Physics beyond instantons. Measuring the physical correlation length
Sourendu Gupta; A. Irbäck
1992-01-01
In broken-symmetry phases of models with discrete global symmetry, the physical correlation length can be measured using time-slice correlators projected to non-zero momenta. A transfer matrix based argument is used to construct the finite-size scaling for this quantity. We extract the correlation length for the two-dimensional ten-state Potts model by this means, and the surface tension from the zero-momentum correlator.
Bunch Length Measurements With Laser/SR Cross-Correlation
Miller, Timothy; /Stanford U., Phys. Dept.; Daranciang, Dan; /Stanford U., Phys. Dept.; Lindenberg, Aaron; /Stanford U., Phys. Dept.; Corbett, Jeff; /SLAC; Fisher, Alan; /SLAC; Goodfellow, John; /SLAC; Huang, Xiaobiao; /SLAC; Mok, Walter; /SLAC; Safranek, James; /SLAC; Wen, Haidan; /SLAC
2012-07-06
By operating SPEAR3 in low-{alpha} mode the storage ring can generate synchrotron radiation pulses of order 1ps. Applications include pump-probe x-ray science and the production of THz radiation in the CSR regime. Measurements of the bunch length are difficult, however, because the light intensity is low and streak cameras typically provide resolution of only a few ps. Tests are now underway to resolve the short bunch length using cross-correlation between a 60-fs Ti:Sapphire laser and the visible SR beam in a BBO crystal. In this paper we report on the experimental setup, preliminary measurements and prospects for further improvement.
NSDL National Science Digital Library
This article focuses on young students encountering the measurement of length. The article cites examples of key concepts in recognizing length as an attribute and in proper and improper ways to measure length. Conservation and additivity of length, standard and non-standard units, iteration, and the zero point are among the topics presented.
CORRELATIONS OF WEIGHT, LENGTH, AND OTHER BODY MEASUREMENTS IN THE WEAKFISH, CYNOSCION RECALlS
occupying more than five minutes. The possi- bility of shrinkage and of loss of weight through evaporationCORRELATIONS OF WEIGHT, LENGTH, AND OTHER BODY MEASUREMENTS IN THE WEAKFISH, CYNOSCION RECALl for pagination #12;CORRELATIONS OF WEIGHT, LENGTH, AND OTHER BODY MEASUREMENTS IN THE WEAKFISH, CYNOSCION REGALIS
Measurement of the Correlation and Coherence Lengths in Boundary Layer Flight Data
NASA Technical Reports Server (NTRS)
Palumbo, Daniel L.
2011-01-01
Wall pressure data acquired during flight tests at several flight conditions are analyzed and the correlation and coherence lengths of the data reported. It is shown how the frequency bandwidth of the analysis biases the correlation length and how the convection of the flow acts to reduce the coherence length. Coherence lengths measured in the streamwise direction appear much longer than would be expected based on classical results for flow over a flat plat.
Picosecond Bunch length and Energy-z correlation measurements at SLAC's A-Line and End Station A
Molloy, Stephen; Emma, P.; Frisch, J.C.; Iverson, R.H.; Ross, M.; McCormick, D.J.; /SLAC; Ross, Marc C.; /Fermilab /SLAC; Walston, S.; /LLNL, Livermore; Blackmore, V.; /Oxford U.
2007-06-27
We report on measurements of picosecond bunch lengths and the energy-z correlation of the bunch with a high energy electron test beam to the A-line and End Station A (ESA) facilities at SLAC. The bunch length and the energy-z correlation of the bunch are measured at the end of the linac using a synchrotron light monitor diagnostic at a high dispersion point in the A-line and a transverse RF deflecting cavity at the end of the linac. Measurements of the bunch length in ESA were made using high frequency diodes (up to 100 GHz) and pyroelectric detectors at a ceramic gap in the beamline. Modeling of the beam's longitudinal phase space through the linac and A-line to ESA is done using the 2-dimensional tracking program LiTrack, and LiTrack simulation results are compared with data. High frequency diode and pyroelectric detectors are planned to be used as part of a bunch length feedback system for the LCLS FEL at SLAC. The LCLS also plans precise bunch length and energy-z correlation measurements using transverse RF deflecting cavities.
Garland Jr., Theodore
) have the highest sprint speeds and longest hindlimbs, horned lizards (Phryno- soma) exhibit the lowest, the horned lizards are a highly derived group of ¯at-bodied, ant specialists (e.g. Sherbrooke, 1981Sprint performance of phrynosomatid lizards, measured on a high-speed treadmill, correlates
Correlation between the forearm plus little finger length and the femoral length.
Naik, Monappa A; Sujir, Premjit; Tripathy, Sujit Kumar; Goyal, Tarun; Rao, Sharath K
2013-08-01
PURPOSE. To assess the correlation between the forearm plus little finger length and the femoral length in 100 volunteers. METHODS. The forearm plus little finger length and the ipsilateral femoral length of 68 male and 32 female volunteers aged 19 to 55 (mean, 35.8) years were measured using a measuring tape. The forearm plus litter finger length was measured from the tip of the olecranon to the tip of the little finger, whereas the femoral length was measured from the tip of the greater trochanter to the level of proximal pole of the patella over the outer aspect of thigh. Two observers made the measurements on 2 separate occasions. Intra- and inter-observer variations were calculated. A value of 0.75 or greater indicated excellent agreement. RESULTS. The mean forearm plus little finger length and femoral length were 39.87 (SD, 2.73) and 39.85 (SD, 2.44) cm, respectively. The mean difference between these 2 measurements was 0.028 (95% CI, -0.109 to 0.165) cm. The correlation between these 2 measurements was 0.861 (p<0.001). Patient age, sex, and body mass index did not affect this correlation. The intra- and inter-observer reliability was excellent. CONCLUSION. The forearm plus little finger length correlated with the femoral length. This method is simple, radiation-free, and can be applied in day-today practice. PMID:24014776
Length measurement in accelerated systems
Bahram Mashhoon; Uwe Muench
2002-06-27
We investigate the limitations of length measurements by accelerated observers in Minkowski spacetime brought about via the hypothesis of locality, namely, the assumption that an accelerated observer at each instant is equivalent to an otherwise identical momentarily comoving inertial observer. We find that consistency can be achieved only in a rather limited neighborhood around the observer with linear dimensions that are negligibly small compared to the characteristic acceleration length of the observer.
Measurement of subpicosecond electron bunch lengths
Lihn, Hung-chi; Bocek, D.; Kung, P.; Settakorn, C.; Wiedemann, H.
1995-11-01
A new frequency-resolved bunch-length measuring system has been developed at the Stanford SUNSHINE facility suitable for subpicosecond electron bunches. This method utilizes a far-infrared Michelson interferometer to measure coherent transition radiation emitted from electron bunches through optical auto-correlation. A simple and systematic way has also been developed to include interference effects caused by the beam splitter, so the electron bunch length can be easily obtained from the measurement. This autocorrelation method demonstrates subpicosecond resolving power that cannot be achieved by existing time-resolved methods.
Telomere Length Correlations among Somatic Tissues in Adult Zebra Finches
Reichert, Sophie; Criscuolo, François; Verinaud, Elodie; Zahn, Sandrine; Massemin, Sylvie
2013-01-01
Telomeres are repetitive non coding DNA sequences located at the end of eukaryotic chromosomes, which maintain the integrity of the genome by hiding the chromosome ends from being recognised as double stranded breaks. Telomeres are emerging as biomarkers for ageing and survival, and are susceptible to reflect different individual life history trajectories. In particular, the telomere length with which one starts in life has been shown to be linked with individual life-long survival, suggesting that telomere dynamics can be a proxy for individual fitness and thereby be implicated in evolutionary trade-offs. As a consequence, an increasing number of studies were conducted on telomeres in the fields of ecology and evolutionary biology, in which telomere length was almost exclusively measured from blood samples. However, not only do the number of repeats of the telomeric sequences vary among species, but also within species with great inter-individual telomere lengths variability with age, tissues, and chromosomes. This raises the issue of the exact biological meaning of telomere measurement in blood cells and stimulated the study of the correlation of telomere lengths among tissues over age. By measuring telomere length in adult zebra finches (Taeniopygia guttata) in different somatic tissues displaying variable cell turnovers (bone marrow, brain, spleen, pectoral muscle, heart, liver and in red blood cells), we checked that the measure of telomere length in red blood cells is related to telomere lengths in the other tissues. Here we show significant relationships between the telomere lengths of red blood cells and several somatic tissues at adulthood. As red blood cells are easily accessible and suitable for the longitudinal monitoring of the individual rate of telomere loss, our study confirms that telomere length measured in red blood cells could serve as a surrogate for telomere length in the whole avian organism. PMID:24349076
NMR Measures of Heterogeneity Length
NASA Astrophysics Data System (ADS)
Spiess, Hans W.
2002-03-01
Advanced solid state NMR spectroscopy provides a wealth of information about structure and dynamics of complex systems. On a local scale, multidimensional solid state NMR has elucidated the geometry and the time scale of segmental motions at the glass transition. The higher order correlation functions which are provided by this technique led to the notion of dynamic heterogeneities, which have been characterized in detail with respect to their rate memory and length scale. In polymeric and low molar mass glass formers of different fragility, length scales in the range 2 to 4 nm are observed. In polymeric systems, incompatibility of backbone and side groups as in polyalkylmethacrylates leads to heteogeneities on the nm scale, which manifest themselves in unusual chain dynamics at the glass transition involving extended chain conformations. References: K. Schmidt-Rohr and H.W. Spiess, Multidimensional Solid-State NMR and Polymers,Academic Press, London (1994). U. Tracht, M. Wilhelm, A. Heuer, H. Feng, K. Schmidt-Rohr, H.W. Spiess, Phys. Rev. Lett. 81, 2727 (1998). S.A. Reinsberg, X.H. Qiu, M. Wilhelm, M.D. Ediger, H.W. Spiess, J.Chem.Phys. 114, 7299 (2001). S.A. Reinsberg, A. Heuer, B. Doliwa, H. Zimmermann, H.W. Spiess, J. Non-Crystal. Solids, in press (2002)
Fundamental correlation lengths of coherent speckle in medical ultrasonic images
R. F. Wagner; M. F. Insana; S. W. Smith
1988-01-01
Refinements to previous analyses of the natural correlation lengths within simple images and between images to be compounded are presented. Comparison of theoretical and experimental results show very good agreement for the case of Rayleigh scattering media: the correlation length within a simple image is comparable to the resolution cell size; the correlation length between images to be spatially compounded
Growing correlation length in supercooled water.
Moore, Emily B; Molinero, Valeria
2009-06-28
The evolution of the structure of water from the stable high temperature liquid to its glass, low-density amorphous ice (LDA), is studied through large-scale molecular dynamics simulations with the mW model [J. Phys. Chem. B 113, 4008 (2009)]. We characterize the density, translational, and orientational ordering of liquid water from the high temperature stable liquid to the low-density glass LDA at the critical cooling rate for vitrification. A continuous transition to a tetrahedrally ordered low-density liquid is observed at 50 K below the temperature of maximum density and 25 K above a temperature of minimum density. The structures of the low-density liquid and glass are consistent with that of a continuous random tetrahedral network. The liquid-liquid transformation temperature T(LL), defined by the maximum isobaric expansivity, coincides with the maximum rate of change in the local structure of water. Long-range structural fluctuations of patches of four-coordinated molecules form in the liquid. The correlation length of the four-coordinated patches in the liquid increases according to a power law in the range 300 K to T(LL)+10 K; a maximum is predicted at T(LL). To the best of our knowledge this is the first direct estimation of the Widom line of supercooled water through the analysis of structural correlations. PMID:19566164
Environmental Correlates of Food Chain Length
Frederic Briand; Joel E. Cohen
1987-01-01
In 113 community food webs from natural communities, the average and maximal lengths of food chains are independent of primary productivity, contrary to the hypothesis that longer food chains should arise when more energy is available at their base. Environmental variability alone also does not appear to constrain average or maximal chain length. Environments that are three dimensional or solid,
Sonographic Measurement of Fetal Ear Length in Turkish Women with a Normal Pregnancy
Özdemir, Mucize Eriç; Uzun, I??l; Karahasano?lu, Ay?e; Aygün, Mehmet; Ak?n, Hale; Yaz?c?o?lu, Fehmi
2014-01-01
Background: Abnormal fetal ear length is a feature of chromosomal disorders. Fetal ear length measurement is a simple measurement that can be obtained during ultrasonographic examinations. Aims: To develop a nomogram for fetal ear length measurements in our population and investigate the correlation between fetal ear length, gestational age, and other standard fetal biometric measurements. Study Design: Cohort study. Methods: Ear lengths of the fetuses were measured in normal singleton pregnancies. The relationship between gestational age and fetal ear length in millimetres was analysed by simple linear regression. In addition, the correlation of fetal ear length measurements with biparietal diameter, head circumference, abdominal circumference, and femur length were evaluated.Ear length measurements were obtained from fetuses in 389 normal singleton pregnancies ranging between 16 and 28 weeks of gestation. Results: A nomogram was developed by linear regression analysis of the parameters ear length and gestational age. Fetal ear length (mm) = y = (1.348 X gestational age)?12.265), where gestational ages is in weeks. A high correlation was found between fetal ear length and gestational age, and a significant correlation was also found between fetal ear length and the biparietal diameter (r=0.962; p<0.001). Similar correlations were found between fetal ear length and head circumference, and fetal ear length and femur length. Conclusion: The results of this study provide a nomogram for fetal ear length. The study also demonstrates the relationship between ear length and other biometric measurements. PMID:25667783
Ozone Correlative Measurements Workshop
NASA Technical Reports Server (NTRS)
Hilsenrath, E. (editor)
1985-01-01
A study was conducted to determine the necessary parameters for the correlation of data on Earth ozone. Topics considered were: (1) measurement accuracy; (2) equipment considerations (SBUV); and (3) ground based measurements to support satellite data.
Drift wave transport scalings introduced by varying correlation length
Weiland, J.; Holod, I. [Department of Electromagnetics, Chalmers University of Technology and EURATOM-VR Association, 41296 Goeteborg (Sweden)
2005-01-01
Scalings of the correlation length of drift wave turbulence with magnetic current q, shear, elongation, and temperature ratio have been introduced into a drift wave transport model. The correlation length is calculated from linear scaling of the fastest growing mode. Such a procedure is supported by previous turbulence simulations with absorbing boundaries for short and long wavelengths. The resulting q and s scalings are now in better agreement with experimental scalings. In particular, the simulation results for transport barrier shots improve.
Extracting the dynamic correlation length of actin networks from microrheology experiments
Adar Sonn-Segev; Anne Bernheim-Groswasser; Yael Roichman
2014-08-21
The mechanical properties of polymer gels based on cytoskeleton proteins (e.g. actin) have been studied extensively due to their significant role in biological cell motility and in maintaining the cell's structural integrity. Microrheology is the natural method of choice for such studies due to its economy in sample volume, its wide frequency range, and its spatial sensitivity. In microrheology, the thermal motion of tracer particles embedded in a complex fluid is used to extract the fluid's viscoelastic properties. Comparing the motion of a single particle to the correlated motion of particle pairs, it is possible to extract viscoelastic properties at different length scales. In a recent study, a crossover between intermediate and bulk response of complex fluids was discovered in microrheology measurements of reconstituted actin networks. This crossover length was related to structural and mechanical properties of the networks, such as their mesh size and dynamic correlation length. Here we capitalize on this result giving a detailed description of our analysis scheme, and demonstrating how this relation can be used to extract the dynamic correlation length of a polymer network. We further study the relation between the dynamic correlation length and the structure of the network, by introducing a new length scale, the average filament length, without altering the network's mesh size. Contrary to the prevailing assumption, that the dynamic correlation length is equivalent to the mesh size of the network, we find that the dynamic correlation length increases once the filament length is reduced below the crossover distance.
Carbon Nanotubes: Measuring Dispersion and Length
Fagan, Jeffrey A.; Bauer, Barry J.; Hobbie, Erik K.; Becker, Matthew L.; Hight-Walker, Angela; Simpson, Jeffrey R.; Chun, Jaehun; Obrzut, Jan; Bajpai, Vardhan; Phelan, Fred R.; Simien, Daneesh; Yeon Huh, Ji; Migler, Kalman B.
2011-03-01
Advanced technological uses of single-wall carbon nanotubes (SWCNTs) rely on the production of single length and chirality populations that are currently only available through liquid phase post processing. The foundation of all of these processing steps is the attainment of individualized nanotube dispersion in solution; an understanding of the collodial properties of the dispersed SWCNTs can then be used to designed appropriate conditions for separations. In many instances nanotube size, particularly length, is especially active in determining the achievable properties from a given population, and thus there is a critical need for measurement technologies for both length distribution and effective separation techniques. In this Progress Report, we document the current state of the art for measuring dispersion and length populations, including separations, and use examples to demonstrate the desirability of addressing these parameters.
Measurement of subpicosecond electron pulse length
Lihn, Hung chi
1996-04-01
A new frequency-resolved bunch-length measuring system has been developed at the Stanford SUNSHINE facility to characterize subpicosecond electron pulses. Using a far-infrared Michelson interferometer, this method measures the spectrum of coherent transition radiation emitted from electron bunches through optical autocorrelation. The electron bunch length is obtained from the measurement with a simple and systematic analysis which includes interference effects caused by the beam splitter. This method demonstrates subpicosecond resolving power that cannot be achieved by existing time-resolved methods. The principle of this method and experimental results are discussed.
Turbulent Radial Correlation Lengths in the DIII-D Tokamak
T.L. Rhodes; J.-N. Leboeuf; R. Sydora; E.J. Doyle; R.A. Moyer; C.L. Rettig; K.H. Burrell; D.M. Thomas; G.R. McKee; W.A. Peebles
2000-08-01
Measurements of the radial correlation length Ar of density fluctuations have been made on the DIII-D tokamak in a variety of L-mode discharges. These measurements span the radial region 0.5 < {rho} < 1 and are found to scale approximately as {rho}{sub {theta},s} or 5-10 {rho}{sub s}. Here {rho}{sub {theta},s} is the poloidal ion Larmor radius calculated using local T{sub e} and poloidal magnetic field and {rho}{sub s} is the same except calculated using the total magnetic field. The {Delta}r data were obtained from a heterodyne reflectometer system. Comparisons to published analytic formulas of Ar have been carried out for a particular discharge condition. The measurements are found to be comparable in magnitude and radial dependence with a slab type formulation of ion temperature gradient (ITG) driven turbulence as well as an electron drift wave turbulence type prediction. Predictions from toroidal ITG and a different slab ITG model were found to be outside the error bars of the measurements. In addition, a detailed comparison to a non-linear gyro-kinetic turbulence code has begun. These and other similar comparisons are believed to be important as they serve to test and benchmark theory and codes as well as to help identify the type(s) of turbulence involved.
Reconciling the correlation length for high-spin Heisenberg antiferromagnets
B. B. Beard; V. Chudnovsky; P. Keller-Marxer
1999-10-19
We present numerical results for the antiferromagnetic Heisenberg model (AFHM) that definitively confirm that chiral perturbation theory, corrected for cutoff effects in the AFHM, leads to a correct field-theoretical description of the low-temperature behavior of the spin correlation length for spins $S \\geq 1/2$. With two independent quantum Monte Carlo algorithms and a finite-size-scaling technique, we explore correlation lengths up to $\\xi \\approx 10^5$ lattice spacings a for spins S=1 and 5/2. We show how the recent prediction of cutoff effects by P. Hasenfratz is approached for moderate $\\xi/a={\\cal O}(100)$, and smoothly connects with other approaches to modeling the AFHM at smaller correlation lengths.
Marine Bi 4iofy LENGTH MEASUREMENTS
Marine Bi 4iofy LENGTH MEASUREMENTS OF LAKE YELLOWSTONE TROUT WOODS HOLE, WASS SPECIAL SCIENTIFIC ;, Director LEI-IGTH MEASUREMEx^ITS OF LAKE YELLOWSTONE TROUT By Oliver B. Cope Fishery Biologist Special clarid lewisi) on Yellowstone Lake and its tributaries since 1936. Prior to that year, considerable
The correlation length for interplanetary magnetic field fluctuations
NASA Technical Reports Server (NTRS)
Fisk, L. A.; Sari, J. W.
1972-01-01
It is argued that it is appropriate to consider two correlation lengths for interplanetary magnetic field fluctuations. For particles with gyro-radii large enough to encounter and be scattered by large-scale tangential discontinuities in the field (particles with energies greater than or approximately equal to several GeV/nucleon) the appropriate correlation length is simply the mean spatial separation between the discontinuities, L approximately 2 x 10 to the 11th power. Particles with gyro-radii much less than this mean separation (energies less than or approximately equal to 100 MeV/nucleon) appear to be unaffected by the discontinuities and respond only to smaller-scale field fluctuations. For these particles the correlation length is shown to be L approximately 10 to the 10th power cm. With this system of two correlation lengths the cosmic-ray diffusion tensor may be altered from what was predicted by, for example, Jokipii and Coleman, and the objections raised recently by Klimas and Sandri to the diffusion analysis of Jokipii may apply only at relatively low energies (approximately 50 MeV/nucleon).
Correlation Lengths of Red and Blue Galaxies: A New Cosmic Ruler
Michael J. Longo
2008-10-22
A comparison of the correlation lengths of red galaxies with blue can provide a new cosmic ruler. Using 269,000 galaxies from the SDSS DR6 survey, I show that the 3D correlation length averaged over many clusters remains very nearly constant at Lo=4.797+/-0.024 Mpc/h from small redshifts out to redshifts of 0.5. This serves as a new measure of cosmic length scales as well as a means of testing the standard cosmological model that is almost free of selection biases. The cluster number density also appears to remain constant over this redshift range.
Photoelectric comparators for measuring graduated linear measures of length
O. V. Yachmentsev
1970-01-01
tical, mechanical, and electronic devices is suitable for making the measurements completely automatic. The testing of linear measures by means of comparators can be divided into the following operations: sighting to the initial graduations of the compared intervals of the reference and the tested measure, taking the reading, and displacing the measures by the length of the compared intervals. These
The torque correlation length and stochastic twist dynamics of DNA
Banigan, Edward J.; Marko, John F.
2014-01-01
We introduce a short correlation length for torque in twisting-stiff biomolecules, which is necessary for the physical property that torque fluctuations be finite in amplitude. We develop a nonequilibrium theory of dynamics of DNA twisting which predicts two crossover time scales for temporal torque correlations in single-molecule experiments. Bending fluctuations can be included, and at linear order we find that they do not affect the twist dynamics. However, twist fluctuations affect bending, and we predict the spatial inhomogeneity of twist, torque, and buckling arising in nonequilibrium “rotor-bead” experiments. PMID:25019813
Torque correlation length and stochastic twist dynamics of DNA
NASA Astrophysics Data System (ADS)
Banigan, Edward J.; Marko, John F.
2014-06-01
We introduce a short correlation length for torque in twisting-stiff biomolecules, which is necessary for the physical property that torque fluctuations be finite in amplitude. We develop a nonequilibrium theory of dynamics of DNA twisting which predicts two crossover time scales for temporal torque correlations in single-molecule experiments. Bending fluctuations can be included, and at linear order we find that they do not affect the twist dynamics. However, twist fluctuations affect bending, and we predict the spatial inhomogeneity of twist, torque, and buckling arising in nonequilibrium "rotor-bead" experiments.
Correlative Measurements Program
NASA Technical Reports Server (NTRS)
Parsons, C. L.
1988-01-01
The GSFC Correlative Measurements Program at the Wallops Flight Facility was represented on the Satellite/Satellite Intercomparisons Working Group. The Correlative Measurements Program uses the Rocket Ozonesonde (ROCOZ-A) and the Electrochemical Concentration Cell (ECC) balloon borne ozonesonde to measure the vertical profile of ozone amount in the atmosphere. The balloon work is described in a separate report. The ROCOZ-A instrument was used for many years to provide in situ truth data for various satellite ozone measuring systems, such as SBUV on Nimbus-7, SAGE-II, SBUV-II on the NOAA series of polar orbiting satellites, SME, LIMS, etc. The particular data sets of interest to the Ozone Trends Panel Working Group were collected at Natal, Brazil. The major results produced for and used by the Ozone Trends Panel are shown. The ROCOZ-A average ozone density profile is plotted versus altitude on the left. ECC ozonesondes were used for the portion of the profile below 20 km, the lower limit for ROCOZ-A. The difference between SAGE-II and ROCOZ-A average density profiles is shown.
Is There Any Correlation Between Patient Height and Patellar Tendon Length?
Navali, Amir M; Jafarabadi, Mohammad Asghari
2015-01-01
Background: A potential specific problem of patellar tendon graft in ACL reconstruction is the possibility of graft-tunnel mismatch which could be more problematic with anatomic ACL reconstruction where the femoral tunnel is placed low on the lateral wall of the lateral femoral condyle. The occasional occurrence of this mismatch raises the question that whether a correlation exists between patient height and patellar tendon length. The purpose of the present study was to measure patellar tendon length as an anthropometric finding and to evaluate whether a correlation exists between patient height and patellar tendon length. Methods: Intra-operative measurement of patellar tendon length was carried out in 267 consecutive patients during bone-patellar tendon-bone (BTB) graft ACL reconstruction. Patient age, gender, height were recorded. The patellar tendon measurements were done independently by two surgeons and the possible inter-observer errors were checked. The data were analyzed using the Pearson correlation. Results: The mean length of the patellar tendon was 46.4 ± 4.8 mm (Mean ± SD) with a range of 32–61 mm. The mean patient height was 177 ± 7 cm (Mean ± SD) with a range of 159–197 cm. A weak positive correlations were found between patient height and patellar tendon length (Pearson r = 0.24, P< 0.001). The linear regression equation for patellar tendon length (y, in millimeters) as a function of patient height (x, in centimeters) can be expressed as y=16.54 + 0.17x. Conclusions: Our study showed a weak correlation between patellar tendon length and patient height. This finding is in contrast to the usual measurements in human anthropometry in which taller individuals have normally longer tendons and ligaments. The graft-tunnel mismatch may be the result of this variation.
Correcting correlation function measurements
NASA Astrophysics Data System (ADS)
Ravan, Shantam; Pujahari, Prabhat; Prasad, Sidharth; Pruneau, Claude A.
2014-02-01
Correlation functions measured as a function of ?? ,?? have emerged as a powerful tool to study the dynamics of particle production in nuclear collisions at high energy. They are however subject, like any other observables, to instrumental effects which must be properly accounted for to extract meaningful physics results. We compare the merits of several techniques used towards measurement of these correlation functions in nuclear collisions. We discuss and distinguish the effects of finite acceptance, and detection efficiency that may vary with collision parameters such as the position of the event in the detector and the instantaneous luminosity of the beam. We focus in particular on instrumental effects which break the factorization of the particle pair detection efficiency, and describe a technique to recover the robustness of correlation observables. We finally introduce a multidimensional weight method to correct for efficiencies that vary simultaneously with particle pseudo rapidity, azimuthal angle, transverse momentum, and the collision vertex position. The method can be generalized to account for any number of "event variables" that may break the factorability of the pair efficiency.
Bunch Length Measurements using Coherent Radiation
Ischebeck, Rasmus; Barnes, Christopher; Blumenfeld, Ian; Decker, Franz-Josef; Hogan, Mark; Iverson, Richard H.; Krejcik, Patrick; Siemann, Robert H.; Walz, Dieter; /SLAC; Kirby, Neil; /Stanford U., Phys. Dept.; Clayton, Chris; Huang, Chengkun; Johnson, Devon K.; Lu, Wei; Marsh, Ken; /UCLA; Deng, Suzhi; Oz, Erdem; /Southern California U.
2005-06-24
The accelerating field that can be obtained in a beam-driven plasma wakefield accelerator depends on the current of the electron beam that excites the wake. In the E-167 experiment, a peak current above 10 kA will be delivered at a particle energy of 28 GeV. The bunch has a length of a few ten micrometers and several methods are used to measure its longitudinal profile. Among these, autocorrelation of coherent transition radiation (CTR) is employed. The beam passes a thin metallic foil, where it emits transition radiation. For wavelengths greater than the bunch length, this transition radiation is emitted coherently. This amplifies the long-wavelength part of the spectrum. A scanning Michelson interferometer is used to autocorrelate the CTR. However, this method requires the contribution of many bunches to build an autocorrelation trace. The measurement is influenced by the transmission characteristics of the vacuum window and beam splitter. We present here an analysis of materials, as well as possible layouts for a single shot CTR autocorrelator.
Boyer, Edmond
Validation of the AIEM through correlation length parameterization at field scale using radar) through different correlation length parameterizations using radar imagery for field-scale studies polarization. Better results were obtained with surface soil moisture (SSM) measured at 10 cm than at 5 cm
Standardisation of crown-rump length measurement.
Ioannou, C; Sarris, I; Hoch, L; Salomon, L J; Papageorghiou, A T
2013-09-01
Correct estimation of gestational age is essential for any study of ultrasound biometry and for everyday clinical practice. However, inconsistency in pregnancy dating may occur through differences in measurement methods or errors during measurement. In the INTERGROWTH-21(st) Project, pregnancies are dated by the last menstrual period, provided that it is certain and associated with a regular menstrual cycle, and the gestational age by dates concurs with a first-trimester ultrasound crown-rump length (CRL) estimation. Hence, there was a need to standardise CRL measurement methodology across the study sites in this international, multicentre project to avoid systematic differences in dating. To achieve uniformity we undertook the following steps: the ultrasound technique was standardised by disseminating an illustrated, operating manual describing CRL plane landmarks and calliper application, and posters describing the correct acquisition technique were disseminated for quick reference. To ensure that all ultrasonographers understood the methodology, they forwarded a log-book to the INTERGROWTH-21(st) Ultrasound Coordinating Unit, containing the answers to a written test on the manual material and five images of a correctly acquired CRL. Interpretation of CRL was also standardised by ensuring that the same CRL regression formula was used across all study sites. These methods should minimise potential systematic errors in dating associated with pooling data from different health institutions, and represent a model for standardising CRL measurement in future studies. PMID:23678951
Including short length scale correlations in quantum chemistry methods
NASA Astrophysics Data System (ADS)
Bhaskaran-Nair, K.; Kowalski, K.; Moreno, J.; Shelton, W.; Jarrell, M.
2014-03-01
Many aspects of computational chemistry and computational material science require accuracies that can only be obtained by a small class of highly accurate computational methods that appropriately account for instantaneous interactions between electrons in molecules or in materials. To aid in addressing the sign problem associated with DMFT based methods we use accurate quantum chemistry methods to treat short length scale correlations within DMFT type formulations and its cluster extensions. The local Green function is obtained from truncated variants of Configuration Interaction and Coupled Cluster methods, which efficiently describe the electron correlation effects. This work is supported by the National Science Foundation award NSF EPS-1003897 with additional support from the Louisiana Board of Regents.
In-vitro correlation between tension and length change in an anterior cruciate ligament substitute.
Good, L
1995-06-01
The length change and tension patterns from multiple insertion locations of an anterior cruciate ligament substitute were studied in 10 cadaver knees. Length change was measured with a spring-loaded isometer of low stiffness, and tension was measured with a piezoelectric load cell. In both instances a thin Kevlar test ligament was positioned in five different femoral and two different tibial ligament insertion locations, that were all located within the normal attachments of the anterior cruciate ligament. Differences were found regarding length changes and tension patterns from a simulated active extension between the central, posterior, and anterior femoral locations. All locations showed larger length change and tension values in extension than in flexion. The anterior femoral ligament insertion location showed length change and tension patterns with increasing values in flexion compared to the other femoral locations. The anterior tibial ligament insertion location showed smaller excursions of both length and tension, than did the central one, but the patterns of the curves were similar. A statistically significant correlation was found between length change and tension patterns throughout a 130-0 degrees range of motion. A statistically significant correlation was also found between the maximum length and tension values. No fixed relationship was found between the magnitude of the length and tension values, when different intervals of the range of motion were studied. RELEVANCE: The intraoperative employment of length change measurements of a test ligament in anterior cruciate ligament reconstruction gives information on where high tension can be expected in the range of motion of the knee, and how this can differ depending on the angle of graft fixation. The information gained can also be used to improve drill channel location. However, no predictions on the magnitude of tension can be made, mainly due to large biological variability. PMID:11415553
Bunch length and impedance measurements in SPEAR
Bane, K.; Donald, M.; Hofmann, A.; Jowett, J.; Lockman, W.; Morton, P.; Stege, R.; Spence, W.; Wilson, P.
1988-05-01
Subsequent to an extensive smoothing of the vacuum chamber a comprehensive study of the SPEAR impedance was undertaken. Bunch length, synchrotron quadrupole mode frequency, and parasitic mode loss were measured as functions of beam current. The results showed that, although the gross longitudinal impedance had indeed been reduced, the 'capacitive' component had also decreased relative to the 'inductive'--to the extent that previously compensated potential well distortion now induced bunch lengthening at low currents, and the turbulent threshold had actually been lowered. A specially designed multi-cell disc-loaded 'capacitor' cavity was shown to be capable of removing this effect by restoring the original compensation. A model of the new SPEAR impedance is also obtained. 7 refs., 6 figs.
NASA Astrophysics Data System (ADS)
Nishimoto, Masahiko; Ogata, Kohichi
Gaussian rough surfaces can be characterized by two roughness parameters, the root-mean-square height and correlation length. For accurate estimation of these parameters from measured surface height-profile, data samples with sufficiently long record length are necessary. In this letter, an expression of correlation length in terms of a surface slope function is introduced in order to estimate correlation length and analytical expression of the data record length required for accurate estimation is derived. The result shows that the method using the slope function can reduce the data record length approximately 60% as compared to the commonly employed method using the correlation function. In order to check the result, a Monte Carlo simulation is also carried out and the validity of the result is confirmed.
Dynamic, In Situ Measurement of Sea-Ice Characteristic Length
Fox, Colin
1 Dynamic, In Situ Measurement of Sea-Ice Characteristic Length Colin Fox Mathematics Department, Auckland, New Zealand Abstract We present a method for measuring the char- acteristic length of sea ice a range of localized measurements. The method is used to detemine the characteristic length of the sea ice
Tree--Based Wavelet Regression for Correlated Data using the Minimum Description Length Principle
Lee, Thomas
Tree--Based Wavelet Regression for Correlated Data using the Minimum Description Length Principle, and that it uses the minimum description length principle to define its ``best'' estimate. The proposed procedure and correlated noise. Keywords: correlated noise, minimum description length principle, non--Gaussian noise, tree
Measuring the effective channel length of MOSFETs
K. K. Ng; J. R. Brews
1990-01-01
Eleven measurement methods are outlined, and their assumptions are examined. The methods are analyzed, critiqued, and compared. Recommendations are made as to which methods are best under various conditions
Bunch length measurements in the SLC damping ring
Decker, F.J.; Limberg, T.; Minty, M.; Ross, M.
1993-05-01
The synchrotron light of the SLC damping ring was used to measure the bunch length with a streak camera at different times in the damping cycle. There are bunch length oscillations after injection, different equilibrium length during the cycle due to rf manipulations to avoid microwave instability oscillations, and just before extraction there is a longitudinal phase space rotation (bunch muncher) to shorten the bunch length. Measurements under these different conditions are presented and compared with BPM pulse height signals. Calibration and adjustment issues and the connection of the streak camera to the SLC control system are also discussed.
Measurements of Newton's gravitational constant and the length of day
Anderson, John D; Trimble, Virginia; Feldman, Michael R
2015-01-01
About a dozen measurements of Newton's gravitational constant, G, since 1962 have yielded values that differ by far more than their reported random plus systematic errors. We find that these values for G are oscillatory in nature, with a period of P = 5.899 +/- 0.062 yr, an amplitude of (1.619 +/- 0.103) x 10^{-14} m^3 kg^{-1} s^{-2}, and mean-value crossings in 1994 and 1997. However, we do not suggest that G is actually varying by this much, this quickly, but instead that something in the measurement process varies. Of other recently reported results, to the best of our knowledge, the only measurement with the same period and phase is the Length of Day (LOD - defined as a frequency measurement such that a positive increase in LOD values means slower Earth rotation rates and therefore longer days). The aforementioned period is also about half of a solar activity cycle, but the correlation is far less convincing. The 5.9 year periodic signal in LOD has previously been interpreted as due to fluid core motions ...
Mach-Zehnder Modulator Arm-Length-Mismatch Measurement Technique
NASA Astrophysics Data System (ADS)
Geary, Kevin; Kim, Seong-Ku; Seo, Byoung-Joon; Fetterman, Harold R.
2005-03-01
This paper describes a robust measurement technique for determining the effective length mismatch of the two arms of a Mach-Zehnder modulator (MZM), based on its broad-band filter characteristics. The proposed method involves measuring the Vpi (lambda), n(lambda), and transfer function of a modulator at various externally applied bias points. This mismatch measurement technique is applied to a packaged polymer rib waveguide MZM, and it is shown that it has an arm-length mismatch of 1.9 ?m. Poling-induced writing is then proposed as a fabrication technique that can consistently produce polymer MZMs with arm-length-mismatch values less than 2 ?m.
Correlated response in reproductive and life history traits to selection on testis length
Pitnick, Scott
Correlated response in reproductive and life history traits to selection on testis length, testis length, and other reproductive and life history traits, including body size, age at ®rst underlying these interspeci®c patterns, we imposed replicated bidirectional selection for testis length
The feather-length of small passerines: a measurement for wing-length in live birds and museum skins
Lukas Jenni; Rafael Winkler
1989-01-01
Wing-length is difficult to measure reproducibly, and to compare between live birds and museum skins. Recently the length of Primary 8 was suggested as a measure of wing-length in live small passerines; smaller variation was found between observers than in wing-length.This paper examines which feather-length out of Primaries 1 and 6–¸9 best represents wing-length in 51 passerine species. It was
Basnet, Bishal Babu; Parajuli, Prakash Kumar; Singh, Raj Kumar; Suwal, Pramita; Shrestha, Pragya; Baral, Dharanidhar
2015-01-01
Background Establishment of proper occlusal vertical dimension (OVD) is one of the important tasks for successful prosthodontic therapy. An ideal method for determining OVD in terms of cost, time, and instrument requirements has been sought in prosthodontics by various investigators. However, no such single method has been formulated. In the current anthropometric study, the relationship of the length of the thumb to the OVD was tested in two ethnic groups of Nepal, Aryans, and Mongoloids. The result of this study can be useful in determining proper OVD in edentulous patients. Aims and objectives The primary aim of the present study was to evaluate the correlation between the length of the thumb and OVD in Aryan and Mongoloid ethnic groups. The secondary aim was to compare the correlation between OVD and other anatomic measurements (eye–ear distance and pupil-to-rima oris distance) in these ethnicities. Materials and methods The OVD, thumb length, eye–ear distance and distance between pupil of eye and rima oris were measured in a total of 500 adult dentulous volunteers. The correlation between OVD and thumb length as well as other anatomic measurements was checked with Pearson’s product moment correlation coefficient. Linear regression analysis was performed to determine the relationship of OVD to the length of the thumb. Results The thumb length was significantly (P?0.05) correlated with strong and positive values (Pearson’s coefficient =0.874 in the whole population, 0.826 in Aryans, and 0.944 in Mongoloids). Regression analysis showed that thumb length was significantly related to OVD in both ethnic groups. Conclusion Within the limitations of the present study, the result implies that thumb length can be used as an adjunct for establishing OVD in the edentulous patients. PMID:25678817
Far-from-equilibrium measurements of thermodynamic length
Feng, Edward H.; Crooks, Gavin E.
2008-11-05
Thermodynamic length is a path function that generalizes the notion of length to the surface of thermodynamic states. Here, we show how to measure thermodynamic length in far-from-equilibrium experiments using the work fluctuation relations. For these microscopic systems, it proves necessary to define the thermodynamic length in terms of the Fisher information. Consequently, the thermodynamic length can be directly related to the magnitude of fluctuations about equilibrium. The work fluctuation relations link the work and the free energy change during an external perturbation on a system. We use this result to determine equilibrium averages at intermediate points of the protocol in which the system is out-of-equilibrium. This allows us to extend Bennett's method to determine the potential of mean force, as well as the thermodynamic length, in single molecule experiments.
Comorbidity as a correlate of length of stay for hospitalized patients with acute chest pain
Kunihiko Matsui; Lee Goldman; Paula A. Johnson; Karen M. Kuntz; E. Francis Cook; Thomas H. Lee
1996-01-01
OBJECTIVE: To determine whether comorbid medical conditions as measured with the Charlson Comorbidity Index are independent correlates\\u000a of length of stay after adjusting for other clinical and socioeconomic data.\\u000a \\u000a \\u000a DESIGN: Prospective cohort study.\\u000a \\u000a \\u000a \\u000a \\u000a SETTING: Urban teaching hospital.\\u000a \\u000a \\u000a \\u000a \\u000a PATIENTS: All 1,261 patient aged 30 years or more who were admitted to this hospital after coming to the emergency department with\\u000a acute
Measuring the Length of a Captured Burmese Python
Skip Snow (National Park Service) measures the length of a captured Burmese python (Python molurus) at the South Florida Research Center, Everglades National Park. Photo courtesy of Lori Oberhofer, NPS. ...
Correlations between Muscle Activities and Strap Length and Types of School Bag during Walking.
Yoon, Jung-Gyu
2014-12-01
[Purpose] The purpose of this study was to examine correlations between muscle activities and strap length and type of the school bag during walking. [Subjects and Methods] The subjects of this study were 20 healthy students. An 8-channel electromyograph (8-EMG) (Pocket EMG, BTS, Italy) was used to measure the muscle activities of the right upper trapezius, left upper trapezius, right erector spinae and left erector spinae during walking with the bag. The collected data were analyzed using Kendall's coefficient of concordance. [Results] The muscle activities of the right upper trapezius, left upper trapezius, right erector spinae and left erector spinae were significantly higher when walking with a shoulder bag than when walking with a backpack. No significant correlations were found between muscle activities and strap lengths of the bag. [Conclusion] While carrying a bag, the activities of the trunk muscles were influenced more by the type of the bag than by the strap length. These results indicate that a backpack is a better method of carrying a load than a shoulder bag. PMID:25540502
Correlations between Muscle Activities and Strap Length and Types of School Bag during Walking
Yoon, Jung-Gyu
2014-01-01
[Purpose] The purpose of this study was to examine correlations between muscle activities and strap length and type of the school bag during walking. [Subjects and Methods] The subjects of this study were 20 healthy students. An 8-channel electromyograph (8-EMG) (Pocket EMG, BTS, Italy) was used to measure the muscle activities of the right upper trapezius, left upper trapezius, right erector spinae and left erector spinae during walking with the bag. The collected data were analyzed using Kendall’s coefficient of concordance. [Results] The muscle activities of the right upper trapezius, left upper trapezius, right erector spinae and left erector spinae were significantly higher when walking with a shoulder bag than when walking with a backpack. No significant correlations were found between muscle activities and strap lengths of the bag. [Conclusion] While carrying a bag, the activities of the trunk muscles were influenced more by the type of the bag than by the strap length. These results indicate that a backpack is a better method of carrying a load than a shoulder bag. PMID:25540502
Nakhli, Fouad R.
2014-01-01
Purpose To investigate the relationship between optical biometry and applanation ultrasound measurement of the axial length of the eye. Materials and methods This prospective study enrolled 55 (68 eyes) consecutive patients scheduled for cataract surgery at Dhahran Eye Specialist Hospital (DESH). Every eye underwent two measurements each with an optical biometer and with applanation ultrasound. Only patients with cataract and no other ophthalmic pathology or disease were enrolled. Comparison, correlation and repeatability of axial length with both devices were analyzed. Agreement between devices was evaluated. A regression formula to convert measurements between devices was investigated. A p value less than 0.05 was statistically significant. Results There was strong repeatability (99.4%) and agreement (r = 0.987) between both devices (p < 0.001); the difference between devices was mainly in short eyes (p = 0.031). Conclusion Optical biometry and applanation ultrasound measurements of axial length correlate well. However, optical biometry is preferable in short eyes. PMID:25473345
A correlation study of telomere length in peripheral blood leukocytes and kidney function with age.
Zhang, Wei-Guang; Wang, Yong; Hou, Kai; Jia, Lin-Pei; Ma, Jie; Zhao, De-Long; Zhu, Shu-Ying; Bai, Xiao-Juan; Cai, Guang-Yan; Wang, Yan-Ping; Sun, Xue-Feng; Chen, Xiang-Mei
2015-06-01
The current study aimed to investigate the association between telomere length in peripheral blood leukocytes and kidney function in various age groups of a healthy population. A total of 139 healthy individuals were divided into five groups according to their age: 35?44, 45?54, 55?64, 65?74 and >75 years old. Peripheral blood leukocytes were obtained and the telomere restriction fragment (TRF) length was assayed using a digoxigenin?labeled hybridization probe in Southern blot assays. Laboratory assays of kidney function were also performed. A correlation was observed between TRF length and age (r=?0.314, P<0.001), with the telomere length of the individuals >75 years group being significantly shorter than the telomere length of the 35?44, 45?54 and 55?64 years age groups (P<0.05). By contrast, the TRF length for males versus females did not differ for any of the age groups, while a correlation was observed between TRF length and serum levels of cystatin C (r=?0.195, P<0.05). There was also a correlation between TRF length and glomerular filtration rate (r=?0.184, P<0.05). The current study demonstrated that in this cohort, leukocyte telomere length reduced with age and was correlated with serum levels of cystatin C and glomerular filtration rate. Therefore, TRF length is associated with kidney function and may serve as a marker of aging. PMID:25646618
Core Turbulence Correlation Lengths in Enhanced Confinement NCS Plasmas on DIII--D
NASA Astrophysics Data System (ADS)
Doyle, E. J.; Rhodes, T. L.; Peebles, W. A.; Rettig, C. L.
1998-11-01
The properties of core plasma turbulence in enhanced confinment negative central shear (NCS) discharges are of interest for an understanding of both transport in these plasmas and also magnetic and E× B shear effects on turbulence. Previous studies on DIII--D have demonstrated a reduction in core turbulence levels in NCS discharges consistent with pictures of E× B shear flow regulation of turbulence.(C.L. Rettig et al.), Phys. Plasmas 5, 1727 (1998). More detailed studies of core turbulence properties using a correlation reflectometer are now possible since the addition of a reflectometer sustem for core profile measurements on DIII--D. Preliminary data indicate that the turbulence correlation length in the plasma core is reduced in NCS plasmas, indicating a smaller step size for turbulent transport processes.
Effective length measurements of prototype Main Injector Dipole endpacks
Glass, H.D.; Brown, B.C.; Harding, D.J.
1993-03-03
An endpack design has been developed for the Fermilab Main Injector Dipole. A major part of the design process was the testing of a series of prototype removable endpacks. The magnetic parameters that were tested included the effective length and the field shape variation. This report presents a description of the measurement techniques and the results for the effective length. The final endpack has an effective length at 1500 A (0.29T) of 2.6 {plus_minus} 0.3 mm greater than the steel length, and the change in effective length from 1500 A to maximum current of 9500 A (1.74T) is {minus}1.88 {plus_minus} 0.05 mm.
Flores-Mir, Carlos; Rosenblatt, Mark R; Major, Paul W.; Carey, Jason P.; Heo, Giseon
2014-01-01
INTRODUCTION: This in vivo study assessed accuracy and reliability of tooth length measurements obtained from conventional panoramic radiographs and CBCT panoramic reconstructions to that of a digital caliper (gold standard). METHODS: The sample consisted of subjects who had CBCT and conventional panoramic radiographic imaging and who required maxillary premolar extraction for routine orthodontic treatment. A total of 48 teeth extracted from 26 subjects were measured directly with digital calipers. Radiographic images were scanned and digitally measured in Dolphin 3D software. Accuracy of tooth length measurements made by CBCT panoramic reconstructions, conventional panoramic radiographs and digital caliper (gold standard) were compared to each other by repeated measures one-way ANOVA with Bonferroni correction and by single measures intraclass correlation coefficient. RESULTS: Repeated root length measures with digital calipers, panoramic radiographs and CBCT constructed panoramic-like images were all individually highly reliable. Compared to the caliper (gold standard), tooth measurements obtained from conventional panoramic radiographs were on average 6.3 mm (SD = 2.0 mm) longer, while tooth measurements from CBCT panoramic reconstructions were an average of 1.7 mm (SD = 1.2 mm) shorter. CONCLUSIONS: In comparison to actual tooth lengths, conventional panoramic radiographs were relatively inaccurate, overestimating the lengths by 29%, while CBCT panoramic reconstructions underestimated the lengths by 4%. PMID:25715716
Fiber Length Measurement In Pulp And Paper Industry
NASA Astrophysics Data System (ADS)
Piirainen, Raili A.
1986-10-01
For the pulp and paper maker, product quality and production costs are the major factors that determine profitability. Quality has to be high enough to satisfy the customer and costs low enough to maintain competitiveness. Accurate and readily available fiber length information is fast becoming one of the most important control factors to achieve these targets. Measurement of fiber length has been difficult and time consuming in the past --- appli-cation to production almost impossible due to the historical nature of the data. The Kajaani fiber length analyzer has revolutionized fiber length analysis. Even more accurate than the microscopic method and infinitely faster than mechanical classifiers, such as Bauer McNett or Clark classifiers, the Kajaani analyzer opens new horizons for the paper maker. The Kajaani method is an optical method and is based on the ability of fibers to change the direction of light polarization. With no critical sample preparation, the results are ready in a few minutes. During this time, the analyzer counts and measures over 3000 individual fibers. Results are printed out either in graphic or numerical form. Some of the typical applications of the Kajaani fiber length analyzer are to determine hardwood/softwood ratios in pulp and paper mills both in brownstock and stock preparation areas, to predict strength properties of mechanical pulp based on the fiber length information, to measure the coarseness of the fibers, to evaluate screening and refining processes and to check the quality of purchased pulp.
Discriminant analysis in correlation similarity measure space
Yong Ma; Shihong Lao; Erina Takikawa; Masato Kawade
2007-01-01
Correlation is one of the most widely used similarity measures in machine learning like Euclidean and Mahalanobis distances. However, compared with proposed numerous discriminant learning algorithms in distance metric space, only a very little work has been conducted on this topic using correlation similarity measure. In this paper, we propose a novel discriminant learning algorithm in correlation measure space, Correlation
EARLINET correlative measurements for CALIPSO
NASA Astrophysics Data System (ADS)
Mattis, Ina; Mona, Lucia; Müller, Detlef; Pappalardo, Gelsomina; Alados-Arboledas, Lucas; D'Amico, Giuseppe; Amodeo, Aldo; Apituley, Arnoud; Baldasano, José Maria; Böckmann, Christine; Bösenberg, Jens; Chaikovsky, Anatoli; Comeron, Adolfo; Giannakaki, Elina; Grigorov, Ivan; Guerrero Rascado, Juan Luis; Gustafsson, Ove; Iarlori, Marco; Linne, Holger; Mitev, Valentin; Molero Menendez, Francisco; Nicolae, Doina; Papayannis, Alexandros; Garcia-Pando, Carlos Perez; Perrone, Maria Rita; Pietruczuk, Aleksander; Putaud, Jean-Philippe; Ravetta, Francois; Rodríguez, Alejandro; Seifert, Patric; Sicard, Michaël; Simeonov, Valentin; Sobolewski, Piotr; Spinelli, Nicola; Stebel, Kerstin; Stohl, Andreas; Tesche, Matthias; Trickl, Thomas; Wang, Xuan; Wiegner, Matthias
2007-10-01
The European Aerosol Research Lidar Network (EARLINET) was established in 2000 to derive a comprehensive, quantitative, and statistically significant data base for the aerosol distribution on the European scale. At present, EARLINET consists of 25 stations: 16 Raman lidar stations, including 8 multi-wavelength Raman lidar stations which are used to retrieve aerosol microphysical properties. EARLINET performs a rigorous quality assurance program for instruments and evaluation algorithms. All stations measure simultaneously on a predefined schedule at three dates per week to obtain unbiased data for climatological studies. Since June 2006 the first backscatter lidar is operational aboard the CALIPSO satellite. EARLINET represents an excellent tool to validate CALIPSO lidar data on a continental scale. Aerosol extinction and lidar ratio measurements provided by the network will be particularly important for that validation. The measurement strategy of EARLINET is as follows: Measurements are performed at all stations within 80 km from the overpasses and additionally at the lidar station which is closest to the actually overpassed site. If a multi-wavelength Raman lidar station is overpassed then also the next closest 3+2 station performs a measurement. Altogether we performed more than 1000 correlative observations for CALIPSO between June 2006 and June 2007. Direct intercomparisons between CALIPSO profiles and attenuated backscatter profiles obtained by EARLINET lidars look very promising. Two measurement examples are used to discuss the potential of multi-wavelength Raman lidar observations for the validation and optimization of the CALIOP Scene Classification Algorithm. Correlative observations with multi-wavelength Raman lidars provide also the data base for a harmonization of the CALIPSO aerosol data and the data collected in future ESA lidar-in-space missions.
Measurement of Trap Length for an Optical Trap
NASA Technical Reports Server (NTRS)
Wrbanek, Susan Y.
2009-01-01
The trap length along the beam axis for an optical trap formed with an upright, oil-immersion microscope was measured. The goals for this effort were twofold. It was deemed useful to understand the depth to which an optical trap can reach for purposes of developing a tool to assist in the fabrication of miniature devices. Additionally, it was desired to know whether the measured trap length favored one or the other of two competing theories to model an optical trap. The approach was to trap a microsphere of known size and mass and raise it from its initial trap position. The microsphere was then dropped by blocking the laser beam for a pre-determined amount of time. Dropping the microsphere in a free-fall mode from various heights relative to the coverslip provides an estimate of how the trapping length changes with depth in water in a sample chamber on a microscope slide. While it was not possible to measure the trap length with sufficient precision to support any particular theory of optical trap formation, it was possible to find regions where the presence of physical boundaries influenced optical traps, and determine that the trap length, for the apparatus studied, is between 6 and 7 m. These results allow more precise control using optical micromanipulation to assemble miniature devices by providing information about the distance over which an optical trap is effective.
Bunch-Length Measurements in PEP-II
Fisher, Alan S.; Novokhatski, A.; Turner, J.L.; Wienands, U.; Yocky, G.; /SLAC; Holtzapple, Robert; /Alfred U.
