Sample records for correlation length measurements

  1. Measurement of surface roughness and correlation length using dichromatic speckle

    NASA Astrophysics Data System (ADS)

    Deka, M.

    1980-03-01

    A computer simulation study of the dichromatic speckle was conducted and the surface roughness and correlation length of sample surfaces were measured using a stylus instrument and similar measurements with dichromatic speckle. The rms difference of the two speckle intensities was analyzed for spot sizes smaller than, comparable and larger than the correlation length of the surface. The rms roughness of the sample ground glasses was calculated from the data obtained from the stylus instrument. The correlation length was obtained from an online multichannel FFT processor connected to the stylus instrument. The correlation length was estimated from the correlation function. The rms difference between the speckle intensities of two different wavelengths were measured for various spot sizes. For each intensity 64 K data samples was collected and processed in a PDP 11/40 computer. These data were used to calculate the second moment of the monochromatic speckle, the cross correlation of these and the rms difference. The roughness and the correlation length of the surface were estimated from these results. The results obtained from the dichromatic speckle are in good agreement with the values obtained from the stylus instrument.

  2. Bunch Length Measurements With Laser/SR Cross-Correlation

    SciTech Connect

    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.

  3. 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.

  4. Measuring Length

    NSDL National Science Digital Library

    Miss Lerdahl

    2010-01-26

    Practice measuring length. Play this fun game to work on length. Measure the teddy Next, practice measuring to the nearest 1/2 inch. Measure to 1/2 inches If your ready for a challenge, practice this next game: Measure to 1/4 inches Play the Fish Tales game! *Once you have played all the games, have an adult sign your planner that you practiced these games! You'll ...

  5. Density, specific surface area, and correlation length of snow measured by high-resolution penetrometry

    NASA Astrophysics Data System (ADS)

    Proksch, Martin; Löwe, Henning; Schneebeli, Martin

    2015-02-01

    Precise measurements of snow structural parameters are crucial to understand the formation of snowpacks by deposition and metamorphism and to characterize the stratigraphy for many applications and remote sensing in particular. The area-wide acquisition of structural parameters at high spatial resolution from state-of-the-art methods is, however, still cumbersome, since the time required for a single profile is a serious practical limitation. As a remedy we have developed a statistical model to extract three major snow structural parameters: density, correlation length, and specific surface area (SSA) solely from the SnowMicroPen (SMP), a high-resolution penetrometer, which allows a meter profile to be measured with millimeter resolution in less than 1 min. The model was calibrated by combining SMP data with 3-D microstructural data from microcomputed tomography which was used to reconstruct full-depth snow profiles from different snow climates (Alpine, Arctic, and Antarctic). Density, correlation length, and SSA were derived from the SMP with a mean relative error of 10.6%, 16.4%, and 23.1%, respectively. For validation, we compared the density and SSA derived from the SMP to traditional measurements and near-infrared profiles. We demonstrate the potential of our method by the retrieval of a two-dimensional stratigraphy at Kohnen Station, Antarctica, from a 46 m long SMP transect. The result clearly reveals past depositional and metamorphic events, and our findings show that the SMP can be used as an objective, high-resolution tool to retrieve essential snow structural parameters efficiently in the field.

  6. Large-amplitude magnetic variations in quasi-parallel shocks - Correlation lengths measured by ISEE 1 and 2

    NASA Technical Reports Server (NTRS)

    Greenstadt, E. W.; Hoppe, M. M.; Russell, C. T.

    1982-01-01

    Wide separations up to more than 1 earth radius between ISEE 1 and 2 during the second half of 1978 have been used to measure the correlation length of magnetic pulsations in quasiparallel shocks. When the two spacecraft were less than a few hundred km apart, magnetic oscillations measured by magnetometers on both spacecraft exhibited virtually identical waveforms, but at distances of several thousand km, the two time series of field variation showed no detailed similarily at all. The correlation coefficients of the pulsations dropped from close to 1.0 for spacecraft separations of less than 100 km to 0.2 for separations of greater than 800 km. A correlation length of several hundred km may be related to the gyroradius of return protons with energy typical of the peaks of diffuse and beam ion distributions.

  7. Measuring Thermodynamic Length

    SciTech Connect

    Crooks, Gavin E

    2007-09-07

    Thermodynamic length is a metric distance between equilibrium thermodynamic states. Among other interesting properties, this metric asymptotically bounds the dissipation induced by a finite time transformation of a thermodynamic system. It is also connected to the Jensen-Shannon divergence, Fisher information, and Rao's entropy differential metric. Therefore, thermodynamic length is of central interestin understanding matter out of equilibrium. In this Letter, we will consider how to denethermodynamic length for a small system described by equilibrium statistical mechanics and how to measure thermodynamic length within a computer simulation. Surprisingly, Bennett's classic acceptance ratio method for measuring free energy differences also measures thermodynamic length.

  8. Measuring Crack Length in Coarse Grain Ceramics

    NASA Technical Reports Server (NTRS)

    Salem, Jonathan A.; Ghosn, Louis J.

    2010-01-01

    Due to a coarse grain structure, crack lengths in precracked spinel specimens could not be measured optically, so the crack lengths and fracture toughness were estimated by strain gage measurements. An expression was developed via finite element analysis to correlate the measured strain with crack length in four-point flexure. The fracture toughness estimated by the strain gaged samples and another standardized method were in agreement.

  9. Correlation of Choroidal Thickness and Volume Measurements with Axial Length and Age Using Swept Source Optical Coherence Tomography and Optical Low-Coherence Reflectometry

    PubMed Central

    Michalewski, Janusz; Nawrocka, Zofia; Bednarski, Maciej; Nawrocki, Jerzy

    2014-01-01

    Purpose. To report choroidal thickness and volume in healthy eyes using swept source optical coherence tomography (SS-OCT). Methods. A prospective observational study of 122 patients examined with swept source OCT (DRI-OCT, Topcon, Japan). In each eye, we performed 256 horizontal scans, 12?mm in length and centered on the fovea. We calculated choroidal thickness manually with a built-in caliper and automatically using DRI-OCT mapping software. Choroidal volume was also automatically calculated. We measured axial length with optical low-coherence reflectometry (Lenstar LS 900, Haag-Streit, Switzerland). Results. The choroid has focally increased thickness under the fovea. Choroid was thinnest in the outer nasal quadrant. In stepwise regression analysis, age was estimated as the most significant factor correlating with decreased choroidal thickness (F = 23.146, P < 0.001) followed by axial length (F = 4.902, P = 0.03). Refractive error was not statistically significant (F = 1.16, P = 0.28). Conclusions. SS-OCT is the first commercially available system that can automatically create choroidal thickness and volume maps. Choroidal thickness is increased at the fovea and is thinnest nasally. Age and axial length are critical for the estimation of choroidal thickness and volume. Choroidal measurements derived from SS-OCT images have potential value for objectively documenting disease-related choroidal thickness abnormalities and monitoring progressive changes over time. PMID:25013793

  10. Measurement of subpicosecond electron bunch lengths

    SciTech Connect

    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.

  11. Analysis of width/length ratios of normal clinical crowns of the maxillary anterior dentition: correlation between dental proportions and facial measurements.

    PubMed

    Zlatari?, Dubravka Knezovi?; Kristek, Ela; Celebi?, Asja

    2007-01-01

    This study aimed to determine how facial measurements explain the variability of dental proportions. The following measurements were obtained from 90 subjects: width and length of each maxillary anterior tooth, length of the nose, length of the upper lip, facial length (including the lengths of the facial thirds), intercanthal width, interalar width, intercommisural width while smiling, and maximum central incisor exposure while smiling. The combination of all facial measurements explained the variability of maxillary anterior teeth width/length ratios by only 20% to 38% in men and 16% to 27% in women. Within the population tested, the results suggest that the use of facial measurements for the selection of artificial denture teeth is generally inaccurate. PMID:17580467

  12. SAXS Determination of the Correlation Length of Semidilute Polyelectrolyte Solutions

    NASA Astrophysics Data System (ADS)

    Dou, Shichen; Colby, Ralph H.

    2006-03-01

    In semidilute solutions, polyelectrolyte chains have a random walk conformation of correlation blobs. The size of those space filling correlation blobs can be measured using Small Angle X-ray Scattering from the wavevector at which there is a peak. In this study we randomly quaternized monodisperse poly(2-vinyl pyridine) (P2VP) and neutralized to make polyelectrolytes with either chloride or iodide counterions. We study a random copolymer for which 60% of the charges are neutralized, at 25 ^oC in three solvents: (1) Ethylene glycol (EG) is a good solvent for P2VP, with dielectric constant ? = 37 making the Bjerrum length 15 å and dielectric spectroscopy measures the fraction of monomers bearing an effective charge f = 0.17 for Cl^- and f = 0.07 for I^- counterions. (2) Water is a poor solvent for P2VP, with ? = 78 making the Bjerrum length 7.1 å and f = 0.25 for I^- counterions. (3) N-methyl formamide (NMF) is a good solvent for P2VP, with ? = 182 making the Bjerrum length 3.1 å and f = 0.60 for I^- counterions (meaning that all counterions are free in NMF). We find that the correlation length of these polyelectrolyte solutions obeys the power law concentration dependence expected by scaling theory, and the correlation length decreases at a given concentration as the solvent is made more polar, because the polyelectrolyte chain has a larger effective charge.

  13. Telomere Length Correlations among Somatic Tissues in Adult Zebra Finches

    PubMed Central

    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

  14. Fundamental correlation lengths of coherent speckle in medical ultrasonic images

    Microsoft Academic Search

    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

  15. Dynamic correlation length scales under isochronal conditions

    NASA Astrophysics Data System (ADS)

    Casalini, R.; Fragiadakis, D.; Roland, C. M.

    2015-02-01

    The origin of the dramatic changes in the behavior of liquids as they approach their vitreous state—increases of many orders of magnitude in dynamic time scales and transport properties—is a major unsolved problem in condensed matter. These changes are accompanied by greater dynamic heterogeneity, which refers to both spatial variation and spatial correlation of molecular mobilities. The question is whether the changing dynamics are coupled to this heterogeneity; that is, does the latter cause the former? To address this, we carried out the first nonlinear dielectric experiments at elevated hydrostatic pressures on two liquids, to measure the third-order harmonic component of their susceptibilities. We extract from this the number of dynamically correlated molecules for various state points and find that the dynamic correlation volume for non-associated liquids depends primarily on the relaxation time, sensibly independent of temperature and pressure. We support this result by molecular dynamic simulations showing that the maximum in the four-point dynamic susceptibility of density fluctuations is essentially invariant along isochrones for molecules that do not form hydrogen bonds. Our findings are consistent with dynamic cooperativity serving as the principal control parameter for the slowing down of molecular motions in supercooled materials.

  16. Environmental Correlates of Food Chain Length

    Microsoft Academic Search

    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,

  17. 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.

  18. Acyl Chain Length of Phosphatidylserine Is Correlated with Plant Lifespan

    PubMed Central

    Tian, Xuejun; Li, Weiqi

    2014-01-01

    Plant lifespan is affected by factors with genetic and environmental bases. The laws governing these two factors and how they affect plant lifespan are unclear. Here we show that the acyl chain length (ACL) of phosphatidylserine (PS) is correlated with plant lifespan. Among the detected eight head-group classes of membrane lipids with lipidomics based on triple quadrupole tandem mass spectrometry, the ACL of PS showed high diversity, in contrast to the ACLs of the other seven classes, which were highly conserved over all stages of development in all plant species and organs and under all conditions that we studied. Further investigation found that acyl chains of PS lengthened during development, senescence, and under environmental stresses and that increasing length was accelerated by promoted- senescence. The acyl chains of PS were limited to a certain carbon number and ceased to increase in length when plants were close to death. These findings suggest that the ACL of PS can count plant lifespan and could be a molecular scale ruler for measuring plant development and senescence. PMID:25058060

  19. Extracting the dynamic correlation length of actin networks from microrheology experiments

    E-print Network

    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.

  20. Carbon Nanotubes: Measuring Dispersion and Length

    SciTech Connect

    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.

  1. Bunch Length Measurements in SPEAR3

    SciTech Connect

    Corbett, W.J.; Fisher, A.; Huang, X.; Safranek, J.; Sebek, J.; /SLAC; Lumpkin, A.; /Argonne; Sannibale, F.; /LBL, Berkeley; Mok, W.; /Unlisted

    2007-11-28

    A series of bunch length measurements were made in SPEAR3 for two different machine optics. In the achromatic optics the bunch length increases from the low-current value of 16.6ps rms to about 30ps at 25ma/bunch yielding an inductive impedance of -0.17{Omega}. Reducing the momentum compaction factor by a factor of {approx}60 [1] yields a low-current bunch length of {approx}4ps rms. In this paper we review the experimental setup and results.

  2. Measurement of subpicosecond electron pulse length

    SciTech Connect

    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.

  3. Determining Correlation and Coherence Lengths in Turbulent Boundary Layer Flight Data

    NASA Technical Reports Server (NTRS)

    Palumbo, Dan

    2012-01-01

    Wall pressure data acquired during flight tests at several flight conditions are analysed and the correlation and coherence lengths of the data reported. It is found that the correlation and coherence lengths are influenced by the origin of the structure producing the pressure and the frequency bandwidth over which the analyses are performed. It is shown how the frequency bandwidth biases the correlation length and how the convection of the pressure field might reduce the coherence measured between sensors. A convected form of the cross correlation and cross spectrum is introduced to compensate for the effects of convection. Coherence lengths measured in the streamwise direction appear much longer than expected. Coherent structures detected using the convected cross correlation do not exhibit an exponential coherent power decay.

  4. Distance and Cable Length Measurement System

    PubMed Central

    Hernández, Sergio Elias; Acosta, Leopoldo; Toledo, Jonay

    2009-01-01

    A simple, economic and successful design for distance and cable length detection is presented. The measurement system is based on the continuous repetition of a pulse that endlessly travels along the distance to be detected. There is a pulse repeater at both ends of the distance or cable to be measured. The endless repetition of the pulse generates a frequency that varies almost inversely with the distance to be measured. The resolution and distance or cable length range could be adjusted by varying the repetition time delay introduced at both ends and the measurement time. With this design a distance can be measured with centimeter resolution using electronic system with microsecond resolution, simplifying classical time of flight designs which require electronics with picosecond resolution. This design was also applied to position measurement. PMID:22303169

  5. Magnetic Correlation Lengths in the Turbulent Solar Wind

    NASA Astrophysics Data System (ADS)

    Ruiz, M. E.; Dasso, S.; Matthaeus, W. H.; Weygand, J. M.; Marsch, E.

    2012-12-01

    We analyze the evolution of the interplanetary magnetic field spatial structure by examining the heliospheric autocorrelation functions (R) based on "in situ" observations and using classical single-spacecraft techniques. Correlation lengths (?) derived from R can be viewed as a measured of the integral scale of the turbulence. We focus on how evolves the anisotropy of ? with respect to the aging of fluid parcels traveling away from the Sun, and according to the anisotropy of the measured ?, distinguishing mainly the values parallel (??) or perpendicular (??) to the direction of the local average magnetic field B0. We find that close to the Sun, ?? < ??, supporting a slab-like spectral model, and a progressive isotropization of ? with a trend to reach an inverted relation, while moving towards higher heliodistances, supporting dynamical spectral transfer of energy. We also present preliminary results on the probability distribution functions (PDFs) of ? from an analysis at different heliodistances from the Sun using observations from Helios, ACE and Ulysses. Advances made to better characterize the nature of interplanetary fluctuations, as those presented here, has significant implications in space and astrophysical plasmas, including scattering and transport of charged energetic particles, and theories of MHD turbulence.

  6. Organizational Turnover: Correlates, Satisfaction, Opportunity, and Length of Service.

    ERIC Educational Resources Information Center

    Bavendam, James M.; Harper, Nancy L.

    In a study of turnover in a midwest trucking firm, the files of 199 terminated drivers were used in a statistical analysis of 19 variables that might have been correlated to length of service. A series of interviews with drivers and key management personnel supplemented the statistical data. It was found that previously identified biographical…

  7. Electron Coherence Length Measurement Using Nanogratings

    NASA Astrophysics Data System (ADS)

    McMorran, Ben; Cronin, Alex

    2007-06-01

    We have measured the transverse coherence length of an electron beam using an electron interferometer constructed of two nanostructure gratings and an imaging detector^1. When one of the gratings is twisted about the optical axis the visibility of the Lau fringes decreases. This dependence is predicted by a theory that assumes a semi-coherent converging beam incident on two gratings. We present this theory along with data to show that the twist dependence of the fringe visibility is primarily sensitive to the transverse coherence length at the detector plane, in a direction parallel to the grating bars. ^1A. Cronin and B. McMorran, Phys. Rev. A 74,061602(R) (2006)

  8. Material Effects and Detector Response Corrections for Bunch Length Measurements

    SciTech Connect

    Zacherl, W.; Blumenfeld, I.; Berry, M.; Decker, F.-J.; Hogan, M.J.; Ischebeck, R.; Iverson, R.; Kirby, N.; Siemann, R.; Walz, D.; /SLAC; Clayton, C.E.; Huang, C.; Joshi, C.; Lu, W.; Marsh, K.A.; Mori, W.B.; Zhou, M.; /UCLA; Katsouleas, T.C.; Muggli, P.; Oz, E.; /Southern California U.

    2007-06-28

    A typical diagnostic used to determine the bunch length of ultra-short electron bunches is the auto-correlation of coherent transition radiation. This technique can produce artificially short bunch length results due to the attenuation of low frequency radiation if corrections for the material properties of the Michelson interferometer and detector response are not made. Measurements were taken using FTIR spectroscopy to determine the absorption spectrum of various materials and the response of a Molectron P1-45 pyroelectric detector. The material absorption data will be presented and limitations on the detector calibration discussed.

  9. Bunch Length Measurements using Coherent Radiation

    SciTech Connect

    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.

  10. Charge fluctuations and correlation lengths in finite electrolytes.

    PubMed

    Kim, Young C; Fisher, Michael E

    2008-05-01

    Fluctuations of the charge Q_{Lambda} inside a subdomain Lambda embedded in an electrolyte contained in a finite cubical box of dimensions LxLxL with periodic boundary conditions are investigated. When Lambda is an LxL "slab" of width W , asymptotically exact expressions for the mean-square fluctuation Q_{Lambda};{2} are obtained in terms of the Lebowitz length xi_{L}(T,rho) and of the "true" or asymptotic screening/decay length xi_{Z,infinity}(T,rho) together, when the charge correlation decay is oscillatory, with the characteristic wavelength lambda_{Z}(T,rho) . In finite systems, the normalized charge fluctuations exhibit threefold scaling behavior in the ratios xi_{Z,infinity}W , Wlambda_{Z} , and WL . This enables one to estimate all the correlation lengths away from criticality quite precisely from finite-size grand canonical Monte Carlo simulations. The results for xi_{Z,infinity},lambda_{Z} , and xi_{L} are presented for the restricted primitive model or hard-sphere 1:1 electrolyte for densities rho less, similar1.3rho_{c} and T greater, similar4T_{c} . The fitted values compare favorably with the expectations of generalized Debye-Hückel theory [Lee and Fisher, Europhys. Lett. 39, 611 (1997)]; specifically, if xi_{D} proportional, variant(Trho);{12} is the Debye length, we find xi_{Z,infinity}

  11. Local-hybrid functional based on the correlation length

    SciTech Connect

    Johnson, Erin R., E-mail: ejohnson29@ucmerced.edu [Chemistry and Chemical Biology, School of Natural Sciences, University of California, Merced, 5200 North Lake Road, Merced, California 95343 (United States)

    2014-09-28

    Local-hybrid functionals involve position-dependent mixing of Hartree-Fock and density-functional exchange, which should allow improved performance relative to conventional hybrids by reducing the inherent delocalization error and improving the long-range behaviour. Herein, the same-spin correlation length, obtained from the Fermi-hole radius, is used as the mixing parameter. The performance of the resulting local-hybrid functional is assessed for standard thermochemical and kinetics benchmarks. The local hybrid is shown to perform significantly better than the corresponding global hybrid in almost all cases.

  12. Standardisation of crown-rump length measurement.

    PubMed

    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

  13. Length of adaptive walk on uncorrelated and correlated fitness landscapes

    NASA Astrophysics Data System (ADS)

    Seetharaman, Sarada; Jain, Kavita

    2014-09-01

    We consider the adaptation dynamics of an asexual population that walks uphill on a rugged fitness landscape which is endowed with a large number of local fitness peaks. We work in a parameter regime where only those mutants that are a single mutation away are accessible, as a result of which the population eventually gets trapped at a local fitness maximum and the adaptive walk terminates. We study how the number of adaptive steps taken by the population before reaching a local fitness peak depends on the initial fitness of the population, the extreme value distribution of the beneficial mutations, and correlations among the fitnesses. Assuming that the relative fitness difference between successive steps is small, we analytically calculate the average walk length for both uncorrelated and correlated fitnesses in all extreme value domains for a given initial fitness. We present numerical results for the model where the fitness differences can be large and find that the walk length behavior differs from that in the former model in the Fréchet domain of extreme value theory. We also discuss the relevance of our results to microbial experiments.

  14. Mask roughness induced LER: geometric model at long correlation lengths

    SciTech Connect

    McClinton, Brittany M.; Naulleau, Patrick P.

    2011-02-11

    Collective understanding of how both the resist and line-edge roughness (LER) on the mask affect the final printed LER has made significant advances. What is poorly understood, however, is the extent to which mask surface roughness couples to image plane LER as a function of illumination conditions, NA, and defocus. Recently, progress has been made in formulating a simplified solution for mask roughness induced LER. Here, we investigate the LER behavior at long correlation lengths of surface roughness on the mask. We find that for correlation lengths greater than 3/NA in wafer dimensions and CDs greater than approximately 0.75/NA, the previously described simplified model, which remains based on physical optics, converges to a 'geometric regime' which is based on ray optics and is independent of partial coherence. In this 'geometric regime', the LER is proportional to the mask slope error as it propagates through focus, and provides a faster alternative to calculating LER in contrast to either full 2D aerial image simulation modeling or the newly proposed physical optics model. Data is presented for both an NA = 0.32 and an NA = 0.5 imaging system for CDs of 22-nm and 50-nm horizontal-line-dense structures.

  15. Reversal modes in FeCoNi nanowire arrays: Correlation between magnetostatic interactions and nanowires length

    NASA Astrophysics Data System (ADS)

    Samanifar, S.; Almasi Kashi, M.; Ramazani, A.; Alikhani, M.

    2015-03-01

    FeCoNi nanowire arrays (175 nm in diameter and lengths ranging from 5 to 40 ?m) were fabricated into nanopores of hard-anodized aluminum oxide templates using pulsed ac electrodeposition technique. Increasing the length had no considerable effect on the composition and crystalline characteristics of Fe47Co38Ni15 nanowires (NWs). By eliminating the dendrites formed at the bottom of the pores, we report a careful investigation on the effect of magnetostatic interactions on magnetic properties and the effect of nanowire length on reversal modes. Hysteresis loop measurements indicated that increasing the length decreases coercivity and squareness values. On the other hand, first-order reversal curve measurements show a linear correlation between the magnetostatic interactions and length of NWs. Comparing reversal modes of the NWs both experimentally and theoretically using angular dependence of coercivity, we find that when L?22 ?m, a vortex domain wall mode is only occurred. When L>22 ?m, a non-monotonic behavior indicates a transition from the vortex to transverse domain wall propagation. As a result, a critical length was found above which the transition between the reversal modes is occurred due the enhanced interactions. The transition angle also shifts toward a lower angle as the length increases. Moreover, with increasing length from 22 to 31 ?m, the single domain structure of NWs changes to a pseudo single domain state. A multidomain-like behavior is also found for the longest NWs length.

  16. In-vitro correlation between tension and length change in an anterior cruciate ligament substitute.

    PubMed

    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

  17. Leg length measurement: a new method to assure the correct leg length in total hip arthroplasty.

    PubMed

    Affatato, S; Toni, A

    2000-07-01

    The precise measurement of leg length plays an important role in total hip arthroplasty. Leg length inequality occurs frequently after total hip arthroplasty and may cause patient discomfort. Current clinical methods used for measuring leg length are not accurate enough to meet the demands of precision required for hip replacement. The aim of this study was to examine the validity of determining leg length differences using an ultrasound system. The proposed system measures the distance between three points, in millimetres, so that the difference between preoperative and postoperative measurements gives an indication about the leg length. The mean ultrasound variation observed in in vitro measurements showed a relative error of 1.7% (range: 52-133 mm) that means a leg length inequality of about 0.4 mm (range: 52-133 mm). The method is non-invasive (ultrasound is not limited by radiation hazards), easy, quick to use, and can be used for standard clinical screening. PMID:11086255

  18. Correlation of the hand length and stature in adult Musahar females of Nepal; an anthropometric study.

    PubMed

    Basnet, K S; Dhungel, S; Panta, P P

    2012-03-01

    Stature of a person is one of the most important and useful anthropometric parameter for establishing identification of unknown living or a dead person. A descriptive cross sectional study was done on 165 Nepalese adult Musahar females of Aurahi Village of Mahottari district, Nepal to predict the stature from their hand length. Measurement of stature and the length of both right and left hands taken with a standard standing height measuring instrument and a slide caliper respectively showed significant (p<0.001) positive correlation between the stature and hand lengths. The multiplication factor which was obtained by dividing the height of the subject by the respective hand lengths was found appropriate parameter to calculate the stature of a questioned person. The importance of the hand length alone will be of a great value for anthropologists and forensic experts. As an alternative method, the coefficient of regression and intercept which were obtained from the measured height and hand length were also proved to be equally valuable to estimate the height of a questioned person. PMID:23441496

  19. Effects of internal waves on signal temporal correlation length in the South China Sea

    NASA Astrophysics Data System (ADS)

    Ren, Yun; Li, Zhenglin

    2010-09-01

    We simulated the temporal correlation of sound transmission using a two-dimensional advective frozen-ocean model with temperature data from a temperature sensor array on a propagation path in the South China Sea (SCS) Experiment 2009, and investigated the relationships of temporal correlation length, source-receiver range, and maximal sound speed fluctuation mainly caused by the solitary internal waves. We found that the temporal correlation length is -1.2-power dependent on source-receiver range and -0.9-power dependent on maximal sound speed fluctuation. The empirical relationship is deduced from one-day environmental measurements in a limited area, needing more works and verification in the future with more acoustic data. But the relationship is useful in many applications in the area of SCS Experiment 2009.

  20. Coding Ropes For Length And Speed Measurements

    NASA Technical Reports Server (NTRS)

    Rupp, Charles C.; Tiesenhausen, Georg Von

    1988-01-01

    Ferromagnetic staples serve as markers. Like crude magnetic-tape-playback head, sensor detects ferromagnetic staples as rope is unwound or wound. Pulses from staples analyzed electronically; numbers of pulses and intervals between them interpreted in terms of velocity of rope and length payed out. Adaptable to laying submarine cables and contstruction of suspension bridges.

  1. Two-color absolute length measuring method based on pulse repetition interval lengths

    NASA Astrophysics Data System (ADS)

    Wei, Dong; Aketagawa, Masato; Takamasu, Kiyoshi; Matsumoto, Hirokazu

    2014-12-01

    A unique absolute length measurement method is proposed and demonstrated for the first time. Since it takes advantage of both the high-accuracy measurement capability of a pulse train interference method and the ability of a two-color method to compensate for environmental changes, the present method is expected to be useful for high-precision length measurement for not only the purposes of laboratory science but also for satisfying the requirements of industry. A length measurement was performed to demonstrate the feasibility of the proposed method.

  2. Assessment of Axial Length Measurements in Mouse Eyes

    PubMed Central

    Park, Han na; Qazi, Yureeda; Tan, Christopher; Jabbar, Seema B.; Cao, Yang; Schmid, Gregor; Pardue, Machelle T.

    2012-01-01

    Purpose To compare measurements of murine ocular axial lengths (AL) made with 780 nm partial coherence interferometry (PCI) and 1310 nm spectral domain–optical coherence tomography (SD-OCT). Methods AL was measured at postnatal day (P) 58 in C57BL/6J mice. Repeated AL measurements were taken using a custom-made 780 nm PCI and a commercial 1310 nm SD-OCT. Intra- and inter-user variability was assessed along the central optical axis as well as two-degree off-axes angles with the SD-OCT. Data were collected and analyzed using Cronbach’s alpha (?), Bland-Altman coefficient of repeatability (CR), agreement plots, and intra-class correlation coefficients (ICC). Results Axial length measurements agreed well between the two instruments (3.262 ± 0.042 mm for PCI; 3.264 ± 0.047 mm for SD-OCT; n= 20 eyes). The ICC for PCI compared to SD-OCT was 0.92, confirming high agreement between the two instruments. Intra-user ICC for the PCI and SD-OCT were 0.814 and 0.995, respectively. Similarly, inter-user ICC for PCI and SD-OCT were 0.970 and 0.943, respectively. Using SD-OCT, a two-degree misalignment of the eye along the horizontal meridian produced mean differences in AL of ?0.002 ± 0.017 mm relative to the centrally aligned images, while similar misalignment along the vertical meridian created 0.005 ± 0.018 mm differences in AL measurements. Conclusions AL measurements from the 780 nm PCI and 1310 nm SD-OCT correlate well. Multiple statistical indices indicate that both instruments have good precision and agreement for measuring murine ocular axial length in vivo. While the vertical meridian had the greater variability in AL in the small mouse eye; two-degree off-axes differences were within the standard deviation of centrally aligned AL. PMID:22246334

  3. Laser differential confocal ultra-long focal length measurement.

    PubMed

    Zhao, Weiqian; Sun, Ruoduan; Qiu, Lirong; Sha, Dingguo

    2009-10-26

    A new laser differential confocal focal-length measurement method is proposed for the measurement of an ultra-long focal-length. The approach proposed uses the property of an axial intensity curve that the absolute zero precisely corresponds to the focus of the objective in a differential confocal focusing system (DCFS) to measure the variation in position of DCFS focus with and without a measured ultra-long focal-length lens (UFL), uses the distance between the two focuses to obtain the UFL focal-length, and thereby achieving the precise measurement of ultra-long focal-length. The method has a high focusing precision, a strong anti-interference capability and a short measurement light-path. The theoretical analyses and preliminary experimental results indicate that the relative measurement error is about 0.01% when the method is used for the measurement of back-focus-distance (BFD). PMID:19997229

  4. Measuring correlations in symbol sequences

    Microsoft Academic Search

    Hanspeter Herzel; Ivo Große

    1995-01-01

    The paper is devoted to relations between correlation functions and mutual information. It is shown that, in sequences over an alphabet of ? symbols, statistical dependences are measured by (? ? 1)2 independent parameters. However, not all of them can be determined by autocorrelation functions. Appropriate sets of correlation functions (including crosscorrelations) are introduced, which allow the detection of all

  5. Measurement: Which Unit of Length is Appropriate?

    NSDL National Science Digital Library

    2008-01-01

    In this game, students are given an object such as a diving board or earthwork and are asked to select the appropriate unit for the measurement of the object, including yards, meters, centimeters, inches, and feet. Students select the correct answer from two possibilities. Their answers and the time taken are recorded. This is an excellent resource to help students understand the difference in units of measurement as well as beginning estimation skills.

  6. 50 CFR Appendix C to Part 622 - Fish Length Measurements

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ...and Fisheries 8 2010-10-01 2010-10-01 false Fish Length Measurements C Appendix C to Part 622 Wildlife and...SOUTH ATLANTIC Pt. 622, App. C Appendix C to Part 622—Fish Length Measurements ER03JY96.000 Figure 1 of Appendix...

  7. Wringing deformation effects in basic length measurements by optical interferometry

    Microsoft Academic Search

    Alexander Titov; Igor Malinovsky; Carlos A. Massone

    2003-01-01

    The effect of wringing deformations on the result of the main types of measurements by optical interferometry is studied in some detail. The wringing bending deformations can be used to improve by 10-20 times the accuracy of length measurements of gauge blocks with nominal lengths of a few millimeters. The data on the surface deformations of steel and quartz reference

  8. 50 CFR Appendix C to Part 622 - Fish Length Measurements

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ...and Fisheries 12 2013-10-01 2013-10-01 false Fish Length Measurements C Appendix C to Part 622 Wildlife and...SOUTH ATLANTIC Pt. 622, App. C Appendix C to Part 622—Fish Length Measurements ER17AP13.000...

  9. 50 CFR Appendix C to Part 622 - Fish Length Measurements

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ...and Fisheries 12 2012-10-01 2012-10-01 false Fish Length Measurements C Appendix C to Part 622 Wildlife and...SOUTH ATLANTIC Pt. 622, App. C Appendix C to Part 622—Fish Length Measurements ER03JY96.000 Figure 1 of Appendix...

  10. 50 CFR Appendix C to Part 622 - Fish Length Measurements

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ...and Fisheries 12 2014-10-01 2014-10-01 false Fish Length Measurements C Appendix C to Part 622 Wildlife and...SOUTH ATLANTIC Pt. 622, App. C Appendix C to Part 622—Fish Length Measurements ER17AP13.000...

  11. 50 CFR Appendix C to Part 622 - Fish Length Measurements

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ...and Fisheries 10 2011-10-01 2011-10-01 false Fish Length Measurements C Appendix C to Part 622 Wildlife and...SOUTH ATLANTIC Pt. 622, App. C Appendix C to Part 622—Fish Length Measurements ER03JY96.000 Figure 1 of Appendix...

  12. From Concrete to Abstract in the Measurement of Length

    NASA Astrophysics Data System (ADS)

    Stephanou, Andreas; Fisher, William P., Jr.

    2013-09-01

    The concatenation of units of length is widely viewed as the paradigmatic expression of fundamental measurement. Survey, assessment, and test scores in educational and psychological measurement are often interpreted in ways that assume a concatenation of units to have been established, even though these assumptions are rarely stated or tested. A concatenation model for measurement is shown to be equivalent to a Rasch model: any two units of measurement placed end to end must together be of the same length as either one of them added to itself. This additive principle and a concatenation model of measurement together serve as a heuristic guide for organizing two experimental approaches to calibrating instruments for measuring length. The capacity to reproduce the unit of measurement from theory with no need for repeated empirical calibration experiments, as in the geometrical bisection of the line and the resultant halving of the length measure, is highlighted as essential to demonstrating a thorough understanding of the construct.

