-decay experiments that set limits to the electron anti-neutrino mass [1]. Using the precision Penning trap system developed at MIT but recently relocated to Florida State University [2], and the simultaneous two-ion cyclotron frequency measurement technique recently developed at MIT [3], we aim to measure this mass difference to better than 30 meV/c^2, more than an order of magnitude improvement over previous measurements [4,5]. Problems being addressed include producing single T^+ ions in the trap without spoiling the vacuum with ^3He, and the extension of the MIT techniques to ions of lighter mass. [1] KATRIN: http://iklau1.fzk.de/tritium [2] See abstract by Redshaw et al. [3] S. Rainville, J.K. Thompson, and D.E. Pritchard, Science 303, 334 (2004). [4] R.S. Van Dyck, D.L. Farnham, and P.B. Schwinberg, PRL 70, 2888 (1993). [5] G. Audi, A.H. Wapstra, and C. Thibault, Nuclear Physics A729, 337 (2003).

Measures of precision for dissimilarity-based multivariate analysis of ecological communities

PubMed Central

Anderson, Marti J; Santana-Garcon, Julia

2015-01-01

Ecological studies require key decisions regarding the appropriate size and number of sampling units. No methods currently exist to measure precision for multivariate assemblage data when dissimilarity-based analyses are intended to follow. Here, we propose a pseudo multivariate dissimilarity-based standard error (MultSE) as a useful quantity for assessing sample-size adequacy in studies of ecological communities. Based on sums of squared dissimilarities, MultSE measures variability in the position of the centroid in the space of a chosen dissimilarity measure under repeated sampling for a given sample size. We describe a novel double resampling method to quantify uncertainty in MultSE values with increasing sample size. For more complex designs, values of MultSE can be calculated from the pseudo residual mean square of a permanova model, with the double resampling done within appropriate cells in the design. R code functions for implementing these techniques, along with ecological examples, are provided. PMID:25438826

High Precision 142Nd/144Nd and 143Nd/144Nd Isotope Ratio Measurements in Rock Samples

NASA Astrophysics Data System (ADS)

Ali, A.; Srinivasan, G.

2009-05-01

The long-lived 147Sm-143Nd system with a half-life (T1/2) of 106 Gyr is generally used for geochronology. The short-lived 146Sm-142Nd system (T1/2= 103 Myr) is used as a geological tracer to track early (˜500 Ma) silicate differentiation [1] events in different planetary bodies. The isotope composition measurements by thermal ionization mass spectrometry (TIMS) require purification of Nd using chemical separation methods. This is important as an impure sample will give both a very poor ion yield and cause beam instability in the mass spectrometer, potentially resulting in a poor analysis [2]. The separation of Nd for 143Nd isotope measurement is, fairly straightforward because there is no isobaric interference of any other REE. While 142Nd isotope analysis needs chemically separated Nd fraction to be ˜100% Ce-free as latter is composed of a substantial amount of 142Ce isotope. A 4-steps technique, modified from Caro et al., [3], for the separation of Nd is established at the Cosmochemistry Laboratory of University of Toronto, Canada and applied to the measurement of Nd isotope ratios in geological reference sample BCR-2 (USGS, Columbia River basalt) using TIMS. Results of the isotopic ratios obtained for BCR-2 are in good agreement with published values [e.g., 4]. Analytical work on the samples discovered as the oldest rocks on Earth [5] from Nuvvuagittuq greenstone belt in Québec, Canada and various meteorites is in progress. An account of the procedures involved is briefly described here. All working solutions and acids were prepared using >18.2 MΩ.cm-1 H2O from a Milli-Q water system. Experiments were performed under Class 100 clean work bench with acid-cleaned apparatus and plastic-ware. The whole rock powders were weighed (20-30 mg) and dissolved in a mixture of HF and HNO3 using PFA vials and heated at 110°C. Further decomposition was done in Teflon bomb in the oven at 205°C. Later on contents of the Teflon bomb were transferred to vials and fluorides

Precise measurement of the left-right cross section asymmetry in Z boson production by electron-positron collisions

DOE Office of Scientific and Technical Information (OSTI.GOV)

Frey, R.E.

1994-12-01

A precise measurement of the left-right cross section asymmetry (A{sub LR}) for Z boson production by e{sup +}e{sup {minus}} collisions has been attained at the SLAC Linear Collider with the SLD detector. The author describes this measurement for the 1993 data run, emphasizing the significant improvements in polarized beam operation which took place for this run, where the luminosity-weighted electron beam polarization averaged 62.6 {+-} 1.2%. Preliminary 1993 results for A{sub LR} are presented. When combined with the (less precise) 1992 result, the preliminary result for the effective weak mixing angle is sin{sup 2}{theta}{sub W}{sup eff} = 0.2290 {+-} 0.0010.

Precision gravity measurement utilizing Accelerex vibrating beam accelerometer technology

NASA Astrophysics Data System (ADS)

Norling, Brian L.

Tests run using Sundstrand vibrating beam accelerometers to sense microgravity are described. Lunar-solar tidal effects were used as a highly predictable signal which varies by approximately 200 billionths of the full-scale gravitation level. Test runs of 48-h duration were used to evaluate stability, resolution, and noise. Test results on the Accelerex accelerometer show accuracies suitable for precision applications such as gravity mapping and gravity density logging. The test results indicate that Accelerex technology, even with an instrument design and signal processing approach not optimized for microgravity measurement, can achieve 48-nano-g (1 sigma) or better accuracy over a 48-h period. This value includes contributions from instrument noise and random walk, combined bias and scale factor drift, and thermal modeling errors as well as external contributions from sampling noise, test equipment inaccuracies, electrical noise, and cultural noise induced acceleration.

Error measuring system of rotary Inductosyn

NASA Astrophysics Data System (ADS)

Liu, Chengjun; Zou, Jibin; Fu, Xinghe

2008-10-01

The inductosyn is a kind of high-precision angle-position sensor. It has important applications in servo table, precision machine tool and other products. The precision of inductosyn is calibrated by its error. It's an important problem about the error measurement in the process of production and application of the inductosyn. At present, it mainly depends on the method of artificial measurement to obtain the error of inductosyn. Therefore, the disadvantages can't be ignored such as the high labour intensity of the operator, the occurrent error which is easy occurred and the poor repeatability, and so on. In order to solve these problems, a new automatic measurement method is put forward in this paper which based on a high precision optical dividing head. Error signal can be obtained by processing the output signal of inductosyn and optical dividing head precisely. When inductosyn rotating continuously, its zero position error can be measured dynamically, and zero error curves can be output automatically. The measuring and calculating errors caused by man-made factor can be overcome by this method, and it makes measuring process more quickly, exactly and reliably. Experiment proves that the accuracy of error measuring system is 1.1 arc-second (peak - peak value).

Precise real-time polarization measurement of terahertz electromagnetic waves by a spinning electro-optic sensor.

PubMed

Yasumatsu, Naoya; Watanabe, Shinichi

2012-02-01

We propose and develop a method to quickly and precisely determine the polarization direction of coherent terahertz electromagnetic waves generated by femtosecond laser pulses. The measurement system consists of a conventional terahertz time-domain spectroscopy system with the electro-optic (EO) sampling method, but we add a new functionality in the EO crystal which is continuously rotating with the angular frequency ω. We find a simple yet useful formulation of the EO signal as a function of the crystal orientation, which enables a lock-in-like detection of both the electric-field amplitude and the absolute polarization direction of the terahertz waves with respect to the probe laser pulse polarization direction at the same time. The single measurement finishes around two periods of the crystal rotations (∼21 ms), and we experimentally prove that the accuracy of the polarization measurement does not suffer from the long-term amplitude fluctuation of the terahertz pulses. Distribution of the measured polarization directions by repeating the measurements is excellently fitted by a gaussian distribution function with a standard deviation of σ = 0.56°. The developed technique is useful for the fast direct determination of the polarization state of the terahertz electromagnetic waves for polarization imaging applications as well as the precise terahertz Faraday or Kerr rotation spectroscopy.

The study of precision measurement of pelvis spatial structure

NASA Astrophysics Data System (ADS)

Ma, Xiang; Ouyang, Jianfei; Qu, Xinghua

2010-03-01

Osteometry is fundamental for anthropometry. It provides the key technology and value to the study of palaeoanthropology, medicine, and criminal investigation. The traditional osteometry that has been widely accepted and used since 18th century has no longer met the information demand for modern research and application. It is significant and necessary to create an advanced 3-dimensional osteometry technique for anthropometry. This paper presents a new quick and accurate method to measure human pelvis through mathematical modeling. The pelvis is a complex combination of bones, which consists of three connected parts: hipbones, sacrum, and coccyx. There are over 40 items to be measured for the 1-dimension characteristics. In this paper, a combined measuring technology is developed for pelvis measurement. It uses machine vision systems and a portable measuring arm to obtain key geometry parameters of the pelvis. The mathematics models of the pelvis spatial structure and its parts are created through the process of data collecting, digging, assembling, and modeling. The experiment shows that the proposed technology can meet traditional osteometry and obtain entire 1D geometric parameters of the pelvis, such as maximum breadth and height, diameter of obstetric conjugata, inclination angle, and sakralneigungswinkel, etc. at the same time after modeling. Besides making the measurements above, the proposed technology can measure the geometry characteristics of pelvis and its parts, such as volume, surface area, curvature, and spatial structure, which are almost impossible for traditional technology. The overall measuring error is less than 0.1mm.

Improving Precision, Maintaining Accuracy, and Reducing Acquisition Time for Trace Elements in EPMA

NASA Astrophysics Data System (ADS)

Donovan, J.; Singer, J.; Armstrong, J. T.

2016-12-01

Trace element precision in electron probe micro analysis (EPMA) is limited by intrinsic random variation in the x-ray continuum. Traditionally we characterize background intensity by measuring on either side of the emission line and interpolating the intensity underneath the peak to obtain the net intensity. Alternatively, we can measure the background intensity at the on-peak spectrometer position using a number of standard materials that do not contain the element of interest. This so-called mean atomic number (MAN) background calibration (Donovan, et al., 2016) uses a set of standard measurements, covering an appropriate range of average atomic number, to iteratively estimate the continuum intensity for the unknown composition (and hence average atomic number). We will demonstrate that, at least for materials with a relatively simple matrix such as SiO2, TiO2, ZrSiO4, etc. where one may obtain a matrix matched standard for use in the so called "blank correction", we can obtain trace element accuracy comparable to traditional off-peak methods, and with improved precision, in about half the time. Donovan, Singer and Armstrong, A New EPMA Method for Fast Trace Element Analysis in Simple Matrices ", American Mineralogist, v101, p1839-1853, 2016 Figure 1. Uranium concentration line profiles from quantitative x-ray maps (20 keV, 100 nA, 5 um beam size and 4000 msec per pixel), for both off-peak and MAN background methods without (a), and with (b), the blank correction applied. We see precision significantly improved compared with traditional off-peak measurements while, in this case, the blank correction provides a small but discernable improvement in accuracy.

Correlated, precision measurements of θ 23 and δ using only the electron neutrino appearance experiments

DOE PAGES

Minakata, Hisakazu; Parke, Stephen J.

2013-06-04

Precision measurement of the leptonic CP violating phase δ will suffer from the, then surviving, large uncertainty of sin 2θ 23 of 10–20% in the experimentally interesting region near maximal mixing of θ 23. We advocate a new method for determination of both θ 23 and δ at the same time using only the ν e and ν̄ e appearance channels and show that sin 2θ 23 can be determined automatically with much higher accuracy, approximately a factor of six, than sinδ. In this method, we identify a new degeneracy for the simultaneous determination of θ 23 and δ, themore » θ 23 intrinsic degeneracy, which must be resolved in order to achieve precision measurement of these two parameters. Spectral information around the vacuum oscillation maxima is shown to be the best way to resolve this degeneracy.« less

Impact of ambiguity resolution and application of transformation parameters obtained by regional GNSS network in Precise Point Positioning

NASA Astrophysics Data System (ADS)

Gandolfi, S.; Poluzzi, L.; Tavasci, L.

2012-12-01

Precise Point Positioning (PPP) is one of the possible approaches for GNSS data processing. As known this technique is faster and more flexible compared to the others which are based on a differenced approach and constitute a reliable methods for accurate positioning of remote GNSS stations, even in some remote area such as Antarctica. Until few years ago one of the major limits of the method was the impossibility to resolve the ambiguity as integer but nowadays many methods are available to resolve this aspect. The first software package permitting a PPP solution was the GIPSY OASIS realized, developed and maintained by JPL (NASA). JPL produce also orbits and files ready to be used with GIPSY. Recently, using these products came possible to resolve ambiguities improving the stability of solutions. PPP permit to estimate position into the reference frame of the orbits (IGS) and when coordinate in others reference frames, such al ITRF, are needed is necessary to apply a transformation. Within his products JPL offer, for each day, a global 7 parameter transformation that permit to locate the survey into the ITRF RF. In some cases it's also possible to create a costumed process and obtain analogous parameters using local/regional reference network of stations which coordinates are available also in the desired reference frame. In this work some tests on accuracy has been carried out comparing different PPP solutions obtained using the same software packages (GIPSY) but considering the ambiguity resolution, the global and regional transformation parameters. In particular two test area have been considered, first one located in Antarctica and the second one in Italy. Aim of the work is the evaluation of the impact of ambiguity resolution and the use of local/regional transformation parameter in the final solutions. Tests shown how the ambiguity resolution improve the precision, especially in the EAST component with a scattering reduction about 8%. And the use of global

Precise SAR measurements in the near-field of RF antenna systems

NASA Astrophysics Data System (ADS)

Hakim, Bandar M.

Wireless devices must meet specific safety radiation limits, and in order to assess the health affects of such devices, standard procedures are used in which standard phantoms, tissue-equivalent liquids, and miniature electric field probes are used. The accuracy of such measurements depend on the precision in measuring the dielectric properties of the tissue-equivalent liquids and the associated calibrations of the electric-field probes. This thesis describes work on the theoretical modeling and experimental measurement of the complex permittivity of tissue-equivalent liquids, and associated calibration of miniature electric-field probes. The measurement method is based on measurements of the field attenuation factor and power reflection coefficient of a tissue-equivalent sample. A novel method, to the best of the authors knowledge, for determining the dielectric properties and probe calibration factors is described and validated. The measurement system is validated using saline at different concentrations, and measurements of complex permittivity and calibration factors have been made on tissue-equivalent liquids at 900MHz and 1800MHz. Uncertainty analysis have been conducted to study the measurement system sensitivity. Using the same waveguide to measure tissue-equivalent permittivity and calibrate e-field probes eliminates a source of uncertainty associated with using two different measurement systems. The measurement system is used to test GSM cell-phones at 900MHz and 1800MHz for Specific Absorption Rate (SAR) compliance using a Specific Anthropomorphic Mannequin phantom (SAM).

How to Measure g Easily with Approximately Equal to One Ten Thousandth Precision in the Beginners' Lab.