2005-06-10
We measured the lengths of colliding e{sup +}e{sup -} bunches in the PEP-II B Factory at SLAC using various techniques. First, at several RF voltages and with both single-bunch and multibunch beams, a synchroscan streak camera measured synchrotron emission through a narrow blue filter. With 3.8 MV of RF, the length of a single positron bunch was 12 mm at low current, rising to 13 mm at 1.5 mA and 14.8 mm at 3 mA. The electrons measured 12.2 mm at 16 MV with little current dependence. Both are longer than the expected low-current value of 10 mm (e{sup +}) and 10.5 mm (e{sup -}), derived from the energy spread and the measured synchrotron tune. We also determined the length for multibunch fills from measurements between 2 and 13 GHz of the bunch spectrum on a BPM button. After correcting for the frequency dependence of cable attenuation, we fitted the measured spectrum to that of a Gaussian bunch. At 3.8 MV, the positron measurement gave 13.2 mm at 1.5 mA/bunch in a full ring, shorter than the 15.6 mm found with the streak camera under these conditions, but we found 11.4 mm for the electrons at 16.7 MV and 1 mA/bunch, in good agreement with the 11 mm from multibunch streak measurements.
Measuring spin diffusion length using spin Seebeck effect
NASA Astrophysics Data System (ADS)
Kannan, Harsha; Fan, Xin; Xiao, John
2014-03-01
Ever since its discovery, spin Seebeck effect (SSE) has attracted plenty of attention. The conversion from thermal gradient to spin current has shown great potential in thermal energy harvesting. SSE can also be utilized as a source to generate pure spin current to unveil new physics. Here we show that it is possible to measure spin diffusion length of a heavy metal Pt by studying the SSE as a function of Pt layer thickness. The SSE signal first increases, peaks, and then decreases with increasing Pt layer thickness. By fitting with a drift-diffusion model, we obtain the spin diffusion length of Pt to be about 2nm, close to that obtained from other techniques. Moreover, we can insert a thin layer of Cu in order to remove the possible proximity effect. Similar spin-diffusion length is obtained from this measurement.
Cytosine Usage Modulates the Correlation between CDS Length and CG Content in Prokaryotic Genomes
Xia, Xuhua
Cytosine Usage Modulates the Correlation between CDS Length and CG Content in Prokaryotic Genomes empirically by prokaryotic genomes. How- ever, the correlation is weak for a number of species, with 4 species in long CDSs. Empirical data from prokaryotic genomes lend strong support for this new hypothesis
Genetic correlation between length of wattles and female body weight at sexual maturity in the foul
Paris-Sud XI, Université de
Genetic correlation between length of wattles and female body weight at sexual maturity in the foul of wattles at sexual maturity. Heritability estimates showed that both cha- racters are highly influenced Secondary sexual characters were proved to be correlated with egg produc- tions and age at sexual maturity
Length Scale Correlations of Cellular Microstructures in Directionally Solidified Binary System
Yunxue Shen
2002-06-27
In a cellular array, a range of primary spacing is found to be stable under given growth conditions. Since a strong coupling of solute field exists between the neighboring cells, primary spacing variation should also influence other microstructure features such as cell shape and cell length. The existence of multiple solutions is examined in this study both theoretically as well as experimentally. A theoretical model is developed that identifies and relates four important microstructural lengths, which are found to be primary spacing, tip radius, cell width and cell length. This general microstructural relationship is shown to be valid for different cells in an array as well as for other cellular patterns obtained under different growth conditions. The unique feature of the model is that the microstructure correlation does not depend on composition or growth conditions since these variables scale microstructural lengths to satisfy the relationship obtained in this study. Detailed directional solidification experimental studies have been carried out in the succinonitrile-salol system to characterize and measure these four length scales. Besides the validation of the model, experimental results showed additional scaling laws to be present. In the regime where only a cellular structure is formed, the shape of the cell, the cell tip radius and the length of the cell are all found to scale individually with the local primary spacing. The presence of multiple solutions of primary spacing is also shown to influence the cell-dendrite transition that is controlled not only by the processing variables (growth velocity, thermal gradient and composition) but also by the local cell spacing. The cell-dendrite transition was found not to be sharp, but occurred over a range of processing conditions. Two critical conditions have been identified such that only cells are present below lower critics condition, and only dendrites are formed above the upper critics condition. Between these two limits, both cells and dendrites have been found to coexist. In this mixed regime, a critical local spacing is found above which a cell is unstable and forms a dendrite. An analytical expression is developed that relates the critical spacing for the cell-dendrite transition with processing conditions.
Length Scale Correlations of Cellular Microstructures in Directionally Solidified Binary System
Yunxue Shen
2002-08-01
In a cellular array, a range of primary spacing is found to be stable under given growth conditions. Since a strong coupling of solute field exists between the neighboring cells, primary spacing variation should also influence other microstructure features such as cell shape and cell length. The existence of multiple solutions is examined in this study both theoretically as well as experimentally. A theoretical model is developed that identifies and relates four important microstructural lengths, which are found to be primary spacing, tip radius, cell width and cell length. This general microstructural relationship is shown to be valid for different cells in an array as well as for other cellular patterns obtained under different growth conditions. The unique feature of the model is that the microstructure correlation does not depend on composition or growth conditions since these variables scale microstructural lengths to satisfy the relationship obtained in this study. Detailed directional solidification experimental studies have been carried out in the succinonitrile-salol system to characterize and measure these four length scales. Besides the validation of the model, experimental results showed additional scaling laws to be present. In the regime where only a cellular structure is formed, the shape of the cell, the cell tip radius and the length of the cell are all found to scale individually with the local primary spacing. The presence of multiple solutions of primary spacing is also shown to influence the cell-dendrite transition that is controlled not only by the processing variables (growth velocity, thermal gradient and composition) but also by the local cell spacing. The cell-dendrite transition was found not to be sharp, but occurred over a range of processing conditions. Two critical conditions have been identified such that only cells are present below lower critics condition, and only dendrites are formed above the upper critics condition. Between these two limits, both cells and dendrites have been found to coexist. In this mixed regime, a critical local spacing is found above which a cell is unstable and forms a dendrite. An analytical expression is developed that relates the critical spacing for the cell-dendrite transition with processing conditions.
How to directly measure a Kondo cloud's length.
Park, Jinhong; Lee, S-S B; Oreg, Yuval; Sim, H-S
2013-06-14
We propose a method to directly measure, by electrical means, the Kondo screening cloud formed by an Anderson impurity coupled to semi-infinite quantum wires, on which an electrostatic gate voltage is applied at distance L from the impurity. We show that the Kondo cloud, and hence the Kondo temperature and the electron conductance through the impurity, are affected by the gate voltage, as L decreases below the Kondo cloud length. Based on this behavior, the cloud length can be experimentally identified by changing L with a keyboard type of gate voltage or tuning the coupling strength between the impurity and the wires. PMID:25165950
Correlation of OH Stretching Frequencies and OH · · · O Hydrogen Bond Lengths in Minerals
Eugen Libowitzky
1999-01-01
Summary. A correlation of O*H stretching frequencies (from infrared spectroscopy) with O>O and H>O bond lengths (from structural data) of minerals was established. References on 65 minerals yielded 125 data pairs for the d(O>O)-v correlation; due to rare or inaccurate data on proton positions, only 47 data pairs were used for the d(H>O)-v correlation. The data cover a wide range
Electron Bunch Length Measurement for LCLS at SLAC
Zelazny, M.; Allison, S.; Chevtsov, Sergei; Emma, P.; Kotturi, K.d.; Loos, H.; Peng, S.; Rogind, D.; Straumann, T.; /SLAC
2007-10-04
At Stanford Linear Accelerator Center (SLAC) a Bunch Length Measurement system has been developed to measure the length of the electron bunch for its new Linac Coherent Light Source (LCLS). This destructive measurement uses a transverse-mounted RF deflector (TCAV) to vertically streak the electron beam and an image taken with an insertable screen and a camera. The device control software was implemented with the Experimental Physics and Industrial Control System (EPICS) toolkit. The analysis software was implemented in Matlab{trademark} using the EPICS/Channel Access Interface for Scilab{trademark} and Matlab{trademark} (labCA). This architecture allowed engineers and physicists to develop and integrate their control and analysis without duplication of effort.
Isometric Instructions: Measure the length from your shoulder to your elbow using the tape measure
Sniadecki, Nathan J.
Isometric Instructions: Part 1: Measure the length from your shoulder to your elbow using the tape measure provided. You will also need to measure the length from your elbow to your hand where you grip. 3. Grab handle attached to the load cell. 4. Adjust position of your elbow so that your arm
Karti, Omer; Selver, Ozlem B; Karahan, Eyyup; Zengin, Mehmet O; Uyar, Murat
2015-01-01
Purpose : To evaluate the normal distribution of exophthalmometric values in Turkish adult population and the effect of age, gender, refractive status and axial length on globe position. Methods : One hundred and twenty-two males and 114 healthy females with age ranging from 18 to 87 years were included in the study. The study population was recruited from patients presenting to our institution for routine refractive examination. Hertel exophthalmometer was used to measure the degree of ocular protrusion. Effect of age, refractive error, interpupillary distance, and axial length on globe position was detected with linear regression analyses. Results : The mean Hertel exophthalmometric size was 15.7+2.6 mm (range; 11 to 21 mm). The mean value for males was 16.1±2.6 mm (range; 11 to 21 mm), and for females 15.5±2.6 mm (range; 11 to 20 mm). The mean distance between the lateral rims of the orbit was 102 + 5.1 mm (range; 88 to 111mm). The mean exophthalmometric values were not statistically different in males and females. Age and mean spherical equivalents were negatively correlated with exophthalmometric measurements. Axial length was positively correlated with exophthalmometric measurements. Conclusion : The exophthalmometric measurement of the eye is affected by the age, spherical equivalent and the axial length. Standard normative values of the Hertel exophthalmometric measurements should be reevaluated with larger samples.
Crack Tip Growth Measurement Using Digital Image Correlation
Phillip L. Reu; Brendan R. Rogillio; Gerald W. Wellman
We present the results of sub-surface crack-length measurements in an aluminium sample that are inferred from surface strains\\u000a calculated using digital image correlation (DIC). DIC is a photometric technique that uses a calibrated stereo camera system\\u000a to calculate the 3D shape and motion of an imaged scene [1,2]. Image correlation has already proven itself to be useful for crack tip
The Square-Lattice Heisenberg Antiferromagnet at Very Large Correlation Lengths
B. B. Beard; R. J. Birgeneau; M. Greven; U. -J. Wiese
1997-12-23
The correlation length of the square-lattice spin-1/2 Heisenberg antiferromagnet is studied in the low-temperature (asymptotic-scaling) regime. Our novel approach combines a very efficient loop cluster algorithm -- operating directly in the Euclidean time continuum -- with finite-size scaling. This enables us to probe correlation lengths up to $\\xi \\approx 350,000$ lattice spacings -- more than three orders of magnitude larger than any previous study. We resolve a conundrum concerning the applicability of asymptotic-scaling formulae to experimentally- and numerically-determined correlation lengths, and arrive at a very precise determination of the low-energy observables. Our results have direct implications for the zero-temperature behavior of spin-1/2 ladders.
BUNCH LENGTH MEASUREMENT ON CANDELA PHOTO-INJECTOR
G. Devanz; B. Leblond; B. Mouton; C. Travier; Faraday Cup
CANDELA photo-injector is made of a 2-cell S-band RF gun, using a dispenser cathode illuminated by a Ti:sapphire laser. This electron source provides a single bunch (at 12.5 Hz), with a charge of 1 nC and an energy of 2 MeV. This paper presents the measurement of the bunch length which is done 1.8 m downstream of the gun exit.
RF front-end design and simulation for Sub-picosecond bunch length measurement
Duan, Liwu; Leng, Yongbin
2015-01-01
Cavity Beam Length Monitor is beam length measurement detector metering ultra short bunch. We designed a RF front-end and make simulations to testify this has high signal-to-noise ratio ensuring beam length measurement precision.
Direct calculation of correlation length based on quasi-cumulant method
NASA Astrophysics Data System (ADS)
Fukushima, Noboru
2014-03-01
We formulate a method of directly obtaining a correlation length without full calculation of correlation functions, as a high-temperature series. The method is based on the quasi-cumulant method, which was formulated by the author in J. Stat. Phys. 111, 1049-1090 (2003) as a complementary method for the high-temperature series expansion originally for an SU(n) Heisenberg model, but is applicable to general spin models according to our recent reformulation. A correlation function divided by its lowest-order nonzero contribution has properties very similar to a generating function of some kind of moments, which we call quasi-moments. Their corresponding quasi-cumulants can be also derived, whose generating function is related to the correlation length. In addition, applications to other numerical methods such as the quantum Monte Carlo method are also discussed. JSPS KAKENHI Grant Number 25914008.
Measurement of Micrometer Diffusion Lengths by Nuclear Spectrometry
Strokan, N.B.; Ivanov, A.M.; Lebedev, A.A. [Ioffe Physicotechnical Institute, Russian Academy of Sciences, St. Petersburg, 194021 (Russian Federation); Syvaejaervi, M.; Yakimova, R. [Linkoeping University, S-581 83 Linkoeping (Sweden)
2005-12-15
A method for determination of diffusion lengths in the range 0.5-50 {mu}m, which corresponds to carrier lifetimes in the nanosecond range, is suggested A calibrated nonequilibrium charge is injected into the base of the reverse-biased diode structure. The injection is provided by alpha particles generated by natural decay in the single-particle counting mode. The nuclear spectrometry technique is used to measure the amount of charge that diffused across the base to the boundary of the electric-field region. The loss of charge during the diffusion is calculated as a function of the depth of alpha particle penetration beyond the electric-field region. The derived power-law functions make it possible to relate the diffusion length with the exponent and numerical factor that describes the loss of charge. The experiment is performed with lightly doped 4H-SiC epitaxial films.
THE MANHATTAN CURVE AND THE CORRELATION OF LENGTH SPECTRA ON HYPERBOLIC SURFACES
Sharp, Richard
THE MANHATTAN CURVE AND THE CORRELATION OF LENGTH SPECTRA ON HYPERBOLIC SURFACES Richard Sharp) is the Manhattan curve associated to (1, 2), defined in [3]. We now recall the definition of C(1, 2 1 and 2 are conjugate in PSL(2, R). We shall now state our main result. Theorem 1. The Manhattan
Dennis Raahave; Elsebeth Christensen; Franck B. Loud; Lisbet L. Knudsen
Introduction: Abdominal pain, bloating, and defecation disturbances are common complaints in gastrointestinal functional disorders. This study ex- plores whether bowel symptoms are correlated to colon transit time (CTT), faecal loading (coprostasis), and colon length; and whether prokinetic inter- vention can reduce CTT, faecal retention, and symptoms. Methods: This observational and interventional study includes 281 patients, and 44 asymptomatic controls. Evaluations
An inverse correlation between loop length and stability in a four-helix-bundle protein
Mochrie, Simon
An inverse correlation between loop length and stability in a four-helix-bundle protein Athena D Nagi and Lynne Regan Background: The loops in proteins are less well characterized than the secondary structural elements that they connect. We have used the four-helix- bundle protein Rop as a model system
Correlation length exponent of the 2-d Z(4) model using an exact method
NASA Astrophysics Data System (ADS)
William, Peter
1990-05-01
Using a recently suggested exact method to determine the partition function of a discrete model, the correlation length exponent v for the two-dimensional Z(4) spin model is estimated. This estimation is made from a study of the zeros of the partition function on finite lattices.
Humphries, T D; Sheppard, D A; Buckley, C E
2015-06-30
For homoleptic 18-electron complex hydrides, an inverse linear correlation has been established between the T-deuterium bond length (T = Fe, Co, Ni) and the average electronegativity of the metal countercations. This relationship can be further employed towards aiding structural solutions and predicting physical properties of novel complex transition metal hydrides. PMID:26077621
New measure of electron correlation
Alex D. Gottlieb; Norbert J. Mauser
2005-09-15
We propose to quantify the "correlation" inherent in a many-electron (or many-fermion) wavefunction by comparing it to the unique uncorrelated state that has the same single-particle density operator as it does.
Hot-electron scattering length by measurement of spin polarization
D. T. Pierce; H. C. Siegmann
1974-01-01
A new method of determining the hot-electron scattering length l is provided by the measurement of the spin of photoemitted electrons from a thin film on a substrate of dissimilar electron-spin polarization (ESP). Results have been obtained for Ni, l=10.8+2.5-1.7 Å for electrons 5.4 +\\/- 0.3 eV above EF, and for Cu, l=10.0+2.6-1.7 Å for electrons 5.2 +\\/- 0.5 eV
Leg length and offset measures with a pinless femoral reference array during THA.
Renkawitz, Tobias; Schuster, Tibor; Grifka, Joachim; Kalteis, Thomas; Sendtner, Ernst
2010-07-01
The bony fixation of reference marker arrays used for computer-assisted navigation during total hip arthroplasty (THA) theoretically involves the risk of fracture, infection, and/or pin loosening. We asked whether intraoperative assessment of leg length (LL) and offset (OS) changes would be accurate using a novel pinless femoral reference system in conjunction with an imageless measurement algorithm based on specific realignment of the relationship between a dynamic femoral and pelvis reference array. LL/OS measurements were recorded during THA in 17 cadaver specimen hips. Preoperatively and postoperatively, specimens were scanned using CT. Linear radiographic LL/OS changes were determined by two investigators using visible fiducial landmarks and image processing software. We found a high correlation of repeated measurements within and between (both 0.95 or greater) the two examiners who did the CT assessments. Pinless LL/OS values showed mean differences less than 1 mm and correlations when compared with CT measurements. PMID:19768517
Postulates for measures of genuine multipartite correlations
Bennett, Charles H. [IBM T. J. Watson Research Center, Yorktown Heights, New York 10598 (United States); Grudka, Andrzej [Institute of Theoretical Physics and Astrophysics, University of Gdansk, PL-80-952 Gdansk (Poland); Faculty of Physics, Adam Mickiewicz University, PL-61-614 Poznan (Poland); Horodecki, Michal; Horodecki, Ryszard [Institute of Theoretical Physics and Astrophysics, University of Gdansk, PL-80-952 Gdansk (Poland); Horodecki, Pawel [Faculty of Applied Physics and Mathematics, Technical University of Gdansk, PL-80-952 Gdansk (Poland)
2011-01-15
A lot of research has been done on multipartite correlations, but the problem of satisfactorily defining genuine multipartite correlations--those not trivially reducible to lower partite correlations--remains unsolved. In this paper we propose three reasonable postulates which each measure or indicator of genuine multipartite correlations (or genuine multipartite entanglement) should satisfy. We also introduce the concept of degree of correlations, which gives partial characterization of multipartite correlations. Then, we show that covariance does not satisfy two postulates and hence it cannot be used as an indicator of genuine multipartite correlations. Finally, we propose a candidate for a measure of genuine multipartite correlations based on the work that can be drawn from a local heat bath by means of a multipartite state.
Local correlation measures and atomic shell structure
NASA Astrophysics Data System (ADS)
Sagar, Robin P.; Guevara, Nicolais L.
2007-04-01
The correlation coefficient and mutual information, used to measure the interdependence between two variables, are generalized to the local level and employed to examine the radial distribution of electron correlation. We compare the behavior of the two local measures with regard to their emphasis on core and valence correlation and show that while there are differences, both are able to correctly reproduce the shell structure in atomic systems.
Measurements of the Influence of Integral Length Scale on Stagnation Region Heat Transfer
NASA Technical Reports Server (NTRS)
Vanfossen, G. James; Ching, Chang Y.
1994-01-01
The purpose was twofold: first, to determine if a length scale existed that would cause the greatest augmentation in stagnation region heat transfer for a given turbulence intensity and second, to develop a prediction tool for stagnation heat transfer in the presence of free stream turbulence. Toward this end, a model with a circular leading edge was fabricated with heat transfer gages in the stagnation region. The model was qualified in a low turbulence wind tunnel by comparing measurements with Frossling's solution for stagnation region heat transfer in a laminar free stream. Five turbulence generating grids were fabricated; four were square mesh, biplane grids made from square bars. Each had identical mesh to bar width ratio but different bar widths. The fifth grid was an array of fine parallel wires that were perpendicular to the axis of the cylindrical leading edge. Turbulence intensity and integral length scale were measured as a function of distance from the grids. Stagnation region heat transfer was measured at various distances downstream of each grid. Data were taken at cylinder Reynolds numbers ranging from 42,000 to 193,000. Turbulence intensities were in the range 1.1 to 15.9 percent while the ratio of integral length scale to cylinder diameter ranged from 0.05 to 0.30. Stagnation region heat transfer augmentation increased with decreasing length scale. An optimum scale was not found. A correlation was developed that fit heat transfer data for the square bar grids to within +4 percent. The data from the array of wires were not predicted by the correlation; augmentation was higher for this case indicating that the degree of isotropy in the turbulent flow field has a large effect on stagnation heat transfer. The data of other researchers are also compared with the correlation.
NASA Astrophysics Data System (ADS)
Mann, Nishan; Patterson, Mark; Hughes, Stephen
2015-06-01
Intrinsic disorder in photonic crystal waveguides occurs via rapid fluctuations of the air-dielectric interface and is typically characterized by a quadratic mean surface roughness and a surface correlation length. We theoretically study the impact of correlation length on extrinsic scattering losses and discuss the numerical implementation for several different waveguide designs. The role of correlation length is found to be strongly influenced by the underlying Bloch modes which are dependent on waveguide design and frequency, and can thus be partly controlled via spatial-dispersion engineering. For most frequencies and waveguide designs, we find an asymptotical increase in losses as the correlation length increases; however, we show that for some frequencies and designs, a maximum scattering loss is achieved for a finite correlation length. Our results also demonstrate the importance of choosing an appropriate correlation function for modeling quickly varying disorder.
Wolkowitz, Owen M.; Mellon, Synthia H.; Epel, Elissa S.; Lin, Jue; Dhabhar, Firdaus S.; Su, Yali; Reus, Victor I.; Rosser, Rebecca; Burke, Heather M.; Kupferman, Eve; Compagnone, Mariana; Nelson, J. Craig; Blackburn, Elizabeth H.
2011-01-01
Background Depression is associated with an unusually high rate of aging-related illnesses and early mortality. One aspect of “accelerated aging” in depression may be shortened leukocyte telomeres. When telomeres critically shorten, as often occurs with repeated mitoses or in response to oxidation and inflammation, cells may die. Indeed, leukocyte telomere shortening predicts early mortality and medical illnesses in non-depressed populations. We sought to determine if leukocyte telomeres are shortened in Major Depressive Disorder (MDD), whether this is a function of lifetime depression exposure and whether this is related to putative mediators, oxidation and inflammation. Methodology Leukocyte telomere length was compared between 18 unmedicated MDD subjects and 17 controls and was correlated with lifetime depression chronicity and peripheral markers of oxidation (F2-isoprostane/Vitamin C ratio) and inflammation (IL-6). Analyses were controlled for age and sex. Principal Findings The depressed group, as a whole, did not differ from the controls in telomere length. However, telomere length was significantly inversely correlated with lifetime depression exposure, even after controlling for age (p<0.05). Average telomere length in the depressed subjects who were above the median of lifetime depression exposure (?9.2 years' cumulative duration) was 281 base pairs shorter than that in controls (p<0.05), corresponding to approximately seven years of “accelerated cell aging.” Telomere length was inversely correlated with oxidative stress in the depressed subjects (p<0.01) and in the controls (p<0.05) and with inflammation in the depressed subjects (p<0.05). Conclusions These preliminary data indicate that accelerated aging at the level of leukocyte telomeres is proportional to lifetime exposure to MDD. This might be related to cumulative exposure to oxidative stress and inflammation in MDD. This suggest that telomere shortening does not antedate depression and is not an intrinsic feature. Rather, telomere shortening may progress in proportion to lifetime depression exposure. PMID:21448457
First ?K atom lifetime and ?K scattering length measurements
NASA Astrophysics Data System (ADS)
Adeva, B.; Afanasyev, L.; Allkofer, Y.; Amsler, C.; Anania, A.; Aogaki, S.; Benelli, A.; Brekhovskikh, V.; Cechak, T.; Chiba, M.; Chliapnikov, P.; Ciocarlan, C.; Constantinescu, S.; Doskarova, P.; Drijard, D.; Dudarev, A.; Duma, M.; Dumitriu, D.; Fluerasu, D.; Gorin, A.; Gorchakov, O.; Gritsay, K.; Guaraldo, C.; Gugiu, M.; Hansroul, M.; Hons, Z.; Horikawa, S.; Iwashita, Y.; Karpukhin, V.; Kluson, J.; Kobayashi, M.; Kruglov, V.; Kruglova, L.; Kulikov, A.; Kulish, E.; Kuptsov, A.; Lamberto, A.; Lanaro, A.; Lednicky, R.; Mariñas, C.; Martincik, J.; Nemenov, L.; Nikitin, M.; Okada, K.; Olchevskii, V.; Pentia, M.; Penzo, A.; Plo, M.; Ponta, T.; Prusa, P.; Rappazzo, G.; Romero Vidal, A.; Ryazantsev, A.; Rykalin, V.; Saborido, J.; Schacher, J.; Sidorov, A.; Smolik, J.; Sugimoto, S.; Takeutchi, F.; Tauscher, L.; Trojek, T.; Trusov, S.; Urban, T.; Vrba, T.; Yazkov, V.; Yoshimura, Y.; Zhabitsky, M.; Zrelov, P.
2014-07-01
The results of a search for hydrogen-like atoms consisting of ??K± mesons are presented. Evidence for ?K atom production by 24 GeV/c protons from CERN PS interacting with a nickel target has been seen in terms of characteristic ?K pairs from their breakup in the same target (178 ± 49) as well as in terms of produced ?K atoms (653 ± 42). Using these results, the analysis yields a first value for the ?K atom lifetime of ? = (2.5-1.8+3.0) fs and a first measurement of the S-wave isospin-odd ?K scattering length | a0- | =1/3 |a1/2 -a3/2 | = (0.11-0.04+0.09) M?-1 (aI for isospin I).
Aulinas, Anna; Ramírez, María-José; Barahona, María-José; Valassi, Elena; Resmini, Eugenia; Mato, Eugènia; Santos, Alicia; Crespo, Iris; Bell, Olga; Surrallés, Jordi; Webb, Susan M.
2015-01-01
Introduction Cushing’s syndrome (CS) increases cardiovascular risk (CVR) and adipocytokine imbalance, associated with an increased inflammatory state. Telomere length (TL) shortening is a novel CVR marker, associated with inflammation biomarkers. We hypothesized that inflammatory state and higher CVR in CS might be related to TL shortening, as observed in premature aging. Aim To evaluate relationships between TL, CVR and inflammation markers in CS. Methods In a cross-sectional study, 77 patients with CS (14 males, 59 pituitary-, 17 adrenal- and 1 ectopic-origin; 21 active disease) and 77 age-, gender-, smoking-matched controls were included. Total white blood cell TL was measured by TRF-Southern technique. Clinical data and blood samples were collected (lipids, adrenal function, glucose). Adiponectin, interleukin-6 (IL6) and C-reactive protein (CRP) were available in a subgroup of patients (n=32). Correlations between TL and clinical features were examined and multiple linear regression analysis was performed to investigate potential predictors of TL. Results Dyslipidemic CS had shorter TL than non-dyslipidemic subjects (7328±1274 vs 7957±1137 bp, p<0.05). After adjustment for age and body mass index, cured and active CS dyslipidemic patients had shorter TL than non-dyslipidemic CS (cured: 7187±1309 vs 7868±1104; active: 7203±1262 vs 8615±1056, respectively, p<0.05). Total cholesterol and triglycerides negatively correlated with TL (r-0.279 and -0.259, respectively, p<0.05), as well as CRP and IL6 (r-0.412 and -0.441, respectively, p<0.05). No difference in TL according the presence of other individual CVR factors (hypertension, diabetes mellitus, obesity) were observed in CS or in the control group. Additional TL shortening was observed in dyslipidemic obese patients who were also hypertensive, compared to those with two or less CVR factors (6956±1280 vs 7860±1180, respectively, p<0.001). Age and dyslipidemia were independent negative predictors of TL. Conclusion TL is shortened in dyslipidemic CS patients, further worse if hypertension and/or obesity coexist and is negatively correlated with increased inflammation markers. Increased lipids and a “low” grade inflammation may contribute to TL shortening and consequently to premature ageing and increased morbidity in CS. PMID:25799396
Correlation measurements with on-off detectors
NASA Astrophysics Data System (ADS)
Sperling, J.; Vogel, W.; Agarwal, G. S.
2013-10-01
We present a general method to detect nonclassical radiation fields with systems of on-off detectors. We especially study higher order correlations for the identification of nonclassical radiation. This allows us to directly characterize quantum correlations by the statistics measured with systems of on-off detectors. Additionally, we generalize our method to multiple detector systems for measurements of correlations between light fields. We also consider multimode radiation fields and isolate nonclassicality in terms of the space time correlations. Finally, we present results for the quantum statistics using on-off detectors operating in nonlinear detection modes.
Representative Elementary Length to Measure Soil Mass Attenuation Coefficient
Borges, J. A. R.; Pires, L. F.; Costa, J. C.
2014-01-01
With increasing demand for better yield in agricultural areas, soil physical property representative measurements are more and more essential. Nuclear techniques such as computerized tomography (CT) and gamma-ray attenuation (GAT) have been widely employed with this purpose. The soil mass attenuation coefficient (?s) is an important parameter for CT and GAT analysis. When experimentally determined (?es), the use of suitable sized samples enable to evaluate it precisely, as well as to reduce measurement time and costs. This study investigated the representative elementary length (REL) of sandy and clayey soils for ?es measurements. Two radioactive sources were employed (241Am and 137Cs), three collimators (2–4?mm diameters), and 14 thickness (x) samples (2–15?cm). Results indicated ideal thickness intervals of 12–15 and 2–4?cm for the sources 137Cs and 241Am, respectively. The application of such results in representative elementary area (REA) evaluations in clayey soil clods via CT indicated that ?es average values obtained for x?>?4?cm and source 241Am might induce to the use of samples which are not large enough for soil bulk density evaluations (?s). As a consequence, ?s might be under- or overestimated, generating inaccurate conclusions about the physical quality of the soil under study. PMID:24672338
Representative elementary length to measure soil mass attenuation coefficient.
Borges, J A R; Pires, L F; Costa, J C
2014-01-01
With increasing demand for better yield in agricultural areas, soil physical property representative measurements are more and more essential. Nuclear techniques such as computerized tomography (CT) and gamma-ray attenuation (GAT) have been widely employed with this purpose. The soil mass attenuation coefficient (?(s)) is an important parameter for CT and GAT analysis. When experimentally determined (?(es)), the use of suitable sized samples enable to evaluate it precisely, as well as to reduce measurement time and costs. This study investigated the representative elementary length (REL) of sandy and clayey soils for ?(es) measurements. Two radioactive sources were employed ((241)Am and (137)Cs), three collimators (2-4 mm diameters), and 14 thickness (x) samples (2-15 cm). Results indicated ideal thickness intervals of 12-15 and 2-4 cm for the sources (137)Cs and (241)Am, respectively. The application of such results in representative elementary area (REA) evaluations in clayey soil clods via CT indicated that ?(es) average values obtained for x > 4 cm and source (241)Am might induce to the use of samples which are not large enough for soil bulk density evaluations (?(s)). As a consequence, ?(s) might be under- or overestimated, generating inaccurate conclusions about the physical quality of the soil under study. PMID:24672338
Extraction of the spin glass correlation length, and finite size effects
NASA Astrophysics Data System (ADS)
Wood, G. G.
2000-03-01
The correlation length for spin glasses at waiting time tw and temperature T, ?(t_w,T), has been extracted from measurements of the thermoremanent magnetization, M_TRM(t,t_w), and the position of the peak of its derivative, S(t)=dgl[-M_TRM(t,t_w)\\over Hgr]/dl n t.(Y.G. Joh, R. Orbach, G.G. Wood, J. Hammann, and E. Vincent, Phys. Rev. Lett. 82), 438 (1999). A universal form is found for both insulating and metallic spin glasses, ?(t_w,T)=(t_w/?_0)^? T/T_g, 0.15length scale containing ?(t_w,T) will exhibit properties associated with finite size. For those particles r
Measurement of the Length of an Optical Trap
NASA Technical Reports Server (NTRS)
Wrbanek, Susan Y.
2010-01-01
NASA Glenn has been involved in developing optical trapping and optical micromanipulation techniques in order to develop a tool that can be used to probe, characterize, and assemble nano and microscale materials to create microscale sensors for harsh flight environments. In order to be able to assemble a sensor or probe candidate sensor material, it is useful to know how far an optical trap can reach; that is, the distance beyond/below the stable trapping point through which an object will be drawn into the optical trap. Typically, to measure the distance over which an optical trap would influence matter in a horizontal (perpendicular to beam propagation) direction, it was common to hold an object in one optical trap, place a second optical trap a known distance away, turn off the first optical trap, and note if the object was moved into the second trap when it was turned on. The disadvantage of this technique is that it only gives information of trap influence distance in horizontal (x y) directions. No information about the distance of the influence of the trap is gained in the direction of propagation of the beam (the z direction). A method was developed to use a time-of-flight technique to determine the length along the propagation direction of an optical trap beam over which an object may be drawn into the optical trap. Test objects (polystyrene microspheres) were held in an optical trap in a water-filled sample chamber and raised to a pre-determined position near the top of the sample chamber. Next, the test objects were released by blocking the optical trap beam. The test objects were allowed to fall through the water for predetermined periods of time, at the end of which the trapping beam was unblocked. It was noted whether or not the test object returned to the optical trap or continued to fall. This determination of the length of an optical trap's influence by this manner assumes that the test object falls through the water in the sample chamber at terminal velocity for the duration of its fall, so that the distance of trap influence can be computed simply by: d = VTt, where d is the trap length (or distance of trap reach), VT is the terminal velocity of the test object, and t is the time interval over which the object is allowed to fall.
Length measurement of a moving rod by a single observer without assumptions concerning its magnitude
Bernhard Rothenstein; Ioan Damian
2005-07-03
We extend the results presented by Weinstein concerning the measurement of the length of a moving rod by a single observer, without making assumptions concerning the distance between the moving rod and the observer who measures its length.
Isometric Instructions: Measure the length from your elbow to your hand where you grip the handle.
Sniadecki, Nathan J.
Isometric Instructions: Part 1: Measure the length from your elbow to your hand where you grip the handle. You will also need to measure the length from your shoulder to your elbow. Part 2: 1. Sit at edge
On correlation measurements of electron Bernstein wave emission
NASA Astrophysics Data System (ADS)
Popov, A.; Irzak, M.
2014-02-01
A systematic study of the electron Bernstein wave (EBW) emission from either overdense plasmas or plasmas with moderate electron temperatures is presented. Starting from description of the bare electrons microscopic thermal radiation we finally arrive at the macroscopic expression for the radiation temperature. The latter is shown to be a sum of the electron temperature and a fluctuating piece caused by the fluctuations of both the EBW emission source and the EBW damping rate within the ECR layer. It is shown that the correlation measurements of the EBW emission at two separate frequencies reveal information on the correlation length of the low frequency turbulence.
Tuvdendorj, Demidmaa; Chinkes, David L.; Zhang, Xiao-Jun; Aarsland, Asle; Herndon, David N.
2014-01-01
Autografting of burn wounds results in generation of donor site wounds. Here we measured donor site wound protein Fractional Synthesis Rate (FSR) in a burn pediatric population and showed that FSR increases over time postsurgery and correlates with the length of hospital stay (LOS) normalized for total body surface area (TBSA) burn size. 3.9±1.1 days after the grafting surgery patients participated in a metabolic study consisting of continuous infusion of L-[ring-2H5]-phenylalanine and donor site wound punch biopsies. Donor site wound protein FSR was 10.4±7.5 %/day. Wound FSR demonstrated linear correlation with the time postsurgery (p < 0.05). Multiple regression analysis showed that LOS/TBSA correlated with donor site wound protein FSR and time postsurgery (p < 0.001) and the following equation describes the relationship: Estimated LOS/TBSA = (FSR - 12.95 – 1.414 × Postsurgery day)/(?17.8). This equation predicted that FSR corrected for the postsurgery day when the metabolic study was conducted accounted for 67 % of the variability (r2 = 0.673) in the LOS/TBSA. Donor site wound protein FSR correlated to LOS/TBSA of burn patients admitted to the intensive care unit. Measurement of protein deposition in regenerating donor site wound using stable isotope technique provides a quantitative measure of wound healing. PMID:20412556
Correlation measurements of tokamak edge plasma fluctuations
Zacek, F.; Kryska, L.; Stoeckel, J. [Institute of Plasma Physics, Prague (Czech Republic)
1992-02-01
A three-channel analog correlator for monitoring edge plasma electrostatic fluctuations is described. The correlator was used for measurement of the turbulent radial particle flux in the OH and combined OH/LHCD regimes on the Castor tokamak. 11 refs., 3 figs.
Measurements of Energy-Energy-Correlations
Erdmann, Martin
5.1 Definition of Energy-Energy-Correlations . . . . . . . . . . . . . . . . . . . 39 5Measurements of Energy-Energy-Correlations of Ultra-High-Energy Cosmic Rays with the Pierre Auger A RWTH Aachen RWTH Aachen #12;#12;Contents 1 Introduction 1 2 Physics of Ultra-High-Energy Cosmic Rays 3
Antonello Lorenzini; F. Brad Johnson; Anthony Oliver; Maria Tresini; Jasmine S. Smith; Mona Hdeib; Christian Sell; Vincent J. Cristofalo; Thomas D. Stamato
2009-01-01
The identification of the cellular mechanisms responsible for the wide differences in species lifespan remains one of the major unsolved problems of the biology of aging. We measured the capacity of nuclear protein to recognize DNA double strand breaks (DSBs) and telomere length of skin fibroblasts derived from mammalian species that exhibit wide differences in longevity. Our results indicate DNA
Comeron, J M; Kreitman, M; Aguadé, M
1999-01-01
Evolutionary analysis of codon bias in Drosophila indicates that synonymous mutations are not neutral, but rather are subject to weak selection at the translation level. Here we show that the effectiveness of natural selection on synonymous sites is strongly correlated with the rate of recombination, in accord with the nearly neutral hypothesis. This correlation, however, is apparent only in genes encoding short proteins. Long coding regions have both a lower codon bias and higher synonymous substitution rates, suggesting that they are affected less efficiently by selection. Therefore, both the length of the coding region and the recombination rate modulate codon bias. In addition, the data indicate that selection coefficients for synonymous mutations must vary by a minimum of one or two orders of magnitude. Two hypotheses are proposed to explain the relationship among the coding region length, the codon bias, and the synonymous divergence and polymorphism levels across the range of recombination rates in Drosophila. The first hypothesis is that selection coefficients on synonymous mutations are inversely related to the total length of the coding region. The second hypothesis proposes that interference among synonymous mutations reduces the efficacy of selection on these mutations. We investigated this second hypothesis by carrying out forward simulations of weakly selected mutations in model populations. These simulations show that even with realistic recombination rates, this interference, which we call the "small-scale" Hill-Robertson effect, can have a moderately strong influence on codon bias. PMID:9872963
NASA Astrophysics Data System (ADS)
Estienne, B.; Regnault, N.; Bernevig, B. A.
2015-05-01
Using the newly developed matrix product state formalism for non-Abelian fractional quantum Hall (FQH) states, we address the question of whether a FQH trial wave function written as a correlation function in a nonunitary conformal field theory (CFT) can describe the bulk of a gapped FQH phase. We show that the nonunitary Gaffnian state exhibits clear signatures of a pathological behavior. As a benchmark we compute the correlation length of a Moore-Read state and find it to be finite in the thermodynamic limit. By contrast, the Gaffnian state has an infinite correlation length in (at least) the non-Abelian sector, and is therefore gapless. We also compute the topological entanglement entropy of several non-Abelian states with and without quasiholes. For the first time in the FQH effect the results are in excellent agreement in all topological sectors with the CFT prediction for unitary states. For the nonunitary Gaffnian state in finite size systems, the topological entanglement entropy seems to behave like that of the composite fermion Jain state at equal filling.
Estienne, B; Regnault, N; Bernevig, B A
2015-05-01
Using the newly developed matrix product state formalism for non-Abelian fractional quantum Hall (FQH) states, we address the question of whether a FQH trial wave function written as a correlation function in a nonunitary conformal field theory (CFT) can describe the bulk of a gapped FQH phase. We show that the nonunitary Gaffnian state exhibits clear signatures of a pathological behavior. As a benchmark we compute the correlation length of a Moore-Read state and find it to be finite in the thermodynamic limit. By contrast, the Gaffnian state has an infinite correlation length in (at least) the non-Abelian sector, and is therefore gapless. We also compute the topological entanglement entropy of several non-Abelian states with and without quasiholes. For the first time in the FQH effect the results are in excellent agreement in all topological sectors with the CFT prediction for unitary states. For the nonunitary Gaffnian state in finite size systems, the topological entanglement entropy seems to behave like that of the composite fermion Jain state at equal filling. PMID:26001015
Measures of dispersion as constraints for length-frequency analysis
Length-frequency analysis (LFA) methods are widely used in popu- lation dynamics studies, particu- larly growth rings on hard parts. LFA is characteristically subjective, and numerous authors have warned peaks. Only data sets that were not based on LFA, composite samples, orback-calculated lengths at age
Absolute Quantum Efficiency Measurements Using Correlated Photons: Toward a Measurement
Alan L. Migdall
2001-01-01
Abstract—Correlated photons can be used to measure the quantum,efficiency of photon counting photodetectors without ties to any externally calibrated standards. We present a study of measurement,systematics aimed at reducing the measurement uncertainties to the 0.1% level, and developing a robust measure- ment protocol. Index Terms—Photodetectors, quantum efficiency, radiometry.
Computer Anxiety: Definition, Measurement, and Correlates.
ERIC Educational Resources Information Center
Cambre, Marjorie A.; Cook, Desmond L.
1985-01-01
Review of general anxiety and its measurement provides a framework for considering computer anxiety. Test and math anxiety are discussed as specific anxieties with potential similarities. Five studies are identified and discussed for their contributions to an understanding of the definition, measurement practices, and correlates of computer…
Single-arm three-wave interferometer for measuring dispersion of short lengths of fiber
Qian, Li
Single-arm three-wave interferometer for measuring dispersion of short lengths of fiber Michael A interferometer to measure directly the second-order dispersion parameter of short lengths of fiber ( on system parameters, such as required bandwidth, wavelength resolution, and fiber length, are discussed
Vlastimil Kunc; Barbara Frame; Ba Nghiep Nguyen; Charles L. Tucker; Gregorio Velez-Garcia
Procedures for fiber length distribution (FLD) measurement of long fiber reinforced injection molded thermoplastics were refined for glass and carbon fibers. Techniques for sample selection, fiber separation, digitization and length measurement for both fiber types are described in detail. Quantitative FLD results are provided for glass and carbon reinforced polypropylene samples molded with a nominal original fiber length of 12.7
Suetterlin, Daniel [PUBLICA Swiss Federal Pension Fund, CH-3000 Berne (Switzerland); Paul Scherrer Institute, CH-5232 Villigen (Switzerland); Erni, Daniel [General and Theoretical Electrical Engineering (ATE), Faculty of Engineering, University of Duisburg-Essen, D-47048 Duisburg (Germany); Schlott, Volker [Department of Large Research Facilities, Paul Scherrer Institute, CH- 5232 Villigen (Switzerland); Sigg, Hans [Laboratory for Micro- and Nanotechnology, Paul Scherrer Institute, CH- 5232 Villigen (Switzerland); Jaeckel, Heinz [Department of Information Technology and Electrical Engineering, Electronics Laboratory, ETHZ, CH-8092 Zurich (Switzerland); Murk, Axel [Department of Microwave Physics, Institute of Applied Physics, University of Berne, CH-3012 Berne (Switzerland)
2010-10-15
A spatial, electro-optical autocorrelation (EOA) interferometer using the vertically polarized lobes of coherent transition radiation (CTR) has been developed as a single-shot electron bunch length monitor at an optical beam port downstream the 100 MeV preinjector LINAC of the Swiss Light Source. This EOA monitor combines the advantages of step-scan interferometers (high temporal resolution) [D. Mihalcea et al., Phys. Rev. ST Accel. Beams 9, 082801 (2006) and T. Takahashi and K. Takami, Infrared Phys. Technol. 51, 363 (2008)] and terahertz-gating technologies [U. Schmidhammer et al., Appl. Phys. B: Lasers Opt. 94, 95 (2009) and B. Steffen et al., Phys. Rev. ST Accel. Beams 12, 032802 (2009)] (fast response), providing the possibility to tune the accelerator with an online bunch length diagnostics. While a proof of principle of the spatial interferometer was achieved by step-scan measurements with far-infrared detectors, the single-shot capability of the monitor has been demonstrated by electro-optical correlation of the spatial CTR interference pattern with fairly long (500 ps) neodymium-doped yttrium aluminum garnet (Nd:YAG) laser pulses in a ZnTe crystal. In single-shot operation, variations of the bunch length between 1.5 and 4 ps due to different phase settings of the LINAC bunching cavities have been measured with subpicosecond time resolution.
P. W. Reimus; Paul W
2010-01-01
A process-oriented modeling approach is implemented to examine the importance of parameter variances, correlation lengths, and especially cross-correlations in contaminant transport predictions over large scales. It is shown that the most important consideration is the correlation between flow rates and retardation processes (e.g., sorption, matrix diffusion) in the system. If flow rates are negatively correlated with retardation factors in systems
Bánszegi, Oxána; Kosztolányi, András; Bakonyi, Gábor; Szabó, Borbála; Dombos, Miklós
2014-01-01
The collembolan, Folsomia candida, is widely used in soil ecotoxicology. In recent years, growth rate of collembolans has become as frequently used endpoint as reproduction rate in ecotoxicological studies. However, measuring collembolan body sizes to estimate growth rate is a complicated and time-consuming task. Here we present a new image analysis method, which facilitates and accelerates the body length measurement of the collembolan Folsomia candida. The new software package, called CollScope, consists of three elements: 1) an imaging device; 2) photographing software; 3) an ImageJ macro for image processing, measurement and data analysis. We give a complete description of the operation of the software, the image analyzing process and describe its accuracy and reliability. The software with a detailed usage manual is attached as Supplementary Material. We report a case study to demonstrate that the automated measurement of collembolan body sizes is highly correlated with the traditional manual measurements (estimated measuring accuracy 0.05 mm). Furthermore, we performed a dose-response ecotoxicity test using cadmium-sulfate by using CollScope as well as classical methods for size measurement. Size data measured by CollScope or manually did not differ significantly. Furthermore the new software package decreased time consumption of the measurements to 42% when tested on 35 animals. Consequently, methodological investigations performed in this study should be regarded as a recommendation for any other routine dose-response study where body growth is an endpoint. PMID:24901322
Bánszegi, Oxána; Kosztolányi, András; Bakonyi, Gábor; Szabó, Borbála; Dombos, Miklós
2014-01-01
The collembolan, Folsomia candida, is widely used in soil ecotoxicology. In recent years, growth rate of collembolans has become as frequently used endpoint as reproduction rate in ecotoxicological studies. However, measuring collembolan body sizes to estimate growth rate is a complicated and time-consuming task. Here we present a new image analysis method, which facilitates and accelerates the body length measurement of the collembolan Folsomia candida. The new software package, called CollScope, consists of three elements: 1) an imaging device; 2) photographing software; 3) an ImageJ macro for image processing, measurement and data analysis. We give a complete description of the operation of the software, the image analyzing process and describe its accuracy and reliability. The software with a detailed usage manual is attached as Supplementary Material. We report a case study to demonstrate that the automated measurement of collembolan body sizes is highly correlated with the traditional manual measurements (estimated measuring accuracy 0.05 mm). Furthermore, we performed a dose-response ecotoxicity test using cadmium-sulfate by using CollScope as well as classical methods for size measurement. Size data measured by CollScope or manually did not differ significantly. Furthermore the new software package decreased time consumption of the measurements to 42% when tested on 35 animals. Consequently, methodological investigations performed in this study should be regarded as a recommendation for any other routine dose-response study where body growth is an endpoint. PMID:24901322
Hu, Y H; Poivey, J P; Rouvier, R; Wang, C T; Tai, C
1999-12-01
1. Heritabilities and genetic correlations in the base population of a closed strain of Muscovy duck, moderately selected for body weight at 10 weeks of age, have been estimated from the data of 9 successive generations for the following traits: male and female body weight at 10 and 18 weeks of age (BW10m, BW18m, BW10f, BW18f) and length of the 8th primary feather at 10 weeks of age (F110m, F110f). 2. Multivariate REML with an animal model was used, pooling data from the 9 generations (3283 and 3289 male and female offspring respectively). The same trait expressed in male and female was considered as 2 different traits. 3. The 8th primary feather was longer in females than in males by 6% to 22% at 10 weeks of age. Body weight was heavier in males than in females by 42% to 58% at 10 weeks of age and by 57% to 75% at 18 weeks of age. 3. The heritability estimates for body weight traits showed moderate values, being a little higher for females than for males at the same age, increasing with age from h2=0.24 at BW10m to h2=0.43 at BW18f. 4. The heritability estimates for feather length showed that a greater response would be obtained in selection for male feather length (h2=0.37) than for female length (h2=0.14). Both have high genetic correlations with body weight so they could be indirectly improved. 5. Heritabilities of the difference in body weights between males and females at 10 weeks (h2=0.07) and 18 weeks of age (h2=0.10) were small, as well as for feather length (h2=0.10). It would probably be difficult to modify sexual dimorphism in body weight through selection. 6. Genetic correlations between BW10m, BW18m and BW10f, BW18f were respectively r(g)=0.77 and r(g)=0.80. They were larger for body weight at the same ages between males and females, r(g)=0.90 (r(g)=0.88 between F110m and F110f). Body weight in males and females at the same age should be better considered as 2 different traits in a selection programme. 7. The cumulated predicted genetic gains expressed per unity of the genetic standard deviation (sigma(g)) over the 8 generations of selection were 1.3 sigma(g) and 1.4 sigma(g) respectively for the BW10m and BW10f. The predicted correlated responses were 1.2 sigma(g) for body weights at 18 weeks of age, 0.9 sigma(g) and 0.7 sigma(g) for F110f and F110m respectively. PMID:10670671
Computer Anxiety: Definition, Measurement, and Correlates.
ERIC Educational Resources Information Center
Cambre, Marjorie A.; Cook, Desmond L.
This review examines the definition, measurement, and correlates of computer anxiety as provided in available research. The concept of computer anxiety reflects an anxiety state, rather than an anxiety trait, thus rendering it susceptible to change over time. Computer anxiety is similar in nature to math anxiety and test anxiety. Two approaches to…
Eddy correlation measurements of submarine groundwater discharge
John Crusius; Peter Berg; Dirk J. Koopmans; Laura Erban
2008-01-01
This paper presents a new, non-invasive means of quantifying groundwater discharge into marine waters using an eddy correlation approach. The method takes advantage of the fact that, in virtually all aquatic environments, the dominant mode of vertical transport near the sediment–water interface is turbulent mixing. The technique thus relies on measuring simultaneously the fluctuating vertical velocity using an acoustic Doppler
Xiaopeng Yang; Kihyo Jung
Determining internal hand link lengths accurately is necessary in hand modeling for the application of ergonomic design and evaluation in virtual environment. Misconceived or cursory estimation of hand link lengths is however not rare in literature or practice. This article describes an optimization method for deriving hand link lengths from measured surface maker data. The method employs an optimization routine
Measurement of femtosecond electron pulse length and the temporal broadening due to space charge
Cao, Jianming
Measurement of femtosecond electron pulse length and the temporal broadening due to space charge;Measurement of femtosecond electron pulse length and the temporal broadening due to space charge Xuan Wang,1 electron pulses as a function of beam intensity was measured on the femtosecond time scale
LENGTH MEASUREMENT OF HIGH BRIGHTNESS ELECTRON BEAM THANKS TO THE 3-PHASE METHOD
Boyer, Edmond
LENGTH MEASUREMENT OF HIGH BRIGHTNESS ELECTRON BEAM THANKS TO THE 3-PHASE METHOD T. Vinatier, C the length of an electron beam without dedicated diagnostics by varying the measurement conditions of its of the measurements performed at PHIL and PITZ comes from the fact that it is applied on high-brightness electron
Tomography via Correlation of Noisy Measurement Records
NASA Astrophysics Data System (ADS)
Ryan, Colm; Johnson, Blake; Gambetta, Jay; Chow, Jerry; Silva, Marcus; Dial, Oliver; Ohki, Thomas
2014-03-01
We present methods and results of shot-by-shot correlation of noisy measurements to extract entangled state and process tomography in a superconducting qubit architecture [2]. We show that averaging continuous values, rather than counting discrete thresholded values, is a valid tomographic strategy and is in fact the better choice in the low signal-to-noise regime. We show that the effort to measure N-body correlations from individual measurements scales exponentially with N, but with sufficient signal-to-noise the approach remains viable for few-body correlations. We provide a new protocol to optimally account for the transient behavior of pulsed measurements. Despite single-shot measurement fidelity that is less than perfect, we demonstrate appropriate processing to extract and verify entangled states and processes. This research was funded by the Office of the Director of National Intelligence (ODNI), Intelligence Advanced Research Projects Activity (IARPA), through the Army Research Office contract no. W911NF-10-1-0324.
Examining Measure Correlations with Incomplete Data Sets
Raykov, Tenko; Schneider, Brooke C.; Marcoulides, George A.; Lichtenberg, Peter A.