  13. Marine Bi 4iofy LENGTH MEASUREMENTS

    E-print Network

    fish on measuring boards. The metric system has been used by all workers. knowledge per- taining to the biology, culture^ and life history of this species had been secured through to the earlier workers,, Dr. Wright and his assistants inaugurated a system for systematically counting

  14. Computable measure of quantum correlation

    NASA Astrophysics Data System (ADS)

    Akhtarshenas, S. Javad; Mohammadi, Hamidreza; Karimi, Saman; Azmi, Zahra

    2015-01-01

    A general state of an system is a classical-quantum state if and only if its associated -correlation matrix (a matrix constructed from the coherence vector of the party , the correlation matrix of the state, and a function of the local coherence vector of the subsystem ), has rank no larger than . Using the general Schatten -norms, we quantify quantum correlation by measuring any violation of this condition. The required minimization can be carried out for the general -norms and any function of the local coherence vector of the unmeasured subsystem, leading to a class of computable quantities which can be used to capture the quantumness of correlations due to the subsystem . We introduce two special members of these quantifiers: The first one coincides with the tight lower bound on the geometric measure of discord, so that such lower bound fully captures the quantum correlation of a bipartite system. Accordingly, a vanishing tight lower bound on the geometric discord is a necessary and sufficient condition for a state to be zero-discord. The second quantifier has the property that it is invariant under a local and reversible operation performed on the unmeasured subsystem, so that it can be regarded as a computable well-defined measure of the quantum correlations. The approach presented in this paper provides a way to circumvent the problem with the geometric discord. We provide some examples to exemplify this measure.

  15. Correlation Lengths, Disorder, and Dynamics of the Vortex Condensate as Heard Through the Noise

    NASA Astrophysics Data System (ADS)

    Rabin, Michael W.

    1998-03-01

    We have demonstrated a new method for probing correlated regions of vortices in type II superconductors.(M. W. Rabin, et al. Phys Rev B Rapid Comm 57 (2), 1 Jan 98) The heart of our measurement is the sensitivity of low frequency noise ( ~1Hz) to a higher frequency ( ~100 Hz) magnetic field perturbation (? H); ? H/H 10-4 substantially reduces the noise by inducing rapid switching among the metastable configurations present in the pinned state. Applied to the peak effect, where the critical current (I_c) increases as a function of either magnetic field (H) or temperature, ? H drops dramatically as H decreases from the peak value (H_p), implying an increasing correlation length (L_n). ? H reaches a minimum at the onset of the peak (H_pl), consistent with Ln reaching a sample-size limit. These measurements suggest a structural phase transition in the static, underlying vortex solid associated with the abrupt softening that causes the peak (Pippard scenario). The relationship among the collective-pinning theory correlation lengths (Lc and R_c, the Larkin lengths), the dynamic correlation length (L_v, based on transport measurements), and Ln will be discussed. For ? H to affect the vortex condensate's memory and reduce low frequency noise, ? H must change the number of vortices in a correlated region enough to force them to repin, hence (partially) scrambling their state, therefore ? H ? 1/L_n. Though voltage noise, like other transport properties, is only measured while the vortices are moving (i.e. when I>I_c), the noise in this regime reflects the pinned vortex configuration because (1) the noise power is comparable and spectral slope are the same for dc current and pulsed current and (2) because noise power is reduced by ? H even when ? H and I are out of sync, i.e. ? H is applied and removed while the current is zero and the vortices are pinned. All measurements were done on single crystals of 2H-NbSe2 with H||c at 4.2K in liquid He.

  16. Measuring the Length of a Captured Burmese Python

    USGS Multimedia Gallery

    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. ...

  17. Coherent Transition Radiation to Measure the SLAC Electron Bunch Length

    SciTech Connect

    Muggli, P.; /Southern California U.; Hogan, M.J.; Barnes, C.D.; Walz, D.; Krejcik, P.; Siemann, R.H.; /SLAC

    2005-05-13

    Coherent transition radiation is used to measure the length of the ultra-short electron bunches available at the Stanford Linear Accelerator Center. The results and the limitations of the method are described.

  18. An anthropometric study to evaluate the correlation between the occlusal vertical dimension and length of the thumb

    PubMed Central

    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

  19. Correlations between Muscle Activities and Strap Length and Types of School Bag during Walking

    PubMed Central

    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

  20. Blood and Dried Blood Spot Telomere Length Measurement by qPCR: Assay Considerations

    PubMed Central

    Zanet, DeAnna L.; Saberi, Sara; Oliveira, Laura; Sattha, Beheroze; Gadawski, Izabella; Côté, Hélène C. F.

    2013-01-01

    Measurement of telomere length is crucial for the study of telomere maintenance and its role in molecular pathophysiology of diseases and in aging. Several methods are used to measure telomere length, the choice of which usually depends on the type and size of sample to be assayed, as well as cost and throughput considerations. The goal of this study was to investigate the factors that may influence the reliability of qPCR-based relative telomere length measurements in whole blood. Day to day intra-individual variability, types of blood anticoagulant, sample storage conditions, processing and site of blood draw were investigated. Two qPCR-based methods to measure telomere length (monoplex vs. multiplex) were also investigated and showed a strong correlation between them. Freezing and thawing of the blood and storage of the blood at 4°C for up to 4 days did not affect telomere length values. Telomere lengths in dried blood spots were significantly higher than both whole blood and peripheral mononuclear blood cells, and were highly correlated with both. We found that telomere length measurements were significantly higher in dried blood spots collected directly from fingertip prick compared to dried blood spots prepared with anticoagulated whole blood collected from the finger, and non-blotted whole blood taken from both finger and arm venipuncture. This suggests that DNA from cells blotted on paper is not equivalent to that collected from venipuncture whole blood, and caution should be taken when comparing between blood sample types. PMID:23451268

  1. Detrending moving-average cross-correlation coefficient: Measuring cross-correlations between non-stationary series

    NASA Astrophysics Data System (ADS)

    Kristoufek, Ladislav

    2014-07-01

    In the paper, we introduce a new measure of correlation between possibly non-stationary series. As the measure is based on the detrending moving-average cross-correlation analysis (DMCA), we label it as the DMCA coefficient ?(?) with a moving average window length ?. We analytically show that the coefficient ranges between -1 and 1 as a standard correlation does. In the simulation study, we show that the values of ?(?) very well correspond to the true correlation between the analyzed series regardless the (non-)stationarity level. Dependence of the newly proposed measure on other parameters-correlation level, moving average window length and time series length-is discussed as well.

  2. A correlation study of telomere length in peripheral blood leukocytes and kidney function with age.

    PubMed

    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

  3. Comparison of optical biometry and applanation ultrasound measurements of the axial length of the eye

    PubMed Central

    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

  4. PBMC telomerase activity, but not leukocyte telomere length, correlates with hippocampal volume in major depression.

    PubMed

    Wolkowitz, Owen M; Mellon, Synthia H; Lindqvist, Daniel; Epel, Elissa S; Blackburn, Elizabeth H; Lin, Jue; Reus, Victor I; Burke, Heather; Rosser, Rebecca; Mahan, Laura; Mackin, Scott; Yang, Tony; Weiner, Michael; Mueller, Susanne

    2015-04-30

    Accelerated cell aging, indexed in peripheral leukocytes by telomere shortness and in peripheral blood mononuclear cells (PBMCs) by telomerase activity, has been reported in several studies of major depressive disorder (MDD). However, the relevance of these peripheral measures for brain indices that are presumably more directly related to MDD pathophysiology is unknown. In this study, we explored the relationship between PBMC telomerase activity and leukocyte telomere length and magnetic resonance imaging-estimated hippocampal volume in un-medicated depressed individuals and healthy controls. We predicted that, to the extent peripheral and central telomerase activity are directly related, PBMC telomerase activity would be positively correlated with hippocampal volume, perhaps due to hippocampal telomerase-associated neurogenesis, neuroprotection or neurotrophic facilitation, and that this effect would be clearer in individuals with increased PBMC telomerase activity, as previously reported in un-medicated MDD. We did not have specific hypotheses regarding the relationship between leukocyte telomere length and hippocampal volume, due to conflicting reports in the published literature. We found, in 25 un-medicated MDD subjects, that PBMC telomerase activity was significantly positively correlated with hippocampal volume; this relationship was not observed in 18 healthy controls. Leukocyte telomere length was not significantly related to hippocampal volume in either group (19 unmedicated MDD subjects and 17 healthy controls). Although the nature of the relationship between peripheral telomerase activity and telomere length and the hippocampus is unclear, these preliminary data are consistent with the possibility that PBMC telomerase activity indexes, and may provide a novel window into, hippocampal neuroprotection and/or neurogenesis in MDD. PMID:25773002

  5. Large coherence length swept source for axial length measurement of the eye.

    PubMed

    Chong, Changho; Suzuki, Takuya; Totsuka, Kohki; Morosawa, Atsushi; Sakai, Tooru

    2009-04-01

    We present and demonstrate a swept source with a large coherence length using a quasi-phase continuous tuning (QPCT) technique. QPCT is a method of minimizing the phase shift per round trip with respect to the tunable filter so that the resonance of lasing becomes high, resulting in high finesse of lasing during a rapid sweep. The demonstrated swept source consists of a fiber ring extended cavity laser with a diffraction grating and a polygon scanner-based tunable filter configuration. The projected beam on the diffraction grating is expanded with a multiple of beam expanders to achieve high finesse of the filter. The source demonstrated an 18 nm swept range at 1060 nm wavelength, 28 mm coherence length, and 6.2 mW peak power at a 2.5 kHz swept rate. OCT imaging results showed that a coherence length of 28 mm enables the measurement of the axial length of a pig's eye with 20 mm length in physical size. PMID:19340103

  6. 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.

  7. Crown and root lengths of incisors, canines, and premolars measured by cone-beam computed tomography in patients with malocclusions

    PubMed Central

    Kim, Seon-Young; Gang, Sung-Nam; Kim, Hee-Jin

    2013-01-01

    Objective The purposes of this study were to determine the accuracy of crown and root length measurements of premolars using cone-beam computed tomography (CBCT) and to generate reference CBCT-based data on incisor, canine, and premolar lengths in patients with malocclusions. Methods Imaging was performed using a CBCT scanner with a 0.292-mm voxel size and 12-bit grayscale. The CBCT-based length measurements were compared with direct measurements of 94 subsequently extracted premolars without metal restorations using the paired t-test. Furthermore, the crown and root lengths of incisors, canines, and premolars in 62 Korean patients with malocclusions were measured using CBCT, and Pearson's correlation coefficients were calculated to examine the relationship between the crown and root length measurements of each tooth type. Results The differences between the CBCT-based and direct measurements of the extracted premolars were not significant, with 95% limits of agreement of -0.90 to 0.90 mm for crown length and -1.23 to 1.18 mm for root length. Weak positive correlations between the crown and root length measurements were observed for the mandibular canine and premolars. Conclusions The CBCT-based measurements showed a wider range of limits of agreements for root length than for crown length. The CBCT-based data can be used as a reference for evaluating root length and resorption of teeth without metal restorations in patients with malocclusions. PMID:24396736

  8. Raman light scattering by electrons in superconductors with a small correlation length

    Microsoft Academic Search

    A. A. Abrikosov; L. A. Falkovsky

    1989-01-01

    The reflection coefficient of light is calculated as function of the frequency change for an isotropic superconductor having a correlation length much less than the light penetration depth. The influence of anisotropy and crystalline orientation is discussed.

  9. Electronic Raman light scattering in superconductors with a short correlation length

    Microsoft Academic Search

    A. A. Abrikosov; L. A. Falkovsky

    1988-01-01

    The reflection coefficient is calculated for an isotropic superconductor with a correlation length much smaller than the light penetration depth. Qualitative formulas are derived for an anisotropic superconductor. Influence of polycrystalline structure is discussed.

  10. Multichannel analysis of correlation length of SEVIRI images around ground-based cloud observatories to determine their representativeness

    NASA Astrophysics Data System (ADS)

    Slobodda, J.; Hünerbein, A.; Lindstrot, R.; Preusker, R.; Ebell, K.; Fischer, J.

    2015-02-01

    Images of measured radiance in different channels of the geostationary Meteosat-9 SEVIRI instrument are analysed with respect to the representativeness of the observations of eight cloud observatories in Europe (e.g. measurements from cloud radars or microwave radiometers). Cloudy situations are selected to get a time series for every pixel in a 300 km × 300 km area centred around each ground station. Then a cross correlation of each time series to the pixel nearest to the corresponding ground site is calculated. In the end a correlation length is calculated to define the representativeness. It is found that measurements in the visible and near infrared channels, which respond to cloud physical properties, are correlated in an area with a 1 to 4 km radius, while the thermal channels, that correspond to cloud top temperature, are correlated to a distance of about 20 km. This also points to a higher variability of the cloud microphysical properties inside a cloud than of the cloud top temperature. The correlation length even increases for the channels at 6.2, 7.3 and 9.7 ?m. They respond to radiation from the upper atmospheric layers emitted by atmospheric gases and higher level clouds, which are more homogeneous than low-level clouds. Additionally, correlations at different distances, corresponding to the grid box sizes of forecast models, were compared. The results suggest the possibility of comparisons between instantaneous cloud observations from ground sites and regional forecast models and ground-based measurements. For larger distances typical for global models the correlations decrease, especially for short-wave measurements and corresponding cloud products. By comparing daily means, the correlation length of each station is increased to about 3 to 10 times the value of instantaneous measurements and also the comparability to models grows.

  11. Pollen size evolution: correlation between pollen volume and pistil length in Asteraceae

    Microsoft Academic Search

    Carolina Torres

    2000-01-01

    Based on the assumptions that pollen tube length is predetermined by provisions in the pollen and that it is a function of\\u000a pistil length, I hypothesise that species with longer pistils will have larger pollen grains than species with shorter pistils,\\u000a and that pistil length and pollen size will be positively correlated in a linear manner. To test this hypothesis,

  12. 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.

  13. A systematic comparison of mathematical models for inherent measurement of ciliary length: how a cell can measure length and volume.

    PubMed

    Ludington, William B; Ishikawa, Hiroaki; Serebrenik, Yevgeniy V; Ritter, Alex; Hernandez-Lopez, Rogelio A; Gunzenhauser, Julia; Kannegaard, Elisa; Marshall, Wallace F

    2015-03-24

    Cells control organelle size with great precision and accuracy to maintain optimal physiology, but the mechanisms by which they do so are largely unknown. Cilia and flagella are simple organelles in which a single measurement, length, can represent size. Maintenance of flagellar length requires an active transport process known as intraflagellar transport, and previous measurements suggest that a length-dependent feedback regulates intraflagellar transport. But the question remains: how is a length-dependent signal produced to regulate intraflagellar transport appropriately? Several conceptual models have been suggested, but testing these models quantitatively requires that they be cast in mathematical form. Here, we derive a set of mathematical models that represent the main broad classes of hypothetical size-control mechanisms currently under consideration. We use these models to predict the relation between length and intraflagellar transport, and then compare the predicted relations for each model with experimental data. We find that three models-an initial bolus formation model, an ion current model, and a diffusion-based model-show particularly good agreement with available experimental data. The initial bolus and ion current models give mathematically equivalent predictions for length control, but fluorescence recovery after photobleaching experiments rule out the initial bolus model, suggesting that either the ion current model or a diffusion-based model is more likely correct. The general biophysical principles of the ion current and diffusion-based models presented here to measure cilia and flagellar length can be generalized to measure any membrane-bound organelle volume, such as the nucleus and endoplasmic reticulum. PMID:25809250

  14. Correlation between hybrid layer thickness, resin tag length and microtensile bond strength of a self-etching adhesive system.

    PubMed

    Rahal, Vanessa; de Oliveira, Fernanda G; Briso, André L F; dos Santos, Paulo H; Sundefeld, Maria L M M; Sundfeld, Renato H

    2012-01-01

    The purpose of this study was to evaluate the correlation between the hybrid layer thickness, resin tag length and resin bond strength of a self-etching adhesive system to sound dentin tissue "in vivo". After performing restorative procedures and tooth extractions, ten specimens were sectioned in a mesiodistal direction. One dental section was used for light microscope analysis, in which both the resin tag length and hybrid layer thickness were measured, while the other section was analyzed using a microtensile test (0.5 mm/min). The fractured surface of the latter section was characterized using a stereoscopic magnifying glass (40x magnifcation). The results were subject to statistical analysis using the Pearson Correlation Test (a = 0.05). The hybrid layer thickness, resin tag length and resin bond strength mean values were 2.19 microm (0.34), 4.34 microm (0.28) and 9.73 MPa (5,55), respectively. In addition, correlation tests between the resin tag length and the resin bond strength (r=0.014) and also between the hybrid layer thickness and bond strength (r=0.43), showed no statistically significant correlation. The microtensile bond strength of Adper Prompt L Pop self-etching adhesive system does not depend on hybrid layer thickness or resin tag length. PMID:23230647

  15. Alignment techniques required by precise measurement of effective focal length

    NASA Technical Reports Server (NTRS)

    Wise, T. D.

    1980-01-01

    The characteristics of false color imagery produced by instrumentation on earth resource mapping satellites are examined. The spatial fidelity of the imagery is dependent upon the geometric accuracy (GA) and the band-to-band registration (BBR) with which the telescope instrument is assembled. BBR and GA require knowledge of telescope effective focal length (EFL) to one part in 10,000 in order that the next generation of earth mappers be able to carry out their missions. The basis for this level of precision is briefly considered, and a description is given of the means by which such precise EFL measurements have been carried out. Attention is given to accuracy requirements, the technique used to measure effective focal length, possible sources of error in the EFL measurement, approaches for eliminating errors, and the results of the efforts to control measurement errors in EFL determinations.

  16. Cytosine Usage Modulates the Correlation between CDS Length and CG Content in Prokaryotic Genomes

    E-print Network

    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

  17. Length Scale Correlations of Cellular Microstructures in Directionally Solidified Binary System

    SciTech Connect

    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.

  18. Length Scale Correlations of Cellular Microstructures in Directionally Solidified Binary System

    SciTech Connect

    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.

  19. The Effects of Internal Waves on the Signal Temporal Correlation Length in the South China Sea

    NASA Astrophysics Data System (ADS)

    Ren, Yun; Wu, Lixin; Li, Zhenglin

    2010-09-01

    The temporal correlation of sound transmission is simulated using a two-dimensional advective frozen-ocean model using the temperature data of a temperature sensor array deployed on the propagation path in the South China Sea (SCS) experiment 2009. The relationships of temporal correlation length, source-receiver range, and sound speed standard deviation (STD) caused by internal waves (including both linear internal waves and solitons) are numerically investigated. It is found that the temporal correlation length is -1.2 power dependent on source-receiver range and -0.9 power dependent on sound speed STD.

  20. Effective crack lengths by compliance measurement for ARALL-2 laminates

    NASA Technical Reports Server (NTRS)

    Wilson, Christopher D.; Wilson, Dale A.

    1991-01-01

    As a means of determining a stress intensity factor solution, the compliance properties of an ARALL-2 laminated-sheet composite were investigated. Fatigue crack growth rate (FCGR) tests were conducted on middle crack tension (MT) specimens fabricated from a layup consisting of three sheets of 2024-T3 aluminum bonded together with unidirectional aramid fibers embedded in epoxy. Excellent fatigue crack growth properties are obtained by the presence of unbroken aramid fibers in the wake of the crack tip. These unbroken fibers act as a bridging mechanism to inhibit further crack growth. To quantify the effect of maximum fatigue load on compliance, a series of FCGR tests were performed. Effective crack lengths were determined to be at least 10 mm shorter than surface measured crack lengths for a 76-mm-wide specimen. The bridging zone was estimated to be at least 5 mm. Compliance and stress intensity factor as functions of effective crack length were determined.

  1. Axial and peripheral eye length measured with optical low coherence reflectometry.

    PubMed

    Schmid, Gregor F

    2003-10-01

    An optical low-coherence reflectometer (OLCR device) is described that allows the precise and noncontact measurement of eye length. The device measures eye length both on-axis and off-axis, thus enabling the determination of eye shape, an ocular parameter thought to be important in the development of refractive error. It is essential for several applications in ophthalmology and vision science. This improved OLCR device operates using a single-beam interferometer with a beam deflection mechanism that allows the precise measurement of eye length along the visual axis and within 15 deg horizontally and vertically from the fovea. The validity of this instrument and its revised software is evaluated by measuring the reproducibility of axial length results in an adult eye and an artificial eye, and by correlating axial eye length measured in a group of ten adult eyes with axial eye length obtained with A-scan ultrasound in the same eyes. The precision obtained with adult subjects is compared with that obtained with children. PMID:14563204

  2. Electron Bunch Length Measurement for LCLS at SLAC

    SciTech Connect

    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.

  3. Absolute length measurement using manually decided stereo correspondence for endoscopy

    NASA Astrophysics Data System (ADS)

    Sasaki, M.; Koishi, T.; Nakaguchi, T.; Tsumura, N.; Miyake, Y.

    2009-02-01

    In recent years, various kinds of endoscope have been developed and widely used to endoscopic biopsy, endoscopic operation and endoscopy. The size of the inflammatory part is important to determine a method of medical treatment. However, it is not easy to measure absolute size of inflammatory part such as ulcer, cancer and polyp from the endoscopic image. Therefore, it is required measuring the size of those part in endoscopy. In this paper, we propose a new method to measure the absolute length in a straight line between arbitrary two points based on the photogrammetry using endoscope with magnetic tracking sensor which gives camera position and angle. In this method, the stereo-corresponding points between two endoscopic images are determined by the endoscopist without any apparatus of projection and calculation to find the stereo correspondences, then the absolute length can be calculated on the basis of the photogrammetry. The evaluation experiment using a checkerboard showed that the errors of the measurements are less than 2% of the target length when the baseline is sufficiently-long.

  4. Correlation length of vorticity in the near wall region of a high Reynolds number boundary layer.

    NASA Astrophysics Data System (ADS)

    Morris, Scott C.; Foss, John; Maher, Matthew

    2002-11-01

    Time series of the spanwise and wall normal components of vorticity were measured in the near wall region of an atmospheric boundary layer. The measurements were acquired at the SLTEST site located in western Utah during a period of neutral thermal stability. The surface was nearly flat, free of vegetation, with a small scale roughness of approximately 2mm. The measurements were acquired at an elevation of 40cm from the surface, or y+=10,300. The Reynolds number based on momentum thickness was approximately 10^6, with a boundary layer thickness of approximately 200m. The vorticity measurements indicate an extremely long correlation time of the near wall vorticity field. Length scales were calculated assuming a convection velocity equal to the local mean. For example, the first zero of the autocorrelation function of the spanwise component of vorticity was found to be at 40m. The same quantity calculated for the wall normal vorticity component was found to be at 220m. This leads to vorticity spectra which deviate from predictions based on isotropic models at moderate to low wave numbers. These data imply a strong causal relationship between the large motions in the outer region of the boundary layer and the near wall motions. A conceptual understanding of the boundary layer turbulent motions which is consistent with these findings will be discussed.

  5. Absolute Bunch Length Measurements by Incoherent Radiation Fluctuation Analysis

    SciTech Connect

    Sannibale, F.; /LBL, Berkeley; Stupakov, G.V.; /SLAC; Zolotorev, M.S.; /LBL, Berkeley; Filippetto, D.; /INFN, Rome; Jagerhofer, L.; /Vienna, Tech. U.

    2009-12-09

    By analyzing the pulse to pulse intensity fluctuations of the radiation emitted by a charge particle in the incoherent part of the spectrum, it is possible to extract information about the spatial distribution of the beam. At the Advanced Light Source (ALS) of the Lawrence Berkeley National Laboratory, we have developed and successfully tested a simple scheme based on this principle that allows for the absolute measurement of the rms bunch length. A description of the method and the experimental results are presented.

  6. Absolute bunch length measurements by incoherent radiation fluctuation analysis

    SciTech Connect

    Sannibale, Fernando; Stupakov, Gennady; Zolotorev, Max; Filippetto, Daniele; Jagerhofer, Lukas

    2008-09-29

    By analyzing the pulse to pulse intensity fluctuations of the radiation emitted by a charge particle in the incoherent part of the spectrum, it is possible to extract information about the spatial distribution of the beam. At the Advanced Light Source (ALS) of the Lawrence Berkeley National Laboratory, we have developed and successfully tested a simple scheme based on this principle that allows for the absolute measurement of the rms bunch length. A description of the method and the experimental results are presented.

  7. Interaural correlations in normal and traumatized cochleas: length and sensory cell loss

    SciTech Connect

    Bohne, B.A.; Bozzay, D.G.; Harding, G.W.

    1986-12-01

    Sizable intraspecies variations have been found in both the length of the organ of Corti (OC) and the amount of damage resulting from exposure to a particular ototraumatic agent. These variations have made it difficult to address certain research questions such as the susceptibility of the previously injured ear to further damage. If intra-animal correlation is high, the variability problem could be circumvented by using the two ears from a given animal for different aspects of the same study. Therefore, correlation coefficients were calculated for OC length and for percentage of missing inner (IHCs) and outer hair cells (OHCs) in a large sample of chinchillas which included controls and animals which had been exposed to noise or treated with ionizing radiation. The correlation coefficients were +0.96 for OC length, +0.93 for IHC loss, and +0.97 for OHC loss.

  8. The correlation between intron length and recombination in drosophila. Dynamic equilibrium between mutational and selective forces.

    PubMed Central

    Comeron, J M; Kreitman, M

    2000-01-01

    Intron length is negatively correlated with recombination in both Drosophila melanogaster and humans. This correlation is not likely to be the result of mutational processes alone: evolutionary analysis of intron length polymorphism in D. melanogaster reveals equivalent ratios of deletion to insertion in regions of high and low recombination. The polymorphism data do reveal, however, an excess of deletions relative to insertions (i.e., a deletion bias), with an overall deletion-to-insertion events ratio of 1.35. We propose two types of selection favoring longer intron lengths. First, the natural mutational bias toward deletion must be opposed by strong selection in very short introns to maintain the minimum intron length needed for the intron splicing reaction. Second, selection will favor insertions in introns that increase recombination between mutations under the influence of selection in adjacent exons. Mutations that increase recombination, even slightly, will be selectively favored because they reduce interference among selected mutations. Interference selection acting on intron length mutations must be very weak, as indicated by frequency spectrum analysis of Drosophila intron length polymorphism, making the equilibrium for intron length sensitive to changes in the recombinational environment and population size. One consequence of this sensitivity is that the advantage of longer introns is expected to decrease inversely with the rate of recombination, thus leading to a negative correlation between intron length and recombination rate. Also in accord with this model, intron length differs between closely related Drosophila species, with the longest variant present more often in D. melanogaster than in D. simulans. We suggest that the study of the proposed dynamic model, taking into account interference among selected sites, might shed light on many aspects of the comparative biology of genome sizes including the C value paradox. PMID:11063693

  9. Measured lengths of supersonic hydrogen-air jet flames—Compared to subsonic flame lengths—and analysis

    Microsoft Academic Search

    James F. Driscoll; Hwanil Huh; Youngbin Yoon; Jeffrey Donbar

    1996-01-01

    Measurements of flame length are reported that help to quantify the overall fuel-air mixing process that occurs within a jet-like flame in the supersonic regime. A nonpremixed, turbulent, hydrogen-air jet flame is stabilized along the axis of a Mach 2.2 coflowing air stream. Supersonic flame lengths are compared to measured lengths of subsonic hydrogen-air flames with coflow that were stabilized

  10. Real time bunch length measurements in the SLC linac

    SciTech Connect

    Sheppard, J.C.; Clendenin, J.E.; James, M.B.; Miller, R.H.; Ross, M.C.

    1985-02-01

    The longitudinal charge distribution of bunches accelerated in the Stanford Linear Collider (SLC) linac will strongly affect the performance of the Collider. Bunch lengths are chosen in a balance between the deleterious effects of longitudinal and transverse wakefields. The former impacts on the beam energy spread whereas the latter is important to the transverse emittance. Two bunch length measurement ports have been installed in the SLC linac: one in the injector region and one after the emittance damping ring to linac reinjection point. These ports utilize a fused quartz Cerenkov radiator in conjunction with an electrooptic streak camera to permit real time monitoring of single s-band buckets with a resolution of several picoseconds. The design of the radiators and light collection optics is discussed with an emphasis on those issues important to high resolution. Experimental results are presented. 7 refs., 4 figs.

  11. Pore directionality and correlation lengths of mesoporous silica channels aligned by physical epitaxy.

    PubMed

    Bolger, Ciara T; Farrell, Richard A; Hughes, Gareth M; Morris, Michael A; Petkov, Nikolay; Holmes, Justin D

    2009-08-25

    Herein we report on the alignment of mesoporous silica, a potential host for sub-10 nm nanostructures, by controlling its deposition within patterned substrates. In-depth characterization of the correlation lengths (length of a linear porous channel), defects of the porous network (delamination), and how the silica mesopores register to the micrometer-sized substrate pattern was achieved by means of novel focused ion beam (FIB) sectioning and in situ SEM imaging, which to our knowledge has not previously been reported for such a system. Our findings establish that, under confinement, directed deposition of the sol within channeled substrates, where the cross-sectional aspect ratio of the channels approaches unity, induces alignment of the mesopores along the length of the channels. The pore correlation length was found to extend beyond the micrometer scale, with high pore uniformity from channel to channel observed with infrequent delamination defects. Such information on pore correlation lengths and defect densities is critical for subsequent nanowire growth within the mesoporous channels, contact layout (electrode deposition etc.), and possible device architectures. PMID:19594114

  12. Correlation of bowel symptoms with colonic transit, length, and faecal load in functional faecal retention

    Microsoft Academic Search

    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

  13. Decoherence and measurement-induced correlations

    SciTech Connect

    Luo Shunlong; Li Nan [Academy of Mathematics and Systems Science, Chinese Academy of Sciences, 100190 Beijing (China)

    2011-11-15

    Decoherence arises from the interaction of a quantum system with the environment or, more precisely, from the measurement in which the environment ''measures'' the quantum system and establishes correlations with it. In this work, we first quantify measurement-induced correlations from both classical and quantum perspectives. Then we quantify decoherence via measurement-induced classical correlations. By virtue of an intrinsic and powerful link between entanglement (as quantified by entanglement of formation) and classical correlations (as quantified by the difference between the total correlations and quantum discord) in pure tripartite systems, we present general analytical formulas for measurement-induced correlations and decoherence measures for qubit systems and, furthermore, reveal a conservation relation for the information-disturbance tradeoff.

  14. Thermodynamic properties and thermal correlation lengths of a Hubbard model with bond-charge interaction

    NASA Astrophysics Data System (ADS)

    Kemper, Andreas; Schadschneider, Andreas

    2003-12-01

    We investigate the thermodynamics of a one-dimensional Hubbard model with bond-charge interaction X using the transfer-matrix renormalization-group method. Numerical results for various quantities such as spin and charge susceptibilities, particle densities, specific heat, and thermal correlation lengths are presented and discussed. We compare our data also to results for the exactly solvable case X/t=1 as well as to bosonization results for weak coupling X/t?1, which shows excellent agreement. We confirm the existence of a Tomonaga-Luttinger and a Luther-Emery liquid phase, in agreement with previous studies at zero temperature. Thermal singlet-pair-correlation lengths are shown to dominate density and spin correlations for finite temperatures in certain parameter regimes.

  15. Correlation of ion dynamics with characteristic length scales and network structural units in bismuth borate glasses

    NASA Astrophysics Data System (ADS)

    Shaw, A.; Ghosh, A.

    2013-09-01

    Ion dynamics in lithium bismuth borate conducting glasses have been reported in wide composition and temperature ranges. The activation energy for the dc conduction has been analysed using Anderson-Stuart model and a correlation between the dc conductivity and the doorway radius has been predicted. The characteristic length scales for ion dynamics, such as mean square displacement and spatial extent of sub-diffusive motion of lithium ions have been determined from the ac conductivity and dielectric spectra, respectively. A direct connection between the ion dynamics and the characteristic length scales and the network structural units have been established.

  16. Correlation of ion dynamics with characteristic length scales and network structural units in bismuth borate glasses.

    PubMed

    Shaw, A; Ghosh, A

    2013-09-21

    Ion dynamics in lithium bismuth borate conducting glasses have been reported in wide composition and temperature ranges. The activation energy for the dc conduction has been analysed using Anderson-Stuart model and a correlation between the dc conductivity and the doorway radius has been predicted. The characteristic length scales for ion dynamics, such as mean square displacement and spatial extent of sub-diffusive motion of lithium ions have been determined from the ac conductivity and dielectric spectra, respectively. A direct connection between the ion dynamics and the characteristic length scales and the network structural units have been established. PMID:24070293

  17. Integral correlation measures for multiparticle physics

    E-print Network

    Eggers, H C; Carruthers, Peter A; Buschbeck, Brigitte

    1993-01-01

    We report on a considerable improvement in the technique of measuring multiparticle correlations via integrals over correlation functions. A modification of measures used in the characterization of chaotic dynamical sytems permits fast and flexible calculation of factorial moments and cumulants as well as their differential versions. Higher order correlation integral measurements even of large multiplicity events such as encountered in heavy ion collisons are now feasible. The change from ``ordinary'' to ``factorial'' powers may have important consequences in other fields such as the study of galaxy correlations and Bose-Einstein interferometry.

  18. Integral correlation measures for multiparticle physics

    E-print Network

    H. C. Eggers; P. Lipa; P. Carruthers; B. Buschbeck

    1993-04-03

    We report on a considerable improvement in the technique of measuring multiparticle correlations via integrals over correlation functions. A modification of measures used in the characterization of chaotic dynamical sytems permits fast and flexible calculation of factorial moments and cumulants as well as their differential versions. Higher order correlation integral measurements even of large multiplicity events such as encountered in heavy ion collisons are now feasible. The change from ``ordinary'' to ``factorial'' powers may have important consequences in other fields such as the study of galaxy correlations and Bose-Einstein interferometry.

  19. First $?K$ atom lifetime and $?K$ scattering length measurements

    E-print Network

    B. Adeva; L. Afanasyev; Y. Allkofer; C. Amsler; A. Anania; S. Aogaki; A. Benelli; V. Brekhovskikh; T. Cechak; M. Chiba; P. Chliapnikov; C. Ciocarlan; S. Constantinescu; P. Doskarova; D. Drijard; A. Dudarev; M. Duma; D. Dumitriu; D. Fluerasu; A. Gorin; O. Gorchakov; K. Gritsay; C. Guaraldo; M. Gugiu; M. Hansroul; Z. Hons; S. Horikawa; Y. Iwashita; V. Karpukhin; J. Kluson; M. Kobayashi; V. Kruglov; L. Kruglova; A. Kulikov; E. Kulish; A. Kuptsov; A. Lamberto; A. Lanaro; R. Lednicky; C. Mariñas; J. Martincik; L. Nemenov; M. Nikitin; K. Okada; V. Olchevskii; M. Pentia; A. Penzo; M. Plo; T. Ponta; P. Prusa; G. Rappazzo; A. Romero Vidal; A. Ryazantsev; V. Rykalin; J. Schacher; A. Sidorov; J. Smolik; S. Sugimoto; F. Takeutchi; L. Tauscher; T. Trojek; S. Trusov; T. Urban; T. Vrba; V. Yazkov; Y. Yoshimura; M. Zhabitsky; P. Zrelov

    2014-03-04

    The results of a search for hydrogen-like atoms consisting of $\\pi^{\\mp}K^{\\pm}$ mesons are presented. Evidence for $\\pi K$ atom production by 24 GeV/c protons from CERN PS interacting with a nickel target has been seen in terms of characteristic $\\pi K$ pairs from their breakup in the same target ($178 \\pm 49$) and from Coulomb final state interaction ($653 \\pm 42$). Using these results the analysis yields a first value for the $\\pi K$ atom lifetime of $\\tau=(2.5_{-1.8}^{+3.0})$ fs and a first model-independent measurement of the S-wave isospin-odd $\\pi K$ scattering length $\\left|a_0^-\\right|=\\frac{1}{3}\\left|a_{1/2}-a_{3/2}\\right|= \\left(0.11_{-0.04}^{+0.09} \\right)M_{\\pi}^{-1}$ ($a_I$ for isospin $I$).