ERIC Educational Resources Information Center

Schoch, Fritz; Winiger, Walter

1991-01-01

The data from measurements of the density of tungsten, steel, aluminum, and PVC spheres are used to extrapolate the infinite density of something such as a neutron star. An apparatus that allows for precision measurements is described. A discussion on error analysis is appended. (KR)

Precision Measurement of the Neutron Twist-3 Matrix Element dn2: Probing Color Forces

DOE Office of Scientific and Technical Information (OSTI.GOV)

Posik, Matthew; Flay, David; Parno, Diana

2014-07-01

Double-spin asymmetries and absolute cross sections were measured at large Bjorken x (0.25 lte x lte 0.90), in both the deep-inelastic and resonance regions, by scattering longitudinally polarized electrons at beam energies of 4.7 and 5.9 GeV from a transversely and longitudinally polarized 3He target. In this dedicated experiment, the spin structure function g2 on 3He was determined with precision at large x, and the neutron twist-three matrix element dn2 was measured at ?Q2? of 3.21 and 4.32 GeV2/c2, with an absolute precision of about 10?5. Our results are found to be in agreement with lattice QCD calculations and resolvemore » the disagreement found with previous data at ?Q2?= 5 GeV2/c2. Combining dn2 and a newly extracted twist-four matrix element, fn2, the average neutron color electric and magnetic forces were extracted and found to be of opposite sign and about 60 MeV/fm in magnitude.« less

Precise Near IR Radial Velocity First Light Observations With iSHELL

NASA Astrophysics Data System (ADS)

Cale, Bryson L.; Plavchan, Peter; Gagné, Jonathan; Gao, Peter; Nishimoto, America; Tanner, Angelle; Walp, Bernie; Brinkworth, Carolyn; Johnson, John Asher; Vasisht, Gautam

2018-01-01

We present our current progress on obtaining precise radial velocities with the new iSHELL spectrograph at NASA's Infrared Telescope Facility. To obtain precise RV's, we use a methane isotopologue absorption gas cell in the calibration unit. Over the past year, we've collected 3-12 epochs of 17 bright G, K, and M dwarfs at a high SNR. By focusing on late type type stars, we obtain relatively higher SNR in the near infrared. We've successfully updated both our spectral and RV extraction pipelines, with a few exceptions. Inherent to the iSHELL data is a wavelength dependent fringing component, which must be incorporated into our model to obtain adequate RV precision. With iSHELL's predecessor, CSHELL, we obtained a precision of 3 m/s on the bright M giant SV Peg. With further progress on our fringing and telluric models, we hope to obtain a precision of <3 m/s with iSHELL, sufficient to detect terrestrial planets in the habitable zone of nearby M dwarfs.

How to obtain traceability on optical radiation measurements?

NASA Astrophysics Data System (ADS)

Matamoros García, Carlos H.

2006-02-01

Traceability to national standards provides confidence in measurements results, granting a guaranty when carrying out governmental rules and when demonstrating conformity with quality requirements such as ISO 9000 or ISO/IEC 17025 (and the Mexican equivalent standards). The appropriate traceability contributes with confidence of the quality of products or services. This paper presents different ways to obtain traceability in Mexico for the optical radiation measurements, mentioning some applications, and highlighting the necessity of having traceability to the appropriate units of the SI. Additionally it present the national standards maintained by Centro Nacional de Metrologia (CENAM), the national metrology institute in Mexico, that give the technical support to Mexican measurements in this field and the international recognition that the personal of the Optics and Radiometry Division had gained in 10 years of development.

Precise dielectric property measurements and E-field probe calibration for specific absorption rate measurements using a rectangular waveguide

PubMed Central

Hakim, B M; Beard, B B; Davis, C C

2018-01-01

Specific absorption rate (SAR) measurements require accurate calculations of the dielectric properties of tissue-equivalent liquids and associated calibration of E-field probes. We developed a precise tissue-equivalent dielectric measurement and E-field probe calibration system. The system consists of a rectangular waveguide, electric field probe, and data control and acquisition system. Dielectric properties are calculated using the field attenuation factor inside the tissue-equivalent liquid and power reflectance inside the waveguide at the air/dielectric-slab interface. Calibration factors were calculated using isotropicity measurements of the E-field probe. The frequencies used are 900 MHz and 1800 MHz. The uncertainties of the measured values are within ±3%, at the 95% confidence level. Using the same waveguide for dielectric measurements as well as calibrating E-field probes used in SAR assessments eliminates a source of uncertainty. Moreover, we clearly identified the system parameters that affect the overall uncertainty of the measurement system. PMID:29520129

Flight Test Performance of a High Precision Navigation Doppler Lidar

NASA Technical Reports Server (NTRS)

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

2009-01-01

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

Precision Measurement of the Mass and Lifetime of the Ξb- Baryon

NASA Astrophysics Data System (ADS)

Aaij, R.; Adeva, B.; Adinolfi, M.; Affolder, A.; Ajaltouni, Z.; Akar, S.; Albrecht, J.; Alessio, F.; Alexander, M.; Ali, S.; Alkhazov, G.; Alvarez Cartelle, P.; Alves, A. A.; Amato, S.; Amerio, S.; Amhis, Y.; An, L.; Anderlini, L.; Anderson, J.; Andreassen, R.; Andreotti, M.; Andrews, J. E.; Appleby, R. B.; Aquines Gutierrez, O.; Archilli, F.; Artamonov, A.; Artuso, M.; Aslanides, E.; Auriemma, G.; Baalouch, M.; Bachmann, S.; Back, J. J.; Badalov, A.; Baesso, C.; Baldini, W.; Barlow, R. J.; Barschel, C.; Barsuk, S.; Barter, W.; Batozskaya, V.; Battista, V.; Bay, A.; Beaucourt, L.; Beddow, J.; Bedeschi, F.; Bediaga, I.; Belogurov, S.; Belous, K.; Belyaev, I.; Ben-Haim, E.; Bencivenni, G.; Benson, S.; Benton, J.; Berezhnoy, A.; Bernet, R.; Bettler, M.-O.; van Beuzekom, M.; Bien, A.; Bifani, S.; Bird, T.; Bizzeti, A.; Bjørnstad, P. M.; Blake, T.; Blanc, F.; Blouw, J.; Blusk, S.; Bocci, V.; Bondar, A.; Bondar, N.; Bonivento, W.; Borghi, S.; Borgia, A.; Borsato, M.; Bowcock, T. J. V.; Bowen, E.; Bozzi, C.; Brambach, T.; Brett, D.; Britsch, M.; Britton, T.; Brodzicka, J.; Brook, N. H.; Brown, H.; Bursche, A.; Buytaert, J.; Cadeddu, S.; Calabrese, R.; Calvi, M.; Calvo Gomez, M.; Campana, P.; Campora Perez, D.; Carbone, A.; Carboni, G.; Cardinale, R.; Cardini, A.; Carson, L.; Carvalho Akiba, K.; Casse, G.; Cassina, L.; Castillo Garcia, L.; Cattaneo, M.; Cauet, Ch.; Cenci, R.; Charles, M.; Charpentier, Ph.; Chefdeville, M.; Chen, S.; Cheung, S.-F.; Chiapolini, N.; Chrzaszcz, M.; Cid Vidal, X.; Ciezarek, G.; Clarke, P. E. L.; Clemencic, M.; Cliff, H. V.; Closier, J.; Coco, V.; Cogan, J.; Cogneras, E.; Cogoni, V.; Cojocariu, L.; Collazuol, G.; Collins, P.; Comerma-Montells, A.; Contu, A.; Cook, A.; Coombes, M.; Coquereau, S.; Corti, G.; Corvo, M.; Counts, I.; Couturier, B.; Cowan, G. A.; Craik, D. C.; Cruz Torres, M.; Cunliffe, S.; Currie, R.; D'Ambrosio, C.; Dalseno, J.; David, P.; David, P. N. Y.; Davis, A.; De Bruyn, K.; De Capua, S.; De Cian, M.; De Miranda, J. M.; De Paula, L.; De Silva, W.; De Simone, P.; Dean, C.-T.; Decamp, D.; Deckenhoff, M.; Del Buono, L.; Déléage, N.; Derkach, D.; Deschamps, O.; Dettori, F.; Di Canto, A.; Dijkstra, H.; Donleavy, S.; Dordei, F.; Dorigo, M.; Dosil Suárez, A.; Dossett, D.; Dovbnya, A.; Dreimanis, K.; Dujany, G.; Dupertuis, F.; Durante, P.; Dzhelyadin, R.; Dziurda, A.; Dzyuba, A.; Easo, S.; Egede, U.; Egorychev, V.; Eidelman, S.; Eisenhardt, S.; Eitschberger, U.; Ekelhof, R.; Eklund, L.; El Rifai, I.; Elsasser, Ch.; Ely, S.; Esen, S.; Evans, H.-M.; Evans, T.; Falabella, A.; Färber, C.; Farinelli, C.; Farley, N.; Farry, S.; Fay, RF; Ferguson, D.; Fernandez Albor, V.; Ferreira Rodrigues, F.; Ferro-Luzzi, M.; Filippov, S.; Fiore, M.; Fiorini, M.; Firlej, M.; Fitzpatrick, C.; Fiutowski, T.; Fol, P.; Fontana, M.; Fontanelli, F.; Forty, R.; Francisco, O.; Frank, M.; Frei, C.; Frosini, M.; Fu, J.; Furfaro, E.; Gallas Torreira, A.; Galli, D.; Gallorini, S.; Gambetta, S.; Gandelman, M.; Gandini, P.; Gao, Y.; García Pardiñas, J.; Garofoli, J.; Garra Tico, J.; Garrido, L.; Gascon, D.; Gaspar, C.; Gauld, R.; Gavardi, L.; Geraci, A.; Gersabeck, E.; Gersabeck, M.; Gershon, T.; Ghez, Ph.; Gianelle, A.; Gianı, S.; Gibson, V.; Giubega, L.; Gligorov, V. V.; Göbel, C.; Golubkov, D.; Golutvin, A.; Gomes, A.; Gotti, C.; Grabalosa Gándara, M.; Graciani Diaz, R.; Granado Cardoso, L. A.; Graugés, E.; Graverini, E.; Graziani, G.; Grecu, A.; Greening, E.; Gregson, S.; Griffith, P.; Grillo, L.; Grünberg, O.; Gui, B.; Gushchin, E.; Guz, Yu.; Gys, T.; Hadjivasiliou, C.; Haefeli, G.; Haen, C.; Haines, S. C.; Hall, S.; Hamilton, B.; Hampson, T.; Han, X.; Hansmann-Menzemer, S.; Harnew, N.; Harnew, S. T.; Harrison, J.; He, J.; Head, T.; Heijne, V.; Hennessy, K.; Henrard, P.; Henry, L.; Hernando Morata, J. A.; van Herwijnen, E.; Heß, M.; Hicheur, A.; Hill, D.; Hoballah, M.; Hombach, C.; Hulsbergen, W.; Hunt, P.; Hussain, N.; Hutchcroft, D.; Hynds, D.; Idzik, M.; Ilten, P.; Jacobsson, R.; Jaeger, A.; Jalocha, J.; Jans, E.; Jaton, P.; Jawahery, A.; Jing, F.; John, M.; Johnson, D.; Jones, C. R.; Joram, C.; Jost, B.; Jurik, N.; Kandybei, S.; Kanso, W.; Karacson, M.; Karbach, T. M.; Karodia, S.; Kelsey, M.; Kenyon, I. R.; Ketel, T.; Khanji, B.; Khurewathanakul, C.; Klaver, S.; Klimaszewski, K.; Kochebina, O.; Kolpin, M.; Komarov, I.; Koopman, R. F.; Koppenburg, P.; Korolev, M.; Kozlinskiy, A.; Kravchuk, L.; Kreplin, K.; Kreps, M.; Krocker, G.; Krokovny, P.; Kruse, F.; Kucewicz, W.; Kucharczyk, M.; Kudryavtsev, V.; Kurek, K.; Kvaratskheliya, T.; La Thi, V. N.; Lacarrere, D.; Lafferty, G.; Lai, A.; Lambert, D.; Lambert, R. W.; Lanfranchi, G.; Langenbruch, C.; Langhans, B.; Latham, T.; Lazzeroni, C.; Le Gac, R.; van Leerdam, J.; Lees, J.-P.; Lefèvre, R.; Leflat, A.; Lefrançois, J.; Leo, S.; Leroy, O.; Lesiak, T.; Leverington, B.; Li, Y.; Likhomanenko, T.; Liles, M.; Lindner, R.; Linn, C.; Lionetto, F.; Liu, B.; Lohn, S.; Longstaff, I.; Lopes, J. H.; Lopez-March, N.; Lowdon, P.; Lucchesi, D.; Luo, H.; Lupato, A.; Luppi, E.; Lupton, O.; Machefert, F.; Machikhiliyan, I. V.; Maciuc, F.; Maev, O.; Malde, S.; Malinin, A.; Manca, G.; Mancinelli, G.; Mapelli, A.; Maratas, J.; Marchand, J. F.; Marconi, U.; Marin Benito, C.; Marino, P.; Märki, R.; Marks, J.; Martellotti, G.; Martín Sánchez, A.; Martinelli, M.; Martinez Santos, D.; Martinez Vidal, F.; Martins Tostes, D.; Massafferri, A.; Matev, R.; Mathe, Z.; Matteuzzi, C.; Maurin, B.; Mazurov, A.; McCann, M.; McCarthy, J.; McNab, A.; McNulty, R.; McSkelly, B.; Meadows, B.; Meier, F.; Meissner, M.; Merk, M.; Milanes, D. A.; Minard, M.-N.; Moggi, N.; Molina Rodriguez, J.; Monteil, S.; Morandin, M.; Morawski, P.; Mordà, A.; Morello, M. J.; Moron, J.; Morris, A.-B.; Mountain, R.; Muheim, F.; Müller, K.; Mussini, M.; Muster, B.; Naik, P.; Nakada, T.; Nandakumar, R.; Nasteva, I.; Needham, M.; Neri, N.; Neubert, S.; Neufeld, N.; Neuner, M.; Nguyen, A. D.; Nguyen, T. D.; Nguyen-Mau, C.; Nicol, M.; Niess, V.; Niet, R.; Nikitin, N.; Nikodem, T.; Novoselov, A.; O'Hanlon, D. P.; Oblakowska-Mucha, A.; Obraztsov, V.; Oggero, S.; Ogilvy, S.; Okhrimenko, O.; Oldeman, R.; Onderwater, C. J. G.; Orlandea, M.; Otalora Goicochea, J. M.; Otto, A.; Owen, P.; Oyanguren, A.; Pal, B. K.; Palano, A.; Palombo, F.; Palutan, M.; Panman, J.; Papanestis, A.; Pappagallo, M.; Pappalardo, L. L.; Parkes, C.; Parkinson, C. J.; Passaleva, G.; Patel, G. D.; Patel, M.; Patrignani, C.; Pearce, A.; Pellegrino, A.; Pepe Altarelli, M.; Perazzini, S.; Perret, P.; Perrin-Terrin, M.; Pescatore, L.; Pesen, E.; Petridis, K.; Petrolini, A.; Picatoste Olloqui, E.; Pietrzyk, B.; Pilař, T.; Pinci, D.; Pistone, A.; Playfer, S.; Plo Casasus, M.; Polci, F.; Poluektov, A.; Polycarpo, E.; Popov, A.; Popov, D.; Popovici, B.; Potterat, C.; Price, E.; Price, J. D.; Prisciandaro, J.; Pritchard, A.; Prouve, C.; Pugatch, V.; Puig Navarro, A.; Punzi, G.; Qian, W.; Rachwal, B.; Rademacker, J. H.; Rakotomiaramanana, B.; Rama, M.; Rangel, M. S.; Raniuk, I.; Rauschmayr, N.; Raven, G.; Redi, F.; Reichert, S.; Reid, M. M.; dos Reis, A. C.; Ricciardi, S.; Richards, S.; Rihl, M.; Rinnert, K.; Rives Molina, V.; Robbe, P.; Rodrigues, A. B.; Rodrigues, E.; Rodriguez Perez, P.; Roiser, S.; Romanovsky, V.; Romero Vidal, A.; Rotondo, M.; Rouvinet, J.; Ruf, T.; Ruiz, H.; Ruiz Valls, P.; Saborido Silva, J. J.; Sagidova, N.; Sail, P.; Saitta, B.; Salustino Guimaraes, V.; Sanchez Mayordomo, C.; Sanmartin Sedes, B.; Santacesaria, R.; Santamarina Rios, C.; Santovetti, E.; Sarti, A.; Satriano, C.; Satta, A.; Saunders, D. M.; Savrina, D.; Schiller, M.; Schindler, H.; Schlupp, M.; Schmelling, M.; Schmidt, B.; Schneider, O.; Schopper, A.; Schubiger, M.; Schune, M.-H.; Schwemmer, R.; Sciascia, B.; Sciubba, A.; Semennikov, A.; Sepp, I.; Serra, N.; Serrano, J.; Sestini, L.; Seyfert, P.; Shapkin, M.; Shapoval, I.; Shcheglov, Y.; Shears, T.; Shekhtman, L.; Shevchenko, V.; Shires, A.; Silva Coutinho, R.; Simi, G.; Sirendi, M.; Skidmore, N.; Skillicorn, I.; Skwarnicki, T.; Smith, N. A.; Smith, E.; Smith, E.; Smith, J.; Smith, M.; Snoek, H.; Sokoloff, M. D.; Soler, F. J. P.; Soomro, F.; Souza, D.; Souza De Paula, B.; Spaan, B.; Spradlin, P.; Sridharan, S.; Stagni, F.; Stahl, M.; Stahl, S.; Steinkamp, O.; Stenyakin, O.; Stevenson, S.; Stoica, S.; Stone, S.; Storaci, B.; Stracka, S.; Straticiuc, M.; Straumann, U.; Stroili, R.; Subbiah, V. K.; Sun, L.; Sutcliffe, W.; Swientek, K.; Swientek, S.; Syropoulos, V.; Szczekowski, M.; Szczypka, P.; Szumlak, T.; T'Jampens, S.; Teklishyn, M.; Tellarini, G.; Teubert, F.; Thomas, C.; Thomas, E.; van Tilburg, J.; Tisserand, V.; Tobin, M.; Todd, J.; Tolk, S.; Tomassetti, L.; Tonelli, D.; Topp-Joergensen, S.; Torr, N.; Tournefier, E.; Tourneur, S.; Tran, M. T.; Tresch, M.; Trisovic, A.; Tsaregorodtsev, A.; Tsopelas, P.; Tuning, N.; Ubeda Garcia, M.; Ukleja, A.; Ustyuzhanin, A.; Uwer, U.; Vacca, C.; Vagnoni, V.; Valenti, G.; Vallier, A.; Vazquez Gomez, R.; Vazquez Regueiro, P.; Vázquez Sierra, C.; Vecchi, S.; Velthuis, J. J.; Veltri, M.; Veneziano, G.; Vesterinen, M.; Viaud, B.; Vieira, D.; Vieites Diaz, M.; Vilasis-Cardona, X.; Vollhardt, A.; Volyanskyy, D.; Voong, D.; Vorobyev, A.; Vorobyev, V.; Voß, C.; de Vries, J. A.; Waldi, R.; Wallace, C.; Wallace, R.; Walsh, J.; Wandernoth, S.; Wang, J.; Ward, D. R.; Watson, N. K.; Websdale, D.; Whitehead, M.; Wicht, J.; Wiedner, D.; Wilkinson, G.; Williams, M. P.; Williams, M.; Wilschut, H. W.; Wilson, F. F.; Wimberley, J.; Wishahi, J.; Wislicki, W.; Witek, M.; Wormser, G.; Wotton, S. A.; Wright, S.; Wyllie, K.; Xie, Y.; Xing, Z.; Xu, Z.; Yang, Z.; Yuan, X.; Yushchenko, O.; Zangoli, M.; Zavertyaev, M.; Zhang, L.; Zhang, W. C.; Zhang, Y.; Zhelezov, A.; Zhokhov, A.; Zhong, L.; LHCb Collaboration