2014-01-01
A two-stage procedure for estimation and testing of observed measure correlations in the presence of missing data is discussed. The approach uses maximum likelihood for estimation and the false discovery rate concept for correlation testing. The method can be utilized in initial exploration oriented empirical studies with missing data, where it is of interest to estimate manifest variable interrelationship indexes and test hypotheses about their population values. The procedure is applicable also with violations of the underlying missing at random assumption, via inclusion of auxiliary variables. The outlined approach is illustrated with data from an aging research study. PMID:25177148
Evolution equation for geometric quantum correlation measures
NASA Astrophysics Data System (ADS)
Hu, Ming-Liang; Fan, Heng
2015-05-01
A simple relation is established for the evolution equation of quantum-information-processing protocols such as quantum teleportation, remote state preparation, Bell-inequality violation, and particularly the dynamics of geometric quantum correlation measures. This relation shows that when the system traverses the local quantum channel, various figures of merit of the quantum correlations for different protocols demonstrate a factorization decay behavior for dynamics. We identified the family of quantum states for different kinds of quantum channels under the action of which the relation holds. This relation simplifies the assessment of many quantum tasks.
NASA Technical Reports Server (NTRS)
Venkatakrishnan, P.
1987-01-01
A physical length scale in the wavefront corresponding to the parameter (r sub 0) characterizing the loss in detail in a long exposure image is identified, and the influence of the correlation scale of turbulence as r sub 0 approaches this scale is shown. Allowing for the effect of 2-point correlations in the fluctuations of the refractive index, Venkatakrishnan and Chatterjee (1987) proposed a modified law for the phase structure function. It is suggested that the departure of the phase structure function from the 5/3 power law for length scales in the wavefront approaching the correlation scale of turbulence may lead to better 'seeing' at longer wavelengths.
Kunc, Vlastimil [ORNL; Frame, Barbara J [ORNL; Nguyen, Ba N. [Pacific Northwest National Laboratory (PNNL); TuckerIII, Charles L. [University of Illinois, Urbana-Champaign; Velez-Garcia, Gregorio [Virginia Polytechnic Institute and State University
2007-01-01
Procedures for fiber length distribution (FLD) measurement of long fiber reinforced injection molded thermoplastics were refined for glass and carbon fibers. Techniques for sample selection, fiber separation, digitization and length measurement for both fiber types are described in detail. Quantitative FLD results are provided for glass and carbon reinforced polypropylene samples molded with a nominal original fiber length of 12.7 mm (1/2 in.) using equipment optimized for molding short fiber reinforced thermoplastics.
ATLAS-3 correlative measurement opportunities with UARS and surface observations
NASA Technical Reports Server (NTRS)
Harrison, Edwin F.; Denn, Fred M.; Gibson, Gary G.
1995-01-01
The third ATmospheric Laboratory for Applications and Science (ATLAS-3) mission was flown aboard the Space Shuttle launched on November 3, 1994. The mission length was approximately 10 days and 22 hours. The ATLAS-3 Earth-viewing instruments provided a large number of measurements which were nearly coincident with observations from experiments on the Upper Atmosphere Research Satellite (UARS). Based on ATLAS-3 instrument operating schedules, simulations were performed to determine when and where correlative measurements occurred between ATLAS and UARS instruments, and between ATLAS and surface observations. Results of these orbital and instrument simulations provide valuable information for scientists to compare measurements between various instruments on the two satellites and at selected surface sites.
Sonographic Cervical Length Measurement before Labor Induction in Term Nulliparous Women
George Daskalakis; Nikolaos Thomakos; Leonardos Hatziioannou; Spyros Mesogitis; Nikolaos Papantoniou; Aris Antsaklis
2006-01-01
Objective: The purpose of the study was to determine if transvaginal sonographic measurement of the cervical length is a useful method to predict successful labor induction in nulliparas. Methods: 137 women who were scheduled for medically indicated induction of labor had a transvaginal sonographic measurement of the cervical length before labor induction. Inclusion criteria were: (1) singleton pregnancy; (2) gestational
SINGLE SHOT ELECTRON-BEAM BUNCH LENGTH MEASUREMENTS , G.M.H. Knippels
Strathclyde, University of
SINGLE SHOT ELECTRON-BEAM BUNCH LENGTH MEASUREMENTS G. Berden , G.M.H. Knippels , D. Oepts, A- nostics. Of these diagnostics, electo-optic detection of the electric field of electron bunches offers a promising single- shot technique for the measurement of the bunch length and shape in the sub
BUNCH LENGTH MEASUREMENTS AT THE TESLA TEST FACILITY USING A STREAK CAMERA
BUNCH LENGTH MEASUREMENTS AT THE TESLA TEST FACILITY USING A STREAK CAMERA K. Honkavaara, Ph. Piot and convenient way to measure bunch lengths in the millimeter and submil- limeter range. At the TESLA Test Facility (TTF) a streak camera with a subpicosecond resolution is in operation. A bunch compressor is used
Disentangling Correlated Scatter In Cluster Mass Measurements
NASA Astrophysics Data System (ADS)
Noh, Yookyung; Cohn, J. D.
2012-01-01
Galaxy cluster masses are of interest for many areas of astrophysics and cosmology. Multi-wavelength observations of clusters are now underway to better constrain masses both for individual clusters and ensembles of clusters. However, many of these cluster mass measurements have been found to have correlated scatter, which can lead to measurement errors and/or bias if not accounted for. We consider mock observational mass measurements of galaxy clusters in a high resolution N-body simulation to better understand how scatters of different mass measurements are related to each other and how physical and observational properties of galaxy clusters are connected to these scatters. By observing each cluster from 96 different directions, we find the range of scatters for each observational method and use principal component analysis (PCA) to identify the combinations of mass measurements which maximize and minimize these mass scatters. We then find the correlation of these scatters with the physical cluster or environmental properties. We also consider the ensemble of clusters, and discuss outliers and what physical and observational properties might distinguish them.
Small-Angle Neutron Scattering Studies of Magnetic Correlation Lengths in Nanoparticle Assemblies
NASA Astrophysics Data System (ADS)
Majetich, Sara
2009-03-01
Small-angle neutron scattering (SANS) measurements of ordered arrays of surfactant-coated magnetic nanoparticle reveal characteristic length scales associated with interparticle and intraparticle magnetic ordering. The high degree of uniformity in the monodisperse nanoparticle size and spacing leads to a pronounced diffraction peak and allows for a straightforward determination of these length scales [1]. There are notable differences in these length scales depending on the particle moment, which depends on the material (Fe, Co, Fe3O4) and diameter, and also on whether the metal particle core is surrounded by an oxide shell. For 8.5 nm particles containing an Fe core and thick Fe3O4 shell, evidence of a spin flop phase is seen in the magnetite shell when a field is applied , but not when the shell thickness is ˜0.5 nm [2]. 8.0 nm particles with an e-Co core and 0.75 nm CoO shell show no exchange bias effects while similar particles with a 2 nm thick shell so significant training effects below 90 K. Polarized SANS studied of 7 nm Fe3O4 nanoparticle assemblies show the ability to resolve the magnetization components in 3D. [4pt] [1] M. Sachan, C. Bonnoit, S. A. Majetich, Y. Ijiri, P. O. Mensah-Bonsu, J. A. Borchers, and J. J. Rhyne, Appl. Phys. Lett. 92, 152503 (2008). [0pt] [2] Yumi Ijiri, Christopher V. Kelly, Julie A. Borchers, James J. Rhyne, Dorothy F. Farrell, Sara A. Majetich, Appl. Phys. Lett. 86, 243102-243104 (2005). [0pt] [3] K. L. Krycka, R. Booth, J. A. Borchers, W. C. Chen, C. Conlon, T. Gentile, C. Hogg, Y. Ijiri, M. Laver, B. B. Maranville, S. A. Majetich, J. Rhyne, and S. M. Watson, Physica B (submitted).
Nonsymmetrized Correlations in Quantum Noninvasive Measurements
NASA Astrophysics Data System (ADS)
Bednorz, Adam; Bruder, Christoph; Reulet, Bertrand; Belzig, Wolfgang
2013-06-01
A long-standing problem in quantum mesoscopic physics is which operator order corresponds to noise expressions like ?I(-?)I(?)?, where I(?) is the measured current at frequency ?. Symmetrized order describes a classical measurement while nonsymmetrized order corresponds to a quantum detector, e.g., one sensitive to either emission or absorption of photons. We show that both order schemes can be embedded in quantum weak-measurement theory taking into account measurements with memory, characterized by a memory function which is independent of a particular experimental detection scheme. We discuss the resulting quasiprobabilities for different detector temperatures and how their negativity can be tested on the level of second-order correlation functions already. Experimentally, this negativity can be related to the squeezing of the many-body state of the transported electrons in an ac-driven tunnel junction.
Nonsymmetrized Correlations in Mesoscopic Current Measurements
NASA Astrophysics Data System (ADS)
Belzig, Wolfgang; Bednorz, Adam; Bruder, Christoph; Reulet, Bertrand
2014-03-01
A long-standing problem in quantum mesoscopic physics is which operator order corresponds to noise expressions like < I(?) I(- ?) > , where I(?) is the measured current at frequency ?. Symmetrized order describes a classical measurement while nonsymmetrized order corresponds to a quantum detector, e.g., one sensitive to either emission or absorption of photons. We show that both order schemes can be embedded in quantum weak-measurement theory taking into account measurements with memory, characterized by a memory function which is independent of a particular experimental detection scheme [A. Bednorz, C. Bruder, B. Reulet, and W. Belzig, Phys. Rev. Lett. 110, 250404 (2013)]. We discuss the resulting quasiprobabilities for different detector temperatures and how their negativity can be tested on the level of second-order correlation functions already. Experimentally, this negativity can be related to the squeezing of the many-body state of the transported electrons in an ac-driven tunnel junction.
Nonsymmetrized correlations in quantum noninvasive measurements.
Bednorz, Adam; Bruder, Christoph; Reulet, Bertrand; Belzig, Wolfgang
2013-06-21
A long-standing problem in quantum mesoscopic physics is which operator order corresponds to noise expressions like , where I(?) is the measured current at frequency ?. Symmetrized order describes a classical measurement while nonsymmetrized order corresponds to a quantum detector, e.g., one sensitive to either emission or absorption of photons. We show that both order schemes can be embedded in quantum weak-measurement theory taking into account measurements with memory, characterized by a memory function which is independent of a particular experimental detection scheme. We discuss the resulting quasiprobabilities for different detector temperatures and how their negativity can be tested on the level of second-order correlation functions already. Experimentally, this negativity can be related to the squeezing of the many-body state of the transported electrons in an ac-driven tunnel junction. PMID:23829718
Measurement of Length and Position with Frequency Combs
NASA Astrophysics Data System (ADS)
Weimann, C.; Hoeller, F.; Schleitzer, Y.; Diez, C. A.; Spruck, B.; Freude, W.; Boeck, Y.; Koos, C.
2015-04-01
We show two different absolute distance measurement methods with micrometer accuracy based on frequency combs, and we discuss possible applications. Using a mode- locked laser and MEMS-based tracking optics, we measure the 3D position of a retroreflector within 10 ms and with a 24 ?m volumetric accuracy. We also investigate modulator-based combs and show that they enable highly sensitive surface topography measurements with microsecond acquisition times and micrometer precision. Moreover, the potential for photonic integration of frequency comb sources is explored.
Mayoral, E; Goicochea, A Gama
2014-12-01
Interfaces involving coexisting phases in condensed matter are essential in many phenomena: wetting, nucleation, morphology, phase separation kinetics, membranes, phase coexistence in nanomaterials, etc. The majority of analytical theories available use concepts derived from mean field artifacts which do not describe adequately these systems. Satisfactory numerical simulation of interfaces at the atomistic to mesoscopic scale is still a challenge. In the present work, the interfacial tension between mixtures of organic solvents and water is obtained from mesoscopic computer simulations. The temperature dependence of the interfacial tension is found to obey a scaling law with an average critical exponent ? = 1.23. Additionally, we calculate the evolution of the correlation length, defined as the thickness of the interface between the immiscible fluids, as a function of temperature and find that it obeys also a scaling law with an average critical exponent being ? = 0.67. Finally, we show that the comparison of ? and ? for these binary mixtures constitutes the first test of Widom's hyperscaling relationship between these exponents in 3d, expressed as ? = ? (d - 1). Based on these values and those for the 3d Ising model it is argued that both systems belong to the same universality class, which opens up the way for the calculation of new scaling exponents. PMID:25299248
G. B Grad; G. M Benites; G Aurelio; A Fernández Guillermet
1999-01-01
An analysis is performed of the experimental information on the key interatomic distances (IDs) of the AlB2 type structure, the so-called omega (?) phase in Ti and Zr, as well as in Ti–V and Zr–Nb alloys. Various remarkable correlations are found between these IDs and standard measures of the atomic size, and with Pauling’s bond-lengths. These observations are discussed in
Cosmological Measurements with General Relativistic Galaxy Correlations
Raccanelli, Alvise; Bertacca, Daniele; Doré, Olivier; Durrer, Ruth
2015-01-01
We investigate the cosmological dependence and the constraining power of large-scale galaxy correlations, including all redshift-distortions, wide-angle, lensing and gravitational potential effects on linear scales. We analyze the cosmological information present in the lensing convergence and in the gravitational potential terms describing the so-called "relativistic effects," and we find that, while smaller than the information contained in intrinsic galaxy clustering, it is not negligible. We investigate how neglecting them does bias cosmological measurements performed by future spectroscopic and photometric large-scale surveys such as SKA and Euclid. We perform a Fisher analysis using the CLASS code, modified to include scale-dependent galaxy bias and redshift-dependent magnification and evolution bias. Our results show that neglecting relativistic terms introduces an error in the forecasted precision in measuring cosmological parameters of the order of a few tens of percent, in particular when measuring ...
Optimizing Stimulus Length for Clinical Nasalance Measures in Swedish
ERIC Educational Resources Information Center
van Doorn, Jan; Bergh, Ida; Brunnegard, Karin
2008-01-01
Standardized passages used for speech nasalance measures may be too long for clinical use with very young or non-compliant patients. The aim of this study was to establish whether nasalance scores from shorter sections of three Swedish speech stimuli were equivalent to those from their corresponding whole stimulus. Nasalance recordings for three…
Cosmological Measurements with General Relativistic Galaxy Correlations
Alvise Raccanelli; Francesco Montanari; Daniele Bertacca; Olivier Doré; Ruth Durrer
2015-05-22
We investigate the cosmological dependence and the constraining power of large-scale galaxy correlations, including all redshift-distortions, wide-angle, lensing and gravitational potential effects on linear scales. We analyze the cosmological information present in the lensing convergence and in the gravitational potential terms describing the so-called "relativistic effects," and we find that, while smaller than the information contained in intrinsic galaxy clustering, it is not negligible. We investigate how neglecting them does bias cosmological measurements performed by future spectroscopic and photometric large-scale surveys such as SKA and Euclid. We perform a Fisher analysis using the CLASS code, modified to include scale-dependent galaxy bias and redshift-dependent magnification and evolution bias. Our results show that neglecting relativistic terms introduces an error in the forecasted precision in measuring cosmological parameters of the order of a few tens of percent, in particular when measuring the matter content of the Universe and primordial non-Gaussianity parameters. Therefore, we argue that radial correlations and integrated relativistic terms need to be taken into account when forecasting the constraining power of future large-scale number counts of galaxy surveys.
Step Length Measurement—Theory and Simulation for Tethered Bead Constant-Force Single Molecule Assay
Anders E. Wallin; Ari Salmi; Roman Tuma
2007-01-01
Linear molecular motors translocate along polymeric tracks using discrete steps. The step length is usually measured using constant-force single molecule experiments in which the polymer is tethered to a force-clamped microsphere. During the enzymatic cycle the motor shortens the tether contour length. Experimental conditions influence the achievable step length resolution, and ideally experiments should be conducted with high clamp-force using
Diffusion length measurements using the scanning electron microscope. [in semiconductor devices
NASA Technical Reports Server (NTRS)
Weizer, V. G.
1975-01-01
A measurement technique employing the scanning electron microscope is described in which values of the true bulk diffusion length are obtained. It is shown that surface recombination effects can be eliminated through the application of highly doped surface field layers. The influence of high injection level effects and low-high junction current generation on the resulting measurement was investigated. Close agreement is found between the diffusion lengths measured by this method and those obtained using a penetrating radiation technique.
A tool for measuring the bending length in thin wires.
Lorenzini, M; Cagnoli, G; Cesarini, E; Losurdo, G; Martelli, F; Piergiovanni, F; Vetrano, F; Viceré, A
2013-03-01
Great effort is currently being put into the development and construction of the second generation, advanced gravitational wave detectors, Advanced Virgo and Advanced LIGO. The development of new low thermal noise suspensions of mirrors, based on the experience gained in the previous experiments, is part of this task. Quasi-monolithic suspensions with fused silica wires avoid the problem of rubbing friction introduced by steel cradle arrangements by directly welding the wires to silica blocks bonded to the mirror. Moreover, the mechanical loss level introduced by silica (?fs ? 10(-7) in thin fused silica wires) is by far less than the one associated with steel. The low frequency dynamical behaviour of the suspension can be computed and optimized, provided that the wire bending shape under pendulum motion is known. Due to the production process, fused silica wires are thicker near the two ends (necks), so that analytical bending computations are very complicated. We developed a tool to directly measure the low frequency bending parameters of fused silica wires, and we tested it on the wires produced for the Virgo+ monolithic suspensions. The working principle and a set of test measurements are presented and explained. PMID:23556827
Angular correlation measurements in 40Ar
J. R. Southon; A. R. Poletti; D. J. Beale
1976-01-01
Proton-gamma angular correlation measurements have been carried out on states in 40Ar populated by the 40Ar(p,p') reaction. Mixing ratios measured include the following (spin sequences are given in parentheses): sigma(2.52-->1.46)=0.41-0.06+0.13(2-->2) sigma(3.21-->1.46)=-0.11+\\/-0.07 (2-->2)sigma(3.51-->1.46)=0.05+\\/-0.11(2-->2)sigma(3.68-->1.46)=0.07-0.05+0.11(3-->2)sigma(3.92-->1.46) 0.3(2-->2). Rigorous spin assignments of 2 and 1 have beenmade to the 3.21 and 4.48 MeV levels, respectively. Excitation energies have been derived for some of the states
Measurements of Microwave Single Photon Correlations: Theory
NASA Astrophysics Data System (ADS)
da Silva, Marcus; Bozyigit, Deniz; Wallraff, Andreas; Blais, Alexandre
2010-03-01
Superconducting circuit implementations of cavity QED have enabled the exploration of various regimes of light-matter interaction. In this work, we present theoretical aspects of the observation of quantum properties of the field emitted from a cavity without access to non-linear/single-photon detectors (which have not been demonstrated reliably in the microwave regime). In particular, we focus on how to perform the measurement of optical coherence functions in pulsed circuit QED experiments using field quadrature measurements of the outputs of a two-sided cavity. We illustrate how the standard Hanbury Brown and Twiss setup can be replaced with the monitoring of these cavity outputs, while still allowing for the calculation of arbitrary first and second order correlation functions. Moreover, we illustrate how the significant noise contributions from thermal fields, amplifiers and mixers can be accounted and compensated for.
Measure of top-down correlation
Iman, R.L.; Conover, W.J.
1985-10-01
Many situations exist in which n objects are ranked by two independent sources. For example, n brands of a given type of food product are ranked by taste test by two different individuals; n input variables to a computer model are ranked with respect to their influence on the model output variables by two different criteria; and company objectives are ranked by management and again by employees. In each of these settings, interest centers primarily on agreement in the top rankings, with disagreements on items at the bottom of the rankings being of little or no importance. That is, can consumers agree on the most preferred brands of a certain type of food product; do different techniques of measuring the sensitivity of an output variable to various input variables in a computer model agree on the selection of the most important variables; and is there agreement between management and employees on the most urgent objectives. A problem with Spearman's rho in the present setting is that it is equally influenced by disagreement on the assignment of rankings at all levels. In this paper, a measure of correlation is provided that is more sensitive to agreement on the top rankings. The statistic used in this setting is the ordinary correlation coefficient computed on Savage (1956) scores. The asymptotic normality of this statistic is shown, tables of the exact distribution are provided for n = 3(1)14, and models are presented for which this is the locally most powerful rank test.
Correction of the measurement of fiber length of short fiber reinforced thermoplastics
Shao-Yun Fu; Yiu-Wing Mai; Emma Chui-Yee Ching; Robert K. Y Li
2002-01-01
Short fiber reinforced thermoplastics are often made using extrusion compounding and injection moulding techniques. Fiber breakage takes place during processing. In finished fiber reinforced parts, there often exists a fiber length distribution. Measurement of fiber length is often performed on photographs of short fibers obtained from burning off or dissolving the matrix. However, relatively long fibers crossing the photographs cannot
Experience of the fibrotest for measuring cotton fiber length and strength properties
Technology Transfer Automated Retrieval System (TEKTRAN)
The Fibrotest is a device developed by Textechno for measuring cotton fiber length and strength properties. The Fibrotest provides abundant information, including more than 20 length and strength parameters in absolute and relative modes, and displays fibrogram, load-elongation curve, and fiber bea...
SPIN-DEPENDENT SCATTERING LENGTHS OF SLOW NEUTRONS WITH NUCLEI BY PSEUDOMAGNETIC MEASUREMENTS
Boyer, Edmond
L-263 SPIN-DEPENDENT SCATTERING LENGTHS OF SLOW NEUTRONS WITH NUCLEI BY PSEUDOMAGNETIC MEASUREMENTS-sur-Yvette, France Résumé. 2014 En mesurant la précession de spin de neutrons en fonction de la polarisation vu par les noyaux. Abstract. - The spin-dependent scattering length of slow neutrons by the nuclei 23
Measurement of MODIS optics effective focal length, distortion, and modulation transfer function
NASA Astrophysics Data System (ADS)
Thurlow, Paul E.; Cline, Richard W.
1993-08-01
A combination MODIS optics characteristics, short back focal length, and relatively distorting optics, has required major revisions in techniques used earlier to characterize effective focal length (EFL) and modulation transfer function (MTF) in the thematic mapper (TM) project. This paper compares measurement approaches used to characterize TM optics and revised methodology intended to characterize MODIS optics at an integration and assembly level.
ERIC Educational Resources Information Center
van den Boer, Madelon; de Jong, Peter F.; Haentjens-van Meeteren, Marleen M.
2013-01-01
Beginning readers' reading latencies increase as words become longer. This length effect is believed to be a marker of a serial reading process. We examined the effects of visual and phonological skills on the length effect. Participants were 184 second-grade children who read 3- to 5-letter words and nonwords. Results indicated that reading…
Bunch length measurement at the Fermilab A0 photoinjector using a Martin-Puplett interferometer
Thurman-Keup, Randy; Fliller, Raymond Patrick; Kazakevich, Grigory; /Fermilab
2008-05-01
We present preliminary measurements of the electron bunch lengths at the Fermilab A0 Photoinjector using a Martin-Puplett interferometer on loan from DESY. The photoinjector provides a relatively wide range of bunch lengths through laser pulse width adjustment and compression of the beam using a magnetic chicane. We present comparisons of data with simulations that account for diffraction distortions in the signal and discuss future plans for improving the measurement.
Optical fiber length measurement by external phase modulation type optical heterodyne reflectometry
Kimura, T.; Sawada, I.; Sasaki, N.; Noda, K. (Dept. of Electrical Engineering, Tokyo Univ. of Agriculture and Technology, 24-16, Nakamachi 2-chome, Koganei-shi, Tokyo 184 (JP))
1989-04-01
A method for measuring optical fiber length is proposed and demonstrated experimentally with external phase modulation optical heterodyne reflectometry using a He-Ne laser as a light source. The system offers a simple length measuring method with satisfactory resolution. The reflected waves from fiber faults, if any, also can be detected by this method by observing two signals which occur at fault points and the fiber end.
Precision Measurement of {pi}{pi} Scattering Lengths in K{sub e4} Decays
Madigozhin, D. T. [Joint Institute for Nuclear Research, Russia, 141980 Moscow region, Dubna, Joliot-Curie 6, JINR (Russian Federation)
2011-05-23
The measurement of the S-wave {pi}{pi} scattering lengths is a fundamental test of the validity of Chiral Perturbation Theory. We report on the final NA48/2 result, based on the full statistics data set of more than one million reconstructed K{sub e4}{sup {+-}} decays. From these events we have determined the decay form factors and {pi}{pi} scattering lengths a{sub 0}{sup 0} and a{sub 0}{sup 2}. The result is the currently most precise measurement of the scattering lengths and is in excellent agreement with the predictions of Chiral Perturbation Theory.
Segmentation and length measurement of the abdominal blood vessels in 3-D MRI images.
Babin, Danilo; Vansteenkiste, Ewout; Pizurica, Aleksandra; Philips, Wilfried
2009-01-01
In diagnosing diseases and planning surgeries the structure and length of blood vessels is of great importance. In this research we develop a novel method for the segmentation of 2-D and 3-D images with an application to blood vessel length measurements in 3-D abdominal MRI images. Our approach is robust to noise and does not require contrast-enhanced images for segmentation. We use an effective algorithm for skeletonization, graph construction and shortest path estimation to measure the length of blood vessels of interest. PMID:19964361
ERIC Educational Resources Information Center
Subramaniam, Karthigeyan
2014-01-01
Prospective secondary mathematics teachers' pedagogical knowledge for teaching the estimation of length measurements was investigated by examining their personal benchmarks for measurement estimation. Benchmarks for measurement estimation are the meaningful representations of units that serve to increase one's understanding of…
Wang, Dong-min; Lu, Qi-peng; Ding, Hai-quan; Huang, Fu-rong
2012-04-01
In noninvasive blood glucose measurement, it is difficult to keep the contact area between skin and internal reflectance element uniform while the mid-infrared spectra of human skin are taken, and this would lead to path-length variations. To study the effect of path-length variations on PLSR calibration model, in the present paper, according to the correlation coefficients between path-lengths and glucose concentrations, two PLSR models were achieved respectively and RMSECV were 31.3 and 4.52 mg x dL(-1), RMSEP were 30.3 and 98.7 mg x dL(-1) for the validation set. The results show that the chance correlations between path-lengths and glucose concentrations will lead to calibration models with different accuracy and robustness. This is useful to improving the reliability of noninvasive measurement of blood glucose by mid-infrared spectroscopy. PMID:22715755
NASA Astrophysics Data System (ADS)
Sofia, Giulia; Marinello, Francesco; Tarolli, Paolo
2014-05-01
Terraces represent an outstanding example that displays centuries of a ubiquitous human-Earth interaction, in a very specific and productive way, and they are a significant part of numerous local economies. They, in fact, optimise the local resources for agricultural purposes, but also exploit marginal landscapes, expanding local populations. The ubiquity, variety, and importance of terraces have motivated studies designed to understand them better both as cultural and ecological features, but also as elements that can deeply influence runoff generation and propagation, contributing to local instabilities, and triggering or aggravating land degradation processes. Their vulnerability in the face of fast-growing urban settlements and the changes in agricultural practices is also well known, prompting protection measures strongly supported by local communities, but also by national and international projects. This work explores the spatial heterogeneity of terraced landscapes, identifying a proper indicator able to discriminate a terraced landscape respect to a more natural one. Recognizing and characterizing terraced areas can offer important multi-temporal insights into issues such as agricultural sustainability, indigenous knowledge systems, human-induced impact on soil degradation or erosive and landslide processes, geomorphological and pedologic processes that influence soil development, and climatic and biodiversity changes. More in detail, the present work introduces a new morphological indicator from LiDAR, effectively implementable for the automatic characterization of terraced landscapes. For the study, we tested the algorithm for environments that differ in term of natural morphology and terracing system. Starting from a LiDAR Digital Terrain Models (DTM), we considered the local auto-correlation (~local self-similarity) of the slope, calculating the correlation between a slope patch and its surrounding areas. We define the resulting map as the "Slope Local Length of Auto-Correlation", or SLLAC map. The SLLAC map texture is characterized by the presence of peculiar elongated fibers that change depending on the landscape morphology, and on the type of terracing system. The differences in texture can be measured, and they can be used to discriminate terraced areas from more natural ones. Given the raising importance of these landscapes, the proposed procedure can offer an important and promising tool to explore the spatial heterogeneity of terraced sites.
A Class of Repeated Measures Concordance Correlation Coefficients
Tonya S. King; Vernon M. Chinchilli; Kai-Ling Wang; Josep L. Carrasco
2007-01-01
The repeated measures concordance correlation coefficient was proposed for measuring agreement between two raters or two methods of measuring a response in the presence of repeated measurements (King et al., 2007). This paper proposes a class of repeated measures concordance correlation coefficients that are appropriate for both continuous and categorical data. We illustrate the methodology with examples comparing (1) 1-hour
NASA Astrophysics Data System (ADS)
Reimus, P. W.
2010-12-01
A process-oriented modeling approach is implemented to examine the importance of parameter variances, correlation lengths, and especially cross-correlations in contaminant transport predictions over large scales. It is shown that the most important consideration is the correlation between flow rates and retardation processes (e.g., sorption, matrix diffusion) in the system. If flow rates are negatively correlated with retardation factors in systems containing multiple flow pathways, then characterizing these negative correlation(s) may have more impact on reactive transport modeling than microscale information. Such negative correlations are expected in porous-media systems where permeability is negatively correlated with clay content and rock alteration (which are usually associated with increased sorption). Likewise, negative correlations are expected in fractured rocks where permeability is positively correlated with fracture apertures, which in turn are negatively correlated with sorption and matrix diffusion. Parameter variances and correlation lengths are also shown to have important effects on reactive transport predictions, but they are less important than parameter cross-correlations. Microscale information pertaining to contaminant transport has become more readily available as characterization methods and spectroscopic instrumentation have achieved lower detection limits, greater resolution, and better precision. Obtaining detailed mechanistic insights into contaminant-rock-water interactions is becoming a routine practice in characterizing reactive transport processes in groundwater systems (almost necessary for high-profile publications). Unfortunately, a quantitative link between microscale information and flow and transport parameter distributions or cross-correlations has not yet been established. One reason for this is that quantitative microscale information is difficult to obtain in complex, heterogeneous systems, so simple systems that lack the complexity and heterogeneity of real aquifer materials are often studied. Another is that instrumentation used to obtain microscale information often probes only one variable or family of variables at a time, so linkages to other variables must be inferred by indirect means from other lines of evidence. Despite these limitations, microscale information can be useful in the development and validation of reactive transport models. For example, knowledge of mineral phases that have strong affinities for contaminants can help in the development of cross-correlations between flow and sorption parameters via characterization of permeability and mineral distributions in aquifers. Likewise, microscale information on pore structures in low-permeability zones and contaminant penetration distances into these zones from higher-permeability zones (e.g., fractures) can provide valuable constraints on the representation of diffusive mass transfer processes between flowing porosity and secondary porosity. The prioritization of obtaining microscale information in any groundwater system can be informed by modeling exercises such as those conducted for this study.
NASA Astrophysics Data System (ADS)
Zhang, Hang; Hua, Chengyun; Ding, Ding; Minnich, Austin J.
2015-03-01
Thermal conductivity measurements over variable lengths on nanostructures such as nanowires provide important information about the mean free paths (MFPs) of the phonons responsible for heat conduction. However, nearly all of these measurements have been interpreted using an average MFP even though phonons in many crystals possess a broad MFP spectrum. Here, we present a reconstruction method to obtain MFP spectra of nanostructures from variable-length thermal conductivity measurements. Using this method, we investigate recently reported length-dependent thermal conductivity measurements on SiGe alloy nanowires and suspended graphene ribbons. We find that the recent measurements on graphene imply that 70% of the heat in graphene is carried by phonons with MFPs longer than 1 micron.
Zhang, Hang; Hua, Chengyun; Ding, Ding; Minnich, Austin J
2015-01-01
Thermal conductivity measurements over variable lengths on nanostructures such as nanowires provide important information about the mean free paths (MFPs) of the phonons responsible for heat conduction. However, nearly all of these measurements have been interpreted using an average MFP even though phonons in many crystals possess a broad MFP spectrum. Here, we present a reconstruction method to obtain MFP spectra of nanostructures from variable-length thermal conductivity measurements. Using this method, we investigate recently reported length-dependent thermal conductivity measurements on SiGe alloy nanowires and suspended graphene ribbons. We find that the recent measurements on graphene imply that 70% of the heat in graphene is carried by phonons with MFPs longer than 1 micron. PMID:25764977
Zhang, Hang; Hua, Chengyun; Ding, Ding; Minnich, Austin J.
2015-01-01
Thermal conductivity measurements over variable lengths on nanostructures such as nanowires provide important information about the mean free paths (MFPs) of the phonons responsible for heat conduction. However, nearly all of these measurements have been interpreted using an average MFP even though phonons in many crystals possess a broad MFP spectrum. Here, we present a reconstruction method to obtain MFP spectra of nanostructures from variable-length thermal conductivity measurements. Using this method, we investigate recently reported length-dependent thermal conductivity measurements on SiGe alloy nanowires and suspended graphene ribbons. We find that the recent measurements on graphene imply that 70% of the heat in graphene is carried by phonons with MFPs longer than 1 micron. PMID:25764977
Research on the measurement technology of effective arm length of swing arm profilometer
NASA Astrophysics Data System (ADS)
Chen, Lin; Jing, Hongwei; Wei, Zhongwei; Li, Jie; Cao, Xuedong
2014-09-01
When the swing arm profilometer(SAP) measuring the mirror, the effective arm length of SAP which haves an obvious influence on the measurement results of the mirror surface shape needs to be measured accurately. It requires the measurement uncertainty of the effective arm length to reach 10?m in order to meet the measurement requirements, in this paper, we present a kind of technology based on laser tracker to measure the effective arm length of SAP. When the swing arm rotates around the shaft axis of swing arm rotary stage, the probe and two laser tracker balls form three sections of circular arc around the shaft axis of swing arm rotary stage in space. Laser tracker tracks and measures the circular arcs of two laser tracker balls, the center coordinates of the circular plane of circular arc can be calculated by data processing. The linear equation that passes through the two center coordinates is the equation of the shaft axis of rotary stage, the vertical distance from the probe to the shaft axis of rotary stage which can be calculated refer to the equation from the point to the line is the effective arm length. After Matlab simulation, this measurement method can meet the measurement accuracy.
Simple focal-length measurement technique with a circular Dammann grating
Zhao Shuai; Wen, J.F.; Chung, P.S
2007-01-01
A novel technique for focal-length measurements with a circular Dammann grating is presented. In the back focal plane of the lens under test, a one-order circular Dammann grating with limited aperture will produce double-humped radial rings. The separation between the two lobes varies with the displacement of the observed plane from the focal plane of the lens. By searching for the position at which the separation is minimal, the focal point of the lens can be located and hence the back focal length can be determined. Experimental results demonstrated that this method is efficient and can be used effectively for a quick check of focal length.
First-principles bond-length correlation for the omega structure of the 4d-transition elements
J. E Garcés; G. B Grad; A Fernández Guillermet; S. J Sferco
1999-01-01
Using the full potential-linearised muffin tin orbitals (FP-LMTO) method, we have studied the shortest interatomic distance (SID) of the AlB2 (C32) type-structure, so-called omega (?) phase, of Y, Zr, Nb, Mo, Tc, Ru, Rh, Pd and Ag. It is shown that the SID in this phase correlates remarkably well with the single bond length D(1) given to these elements by
In-service fiber line identification based on high-resolution fiber length measurement
Yutaka Katsuyama
1995-01-01
An in-service fiber line identification scheme based on high-resolution fiber line length measurement is proposed and demonstrated for single star, survivable, and passive double star architectures to meet the demands of in-service cable reconstruction. In the proposed scheme, a reference fiber is assigned just after the fiber network has been constructed and differences in length between the constructed fiber lines
Effects of Text Length on Lexical Diversity Measures: Using Short Texts with Less than 200 Tokens
ERIC Educational Resources Information Center
Koizumi, Rie; In'nami, Yo
2012-01-01
Despite the importance of lexical diversity (LD) in L2 speaking and writing performance, LD assessment measures are known to be affected by the number of words analyzed in the text. This study aims to identify LD measures that are least affected by text length and can be used for the analysis of short L2 texts (50-200 tokens). We compared the…
Optical fiber digital speckle pattern correlation method for displacement measurement
Rongxun Liu; Xinwei Liu
1995-01-01
This paper briefly reviews present situation on optical fiber-speckle method used for measuring displacements or deformations of an object, and the optical fiber-digital white light speckle patterns correlation method for whole field displacement measurement on a remote surface of a trial object is revealed. The principle of correlation method is demonstrated. A special program for image correlation analysis by computer
Zou, Xihua; Li, Ming; Pan, Wei; Luo, Bin; Yan, Lianshan; Shao, Liyang
2014-05-01
Radio-frequency (RF) frequency shift of incoherent light source based optoelectronic oscillator (OEO) is employed to measure the optical length change. In the proposed OEO using an incoherent light source, the optical length under test is inserted in the optoelectronic hybrid loop. The frequency shift of RF oscillation modes at the output of the OEO reflects the optical length change, with the change being measured via frequency shift analysis. Two OEO configurations are theoretically designed and experimentally performed, while an amplified spontaneous emission (ASE) source serves as the incoherent light source. A linear relationship between the frequency shift and the optical length change has been confirmed for measurement, and a reconfigurable measurement sensitivity is available by selecting different oscillation modes. Moreover, the use of ASE greatly reduces the complexity and the cost for stabilization control on light source, while the derived results are consistent with that obtained in a laser source based OEO both in the measured optical length changes and the phase noise performance. A sensitivity of -28 KHz/cm, -480 KHz/cm or higher, and a resolution of nano-meter scale are obtained, which can be used to monitor the displacement, the changes in refractive index, temperature. PMID:24921811
ACOUSTIC AND KINEMATIC CORRELATES OF PHONOLOGICAL LENGTH CONTRAST IN ITALIAN CONSONANTS
Barbara Gili Fivela; Claudio Zmarich; Pascal Perrier; Christophe Savariaux; Graziano Tisato
2007-01-01
In Italian, length contrast is exploited in the consonant system. Previous articulatory studies have focused on the temporal organization of gestures in Italian geminates and on the lower lip kinematics of the singleton\\/geminate distinction. In this paper, data on lip and tongue gestures are discussed in order to directly test hypotheses on the gestural organization of geminate consonants and to
Cubic law with aperture-length correlation: implications for network scale fluid flow
and modeled fluid flow through fractured rock with the parallel plate approach where the volumetric flow per unit width normal to the direction of flow is proportional to the cubed aperture between the plates to length scaling of opening-mode fractures, total flow rates through natural opening-mode fractures
Wen-Ruey Chang; Mikko Hirvonen; Raoul Grönqvist
2004-01-01
Surface roughness affects friction, but it is not clear which surface roughness characteristics are better correlated with friction. The surface roughness parameters generated from quarry tiles were correlated with the transition friction between the tiles and a commonly used sole testing material, Neolite, with three different mixtures of glycerol and water as contaminants at the interface. Measurement of surface roughness
Cudzinovic, M.; Sopori, B. [comp.] [comp.
1995-11-01
As was noted in the cover letter that accompanied the samples, the eleven bare silicon samples were from various manufacturers. Table I lists the codes for the samples and the manufacturer of each sample. It also notes if the sample was single or poly-crystalline. The samples had been polished on one side before being sent out for measurements, but no further processing was done. The participants of the study were asked to measure either the lifetime or diffusion length of each of the samples using their standard procedure. Table II shows the experimental conditions used by the groups who measured diffusion length. All the diffusion length measurements were performed using the Surface Photovoltage method (SPV). Table M shows the experimental conditions for the lifetime measurements. All the lifetime measurements were made using the Photoconductance Decay method (PCD) under low level injection. These tables show the diameter of the spot size used during the measurement (the effective sampling area), the locations where measurements were taken, and the number of measurements taken at each location. Table N shows the results of the measurements. The table is divided into diffusion length and lifetime measurements for each sample. The values listed are the average values reported by each group. One of the immediate artifacts seen in the data is the large variation in the lifetime measurements. The values from MIT and Mobil are generally close. However, the measurements from NCSU are typically an order of magnitude lower.
NASA Technical Reports Server (NTRS)
Flat, A.; Milnes, A. G.
1978-01-01
In scanning electron microscope (SEM) injection measurements of minority carrier diffusion lengths some uncertainties of interpretation exist when the response current is nonlinear with distance. This is significant in epitaxial layers where the layer thickness is not large in relation to the diffusion length, and where there are large surface recombination velocities on the incident and contact surfaces. An image method of analysis is presented for such specimens. A method of using the results to correct the observed response in a simple convenient way is presented. The technique is illustrated with reference to measurements in epitaxial layers of GaAs. Average beam penetration depth may also be estimated from the curve shape.
Longitudinal-to-Transverse Mapping for Femtosecond Electron Bunch Length Measurement
Xiang, Dao; Ding, Yuantao; /SLAC
2010-08-25
A longitudinal-to-transverse mapping technique is proposed to measure the length and temporal profile of ultrashort electron bunches. In this scheme a special chicane and a radio-frequency deflecting cavity are used to transform the beam's longitudinal distribution into angular distribution which is further converted to transverse distribution after a parallel-to-point imaging beam line. With this technique, the temporal profile of the electron beam is exactly mapped to the transverse profile. This makes it possible to measure ultrashort electron bunch length with a resolution well beyond 1 femtosecond.
Peggy F. Shelbourne; Christine Keller-McGandy; Wenya Linda Bi; Song-Ro Yoon; Louis Dubeau; Nicola J. Veitch; Jean Paul Vonsattel; Nancy S. Wexler; Norman Arnheim; Sarah J. Augood
2007-01-01
Huntington disease is caused by the expansion of a CAG repeat encoding an extended glutamine tract in a protein called huntingtin. Here, we provide evidence supporting the hypothesis that somatic increases of mutation length play a role in the progressive nature and cell-selective aspects of HD pathogenesis. Results from micro-dissected tissue and individual laser-dissected cells obtained from human HD cases
Otto Gleich; Robert J. Dooling; Geoffrey A. Manley
2005-01-01
The inner ear in the group of archosaurs (birds, crocodilians, and extinct dinosaurs) shows a high degree of structural similarity,\\u000a enabling predictions of their function in extinct species based on relationships among similar variables in living birds.\\u000a Behavioral audiograms and morphological data on the length of the auditory sensory epithelium (the basilar papilla) are available\\u000a for many avian species. By
Offerman, Steven R.; Schaefer, Melissa; Thundiyil, Joseph G.; Cook, Matthew D.; Holmes, James F.
2009-01-01
Objectives: We sought to identify factors associated with need for mechanical ventilation (MV), length of intensive care unit (ICU) stay, length of hospital stay, and poor outcome in injection drug users (IDUs) with wound botulism (WB). Methods: This is a retrospective review of WB patients admitted between 1991–2005. IDUs were included if they had symptoms of WB and diagnostic confirmation. Primary outcome variables were the need for MV, length of ICU stay, length of hospital stay, hospital-related complications, and death. Results: Twenty-nine patients met inclusion criteria. Twenty-two (76%) admitted to heroin use only and seven (24%) admitted to heroin and methamphetamine use. Chief complaints on initial presentation included visual changes, 13 (45%); weakness, nine (31%); and difficulty swallowing, seven (24%). Skin wounds were documented in 22 (76%). Twenty-one (72%) patients underwent mechanical ventilation (MV). Antitoxin (AT) was administered to 26 (90%) patients but only two received antitoxin in the emergency department (ED). The time from ED presentation to AT administration was associated with increased length of ICU stay (Regression coefficient = 2.5; 95% CI 0.45, 4.5). The time from ED presentation to wound drainage was also associated with increased length of ICU stay (Regression coefficient = 13.7; 95% CI = 2.3, 25.2). There was no relationship between time to antibiotic administration and length of ICU stay. Conclusion: MV and prolonged ICU stays are common in patients identified with WB. Early AT administration and wound drainage are recommended as these measures may decrease ICU length of stay. PMID:20046244
Research on all fiber beat length measurement system for polarization-maintaining fibers
NASA Astrophysics Data System (ADS)
Peng, Li; Feng, Lishuang; Zhang, Xiaoqing; Hong, Lingfei
2010-12-01
Polarization-maintaining fiber (PMF) has attracted great attentions not only due to its ability to realize coherent optic communication with ultrahigh-capacity, but also because it can be widely employed in high-precise fiber-optic sensors and optic information processors, e.g., fiber-optic gyroscope and fiber-optic amperemeter. Distinct with common monomode optic fibers, additional birefringence is introduced in the PMF, minimizing the effect of mode coupling between two orthogonal polarization modes in optic fibers. Thus, light polarization can be maintained after long distance transmission in the PMF. However, beat-length, which reflects the characteristic of induced birefringence and evaluates the ability of polarization maintaining, is one of the most important parameters for PMF. Accurate measurement of PMF beat length becomes more and more important along with the expanding of its application field. The uniqueness of the measurement results determines the identity of PMF fabrication and the resolution of fiber-optic sensors. The existing measurement methods for PMF beat length are introduced first. Most testing setups are established by several individual components, which lead to complicated setup, inconvenient testing, and unsteady measurement. In this paper, a novel all fiber beat length measurement system is presented, where optic source, integrated optic modulator, stress apply structure, polarization detector, and polarization indicator of output light are included. The configuration and working principle of the whole system, and the designing and realization of each components, are addressed in the paper. Furthermore, the influence on measurement results by the relative direction between applied stress and principal axis of the optic fiber is analyzed. Moreover, optimized designs, including polarized light incidence, pressure apply, and precise movement systems, are performed, which ensure the identical pressure apply direction in the moving process. Finally, measurement of PMF samples is carried out on experimental setup. In comparison with the other existing system, due to its all fiber light incidence structure, the novel beat length measurement system represents great stability and high reliability.
Research on all fiber beat length measurement system for polarization-maintaining fibers
NASA Astrophysics Data System (ADS)
Peng, Li; Feng, Lishuang; Zhang, Xiaoqing; Hong, Lingfei
2011-05-01
Polarization-maintaining fiber (PMF) has attracted great attentions not only due to its ability to realize coherent optic communication with ultrahigh-capacity, but also because it can be widely employed in high-precise fiber-optic sensors and optic information processors, e.g., fiber-optic gyroscope and fiber-optic amperemeter. Distinct with common monomode optic fibers, additional birefringence is introduced in the PMF, minimizing the effect of mode coupling between two orthogonal polarization modes in optic fibers. Thus, light polarization can be maintained after long distance transmission in the PMF. However, beat-length, which reflects the characteristic of induced birefringence and evaluates the ability of polarization maintaining, is one of the most important parameters for PMF. Accurate measurement of PMF beat length becomes more and more important along with the expanding of its application field. The uniqueness of the measurement results determines the identity of PMF fabrication and the resolution of fiber-optic sensors. The existing measurement methods for PMF beat length are introduced first. Most testing setups are established by several individual components, which lead to complicated setup, inconvenient testing, and unsteady measurement. In this paper, a novel all fiber beat length measurement system is presented, where optic source, integrated optic modulator, stress apply structure, polarization detector, and polarization indicator of output light are included. The configuration and working principle of the whole system, and the designing and realization of each components, are addressed in the paper. Furthermore, the influence on measurement results by the relative direction between applied stress and principal axis of the optic fiber is analyzed. Moreover, optimized designs, including polarized light incidence, pressure apply, and precise movement systems, are performed, which ensure the identical pressure apply direction in the moving process. Finally, measurement of PMF samples is carried out on experimental setup. In comparison with the other existing system, due to its all fiber light incidence structure, the novel beat length measurement system represents great stability and high reliability.
Godinho, Bruno M D C; Ogier, Julien R; Quinlan, Aoife; Darcy, Raphael; Griffin, Brendan T; Cryan, John F; O'Driscoll, Caitriona M
2014-10-01
Silencing disease-related genes in the central nervous system (CNS) using short interfering RNA (siRNA) holds great promise for treating neurological disorders. Yet, delivery of RNAi therapeutics to the brain poses major challenges to non-viral systems, especially when considering systemic administration. Cationic nanoparticles have been widely investigated for siRNA delivery, but the tendency of these to aggregate in physiological environments limits their intravenous application. Thus, strategies to increase the stability of nanoparticles have been developed. Here, we investigated the ability of modified cationic amphiphilic or PEGylated amphiphilic cyclodextrins (CD) to formulate stable CD.siRNA nanoparticles. To this end, we describe a simple method for post-modification of pre-formed cationic CD.siRNA nanoparticles at their surface using PEGylated CDs of different PEG lengths. PEGylated CD.siRNA nanoparticles presented reduced surface charges and increased stability in physiological salt conditions. Stability of PEGylated CD.siRNA nanoparticles in vitro increased with both PEG length and PEG density at the surface. Furthermore, in a comparative pharmacokinetic study, increased systemic exposure and reduced clearance were achieved with CD-formulations when compared to naked siRNAs. However, no significant differences were observed among non-PEGylated and PEGylated CD.siRNAs suggesting that longer PEG lengths might be required for improving stability in vivo. PMID:24992319
Measurement of bunch length in Indus-1 storage ring using fast photodiode.
Garg, Akash Deep; Nathwani, R K; Holikatti, A C; Karnewar, Akhilesh Kumar; Tyagi, Y; Yadav, S; Puntambekar, T A; Navathe, C P
2012-11-01
The length of electron bunches in a storage ring is an important parameter for both synchrotron radiation users and accelerator physicists. Several methods are used for measurements of bunch length using electronic and optical instruments. We have measured temporal profile of synchrotron radiation emitted from dipole magnet of Indus-1 by using fast photodiode. Bunch length is calculated by assuming gaussian profile for the particles inside bunch. The results show that bunch length is increasing with the decrease of gap voltage of RF cavity. These measurements were carried out at low beam current; at high voltage results are in close agreement with theory and the values estimated using ZAP code. In the second experiment, the results show that bunch length increases with the increase of beam current inside the bunch, and above threshold current, it follows Chao-Gareyte scaling law. The longitudinal broadband impedance for Indus-1 SRS was estimated using Keil-Schnell criterion and results were compared with theoretical estimated values using ZAP code. PMID:23206055
Gutierrez-Rodrigues, Fernanda; Santana-Lemos, Bárbara A.; Scheucher, Priscila S.; Alves-Paiva, Raquel M.; Calado, Rodrigo T.
2014-01-01
Telomere length measurement is an essential test for the diagnosis of telomeropathies, which are caused by excessive telomere erosion. Commonly used methods are terminal restriction fragment (TRF) analysis by Southern blot, fluorescence in situ hybridization coupled with flow cytometry (flow-FISH), and quantitative PCR (qPCR). Although these methods have been used in the clinic, they have not been comprehensively compared. Here, we directly compared the performance of flow-FISH and qPCR to measure leukocytes' telomere length of healthy individuals and patients evaluated for telomeropathies, using TRF as standard. TRF and flow-FISH showed good agreement and correlation in the analysis of healthy subjects (R2?=?0.60; p<0.0001) and patients (R2?=?0.51; p<0.0001). In contrast, the comparison between TRF and qPCR yielded modest correlation for the analysis of samples of healthy individuals (R2?=?0.35; p<0.0001) and low correlation for patients (R2?=?0.20; p?=?0.001); Bland-Altman analysis showed poor agreement between the two methods for both patients and controls. Quantitative PCR and flow-FISH modestly correlated in the analysis of healthy individuals (R2?=?0.33; p<0.0001) and did not correlate in the comparison of patients' samples (R2?=?0.1, p?=?0.08). Intra-assay coefficient of variation (CV) was similar for flow-FISH (10.8±7.1%) and qPCR (9.5±7.4%; p?=?0.35), but the inter-assay CV was lower for flow-FISH (9.6±7.6% vs. 16±19.5%; p?=?0.02). Bland-Altman analysis indicated that flow-FISH was more precise and reproducible than qPCR. Flow-FISH and qPCR were sensitive (both 100%) and specific (93% and 89%, respectively) to distinguish very short telomeres. However, qPCR sensitivity (40%) and specificity (63%) to detect telomeres below the tenth percentile were lower compared to flow-FISH (80% sensitivity and 85% specificity). In the clinical setting, flow-FISH was more accurate, reproducible, sensitive, and specific in the measurement of human leukocyte's telomere length in comparison to qPCR. In conclusion, flow-FISH appears to be a more appropriate method for diagnostic purposes. PMID:25409313
Alignment and arm length measurement of the swing arm profilometer using a laser tracker
NASA Astrophysics Data System (ADS)
Jing, Hongwei; King, Christopher; Walker, David
2010-10-01
In this paper, we present the use of the laser tracker to aid the alignment of a Swing Arm Profilometer (SAP) and measure the length of the swinging arm, thus calibrating the operating radius of the SAP. The measurement uncertainty analysis is given. A laser tracker is used to align the SAP to ensure the path of the probe head passes through the rotary axis of the rotary table. By building the coordinate system by laser tracker measurement on the rotary table and measuring the swinging arc of the arm, we can determine whether the swinging path of the probe head passes through the rotary axis of the rotary table and perform the corresponding adjustment if necessary. A laser tracker is also used to measure the arm length, i.e. the length between the probe's ball centre and the rotation axis of the swinging arm. By placing a retroreflector or the tracker ball on the swinging arm and scanning the swinging path of the arm using the laser tracker, we can acquire the data of an arc and fit to determine the length of the probe head center to rotation axis of swinging arm, thus giving accurate SAP calibration data.
Correlation of atmospheric optical turbulence and meteorological measurements
Gail M. Tirrell Vaucher
1989-01-01
The correlation of meteorological events such as the jet stream, gravity waves and boundary layer circulation with the optical turbulence parameters, the transverse coherence length r sub o and the isoplanatic angle is essential for interpreting and forecasting imaging and laser systems performance. In support of the United States Air Force Relay Mirror Experiment, the Naval Postgraduate School performed a
NASA Astrophysics Data System (ADS)
Min, Qilong; Clothiaux, Eugene E.
2003-08-01
An algorithm for retrieving the first two moments of the photon path length probability density function for both the oxygen A-band and the 0.820 ?m water vapor band from measurements of the second generation Rotating Shadowband Spectrometer (RSS) is developed and applied to data from the Atmospheric Radiation Measurements (ARM) Program Southern Great Plains (SGP) site. In the algorithm, solar direct-beam measurements are used to characterize the instrument response function in pixel (i.e., wavelength) space. By using nonlinear least squares regression with a two-parameter gamma function constraint, the mean and variance of the photon path length probability density function for cloudy skies are subsequently retrieved from spectral measurements in both bands. Two case studies illustrate that the variance of the photon path length probability density function is more sensitive than the mean of the probability density function to vertical cloud structure. Interestingly, the first two moments of the photon path length probability density function appear to exhibit sufficient sensitivity to detect cirrus that the ARM SGP millimeter-wave cloud radar failed to detect. Photon path length probability density functions from both the oxygen A-band and 0.820 ?m water vapor band provide additional insights into radiative transfer through a variety of cloudy conditions, improving our understanding of water vapor absorption of solar radiation in these conditions.