  20. 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.

  1. Dynamical heterogeneity in a highly supercooled liquid: Consistent calculations of correlation length, intensity, and lifetime

    Microsoft Academic Search

    Hideyuki Mizuno; Ryoichi Yamamoto

    2011-01-01

    We have investigated dynamical heterogeneity in a highly supercooled liquid using molecular-dynamics simulations in three dimensions. Dynamical heterogeneity can be characterized by three quantities: correlation length xi4, intensity chi4, and lifetime tauhetero. We evaluated all three quantities consistently from a single order parameter. In a previous study [H. Mizuno and R. Yamamoto, Phys. Rev. EPLEEE81539-375510.1103\\/PhysRevE.82.030501 82, 030501(R) (2010)], we examined

  2. Representative Elementary Length to Measure Soil Mass Attenuation Coefficient

    PubMed Central

    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

  3. Representative elementary length to measure soil mass attenuation coefficient.

    PubMed

    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

  4. Dyslipidemia and Chronic Inflammation Markers Are Correlated with Telomere Length Shortening in Cushing’s Syndrome

    PubMed Central

    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

  5. Audiogram, body mass, and basilar papilla length: correlations in birds and predictions for extinct archosaurs

    NASA Astrophysics Data System (ADS)

    Gleich, Otto; Dooling, Robert J.; Manley, Geoffrey A.

    2005-12-01

    The inner ear in the group of archosaurs (birds, crocodilians, and extinct dinosaurs) shows a high degree of structural similarity, enabling predictions of their function in extinct species based on relationships among similar variables in living birds. Behavioral audiograms and morphological data on the length of the auditory sensory epithelium (the basilar papilla) are available for many avian species. By bringing different data sets together, we show that body mass and the size of the basilar papilla are significantly correlated, and the most sensitive frequency in a given species is inversely related to the body mass and the length of the basilar papilla. We also demonstrate that the frequency of best hearing is correlated with the high-frequency limit of hearing. Small species with a short basilar papilla hear higher frequencies compared with larger species with a longer basilar papilla. Based on the regression analysis of two significant correlations in living archosaurs (best audiogram frequency vs body mass and best audiogram frequency vs papillar length), we suggest that hearing in large dinosaurs was restricted to low frequencies with a high-frequency limit below 3 kHz.

  6. Method for High Accuracy Multiplicity Correlation Measurements

    NASA Astrophysics Data System (ADS)

    Søgaard, C.; Gulbrandsen, K.

    2015-03-01

    A novel method for measuring particle multiplicity correlations is presented. The method takes reduced acceptance and detection efficiency into account, in a purely statistical manner. The method does therefore not require any information from simulations - only knowledge of the detectors capability. The method provides the ability to measure forward-backward particle multiplicity correlations with high accuracy and negligible bias. The validity of the method is provided through numerous simulations. The correlation values calculated from carefully selected detection acceptances and efficiencies are compared to the correlation values at the event-generator level. Further validity to the method is given by incorporating different event generators into the simulations. Although the emphasis is on fwd-bwd correlations, the method can be extended to other multiplicity correlation measurements.

  7. EN-011 Ecology January 2002 Measuring the Length of Coarse Woody Debris

    E-print Network

    EN-011 Ecology January 2002 Measuring the Length of Coarse Woody Debris By P.L. Marshall and G methods CITATION: Marshall, P.L. and G. Davis. 2001. Measuring the Length of Coarse Woody Debris. Research for including length in a CWD survey are varied. CWD length may be part of studies that: include the dimensions

  8. Dynamical heterogeneity in a highly supercooled liquid: Consistent calculations of correlation length, intensity, and lifetime

    NASA Astrophysics Data System (ADS)

    Mizuno, Hideyuki; Yamamoto, Ryoichi

    2011-07-01

    We have investigated dynamical heterogeneity in a highly supercooled liquid using molecular-dynamics simulations in three dimensions. Dynamical heterogeneity can be characterized by three quantities: correlation length ?4, intensity ?4, and lifetime ?hetero. We evaluated all three quantities consistently from a single order parameter. In a previous study [H. Mizuno and R. Yamamoto, Phys. Rev. EPLEEE81539-375510.1103/PhysRevE.82.030501 82, 030501(R) (2010)], we examined the lifetime ?hetero(t) in two time intervals t=?? and ?ngp, where ?? is the ?-relaxation time and ?ngp is the time at which the non-Gaussian parameter of the Van Hove self-correlation function is maximized. In the present study, in addition to the lifetime ?hetero(t), we evaluated the correlation length ?4(t) and the intensity ?4(t) from the same order parameter used for the lifetime ?hetero(t). We found that as the temperature decreases, the lifetime ?hetero(t) grows dramatically, whereas the correlation length ?4(t) and the intensity ?4(t) increase slowly compared to ?hetero(t) or plateaus. Furthermore, we investigated the lifetime ?hetero(t) in more detail. We examined the time-interval dependence of the lifetime ?hetero(t) and found that as the time interval t increases, ?hetero(t) monotonically becomes longer and plateaus at the relaxation time of the two-point density correlation function. At the large time intervals for which ?hetero(t) plateaus, the heterogeneous dynamics migrate in space with a diffusion mechanism, such as the particle density.

  9. Dynamical heterogeneity in a highly supercooled liquid: Consistent calculations of correlation length, intensity, and lifetime

    E-print Network

    Hideyuki Mizuno; Ryoichi Yamamoto

    2011-05-30

    We have investigated dynamical heterogeneity in a highly supercooled liquid using molecular-dynamics simulations in three dimensions. Dynamical heterogeneity can be characterized by three quantities: correlation length $\\xi_4$, intensity $\\chi_4$, and lifetime $\\tau_{\\text{hetero}}$. We evaluated all three quantities consistently from a single order parameter. In a previous study (H. Mizuno and R. Yamamoto, Phys. Rev. E {\\bf 82}, 030501(R) (2010)), we examined the lifetime $\\tau_{\\text{hetero}}(t)$ in two time intervals $t=\\tau_\\alpha$ and $\\tau_{\\text{ngp}}$, where $\\tau_\\alpha$ is the $\\alpha$-relaxation time and $\\tau_{\\text{ngp}}$ is the time at which the non-Gaussian parameter of the Van Hove self-correlation function is maximized. In the present study, in addition to the lifetime $\\tau_{\\text{hetero}}(t)$, we evaluated the correlation length $\\xi_4(t)$ and the intensity $\\chi_4(t)$ from the same order parameter used for the lifetime $\\tau_{\\text{hetero}}(t)$. We found that as the temperature decreases, the lifetime $\\tau_{\\text{hetero}}(t)$ grows dramatically, whereas the correlation length $\\xi_4(t)$ and the intensity $\\chi_4(t)$ increase slowly compared to $\\tau_{\\text{hetero}}(t)$ or plateaus. Furthermore, we investigated the lifetime $\\tau_{\\text{hetero}}(t)$ in more detail. We examined the time-interval dependence of the lifetime $\\tau_{\\text{hetero}}(t)$ and found that as the time interval $t$ increases, $\\tau_{\\text{hetero}}(t)$ monotonically becomes longer and plateaus at the relaxation time of the two-point density correlation function. At the large time intervals for which $\\tau_{\\text{hetero}}(t)$ plateaus, the heterogeneous dynamics migrate in space with a diffusion mechanism, such as the particle density.

  10. 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.

  11. Length measurement of a moving rod by a single observer without assumptions concerning its magnitude

    E-print Network

    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.

  12. Measurements of Energy-Energy-Correlations

    E-print Network

    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

  13. Scale and time dependence of serial correlations in word-length time series of written texts

    NASA Astrophysics Data System (ADS)

    Rodriguez, E.; Aguilar-Cornejo, M.; Femat, R.; Alvarez-Ramirez, J.

    2014-11-01

    This work considered the quantitative analysis of large written texts. To this end, the text was converted into a time series by taking the sequence of word lengths. The detrended fluctuation analysis (DFA) was used for characterizing long-range serial correlations of the time series. To this end, the DFA was implemented within a rolling window framework for estimating the variations of correlations, quantified in terms of the scaling exponent, strength along the text. Also, a filtering derivative was used to compute the dependence of the scaling exponent relative to the scale. The analysis was applied to three famous English-written literary narrations; namely, Alice in Wonderland (by Lewis Carrol), Dracula (by Bram Stoker) and Sense and Sensibility (by Jane Austen). The results showed that high correlations appear for scales of about 50-200 words, suggesting that at these scales the text contains the stronger coherence. The scaling exponent was not constant along the text, showing important variations with apparent cyclical behavior. An interesting coincidence between the scaling exponent variations and changes in narrative units (e.g., chapters) was found. This suggests that the scaling exponent obtained from the DFA is able to detect changes in narration structure as expressed by the usage of words of different lengths.

  14. Measurements of Correlation-Enhanced Collision Rates

    NASA Astrophysics Data System (ADS)

    Anderegg, F.; Dubin, D. H. E.; O'Neil, T. M.; Driscoll, C. F.

    2008-11-01

    We measure the perp-to-parallel collision rate ?| in laser-cooled Magnesium ion plasmas in the strongly-magnetized and correlated regime; and obtain close agreement with the ``Salpeter correlation enhancement'' first studied for fusion in dense plasmas such as stars. The cyclotron energy, like nuclear energy, is released only through rare close-range collisions. These close collisions are suppressed by strong magnetization, because collisional impact distances are rarely as small as a cyclotron radius rc. However, theory predicts that particle correlations reduce this suppression of collisionality, enhancing the rare close collisions by e^?, where ??e^2 / aT is the correlation parameter. We control the plasma temperature over the range 4 0-6 < T < 1eV, giving correlation parameters up to ? 0, with measured collision rates 2 < ?| 2 10^4 sec-1. At low temperatures, the measured ?| are enhanced by up to 10^9 compared to uncorrelated theory, consistent with the predicted correlation enhancement. When the plasma density is reduced from 2 to 0.12 x10^7cm-3, the correlations are eliminated and the measured ?| agree with uncorrelated theory. E.E. Salpeter and H.M. Van Horn, Astrophys. J. 155, 183 (1969). D.H.E. Dubin, Phys. Rev. Lett. 94, 025002 (2005).

  15. Knemometry in childhood: accuracy and standardization of a new technique of lower leg length measurement.

    PubMed

    Hermanussen, M; Geiger-Benoit, K; Burmeister, J; Sippell, W G

    1988-01-01

    Recently, a new anthropometric method of accurate lower leg length measurement (knemometry) was introduced. The present study was performed to investigate rigorously its strengths and weaknesses for auxological purposes, and to promote a standardized method of use. The data are based on 6 x 2200 single estimations of the lower leg length in 90 children of both sexes with normal, tall or short stature aged between 2.4 and 17.1 years. The overall technical error of this measurement was found to be 0.16 mm, which is reduced to 0.13 mm if the first estimation within each series of six is ignored. The following sources of systematic error could be detected: intra-daily variation, dependency on physical pressure put on or removed from the leg, vigorous physical activity prior to the measuring procedure, and a slow but significant correlation between day-to-day variation of lower leg length and body weight (r = 0.299, b = 0.372 mm/kg). There was no covariation with atmospheric parameters such as outside temperature, barometric pressure and others. After elimination of a linear trend from the individual growth curves, there was a remaining day-to-day variation of SD = 0.697 mm. This represents real changes of lower leg length and cannot be explained by the technical error of measurement which contributes to less than 10% of the total variation. Some of this day-to-day variation may be explained by non-linearity of growth. Knemometry appears to be a robust and precise new tool for the investigation of short term kinetics of longitudinal growth. Proposals for a standardized use of this technique are given. PMID:3348587

  16. Line Tensions, Correlation Lengths, and Critical Exponents in Lipid Membranes Near Critical Points

    PubMed Central

    Honerkamp-Smith, Aurelia R.; Cicuta, Pietro; Collins, Marcus D.; Veatch, Sarah L.; den Nijs, Marcel; Schick, M.; Keller, Sarah L.

    2008-01-01

    Membranes containing a wide variety of ternary mixtures of high chain-melting temperature lipids, low chain-melting temperature lipids, and cholesterol undergo lateral phase separation into coexisting liquid phases at a miscibility transition. When membranes are prepared from a ternary lipid mixture at a critical composition, they pass through a miscibility critical point at the transition temperature. Since the critical temperature is typically on the order of room temperature, membranes provide an unusual opportunity in which to perform a quantitative study of biophysical systems that exhibit critical phenomena in the two-dimensional Ising universality class. As a critical point is approached from either high or low temperature, the scale of fluctuations in lipid composition, set by the correlation length, diverges. In addition, as a critical point is approached from low temperature, the line tension between coexisting phases decreases to zero. Here we quantitatively evaluate the temperature dependence of line tension between liquid domains and of fluctuation correlation lengths in lipid membranes to extract a critical exponent, ?. We obtain ? = 1.2 ± 0.2, consistent with the Ising model prediction ? = 1. We also evaluate the probability distributions of pixel intensities in fluorescence images of membranes. From the temperature dependence of these distributions above the critical temperature, we extract an independent critical exponent of ? = 0.124 ± 0.03, which is consistent with the Ising prediction of ? = 1/8. PMID:18424504

  17. Measurements of Correlation-Enhanced Collision Rates

    Microsoft Academic Search

    F. Anderegg; D. H. E. Dubin; T. M. O'Neil; C. F. Driscoll

    2008-01-01

    We measure the perp-to-parallel collision rate nu| in laser-cooled Magnesium ion plasmas in the strongly-magnetized and correlated regime; and obtain close agreement with the ``Salpeter correlation enhancement'' first studied for fusion in dense plasmas such as stars. The cyclotron energy, like nuclear energy, is released only through rare close-range collisions. These close collisions are suppressed by strong magnetization, because collisional

  18. Correlate measurements at different test sites

    Microsoft Academic Search

    B. Fourestie; Z. Altman; J. Wiart; A. Azoulay

    1999-01-01

    A new method for systematic correlation of measurements in semi-anechoic and anechoic chambers is presented. A signal measured in a semi-anechoic chamber is first processed using the matrix-pencil method which is applied sequentially on small frequency intervals. On each interval the measured signal is decomposed into its propagating wave components. The component corresponding to the wave reflected from the ground

  19. Understanding the amplitudes of noise correlation measurements

    USGS Publications Warehouse

    Tsai, Victor C.

    2011-01-01

    Cross correlation of ambient seismic noise is known to result in time series from which station-station travel-time measurements can be made. Part of the reason that these cross-correlation travel-time measurements are reliable is that there exists a theoretical framework that quantifies how these travel times depend on the features of the ambient noise. However, corresponding theoretical results do not currently exist to describe how the amplitudes of the cross correlation depend on such features. For example, currently it is not possible to take a given distribution of noise sources and calculate the cross correlation amplitudes one would expect from such a distribution. Here, we provide a ray-theoretical framework for calculating cross correlations. This framework differs from previous work in that it explicitly accounts for attenuation as well as the spatial distribution of sources and therefore can address the issue of quantifying amplitudes in noise correlation measurements. After introducing the general framework, we apply it to two specific problems. First, we show that we can quantify the amplitudes of coherency measurements, and find that the decay of coherency with station-station spacing depends crucially on the distribution of noise sources. We suggest that researchers interested in performing attenuation measurements from noise coherency should first determine how the dominant sources of noise are distributed. Second, we show that we can quantify the signal-to-noise ratio of noise correlations more precisely than previous work, and that these signal-to-noise ratios can be estimated for given situations prior to the deployment of seismometers. It is expected that there are applications of the theoretical framework beyond the two specific cases considered, but these applications await future work.

  20. Identification of Optimal Satellite Compositing Length Using GLOBE Budburst Measurements

    Microsoft Academic Search

    Michael White

    Phenology, the study of recurring biological cycles and their connection to climate, is a critical and growing field of glDbal change research. In particular, scientists now recognize that regular satellite monitoring of the timing and length of the terrestrial growing season is a valuable metric ofbiospheric responses to short- and long-term climate variability. While many methodologies exist with which to

  1. Correlation of interannual length-of-day variation with El Nino/Southern Oscillation, 1972-1986

    NASA Astrophysics Data System (ADS)

    Chao, B. Fong

    1988-07-01

    Correlation between interannual length-of-day (LOD) changes and an index representation of El Nino/Southern Oscillation (ENSO) for the period of 1972-1986 was examined in two ways: as the cross-correlation function in the time domain and as the complex coherence spectrum in the frequency domain. The ENSO representation was derived from barometric measurements from the Tahiti and Darwin, Australia, meteorological stations, as the difference of the sea-level pressure between the two locations. The cross correlation between this ENSO representation and LOD variation on the interannual time scale was found to have a maximum value of 0.68 and the LOD phase lag of 2 months, indicating that most of the interannual LOD variation is caused by ENSO, and that the transfer of ENSO's axial angular momentum to the solid earth lags behind the Tahiti-Darwin pressure variation by about 2 months. The corresponding coherence spectrum showed minimum correlation around biennial periods, indicating an influence of the stratospheric quasi-biennial oscillation on LOD variations.

  2. Correlation of interannual length-of-day variation with El Nino/Southern Oscillation, 1972-1986

    NASA Technical Reports Server (NTRS)

    Chao, B. Fong

    1988-01-01

    Correlation between interannual length-of-day (LOD) changes and an index representation of El Nino/Southern Oscillation (ENSO) for the period of 1972-1986 was examined in two ways: as the cross-correlation function in the time domain and as the complex coherence spectrum in the frequency domain. The ENSO representation was derived from barometric measurements from the Tahiti and Darwin, Australia, meteorological stations, as the difference of the sea-level pressure between the two locations. The cross correlation between this ENSO representation and LOD variation on the interannual time scale was found to have a maximum value of 0.68 and the LOD phase lag of 2 months, indicating that most of the interannual LOD variation is caused by ENSO, and that the transfer of ENSO's axial angular momentum to the solid earth lags behind the Tahiti-Darwin pressure variation by about 2 months. The corresponding coherence spectrum showed minimum correlation around biennial periods, indicating an influence of the stratospheric quasi-biennial oscillation on LOD variations.

  3. TERRA Expression Levels Do Not Correlate with Telomere Length and Radiation Sensitivity in Human Cancer Cell Lines

    PubMed Central

    Smirnova, Alexandra; Gamba, Riccardo; Khoriauli, Lela; Vitelli, Valerio; Nergadze, Solomon G.; Giulotto, Elena

    2013-01-01

    Mammalian telomeres are transcribed into long non-coding telomeric repeat-containing RNA (TERRA) molecules that seem to play a role in the maintenance of telomere stability. In human cells, CpG-island promoters drive TERRA transcription and are regulated by methylation. It was suggested that the amount of TERRA may be related to telomere length. To test this hypothesis we measured telomere length and TERRA levels in single clones isolated from five human cell lines: HeLa (cervical carcinoma), BRC-230 (breast cancer), AKG and GK2 (gastric cancers), and GM847 (SV40 immortalized skin fibroblasts). However, these two parameters did not correlate with each other. Moreover, cell survival to ?-rays did not show a significant variation among the clones, suggesting that, in this cellular system, the intra-population variability in telomere length and TERRA levels does not influence sensitivity to ionizing radiation. This conclusion was supported by the observation that in a cell line in which telomeres were greatly elongated by the ectopic expression of telomerase, TERRA expression levels and radiation sensitivity were similar to the parental HeLa cell line. PMID:23717814

  4. Quantum correlation measure in arbitrary bipartite systems

    NASA Astrophysics Data System (ADS)

    Yu, Chang-shui; Wu, Shao-xiong; Wang, Xiaoguang; Yi, X. X.; Song, He-shan

    2014-07-01

    Quantum correlation with a novel definition is presented for an arbitrary bipartite quantum state in terms of the skew information of the complete set of rank-one orthogonal projectors. This definition not only inherits the good properties of skew information including the contractivity, but also shows a powerful analytic computability for a large range of states. In addition, the measure for a general state can be easily numerically obtained by the well-developed technique of the approximate joint diagonalization. As a comparison, we give both the analytic and the numerical quantum correlation for many high-dimensional states. The relation between our measure and quantum metrology is also analyzed.

  5. Eddy Correlation Flux Measurement System (ECOR) Handbook

    SciTech Connect

    Cook, DR

    2011-01-31

    The eddy correlation (ECOR) flux measurement system provides in situ, half-hour measurements of the surface turbulent fluxes of momentum, sensible heat, latent heat, and carbon dioxide (CO2) (and methane at one Southern Great Plains extended facility (SGP EF) and the North Slope of Alaska Central Facility (NSA CF). The fluxes are obtained with the eddy covariance technique, which involves correlation of the vertical wind component with the horizontal wind component, the air temperature, the water vapor density, and the CO2 concentration.

  6. Tomography via correlation of noisy measurement records

    NASA Astrophysics Data System (ADS)

    Ryan, Colm A.; Johnson, Blake R.; Gambetta, Jay M.; Chow, Jerry M.; da Silva, Marcus P.; Dial, Oliver E.; Ohki, Thomas A.

    2015-02-01

    We present methods and results for tomographic measurement of quantum systems through shot-by-shot correlation of individual qubit measurements. Rather than inferring the qubit state after each measurement, we show that averaging of continuous soft values is a valid tomographic strategy and is in fact the better choice in the regime of low signal-to-noise ratio. We experimentally demonstrate a matched filter approach to account for a transient measurement response, and use this to show that tomography of entangled states is feasible despite the asymptotic exponential effort required to obtain N -body corrleations.

  7. Quantum correlations and least disturbing local measurements

    SciTech Connect

    Rossignoli, R.; Canosa, N.; Ciliberti, L. [Departamento de Fisica-IFLP, Universidad Nacional de La Plata, C.C. 67, La Plata (1900) (Argentina)

    2011-11-15

    We examine the evaluation of the minimum information loss due to an unread local measurement in mixed states of bipartite systems, for a general entropic form. Such a quantity provides a measure of quantum correlations, reducing for pure states to the generalized entanglement entropy, while in the case of mixed states it vanishes just for classically correlated states with respect to the measured system, as the quantum discord. General stationary conditions are provided, together with their explicit form for general two-qubit states. Closed expressions for the minimum information loss as measured by quadratic and cubic entropies are also derived for general states of two-qubit systems. As an application, we analyze the case of states with maximally mixed marginals, where a general evaluation is provided, as well as X states and the mixture of two aligned states.

  8. Generating nonclassical correlations without fully aligning measurements

    SciTech Connect

    Wallman, Joel J.; Bartlett, Stephen D. [School of Physics, University of Sydney, Sydney, New South Wales 2006 (Australia); Liang, Yeong-Cherng [School of Physics, University of Sydney, Sydney, New South Wales 2006 (Australia); Group of Applied Physics, University of Geneva, CH-1211 Geneva 4 (Switzerland)

    2011-02-15

    We investigate the scenario where spatially separated parties perform measurements in randomly chosen bases on an N-partite Greenberger-Horne-Zeilinger state. We show that without any alignment of the measurements, the observers will obtain correlations that violate a Bell inequality with a probability that rapidly approaches 1 as N increases and that this probability is robust against noise. We also prove that restricting these randomly chosen measurements to a plane perpendicular to a common direction will always generate correlations that violate some Bell inequality. Specifically, if each observer chooses their two measurements to be locally orthogonal, then the N observers will violate one of two Bell inequalities by an amount that increases exponentially with N. These results are also robust against noise and perturbations of each observer's reference direction from the common direction.

  9. Correlates of rehabilitation hospital length of stay among older African-American patients.

    PubMed Central

    Mills, Terry L.; Lichtenberg, Peter A.; Wakeman, Melanie A.; Scott-Okafor, Hellena

    2002-01-01

    This study addresses a gap in the current literature on the correlates of rehabilitation hospital length of stay for older African Americans. Using data from 616 consecutively admitted rehabilitation patients who ranged in age from 50 to 103 years old, we tested the effect of patient's primary medical impairment; structural factors such as admit and discharge setting; level of depression (Geriatric Depression Scale); functional ability upon hospital admission (FIM score); and other control variables. Hierarchical linear regression models show that medical impairment alone was not a robust predictor of LOS. However, when controlling for structural and psychosocial factors, and medical condition, then circulation/amputation impairment was directly associated with longer LOS. Being unmarried or at risk for depression were also directly related to longer LOS. Consequently, rehabilitation administrators and hospital staff should note these findings to determine whether and how these factors affect discharge outcomes in their particular rehabilitative environments. PMID:12392049

  10. Titin isoform size is not correlated with thin filament length in rat skeletal muscle

    PubMed Central

    Greaser, Marion L.; Pleitner, Jonathan M.

    2014-01-01

    The mechanisms controlling thin filament length (TFL) in muscle remain controversial. It was recently reported that TFL was related to titin size, and that the latter might be involved in TFL determination. Titin plays several crucial roles in the sarcomere, but its function as it pertains to the thin filament has not been explored. We tested this relationship using several muscles from wild type rats and from a mutant rat model (Greaser et al., 2008) which results in increased titin size. Myofibrils were isolated from skeletal muscles [extensor digitorum longus (EDL), external oblique (EO), gastrocnemius (GAS), longissimus dorsi (LD), psoas major (PM), and tibialis anterior(TA)] using both adult wild type (WT) and homozygous mutant (HM) rats (n = 6 each). Phalloidin and antibodies against tropomodulin-4 (Tmod-4) and nebulin's N-terminus were used to determine TFL. The WT rats studied express skeletal muscle titin sizes ranging from 3.2 to 3.7 MDa, while the HM rats express a giant titin isoform sized at 3.8 MDa. No differences in phalloidin based TFL, nebulin distance, or Tmod distance were observed across genotypes. However, the HM rats demonstrated a significantly increased (p < 0.01) rest sarcomere length relative to the WT phenotype. It appears that the increased titin size, predominantly observed in HM rats' middle Ig domain, allows for increased extensibility. The data indicates that, although titin performs many sarcomeric functions, its correlation with TFL and structure could not be demonstrated in the rat. PMID:24550844

  11. Measurements of Correlation-Enhanced Collision Rates

    E-print Network

    California at San Diego, University of

    measurements of collision rate in laser-cooled magnesium ion plasmas with density n 107cm-3 and temperature 2T . (All symbols are defined below.) Laser cooling enables ion plasma equilibria well into the cryogenic stars, and laser fusion plasmas. Nuclear reaction rates in dense correlated plasmas are, according

  12. Persistence Length of Human Cardiac ?-Tropomyosin Measured by Single Molecule Direct Probe Microscopy

    PubMed Central

    Loong, Campion K. P.; Zhou, Huan-Xiang; Chase, P. Bryant

    2012-01-01

    ?-Tropomyosin (?Tm) is the predominant tropomyosin isoform in adult human heart and constitutes a major component in Ca2+-regulated systolic contraction of cardiac muscle. We present here the first direct probe images of WT human cardiac ?Tm by atomic force microscopy, and quantify its mechanical flexibility with three independent analysis methods. Single molecules of bacterially-expressed human cardiac ?Tm were imaged on poly-lysine coated mica and their contours were analyzed. Analysis of tangent-angle (?(s)) correlation along molecular contours, second moment of tangent angles (), and end-to-end length (Le-e) distributions respectively yielded values of persistence length (Lp) of 41–46 nm, 40–45 nm, and 42–52 nm, corresponding to 1–1.3 molecular contour lengths (Lc). We also demonstrate that a sufficiently large population, with at least 100 molecules, is required for a reliable Lp measurement of ?Tm in single molecule studies. Our estimate that Lp for ?Tm is only slightly longer than Lc is consistent with a previous study showing there is little spread of cooperative activation into near-neighbor regulatory units of cardiac thin filaments. The Lp determined here for human cardiac ?Tm perhaps represents an evolutionarily tuned optimum between Ca2+ sensitivity and cooperativity in cardiac thin filaments and likely constitutes an essential parameter for normal function in the human heart. PMID:22737252

  13. Quantum Correlations and the Measurement Problem

    NASA Astrophysics Data System (ADS)

    Bub, Jeffrey

    2014-10-01

    The transition from classical to quantum mechanics rests on the recognition that the structure of information is not what we thought it was: there are operational, i.e., phenomenal, probabilistic correlations that lie outside the polytope of local correlations. Such correlations cannot be simulated with classical resources, which generate classical correlations represented by the points in a simplex, where the vertices of the simplex represent joint deterministic states that are the common causes of the correlations. The `no go' hidden variable theorems tell us that we can't shoe-horn phenomenal correlations outside the local polytope into a classical simplex by supposing that something has been left out of the story. The replacement of the classical simplex by the quantum convex set as the structure representing probabilistic correlations is the analogue for quantum mechanics of the replacement of Newton's Euclidean space and time by Minkowski spacetime in special relativity. The nonclassical features of quantum mechanics, including the irreducible information loss on measurement, are generic features of correlations that lie outside the classical simplex. This paper is an elaboration of these ideas, which have their source in work by Pitowsky (J. Math. Phys. 27:1556, 1986; Math. Program. 50:395, 1991; Phys. Rev. A 77:062109, 2008), Garg and Mermin (Found. Phys. 14:1-39, 1984), Barrett (Phys. Rev. A 75:032304, 2007; Phys. Rev. A 7:022101, 2005) and others, e.g., Brunner et al. (arXiv:1303.2849, 2013), but the literature goes back to Boole (An Investigation of the Laws of Thought, Dover, New York, 1951). The final section looks at the measurement problem of quantum mechanics in this context. A large part of the problem is removed by seeing that the inconsistency in reconciling the entangled state at the end of a quantum measurement process with the definiteness of the macroscopic pointer reading and the definiteness of the correlated value of the measured micro-observable depends on a stipulation that is not required by the structure of the quantum possibility space. Replacing this stipulation by an alternative consistent stipulation is the first step to resolving the problem.

  14. Questioning the relationship between the $?$4 susceptibility and the dynamical correlation length in a glass former

    E-print Network

    Rémy Colin; Ahmed Alsayed; Cyprien Gay; Bérengère Abou

    2015-03-13

    Clusters of fast and slow correlated particles, identified as dynamical heterogeneities (DHs), constitute a central aspect of glassy dynamics. A key ingredient of the glass transition scenario is a significant increase of the cluster size $\\xi$4 as the transition is approached. In need of easy-to-compute tools to measure $\\xi$4, the dynamical susceptibility $\\chi$4 was introduced recently. Here, we investigate DHs in dense microgel suspensions using image correlation, and compute both $\\chi$4 and the four-point correlation function G4. The spatial decrease of G4 provides a direct access to $\\xi$4, which is found to grow significantly with increasing volume fraction. However, this increase is not captured by $\\chi$4. We show that the assumptions that validate the connection between $\\chi$4 and $\\xi$4 are not fulfilled in our experiments. Our findings question the relevance of the broadly used $\\chi$4 in describing DHs.

  15. Susceptibility $?$4 fails to capture significant increase of dynamic correlation length near glass transition

    E-print Network

    Rémy Colin; Ahmed Alsayed; Cyprien Gay; Bérengère Abou

    2014-12-28

    Clusters of fast and slow correlated particles, identified as dynamical heterogeneities (DHs), con-stitute a central aspect of glassy dynamics. A key ingredient of the glass transition scenario is a significant increase of the cluster size $\\xi$4 as the transition is approached. In need of easy-to-compute tools to measure $\\xi$4, the dynamical susceptibility $\\chi$4 was introduced recently. Here, we investigate DHs in dense microgel suspensions using image correlation, and compute both $\\chi$4 and the four-point correlation function G4. The spatial decrease of G4 provides a direct access to $\\xi$4, which is found to grow significantly with increasing volume fraction. However, this increase is not captured by $\\chi$4. We show that the assumptions that validate the connection between $\\chi$4 and $\\xi$4 are not fulfilled in our experiments. Our findings question the relevance of the broadly used $\\chi$4 in describing DHs.

  16. Measures and models for angular correlation and angular-linear correlation. [correlation of random variables

    NASA Technical Reports Server (NTRS)

    Johnson, R. A.; Wehrly, T.

    1976-01-01

    Population models for dependence between two angular measurements and for dependence between an angular and a linear observation are proposed. The method of canonical correlations first leads to new population and sample measures of dependence in this latter situation. An example relating wind direction to the level of a pollutant is given. Next, applied to pairs of angular measurements, the method yields previously proposed sample measures in some special cases and a new sample measure in general.

  17. Development of an Optimization Method for Determining Human Hand Link Lengths Based on Surface Measurement

    Microsoft Academic Search

    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

  18. A new landscape metric for the identification of terraced sites: The Slope Local Length of Auto-Correlation (SLLAC)

    NASA Astrophysics Data System (ADS)

    Sofia, Giulia; Marinello, Francesco; Tarolli, Paolo

    2014-10-01

    This work presents the potential for high-resolution remote sensing data (LiDAR digital terrain models) to determine the spatial heterogeneity of terraced landscapes. The study objective is achieved through the identification of a new parameter that distinguishes this unique landscape form from more natural land formations. The morphological indicator proposed is called the Slope Local Length of Auto-Correlation (SLLAC), and it is derived from the local analysis of slope self-similarity. The SLACC is obtained over two steps: (i) calculating the correlation between a slope patch and a defined surrounding area and (ii) identifying the characteristic length of correlation for each neighbourhood. The SLLAC map texture can be measured using a surface metrology metric called the second derivative of peaks, or Spc. For the present study, we tested the algorithm for two types of landscapes: a Mediterranean and an Alpine one. The research method involved an examination of both real LiDAR DTMs and simulated ones, in which it was possible to control terrace shapes and the percentage of area covered by terraces. The results indicate that SLLAC maps exhibit a random aspect for natural surfaces. In contrast, terraced landscapes demonstrate a higher degree of order, and this behaviour is independent of the morphological context and terracing system. The outcomes of this work also prove that Spc values decrease as the area of terraced surfaces increases within the investigated region: the Spc for terraced areas is significantly different from the Spc of a natural landscape. In areas of smooth natural morphology, the Spc identifies terraced areas with a 20% minimum height range covered in terraces. In contrast, in areas of steep morphologies and vertical cliffs, the algorithm performs well when terraces cover at least 50% of the investigated surface. Given the increasing importance of terraced landscapes, the proposed procedure offers a significant and promising tool for the exploration of spatial heterogeneity in terraced sites.

  19. On the saturation of the refractive index structure function. II - Influence of the correlation length on astronomical 'seeing'

    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.

  20. Monitoring quantum transport: Backaction and measurement correlations

    NASA Astrophysics Data System (ADS)

    Hussein, Robert; Gómez-García, Jorge; Kohler, Sigmund

    2014-10-01

    We investigate a tunnel contact coupled to a double quantum dot (DQD) and employed as a charge monitor for the latter. We consider both the classical limit and the quantum regime. In the classical case, we derive measurement correlations from conditional probabilities, yielding quantitative statements about the parameter regime in which the detection scheme works well. Moreover, we demonstrate that not only the DQD occupation but also the corresponding current may strongly correlate with the detector current. The quantum-mechanical solution, obtained with a Bloch-Redfield master equation, shows that the backaction of the measurement tends to localize the DQD electrons, and thus significantly reduces the DQD current. Moreover, it provides the effective parameters of the classical treatment. It turns out that already the classical description is adequate for most operating regimes.