2014-12-01

We report on measurements of the mass and lifetime of the Ξb- baryon using about 1800 Ξb- decays reconstructed in a proton-proton collision data set corresponding to an integrated luminosity of 3.0 fb-1 collected by the LHCb experiment. The decays are reconstructed in the Ξb-→Ξc0π-, Ξc0→p K-K-π+ channel and the mass and lifetime are measured using the Λb0→Λc+π- mode as a reference. We measure M (Ξb-)-M (Λb0)=178.36 ±0.46 ±0.16 MeV /c2 , (τΞb-/τΛb0)=1.089 ±0.026 ±0.011 , where the uncertainties are statistical and systematic, respectively. These results lead to a factor of 2 better precision on the Ξb- mass and lifetime compared to previous best measurements, and are consistent with theoretical expectations.

The effect of technical replicate (repeats) on Nix Pro Color Sensor™ measurement precision for meat: A case-study on aged beef colour stability.

PubMed

Holman, Benjamin W B; Collins, Damian; Kilgannon, Ashleigh K; Hopkins, David L

2018-01-01

The Nix Pro Colour Sensor™ (NIX) can be potentially used to measure meat colour, but procedural guidelines that assure measurement reproducibility and repeatability (precision) must first be established. Technical replicate number (r) will minimise response variation, measureable as standard error of predicted mean (SEM), and contribute to improved precision. Consequently, we aimed to explore the effects of r on NIX precision when measuring aged beef colour (colorimetrics; L*, a*, b*, hue and chroma values). Each colorimetric SEM declined with increasing r to indicate improved precision and followed a diminishing rate of improvement that allowed us to recommend r=7 for meat colour studies using the NIX. This definition was based on practical limitations and a* variability, as additional r would be required if other colorimetrics or advanced levels of precision are necessary. Beef ageing and display period, holding temperature, loin and sampled portion were also found to contribute to colorimetric variation, but were incorporated within our definition of r. Crown Copyright © 2017. Published by Elsevier Ltd. All rights reserved.

The Limits of Measurement: Misplaced Precision, Phronesis, and Other Aristotelian Cautions for the Makers of PISA, APPR, Etc.

ERIC Educational Resources Information Center

Meyer, Heinz-Dieter

2017-01-01

Quantitative measures of student performance are increasingly used as proxies of educational quality and teacher ability. Such assessments assume that the quality of educational practices can be unambiguously quantitatively measured and that such measures are sufficiently precise and robust to be aggregated into policy-relevant rankings like…

The Paradox of Abstraction: Precision Versus Concreteness.

PubMed

Iliev, Rumen; Axelrod, Robert

2017-06-01

We introduce a novel measure of abstractness based on the amount of information of a concept computed from its position in a semantic taxonomy. We refer to this measure as precision. We propose two alternative ways to measure precision, one based on the path length from a concept to the root of the taxonomic tree, and another one based on the number of direct and indirect descendants. Since more information implies greater processing load, we hypothesize that nouns higher in precision will have a processing disadvantage in a lexical decision task. We contrast precision to concreteness, a common measure of abstractness based on the proportion of sensory-based information associated with a concept. Since concreteness facilitates cognitive processing, we predict that while both concreteness and precision are measures of abstractness, they will have opposite effects on performance. In two studies we found empirical support for our hypothesis. Precision and concreteness had opposite effects on latency and accuracy in a lexical decision task, and these opposite effects were observable while controlling for word length, word frequency, affective content and semantic diversity. Our results support the view that concepts organization includes amodal semantic structures which are independent of sensory information. They also suggest that we should distinguish between sensory-based and amount-of-information-based abstractness.

Precise and absolute measurements of complex third-order optical susceptibility

NASA Astrophysics Data System (ADS)

Santran, Stephane; Canioni, Lionel; Cardinal, Thierry; Fargin, Evelyne; Le Flem, Gilles; Rouyer, Claude; Sarger, Laurent

2000-11-01

We present precise and absolute measurements of full complex third order optical susceptibility on different fused silica and original glasses composed of tellurium, titanium, niobium erbium. These materials are designed to be the key point for applications ranging form high power laser systems to optoelectronics, their nonlinear index of refraction is a major property and thus must be accurately known. Due to the accuracy and sensitivity of our technique, we have been able to find a large dispersion (more than 30%) of the non linear index of fused silica glasses as a function of their processing mode. On the other hand, measurements on tellurium glasses have shown very strong nonlinearities (40 times higher than fused silica), to be linked to the configurations of their cations and anions. Although the titanium and niobium glasses are less nonlinear, they can be promising matrices for addition of luminescent entities like erbium leading to very interesting laser amplification materials. The experimental set-up is a collinear pump-probe (orthogonally polarized) experiment using transient absorption technique. It is built with around a 100 femtosecond laser oscillator. A fast oscillating delay between the pump and the probe allows us to measure the electronic nonlinearity in quasi real-time. This experiment has the following specifications: an absolute measurement accuracy below 10% mainly due to the laser parameters characterization, a relative measurement accuracy of 1% and a resolution less than 5.10-24m2/V2(50 times less than fused silica).

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

NASA Technical Reports Server (NTRS)

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

2012-01-01

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

Study of Fricke-gel dosimeter calibration for attaining precise measurements of the absorbed dose

DOE Office of Scientific and Technical Information (OSTI.GOV)

Liosi, Giulia Maria; Benedini, Sara; Giacobbo, Francesca

2015-07-01

A method has been studied for attaining, with good precision, absolute measurements of the spatial distribution of the absorbed dose by means of the Fricke gelatin Xylenol Orange dosimetric system. With this aim, the dose response to subsequent irradiations was analyzed. In fact, the proposed modality is based on a pre-irradiation of each single dosimeter in a uniform field with a known dose, in order to extrapolate a calibration image for a subsequent non-uniform irradiation with an un-known dose to be measured. (authors)

Precision measurements of the top quark mass from the Tevatron in the pre-LHC era.

PubMed

Galtieri, Angela Barbaro; Margaroli, Fabrizio; Volobouev, Igor

2012-05-01

The top quark is the heaviest of the six quarks of the standard model (SM). Precise knowledge of its mass is important for imposing constraints on a number of physics processes, including interactions of the as yet unobserved Higgs boson. The Higgs boson is the only missing particle of the SM, central to the electroweak symmetry breaking mechanism and generation of particle masses. In this review, experimental measurements of the top quark mass accomplished at the Tevatron, a proton-antiproton collider located at the Fermi National Accelerator Laboratory, are described. Topologies of top quark events and the methods used to separate signal events from background sources are discussed. Data analysis techniques used to extract information about the top mass value are reviewed. The combination of several of the most precise measurements performed with the two Tevatron particle detectors, CDF and DØ, yields a value of M(t) = 173.2 ± 0.9 GeV/c(2).

A high-precision velocity measuring system design for projectiles based on S-shaped laser screen

NASA Astrophysics Data System (ADS)

Liu, Huayi; Qian, Zheng; Yu, Hao; Li, Yutao

2018-03-01

The high-precision measurement of the velocity of high-speed flying projectile is of great significance for the evaluation and development of modern weapons. The velocity of the high-speed flying projectile is usually measured by laser screen velocity measuring system. But this method cannot achieve the repeated measurements, so we cannot make an indepth evaluation of the uncertainty about the measuring system. This paper presents a design based on S-shaped laser screen velocity measuring system. This design can achieve repeated measurements. Therefore, it can effectively reduce the uncertainty of the velocity measuring system. In addition, we made a detailed analysis of the uncertainty of the measuring system. The measurement uncertainty is 0.2% when the velocity of the projectile is about 200m/s.

Precise measurement of Fe isotopes in marine samples by multi-collector inductively coupled plasma mass spectrometry (MC-ICP-MS).

PubMed

de Jong, Jeroen; Schoemann, Véronique; Tison, Jean-Louis; Becquevort, Sylvie; Masson, Florence; Lannuzel, Delphine; Petit, Jérôme; Chou, Lei; Weis, Dominique; Mattielli, Nadine

2007-04-18

A novel analytical technique for isotopic analysis of dissolved and particulate iron (Fe) from various marine environments is presented in this paper. It combines coprecipitation of dissolved Fe (DFe) samples with Mg(OH)(2), and acid digestion of particulate Fe (PFe) samples with double pass chromatographic separation. Isotopic data were obtained using a Nu Plasma MC-ICP-MS in dry plasma mode, applying a combination of standard-sample bracketing and external normalization by Cu doping. Argon interferences were determined prior to each analysis and automatically subtracted during analysis. Sample size can be varied between 200 and 600 ng of Fe per measurement and total procedural blanks are better than 10 ng of Fe. Typical external precision of replicate analyses (1S.D.) is +/-0.07 per thousand on delta(56)Fe and +/-0.09 per thousand on delta(57)Fe while typical internal precision of a measurement (1S.E.) is +/-0.03 per thousand on delta(56)Fe and +/-0.04 per thousand on delta(57)Fe. Accuracy and precision were assured by the analysis of reference material IRMM-014, an in-house pure Fe standard, an in-house rock standard, as well as by inter-laboratory comparison using a hematite standard from ETH (Zürich). The lowest amount of Fe (200 ng) at which a reliable isotopic measurement could still be performed corresponds to a DFe or PFe concentration of approximately 2 nmol L(-1) for a 2 L sample size. To show the versatility of the method, results are presented from contrasting environments characterized by a wide range of Fe concentrations as well as varying salt content: the Scheldt estuary, the North Sea, and Antarctic pack ice. The range of DFe and PFe concentrations encountered in this investigation falls between 2 and 2000 nmol L(-1) Fe. The distinct isotopic compositions detected in these environments cover the whole range reported in previous studies of natural Fe isotopic fractionation in the marine environment, i.e. delta(56)Fe varies between -3.5 per

High-Precision Ionosphere Monitoring Using Continuous Measurements from BDS GEO Satellites

PubMed Central

Yang, Haiyan; Yang, Xuhai; Zhang, Zhe; Zhao, Kunjuan

2018-01-01

The current constellation of the BeiDou Navigation Satellite System (BDS) consists of five geostationary earth orbit (GEO) satellites, five inclined geosynchronous satellite orbit (IGSO) satellites, and four medium earth orbit (MEO) satellites. The advantage of using GEO satellites to monitor the ionosphereis the almost motionless ionospheric pierce point (IPP), which is analyzed in comparison with the MEO and IGSO satellites. The results from the analysis of the observations using eight tracking sites indicate that the ionospheric total electron content (TEC) sequence derived from each GEO satellite at their respective fixed IPPs is always continuous. The precision of calculated vertical TEC (VTEC) using BDS B1/B2, B1/B3, and B2/B3 dual-frequency combinationsis compared and analyzed. The VTEC12 precision based on the B1/B2 dual-frequency measurements using the smoothed code and the raw code combination is 0.69 and 5.54 TECU, respectively, which is slightly higher than VTEC13 and much higher than VTEC23. Furthermore, the ionospheric monitoring results of site JFNG in the northern hemisphere, and CUT0 in the southern hemisphere during the period from 1 January to 31 December 2015 are presented and discussed briefly. PMID:29495506

High-Precision Ionosphere Monitoring Using Continuous Measurements from BDS GEO Satellites.

PubMed

Yang, Haiyan; Yang, Xuhai; Zhang, Zhe; Zhao, Kunjuan

2018-02-27

The current constellation of the BeiDou Navigation Satellite System (BDS) consists of five geostationary earth orbit (GEO) satellites, five inclined geosynchronous satellite orbit (IGSO) satellites, and four medium earth orbit (MEO) satellites. The advantage of using GEO satellites to monitor the ionosphereis the almost motionless ionospheric pierce point (IPP), which is analyzed in comparison with the MEO and IGSO satellites. The results from the analysis of the observations using eight tracking sites indicate that the ionospheric total electron content (TEC) sequence derived from each GEO satellite at their respective fixed IPPs is always continuous. The precision of calculated vertical TEC (VTEC) using BDS B1/B2, B1/B3, and B2/B3 dual-frequency combinationsis compared and analyzed. The VTEC 12 precision based on the B1/B2 dual-frequency measurements using the smoothed code and the raw code combination is 0.69 and 5.54 TECU, respectively, which is slightly higher than VTEC 13 and much higher than VTEC 23 . Furthermore, the ionospheric monitoring results of site JFNG in the northern hemisphere, and CUT0 in the southern hemisphere during the period from 1 January to 31 December 2015 are presented and discussed briefly.

High precision radial velocities with GIANO spectra

NASA Astrophysics Data System (ADS)

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

2016-06-01

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

SPM interferometer with large range for mirco-vibration measurement

NASA Astrophysics Data System (ADS)

Fu, Mingyi; Tang, Chaowei; He, Guotian; Hu, Jun; Wang, Li

2007-12-01

The measuring range and precision are two inconsistent parameters of traditional optical interferometry. In this paper, the interferometer measuring vibration with high precision and large range is proposed and its measuring principle is analyzed in detail. The interferometer obtains phase information by processing interference signals with two real-time phase discriminator and the vibration displacement could be gotten by expanding this phase. The measuring range was enlarged from half wavelength to millimeter. Meanwhile, the measuring precision was independent of external disturbance and vibration displacement measurement with high precision was realized. The measuring range of vibration displacement for 6000.5nm and the repeatable measuring precision was 5.72nm from experiment. The feasibility of the measuring method was validated by experiments.