Tree-Based Wavelet Regression for Correlated Data using the Minimum Description Length Principle
Thomas C. M. Lee
2000-01-01
This article considers the problem of nonparametric regression using wavelet techniques.Its main contribution is the proposal of a new wavelet estimation procedurefor recovering functions corrupted by correlated noise, although a similar procedure forindependent noise is also presented. Two special features of the proposed procedure arethat, it imposes a so--called tree constraint on the wavelet coefficients, and that it usesthe minimum
The densities, correlations and length distributions of vortices produced at a gaussian quench
Karra, G
1996-01-01
We present a model for the formation of relativistic global vortices (strings) at a quench, and calculate their density and correlations. The significance of these results to early universe and condensed-matter physics is discussed. In particular, there is always open, or infinite, string.
Dysversion of the optic disc and axial length measurements in a presumed amblyopic population
Philip Lempert; Lynn Porter
1998-01-01
Purpose: Our purpose was to evaluate anatomic variations of eyes presumed to be amblyopic. Method: Computer imaging and photography of the optic discs of 205 amblyopic subjects were performed and the axial lengths of 183 of the subjects were measured. The paired optic nerve images were evaluated for symmetry of disc contours and orientation of central blood vessels to detect
Acoustic method for measuring the sound speed of gases over small path lengths
Acoustic method for measuring the sound speed of gases over small path lengths J. S. Olfert,a M. D, Canada Received 9 February 2007; accepted 8 April 2007; published online 9 May 2007 Acoustic "phase shift this method the discrete acoustic wave and phase detection DAWPD method. Experimental results show
Sung-Hwan Cho; Won-Tae Kim; Choon-Soeb Tae; M Zaheeruddin
2004-01-01
This study examined the temperature dependent regression models of energy consumption as a function of the length of the measurement period. The methodology applied was to construct linear regression models of daily energy consumption from 1 day to 3 months data sets and compare the annual heating energy consumption predicted by these models with actual annual heating energy consumption. A
Failure of the Cross Correlation Measurement Technique
NASA Astrophysics Data System (ADS)
McGill, Ken; Ham, Katie; Schock, Kris
2014-03-01
The experiment involves creating a sound wave that propagates down a pipe with 8 transducers attached at equally spaced intervals of 0.01016 meters. The numerical method used to solve for the phase component, the Cross Correlation Method, creates a high correlation value, but the speed of sound varies immensely. The method involves a Fast Fourier Transform of the collected data, which is used to find the phase of the sound wave, and the slope of the position versus time graph, which is used to calculate the speed of sound. This high correlation values shows that the data is correct, but the numerical method for analyzing the data is incorrect. We would like to thank Dr. Ken McGill for all of his time, help, and guidance with this research project. We would also like to thank Georgia College and State University for both the resources and space necessary for this experiment.
Focal length measurement of a microlens-array by grating shearing interferometry.
Zhu, Xianchang; Hu, Song; Zhao, Lixin
2014-10-10
Based on grating shearing interferometry, a simple technique is introduced for focal length measurements of a microlens-array (MLA). The measurement system is composed of a He-Ne laser, condenser, collimator, the MLA under testing, a Ronchi grating, and CCD sensor. The plane wavefront from the collimator is transformed to a spherical wavefront by the MLA, while the curvature center is at the focus. Interference stripes appear at the overlap between the zero-order and first-order diffractive patterns of the grating and are detected by the CCD sensor. By analyzing the period change of stripes, the focal length is determined after the defocus of the grating is calculated. To validate the feasibility, an experiment is performed. The measurement uncertainty is discussed and measurement accuracy was determined to be 2%. PMID:25322367
Shiro Ishikawa; Shinkichi Kamata; Noriaki Usui; Toshio Sawai; Keisuke Nose; Akira Okada
2003-01-01
Pulmonary hypoplasia is involved in patients with various surgical diseases. The aim of this study was to evaluate the clinical usefulness of measurement of the chest\\/trunk-length ratio (C\\/T) for predicting pulmonary hypoplasia in patients with congenital anomalies, with the exception of mass-like lesions in the thorax such as diaphragmatic hernia and cystic lung diseases. For measurement of C\\/T on fetal
NASA Astrophysics Data System (ADS)
Hogan, Conor; Palummo, Maurizia; Gierschner, Johannes; Rubio, Angel
2013-01-01
Excited states of ethylene-linked free-base porphyrin oligomers and polymer are studied using many-body perturbation theory (MBPT) within the GW approximation and the Bethe-Salpeter equation. Trends in the electronic levels with oligomer length are analysed and the correct long-range behaviour in the band gap is obtained. High polarizabilities and strong redshifts in the optical absorption peaks are predicted in agreement with observations on other strongly conjugated oligoporphyrins. We explain these trends by means of spatial and spectral analyses of the exciton character. Although Wannier-Mott and charge-transfer excitons are identified in the optical spectra, the strongest polarizabilities are actually associated with small, tightly bound excitons (Frenkel-like), in contrast to expectations. Furthermore, the common procedure of extrapolating polymer properties from oligomer calculations is examined from a MBPT perspective.
Correlation measures in bipartite states and entanglement irreversibility
Shengjun Wu
2012-07-24
We derive quantitative relations among several naturally defined measures of classical and nonclassical correlations in a bipartite quantum state. We also obtain an upper bound of entanglement irreversibility and a sufficient condition for reversible entanglement. The additivity of entanglement of formation is directly related to the additivity of quantum discord as well as a certain measure of classical correlation.
Simple focal-length measurement technique with a circular Dammann grating.
Zhao, Shuai; Wen, Jacky Fung; Chung, Po Sheun
2007-01-01
A novel technique for focal-length measurements with a circular Dammann grating is presented. In the back focal plane of the lens under test, a one-order circular Dammann grating with limited aperture will produce double-humped radial rings. The separation between the two lobes varies with the displacement of the observed plane from the focal plane of the lens. By searching for the position at which the separation is minimal, the focal point of the lens can be located and hence the back focal length can be determined. Experimental results demonstrated that this method is efficient and can be used effectively for a quick check of focal length. PMID:17167552
NASA Astrophysics Data System (ADS)
Barši?, Gorana; Mahovi?, Sanjin; Bartolo Picotto, Gian; Amer, Mohamed A.; Runje, Biserka
2011-09-01
In the Laboratory for Precise Measurements of Length, LFSB, which is now the Croatian National Laboratory for Length, unique roughness reference standards were developed in the year 1986. Because of the world-class quality of those standards and their measuring features, the same were sold in several European countries, and today they, among others, are used as roughness reference standards in Italy, Slovenia and Croatia. However, especially in the last decade, there was significant progress in the field of nanotechnology that led to the development of new measuring equipment. The above-mentioned standards due to their size, production technology and measuring features cannot fully meet metrological requirements in the field of nanometrology, i.e. they are not compatible with scanning probe microscopes. Therefore, it was decided to search for possible limitations in the procedure of groove depth measurements on the LFSB standards. In order to include as many measuring devices as possible, i.e. measurement methods, in this research, in 2008 the LFSB launched EURAMET Project 1012 'Limitations of methods for measuring the depth of the groove' in collaboration with national metrology institutes of Italy and Egypt. In this paper the results of measurements performed within the project are presented, and based on the obtained results, the advantages and limitations of the LFSB standards have been discussed, with recommendations for their improvement.
Photoelectron track length distributions measured in a negative ion time projection chamber
Prieskorn, Z R; Kaaret, P E; Black, J K
2014-01-01
We report photoelectron track length distributions between 3 and 8 keV in gas mixtures of Ne+CO2+CH3NO2 (260:80:10 Torr) and CO2+CH3NO2 (197.5: 15 Torr). The measurements were made using a negative ion time projection chamber (NITPC) at the National Synchrotron Light Source (NSLS) at the Brookhaven National Laboratory (BNL). We report the first quantitative analysis of photoelectron track length distributions in a gas. The distribution of track lengths at a given energy is best fit by a lognormal distribution. A powerlaw distribution of the form, f(E)=a(E/Eo)n, is found to fit the relationship between mean track length and energy. We find n=1.29 +/- 0.07 for Ne+CO2+CH3NO2 and n=1.20 +/- 0.09 for CO2+CH3NO2. Understanding the distribution of photoelectron track lengths in proportional counter gases is important for optimizing the pixel size and the dimensions of the active region in electron-drift time projection chambers (TPCs) and NITPC X-ray polarimeters.
Zhang, Yi-Feng; Zhang, Yan; Lu, Cui-Yun; Cao, Ding-Chen; Sun, Xiao-Wen
2008-05-01
Forty-seven microsatellite markers were selected to analyze the genomic DNA of 92 progenies derived from the recombinant inbred lines (RIL) of common carp, which came from the cross between Barbless carp and Hebao-cold tolerance red carp. The results showed that a total of 162 different alleles were found, and the number of alleles in each locus was 2 to 6. The DNA fragment length was 100 bp to 444 bp, and the number of mean valid alleles was 1.3069 to 4.2288. The value of heterozygosity was 0.2361 to 0.7677, and the mean polymorphism information content (PIC) was 0.5368. A GLM procedure was used to analyze the effects of these 47 microsatellites on body weight, length and height. Results uncovered HLJ695, HLJ716, HLJ739, HLJ759, HLJ774 and K16 had a significant impact on body weight, length and height, and HLJ776 had a significant impact on height. In addition, the genotypes of these correlative loci were determined. PMID:18487152
Is Socioeconomic Status Associated With Biological Aging as Measured by Telomere Length?
Robertson, Tony; Batty, G. David; Der, Geoff; Fenton, Candida; Shiels, Paul G.; Benzeval, Michaela
2013-01-01
It has been hypothesized that one way in which lower socioeconomic status (SES) affects health is by increasing the rate of biological aging. A widely used marker of biological aging is telomere length. Telomeres are structures at the ends of chromosomes that erode with increasing cell proliferation and genetic damage. We aimed to identify, through systematic review and meta-analysis, whether lower SES (greater deprivation) is associated with shorter telomeres. Thirty-one articles, including 29 study populations, were identified. We conducted 3 meta-analyses to compare the telomere lengths of persons of high and low SES with regard to contemporaneous SES (12 study populations from 10 individual articles), education (15 study populations from 14 articles), and childhood SES (2 study populations from 2 articles). For education, there was a significant difference in telomere length between persons of high and low SES in a random-effects model (standardized mean difference (SMD) = 0.060, 95% confidence interval (CI): 0.002, 0.118; P = 0.042), although a range of sensitivity analyses weakened this association. There was no evidence for an association between telomere length and contemporaneous SES (SMD = 0.104, 95% CI: ?0.027, 0.236; P = 0.119) or childhood SES (SMD = ?0.037, 95% CI: ?0.143, 0.069; P = 0.491). These results suggest weak evidence for an association between SES (as measured by education) and biological aging (as measured by telomere length), although there was a lack of consistent findings across the SES measures investigated here. PMID:23258416
Validation of atmospheric sounders by correlative measurements.
Pougatchev, Nikita
2008-09-10
A linear mathematical model for the statistical estimate of the bias and noise of satellite sounders and a case study are presented. The model provides the tool for proper comparison of actual performance of the remote sensing system while in orbit to correlative data sets. The model accounts for: (i) noncoincidence in time and space of satellite and validating systems sampling; (ii) different characteristics of the validated and validating systems, e.g., different vertical resolutions and noise levels. In the case study the model is applied to validation of temperature profile retrievals using radiosondes for the reference. PMID:18784779
William M. Carey
1997-01-01
Experimental measurements of signal coherence and array signal gain are reviewed for both deep and shallow water sound channels. The signal gain is related to the horizontal coherence length through relationships from the statistical theory of antennas. Signal gain measurements in the transverse direction are proffered as a practical measure of coherence length for both broadband and narrowband signals. Using
NASA Astrophysics Data System (ADS)
Gumus, Kutalmis; Erkaya, Halil
2013-04-01
Nowadays the developments in the technologies are contributed to accuracy and reliability of terrestrial laser Scanning Technology. Therefore, Terrestrial laser scanners (TLS) are used in many engineering applications. The working principle of Terrestrial laser scanners is similar to reflectorless total stations. Terrestrial laser scanner is a device that can quickly measure the 3-dimensional point cloud of an image that is scanned in the form of x, y, z points. With the help of these operations, the realistic 3D models of scanned objects are generated. Terrestrial laser scanners have also significant advantages that distinguish them from traditional measurement methods. The accuracy and reliability of final products of TLS depends on accuracy and resolution of data obtained from laser scanner. The scientific research studies are carried out focusing on accuracy and sensitivity. Studies in this paper were made in Calibration Baseline (20-meter) and EDM Baseline (300 -meter) in the department of Geomatic Engineering, at the Yildiz Technical University. Purpose of this study is to determine the accuracy and sensitivity of length measuring of Optech ILRIS 3D Terrestrial Laser Scanner and Total station. Tests were carried out with specially prepared targets and in environments where they included the environmental and laboratory impacts. In this paper, geometric and nominal measurements of 3-dimensional (3D) models or point coordinate gathered by scanning object surfaces and targets using TLS were compared to the measurements of Total Stations (1+2ppm). In particular, the effects of the accuracy and sensitivity of the measuring length of the targets were determined. This reference targets shifted at varying intervals from the center of the scan point. TLS measurements were made between reference points and the starting point. The point clouds obtained by scanning created surface models. The differences in these movement directions of created surface models have identifying the movement of the reference object. The Tests determining the accuracy of length measurement of Optech ILRIS 3D Terrestrial Laser Scanner and Total Station are discussed.
Monotonic correlation analysis of image quality measures for image fusion
NASA Astrophysics Data System (ADS)
Kaplan, Lance M.; Burks, Stephen D.; Moore, Richard K.; Nguyen, Quang
2008-04-01
The next generation of night vision goggles will fuse image intensified and long wave infra-red to create a hybrid image that will enable soldiers to better interpret their surroundings during nighttime missions. Paramount to the development of such goggles is the exploitation of image quality (IQ) measures to automatically determine the best image fusion algorithm for a particular task. This work introduces a novel monotonic correlation coefficient to investigate how well possible IQ features correlate to actual human performance, which is measured by a perception study. The paper will demonstrate how monotonic correlation can identify worthy features that could be overlooked by traditional correlation values.
NASA Astrophysics Data System (ADS)
Balling, Petr; Mašika, Pavel; K?en, Petr; Doležal, Miroslav
2012-09-01
In this paper we describe the progress we have made in our simultaneous length measurement and the femtosecond comb interferometric spectroscopy in a conventional arrangement with a moving mirror. Scanning and detection over an interval longer than the distance between two consecutive pulses of the frequency comb allow for a spectral resolution of the individual frequency modes of the comb. Precise knowledge of comb mode frequency leads to a precise estimation of the spectral characteristics of inspected phenomena. Using the pulse train of the frequency comb allows for measurement with highly unbalanced lengths of interferometer arms, i.e. an absolute long distance measurement. Further, we present a non-contact (double sided) method of measurement of the length/thickness of plane-parallel objects (gauge blocks, glass samples) by combining the fs comb (white light) with single frequency laser interferometry. The position of a fringe packet is evaluated by estimating the stationary phase position for any wavelength in the spectral band used. The repeatability of this position estimation is a few nanometres regardless of whether dispersion of the arms is compensated (transform limited fringe packet ˜10 fringes FWHM) or highly different (fringe packet stretched to >200 fringes FWHM). The measurement of steel gauge block by this method was compared with the standard method, and deviation (+13 ± 12) nm for gauge blocks (2 to 100) mm was found. The measurement of low reflecting ceramic gauges or clear glass samples was also tested. In the case of glass, it becomes possible to measure simultaneously both the thickness and the refractive index (and dispersion) of flat samples.
NASA Astrophysics Data System (ADS)
Kumar, Bharat; Crittenden, Scott R.
2013-03-01
We present a method to obtain the Debye screening length of a dilute electrolytic solution by measuring the capacitve force using atomic force microscopy (AFM). A small AC bias voltage of frequency ? was applied between an AFM cantilever and conducting substrate in an electrolytic solution and the resulting capacitive force between them was measured from the cantilever oscillations. The 2 ? component of the oscillating force was used to obtain the capacitance gradient between the AFM cantilever tip and substrate as a function of tip-sample distance z. An analytic expression relating tip-sample distance z and capacitance gradient between AFM tip and conducting substrate in an electrolytic solution was derived using the solution of the linearized Poisson-Boltzmann equation. We find that the analytic expression fits well with the experimental data for dilute KCl-water solutions. The fit parameters were further used to calculate the Debye screening length of the electrolytic solution. We present a method to obtain the Debye screening length of a dilute electrolytic solution by measuring the capacitve force using atomic force microscopy (AFM). A small AC bias voltage of frequency ? was applied between an AFM cantilever and conducting substrate in an electrolytic solution and the resulting capacitive force between them was measured from the cantilever oscillations. The 2 ? component of the oscillating force was used to obtain the capacitance gradient between the AFM cantilever tip and substrate as a function of tip-sample distance z. An analytic expression relating tip-sample distance z and capacitance gradient between AFM tip and conducting substrate in an electrolytic solution was derived using the solution of the linearized Poisson-Boltzmann equation. We find that the analytic expression fits well with the experimental data for dilute KCl-water solutions. The fit parameters were further used to calculate the Debye screening length of the electrolytic solution. This research is funded by Army Research Office under grant # W911NF-11-1-0251
On the measurement of slip length for liquid flow over super-hydrophobic surface
Jian Li; Ming Zhou; Lan Cai; Xia Ye; Run Yuan
2009-01-01
To design a surface with large slip or larger drag reduction is a pop issue in the fields of liquid transporting and body\\u000a swimming. In this context, it is a crucial problem to measure the slip length for these surfaces. Here we propose a novel\\u000a method by using rheometer for this objective. This method is implemented by designing the distribution
Ultrasonic measurement of stress in railroad wheels and in long lengths of welded rail
NASA Technical Reports Server (NTRS)
Clotfelter, W. N.; Risch, E. R.
1974-01-01
The failure of high speed emergency braking is discussed for railroad wheels and track. It is shown that high compressive residual stresses exist in the rims of new wheels which generate excessive heat, reducing the stress levels. Thermal stresses that build up in continuous lengths of welded track are reported and nondestructive methods of measuring stresses in thick steel are presented for identification, replacement, or adjustment before hazardous failures occur.
Impedance Analysis of Bunch Length Measurements at the ATF Damping Ring
Bane, Karl LF
2001-07-25
We present energy spread and bunch length measurements at the Accelerator Test Facility (ATF) at KEK, as functions of current, for different ring rf voltages, and with the beam both on and off the coupling resonance. We fit the on-coupling bunch shapes to those of an impedance model consisting of a resistor and an inductor connected in series. We find that the fits are reasonably good, but that the resulting impedance is unexpectedly large.
Corpus Callosum Measurements Correlate with Developmental Delay in Smith-Lemli-Opitz Syndrome
Lee, Ryan W.Y.; Yoshida, Shoko; Jung, Eun Sol; Mori, Susumu; Baker, Eva H.; Porter, Forbes D.
2013-01-01
Background Smith-Lemli-Opitz syndrome (SLOS) is a multiple malformation, neurodevelopmental disorder of cholesterol metabolism caused by mutations in 7-dehydrocholesterol reductase (DHCR7). Corpus callosum (CC) malformations and developmental delay are common manifestations of this disorder, but the relationship between the two has not been evaluated. We tested the hypothesis that shorter callosal length and smaller area correlates with higher serum 7-dehydrocholesterol (7DHC) and increased severity of neurodevelopmental delay in a large cohort of SLOS patients. Methods Thirty-six individuals with SLOS (18M/18F) between 0.20 and 12.5 years (mean = 3.9, SD = 3.6) and 36 typically developing controls (18M/18F) between 0.12 and 12.8 years (mean = 4.0, SD = 3.6) were each imaged one time on a 1.5T MR scanner. One mid-sagittal image per study was selected for manual measurement of CC cross-sectional area and length. Gross motor, fine motor, and language developmental quotients, anatomical severity score, and serum sterol levels were assessed with imaging measurements. Results Shorter CC length and smaller area correlated with lower developmental quotient in gross motor and language domains. Furthermore, length and area negatively correlated with a serum 7DHC, 8DHC, sterol ratio, and anatomical severity score, and positively correlated with total cholesterol. The degree of developmental delay ranged from mild to severe, involving all domains. Conclusions For individuals with SLOS, smaller callosal area and length are associated with higher serum 7DHC, anatomic severity, and motor and language delay. These findings suggest the relationship between callosal development, biochemistry, and neurodevelopment may lead to finding predictors of outcome in SLOS. PMID:23859856
Ng, Jason; Sehgal, Vinod; Ng, Justin K; Gordon, David; Goldberger, Jeffrey J
2014-02-01
Atrial fibrillation (AF) electrograms are characterized by varying morphologies, amplitudes, and cycle lengths (CLs), presenting a challenge for automated detection of individual activations and the activation rate. In this study, we evaluate an algorithm to detect activations and measure CLs from AF electrograms. This algorithm iteratively adjusts the detection threshold level until the mean CL converges with the median CL to detect all individual activations. A total of 291 AF electrogram recordings from 13 patients (11 male, 58 ± 10 years old) undergoing AF ablation were obtained. Using manual markings by two independent reviewers as the standard, we compared the cycle length iteration algorithm with a fixed threshold algorithm and dominant frequency (DF) for the estimation of CL. At segment lengths of 10 s, when comparing the algorithm detected to the manually detected activation, the undersensing, oversensing, and total discrepancy rates were 2.4%, 4.6%, and 7.0%, respectively, and with absolute differences in mean and median CLs were 7.9 ± 9.6 ms and 5.6 ± 6.8 ms, respectively. These results outperformed DF and fixed threshold-based measurements. This robust method can be used for CL measurements in either real-time and offline settings and may be useful in the mapping of AF. PMID:24216630
A multifunctional optical correlator for picosecond UV laser pulse measurement
Abudureyimu, Reheman [ORNL; Wang, Yang [University of Alabama, Huntsville; Garcia, Frances [University of Tennessee, Knoxville (UTK); Long, Cary D [ORNL; Huang, Chunning [ORNL; Takeda, Yasuhiro [ORNL; Liu, Yun [ORNL
2014-01-01
A compact optical correlator system that measures both the autocorrelation between two infrared (IR) lights and the cross-correlation between an IR and an ultraviolet (UV) light using a single nonlinear optical crystal has been designed and experimentally demonstrated. The rapid scanning of optical delay line, switching between auto and cross-correlations, crystal angle tuning, and data acquisition and processing are all computer controlled. Pulse widths of an IR light from a mode-locked laser are measured by the correlator and the results are compared with a direct measurement using a high-speed photodetector system. The correlator has been used to study the parameter dependence of the pulse width of a macropulse UV laser designed for laser-assisted hydrogen ion (H-) beam stripping for the Spallation Neutron Source at Oak Ridge National Laboratory.
Measurement and analysis of two- and three-particle correlations
M. Csanad
2006-02-17
Allowed regions of core fraction versus partial coherence are obtained from analysis of both two- and three-pion Bose-Einstein correlations measured at PHENIX in $\\sqrt{s_{NN}}=200$ GeV Au+Au collisions. Two-pion Bose-Einstein correlation functions for different average transverse momenta are used to analyze chiral symmetry restoration.
Absolute detector quantum-efficiency measurements using correlated photons
A. L. Migdall; R. U. Datla; A. Sergienko; J. S. Orszak; Y. H. Shih
1995-01-01
An experimental system using correlated photons for radiometric purposes has been set up at the National Institute of Standards and Technology (NIST). We use pairs of correlated photons to produce spatial maps of the absolute efficiency of a photomultiplier photocathode at four wavelengths. We also compare this technique with measurements carried out by conventional means tied to existing radiometric standards.
Multivariate distributions with correlation matrices for nonlinear repeated measurements
J. K. Lindsey; P. J. Lindsey
2006-01-01
The polynomial growth curve model based on the multivariate normal distribution has dominated the analysis of continuous longitudinal repeated measurements for the last 50 years. The main reasons include the ease of modelling dependence because of the availability of the correlation matrix and the linearity of the regression coefficients. However, a variety of other useful distributions also involve a correlation
Measuring absolute infrared spectral radiance with correlated visible photons
Sergienko, Alexander
techniques have shown promise in two areas of radiometry: absolute measurement of detector quantum efficiency of measuring absolute spec- tral radiance without externally calibrated stan- dards, one employs the processMeasuring absolute infrared spectral radiance with correlated visible photons: technique
Method of glass melter electrode length measurement using time domain reflectometry (TDR)
Tarpley, James M.; Zamecnik, John R.
2000-02-28
The present invention overcomes the drawbacks inherent in the prior art and solves the problems inherent in conventional Joule-heated vitrification melters, where the melter preferably comprises a vessel having a refractory liner and an opening for receiving material which is converted into molten vitreous material in the vessel. The vessel has an outlet port for removing molten vitreous material from the vessel. A plurality of electrodes is disposed in the vessel and electrical energy is passed between electrode pairs through feed material and molten vitreous material in the vessel. Typically, the electrodes erode and wear in time, and this invention seeks to monitor and evaluate the length and condition of the electrodes. The present invention uses time domain reflectometry (TDR) methods to accurately measure the length of an electrode that is subject to wear and electrolytic decomposition due to the extreme conditions in which the electrode is required to operate. Specifically, TDR would be used to measure the length and effects of erosion of molybdenum electrodes used in Joule-heated vitrification melter. Of course, the inventive concept should not be limited to this preferred environment.
Application of flow-FISH for dynamic measurement of telomere length in cell division.
Borisov, Vyacheslav I; Korolkova, Olga Y; Kozhevnikov, Vladimir S
2014-01-01
This method makes it possible to measure the fluorescence of a DNA probe in cells with known division number and targeted surface antigen. In fact, this method is a combination or consistent application of three other methods: cell tracking by vital dye, surface immunophenotyping, and flow-FISH. The idea in developing this method was to study telomere length changes in cells with known surface antigen after every new cell division. First, the in vitro cell culturing and staining with CFSE vital dye are performed. Then, cells are stained with surface MAbs labeled with biotin, followed by incubation with streptavidin-labeled fluorochrome. After that, cells are fixed with BS(3) reagent followed by the flow-FISH procedure with PNA-probe complementary to telomere DNA repeats. Finally, in one tube, it is possible to determine telomere length in surface antigen-labeled cells that have made the exact same number of divisions after incubation. PMID:24984965
Bazoni, R F; Lima, C H M; Ramos, E B; Rocha, M S
2015-05-20
By using optical tweezers with an adjustable trap stiffness, we have performed systematic single molecule stretching experiments with two types of DNA-intercalator complexes, in order to investigate the effects of the maximum applied forces on the mechanical response of such complexes. We have explicitly shown that even in the low-force entropic regime the persistence length of the DNA-intercalator complexes is strongly force-dependent, although such behavior is not exhibited by bare DNA molecules. We discuss the possible physicochemical effects that can lead to such results. In particular, we propose that the stretching force can promote partial denaturation on the highly distorted double-helix of the DNA-intercalator complexes, which interfere strongly in the measured values of the persistence length. PMID:25913936
Bunch Length Measurements at the ATF Damping Ring in April 2000
Bane, K.L.F.; /SLAC; Naito, T.; Okugi, T.; Urakawa, J.; /KEK, Tsukuba
2005-12-19
We want to accurately know the energy spread and bunch length dependence on current in the ATF damping ring. One reason is to know the strength of the impedance: From the energy spread measurements we know whether or not we are above the threshold to the microwave instability, and from the energy spread and bunch length measurements we find out the extent of potential-well bunch lengthening (PWBL). Another reason for these measurements is to help in our understanding of the intra-beam scattering (IBS) effect in the ATF. The ATF as it is now, running below design energy and with the wigglers turned off, is strongly affected by IBS. To check for consistency with IBS theory of, for example, the measured vertical beam size, we need to know all dimensions of the beam, including the longitudinal one. But beyond this practical reason for studying IBS, IBS is currently a hot research topic at many accelerators around the world (see e.g. Ref. [1]), and the effect in actual machines is not well understood. Typically, when comparing theory with measurements fudge factors are needed to get agreement (see e.g. Ref. [1]). With its strong IBS effect, the ATF is an ideal machine for studying IBS, and an indispensable ingredient for this study is a knowledge of the longitudinal phase space of the beam. The results of earlier bunch lengthening measurements in the ATF can be found in Refs. [2]-[4]. Measurements of current dependent effects, especially bunch length measurements using a streak camera, can be difficult to perform accurately. For example, space charge in the camera itself can lead to systematic errors in the measurement results. It is important the results be accurate and reproducible. In the measurements of both December 1998[3] and December 1999[4], by using light filters, the authors first checked that space charge in the streak camera was not significant. And then the Dec 99 authors show that their results agree with those Dec 98, i.e. on the dates of the two measurements the results were reproducible. Since IBS is so strong in the ATF, in the Dec 99 measurements an attempt was made to estimate the impedance effect using the following method: First, from the form of the energy spread vs. current measurements it was concluded that the threshold to the microwave instability was beyond 2 mA. Then, by dividing the bunch length vs. current curve by the energy spread vs. current curve the effect of IBS was divided out, and PWBL was approximated. The assumption is that PWBL can be treated as a perturbation on top of IBS. The result was that this component of bunch lengthening was found to grow by 7-15% (depending on the rf voltage) between the currents of .5 mA and 2 mA, about a factor of 3 less than the total bunch length growth. The conclusion was that the inductive component of the impedance was small, in fact much smaller than had been concluded earlier in Ref. [2]. Electron machines generally run in a parameter regime where IBS is an insignificant effect, and impedance measurements and calculations have also normally been performed for machines where IBS is unimportant. To simplify the interpretation of the impedance from bunch length measurements, in April 2000 the energy spread and bunch length measurements of Dec 99 were repeated, but now with the beam on a linear (difference) coupling resonance, where the horizontal and vertical emittances were approximately equal. For this case the effect of IBS was expected to be very small. An energy spread vs. current measurement under such conditions will also allow us to more clearly see whether we reach the threshold to the microwave instability. As part of the April data taking we, in addition, repeated the earlier off-coupling measurements, in order to check the reproducibility of the earlier results. In this report we present and analyze this recent set of data, and compare it with the results of the earlier measurements, particularly those of Dec 99. The measurements and analysis of data in this report follow essentially the same procedure as was used in Ref. [4]. In the prese
Correlations among adiposity measures in school-aged children
2013-01-01
Background Given that it is not feasible to use dual x-ray absorptiometry (DXA) or other reference methods to measure adiposity in all pediatric clinical and research settings, it is important to identify reasonable alternatives. Therefore, we sought to determine the extent to which other adiposity measures were correlated with DXA fat mass in school-aged children. Methods In 1110 children aged 6.5-10.9 years in the pre-birth cohort Project Viva, we calculated Spearman correlation coefficients between DXA (n=875) and other adiposity measures including body mass index (BMI), skinfold thickness, circumferences, and bioimpedance. We also computed correlations between lean body mass measures. Results 50.0% of the children were female and 36.5% were non-white. Mean (SD) BMI was 17.2 (3.1) and total fat mass by DXA was 7.5 (3.9) kg. DXA total fat mass was highly correlated with BMI (rs=0.83), bioimpedance total fat (rs=0.87), and sum of skinfolds (rs=0.90), and DXA trunk fat was highly correlated with waist circumference (rs=0.79). Correlations of BMI with other adiposity indices were high, e.g., with waist circumference (rs=0.86) and sum of subscapular plus triceps skinfolds (rs=0.79). DXA fat-free mass and bioimpedance fat-free mass were highly correlated (rs=0.94). Conclusions In school-aged children, BMI, sum of skinfolds, and other adiposity measures were strongly correlated with DXA fat mass. Although these measurement methods have limitations, BMI and skinfolds are adequate surrogate measures of relative adiposity in children when DXA is not practical. PMID:23799991
NSDL National Science Digital Library
2012-01-01
This lesson introduces students to the measurable attribute of length and provides practice in measuring length using non-standard units. The lesson is launched using the story Ladybug on the Move by Richard Fowler. Lesson objectives, teaching ideas, and handouts are included.
Correlates of Objectively Measured Sedentary Behavior in US Preschool Children
Byun, Wonwoo; Dowda, Marsha
2011-01-01
OBJECTIVE: To identify correlates of objectively measured sedentary behavior in a diverse sample of preschool children. METHODS: A total of 331 children (51% male, 51% black) from a wide range of ethnic and socioeconomic backgrounds in greater Columbia, South Carolina, were recruited for this study. Sedentary behavior (minutes/hour) was measured by using ActiGraph accelerometers (<37.5 counts per 15 seconds) over a 2-week period. All potential correlates except for anthropometric data of children were measured by a parent survey. Correlation and regression analyses were conducted to examine associations between 29 potential correlates across multiple domains (demographic, biological, psychosocial, behavioral, and physical environmental) and sedentary behavior measured by accelerometry in preschool children. RESULTS: Girls spent more time in sedentary behavior than boys (33.2 vs 32.4 minutes/hour; P = .05). Six and 8 potential correlates were found to be significant in univariate analyses for boys and girls, respectively. In the gender-specific final model, for boys, a child's weekday TV/video games and physical activity equipment in the home were significant correlates of sedentary behavior (R2 = 0.091). For girls, BMI z score and child's athletic coordination were significantly associated with sedentary behavior (R2 = 0.069). CONCLUSION: Several factors were identified as correlates of objectively measured sedentary behavior in American preschool children. However, there were no common correlates that influenced sedentary behavior for both boys and girls. Future interventions for reducing sedentary behavior could target correlates identified in this study. PMID:22007010
Diffusion length measurement using the scanning electron microscope. [for silicon solar cell
NASA Technical Reports Server (NTRS)
Weizer, V. G.
1975-01-01
The present work describes a measuring technique employing the scanning electron microscope in which values of the true bulk diffusion length are obtained. It is shown that surface recombination effects can be eliminated through application of highly doped surface field layers. The effects of high injection level and low-high junction current generation are investigated. Results obtained with this technique are compared to those obtained by a penetrating radiation (X-ray) method, and a close agreement is found. The SEM technique is limited to cells that contain a back surface field layer.
Inlet Turbulence and Length Scale Measurements in a Large Scale Transonic Turbine Cascade
NASA Technical Reports Server (NTRS)
Thurman, Douglas; Flegel, Ashlie; Giel, Paul
2014-01-01
Constant temperature hotwire anemometry data were acquired to determine the inlet turbulence conditions of a transonic turbine blade linear cascade. Flow conditions and angles were investigated that corresponded to the take-off and cruise conditions of the Variable Speed Power Turbine (VSPT) project and to an Energy Efficient Engine (EEE) scaled rotor blade tip section. Mean and turbulent flowfield measurements including intensity, length scale, turbulence decay, and power spectra were determined for high and low turbulence intensity flows at various Reynolds numbers and spanwise locations. The experimental data will be useful for establishing the inlet boundary conditions needed to validate turbulence models in CFD codes.
Axial length measurement acquisition rates of two optical biometers in cataractous eyes
Epitropoulos, Alice
2014-01-01
Purpose To compare the ability of two optical biometers to acquire the axial length (AL) measurement in cataractous eyes. Methods This prospective, comparative, single-center study comprised 105 eyes (63 patients). AL was acquired by the composite mean value of 20 measurements (composite-20 IM) and five measurements (composite-5 IM) (IOLMaster® 500 version 7.1 software), and the standard mean value of the first five measurements (standard-5 LS, Lenstar LS 900®). Anterior chamber depth (ACD) and average keratometry (K) readings were acquired. Results AL was acquired in 83.8%, 92.4%, and 84.8% of eyes for the composite-5 IM, composite-20 IM, and standard-5 LS, respectively. Standard-5 LS AL measurements were significantly shorter (P<0.001). IOLMaster® 500-acquired ACD (corneal epithelium to lens) measurements were significantly shorter (P<0.001). IOLMaster® 500 average K measurements were significantly steeper (P<0.001). Conclusion The composite-20 IM had the highest AL acquisition success rate of the three versions evaluated. AL, ACD, and average Ks were statistically different between the two biometers, although the differences were clinically insignificant. PMID:25092960
Statistical Measures of Planck Scale Signal Correlations in Interferometers
Craig J. Hogan; Ohkyung Kwon
2015-06-26
A model-independent statistical framework is presented to interpret data from systems where the mean time derivative of positional cross correlation between world lines, a measure of spreading in a quantum geometrical wave function, is measured with a precision smaller than the Planck time. The framework provides a general way to constrain possible departures from perfect independence of classical world lines, associated with Planck scale bounds on positional information. A parametrized candidate set of possible correlation functions is shown to be consistent with the known causal structure of the classical geometry measured by an apparatus, and the holographic scaling of information suggested by gravity. Frequency-domain power spectra are derived that can be compared with interferometer data. Simple projections of sensitivity for specific experimental set-ups suggests that measurements will directly yield constraints on a universal time derivative of the correlation function, and thereby confirm or rule out a class of Planck scale departures from classical geometry.
Statistical Measures of Planck Scale Signal Correlations in Interferometers
Craig J. Hogan; Ohkyung Kwon
2015-06-22
A model-independent statistical framework is presented to interpret data from systems where the mean time derivative of positional cross correlation between world lines, a measure of spreading in a quantum geometrical wave function, is measured with a precision smaller than the Planck time. The framework provides a general way to constrain possible departures from perfect independence of classical world lines, associated with Planck scale bounds on positional information. A parametrized candidate set of possible correlation functions is shown to be consistent with the known causal structure of the classical geometry measured by an apparatus, and the holographic scaling of information suggested by gravity. Frequency-domain power spectra are derived that can be compared with interferometer data. Simple projections of sensitivity for specific experimental set-ups suggests that measurements will directly yield constraints on a universal time derivative of the correlation function, and thereby confirm or rule out a class of Planck scale departures from classical geometry.
Isotopic fractionation in proteins as a measure of hydrogen bond length
McKenzie, Ross H; Ramesh, Sai
2015-01-01
If a deuterated molecule containing strong intramolecular hydrogen bonds is placed in a hydrogenated solvent it may preferentially exchange deuterium for hydrogen. This preference is due to the difference between the vibrational zero-point energy for hydrogen and deuterium. It is found that the associated fractionation factor $\\Phi$ is correlated with the strength of the intramolecular hydrogen bonds. This correlation has been used to determine the length of the H-bonds (donor-acceptor separation) in a diverse range of enzymes and has been argued to support the existence of short low-barrier H-bonds. Starting with a potential energy surface based on a simple diabatic state model for H-bonds we calculate $\\Phi$ as a function of the proton donor-acceptor distance $R$. For numerical results, we use a parameterization of the model for symmetric O-H.... O bonds. We consider the relative contributions of the O-H stretch vibration, O-H bend vibrations (both in plane and out of plane), tunnelling splitting effects at...
Kabata, Tamon; Maeda, Toru; Kajino, Yoshitomo; Tsuchiya, Hiroyuki
2014-01-01
Background Several studies have shown that better placement of the acetabular cup and femoral stem can be achieved in total hip arthroplasty (THA) by using the computer navigation system rather than the free-hand alignment methods. However, there have been no comparisons of the relevant clinical advantages in using the computer navigation as opposed to the manual intraoperative measurement devices. The purpose of this study is to determine whether the use of computer navigation can improve postoperative leg length discrepancy (LLD) compared to the use of the measurement device. Methods We performed a retrospective study comparing 30 computer-assisted THAs with 40 THAs performed using a simple manual measurement device. Results The postoperative LLD was 3.0 mm (range, 0 to 8 mm) in the computer-assisted group and 2.9 mm (range, 0 to 10 mm) in the device group. Statistically significant difference was not seen between the two groups. Conclusions The results showed good equalization of the leg lengths using both computed tomography-based navigation and the simple manual measurement device. PMID:24900895
Measurement of s-wave scattering lengths in a two-component Bose-Einstein condensate
NASA Astrophysics Data System (ADS)
Egorov, M.; Opanchuk, B.; Drummond, P.; Hall, B. V.; Hannaford, P.; Sidorov, A. I.
2013-05-01
We use collective oscillations of a two-component Bose-Einstein condensate (2CBEC) of 87Rb atoms prepared in the internal states |1>?|F=1,mF=-1> and |2>?|F=2,mF=1> for the precision measurement of the interspecies scattering length a12 with a relative uncertainty of 1.6×10-4. We show that in a cigar-shaped trap the three-dimensional (3D) dynamics of a component with a small relative population can be conveniently described by a one-dimensional (1D) Schrödinger equation for an effective harmonic oscillator. The frequency of the collective oscillations is defined by the axial trap frequency and the ratio a12/a11, where a11 is the intraspecies scattering length of a highly populated component 1 and is largely decoupled from the scattering length a22, the total atom number and loss terms. By fitting numerical simulations of the coupled Gross-Pitaevskii equations to the recorded temporal evolution of the axial width we obtain the value a12=98.006(16)a0, where a0 is the Bohr radius. Our reported value is in reasonable agreement with the theoretical prediction a12=98.13(10)a0 but deviates significantly from the previously measured value a12=97.66a0 [Phys. Rev. Lett.PRLTAO0031-900710.1103/PhysRevLett.99.190402 99, 190402 (2007)] which is commonly used in the characterization of spin dynamics in degenerate 87Rb atoms. Using Ramsey interferometry of the 2CBEC we measure the scattering length a22=95.44(7)a0 which also deviates from the previously reported value a22=95.0a0 [Phys. Rev. Lett.PRLTAO0031-900710.1103/PhysRevLett.99.190402 99, 190402 (2007)]. We characterize two-body losses for component 2 and obtain the loss coefficients ?12=1.51(18)×10-14cm3/s and ?22=8.1(3)×10-14cm3/s.
Measurement of intact-core length of atomizing liquid jets by image deconvolution
NASA Astrophysics Data System (ADS)
Woodward, Roger; Burch, Robert; Kuo, Kenneth; Cheung, Fan-Bill
1993-11-01
The investigation of liquid jet breakup and spray development is critical to the understanding of combustion phenomena in liquid propellant rocket engines. Much work has been done to characterize low-speed liquid jet breakup and dilute sprays, but atomizing jets and dense sprays have yielded few quantitative measurements due to their high liquid load fractions and hence their optical opacity. Focus was on a characteristic of the primary breakup process of round liquid jets, namely the length of the intact-liquid core. The specific application considered is that of shear-coaxial-type rocket engine injectors in which liquid oxygen is injected through the center post while high velocity gaseous hydrogen is injected through a concentric annulus, providing a shear force to the liquid jet surface. Real-time x ray radiography, capable of imaging through the dense two-phase region surrounding the liquid core, is used to make the measurements. The intact-liquid-core length data were obtained and interpreted using two conceptually different methods to illustrate the effects of chamber pressure, gas-to-liquid momentum ratio, and cavitation.
Scattering Corrections in Neutron beta-decay Angular Correlation Measurements
Robert Pattie
2010-01-01
Measurements of angular correlations in neutron beta-decay, such as the electron momentum-neutron spin correlation A, require precise knowledge of the energy and momentum of the emitted electron and or proton. However, accurate determination of these observables is often limited by our understanding of scattering from materials before detection. Over the past decade, the UCNA experiment has developed a PENELOPE-based Monte
NASA Astrophysics Data System (ADS)
Leon, R. P.
Diffusion lengths and surface recombination velocities were measured in GaAs diodes and InP finished solar cells. The basic technique used was charge collection microscopy, also known as electron beam induced current (EBIC). The normalized currents and distances from the pn junction were read directly from the calibrated curves obtained while using the line-scan mode in an SEM. These values were then equated to integral and infinite series expressions resulting from the solution of the diffusion equation with both extended-generation and point-generation functions. This expands previous work by examining both thin and thick samples. The surface recombination velocity was either treated as an unknown in a system of two equations or measured directly using low e(-) beam accelerating voltages. These techniques give accurate results by accounting for the effects of surface recombination and the finite size of the generation volume.
NASA Astrophysics Data System (ADS)
Leon, R. P.
1987-05-01
Diffusion lengths and surface recombination velocities were measured in GaAs diodes and InP finished solar cells. The basic techniques used was charge collection microscopy also known as electron beam induced current (EBIC). The normalized currents and distances from the pn junction were read directly from the calibrated curves obtained while using the line scan mode in an SEM. These values were then equated to integral and infinite series expressions resulting from the solution of the diffusion equation with both extended generation and point generation functions. This expands previous work by examining both thin and thick samples. The surface recombination velocity was either treated as an unknown in a system of two equations, or measured directly using low e(-) beam accelerating voltages. These techniques give accurate results by accounting for the effects of surface recombination and the finite size of the generation volume.
NASA Technical Reports Server (NTRS)
Leon, R. P.
1987-01-01
Diffusion lengths and surface recombination velocities were measured in GaAs diodes and InP finished solar cells. The basic techniques used was charge collection microscopy also known as electron beam induced current (EBIC). The normalized currents and distances from the pn junction were read directly from the calibrated curves obtained while using the line scan mode in an SEM. These values were then equated to integral and infinite series expressions resulting from the solution of the diffusion equation with both extended generation and point generation functions. This expands previous work by examining both thin and thick samples. The surface recombination velocity was either treated as an unknown in a system of two equations, or measured directly using low e(-) beam accelerating voltages. These techniques give accurate results by accounting for the effects of surface recombination and the finite size of the generation volume.
NASA Technical Reports Server (NTRS)
Leon, R. P.
1987-01-01
Diffusion lengths and surface recombination velocities were measured in GaAs diodes and InP finished solar cells. The basic technique used was charge collection microscopy, also known as electron beam induced current (EBIC). The normalized currents and distances from the pn junction were read directly from the calibrated curves obtained while using the line-scan mode in an SEM. These values were then equated to integral and infinite series expressions resulting from the solution of the diffusion equation with both extended-generation and point-generation functions. This expands previous work by examining both thin and thick samples. The surface recombination velocity was either treated as an unknown in a system of two equations or measured directly using low e(-) beam accelerating voltages. These techniques give accurate results by accounting for the effects of surface recombination and the finite size of the generation volume.
Precision measurement of {pi}{pi} scattering lengths at the NA48/2 experiment
Venditti, Stefano [Universita di Pisa, Largo B. Pontecorvo 3, 56127 Pisa (Italy)
2010-12-28
The NA48/2 experiment at CERN [1] collected {approx}18{center_dot}10{sup 9} charged kaon decays during the years 2003/4. Along with the primary goals of the collaboration, i.e. the measurement of the CP-violating asymmetry in the K{sup {+-}}{yields}{pi}{sup {+-}}{pi}{sup +}{pi}{sup -} and K{sup {+-}}{yields}{pi}{sup {+-}}{pi}{sup 0}{pi}{sup 0} decays thanks to the simultaneous collection of K{sup +} and K{sup -} events, the collected data allowed to perform many other interesting analyses. In this paper two independent measurements of {pi}{pi} scattering lengths will be reviewed, using NA48/2 data from the K{sup {+-}}{yields}e{sup {+-}}{nu}{pi}{sup +}{pi}{sup -} decay and from the cusp effect in K{sup {+-}}{yields}{pi}{sup {+-}}{pi}{sup +}{pi}{sup -} respectively.
Measuring Omega and the real correlation function from the redshift correlation function
NASA Technical Reports Server (NTRS)
Hamilton, A. J. S.
1992-01-01
Peculiar velocities distort the correlation function of galaxies in redshift space. In the linear regime, the distortion has a characteristic quadrupole plus hexadecapole form. The amplitude of the distortion depends on the cosmological density parameter Omega. Practical formulas are derived here which can be applied to redshift galaxy catalogs to measure Omega in the linear regime. The formulas also yield the real underlying correlation function in the linear regime, corrected for peculiar velocities.
Error estimations of 3D digital image correlation measurements
NASA Astrophysics Data System (ADS)
Becker, Thomas; Splitthof, Karsten; Siebert, Thorsten; Kletting, Peter
2006-08-01
Systematical errors of digital image correlation (DIC) measurements build a limiting factor for the accuracy of the resulting quantities. A major source for introducing systematical errors is the system calibration. We present a 3D digital image correlation system, which provides error information not only of diverse error sources but even more the propagation of errors throughout the calculations to the resulting contours, displacements and strains. On the basis of this system we discuss error sources, error propagation and the impact on correlation results. Performance tests for studying the impact of calibration errors on the resulting data are shown.
Analyzing complex networks through correlations in centrality measurements
NASA Astrophysics Data System (ADS)
Furlan Ronqui, José Ricardo; Travieso, Gonzalo
2015-05-01
Many real world systems can be expressed as complex networks of interconnected nodes. It is frequently important to be able to quantify the relative importance of the various nodes in the network, a task accomplished by defining some centrality measures, with different centrality definitions stressing different aspects of the network. It is interesting to know to what extent these different centrality definitions are related for different networks. In this work, we study the correlation between pairs of a set of centrality measures for different real world networks and two network models. We show that the centralities are in general correlated, but with stronger correlations for network models than for real networks. We also show that the strength of the correlation of each pair of centralities varies from network to network. Taking this fact into account, we propose the use of a centrality correlation profile, consisting of the values of the correlation coefficients between all pairs of centralities of interest, as a way to characterize networks. Using the yeast protein interaction network as an example we show also that the centrality correlation profile can be used to assess the adequacy of a network model as a representation of a given real network.
Direct measurements of hydrophobic slippage using double-focus fluorescence cross-correlation
Olga I. Vinogradova; Kaloian Koynov; Andreas Best; François Feuillebois
2008-02-04
We report results of direct measurements of velocity profiles in a microchannel with hydrophobic and hydrophilic walls, using a new high precision method of double-focus spacial fluorescence cross-correlation under a confocal microscope. In the vicinity of both walls the measured velocity profiles do not turn to zero by giving a plateau of constant velocity. This apparent slip is proven to be due to a Taylor dispersion, an augmented by shear diffusion of nanotracers in the direction of flow. Comparing the velocity profiles near the hydrophobic and hydrophilic walls for various conditions shows that there is a true slip length due to hydrophobicity. This length, of the order of several tens of nanometers, is independent on electrolyte concentration and shear rate.
Newman, Mark
1 Measures of sexual partnerships: lengths, gaps, overlaps and sexually transmitted infection Betsy system of sexually transmitted infections. We describe the distributions of gaps, lengths and overlaps language. We limited our analysis to the 1051 (88%) of participants who reported ever engaging in vaginal
2011-01-01
Background Surprisingly, in several multi-cellular eukaryotes optimal codon use correlates negatively with gene length. This contrasts with the expectation under selection for translational accuracy. While suggested explanations focus on variation in strength and efficiency of translational selection, it has rarely been noticed that the negative correlation is reported only in organisms whose optimal codons are biased towards codons that end with G or C (-GC). This raises the question whether forces that affect base composition - such as GC-biased gene conversion - contribute to the negative correlation between optimal codon use and gene length. Results Yeast is a good organism to study this as equal numbers of optimal codons end in -GC and -AT and one may hence compare frequencies of optimal GC- with optimal AT-ending codons to disentangle the forces. Results of this study demonstrate in yeast frequencies of GC-ending (optimal AND non-optimal) codons decrease with gene length and increase with recombination. A decrease of GC-ending codons along genes contributes to the negative correlation with gene length. Correlations with recombination and gene expression differentiate between GC-ending and optimal codons, and also substitution patterns support effects of GC-biased gene conversion. Conclusion While the general effect of GC-biased gene conversion is well known, the negative correlation of optimal codon use with gene length has not been considered in this context before. Initiation of gene conversion events in promoter regions and the presence of a gene conversion gradient most likely explain the observed decrease of GC-ending codons with gene length and gene position. PMID:21481245
Rehm, Thomas; Baums, Christoph G; Strommenger, Birgit; Beyerbach, Martin; Valentin-Weigand, Peter; Goethe, Ralph
2007-01-01
Amplified fragment length polymorphism (AFLP) typing was applied to 116 Streptococcus suis isolates with different clinical backgrounds (invasive/pneumonia/carrier/human) and with known profiles of virulence-associated genes (cps1, -2, -7 and -9, as well as mrp, epf and sly). A dendrogram was generated that allowed identification of two clusters (A and C) with different subclusters (A1, A2, C1 and C2) and two heterogeneous groups of strains (B and D). For comparison, three strains from each AFLP subcluster and group were subjected to multilocus sequence typing (MLST) analysis. The closest relationship and lowest diversity were found for patterns clustering within AFLP subcluster A1, which corresponded with sequence type (ST) complex 1. Strains within subcluster A1 were mainly invasive cps1 and mrp+ epf+ (or epf*) sly+ cps2+ strains of porcine or human origin. A new finding of this study was the clustering of invasive mrp* cps9 isolates within subcluster A2. MLST analysis suggested that A2 correlates with a single ST complex (ST87). In contrast to A1 and A2, subclusters C1 and C2 contained mainly pneumonia isolates of genotype cps7 or cps2 and epf- sly-. In conclusion, this study demonstrates that AFLP allows identification of clusters of S. suis strains with clinical relevance. PMID:17172524
Axial Length Measurement Failure Rates with the IOLMaster and Lenstar LS 900 in Eyes with Cataract
Pesudovs, Konrad; Yang, Xin; Bao, Fangjun; Yu, Ayong; Lin, Shishi; Feng, Yifan; Huang, Jinhai
2015-01-01
Purpose To evaluate axial length (AL) measurement failure rate with the IOLMaster (Carl Zeiss AG, Germany) and Lenstar LS 900 (Haag-Streit AG, Switzerland) in eyes with cataract. Methods Two hundred and ninety-six eyes of 170 patients with cataract were enrolled. Cataract type and severity were graded using the Lens Opacities Classification System III (LOCS III) and AL measurements were attempted with IOLMaster (version 5.4) and Lenstar LS 900 (version 1.1). Chi-squared analysis was used to assess if the difference in AL measurement acquisition rate was statistically significant between the two devices. The association of the different cataract types and severity with the AL measurement acquisition rate was evaluated with logistic regression analysis. Results AL measurements were obtained in 184 eyes (62.16%) using the IOLMaster and 191 eyes (64.53%) using the Lenstar, which corresponds to a failure rate of 37.84% and 35.47% respectively. Chi-square analysis indicated no significant difference between the Lenstar and IOLMaster for AL measurement failure rate (x2 = 0.356, P = 0.550). Logistic regression analysis indicated no association between acquisition rates and cortical or nuclear cataracts with either device. There was a statistically significant association between acquisition rates and increasing severity of posterior subcapsular cataracts with the IOLMaster (? = -1.491, P<0.001) and Lenstar LS 900 (? = -1.507, P<0.001). Conclusion The IOLMaster and Lenstar LS 900 have similar AL measurement failure rates (35–38%) for Chinese public hospital cataract patients. Increasing severity of posterior subcapsular cataracts was problematic for both devices. PMID:26061554
Helle, Samuli
METHODS Digit length ratio (2D/4D): comparing measurements from X-rays and photographs in field-Verlag 2009 Abstract The ratio of second-to-fourth digit length (2D/4D) has been suggested to be a useful in measuring 2D/4D. We examined the age and sex dependency and lateral asymmetry of 2D/4D in field voles
Satoshi Inada; Masahiro Yoshita; Makoto Okano; Toshiyuki Ihara; Hidefumi Akiyama; Liming Zhang
2008-01-01
We measured the cavity length dependence of the internal differential quantum efficiency etaint and the internal optical loss alphaint in 1500-nm-wavelength laser diodes (LDs). By evaluating alphaint directly from gain\\/absorption spectra for various injection current densities and measuring the external differential quantum efficiency etaext, we obtained the etaint and alphaint values of all the LDs with different cavity lengths. The
Bing Qi; Andrew Tausz; Li Qian; Hoi-Kwong Lo
2005-01-01
We propose and experimentally demonstrate a single-mode fiber length and dispersion measurement system based on what we believe to be a novel frequency-shifted asymmetric Sagnac interferometer incorporating an acousto-optic modulator (AOM). By sweeping the driving frequency of the AOM, which is asymmetrically placed in the Sagnac loop, the optical length of the fiber can be determined by measuring the corresponding
D A Rajon; D W Jokisch; P W Patton; A P Shah; C J Watchman; W E Bolch
2002-01-01
Chord-length distributions through the trabecular regions of the skeleton have been investigated since the early 1960s. These distributions have become important features for bone marrow dosimetry; as such, current models rely on the accuracy of their measurements. Recent techniques utilize nuclear magnetic resonance (NMR) microscopy to acquire 3D images of trabecular bone that are then used to measure 3D chord-length
Acoustic ship signature measurements by cross-correlation method.