  1. FIBER LENGTH DISTRIBUTION MEASUREMENT FOR LONG GLASS AND CARBON FIBER REINFORCED INJECTION MOLDED THERMOPLASTICS

    SciTech Connect

    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.

  2. Correlates of implicit cognitive line length representation in two-dimensional space.

    PubMed

    Doty, Richard L; Koti, Ajay; O'Hara, Thomas A; Landy, Jeffrey; Shin, Christina; Silas, Jonathan

    2014-10-01

    Twenty-eight sex- and age-matched participants, half dextrals and half sinstrals, were instructed to move a pen-sized planometer three inches (7.6 cm) while blindfolded. Under separate trials, movements were made at four angles, towards and away from the body, and at two distances from the body (30 cm, 53 cm). Half were made with the right hand and half with the left hand. Line estimates increased in length across blocks of trials in a linear fashion and progressively overestimated the three-inch imagined criterion. Lines made moving towards the body were longer than those made moving away from the body, implying an egocentric frame of reference in making the estimates. Line estimates made at an oblique angle differed significantly from estimates made at other angles. No influences of sex, handedness, or the hand used in making the estimates were observed. The findings suggest that motoric estimates of line lengths made without visual cues-a unique measure of an implicit cognitive concept-are significantly altered by temporal and spatial factors, but not by sex or hemispheric laterality. PMID:25244556

  3. Young Children's Understandings of Length Measurement: Evaluating a Learning Trajectory

    ERIC Educational Resources Information Center

    Szilagyi, Janka; Clements, Douglas H.; Sarama, Julie

    2013-01-01

    This study investigated the development of length measurement ideas in students from prekindergarten through 2nd grade. The main purpose was to evaluate and elaborate the developmental progression, or levels of thinking, of a hypothesized learning trajectory for length measurement to ensure that the sequence of levels of thinking is consistent…

  4. A New Path Length Measure Based on GO for Gene Similarity with Evaluation using SGD Pathways

    Microsoft Academic Search

    Anurag Nagar; Hisham Al-mubaid

    2008-01-01

    We propose a new method for measuring the semantic similarity of genes based on path length between their annotation terms in the Gene Ontology. Our method applies an exponential transfer function to the average path length between two genes to compute their similarity. The non-linear measure ensures that the semantic similarity decreases with distance and proves to be quite competitive

  5. Photoluminescence-based measurements of the energy gap and diffusion length of Zn3P2

    E-print Network

    Kimball, Gregory

    Photoluminescence-based measurements of the energy gap and diffusion length of Zn3P2 Gregory M 2009; accepted 20 August 2009; published online 14 September 2009 The steady-state photoluminescence-resolved photoluminescence decay measurements, implying minority-carrier diffusion lengths of 7 m. © 2009 American Institute

  6. Investigation on series of length of coding and non-coding DNA sequences of bacteria using multifractal detrended cross-correlation analysis.

    PubMed

    Stan, Cristina; Cristescu, Monica Teodora; Luiza, Buimaga Iarinca; Cristescu, C P

    2013-03-21

    In the framework of multifractal detrended cross-correlation analysis, we investigate characteristics of series of length of coding and non-coding DNA sequences of some bacteria and archaea. We propose the use of a multifractal cross-correlation series that can be defined for any pair of equal lengths data sequences (or time series) and that can be characterized by the full set of parameters that are attributed to any time series. Comparison between characteristics of series of length of coding and non-coding DNA sequences and of their associated multifractal cross-correlation series for selected groups is used for the identification of class affiliation of certain bacteria and archaea. The analysis is carried out using the dependence of the generalized Hurst exponent on the size of fluctuations, the shape of the singularity spectra, the shape and relative disposition of the curves of the singular measures scaling exponent and the values of the associated parameters. Empirically, we demonstrate that the series of lengths of coding and non-coding sequences as well as the associated multifractal cross-correlation series can be approximated as universal multifractals. PMID:23313335

  7. 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.

  8. DCM: device correlated metrology for overlay measurements

    NASA Astrophysics Data System (ADS)

    Chen, Charlie; Huang, George K. C.; Pai, Yuan Chi; Wu, Jimmy C. H.; Cheng, Yu Wei; Hsu, Simon C. C.; Yu, Chun Chi; Amir, Nuriel; Choi, Dongsub; Itzkovich, Tal; Tarshish-Shapir, Inna; Tien, David C.; Huang, Eros; Kuo, Kelly T. L.; Kato, Takeshi; Inoue, Osamu; Kawada, Hiroki; Okagawa, Yutaka; Huang, Luis; Hsu, Matthew; Su, Amei

    2013-04-01

    One of the main issues with overlay error metrology accuracy is the bias between results based on overlay (OVL) targets and actual device overlay error. In this study, we introduce the concept of Device Correlated Metrology (DCM), which is a systematic approach to quantifying and overcoming the bias between target-based overlay results and device overlay issues. For systematically quantifying the bias components between target and device, we introduce a new hybrid target integrating an optical OVL target with a device mimicking CD-SEM (Critical Dimension - Scanning Electron Microscope) target. The hybrid OVL target is designed to accurately represent the process influence found on the real device. In the general case, the CD-SEM can measure the bias between target and device on the same layer at AEI (After Etch Inspection) for all layers, the OVL between layers at AEI for most cases and at ADI (After Develop Inspection) for limited cases such as DPL (Double Patterning Lithography). The results shown demonstrate that for the new process compatible hybrid targets the bias between target and device is small, of the order of CD-SEM measurement uncertainty. Direct OVL measurements by CD-SEM show excellent correlation with optical OVL measurements in certain conditions. This correlation helps verify the accuracy of the optical measurement results and is applicable for imaging based OVL metrology methods using AIM or AIMid OVL targets, and scatterometry-based overlay methods such as SCOL (Scatterometry OVL). Future plans include broadening the hybrid target design to better mimic each layer's process conditions such as pattern density. We are also designing hybrid targets for memory devices.

  9. Correlation between DNA restriction fragment length polymorphisms in Leptospira interrogans serovar pomona type kennewicki and host animal source.

    PubMed Central

    Bolin, C A; Zuerner, R L

    1996-01-01

    Isolates (n = 147) of Leptospira interrogans serovar pomona type kennewicki from cattle, swine, horses, and wildlife were analyzed by DNA restriction endonuclease analysis. Restriction fragment length polymorphisms were identified in DNA digested with HpaII, and the restriction fragment length polymorphisms were correlated with the host animal source of the isolates. These results will be useful in understanding the epidemiology of serovar pomona infections in livestock. PMID:8789028

  10. Correlation between CAG repeat length and clinical features in Machado-Joseph disease

    SciTech Connect

    Maciel, P.; Gaspar, C.; Silveira, I. [Montreal General Hospital Research Institute (Canada)] [and others

    1995-07-01

    Machado-Joseph disease (MJD) is associated with the expansion of a CAG trinucleotide repeat in a novel gene on 14q32.1. We confirmed the presence of this expansion in 156 MJD patients from 33 families of different geographic origins: 15 Portuguese Azorean, 2 Brazilian, and 16 North American of Portuguese Azorean descent. Normal chromosomes contain between 12 and 37 CAG repeats in the MJD gene, whereas MJD gene carriers have alleles within the expanded range of 62-84 CAG units. The distribution of expanded alleles and the gap between normal and expanded allele sizes is either inconsistent with a premutation hypothesis or most (if not all) of the alleles we studied descend from a common ancestor. There is a strong correlation between the expanded repeat size and the age at onset of the disease as well as the clinical presentation. There is mild instability of the CAG tract length with transmission of the expanded alleles; both increase and decrease in size between parents and progeny occur, with larger variations in male than in female transmissions. Together, these effects can partly explain the variability of age at onset and of phenotypic features in MJD; however, other modifying factors must exist. 37 refs., 6 figs.

  11. Hyperscaling relationship between the interfacial tension of liquids and their correlation length near the critical point.

    PubMed

    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

  12. Efficient entanglement length measurements for photonic cluster state sources

    E-print Network

    Ilai Schwarz; Terry Rudolph

    2012-02-27

    We present a procedure for confirming the generation of long strings of photons in an entangled (cluster) state that does not rely on complete state tomography and that works even at low collection efficiencies. The scheme has the added advantage of being passive - it does not require switching of optical elements to perform measurements in different bases for instance.

  13. Measurements of correlation-enhanced collision rates

    NASA Astrophysics Data System (ADS)

    Anderegg, F.; Dubin, D. H. E.; O'Neil, T. M.; Driscoll, C. F.

    2013-03-01

    We present the first detailed experimental measurements of the Salpeter collisional enhancement factor in correlated plasma. This factor is predicted to enhance the nuclear reaction rate in dense correlated plasmas such as in giant planet interiors, brown dwarfs and degenerate stars. Recent non-neutral plasma theory establishes that it also applies to the perpendicular-to-parallel collisions in magnetized plasmas. The enhancement is caused by plasma screening of the repulsive Coulomb potential between charges, allowing closer collisions for a given particle energy. The enhancement factor is large when the plasma correlation factor ? is larger than unity, scaling as g(?) ? e?. We perform measurements of collision rate in laser-cooled magnesium ion plasmas with density n ˜ 107cm-3 and temperature 2.5 × 10-6 < T < 1 eV, resulting in 0 < ? < 25. We observe that at high ? (i.e. low temperature), the collision rate is increased by a factor up to 109 over the uncorrelated theory prediction, consistent with the Salpeter enhancement.

  14. The Length Measurement in the Turkish Mathematics Curriculum: Its Potential to Contribute to Students' Learning

    ERIC Educational Resources Information Center

    Tan-Sisman, Gulcin; Aksu, Meral

    2012-01-01

    "Knowing and doing measurement" is a fundamental competency in real life since measuring attributes of objects in appropriate units and using measuring tools assist students to quantify and understand the world. For this reason, the study of measurement has a special place in every mathematics curriculum. Among the domains of measurement, length

  15. Focal length measurement based on the wavefront difference method by a Fizeau interferometer.

    PubMed

    Yang, Zhongming; Gao, Zhishan; Dou, Jiantai; Wang, Xinxing

    2014-09-01

    A method for measuring the focal length of the lens by a Fizeau interferometer is proposed. Based on the Gaussian imaging equation and the longitudinal displacements of the object point and image point, a precise formula for focal length calculation is deduced. The longitudinal displacement of the object points is determined by the wavefront difference method with a subnanometer resolution. An experimental system for focal length measurements is set up to verify the principle. The sources of uncertainty in measurement are discussed. Both the positive and negative lens experimental results indicate that the measurement accuracy is less than 0.16% under normal experimental environment. PMID:25321352

  16. Establishment of a Method to Measure Length of the Ulnar Nerve and Standardize F-wave Values in Clinically Normal Beagles

    PubMed Central

    HIRASAWA, Shun; SHIMIZU, Miki; MARUI, Yuumi; KISHIMOTO, Miori; OKUNO, Seiichi

    2014-01-01

    We designed a new method of measuring the length of the ulnar nerve and determining standard values for F-wave parameters of the ulnar nerve in clinically normal beagles. Nerve length must be precisely measured to determine F-wave latency and conduction velocity. The length of the forelimb has served as the length of the ulnar nerve for F-wave assessments, but report indicates that F-wave latency is proportional to the length of the pathway traveled by nerve impulses. Therefore, we measured the surface distance from a stimulus point to the spinous process of the first thoracic vertebra (nerve length 1) and the anterior horn of the scapula (nerve length 2) as landmarks through the olecranon and the shoulder blade acromion. The correlation coefficients between the shortest F-wave latency and the length of nerves 1, 2 or the forelimb were 0.61, 0.7 and 0.58. Nerve length 2 generated the highest value. Furthermore, the anterior horn of the scapula was easily palpated in any dog regardless of well-fed body. We concluded that nerve length 2 was optimal for measuring the length of the ulnar nerve. PMID:25649942

  17. Bunch Length and Impedance Measurements at SPEAR3

    SciTech Connect

    Corbett, W.J.; Cheng, W.X.; Fisher, A.S.; Huang, X.; /SLAC

    2011-11-02

    Streak camera measurements were made at SPEAR3 to characterize longitudinal coupling impedance. For the nominal optics, data was taken at three rf voltages and a single-bunch current range of 0-20mA. Both bunchcentroid phase shift and bunch lengthening were recorded to extract values for resistive and reactive impedance. An (R+L) and a Q=1 model were then back-substituted into the Haissinski equation and compared with raw profile data. In the short bunch (low-{alpha}) mode, distribution 'bursting' was observed.

  18. Subpicometer Length Measurement Using Semiconductor Laser Tracking Frequency Gauge

    NASA Technical Reports Server (NTRS)

    Thapa, Rajesh; Phillips, James D.; Rocco, Emanuele; Reasenburg, Robert D.

    2011-01-01

    We have demonstrated heretofore unattained distance precision of 0:14pm (2pm) incremental and 14nm (2.9 micrometers) absolute in a resonant (nonresonant) interferometer at an averaging time of 1 s, using inexpensive telecommunications diode lasers. We have controlled the main source of error, that due to spurious reflection and the resulting amplitude modulation. In the resonant interferometer, absolute distance precision is well under lambda/6. Therefore, after an interruption, an absolute distance measurement can be used to return to the same interferometer order.

  19. A tool for measuring the bending length in thin wires

    NASA Astrophysics Data System (ADS)

    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.

  20. Measuring system for cable length and diameter based on photoelectric technology

    NASA Astrophysics Data System (ADS)

    Zhu, WeiMin; Zhou, Zhou; Wei, Ping; Qi, Fang

    2012-10-01

    Precise online measurement of cable diameter and length will ensure stability of quality production and production speed. This paper describes a measuring device to measure cable length and diameter simultaneously, accomplish online production process control. The device consists mainly of a synchronous sampling part, calculation and control part. The synchronous sampling part consists of two parallel rollers one meter far from each other. A measuring band cinctures the rollers and move together with them. There are two electromagnetic chucks on the measuring band which are controlled by two photoelectric position switches to hold or release a cable, in order to make the cable move with measuring system synchronously. An optical encoder is connected to one of the rollers coaxially to measure cable length. For cable diameter measurement, two orthogonal CCD sensors are used. Accuracy of online diameter measurement is mainly affected by vibration of cable movement. In order to reduce the cable diameter measurement error caused by vibration, measuring system uses a mechanical damping device and high-speed CCD sensors which exposure time is up to microseconds. The calculation and control part of measuring device can filter, amplify and binarizate electrical signals from synchronous sampling part, then they are processed by microcontroller 8051 to complete cable length and diameter measurement. As well, the measuring device can set error limits and detect online whether cable length and diameter size are in default range , if not it would give corresponding alarm.

  1. Exciton diffusion lengths of organic semiconductor thin films measured by spectrally resolved photoluminescence quenching

    NASA Astrophysics Data System (ADS)

    Lunt, Richard R.; Giebink, Noel C.; Belak, Anna A.; Benziger, Jay B.; Forrest, Stephen R.

    2009-03-01

    We demonstrate spectrally resolved photoluminescence quenching as a means to determine the exciton diffusion length of several archetype organic semiconductors used in thin film devices. We show that aggregation and crystal orientation influence the anisotropy of the diffusion length for vacuum-deposited polycrystalline films. The measurement of the singlet diffusion lengths is found to be in agreement with diffusion by Förster transfer, whereas triplet diffusion occurs primarily via Dexter transfer.

  2. 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.

  3. High Avidity Antibodies to Full-Length VAR2CSA Correlate with Absence of Placental Malaria

    PubMed Central

    Tutterrow, Yeung Lo; Salanti, Ali; Avril, Marion; Smith, Joseph D.; Pagano, Ian S.; Ako, Simon; Fogako, Josephine; Leke, Rose G. F.; Taylor, Diane Wallace

    2012-01-01

    VAR2CSA mediates sequestration of Plasmodium falciparum-infected erythrocytes in the placenta, increasing the risk of poor pregnancy outcomes. Naturally acquired antibodies (Ab) to placental parasites at delivery have been associated with improved pregnancy outcomes, but Ab levels and how early in pregnancy Ab must be present in order to eliminate placental parasites before delivery remains unknown. Antibodies to individual Duffy-binding like domains of VAR2CSA have been studied, but the domains lack many of the conformational epitopes present in full-length VAR2CSA (FV2). Thus, the purpose of this study was to describe the acquisition of Ab to FV2 in women residing in high and low transmission areas and determine how Ab levels during pregnancy correlate with clearance of placental parasites. Plasma samples collected monthly throughout pregnancy from pregnant women living in high and low transmission areas in Cameroon were evaluated for Ab to FV2 and the proportion of high avidity Ab (i.e., Ab that remain bound in the presence of 3M NH4SCN) was assessed. Ab levels and proportion of high avidity Ab were compared between women with placental malaria (PM+) and those without (PM?) at delivery. Results showed that PM? women had significantly higher Ab levels (p?=?0.0047) and proportion of high avidity Ab (p?=?0.0009) than PM+ women throughout pregnancy. Specifically, women with moderate to high Ab levels (>5,000 MFI) and those with ?35% high avidity Ab at 5–6 months were found to have 2.3 (95% CI, 1.0–4.9) and 7.6-fold (p?=?0.0013, 95% CI: 1.2–50.0) reduced risk of placental malaria, respectively. These data show that high levels of Ab to FV2, particularly those with high avidity for FV2, produced by mid-pregnancy are important in clearing parasites from the placenta. Both high Ab levels and proportion of high avidity Ab to FV2 may serve as correlates of protection for assessing immunity against placental malaria. PMID:22761948

  4. Probing macroscopic realism via Ramsey correlation measurements.

    PubMed

    Asadian, A; Brukner, C; Rabl, P

    2014-05-16

    We describe a new and experimentally feasible protocol for performing fundamental tests of quantum mechanics with massive objects. In our approach, a single two-level system is used to probe the motion of a nanomechanical resonator via multiple Ramsey interference measurements. This scheme enables the measurement of modular variables of macroscopic continuous-variable systems; we show that correlations thereof violate a Leggett-Garg inequality and can be applied for tests of quantum contextuality. Our method can be implemented with a variety of different solid-state or photonic qubit-resonator systems, and it provides a clear experimental signature to distinguish the predictions of quantum mechanics from those of other alternative theories at a macroscopic scale. PMID:24877918

  5. Probing Macroscopic Realism via Ramsey Correlation Measurements

    NASA Astrophysics Data System (ADS)

    Asadian, A.; Brukner, C.; Rabl, P.

    2014-05-01

    We describe a new and experimentally feasible protocol for performing fundamental tests of quantum mechanics with massive objects. In our approach, a single two-level system is used to probe the motion of a nanomechanical resonator via multiple Ramsey interference measurements. This scheme enables the measurement of modular variables of macroscopic continuous-variable systems; we show that correlations thereof violate a Leggett-Garg inequality and can be applied for tests of quantum contextuality. Our method can be implemented with a variety of different solid-state or photonic qubit-resonator systems, and it provides a clear experimental signature to distinguish the predictions of quantum mechanics from those of other alternative theories at a macroscopic scale.

  6. A precise measurement of the spin-dependent neutron scattering length of 3 He

    Microsoft Academic Search

    O. Zimmer; G. Ehlers; B. Farago; H. Humblot; W. Ketter; R. Scherm

    2002-01-01

    The poor knowledge of the spin-dependent neutron scattering length of 3He has until now handicapped nuclear four body theory and the interpretation of excitations in the quantum liquid. We have measured, for the first time directly, the real part of the bound incoherent neutron scattering length, bi' of 3He. A neutron spin echo spectrometer was used to detect pseudomagnetic precession

  7. 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.

  8. 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...

  9. Measure of top-down correlation

    SciTech Connect

    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.

  10. Maternal and ambient environmental effects of light on germination in Plantago lanceolata: correlated responses to selection on leaf length

    Microsoft Academic Search

    A. Van Hinsberg

    1998-01-01

    1. Seeds from artificial selection lines were exposed to different maternal and ambient conditions, simulating sunlight and vegetation shade. 2. Lines selected for longer leaves also produced larger seeds, indicating a positive genetic correlation between leaf length and seed size. 3. Light conditions during maturation had no large effect on seed size. 4. Seed germination was reduced by a low

  11. Estimation of path length factor for measurement of haemoglobin concentration in the exposed cortical tissue

    NASA Astrophysics Data System (ADS)

    Sakaguchi, K.; Tachibana, T.; Yokoyama, K.; Furukawa, S.; Katsura, T.; Maki, A.; Kawaguchi, H.; Okada, E.

    2005-08-01

    The change in oxy- and deoxy haemoglobin in the cortical tissue caused by brain function can be measured from multi-spectral images of exposed cortex. We cannot ignore the wavelength dependence of mean optical path length of detected light to calculate the accurate changes in concentrations of oxy- and deoxy- haemoglobin in the cortical tissue. The optical path length factor, which reflects the wavelength dependence of mean optical path length, is experimentally estimated from the multi-spectral images of exposed cortex of guinea pigs. The optical path length factor improves the accuracy in changes in concentrations of oxy- and deoxy-haemoglobin obtained from the multi-spectral images.

  12. Modeling the Length Effect: Specifying the Relation with Visual and Phonological Correlates of Reading

    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…

  13. High resolution sound velocity measurement in liquid3He using path length modulation technique

    Microsoft Academic Search

    Y. Lee; P. J. Hamot; D. T. Sprague; T. M. Haard; J. B. Kycia; M. R. Rand; W. P. Halperin

    1996-01-01

    Employing path length modulation technique, we are able to make high resolution sound velocity measurements (≈ 10 ppm) with a relatively short path length. We present new values of F {2\\/3} calculated from zeroand first-sound velocity measurements at 12.6 MHz in liquid3He over the pressure range of 0.6 to 14 bar. We also report a newly observed behavior in high

  14. High resolution sound velocity measurement in liquid 3 He using path length modulation technique

    Microsoft Academic Search

    Y. Lee; P. J. Hamot; D. T. Sprague; T. M. Haard; J. B. Kycia; M. R. Rand; W. P. Halperin

    1996-01-01

    Employing path length modulation technique, we are able to make high resolution sound velocity measurements (? 10 ppm) with\\u000a a relatively short path length. We present new values ofF\\u000a 23 calculated from zeroand first-sound velocity measurements at 12.6 MHz in liquid3He over the pressure range of 0.6 to 14 bar. We also report a newly observed behavior in high frequency

  15. Distributed fiber beat length, birefringence and differential group delay measurement using BOTDA technique

    NASA Astrophysics Data System (ADS)

    Xie, Shangran; Bao, Xiaoyi; Chen, Liang

    2011-05-01

    A novel method for distributed fiber beat length, birefringence and differential group delay (DGD) measurement based on Brillouin optical time domain analysis (BOTDA) technique is proposed. The difference of local maximum and minimum Brillouin gain is determined by scanning input state of polarization (SOP) of pulsed probe wave to recover local beat length. The average beat length, birefringence and DGD measured on 100m SMF28 at 1550nm wavelength with 1m spatial resolution is 11.8m, 1.4×10-7 and 0.21ps respectively.

  16. Phase correlation processing for DPIV measurements

    Microsoft Academic Search

    Adric C. Eckstein; John Charonko; Pavlos Vlachos

    2008-01-01

    A novel digital particle image velocimetry (DPIV) correlation method is presented, the Gaussian transformed phase correlation\\u000a (GTPC) estimator, using nonlinear filtering techniques coupled with the phase-transform (PHAT) generalized cross-correlation\\u000a filter. The use of spatial windowing is shown to be ideally suited for the use of phase correlation estimators, due to their\\u000a invariance to the loss of correlation effects. Error analysis

  17. Polarization gating enables sarcomere length measurements by laser diffraction in fibrotic muscle

    NASA Astrophysics Data System (ADS)

    Young, Kevin W.; Dayanidhi, Sudarshan; Lieber, Richard L.

    2014-11-01

    Sarcomere length is a key parameter commonly measured in muscle physiology since it dictates striated muscle active force. Laser diffraction (LD)-based measurements of sarcomere length are time-efficient and sample a greater number of sarcomeres compared with traditional microscopy-based techniques. However, a limitation to LD techniques is that signal quality is severely degraded by scattering events as photons propagate through tissue. Consequently, sarcomere length measurements are unattainable when the number of scattering events is sufficiently large in muscle tissue with a high scattering probability. This occurs in fibrotic skeletal muscle seen in muscular dystrophies and secondary to tissue trauma, thus eliminating the use of LD to study these skeletal muscle ailments. Here, we utilize polarization gating to extract diffracted signals that are buried in noise created by scattering. Importantly, we demonstrate that polarization-gated laser diffraction (PGLD) enables sarcomere length measurements in muscles from chronically immobilized mice hind limbs; these muscles have a substantial increase of intramuscular connective tissue that scatter light and disable sarcomere length measurements by traditional LD. Further, we compare PGLD sarcomere lengths to those measured by bright field (BF) and confocal microscopy as positive controls and reveal a significant bias of BF but not of confocal microscopy.

  18. Correlation between the lengths of the upper limb and cubital tunnel: potential use in patients with proximal ulnar nerve entrapment

    Microsoft Academic Search

    R. Shane Tubbs; Marios Loukas; Nihal Apaydin; Tiffany D. Cossey; Bulent Yalçin; Mohammadali M. Shoja; Aaron A. Cohen-Gadol

    2010-01-01

    Introduction  We hypothesized that a correlation may exist between the length of the upper limb and the length of the cubital tunnel, which\\u000a transmits the ulnar nerve from the arm to the forearm. If true, this association might aid in predicting individuals at greater\\u000a risk of developing ulnar nerve compression at this site.\\u000a \\u000a \\u000a \\u000a \\u000a Materials and methods  A total of 46 cadaveric upper

  19. Exploring the spatial heterogeneity of terraced landscapes using LiDAR: the Slope Local Length of Auto-Correlation (SLLAC).

    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.

  20. The importance of parameter variances, correlations lengths, and cross-correlations in reactive transport models: key considerations for assessing the need for microscale information

    SciTech Connect

    Reimus, Paul W [Los Alamos National Laboratory

    2010-12-08

    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. lf 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.

  1. Reference ranges of fetal cisterna magna length and area measurements by 3-dimensional ultrasonography using the multiplanar mode.

    PubMed

    Passos, Ana Paula; Araujo Júnior, Edward; Bruns, Rafael Frederico; Nardozza, Luciano Marcondes Machado; Moron, Antonio Fernandes

    2015-02-01

    This study aimed to establish reference values for the length and area of the fetal cisterna magna using the multiplanar mode of 3-dimensional ultrasonography. A cross-sectional study including 224 normal pregnant women between 17 weeks 0 days and 29 weeks 6 days of gestation was carried out. The area and length of the fetal cisterna magna were measured in the axial plane at the level of the cerebellar transverse diameter. Reliability was determined by intraclass correlation coefficient. The mean length and area of the fetal cisterna magna ranged from 0.50 ± 0.10 to 0.79 ± 0.18 cm and 0.95 ± 0.18 to 3.09 ± 0.62 cm(2), respectively. Intraobserver reliability for the length and area (intraclass coefficients: 0.86 and 0.91, respectively) and interobserver reliability (intraclass coefficients: 0.64 and 0.82, respectively) were good. Three-dimensional ultrasonography using the multiplanar mode is a reliable method for the determination of reference values for the length and area of the fetal cisterna magna. PMID:24846899

  2. Length dependent thermal conductivity measurements yield phonon mean free path spectra in nanostructures.

    PubMed

    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

  3. Length Dependent Thermal Conductivity Measurements Yield Phonon Mean Free Path Spectra in Nanostructures

    PubMed Central

    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

  4. Length Dependent Thermal Conductivity Measurements Yield Phonon Mean Free Path Spectra in Nanostructures

    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.

  5. Length measurement of the eye using a swept-source interferometer.

    PubMed

    Al-Mohamedi, Haroun; Prinz, Andreas; Mieskes, Guido; Oltrup, Theo; Bende, Thomas

    2014-02-01

    In this article, a swept-source setup based on a semiconductor optical amplifier at the central wavelength of 1050 nm for measurements of the axial length inside the eye is presented. The large coherence length is achieved using a tunable optical filter, consisting of a reflective diffraction grating, two Littrow prisms, and a scanner. It was possible to achieve a coherence length of 40 mm, which allowed interference measurements in this range to be made. Measurements of the biomedical data of a human model eye are presented. To realize faster measurements, the data acquisition must be increased to more than 2 MS/s. In further studies, the usage of a field-programmable gate array, to achieve faster measurements, will be considered. PMID:24096435

  6. Tyre contact length on dry and wet road surfaces measured by three-axial accelerometer

    NASA Astrophysics Data System (ADS)

    Matilainen, Mika; Tuononen, Ari

    2015-02-01

    We determined the tyre contact length on dry and wet roads by measuring the accelerations of the inner liner with a three-axial accelerometer. The influence of the tyre pressure, driving velocity, and tread depth on the contact length was studied in both types of road surface conditions. On dry asphalt the contact length was almost constant, regardless of the driving velocity. On wet asphalt the presence of water could be detected even at low driving velocities (e.g. 20 km/h for a worn tyre) as the contact length began to decrease from that found in the dry asphalt situation. In addition to improving the performance of active safety systems and driver warning systems, the contact length information could be beneficial for classifying and studying the aquaplaning behaviour of tyres.

  7. Calibration for the errors resulted from aberration in long focal length measurement

    NASA Astrophysics Data System (ADS)

    Yao, Jiang; Luo, Jia; He, Fan; Bai, Jian; Wang, Kaiwei; Hou, Xiyun; Hou, Changlun

    2014-09-01

    In this paper, a high-accuracy calibration method for errors resulted from aberration in long focal length measurement, is presented. Generally, Gaussian Equation is used for calculation without consideration of the errors caused by aberration. However, the errors are the key factor affecting the accuracy in the measurement system of a large aperture and long focal length lens. We creatively introduce an effective way to calibrate the errors, with detailed analysis of the long focal length measurement based on divergent light and Talbot interferometry. Aberration errors are simulated by Zemax. Then, we achieve auto-correction with the help of Visual C++ software and the experimental results reveal that the relative accuracy is better than 0.01%.By comparing modified values with experimental results obtained in knife-edge testing measurement, the proposed method is proved to be highly effective and reliable.

  8. Toward subnanometer uncertainty in interferometric length measurements of short gauge blocks.

    PubMed

    Malinovsky, I; Titov, A; Dutra, J A; Belaïdi, H; França, R dos S; Massone, C A

    1999-01-01

    A primary-level comparator, with a reproducibility of 0.2 nm and intended for realization of a Systeme International length unit in the range of 1-100 mm, is reported. High-precision differential measurements of phase change on reflection from blocks and end plates are demonstrated. A set of experiments has been developed to measure systematic error associated with nonideal interferometer optics and deviations from flatness of an auxiliary plate. For specially selected high-grade 6-mm blocks, reproducible wringing has been achieved with a random uncertainty in length measurements of 0.1-0.2 nm. Subnanometer wear-off of the blocks as a result of the cleaning has been detected. Under the conditions of reproducible wringing, the accuracy of the length measurements is evaluated to be in the 2-3-nm range for 6-mm blocks. PMID:18305592

  9. Correlation of admitted nursing home residents’ hospital length of stay and vitamin D levels

    PubMed Central

    Mc Williams, Carla; Golestany, Kourosh; Sharma, Rohit; Nejati, Golali; Cyrus-Murden, Anna; Kripichnikov, Dmitri

    2011-01-01

    Objective To determine the relationship between low vitamin D levels and hospital length of stay in nursing home residents who were admitted to acute medical floors in an urban community teaching hospital. Methods This prospective cohort study used multiple regression analysis for patients transferred from nursing homes to the hospital. On admission, patients’ serum 25(OH)D levels were obtained by blood draw using partially purified lipid extracts via a competitive protein binding assay. We defined low levels of serum 25(OH)D as <30 ng/ml. Patient medical histories were compiled by retrospective chart review and/or patient interview. Medical histories were analyzed with special emphasis on history of falls, osteoporosis, comorbidities, medication profile, and hospital length of stay. Results The mean serum 25(OH)D level for 71 patients (N = 71) was 22.69 ng/ml (±SD 10.967); the median, 23 ng/ml. Low serum concentrations of 25(OH)D were recorded in 51 patients (72%) all of whom had a longer mean hospital length of stay (13.72 days ± SD 10.778) than the 20 patients with higher vitamin D levels (7.72 days ± SD 4.070). Conclusion Low vitamin D levels in nursing home residents admitted to a community hospital were directly associated with increased hospital length of stay. PMID:23882336

  10. Eddy correlation measurements in wet environmental conditions

    NASA Astrophysics Data System (ADS)

    Cuenca, R. H.; Migliori, L.; O Kane, J. P.

    2003-04-01

    The lower Feale catchment is a low-lying peaty area of 200 km^2 situated in southwest Ireland that is subject to inundation by flooding. The catchment lies adjacent to the Feale River and is subject to tidal signals as well as runoff processes. Various mitigation strategies are being investigated to reduce the damage due to flooding. Part of the effort has required development of a detailed hydrologic balance for the study area which is a wet pasture environment with local field drains that are typically flooded. An eddy correlation system was installed in the summer of 2002 to measure components of the energy balance, including evapotranspiration, along with special sensors to measure other hydrologic variables particular to this study. Data collected will be essential for validation of surface flux models to be developed for this site. Data filtering is performed using a combination of software developed by the Boundary-Layer Group (BLG) at Oregon State University together with modifications made to this system for conditions at this site. This automated procedure greatly reduces the tedious inspection of individual records. The package of tests, developed by the BLG for both tower and aircraft high frequency data, checks for electronic spiking, signal dropout, unrealistic magnitudes, extreme higher moment statistics, as well as other error scenarios not covered by the instrumentation diagnostics built into the system. Critical parameter values for each potential error were developed by applying the tests to real fast response turbulent time series. Potential instrumentation problems, flux sampling problems, and unusual physical situations records are flagged for removal or further analysis. A final visual inspection step is required to minimize rejection of physically unusual but real behavior in the time series. The problems of data management, data quality control, individual instrumentation sensitivity, potential underestimation of latent and sensible heat and possible sources of energy balance closure errors for this wet environment and micrometeorological conditions are discussed.