Measures of precision for dissimilarity-based multivariate analysis of ecological communities.

PubMed

Anderson, Marti J; Santana-Garcon, Julia

2015-01-01

Ecological studies require key decisions regarding the appropriate size and number of sampling units. No methods currently exist to measure precision for multivariate assemblage data when dissimilarity-based analyses are intended to follow. Here, we propose a pseudo multivariate dissimilarity-based standard error (MultSE) as a useful quantity for assessing sample-size adequacy in studies of ecological communities. Based on sums of squared dissimilarities, MultSE measures variability in the position of the centroid in the space of a chosen dissimilarity measure under repeated sampling for a given sample size. We describe a novel double resampling method to quantify uncertainty in MultSE values with increasing sample size. For more complex designs, values of MultSE can be calculated from the pseudo residual mean square of a permanova model, with the double resampling done within appropriate cells in the design. R code functions for implementing these techniques, along with ecological examples, are provided. © 2014 The Authors. Ecology Letters published by John Wiley & Sons Ltd and CNRS.

High-precision diode-laser-based temperature measurement for air refractive index compensation.

PubMed

Hieta, Tuomas; Merimaa, Mikko; Vainio, Markku; Seppä, Jeremias; Lassila, Antti

2011-11-01

We present a laser-based system to measure the refractive index of air over a long path length. In optical distance measurements, it is essential to know the refractive index of air with high accuracy. Commonly, the refractive index of air is calculated from the properties of the ambient air using either Ciddor or Edlén equations, where the dominant uncertainty component is in most cases the air temperature. The method developed in this work utilizes direct absorption spectroscopy of oxygen to measure the average temperature of air and of water vapor to measure relative humidity. The method allows measurement of temperature and humidity over the same beam path as in optical distance measurement, providing spatially well-matching data. Indoor and outdoor measurements demonstrate the effectiveness of the method. In particular, we demonstrate an effective compensation of the refractive index of air in an interferometric length measurement at a time-variant and spatially nonhomogeneous temperature over a long time period. Further, we were able to demonstrate 7 mK RMS noise over a 67 m path length using a 120 s sample time. To our knowledge, this is the best temperature precision reported for a spectroscopic temperature measurement. © 2011 Optical Society of America

Precision Linear Actuator for Space Interferometry Mission (SIM) Siderostat Pointing

NASA Technical Reports Server (NTRS)

Cook, Brant; Braun, David; Hankins, Steve; Koenig, John; Moore, Don

2008-01-01

'SIM PlanetQuest will exploit the classical measuring tool of astrometry (interferometry) with unprecedented precision to make dramatic advances in many areas of astronomy and astrophysics'(1). In order to obtain interferometric data two large steerable mirrors, or Siderostats, are used to direct starlight into the interferometer. A gimbaled mechanism actuated by linear actuators is chosen to meet the unprecedented pointing and angle tracking requirements of SIM. A group of JPL engineers designed, built, and tested a linear ballscrew actuator capable of performing submicron incremental steps for 10 years of continuous operation. Precise, zero backlash, closed loop pointing control requirements, lead the team to implement a ballscrew actuator with a direct drive DC motor and a precision piezo brake. Motor control commutation using feedback from a precision linear encoder on the ballscrew output produced an unexpected incremental step size of 20 nm over a range of 120 mm, yielding a dynamic range of 6,000,000:1. The results prove linear nanometer positioning requires no gears, levers, or hydraulic converters. Along the way many lessons have been learned and will subsequently be shared.

High-precision branching-ratio measurement for the superallowed β+ emitter 26Alm

NASA Astrophysics Data System (ADS)

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

2012-05-01

A high-precision branching-ratio measurement for the superallowed β+ emitter 26Alm was performed at the TRIUMF-ISAC radioactive ion beam facility. An upper limit of ⩽12 ppm at 90% confidence level was found for the second forbidden β+ decay of 26Alm to the 21+ state at 1809 keV in 26Mg. An inclusive upper limit of ⩽15 ppm at 90% confidence level was found when considering all possible nonanalog β+/EC decay branches of 26Alm, resulting in a superallowed branching ratio of 100.0000-0.0015+0%.

Precise orbit computation and sea surface modeling

NASA Technical Reports Server (NTRS)

Wakker, Karel F.; Ambrosius, B. A. C.; Rummel, R.; Vermaat, E.; Deruijter, W. P. M.; Vandermade, J. W.; Zimmerman, J. T. F.

1991-01-01

The research project described below is part of a long-term program at Delft University of Technology aiming at the application of European Remote Sensing satellite (ERS-1) and TOPEX/POSEIDON altimeter measurements for geophysical purposes. This program started in 1980 with the processing of Seasat laser range and altimeter height measurements and concentrates today on the analysis of Geosat altimeter data. The objectives of the TOPEX/POSEIDON research project are the tracking of the satellite by the Dutch mobile laser tracking system MTLRS-2, the computation of precise TOPEX/POSEIDON orbits, the analysis of the spatial and temporal distribution of the orbit errors, the improvement of ERS-1 orbits through the information obtained from the altimeter crossover difference residuals for crossing ERS-1 and TOPEX/POSEIDON tracks, the combination of ERS-1 and TOPEX/POSEIDON altimeter data into a single high-precision data set, and the application of this data set to model the sea surface. The latter application will focus on the determination of detailed regional mean sea surfaces, sea surface variability, ocean topography, and ocean currents in the North Atlantic, the North Sea, the seas around Indonesia, the West Pacific, and the oceans around South Africa.

Responsive upper limb and cognitive fatigue measures during light precision work: an 8-hour simulated micro-pipetting study.

PubMed

Yung, Marcus; Wells, Richard P

2017-07-01

Many contemporary occupations are characterised by long periods of low loads. These lower force levels, which are relevant to the development of work-related musculoskeletal disorders, are usually not the focus of fatigue studies. In studies that did measure fatigue in light manual or precision work, within and between measurement responses were inconsistent. The aim of this study was to identify fatigue measures that were responsive at lower force levels (<10% MVC) over the course of an 8-h period. A complementary set of fatigue measures, reflecting both neuromuscular and cognitive mechanisms, was measured during a light precision micro-pipetting task performed by 11 participants. Nine measures were found to be significantly responsive over the 8-h period, including: ratings of perceived fatigue, postural tremor, blink frequency and critical flicker fusion frequency threshold. Common field measures, specifically electromyography RMS amplitude and maximum voluntary contractions, did not lead to extraordinary time effects. Practitioner summary: The findings provide insight towards the responsiveness of a complementary set of field usable fatigue measures at low work intensities Although commonly used measures did not reveal significant increases in fatigue, nine alternative measures were significantly responsive over the 8-h period.

A Broad Bank Lidar for Precise Atmospheric CO2 Column Absorption Measurement from Space

NASA Technical Reports Server (NTRS)

Georgieva, E. M.; Heaps, W. S.; Huang, W.

2010-01-01

Accurate global measurement of carbon dioxide column with the aim of discovering and quantifying unknown sources and sinks has been a high priority for the last decade. In order to uncover the "missing sink" that is responsible for the large discrepancies in the budget the critical precision for a measurement from space needs to be on the order of 1 ppm. To better understand the CO2 budget and to evaluate its impact on global warming the National Research Council (NRC) in its recent decadal survey report (NACP) to NASA recommended a laser based total CO2 mapping mission in the near future. That's the goal of Active Sensing of CO2 Emissions over Nights, Days, and Seasons (ASCENDS) mission - to significantly enhance the understanding of the role of CO2 in the global carbon cycle. Our current goal is to develop an ultra precise, inexpensive new lidar system for column measurements of CO2 changes in the lower atmosphere that uses a Fabry-Perot interferometer based system as the detector portion of the instrument and replaces the narrow band laser commonly used in lidars with a high power broadband source. This approach reduces the number of individual lasers used in the system and considerably reduces the risk of failure. It also tremendously reduces the requirement for wavelength stability in the source putting this responsibility instead on the Fabry- Perot subsystem.

High-precision thermal expansion measurements using small Fabry-Perot etalons

NASA Astrophysics Data System (ADS)

Davis, Mark J.; Hayden, Joseph S.; Farber, Daniel L.

2007-09-01

Coefficient of thermal expansion (CTE) measurements using small Fabry-Perot etalons were conducted on high and low thermal expansion materials differing in CTE by a factor of nearly 400. The smallest detectable change in length was ~10 -12 m. The sample consisted of a mm-sized Fabry-Perot etalon equipped with spherical mirrors; the material-under-test served as the 2.5 mm-thick spacer between the mirrors. A heterodyne optical setup was used with one laser locked to an ~780 nm hyperfine line of Rb gas and the other locked to a resonance of the sample etalon; changes in the beat frequency between the two lasers as a function of temperature directly provided a CTE value. The measurement system was tested using the high-CTE SCHOTT optical glass N-KF9 (CTE = 9.5 ppm/K at 23 °C). Measurements conducted under reproducibility conditions using five identically-prepared N-KF9 etalons demonstrate a precision of 0.1 ppm/K; absolute values (accuracy) are within 2-sigma errors with those made using mechanical dilatometers with 100-mm long sample rods. Etalon-based CTE measurements were also made on a high-CTE (~10.5 ppm/K), proprietary glass-ceramic used for high peak-pressure electrical feedthroughs and revealed statistically significant differences among parts made under what were assumed to be identical conditions. Finally, CTE measurements were made on etalons constructed from SCHOTT's ultra-low CTE Zerodur (R) glass-ceramic (CTE about -20 ppb/K at 50 °C for the material tested herein).

Influence of sulfur-bearing polyatomic species on high precision measurements of Cu isotopic composition

USGS Publications Warehouse

Pribil, M.J.; Wanty, R.B.; Ridley, W.I.; Borrok, D.M.

2010-01-01

An increased interest in high precision Cu isotope ratio measurements using multi-collector inductively coupled plasma mass spectrometry (MC-ICP-MS) has developed recently for various natural geologic systems and environmental applications, these typically contain high concentrations of sulfur, particularly in the form of sulfate (SO42-) and sulfide (S). For example, Cu, Fe, and Zn concentrations in acid mine drainage (AMD) can range from 100??g/L to greater than 50mg/L with sulfur species concentrations reaching greater than 1000mg/L. Routine separation of Cu, Fe and Zn from AMD, Cu-sulfide minerals and other geological matrices usually incorporates single anion exchange resin column chromatography for metal separation. During chromatographic separation, variable breakthrough of SO42- during anion exchange resin column chromatography into the Cu fractions was observed as a function of the initial sulfur to Cu ratio, column properties, and the sample matrix. SO42- present in the Cu fraction can form a polyatomic 32S-14N-16O-1H species causing a direct mass interference with 63Cu and producing artificially light ??65Cu values. Here we report the extent of the mass interference caused by SO42- breakthrough when measuring ??65Cu on natural samples and NIST SRM 976 Cu isotope spiked with SO42- after both single anion column chromatography and double anion column chromatography. A set of five 100??g/L Cu SRM 976 samples spiked with 500mg/L SO42- resulted in an average ??65Cu of -3.50?????5.42??? following single anion column separation with variable SO42- breakthrough but an average concentration of 770??g/L. Following double anion column separation, the average SO42-concentration of 13??g/L resulted in better precision and accuracy for the measured ??65Cu value of 0.01?????0.02??? relative to the expected 0??? for SRM 976. We conclude that attention to SO42- breakthrough on sulfur-rich samples is necessary for accurate and precise measurements of ??65Cu and may require

Development and Testing of a High-Precision Position and Attitude Measuring System for a Space Mechanism

NASA Technical Reports Server (NTRS)

Khanenya, Nikolay; Paciotti, Gabriel; Forzani, Eugenio; Blecha, Luc

2016-01-01

This paper describes a high-precision optical metrology system - a unique ground test equipment which was designed and implemented for simultaneous precise contactless measurements of 6 degrees-of-freedom (3 translational + 3 rotational) of a space mechanism end-effector [1] in a thermally controlled ISO 5 clean environment. The developed contactless method reconstructs both position and attitude of the specimen from three cross-sections measured by 2D distance sensors [2]. The cleanliness is preserved by the hermetic test chamber filled with high purity nitrogen. The specimen's temperature is controlled by the thermostat [7]. The developed method excludes errors caused by the thermal deformations and manufacturing inaccuracies of the test jig. Tests and simulations show that the measurement accuracy of an object absolute position is of 20 micron in in-plane measurement (XY) and about 50 micron out of plane (Z). The typical absolute attitude is determined with an accuracy better than 3 arcmin in rotation around X and Y and better than 10 arcmin in Z. The metrology system is able to determine relative position and movement with an accuracy one order of magnitude lower than the absolute accuracy. Typical relative displacement measurement accuracies are better than 1 micron in X and Y and about 2 micron in Z. Finally, the relative rotation can be measured with accuracy better than 20 arcsec in any direction.

Precision measurement of the mass and lifetime of the Ξb⁻ baryon.