Fillinger, Laurent; Sutin, Alexander; Sedunov, Alexander
2011-02-01
Cross-correlation methods were applied for the estimation of the power spectral density and modulation spectrum of underwater noise generated by moving vessels. The cross-correlation of the signal from two hydrophones allows the separation of vessel acoustic signatures in a busy estuary. Experimental data recorded in the Hudson River are used for demonstration that cross-correlation method measured the same ship noise and ship noise modulation spectra as conventional methods. The cross-correlation method was then applied for the separation of the acoustic signatures of two ships present simultaneously. Presented methods can be useful for ship traffic monitoring and small ship classification, even in noisy harbor environments. PMID:21361436
Jenkins, D.M.; Lysak, P.D.; Capone, D.E. [Penn State University Applied Research Laboratory, 2001 Jefferson Davis Highway Alexandria, VA 22301 (United States); Brown, W.L. [Westinghouse, LLC (United States); Askari, V. [Advanced Measurement and Analysis Group, 2396 Dunwin Drive, Mississauga, Ontario, L5L 1J9 (Canada)
2006-07-01
Based on past experience with ultrasonic cross-correlation flow meters in power plant environments, the presence of spatially correlated noise due to pressure waves, vibration, or sources other than transport of turbulent eddies will cause a bias in the time delays measured by the meter. Several techniques were developed to detect the existence of such correlated noise and correct for its effect at plant conditions. An analytical and experimental investigation was performed to further understand the basic physics of the noise mechanisms. The dominant error mechanisms investigated in this work were speed of sound perturbations due to pressure fluctuations and beam path length changes due to wall vibration. An analytical model was formulated which estimates the signal level of the flow meter based on the turbulent velocity field. From this model, an estimate of the system noise which would cause contamination could be determined. A test at a water tunnel facility was performed in order to evaluate the noise mechanisms. During this test, measurements were taken with and without controlled noise sources. Pressure and acceleration measurements were used to evaluate a coherent noise removal technique developed to mitigate the impact of noise in the ultrasonic cross-correlation flow measurement. The coherent noise removal technique was shown to be effective in removing noise during the water tunnel test. (authors)
Correlative studies in optical reflectance measurements of cerebral blood oxygenation
NASA Astrophysics Data System (ADS)
Kan Wan, Siew; Guo, Zhixiong
2006-03-01
A numerical study is made of correlation development for measuring cerebral blood oxygen saturation (StO) noninvasively using optical reflectance ratio of dual wavelengths. The Monte Carlo (MC) method was used for simulating reflectance measurements in a model neck tissue, where the cerebral blood oxygenation was monitored through the blood flows in the common carotid artery (CCA) and jugular vein. Reflectance ratios between two wavelengths at 633 and 800 nm were obtained under different blood vessel conditions. The results revealed a quantifiable correlation between the reflectance ratio and the cerebral StO level. Correlations for each of the blood vessel parameters such as the location, size, and hemoglobin concentration of the CCA or jugular vein (JV) were developed.
Photon-burst correlation techniques for atmospheric crosswind measurements
C. Y. She; R. F. Kelley
1984-01-01
With a cw visible laser, the method of photon-burst correlation is used measure atmospheric crosswinds. A scaling law, including the effects of atmospheric turbulence, for performance evaluation of both laser Doppler (LDV) and laser time-of-flight (LTV) velocimeters, is introduced theoretically and established experimentally with field experiments. Crosswind measurements in the night at a range of 500 m with a low-power
PROTOTYPE CORRELATION MASK FLAME PHOTOMETRIC DETECTOR FOR MEASURING SULFUR DIOXIDE
A prototype flame photometric detector system (FPD) to measure gaseous sulfur compounds was fabricated using a previously developed correlation mask optical system and a new flame housing. Also, a new burner for the FPD system was optimized to view the excited molecular sulfur em...
Measurement of the correlation in a multidimensional feature space
Nirmalya Sen; Rahul Das Gupta; Sandipan Chakroborty
2010-01-01
This paper introduces an index which can be used as a measure of correlation between features of a multidimensional feature vector. The proposed index has been intuitively explained using constant distance loci of Mahalanobis metric. More rigorous explanation has been given using orthogonal decomposition of the vector space. The application of the proposed index has been given using 2D synthetic
Entanglement as measure of electronelectron correlation in quantum chemistry calculations
Kais, Sabre
Entanglement as measure of electronelectron correlation in quantum chemistry calculations Zhen, United States Received 19 March 2005; in final form 12 July 2005 Abstract In quantum chemistry point and the major approach for quanti- tative electronic structure calculations. In quantum chemistry
Measuring telomere length and telomere dynamics in evolutionary biology and ecology
Nussey, Daniel H; Baird, Duncan; Barrett, Emma; Boner, Winnie; Fairlie, Jennifer; Gemmell, Neil; Hartmann, Nils; Horn, Thorsten; Haussmann, Mark; Olsson, Mats; Turbill, Chris; Verhulst, Simon; Zahn, Sandrine; Monaghan, Pat
2014-01-01
Telomeres play a fundamental role in the protection of chromosomal DNA and in the regulation of cellular senescence. Recent work in human epidemiology and evolutionary ecology suggests adult telomere length (TL) may reflect past physiological stress and predict subsequent morbidity and mortality, independent of chronological age. Several different methods have been developed to measure TL, each offering its own technical challenges. The aim of this review is to provide an overview of the advantages and drawbacks of each method for researchers, with a particular focus on issues that are likely to face ecologists and evolutionary biologists collecting samples in the field or in organisms that may never have been studied in this context before. We discuss the key issues to consider and wherever possible try to provide current consensus view regarding best practice with regard to sample collection and storage, DNA extraction and storage, and the five main methods currently available to measure TL. Decisions regarding which tissues to sample, how to store them, how to extract DNA, and which TL measurement method to use cannot be prescribed, and are dependent on the biological question addressed and the constraints imposed by the study system. What is essential for future studies of telomere dynamics in evolution and ecology is that researchers publish full details of their methods and the quality control thresholds they employ. PMID:25834722
Pislaru, Cristina; Urban, Matthew W; Pislaru, Sorin V; Kinnick, Randall R; Greenleaf, James F
2014-08-01
Our aims were (i) to compare in vivo measurements of myocardial elasticity by shear wave dispersion ultrasound vibrometry (SDUV) with those by the conventional pressure-segment length method, and (ii) to quantify changes in myocardial viscoelasticity during systole and diastole after reperfused acute myocardial infarction. The shear elastic modulus (?1) and viscous coefficient (?2) of left ventricular myocardium were measured by SDUV in 10 pigs. Young's elastic modulus was independently measured by the pressure-segment length method. Measurements made with the SDUV and pressure-segment length methods were strongly correlated. At reperfusion, ?1 and ?2 in end-diastole were increased. Less consistent changes were found during systole. In all animals, ?1 increased linearly with left ventricular pressure developed during systole. Preliminary results suggest that ?1 is preload dependent. This is the first study to validate in vivo measurements of myocardial elasticity by a shear wave method. In this animal model, the alterations in myocardial viscoelasticity after a myocardial infarction were most consistently detected during diastole. PMID:24814645
Accuracy of axial length measurements from immersion B-scan ultrasonography in highly myopic eyes
Yang, Qing-Hua; Chen, Bing; Peng, Guang-Hua; Li, Zhao-Hui; Huang, Yi-Fei
2014-01-01
AIM To evaluate the accuracy of axial length (AL) measurements obtained from immersion B-scan ultrasonography (immersion B-scan) for intraocular lens (IOL) power calculation in patients with high myopia and cataracts. METHODS Immersion B-scan, contact A-scan ultrasonography (contact A-scan), and the IOLMaster were used to preoperatively measure the AL in 102 eyes from 102 patients who underwent phacoemulsification and IOL implantation. Patients were divided into two groups according to the AL: one containing patients with 22 mm?AL<26 mm(group A) and the other containing patients with AL?26 mm (group B). The mean error (ME) was calculated from the difference between the AL measurement methods predicted refractive error and the actual postoperative refractive error. RESULTS In group A, ALs measured by immersion B-scan (23.48±1.15) didn't differ significantly from those measured by the IOLMaster (23.52±1.17) or from those by contact A-scan (23.38±1.20). In the same group, the standard deviation (SD) of the mean error (ME) of immersion B-scan (-0.090±0.397 D) didn't differ significantly from those of IOLMaster (-0.095±0.411 D) and contact A-scan (-0.099±0.425 D). In group B, ALs measured by immersion B-scan (27.97±2.21 mm) didn't differ significantly from those of the IOLMaster (27.86±2.18 mm), but longer than those measured by Contact A-scan (27.75±2.23 mm, P=0.009). In the same group, the standard deviation (SD) of the mean error (ME) of immersion B-scan (-0.635±0.157 D) didn't differ significantly from those of the IOLMaster (-0.679±0.359 D), but differed significantly from those of contact A-scan (-0.953±1.713 D, P=0.028). CONCLUSION Immersion B-scan exhibits measurement accuracy comparable to that of the IOLMaster, and is thus a good alternative in measuring AL in eyes with high myopia when the IOLMaster can't be used, and it is more accurate than the contact A-scan. PMID:24967188
Rheology of fluids measured by correlation force spectroscopy
NASA Astrophysics Data System (ADS)
Radiom, Milad; Robbins, Brian; Honig, Christopher D. F.; Walz, John Y.; Paul, Mark R.; Ducker, William A.
2012-04-01
We describe a method, correlation force spectrometry (CFS), which characterizes fluids through measurement of the correlations between the thermally stimulated vibrations of two closely spaced micrometer-scale cantilevers in fluid. We discuss a major application: measurement of the rheological properties of fluids at high frequency and high spatial resolution. Use of CFS as a rheometer is validated by comparison between experimental data and finite element modeling of the deterministic ring-down of cantilevers using the known viscosity of fluids. The data can also be accurately fitted using a harmonic oscillator model, which can be used for rapid rheometric measurements after calibration. The method is non-invasive, uses a very small amount of fluid, and has no actively moving parts. It can also be used to analyze the rheology of complex fluids. We use CFS to show that (non-Newtonian) aqueous polyethylene oxide solution can be modeled approximately by incorporating an elastic spring between the cantilevers.
Absolute Measurement Of Laminar Shear Rate Using Photon Correlation Spectroscopy
Elliot Jenner; Brian D'Urso
2015-05-11
An absolute measurement of the components of the shear rate tensor $\\mathcal{S}$ in a fluid can be found by measuring the photon correlation function of light scattered from particles in the fluid. Previous methods of measuring $\\mathcal{S}$ involve reading the velocity at various points and extrapolating the shear, which can be time consuming and is limited in its ability to examine small spatial scale or short time events. Previous work in Photon Correlation Spectroscopy has involved only approximate solutions, requiring free parameters to be scaled by a known case, or different cases, such as 2-D flows, but here we present a treatment that provides quantitative results directly and without calibration for full 3-D flow. We demonstrate this treatment experimentally with a cone and plate rheometer.
Soft defect printability: correlation to optical flux-area measurements
NASA Astrophysics Data System (ADS)
Taylor, Darren; Fiekowsky, Peter
2001-01-01
Soft defects on photomasks have, historically, been difficult to measure, and predict how the measured size of a soft defect will correlate to what prints, if at all. Over the past few years KLA-Tencor STARlight surface inspection has become the inspection of choice for soft defects. Though the capture rate of this tool is exceptional, the defect sizing capability has lacked in accuracy. Customer specifications have traditionally been built around defect size and transmission. If a given defect cannot be accurately sized then it cannot be accurately dispositioned. In this study we are attempting to show a correlation between the AVI defect measurement tool sizing and what actually prints on the wafer. We will show defect sizing both from the KLA-Tencor STARlight and pattern tools, the AVI tool, AIMS and VSS printability data.
Comparative Study of Bunch Length And Arrival Time Measurements at FLASH
Schlarb, H.; Azima, A.; Dusterer, S.; Huning, M.; Knabbe, E.A.; Roehrs, M.; Rybnikov, V.; Schmidt, B.; Steffen, B.; /DESY; Ross, M.C.; /SLAC; Schmueser, P.; Winter, A.; /Hamburg U.
2007-04-16
Diagnostic devices to precisely measure the longitudinal electron beam profile and the bunch arrival time require elaborate new instrumentation techniques. At FLASH, two entirely different methods are used. The bunch profile can be determined with high precision by a transverse deflecting RF structure, but the method is disruptive and does not allow to monitor multiple bunches in a macro-pulse train. It is therefore complemented by two non-disruptive electrooptical devices, called EO and TEO. The EO setup uses a dedicated diagnostic laser synchronized to the machine RF. The longitudinal electron beam profile is encoded in the intensity profile of a chirped laser pulse and analyzed by looking at the spectral composition of the pulse. The second setup, TEO, utilizes the TiSa-based laser system used for pump-probe experiments. Here, the temporal electron shape is encoded into the spatial dimension of the laser pulse by an intersection angle between the laser and the electron beam at the EO-crystal. In this paper, we present a comparative study of bunch length and arrival time measurements performed simultaneously with all three experimental techniques.
Technology Transfer Automated Retrieval System (TEKTRAN)
Genetic parameters for length of productive life given the opportunity (LPL|O), measured as days between first calving and disposal conditioned on one of six opportunity groups, (e.g., L2 is length of productive life in days given the opportunity to live 2 yr after first calving), and lifetime produ...
Measuring short electron bunch lengths using coherent Smith-Purcell radiation
Nguyen, D.C.
1999-03-30
A method is provided for directly determining the length of sub-picosecond electron bunches. A metallic grating is formed with a groove spacing greater than a length expected for the electron bunches. The electron bunches are passed over the metallic grating to generate coherent and incoherent Smith-Purcell radiation. The angular distribution of the coherent Smith-Purcell radiation is then mapped to directly deduce the length of the electron bunches. 8 figs.
Measuring short electron bunch lengths using coherent smith-purcell radiation
Nguyen, Dinh C. (Los Alamos, NM)
1999-01-01
A method is provided for directly determining the length of sub-picosecond electron bunches. A metallic grating is formed with a groove spacing greater than a length expected for the electron bunches. The electron bunches are passed over the metallic grating to generate coherent and incoherent Smith-Purcell radiation. The angular distribution of the coherent Smith-Purcell radiation is then mapped to directly deduce the length of the electron bunches.
Kawashima, Kazuko; Shikama, Hiroshi; Imoto, Kazuhiko; Izawa, Mitsuo; Nishimura, Susumu (National Cancer Center Research Institute, Tokyo (Japan)); Naruke, Tsuguo; Okabayashi, Kenzo (National Cancer Center Hospital, Tokyo (Japan))
1988-04-01
Restriction length fragment polymorphism of the L-MYC gene was examined in DNAs from lung cancer tissues and normal tissues of 51 Japanese patients with lung cancer. In individual patients, no difference was seen between the restriction length fragments of the two alleles of L-MYC (6-kilobase (kb)) and 10-kb fragments in EcoRI digests in lung cancer tissues and normal tissues. But a striking correlation was found between the restriction length fragment polymorphism pattern of L-MYC and the extent of metastasis, particularly to the lymph nodes at the time of surgery: Patients with only the L band (10 kb) had few lymph node metastatic lesions, whereas patients with either the S band (6 kb) or the S and L bands almost always had lymph node metastatic lesion. A similar correlation was found between the presence of the S band and metastases to other organs. This correlation was particularly marked in cases of adenocarcinoma. These results indicate a clear genetic influence on metastases and a consequent poor prognosis for certain patients of lung cancer; L-MYC restriction length fragment polymorphism is thus shown to be a useful marker for predicting the metastatic potential of human lung cancer.
Measurement and correlation of jet fuel viscosities at low temperatures
NASA Technical Reports Server (NTRS)
Schruben, D. L.
1985-01-01
Apparatus and procedures were developed to measure jet fuel viscosity for eight current and future jet fuels at temperatures from ambient to near -60 C by shear viscometry. Viscosity data showed good reproducibility even at temperatures a few degrees below the measured freezing point. The viscosity-temperature relationship could be correlated by two linear segments when plotted as a standard log-log type representation (ASTM D 341). At high temperatures, the viscosity-temperature slope is low. At low temperatures, where wax precipitation is significant, the slope is higher. The breakpoint between temperature regions is the filter flow temperature, a fuel characteristic approximated by the freezing point. A generalization of the representation for the eight experimental fuels provided a predictive correlation for low-temperature viscosity, considered sufficiently accurate for many design or performance calculations.
Measurement of angular correlations based on secondary vertex reconstruction at
V. Khachatryan; A. M. Sirunyan; A. Tumasyan; W. Adam; T. Bergauer; M. Dragicevic; J. Erö; C. Fabjan; M. Friedl; R. Frühwirth; V. M. Ghete; J. Hammer; S. Hänsel; C. Hartl; M. Hoch; N. Hörmann; J. Hrubec; M. Jeitler; G. Kasieczka; W. Kiesenhofer; M. Krammer; D. Liko; I. Mikulec; M. Pernicka; H. Rohringer; R. Schöfbeck; J. Strauss; A. Taurok; F. Teischinger; P. Wagner; W. Waltenberger; G. Walzel; E. Widl; C.-E. Wulz; V. Mossolov; N. Shumeiko; J. Suarez Gonzalez; L. Benucci; K. Cerny; E. A. De Wolf; X. Janssen; T. Maes; L. Mucibello; S. Ochesanu; B. Roland; R. Rougny; M. Selvaggi; H. Van Haevermaet; P. Van Mechelen; N. Van Remortel; S. Beauceron; F. Blekman; S. Blyweert; J. D’Hondt; O. Devroede; R. Gonzalez Suarez; A. Kalogeropoulos; J. Maes; M. Maes; S. Tavernier; W. Van Doninck; P. Van Mulders; G. P. Van Onsem; I. Villella; O. Charaf; B. Clerbaux; G. De Lentdecker; V. Dero; A. P. R. Gay; G. H. Hammad; T. Hreus; P. E. Marage; L. Thomas; C. Vander Velde; P. Vanlaer; J. Wickens; V. Adler; S. Costantini; M. Grunewald; B. Klein; A. Marinov; J. Mccartin; D. Ryckbosch; F. Thyssen; M. Tytgat; L. Vanelderen; P. Verwilligen; S. Walsh; N. Zaganidis; S. Basegmez; G. Bruno; J. Caudron; L. Ceard; J. De Favereau De Jeneret; C. Delaere; P. Demin; D. Favart; A. Giammanco; G. Grégoire; J. Hollar; V. Lemaitre; J. Liao; O. Militaru; S. Ovyn; D. Pagano; A. Pin; K. Piotrzkowski; N. Schul; N. Beliy; T. Caebergs; E. Daubie; G. A. Alves; D. De Jesus Damiao; M. E. Pol; M. H. G. Souza; W. Carvalho; E. M. Da Costa; C. De Oliveira Martins; S. Fonseca De Souza; L. Mundim; H. Nogima; V. Oguri; W. L. Prado Da Silva; A. Santoro; S. M. Silva Do Amaral; A. Sznajder; F. Torres Da Silva De Araujo; F. A. Dias; M. A. F. Dias; T. R. Fernandez Perez Tomei; E. M. Gregores; F. Marinho; S. F. Novaes; Sandra S. Padula; N. Darmenov; L. Dimitrov; V. Genchev; P. Iaydjiev; S. Piperov; M. Rodozov; S. Stoykova; G. Sultanov; V. Tcholakov; R. Trayanov; I. Vankov; M. Dyulendarova; R. Hadjiiska; V. Kozhuharov; L. Litov; E. Marinova; M. Mateev; B. Pavlov; P. Petkov; J. G. Bian; G. M. Chen; H. S. Chen; C. H. Jiang; D. Liang; S. Liang; J. Wang; X. Wang; Z. Wang; M. Xu; M. Yang; J. Zang; Z. Zhang; Y. Ban; S. Guo; Y. Guo; W. Li; Y. Mao; S. J. Qian; H. Teng; L. Zhang; B. Zhu; W. Zou; A. Cabrera; B. Gomez Moreno; A. A. Ocampo Rios; A. F. Osorio Oliveros; J. C. Sanabria; N. Godinovic; D. Lelas; K. Lelas; R. Plestina; D. Polic; I. Puljak; Z. Antunovic; M. Dzelalija; V. Brigljevic; S. Duric; K. Kadija; S. Morovic; A. Attikis; M. Galanti; J. Mousa; C. Nicolaou; F. Ptochos; P. A. Razis; H. Rykaczewski; M. Finger; Y. Assran; M. A. Mahmoud; A. Hektor; M. Kadastik; K. Kannike; M. Müntel; M. Raidal; L. Rebane; V. Azzolini; P. Eerola; S. Czellar; J. Härkönen; A. Heikkinen; V. Karimäki; R. Kinnunen; J. Klem; M. J. Kortelainen; T. Lampén; K. Lassila-Perini; S. Lehti; T. Lindén; P. Luukka; T. Mäenpää; E. Tuominen; J. Tuominiemi; E. Tuovinen; D. Ungaro; L. Wendland; K. Banzuzi; A. Korpela; T. Tuuva; D. Sillou; M. Besancon; S. Choudhury; M. Dejardin; D. Denegri; B. Fabbro; J. L. Faure; F. Ferri; S. Ganjour; F. X. Gentit; A. Givernaud; P. Gras; G. Hamel de Monchenault; P. Jarry; E. Locci; J. Malcles; M. Marionneau; L. Millischer; J. Rander; A. Rosowsky; I. Shreyber; M. Titov; P. Verrecchia; S. Baffioni; F. Beaudette; L. Bianchini; M. Bluj; C. Broutin; P. Busson; C. Charlot; T. Dahms; L. Dobrzynski; R. Granier de Cassagnac; M. Haguenauer; P. Miné; C. Mironov; C. Ochando; P. Paganini; D. Sabes; R. Salerno; Y. Sirois; C. Thiebaux; B. Wyslouch; A. Zabi; J.-L. Agram; J. Andrea; A. Besson; D. Bloch; D. Bodin; J.-M. Brom; M. Cardaci; E. C. Chabert; C. Collard; E. Conte; F. Drouhin; C. Ferro; J.-C. Fontaine; D. Gelé; U. Goerlach; S. Greder; P. Juillot; M. Karim; A.-C. Le Bihan; Y. Mikami; P. Van Hove; F. Fassi; D. Mercier; C. Baty; N. Beaupere; M. Bedjidian; O. Bondu; G. Boudoul; D. Boumediene; H. Brun; N. Chanon; R. Chierici; D. Contardo; P. Depasse; H. El Mamouni; A. Falkiewicz; J. Fay; S. Gascon; B. Ille; T. Kurca; T. Le Grand; M. Lethuillier; L. Mirabito; S. Perries; V. Sordini; S. Tosi; Y. Tschudi; P. Verdier; H. Xiao; L. Megrelidze; V. Roinishvili; D. Lomidze; G. Anagnostou; M. Edelhoff; L. Feld; N. Heracleous; O. Hindrichs; R. Jussen; K. Klein; J. Merz; N. Mohr; A. Ostapchuk; A. Perieanu; F. Raupach; J. Sammet; S. Schael; D. Sprenger; H. Weber; M. Weber; B. Wittmer; M. Ata; W. Bender; M. Erdmann; J. Frangenheim; T. Hebbeker; A. Hinzmann; K. Hoepfner; C. Hof; T. Klimkovich; D. Klingebiel; P. Kreuzer; D. Lanske; C. Magass; G. Masetti; M. Merschmeyer; A. Meyer; P. Papacz; H. Pieta; H. Reithler; S. A. Schmitz; L. Sonnenschein; J. Steggemann; D. Teyssier; M. Bontenackels; M. Davids; M. Duda; G. Flügge; H. Geenen; M. Giffels; W. Haj Ahmad; D. Heydhausen; T. Kress; Y. Kuessel; A. Linn; A. Nowack; L. Perchalla; O. Pooth; J. Rennefeld
2011-01-01
A measurement of the angular correlations between beauty and anti-beauty hadrons () produced in pp collisions at a centre-of-mass energy of 7 TeV at the CERN LHC is presented, probing for the first time the\\u000a region of small angular separation. The B hadrons are identified by the presence of displaced secondary vertices from their\\u000a decays. The B hadron angular separation
A quantitative measure of phase correlations in density fields
NASA Technical Reports Server (NTRS)
Scherrer, Robert J.; Melott, Adrian L.; Shandarin, Sergei F.
1991-01-01
A quantitative measure of the phase correlations in a density field is presented based on the location of the maxima of the Fourier components of that field. It is found that this measue can easily detect non-Gaussian behavior either in artificially constructed density fields or those that become non-Gaussian from gravitational clustering of Gaussian initial conditions. It is found that different initial power spectra produce somewhat distinguishable signals, and the signals are robust against sparse sampling.
Beta Neutrino Correlation Measurement with Trapped Radioactive Ions
Velten, Ph.; Ban, G.; Durand, D.; Flechard, X.; Lienard, E.; Mauger, F.; Naviliat-Cuncic, O. [LPC-Caen, ENSICAEN, Universite de Caen, CNRS/IN2P3-ENSI, Caen (France); Mery, A. [CIMAP, ENSICAEN, Universite de Caen, CNRS/IN2P3-ENSI, Caen (France); Rodriguez, D. [Dep. de Fisica Atomica, Molecular y Nuclear, Facultad de Ciencias, Universitad de Granada, Granada (Spain); Thomas, J.-C. [GANIL, CEA/DSM-CNRS/IN2P3, Caen (France)
2010-04-30
The beta-neutrino angular correlation coefficient provides a sensitive observable to search for physics beyond the standard electroweak model in nuclear beta decay. We address here the measurement of this parameter in the pure Gamow-Teller transition of {sup 6}He. A deviation from the standard model prediction would indicate the existence of tensor like couplings, possibly mediated by new bosons like leptoquarks. The aim of the LPCTrap experiment is to measure this coefficient with a statistical uncertainty of 0.5% using a novel transparent Paul trap. The status of the experiment is briefly presented along with the work in progress.
Norbash, A.M.; Marks, M.P.; Lane, B. [Stanford Univ. Medical Center, CA (United States)
1994-05-01
To determine whether there is a physiologic explanation for the predisposition of patients with certain angiographic characteristics to symptoms of hemorrhage and steal. Superselective transcatheter feeding arterial pressure and mean arterial pressure measurements were obtained before embolotherapy in 32 patients with cerebral arteriovenous malformations. Pressures were correlated with previously described angioarchitectural characteristics predisposing to hemorrhage and steal. These included size of the arteriovenous malformation, feeding artery length, venous drainage pattern, and angiomatous change. The feeding arterial pressure and feeding arterial pressure/mean arterial pressure ratios were significantly decreased in patients with angiomatous change. Feeding arterial pressure and feeding arterial pressure/mean arterial pressure ratios progressively decreased as lesions went from peripheral, to mixed, to central venous drainage. A trend for lower feeding arterial pressure was also demonstrated with greater feeding pedicle length. A statistically significant correlation could not be demonstrated between feeding arterial pressure or feeding arterial pressure/mean arterial pressure ratios and size of the arteriovenous malformation, hemorrhage, or symptoms of steal. Feeding arterial pressure measurements help provide a physiologic basis for the relationship between certain angiographic characteristics and hemorrhage and steal symptoms in patients with arteriovenous malformation. 27 refs., 1 fig.
NASA Astrophysics Data System (ADS)
Cao, Hui-bin; Liu, Jian-guo; Gui, Hua-qiao; Wang, Jie; Wang, Huan-qin
2014-11-01
To meet the need of long distance transmission in low turbidity measurement system for low-loss, a new optical structure with wavelength 1310nm and 1550nm as the incident light is employed. In this research, experiments have been done for different optical length of the two wavelength light sources. The results show that: first, the transmitted light intensity has big difference under the circumstance of same concentration and optical length, though the loss has no remarkable difference transmitted in optical fiber between 1310nm and 1550nm. Second, the optimized optical length for better absorbance has been determined for 1310nm and 1550nm and it is irrelevant to the incident intensity. Third, the intensity of the two transmitted light decreases exponentially with the increase of optical length. For example, when the range of the optical length of 1310nm is 0.5mm-2mm, the transmitted intensity is about 60%-79% and the absorbance is 0.12-0.42. The transmitted intensity is about 5%-44%. When the range of the optical length of 1550nm is 0.5mm-2mm and the absorbance is still 0.12-0.42. Our experimental data provides the basis both for the optical length selection of these two light sources in water and the near-infrared spectral wavelength selection.
3D shape measurement with phase correlation based fringe projection
NASA Astrophysics Data System (ADS)
Kühmstedt, Peter; Munckelt, Christoph; Heinze, Matthias; Bräuer-Burchardt, Christian; Notni, Gunther
2007-06-01
Here we propose a method for 3D shape measurement by means of phase correlation based fringe projection in a stereo arrangement. The novelty in the approach is characterized by following features. Correlation between phase values of the images of two cameras is used for the co-ordinate calculation. This work stands in contrast to the sole usage of phase values (phasogrammetry) or classical triangulation (phase values and image co-ordinates - camera raster values) for the determination of the co-ordinates. The method's main advantage is the insensitivity of the 3D-coordinates from the absolute phase values. Thus it prevents errors in the determination of the co-ordinates and improves robustness in areas with interreflections artefacts and inhomogeneous regions of intensity. A technical advantage is the fact that the accuracy of the 3D co-ordinates does not depend on the projection resolution. Thus the achievable quality of the 3D co-ordinates can be selectively improved by the use of high quality camera lenses and can participate in improvements in modern camera technologies. The presented new solution of the stereo based fringe projection with phase correlation makes a flexible, errortolerant realization of measuring systems within different applications like quality control, rapid prototyping, design and CAD/CAM possible. In the paper the phase correlation method will be described in detail. Furthermore, different realizations will be shown, i.e. a mobile system for the measurement of large objects and an endoscopic like system for CAD/CAM in dental industry.
Bing Qi; Andrew Tausz; Li Qian; Hoi-Kwong Lo
2006-07-22
We propose and experimentally demonstrate a single-mode fiber length and dispersion measurement system based on a novel frequency-shifted asymmetric Sagnac interferometer incorporating an acousto-optic modulator (AOM). By sweeping the driving frequency of the AOM, which is asymmetrically placed in the Sagnac loop, the optical length of the fiber can be determined by measuring the corresponding variation in the phase delay between the two counter-propagating light beams. Combined with a high-resolution data processing algorithm, this system yields a dynamic range from a few centimeters to 60km (limited only by our availability of long fibers) with a resolution about 1ppm for long fibers.
Measuring Fisher Information Accurately in Correlated Neural Populations
Kohn, Adam; Pouget, Alexandre
2015-01-01
Neural responses are known to be variable. In order to understand how this neural variability constrains behavioral performance, we need to be able to measure the reliability with which a sensory stimulus is encoded in a given population. However, such measures are challenging for two reasons: First, they must take into account noise correlations which can have a large influence on reliability. Second, they need to be as efficient as possible, since the number of trials available in a set of neural recording is usually limited by experimental constraints. Traditionally, cross-validated decoding has been used as a reliability measure, but it only provides a lower bound on reliability and underestimates reliability substantially in small datasets. We show that, if the number of trials per condition is larger than the number of neurons, there is an alternative, direct estimate of reliability which consistently leads to smaller errors and is much faster to compute. The superior performance of the direct estimator is evident both for simulated data and for neuronal population recordings from macaque primary visual cortex. Furthermore we propose generalizations of the direct estimator which measure changes in stimulus encoding across conditions and the impact of correlations on encoding and decoding, typically denoted by Ishuffle and Idiag respectively. PMID:26030735
Measuring fisher information accurately in correlated neural populations.
Kanitscheider, Ingmar; Coen-Cagli, Ruben; Kohn, Adam; Pouget, Alexandre
2015-06-01
Neural responses are known to be variable. In order to understand how this neural variability constrains behavioral performance, we need to be able to measure the reliability with which a sensory stimulus is encoded in a given population. However, such measures are challenging for two reasons: First, they must take into account noise correlations which can have a large influence on reliability. Second, they need to be as efficient as possible, since the number of trials available in a set of neural recording is usually limited by experimental constraints. Traditionally, cross-validated decoding has been used as a reliability measure, but it only provides a lower bound on reliability and underestimates reliability substantially in small datasets. We show that, if the number of trials per condition is larger than the number of neurons, there is an alternative, direct estimate of reliability which consistently leads to smaller errors and is much faster to compute. The superior performance of the direct estimator is evident both for simulated data and for neuronal population recordings from macaque primary visual cortex. Furthermore we propose generalizations of the direct estimator which measure changes in stimulus encoding across conditions and the impact of correlations on encoding and decoding, typically denoted by Ishuffle and Idiag respectively. PMID:26030735
EARLINET correlative measurements for CALIPSO: First intercomparison results
NASA Astrophysics Data System (ADS)
Pappalardo, Gelsomina; Wandinger, Ulla; Mona, Lucia; Hiebsch, Anja; Mattis, Ina; Amodeo, Aldo; Ansmann, Albert; Seifert, Patric; Linné, Holger; Apituley, Arnoud; Alados Arboledas, Lucas; Balis, Dimitris; Chaikovsky, Anatoli; D'Amico, Giuseppe; de Tomasi, Ferdinando; Freudenthaler, Volker; Giannakaki, Elina; Giunta, Aldo; Grigorov, Ivan; Iarlori, Marco; Madonna, Fabio; Mamouri, Rodanthi-Elizabeth; Nasti, Libera; Papayannis, Alexandros; Pietruczuk, Aleksander; Pujadas, Manuel; Rizi, Vincenzo; Rocadenbosch, Francesc; Russo, Felicita; Schnell, Franziska; Spinelli, Nicola; Wang, Xuan; Wiegner, Matthias
2010-01-01
A strategy for European Aerosol Research Lidar Network (EARLINET) correlative measurements for Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observation (CALIPSO) has been developed. These EARLINET correlative measurements started in June 2006 and are still in progress. Up to now, more than 4500 correlative files are available in the EARLINET database. Independent extinction and backscatter measurements carried out at high-performance EARLINET stations have been used for a quantitative comparison with CALIPSO level 1 data. Results demonstrate the good performance of CALIPSO and the absence of evident biases in the CALIPSO raw signals. The agreement is also good for the distribution of the differences for the attenuated backscatter at 532 nm ((CALIPSO-EARLINET)/EARLINET (%)), calculated in the 1-10 km altitude range, with a mean relative difference of 4.6%, a standard deviation of 50%, and a median value of 0.6%. A major Saharan dust outbreak lasting from 26 to 31 May 2008 has been used as a case study for showing first results in terms of comparison with CALIPSO level 2 data. A statistical analysis of dust properties, in terms of intensive optical properties (lidar ratios, Ångström exponents, and color ratios), has been performed for this observational period. We obtained typical lidar ratios of the dust event of 49 ± 10 sr and 56 ± 7 sr at 355 and 532 nm, respectively. The extinction-related and backscatter-related Ångström exponents were on the order of 0.15-0.17, which corresponds to respective color ratios of 0.91-0.95. This dust event has been used to show the methodology used for the investigation of spatial and temporal representativeness of measurements with polar-orbiting satellites.
Offset balancing in pseudo-correlation radiometers for CMB measurements
Aniello Mennella; Marco Bersanelli; Michael Seiffert; Danielle Kettle; Neil Roddis; Althea Wilkinson; Peter Meinhold
2003-08-25
Radiometeric CMB measurements need to be highly stable and this stability is best obtained with differential receivers. The residual 1/f noise in the differential output is strongly dependent on the radiometer input offset which can be cancelled using various balancing strategies. In this paper we discuss a software method implemented in the Planck-LFI pseudo-correlation receivers which uses a tunable "gain modulation factor, r, in the sky-load difference. Numerical simulations and experimental data show how proper tuning of the parameter r ensures a very stable differential output with knee frequencies of the order of few mHz. Various approaches to calculate r using the radiometer total power data are discussed with some examples relevant to Planck-LFI. Although the paper focuses on pseudo-correlation receivers and the examples are relative to Planck-LFI, the proposed method and its analysis is general and can be applied to a large class of differential radiometric receivers.
Estimating correlation for a real-time measure of connectivity.
Arunkumar, Akhil; Panday, Ashish; Joshi, Bharat; Ravindran, Arun; Zaveri, Hitten P
2012-01-01
There has recently been considerable interest in connectivity analysis of fMRI and scalp and intracranial EEG time-series. The computational requirements of the pair-wise correlation (PWC), the core time-series measure used to estimate connectivity, presents a challenge to the real-time estimation of the PWC between all pairs of multiple time-series. We describe a parallel algorithm for computing PWC in real-time for streaming data from multiple channels. The algorithm was implemented on the Intel Xeon™ and IBM Cell Broadband Engine™ platforms. We evaluated time to estimate correlation for signals recorded with different acquisition parameters as a comparison to real-time constraints. We demonstrate that the execution time of these efficient implementations meet real-time constraints in most instances. PMID:23367098
Shchelkunov, S.V.; Marshall, T.C. [Department of Applied Physics, Columbia University, New York City, NY 10027 (United States); Hirshfield, J.L. [Department of Physics, Yale University, New Haven, CT 06520-8120 (United States); Omega-P, Inc., New Haven, CT 06520 (United States); LaPointe, M.A. [Omega-P, Inc., New Haven, CT 06520 (United States); Department of Physics, Yale University, New Haven, CT 06520-8120 (United States)
2004-12-07
We report progress in the development of a nondestructive technique to measure bunch rms-length in the psec range and below, and eventually in the fsec range, by measuring the high-frequency spectrum of wake field radiation which is caused by the passage of a relativistic electron bunch through a channel surrounded by a dielectric. We demonstrate both experimentally and numerically that the generated spectrum is determined by the bunch rms-length, while the choice of the axial and longitudinal charge distribution is not important. Measurement of the millimeter-wave spectrum will determine the bunch rms-length in the psec range. This has been done using a series of calibrated mesh filters and the charge bunches produced by the 50MeV rf linac system at ATF, Brookhaven. We have developed the analysis of the factors crucial for achieving good accuracy in this measurement, and find the experimental data are fully understood by the theory. We point out that this technique also may be used for measuring fsec bunch lengths, using a prepared planar wake field microstructure.
Ozkan Celik; Marcia K. O'Malley; Corwin Boake; Harvey S. Levin; Nuray Yozbatiran; Timothy A. Reistetter
2010-01-01
In this paper, we analyze the correlations between four clinical measures (Fugl-Meyer upper extremity scale, Motor Activity Log, Action Research Arm Test, and Jebsen-Taylor Hand Function Test) and four robotic measures (smoothness of movement, trajectory error, average number of target hits per minute, and mean tangential speed), used to assess motor recovery. Data were gathered as part of a hybrid
Analysis of the EARLINET correlative measurements for CALIPSO
NASA Astrophysics Data System (ADS)
Pappalardo, Gelsomina; Mona, Lucia; Wandinger, Ulla; Mattis, Ina; Amodeo, Aldo; Ansmann, Albert; Apituley, Arnoud; Alados-Arboledas, Lucas; Balis, Dimitris; Chaikovsky, Anatoli; Comeron, Adolfo; D'Amico, Giuseppe; Freudenthaler, Volker; Giunta, Aldo; Grigorov, Ivan; Hiebsch, Anja; Linnè, Holger; Madonna, Fabio; Papayannis, Alexandros; Perrone, Maria Rita; Pietruczuk, Aleksander; Pujadas, Manuel; Rizi, Vincenzo; Spinelli, Nicola; Wiegner, Matthias
2009-09-01
Lidar techniques represent the most suitable tool to obtain information on the aerosol vertical distribution and therefore to close this kind of observational gap. Lidar networks are fundamental to study aerosol on large spatial scale and to investigate transport and modification phenomena. These are the motivations why EARLINET, the European Aerosol Research Lidar Network, was established in 2000. At present, EARLINET consists of 25 lidar stations: 7 single backscatter lidar stations, 9 Raman lidar stations with the UV Raman channel for independent measurements of aerosol extinction and backscatter, and 9 multiwavelength Raman lidar stations (elastic channel at 1064 nm, 532 nm, 355 nm, Raman channels at 532 nm and 355 nm, plus depolarization channel at 532 nm) for the retrieval of aerosol microphysical properties. EARLINET data can significantly contribute to the quantification of aerosol concentrations, radiative properties, long-range transport and budget, and prediction of future trends on European and global scale. It can also contribute to improve model treatment on a wide range of scales and to a better exploitation of present and future satellite data. EARLINET is playing an important role in the validation and in the full exploitation of the CALIPSO mission. EARLINET started correlative measurements for CALIPSO since June 2006. A strategy for correlative measurements has been defined on the base of the analysis of the high resolution ground track data provided by NASA. Results in terms of comparisons between EARLINET and available CALIPSO products, both level 1 and level 2 data, are presented.
Correlates of objectively measured physical activity in cardiac patients.
Byun, Wonwoo; Ozemek, Cemal; Riggin, Katrina; Strath, Scott; Kaminsky, Leonard
2014-10-01
Cardiac patients would benefit from increasing their physical activity (PA) levels. Understanding of factors that influence cardiac patients' PA participation would benefit the development of effective interventions. Therefore, the purpose of this study was to determine correlates of objectively-measured PA in cardiac patients. Participants were 65 cardiac patients (74% male, 95% white), age 58.6±10.6 years. The amount of time spent in PA was measured by ActiGraph GT3X accelerometers for 7 days prior to joining cardiac rehabilitation programs (CRP). A total of 25 potential determinants of PA across multiple domains (demographic, clinical, psychosocial, and behavioral) were measured via self-reported questionnaire and clinical examinations. Backward elimination model selection procedures were performed to examine associations of potential determinants with total PA (min/day) and moderate-to-vigorous PA (MVPA) (min/day). Patients spent 153.8±62.8 and 8.4±8.1 min/day in total PA and MVPA, respectively. Across four domains, ten and five potential correlates were found to be significant in univariate analyses for MVPA and total PA, respectively. In the final model, functional capacity, PA readiness, and participation in regular exercise were positively associated with MVPA (R(2) =26.6%). Functional capacity and PA readiness were also positively associated with total PA (R(2) =15.9%). Future initiatives to increase PA levels in cardiac patients could be improved by considering patients' functional capacity, PA readiness, and exercise history in designing interventions. PMID:25414828
Correlates of objectively measured physical activity in cardiac patients
Ozemek, Cemal; Riggin, Katrina; Strath, Scott; Kaminsky, Leonard
2014-01-01
Cardiac patients would benefit from increasing their physical activity (PA) levels. Understanding of factors that influence cardiac patients’ PA participation would benefit the development of effective interventions. Therefore, the purpose of this study was to determine correlates of objectively-measured PA in cardiac patients. Participants were 65 cardiac patients (74% male, 95% white), age 58.6±10.6 years. The amount of time spent in PA was measured by ActiGraph GT3X accelerometers for 7 days prior to joining cardiac rehabilitation programs (CRP). A total of 25 potential determinants of PA across multiple domains (demographic, clinical, psychosocial, and behavioral) were measured via self-reported questionnaire and clinical examinations. Backward elimination model selection procedures were performed to examine associations of potential determinants with total PA (min/day) and moderate-to-vigorous PA (MVPA) (min/day). Patients spent 153.8±62.8 and 8.4±8.1 min/day in total PA and MVPA, respectively. Across four domains, ten and five potential correlates were found to be significant in univariate analyses for MVPA and total PA, respectively. In the final model, functional capacity, PA readiness, and participation in regular exercise were positively associated with MVPA (R2 =26.6%). Functional capacity and PA readiness were also positively associated with total PA (R2 =15.9%). Future initiatives to increase PA levels in cardiac patients could be improved by considering patients’ functional capacity, PA readiness, and exercise history in designing interventions. PMID:25414828
Measures of quantum correlations in infinite-dimensional systems
M. E. Shirokov
2015-06-21
Several important measures of quantum correlations of a state of a finite-dimensional composite system are defined as linear combinations of marginal entropies of this state. This paper is devoted to the infinite-dimensional generalizations of such quantities and to the analysis of their properties. We introduce the notion of faithful extension of a linear combination of marginal entropies and consider several concrete examples starting with the quantum mutual information and the quantum conditional entropy. Then we show that the conditional mutual information can be uniquely defined as a lower semicontinuous function on the set of all states of a tripartite infinite-dimensional system possessing all the basic properties valid in finite dimensions. Infinite-dimensional generalizations of some other measures of quantum correlations in multipartite quantum systems are also considered. It is shown that almost all of these generalized measures are globally lower semicontinuous and possess local continuity properties which essentially simplify their use in analysis of quantum systems. In the second part of the paper we consider applications of the general results of its first part, in particular, to the theory of infinite-dimensional quantum channels and their capacities. We also show the existence of the Fawzi-Renner recovery channel reproducing marginal states for all tripartite states (including states with infinite marginal entropies) starting with the corresponding finite-dimensional result.
Measuring the antineutrino-beta Correlation in the Nab Experiment
NASA Astrophysics Data System (ADS)
Sprow, Aaron; Nab Collaboration
2015-04-01
The Nab experiment will be performed at the Spallation Neutron Source to measure the electron-neutrino correlation parameter a and the Fierz interference term b for unpolarized neutron beta decays. We instrumented a segmented silicon detector with fast preamplifier channels and are developing a data acquisition system with digital pulse processing for this experiment. In collaboration with UCNB, we tested the system performance with neutron beta decay events and calibration sources. We will present an overview of the Nab experiment and results of these tests.
Sub-Rayleigh limit imaging via intensity correlation measurements
NASA Astrophysics Data System (ADS)
Yao, Xu-Ri; Li, Long-Zhen; Liu, Xue-Feng; Yu, Wen-Kai; Zhai, Guang-Jie
2015-04-01
We demonstrate sub-Rayleigh limit imaging of an object via intensity correlation measurements. The image completely unaffected by the disturbance of diffraction-limit is achieved under the condition that the imaging system has an appropriate field of view. The resolution of this sub-Rayleigh limit imaging system is only tied to the lateral resolution of the illumination light. Project supported by the National Major Scientific Instruments Development Project of China (Grant No. 2013YQ030595), the Hi-Tech Research and Development Program of China (Grant No. 2011AA120102), and the National Natural Science Foundation of China (Grant No. 11275024).
Intensity and angular correlation measurements of /sup 103/Ru
Darwish, S.M.; Abdel-Malak, S.; Abou-Leila, M.A.; Walley-Eldin, N.; Hassan, A.M.
1987-01-01
The level scheme of /sup 103/Rh was investigated using a HPGe detector and a Ge(Li)-NaI(Tl) coincidence spectrometer. Four new transitions were observed, confirmed, and fitted into a proposed level scheme. The ..beta../sup -/ branching ratios and the log ft values were obtained. A measurement of the 513.98--53.3-keV ..gamma gamma.. angular correlation using a HPGe-NaI(Tl) fast coincidence spectrometer yielded the spin assignment 7/2 for the 607.2-keV level and a multipole mixing ratio E1+9.83%M2 for the 513.98-keV ..gamma.. transition.
G. Aurelio; A. Fernández Guillermet
2000-01-01
This paper deals with (i) the establishment of Pauling’s bond length vs. bond number relation (BLBNR) for Ti, Zr and Hf, and (ii) the analysis of the connections between the parameters entering into the BLBNR and the experimental interatomic distances (IDs) in the known solid phases of these elements. Recently assessed ID data on the hcp structure, which is the
Mode locking the Nd:Glass laser with BDN: Measurements of dye recovery times and laser pulse lengths
R. C. Greenhow
1975-01-01
The recovery times for transient bleaching of theQ-switch dye bis(4-dimethylaminodithiobenzil)nickel (BDN) in the solvents dichlorethane and iodoethane have been determined. The lengths of pulses from an Nd:glass laser mode locked with BDN have also been measured by means of the two-photon fluorescence technique.
Super-resolving interference without intensity-correlation measurement
NASA Astrophysics Data System (ADS)
Cao, De-Zhong; Xu, Bao-Long; Zhang, Su-Heng; Wang, Kaige
2015-05-01
The high-order intensity correlation function of N -photon interference with thermal light observed in a recent experiment [S. Oppel, T. Büttner, P. Kok, and J. von Zanthier, Phys. Rev. Lett. 109, 233603 (2012), 10.1103/PhysRevLett.109.233603] is analyzed. The terms in the expansion of the N th -order correlation function are put into three groups. One group contributes a homogeneous background. Both of the other two contribute (N -1 ) -fold super-resolving fringes. In principle they correspond to coherent and incoherent superpositions of classical optical fields, respectively. Therefore similar super-resolving fringes can be obtained without intensity-correlation measurements. We report the experimental results of the coherent and incoherent super-resolving diffraction fringes, which are observed directly in the intensity distribution. The N -1 sources in both the coherent and incoherent cases are set in certain definite positions. In the coherent case, moreover, the phase difference between two adjacent source fields is ? . The fringe visibility is unity in the incoherent case, while it decreases as N increases in the incoherent case.
NASA Astrophysics Data System (ADS)
Gao, Long; Yu, Bo-Xiang; Ding, Ya-Yun; Zhou, Li; Wen, Liang-Jian; Xie, Yu-Guang; Wang, Zhi-Gang; Cai, Xiao; Sun, Xi-Lei; Fang, Jian; Xue, Zhen; Zhang, Ai-Wu; Lü, Qi-Wen; Sun, Li-Jun; Ge, Yong-Shuai; Liu, Ying-Biao; Niu, Shun-Li; Hu, Tao; Cao, Jun; Lü, Jun-Guang
2013-07-01
An attenuation length measurement device was constructed using an oscilloscope and LabVIEW for signal acquisition and processing. The performance of the device has been tested in a variety of ways. The test results show that the set-up has a good stability and high precision (sigma/mean reached 0.4 percent). Besides, the accuracy of the measurement system will decrease by about 17 percent if a filter is used. The attenuation length of a gadolinium-loaded liquid scintillator (Gd-LS) was measured as 15.10±0.35 m where Gd-LS was heavily used in the Daya Bay Neutrino Experiment. In addition, one method based on the Beer-Lambert law was proposed to investigate the reliability of the measurement device, the R-square reached 0.9995. Moreover, three purification methods for Linear Alkyl Benzene (LAB) production were compared in the experiment.
Oxygen measurement by multimode diode lasers employing gas correlation spectroscopy.
Lou, Xiutao; Somesfalean, Gabriel; Chen, Bin; Zhang, Zhiguo
2009-02-10
Multimode diode laser (MDL)-based correlation spectroscopy (COSPEC) was used to measure oxygen in ambient air, thereby employing a diode laser (DL) having an emission spectrum that overlaps the oxygen absorption lines of the A band. A sensitivity of 700 ppm m was achieved with good accuracy (2%) and linearity (R(2)=0.999). For comparison, measurements of ambient oxygen were also performed by tunable DL absorption spectroscopy (TDLAS) technique employing a vertical cavity surface emitting laser. We demonstrate that, despite slightly degraded sensitivity, the MDL-based COSPEC-based oxygen sensor has the advantages of high stability, low cost, ease-of-use, and relaxed requirements in component selection and instrument buildup compared with the TDLAS-based instrument. PMID:19209216
NASA Astrophysics Data System (ADS)
Bracher, G.; Schraml, K.; Jakubeit, C.; Kaniber, M.; Finley, J. J.
2011-12-01
We present optical investigations of rectangular surface plasmon polariton (SPP) waveguides (WGs) lithographically defined on GaAs substrates. The plasmon propagation length is directly determined using a confocal microscope, with independent polarization control in both excitation and detection channels. Surface plasmon polaritons are launched along the waveguide using a lithographically defined defect at one end. At the remote end of the waveguide, they scatter into the far-field, where they are imaged using a CCD camera. By monitoring the length dependence of the intensity of scattered light from the waveguide end, we directly extract the propagation length, obtaining values ranging from LSPP = 10 to 40 ?m depending on the waveguide width (?WG = 2-5 ?m) and excitation wavelength (760-920 nm). Results are in good accord with theoretical expectations demonstrating the high quality of the lithographically defined structures. The results obtained are of strong relevance for the development of future semiconductor based integrated plasmonic technologies.