  11. Validation of Three Instructional Modes With Conservers and Nonconservers of Length Using Linear Metric Measurement.

    ERIC Educational Resources Information Center

    Smith, Susan R.; And Others

    This study attempted to gather empirical evidence to guide educators in their teaching of linear measurement to primary school children. It attempted to answer the question "What modes of instruction are most effective for teaching linear measurement concepts to conservers and nonconservers of length?" (as defined by Jean Piaget), using a…

  12. 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…

  13. Single-Molecule Measurements of the Persistence Length of Double-Stranded RNA

    E-print Network

    Dekker, Nynke

    RNA using two different single-molecule techniques: magnetic tweezers and atomic force microscopy. We deduce single- molecule techniques, magnetic tweezers and atomic force microscopy (AFM), to measure itsSingle-Molecule Measurements of the Persistence Length of Double-Stranded RNA J. A. Abels, F

  14. Measurement of air refractive index fluctuation based on interferometry with two different reference cavity lengths.

    PubMed

    Chen, Qianghua; Luo, Huifu; Wang, Sumei; Wang, Feng; Chen, Xinhua

    2012-09-01

    A measurement method based on interferometry with two different reference cavity lengths is presented and applied in air refractive index measurement in which the two cavity lengths and a laser wavelength are combined to generate two wavelength equivalents of cavity. Corresponding calculation equations are derived, and the optical path configuration is designed, which is inspired by the traditional synthetic wavelength method. Theoretical analyses indicate that the measurement uncertainty of the determined index of refraction is about 2.3×10(-8), which is mainly affected by the length precision of the long vacuum cavity and the ellipticity of polarization components of the dual-frequency laser, and the range of nonambiguity is 3.0×10(-5), which is decided by the length difference of the two cavities. Experiment results show that the accuracy of air refractive index measurement is better than 5.0×10(-8) when the laboratory conditions changes slowly. The merit of the presented method is that the classical refractometry can be also used without evacuation of the gas cavity during the experiment. Furthermore, the application of the traditional synthetic wavelength method may be extended by using the wavelength equivalents of cavity, any value of which can be easily acquired by changing cavity length rather than using actual wavelengths whose number is limited. PMID:22945157

  15. Comparison of standardized clinical evaluation of wounds using ruler length by width and Scout length by width measure and Scout perimeter trace.

    PubMed

    Langemo, Diane; Spahn, James; Spahn, Thomas; Pinnamaneni, V Chowdry

    2015-03-01

    The study objective was to examine precision in wound measurement using a recently Food and Drug Administration-approved Scout (WoundVision, LLC, Indianapolis, Indiana) device to measure wound length (L) and width (W). Wound perimeter and a ruler measurement of L and W were also made. Images of 40 actual patient wounds were measured using the Scout device. All 3 techniques (length, width, perimeter) demonstrated acceptable within and between reader precision; however, the best precision was in wound perimeter measurement. PMID:25679463

  16. Fabrication of CNT-Dispersed CFRP Using Length-Controlled CNTs: Measurement of CNT Length and Characterization of Mechanical Properties

    Microsoft Academic Search

    Tomohiro Yokozeki; Takahira Aoki; Akiko Arai; Masaru Ishibashi; Takashi Yanagisawa

    2009-01-01

    The incorporation of carbon nanotubes (CNTs) into polymers is expected to improve the physical properties of polymers and fiber-reinforced plastics. Moldability of CNT-dispersed polymers is the key technology for the successful improvement of properties. As CNT length has great impact on the moldability (e.g., viscosity) as well as physical performance of nanocomposites, length control of CNT by milling process is

  17. First working group meeting on the minority carrier diffusion length/lifetime measurement: Results of the round robin lifetime/diffusion length tests

    SciTech Connect

    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.

  18. Bunch Length Measurements at the JLab FEL Using Coherent Transition and Synchrotron Radiation

    SciTech Connect

    Pavel Evtushenko; James Coleman; Kevin Jordan; J. Michael Klopf; George Neil; Gwyn Williams

    2006-05-01

    The JLab FEL is routinely operated with sub-picosecond bunches. The short bunch length is important for high gain of the FEL. Coherent transition radiation has been used for the bunch length measurements for many years [1]. This diagnostic can be used only in the pulsed beam mode. It is our goal to run the FEL with CW beam and a 74.85 MHz micropulse repetition rate, which, with the 135 pC nominal bunch charge corresponds to the beam average current of 10 mA. Hence it is very desirable to have the possibility of making bunch length measurements when running CW beam with any micropulse frequency. We use a Fourier transform infrared (FTIR) interferometer, which is essentially a Michelson interferometer, to measure the spectrum of the coherent synchrotron radiation generated in the last dipole of the magnetic bunch compressor upstream of the FEL wiggler. This noninvasive diagnostic provides bunch length measurements for CW beam operation at any micropulse frequency. We also compare the measurements made with the help of the FTIR interferometer with data obtained using the Martin-Puplett interferometer [1]. Results of the two diagnostics agree within 15 %. Here we present a description of the experimental setup, data evaluation procedure and results of the beam measurements.

  19. Longitudinal-to-Transverse Mapping for Femtosecond Electron Bunch Length Measurement

    SciTech Connect

    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.

  20. Interpretation of scanning electron microscope measurements of minority carrier diffusion lengths in semiconductors

    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.

  1. 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.

  2. 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.

  3. Improving surface measurement by adaptive focal length adjustment and approximation networks

    NASA Astrophysics Data System (ADS)

    Apolinar Muñoz Rodríguez, J.

    2013-06-01

    A three-dimensional model to perform measurements of variable range is presented. This model is performed by a Bezier network via projection of a laser line and an adaptive focal length. The variation of the measurement range is provided by the adjustment of the camera placement and the focal length. The modifications of these parameters are determined by image processing of the laser line during the vision task. The initial calibration of the vision parameters is deduced by means of the variation of focal length. The technique is applied to retrieve the contour of complex shapes by means of the adjustment of the measurement range. This technique avoids external re-calibration to compute the surface depth when the measurement range is adjusted. Therefore, the accuracy of the surface measurement is improved. It is because the errors of re-calibration are not added to the system during the measurement process. The change of the measurement range is achieved in fractions of a second. The contribution of this technique is stated by an evaluation based on the lighting methods that perform measurements of variable range. Also, the time to obtain measurements of variable range is described in the evaluation.

  4. Connection between measurement disturbance relation and multipartite quantum correlation

    NASA Astrophysics Data System (ADS)

    Li, Jun-Li; Du, Kun; Qiao, Cong-Feng

    2015-01-01

    It is found that the measurement disturbance relation (MDR) determines the strength of quantum correlation and hence is one of the essential facets of the nature of quantum nonlocality. In reverse, the exact form of MDR may be ascertained through measuring the correlation function. To this aim, an optical experimental scheme is proposed. Moreover, by virtue of the correlation function, we find that the quantum entanglement, the quantum nonlocality, and the uncertainty principle can be explicitly correlated.

  5. Improvement in the measurement of focal length using spot patterns and spherical aberration.

    PubMed

    Mejía, Yobani

    2013-08-10

    Using an optical setup that includes a square array of 3×3 holes, we used nine meridional rays to measure the effective focal length of a lens. We observed the selected meridional rays as a spot pattern on a diffuse screen. First, we generated a regular square spot pattern (reference pattern) without a lens to test, and then we generated two spot patterns in two different axial positions when the lens being tested refracts the rays. By selecting two sets of four rays of each spot pattern, we were able to measure the difference of the longitudinal (primary) spherical aberration in two positions. With this difference we were able to improve the calculation of the effective focal length. To determine the method's precision, we first simulated the relative error in the effective focal length considering the error in the measurement of the ray heights. Then we determined the experimental relative error by means of the standard deviation of the focal lengths obtained for each spot (in the image of reference and for the images at the two different locations) for both sets of four spots. The experimental results agree very well with the simulation. The error analysis allows us to establish under what conditions it is possible to obtain relative errors of less than 1% in the effective focal length. PMID:23938404

  6. Fish Total Length Measurement Error from Recreational Anglers: Causes and Contribution to Noncompliance for the Mille Lacs Walleye Fishery

    Microsoft Academic Search

    Kevin S. Page; Gerold C. Grant; Paul Radomski; Thomas S. Jones; Richard E. Bruesewitz

    2004-01-01

    To estimate angler noncompliance with size limits due to measurement error by anglers, we used estimates of measurement error derived from (1) lengths of walleye Sander vitreus tagged and measured by biologists subsequently caught and voluntarily measured by anglers and (2) from dead walleyes of known length that anglers voluntarily measured during interviews at lake access sites. We also investigated

  7. Path-length measurement performance evaluation of polarizing laser interferometer prototype

    NASA Astrophysics Data System (ADS)

    Li, Yu-qiong; Luo, Zi-ren; Liu, He-shan; Dong, Yu-hui; Jin, Gang

    2015-02-01

    The space laser interferometer has been considered the most promising means for detecting gravitational waves and improving the accuracy and spatial resolution of the Earth's gravity model. An on-ground polarizing laser interferometer prototype equipped with one reference interferometer and two measurement interferometers having equal-length arms is presented in the paper. The laser interferometer prototype is designed as the demonstration of a Chinese space laser interferometer antenna in the future, of which the path-length measurement performance evaluation and preliminary noise analysis are investigated here. The results show that the path-length measurement sensitivity is better than 200 pm/Hz½ in the frequency band of 10 mHz-1 Hz, and the sensitivity of measuring the motion of a sinusoidally driven testmass is better than 100 pm within the frequency regime of 1 mHz-1 Hz. In this way, laboratory activities have demonstrated the feasibility of this prototype to measure tiny path-length fluctuations of the simulated testmass. As a next step, adopting an integrated design of optics and optical substrate to enhance the stability of the laser interferometer is being planned, and other key techniques included in the space laser interferometer such as laser pointing modulation and laser phase-locking control are to be implanted into this prototype are under consideration.

  8. Correlation length of vorticity in the near wall region of a high Reynolds number boundary layer

    Microsoft Academic Search

    Scott C. Morris; John Foss; Matthew Maher

    2002-01-01

    Time series of the spanwise and wall normal components of vorticity were measured in the near wall region of an atmospheric boundary layer. The measurements were acquired at the SLTEST site located in western Utah during a period of neutral thermal stability. The surface was nearly flat, free of vegetation, with a small scale roughness of approximately 2mm. The measurements

  9. Lifetime and diffusion length measurements on silicon material and solar cells

    NASA Technical Reports Server (NTRS)

    Othmer, S.; Chen, S. C.

    1978-01-01

    Experimental methods were evaluated for the determination of lifetime and diffusion length in silicon intentionally doped with potentially lifetime-degrading impurities found in metallurgical grade silicon, impurities which may be residual in low-cost silicon intended for use in terrestrial flat-plate arrays. Lifetime measurements were made using a steady-state photoconductivity method. Diffusion length determinations were made using short-circuit current measurements under penetrating illumination. Mutual consistency among all experimental methods was verified, but steady-state photoconductivity was found preferable to photoconductivity decay at short lifetimes and in the presence of traps. The effects of a number of impurities on lifetime in bulk material, and on diffusion length in cells fabricated from this material, were determined. Results are compared with those obtained using different techniques. General agreement was found in terms of the hierarchy of impurities which degrade the lifetime.

  10. Traceability transfer in high accuracy contact temperature measurements for length interferometry

    NASA Astrophysics Data System (ADS)

    Costa, P. A.; Bessa, M. S.; Schutz, J. S.; Azeredo, C. L. S.; França, R. S.; Quelhas, K. N.; Malinovski, I.

    2015-01-01

    Some relevant components of uncertainty in interferometric measurements are associated with temperature measurements of material standards. This paper proposes a traceability transfer chain through a high accuracy contact temperature measurement system towards other temperature measurements systems. Those are traced to the best national metrological references in appropriate configurations for gauge-block length calibrations, allowing in that way investigations of effects and uncertainty components linked to temperature measurement of those blocks as further reductions in these uncertainties. As an application example a study of temperature gradients on gauge blocks is shown

  11. Correlating DSC and X-Ray Measurements Of Crystallinity

    NASA Technical Reports Server (NTRS)

    Yen, Shiao-Ping S.; Lowry, Lynn E.; Bankston, Clyde P.

    1991-01-01

    Experiment demonstrated approximate linear correlation between degree of crystallinity of multiphase polymer (as calculated from x-ray diffraction measurements) and heat of fusion of polymer (as calculated from differential scanning calorimetry (DSC) measurements). Correlation basis of simple new technique for estimating degree of crystallinity of specimens of polymer from DSC measurements alone.

  12. Direct Comparison of Flow-FISH and qPCR as Diagnostic Tests for Telomere Length Measurement in Humans

    PubMed Central

    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

  13. Morphological features and length measurements of fetal lateral ventricles at 16-25 weeks of gestation by magnetic resonance imaging.

    PubMed

    Taketani, Kaori; Yamada, Shigehito; Uwabe, Chigako; Okada, Tomohisa; Togashi, Kaori; Takakuwa, Tetsuya

    2014-07-24

    Normal growth of the lateral ventricles (LVs) was characterized three-dimensionally using magnetic resonance imaging (MRI) data from 16 human fetuses at 16-25 weeks of gestation. The LV was differentiated into 4 primary regions, the anterior horn, central parts, posterior horn, and inferior horn, at 16 weeks of gestation. The LV changed shape mainly by elongation and narrowing, which correspond to the external and internal growth of the surrounding cerebrum. Six length parameters measured in the LV correlated with biparietal diameter by simple regression analysis (R(2) range, 0.56-0.93), which may be valuable for establishing a standardized prenatal protocol to assess fetal well-being and development across intrauterine periods. No correlation was found between biparietal diameter and LV volume (R(2) =0.13). PMID:25059317

  14. Silver ion dynamics in mixed network former glasses: Evidence of correlation with characteristic lengths and network structure

    NASA Astrophysics Data System (ADS)

    Kabi, S.; Ghosh, A.

    2012-10-01

    We have presented conductivity spectra at different temperatures for mixed network former silver borophosphate glasses. By mapping the conductivity spectra onto time dependence of the mean square displacement of mobile ions in the framework of linear response theory, we have obtained two characteristic lengths of ion dynamics viz characteristic mean square displacement at which crossover from diffusive to subdiffusive ion dynamics and spatial extent of localized motion of mobile silver ions occur. We have shown that the mixed network effect in these glasses is correlated to these characteristic lengths which are strongly influenced by the Coulomb repulsion between the mobile silver ions as well as the interaction between the mobile ions and the glass network.

  15. MEALWORM MORPHOLOGY Objective: Learn the anatomy of a mealworm and measure body length, body mass, the

    E-print Network

    Rose, Michael R.

    the scale for the image, use the straight-line tool to mark the straight-line body and images. #12;Results Table: Mealworm Body Length (cm) Body Width (cm) BMEALWORM MORPHOLOGY Objective: Learn the anatomy of a mealworm and measure body

  16. ESTIMATION OF SOYBEAN ROOT LENGTH DENSITY DISTRIBUTION WITH DIRECT AND SENSOR BASED MEASUREMENTS OF CLAYPAN MORPHOLOGY

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Hydrologic and morphological properties of claypan landscapes cause variability in soybean root and shoot biomass. This study was conducted to develop predictive models of soybean root length density distribution (RLDd) using direct measurements and sensor based estimators of claypan morphology. A c...

  17. Curricular Treatments of Length Measurement in the United States: Do They Address Known Learning Challenges?

    ERIC Educational Resources Information Center

    Smith, John P., III; Males, Lorraine M.; Dietiker, Leslie C.; Lee, KoSze; Mosier, Aaron

    2013-01-01

    Extensive research has shown that elementary students struggle to learn the basic principles of length measurement. However, where patterns of errors have been documented, the origins of students' difficulties have not been identified. This study investigated the hypothesis that written elementary mathematics curricula contribute to the…

  18. Direct Measurement of Sub-Debye-Length Attraction between Oppositely Charged Surfaces Nir Kampf,1

    E-print Network

    Andelman, David

    Direct Measurement of Sub-Debye-Length Attraction between Oppositely Charged Surfaces Nir Kampf,1 directly the attractive forces between oppositely charged solid surfaces (charge densities þ, À) across-Boltzmann theory, when due account is taken of the independently-determined surface charge asymmetry (þ Þ jÀj). DOI

  19. A New Path Length Measure Based on GO for Gene Similarity with Evaluation Using SGD Pathways

    E-print Network

    Al-Mubaid, Hisham

    A New Path Length Measure Based on GO for Gene Similarity with Evaluation Using SGD Pathways Anurag the Saccharomyces Genome Database (SGD) taking part in various cellular pathways. We analyzed 152 pathways from SGD methods in certain cases. Keywords: Gene similarity, GO term similarity, Gene similarity in SGD. 1

  20. Acoustic method for measuring the sound speed of gases over small path lengths

    E-print Network

    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

  1. Telomere length of transferred lymphocytes correlates with in vivo persistence and tumor regression in melanoma patients receiving cell transfer therapy

    PubMed Central

    Zhou, Juhua; Shen, Xinglei; Hodes, Richard J.; Rosenberg, Steven A.; Robbins, Paul F.

    2005-01-01

    Recent studies have indicated that adoptive immunotherapy with autologous anti-tumor tumor-infiltrating lymphocytes (TILs) following non-myeloablative chemotherapy mediates tumor regression in approximately 50% of treated patients with metastatic melanoma, and that tumor regression is correlated with the degree of persistence of adoptively transferred T cells in peripheral blood. These findings, which suggested that the proliferative potential of transferred T cells may play a role in clinical responses, led to the current studies in which telomere length as well as phenotypic markers expressed on the administered TILs were examined. TILs that were associated with objective clinical responses following adoptive transfer possessed a mean telomere length of 6.3 kb, whereas TILs that were not associated with significant clinical responses were significantly shorter, averaging 4.9 kb (p<0.01). Furthermore, individual TIL-derived T cell clonotypes that persisted in vivo following adoptive cell transfer possessed telomeres that were longer than telomeres of T cell clonotypes that failed to persist (6.2 kb versus 4.5 kb respectively, p<0.001). Expression of the co-stimulatory molecule CD28 also appeared to be associated with long telomeres and T cell persistence. These results, indicating that the telomere length of transferred lymphocytes correlated with in vivo T cell persistence following adoptive transfer, and coupled with the previous observation that T cell persistence was associated with clinical responses in this adoptive immunotherapy trial, suggest that telomere length and the proliferative potential of the transferred T cells may play a significant role in mediating response to adoptive immunotherapy. PMID:16272366

  2. Streptomyces griseus Protease B: Secretion Correlates with the Length of the Propeptide

    PubMed Central

    Baardsnes, J.; Sidhu, S.; MacLeod, A.; Elliott, J.; Morden, D.; Watson, J.; Borgford, T.

    1998-01-01

    Streptomyces griseus protease B, a member of the chymotrypsin superfamily, is encoded by a gene that expresses a pre-pro-mature protein. During secretion the precursor protein is processed into a mature, fully folded protease. In this study, we constructed a family of genes which encode deletions at the amino-terminal end of the propeptide. The secretion of active protease B was seen to decrease in an exponential manner according to the length of the deletion. The results underscore the intimate relationship between folding and secretion in bacterial protease expression. They further suggest that the propeptide segment of the zymogen stabilizes the folding of the mature enzyme through many small binding interactions over the entire surface of the peptide rather than through a few specific contacts. PMID:9620979

  3. Does the orbit-averaged theory require a scale separation between periodic orbit size and perturbation correlation length?

    SciTech Connect

    Zhang, Wenlu [Institute of Physics, Chinese Academy of Sciences, Beijing 100190 (China) [Institute of Physics, Chinese Academy of Sciences, Beijing 100190 (China); Department of Modern Physics, University of Science and Technology of China, Hefei, Anhui 230026 (China); Department of Physics and Astronomy, University of California, Irvine, California 92697 (United States); Lin, Zhihong [Department of Physics and Astronomy, University of California, Irvine, California 92697 (United States) [Department of Physics and Astronomy, University of California, Irvine, California 92697 (United States); Fusion Simulation Center, Peking University, Beijing 100871 (China)

    2013-10-15

    Using the canonical perturbation theory, we show that the orbit-averaged theory only requires a time-scale separation between equilibrium and perturbed motions and verifies the widely accepted notion that orbit averaging effects greatly reduce the microturbulent transport of energetic particles in a tokamak. Therefore, a recent claim [Hauff and Jenko, Phys. Rev. Lett. 102, 075004 (2009); Jenko et al., ibid. 107, 239502 (2011)] stating that the orbit-averaged theory requires a scale separation between equilibrium orbit size and perturbation correlation length is erroneous.

  4. Infrared Spectroscope for Electron Bunch-length Measurement: Heat Sensor Parameters Analysis

    SciTech Connect

    Domgmo-Momo, Gilles; /Towson U. /SLAC

    2012-09-05

    The Linac Coherent Light Source (LCLS) is used for many experiments. Taking advantage of the free electron laser (FEL) process, scientists of various fields perform experiments of all kind. Some for example study protein folding; other experiments are more interested in the way electrons interact with the molecules before they are destroyed. These experiments among many others have very little information about the electrons x-ray produced by the FEL, except that the FEL is using bunches less than 10 femtoseconds long. To be able to interpret the data collected from those experiments, more accurate information is needed about the electron's bunch-length. Existing bunch length measurement techniques are not suitable for the measurement of such small time scales. Hence the need to design a device that will provide more precise information about the electron bunch length. This paper investigates the use of a pyreoelectric heat sensor that has a sensitivity of about 1.34 micro amps per watt for the single cell detector. Such sensitivity, added to the fact that the detector is an array sensor, makes the detector studied the primary candidate to be integrated to an infrared spectrometer designed to better measure the LCLS electron bunch length.

  5. Multichannel analysis of correlation length of SEVIRI images around ground-based cloud observatories to determine their representativeness

    NASA Astrophysics Data System (ADS)

    Slobodda, J.; Hünerbein, A.; Lindstrot, R.; Preusker, R.; Ebell, K.; Fischer, J.

    2014-06-01

    Images of the geostationary Meteosat-9 SEVIRI instrument during the year 2012 are analyzed with respect to the representativeness of the observations of eight cloud observatories in Europe. Cloudy situations are selected to get a time series for every pixel in a 300 km × 300 km area centered around each ground station. Then the Pearson correlation coefficient of each time series to the one of the pixel nearest to the corresponding ground site is calculated. The area for which a station is representative is defined by the characteristic radius around each station for each SEVIRI channel, where the average correlation falls below 0.9. It is found that measurements in the visible and near infrared channels, which respond to cloud microphysics, are correlated in an area with a 1 to 4 km radius, while the thermal channels, that correspond to cloud top temperature, are correlated to a distance of about 20 km. The defined radius even increases for the water vapor and ozone channels. While all stations in Central Europe are quite alike, the correlations around the station in the mountains of southern Italy are much lower. Additionally correlations at different distances corresponding to the grid box sizes of forecast models were compared. The results show good comparability between regional forecast models (grid size ? 10 km) and ground-based measurements since the correlations in less than 10 km distance are in all cases higher than 0.8. For larger distances like they are typical for global models (grid size ? 20 km) the correlations decrease to 0.6, especially for shortwave measurements and corresponding cloud products. By comparing daily means, the characteristic radius of each station is increased to about 3 to 10 times the value of instantaneous measurements and also the comparability to models grows.

  6. Thermodynamics and crossover phenomena in the correlation lengths of the one-dimensional t-J model

    NASA Astrophysics Data System (ADS)

    Sirker, J.; Klümper, A.

    2002-12-01

    We investigate the thermodynamics of the one-dimensional t-J model using transfer matrix renormalization group algorithms and present results for quantities like particle number, specific heat, spin susceptibility, and compressibility. Based on these results we confirm a phase diagram consisting of a Tomonaga-Luttinger liquid (TLL) phase for small J/t and a phase-separated state for J/t large. Close to phase separation we find a spin-gap (Luther-Emery) phase at low densities consistent with predictions by other studies. At the supersymmetric point we compare our results with exact results from the Bethe ansatz and find excellent agreement. In particular we focus on the calculation of correlation lengths and static correlation functions and study the crossover from the nonuniversal high-T lattice into the quantum critical regime. At the supersymmetric point we compare in detail with predictions by conformal field theory and TLL theory and show the importance of logarithmic corrections.

  7. Air method measurements of apple vessel length distributions with improved apparatus and theory.

    PubMed

    Cohen, Shabtai; Bennink, John; Tyree, Mel

    2003-08-01

    Studies showing that rootstock dwarfing potential is related to plant hydraulic conductance led to the hypothesis that xylem properties are also related. Vessel length distribution and other properties of apple wood from a series of varieties were measured using the 'air method' in order to test this hypothesis. Apparatus was built to measure and monitor conductivity to air of fresh wood segments of different lengths. Theory for determining vessel length distribution was improved to give a single parameter uni-modal vessel length probability density function. The function, derived by combining the exponential extinction (with extinction coefficient k) of wood conductivity to air (C) as wood length (x) increases (i.e. C=Co exp (-kx)) with the differential double difference formula, is Px=xxk2 exp (-kx), where Px is the fraction of vessels of length x. The main parameter of the distribution, k, was found to be the inverse of the mode of the distribution, i.e. the most common vessel length, Lo. Lo for ten apple rootstock and scion varieties varied from 5.6+/-0.1 cm (+/-SE) for MM.111 to 9.0+/-1.0 for Prunifolia (P <0.05). Average maximum vessel length was approximately 50 cm, and differences were not significant. Effective vessel radii ranged from 14 for Prunifolia to 24.3+/-0.7 micro m for M.26, with standard errors less than 12% of the mean. Specific conductivity of a 15 cm wood segment ranged from 2x109-4) to 1.6+/-0.2x10(-2) dm3 s(-1) kPa(-1) m(-1) for maruba and M.26, respectively, with standard errors up to 63% of the mean. Vessel density at the air entry point ranged from 18+/-3 to 42+/-6 vessels mm-2 for M.26 and MM.106, respectively, with standard errors as high as 89% of the mean. It was concluded that there is no general relationship between the wood properties investigated and rootstock size class, and that plasticity increases from vessel lengths to radii to specific conductivity and vessel densities. PMID:12815034

  8. Microlenses focal length measurement using Z-scan and parallel moiré deflectometry

    NASA Astrophysics Data System (ADS)

    Rasouli, Saifollah; Rajabi, Y.; Sarabi, H.

    2013-12-01

    In this paper, a simple and accurate method based on Z-scan and parallel moiré deflectometry for measuring the focal length of microlenses is reported. A laser beam is focused by one lens and is re-collimated by another lens, and then strikes a parallel moiré deflectometer. In the presence of a microlens near the focal point of the first lens, the radius of curvature of the beam is changed; the parallel moiré fringes are formed only due to the beam divergence or convergence. The focal length of the microlens is obtained from the moiré fringe period graph without the need to know the position of the principal planes. This method is simple, more reliable, and completely automated. The implementation of the method is straightforward. Since a focused laser beam and Z-scan in free space are used, it can be employed for determining small focal lengths of small size microlenses without serious limitation on their size.

  9. Measurement of coherence length and incoherent source size of hard x-ray undulator beamline at Pohang Light Source-II

    NASA Astrophysics Data System (ADS)

    Park, So Yeong; Hong, Chung Ki; Lim, Jun

    2014-04-01

    We measured the spatial coherence length and incoherent source size of a hard x-ray undulator beamline at Pohang Light Source-II, the stored electron energy of which has been increased from 2.5 GeV to 3 GeV. The coherence length was determined by single-slit measurement of the visibility of the Fresnel diffraction pattern. The correlated incoherent source size was cross-checked for three different optics: the single slit, beryllium parabolic compound refractive lenses, and the Fresnel zone plate. We concluded that the undulator beamline has an effective incoherent source size (FWHM) of 540 ?m (horizontal) × 50 ?m (vertical).

  10. Measurement of coherence length and incoherent source size of hard x-ray undulator beamline at Pohang Light Source-II.

    PubMed

    Park, So Yeong; Hong, Chung Ki; Lim, Jun

    2014-04-01

    We measured the spatial coherence length and incoherent source size of a hard x-ray undulator beamline at Pohang Light Source-II, the stored electron energy of which has been increased from 2.5 GeV to 3 GeV. The coherence length was determined by single-slit measurement of the visibility of the Fresnel diffraction pattern. The correlated incoherent source size was cross-checked for three different optics: the single slit, beryllium parabolic compound refractive lenses, and the Fresnel zone plate. We concluded that the undulator beamline has an effective incoherent source size (FWHM) of 540 ?m (horizontal) × 50 ?m (vertical). PMID:24784668

  11. Measurement of coherence length and incoherent source size of hard x-ray undulator beamline at Pohang Light Source-II

    SciTech Connect

    Park, So Yeong; Hong, Chung Ki [Department of Physics, POSTECH, Pohang 790-784 (Korea, Republic of)] [Department of Physics, POSTECH, Pohang 790-784 (Korea, Republic of); Lim, Jun, E-mail: limjun@postech.ac.kr [Pohang Accelerator Laboratory, POSTECH, Pohang 790-784 (Korea, Republic of)] [Pohang Accelerator Laboratory, POSTECH, Pohang 790-784 (Korea, Republic of)

    2014-04-15

    We measured the spatial coherence length and incoherent source size of a hard x-ray undulator beamline at Pohang Light Source-II, the stored electron energy of which has been increased from 2.5 GeV to 3 GeV. The coherence length was determined by single-slit measurement of the visibility of the Fresnel diffraction pattern. The correlated incoherent source size was cross-checked for three different optics: the single slit, beryllium parabolic compound refractive lenses, and the Fresnel zone plate. We concluded that the undulator beamline has an effective incoherent source size (FWHM) of 540 ?m (horizontal) × 50 ?m (vertical)

  12. Spatial correlation of measured unsteady surface pressure behind a backward-facing step

    NASA Astrophysics Data System (ADS)

    Bilka, Michael J.; Paluta, Mark R.; Silver, Jonathan C.; Morris, Scott C.

    2015-02-01

    The spatial correlations of the unsteady surface pressure for a backward-facing step were studied experimentally. The measurements were acquired using an array of surface pressure sensors within an anechoic wind tunnel which was designed to minimize acoustic contamination. The maximum Reynolds number based on the step height was 59,200. The spatial characteristics of the surface pressure were studied in two parts. First, a linear array of microphones oriented in the streamwise direction was used to obtain the evolution of the pressure spectra, length scale, and phase speed. Second, an array oriented in the spanwise direction was used to provide the coherence and integral length scales in that direction. The correlation length functions were found to vary with downstream location in the separated region behind the step. After reattachment, the integral scales of the surface pressure continued to increase in magnitude as far as 18 step heights downstream of the step.

  13. Groove depth measurements on roughness reference standards of the Croatian National Laboratory for Length (LFSB)

    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.

  14. Traveling length and minimal traveling time for flow through percolation networks with long-range spatial correlations.

    PubMed

    Araújo, A D; Moreira, A A; Makse, H A; Stanley, H E; Andrade, J S

    2002-10-01

    We study the distributions of traveling length l and minimal traveling time t(min) through two-dimensional percolation porous media characterized by long-range spatial correlations. We model the dynamics of fluid displacement by the convective movement of tracer particles driven by a pressure difference between two fixed sites ("wells") separated by Euclidean distance r. For strongly correlated pore networks at criticality, we find that the probability distribution functions P(l) and P(t(min)) follow the same scaling ansatz originally proposed for the uncorrelated case, but with quite different scaling exponents. We relate these changes in dynamical behavior to the main morphological difference between correlated and uncorrelated clusters, namely, the compactness of their backbones. Our simulations reveal that the dynamical scaling exponents d(l) and d(t) for correlated geometries take values intermediate between the uncorrelated and homogeneous limiting cases, where l(*) approximately r(d(l)) and t(*)(min) approximately r(d(t)), and l(*) and t(*)(min) are the most probable values of l and t(min), respectively. PMID:12443319

  15. Measure of nonclassical correlation in coherence-vector representation

    SciTech Connect

    Zhou, Tao; Cui, Jingxin [State Key Laboratory of Low-dimensional Quantum Physics and Department of Physics, Tsinghua University, 100084 Beijing (China); Long, Gui Lu [State Key Laboratory of Low-dimensional Quantum Physics and Department of Physics, Tsinghua University, 100084 Beijing (China); Tsinghua National Laboratory for Information Science and Technology, Tsinghua University, 100084 Beijing (China)

    2011-12-15

    We consider the coherence-vector representation of a bipartite state and obtain a necessary and sufficient condition for a zero-discord state. Based on this, a measure of quantum, classical, and total amount of correlations in bipartite states is proposed in this representation. Analytical expressions for this measure are available for any bipartite states. Our measure of nonclassical correlation coincides with the geometric measure of quantum discord for some particular states.

  16. Measuring correlations between non-stationary series with DCCA coefficient

    NASA Astrophysics Data System (ADS)

    Kristoufek, Ladislav

    2014-05-01

    In this short report, we investigate the ability of the DCCA coefficient to measure correlation level between non-stationary series. Based on a wide Monte Carlo simulation study, we show that the DCCA coefficient can estimate the correlation coefficient accurately regardless the strength of non-stationarity (measured by the fractional differencing parameter d). For a comparison, we also report the results for the standard Pearson correlation coefficient. The DCCA coefficient dominates the Pearson coefficient for non-stationary series.

  17. Internalized Heterosexism: Measurement, Psychosocial Correlates, and Research Directions

    ERIC Educational Resources Information Center

    Szymanski, Dawn M.; Kashubeck-West, Susan; Meyer, Jill

    2008-01-01

    This article provides an integrated critical review of the literature on internalized heterosexism/internalized homophobia (IH), its measurement, and its psychosocial correlates. It describes the psychometric properties of six published measures used to operationalize the construct of IH. It also critically reviews empirical studies on correlates

  18. Correlation between the content of intermediate chain-length fatty acids and copper in the milk of Fulani women.

    PubMed

    Shores, J T; VanderJagt, D J; Millson, M; Huang, Y S; Glew, R H

    2000-10-01

    Intermediate chain-length fatty acids (C10-C14) in human milk triglycerides provide an easily absorbable fuel that provide a significant amount of the energy needed for growth during the first few months of life. The C10-C14 fatty acid and trace mineral content of human milk is variable. In this report we examined the relationship between the content of calcium, copper, magnesium, manganese, phosphorus, and zinc, and the weight percentage of C10-C14 fatty acids in milk from 33 Fulani women in northern Nigeria between 2 and 24 weeks post-gestation. The milk from these women contained proportions of C10-C14 fatty acids that were comparable to those reported for other populations around the world, as were the concentrations of Ca, Cu, Mg, Mn, Zn and P. Significant correlations were observed between the milk content of Cu and the wt% of C10 (P=0. 005, r=0.475), C12 (P=0.001, r=0.539), C14 (P=0.44, r=0.352) and the total intermediate chain-length fatty acids (P=0.008, r=0.450). No correlations were observed between these fatty acids and any of the other five minerals. We speculate that the relationship between Cu and fatty acids could be related to a requirement for Cu by an enzyme required for C10-C14 fatty acid biosynthesis (e.g. decanoyl deacylase) in mammary tissue, or to some unique Cu binding properties of the intermediate chain length fatty acids. PMID:11049695

  19. Measuring limb length discrepancy using pelvic radiographs: the most reproducible method.

    PubMed

    Heaver, Catriona; St Mart, Jean-Pierre; Nightingale, Peter; Sinha, Aabha; Davis, Edward T

    2013-01-01

    Leg length inequality following total hip replacement remains common. In an effort to reduce this occurrence, surgeons undertake pre-operative measurements, templating and use various forms of intraoperative measurements, including computer navigation. This study aims to delineate which measurement technique is most appropriate for measuring leg length inequality from a pelvic radiograph. Three observers took a total of 9600 measurements from 100 pelvic radiographs. Four lines were constructed on each of the radiographs, bisecting the acetabular teardrops, ischial spines, inferior sacroiliac joint and inferior obturator foramen. Measurements were taken from these lines to the most prominent medial point on the lesser trochanter and to the tip of the greater trochanter. The effect of pelvic positioning was also assessed using radiographs of a synthetic pelvis and femur. Intra-observer and inter-observer variability were calculated. Measuring from the inferior aspect of the ischial tuberosities to the most prominent medial point on the lesser trochanter appears to be the best method for measuring LLD however large error margin still exist, even when corrected for magnification errors. PMID:23934902

  20. The correlation analysis of the angle measurements

    Microsoft Academic Search

    Domantas Bru?as; Jonas Skeivalas; Vytautas Giniotis

    2007-01-01

    The test bench for testing and calibrating the measuring geodetic instruments for flat angle measurements has been created at Vilnius Gediminas Technical University, Institute of Geodesy. This test rig incorporates multiple?angular position determination principles ? photoelectric angular encoder, polygon?autocollimator and circular?scale?microscope. Such a diversity of implemented methods allows cross?calibration and testing each principle using the other one. Similarly, there may

  1. Measurement of Bunch-Length by a Mode-Locked Laser with a Time Resolution of 10 Picoseconds

    Microsoft Academic Search

    R. Fischer; R. Rossmanith

    1973-01-01

    In accelerators working at accelerating frequencies of several 100 MHz the bunch length is in the order of several hundred picoseconds. For obtaining good measurements the time resolution of the measuring apparatus should be 10 ps. With convenient electronic components such a high time resolution cannot be obtained. In this paper a method is described for measuring the bunch length

  2. Repeatability of On- and Off-Axis Eye Length Measurements using the Lenstar

    PubMed Central

    Schulle, Krystal L.; Berntsen, David A.