PubMed

Aaij, R; Adeva, B; Adinolfi, M; Affolder, A; Ajaltouni, Z; Akar, S; Albrecht, J; Alessio, F; Alexander, M; Ali, S; Alkhazov, G; Alvarez Cartelle, P; Alves, A A; Amato, S; Amerio, S; Amhis, Y; An, L; Anderlini, L; Anderson, J; Andreassen, R; Andreotti, M; Andrews, J E; Appleby, R B; Aquines Gutierrez, O; Archilli, F; Artamonov, A; Artuso, M; Aslanides, E; Auriemma, G; Baalouch, M; Bachmann, S; Back, J J; Badalov, A; Baesso, C; Baldini, W; Barlow, R J; Barschel, C; Barsuk, S; Barter, W; Batozskaya, V; Battista, V; Bay, A; Beaucourt, L; Beddow, J; Bedeschi, F; Bediaga, I; Belogurov, S; Belous, K; Belyaev, I; Ben-Haim, E; Bencivenni, G; Benson, S; Benton, J; Berezhnoy, A; Bernet, R; Bettler, M-O; van Beuzekom, M; Bien, A; Bifani, S; Bird, T; Bizzeti, A; Bjørnstad, P M; Blake, T; Blanc, F; Blouw, J; Blusk, S; Bocci, V; Bondar, A; Bondar, N; Bonivento, W; Borghi, S; Borgia, A; Borsato, M; Bowcock, T J V; Bowen, E; Bozzi, C; Brambach, T; Brett, D; Britsch, M; Britton, T; Brodzicka, J; Brook, N H; Brown, H; Bursche, A; Buytaert, J; Cadeddu, S; Calabrese, R; Calvi, M; Calvo Gomez, M; Campana, P; Campora Perez, D; Carbone, A; Carboni, G; Cardinale, R; Cardini, A; Carson, L; Carvalho Akiba, K; Casse, G; Cassina, L; Castillo Garcia, L; Cattaneo, M; Cauet, Ch; Cenci, R; Charles, M; Charpentier, Ph; Chefdeville, M; Chen, S; Cheung, S-F; Chiapolini, N; Chrzaszcz, M; Cid Vidal, X; Ciezarek, G; Clarke, P E L; Clemencic, M; Cliff, H V; Closier, J; Coco, V; Cogan, J; Cogneras, E; Cogoni, V; Cojocariu, L; Collazuol, G; Collins, P; Comerma-Montells, A; Contu, A; Cook, A; Coombes, M; Coquereau, S; Corti, G; Corvo, M; Counts, I; Couturier, B; Cowan, G A; Craik, D C; Cruz Torres, M; Cunliffe, S; Currie, R; D'Ambrosio, C; Dalseno, J; David, P; David, P N Y; Davis, A; De Bruyn, K; De Capua, S; De Cian, M; De Miranda, J M; De Paula, L; De Silva, W; De Simone, P; Dean, C-T; Decamp, D; Deckenhoff, M; Del Buono, L; Déléage, N; Derkach, D; Deschamps, O; Dettori, F; Di Canto, A; Dijkstra, H; Donleavy, S; Dordei, F; Dorigo, M; Dosil Suárez, A; Dossett, D; Dovbnya, A; Dreimanis, K; Dujany, G; Dupertuis, F; Durante, P; Dzhelyadin, R; Dziurda, A; Dzyuba, A; Easo, S; Egede, U; Egorychev, V; Eidelman, S; Eisenhardt, S; Eitschberger, U; Ekelhof, R; Eklund, L; El Rifai, I; Elsasser, Ch; Ely, S; Esen, S; Evans, H-M; Evans, T; Falabella, A; Färber, C; Farinelli, C; Farley, N; Farry, S; Fay, R F; Ferguson, D; Fernandez Albor, V; Ferreira Rodrigues, F; Ferro-Luzzi, M; Filippov, S; Fiore, M; Fiorini, M; Firlej, M; Fitzpatrick, C; Fiutowski, T; Fol, P; Fontana, M; Fontanelli, F; Forty, R; Francisco, O; Frank, M; Frei, C; Frosini, M; Fu, J; Furfaro, E; Gallas Torreira, A; Galli, D; Gallorini, S; Gambetta, S; Gandelman, M; Gandini, P; Gao, Y; García Pardiñas, J; Garofoli, J; Garra Tico, J; Garrido, L; Gascon, D; Gaspar, C; Gauld, R; Gavardi, L; Geraci, A; Gersabeck, E; Gersabeck, M; Gershon, T; Ghez, Ph; Gianelle, A; Gianì, S; Gibson, V; Giubega, L; Gligorov, V V; Göbel, C; Golubkov, D; Golutvin, A; Gomes, A; Gotti, C; Grabalosa Gándara, M; Graciani Diaz, R; Granado Cardoso, L A; Graugés, E; Graverini, E; Graziani, G; Grecu, A; Greening, E; Gregson, S; Griffith, P; Grillo, L; Grünberg, O; Gui, B; Gushchin, E; Guz, Yu; Gys, T; Hadjivasiliou, C; Haefeli, G; Haen, C; Haines, S C; Hall, S; Hamilton, B; Hampson, T; Han, X; Hansmann-Menzemer, S; Harnew, N; Harnew, S T; Harrison, J; He, J; Head, T; Heijne, V; Hennessy, K; Henrard, P; Henry, L; Hernando Morata, J A; van Herwijnen, E; Heß, M; Hicheur, A; Hill, D; Hoballah, M; Hombach, C; Hulsbergen, W; Hunt, P; Hussain, N; Hutchcroft, D; Hynds, D; Idzik, M; Ilten, P; Jacobsson, R; Jaeger, A; Jalocha, J; Jans, E; Jaton, P; Jawahery, A; Jing, F; John, M; Johnson, D; Jones, C R; Joram, C; Jost, B; Jurik, N; Kandybei, S; Kanso, W; Karacson, M; Karbach, T M; Karodia, S; Kelsey, M; Kenyon, I R; Ketel, T; Khanji, B; Khurewathanakul, C; Klaver, S; Klimaszewski, K; Kochebina, O; Kolpin, M; Komarov, I; Koopman, R F; Koppenburg, P; Korolev, M; Kozlinskiy, A; Kravchuk, L; Kreplin, K; Kreps, M; Krocker, G; Krokovny, P; Kruse, F; Kucewicz, W; Kucharczyk, M; Kudryavtsev, V; Kurek, K; Kvaratskheliya, T; La Thi, V N; Lacarrere, D; Lafferty, G; Lai, A; Lambert, D; Lambert, R W; Lanfranchi, G; Langenbruch, C; Langhans, B; Latham, T; Lazzeroni, C; Le Gac, R; van Leerdam, J; Lees, J-P; Lefèvre, R; Leflat, A; Lefrançois, J; Leo, S; Leroy, O; Lesiak, T; Leverington, B; Li, Y; Likhomanenko, T; Liles, M; Lindner, R; Linn, C; Lionetto, F; Liu, B; Lohn, S; Longstaff, I; Lopes, J H; Lopez-March, N; Lowdon, P; Lucchesi, D; Luo, H; Lupato, A; Luppi, E; Lupton, O; Machefert, F; Machikhiliyan, I V; Maciuc, F; Maev, O; Malde, S; Malinin, A; Manca, G; Mancinelli, G; Mapelli, A; Maratas, J; Marchand, J F; Marconi, U; Marin Benito, C; Marino, P; Märki, R; Marks, J; Martellotti, G; Martín Sánchez, A; Martinelli, M; Martinez Santos, D; Martinez Vidal, F; Martins Tostes, D; Massafferri, A; Matev, R; Mathe, Z; Matteuzzi, C; Maurin, B; Mazurov, A; McCann, M; McCarthy, J; McNab, A; McNulty, R; McSkelly, B; Meadows, B; Meier, F; Meissner, M; Merk, M; Milanes, D A; Minard, M-N; Moggi, N; Molina Rodriguez, J; Monteil, S; Morandin, M; Morawski, P; Mordà, A; Morello, M J; Moron, J; Morris, A-B; Mountain, R; Muheim, F; Müller, K; Mussini, M; Muster, B; Naik, P; Nakada, T; Nandakumar, R; Nasteva, I; Needham, M; Neri, N; Neubert, S; Neufeld, N; Neuner, M; Nguyen, A D; Nguyen, T D; Nguyen-Mau, C; Nicol, M; Niess, V; Niet, R; Nikitin, N; Nikodem, T; Novoselov, A; O'Hanlon, D P; Oblakowska-Mucha, A; Obraztsov, V; Oggero, S; Ogilvy, S; Okhrimenko, O; Oldeman, R; Onderwater, C J G; Orlandea, M; Otalora Goicochea, J M; Otto, A; Owen, P; Oyanguren, A; Pal, B K; Palano, A; Palombo, F; Palutan, M; Panman, J; Papanestis, A; Pappagallo, M; Pappalardo, L L; Parkes, C; Parkinson, C J; Passaleva, G; Patel, G D; Patel, M; Patrignani, C; Pearce, A; Pellegrino, A; Pepe Altarelli, M; Perazzini, S; Perret, P; Perrin-Terrin, M; Pescatore, L; Pesen, E; Petridis, K; Petrolini, A; Picatoste Olloqui, E; Pietrzyk, B; Pilař, T; Pinci, D; Pistone, A; Playfer, S; Plo Casasus, M; Polci, F; Poluektov, A; Polycarpo, E; Popov, A; Popov, D; Popovici, B; Potterat, C; Price, E; Price, J D; Prisciandaro, J; Pritchard, A; Prouve, C; Pugatch, V; Puig Navarro, A; Punzi, G; Qian, W; Rachwal, B; Rademacker, J H; Rakotomiaramanana, B; Rama, M; Rangel, M S; Raniuk, I; Rauschmayr, N; Raven, G; Redi, F; Reichert, S; Reid, M M; dos Reis, A C; Ricciardi, S; Richards, S; Rihl, M; Rinnert, K; Rives Molina, V; Robbe, P; Rodrigues, A B; Rodrigues, E; Rodriguez Perez, P; Roiser, S; Romanovsky, V; Romero Vidal, A; Rotondo, M; Rouvinet, J; Ruf, T; Ruiz, H; Ruiz Valls, P; Saborido Silva, J J; Sagidova, N; Sail, P; Saitta, B; Salustino Guimaraes, V; Sanchez Mayordomo, C; Sanmartin Sedes, B; Santacesaria, R; Santamarina Rios, C; Santovetti, E; Sarti, A; Satriano, C; Satta, A; Saunders, D M; Savrina, D; Schiller, M; Schindler, H; Schlupp, M; Schmelling, M; Schmidt, B; Schneider, O; Schopper, A; Schubiger, M; Schune, M-H; Schwemmer, R; Sciascia, B; Sciubba, A; Semennikov, A; Sepp, I; Serra, N; Serrano, J; Sestini, L; Seyfert, P; Shapkin, M; Shapoval, I; Shcheglov, Y; Shears, T; Shekhtman, L; Shevchenko, V; Shires, A; Silva Coutinho, R; Simi, G; Sirendi, M; Skidmore, N; Skillicorn, I; Skwarnicki, T; Smith, N A; Smith, E; Smith, E; Smith, J; Smith, M; Snoek, H; Sokoloff, M D; Soler, F J P; Soomro, F; Souza, D; Souza De Paula, B; Spaan, B; Spradlin, P; Sridharan, S; Stagni, F; Stahl, M; Stahl, S; Steinkamp, O; Stenyakin, O; Stevenson, S; Stoica, S; Stone, S; Storaci, B; Stracka, S; Straticiuc, M; Straumann, U; Stroili, R; Subbiah, V K; Sun, L; Sutcliffe, W; Swientek, K; Swientek, S; Syropoulos, V; Szczekowski, M; Szczypka, P; Szumlak, T; T'Jampens, S; Teklishyn, M; Tellarini, G; Teubert, F; Thomas, C; Thomas, E; van Tilburg, J; Tisserand, V; Tobin, M; Todd, J; Tolk, S; Tomassetti, L; Tonelli, D; Topp-Joergensen, S; Torr, N; Tournefier, E; Tourneur, S; Tran, M T; Tresch, M; Trisovic, A; Tsaregorodtsev, A; Tsopelas, P; Tuning, N; Ubeda Garcia, M; Ukleja, A; Ustyuzhanin, A; Uwer, U; Vacca, C; Vagnoni, V; Valenti, G; Vallier, A; Vazquez Gomez, R; Vazquez Regueiro, P; Vázquez Sierra, C; Vecchi, S; Velthuis, J J; Veltri, M; Veneziano, G; Vesterinen, M; Viaud, B; Vieira, D; Vieites Diaz, M; Vilasis-Cardona, X; Vollhardt, A; Volyanskyy, D; Voong, D; Vorobyev, A; Vorobyev, V; Voß, C; de Vries, J A; Waldi, R; Wallace, C; Wallace, R; Walsh, J; Wandernoth, S; Wang, J; Ward, D R; Watson, N K; Websdale, D; Whitehead, M; Wicht, J; Wiedner, D; Wilkinson, G; Williams, M P; Williams, M; Wilschut, H W; Wilson, F F; Wimberley, J; Wishahi, J; Wislicki, W; Witek, M; Wormser, G; Wotton, S A; Wright, S; Wyllie, K; Xie, Y; Xing, Z; Xu, Z; Yang, Z; Yuan, X; Yushchenko, O; Zangoli, M; Zavertyaev, M; Zhang, L; Zhang, W C; Zhang, Y; Zhelezov, A; Zhokhov, A; Zhong, L

2014-12-12

We report on measurements of the mass and lifetime of the Ξ(b)⁻ baryon using about 1800 Ξ(b)⁻ decays reconstructed in a proton-proton collision data set corresponding to an integrated luminosity of 3.0  fb⁻¹ collected by the LHCb experiment. The decays are reconstructed in the Ξ(b)⁻→Ξ(c)⁰π⁻, Ξ(c)⁰→pK⁻K⁻π⁺ channel and the mass and lifetime are measured using the Λ(b)⁰→Λ(c)⁺π⁻ mode as a reference. We measure M(Ξ(b)⁻)-M(Λ(b)⁰)=178.36±0.46±0.16  MeV/c², (τ(Ξ(b)⁻)/τ(Λ(b)⁰)=1.089±0.026±0.011, where the uncertainties are statistical and systematic, respectively. These results lead to a factor of 2 better precision on the Ξ(b)⁻ mass and lifetime compared to previous best measurements, and are consistent with theoretical expectations.

Joseph F. Keithley Award For Advances in Measurement Science Talk: Precision Noise Measurements at Microwave and Optical Frequencies

NASA Astrophysics Data System (ADS)

Ivanov, Eugene

2010-03-01

The quest to detect Gravitational Waves resulted in a number of important developments in the fields of oscillator frequency stabilization and precision noise measurements. This was due to the realization of similarities between the principles of high sensitivity measurements of weak mechanical forces and phase/amplitude fluctuations of microwave signals. In both cases interferometric carrier suppression and low-noise amplification of the residual noise sidebands were the main factors behind significant improvements in the resolution of spectral measurements. In particular, microwave frequency discriminators with almost thermal noise limited sensitivity were constructed leading to microwave oscillators with more than 25dB lower phase noise than the previous state-of-the-art. High power solid-state microwave amplifiers offered further opportunity of oscillator phase noise reduction due to the increased energy stored in the high-Q resonator of the frequency discriminator. High power microwave oscillators with the phase noise spectral density close to -160dBc/Hz at 1kHz Fourier frequency have been recently demonstrated. The principles of interferometric signal processing have been applied to the study of noise phenomena in microwave components which were considered to be ``noise free''. This resulted in the first experimental evidence of phase fluctuations in microwave circulators. More efficient use of signal power enabled construction of the ``power recycled'' interferometers with spectral resolution of -200dBc/Hz at 1kHz Fourier frequency. This has been lately superseded by an order of magnitude with a waveguide interferometer due to its higher power recycling factor. A number of opto-electronic measurement systems were developed to characterize the fidelity of frequency transfer from the optical to the microwave domain. This included a new type of a phase detector capable of measuring phase fluctuations of the weak microwave signals extracted from the demodulated

Precision measurement of the photon detection efficiency of silicon photomultipliers using two integrating spheres.

PubMed

Yang, Seul Ki; Lee, J; Kim, Sug-Whan; Lee, Hye-Young; Jeon, Jin-A; Park, I H; Yoon, Jae-Ryong; Baek, Yang-Sik

2014-01-13

We report a new and improved photon counting method for the precision PDE measurement of SiPM detectors, utilizing two integrating spheres connected serially and calibrated reference detectors. First, using a ray tracing simulation and irradiance measurement results with a reference photodiode, we investigated irradiance characteristics of the measurement instrument, and analyzed dominating systematic uncertainties in PDE measurement. Two SiPM detectors were then used for PDE measurements between wavelengths of 368 and 850 nm and for bias voltages varying from around 70V. The resulting PDEs of the SiPMs show good agreement with those from other studies, yet with an improved accuracy of 1.57% (1σ). This was achieved by the simultaneous measurement with the NIST calibrated reference detectors, which suppressed the time dependent variation of source light. The technical details of the instrumentation, measurement results and uncertainty analysis are reported together with their implications.

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

NASA Astrophysics Data System (ADS)

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

2016-02-01

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

A comparison of protocols and observer precision for measuring physical stream attributes

USGS Publications Warehouse

Whitacre, H.W.; Roper, B.B.; Kershner, J.L.

2007-01-01

Stream monitoring programs commonly measure physical attributes to assess the effect of land management on stream habitat. Variability associated with the measurement of these attributes has been linked to a number of factors, but few studies have evaluated variability due to differences in protocols. We compared six protocols, five used by the U.S. Department of Agriculture Forest Service and one by the U.S. Environmental Protection Agency, on six streams in Oregon and Idaho to determine whether differences in protocol affect values for 10 physical stream attributes. Results from Oregon and Idaho were combined for groups participating in both states, with significant differences in attribute means for 9 out of the 10 stream attributes. Significant differences occurred in 5 of 10 in Idaho, and 10 of 10 in Oregon. Coefficients of variation, signal-to-noise ratio, and root mean square error were used to evaluate measurement precision. There were differences among protocols for all attributes when states were analyzed separately and as a combined dataset. Measurement differences were influenced by choice of instruments, measurement method, measurement location, attribute definitions, and training approach. Comparison of data gathered by observers using different protocols will be difficult unless a core set of protocols for commonly measured stream attributes can be standardized among monitoring programs.

Precision Isotope Shift Measurements in Calcium Ions Using Quantum Logic Detection Schemes.