The Effect of Error Correlation on Interfactor Correlation in Psychometric Measurement
ERIC Educational Resources Information Center
Westfall, Peter H.; Henning, Kevin S. S.; Howell, Roy D.
2012-01-01
This article shows how interfactor correlation is affected by error correlations. Theoretical and practical justifications for error correlations are given, and a new equivalence class of models is presented to explain the relationship between interfactor correlation and error correlations. The class allows simple, parsimonious modeling of error…
Strongly correlated two-dimensional plasma explored from entropy measurements.
Kuntsevich, A Y; Tupikov, Y V; Pudalov, V M; Burmistrov, I S
2015-01-01
Charged plasma and Fermi liquid are two distinct states of electronic matter intrinsic to dilute two-dimensional electron systems at elevated and low temperatures, respectively. Probing their thermodynamics represents challenge because of lack of an adequate technique. Here, we report a thermodynamic method to measure the entropy per electron in gated structures. Our technique appears to be three orders of magnitude superior in sensitivity to a.c. calorimetry, allowing entropy measurements with only 10(8) electrons. This enables us to investigate the correlated plasma regime, previously inaccessible experimentally in two-dimensional electron systems in semiconductors. In experiments with clean two-dimensional electron system in silicon-based structures, we traced entropy evolution from the plasma to Fermi liquid regime by varying electron density. We reveal that the correlated plasma regime can be mapped onto the ordinary non-degenerate Fermi gas with an interaction-enhanced temperature-dependent effective mass. Our method opens up new horizons in studies of low-dimensional electron systems. PMID:26099565
Proton transfer and correlations between the CO, OH, NH and O?N bond lengths in amine phenolates
I. Majerz; Z. Malarski; L. Sobczyk
1997-01-01
A relationship between the geometrical parameters of the O-H? N bridge based on the results of X-ray diffraction studies of a number of amine-phenol hydrogen-bonded complexes covering a broad ?p Ka range from ?3.91 to 5.93 are proposed. The analysis shows that the shortest bridges are realized when the proton transfer degree, reflected in the C-O bond length, reaches about
Hossein Ali Khonakdar; Mahdi Golriz; Seyed-Hassan Jafari; Udo Wagenknecht
2009-01-01
PET\\/PEN blends were prepared over the full composition range via a melt mixing process under various processing conditions. This resulted in transesterification reactions and formation of copolymer structures with various average sequence block lengths (L?nPET L?nPET) and degree of randomness (RD) determined by 1H NMR. It was seen that with an increase in time and temperature of mixing copolymer content
NASA Astrophysics Data System (ADS)
Duncan, J. L.; Harvie, J. L.; McKean, D. C.; Cradock, S.
1986-07-01
Infrared spectra of the molecules Si 2HD 5, SiHD 2CH 3, SiH 3CHD 2, SiHD 2X (X = F, Cl, Br, I) have been recorded at 0.05 cm -1 resolution. Analyses of "perpendicular" fundamentals of these very slightly asymmetric top molecules permit the accurate determination of their ground state ( A0— B0) constants, from which the A 0 rotational constants may be obtained. When combined with all known Raman and microwave constants, this enables the ground state structures to be determined with precision, allowance being made for the shortening of SiH(CH) bonds on deuteration. For disilane this work represents the first spectroscopic determination of a complete structure, while for the silyl halides it demonstrates overestimates in the SiH bond length of nearly 1% by previous workers. In the case of methyl silane, comparison with a recent ab initio structure calculation reveals a considerable overestimate of the CSi bond length in the latter. A correlation between isolated SiH stretching frequency and ground state bond length over 15 molecules reveals a somewhat reduced sensitivity compared with the corresponding CH correlation. Nevertheless, a predictive capability of better than ±0.003 Å seems possible from the isolated SiH stretching frequency, at least for molecules with fully saturated bonding.
Osterberg, E C; Maganty, A; Ramasamy, R; Eid, J F
2014-01-01
Inflatable penile prosthesis (IPP) remains the gold standard for the surgical treatment of refractory erectile dysfunction; however, current literature to aid surgeons on how best to counsel patients on their postoperative inflated penile length is lacking. The aim of this study was to identify preoperative parameters that could better predict postoperative penile length following insertion of an IPP. Twenty men were enrolled in a prospective study examining penile lengths before and after IPP surgery. Patients with Peyronie's disease were excluded from this analysis. Baseline preoperative characteristics, including body mass index, history of hypertension, diabetes, Sexual Health Inventory for Men scores and/or prior radical prostatectomy were recorded. All patients underwent implantation with a three-piece inflatable Coloplast penile prosthesis. We compared stretched penile length to pharmacologically induced erect lengths. Postoperatively, we measured inflated penile lengths at 6 weeks and assessed patients' perception of penile size at 12 weeks. The median (±interquartile range) stretched penile length and pharmacologically induced erect penile length was 15 (±3) and 14.25 (±2)?cm, respectively (P=0.5). Median post-prosthesis penile length (13.5±2.13?cm) was smaller than preoperative pharmacologically induced length (P=0.02) and preoperative stretched penile length (P=0.01). The majority of patients (70%) had a decrease in penile length (median loss 0.5±1.5?cm); however, this loss was perceptible by 43% of men. Stretched penile length and pharmacologically induced erect penile length were equally good predictors of postoperative inflated length (Spearman's correlation 0.8 and 0.9, respectively). Pharmacologically induced erect penile length and stretched penile lengths are equal predictors of post-prosthesis penile length. The majority of men will experience some decrease in penile length following prosthesis implantation; however <50% report a subjective loss of penile length. PMID:24430278
NSDL National Science Digital Library
American Association for the Advancement of Science (; )
2005-03-28
This Science Update explores male agression patterns and their correlation to pre-natal testosterone exposure. Although life experience plays a huge role in shaping who we are, the foundations of our personality begin in the womb. One recent study looks to finger length for signs of a man's pre-natal exposure to testosterone.n women, the index and ring finger are roughly equal in length. But in most men, the ring finger is longer. That's a result of fetal exposure to testosterone. Psychologists Alison Bailey and Pete Hurd, of the University of Alberta in Canada, studied these finger ratios in male college students. And they found that men with more dramatic differences tended to be more aggressive. Additional links to resources are given for further inquiry.
Time Resolved Correlation measurements of temporally heterogeneous dynamics
Agnes Duri; Hugo Bissig; Veronique Trappe; Luca Cipelletti
2005-08-01
Time Resolved Correlation (TRC) is a recently introduced light scattering technique that allows to detect and quantify dynamic heterogeneities. The technique is based on the analysis of the temporal evolution of the speckle pattern generated by the light scattered by a sample, which is quantified by $c\\_I(t,\\tau)$, the degree of correlation between speckle images recorded at time $t$ and $t+\\tau$. Heterogeneous dynamics results in significant fluctuations of $c\\_I(t,\\tau)$ with time $t$. We describe how to optimize TRC measurements and how to detect and avoid possible artifacts. The statistical properties of the fluctuations of $c\\_I$ are analyzed by studying their variance, probability distribution function, and time autocorrelation function. We show that these quantities are affected by a noise contribution due to the finite number $N$ of detected speckles. We propose and demonstrate a method to correct for the noise contribution, based on a $N\\to \\infty$ extrapolation scheme. Examples from both homogeneous and heterogeneous dynamics are provided. Connections with recent numerical and analytical works on heterogeneous glassy dynamics are briefly discussed.
Time-resolved-correlation measurements of temporally heterogeneous dynamics
NASA Astrophysics Data System (ADS)
Duri, Agnès; Bissig, Hugo; Trappe, Véronique; Cipelletti, Luca
2005-11-01
Time resolved correlation (TRC) is a recently introduced light scattering technique that allows one to detect and quantify dynamic heterogeneities. The technique is based on the analysis of the temporal evolution of the speckle pattern generated by the light scattered by a sample, which is quantified by cI(t,?) , the degree of correlation between speckle images recorded at time t and t+? . Heterogeneous dynamics results in significant fluctuations of cI(t,?) with time t . We describe how to optimize TRC measurements and how to detect and avoid possible artifacts. The statistical properties of the fluctuations of cI are analyzed by studying their variance, probability distribution function, and time autocorrelation function. We show that these quantities are affected by a noise contribution due to the finite number N of detected speckles. We propose and demonstrate a method to correct for the noise contribution, based on a N?? extrapolation scheme. Examples from both homogeneous and heterogeneous dynamics are provided. Connections with recent numerical and analytical works on heterogeneous glassy dynamics are briefly discussed.
Measurements of 3D slip velocities and plasma column lengths of a gliding arc discharge
NASA Astrophysics Data System (ADS)
Zhu, Jiajian; Gao, Jinlong; Ehn, Andreas; Aldén, Marcus; Li, Zhongshan; Moseev, Dmitry; Kusano, Yukihiro; Salewski, Mirko; Alpers, Andreas; Gritzmann, Peter; Schwenk, Martin
2015-01-01
A non-thermal gliding arc discharge was generated at atmospheric pressure in an air flow. The dynamics of the plasma column and tracer particles were recorded using two synchronized high-speed cameras. Whereas the data analysis for such systems has previously been performed in 2D (analyzing the single camera image), we provide here a 3D data analysis that includes 3D reconstructions of the plasma column and 3D particle tracking velocimetry based on discrete tomography methods. The 3D analysis, in particular, the determination of the 3D slip velocity between the plasma column and the gas flow, gives more realistic insight into the convection cooling process. Additionally, with the determination of the 3D slip velocity and the 3D length of the plasma column, we give more accurate estimates for the drag force, the electric field strength, the power per unit length, and the radius of the conducting zone of the plasma column.
NASA Astrophysics Data System (ADS)
Mtsuko, D.; Koshio, A.; Yudasaka, M.; Iijima, S.; Ahlskog, M.
2015-05-01
Low temperature transport in multiwalled carbon nanotubes (MWNTs) has been studied at different diameters and lengths, within 2 -10 nm , and 0.3 -3.5 ? m , respectively. In a majority of the samples, semiconductivity showed up as a transport gap in the gate voltage controlled conduction, but metallic MWNTs are found in all diameters. The transport gap is seen to be quantitatively determined by a diameter dependent band gap, and length dependent localization of charge carriers. The band gap of semiconducting MWNTs is estimated to be smaller than that extrapolated from the conventional expression applicable to semiconducting single wall carbon nanotubes. The results constitute a systematical study on size dependent transport and especially of semiconductivity in MWNTs.
Advances in Air-Sea Flux Measurement by Eddy Correlation
NASA Astrophysics Data System (ADS)
Blomquist, Byron W.; Huebert, Barry J.; Fairall, Christopher W.; Bariteau, Ludovic; Edson, James B.; Hare, Jeffrey E.; McGillis, Wade R.
2014-09-01
Eddy-correlation measurements of the oceanic flux are useful for the development and validation of air-sea gas exchange models and for analysis of the marine carbon cycle. Results from more than a decade of published work and from two recent field programs illustrate the principal interferences from water vapour and motion, demonstrating experimental approaches for improving measurement precision and accuracy. Water vapour cross-sensitivity is the greatest source of error for flux measurements using infrared gas analyzers, often leading to a ten-fold bias in the measured flux. Much of this error is not related to optical contamination, as previously supposed. While various correction schemes have been demonstrated, the use of an air dryer and closed-path analyzer is the most effective way to eliminate this interference. This approach also obviates density corrections described by Webb et al. (Q J R Meteorol 106:85-100, 1980). Signal lag and frequency response are a concern with closed-path systems, but periodic gas pulses at the inlet tip provide for precise determination of lag time and frequency attenuation. Flux attenuation corrections are shown to be 5 % for a cavity ring-down analyzer (CRDS) and dryer with a 60-m inlet line. The estimated flux detection limit for the CRDS analyzer and dryer is a factor of ten better than for IRGAs sampling moist air. While ship-motion interference is apparent with all analyzers tested in this study, decorrelation or regression methods are effective in removing most of this bias from IRGA measurements and may also be applicable to the CRDS.
Sannibale, Fernando; Zolotorev, Max S.; Filippetto, Daniele; Stupakov, Gennady V.
2007-06-22
By analysing the pulse to pulse intensity fluctuations ofthe radiation emitted by a charge particle in the incoherent part of thespectrum, it is possible to extract information about the spatialdistribution of the beam. At the Advanced Light Source (ALS) of theLawrence Berkeley National Laboratory, we have developed and tested asimple scheme based on this principle that allows for the absolutemeasurement of the bunch length. A description of the method and theexperimental results are presented.
Water Velocity Measurement on an Extended-Length Submerged Bar Screen at John Day Dam
Weiland, Mark A.; Escher, Charles
2001-04-02
This report describes a study of water velocity around an extended-length submerged bar screen (ESBS) at John Day Dam. The study was conducted for the U.S. Army Corps of Engineers by AScI Corporation and MEVATEC Corporation in March of 2000. This report was prepared by Pacific Northwest National Laboratory. ESBS are being studied as one method for diverting juvenile migrating fish from the dam's turbine intakes into the gate well and through the juvenile fish bypass channels.
NASA Astrophysics Data System (ADS)
Kim, Kang; Saito, Shinji
2013-03-01
We report an extensive and systematic investigation of the multi-point and multi-time correlation functions to reveal the spatio-temporal structures of dynamic heterogeneities in glass-forming liquids. Molecular dynamics simulations are carried out for the supercooled states of various prototype models of glass-forming liquids such as binary Kob-Andersen, Wahnström, soft-sphere, and network-forming liquids. While the first three models act as fragile liquids exhibiting super-Arrhenius temperature dependence in their relaxation times, the last is a strong glass-former exhibiting Arrhenius behavior. First, we quantify the length scale of the dynamic heterogeneities utilizing the four-point correlation function. The growth of the dynamic length scale with decreasing temperature is characterized by various scaling relations that are analogous to the critical phenomena. We also examine how the growth of the length scale depends upon the model employed. Second, the four-point correlation function is extended to a three-time correlation function to characterize the temporal structures of the dynamic heterogeneities based on our previous studies [K. Kim and S. Saito, Phys. Rev. E 79, 060501-R (2009), 10.1103/PhysRevE.79.060501; K. Kim and S. Saito, J. Chem. Phys. 133, 044511 (2010), 10.1063/1.3464331]. We provide comprehensive numerical results obtained from the three-time correlation function for the above models. From these calculations, we examine the time scale of the dynamic heterogeneities and determine the associated lifetime in a consistent and systematic way. Our results indicate that the lifetime of the dynamical heterogeneities becomes much longer than the ?-relaxation time determined from a two-point correlation function in fragile liquids. The decoupling between the two time scales is remarkable, particularly in supercooled states, and the time scales differ by more than an order of magnitude in a more fragile liquid. In contrast, the lifetime is shorter than the ?-relaxation time in tetrahedral network-forming strong liquid, even at lower temperatures.
NASA Astrophysics Data System (ADS)
Dunlop, Katherine M.; Kuhnz, Linda A.; Ruhl, Henry A.; Huffard, Christine L.; Caress, David W.; Henthorn, Richard G.; Hobson, Brett W.; McGill, Paul; Smith, Kenneth L.
2015-02-01
The 25 year time-series collected at Station M, ~4000 m on the Monterey Deep-sea Fan, has substantially improved understanding of the role of the deep-ocean benthic environment in the global carbon cycle. However, the role of deep-ocean benthic megafauna in carbon bioturbation, remineralization and sequestration is relatively unknown. It is important to gather both accurate and precise measurements of megafaunal community abundance, size distribution and biomass to further define their role in deep-sea carbon cycling and possible sequestration. This study describes initial results from a stereo camera system attached to a remotely operated vehicle and analyzed using the EventMeasure photogrammetric measurement software to estimate the density, length and biomass of 10 species of mobile epibenthic megafauna. Stereo length estimates were compared to those from a single video camera system equipped with sizing lasers and analyzed using the Monterey Bay Aquarium Research Institute's Video Annotation and Reference System. Both camera systems and software were capable of high measurement accuracy and precision (<±1 mm measurement error and precision). However, the oblique angle of the single video camera caused the spatial scale of the image perspective to change with distance from the camera, resulting in error when measurements were not parallel or vertical to two horizontal-oriented scaling lasers. Analysis showed that the stereo system recorded longer lengths and higher biomass estimates than the single video camera system for the majority of the 10 megafauna species studied. The stereo image analysis process took substantially longer than the video analysis and the value of the EventMeasure software tool would be improved with developments in analysis automation. The stereo system is less influenced by object orientation and height, and is potentially a useful tool to be mounted on an autonomous underwater vehicle and for measuring deep-sea pelagic animals where the use of lasers is not feasible.
NASA Astrophysics Data System (ADS)
Y Ning, Z.; Fu, M. Q.; Shi, T. W.; Guo, Y.; Wei, X. L.; Gao, S.; Chen, Q.
2014-07-01
The relationship between property and structure is one of the most important fundamental questions in the field of nanomaterials and nanodevices. Understanding the multiproperties of a given nano-object also aids in the development of novel nanomaterials and nanodevices. In this paper, we develop for the first time a comprehensive platform for in situ multiproperty measurements of individual nanomaterials using a scanning electron microscope (SEM). Mechanical, electrical, electromechanical, optical, and photoelectronic properties of individual nanomaterials, with lengths that range from less than 200 nm to 20 ?m, can be measured in situ with an SEM on the platform under precisely controlled single-axial strain and environment. An individual single-walled carbon nanotube (SWCNT) was measured on the platform. Three-terminal electronic measurements in a field effect transistor structure showed that the SWCNT was semiconducting and agreed with the structure characterization by transmission electron microscopy after the in situ measurements. Importantly, we observed a bandgap increase of this SWCNT with increasing axial strain, and for the first time, the experimental results quantitatively agree with theoretical predictions calculated using the chirality of the SWCNT. The vibration performance of the SWCNT, a double-walled CNT, and a triple-walled CNT were also studied as a function of axial strain, and were proved to be in good agreement with classical beam theory, although the CNTs only have one, two, or three atomic layers, respectively. Our platform has wide applications in correlating multiproperties of the same individual nanostructures with their atomic structures.
Ning, Z Y; Fu, M Q; Shi, T W; Guo, Y; Wei, X L; Gao, S; Chen, Q
2014-07-11
The relationship between property and structure is one of the most important fundamental questions in the field of nanomaterials and nanodevices. Understanding the multiproperties of a given nano-object also aids in the development of novel nanomaterials and nanodevices. In this paper, we develop for the first time a comprehensive platform for in situ multiproperty measurements of individual nanomaterials using a scanning electron microscope (SEM). Mechanical, electrical, electromechanical, optical, and photoelectronic properties of individual nanomaterials, with lengths that range from less than 200 nm to 20 ?m, can be measured in situ with an SEM on the platform under precisely controlled single-axial strain and environment. An individual single-walled carbon nanotube (SWCNT) was measured on the platform. Three-terminal electronic measurements in a field effect transistor structure showed that the SWCNT was semiconducting and agreed with the structure characterization by transmission electron microscopy after the in situ measurements. Importantly, we observed a bandgap increase of this SWCNT with increasing axial strain, and for the first time, the experimental results quantitatively agree with theoretical predictions calculated using the chirality of the SWCNT. The vibration performance of the SWCNT, a double-walled CNT, and a triple-walled CNT were also studied as a function of axial strain, and were proved to be in good agreement with classical beam theory, although the CNTs only have one, two, or three atomic layers, respectively. Our platform has wide applications in correlating multiproperties of the same individual nanostructures with their atomic structures. PMID:24959846
Michel, D T; Davis, A K; Goncharov, V N; Sangster, T C; Hu, S X; Igumenshchev, I V; Meyerhofer, D D; Seka, W; Froula, D H
2015-04-17
Measurements of the conduction-zone length (110±20???m at t=2.8??ns), the averaged mass ablation rate of the deuterated plastic (7.95±0.3???g/ns), shell trajectory, and laser absorption are made in direct-drive cryogenic implosions and are used to quantify the electron thermal transport through the conduction zone. Hydrodynamic simulations that use nonlocal thermal transport and cross-beam energy transfer models reproduce these experimental observables. Hydrodynamic simulations that use a time-dependent flux-limited model reproduce the measured shell trajectory and the laser absorption but underestimate the mass ablation rate by ?10% and the length of the conduction zone by nearly a factor of 2. PMID:25933317
NASA Technical Reports Server (NTRS)
Vonroos, O. H. (inventor)
1978-01-01
Carrier lifetimes and bulk diffusion length are qualitatively measured as a means for qualification of a P-N junction photovoltaic solar cell. High frequency (blue) monochromatic light pulses and low-frequency (red) monochromatic light pulses were alternately applied to the cell while it was irradiated by light from a solar simulator, and synchronously displaying the derivative of the output voltage of the cell on an oscilloscope. The output voltage is a measure of the lifetimes of the minority carriers (holes) in the diffused N layer and majority carriers (electrons) in the bulk P material, and of the diffusion length of the bulk silicon. By connecting a reference cell in this manner with a test cell to be tested in reverse parallel, the display of a test cell that matches the reference cell will be a substantially zero output.
Celik, Ozkan; O'Malley, Marcia K; Boake, Corwin; Levin, Harvey S; Yozbatiran, Nuray; Reistetter, Timothy A
2010-08-01
In this paper, we analyze the correlations between four clinical measures (Fugl-Meyer upper extremity scale, Motor Activity Log, Action Research Arm Test, and Jebsen-Taylor Hand Function Test) and four robotic measures (smoothness of movement, trajectory error, average number of target hits per minute, and mean tangential speed), used to assess motor recovery. Data were gathered as part of a hybrid robotic and traditional upper extremity rehabilitation program for nine stroke patients. Smoothness of movement and trajectory error, temporally and spatially normalized measures of movement quality defined for point-to-point movements, were found to have significant moderate to strong correlations with all four of the clinical measures. The strong correlations suggest that smoothness of movement and trajectory error may be used to compare outcomes of different rehabilitation protocols and devices effectively, provide improved resolution for tracking patient progress compared to only pre- and post-treatment measurements, enable accurate adaptation of therapy based on patient progress, and deliver immediate and useful feedback to the patient and therapist. PMID:20388607
Correlated Protein Motion Measurements of Dihydrofolate Reductase Crystals
NASA Astrophysics Data System (ADS)
Xu, Mengyang; Niessen, Katherine; Pace, James; Cody, Vivian; Markelz, Andrea
2014-03-01
We report the first direct measurements of the long range structural vibrational modes in dihydrofolate reductase (DHFR). DHFR is a universal housekeeping enzyme that catalyzes the reduction of 7,8-dihydrofolate to 5,6,7,8-tetra-hydrofolate, with the aid of coenzyme nicotinamide adenine dinucleotide phosphate (NADPH). This crucial enzymatic role as the target for anti-cancer [methotrexate (MTX)], and other clinically useful drugs, has made DHFR a long-standing target of enzymological studies. The terahertz (THz) frequency range (5-100 cm-1), corresponds to global correlated protein motions. In our lab we have developed Crystal Anisotropy Terahertz Microscopy (CATM), which directly measures these large scale intra-molecular protein vibrations, by removing the relaxational background of the solvent and residue side chain librational motions. We demonstrate narrowband features in the anisotropic absorbance for mouse DHFR with the ligand binding of NADPH and MTX single crystals as well as Escherichia coli DHFR with the ligand binding of NADPH and MTX single crystals. This work is supported by NSF grant MRI2 grant DBI2959989.
Measuring ?- ? angular correlation with laser trapped 6He
NASA Astrophysics Data System (ADS)
Leredde, Arnaud; Bailey, Kevin; Mueller, Peter; O'Connor, Thomas; Bagdasarova, Yelena; Garcia, Alejandro; Hong, Ran; Sternberg, Matthew; Storm, Derek; Swanson, Erik; Wauters, Frederik; Zumwalt, David W.; Flechard, Xavier; Lienard, Etienne; Knetch, Andreas; Naviliat-Cuncic, Oscar
2014-09-01
Exotic current contributions to the weak interaction can be constrained through measuring the beta-neutrino angular correlation parameter a?? in nuclear beta decay - providing opportunities to find evidence for physics beyond the Standard Model. Our goal is to measure a?? with a precision of 0.1% for the beta decay of 6He (t1/2 = 807 ms) which is particularly sensitive to the exotic tensor currents. For this purpose, we have built a double magneto-optical trap (MOT) system to provide a cold and point-like source of 6He. Of the 1x1010 6He atoms/s produced via the 7Li(d,3He)6He nuclear reaction, roughly 1000 atoms/s are captured in the first MOT and periodically transferred to the second, low background MOT that is surrounded by a detector system. Coincidence detection of the beta particle and the recoiling ion offers kinematic reconstruction of a?? in combination with high statistic numerical simulations of the detector setup. The performance of the trap setup, preliminary coincidence data, and studies of systematic uncertainties will be presented. This work is supported by DOE, Office of Nuclear Physics, under contract nos. DE-AC02-06CH11357 and DE-FG02-97ER41020.
Forde, Elizabeth; Booth, Jeremy; Leech, Michelle
2014-01-01
The established dosimetric benefits of intensity-modulated radiation therapy (IMRT) and volumetric-modulated arc therapy have lead to their increased use in prostate radiotherapy. Complimenting these techniques, volumetric image guidance has supported increased positional accuracy. In addition, 3-dimensional image guidance has also allowed for assessment of potential dosimetric variation that can be attributed to a deformation of either internal or external structures, such as rectal distension or body contour. Compounding these issues is the variation of tissue density through which the new field position passes and also the variation of dose across a modulated beam. Despite the growing level of interest in this area, there are only a limited number of articles that examine the effect of a variation in beam path length, particularly across a modulated field. IMRT and volumetric-modulated radiation therapy (VMAT) fields are dynamic in nature, and the dose gradient within these fields is variable. Assessment of variation of path length away from the beam?s central axis and across the entire field is vital where there is considerable variation of dose within the field, such as IMRT and VMAT. In these cases, reliance on the traditional central axis to focus skin distances is no longer appropriate. This article discusses these more subtle challenges that may have a significant clinical effect if left unrecognized and undervalued. PMID:24630910
Myer, Gregory D.; Ford, Kevin R.; Khoury, Jane; Succop, Paul; Hewett, Timothy E.
2010-01-01
Background Prospective measures of high knee abduction moment during landing identify female athletes at high risk for non-contact anterior cruciate ligament injury. Biomechanical laboratory measurements predict high knee abduction moment landing mechanics with high sensitivity (85%) and specificity (93%). The purpose of this study was to identify correlates to laboratory-based predictors of high knee abduction moment for use in a clinic-based anterior cruciate ligament injury risk prediction algorithm. The hypothesis was that clinically obtainable correlates derived from the highly predictive laboratory-based models would demonstrate high accuracy to determine high knee abduction moment status. Methods Female basketball and soccer players (N=744) were tested for anthropometrics, strength and landing biomechanics. Pearson correlation was used to identify clinically feasible correlates and logistic regression to obtain optimal models for high knee abduction moment prediction. Findings Clinical correlates to laboratory-based measures were identified and predicted high knee abduction moment status with 73% sensitivity and 70% specificity. The clinic-based prediction algorithm, including (Odds Ratio: 95% confidence interval) knee valgus motion (1.43:1.30–1.59 cm), knee flexion range of motion (.98:0.96–1.01 deg), body mass (1.04:1.02–1.06 kg), tibia length (1.38:1.25–1.52 cm) and quadriceps to hamstring ratio (1.70:1.06–2.70) predicted high knee abduction moment status with C statistic 0.81. Interpretation The combined correlates of increased knee valgus motion, knee flexion range of motion, body mass, tibia length and quadriceps to hamstrings ratio predict high knee abduction moment status in female athletes with high sensitivity and specificity. PMID:20554101
So Young Yoon; Hwa Jung Sung; Kyong Hwa Park; In Keun Choi; Seok Jin Kim; Sang Cheul Oh; Jae Hong Seo; Chul Won Choi; Byung Soo Kim; Sang Won Shin; Yeul Hong Kim; Jun Suk Kim
2007-01-01
This study evaluated the telomere length changes (?TL) of peripheral blood mononuclear cells before and after repetitive standard-dose nonmyeloablative chemotherapy and the association of ?TL with treatment response and myelosuppression severity. TL was measured with Southern blot analysis in 32 solid-cancer patients without bone marrow metastasis. The mean TL before chemotherapy (t0 TL) and after the 2nd (t1 TL), 4th
Hyldig-Nielsen, J.J.; Morling, N.; Oedum, N.; Ryder, L.P.; Platz, P.; Jakobsen, B.; Svejgaard, A.
1987-03-01
The restriction fragment length polymorphism (RFLP) of the class II HLA-DP subregion of the major histocompatibility complex (MHC) of humans has been unraveled by Southern blotting using DP/sub ..cap alpha../ and DP/sub ..beta../ probes in a study of 46 unrelated individuals with known HLA-DP types. Contrary to earlier preliminary findings with a limited number of enzymes, the RFLP appears to be quite extensive both with the DP/sub ..beta../ (14 different DNA markers defined by individual fragments or clusters thereof) and the DP/sub ..cap alpha../ (8 markers) probes, especially when enzyme recognizing only four base pairs were used. A few markers were absolutely or strongly associated with individual DP antigens, whereas most were associated with two or more DP antigens as defined by primed lymphocyte typing. Thus, Southern blotting seems feasible for typing for most DP determinants by specific fragments or subtraction between the various more broadly reactive DNA markers, and the RFLP provides further information on the DP subregion in addition to that provided by primed lymphocyte typing. In two recombinant families, the DP/sub ..beta../ and DP/sub ..cap alpha../ DNA markers segregated with DP antigens, whereas the DR/sub ..beta../, DQ/sub ..beta../, DQ/sub ..cap alpha../, and DX/sub ..cap alpha../ markers followed the DR and DQ antigens.
Chu, Zonglin; Feng, Yujun
2012-01-17
Long-chain amidosulfobetaine surfactants, 3-(N-fattyamidopropyl-N,N-dimethyl ammonium) propanesulfonates (n-DAS, n > 18), are insoluble in pure water due to their high Krafft temperature (T(K)), while they are soluble when inorganic salt is added to the surfactant solution as the T(K) of these zwitterionic surfactants is decreased. The influence of the salt content and ionic species of the added electrolytes on the T(K) of the series of amidosulfobetaine surfactants was examined by means of UV-vis spectrophometry and visual inspection. It was found that the T(K) of these surfactants depends strongly on not only the hydrophobic alkyl length (n), but also the salinity of the aqueous environment. When the salt concentration is increased from 0 to 100 mM, the T(K) shows a sharp decrease; when the salinity is fixed between 100 and 2000 mM, the T(K) varies linearly with n with a slope of ~7.7 irrespective of the salt species and the salt content. When the salt concentration is further increased above 2000 mM, a linear function is still observed, but the slope increases slightly. PMID:22149531
Agimelen, Okpeafoh S; McGinty, John; Tachtatzis, Christos; Dziewierz, Jerzy; Haley, Ian; Sefcik, Jan; Mulholland, Anthony J
2015-01-01
Efficient processing of particulate products across various manufacturing steps requires that particles possess desired attributes such as size and shape. Controlling the particle production process to obtain required attributes will be greatly facilitated using robust algorithms providing the size and shape information of the particles from in situ measurements. However, obtaining particle size and shape information in situ during manufacturing has been a big challenge. This is because the problem of estimating particle size and shape (aspect ratio) from signals provided by in-line measuring tools is often ill posed, and therefore it calls for appropriate constraints to be imposed on the problem. One way to constrain uncertainty in estimation of particle size and shape from in-line measurements is to combine data from different measurements such as chord length distribution (CLD) and imaging. This paper presents two different methods for combining imaging and CLD data obtained with in-line tools in order to ...
Tao, X. D.; Feng, Z.; Miao, B. F.; Sun, L.; You, B.; Wu, D.; Du, J.; Zhang, W.; Ding, H. F., E-mail: hfding@nju.edu.cn [Department of Physics, National Laboratory of Solid State Microstructures, Nanjing University, 22 Hankou Road, Nanjing 210093 (China)
2014-05-07
We present the experimental study of the spin Hall angle (SHA) and spin diffusion length of Pd with the spin pumping and microwave photoresistance effects. The Py/Pd bilayer stripes are excited with an out-of-plane microwave magnetic field. The pure spin current is thus pumped and transforms into charge current via the inverse spin Hall effect (ISHE) in Pd layer, yielding an ISHE voltage. The ISHE voltage can be distinguished from the unwanted signal caused by the anisotropic magnetoresistance according to their different symmetries. Together with Pd thickness dependent measurements of in and out-of-plane precessing angles and effective spin mixing conductance, the SHA and spin-diffusion length of Pd are quantified as 0.0056?±?0.0007 and 7.3?±?0.7?nm, respectively.
NASA Astrophysics Data System (ADS)
Steyn-Ross, Moira L.; Steyn-Ross, D. A.; Sleigh, J. W.; Whiting, D. R.
2003-08-01
In a recent series of papers, the authors have developed a stochastic theory to describe the electrical response of a spatially homogeneous cerebral cortex to infusion of a general anesthetic agent. We showed that by modeling the GABAergic (propofol-like) drug effect as a prolongation of the inhibitory postsynaptic impulse response, we obtain a prediction that there will be a hysteretically separated pair of first-order phase transitions in the population-average excitatory soma voltage, the first occurring at the point of induction of unconsciousness, and the second at the point of emergence from unconsciousness. In the present paper we generalize our earlier “zero-dimensional” homogeneous cortex to a one-dimensional (1D) line of cortical “mass,” thus allowing for the possibility of spatial inhomogeneities in neural activity. Following the spirit of our earlier adiabatic (“slow membrane”) philosophy, we impose a spatioadiabatic approximation that permits us to compute analytic expressions for changes in EEG (electroencephalographic) correlation length and EEG spatial covariance as a function of anesthetic effect. We establish that the correlation length of the EEG fluctuations is expected to increase at the approach to the transition points, and this finding is consistent with both the homogeneous-cortex prediction of increased correlation time (“critical slowing down”) near transition, and the recent, comprehensive anesthetic study by John et al.?[Conscious. Cogn. 10, 165 (2001)] reporting an increase in EEG coherence near the points of loss and recovery of consciousness. In addition, we find that if the long-range (corticocortical) excitatory-to-inhibitory connectivity in the 1D cortex is stronger than the long-range excitatory-to-excitatory connectivity, then the spatioadiabatic system can organize itself into large-amplitude spatial patterns (“dissipative structures”) consisting of giant stationary quasiperiodic voltage fluctuations distributed along the cortical rod.
Manjula, B N; Tsai, A; Upadhya, R; Perumalsamy, K; Smith, P K; Malavalli, A; Vandegriff, K; Winslow, R M; Intaglietta, M; Prabhakaran, M; Friedman, J M; Acharya, A S
2003-01-01
Increasing the molecular size of acellular hemoglobin (Hb) has been proposed as an approach to reduce its undesirable vasoactive properties. The finding that bovine Hb surface decorated with about 10 copies of PEG5K per tetramer is vasoactive provides support for this concept. The PEGylated bovine Hb has a strikingly larger molecular radius than HbA (1). The colligative properties of the PEGylated bovine Hb are distinct from those of HbA and even polymerized Hb, suggesting a role for the colligative properties of PEGylated Hb in neutralizing the vasoactivity of acellular Hb. To correlate the colligative properties of surface-decorated Hb with the mass of the PEG attached and also its vasoactivity, we have developed a new maleimide-based protocol for the site-specific conjugation of PEG to Hb, taking advantage of the unusually high reactivity of Cys-93(beta) of oxy HbA and the high reactivity of the maleimide to protein thiols. PEG chains of 5, 10, and 20 kDa have been functionalized at one of their hydroxyl groups with a maleidophenyl moiety through a carbamate linkage and used to conjugate the PEG chains at the beta-93 Cys of HbA to generate PEGylated Hbs carrying two copies of PEG (of varying chain length) per tetramer. Homogeneous preparations of (SP-PEG5K)(2)-HbA, (SP-PEG10K)(2)-HbA, and (SP-PEG20K)(2)-HbA have been isolated by ion exchange chromatography. The oxygen affinity of Hb is increased slightly on PEGylation, but the length of the PEG-chain had very little additional influence on the O(2) affinity. Both the hydrodynamic volume and the molecular radius of the Hb increased on surface decoration with PEG and exhibited a linear correlation with the mass of the PEG chain attached. On the other hand, both the viscosity and the colloidal osmotic pressure (COP) of the PEGylated Hbs exhibited an exponential increase with the increase in PEG chain length. In contrast to the molecular volume, viscosity, and COP, the vasoactivity of the PEGylated Hbs was not a direct correlate of the PEG chain length. There appeared to be a threshold for the PEG chain length beyond which the protection against vasoactivity is decreased. These results suggest that the modulation of the vasoactivity of Hb by PEG could be a function of the surface shielding afforded by the PEG, the latter being a function of the disposition of the PEG chain on the protein surface, which in turn is a function of the length of the PEG chain. Thus, the biochemically homogeneous PEGylated Hbs described in the present study, surface-decorated with PEG chains of appropriate size, could serve as potential candidates for Hb-based oxygen carriers. PMID:12643758
NASA Astrophysics Data System (ADS)
Makarevich, V.
2012-01-01
The COOMET Project No 507/BY/10, 'Supplementary comparison of length standards for measuring gear parameters', KCDB Reference COOMET.L-S10, was organized by the COOMET Technical Committee TC 1.5 'Length and Angle'. This comparison started in September 2010 and finished in September 2011. It was piloted by the Belarusian State Institute of Metrology, BelGIM, Minsk, the Republic of Belarus, with VNIIMS (Moscow, Russia) as the other participant. The transfer standard was a gear involute master provided by BelGIM. This standard has two base circle radii of 150 mm and 60 mm, and corresponding profiles on the left and on the right. The involute profile was measured from root towards tip of the tooth. The scanning was performed in automatic mode along the mid-section of the base cylinder over the complete estimation range, with a scanning speed of 2 mm s-1. The software program GEAR PRO involute was used to determine three parameters: the total profile deviation, the profile form deviation and the profile slope deviation. Each participant performed ten measurements for each of two involute profiles with basic circle radius of 150 mm and 60 mm, respectively. The measurement result for each parameter was calculated as a mean value from the ten measurements. The comparison results demonstrate that the measured values are consistent with the stated uncertainties and that the measurement standards under comparison are equivalent. Main text. To reach the main text of this paper, click on Final Report. Note that this text is that which appears in Appendix B of the BIPM key comparison database kcdb.bipm.org/. The final report has been peer-reviewed and approved for publication by COOMET, according to the provisions of the CIPM Mutual Recognition Arrangement (MRA).
PRIOR GENETIC CORRELATIONS AND NON-MEASURED TRAITS
Technology Transfer Automated Retrieval System (TEKTRAN)
Current international genetic evaluations are based on how related country populations are genetically (across-country genetic correlations). Those correlations may be influenced strongly by prior expectations that were not based on sound scientific principles. Objective methods to predict prior cor...
Measurement and modification of biexciton-exciton time correlations.
Huber, Tobias; Predojevi?, Ana; Zoubi, Hashem; Jayakumar, Harishankar; Solomon, Glenn S; Weihs, Gregor
2013-04-22
Photons which are generated in a two-photon cascade process have an underlying time correlation since the spontaneous emission of the upper level populates the intermediate state. This correlation leads to a reduction of the purity of the photon emitted from the intermediate state. Here we characterize this time correlation for the biexciton-exciton cascade of an InAs/GaAs quantum dot. We show that the correlation can be reduced by tuning the biexciton transition in resonance to a planar distributed Bragg reflector cavity. The enhanced and inhibited emission into the cavity accelerates the biexciton emission and slows down the exciton emission thus reduces the correlation and increases the purity of the exciton photon. This is essential for schemes like creating time-bin entangled photon pairs from quantum dot systems. PMID:23609694
Eich, T; Sieglin, B; Scarabosio, A; Fundamenski, W; Goldston, R J; Herrmann, A
2011-11-18
Experimental measurements of the SOL power decay length (?(q)) estimated from analysis of fully attached divertor heat load profiles from two tokamaks, JET and ASDEX Upgrade, are presented. Data was measured by means of infrared thermography. An empirical scaling reveals parametric dependency ?(q) in mm = 0.73B(T)(-0.78)q(cyl)(1.2)P(SOL)(0.1)R(geo)(0), where B(T)(T) describes the toroidal magnetic field, q(cyl) the cylindrical safety factor, P(SOL)(MW) the power crossing the separatrix and R(geo)(m) the major radius of the device. A comparison of these measurements to a heuristic particle drift-based model shows satisfactory agreement in both absolute magnitude and scaling. Extrapolation to ITER gives ?(q) ? 1 mm. PMID:22181888
M. G. Huber; M. Arif; W. C. Chen; T. R. Gentile; D. S. Hussey; T. C. Black; D. A. Pushin; C. B. Shahi; F. E. Wietfeldt; L. Yang
2014-09-30
We report a determination of the n-$^3$He scattering length difference $\\Delta b^{\\prime} = b_{1}^{\\prime}-b_{0}^{\\prime} = $ ($-5.411$ $\\pm$ $0.031$ (statistical) $\\pm$ $0.039$ (systematic)) fm between the triplet and singlet states using a neutron interferometer. This revises our previous result $\\Delta b^{\\prime} = $ (-5.610 $\\pm$ $0.027$ (statistical) $\\pm$ $0.032$ (systematic) fm obtained using the same technique in 2008. This revision is due to a re-analysis of the 2008 experiment that includes a more robust treatment of the phase shift caused by magnetic field gradients near the $^3$He cell. Furthermore, we more than doubled our original data set from 2008 by acquiring six months of additional data in 2013. Both the new data set and a re-analysis of the older data are in good agreement. Scattering lengths of low Z isotopes are valued for use in few-body nuclear effective field theories, provide important tests of modern nuclear potential models and in the case of $^3$He aid in the interpretation of neutron scattering from quantum liquids. The difference $\\Delta b^{\\prime}$ was determined by measuring the relative phase shift between two incident neutron polarizations caused by the spin-dependent interaction with a polarized $^3$He target. The target $^3$He gas was sealed inside a small, flat windowed glass cell that was placed in one beam path of the interferometer. The relaxation of $^3$He polarization was monitored continuously with neutron transmission measurements. The neutron polarization and spin flipper efficiency were determined separately using $^3$He analyzers and two different polarimetry analysis methods. A summary of the measured scattering lengths for n-$^3$He with a comparison to nucleon interaction models is given.
Picosecond electron bunch length measurement by electro-optic detection of the Wakefield
M. J. Fitch, A. C. Melissinos and P. L. Colestock
1999-05-17
The longitudinal profile of an 10 nC electron bunch of a few picoseconds duration will be measured by electro-optic detection of the wakefield. The polarization of a short in-frared probe laser pulse (derived from the photocathode excitation laser) is modulated in a LiTaO3 crystal by the transient electric field of the bunch. The bunch profile is measured by scanning the delay between the laser and the bunch, and is sensitive to head/tail asymmetries. A single-shot extension of the technique is possible using a longer chirped laser pulse.
Rodriguez, Alina; Kaakinen, Marika; Couto Alves, Alexessander; Sebert, Sylvain; Millwood, Iona Y.; Laitinen, Jaana; O’Reilly, Paul F.; Jarvelin, Marjo-Riitta; Blakemore, Alexandra I. F.
2014-01-01
Studies of leukocyte telomere length (LTL) and adiposity have produced conflicting results, and the relationship between body mass index (BMI) and telomere length throughout life remains unclear. We therefore tested association of adult LTL measured in 5,598 participants with: i) childhood growth measures (BMI and age at adiposity rebound (AR)); ii) change in BMI from childhood to adulthood and iii) adult BMI, waist-to-hip ratio (WHR), body adiposity index (BAI). Childhood BMI at AR was positively associated with LTL at 31 years in women (P?=?0.041). Adult BMI and WHR in both men (P?=?0.025 and P?=?0.049, respectively) and women (P?=?0.029 and P?=?0.008, respectively), and BAI in women (P?=?0.021) were inversely associated with LTL at 31 years. An increase in standardised BMI between early childhood and adulthood was associated with shorter adult LTL in women (P?=?0.008). We show that LTL is inversely associated with multiple measures of adiposity in both men and women. Additionally, BMI increase in women from childhood to adulthood is associated with shorter telomeres at age 31, potentially indicating accelerated biological ageing. PMID:24919187
Herriott Cell Interferometer for Density Measurements in Small-Scale Length Plasmas
Erik Antonsen; Rodney Burton; Scott Engelman; Greg Spanjers
2000-01-01
The introduction of a Herriott cell into a standard quadrature heterodyne interferometer is evaluated and demonstrated to increase the resolution of the system. Measurements of electron and neutral density during and after the current pulse are sought for modeling purposes for spacecraft contamination from Pulsed Plasma Thrusters. Testing is performed on the UIUC PPT-4, a coaxial electrothermal Pulsed Plasma Thruster
Kenneth D. Carlander
1982-01-01
Tabulation of ?, the intercept values of rectilinear body-scale regressions used in Fraser-Lee calculation of growth from scales, for several species of centrarchids and percids showed wide variation from population to population. This variation is believed to be less the result of actual differences among populations than the result of measuring scales at different angles, collecting scales from different areas
Correlating wine quality indicators to chemical and sensory measurements.
Hopfer, Helene; Nelson, Jenny; Ebeler, Susan E; Heymann, Hildegarde
2015-01-01
Twenty-seven commercial Californian Cabernet Sauvignon wines of different quality categories were analyzed with sensory and chemical methods. Correlations between five quality proxies-points awarded during a wine competition, wine expert scores, retail price, vintage, and wine region-were correlated to sensory attributes, volatile compounds, and elemental composition. Wine quality is a multi-faceted construct, incorporating many different layers. Depending on the quality proxy studied, significant correlations between quality and attributes, volatiles and elements were found, some of them previously reported in the literature. PMID:25985352
The cross-correlation measure for families of binary sequences Katalin Gyarmati
Katalin, Gyarmati
measure, the cross-correlation measure of order k is intro- duced to study the connection between characterized by using the notion of linear complexity, and tests based on mathematical statistics ("poker test, t with a, b, t N, 1 a a + (t - 1)b N, while the correlation measure of order k of EN is defined as Ck
FRONTIERS ARTICLE Fluorescence correlation spectroscopy as a tool for measuring the rotational
Enderlein, Jörg
FRONTIERS ARTICLE Fluorescence correlation spectroscopy as a tool for measuring the rotational correlation spectroscopy (FCS) for measuring rotational diffu- sion of macromolecules, and present a new experimental scheme, pulsed-interleaved excitation or PIE-FCS, which allows for measuring all conceivable
Behavioral Measures and their Correlation with IPM Iteration Counts on Semi-Definite Programming
Chuan, Toh Kim
Behavioral Measures and their Correlation with IPM Iteration Counts on Semi-Definite Programming-point method (IPM) iterations when these methods are used to solve semidefinite programming (SDP) problem and measure the correlation between these measures and IPM iteration counts (solved using the software SDPT3
NASA Astrophysics Data System (ADS)
Cinthio, M.; Ahlgren, Å. R.; Persson, H. W.; Lindström, K.
We have recently shown that there is a previous unknown longitudinal movement present in the arterial wall. We aim now to investigate whether the longitudinal movement causes length alteration of the arterial wall. The objective of this paper was to describe a new non-invasive ultrasonic technique that measures the length alteration of arteries in human in-vivo. Results indicate that a significant length alteration is present in the common carotid artery.
Correlation function as a measure of the structure
O. Buryak; A. Doroshkevich
1995-06-04
Geometrical model of structure of the universe is examined to obtain analytical expression for the two points nonlinear correlation function. According to the model the objects (galaxies) are concentrated into two types of structure elements - filaments and sheets. We considered the filaments ( similar to galaxy filaments ) simply as straight lines and the sheets ( similar to superclusters of galaxies ) simply as planes. The homogeneously distributed objects are also taken into consideration. The spatial distribution of lines, planes and points is uncorrelated. The nonlinear correlation function depends on four parameters and is similar to the observed and simulated ones for different samples. It describes quite well the correlation of galaxies, clusters of galaxies and dark matter distribution. Possible interpretation of the parameters of nonlinear correlation function is discussed.
NASA Astrophysics Data System (ADS)
Kim, Yong Hyun; Song, Kwang Yong
2014-05-01
Optical time-domain measurement and characterization of intermodal beat length in an elliptic-core two-mode fiber (ecore TMF) is demonstrated using Brillouin dynamic grating. A mode-selective coupler is used for selective launch and retrieval of different modes, and the operations of BDG for four different pairs of pump-probe (LP01 x-LP11 x, LP01 x-LP11 y, LP01 y-LP11 x, LP01 y-LP11 y) are observed, representing a fine structure of modal birefringence in the e-core TMF. Distributed measurement of the BDG spectrum is performed for each pair of pump-probe with 1.5 m spatial resolution mapping the difference of the effective refractive indexes of spatial and polarization modes along a 75 m TMF.
Role of weak measurements on states ordering and monogamy of quantum correlation
Ming-Liang Hu; Heng Fan; Dong-Ping Tian
2015-04-10
The information-theoretic definition of quantum correlation, e.g., quantum discord, is measurement dependent. By considering the more general quantum measurements, weak measurements, which include the projective measurement as a limiting case, we show that while weak measurements can enable one to capture more quantumness of correlation in a state, it can also induce other counterintuitive quantum effects. Specifically, we show that the general measurements with different strengths can impose different orderings for quantum correlations of some states. It can also modify the monogamous character for certain classes of states as well which may diminish the usefulness of quantum correlation as a resource in some protocols. In this sense, we say that the weak measurements play a dual role in defining quantum correlation.
NASA Astrophysics Data System (ADS)
Hou, X. D.; Bushby, A. J.; Jennett, N. M.
2010-11-01
It is ironic that recent developments in instrumented indentation, such as the drive to obtain tensile properties from indentation data and to understand length-scale effects in plasticity, have seen a return to direct imaging of indentations. Significant uncertainties in contact size arise when using contact mechanics calculations that do not take into account the lateral dilation of elastic recovery (Hou et al 2008 J. Phys. D: Appl. Phys. 41 074006) and important sink-in and pile-up contributions to the contact response (Lim and Chaudhri 1999 Phil. Mag. A 79 2979-3000). High resolution, direct measurement avoids these problems. Accurate wear volume and coating thickness measurements obtained by cap grinding methods also depend on high accuracy and low uncertainty direct measurement methods. The use of metrological atomic force microscopy to measure and certify the shape of indenters is well established (Aldrich-Smith et al 2005 Z. Metallk. 96 1267-71) and is essential for valid mechanical property measurement by instrumented indentation. In this paper, we consider indent measurement and compare three direct measurement techniques: optical microscopy, metrological atomic force microscopy (AFM) and confocal laser scanning microscopy (CLSM). We compare the relative merits and uncertainties of various 2D and 3D analysis methods with a new analysis method of differentiating 3D data obtained from AFM and CLSM. This new method has the lowest uncertainty (2.8% for a 50 µm diameter indent at the 95% confidence level). Better still, it enables objective measurements of indent size that avoid the issues caused by difficult-to-standardize parameters (such as illumination angle, contrast and brightness settings), which strongly affect manual estimates of the edge position of an indentation/crater (Gee et al 2002 NPL Measurement Good Practice Guide No 57).
NSDL National Science Digital Library
Anderson-Cook, C.
The applets, created by Virginia Tech's Department of Statistics, allow you to see how different bivariate data look under different correlation structures. The "Movie" applet either creates data for a particular correlation or animates a multitude data sets ranging correlations from -1 to 1. The "Creation" applet allows the user to create a data set by adding or deleting points from the screen.
Boundary Curvature Effect on Thin-film Drainage and Slip Length Measurements
Angbo Fang
2014-07-20
The thin-liquid film drainage between two curved surfaces is a fundamental process for many hydrodynamic measurements, for which Vinogradova's formula has played a central role when flow slip occurs at fluid-solid interfaces. By performing a rigorous order-of-magnitude analysis, we reveal the importance of the curvature contribution to boundary flow, neglected sofar. Vinogradova's result is found to considerably underestimate the slip-induced reduction of the hydrodynamic drainage force. Our theory can play a crucial role in distinguishing finite-slip from no-slip and quantifying the degree of flow slip at fluid-solid surfaces, which is a fundamental but controversial issue in fluid dynamics. Moreover, qualitatively different from previous theories, our theory predicts a finite hydrodynamic repulsive force for two hydrophobic particles in touch, thus allowing particle collision to occur in a finite time without any additional attractive surface forces. This finding has deep and immediate implications on particle coagulation, adsorption and sedimentation processes relevant for numerous industrial technologies as well as natural phenomena on the earth.
Non-Markovianity: initial correlations and nonlinear optical measurements
Dijkstra, Arend G.; Tanimura, Yoshitaka
2012-01-01
By extending the response function approach developed in nonlinear optics, we analytically derive an expression for the non-Markovianity in the time evolution of a system in contact with a quantum mechanical bath, and find a close connection with the directly observable nonlinear optical response. The result indicates that memory in the bath-induced fluctuations rather than in the dissipation causes non-Markovianity. Initial correlations between states of the system and the bath are shown to be essential for a correct understanding of the non-Markovianity. These correlations are included in our treatment through a preparation function. PMID:22753819
NASA Astrophysics Data System (ADS)
Benjamini, Dan; Basser, Peter J.