    2012-01-01

    Purpose To determine the repeatability of eye length measurements made centrally and off-axis using a low-coherence interferometer. Methods Eye length was measured (left eye) in twenty-nine adults with a Haag-Streit Lenstar LS 900. Five measurements were made centrally, 10° temporally, and 10° nasally on the retina by the same examiner at two separate visits. Inter-visit repeatability was assessed by plotting the difference versus the mean of each pair of measurements (bias) and calculating the 95% limits of agreement (LoA). Within-session repeatability was determined by calculating the within-subject standard deviation (Sw) of five consecutive measurements at a visit. Due to variability noted 10° nasally, the Sw was also determined on a subset of 10 subjects using five measurements at one visit 30° nasally and 30° temporally. Results The mean ± SD age, spherical equivalent refractive error, and central axial length (at visit 1) were 24.0 ± 1.4 years, ?3.46 ± 2.69 D, and 24.91 ± 1.10 mm, respectively. There was no significant bias for central, 10° nasal, or 10° temporal measurements between visits (all p > 0.09). The 95% LoA were: ±0.05 mm central, ±0.12 mm 10° nasal, and ±0.05 mm 10° temporal. The Sw (visit 1) were: 0.025 mm central, 0.045 mm 10° nasal, and 0.028 mm 10° temporal. The Sw in the subset of subjects with 30° measurements were 0.023 mm (30° nasal) and 0.030 mm (30° temporal). Conclusions Lenstar central and off-axis eye length measurements are very repeatable, though repeatability was not as good 10° nasally on the retina as indicated by the larger 95% LoA between visits and larger Sw. The Sw for measurements centrally and 30° off-axis were similar, suggesting the reduced repeatability 10° nasally is anatomical in nature. Despite greater variability 10° nasally, Lenstar off-axis repeatability is still superior to the repeatability of on-axis ultrasonography. PMID:23208194

  3. Measurement of atmospheric coherence length with differential movement of the image sensor

    NASA Astrophysics Data System (ADS)

    Jia, Yu-gang; Tong, Shou-feng

    2013-08-01

    This paper gives the introduction about a new measuring device which is to measure th e atmospheric coherence length by using the differential movement principle.The system can observe the edge of the sun in the day time, and also observe planets at night. This system can measure the atmospheric coherence length in both horizontal and slant directions. The measurement in the day time requests the assistance of the attenuator and beacon beam of the atmospheric coherence length in the direction of the slant path.The working principle is the laser beam scattered by atmospheric turbulence through into the receiving optical system. Because the receiving system which is consists of two completely symmetrical telephoto optical system. Therefore?two optical channels in turbulence device are completely identical. After passing through the optical channels, the beam focusing is finished. By adjusting the optical system manually or automatically, two light point images can be formed on the photosensitive element of the CCD. Atmospheric turbulence can cause phase fluctuation of wave front. After aggregation by the receiving lens, The photosensitive element of CCD can collect the relative jitter of the two imaging optical centroid positions we require, and researchers can obtain relative changes from the two centroid positions by the calculations of computer software, as the result, the atmospheric coherence length is obtained. By means of the simulation of the optical system and the imaging quality optimization by Code V, researchers can rather achieve transfer function diagram, the circle of confusion value in different views and energy distribution. From above, researchers can examine whether the optical system is being qualified, or the method is leading to a better observation effect. At end of this dissertation, the limitations of this system will be analyzed, and the improvement methods and suggestions will be provided.

  4. 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.

  5. Absolute Bunch Length Measurements at the ALS by Incoherent Synchrotron Radiation Fluctuation Analysis

    SciTech Connect

    Filippetto, D.; /Frascati; Sannibale, F.; Zolotorev, Max Samuil; /LBL, Berkeley; Stupakov, G.V.; /SLAC

    2008-01-24

    By analyzing the pulse to pulse intensity fluctuations of the radiation emitted by a charge particle in the incoherent part of the spectrum, it is possible to extract information about the spatial distribution of the beam. At the Advanced Light Source (ALS) of the Lawrence Berkeley National Laboratory, we have developed and tested a simple scheme based on this principle that allows for the absolute measurement of the bunch length. A description of the method and the experimental results are presented.

  6. Electron Bunch Length Measurements in the E-167 Plasma Wakefield Experiment

    SciTech Connect

    Blumenfeld, I.; Auerbach, D.; Berry, M.; Clayton, C.E.; Decker, F.J.; Hogan, M.J.; Huang, Cheng-Kun; Ischebeck, R.; Iverson, R.; Johnson, D.; Joshi, C.; Katsouleas, T.; Kirby, N.; Lu, Wei; Marsh, K.A.; Mori, W.B.; Muggli, P.; Oz, E.; Siemann, R.H.; Walz, D.; Zacherl, W.; /SLAC /UCLA /Southern California U.

    2007-03-27

    Bunch length is of prime importance to beam driven plasma wakefield acceleration experiments due to its inverse relationship to the amplitude of the accelerating wake. We present here a summary of work done by the E167 collaboration measuring the SLAC ultra-short bunches via autocorrelation of coherent transition radiation. We have studied material transmission properties and improved our autocorrelation traces using materials with better spectral characteristics.

  7. In situ measurement of fish body length using perspective-based remote stereo-video

    Microsoft Academic Search

    R. L. Dunbrack

    2006-01-01

    Size–frequency distributions provide important information on population-level processes in fishes, but for some non-commercial species the collection of length data through direct sampling may be unacceptably destructive. Although in situ measurement techniques based on photographic or video image analysis are non-destructive, these generally require diver-operated equipment and consequently are labor-intensive and limited in both working depth and deployment time. A

  8. Measurement of the temperature dependence of pulse lengths in an n-type germanium detector

    E-print Network

    I. Abt; A. Caldwell; J. Liu; B. Majorovits; O. Volynets

    2011-12-21

    The temperature dependence of the pulse length was measured for an 18-fold segmented n-type germanium detector in the temperature range of 77-120 K. The interactions of 122 keV photons originating from a Europium-152 source were selected and pulses as observed on the core and segment electrodes were studied. In both cases, the temperature dependence can be well described by a Boltzmann-like ansatz.

  9. Measurements of electric charge and screening length of microparticles in a plasma sheath

    SciTech Connect

    Nakamura, Y.; Ishihara, O. [Department of Physics, Faculty of Engineering, Yokohama National University, 79-5 Tokiwadai, Hodogaya-ku, Yokohama 240-8501 (Japan)

    2009-04-15

    An experiment is described in which microparticles are levitated within a rf sheath above a conducting plate in argon plasma. The microparticles forming a two-dimensional crystal structure are considered to possess Debye screening Coulomb potential {phi}(r)=(Q/4{pi}{epsilon}{sub 0}r)exp(-r/{lambda}), where Q is the electric charge, r is distance, and {lambda} is the screening length. When the crystal structure is slanted with an angle {theta}, a particle experiences a force Mg sin {theta}, where M is the mass of the particle and g is acceleration due to gravity, which must be equal to the Debye screened Coulomb force from other particles. By changing {theta}, relations for {lambda}(Q) are measured. The screening length {lambda} and Q are determined uniquely from the crossing points of several relations. The electric charge Q is also estimated from a floating potential measured with a probe. The measured {lambda} is nearly equal to an ion Debye length.

  10. 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.

  11. Fissile mass-multiplication factor correlation for Pu measurement

    SciTech Connect

    Lu, Ming-Shih; Teichmann, T. [Brookhaven National Lab., Upton, NY (United States); De Ridder, P. [International Atomic Energy Agency, Vienna (Austria); Verrecchia, G.P.D.; Chare, P. [Commission of the European Communities, Luxembourg (Luxembourg). Safeguards Directorate; Vocino, V. [Commission of the European Communities, Ispra (Italy). Joint Research Centre

    1993-06-01

    An empirical correlation between the fissile mass and the leakage multiplication factor, as determined by High Level Neutron Coincidence (HLNC) counting, was developed based on available measurement data. This correlation has been used successfully for the simulation of HLNC counting. With the singles count rate (totals), the correlation can be used to obtain a quick estimate of the plutonium mass of the sample in less time than required to measure the real coincidence count rate. The correlation can also be used to evaluate samples contaminated with ({alpha},n) sources such as fluorine.

  12. Automatic measurement of pennation angle and fascicle length of gastrocnemius muscles using real-time ultrasound imaging.

    PubMed

    Zhou, Guang-Quan; Chan, Phoebe; Zheng, Yong-Ping

    2015-03-01

    Muscle imaging is a promising field of research to understand the biological and bioelectrical characteristics of muscles through the observation of muscle architectural change. Sonomyography (SMG) is a technique which can quantify the real-time architectural change of muscles under different contractions and motions with ultrasound imaging. The pennation angle and fascicle length are two crucial SMG parameters to understand the contraction mechanics at muscle level, but they have to be manually detected on ultrasound images frame by frame. In this study, we proposed an automatic method to quantitatively identify pennation angle and fascicle length of gastrocnemius (GM) muscle based on multi-resolution analysis and line feature extraction, which could overcome the limitations of tedious and time-consuming manual measurement. The method started with convolving Gabor wavelet specially designed for enhancing the line-like structure detection in GM ultrasound image. The resulting image was then used to detect the fascicles and aponeuroses for calculating the pennation angle and fascicle length with the consideration of their distribution in ultrasound image. The performance of this method was tested on computer simulated images and experimental images in vivo obtained from normal subjects. Tests on synthetic images showed that the method could identify the fascicle orientation with an average error less than 0.1°. The result of in vivo experiment showed a good agreement between the results obtained by the automatic and the manual measurements (r=0.94±0.03; p<0.001, and r=0.95±0.02, p<0.001). Furthermore, a significant correlation between the ankle angle and pennation angle (r=0.89±0.05; p<0.001) and fascicle length (r=-0.90±0.04; p<0.001) was found for the ankle plantar flexion. This study demonstrated that the proposed method was able to automatically measure the pennation angle and fascicle length of GM ultrasound images, which made it feasible to investigate muscle-level mechanics more comprehensively in vivo. PMID:25465963

  13. Correlation of anterior segment optical coherence tomography measurements with graft trephine diameter following descemet stripping automated endothelial keratoplasty

    PubMed Central

    2012-01-01

    Background To assess repeatability of the Zhongshan Assessment Program (ZAP) software measurement of Anterior Segment Optical Coherence Tomography (ASOCT) images and correlate with graft trephine diameter following Descemet Stripping Automated Endothelial Keratoplasty (DSAEK) Methods Retrospectively evaluated interventional case series. 121 consecutive eyes undergoing DSAEK over a 26 month period underwent ASOCT imaging 1month after their surgery. ASOCT images were processed using ZAP software which measured the graft and cornea parameters including anterior and posterior graft arc length and cord length, posterior cornea arc length (PCAL) and anterior chamber width. Results The graft measurements showed good repeatability on ASOCT using ZAP with high intra class coefficient and small variation in the coefficient of variation. On ASOCT, the mean recipient PCAL was 12.99+/?0.69mm and the anterior chamber width was 11.16+/?0.57mm. The mean Graft anterior arc length was 9.69+/?0.66mm and the mean Graft anterior cord length was 8.92+/?2.94mm. The mean graft posterior arc length was 9.24+/?0.75mm and the mean graft posterior cord length was 8.15+/?0.57mm. Graft posterior arc length (rho=0.788, p< 0.001) correlated best with intra-operative graft trephine diameter. The mean ratio of posterior graft arc length to PCAL was 0.712 +/? 0.056. Conclusions We have validated the repeatability of the ZAP software for DSAEK graft measurements from ASOCT images and shown that the graft arc length parameters calculated from the ASOCT images correlate well with the intra-operative graft trephine diameter. This software may help surgeons determine the optimal DSAEK graft size based on pre-operative ASOCT measurements of the recipient eye. PMID:22824516

  14. Scattering length measurements from radiative pion capture and neutron-deuteron breakup

    SciTech Connect

    Gibson, B.F. [Los Alamos National Lab., NM (United States); Tornow, W. [Duke Univ., Durham, NC (United States). Dept. of Physics]|[Triangle Universities Nuclear Lab., Durham, NC (United States); Carman, T.S. [Lawrence Livermore National Lab., CA (United States)] [and others

    1997-07-01

    The neutron-neutron and neutron-proton {sup 1}S{sub 0} scattering lengths a{sub nn} and a{sub np}, respectively, were determined simultaneously from the neutron-deuteron breakup reaction. Their comparison with the recommended values obtained from two body reactions gives a measure of the importance of three-nucleon force effects in the three-nucleon continuum. In order to check on the result obtained for a{sub nn} from the two-body {pi}{sup {minus}}-d capture reaction, a new measurement was performed at LANL. Preliminary results of the three experiments are given.

  15. Photon path length distributions for cloudy atmospheres from GOSAT satellite measurements

    NASA Astrophysics Data System (ADS)

    Kremmling, Beke; Penning de Vries, Marloes; Wagner, Thomas

    2014-05-01

    The presence of clouds in the atmosphere has significant influence on the photon paths of the scattered sunlight. Besides reflections of radiation at the cloud top, additional scattering events inside the cloud may occur and thus lengthening or shortening of the photon path in the atmosphere. Clouds consisting of multiple layers or patches may lead to a "ping pong" behaviour of the photons due to reflections at the individual surfaces. The objective of our study is the retrieval of photon path length distributions for various atmospheric cloud situations which will lead to a better understanding of the influence of clouds on the atmospheric radiative transport. Following principles from ground based photon path length retrieval (Funk et al., 2003), our research uses the combination of space based measurements of the oxygen A-band and radiative transfer simulations. The experimental spectra originate from the Japanese Greenhouse gases Observing SATellite (GOSAT), more precisely the Fourier Transform Spectrometer TANSO-FTS. Its high spectral resolution allows to almost completely resolve the individual absorption lines which is a prerequisite to our study. The Monte Carlo radiative transfer model McArtim (Deutschmann et al., 2011) is used to model the measured spectra. This model allows user-defined input for the altitude dependent cross sections and furthermore the incorporation of three dimensional cloud shapes and properties. From the simulation output and the sun-satellite geometry, photon path length distributions can be obtained. Distributions of photon path lengths are presented for a selection of GOSAT observations of entirely cloud covered atmospheres with similar measurement geometries.

  16. Ultrasound Measurement of Cervical Length as Predictor of Threatened Preterm Birth: a Predictive Model

    PubMed Central

    El-Ardat, Mohammad Abou; Gavrankapetanovic, Fatima; Abou El-Ardat, Khalil A.; Dekovic, Sanjin; Murtezic, Senad; Mehmedbasic, Eldar; Hiros, Nadja

    2014-01-01

    ABSTRACT Introduction: The incidence of preterm delivery has been increasing even in developed countries and remains a serious problem for fetuses and neonates. Although many predictors for preterm delivery have been proposed, complete prediction and prevention have not yet been established. Aims: To examine the potential association between sonographic measurement of cervical length and threatened preterm birth (TPTB) in pregnant woman at 24-36 weeks of gestation. Materials and methods: A cross-sectional study included a total of 360 pregnant woman at 24-36 weeks of gestation categorized in two groups: TPTB group (n=160) and non TPTB group (n=200). The study was carried out at the Department of Obstetrics and Gynecology of the Clinical Center University of Sarajevo (KCUS). Sociodemographic and clinical characteristics of patients were obtained from medical records and physical examination by gynecologist. Transvaginal sonography was carried out by GE Voluson 730. Results: There was a significant association between TPTB and sonographic measurement of cervical length <25 mm (P<0.001). The logistic regression model was statistically significant, x2(7) = 281.530, P<0. 001. The model explained 72.6% of the variance in TPTB and correctly classified 88.1% of cases. Sensitivity was 83.8%, specificity was 91.5%, positive predictive value was 88.7% and negative predictive value was 87.6%. Out of the 7 predictor variables only 5 were statistically significant: cervical length, cervical consistency, rupture of membranes, uterine contractions and amine odor test. Conclusion: The findings of this study suggest association between sonographic measurement of cervical length and TPTB. PMID:25568578

  17. Comparison between Measured and Calculated Length of Side Branch Ostium in Coronary Bifurcation Lesions with Intravascular Ultrasound

    PubMed Central

    Ryu, Hyeon Min; Kim, Byeong-Keuk; Kim, Jung-Sun; Ko, Young-Guk; Choi, Donghoon; Jang, Yangsoo

    2012-01-01

    Purpose Accurate evaluation of side branch (SB) ostium could be critical to the treatment of bifurcation lesions. We compared measured and calculated values of side branch ostial length (SBOL) in coronary bifurcation lesions with intravascular ultrasound (IVUS). Materials and Methods Pre-intervention and post-intervention IVUS was performed in 113 patients who underwent stent implantation of bifurcation lesions. For the IVUS longitudinal reconstruction of the bifurcation lesions, SBOL, SB diameter, and the angle between the distal portion of the main vessel (MV) and SB were directly measured. In addition, SBOL was calculated as: SB diameter/sin (angle between distal MV and SB). The relationship between measured and calculated SBOL was then evaluated. Results The angled between the distal MV and SB were 57.3±12.4° at pre-intervention and 59.4±12.6° at post-intervention. The mean measured and calculated SBOL values were 2.91±0.86 mm and 3.06±0.77 mm at pre-intervention and 2.79±0.82 mm and 2.92±0.69 mm at post-intervention, respectively. Differences between measured and calculated SBOL were 0.15±0.44 mm at pre-intervention and 0.13±0.41 mm at post-intervention. We found that calculated SBOL was correlated with measured SBOL (pre-intervention r=0.863, p<0.001; post-intervention r=0.868, p<0.001). Conclusion There was a good correlation between measured and calculated SBOLs of the bifurcation lesions in IVUS longitudinal reconstruction. SBOL in the bifurcation lesions can therefore be estimated using the SB diameter and the angle between distal MV and SB. PMID:22665331

  18. Standard Length versus Total Length

    Microsoft Academic Search

    William F. Royce

    1942-01-01

    In an effort to determine the length measurement most representative of the bulk of the fish, the standard length and the total length were each compared with the weight of the fish. This comparison was made for four species of game fish, yellow perch (Perca flavescens), wall-eyed pike (Stizostedion v. vitreum), rock bass (Ambloplites rupestris), and lake trout (Cristivomer n.

  19. Method of glass melter electrode length measurement using time domain reflectometry (TDR)

    SciTech Connect

    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.

  20. Measuring the Small Angle Correlation Function in HST Data

    NASA Astrophysics Data System (ADS)

    Morganson, Eric P.; Blandford, R.

    2008-03-01

    We make the first statistically significant measurement of the small angle correlation function (SACF). Our improvement on previous measurements stems from using better data, designing source extraction routines that do not exclude close pairs and creating custom images to estimate small angle systematics. We use the faintest sources in the Hubble GOODS and UDF datasets (25 < V < 29) and find that their correlation functions exceed unity on subarcsecond scales. The correlation functions of these sources are consistent with a power law with exponent of roughly -2 and different correlation angles which range between .3" and 1". This is notably different from the cosmological angular correlation function which has an exponent of roughly -.7. This shows that the SACF is influenced by galactic-scale physics. We believe this measurement can be used to constrain galactic formation models. In addition, we will using the lensing of the SACF as a distance probe to these faint sources.

  1. Computational prediction of origin of replication in bacterial genomes using correlated entropy measure (CEM).

    PubMed

    Parikh, Harsh; Singh, Apoorvi; Krishnamachari, Annangarachari; Shah, Kushal

    2015-02-01

    We have carried out an analysis on 500 bacterial genomes and found that the de-facto GC skew method could predict the replication origin site only for 376 genomes. We also found that the auto-correlation and cross-correlation based methods have a similar prediction performance. In this paper, we propose a new measure called correlated entropy measure (CEM) which is able to predict the replication origin of all these 500 bacterial genomes. The proposed measure is context sensitive and thus a promising tool to identify functional sites. The process of identifying replication origins from the output of CEM and other methods has been automated to analyze a large number of genomes in a faster manner. We have also explored the applicability of SVM based classification of the workability of each of these methods on all the 500 bacterial genomes based on its length and GC content. PMID:25576764

  2. Application of flow-FISH for dynamic measurement of telomere length in cell division.

    PubMed

    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

  3. Self-imaging pitch variation applied to focal length digital measurements

    NASA Astrophysics Data System (ADS)

    Tebaldi, Myrian; Forte, Gustavo; Torroba, Roberto; Bolognini, Néstor; Tagliaferri, Alberto

    2005-06-01

    Several approaches were developed in the literature for focal length measurements. In our experimental arrangement, a collimated laser beam illuminates a test lens with a Ronchi grating placed against this lens. This procedure gives rise to a series of classical Talbot images, although magnified due to the non-parallel illumination. In this configuration, we propose to relate the self-images positions and pitches to obtain the focal length. We designed a software that helps first to precisely focus each self-image plane by a best-contrast algorithm and then to take an intensity histogram along a direction perpendicular to the grating lines. A theoretical explanation, experimental results and error analysis are presented.

  4. Measurement and analysis of two- and three-particle correlations

    E-print Network

    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.

  5. Mesures de correlation robustes aux occultations Correlation measures that are robust near occlusions

    E-print Network

    Paris-Sud XI, Université de

    Mesures de corr´elation robustes aux occultations Correlation measures that are robust near`eme des occultations. Un protocole d'´evaluation est propos´e (huit crit`eres, trois paires d'images synth`eme famille), dont les seize mesures propos´ees, sont les plus robustes aux occultations. Mots Cl´es Corr

  6. Bunch Length Measurements at the ATF Damping Ring in April 2000

    SciTech Connect

    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

  7. Comparison of Echo 7 field line length measurements to magnetospheric model predictions

    NASA Technical Reports Server (NTRS)

    Nemzek, R. J.; Malcolm, P. R.; Winckler, J. R.

    1992-01-01

    The Echo 7 sounding rocket experiment injected electron beams on central tail field lines near L = 6.5. Numerous injections returned to the payload as 'conjugate echoes' after mirroring in the southern hemisphere. Field line lengths calculated from measured conjugate echo bounce times and energies are compared to predictions made by integrating electron trajectories through various magnetospheric models. Although Kp at launch was 3-, quiet time magnetic models best fit the echo measurements. Geosynchronous satellite magnetometer measurements near the Echo 7 field lines during the flight were best modeled by the Olson-Pfitzer Dynamic Model and the Tsyganenko-Usmanov model for Kp = 3. The discrepancy between the models that best fit the Echo 7 data and those that fit the satellite data was most likely due to uncertainties in the small-scale configuration of the magnetospheric models. The field line length measured by the conjugate echoes showed some temporal variation in the magnetic field, also indicated by the satellite magnetometers. This demonstrates the utility an Echo-style experiment could have in substorm studies.

  8. Assessing Long-Term Wind Conditions by Combining Different Measure-Correlate-Predict Algorithms: Preprint

    SciTech Connect

    Zhang, J.; Chowdhury, S.; Messac, A.; Hodge, B. M.

    2013-08-01

    This paper significantly advances the hybrid measure-correlate-predict (MCP) methodology, enabling it to account for variations of both wind speed and direction. The advanced hybrid MCP method uses the recorded data of multiple reference stations to estimate the long-term wind condition at a target wind plant site. The results show that the accuracy of the hybrid MCP method is highly sensitive to the combination of the individual MCP algorithms and reference stations. It was also found that the best combination of MCP algorithms varies based on the length of the correlation period.

  9. Correlation of Chromosomal Instability, Telomere Length and Telomere Maintenance in Microsatellite Stable Rectal Cancer: A Molecular Subclass of Rectal Cancer

    PubMed Central

    Boardman, Lisa A.; Johnson, Ruth A.; Viker, Kimberly B.; Hafner, Kari A.; Jenkins, Robert B.; Riegert-Johnson, Douglas L.; Smyrk, Thomas C.; Litzelman, Kristin; Seo, Songwon; Gangnon, Ronald E.; Engelman, Corinne D.; Rider, David N.; Vanderboom, Russell J.; Thibodeau, Stephen N.; Petersen, Gloria M.; Skinner, Halcyon G.

    2013-01-01

    Introduction Colorectal cancer (CRC) tumor DNA is characterized by chromosomal damage termed chromosomal instability (CIN) and excessively shortened telomeres. Up to 80% of CRC is microsatellite stable (MSS) and is historically considered to be chromosomally unstable (CIN+). However, tumor phenotyping depicts some MSS CRC with little or no genetic changes, thus being chromosomally stable (CIN-). MSS CIN- tumors have not been assessed for telomere attrition. Experimental Design MSS rectal cancers from patients ?50 years old with Stage II (B2 or higher) or Stage III disease were assessed for CIN, telomere length and telomere maintenance mechanism (telomerase activation [TA]; alternative lengthening of telomeres [ALT]). Relative telomere length was measured by qPCR in somatic epithelial and cancer DNA. TA was measured with the TRAPeze assay, and tumors were evaluated for the presence of C-circles indicative of ALT. p53 mutation status was assessed in all available samples. DNA copy number changes were evaluated with Spectral Genomics aCGH. Results Tumors were classified as chromosomally stable (CIN-) and chromosomally instable (CIN+) by degree of DNA copy number changes. CIN- tumors (35%; n=6) had fewer copy number changes (<17% of their clones with DNA copy number changes) than CIN+ tumors (65%; n=13) which had high levels of copy number changes in 20% to 49% of clones. Telomere lengths were longer in CIN- compared to CIN+ tumors (p=0.0066) and in those in which telomerase was not activated (p=0.004). Tumors exhibiting activation of telomerase had shorter tumor telomeres (p=0.0040); and tended to be CIN+ (p=0.0949). Conclusions MSS rectal cancer appears to represent a heterogeneous group of tumors that may be categorized both on the basis of CIN status and telomere maintenance mechanism. MSS CIN- rectal cancers appear to have longer telomeres than those of MSS CIN+ rectal cancers and to utilize ALT rather than activation of telomerase. PMID:24278232

  10. Ladybug Lengths

    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.

  11. Corner cube reflector lateral displacement evaluation simultaneously with interferometer length measurement

    NASA Astrophysics Data System (ADS)

    Zamiela, Grzegorz; Dobosz, Marek

    2013-09-01

    The novel corner cube reflector (CCR) system for a distance measuring interferometer is presented. The proposed system allows reflector lateral displacement evaluation (relative to the beam axis) simultaneously with the interferometer length measurement. Laser beam in measuring arm of the interferometer is divided into two parallel beams that are used for the interferometer distance measurement and lateral shifts of the assembly in relation to the beam axis.The CCR assembly is based on applying a position sensitive detector placed behind the CCR that has truncated vertex. Due to the proposed configuration of the cube corner and photodetector, the rotations of the CCR assembly does not cause error in the lateral displacement measurement in relation to the beam axis.The theoretical analysis and experimental verification of the system metrological feasibilities are presented. The general limitations and design problems are shown. The proposed system can be used basically for measurement and compensation of global or local cosine errors especially in short range of the interferometer displacement measurement, where known techniques are ineffective. Possible applications of the system for Coordinate Measuring Machines accuracy testing are indicated.

  12. Power and frequency measurements from a uniform backward wave oscillator as a function of length

    SciTech Connect

    Moreland, L.D.; Roitman, A.M.; Schamiloglu, E.; Pegel, I.V. [Univ. of New Mexico, Albuquerque, NM (United States); Lemke, R.W. [Sandia National Labs., Albuquerque, NM (United States)

    1994-12-31

    The authors describe results from an experiment where the number of ripple periods in the slow wave structure of a backward wave oscillator (BWO) is increased. Both microwave power and frequency measurements are made for each shot. For a given cathode voltage and beam current, the microwave peak power and frequency are plotted as a function of BWO length. In previous investigations, the observation of two power maxima as a function of length was explained by the interaction of the electron beam with the forward traveling wave and reflections at the transition from the slow wave structure into the output waveguide. However, recent numerical calculations using the phase dynamics of electron beam and electromagnetic modes suggest that the power maxima are due to the phase relationship between the electron beam density wave and the backward wave. Experiments were performed on the Sinus-6, a relativistic electron beam accelerator. By adjusting the pressure in the Sinus-6 spark gap switch, cathode voltages between 400 kV to 650 kV can be obtained. The experiment was repeated for different sets of beam parameters. In all cases, the magnetic field used for beam transport was longer than the length of the slow wave structure. The experimental results are compared with phase model calculations and PIC code simulations using KARAT and TWOQUICK.

  13. Identification of source of oscillations in apparent sarcomere length measured by laser diffraction.

    PubMed Central

    Burton, K; Huxley, A F

    1995-01-01

    The most widely used technique for dynamic estimates of sarcomere length in muscle is laser light diffraction. We have identified conditions under which artifactual oscillations can arise in apparent sarcomere length measured by this technique and report methods to reduce the effect. Altringham et al. (1984) first reported that the diffraction angle can exhibit one cycle of oscillation for each sarcomere length displacement of the illuminated portion of the fiber. We find that the amplitude of similar oscillations is strongly dependent on the intensity of light scattered from objects near the fiber and on the spacing between fiber and scatterer. The oscillations can be eliminated by minimizing scattered light and positioning the fiber a few millimeters from sources of scattering. A theoretical description shows that oscillations of this kind are expected from interference of scattered and diffracted light. Interference fringes were observed along the meridian of the pattern, and these moved during translation of either a fiber or a grating. The movement of fringes across the diffraction order shifts the centroid back and forth and, when associated with steady shortening, can give rise to "steps" and "pauses" in apparent striation spacing. Images FIGURE 1 FIGURE 3 FIGURE 4 FIGURE 5 FIGURE 6 FIGURE 7 FIGURE 8 PMID:7647247

  14. Comparison between Conventional Blind Embryo Transfer and Embryo Transfer Based on Previously Measured Uterine Length

    PubMed Central

    Saharkhiz, Nasrin; Nikbakht, Roshan; Salehpour, Saghar

    2014-01-01

    Background Embryo transfer (ET) is one of the most important steps in assisted re- productive technology (ART) cycles and affected by many factors namely the depth of embryo deposition in uterus. In this study, the outcomes of intracytoplasmic sperm injec- tion (ICSI) cycles after blind embryo transfer and embryo transfer based on previously measured uterine length using vaginal ultrasound were compared. Materials and Methods This prospective randomised clinical trial included one hun- dred and forty non-donor fresh embryo transfers during January 2010 to June 2011. In group I, ET was performed using conventional (blind) method at 5-6cm from the external os, and in group II, ET was done at a depth of 1-1.5 cm from the uterine fundus based on previously measured uterine length using vaginal sonography. Appropriate statistical analysis was performed using Student’s t test and Chi-square or Fisher’s exact test. The software that we used was PASW statistics version 18. A p value <0.05 was considered statistically significant. Results Chemical pregnancy rate was 28.7% in group I and 42.1% in group II, while the difference was not statistically significant (p=0.105). Clinical pregnancy, ongoing preg- nancy and implantation rates for group I were 21.2%, 17.7%, and 12.8%, while for group II were 33.9%, 33.9%, and 22.1, respectively. In group I and group II, abortion rates were 34.7% and 0%, respectively, indicating a statistically significant difference (p<0.005). No ectopic pregnancy occurred in two groups. Conclusion The use of uterine length measurement during treatment cycle in order to place embryos at depth of 1-1.5cm from fundus significantly increases clinical and ongo- ing pregnancy and implantation rates, while leads to a decrease in abortion rate (Registra- tion Number: IRCT2014032512494N1). PMID:25379152

  15. Note: emittance measurements of intense pulsed proton beam for different pulse length and repetition rate.

    PubMed

    Miracoli, R; Gammino, S; Celona, L; Castro, G; Mascali, D; Gobin, R; Delferrière, O; Adroit, G; Senèe, F; Ciavola, G

    2012-05-01

    The high intensity ion source (SILHI), in operation at CEA-Saclay, has been used to produce a 90 mA pulsed proton beam with pulse length and repetition rates suitable for the European Spallation Source (ESS) linac. Typical r-r(') rms normalized emittance values smaller than 0.2? mm mrad have been measured for operation in pulsed mode (0.01 < duty cycle < 0.15 and 1 ms < pulse duration < 10 ms) that are relevant for the design update of the Linac to be used at the ESS in Lund. PMID:22667673

  16. Note: Emittance measurements of intense pulsed proton beam for different pulse length and repetition rate

    NASA Astrophysics Data System (ADS)

    Miracoli, R.; Gammino, S.; Celona, L.; Castro, G.; Mascali, D.; Gobin, R.; Delferrière, O.; Adroit, G.; Senèe, F.; Ciavola, G.

    2012-05-01

    The high intensity ion source (SILHI), in operation at CEA-Saclay, has been used to produce a 90 mA pulsed proton beam with pulse length and repetition rates suitable for the European Spallation Source (ESS) linac. Typical r-r' rms normalized emittance values smaller than 0.2? mm mrad have been measured for operation in pulsed mode (0.01 < duty cycle < 0.15 and 1 ms < pulse duration < 10 ms) that are relevant for the design update of the Linac to be used at the ESS in Lund.

  17. 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.