PubMed

Gebert, Florian; Wan, Yong; Wolf, Fabian; Angstmann, Christopher N; Berengut, Julian C; Schmidt, Piet O

2015-07-31

We demonstrate an efficient high-precision optical spectroscopy technique for single trapped ions with nonclosed transitions. In a double-shelving technique, the absorption of a single photon is first amplified to several phonons of a normal motional mode shared with a cotrapped cooling ion of a different species, before being further amplified to thousands of fluorescence photons emitted by the cooling ion using the standard electron shelving technique. We employ this extension of the photon recoil spectroscopy technique to perform the first high precision absolute frequency measurement of the 2D(3/2)→2P(1/2) transition in calcium, resulting in a transition frequency of f=346 000 234 867(96)  kHz. Furthermore, we determine the isotope shift of this transition and the 2S(1/2)→2P(1/2) transition for 42Ca+, 44Ca+, and 48Ca+ ions relative to 40Ca+ with an accuracy below 100 kHz. Improved field and mass shift constants of these transitions as well as changes in mean square nuclear charge radii are extracted from this high resolution data.

Precision gravimetric survey at the conditions of urban agglomerations

NASA Astrophysics Data System (ADS)

Sokolova, Tatiana; Lygin, Ivan; Fadeev, Alexander

2014-05-01

Large cities growth and aging lead to the irreversible negative changes of underground. The study of these changes at the urban area mainly based on the shallow methods of Geophysics, which extensive usage restricted by technogenic noise. Among others, precision gravimetry is allocated as method with good resistance to the urban noises. The main the objects of urban gravimetric survey are the soil decompaction, leaded to the rocks strength violation and the karst formation. Their gravity effects are too small, therefore investigation requires the modern high-precision equipment and special methods of measurements. The Gravimetry division of Lomonosov Moscow State University examin of modern precision gravimeters Scintrex CG-5 Autograv since 2006. The main performance characteristics of over 20 precision gravimeters were examined in various operational modes. Stationary mode. Long-term gravimetric measurements were carried at a base station. It shows that records obtained differ by high-frequency and mid-frequency (period 5 - 12 hours) components. The high-frequency component, determined as a standard deviation of measurement, characterizes the level of the system sensitivity to external noise and varies for different devices from 2 to 5-7 μGals. Midrange component, which closely meet to the rest of nonlinearity gravimeter drifts, is partially compensated by the equipment. This factor is very important in the case of gravimetric monitoring or observations, when midrange anomalies are the target ones. For the examined gravimeters, amplitudes' deviations, associated with this parameter may reach 10 μGals. Various transportation modes - were performed by walking (softest mode), lift (vertical overload), vehicle (horizontal overloads), boat (vertical plus horizontal overloads) and helicopter. The survey quality was compared by the variance of the measurement results and internal convergence of series. The measurement results variance (from ±2 to ±4 μGals) and its

Precision Measurement of Phonon-Polaritonic Near-Field Energy Transfer between Macroscale Planar Structures Under Large Thermal Gradients.

PubMed

Ghashami, Mohammad; Geng, Hongyao; Kim, Taehoon; Iacopino, Nicholas; Cho, Sung Kwon; Park, Keunhan

2018-04-27

Despite its strong potentials in emerging energy applications, near-field thermal radiation between large planar structures has not been fully explored in experiments. Particularly, it is extremely challenging to control a subwavelength gap distance with good parallelism under large thermal gradients. This article reports the precision measurement of near-field radiative energy transfer between two macroscale single-crystalline quartz plates that support surface phonon polaritons. Our measurement scheme allows the precise control of a gap distance down to 200 nm in a highly reproducible manner for a surface area of 5×5  mm^{2}. We have measured near-field thermal radiation as a function of the gap distance for a broad range of thermal gradients up to ∼156  K, observing more than 40 times enhancement of thermal radiation compared to the blackbody limit. By comparing with theoretical prediction based on fluctuational electrodynamics, we demonstrate that such remarkable enhancement is owing to phonon-polaritonic energy transfer across a nanoscale vacuum gap.

Precision Measurement of Phonon-Polaritonic Near-Field Energy Transfer between Macroscale Planar Structures Under Large Thermal Gradients

NASA Astrophysics Data System (ADS)

Ghashami, Mohammad; Geng, Hongyao; Kim, Taehoon; Iacopino, Nicholas; Cho, Sung Kwon; Park, Keunhan

2018-04-01

Despite its strong potentials in emerging energy applications, near-field thermal radiation between large planar structures has not been fully explored in experiments. Particularly, it is extremely challenging to control a subwavelength gap distance with good parallelism under large thermal gradients. This article reports the precision measurement of near-field radiative energy transfer between two macroscale single-crystalline quartz plates that support surface phonon polaritons. Our measurement scheme allows the precise control of a gap distance down to 200 nm in a highly reproducible manner for a surface area of 5 × 5 mm2 . We have measured near-field thermal radiation as a function of the gap distance for a broad range of thermal gradients up to ˜156 K , observing more than 40 times enhancement of thermal radiation compared to the blackbody limit. By comparing with theoretical prediction based on fluctuational electrodynamics, we demonstrate that such remarkable enhancement is owing to phonon-polaritonic energy transfer across a nanoscale vacuum gap.

High-precision half-life and branching-ratio measurements for superallowed Fermi β+ emitters at TRIUMF - ISAC

NASA Astrophysics Data System (ADS)

Laffoley, A. T.; Dunlop, R.; Finlay, P.; Grinyer, G. F.; Andreoiu, C.; Austin, R. A. E.; Ball, G. C.; Bandyopadhyay, D.; Blank, B.; Bouzomita, H.; Chagnon-Lessard, S.; Chester, A.; Cross, D. S.; Demand, G.; Diaz Varela, A.; Djongolov, M.; Ettenauer, S.; Garnsworthy, A. B.; Garrett, P. E.; Giovinazzo, J.; Glister, J.; Green, K. L.; Hackman, G.; Hadinia, B.; Jamieson, D. S.; Ketelhut, S.; Leach, K. G.; Leslie, J. R.; Pearson, C. J.; Phillips, A. A.; Rand, E. T.; Starosta, K.; Sumithrarachchi, C. S.; Svensson, C. E.; Tardiff, E. R.; Thomas, J. C.; Towner, I. S.; Triambak, S.; Unsworth, C.; Williams, S. J.; Wong, J.; Yates, S. W.; Zganjar, E. F.

2014-03-01

A program of high-precision half-life and branching-ratio measurements for superallowed Fermi β emitters is being carried out at TRIUMF's Isotope Separator and Accelerator (ISAC) radioactive ion beam facility. Recent half-life measurements for the superallowed decays of 14O, 18Ne, and 26Alm, as well as branching-ratio measurements for 26Alm and 74Rb are reported. These results provide demanding tests of the Standard Model and the theoretical isospin symmetry breaking (ISB) corrections in superallowed Fermi β decays.

Precise methane absorption measurements in the 1.64 μm spectral region for the MERLIN mission.

PubMed

Delahaye, T; Maxwell, S E; Reed, Z D; Lin, H; Hodges, J T; Sung, K; Devi, V M; Warneke, T; Spietz, P; Tran, H

2016-06-27

In this article we describe a high-precision laboratory measurement targeting the R(6) manifold of the 2 ν 3 band of 12 CH 4 . Accurate physical models of this absorption spectrum will be required by the Franco-German, Methane Remote Sensing LIDAR (MERLIN) space mission for retrievals of atmospheric methane. The analysis uses the Hartmann-Tran profile for modeling line shape and also includes line-mixing effects. To this end, six high-resolution and high signal-to-noise absorption spectra of air-broadened methane were recorded using a frequency-stabilized cavity ring-down spectroscopy apparatus. Sample conditions corresponded to room temperature and spanned total sample pressures of 40 hPa - 1013 hPa with methane molar fractions between 1 μmol mol -1 and 12 μmol mol -1 . All spectroscopic model parameters were simultaneously adjusted in a multispectrum nonlinear least-squares fit to the six measured spectra. Comparison of the fitted model to the measured spectra reveals the ability to calculate the room-temperature, methane absorption coefficient to better than 0.1% at the on-line position of the MERLIN mission. This is the first time that such fidelity has been reached in modeling methane absorption in the investigated spectral region, fulfilling the accuracy requirements of the MERLIN mission. We also found excellent agreement when comparing the present results with measurements obtained over different pressure conditions and using other laboratory techniques. Finally, we also evaluated the impact of these new spectral parameters on atmospheric transmissions spectra calculations.

Precise methane absorption measurements in the 1.64 μm spectral region for the MERLIN mission

PubMed Central

Delahaye, T.; Maxwell, S.E.; Reed, Z.D.; Lin, H.; Hodges, J.T.; Sung, K.; Devi, V.M.; Warneke, T.; Spietz, P.; Tran, H.

2016-01-01

In this article we describe a high-precision laboratory measurement targeting the R(6) manifold of the 2ν3 band of 12CH4. Accurate physical models of this absorption spectrum will be required by the Franco-German, Methane Remote Sensing LIDAR (MERLIN) space mission for retrievals of atmospheric methane. The analysis uses the Hartmann-Tran profile for modeling line shape and also includes line-mixing effects. To this end, six high-resolution and high signal-to-noise absorption spectra of air-broadened methane were recorded using a frequency-stabilized cavity ring-down spectroscopy apparatus. Sample conditions corresponded to room temperature and spanned total sample pressures of 40 hPa – 1013 hPa with methane molar fractions between 1 μmol mol−1 and 12 μmol mol−1. All spectroscopic model parameters were simultaneously adjusted in a multispectrum nonlinear least-squares fit to the six measured spectra. Comparison of the fitted model to the measured spectra reveals the ability to calculate the room-temperature, methane absorption coefficient to better than 0.1% at the on-line position of the MERLIN mission. This is the first time that such fidelity has been reached in modeling methane absorption in the investigated spectral region, fulfilling the accuracy requirements of the MERLIN mission. We also found excellent agreement when comparing the present results with measurements obtained over different pressure conditions and using other laboratory techniques. Finally, we also evaluated the impact of these new spectral parameters on atmospheric transmissions spectra calculations. PMID:27551656

The Paradox of Abstraction: Precision Versus Concreteness

ERIC Educational Resources Information Center

Iliev, Rumen; Axelrod, Robert

2017-01-01

We introduce a novel measure of abstractness based on the amount of information of a concept computed from its position in a semantic taxonomy. We refer to this measure as "precision". We propose two alternative ways to measure precision, one based on the path length from a concept to the root of the taxonomic tree, and another one based…

Electroweak precision observables and Higgs-boson signal strengths in the Standard Model and beyond: present and future

DOE PAGES

de Blas, J.; Ciuchini, M.; Franco, E.; ...

2016-12-27

We present results from a state-of-the-art fit of electroweak precision observables and Higgs-boson signal-strength measurements performed using 7 and 8 TeV data from the Large Hadron Collider. Based on the HEPfit package, our study updates the traditional fit of electroweak precision observables and extends it to include Higgs-boson measurements. As a result we obtain constraints on new physics corrections to both electroweak observables and Higgs-boson couplings. We present the projected accuracy of the fit taking into account the expected sensitivities at future colliders.

Electroweak precision observables and Higgs-boson signal strengths in the Standard Model and beyond: present and future

DOE Office of Scientific and Technical Information (OSTI.GOV)

de Blas, J.; Ciuchini, M.; Franco, E.

We present results from a state-of-the-art fit of electroweak precision observables and Higgs-boson signal-strength measurements performed using 7 and 8 TeV data from the Large Hadron Collider. Based on the HEPfit package, our study updates the traditional fit of electroweak precision observables and extends it to include Higgs-boson measurements. As a result we obtain constraints on new physics corrections to both electroweak observables and Higgs-boson couplings. We present the projected accuracy of the fit taking into account the expected sensitivities at future colliders.

Precise U and Pu isotope ratio measurements in nuclear samples by hyphenating capillary electrophoresis and MC-ICPMS.

PubMed

Martelat, Benoit; Isnard, Helene; Vio, Laurent; Dupuis, Erwan; Cornet, Terence; Nonell, Anthony; Chartier, Frederic

2018-06-22

Precise isotopic and elemental characterization of spent nuclear fuel is a major concern for the validation of the neutronic calculation codes and waste management strategy in the nuclear industry. Generally, the elements of interest, particularly U and Pu which are the two major elements present in spent fuel, are purified by ion exchange or extractant resins before off-line measurements by thermal ionization mass spectrometry. The aim of the present work was to develop a new analytical approach based on capillary electrophoresis (CE) hyphenated to a multicollector inductively coupled plasma mass spectrometer (MC-ICPMS) for online isotope ratio measurements. An electrophoretic separation protocol of U, Pu and the fraction containing fission products and minor actinides (Am and Cm) was developed using acetic acid as the electrolyte and complexing agent. The instrumentation for CE was designed to be used in a glove box and a laboratory-built interface was developed for hyphenation with MC-ICPMS. The separation was realized with only a few nL of a solution of spent nuclear fuel and the reproducibilities obtained on the U and Pu isotope ratios were on the order of a few ‰ which is comparable to those obtained by thermal ionization mass spectrometer (TIMS). This innovative protocol allowed a tremendous reduction of the analyte masses from μg to ng and also a drastic reduction of the liquid waste production from mL to μL. In addition, the time of analysis was shorted by at least a factor three. All of these improved parameters are of major interest for nuclear applications.

A point of application study to determine the accuracy, precision and reliability of a low-cost balance plate for center of pressure measurement.

PubMed

Goble, Daniel J; Khan, Ehran; Baweja, Harsimran S; O'Connor, Shawn M

2018-04-11

Changes in postural sway measured via force plate center of pressure have been associated with many aspects of human motor ability. A previous study validated the accuracy and precision of a relatively new, low-cost and portable force plate called the Balance Tracking System (BTrackS). This work compared a laboratory-grade force plate versus BTrackS during human-like dynamic sway conditions generated by an inverted pendulum device. The present study sought to extend previous validation attempts for BTrackS using a more traditional point of application (POA) approach. Computer numerical control (CNC) guided application of ∼155 N of force was applied five times to each of 21 points on five different BTrackS Balance Plate (BBP) devices with a hex-nose plunger. Results showed excellent agreement (ICC > 0.999) between the POAs and measured COP by the BBP devices, as well as high accuracy (<1% average percent error) and precision (<0.1 cm average standard deviation of residuals). The ICC between BBP devices was exceptionally high (ICC > 0.999) providing evidence of almost perfect inter-device reliability. Taken together, these results provide an important, static corollary to the previously obtained dynamic COP results from inverted pendulum testing of the BBP. Copyright © 2018 Elsevier Ltd. All rights reserved.

A time projection chamber for high accuracy and precision fission cross-section measurements

DOE PAGES

Heffner, M.; Asner, D. M.; Baker, R. G.; ...

2014-05-22

The fission Time Projection Chamber (fissionTPC) is a compact (15 cm diameter) two-chamber MICROMEGAS TPC designed to make precision cross-section measurements of neutron-induced fission. The actinide targets are placed on the central cathode and irradiated with a neutron beam that passes axially through the TPC inducing fission in the target. The 4π acceptance for fission fragments and complete charged particle track reconstruction are powerful features of the fissionTPC which will be used to measure fission cross-sections and examine the associated systematic errors. This study provides a detailed description of the design requirements, the design solutions, and the initial performance ofmore » the fissionTPC.« less

Precision Engineering - SRO 154.

DTIC Science & Technology

1986-01-01

Operation The principle of interferometric displacement measurement devices is that if two identical, coherent, monochromatic light beams are directed...laser interferometric feedback to enhance the accuracy and precision of a lead screw stage. The precision translation stage was designed to produce...and the deepest was 22 micrometers (875 microinches). Figures 5, 6 and 7 are Nomarsky photomicrographs showing the begin- ning, middle and end of a

Assessment of MFLL column CO2 measurements obtained during the ACT-America field campaigns

NASA Astrophysics Data System (ADS)

Lin, B.; Browell, E. V.; Kooi, S. A.; Dobler, J. T.; Campbell, J.; Fan, T. F.; Pal, S.; O'Dell, C. W.; Obland, M. D.; Erxleben, W. H.; McGregor, D.; Kochanov, R. V.; DiGangi, J. P.; Davis, K. J.; Choi, Y.