2014-12-01
In this work, we present an experimental design and analytical framework to measure the nonparametric joint radius-length (R-L) distribution of an ensemble of parallel, finite cylindrical pores, and more generally, the eccentricity distribution of anisotropic pores. Employing a novel 3D double pulsed-field gradient acquisition scheme, we first obtain both the marginal radius and length distributions of a population of cylindrical pores and then use these to constrain and stabilize the estimate of the joint radius-length distribution. Using the marginal distributions as constraints allows the joint R-L distribution to be reconstructed from an underdetermined system (i.e., more variables than equations), which requires a relatively small and feasible number of MR acquisitions. Three simulated representative joint R-L distribution phantoms corrupted by different noise levels were reconstructed to demonstrate the process, using this new framework. As expected, the broader the peaks in the joint distribution, the less stable and more sensitive to noise the estimation of the marginal distributions. Nevertheless, the reconstruction of the joint distribution is remarkably robust to increases in noise level; we attribute this characteristic to the use of the marginal distributions as constraints. Axons are known to exhibit local compartment eccentricity variations upon injury; the extent of the variations depends on the severity of the injury. Nonparametric estimation of the eccentricity distribution of injured axonal tissue is of particular interest since generally one cannot assume a parametric distribution a priori. Reconstructing the eccentricity distribution may provide vital information about changes resulting from injury or that occurred during development.
Methods for estimating peak physiological performance and correlating performance measures
Hardin, Jo
on sample size. Here, we suggest an alternative approach that involves estimating a specific performance of sample size. Additionally, we address the estimation of correlations between two different performance by an unknown amount. Moreover, the magnitude of the bias depends on sample size, since a larger sample size
Measurement of the space-time correlation function of thermal acoustic radiation
NASA Astrophysics Data System (ADS)
Passechnik, V. I.; Anosov, A. A.; Barabanenkov, Yu. N.; Sel'Sky, A. G.
2003-09-01
The space-time correlation function of thermal acoustic radiation pressure is measured for a stationary heated source (a narrow plasticine plate). The correlation dependence is obtained by the multiplication of two signals shifted in time with respect to each other and measured by two receivers. The dependence exhibits an oscillating behavior and changes sign when the source is displaced by half the spatial period of the correlation function.
Massachusetts at Amherst, University of
American Wind Energy Association, Denver, May 2005 Uncertainties in Results of Measure-Correlate-Predict Blvd., Rockville, MD 20850 Telephone: 301-294-2804, Email: rogersj1@westat.com Abstract Measure-correlate-predict (MCP) algorithms are used to predict the wind resource at target sites for wind power development. MCP
ERIC Educational Resources Information Center
Fan, Xitao
This study focused on the issue of measurement reliability and its attenuation on correlation between two composites and two seemingly different approaches for correcting the attenuation. As expected, Monte Carlo simulation results show that correlation coefficients uncorrected for measurement error are systematically biased downward. For the data…
E S Hallin; S E Feldon
1988-01-01
Quantitative clinical and computed tomographic (CT) measures of Graves' ophthalmopathy were obtained in 76 patients. Significant correlation of several CT parameters of the mid-orbital axial CT slice with optic nerve involvement was established. By means of clinical measures, only limitation of ocular motility was found to correlate with the optic neuropathy. The results suggested that there were two distinct populations
NASA Technical Reports Server (NTRS)
Tabib-Azar, Massood
1997-01-01
We report values of minority carrier diffusion length in n-type 6H SiC measured using a planar Electron Beam Induced Current (EBIC) method. Values of hole diffusion length in defect free regions of n-type 6H SiC, with a doping concentration of 1.7El7 1/cu cm, ranged from 1.46 microns to 0.68 microns. We next introduce a novel variation of the planar method used above. This 'planar mapping' technique measured diffusion length along a linescan creating a map of diffusion length versus position. This map is then overlaid onto the EBIC image of the corresponding linescan, allowing direct visualization of the effect of defects on minority carrier diffusion length. Measurements of the above n-type 6H SiC resulted in values of hole diffusion length ranging from 1.2 micron in defect free regions to below 0.1 gm at the center of large defects. In addition, measurements on p-type 6H SiC resulted in electron diffusion lengths ranging from 1.42 micron to 0.8 micron.
Reduction of Gun Erosion and Correlation of Gun Erosion Measurements
NASA Technical Reports Server (NTRS)
Bogdanoff, Dave; Wercinski, Paul (Technical Monitor)
1997-01-01
Gun barrel erosion is serious problem with two-stage light gas guns. Excessive barrel erosion can lead to poor or failed launches and frequent barrel changes, with the corresponding down time. Also, excessive barrel erosion can limit the maximum velocity obtainable by loading down the hydrogen working gas with eroded barrel material. Guided by a CFD code, the operating conditions of the Ames 0.5-inch gun were modified to reduce barrel erosion. The changes implemented included: (1) reduction in the piston mass, powder mass and hydrogen fill pressure; and (2) reduction in pump tube volume, while maintaining hydrogen mass. The latter change was found, in particular, to greatly reduce barrel erosion. For muzzle velocity ranges of 6.1 - 6.9 km/sec, the barrel erosion was reduced by a factor of 10. Even for the higher muzzle velocity range of 7.0 - 8.2 km/sec, the barrel erosion was reduced by a factor of 4. Gun erosion data from the Ames 0.5-inch, 1.0-inch, and 1.5-inch guns operated over a wide variety of launch conditions was examined and it was found that this data could be correlated using four different parameters: normalized powder charge energy, normalized hydrogen energy density, normalized pump tube volume and barrel diameter. The development of the correlation and the steps used to collapse the experimental data are presented. Over a certain parameter range in the correlation developed, the barrel erosion per shot is found to increase very rapidly. The correlation should prove useful in the selection of gun operating conditions and the design of new guns. Representative shapes of eroded gun barrels are also presented.
Measuring temporal speckle correlations at ultrafast x-ray sources.
Gutt, C; Stadler, L-M; Duri, A; Autenrieth, T; Leupold, O; Chushkin, Y; Grübel, G
2009-01-01
We present a new method to extract the intermediate scattering function from series of coherent diffraction patterns taken with 2D detectors. Our approach is based on analyzing speckle patterns in terms of photon statistics. We show that the information obtained is equivalent to the conventional technique of calculating the intensity autocorrelation function. Our approach represents a route for correlation spectroscopy on ultrafast timescales at X-ray free-electron laser sources. PMID:19129872
Correlated optical measurements and plasmon mapping of silver nanorods
Guiton, Beth S [ORNL; Iberi, Vighter [University of Tennessee, Knoxville (UTK); Li, Shuzhou [Nanyang Technological University; Leonard, Donovan N [ORNL; Parish, Chad M [ORNL; Kotula, Paul G [Sandia National Laboratories (SNL); Varela del Arco, Maria [ORNL; Schatz, George C. [Northwestern University, Evanston; Pennycook, Stephen J [ORNL; Camden, Jon P [University of Tennessee, Knoxville (UTK)
2011-01-01
Plasmonics is a rapidly growing field, yet imaging of the plasmonic modes in complex nanoscale architectures is extremely challenging. Here we obtain spatial maps of the localized surface plasmon modes of high-aspect-ratio silver nanorods using electron energy loss spectroscopy (EELS) and correlate to optical data and classical electrodynamics calculations from the exact same particles. EELS mapping is thus demonstrated to be an invaluable technique for elucidating complex and overlapping plasmon modes.
NASA Astrophysics Data System (ADS)
Ling, Mingxiang; Li, Huimin; Li, Qisheng
2014-12-01
Measurement uncertainty evaluation based on the Monte Carlo method (MCM) with the assumption that all uncertainty sources are independent is common. For some measure problems, however, the correlation between input quantities is of great importance and even essential. The purpose of this paper is to provide an uncertainty evaluation method based on MCM that can handle correlated cases, especially for measurement in which uncertainty sources are correlated and submit to non-Gaussian distribution. In this method, a linear-nonlinear transformation technique was developed to generate correlated random variables sampling sequences with target prescribed marginal probability distribution and correlation coefficients. Measurement of the arm stretch of a precision centrifuge of 10-6 order was implemented by a high precision approach and associated uncertainty evaluation was carried out using the mentioned method and the method proposed in the Guide to the Expression of Uncertainty in Measurement (GUM). The obtained results were compared and discussed at last.
Kansas, University of
Study of variation of the Laplacian parameter of DGD time derivative with fiber length using observed that the DGD variation with time becomes more rapid for longer length fibers. The DGD time to converge to a lower value as the fiber length is increased. This observation, which needs further
Zhang, YuMing
length are fun- damental in robotic and automated welding operations. Length of welding arc determines of Arc Length Pengjiu Li and YuMing Zhang, Senior Memeber, IEEE Abstract--During arc welding, the arc heats and melts the work- piece as heat flux. When the welding current is given, the distribu- tion
Williams, Kiel; /SLAC
2012-09-07
The electron pulses generated by the Linac Coherent Light Source at the SLAC National Accelerator Laboratory occur on the order of tens of femtoseconds and cannot be directly measured by conventional means. The length of the pulses can instead be reconstructed by measuring the spectrum of optical transition radiation emitted by the electrons as they move toward a conducting foil. Because the emitted radiation occurs in the mid-infrared from 0.6 to 30 microns a novel optical layout is required. Using a helium-neon laser with wavelength 633 nm, a series of gold-coated off-axis parabolic mirrors were positioned to direct a beam through a zinc selenide prism and to a focus at a CCD camera for imaging. Constructing this layout revealed a number of novel techniques for reducing the aberrations introduced into the system by the off-axis parabolic mirrors. The beam had a recorded radius of less than a millimeter at its final focus on the CCD imager. This preliminary setup serves as a model for the spectrometer that will ultimately measure the LCLS electron pulse duration.
Multimode optical fiber core measurement by speckle correlation
Rodrigo H. Henao; Juan A. Pomarico; Nelida A. Russo; Roberto D. Torroba; Marcelo Trivi
1996-01-01
The modal distribution at the output of a multimode optical fiber behaves as a speckle pattern. Further, a speckle pattern carries information on the pupil diameter of the optical system exit aperture. Pupil measurements by speckle size determination may not be an easy task, because of the statistical nature of the speckle phenomena. The measurement of a multimode fiber core
Collery, Ross F.; Veth, Kerry N.; Dubis, Adam M.; Carroll, Joseph; Link, Brian A.
2014-01-01
Refractive errors in vision can be caused by aberrant axial length of the eye, irregular corneal shape, or lens abnormalities. Causes of eye length overgrowth include multiple genetic loci, and visual parameters. We evaluate zebrafish as a potential animal model for studies of the genetic, cellular, and signaling basis of emmetropization and myopia. Axial length and other eye dimensions of zebrafish were measured using spectral domain-optical coherence tomography (SD-OCT). We used ocular lens and body metrics to normalize and compare eye size and relative refractive error (difference between observed retinal radial length and controls) in wild-type and lrp2 zebrafish. Zebrafish were dark-reared to assess effects of visual deprivation on eye size. Two relative measurements, ocular axial length to body length and axial length to lens diameter, were found to accurately normalize comparisons of eye sizes between different sized fish (R2?=?0.9548, R2?=?0.9921). Ray-traced focal lengths of wild-type zebrafish lenses were equal to their retinal radii, while lrp2 eyes had longer retinal radii than focal lengths. Both genetic mutation (lrp2) and environmental manipulation (dark-rearing) caused elongated eye axes. lrp2 mutants had relative refractive errors of ?0.327 compared to wild-types, and dark-reared wild-type fish had relative refractive errors of ?0.132 compared to light-reared siblings. Therefore, zebrafish eye anatomy (axial length, lens radius, retinal radius) can be rapidly and accurately measured by SD-OCT, facilitating longitudinal studies of regulated eye growth and emmetropization. Specifically, genes homologous to human myopia candidates may be modified, inactivated or overexpressed in zebrafish, and myopia-sensitizing conditions used to probe gene-environment interactions. Our studies provide foundation for such investigations into genetic contributions that control eye size and impact refractive errors. PMID:25334040
Bell Length in the Entanglement Geometry
NASA Astrophysics Data System (ADS)
Fiscaletti, Davide; Licata, Ignazio
2015-07-01
A geometric approach to entangled qubit pairs is outlined via Bohm Theory. An entropic quantum correlation distance is here proposed as a mark of the non-local "handshaking" between two systems under the action of Quantum Potential. The Bell-CHSH inequalities and Berry Phase are analyzed in terms of this new correlation measure we called Bell Length, in honour of J.S. Bell (1928-1990).
Electrical conductivity measurements of nanofluids and development of new correlations.
Konakanchi, Hanumantharao; Vajjha, Ravikanth; Misra, Debasmita; Das, Debendra
2011-08-01
In this study the electrical conductivity of aluminum oxide (Al2O3), silicon dioxide (SiO2) and zinc oxide (ZnO) nanoparticles dispersed in propylene glycol and water mixture were measured in the temperature range of 0 degrees C to 90 degrees C. The volumetric concentration of nanoparticles in these fluids ranged from 0 to 10% for different nanofluids. The particle sizes considered were from 20 nm to 70 nm. The electrical conductivity measuring apparatus and the measurement procedure were validated by measuring the electrical conductivity of a calibration fluid, whose properties are known accurately. The measured electrical conductivity values agreed within +/- 1% with the published data reported by the manufacturer. Following the validation, the electrical conductivities of different nanofluids were measured. The measurements showed that electrical conductivity of nanofluids increased with an increase in temperature and also with an increase in particle volumetric concentration. For the same nanofluid at a fixed volumetric concentration, the electrical conductivity was found to be higher for smaller particle sizes. From the experimental data, empirical models were developed for three nanofluids to express the electrical conductivity as functions of temperature, volumetric concentration and the size of the nanoparticles. PMID:22103081
Absolute quantum efficiency measurements using correlated photons: A study of systematics
A. L. Migdall
2000-01-01
Correlated photons can be used to measure the quantum efficiency of photon counting photodetectors without ties to any externally calibrated standards. We present a study of the measurement systematics for the purpose of reducing the measurement uncertainties to the 0.1% level and developing a robust measurement protocol
Electrophysiological correlates of listening effort: neurodynamical modeling and measurement.
Strauss, Daniel J; Corona-Strauss, Farah I; Trenado, Carlos; Bernarding, Corinna; Reith, Wolfgang; Latzel, Matthias; Froehlich, Matthias
2010-06-01
An increased listing effort represents a major problem in humans with hearing impairment. Neurodiagnostic methods for an objective listening effort estimation might support hearing instrument fitting procedures. However the cognitive neurodynamics of listening effort is far from being understood and its neural correlates have not been identified yet. In this paper we analyze the cognitive neurodynamics of listening effort by using methods of forward neurophysical modeling and time-scale electroencephalographic neurodiagnostics. In particular, we present a forward neurophysical model for auditory late responses (ALRs) as large-scale listening effort correlates. Here endogenously driven top-down projections related to listening effort are mapped to corticothalamic feedback pathways which were analyzed for the selective attention neurodynamics before. We show that this model represents well the time-scale phase stability analysis of experimental electroencephalographic data from auditory discrimination paradigms. It is concluded that the proposed neurophysical and neuropsychological framework is appropriate for the analysis of listening effort and might help to develop objective electroencephalographic methods for its estimation in future. PMID:21629585
Ultrasonic velocity measurement using phase-slope cross-correlation methods
NASA Technical Reports Server (NTRS)
Hull, D. R.; Kautz, H. E.; Vary, A.
1984-01-01
Computer implemented phase-slope and cross-correlation methods are introduced for measuring time delays between pairs of broadband ultrasonic pulse-echo signals for determining velocity in engineering materials. The phase-slope and cross-correlation methods are compared with the overlap method which is currently in wide use. Comparison of digital versions of the three methods shows similar results for most materials having low ultrasonic attenuation. However, the cross-correlation method is preferred for highly attenuating materials. An analytical basis for the cross-correlation method is presented. Examples are given for the three methods investigated to measure velocity in representative materials in the megahertz range.
NASA Astrophysics Data System (ADS)
Fiekowsky, Peter; Selassie, Daniel
1999-12-01
The search for the 'holy grail' of a fast, reliable, inexpensive predictor of defect printability has reached a new level. Taking images from several inspection tools (KLA-351, KLA-353, and KLA Starlight) during defect review, the AVI Photomask Metrology System provides measurement repeatability better than 5 nm, and significantly better correlation to printability than Scanning Electron Microscope (SEM) measurements. SEM measurements of printed defects are compared to various measurements of the defects on the mask. Analysis shows, as expected, that optical area measurements provide the best correlation to printability. Further, images from existing inspection tools are shown to be sufficient to produce these measurements using AVI's new 'Flux-area' technique.
Boyer, Edmond
-65 THE MEASUREMENT OF ELECTRON DIFFUSION LENGTHS IN GaAs J. P. GOWERS Mullard Research Laboratories, Redhill, Surrey variables, the escape probability P and the electron diffusion length L. The measurement of L is therefore
NASA Astrophysics Data System (ADS)
Maglich, Bogdan; Radovic, Anna; Druey, Christian
2012-10-01
Genome length, L=, no. of DNA nucleotide base pairs in cell of bovine (b) and porcine (p) tissues, closest to human genome, were hitherto measured by genomic sequencing Lb=3, Lp=2.7 Giga base pairs [1,2] (Gbp) errors not given. - We report measurements of Lb/Lp and Lb, Lp without sequencing by atometry [3,4]. No. of O and C atoms, N, in nucleotide molecules, was obtained from prompt ? rate, G, emitted in inel. scatt. 14 MeV neutrons, with nuclei of C, O, in nucleotide molecule. Since G prop. N, Lb/Lp=Gb/Gp. p and b meat was irradiated for 30'. From msd G we obtained Lb /Lp=1.28±0.02 16% greater than [1,2]. We got absolute Lb=1.65/f, Lp=1.28/f Gbp, 0.3
Kronecker product linear exponent AR(1) correlation structures for multivariate repeated measures.
Simpson, Sean L; Edwards, Lloyd J; Styner, Martin A; Muller, Keith E
2014-01-01
Longitudinal imaging studies have moved to the forefront of medical research due to their ability to characterize spatio-temporal features of biological structures across the lifespan. Credible models of the correlations in longitudinal imaging require two or more pattern components. Valid inference requires enough flexibility of the correlation model to allow reasonable fidelity to the true pattern. On the other hand, the existence of computable estimates demands a parsimonious parameterization of the correlation structure. For many one-dimensional spatial or temporal arrays, the linear exponent autoregressive (LEAR) correlation structure meets these two opposing goals in one model. The LEAR structure is a flexible two-parameter correlation model that applies to situations in which the within-subject correlation decreases exponentially in time or space. It allows for an attenuation or acceleration of the exponential decay rate imposed by the commonly used continuous-time AR(1) structure. We propose the Kronecker product LEAR correlation structure for multivariate repeated measures data in which the correlation between measurements for a given subject is induced by two factors (e.g., spatial and temporal dependence). Excellent analytic and numerical properties make the Kronecker product LEAR model a valuable addition to the suite of parsimonious correlation structures for multivariate repeated measures data. Longitudinal medical imaging data of caudate morphology in schizophrenia illustrates the appeal of the Kronecker product LEAR correlation structure. PMID:24586419
Endoscopic measurement using radial metrology with digital correlation
NASA Technical Reports Server (NTRS)
Matthys, Donald R.; Gilbert, John A.; Greguss, Pal
1991-01-01
Radial metrology combines standard optical measurement techniques with a unique panoramic annular lens (PAL) system to study material properties and deformations on the inner surfaces of the cavities found, for example, inside pipes, tubes, and boreholes. A PAL profilometer using speckle metrology is analyzed and the equations obtained from the analysis are used to calibrate the PAL profilometer when it is used to profile the inner surface of a cylindrical pipe and to measure the deformation of the pipe when it is subjected to diametral compression.
A Binomial Test of Group Differences with Correlated Outcome Measures
ERIC Educational Resources Information Center
Onwuegbuzie, Anthony J.; Levin, Joel R.; Ferron, John M.
2011-01-01
Building on previous arguments for why educational researchers should not provide effect-size estimates in the face of statistically nonsignificant outcomes (Robinson & Levin, 1997), Onwuegbuzie and Levin (2005) proposed a 3-step statistical approach for assessing group differences when multiple outcome measures are individually analyzed within…
Calibration of fully anechoic rooms and correlation with OATS measurements
R. A. McConnell; C. Vitek
1996-01-01
Fully anechoic rooms may gradually replace open area test sites as the preferred type of testing facility for the measurement of radiated emissions. The fully anechoic room offers several advantages over the open area test site. Immunity to high ambient signal levels, the capability of being located in metropolitan areas close to the customer base, more uniform field over a
NASA Technical Reports Server (NTRS)
Hubbard, S. M.; Tabib-Azar, M.; Balley, S.; Rybickid, G.; Neudeck, P.; Raffaelle, R.
2004-01-01
Minority-Carrier diffusion lengths of n-type 6H-SiC were measured using the electron-beam induced current (EBIC) technique. Experimental values of primary beam current, EBIC, and beam voltage were obtained for a variety of SIC samples. This data was used to calculate experimental diode efficiency vs. beam voltage curves. These curves were fit to theoretically calculated efficiency curves, and the diffusion length and metal layer thickness were extracted. The hole diffusion length in n-6H SiC ranged from 0.93 +/- 0.15 microns.
Correlation Attenuation Due to Measurement Error: A New Approach Using the Bootstrap Procedure
ERIC Educational Resources Information Center
Padilla, Miguel A.; Veprinsky, Anna
2012-01-01
Issues with correlation attenuation due to measurement error are well documented. More than a century ago, Spearman proposed a correction for attenuation. However, this correction has seen very little use since it can potentially inflate the true correlation beyond one. In addition, very little confidence interval (CI) research has been done for…
Dominique Rigaud; Matteo Valenza
1994-01-01
Low frequency techniques of cross spectrum and correlation coefficient measurements are presented and applied to investigate drain and substrate noises of MOS transistors when multiplication occurs in the channel. For low substrate currents it is shown that the experimental data agree with theoretical expectations: the correlation coefficient is maximum at low frequencies and reaches its minimum value which is only
A binless correlation measure reduces the variability of memory reactivation estimates
Peter B. Kruskal; Jessica J. Stanis; Bruce L. McNaughton; Peter J. Thomas
2007-01-01
SUMMARY The standard procedure for measuring correlations between pairs of spike trains is to count the numbers of spikes occurring within a specified set of time intervals partitioning the continuous time line into discrete bins of width w (seconds). One then computes the Pearson correlation between pairs of the bin occupancy vectors. This method introduces a form of quantization noise,
3D digital image correlation methods for full-field vibration measurement
Mark N. Helfrick; Christopher Niezrecki; Peter Avitabile; Timothy Schmidt
2011-01-01
In the area of modal test\\/analysis\\/correlation, significant effort has been expended over the past twenty years in order to make reduced models and to expand test data for correlation and eventual updating of the finite element models. This has been restricted by vibration measurements which are traditionally limited to the location of relatively few applied sensors. Advances in computers and
Spatial Capacity Estimation for Correlated MIMO Channels Based on Measured SISO Data Records
Andreas Knopp; Christian A. Hofmann; Robert T. Schwarz; Mohamed Chouayakh; Berthold Lankl
2007-01-01
A novel strategy of precalculating potential MIMO spectral efficiencies of correlated channels based on single, measured or appropriately modeled SISO impulse responses is presented. Additionally, the model is capable of comprising the physical nature of the channel in form of its frequency response. The method is applied to indoor MIMO channels where the correlation is introduced by a strong Line-Of-Sight
In-vivo measuring of blood-flow changes using diffusing wave correlation techniques
Igor V. Meglinsky; David A. Boas; Arjun G. Yodh; Britton Chance
1997-01-01
We have non-invasively measured in vivo blood flow changes using photon correlation spectroscopy with a simple correlation diffusion model to study and quantify blood flow in the human arm during cuff ischemia. The method utilizes the Doppler broadening of light that arises in a multiply scattering dynamic media, and is also responsive to changes in absorption and scattering coefficients. Our
A critical assessment of different measures of the information carried by correlated neuronal firing
Stefano Panzeri; Gianni Pola; Filippo Petroni; Malcolm P. Young; Rasmus S. Petersen
2002-01-01
Information theoretic measures have been proposed as a quantitative framework to clarify the role of correlated neuronal activity in the brain. In this paper we review some recent methods that allow precise assessments of the role of correlation in stimulus coding and decoding by the nervous system. We present new results that make explicit links between types of encoding and
A correlation force spectrometer for single molecule measurements under tensile load
Paul, Mark
A correlation force spectrometer for single molecule measurements under tensile load Milad Radiom,1.1520 Comparing the dual trap technique with atomic force microscopy (AFM) single molecule force correlation force spectroscopy (CFS). We describe an instrument that is designed for characterizing
Thomas Chung; Stephen D. Bartlett; Andrew C. Doherty
2009-04-17
In measurement-based quantum computation (MBQC), local adaptive measurements are performed on the quantum state of a lattice of qubits. Quantum gates are associated with a particular measurement sequence, and one way of viewing MBQC is that such a measurement sequence prepares a resource state suitable for `gate teleportation'. We demonstrate how to quantify the performance of quantum gates in MBQC by using correlation functions on the pre-measurement resource state.
Peter D. Wentzell; Mitchell T. Lohnes
1999-01-01
Procedures to compensate for correlated measurement errors in multivariate data analysis are described. These procedures are based on the method of maximum likelihood principal component analysis (MLPCA), previously described in the literature. MLPCA is a decomposition method similar to conventional PCA, but it takes into account measurement uncertainty in the decomposition process, placing less emphasis on measurements with large variance.
Vormann, Matthias
Correlation and Coherence Measurements of a Spherical Wave Travelling in the Atmospheric Boundary the amplitude and phase of the propagating acoustic wave. Measuring the time dependent complex amplitude and temperature fluctuation within the time interval of measurement is of interest. The sounding wave is reduced
Spike correlation measures that eliminate stimulus e ects in response to white noise
Nykamp, Duane Q.
, without stimulus repeats, model-free measures cannot in general remove these stimulus-induced components. Nykamp #3; Abstract When measured in response to non-repeating white noise, standard covari- ance be approximated by a linear-nonlinear system. One of these measures fully characterizes the correlations
Kim, J; Portier, M; Dugué, J; Leduc, M; Cohen-Tannoudji, Claude
2005-01-01
We observe light-induced frequency shifts in one-color photoassociative spectra of magnetically trapped $^4$He$^*$ atoms in the metastable $2^3S_1$ state. A pair of ultracold spin-polarized $2^3S_1$ helium atoms is excited into a molecular bound state in the purely long range $0_u^+$ potential connected to the $2^3S_1 - 2^3P_0$ asymptote. The shift arises from the optical coupling of the molecular excited bound state with the scattering states and the bound states of two colliding $2^3S_1$ atoms. A linear dependence of frequency-shifts is found as a function of the PA laser intensity and measured for several ro-vibrational levels in the $0^+_u$ potential. Comparison with a theoretical analysis provides a good indication for the s-wave scattering length $a$ of the quintet ($^5\\Sigma_g^+$) potential, 6.6 nm $< a <$ 7.7 nm, which is significantly lower than previous results obtained by non-spectroscopic methods.
Technology Transfer Automated Retrieval System (TEKTRAN)
Measurements of texture properties related to tenderness at different locations within deboned broiler breast fillets have been used to validate techniques for texture analysis and establish correlations between different texture evaluation methods. However, it has been demonstrated that meat text...
Field methods to measure surface displacement and strain with the Video Image Correlation method
NASA Technical Reports Server (NTRS)
Maddux, Gary A.; Horton, Charles M.; Mcneill, Stephen R.; Lansing, Matthew D.
1994-01-01
The objective of this project was to develop methods and application procedures to measure displacement and strain fields during the structural testing of aerospace components using paint speckle in conjunction with the Video Image Correlation (VIC) system.
CORRELATION BETWEEN THE ACOUSTIC NOISE FIELD MEASURED IN A Posidonia oceanica BED
Jesus, Sérgio M.
of plant's photosynthesis. Noise power in the band 2-7 CORRELATION BETWEEN THE ACOUSTIC NOISE FIELD MEASURED IN A Posidonia oceanica BED, University of Liège, 4 Marine Plant Ecology Research Group Belgium Center of Marine Sciences (CCMar
Identification of Noise Sources in High Speed Jets via Correlation Measurements: A Review
NASA Technical Reports Server (NTRS)
Bridges, James (Technical Monitor); Panda, Jayanta
2005-01-01
Significant advancement has been made in the last few years to identify noise sources in high speed jets via direct correlation measurements. In this technique turbulent fluctuations in the flow are correlated with far field acoustics signatures. In the 1970 s there was a surge of work using mostly intrusive probes, and a few using Laser Doppler Velocimetry, to measure turbulent fluctuations. The later experiments established "shear noise" as the primary source for the shallow angle noise. Various interpretations and criticisms from this time are described in the review. Recent progress in the molecular Rayleigh scattering based technique has provided a completely non-intrusive means of measuring density and velocity fluctuations. This has brought a renewed interest on correlation measurements. We have performed five different sets of experiments in single stream jets of different Mach number, temperature ratio and nozzle configurations. The present paper tries to summarize the correlation data from these works.
One and two-dimensional analysis of 3/? correlations measured in Pb/+Pb interactions
NASA Astrophysics Data System (ADS)
NA44 Collaboration; Bearden, I. G.; Bøggild, H.; Boissevain, J.; Christiansen, P.; Conin, L.; Dodd, J.; Erazmus, B.; Esumi, S.; Fabjan, C. W.; Ferenc, D.; Fields, D. E.; Franz, A.; Gaardhøje, J.; Hansen, A. G.; Hansen, O.; Hardtke, D.; van Hecke, H.; Holzer, E. B.; Humanic, T. J.; Hummel, P.; Jacak, B. V.; Jayanti, R.; Kaimi, K.; Kaneta, M.; Kohama, T.; Kopytine, M.; Leltchouk, M.; Ljubi?i?, A.; Lö, B.; Maeda, N.; Martin, L.; Medvedev, A.; Murray, M.; Ohnishi, H.; Pai?, G.; Pandey, S. U.; Piuz, F.; Pluta, J.; Polychronakos, V.; Potekhin, M.; Poulard, G.; Reichold, D.; Sakaguchi, A.; Schmidt-Sø, J.; Simon-Gillo, J.; Sondheim, W.; Sugitate, T.; Sullivan, J. P.; Sumi, Y.; Willis, W. J.; Wolf, K. L.; Xu, N.; Zachary, D. S.
2001-09-01
?-?-?- correlations from Pb/+Pb collisions at 158 GeV//c per nucleon are presented as measured by the focusing spectrometer of the NA44 experiment at CERN. The three-body effect is found to be stronger for Pb/+Pb than for S/+Pb. The two-dimensional three-particle correlation function is also measured and the longitudinal extension of the source is larger than the transverse extension.
One and two-dimensional analysis of 3? correlations measured in Pb+Pb interactions
NASA Astrophysics Data System (ADS)
Bearden, I. G.; Bøggild, H.; Boissevain, J.; Christiansen, P.; Conin, L.; Dodd, J.; Erazmus, B.; Esumi, S.; Fabjan, C. W.; Ferenc, D.; Fields, D. E.; Franz, A.; Gaardhøje, J.; Hansen, A. G.; Hansen, O.; Hardtke, D.; van Hecke, H.; Holzer, E. B.; Humanic, T. J.; Hummel, P.; Jacak, B. V.; Jayanti, R.; Kaimi, K.; Kaneta, M.; Kohama, T.; Kopytine, M.; Leltchouk, M.; Ljubi?i?, A.; Lö, B.; Maeda, N.; Martin, L.; Medvedev, A.; Murray, M.; Ohnishi, H.; Pai?, G.; Pandey, S. U.; Piuz, F.; Pluta, J.; Polychronakos, V.; Potekhin, M.; Poulard, G.; Reichold, D.; Sakaguchi, A.; Schmidt-Sø, J.; Simon-Gillo, J.; Sondheim, W.; Sugitate, T.; Sullivan, J. P.; Sumi, Y.; Willis, W. J.; Wolf, K. L.; Xu, N.; Zachary, D. S.; NA44 Collaboration
2001-09-01
?-?-?- correlations from Pb+Pb collisions at 158 GeV/c per nucleon are presented as measured by the focusing spectrometer of the NA44 experiment at CERN. The three-body effect is found to be stronger for Pb+Pb than for S+Pb. The two-dimensional three-particle correlation function is also measured and the longitudinal extension of the source is larger than the transverse extension.
Theoretical analysis of correlation-based quality measures for weighted averaging image fusion
Chuanming Wei; Rick S. Blum
2010-01-01
Recently introduced correlation-based quality measures have received lots of attention due to the fact that they do not need ground-truth reference images to evaluate the performance of image fusion algorithms. In this paper we focus on theoretical analysis of these correlation-based quality measures when they are used to judge the performance of weighted averaging image fusion algorithms. The purpose of
Theoretical analysis of correlation-based quality measures for weighted averaging image fusion
Chuanming Wei; Rick S. Blum
2009-01-01
Recently introduced correlation-based quality measures have received lots of attention due to the fact that they do not need ground-truth reference images to evaluate the performance of image fusion algorithms. In this paper we focus on theoretical analysis of these correlation-based quality measures when they are used to judge the performance of weighted averaging image fusion algorithms. The purpose of
Spatial Correlation and Eigenvalue Statistics Investigation of Wideband MIMO Channel Measurements
Attaphongse Taparugssanagorn; Tommi Jämsä; Juha Ylitalo
2006-01-01
Spatial correlation is one of substantial factors for multiple-input multiple-output (MIMO) wireless communication systems. The spatial correlation must be therefore taken into account in system simulations. This paper results from outdoor wideband MIMO channel measurements performed at 2.53 GHz with a bandwidth of 100 MHz in urban microcell scenario. The measurements were conducted for vehicular speed of 20 km\\/h. A
H. Fischer; E. Redemann; F. Fergg; D. Rabus
1985-01-01
Compact two-channel IR radiometers for solar occultation experiments have been constructed in order to measure concentration profiles of stratospheric trace gases. The instruments can be used as filter-or gas correlation-type radiometers depending on the trace gas under investigation. Within the LIMS correlative measurement program, balloon flights were performed with a payload of up to four of these two-channel radiometers. From
Surface Roughness Measurement on a Wing Aircraft by Speckle Correlation
Salazar, Félix; Barrientos, Alberto
2013-01-01
The study of the damage of aeronautical materials is important because it may change the microscopic surface structure profiles. The modification of geometrical surface properties can cause small instabilities and then a displacement of the boundary layer. One of the irregularities we can often find is surface roughness. Due to an increase of roughness and other effects, there may be extra momentum losses in the boundary layer and a modification in the parasite drag. In this paper we present a speckle method for measuring the surface roughness on an actual unmanned aircraft wing. The results show an inhomogeneous roughness distribution on the wing, as expected according to the anisotropic influence of the winds over the entire wing geometry. A calculation of the uncertainty of the technique is given. PMID:24013488
Measurement of dynamic critical exponents in strongly correlated systems
NASA Astrophysics Data System (ADS)
Lee, Ji-Woo; Lee, Yong Chul; Park, Tae Young
2010-03-01
We propose a method of obtaining dynamic critical exponents by measuring the gap between the ground-state energy and the first-excited state energy. The finite-size scaling of the gap produces the dynamic critical exponent directly. For one-dimensional hardcore boson Hubbard model at half-filling, we applied our method to obtain z=0.975 ±0.002. For one-dimensional spinless fermion model, we obtained z=0.95 ±0.02. The ground-state energy is obtained by modified Lanczos method and the excited spectrum is obtained by Grosso's method. We expect our method can be very useful in obtaining dynamic critical exponent without using two-parameter finite-size scaling of order parameters such as superfluid density. Application to other models is also presented.
V. Bantseev; K. Herbert; J. G. Sivak; J. R. Trevithick
\\u000a Lenses of rats, selected by clarity and\\/or low protein leakage during preincubation, were incubated in medium 199 (M199).\\u000a 60Co-?-irradiation simulated radiation encountered in space, although ?-irradiation causes less damage than cosmic rays. At\\u000a the termination of incubation, lenses were scanned by a Scanning Lens Monitor. Protein leakage was positively correlated with\\u000a variability in focal length (p <0.04). Irradiated lenses had
Di Nardo, R
2012-01-01
We present soft-QCD measurements in proton-proton collisions at $sqrt{s}= 900$ GeV and $sqrt{s}= 7$ TeV recorded with the ATLAS detector at the LHC using a single-arm minimum bias trigger. The charged particle multiplicities, its dependence on transverse momentum and pseudo-rapidity and its correlation with the average transverse momentum will be shown. Moreover, the measurement of the underlying event properties using charged particles only and neutral plus charged particles is discussed. Finally the measurement of the two-particle angular correlations is presented. All the measurements are compared with different Monte Carlo predictions.
Correlations of Stratospheric Abundances of CH4 and N2O Derived from ATMOS Measurements
NASA Technical Reports Server (NTRS)
Rinsland, C. P.; Manney, G. L.; Gunson, M. R.; Rinsland, C. P.; Zander, R.
1998-01-01
Atmospheric Trace MOlecule Spectroscopy (ATMOS) measurements made over a wide range of altitudes and latitudes demonstrate compact correlations between mixing ratios of CH, and N,O. Tight but distinct correlations are observed for the tropics, the springtime Arctic vortex, and the extra-tropics/extra-vortex regions, indicating dynamical isolation between these regions. Little variability is apparent in correlations between CH4 and N20 from measurements made in different years (1992, 1993, and 1994), seasons (March/April and November), and hemispheres.
NASA Astrophysics Data System (ADS)
Xue, Zhenyu; Charonko, John J.; Vlachos, Pavlos P.
2014-11-01
In particle image velocimetry (PIV) the measurement signal is contained in the recorded intensity of the particle image pattern superimposed on a variety of noise sources. The signal-to-noise-ratio (SNR) strength governs the resulting PIV cross correlation and ultimately the accuracy and uncertainty of the resulting PIV measurement. Hence we posit that correlation SNR metrics calculated from the correlation plane can be used to quantify the quality of the correlation and the resulting uncertainty of an individual measurement. In this paper we extend the original work by Charonko and Vlachos and present a framework for evaluating the correlation SNR using a set of different metrics, which in turn are used to develop models for uncertainty estimation. Several corrections have been applied in this work. The SNR metrics and corresponding models presented herein are expanded to be applicable to both standard and filtered correlations by applying a subtraction of the minimum correlation value to remove the effect of the background image noise. In addition, the notion of a ‘valid’ measurement is redefined with respect to the correlation peak width in order to be consistent with uncertainty quantification principles and distinct from an ‘outlier’ measurement. Finally the type and significance of the error distribution function is investigated. These advancements lead to more robust and reliable uncertainty estimation models compared with the original work by Charonko and Vlachos. The models are tested against both synthetic benchmark data as well as experimental measurements. In this work, {{U}68.5} uncertainties are estimated at the 68.5% confidence level while {{U}95} uncertainties are estimated at 95% confidence level. For all cases the resulting calculated coverage factors approximate the expected theoretical confidence intervals, thus demonstrating the applicability of these new models for estimation of uncertainty for individual PIV measurements.
NASA Technical Reports Server (NTRS)
Anderson, Stuart M.; Zahniser, Mark S.
1991-01-01
Biogenic emissions from and dry deposition to terrestrial surfaces are important processes determining the trace gas composition of the atmosphere. An instrument has been developed for flux measurements of gases such as CH4, N2O, and O3 based on the eddy correlation technique which combines trace gas fluctuation measurements with simultaneous windfield measurements. The instrument combines a tunable diode laser infrared light source with an open-path multipass absorption cell in order to provide the fast time response and short base pathlength required for the eddy correlation method. Initial field tests using the instrument to measure methane emissions from a local wetland demonstrate the capability for high precision eddy correlation flux measurements.
3D shape measurement of static and moving objects with adaptive spatiotemporal correlation.
Harendt, Bastian; Grosse, Marcus; Schaffer, Martin; Kowarschik, Richard
2014-11-01
Common correlation-based photogrammetric 3D shape measurement techniques evaluate either temporal or spatial features. Temporal approaches achieve high accuracies but are limited to the measurement of static objects. Spatial techniques can deal with moving objects but provide relatively inaccurate results. Our goal is to combine these methods in order to measure dynamic scenes that contain static and moving objects. Therefore, we present a spatiotemporal correlation that adapts its temporal and spatial support locally to the motion of the measured objects. In addition, our technique compensates motion by warping the correlated image regions temporally. Our approach is based on structured illumination of random patterns, which are well suited for dynamic scenes due to high possible frame rates. The proposed technique is tested with simulated data and real measurements. PMID:25402918
Accurate Measurement of Satellite Antenna Surface Using 3D Digital Image Correlation Technique
B. Pan; H. Xie; L. Yang; Z. Wang
2009-01-01
Application of the three-dimensional digital image correlation technique (3D DIC) to the accurate measurement of full-field surface profile of a 730 mm-diameter carbon fibre composite satellite antenna is investigated in this article. The basic principles of the 3D DIC technique are described. The measured profile was compared with the one measured with a three-dimensional coordinate measuring machine. The results clearly
Durisic, Nela; Bachir, Alexia I.; Kolin, David L.; Hebert, Benedict; Lagerholm, B. Christoffer; Grutter, Peter; Wiseman, Paul W.
2007-01-01
Semiconductor nanocrystals or quantum dots (QDs) are becoming widely used as fluorescent labels for biological applications. Here we demonstrate that fluorescence fluctuation analysis of their diffusional mobility using temporal image correlation spectroscopy is highly susceptible to systematic errors caused by fluorescence blinking of the nanoparticles. Temporal correlation analysis of fluorescence microscopy image time series of streptavidin-functionalized (CdSe)ZnS QDs freely diffusing in two dimensions shows that the correlation functions are fit well to a commonly used diffusion decay model, but the transport coefficients can have significant systematic errors in the measurements due to blinking. Image correlation measurements of the diffusing QD samples measured at different laser excitation powers and analysis of computer simulated image time series verified that the effect we observe is caused by fluorescence intermittency. We show that reciprocal space image correlation analysis can be used for mobility measurements in the presence of blinking emission because it separates the contributions of fluctuations due to photophysics from those due to transport. We also demonstrate application of the image correlation methods for measurement of the diffusion coefficient of glycosyl phosphatidylinositol-anchored proteins tagged with QDs as imaged on living fibroblasts. PMID:17526586
Liu, Sze Yan; Manly, Jennifer J.; Capistrant, Benjamin D.; Glymour, M. Maria
2015-01-01
Introduction Legally mandated segregation policies dictated significant differences in the educational experiences of black and white Americans through the first half of the 20th century, with markedly lower quality in schools attended by black children. We determined whether school term length, a common marker of school quality, was associated with blood pressure and hypertension among a cohort of older Americans who attended school during the de jure segregation era. Methods National Health and Nutrition Examination Survey I and II data were linked to state level historical information on school term length. We used race and gender-stratified linear regression models adjusted for age, state and year of birth to estimate effects of term length on systolic and diastolic blood pressure (SBP and DBP) and hypertension for US-born adults. We also tested whether correcting years of schooling for term length differences attenuated estimated racial disparities. Results Among black women, 10% longer school term was associated with lower SBP, DBP and hypertension prevalence (2.1 mmHg, 1.0 mmHg, and 5.0 percentage points respectively). Associations for whites and for black men were not statistically significant. Adjustment for education incorporating corrections for differences in school term length slightly attenuated estimated racial disparities. Conclusions Longer school term length predicted better BP outcomes among black women, but not black men or whites. PMID:26076495
NASA Astrophysics Data System (ADS)
Gopaul, N. S.; Wang, J. G.; Hu, B.
2014-11-01
An image-aided inertial navigation implies that the errors of an inertial navigator are estimated via the Kalman filter using the aiding measurements derived from images. The standard Kalman filter runs under the assumption that the process noise vector and measurement noise vector are white, i.e. independent and normally distributed with zero means. However, this does not hold in the image-aided inertial navigation. In the image-aided inertial integrated navigation, the relative positions from optic-flow egomotion estimation or visual odometry are pairwise correlated in terms of time. It is well-known that the solution of the standard Kalman filter becomes suboptimal if the measurements are colored or time-correlated. Usually, a shaping filter is used to model timecorrelated errors. However, the commonly used shaping filter assume that the measurement noise vector at epoch k is not only correlated with the one from epoch k - 1 but also with the ones before epoch k - 1 . The shaping filter presented in this paper uses Cholesky factors under the assumption that the measurement noise vector is pairwise time-correlated i.e. the measurement noise are only correlated with the ones from previous epoch. Simulation results show that the new algorithm performs better than the existing algorithms and is optimal.
IMF Length Scales and Predictability: The Two Length Scale Medium
NASA Technical Reports Server (NTRS)
Collier, Michael R.; Szabo, Adam; Slavin, James A.; Lepping, R. P.; Kokubun, S.
1999-01-01
We present preliminary results from a systematic study using simultaneous data from three spacecraft, Wind, IMP 8 (Interplanetary Monitoring Platform) and Geotail to examine interplanetary length scales and their implications on predictability for magnetic field parcels in the typical solar wind. Time periods were selected when the plane formed by the three spacecraft included the GSE (Ground Support Equipment) x-direction so that if the parcel fronts were strictly planar, the two adjacent spacecraft pairs would determine the same phase front angles. After correcting for the motion of the Earth relative to the interplanetary medium and deviations in the solar wind flow from radial, we used differences in the measured front angle between the two spacecraft pairs to determine structure radius of curvature. Results indicate that the typical radius of curvature for these IMF parcels is of the order of 100 R (Sub E). This implies that there are two important IMF (Interplanetary Magnetic Field) scale lengths relevant to predictability: (1) the well-established scale length over which correlations observed by two spacecraft decay along a given IMF parcel, of the order of a few tens of Earth radii and (2) the scale length over which two spacecraft are unlikely to even observe the same parcel because of its curvature, of the order of a hundred Earth radii.
Hou, Lifang; Wang, Sheng; Dou, Chang; Zhang, Xiao; Yu, Yue; Zheng, Yinan; Avula, Umakanth; Hoxha, Mirjam; Díaz, Anaité; McCracken, John; Barretta, Francesco; Marinelli, Barbara; Bertazzi, Pier Alberto; Schwartz, Joel; Baccarelli, Andrea A.
2013-01-01
Background Ambient particular matter (PM) exposure has been associated with short- and long-term effects on cardiovascular disease (CVD). Telomere length (TL) is a biomarker of CVD risk that is modified by inflammation and oxidative stress, two key pathways for PM effects. Whether PM exposure modifies TL is largely unexplored. Objectives To investigate effects of PM on blood TL in a highly-exposed population. Methods We measured blood TL in 120 blood samples from truck drivers and 120 blood samples from office workers in Beijing, China. We measured personal PM2.5 and Elemental Carbon (EC, a tracer of traffic particles) using light-weight monitors. Ambient PM10 was obtained from local monitoring stations. We used covariate-adjusted regression models to estimate percent changes in TL per an interquartile-range increase in exposure. Results Covariate-adjusted TL was higher in drivers (mean=0.87, 95%CI: 0.74; 1.03) than in office workers (mean=0.79, 95%CI: 0.67; 0.93; p=0.001). In all participants combined, TL increased in association with personal PM2.5 (+5.2%, 95%CI: 1.5; 9.1; p=0.007), personal EC (+4.9%, 95%CI: 1.2; 8.8; p=0.01), and ambient PM10 (+7.7%, 95%CI: 3.7; 11.9; p<0.001) on examination days. In contrast, average ambient PM10 over the 14 days before the examinations was significantly associated with shorter TL (?9.9%, 95%CI: ?17.6; ?1.5; p=0.02). Conclusions Short-term exposure to ambient PM is associated with increased blood TL, consistent with TL roles during acute inflammatory responses. Longer exposures may shorten TL as expected after prolonged pro-oxidant exposures. The observed TL alterations may participate in the biological pathways of short- and long-term PM effects. PMID:22871507
Technology Transfer Automated Retrieval System (TEKTRAN)
A twelve week study was conducted on the egg albumen from both pasteurized and non-pasteurized shell eggs using visible-near infrared spectroscopy. Correlation of the chemical changes detected in the spectra to the measurement of Haugh units (measure of interior egg quality) was carried out using pr...
A positive correlation between self-ratings of depression and laboratory-measured aggression
James M. Bjork; Donald M. Dougherty; F. Gerard Moeller
1997-01-01
Aggression and depressive symptoms have been linked using self-rating scales as measures of aggression. In order to study this relationship using an objective measure of aggression, we studied normal controls (42 women and 23 men) with the Point Subtraction Aggression Paradigm (PSAP) and the Beck Depression Inventory (BDI). There was a significant positive correlation (r = 0.442, P = 0.003)
Correlation of quality measurements to visible-near infrared spectra of pasteurized egg
Technology Transfer Automated Retrieval System (TEKTRAN)
A twelve week study was conducted on the egg albumen from both pasteurized and non-pasteurized shell eggs using visible-near infrared spectroscopy. Correlation of the chemical changes detected in the spectra to the measurement of Haugh units (measure of interior egg quality) was carried out using ch...
Correlation of seismotectonic variables and GPS strain measurements in western Turkey
Wilson, Thomas H.
Correlation of seismotectonic variables and GPS strain measurements in western Turkey Ali Osman O Mediterranean and western Turkey area. This analysis was conducted in three tectonic subdivisions corresponding measurements in western Turkey, J. Geophys. Res., 109, B11306, doi:10.1029/2004JB003101. 1. Introduction [2
A fast response atmospheric CO2 sensor for eddy correlation flux measurements
E. P. Jones; T. V. Ward; H. H. Zwick
1978-01-01
The direct measurement of carbon dioxide fluxes in the atmospheric boundary layer is of considerable importance in studies of ocean atmosphere exchange and in productivity of crops and forests. A promising technique for measuring CO2 fluxes, the eddy correlation method, requires a sensitive fast response sensor. We describe the sensor requirements and present a design which has proved successful in
Toshitaka Funazukuri; Chang Yi Kong; Seiichiro Kagei
2006-01-01
Dr. Aydin Akgerman greatly contributed to studies on diffusion in liquids and supercritical fluids, in particular, measurements by the Taylor dispersion method. Based on his work, this article describes recent progress in measurements for binary diffusion coefficients in supercritical fluids by using the chromatographic impulse response technique as well as the Taylor dispersion method, and in the predictive empirical correlations.
Bias of Coefficient Alpha for Fixed Congeneric Measures with Correlated Errors.
ERIC Educational Resources Information Center
Raykov, Tenko
2001-01-01
Studied the population discrepancy of coefficient alpha from the composite reliability coefficient for fixed congeneric measures with correlated errors and expressed it in terms of parameters of the measures. Recommends structural equation modeling for identifying cases in which the discrepancy can be large. (SLD)
An Experiment for Measuring the Electron-Antineutrino Correlation in Neutron Beta Decay
A. K. Komives; F. E. Wietfeldt; B. Fisher; C. Trull; G. Jones; B. Collett; B. G. Yerozolimsky; R. Wilson; S. Balashov; Yu. Mostovoy; M. Leuschner; J. Byrne; F. B. Bateman; M. S. Dewey; J. S. Nico; A. K. Thompson
2004-01-01
Of the several important coefficients describing neutron beta decay, the one describing the electron-antineutrino correlation, ``a'', has the largest fractional uncertainty: 4%. Improving the precision of the ``a'' coefficient will strengthen tests of the Standard Electroweak Model in the neutron decay system. Additionally, ``a'' is free of the complications involved with measuring neutron polarization precisely. A precise measurement of ``a''
Measurements of Spin Correlation in $t\\bar{t}$ Events at D0
Bloom, Kenneth; /Nebraska U.
2011-09-01
Two recent measurements by the D0 Collaboration of spin correlation in t{bar t} production using 5.4 fb{sup -1} of Tevatron p{bar p} collider data are presented. Both rely on the dilepton final state of t{bar t}. One measurement relies on full reconstruction of the top quark kinematics, and the other makes use of leading-order matrix elements to characterize the kinematics. The latter measurement is the first ever to have sufficient analyzing power to exclude the no-correlation hypothesis.
Burns, Carolyn A.; Gauglitz, Phillip A.; Russell, Renee L.
2010-01-20
This report documents testing funded by CH2M Hill Plateau Remediation and performed by Pacific Northwest National Laboratory (PNNL) in collaboration with Fauske and Associates, LLC (FAI) to determine the behavior of vessel spanning bubbles. The shear strengths of four samples of kaolin/water mixtures obtained by PNNL from FAI were measured and are reported here. The measured shear strengths of these samples were then used to determine how the Rassat correlation fit these new measurements or if a new correlation was needed. These results were then compared with previously reported data.
3D displacement field measurement with correlation based on the micro-geometrical surface texture
NASA Astrophysics Data System (ADS)
Bubaker-Isheil, Halima; Serri, Jérôme; Fontaine, Jean-François
2011-07-01
Image correlation methods are widely used in experimental mechanics to obtain displacement field measurements. Currently, these methods are applied using digital images of the initial and deformed surfaces sprayed with black or white paint. Speckle patterns are then captured and the correlation is performed with a high degree of accuracy to an order of 0.01 pixels. In 3D, however, stereo-correlation leads to a lower degree of accuracy. Correlation techniques are based on the search for a sub-image (or pattern) displacement field. The work presented in this paper introduces a new correlation-based approach for 3D displacement field measurement that uses an additional 3D laser scanner and a CMM (Coordinate Measurement Machine). Unlike most existing methods that require the presence of markers on the observed object (such as black speckle, grids or random patterns), this approach relies solely on micro-geometrical surface textures such as waviness, roughness and aperiodic random defects. The latter are assumed to remain sufficiently small thus providing an adequate estimate of the particle displacement. The proposed approach can be used in a wide range of applications such as sheet metal forming with large strains. The method proceeds by first obtaining cloud points using the 3D laser scanner mounted on a CMM. These points are used to create 2D maps that are then correlated. In this respect, various criteria have been investigated for creating maps consisting of patterns, which facilitate the correlation procedure. Once the maps are created, the correlation between both configurations (initial and moved) is carried out using traditional methods developed for field measurements. Measurement validation was conducted using experiments in 2D and 3D with good results for rigid displacements in 2D, 3D and 2D rotations.
A New Basis for Interpretation of the Planck Length
C. L. Herzenberg
2006-10-17
A critical length has recently been identified that appears to provide a fundamental limit distinguishing quantum behavior from classical behavior. Because of the unique association between critical length and mass, it appears that we can correlate the mass of an object with the size over which its quantum behavior is manifested. When the expression for the critical length is set equal to the Planck length, we find an associated mass value that in magnitude corresponds to an approximation of the mass of the visible universe. This would appear to suggest that the quantum behavior associated with the universe as a whole would be manifested at distances comparable to or smaller than the Planck length. Accordingly, it would appear that all position measurements would be subject to uncertainties at the limit of the Planck length, so that the Planck length sets a fundamental limit on position determination.