  18. Information Measures for Long-Range Correlated Sequences: the Case of the 24 Human Chromosome Sequences

    E-print Network

    Carbone, A

    2013-01-01

    The Shannon (block) entropy of the clusters generated by intersecting a long-range correlated sequence with its moving average is studied. The entropy is given by two terms, respectively increasing logarithmically and linearly (besides a constant term), corresponding to clusters with power-law or exponentially distributed lengths. Then, the entropy measure is implemented on the 24 human chromosome sequences. Interestingly, it is found that, for the power-law correlated clusters, the nucleotide composition is, on the average, equal to the nucleotide composition of the whole sequence, while, for the exponentially correlated clusters, it fluctuates around the average value. Even more interestingly, it is found that the variance of the fluctuations is a characteristic property of each chromosome. How these fluctuations correlate to biological properties such as segmental duplications, gene density of each chromosome is finally discussed.

  19. Asynchronous quantum correlation: measurement acting as a beamsplitter

    E-print Network

    F. V. Kowalski; R. S. Browne

    2014-08-25

    A two-body quantum correlation is calculated for a particle either reflecting from a mirror, traversing a finite barrier/well, or trapped within an infinite well. Correlated interference results when the incident and reflected particle substates and their associated mirror (or barrier-well) substates overlap. Using the Copenhagen interpretation, an asynchronous joint probability density, which is a function both of the different positions and different times at which the particle and mirror (or barrier-well) are measured, is derived assuming that no interaction occurs between each measurement. Measurement of the particle first, in the correlated interference region, causes a splitting of the mirror (or barrier-well) substate into ones which have and have not reflected the particle. Later measurement of the mirror's (or barrier-well's) position reveals this interference. Synchronous correlated interference is limited spatially and temporally by the two-body wavegroup size and speed. However, the splitting caused by first measuring the particle can prolong the interference of these split mirror (or barrier-well) states. An analog of the Doppler shift in this two-body system is shown to be a consequence of the asynchronous measurement formalism. Coherence transfer and the use of asynchronous correlations to observe macroscopic interference effects in the mirror (or barrier-well), after having reflected a microscopic particle, are also described. This theoretical work, modeling asynchronous measurement in such two-body systems, relies fundamentally on wavefunction collapse.

  20. The Measurement and Correlates of Career Decision Making.

    ERIC Educational Resources Information Center

    Harren, Vincent A.; Kass, Richard A.

    This paper presents a theoretical framework for understanding career decision making (CDM); introduces an instrument, Assessment of Career Decision Making (ACDM) to measure CDM with college students; and presents correlational data on sex role and cognitive style factors hypothesized to influence CDM. The ACDM, designed to measure the Tiedeman and…

  1. Spectral radiance measurements and calculated soot concentrations along the length of an experimental combustor

    NASA Technical Reports Server (NTRS)

    Norgren, C. T.; Ingebo, R. D.

    1976-01-01

    Radiometric data were obtained over a range of parametric test conditions at three positions along the length of an experimental combustor segment corresponding to the primary, intermediate, and dilution zones. The concentration of soot entrained in the combustion gases was calculated by a technique using spectral radiance measurements. Tests were conducted primarily with Jet A fuel, although limited data were taken with two fuels having higher aromatic content, diesel oil number 2 and a blend of 40 percent tetralin in Jet A fuel. Radiometric observation of the combustion gases indicated that the maximum total radiance peaked at the intermediate zone, which was located immediately upstream of the dilution holes. Soot concentrations calculated from optical measurements in the dilution zone compared favorably with those obtained by in situ gas sampling at the exhaust. The total radiance increased with the higher aromatic content fuels.

  2. Design of measurement-based correlation models for shadow fading

    Microsoft Academic Search

    Matthias Patzold; Nurilla Avazov; V. D. Nguyen

    2010-01-01

    This paper deals with the design of measurement-based correlation models for shadow fading. Based on the correlation model, we design a simulation model using the sumof-sinusoids (SOS) method to enable the simulation of spatial lognormal processes characterizing real-world shadow fading scenarios. The model parameters of the simulation model are computed by applying the Lp-norm method (LPNM). This method facilitates an

  3. Sonar Measurement of Fetal Crown-Rump Length as Means of Assessing Maturity in First Trimester of Pregnancy

    Microsoft Academic Search

    Hugh P. Robinson

    1973-01-01

    A method is reported by which the “in utero” crown-rump length of the fetus may be determined by sonar in the first trimester of pregnancy. The accuracy of the technique was assessed by comparing the sonar and the direct postabortum measurements of fetuses in cases of missed abortion. A normal curve of fetal crown-rump length was derived from 214 examinations

  4. Overcoming ambiguities in classical and quantum correlation measures

    NASA Astrophysics Data System (ADS)

    Paula, F. M.; Saguia, A.; de Oliveira, Thiago R.; Sarandy, M. S.

    2014-10-01

    We identify ambiguities in the available frameworks for defining quantum, classical, and total correlations as measured by discord-like quantifiers. More specifically, we determine situations for which either classical or quantum correlations are not uniquely defined due to degeneracies arising from the optimization procedure over the state space. In order to remove such degeneracies, we introduce a general approach where correlations are independently defined, escaping therefore from a degenerate subspace. As an illustration, we analyze the trace-norm geometric quantum discord for two-qubit Bell-diagonal states.

  5. Scattering Corrections in Neutron ?-decay Angular Correlation Measurements

    NASA Astrophysics Data System (ADS)

    Pattie, Robert

    2010-11-01

    Measurements of angular correlations in neutron ?-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 Carlo simulation to estimate this systematic effect on the measured ? asymmetry A. Other experiments, proposed and active, will measure angular correlations using similar detection methods. We will discuss our results as well as the general implications of these simulations as they apply to other detector geometries and electric/magnetic field profiles.

  6. In vivo measurement of ACL length and relative strain during walking

    PubMed Central

    Taylor, K A; Cutcliffe, H C; Queen, R M; Utturkar, G M; Spritzer, C E; Garrett, W E; DeFrate, L E

    2012-01-01

    Although numerous studies have addressed the effects of ACL injury and reconstruction on knee joint motion, there is currently little data available describing in vivo ACL strain during activities of daily living. Data describing in vivo ACL strain during activities such as gait is critical to understanding the biomechanical function of the ligament, and ultimately, to improving the surgical treatment of patients with ACL rupture. Thus, our objective was to characterize the relative strain in the ACL during both the stance and swing phases of normal level walking. Eight normal subjects were recruited for this study. Through a combination of magnetic resonance imaging, biplanar fluoroscopy, and motion capture, we created in vivo models of each subject’s normal walking movements to measure knee flexion, ACL length, and relative ACL strain during gait. Regression analysis demonstrated an inverse relationship between knee flexion and ACL length (R2=0.61, p<0.001). Furthermore, relative strain in the ACL peaked at 13±2% (mean± 95%CI) during mid-stance when the knee was near full extension. Additionally, there was a second local maximum of 10±7% near the end of swing phase, just prior to heel strike. These data are a vital step in further comprehending the normal in vivo biomechanics experienced by the ACL. In the future, this information could prove critical to improving ACL reconstruction and provide useful validation to future computational models investigating ACL function. PMID:23178040

  7. Diffraction effects in coherent transition radiation diagnostics for sub-mm bunch length measurement

    SciTech Connect

    Maxwell, T.J.; Mihalcea, D.; /Northern Illinois U.; Piot, P.; /Northern Illinois U. /Fermilab

    2008-09-01

    Electrons crossing the boundary between different media generate bursts of transition radiation. In the case of bunches of N electrons, the radiation is coherent and has an N-squared enhancement at wavelengths related to the longitudinal bunch distribution. This coherent transition radiation has therefore attracted attention as an interceptive charged particle beam diagnostic technique. Many analytical descriptions have been devised describing the spectral distribution generated by electron bunches colliding with thin metallic foils making different simplifying assumptions. For typical bunches having lengths in the sub-millimeter range, measurable spectra are generated up into the millimeter range. Analysis of this THz radiation is performed using optical equipment tens of millimeters in size. This gives rise to concern that optical diffraction effects may spread the wavefront of interest into regions larger than the optical elements and partially escape detection, generating a wavelength-dependent instrument response. In this paper we present a model implementing vector diffraction theory to analyze these effects in bunch length diagnostics based on coherent transition radiation.

  8. Contact line extraction and length measurements in model sediments and sedimentary rocks.

    PubMed

    Rodriguez, Elena; Prodanovi?, Maša; Bryant, Steven L

    2012-02-15

    The mechanisms that govern the transport of colloids in the unsaturated zone of soils are still poorly understood, because of the complexity of processes that occur at pore scale. These mechanisms are of specific interest in quantifying water quality with respect to pathogen transport (e.g. Escherichia coli, Cryptosporidium) between the source (e.g. farms) and human users. Besides straining in pore throats and constrictions of smaller or equivalent size, the colloids can be retained at the interfaces between air, water, and grains. Theories competing to explain this mechanism claim that retention can be caused by adhesion at the air-water-interface (AWI) between sediment grains or by straining at the air-water-solid (AWS) contact line. Currently, there are no established methods for the estimation of pathogen retention in unsaturated media because of the intricate influence of AWI and AWS on transport and retention. What is known is that the geometric configuration and connectivity of the aqueous phase is an important factor in unsaturated transport. In this work we develop a computational method based on level set functions to identify and quantify the AWS contact line (in general the non-wetting-wetting-solid contact line) in any porous material. This is the first comprehensive report on contact line measurement for fluid configurations from both level-set method based fluid displacement simulation and imaged experiments. The method is applicable to any type of porous system, as long as the detailed pore scale geometry is available. We calculated the contact line length in model sediments (packs of spheres) as well as in real porous media, whose geometry is taken from high-resolution images of glass bead packs and sedimentary rocks. We observed a strong dependence of contact line length on the geometry of the sediment grains and the arrangement of the air and water phases. These measurements can help determine the relative contribution of the AWS line to pathogen retention. PMID:22154497

  9. Phase-noise-compensated optical frequency domain reflectometry with measurement range beyond laser coherence length realized using concatenative reference method.

    PubMed

    Fan, Xinyu; Koshikiya, Yusuke; Ito, Fumihiko

    2007-11-15

    A novel type of optical frequency domain reflectometry with a measurement range much longer than the laser coherence length is proposed and experimentally demonstrated. To reduce the influence of laser phase noise, the measurement signal is compensated by using reference signals generated from a single auxiliary interferometer supported by a newly proposed compensation process. The compensation is accomplished numerically with a computer for each section of the delay fiber length in an auxiliary interferometer after only one data acquisition. By using the proposed technique, it is confirmed experimentally that the laser phase noise is well compensated even beyond the coherence length. PMID:18026262

  10. Two Point Space-Time Correlation of Density Fluctuations Measured in High Velocity Free Jets

    NASA Technical Reports Server (NTRS)

    Panda, Jayanta

    2006-01-01

    Two-point space-time correlations of air density fluctuations in unheated, fully-expanded free jets at Mach numbers M(sub j) = 0.95, 1.4, and 1.8 were measured using a Rayleigh scattering based diagnostic technique. The molecular scattered light from two small probe volumes of 1.03 mm length was measured for a completely non-intrusive means of determining the turbulent density fluctuations. The time series of density fluctuations were analyzed to estimate the integral length scale L in a moving frame of reference and the convective Mach number M(sub c) at different narrow Strouhal frequency (St) bands. It was observed that M(sub c) and the normalized moving frame length scale L*St/D, where D is the jet diameter, increased with Strouhal frequency before leveling off at the highest resolved frequency. Significant differences were observed between data obtained from the lip shear layer and the centerline of the jet. The wave number frequency transform of the correlation data demonstrated progressive increase in the radiative part of turbulence fluctuations with increasing jet Mach number.

  11. Measuring telomere length and telomere dynamics in evolutionary biology and ecology

    PubMed Central

    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.

  12. Extension of traceable calibration for electronic distance measuring instruments beyond the length of the laboratory

    NASA Astrophysics Data System (ADS)

    Forde, Lucy C.; Howick, Eleanor F.

    2003-11-01

    Electronic distance measuring instruments (EDMs) are devices used by surveyors where calibrated tape measures are not adequate or appropriate. Modern EDMs are generally accurate and reliable, are commonly capable of measuring up to 6 km, and may be combined with an electronic theodolite in a total station unit. Precise traceable calibration of EDMs is possible using a linear displacement interferometer, for example, with the respective reflectors in back-to-back configuration. Calibration data may be analysed for scale error and cyclical error. The distances so calibrated are usually constrained by the length of laboratory (and/or straight rails) available, as well as by the maximum working distance of the interferometer, but may be extended further with caution by the introduction of mirrors to fold the EDM beam. This paper describes the apparatus used to calibrate an EDM up to 200 m in a 60 m laboratory, and investigates some of the problems and artefacts that can arise, for example, from unwanted intermediate reflections of the EDM beam.

  13. Length scales and structural dynamics in nematogen pseudonematic domains measured with 2D IR vibrational echoes and optical Kerr effect experiments.

    PubMed

    Sokolowsky, Kathleen P; Bailey, Heather E; Fayer, Michael D

    2014-07-17

    Nematogen liquids in the isotropic phase are macroscopically homogeneous but on multinanometer length scales have pseudonematic domains with correlation lengths that grow as the isotropic to nematic phase transition temperature (TNI) is approached from above. Orientational relaxation of nematogens in the isotropic phase manifests as two fast power laws and a slow exponential decay when measured by optical heterodyne detected optical Kerr effect (OHD-OKE) experiments. The long time exponential relaxation is associated with complete randomization of pseudonematic domains. We examine the effect of local orientational correlation on spectral diffusion (structural evolution) experienced by a vibrational probe molecule within the pseudonematic domains of 4-cyano-4'-pentylbiphenyl (5CB) using two-dimensional infrared (2D IR) vibrational echo spectroscopy. The addition of low concentration 4-pentyl-4'-thiocyanobiphenyl (5SCB) as a long-lived vibrational probe to 5CB is shown to lower TNI of the sample slightly, but the fast power law dynamics and exponential decays observed by OHD-OKE spectroscopy are unchanged. We compare the complete orientational relaxation and spectral diffusion for samples of 5SCB in 5CB to 5SCB in 4-pentylbiphenyl (5B) at four temperatures above TNI. 5B has a molecular structure similar to 5CB but is not a nematogen. At all but the lowest temperature, the spectral diffusion in 5CB and 5B is described well as a triexponential decay with very similar time constants. The results demonstrate that the presence of local orientational order at temperatures well above TNI does not affect the spectral diffusion (structural evolution) within pseudonematic domains when the correlation lengths are short. However, when the temperature of the sample is held very close to TNI, the spectral diffusion in 5CB slows dramatically while that in 5B does not. It is only as the correlation length becomes very long that its presence impacts the spectral diffusion (structural fluctuations) sensed by the vibrational probes located in pseudonematic domains. The orientational relaxation is modeled with schematic mode coupling theory (MCT). Fitting with MCT provides density and orientational correlation functions. The density correlation decays are similar for 5B and 5CB, but the orientational correlation decays are much slower for 5CB. Additionally, the time dependence of the spectral diffusion in 5CB is strikingly similar to that of the density correlation function decay, while the orientational correlation function decay is far too slow to contribute to the spectral diffusion. Therefore, density fluctuations are likely the source of spectral diffusion at temperatures at least 5 K above TNI. PMID:24521155

  14. The correlation of organoleptic and instrumental halitosis measurements.

    PubMed

    Brunner, Flavio; Kurmann, Miranda; Filippi, Andreas

    2010-01-01

    Numerous detection systems are available for measuring halitosis. In order to examine their agreement, a study was conducted comparing four selected measuring methods in 100 subjects (52 females, 48 males; mean age: 25 years). Organoleptic halitosis measurement was carried out by an odor judge, and compared with instrumental halitosis measurement by sulfide monitoring using Halimeter, Fresh Kiss, and Halitox (halitosis linked toxin detection assay), with which both VSC (volatile sulphur compounds) and polyamines can be detected. The results show that the values recorded by the Halimeter correlated best with the organoleptic assessment and the least with the results of Fresh Kiss. PMID:20533102

  15. Accuracy of axial length measurements from immersion B-scan ultrasonography in highly myopic eyes

    PubMed Central

    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

  16. CORRELATION OF EGG PHYSICAL QUALITY MEASUREMENTS AND FUNCTIONAL DETERMINATIONS

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Both physical and functional determinations have served as a means for determining shell egg quality. A study was conducted to determine if correlations exist between these types of egg quality measurements. Shell eggs were collected weekly after processing from a U.S. inline processing facility f...

  17. PROTOTYPE CORRELATION MASK FLAME PHOTOMETRIC DETECTOR FOR MEASURING SULFUR DIOXIDE

    EPA Science Inventory

    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...

  18. PAIN MEDICINE Neural Correlates of Chronic Low Back Pain Measured

    E-print Network

    Napadow, Vitaly

    PAIN MEDICINE Neural Correlates of Chronic Low Back Pain Measured by Arterial Spin Labeling Ajay D.D., Randy L. Gollub, M.D., Ph.D.# ABSTRACT Background: The varying nature of chronic pain (CP) is difficult and radicular pain and matched healthy normal subjects, undergoing identical procedures, participated in three

  19. The Measurement and Lensing of the Faint Source Correlation Function

    NASA Astrophysics Data System (ADS)

    Morganson, Eric P.

    2009-01-01

    The faint source correlation function (FSCF) has previously been a barely measured and totally unused quantity. While it had been tentatively observed down to scales of a few arcseconds in the HDF, its amplitude was on the order of 10-1. I show, using a combination of higher quality data (GOODS and UDF), superior pair-finding source extraction and extensive use of custom image simulations to counter systematics, that the FSCF is not only measurable down to scales of 0.3'' (2.6 kpc at most) but that on such short distance scales it also exceeds unity for 25 < V < 28 sources. My measurement of the FSCF as a power law with an index of -2.5 rather than the measured large-scale index of -0.7 shows that the physics of galactic-scale correlation functions is different from that of the cosmological correlation function. I also measured a reduced three point correlation function, confirming that the FSCF is non-Gaussian, and used the measurement of close pairs to set upper limits on the cosmic string density. Applications of lensing on the FSCF are most interesting. I show, theoretically, that gravitational lenses induce a local anisotropy in the FSCF that is proportional to the lensing shear. For lenses of known mass profile, we can invert the lens equation to solve for the distance to the source using the shear and the induced anisotropy. This produces a distance estimate of the faintest sources without using any spectral information. I establish the framework for using this technique with a large population of galaxy scale lenses, a single large cluster lens or a large field with cosmic shear. Large future datasets with a wide range of lens redshifts will allow us to measure this effect precisely to gain a true, non-spectral distance distribution of the faintest sources.

  20. Comparative Study of Bunch Length And Arrival Time Measurements at FLASH

    SciTech Connect

    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.

  1. Correlation measurements with {sup 252}Cf to characterize fissile material

    SciTech Connect

    Mattingly, J.K.; Mihalczo, J.T.; Valentine, T.E.; Mullens, J.A.; March-Leuba, J.; Uckan, T.

    2000-07-01

    Measurements using {sup 252}Cf as a timed source of neutrons and gammas have in recent years undergone significant maturation. These methods use {sup 252}Cf as an observable source of spontaneous fission neutrons and gammas in conjunction with one or more neutron-sensitive and/or gamma-sensitive detectors to measure the time distribution of correlated detector counts following (a) an observed {sup 252}Cf-fission event and/or (b) a counting event in another detector. Detection of {sup 252}Cf spontaneous fission is frequently achieved via use of a small ionization chamber in which the {sup 252}Cf is contained; in this case, the timing of source emission events is random. However, one application subsequently described uses a neutron-absorbent shutter to modulate {sup 252}Cf emissions to produce a neutron source with deterministic timing. Other applications, frequently termed noise-analysis measurements, transform the time distributions to the frequency domain. Collectively, these correlation methods use {sup 252}Cf to excite the fissile ray of detectors and analyzed using standard time-correlation and/or frequency-analysis techniques. In recent years, numerous advances have been made in the application of these methods to in situ or field measurements directed at characterizing various configurations of fissile material in operational facilities. Applications include reactor physics measurements, nuclear criticality safety, nondestructive analysis and nonintrusive monitoring of enrichment (or deenrichment) processes, and inventory tracking for nuclear materials control and accountability.

  2. Measurement-induced disturbances and nonclassical correlations of Gaussian states

    SciTech Connect

    Mista, Ladislav Jr. [Department of Optics, Palacky University, 17. listopadu 12, CZ-771 46 Olomouc (Czech Republic); School of Physics and Astronomy, University of St. Andrews, North Haugh, St. Andrews, Fife, KY16 9SS, Scotland (United Kingdom); Tatham, Richard; Korolkova, Natalia [School of Physics and Astronomy, University of St. Andrews, North Haugh, St. Andrews, Fife, KY16 9SS, Scotland (United Kingdom); Girolami, Davide; Adesso, Gerardo [School of Mathematical Sciences, University of Nottingham, University Park, Nottingham NG7 2RD (United Kingdom)

    2011-04-15

    We study quantum correlations beyond entanglement in two-mode Gaussian states of continuous-variable systems by means of the measurement-induced disturbance (MID) and its ameliorated version (AMID). In analogy with the recent studies of the Gaussian quantum discord, we define a Gaussian AMID by constraining the optimization to all bi-local Gaussian positive operator valued measurements. We solve the optimization explicitly for relevant families of states, including squeezed thermal states. Remarkably, we find that there is a finite subset of two-mode Gaussian states comprising pure states where non-Gaussian measurements such as photon counting are globally optimal for the AMID and realize a strictly smaller state disturbance compared to the best Gaussian measurements. However, for the majority of two-mode Gaussian states the unoptimized MID provides a loose overestimation of the actual content of quantum correlations, as evidenced by its comparison with Gaussian discord. This feature displays strong similarity with the case of two qubits. Upper and lower bounds for the Gaussian AMID at fixed Gaussian discord are identified. We further present a comparison between Gaussian AMID and Gaussian entanglement of formation, and classify families of two-mode states in terms of their Gaussian AMID, Gaussian discord, and Gaussian entanglement of formation. Our findings provide a further confirmation of the genuinely quantum nature of general Gaussian states, yet they reveal that non-Gaussian measurements can play a crucial role for the optimized extraction and potential exploitation of classical and nonclassical correlations in Gaussian states.

  3. Measurement of electrostriction in bone using digital image correlation

    NASA Astrophysics Data System (ADS)

    Xu, Lianyun; Hou, Zhende; Fu, Donghui; Yang, Lei; Yi, Weitian; Kang, Huimin

    2015-02-01

    The electromechanical properties of bone may play roles in the growth of bone tissue. The electrostriction effect of bone, which is one of the electromechanical properties of bone, was investigated using the digital image correlation technique (DIC). The advantage of using DIC is that the light beam used for the displacement measurement does not interfere with the electric field exerted on the bone specimen. To measure the bending deflections of a bone cantilever in an electric field, the displacement of the free end surface of the cantilever was measured using the image correlation technique. The experimental results show that the bending direction of the bone cantilevers is independent of the electric field direction and that the bending deflections are proportional to the square of the applied voltages. The attractive force between the charges on the electrode and the unlike charges in the specimen can be equivalent to a uniform distribution load regardless of the thickness of the bone specimen.

  4. 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.

  5. Correlation techniques and measurements of wave-height statistics

    NASA Technical Reports Server (NTRS)

    Guthart, H.; Taylor, W. C.; Graf, K. A.; Douglas, D. G.

    1972-01-01

    Statistical measurements of wave height fluctuations have been made in a wind wave tank. The power spectral density function of temporal wave height fluctuations evidenced second-harmonic components and an f to the minus 5th power law decay beyond the second harmonic. The observations of second harmonic effects agreed very well with a theoretical prediction. From the wave statistics, surface drift currents were inferred and compared to experimental measurements with satisfactory agreement. Measurements were made of the two dimensional correlation coefficient at 15 deg increments in angle with respect to the wind vector. An estimate of the two-dimensional spatial power spectral density function was also made.

  6. Individual differences in allocation of funds in the dictator game associated with length of the arginine vasopressin 1a receptor RS3 promoter region and correlation between RS3 length and hippocampal mRNA.

    PubMed

    Knafo, A; Israel, S; Darvasi, A; Bachner-Melman, R; Uzefovsky, F; Cohen, L; Feldman, E; Lerer, E; Laiba, E; Raz, Y; Nemanov, L; Gritsenko, I; Dina, C; Agam, G; Dean, B; Bornstein, G; Ebstein, R P

    2008-04-01

    Human altruism is a widespread phenomenon that puzzled evolutionary biologists since Darwin. Economic games illustrate human altruism by showing that behavior deviates from economic predictions of profit maximization. A game that most plainly shows this altruistic tendency is the Dictator Game. We hypothesized that human altruistic behavior is to some extent hardwired and that a likely candidate that may contribute to individual differences in altruistic behavior is the arginine vasopressin 1a (AVPR1a) receptor that in some mammals such as the vole has a profound impact on affiliative behaviors. In the current investigation, 203 male and female university students played an online version of the Dictator Game, for real money payoffs. All subjects and their parents were genotyped for AVPR1a RS1 and RS3 promoter-region repeat polymorphisms. Parents did not participate in online game playing. As variation in the length of a repetitive element in the vole AVPR1a promoter region is associated with differences in social behavior, we examined the relationship between RS1 and RS3 repeat length (base pairs) and allocation sums. Participants with short versions (308-325 bp) of the AVPR1a RS3 repeat allocated significantly (likelihood ratio = 14.75, P = 0.001, df = 2) fewer shekels to the 'other' than participants with long versions (327-343 bp). We also implemented a family-based association test, UNPHASED, to confirm and validate the correlation between the AVPR1a RS3 repeat and monetary allocations in the dictator game. Dictator game allocations were significantly associated with the RS3 repeat (global P value: likelihood ratio chi(2) = 11.73, df = 4, P = 0.019). The association between the AVPR1a RS3 repeat and altruism was also confirmed using two self-report scales (the Bardi-Schwartz Universalism and Benevolence Value-expressive Behavior scales). RS3 long alleles were associated with higher scores on both measures. Finally, long AVPR1a RS3 repeats were associated with higher AVPR1a human post-mortem hippocampal messenger RNA levels than short RS3 repeats (one-way analysis of variance (ANOVA): F = 15.04, P = 0.001, df = 14) suggesting a functional molecular genetic basis for the observation that participants with the long RS3 repeats allocate more money than participants with the short repeats. This is the first investigation showing that a common human polymorphism, with antecedents in lower mammals, contributes to decision making in an economic game. The finding that the same gene contributing to social bonding in lower animals also appears to operate similarly in human behavior suggests a common evolutionary mechanism. PMID:17696996

  7. Measuring short electron bunch lengths using coherent smith-purcell radiation

    DOEpatents

    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.

  8. GENETIC PARAMETERS FOR SIX MEASURES OF LENGTH OF PRODUCTIVE LIFE AND THREE MEASURES OF LIFETIME PRODUCTION BY SIX YEARS AFTER FIRST CALVING FOR HEREFORD COWS

    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...

  9. Improved extended digital image correlation for crack tip deformation measurement

    NASA Astrophysics Data System (ADS)

    Chen, Jinlong; Zhan, Nan; Zhang, Xiaochuan; Wang, Jixiao

    2015-02-01

    The objective is to find an appropriate shape function which can enhance the performance of Extended Digital Image Correlation (X-DIC). This paper presents an improved X-DIC methodology to measure the discontinuous deformation across the crack. After simplifying the shape function of crack tip element based on the linear elastic fracture mechanics, non-rectangular subset is proposed to eliminate the effect of the crack width on the measurement accuracy. Then, the work verifies the performance of improved X-DIC by measuring the deformation of a specimen with a mode I crack. Experimental results show that the proposed method is effective at improving the measurement accuracy and enhancing the computational efficiency of X-DIC. In the end, the thesis provides a practical application of improved X-DIC to crack tip deformation measurement.

  10. Used digital speckle correlation method to measure vibration

    NASA Astrophysics Data System (ADS)

    Yan, Haitao; Zhen, Zhiqiang; Tang, Zhengxin

    2009-11-01

    Used digital speckle correlation method (DSCM) to measure is researched. The experiment is designed and the laser irradiates a PZT which is driven by some signal to obtain the dynamic speckle patterns. The dynamic speckle patterns are shot by CCD, then the DSCM is used to process the sequential images and also the experiment is simulated. The movement of reflection target is controlled by PZT which is driven by the different model signal. When the reflection target is moving, the dynamic speckle patterns are shot by CCD, the sequential images are stored in computer through an image board. Then the digital speckle correlation method is used to process the sequential images. There are three output parameters after the images correlation calculation: (xi ,yi) and ? that represent for position and moving direction of the object, Initial (xi ,yi) is (0,0). (?xi , ?yi) represents pixel difference in coordinates of two adjacent images. ? is the angle specifying the direction of the object's motion relative to the x-axis: ??[00,900]. Varying the speed of the aluminum plate, variant values of (?xi ,?i) are obtained and varying the direction of numeric control caterpillar track, variant values of ? were obtained. From the obtained displacement and the collected frequency, the vibration frequency was obtained. The experimental results show the DSCM can confirm the frequency and displacement of vibration, and have a good agreement with the simulation results, and the results show the digital speckle correlation method can be used to measure vibation.

  11. Interplay between computable measures of entanglement and other quantum correlations

    SciTech Connect

    Girolami, Davide; Adesso, Gerardo [School of Mathematical Sciences, University of Nottingham, University Park, Nottingham NG7 2RD (United Kingdom)

    2011-11-15

    Composite quantum systems can be in generic states characterized not only by entanglement but also by more general quantum correlations. The interplay between these two signatures of nonclassicality is still not completely understood. In this work we investigate this issue, focusing on computable and observable measures of such correlations: entanglement is quantified by the negativity N, while general quantum correlations are measured by the (normalized) geometric quantum discord D{sub G}. For two-qubit systems, we find that the geometric discord reduces to the squared negativity on pure states, while the relationship D{sub G}{>=}N{sup 2} holds for arbitrary mixed states. The latter result is rigorously extended to pure, Werner, and isotropic states of two-qudit systems for arbitrary d, and numerical evidence of its validity for arbitrary states of a qubit and a qutrit is provided as well. Our results establish an interesting hierarchy, which we conjecture to be universal, between two relevant and experimentally friendly nonclassicality indicators. This ties in with the intuition that general quantum correlations should at least contain and in general exceed entanglement on mixed states of composite quantum systems.

  12. Isometric Instructions: Measure the length from your elbow to your hand where you grip the handle.

    E-print Network

    Sniadecki, Nathan J.

    . This is will prevent you from using your legs. 3. Grab the handle attached to the load cell and adjust the length be no slack in the chain. The reading on the protractor should be 35 degrees. Have your partner confirm the maximum load achieved. 6. Repeat for arm angles 120, 90, 75, and 60 degrees by adjusting the length

  13. Correlations between LDEX Measurements and the Lunar Plasma Environment

    NASA Astrophysics Data System (ADS)

    Szalay, Jamey; Horanyi, Mihaly; Poppe, Andrew; Halekas, Jasper

    2014-05-01

    The Lunar Dust Experiment (LDEX) aboard the Lunar Atmosphere and Dust Environment Explorer (LADEE) is an impact ionization dust detector capable of measuring the mass of sub-micron sized dust grains above the lunar surface. LDEX can also search for the putative population of grains with radii on the order of ~ 0.1 ?m lofted over the terminator regions by measuring the collective current of dust grains that are below the detection threshold for single impacts. This current, intended to measure the collective impact plasma from multiple small grain impacts, has also shown considerable correlations with plasma measurements from the ARTEMIS (Acceleration, Reconnection, Turbulence, & Electrodynamics of Moon's Interaction with the Sun) mission. Through LADEE's many orbits, LDEX sees time periods with very low variability, having almost no activity as well as periods with very high variability. Since this type of high activity is also observed in anti-ram pointing measurements, much of this current cannot be explained by collections of small dust grain impacts. Given this, comparisons to ARTEMIS data provide a promising way to explain such measurements. This presentation will focus on the correlations between LDEX and ARTEMIS data.

  14. Topography measurements for correlations of standard cartridge cases

    NASA Astrophysics Data System (ADS)

    Vorburger, T. V.; Song, J.; Chu, W.; Renegar, T. B.; Zheng, A.; Yen, J.; Thompson, R. M.; Silver, R.; Bachrach, B.; Ols, M.

    2010-06-01

    The National Institute of Standards and Technology Standard Reference Materials (SRM) 2460 Standard Bullets and 2461 Standard Cartridge Cases are intended for use as check standards for crime laboratories to help verify that their computerized optical imaging equipment for ballistics image acquisitions and correlations is operating properly. Using topography measurements and cross-correlation methods, our earlier results for the SRM bullets and recent results for the SRM cartridge cases both demonstrate that the individual units of the SRMs are highly reproducible. Currently, we are developing procedures for topographic imaging of the firing pin impressions, breech face impressions, and ejector marks of the standard cartridge cases. The initial results lead us to conclude that all three areas can be measured accurately and routinely using confocal techniques. We are also nearing conclusion of a project with crime lab experts to test sets of both SRM cartridge cases and SRM bullets using the automated commercial systems of the National Integrated Ballistics Information Network.

  15. 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.

  16. 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.

  17. Reliability and accuracy of an automated tracking algorithm to measure controlled passive and active muscle fascicle length changes from ultrasound.

    PubMed

    Gillett, Jarred G; Barrett, Rod S; Lichtwark, Glen A

    2013-01-01

    Manual tracking of muscle fascicle length changes from ultrasound images is a subjective and time-consuming process. The purpose of this study was to assess the repeatability and accuracy of an automated algorithm for tracking fascicle length changes in the medial gastrocnemius (MG) muscle during passive length changes and active contractions (isometric, concentric and eccentric) performed on a dynamometer. The freely available, automated tracking algorithm was based on the Lucas-Kanade optical flow algorithm with an affine optic flow extension, which accounts for image translation, dilation, rotation and shear between consecutive frames of an image sequence. Automated tracking was performed by three experienced assessors, and within- and between-examiner repeatability was computed using the coefficient of multiple determination (CMD). Fascicle tracking data were also compared with manual digitisation of the same image sequences, and the level of agreement between the two methods was calculated using the coefficient of multiple correlation (CMC). The CMDs across all test conditions ranged from 0.50 to 0.93 and were all above 0.98 when recomputed after the systematic error due to the estimate of the initial fascicle length on the first ultrasound frame was removed from the individual fascicle length waveforms. The automated and manual tracking approaches produced similar fascicle length waveforms, with an overall CMC of 0.88, which improved to 0.94 when the initial length offset was removed. Overall results indicate that the automated fascicle tracking algorithm was a repeatable, accurate and time-efficient method for estimating fascicle length changes of the MG muscle in controlled passive and active conditions. PMID:22235878

  18. Tomography and Correlation Function Measurements of Itinerant Microwave Photons

    NASA Astrophysics Data System (ADS)

    Wallraff, Andreas

    2011-03-01

    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 [1]. We clearly observe single-photon coherence in first-order and photon antibunching in second-order correlation function measurements of the propagating fields [2]. We also present first measurements in which we reconstruct the Wigner function of itinerant single photon Fock states and their superposition with the vacuum. To perform these measurements we have developed efficient methods to separate the detected single photon signal from the noise added by the amplifier by analyzing the moments of the measured amplitude distribution up to 4th order. The techniques and methods demonstrated in this work may find application in quantum optics and quantum information processing experiments at microwave frequencies.[4pt] [1] M. P. da Silva, D. Bozyigit, A. Wallraff, and A. Blais, Phys. Rev. A 82, 043804 (2010)[0pt] [2] D. Bozyigit, C. Lang, L. Steffen, J. M. Fink, C. Eichler, M. Baur, R. Bianchetti, P. J. Leek, S. Filipp, M. P. da Silva, A. Blais, and A. Wallraff, Nat. Phys. in print (2010), also arXiv:1002.3738

  19. Applications of correlation and quantum entanglement to optical measurement

    NASA Astrophysics Data System (ADS)

    Simon, David S.