2017-12-01

Accurate observations of atmospheric CO2 with airborne and space-based lidar systems such as those used during the Atmospheric Carbon and Transport - America (ACT-America) field campaigns and proposed for the NASA ASCENDS mission would improve our knowledge of CO2 distributions and variations on both regional and global scales, reduce the uncertainties in atmospheric CO2 transport and fluxes, and increase confidence in predictions of future climate changes. To reach these scientific goals, atmospheric column CO2 (XCO2) measurements of the Harris Corporation's Multifunctional Fiber Laser Lidar (MFLL) obtained during the first two ACT-America flight campaigns have been thoroughly investigated by the ACT-America lidar measurement group. MFLL is an intensity-modulated continuous-wave lidar operating in the 1.57-mm CO2 absorption band. Atmospheric XCO2 amounts are retrieved based on the integrated path differential absorption of the lidar signals at online and offline wavelengths between the aircraft and the ground. NASA Langley Research Center and Harris have been collaborating in the development and evaluation of this CO2 lidar approach for a number of years. To gain insights into the lidar performance, the measurement group has collected all possible lidar measurements with corresponding in-situ atmospheric profile information from the first two ACT-America field campaigns, including the data from several flight legs dedicated to lidar calibration. Initially large differences (-1 to 2 %) were found between lidar measured CO2 optical depths and those derived from in-situ observations and spectroscopy from HITRAN2008. When an improved spectroscopic model (Pre-HITRAN2016) was applied, the large systematic errors were much more consistent leading to the development of an empirical linear correction of measured optical depth based on the calibration flight data. This correction accounts for remaining uncertainties in spectroscopic models, environmental conditions, such as

A case study of precision farming for nutrient management of corn

NASA Astrophysics Data System (ADS)

Blanco, Alfonso; Hunt, Ray; Gomez, Richard B.; Roper, William E.

2003-08-01

Precision farming relies on the cost effectiveness of collecting and interpreting data, which describes the variations of agricultural conditions such as crop stresses, nutrient deficiencies, water stresses, or pest infestation. Hyperspectral remote sensing from satellites and airborne sensors can be a way to obtain data needed to develop site-specific farming management strategies. The primary objective of the hyperspectral applications in precision farming is to provide farmers with a technology, which can detect specific crop conditions that can be used to program variable-rate applications. Applications of water, pesticides, and fertilizer can be tailored to the needs of the agricultural crops, based on the conditions reflected on the imagery. This paper presents an experimental study performed in Beltsville, Maryland for assessing the plant density and nutrient uptake of corn using a simple photographic method from a model airplane versus obtaining hyperspectral imagery from an airborne sensor. The hyperspectral sensor utilized in this study was the AISA sensor. These remote sensors can measure the temperature of plants; or to be more specific, they can measure how much energy plants emit at the visible and near-infrared wavelengths of the spectrum, such as water and vegetation.

High-precision measurements of cementless acetabular components using model-based RSA: an experimental study.

PubMed

Baad-Hansen, Thomas; Kold, Søren; Kaptein, Bart L; Søballe, Kjeld

2007-08-01

In RSA, tantalum markers attached to metal-backed acetabular cups are often difficult to detect on stereo radiographs due to the high density of the metal shell. This results in occlusion of the prosthesis markers and may lead to inconclusive migration results. Within the last few years, new software systems have been developed to solve this problem. We compared the precision of 3 RSA systems in migration analysis of the acetabular component. A hemispherical and a non-hemispherical acetabular component were mounted in a phantom. Both acetabular components underwent migration analyses with 3 different RSA systems: conventional RSA using tantalum markers, an RSA system using a hemispherical cup algorithm, and a novel model-based RSA system. We found narrow confidence intervals, indicating high precision of the conventional marker system and model-based RSA with regard to migration and rotation. The confidence intervals of conventional RSA and model-based RSA were narrower than those of the hemispherical cup algorithm-based system regarding cup migration and rotation. The model-based RSA software combines the precision of the conventional RSA software with the convenience of the hemispherical cup algorithm-based system. Based on our findings, we believe that these new tools offer an improvement in the measurement of acetabular component migration.

A precision mechanical nerve stimulator

NASA Technical Reports Server (NTRS)

Tcheng, Ping; Supplee, Frank H., Jr.; Prass, Richard L.

1988-01-01

An electromechanical device, used to apply and monitor stimulating pulses to a mammalian motor nerve, has been successfully developed at NASA Langley Research Center. Two existing force transducers, a flight skin friction balance and a miniature skin friction balance which were designed for making aerodynamic drag measurements, were modified and incorporated to form this precision instrument. The nerve stimulator is a type one servomechanism capable of applying and monitoring stimulating pulses of 0 to 10 grams with a precision of better than +/- 0.05 grams. Additionally, the device can be independently used to apply stimulating pulses by displacing the nerve from 0 to 0.25 mm with a precision of better than +/- 0.001 mm while measuring the level of the load applied.

High precision applications of the global positioning system

NASA Technical Reports Server (NTRS)

Lichten, Stephen M.

1991-01-01

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

Precise measurements of beam spin asymmetries in semi-inclusive π0 production

NASA Astrophysics Data System (ADS)

Aghasyan, M.; Avakian, H.; Rossi, P.; De Sanctis, E.; Hasch, D.; Mirazita, M.; Adikaram, D.; Amaryan, M. J.; Anghinolfi, M.; Baghdasaryan, H.; Ball, J.; Battaglieri, M.; Batourine, V.; Bedlinskiy, I.; Bennett, R. P.; Biselli, A. S.; Branford, D.; Briscoe, W. J.; Bültmann, S.; Burkert, V. D.; Carman, D. S.; Chandavar, S.; Cole, P. L.; Collins, P.; Contalbrigo, M.; Crede, V.; D'Angelo, A.; Daniel, A.; Dashyan, N.; De Vita, R.; Deur, A.; Dey, B.; Dickson, R.; Djalali, C.; Dodge, G. E.; Doughty, D.; Dupre, R.; Egiyan, H.; El Alaoui, A.; Elouadrhiri, L.; Eugenio, P.; Fedotov, G.; Fegan, S.; Fradi, A.; Gabrielyan, M. Y.; Garçon, M.; Gevorgyan, N.; Gilfoyle, G. P.; Giovanetti, K. L.; Girod, F. X.; Goetz, J. T.; Gohn, W.; Golovatch, E.; Gothe, R. W.; Graham, L.; Griffioen, K. A.; Guegan, B.; Guidal, M.; Guler, N.; Guo, L.; Hafidi, K.; Hanretty, C.; Hicks, K.; Holtrop, M.; Hyde, C. E.; Ilieva, Y.; Ireland, D. G.; Isupov, E. L.; Jawalkar, S. S.; Jenkins, D.; Jo, H. S.; Joo, K.; Keller, D.; Khandaker, M.; Khetarpal, P.; Kim, A.; Kim, W.; Klein, A.; Klein, F. J.; Kubarovsky, V.; Kuhn, S. E.; Kuleshov, S. V.; Kuznetsov, V.; Kvaltine, N. D.; Livingston, K.; Lu, H. Y.; MacGregor, I. J. D.; Markov, N.; Mayer, M.; McAndrew, J.; McKinnon, B.; Meyer, C. A.; Micherdzinska, A. M.; Mokeev, V.; Moreno, B.; Moutarde, H.; Munevar, E.; Nadel-Turonski, P.; Ni, A.; Niccolai, S.; Niculescu, G.; Niculescu, I.; Osipenko, M.; Ostrovidov, A. I.; Paolone, M.; Pappalardo, L.; Paremuzyan, R.; Park, K.; Park, S.; Pasyuk, E.; Pereira, S. Anefalos; Phelps, E.; Pisano, S.; Pogorelko, O.; Pozdniakov, S.; Price, J. W.; Procureur, S.; Prok, Y.; Protopopescu, D.; Raue, B. A.; Ricco, G.; Rimal, D.; Ripani, M.; Rosner, G.; Sabatié, F.; Saini, M. S.; Salgado, C.; Schott, D.; Schumacher, R. A.; Seder, E.; Seraydaryan, H.; Sharabian, Y. G.; Smith, G. D.; Sober, D. I.; Stepanyan, S. S.; Stepanyan, S.; Stoler, P.; Strakovsky, I.; Strauch, S.; Taiuti, M.; Tang, W.; Taylor, C. E.; Tkachenko, S.; Ungaro, M.; Voskanyan, H.; Voutier, E.; Watts, D.; Weinstein, L. B.; Weygand, D. P.; Wood, M. H.; Zana, L.; Zhang, J.; Zhao, B.; Zhao, Z. W.

2011-10-01

We present studies of single-spin asymmetries for neutral pion electroproduction in semi-inclusive deep-inelastic scattering of 5.776 GeV polarized electrons from an unpolarized hydrogen target, using the CEBAF Large Acceptance Spectrometer (CLAS) at the Thomas Jefferson National Accelerator Facility. A substantial sinϕh amplitude has been measured in the distribution of the cross section asymmetry as a function of the azimuthal angle ϕh of the produced neutral pion. The dependence of this amplitude on Bjorken x and on the pion transverse momentum is extracted with significantly higher precision than previous data and is compared to model calculations.

Precise Measurements of Beam Spin Asymmetries in Semi-Inclusive π 0 production

DOE PAGES

Aghasyan, M.; Avakian, H.; Rossi, P.; ...

2011-10-01

We present studies of single-spin asymmetries for neutral pion electroproduction in semi-inclusive deep-inelastic scattering of 5.776 GeV polarized electrons from an unpolarized hydrogen target, using the CEBAF Large Acceptance Spectrometer (CLAS) at the Thomas Jefferson National Accelerator Facility. A substantial sin Φ h amplitude has been measured in the distribution of the cross section asymmetry as a function of the azimuthal angle Φ h of the produced neutral pion. The dependence of this amplitude on Bjorken x and on the pion transverse momentum is extracted with significantly higher precision than previous data and is compared to model calculations.

Precision measurement and interpretation of inclusive W + W - Z/γ * production cross sections with the ATLAS detector

DOE PAGES

Aaboud, M.; Aad, G.; Abbott, B.; ...

2017-06-02

High-precision measurements by the ATLAS Collaboration are presented of inclusive W +→ℓ +νW +→ℓ -more » $$\\bar{v}$$ and Z/γ*→ℓℓ (ℓ = e,μ) Drell-Yan production cross sections at the LHC. The data were collected in proton–proton collisions at s√=7 TeV with an integrated luminosity of 4.6 fb -1. Differential W +W - cross sections are measured in a lepton pseudorapidity range |η ℓ| <2.5. Differential Z/γ* cross sections are measured as a function of the absolute dilepton rapidity, for |y ℓℓ|<3.6, for three intervals of dilepton mass, m ℓℓ, extending from 46 to 150 GeV. The integrated and differential electron- and muon-channel cross sections are combined and compared to theoretical predictions using recent sets of parton distribution functions. The data, together with the final inclusive e ± p scattering cross-section data from H1 and ZEUS, are interpreted in a next-to-next-to-leading-order QCD analysis, and a new set of parton distribution functions, ATLAS-epWZ16, is obtained. The ratio of strange-to-light sea-quark densities in the proton is determined more accurately than in previous determinations based on collider data only, and is established to be close to unity in the sensitivity range of the data. Lastly, a new measurement of the CKM matrix element |V cs| is also provided.« less

A comparison of computer-assisted and manual wound size measurement.

PubMed

Thawer, Habiba A; Houghton, Pamela E; Woodbury, M Gail; Keast, David; Campbell, Karen

2002-10-01

Accurate and precise wound measurements are a critical component of every wound assessment. To examine the reliability and validity of a new computerized technique for measuring human and animal wounds, chronic human wounds (N = 45) and surgical animal wounds (N = 38) were assessed using manual and computerized techniques. Using intraclass correlation coefficients, intrarater and interrater reliability of surface area measurements obtained using the computerized technique were compared to those obtained using acetate tracings and planimetry. A single measurement of surface area using either technique produced excellent intrarater and interrater reliability for both human and animal wounds, but the computerized technique was more precise than the manual technique for measuring the surface area of animal wounds. For both types of wounds and measurement techniques, intrarater and interrater reliability improved when the average of three repeated measurements was obtained. The precision of each technique with human wounds and the precision of the manual technique with animal wounds also improved when three repeated measurement results were averaged. Concurrent validity between the two techniques was excellent for human wounds but poor for the smaller animal wounds, regardless of whether single or the average of three repeated surface area measurements was used. The computerized technique permits reliable and valid assessment of the surface area of both human and animal wounds.

Power and Precision in Confirmatory Factor Analytic Tests of Measurement Invariance

ERIC Educational Resources Information Center

Meade, Adam W.; Bauer, Daniel J.

2007-01-01

This study investigates the effects of sample size, factor overdetermination, and communality on the precision of factor loading estimates and the power of the likelihood ratio test of factorial invariance in multigroup confirmatory factor analysis. Although sample sizes are typically thought to be the primary determinant of precision and power,…

Radio Telescopes' Precise Measurements Yield Rich Scientific Payoffs

NASA Astrophysics Data System (ADS)

2008-01-01

Having the sharpest pictures always is a big advantage, and a sophisticated radio-astronomy technique using continent-wide and even intercontinental arrays of telescopes is yielding extremely valuable scientific results in a wide range of specialties. That's the message delivered to the American Astronomical Society's meeting in Austin, Texas, by Mark Reid of the Harvard-Smithsonian Center for Astrophysics, a leading researcher in the field of ultra-precise astronomical position measurements. Very Long Baseline Interferometry provides extremely high precision that can extend use of the parallax technique to many more celestial objects. Parallax is a direct means of measuring cosmic distances by detecting the slight shift in an object’s apparent position in the sky caused by Earth’s orbital motion. Credit: Bill Saxton, NRAO/AUI/NSF "Using radio telescopes, we are measuring distances and motions of celestial bodies with unprecedented accuracy. That's helping us better understand many processes ranging from star formation to the scale of the entire Universe," Reid said. The observing technique, called Very Long Baseline Interferometry (VLBI), was pioneered in 1967, but has come into continuous use only in the past 10-15 years. The National Science Foundation's Very Long Baseline Array (VLBA), a system of 10 radio-telescope antennas ranging from Hawaii to the Caribbean, was dedicated in 1993. There are other VLBI systems in Europe and Asia, and large radio telescopes around the world cooperate regularly to increase sensitivity. VLBI observations routinely produce images hundreds of times more detailed than those made at visible-light wavelengths by the Hubble Space Telescope. Several groups of researchers from across the globe use the VLBA to study stellar nurseries in our own Milky Way Galaxy and measure distances to regions where new stars are forming. The key has been to improve measurement accuracy to a factor of a hundred times better than that produced by the

Precision determination of the D0 mass.

PubMed

Cawlfield, C; Eisenstein, B I; Karliner, I; Kim, D; Lowrey, N; Naik, P; Selen, M; White, E J; Wiss, J; Mitchell, R E; Shepherd, M R; Besson, D; Pedlar, T K; Cronin-Hennessy, D; Gao, K Y; Hietala, J; Kubota, Y; Klein, T; Lang, B W; Poling, R; Scott, A W; Smith, A; Zweber, P; Dobbs, S; Metreveli, Z; Seth, K K; Tomaradze, A; Ernst, J; Ecklund, K M; Severini, H; Love, W; Savinov, V; Aquines, O; Li, Z; Lopez, A; Mehrabyan, S; Mendez, H; Ramirez, J; Huang, G S; Miller, D H; Pavlunin, V; Sanghi, B; Shipsey, I P J; Xin, B; Adams, G S; Anderson, M; Cummings, J P; Danko, I; Hu, D; Moziak, B; Napolitano, J; He, Q; Insler, J; Muramatsu, H; Park, C S; Thorndike, E H; Yang, F; Coan, T E; Gao, Y S; Artuso, M; Blusk, S; Butt, J; Li, J; Menaa, N; Mountain, R; Nisar, S; Randrianarivony, K; Sia, R; Skwarnicki, T; Stone, S; Wang, J C; Zhang, K; Bonvicini, G; Cinabro, D; Dubrovin, M; Lincoln, A; Asner, D M; Edwards, K W; Briere, R A; Ferguson, T; Tatishvili, G; Vogel, H; Watkins, M E; Rosner, J L; Adam, N E; Alexander, J P; Cassel, D G; Duboscq, J E; Ehrlich, R; Fields, L; Galik, R S; Gibbons, L; Gray, R; Gray, S W; Hartill, D L; Heltsley, B K; Hertz, D; Jones, C D; Kandaswamy, J; Kreinick, D L; Kuznetsov, V E; Mahlke-Krüger, H; Onyisi, P U E; Patterson, J R; Peterson, D; Pivarski, J; Riley, D; Ryd, A; Sadoff, A J; Schwarthoff, H; Shi, X; Stroiney, S; Sun, W M; Wilksen, T; Athar, S B; Patel, R; Potlia, V; Yelton, J; Rubin, P

2007-03-02

A precision measurement of the D0 meson mass has been made using approximately 281 pb(-1) of e+e- annihilation data taken with the CLEO-c detector at the psi(3770) resonance. The exclusive decay D0-->K_{S}phi has been used to obtain M(D0)=1864.847+/-0.150(stat)+/-0.095(syst) MeV. This corresponds to M(D0D*0)=3871.81+/-0.36 MeV, and leads to a well-constrained determination of the binding energy of the proposed D0D*0 molecule X(3872), as Eb=0.6+/-0.6 MeV.