Huth, Michael
B1 Problem Statement This task is to estimate the heights of objects, e.g. trees, by measuring the length of shadows. The height of objects can be estimated using similar triangles. a/(c+d) = b of a tree (a) , he can estimate the height of top of the tree. This project assumes that the person's height
Sethna, James P.
by etching into microelectromechanical structures and tend to be the initiation sites for failure by fracture anisotropic etching rates.3 Failure in such devices is often a result of fracture which initiated at sharpMacroscopic measure of the cohesive length scale: Fracture of notched single-crystal silicon
Transmission Efficiency Measurements and Correlations with Physical Characteristics of the Lubricant
NASA Technical Reports Server (NTRS)
Coy, J. J.; Mitchell, A. M.; Hamrock, B. J.
1984-01-01
Data from helicopter transmission efficiency tests were compared to physical properties of the eleven lubricants used in those tests. The tests were conducted with the OH-58 helicopter main rotor transmission. Efficiencies ranged from 98.3 to 98.8 percent. The data was examined for correlation of physical properties with efficiency. There was a reasonable correlation of efficiency with absolute viscosity if the viscosity was first corrected for temperature and pressure in the lubricated contact. Between lubricants, efficiency did not correlate well with viscosity at atmospheric pressure. Between lubricants, efficiency did not correlate well with calculated lubricant film forming capacity. Bench type sliding friction and wear measurements could not be correlated to transmission efficiency and component wear.
Photoacoustic correlation spectroscopy and its application to low-speed flow measurement
Chen, Sung-Liang; Ling, Tao; Huang, Sheng-Wen; Baac, Hyoung Won; Guo, L. Jay
2010-01-01
A photoacoustic correlation technique, inspired by its optical counterpart—the fluorescence correlation spectroscopy (FCS), was tested for the first time to demonstrate the feasibility of low-speed flow measurement based on photoacoustic signal detection. A pulsed laser was used to probe the flow of light-absorbing beads. A photoacoustic correlation system of 0.8 sec temporal resolution was built and flow speeds ranging from 249 to 14.9 µm/s with corresponding flow time from 4.42 to 74.1 sec were measured. The experiment serves as a proof of concept for photoacoustic correlation spectroscopy, which may have many potential applications similar to FCS. PMID:20410966
3D digital image correlation methods for full-field vibration measurement
NASA Astrophysics Data System (ADS)
Helfrick, Mark N.; Niezrecki, Christopher; Avitabile, Peter; Schmidt, Timothy
2011-04-01
In the area of modal test/analysis/correlation, significant effort has been expended over the past twenty years in order to make reduced models and to expand test data for correlation and eventual updating of the finite element models. This has been restricted by vibration measurements which are traditionally limited to the location of relatively few applied sensors. Advances in computers and digital imaging technology have allowed 3D digital image correlation (DIC) methods to measure the shape and deformation of a vibrating structure. This technique allows for full-field measurement of structural response, thus providing a wealth of simultaneous test data. This paper presents some preliminary results for the test/analysis/correlation of data measured using the DIC approach along with traditional accelerometers and a scanning laser vibrometer for comparison to a finite element model. The results indicate that all three approaches correlated well with the finite element model and provide validation for the DIC approach for full-field vibration measurement. Some of the advantages and limitations of the technique are presented and discussed.
NASA Astrophysics Data System (ADS)
van Waerbeke, L.; Mellier, Y.; Schneider, P.; Fort, B.; Mathez, G.
1997-01-01
A new method for measuring the shear induced by gravitational light deflection is proposed. It is based on analyzing the anisotropy induced in the auto-correlation function of the extragalactic background light which is produced by very faint distant galaxies. The auto-correlation function can be measured `locally', and its anisotropy is caused by the tidal gravitational field of the deflecting mass distribution in the foreground of these faint background galaxies. Since the method does not require individual galaxy detection, it can be used to measure the shear of extremely faint galaxies which are not detectable individually, but are present in the noise. The shear estimated from the auto-correlation function of the image provides an independent measurement which can be compared to the shear obtained from the distortion of individual galaxy images. Combining these two independent estimates clearly increases the sensitivity of shear measurements. In addition, our new method may allow to determine the local magnification caused by the deflector if the auto-correlation function is caused by a large number density of faint galaxies; in this case, the intrinsic auto-correlation function may provide a `standard source' with respect to which shear and magnification can be obtained. Applications to real and synthetic data are shown and the feasibility of our new method is demonstrated. In particular, we present the shear maps obtained with our new method for the double QSO 2345+007 and the cluster Cl0024+16 and compare them to published shear maps.
Measuring the correlation of two optical frequencies using four-wave mixing.
Anthur, Aravind P; Watts, Regan T; Huynh, Tam N; Venkitesh, Deepa; Barry, Liam P
2014-11-10
We use the physics of four-wave mixing to study the decorrelation of two optical frequencies as they propagate through different fiber delays. The phase noise relationship between the four-wave mixing components is used to quantify and measure the correlation between the two optical frequencies using the correlation coefficient. We show the difference in the evolution of decorrelation between frequency-dependent and frequency-independent components of phase noise. PMID:25402993
H. W. Schmitt; J. H. Neiler; F. J. Walter
1966-01-01
Fission-fragment mass and energy distributions and mass-versus-energy correlations have been obtained for 252Cf spontaneous fission and 235U thermal-neutron-induced fission. Silicon surface-barrier detectors were used in energy correlation measurements; absolute fragment energies were obtained by means of the mass-dependent energy calibration developed recently at this laboratory. Average total fragment kinetic energies before neutron emission are found to be 186.5+\\/-1.2 MeV for
Spatial Correlation of Solar-Wind Turbulence from Two-Point Measurements
NASA Technical Reports Server (NTRS)
Matthaeus, W. H.; Milano, L. J.; Dasso, S.; Weygand, J. M.; Smith, C. W.; Kivelson, M. G.
2005-01-01
Interplanetary turbulence, the best studied case of low frequency plasma turbulence, is the only directly quantified instance of astrophysical turbulence. Here, magnetic field correlation analysis, using for the first time only proper two-point, single time measurements, provides a key step in unraveling the space-time structure of interplanetary turbulence. Simultaneous magnetic field data from the Wind, ACE, and Cluster spacecraft are analyzed to determine the correlation (outer) scale, and the Taylor microscale near Earth's orbit.
Spatial Correlation of Solar-Wind Turbulence from Two-Point Measurements
Matthaeus, W.H.; Milano, L.J. [Bartol Research Institute, Department of Physics and Astronomy, University of Delaware, Newark, Delaware 19716 (United States); Dasso, S. [Instituto de Astronomia y Fisica del Espacio (IAFE) and Departamento de Fisica, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, 1428 Buenos Aires (Argentina); Weygand, J.M.; Kivelson, M.G. [IGPP, UCLA, Los Angeles, California 90095 (United States); Smith, C.W. [Institute for Earth, Oceans and Space, University of New Hampshire, Durham, New Hampshire 03824 (United States)
2005-12-02
Interplanetary turbulence, the best studied case of low frequency plasma turbulence, is the only directly quantified instance of astrophysical turbulence. Here, magnetic field correlation analysis, using for the first time only proper two-point, single time measurements, provides a key step in unraveling the space-time structure of interplanetary turbulence. Simultaneous magnetic field data from the Wind, ACE, and Cluster spacecraft are analyzed to determine the correlation (outer) scale, and the Taylor microscale near Earth's orbit.
Green, M.I.; Nelson, D.; Marks, S.; Gee, B.; Wong, W.; Meneghetti, J.
1989-03-01
A matched pair of curved integral coils has been designed, fabricated and calibrated at Lawrence Berkeley Laboratory for measuring Advanced Light Source (ALS) Booster Dipole Magnets. Distinctive fabrication and calibration techniques are described. The use of multifilar magnet wire in fabrication integral search coils is described. Procedures used and results of AC and DC measurements of transfer function, effective length and uniformity of the prototype booster dipole magnet are presented in companion papers. 8 refs.
Tensor Correlations Measured in 3He(e,e'pp)n
H. Baghdasaryan; L. B. Weinstein; J. M. Laget; K. P. Adhikari; M. Aghasyan; M. Amarian; M. Anghinolfi; H. Avakian; J. Ball; M. Battaglieri; I. Bedlinskiy; B. L. Berman; A. S. Biselli; C. Bookwalter; W. J. Briscoe; W. K. Brooks; S. Bültmann; V. D. Burkert; D. S. Carman; V. Crede; A. DAngelo; A. Daniel; N. Dashyan; R. DeVita; E. DeSanctis; A. Deur; B. Dey; R. Dickson; C. Djalali; G. E. Dodge; D. Doughty; R. Dupre; H. Egiyan; A. El Alaoui; L. El Fassi; P. Eugenio; S. Fegan; M. Y. Gabrielyan; G. P. Gilfoyle; K. L. Giovanetti; W. Gohn; R. W. Gothe; K. A. Griffioen; M. Guidal; L. Guo; V. Gyurjyan; H. Hakobyan; C. Hanretty; C. E. Hyde; K. Hicks; M. Holtrop; Y. Ilieva; D. G. Ireland; K. Joo; D. Keller; M. Khandaker; P. Khetarpal; A. Kim; W. Kim; A. Klein; F. J. Klein; P. Konczykowski; V. Kubarovsky; S. E. Kuhn; S. V. Kuleshov; V. Kuznetsov; N. D. Kvaltine; K. Livingston; H. Y. Lu; I.J.D. MacGregor; N. Markov; M. Mayer; J. McAndrew; B. McKinnon; C. A. Meyer; K. Mikhailov; V. Mokeev; B. Moreno; K. Moriya; B. Morrison; H. Moutarde; E. Munevar; P. Nadel-Turonski; C. Nepali; S. Niccolai; G. Niculescu; I. Niculescu; M. Osipenko; A. I. Ostrovidov; R. Paremuzyan; E. Pasyuk; S. Anefalos Pereira; S. Pisano; O. Pogorelko; S. Pozdniakov; J. W. Price; S. Procureur; D. Protopopescu; G. Ricco; M. Ripani; G. Rosner; P. Rossi; C. Salgado; R. A. Schumacher; H. Seraydaryan; G. D. Smith; D. I. Sober; D. Sokhan; S. S. Stepanyan; P. Stoler; S. Strauch; M. Taiuti; W. Tang; C. E. Taylor; D. J. Tedeschi; M. Ungaro; M. F. Vineyard; E. Voutier; D. P. Watts; D. P. Weygand; M. H. Wood; B. Zhao; Z. W. Zhao
2010-01-01
We have measured the 3He(e,eâ²pp)n reaction at an incident energy of 4.7 GeV over a wide kinematic range. We identified spectator correlated pp and pn nucleon pairs by using kinematic cuts and measured their relative and total momentum distributions. This is the first measurement of the ratio of pp to pn pairs as a function of pair total momentum ptot.
Tensor Correlations Measured in He3(e,e'pp)n
H. Baghdasaryan; L. B. Weinstein; J. M. Laget; K. P. Adhikari; M. Aghasyan; M. Amarian; M. Anghinolfi; H. Avakian; J. Ball; M. Battaglieri; I. Bedlinskiy; R. P. Bennett; B. L. Berman; A. S. Biselli; C. Bookwalter; W. J. Briscoe; W. K. Brooks; S. Bültmann; V. D. Burkert; D. S. Carman; V. Crede; A. D'Angelo; A. Daniel; N. Dashyan; R. de Vita; E. de Sanctis; A. Deur; B. Dey; R. Dickson; C. Djalali; G. E. Dodge; D. Doughty; R. Dupre; H. Egiyan; A. El Alaoui; L. El Fassi; P. Eugenio; S. Fegan; M. Y. Gabrielyan; G. P. Gilfoyle; K. L. Giovanetti; W. Gohn; R. W. Gothe; K. A. Griffioen; M. Guidal; L. Guo; V. Gyurjyan; H. Hakobyan; C. Hanretty; C. E. Hyde; K. Hicks; M. Holtrop; Y. Ilieva; D. G. Ireland; K. Joo; D. Keller; M. Khandaker; P. Khetarpal; A. Kim; W. Kim; A. Klein; F. J. Klein; P. Konczykowski; V. Kubarovsky; S. E. Kuhn; S. V. Kuleshov; V. Kuznetsov; N. D. Kvaltine; K. Livingston; H. Y. Lu; I. J. D. MacGregor; N. Markov; M. Mayer; J. McAndrew; B. McKinnon; C. A. Meyer; K. Mikhailov; V. Mokeev; B. Moreno; K. Moriya; B. Morrison; H. Moutarde; E. Munevar; P. Nadel-Turonski; C. Nepali; S. Niccolai; G. Niculescu; I. Niculescu; M. Osipenko; A. I. Ostrovidov; R. Paremuzyan; E. Pasyuk; S. Anefalos Pereira; S. Pisano; O. Pogorelko; S. Pozdniakov; J. W. Price; S. Procureur; D. Protopopescu; G. Ricco; M. Ripani; G. Rosner; P. Rossi; F. Sabatié; C. Salgado; R. A. Schumacher; H. Seraydaryan; G. D. Smith; D. I. Sober; D. Sokhan; S. S. Stepanyan; P. Stoler; S. Strauch; M. Taiuti; W. Tang; C. E. Taylor; D. J. Tedeschi; M. Ungaro; M. F. Vineyard; E. Voutier; D. P. Watts; D. P. Weygand; M. H. Wood; B. Zhao; Z. W. Zhao
2010-01-01
We have measured the He3(e,e'pp)n reaction at an incident energy of 4.7 GeV over a wide kinematic range. We identified spectator correlated pp and pn nucleon pairs by using kinematic cuts and measured their relative and total momentum distributions. This is the first measurement of the ratio of pp to pn pairs as a function of pair total momentum ptot.
Distributed dynamic strain measurement using a correlation-based Brillouin sensing system
Kazuo Hotate; Sean S. L. Ong
2003-01-01
Conventional fiber Brillouin-based strain sensors are capable of distributed sensing, making them advantageous over fiber Bragg grating-based sensors for structural monitoring applications. However, Brillouin sensors have low spatial resolution and are inappropriate for dynamic strain measurements as they have large measurement times of several minutes. We present a correlation-based continuous-wave technique for high spatial resolution and distributed dynamic strain measurements
Entanglement as Measure of Electron-Electron Correlation in Quantum Chemistry Calculations
Zhen Huang; Sabre Kais
2005-07-15
In quantum chemistry calculations, the correlation energy is defined as the difference between the Hartree-Fock limit energy and the exact solution of the nonrelativistic Schrodinger equation. With this definition, the electron correlation effects are not directly observable. In this report, we show that the entanglement can be used as an alternative measure of the electron correlation in quantum chemistry calculations. Entanglement is directly observable and it is one of the most striking properties of quantum mechanics. As an example we calculate the entanglement for He atom and H2 molecule with different basis sets.
Zhang, Yan; Tu, You-Hui; Fei, Guang-He
2015-01-01
Background The chronic obstructive pulmonary disease (COPD) assessment test (CAT) is a validated simple instrument to assess health status, and it correlates well with the severity of airway obstruction in COPD patients. However, little is known about the relationships between CAT scores and quantitative computed tomography (CT) measurements of emphysema and airway wall thickness in COPD patients in the People’s Republic of China. Methods One hundred and twelve participants including 63 COPD patients and 49 normal control subjects were recruited. All participants were examined with high-resolution CT to get the measurements of emphysema (percentage of pixels below ?950 HU [%LAA–950]) and airway wall thickness (wall area percentage and the ratio of airway wall thickness to total diameter). Meanwhile, they completed the CAT and modified Medical Research Council questionnaire independently. Results Significantly higher CAT scores and CT measurements were found in COPD patients compared with normal control subjects (P<0.05), and there was a tendency of higher CAT scores and CT measurements with increasing disease severity measured by GOLD staging system. Positive correlations were found between CAT scores and CT measurements (P<0.01). Using multiple linear stepwise regression, CAT score =?46.38+0.778× (wall area percentage) +0.203× (%LAA–950) (P<0.001). Meanwhile, CAT scores and CT measurements in COPD patients all positively correlated with the modified Medical Research Council grades and negatively correlated with FEV1% (P<0.01). Conclusion CAT scores correlate well with the quantitative CT measurements in COPD patients, which may provide an imaging evidence that the structural changes of the lungs in this disease are associated with the health status measured by CAT. PMID:25784797
NASA Astrophysics Data System (ADS)
Bozyigit, D.; Lang, C.; Steffen, L.; Fink, J. M.; Eichler, C.; Baur, M.; Bianchetti, R.; Leek, P. J.; Filipp, S.; da Silva, M. P.; Blais, A.; Wallraff, A.
2011-02-01
At optical frequencies the radiation produced by a source, such as a laser, a black body or a single-photon emitter, is frequently characterized by analysing the temporal correlations of emitted photons using single-photon counters. At microwave frequencies, however, there are no efficient single-photon counters yet. Instead, well-developed linear amplifiers allow for efficient measurement of the amplitude of an electromagnetic field. Here, we demonstrate first- and second-order correlation function measurements of a pulsed microwave-frequency single-photon source integrated on the same chip with a 50/50 beam splitter followed by linear amplifiers and quadrature amplitude detectors. We clearly observe single-photon coherence in first-order and photon antibunching in second-order correlation function measurements of the propagating fields.
Lack of measurement independence can simulate quantum correlations even when signaling can not
NASA Astrophysics Data System (ADS)
Banik, Manik
2013-09-01
In the Bell scenario, any nonlocal correlation shared between two spatially separated parties can be modeled deterministically either by allowing communications between the two parties or by restricting their free will in choosing the measurement settings. Recently, the Bell scenario has been generalized into a “semiquantum” scenario where external quantum inputs are provided to the parties. We show that in the semiquantum scenario, entangled states produce correlations whose deterministic explanation is possible only if measurement independence is reduced. Thus in simulating quantum correlation the semiquantum scenario reveals a qualitative distinction between signaling and measurement dependence which is absent in the Bell scenario. We further show that such distinction is not observed in the “steering-game” scenario, a special case of the semiquantum scenario.
FILAMENT LENGTHS IN STRIATED MUSCLE
SALLY G. PAGE; H. E. HUXLEY
1963-01-01
Filament lengths in resting and excited frog muscles have been measured in the electron microscope, and investigations made of the changes in length that are found under different conditions, to distinguish between those changes which arise during preparation and the actual differences in the living muscles. It is concluded that all the measured differences in filament length are caused by
Göhring, Janett; Fulcher, Nick; Jacak, Jaroslaw; Riha, Karel
2014-01-01
Telomeres comprise the protective caps of natural chromosome ends and function in the suppression of DNA damage signaling and cellular senescence. Therefore, techniques used to determine telomere length are important in a number of studies, ranging from those investigating telomeric structure to effects on human disease. Terminal restriction fragment (TRF) analysis has for a long time shown to be one of the most accurate methods for quantification of absolute telomere length and range from a number of species. As this technique centers on standard Southern blotting, telomeric DNA is observed on resulting autoradiograms as a heterogeneous smear. Methods to accurately determine telomere length from telomeric smears have proven problematic, and no reliable technique has been suggested to obtain mean telomere length values. Here, we present TeloTool, a new program allowing thorough statistical analysis of TRF data. Using this new method, a number of methodical biases are removed from previously stated techniques, including assumptions based on probe intensity corrections. This program provides a standardized mean for quick and reliable extraction of quantitative data from TRF autoradiograms; its wide application will allow accurate comparison between datasets generated in different laboratories. PMID:24366880
NASA Technical Reports Server (NTRS)
Leon, R. P.
1987-01-01
Accurate evaluations of diffusion lengths for heavily to moderately doped III-V semiconductors and/or radiation damaged solar cells have been made possible by using experimental and numerical techniques. The techniques employed were electron beam induced current and low voltage electron microscopy.
Correlation reflectometry at TEXTOR
NASA Astrophysics Data System (ADS)
Krämer-Flecken, A.; Soldatov, S.; Vowinkel, B.; Müller, P.
2010-11-01
In high temperature fusion plasmas the transport of energy and particles is commonly believed to be driven by turbulence. Turbulence quantities as correlation length and decorrelation time are important for the confinement properties of a plasma. Besides other diagnostics, correlation reflectometry has proven to be a suitable tool for the measurement of turbulence properties. At the medium sized Toroidal EXperiment for Technical Oriented Research (TEXTOR) the existing correlation reflectometry has been recently upgraded. A new reflectometer based on a microwave synthesizer has been developed and installed for the investigation of turbulence properties in a fusion plasma. Together with the existing reflectometer the measurement of radial correlation length and decorrelation time becomes available. Both reflectometers are computer controlled and allow to program individual frequency sequences and the duration of each frequency step. With the existing poloidal antenna array at ? =0° and on top of the vacuum vessel, the system allows the measurement of radial correlation and poloidal correlations at the same time. First experiments have been performed and the results on the radial correlation length of density fluctuations in a fusion plasma are presented.
NSDL National Science Digital Library
Utah LessonPlans
2012-09-18
In this math lesson, learners explore the concept of using units to measure length. Learners first read "Ladybug on the Move" by Richard Fowler and measure the distance the ladybug travels on each page using yarn. Next, learners make their own "Go Ladybug Go!" books and use lima beans and a ladybug ruler to make and record measurements.
Robust sub-micrometer displacement measurement using dual wavelength speckle correlation.
Farsad, Mahsa; Evans, Chris; Farahi, Faramarz
2015-06-01
The unique characteristics of speckle correlation techniques including simple setup and fast, non-contact, high resolution measurement capability offer great potential for industrial applications. Robustness is an important requirement for industrial applications, which limits the application of many common techniques such as interferometric or photographic measurements, especially in mechanical workshops. This paper introduces an innovative technique for displacement measurement using speckle photography that is robust to disturbances, imaging errors, and does not require a large number of database patterns for calibration. It uses the relative correlation of the speckle patterns generated by two parallel, overlapping laser beams with an identical spot size and different wavelengths for relative displacement measurement in sub-micrometer order, and requires only one reference pattern that is updated frequently during the measurement process. The method is demonstrated over 200 µm range and is extendable to longer ranges. PMID:26072852
Romodina, Maria N.; Khokhlova, Maria D.; Lyubin, Evgeny V.; Fedyanin, Andrey A.
2015-01-01
The effect of magnetic interactions on the Brownian motion of two magnetic microparticles is investigated. The cross-correlations of the thermal fluctuations of the two magnetic microbeads are directly measured using double-trap optical tweezers. It is experimentally demonstrated that the cross-correlation function is governed by the gradient of the magnetic force between the microparticles. The magnetic forces are measured with femtonewton precision, and the magnetic dipole moments of individual microparticles are determined within an accuracy on the order of fA-m2. PMID:26035153
Romodina, Maria N; Khokhlova, Maria D; Lyubin, Evgeny V; Fedyanin, Andrey A
2015-01-01
The effect of magnetic interactions on the Brownian motion of two magnetic microparticles is investigated. The cross-correlations of the thermal fluctuations of the two magnetic microbeads are directly measured using double-trap optical tweezers. It is experimentally demonstrated that the cross-correlation function is governed by the gradient of the magnetic force between the microparticles. The magnetic forces are measured with femtonewton precision, and the magnetic dipole moments of individual microparticles are determined within an accuracy on the order of fA-m(2). PMID:26035153
Measurement Of The {beta}-{nu} Correlation In 6He Using A Transparent Paul Trap
Lienard, E.; Ban, G.; Darius, G.; Durand, D.; Flechard, X.; Herbane, M.; Labalme, M.; Mauger, F.; Mery, A.; Naviliat-Cuncic, O.; Rodriguez, D. [LPC-IN2P3-ENSICAEN, 6 Bd du Marechal Juin, 14050 Caen Cedex (France)
2006-04-26
The angular correlation between the electron and the neutrino in nuclear {beta}-decay constitutes a sensitive observable to search for the existence of exotic couplings in the weak interaction. In this contribution, we describe the progress of the LPCTrap experiment, devoted to measure the {beta}-{nu} angular correlation in the pure Gamow-Teller (GT) decay of 6He using a transparent Paul trap. We present a first coincidence spectrum, obtained during the commissioning run, which is the first {beta}-recoil coincidence measurement obtained from any ion trap.
Basic properties of the current-current correlation measure for random Schroedinger operators
Hislop, Peter D.; Lenoble, Olivier [Mathematics Department, University of Kentucky, Lexington, Kentucky 40506-0027 (United States); Mathematics Department, University of California, Irvine, California 92697-3875 (United States)
2006-11-15
The current-current correlation measure plays a crucial role in the theory of conductivity for disordered systems. We prove a Pastur-Shubin-type formula for the current-current correlation measure expressing it as a thermodynamic limit for random Schroedinger operators on the lattice and the continuum. We prove that the limit is independent of the self-adjoint boundary conditions and independent of a large family of expanding regions. We relate this finite-volume definition to the definition obtained by using the infinite-volume operators and the trace-per-unit volume.
NASA Astrophysics Data System (ADS)
Jeong, Ji Ho; Lee, Sang Bae; Jhon, Young Min; Song, Kwang Yong; Jeong, Je-Myung; Lee, Kwanil
2014-07-01
We propose and experimentally demonstrate a novel method for the extension of the measurement range in Brillouin optical correlation domain analysis by switching the pump and probe waves for selectively inducing the stimulated Brillouin scattering (SBS) in the sensing fiber. In this scheme, two correlation peaks are located in the sensing fiber and SBS is alternatively induced at each position by pump/probe selective switching and optical attenuation. In the experiment, twice enlargement of measurement range is successfully achieved with 146-m fiber with a 10-cm spatial resolution.
NASA Astrophysics Data System (ADS)
Lu, Mifang; Kobayashi, Hirokazu; Nonaka, Koji
2013-12-01
In order to reduce polarization impact in remote fiber sensing, we propose a polarization-stabilized pulse correlation measurement technique using polarization scrambled pulse train (PSP), in which the polarization state of each pulse is randomized. We illustrate the principle of the stabilization technique and verify experimental generation of PSP. Moreover, we perform fiber strain measurement using PSP-based pulse correlation tele-monitoring under various polarization states on a multi-region fiber sensing system. Our results show good stability against polarization fluctuation, indicating that the technique has great potential for use in harsh environment tele-monitoring.
NASA Astrophysics Data System (ADS)
Mohamad, M.; Sabbri, A. R. M.; Mat Jafri, M. Z.; Omar, A. F.
2014-11-01
Near infrared (NIR) spectroscopy technique serves as an important tool for the measurement of moisture content of skin owing to the advantages it has over the other techniques. The purpose of the study is to develop a correlation between NIR spectrometer with electrical conventional techniques for skin moisture measurement. A non-invasive measurement of moisture content of skin was performed on different part of human face and hand under control environment (temperature 21 ± 1 °C, relative humidity 45 ± 5 %). Ten healthy volunteers age between 21-25 (male and female) participated in this study. The moisture content of skin was measured using DermaLab® USB Moisture Module, Scalar Moisture Checker and NIR spectroscopy (NIRQuest). Higher correlation was observed between NIRQuest and Dermalab moisture probe with a coefficient of determination (R2) above 70 % for all the subjects. However, the value of R2 between NIRQuest and Moisture Checker was observed to be lower with the R2 values ranges from 51.6 to 94.4 %. The correlation of NIR spectroscopy technique successfully developed for measuring moisture content of the skin. The analysis of this correlation can help to establish novel instruments based on an optical system in clinical used especially in the dermatology field.
Large deformation measurement scheme for 3D digital image correlation method
NASA Astrophysics Data System (ADS)
Tang, Zhengzong; Liang, Jin; Xiao, Zhenzhong; Guo, Cheng
2012-02-01
Difficulties often arise for digital image correlation (DIC) technique when serious de-correlation occurs between the reference image and the deformed image due to large deformation. An updating reference image scheme could be employed to deal with large deformation situation, however that will introduce accumulated errors. A large deformation measurement scheme, combining improved coarse search method and updating reference image scheme, is proposed in this paper. For a series of deformation images, the correlation calculation begins with a seed point and spreads out. An improved coarse search method is developed to calculate the initial correlation parameters for the seed point, which guarantees that the correlation calculation can be carried out successfully even in large deformation situation. Only for extremely large deformation, the reference image is updated. Using this method, not only extremely large deformation can be measured successfully but also the accumulated error could be controlled. A polymer material tensile test and a foam compression test are used to verify the proposed scheme. Experimental results show that up to 450% tensile deformation and 83% compression deformation can be measured successfully.
Li, Jun; Qiu, Lina
2014-01-01
Functional near-infrared spectroscopy (fNIRS) was used to investigate resting state connectivity of language areas including bilateral inferior frontal gyrus (IFG) and superior temporal gyrus (STG). Thirty-two subjects participated in the experiment, including twenty adults and twelve children. Spontaneous hemodynamic fluctuations were recorded, and then intra- and inter-hemispheric temporal correlations of these signals were computed. The correlations of all hemoglobin components were observed significantly higher for adults than children. Moreover, the differences for the STG were more significant than for the IFG. In the adult group, differences in the correlations between males and females were not significant. Our results suggest by measuring resting state intra- and inter-hemispheric correlations, fNIRS is able to provide qualitative and quantitative evaluation on the functioning of the cortical network. PMID:24575351
Yang, X; Xia, G
2013-07-01
Female entertainment workers (FEWs) in China are at increased risk of HIV and other sexually transmitted infections, but correlates of their risky sexual behaviour remain poorly understood. Using data from a series of four surveys, this paper employs repeated measures analysis to identify individual and social correlates of consistent condom use among FEWs in Shanghai. Results reveal that both individual cognitive and social influence factors are statistically significant in their bivariate relationships to consistent condom use with a stable or non-stable partner; only prevention motivation and perceived self-efficacy in condom use remain significant in the multiple regressions. When individual and social correlates are examined together, only peer support for condom use remains a significant and independent correlate of consistent condom use in sex with a non-stable partner. Behavioural intervention is urgently needed and should take a multilevel approach, emphasizing individual prevention motivation and behavioural skills training and promoting peer/social support. PMID:23970771
Measuring the hospital length of stay/readmission cost trade-off under a bundled payment mechanism.
Carey, Kathleen
2015-07-01
If patients are discharged from the hospital prematurely, many may need to return within a short period of time. This paper investigates the relationship between length of stay and readmission within 30?days of discharge from an acute care hospitalization. It applies a two-part model to data on Medicare patients treated for heart attack in New York state hospitals during 2008 to obtain the expected cost of readmission associated with length of stay. The expected cost of a readmission is compared with the marginal cost of an additional day in the initial stay to examine the cost trade-off between an extra day of care and the expected cost of readmission. The cost of an additional day of stay was offset by expected cost savings from an avoided readmission in the range of 15% to 65%. Results have implications for payment reform based on bundled payment reimbursement mechanisms. Copyright © 2014 John Wiley & Sons, Ltd. PMID:24803387
Raimondi, P.; Field, R.Clive; Phinney, N.; Ross, M.C.; Slaton, T.; Traller, R.; /SLAC
2011-08-26
At the Interaction Point (IP) of the SLC Final Focus, beam-beam deflection scans routinely provide a measurement of the sum in quadrature of the electron and positron transverse beam sizes, but no information on the individual beam sizes. During the 1996 SLC run, an upgrade to the Final Focus beam position monitor system allowed a first measurement of the absolute beam energy loss of both beams on each step of the deflection scan. A fit to the energy loss distributions of the two beams provides a measurement not only of the individual transverse beam sizes at the IP but also of the individual bunch lengths.
Fast ECE correlation radiometry for fluctuation measurements in JET and PBX-M
Zolfaghari, A.M.; Luckhardt, S.; Woskov, P.P.; Cohn, D.R.; Jones, S.; Kesner, J.; Machuzak, J.; Ramos, J.J. (MIT Plasma Fusion Center, Cambridge, Massachusetts 02139 (United States)); Bartlett, D.V.; Costley, A.E.; Cripwell, P.; Porte, L.; Smith, R.J. (JET Joint Undertaking, Abingdon, Oxon OX14 3EA (United Kingdom)); Kaita, R. (Princeton Plasma Physics Laboratory, Princeton, New Jersey 08544 (United States))
1992-10-01
We discuss the fluctuation characteristics expected from MHD modes including ballooning modes and show how they can be studied using measurements of ECE. A novel technique, ECE correlation radiometry, which enables the location and spatial structure of long wavelength ({ital L}{gt}0.1{times}{ital a}) MHD modes to be determined, is described. Measurements on JET with a 44-channel ECE heterodyne radiometer are presented and show the existence of high-frequency (high {ital n} number) MHD modes under high poloidal beta, pellet-enhanced performance (PEP) plasma conditions. Similar measurements are planned for PBX-M and the measurement system is described.
Richard Ruelle; Patrick L. Hudson
1977-01-01
The mean total length of young-of-the-year paddlefish (Polyodon spathula) from Lewis and Clark Lake (a main-stem Missouri River reservoir at the Nebraska-South Dakota border) was 215 mm on 31 August of the first summer of life and estimated to be 296 mm by the end of the first growing season; average growth rate was 2.7 mm\\/day. The diet in 1972
CORRELATION OF CERVICAL LORDOSIS MEASUREMENT WITH INCIDENCE OF MOTOR VEHICLE ACCIDENTS
Marshall, Dorothy L.; Tuchin, Peter J.
1996-01-01
A retrospective analysis of 500 patient radiographs was conducted to measure the clinical correlation of cervical lordosis measurements and incidence of motor vehicle accident (MVA). Five hundred lateral cervical radiographs were selected at random from the practice of one of the authors (DLM). The C1-7 angle of the cervical curve was then measured by two blinded examiners. Inter-examiner reliability had a confidence interval of 95%. Eighty-two percent of patients who have had a MVA had an abnormal lordosis. The mean lordosis of patients who had been involved in a MVA was 26.1 degrees (SD 11.4), compared with 36.4 (SD 8.4) for those who had not been involved in a MVA. The results suggest a correlation of reduced cervical lordosis measurements following motor vehicle accident (MVA). PMID:17987143
Rohafza, Maryam; Fluet, Gerard G; Qiu, Qinyin; Adamovich, Sergei
2012-01-01
One of the obstacles in the development of rehabilitation robotics has been inadequacy in the measurement of treatment effects due to interventions. A measurement tool that will efficiently produce a large reliable sample of measurements collected during a single session that can also produce a rich set of data which reflects a subject's ability to perform meaningful functional activities has not been developed. This paper presents three linear regression models generated from seven kinematic measures collected during the performance of virtually simulated rehabilitation activities that were integrated with haptic robots by 19 persons with upper extremity hemiparesis due to chronic stroke. One of these models demonstrated a statistically significant correlation with the subjects' scores on the Jebsen Test of Hand Function (JTHF), a battery of six standardized upper extremity functional activities. The second and third models demonstrated a statistically significant correlation with the subjects' change scores on the JTHF. PMID:23366834
Status update on the measurement of the ?- ? angular correlation with trapped 8B ions
NASA Astrophysics Data System (ADS)
Perez Galvan, Adrian; BPT Collaboration
2014-09-01
Measurements of the ?- ? angular correlation coefficient (a??) in ?-decay provide information on the presence of possible exotic interactions beyond the Standard Model. The 8Li-8B radioactive mirror nuclei represent a particularly attractive system for these studies due to their small masses, large Q-value, and a triple-correlation that enhance the sensitivity to detect so-called ``New Physics.'' Furthermore, it is possible to search for the existence of second-class-currents in the Standard Model and to test the Conserved-Vector-Current hypothesis by comparing correlation measurements in 8Li and 8B. Our collaboration has already performed a measurement of a?? with trapped 8Li ions using the Beta-Decay Paul Trap at Argonne National Laboratory with an uncertainty of approximately 1 percent. Tests with a small sample of 8B decays obtained during a preliminary run showed that a measurement of comparable sensitivity is feasible. In this talk we present the current status on the ongoing effort to achieve a high statistics measurement using trapped 8B ions. Measurements of the ?- ? angular correlation coefficient (a??) in ?-decay provide information on the presence of possible exotic interactions beyond the Standard Model. The 8Li-8B radioactive mirror nuclei represent a particularly attractive system for these studies due to their small masses, large Q-value, and a triple-correlation that enhance the sensitivity to detect so-called ``New Physics.'' Furthermore, it is possible to search for the existence of second-class-currents in the Standard Model and to test the Conserved-Vector-Current hypothesis by comparing correlation measurements in 8Li and 8B. Our collaboration has already performed a measurement of a?? with trapped 8Li ions using the Beta-Decay Paul Trap at Argonne National Laboratory with an uncertainty of approximately 1 percent. Tests with a small sample of 8B decays obtained during a preliminary run showed that a measurement of comparable sensitivity is feasible. In this talk we present the current status on the ongoing effort to achieve a high statistics measurement using trapped 8B ions. This work was supported under Contracts DE-AC52-07NA27344 (LLNL), DEAC02-06CH11357 (ANL), DE-FG02-98ER41086 (Northwestern U.), and NSERC, Canada, under Application No. 216974.
NASA Technical Reports Server (NTRS)
Furcinitti, P.; Kuppenheimer, J. D.; Narducci, L. M.; Tuft , R. A.
1972-01-01
When an amplitude-stabilized He-Ne laser beam is scattered by a rotating ground glass with small surface inhomogeneities, the probability density of the instantaneous scattered-wave amplitude is Gaussian. In this paper, we suggest the use of the joint photon-count probability distribution to measure the absolute value of the electric-field amplitude-correlation function for random Gaussian light fields, and report the results of an experiment in which the Gaussian field is produced by scattering a light beam through a rotating ground glass. This procedure offers an alternative to other conventional methods, such as self-beating spectroscopy and irradiance-correlation techniques. The correlation time of the scattered-field amplitude in the present experiment has been measured with an accuracy of approximately 0.8%.
Cohen, Ohad; Fine, Ilya; Monashkin, Emanuel; Karasik, Avraham
2003-01-01
To correlate occlusion red near-infrared spectroscopy technology with intravenous and interstitial glucose levels, occlusion red near-infrared spectroscopy and glucose levels were measured in five subjects with diabetes mellitus during a stepped hyperinsulinemic hypoglycemic clamp. Validation was achieved using a standard error grid and linear correlations. During hyperinsulinemic hypoglycemic clamp linear correlation was significant at r = 0.836, and the intercept was 43.3 mg/dL. Of the glucose measurements, 94.3% were assigned to zones A and B of the standard error grid, the zones of the greatest therapeutic relevance. Expected interference from serum triglycerides, catecholamines, and cortisol was not apparent. These results demonstrate the applicability of occlusion red near-infrared spectroscopy for in vivo glucose monitoring. The technology has implications for continuous non-invasive glucose sensing. PMID:12725702
X. F. Yao; L. B. Meng; J. C. Jin; H. Y. Yeh
2005-01-01
Applications of the digital speckle correlation method (DSCM) for the full-field deformation measurement of carbon fiber\\/epoxy composite pressure vessel were investigated and the basic principles of displacement measurement by the DSCM are briefly given. The full-field displacement and strain distribution of a composite pressure vessel were evaluated under internal pressure. The results of the average strain value show a good
Measurement and correlation of high pressure phase behavior of carbon dioxide + water system
Ji Min Han; Hun Yong Shin; Byoung-Moo Min; Keun-Hee Han; Ara Cho
2009-01-01
A visual and variable volume view cell analyzer was installed and the phase behaviors of the carbon dioxide+water system were measured in the temperature and pressure ranges from 313.2K to 343.2K and from 4.33MPa to 18.34MPa, respectively. The measured data were correlated with the MF-NLF-HB equation of state to consider the effects of the hydrogen bonding of the saturated liquid
Diffuse correlation spectroscopy for non-invasive, micro-vascular cerebral blood flow measurement
Durduran, Turgut; Yodh, Arjun G.
2013-01-01
Diffuse correlation spectroscopy (DCS) uses the temporal fluctuations of near-infrared (NIR) light to measure cerebral blood flow (CBF) non-invasively. Here, we provide a brief history of DCS applications in brain with an emphasis on the underlying physical ideas, common instrumentation and validation. Then we describe recent clinical research that employs DCS-measured CBF as a biomarker of patient well-being, and as an indicator of hemodynamic and metabolic response to functional stimuli. PMID:23770408
On the measurement of the electron-neutrino correlation in neutron beta decay
2004-01-01
A new approach to the measurement of A, the electron-neutrino correlation, in neutron beta decay is presented. A precise measurement of A can lead to a precise determination of G{sub A}\\/G{sub V}. Coincidences between electrons and protons are detected in a field-expansion spectrometer. Both electrons and protons are detected in segmented Si detectors. The spectrometer configuration has a long, 1
Measuring the growth of matter fluctuations with third-order galaxy correlations
NASA Astrophysics Data System (ADS)
Hoffmann, K.; Bel, J.; Gaztañaga, E.; Crocce, M.; Fosalba, P.; Castander, F. J.
2015-02-01
Measurements of the linear growth factor D at different redshifts z are key to distinguish among cosmological models. One can estimate the derivative dD(z)/dln (1 + z) from redshift space measurements of the 3D anisotropic galaxy two-point correlation ?(z), but the degeneracy of its transverse (or projected) component with galaxy bias b, i.e. ??(z) ? D2(z)b2(z), introduces large errors in the growth measurement. Here, we present a comparison between two methods which breaks this degeneracy by combining second- and third-order statistics. One uses the shape of the reduced three-point correlation and the other a combination of third-order one- and two-point cumulants. These methods use the fact that, for Gaussian initial conditions and scales larger than 20 h-1 Mpc, the reduced third-order matter correlations are independent of redshift (and therefore of the growth factor), while the third-order galaxy correlations depend on b. We use matter and halo catalogues from the MICE-GC simulation to test how well we can recover b(z) and therefore D(z) with these methods in 3D real space. We also present a new approach, which enables us to measure D directly from the redshift evolution of the second- and third-order galaxy correlations without the need of modelling matter correlations. For haloes with masses lower than 1014 h-1 M?, we find 10 per cent deviations between the different estimates of D, which are comparable to current observational errors. At higher masses, we find larger differences that can probably be attributed to the breakdown of the bias model and non-Poissonian shot noise.
Paris-Sud XI, Université de
ATTEMPT OF ALPINE GLACIER FLOW MODELING BASED ON CORRELATION MEASUREMENTS OF HIGH RESOLUTION SAR TerraSAR-X SAR images and a Digital Elevation Model. First, a glacier flow model is established the glacier obtained from the sub-pixel image corre- lation of a series of TerraSAR-X SAR images is used
SURFACE WAVE DISPERSION MEASUREMENTS AND TOMOGRAPHY FROM AMBIENT SEISMIC NOISE CORRELATION IN CHINA
Xiaodong Song; Zhen Xu; Xinlei Sun; Sihua Zheng; Yingjie Yang; Michael H. Ritzwoller
2008-01-01
We perform ambient noise tomography of China using the data from the China National Seismic Network and surrounding global and PASSCAL stations. The results so far are summarized below. (1) Dispersion measurements and tomography. For most of the station pairs, we retrieve good Rayleigh waveforms from ambient noise correlations using 18-months of continuous data at all distance ranges across the
STUDY ON INFRARED GAS-FILTER CORRELATION SPECTROMETER FOR MEASURING LOW-CONCENTRATION METHANOL GASES
A gas-filter correlation spectrometer that employed a wide spectral band of infrared radiation and gas-filter cell has been built and successfully tested to measure methanol concentrations up to 113 ppm. The instrument demonstrates a detection limit of approximately 1.0 ppm. The ...
Bone strain measurement using 3D digital image correlation of second harmonic generation images
S Wentzell; R S Nesbitt; J Macione; R Knapp; S P Kotha
2011-01-01
Collagen fibrils contribute to the structural integrity and crack resistance of bone, but their response to stress while in bundles of fibrils is not well known. Digital image correlation (DIC) is a powerful technique for measuring strain by comparing images of deformed samples to non-deformed samples, while second harmonic generation microscopy (SHGM) captures bright, high contrast images of bone with
Sridhar, Srinivas
ferrites, and exotic materials such as charge and spin density waves CDW, SDW .5 In all of these previous in the paraelectric material SrTiO3 are shown to occur due to the rapid increase of dielectric constantPrecision microwave dielectric and magnetic susceptibility measurements of correlated electronic
Auto-correlation based intelligent technique for complex waveform presentation and measurement
K P S Rana; R Singh; K S Sayann
2009-01-01
Waveform acquisition and presentation forms the heart of many measurement systems. Particularly, data acquisition and presentation of repeating complex signals like sine sweep and frequency-modulated signals introduces the challenge of waveform time period estimation and live waveform presentation. This paper presents an intelligent technique, for waveform period estimation of both the complex and simple waveforms, based on the normalized auto-correlation
Correlation Measurements of Individual Microwave Photons Emitted from a Symmetric Cavity
Wallraff, Andreas
to reliably detect fields on the single photon level using averaging techniques [5] they necessarily add noiseCorrelation Measurements of Individual Microwave Photons Emitted from a Symmetric Cavity D1K 2R1 Canada. Abstract. Superconducting circuits have been successfully established as systems
Correlation measurements of individual microwave photons emitted from a symmetric cavity
Wallraff, Andreas
to reliably detect fields on the single photon level using averaging techniques [5] they necessarily add noiseCorrelation measurements of individual microwave photons emitted from a symmetric cavity D1K 2R1 Canada. Abstract. Superconducting circuits have been successfully established as systems
Theo Pauw
This study examines remote sensing of plant ?'diver sity levels in a mountainous area close to Worcester, Western Cape, covered in fynbos vegetation. Species richness data for 37 5x10m plots from an earlier field study is used as a measure of ?'diversity. The Spearman correlation between this and various remotely sensed variables computed from a SPOT image and an orthophoto
Speciated Fine Particle Deposition to a Forest Canopy Measured by Eddy-Correlation Mass Spectrometry
J. O. Allen; D. A. Gonzales; A. E. Delia; J. L. Jimenez; K. A. Smith; M. Canagaratna; J. T. Jayne; D. R. Worsnop
2002-01-01
Dry deposition serves as an important mechanism for the removal particles from the atmosphere and for the addition of material to ecosystems. Here we report on measurements of aerosol particle deposition using eddy-correlation mass spectrometry data collected during the PROPHET 2001 study which was conducted at the University of Michigan Biological Station in a north Michigan forest. Aerosol composition was
Biases of PIV measurement of turbulent flow and the masked correlation-based interrogation algorithm
Gui, Lichuan
and not high enough for rapid measurement and study of turbulent ¯ows in many cases. The correlation- based. Experimental tests in the Iowa Institute of Hydraulic Research towing tank with a towed PIV system technique for evaluating digital recordings in particle image velocimetry (PIV) experiments (Cene- dese
Bratzel, Graham; Buehler, Markus J
2012-03-01
Spider silk is a self-assembling biopolymer that outperforms many known materials in terms of its mechanical performance despite being constructed from simple and inferior building blocks. While experimental studies have shown that the molecular structure of silk has a direct influence on the stiffness, toughness, and failure strength of silk, few molecular-level analyses of the nanostructure of silk assemblies in particular under variations of genetic sequences have been reported. Here we report atomistic-level structures of the MaSp1 protein from the Nephila Clavipes spider dragline silk sequence, obtained using an in silico approach based on replica exchange molecular dynamics (REMD) and explicit water molecular dynamics. We apply this method to study the effects of a systematic variation of the poly-alanine repeat lengths, a parameter controlled by the genetic makeup of silk, on the resulting molecular structure of silk at the nanoscale. Confirming earlier experimental and computational work, a structural analysis reveals that poly-alanine regions in silk predominantly form distinct and orderly ?-sheet crystal domains while disorderly regions are formed by glycine-rich repeats that consist of 3(10)-helix type structures and ?-turns. Our predictions are directly validated against experimental data based on dihedral angle pair calculations presented in Ramachandran plots combined with an analysis of the secondary structure content. The key result of our study is our finding of a strong dependence of the resulting silk nanostructure depending on the poly-alanine length. We observe that the wildtype poly-alanine repeat length of six residues defines a critical minimum length that consistently results in clearly defined ?-sheet nanocrystals. For poly-alanine lengths below six, the ?-sheet nanocrystals are not well-defined or not visible at all, while for poly-alanine lengths at and above six, the characteristic nanocomposite structure of silk emerges with no significant improvement of the quality of the ?-sheet nanocrystal geometry. We present a simple biophysical model that explains these computational observations based on the mechanistic insight gained from the molecular simulations. Our findings set the stage for understanding how variations in the spidroin sequence can be used to engineer the structure and thereby functional properties of this biological superfiber, and present a design strategy for the genetic optimization of spidroins for enhanced mechanical properties. The approach used here may also find application in the design of other self-assembled molecular structures and fibers and in particular biologically inspired or completely synthetic systems. PMID:22340682
Cui, Jiwen; Li, Junying; Feng, Kunpeng; Tan, Jiubin
2015-07-15
A three-dimensional (3D) fiber probe is proposed for the measurement of micro parts. The probe is made of a fiber Bragg grating (FBG) that acts as a micro focal-length cylindrical lens (MFLC-lens) of two mutually orthogonal micro focal-length collimation (MFL-collimation) optical paths. The radial displacement of the probe tip is transformed into the shift of the fringe image collimated by the MFL-collimation optical path; the axial displacement of the probe tip is transformed into the power ratio variation caused by the Bragg wavelength shift. Advantages of the probe are high precision, low cost, high measurable aspect ratio, and capability of decoupling the 3D tactility. PMID:26176466
NASA Astrophysics Data System (ADS)
Garcia, Hernando; Johnson, Anthony M.; Oguama, Ferdinand A.; Trivedi, Sudhir
2003-10-01
The nonlinear refractive index n2 of silica fiber (24 m) and erbium-doped fiber (10 m) is measured to within an accuracy of 5% by use of time-delayed photorefractive beam coupling of intense 53-ps, 1.064-?m pulses that experience self-phase modulation in the fibers. The resultant induced grating autocorrelation response yields a value of n2/Aeff and a calibration standard for the fiber. A phase shift of the order of 0.19? can be detected and is limited only by laser amplitude fluctuations. A unique advantage of this technique is its ability to measure n2 accurately in short lengths (z <= 25 m) of fiber, whereas other approaches typically use much longer lengths of fiber (z >= 100 m).
J. Shen; A. Mandelis; B. D. Aloysius
1996-01-01
The application of a thermal-wave resonant cavity to thermal-diffusivity measurements of gases has been investigated. The cavity was constructed using a thin aluminum foil wall as the intensitv-modulated laser-beam oscillator source opposite a pyroclectric polyvilidene fluoride wall acting as a signal transducer. Theoretically, cavity-length and modulation-frequency scans both produce resonance-like extrema in lock-in in-phase and quadrature curses. These extrema can
First bunch length studies in the SLC South Final Focus
Zimmerman, F.; Yocky, G.; Whittum, D.H.; Thompson, K.A.; Ng, C.; McCormick, D.; Markiewicz, T.; Bane, K.L.F.
1998-06-01
The authors report the first studies of bunch length in collision in an operating linear collider, making use of a new rf bunch length monitor installed in the South Final Focus of the Stanford Linear Collider (SLC) prior to the 1997/98 luminosity run. The theoretical and measured monitor responses to linac injection phase and bunch compressor voltage are described. Correlations with beamstrahlung and luminosity are discussed.
Berillis, Panagiotis; Panagiotopoulos, Nikolaos; Boursiaki, Vaia; Karapanagiotidis, Ioannis T; Mente, Eleni
2015-08-01
Skeletal deformities of gilthead seabream (Sparus aurata) are a major factor affecting the production cost, the external morphology and survival and growth of the fish. Adult individuals of S. aurata were collected from a commercial fish farm in Greece and were divided into two groups: one with the presence of lordosis, a skeletal deformity, and one without any skeletal deformity. Fishes were X-rayed, and cervical, abdominal and caudal vertebrae lengths were measured. Vertebrae were taken from the site of the vertebral column where lordosis occurred. One part was decalcified and prepared for collagen examination with transmission electron microscopy, and the rest were incinerated, and the Ca and P contents were measured. The stoichiometries of the samples were obtained by EDS (Energy Dispersive Spectroscopy). The same procedure was followed for fish without skeletal deformities (vertebrae were taken from the middle region of the vertebral column). The decalcified vertebrae parts were examined with TEM, collagen micrographs were taken and the fibrils' periods and diameters were measured. There were no significant differences for both Ca and P or the collagen fibrils' periods between the two fish groups. The mean lengths of the cervical, abdominal and caudal vertebrae where lordosis occurred were similar to the lengths of the respective regions of the individuals without the skeletal deformity. The TEM examination showed a significantly smaller mean vertebrae collagen fibril diameter from the fishes with lordosis compared with those from the controls, revealing the significance of collagen to bone structure. PMID:26000955
ERIC Educational Resources Information Center
Stanley, Julian C.; Livingston, Samuel A.
Besides the ubiquitous Pearson product-moment r, there are a number of other measures of relationship that are attenuated by errors of measurement and for which the relationship between true measures can be estimated. Among these are the correlation ratio (eta squared), Kelley's unbiased correlation ratio (epsilon squared), Hays' omega squared,…
Fundamental limits on the digital phase measurement method based on cross-correlation analysis
NASA Astrophysics Data System (ADS)
Liang, Yu-Rong; Duan, Hui-Zong; Yeh, Hsien-Chi; Luo, Jun
2012-09-01
Ultra-precision phase measurement is a key technology for state-of-the-art laser interferometry. In this paper we present a fully digital phase measurement method based on cross-correlation analysis, and analyze the measurement errors caused by sampling quantization, intrinsic white noise and non-integral-cycle sampling. The last error source results in a cyclic error that has not been reported ever. We used a high-performance data acquisition system to carry out the cross-correlation-based phase measurement, and obtained a noise level of 1.2 × 10-6 rad/Hz1/2@1 Hz. Moreover, the cyclic phase error of about 10-2 rad/Hz1/2, caused by non-integral-cycle sampling, had been observed. In order to demonstrate the application of this precision phase measurement method, an ultra-precision heterodyne laser interferometer, consisting of digital phase measurement system and ultra-stable optical bench, was constructed for displacement measurement. The experimental results showed that a measurement resolution of 63 pm had been achieved.