Autonomous precision landing using terrain-following navigation

NASA Technical Reports Server (NTRS)

Vaughan, R. M.; Gaskell, R. W.; Halamek, P.; Klumpp, A. R.; Synnott, S. P.

1991-01-01

Terrain-following navigation studies that have been done over the past two years in the navigation system section at JPL are described. A descent to Mars scenario based on Mars Rover and Sample Return mission profiles is described, and navigation and image processing issues pertaining to descent phases where landmark picture can be obtained are examined. A covariance analysis is performed to verify that landmark measurements from a terrain-following navigation system can satisfy precision landing requirements. Image processing problems involving known landmarks in actual pictures are considered. Mission design alternatives that can alleviate some of these problems are suggested.

LYSO based precision timing calorimeters

DOE PAGES

Bornheim, A.; Apresyan, A.; Ronzhin, A.; ...

2017-11-01

In this report we outline the study of the development of calorimeter detectors using bright scintillating crystals. We discuss how timing information with a precision of a few tens of pico seconds and below can significantly improve the reconstruction of the physics events under challenging high pileup conditions to be faced at the High-Luminosity LHC or a future hadron collider. The particular challenge in measuring the time of arrival of a high energy photon lies in the stochastic component of the distance of initial conversion and the size of the electromagnetic shower. We present studies and measurements from test beamsmore » for calorimeter based timing measurements to explore the ultimate timing precision achievable for high energy photons of 10 GeV and above. We focus on techniques to measure the timing with a high precision in association with the energy of the photon. We present test-beam studies and results on the timing performance and characterization of the time resolution of LYSO-based calorimeters. We demonstrate time resolution of 30 ps is achievable for a particular design.« less

LYSO based precision timing calorimeters

NASA Astrophysics Data System (ADS)

Bornheim, A.; Apresyan, A.; Ronzhin, A.; Xie, S.; Duarte, J.; Spiropulu, M.; Trevor, J.; Anderson, D.; Pena, C.; Hassanshahi, M. H.

2017-11-01

In this report we outline the study of the development of calorimeter detectors using bright scintillating crystals. We discuss how timing information with a precision of a few tens of pico seconds and below can significantly improve the reconstruction of the physics events under challenging high pileup conditions to be faced at the High-Luminosity LHC or a future hadron collider. The particular challenge in measuring the time of arrival of a high energy photon lies in the stochastic component of the distance of initial conversion and the size of the electromagnetic shower. We present studies and measurements from test beams for calorimeter based timing measurements to explore the ultimate timing precision achievable for high energy photons of 10 GeV and above. We focus on techniques to measure the timing with a high precision in association with the energy of the photon. We present test-beam studies and results on the timing performance and characterization of the time resolution of LYSO-based calorimeters. We demonstrate time resolution of 30 ps is achievable for a particular design.

High precision laser ranging by time-of-flight measurement of femtosecond pulses

NASA Astrophysics Data System (ADS)

Lee, Joohyung; Lee, Keunwoo; Lee, Sanghyun; Kim, Seung-Woo; Kim, Young-Jin

2012-06-01

Time-of-flight (TOF) measurement of femtosecond light pulses was investigated for laser ranging of long distances with sub-micrometer precision in the air. The bandwidth limitation of the photo-detection electronics used in timing femtosecond pulses was overcome by adopting a type-II nonlinear second-harmonic crystal that permits the production of a balanced optical cross-correlation signal between two overlapping light pulses. This method offered a sub-femtosecond timing resolution in determining the temporal offset between two pulses through lock-in control of the pulse repetition rate with reference to the atomic clock. The exceptional ranging capability was verified by measuring various distances of 1.5, 60 and 700 m. This method is found well suited for future space missions based on formation-flying satellites as well as large-scale industrial applications for land surveying, aircraft manufacturing and shipbuilding.

High-precision x-ray spectroscopy of highly charged ions with microcalorimeters

NASA Astrophysics Data System (ADS)

Kraft-Bermuth, S.; Andrianov, V.; Bleile, A.; Echler, A.; Egelhof, P.; Grabitz, P.; Ilieva, S.; Kilbourne, C.; Kiselev, O.; McCammon, D.; Meier, J.

2013-09-01

The precise determination of the energy of the Lyman α1 and α2 lines in hydrogen-like heavy ions provides a sensitive test of quantum electrodynamics in very strong Coulomb fields. To improve the experimental precision, the new detector concept of microcalorimeters is now exploited for such measurements. Such detectors consist of compensated-doped silicon thermistors and Pb or Sn absorbers to obtain high quantum efficiency in the energy range of 40-70 keV, where the Doppler-shifted Lyman lines are located. For the first time, a microcalorimeter was applied in an experiment to precisely determine the transition energy of the Lyman lines of lead ions at the experimental storage ring at GSI. The energy of the Ly α1 line E(Ly-α1, 207Pb81+) = (77937 ± 12stat ± 25syst) eV agrees within error bars with theoretical predictions. To improve the experimental precision, a new detector array with more pixels and better energy resolution was equipped and successfully applied in an experiment to determine the Lyman-α lines of gold ions 197Au78+.

Does quantitative ultrasound imaging enhance precision and discrimination?

PubMed

Frost, M L; Blake, G M; Fogelman, I

2000-01-01

The aim of this study was to compare quantitative ultrasound (QUS) measurements obtained using a new calcaneal QUS imaging device with a conventional non-imaging device using fixed transducers. The study group consisted of 340 healthy women with no risk factors associated with osteoporosis (176 premenopausal and 164 postmenopausal) and 83 women with one or more vertebral fractures. All women had QUS measurements performed on the Osteometer DTU-one (imaging) and Walker-Sonix UBA575+ (non-imaging) devices and bone mineral density (BMD) measurements performed at the spine and hip. A subgroup of 81 women had additional dual-energy X-ray absorptiometry (DXA) scans at the calcaneus. Short-term standardized precision (SP = SD/young adult SD) based on duplicate measurements was significantly better on the DTU for broadband ultrasound attenuation (BUA) (SP: DTU 0.15 vs UBA 0.21,p = 0.01) and speed of sound (SOS) (SP: DTU 0.14 vs UBA 0.18, p = 0.01). However, long-term SP of the DTU was comparable to or significantly poorer than the SP of the UBA device. The BUA and SOS measurements obtained on the DTU and UBA were significantly correlated (r = 0.76 and 0.89 for BUA and SOS measurements respectively). The correlations between QUS and BMD measurements were all significant, ranging from 0.53 to 0.72. No significant improvements in the correlation with axial or peripheral BMD were observed using the imaging device. All the QUS measurement parameters showed a significant negative relationship between age and years since menopause in the postmenopausal group. Annual losses were lower for the DTU for BUA (DTU 0.22 dB/MHz per year vs UBA 0.44 dB/MHz per year) but comparable for SOS (DTU 0.29 m/s per-year vs UBA 0.22 m/s per year). However, when these figures were standardized to take into account the clinical range, the annual losses were similar on the DTU and UBA. Age-adjusted odds ratios for each SD decline were similar on the DTU for BUA (DTU 3.2 vs UBA 3.3) and SOS (DTU 3.4 vs

Commissioning Procedures for Mechanical Precision and Accuracy in a Dedicated LINAC

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ballesteros-Zebadua, P.; Larrga-Gutierrez, J. M.; Garcia-Garduno, O. A.

2008-08-11

Mechanical precision measurements are fundamental procedures for the commissioning of a dedicated LINAC. At our Radioneurosurgery Unit, these procedures can be suitable as quality assurance routines that allow the verification of the equipment geometrical accuracy and precision. In this work mechanical tests were performed for gantry and table rotation, obtaining mean associated uncertainties of 0.3 mm and 0.71 mm, respectively. Using an anthropomorphic phantom and a series of localized surface markers, isocenter accuracy showed to be smaller than 0.86 mm for radiosurgery procedures and 0.95 mm for fractionated treatments with mask. All uncertainties were below tolerances. The highest contribution tomore » mechanical variations is due to table rotation, so it is important to correct variations using a localization frame with printed overlays. Mechanical precision knowledge would allow to consider the statistical errors in the treatment planning volume margins.« less

The Effect of Quantum-Mechanical Interference on Precise Measurements of the n = 2 Triplet P Fine Structure of Helium

DOE Office of Scientific and Technical Information (OSTI.GOV)

Marsman, A.; Horbatsch, M.; Hessels, E. A., E-mail: hessels@yorku.ca

2015-09-15

For many decades, improvements in both theory and experiment of the fine structure of the n = 2 triplet P levels of helium have allowed for an increasingly precise determination of the fine-structure constant. Recently, it has been observed that quantum-mechanical interference between neighboring resonances can cause significant shifts, even if such neighboring resonances are separated by thousands of natural widths. The shifts depend in detail on the experimental method used for the measurement, as well as the specific experimental parameters employed. Here, we review how these shifts apply for the most precise measurements of the helium 2{sup 3}P fine-structuremore » intervals.« less

Complementarity between nonstandard Higgs boson searches and precision Higgs boson measurements in the MSSM

DOE Office of Scientific and Technical Information (OSTI.GOV)

Carena, Marcela; Haber, Howard E.; Low, Ian

Precision measurements of the Higgs boson properties at the LHC provide relevant constraints on possible weak-scale extensions of the Standard Model (SM). In the context of the minimal supersymmetric Standard Model (MSSM) these constraints seem to suggest that all the additional, non-SM-like Higgs bosons should be heavy, with masses larger than about 400 GeV. This article shows that such results do not hold when the theory approaches the conditions for “alignment independent of decoupling,” where the lightest CP-even Higgs boson has SM-like tree-level couplings to fermions and gauge bosons, independently of the nonstandard Higgs boson masses. In addition, the combinationmore » of current bounds from direct Higgs boson searches at the LHC, along with the alignment conditions, have a significant impact on the allowed MSSM parameter space yielding light additional Higgs bosons. In particular, after ensuring the correct mass for the lightest CP-even Higgs boson, we find that precision measurements and direct searches are complementary and may soon be able to probe the region of non-SM-like Higgs boson with masses below the top quark pair mass threshold of 350 GeV and low to moderate values of tanβ.« less

Complementarity between nonstandard Higgs boson searches and precision Higgs boson measurements in the MSSM

DOE Office of Scientific and Technical Information (OSTI.GOV)

Carena, Marcela; Haber, Howard E.; Low, Ian

Precision measurements of the Higgs boson properties at the LHC provide relevant constraints on possible weak-scale extensions of the Standard Model (SM). In the context of the minimal supersymmetric Standard Model (MSSM) these constraints seem to suggest that all the additional, non-SM-like Higgs bosons should be heavy, with masses larger than about 400 GeV. This article shows that such results do not hold when the theory approaches the conditions for “alignment independent of decoupling,” where the lightest CP -even Higgs boson has SM-like tree-level couplings to fermions and gauge bosons, independently of the nonstandard Higgs boson masses. The combination ofmore » current bounds from direct Higgs boson searches at the LHC, along with the alignment conditions, have a significant impact on the allowed MSSM parameter space yielding light additional Higgs bosons. In particular, after ensuring the correct mass for the lightest CP -even Higgs boson, we find that precision measurements and direct searches are complementary and may soon be able to probe the region of non-SM-like Higgs boson with masses below the top quark pair mass threshold of 350 GeV and low to moderate values of tanβ« less

Complementarity between nonstandard Higgs boson searches and precision Higgs boson measurements in the MSSM

DOE PAGES

Carena, Marcela; Haber, Howard E.; Low, Ian; ...

2015-02-03

Precision measurements of the Higgs boson properties at the LHC provide relevant constraints on possible weak-scale extensions of the Standard Model (SM). In the context of the minimal supersymmetric Standard Model (MSSM) these constraints seem to suggest that all the additional, non-SM-like Higgs bosons should be heavy, with masses larger than about 400 GeV. This article shows that such results do not hold when the theory approaches the conditions for “alignment independent of decoupling,” where the lightest CP-even Higgs boson has SM-like tree-level couplings to fermions and gauge bosons, independently of the nonstandard Higgs boson masses. In addition, the combinationmore » of current bounds from direct Higgs boson searches at the LHC, along with the alignment conditions, have a significant impact on the allowed MSSM parameter space yielding light additional Higgs bosons. In particular, after ensuring the correct mass for the lightest CP-even Higgs boson, we find that precision measurements and direct searches are complementary and may soon be able to probe the region of non-SM-like Higgs boson with masses below the top quark pair mass threshold of 350 GeV and low to moderate values of tanβ.« less

Metrological-grade tunable coherent source in the mid-infrared for molecular precision spectroscopy

NASA Astrophysics Data System (ADS)

Insero, G.; Clivati, C.; D'Ambrosio, D.; Cancio Pastor, P.; Verde, M.; Schunemann, P. G.; Zondy, J.-J.; Inguscio, M.; Calonico, D.; Levi, F.; De Natale, P.; Santambrogio, G.; Borri, S.

2018-02-01

We report on a metrological-grade mid-IR source with a 10-14 short-term instability for high-precision spectroscopy. Our source is based on the combination of a quantum cascade laser and a coherent radiation obtained by difference-frequency generation in an orientation-patterned gallium phosphide (OP-GaP) crystal. The pump and signal lasers are locked to an optical frequency comb referenced to the primary frequency standard via an optical fiber link. We demonstrate the robustness of the apparatus by measuring a vibrational transition around 6 μm on a metastable state of CO molecuels with 11 digits of precision.

Precision Branching Ratio Measurement for the Superallowed β+ Emitter Ga62 and Isospin-Symmetry-Breaking Corrections in A≥62 Nuclei

NASA Astrophysics Data System (ADS)

Hyland, B.; Svensson, C. E.; Ball, G. C.; Leslie, J. R.; Achtzehn, T.; Albers, D.; Andreoiu, C.; Bricault, P.; Churchman, R.; Cross, D.; Dombsky, M.; Finlay, P.; Garrett, P. E.; Geppert, C.; Grinyer, G. F.; Hackman, G.; Hanemaayer, V.; Lassen, J.; Lavoie, J. P.; Melconian, D.; Morton, A. C.; Pearson, C. J.; Pearson, M. R.; Phillips, A. A.; Schumaker, M. A.; Smith, M. B.; Towner, I. S.; Valiente-Dobón, J. J.; Wendt, K.; Zganjar, E. F.

2006-09-01

A high-precision branching ratio measurement for the superallowed β+ decay of Ga62 was performed at the Isotope Separator and Accelerator radioactive ion beam facility. Nineteen γ rays emitted following β+ decay of Ga62 were identified, establishing the dominant superallowed branching ratio to be (99.861±0.011)%. Combined with recent half-life and Q-value measurements, this branching ratio yields a superallowed ft value of 3075.6±1.4s for Ga62 decay. These results demonstrate the feasibility of high-precision superallowed branching ratio measurements in the A≥62 mass region and provide the first stringent tests of the large isospin-symmetry-breaking effects predicted for these decays.