    Entangled-photon methods have led to a number of new techniques and effects in optical imaging, communication, and measurement. These range from dispersion cancelation techniques to ghost imaging and quantum lithography. Although all of these methods made use of entangled quantum systems in their original forms, in some cases it has since been found that similar effects can be reproduced with the entangled-photon pairs replaced by classically correlated beams. The goal in this thesis is to develop a cluster of new methods using entangled photon pairs or classically-correlated light beams for applications in optical imaging and measurement. In each of these methods, the photons are detected pairwise by two detectors connected via a coincidence circuit. Thus, the devices to he described have correlated or entangled biphoton states, rather than individual photons, as their basic operating unit. The major theme running through the proposed applications is that correlation and entanglement allow unprecedented control over the phases of these pairs. This control allows useful new effects that are impossible in devices whose operation depends on the detection of individual photons. The applications discussed fall into three general categories. First we show that by arranging for pairwise phase cancelations we may reduce or eliminate a number of distorting influences, allowing improved image quality and reduced noise. Within this category, we will concentrate on the cancelation of optical turbulence caused by passage of light through fluids and on cancelation of static abberations introduced by passage through an optical system. The second category of application is microscopy. Two new devices (the correlation confocal microscope and twin-photon microscope) are described which make use of pairwise phase correlations to improve lateral resolution in confocal microscopy. These differ from each other and from the standard two-photon microscope by the manner in which the correlation is imposed. Finally, the third category of application involves the characterization of periodic structures on the surfaces of materials. Two techniques (quantum scatterometry and holographic scatterometry) are proposed to enhance nonimaging surface structure characterization by means of correlated photon methods.

  20. Measurement of photon correlations with multipixel photon counters

    E-print Network

    Dmitry Kalashnikov; Leonid A. Krivitsky

    2014-08-01

    Development of reliable photon number resolving detectors (PNRD), devices which are capable to distinguish 1,2,3.. photons, is of a great importance for quantum optics and its applications. A new class of affordable PNRD is based on multipixel photon counters (MPPC). Here we review results of experiments on using MPPCs for direct characterization of squeezed vacuum (SV) states, generated via parametric downconversion (PDC). We use MPPCs to measure the second order normalized intensity correlation function (g^(2)) and directly detect the two-mode squeezing of SV states. We also present a method of calibration of crosstalk probability in MPPCs based on g^(2) measurements of coherent states.

  1. Sprint performance of phrynosomatid lizards, measured on a high-speed treadmill, correlates with hindlimb length

    E-print Network

    Garland Jr., Theodore

    speeds and shortest limbs, and the Sceloporus group (including Uta and Urosaurus) is intermediate in both, 1994). The Sceloporus group is somewhat of an intermediate generalist in both morphology and behaviour

  2. Optimal design of optical length in low turbidity measurement system with wavelength 1310 nm and 1550 nm

    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.

  3. Correlations of Clinical and Laboratory Measures of Balance in Older Men and Women: The MOBILIZE Boston Study

    PubMed Central

    Nguyen, Uyen-Sa D.T.; Kiel, Douglas P.; Li, Wenjun; Galica, Andrew M.; Kang, Hyun Gu; Casey, Virginia A.; Hannan, Marian T.

    2012-01-01

    Objective Impaired balance is associated with falls in older adults. However, there is no accepted gold standard on how balance should be measured. Few studies have examined measures of postural sway and clinical balance concurrently in large samples of community-dwelling older adults. We examined the associations among four types of measures of laboratory- and clinic-based balance in a large population-based cohort of older adults. Methods We evaluated balance measures in the MOBILIZE Boston Study (276 men, 489 women, 64–97 years). Measures included: (1) laboratory-based anteroposterior (AP) path length and average sway speed, mediolateral (ML) average sway and root-mean-square, and area of ellipse postural sway; (2) Short Physical Performance Battery (SPPB); (3) Berg Balance Scale; and (4) one-leg stand. Spearman Rank Correlation Coefficients (r) were assessed among the balance measures. Results Area of ellipse sway was highly correlated with the ML sway measures (r >0.9, p < 0.0001), and sway speed was highly correlated with AP sway (r=0.97, p < 0.0001). The Berg Balance Scale was highly correlated with SPPB (r=0.7, p<0.001), and one-leg stand (r=0.8, p<0.001). Correlations between the laboratory- and clinic-based balance measures were low but statistically significant (0.2 < r < 0.3, p<0.0001). Conclusion Clinic-based balance measures, and laboratory-based measures comparing area of ellipse with ML sways or sway speed with AP sway, are highly correlated. Clinic- with laboratory-based measures are less correlated. As both laboratory- and clinic-based measures inform balance in older adults but are not highly correlated with each other, future work should investigate the differences. PMID:22745045

  4. Ternary Fission Studies by Correlation Measurements with Ternary Particles

    NASA Astrophysics Data System (ADS)

    Mutterer, Manfred

    2011-10-01

    The rare ternary fission process has been studied mainly by inclusive measurements of the energy distributions and fractional yields of the light charged particles (LCPs) from fission, or by experiments on the angular and energy correlation between LCPs and fission fragments (FFs). The present contribution presents a brief overview of more elaborate correlation measurements that comprise the emission of neutrons and ? rays with LCPs and FFs, or the coincident registration of two LCPs. These measurements have permitted identification of new modes of particle-accompanied fission, such as the population of excited states in LCPs, the formation of neutron-unstable nuclei as short-lived intermediate LCPs, as well as the sequential decay of particle-unstable LCPs and quaternary fission. Furthermore, the neutron multiplicity numbers bar ? (A) and distributions of fragment masses A, measured for the ternary fission modes with various LCP isotopes, give a valuable hint of the role played by nuclear shell structure in the fission process near scission. Finally, two different hitherto unknown asymmetries in ternary ?-particle emission with respect to the fission axis, called the TRI and ROT effect, were studied in fission reactions induced by polarised cold neutrons.

  5. Direct Photon-Hadron Correlations Measured with PHENIX

    E-print Network

    Megan Connors; for the PHENIX Collaboration

    2009-09-24

    Direct photon-hadron correlations greatly improve our ability to perform jet tomography in heavy-ion collisions because the momentum of the direct photon can be used to constrain the initial momentum of the opposing jet. By comparing the spectrum of away-side hadrons observed in heavy ion collisions to the spectrum seen in nucleon collisions we can quantify the medium modification to the fragmentation function due to energy loss of the away-side parton. High $p_{T}$ direct photon-hadron correlations have been measured with the PHENIX detector using a statistical subtraction method to remove the photon contribution from meson decays. The increased integrated luminosity in the most recent Au+Au RHIC run at $\\sqrt{s_{NN}}$ = 200 GeV provides substantially improved statistical precision and enhances the kinematic reach. These measurements are compared to PHENIX p+p results and several theoretical models of energy loss. In addition, we compare direct photon-hadron and $\\pi^{0}$-hadron correlations.

  6. Increasing correlation length in bulk supercooled H2O, D2O, and NaCl solution determined from small angle x-ray scattering.

    PubMed

    Huang, Congcong; Weiss, T M; Nordlund, D; Wikfeldt, K T; Pettersson, L G M; Nilsson, A

    2010-10-01

    Using small angle x-ray scattering, we find that the correlation length of bulk liquid water shows a steep increase as temperature decreases at subzero temperatures (supercooling) and that it can, similar to the thermodynamic response functions, be fitted to a power law. This indicates that the anomalous properties of water are attributable to fluctuations between low- and high-density regions with rapidly growing average size upon supercooling. The substitution of H(2)O with D(2)O, as well as the addition of NaCl salt, leads to substantial changes of the power law behavior of the correlation length. Our results are consistent with the proposed existence of a liquid-liquid critical point in the deeply supercooled region but do not exclude a singularity-free model. PMID:20942543

  7. Offset balancing in pseudo-correlation radiometers for CMB measurements

    E-print Network

    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.

  8. Correlated speckle noise in white-light interferometry: theoretical analysis of measurement uncertainty

    SciTech Connect

    Hering, Marco; Koerner, Klaus; Jaehne, Bernd

    2009-01-20

    The partial coherent illumination of the specimen, which is required for white-light interferometric measurements of optically rough surfaces, directly leads to speckle. The electric field of such speckle patterns strongly fluctuates in amplitude and phase. This spatially correlated noise influences the accuracy of the measuring device. Although a variety of noise sources in white-light interferometry has been studied in recent years, they do not account for spatial correlation and, hence, they cannot be applied to speckle noise. Thus, we derive a new model enabling quantitative predictions for measurement uncertainty caused by speckle. The model reveals that the accuracy can be attributed mainly to the degree of spatial correlation, i.e., the average size of a speckle, and to the coherence length of the light source. The same parameters define the signal-to-noise ratio in the spectral domain. The model helps to design filter functions that are perfectly adapted to the noise characteristics of the respective device, thus improving the accuracy of postprocessing algorithms for envelope detection. The derived expressions are also compared to numerical simulations and experimental data of two different types of interferometers. These results are a first validation of the theoretical considerations of this article.

  9. Displacement measurements of highway bridges using digital image correlation methods

    NASA Astrophysics Data System (ADS)

    Chiang, Chih-Hung; Shih, Ming-Hsiang; Chen, Welltin; Yu, Chih-Peng

    2011-12-01

    Digital image correlation methods (DICMs) are important tools in experimental solid mechanics. DICM is becoming very versatile and cost effective due to the dramatic improvement over the digital cameras. Current study applies DICMs to displacement measurements of full-scale concrete beams. Computer programs are implemented and tested against the contact measurements using a linear variable differential transformer (LVDT). The calculated displacements agree with the LVDT measurements that the difference is mostly within 3%. The DICM programs produce similar displacement fields to those obtained using two computer codes written by other researchers. The DICM programs compute a singlepoint in merely seconds while completing the displacement calculation for a whole-field region of one mega pixels in one hour. Additional tests on the vertical displacement of a highway bridge also achieve a reasonable result which can be extended to health monitoring of bridges.

  10. High-pT direct photon azimuthal correlation measurements

    NASA Astrophysics Data System (ADS)

    Hamed, Ahmed M.

    2014-11-01

    The azimuthal correlations of direct photons (?dir) with high transverse momentum (pT), produced at mid-rapidity (|? ?dir | < 1) in Au + Au collisions at center-of-mass energy ?{sNN} = 200GeV, are measured and compared to those of neutral pions (?0) in the same kinematic range. The measured azimuthal elliptic anisotropy of direct photon, v2?dir (pT), at high pT (8 < pT?dir < 20GeV / c) is found to be smaller than that of ?0 and consistent with zero when using the forward detectors (2.4 < | ? | < 4.0) in reconstructing the event plane. The associated charged hadron spectra recoiled from ?dir show more suppression than those recoiled from ?0 (IAA?dir -h± < IAA?0 -h±) in the new measured kinematic range 12 < pT?dir ,?0 < 24GeV / c and 3 < pTassoc < 24GeV / c.

  11. Measurement of fluid velocity fields using digital correlation techniques

    NASA Technical Reports Server (NTRS)

    Matthys, Donald R.; Puliparambil, Joseph T.; Gilbert, John A.

    1990-01-01

    A new aperiodic recording technique for measuring fluid velocity fields by digital correlation is introduced which uses a low-powered He-Ne laser, a desktop computer, and a lightly seeded fluid. In contrast to optical methods, this technique does not need to use laser light to interrogate the image pattern, so no secondary speckle is introduced. Also, the lower limit of displacement measurement is determined by the resolution of the sensor used and the magnification of the camera, and can be much lower than the speckle size, so a considerably wider range of measurement is possible than with optical processing. The technique can be completely automated and is potentially much faster than all of the optical methods currently used for flow visualization.

  12. Measurement of helicopter rotor blade deformation using digital image correlation

    NASA Astrophysics Data System (ADS)

    Sirohi, Jayant; Lawson, Michael S.

    2012-04-01

    An experimental study on the application of the digital image correlation (DIC) technique to measure the deformation of rotating helicopter blades is described. Measurements on two different rotors of diameter 24 and 39 in., with different rotor hubs, were carried out to explore applicability of the technique over a range of scales. Commercial DIC software was synchronized with the frequency of rotation such that rotor blade images could be obtained at a constant rotor azimuth. Bending and torsion mode shapes were extracted from the data with deformation as high as 0.4 in. measured with an accuracy of 0.0038 in. This technique is very advantageous because it is noncontact, cost effective, accurate and simple to implement while yielding full-field, three-dimensional data with a high spatial resolution.

  13. Neural Correlates of Temporal Auditory Processing in Developmental Dyslexia during German Vowel Length Discrimination: An fMRI Study

    ERIC Educational Resources Information Center

    Steinbrink, Claudia; Groth, Katarina; Lachmann, Thomas; Riecker, Axel

    2012-01-01

    This fMRI study investigated phonological vs. auditory temporal processing in developmental dyslexia by means of a German vowel length discrimination paradigm (Groth, Lachmann, Riecker, Muthmann, & Steinbrink, 2011). Behavioral and fMRI data were collected from dyslexics and controls while performing same-different judgments of vowel duration in…

  14. Polarization gating enables sarcomere length measurements by laser diffraction in fibrotic muscle.

    PubMed

    Young, Kevin W; Dayanidhi, Sudarshan; Lieber, Richard L

    2014-11-01

    Raman spectroscopy (RS) has been extensively used to characterize bone composition. However, the link between bone biomechanics and RS measures is not well established. Here, we leveraged the sensitivity of RS polarization to organization, thereby assessing whether RS can explain differences in bone toughness in genetic mouse models for which traditional RS peak ratios are not informative. In the selected mutant mice—activating transcription factor 4 (ATF4) or matrix metalloproteinase 9 (MMP9) knock-outs—toughness is reduced but differences in bone strength do not exist between knock-out and corresponding wild-type controls. To incorporate differences in the RS of bone occurring at peak shoulders, a multivariate approach was used. Full spectrum principal components analysis of two paired, orthogonal bone orientations (relative to laser polarization) improved genotype classification and correlation to bone toughness when compared to traditional peak ratios. When applied to femurs from wild-type mice at 8 and 20 weeks of age, the principal components of orthogonal bone orientations improved age classification but not the explanation of the maturation-related increase in strength. Overall, increasing polarization information by collecting spectra from two bone orientations improves the ability of multivariate RS to explain variance in bone toughness, likely due to polarization sensitivity to organizational changes in both mineral and collagen. PMID:25422904

  15. Correlates of objectively measured physical activity in cardiac patients

    PubMed Central

    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

  16. Photoacoustic correlation spectroscopy for in vivo blood flow speed measurement

    NASA Astrophysics Data System (ADS)

    Chen, Sung-Liang; Xie, Zhixing; Carson, Paul L.; Wang, Xueding; Guo, L. Jay

    2012-02-01

    Photoacoustic imaging has been widely used in structural and functional imaging. Because of its safety, high resolution, and high imaging depth, it has great potential for a variety of medical studies. Capillaries are the smallest blood vessels and enable the exchange of oxygen and nutrients. Noninvasive flow speed measurement of capillaries in vivo can benefit the study of vascular tone changes and rheological properties of blood cells in capillaries. Recently, there has been a growing interest in photoacoustic velocimetry, such as photoacoustic Doppler and M-mode photoacoustic flow imaging. Methods capable of high-resolution imaging and low-speed flow measurement are suitable to measure blood speeds in capillaries. Previously we proposed photoacoustic correlation spectroscopy (PACS) and shown its feasibility for lowspeed flow measurement. Here, in vivo measurement of blood speeds in capillaries in a chick embryo model by PACS technique is demonstrated. The laser-scanning photoacoustic microscopy system is used for fast imaging acquisition and high-resolution imaging. The measured speed in capillaries is similar to those found in literatures, which confirm the feasibility of the PACS method for blood velocimetry. This technique suggests a fairly simple way to study blood flow speeds in capillaries.

  17. Correlated responses to long-term selection for clutch length in dwarf brown-egg layers carrying or not carrying the naked neck gene.

    PubMed

    Chen, C F; Tixier-Boichard, M

    2003-05-01

    Two dwarf brown-egg layer lines, differing in their genotype for the naked neck gene (NA), line L2 (NA*NA/*NA) and line L1 (NA*N/*N), have been selected for 16 generations for increased average clutch length. A control line from the same base population, dwarf and segregating for the NA gene, was maintained by random mating. Genetic parameters were estimated by a multivariate derivative-free restricted maximum likelihood procedure, and the NA gene effect was estimated within the unselected control line. The studied traits included clutch traits, egg production traits, abnormal eggs, egg weight at 36 wk, and BW at 42 wk. The average clutch length, egg number, and maximum clutch length were normalized using the Box-Cox transformation. In response to 16 generations of direct selection for increased average clutch length, other egg production traits, such as laying rate and total egg number, have been indirectly improved in a dwarf layer genetic background. The estimated heritabilities were 0.406 to 0.424 for transformed average clutch length (TCL), 0.373 to 0.411 for transformed egg number (TEN), 0.529 to 0.559 for age at first egg (AFE), 0.275 to 0.282 for laying rate (LR), 0.455 for dutch number (CN), and 0.319 for the number of double-yolked eggs (DYEN). The TCL had high genetic correlations with TEN (0.777), LR (0.863), maximum clutch length (0.902), and CN (-0.845). Selection for increased average clutch length was an effective method for increasing egg production. Line L2 showed a higher egg weight than L1, which indicates that the combined effect of NA and DW genes was favorable to maintain egg weight when egg number could be improved. Line L1 showed a higher number of DYEN, suggesting that the regulation of follicular maturation was changed in this line. PMID:12762391

  18. Importance of Independent Measurement of Width and Length of Lateral Meniscus During Preoperative Sizing for Meniscal Allograft Transplantation

    Microsoft Academic Search

    Jung-Ro Yoon; Taik-Sun Kim; Joon-Ho Wang; Ho-Hyun Yun; Hyungtae Lim; Jae-Hyuk Yang

    2011-01-01

    Background: Successful meniscus transplantation depends on an accurate sizing of the meniscal allograft. Although accurate sizing of the meniscal allograft is crucial during meniscus transplantation, the accuracy of meniscal measurement methods is still in debate.Purpose: This study was undertaken to evaluate the relationship between the width and length of the lateral meniscus. These anatomic dimensions were also evaluated in the

  19. Measuring the facial phenotype of individuals with prenatal alcohol exposure: correlations with brain dysfunction.

    PubMed

    Astley, S J; Clarren, S K

    2001-01-01

    The purpose of this report is to demonstrate how to measure the magnitude of expression of the fetal alcohol syndrome (FAS) facial phenotype using the new 4-Digit Diagnostic Code and the previously developed D-score and to demonstrate how these two measures of the FAS facial phenotype correlate with brain function and structure; correlations that fail to be identified by the older gestalt method of facial measurement. The D-score and the facial component of the 4-Digit Diagnostic Code quantitatively measure the magnitude of expression of the FAS facial phenotype using three facial features (palpebral fissure length, philtrum smoothness, and upper lip thinness). These facial measurement systems were developed by the Washington State FAS Diagnostic and Prevention Network (FAS DPN) of clinics and are used to screen and diagnose the facial component of FAS for all patients evaluated in the network of clinics (1500 to date). The 4-Digit Diagnostic Code is a comprehensive diagnostic system developed by the FAS DPN in 1997 to diagnose the full spectrum of outcomes among patients with prenatal alcohol exposure. The four digits reflect the magnitude of expression of the four key diagnostic features of FAS in the following order: (1) growth deficiency; (2) the FAS facial phenotype; (3) brain dysfunction; (4) gestational alcohol exposure. The 4-Digit Diagnostic Code was developed to overcome the subjective, highly variable gestalt method of diagnosis that has been used as the standard to date, worldwide. Prior to the development of the 4-Digit Diagnostic Code, the first 445 patients evaluated in the FAS DPN were diagnosed using the gestalt method. For research purposes, their gestalt diagnoses were transformed into 4-Digit Diagnostic Codes, presenting a unique opportunity to directly compare the two diagnostic methods. When the facial phenotype was measured using the 4-Digit Diagnostic Code or D-score, the magnitude of expression of the FAS facial phenotype was significantly correlated with structural, neurologic, and functional measures of brain damage, and the phenotype of those receiving a 4-Digit Diagnosis of FAS showed little variability. When the gestalt method of diagnosis was used, the magnitude of expression of the FAS facial phenotype did not correlate with structural, neurologic and functional measures of brain damage, and the facial phenotype of those receiving a gestalt diagnosis of FAS was highly variable. The 4-Digit Diagnostic Code and D-score thus provide more precise and accurate measures of the FAS facial phenotype and reveal important correlations with brain structure and function, suggesting that intermediate expressions of the FAS facial phenotype may serve as important risk factors for brain damage caused by prenatal alcohol exposure. PMID:11259212

  20. Attenuation length measurements of a liquid scintillator with LabVIEW and reliability evaluation of the device

    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.

  1. Line scan fluorescence correlation spectroscopy for three-dimensional microfluidic flow velocity measurements

    NASA Astrophysics Data System (ADS)

    Pan, Xiaotao; Shi, Xianke; Korzh, Vladimir; Yu, Hanry; Wohland, Thorsten

    2009-03-01

    The flow direction of microfluidics in biological applications is not limited to two dimensions, but often extends to three dimensions. Currently there are optical methods available for the measurement of 3-D microfluidic flow vectors, but with low spatial resolution. Line scan fluorescence correlation spectroscopy (FCS) was proposed to determine flow directions in 2-D within microchannels and small blood vessels in our previous work. Importantly, its spatial resolution was demonstrated to be as good as 0.5 ?m. In this work, we extend line scan FCS to the third dimension for the characterization of 3-D flow velocity vectors. The spatial resolution is close to the diffraction limit using a scan length of 0.5 ?m in all three dimensions. The feasibility of line scan FCS for 3-D microfluidic flow is verified by measurements in microchannels and small blood vessels of zebrafish embryos.

  2. Tunable non-local entanglement of electrons probed by noise cross-correlation measurement

    NASA Astrophysics Data System (ADS)

    Wei, Jian

    2010-03-01

    Nonlocal entanglement is crucial for quantum information processes. While nonlocal entanglement has been realized for photons, it is much more difficult to demonstrate for electrons. One approach that has been proposed is to use hybrid superconducting/normal-metal devices. When the distance between two normal-metal electrodes connected to a superconductor is comparable to the superconducting coherence length, theory predicts that two electrons in the normal-metal electrodes with opposite spin are entangled by Cooper pairs, leading to non-local entanglement of electrons. Such entanglement can be understood by a non-local process called crossed Andreev reflection (CAR), in which a Cooper pair splits into two coherent electrons with one in each normal-metal electrode, generating instantaneous current of the same sign, and inducing a positive current correlation. Experimentally, CAR is indicated by a negative non-local resistance. However, another non-local process, elastic cotunneling (EC), in which one electron tunnels through the superconductor from one normal-metal electrode to the other, contributes to a positive non-local resistance that cancels the contribution due to CAR, preventing us from measuring and control of the CAR component. Fortunately, EC leads to a negative current correlation with bias dependence different from that of CAR. Thus, noise correlation measurement is expected to be able to distinguish these two non-local processes. By cross-correlation measurements as well as measurements of the local and nonlocal resistance, we present here experimental evidence showing that by independently controlling the energy of electrons at the superconductor/normal-metal interfaces, nonlocal Andreev reflection, the signature of spin-entanglement, can be maximized, qualitatively in agreement with theoretical predication.

  3. CALIBRATION OF ABBE REFRACTOMETER WITH COMPENSATING PRISMS, TO MEASURE REFRACTIVE INDEX FOR ANY WAVE LENGTH

    Microsoft Academic Search

    L. E. Dodd

    1931-01-01

    The Abbe refractometer in its usual form with compensating prisms is restricted to reading index of the test liquid for but one wave length, usually ?D. Although the setting of the compensating prisms for achromatization permits, by the aid of either a numerical or a graphical chart supplied with the instrument, an evaluation of the dispersion nF—nC of the liquid,

  4. BUNCH LENGTH MEASUREMENTS AT THE TESLA TEST FACILITY USING A STREAK CAMERA

    E-print Network

    . The photocathode used (S-20) is sensitive for wavelengths between 200 and 800nm. The input optics is adapted an injector based on a laser driven rf gun [1]. Its beam is used to test and to per- form various experiments an upper limit on the compressed bunch length. Effects of the rf gun phase and the phase of the first accel

  5. Quantum dots thermal stability improves simultaneous phenotype-specific telomere length measurement by FISH-flow cytometry

    PubMed Central

    Kapoor, Veena; Hakim, Fran T; Rehman, Najibah; Gress, Ronald E; Telford, William G

    2009-01-01

    Telomere length analysis has been greatly simplified by the quantitative flow cytometry technique flow-FISH. In this method, a fluorescein-labeled synthetic oligonucleotide complementary to the telomere terminal repeat sequence is hybridized to the telomere sequence and the resulting fluorescence measured by flow cytometry. This technique has supplanted the traditional laborious Southern blot telomere length measurement techniques in many laboratories, and allows single cell analysis of telomere length in high-throughput sample formats. Nevertheless, the harsh conditions required for telomere probe annealing (82°C) has made it difficult to successfully combine this technique with simultaneous immunolabeling. Most traditional organic fluorescent probes (i.e. fluorescein, phycoerythrin, etc.) have limited thermal stability and do not survive the high-temperature annealing process, despite efforts to covalently crosslink the antigen-antibody-fluorophore complex. This loss of probe fluorescence has made it difficult to measure flow-FISH in complex lymphocyte populations, and has generally forced investigators to use fluorescent-activated cell sorting to pre-separate their populations, a laborious technique that requires prohibitively large numbers of cells. In this study, we have substituted quantum dots (nanoparticles) for traditional fluorophores in FISH-flow. Quantum dots were demonstrated to possess much greater thermal stability than traditional low molecular weight and phycobiliprotein fluorophores. Quantum dot antibody conjugates directed against monocyte and T cell antigens were found to retain most of their fluorescence following the high-temperature annealing step, allowing simultaneous fluorescent immunophenotyping and telomere length measurement. Since quantum dots have very narrow emission bandwidths, we were able to analyze multiple quantum dot-antibody conjugates (Qdot 605, 655 and 705) simultaneously with FISH-flow measurement to assess the age-associated decline in telomere length in both human monocytes and T cell subsets. With quantum dot immunolabeling, the mean decrease rate in telomere length for CD4+ cells was calculated at 41.8bp/year, very close to previously reported values using traditional flow-FISH and Southern blotting. This modification to the traditional flow-FISH technique should therefore allow simultaneous fluorescent immunophenotyping and telomere length measurement, permitting complex cell subset-specific analysis in small numbers of cells without the requirement for prior cell sorting. PMID:19268672

  6. Quantum dots thermal stability improves simultaneous phenotype-specific telomere length measurement by FISH-flow cytometry.

    PubMed

    Kapoor, Veena; Hakim, Fran T; Rehman, Najibah; Gress, Ronald E; Telford, William G

    2009-05-15

    Telomere length analysis has been greatly simplified by the quantitative flow cytometry technique FISH-flow. In this method, a fluorescein-labeled synthetic oligonucleotide complementary to the telomere terminal repeat sequence is hybridized to the telomere sequence and the resulting fluorescence measured by flow cytometry. This technique has supplanted the traditional laborious Southern blot telomere length measurement techniques in many laboratories, and allows single cell analysis of telomere length in high-throughput sample formats. Nevertheless, the harsh conditions required for telomere probe annealing (82 degrees C) has made it difficult to successfully combine this technique with simultaneous immunolabeling. Most traditional organic fluorescent probes (i.e. fluorescein, phycoerythrin, etc.) have limited thermal stability and do not survive the high temperature annealing process, despite efforts to covalently crosslink the antigen-antibody-fluorophore complex. This loss of probe fluorescence has made it difficult to measure FISH-flow in complex lymphocyte populations, and has generally forced investigators to use fluorescent-activated cell sorting to pre-separate their populations, a laborious technique that requires prohibitively large numbers of cells. In this study, we have substituted quantum dots (nanoparticles) for traditional fluorophores in FISH-flow. Quantum dots were demonstrated to possess much greater thermal stability than traditional low molecular weight and phycobiliprotein fluorophores. Quantum dot antibody conjugates directed against monocyte and T cell antigens were found to retain most of their fluorescence following the high temperature annealing step, allowing simultaneous fluorescent immunophenotyping and telomere length measurement. Since quantum dots have very narrow emission bandwidths, we were able to analyze multiple quantum dot antibody conjugates (Qdot 605, 655 and 705) simultaneously with FISH-flow measurement to assess the age-associated decline in telomere length in both human monocytes and T cell subsets. With quantum dot immunolabeling, the mean decrease rate in telomere length for CD4+ cells was calculated at 41.8 bp/year, very close to previously reported values using traditional flow-FISH and Southern blotting. This modification to the traditional flow-FISH technique should therefore allow simultaneous fluorescent immunophenotyping and telomere length measurement, permitting complex cell subset-specific analysis in small numbers of cells without the requirement for prior cell sorting. PMID:19268672

  7. Measurement of the imaginary part of the I = 1 N-barN S-wave scattering length

    SciTech Connect

    Mutchler, G.S.; Clement, J.; Kruk, J.; Moss, R.; Hungerford, E.; Kishimoto, T.; Mayes, B.; Pinsky, L.; Tang, L.; Xue, Y.; and others

    1988-08-01

    The survival time spectrum of slow antineutrons produced in a liquid-hydrogen target has been measured. From these data the imaginary part of the I = 1 spin-averaged S-wave antineutron proton scattering length has been deduced to be Ima/sub 1/ = -0.83 +- 0.07 fm. The result lies within the range of values calculated from current potential models. In addition, by combining a/sub 1/ with the antiproton-proton scattering length deduced from antiprotonic atoms, the imaginary part of the I = 0 spin-averaged N-barN scattering length was calculated to be Ima/sub 0/ = -1.07 +- 0.16 fm.

  8. X-Band deflecting cavity design for ultra-short bunch length measurement of SXFEL at SINAP

    E-print Network

    Tan, Jian-Hao; Fang, Wen-Cheng; Tong, De-Chun; Zhao, Zhen-Tang

    2014-01-01

    For the development of the X-ray Free Electron Lasers test facility (SXFEL) at SINAP, ultra-short bunch is the crucial requirement for excellent lasing performance. It's a big challenge for deflecting cavity to measure the length of ultra-short bunch, and higher deflecting gradient is required for higher measurement resolution. X-band travelling wave deflecting structure has features of higher deflecting voltage and compact structure, which is good performance at ultra-short bunch length measurement. In this paper, a new X-band deflecting structure has been designed operated at HEM11-2pi/3 mode. For suppressing the polarization of deflecting plane of the HEM11 mode, two symmetrical caves are added on the cavity wall to separate two polarized modes. More details of design and simulation results are presented in this paper.

  9. A Correlational and Factor Analytic Study of Four Questionnaire Measures of Organizational Culture

    Microsoft Academic Search

    Athena Xenikou; Adrian Furnham

    1996-01-01

    A review of the literature revealed four major self-report measures of organizational culture measuring organizational behavioral norms or values. This study set out to compare these different measures by correlational and factor analysis. The results of the correlational analysis showed the convergent validity of the questionnaires in a number of significant correlations among the overlapping subscales intended to measure the

  10. 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.

  11. Finger Length

    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.

  12. ABSOLUTE BUNCH LENGTH MEASUREMENTS AT THE ALS BY INCOHERENTSYNCHROTRON RADIATION FLUCTUATION ANALYSIS

    SciTech Connect

    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.

  13. Water Velocity Measurement on an Extended-Length Submerged Bar Screen at John Day Dam

    SciTech Connect

    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.

  14. Frequency of nonallelic homologous recombination is correlated with length of homology: evidence that ectopic synapsis precedes ectopic crossing-over.

    PubMed

    Liu, Pengfei; Lacaria, Melanie; Zhang, Feng; Withers, Marjorie; Hastings, P J; Lupski, James R

    2011-10-01

    Genomic disorders constitute a class of diseases that are associated with DNA rearrangements resulting from region-specific genome instability, that is, genome architecture incites genome instability. Nonallelic homologous recombination (NAHR) or crossing-over in meiosis between sequences that are not in allelic positions (i.e., paralogous sequences) can result in recurrent deletions or duplications causing genomic disorders. Previous studies of NAHR have focused on description of the phenomenon, but it remains unclear how NAHR occurs during meiosis and what factors determine its frequency. Here we assembled two patient cohorts with reciprocal genomic disorders; deletion associated Smith-Magenis syndrome and duplication associated Potocki-Lupski syndrome. By assessing the full spectrum of rearrangement types from the two cohorts, we find that complex rearrangements (those with more than one breakpoint) are more prevalent in copy-number gains (17.7%) than in copy-number losses (2.3%); an observation that supports a role for replicative mechanisms in complex rearrangement formation. Interestingly, for NAHR-mediated recurrent rearrangements, we show that crossover frequency is positively associated with the flanking low-copy repeat (LCR) length and inversely influenced by the inter-LCR distance. To explain this, we propose that the probability of ectopic chromosome synapsis increases with increased LCR length, and that ectopic synapsis is a necessary precursor to ectopic crossing-over. PMID:21981782

  15. Dynamics of lithium ions in borotellurite mixed former glasses: Correlation between the characteristic length scales of mobile ions and glass network structural units

    SciTech Connect

    Shaw, A.; Ghosh, A., E-mail: sspag@iacs.res.in [Department of Solid State Physics, Indian Association for the Cultivation of Science, Jadavpur, Kolkata 700032 (India)

    2014-10-28

    We have studied the mixed network former effect on the dynamics of lithium ions in borotellurite glasses in wide composition and temperature ranges. The length scales of ion dynamics, such as characteristic mean square displacement and spatial extent of sub-diffusive motion of lithium ions have been determined from the ac conductivity and dielectric spectra, respectively, in the framework of linear response theory. The relative concentrations of different network structural units have been determined from the deconvolution of the FTIR spectra. A direct correlation between the ion dynamics and the characteristic length scales and the relative concentration of BO{sub 4} units has been established for different compositions of the borotellurite glasses.

  16. Dynamics of lithium ions in borotellurite mixed former glasses: correlation between the characteristic length scales of mobile ions and glass network structural units.

    PubMed

    Shaw, A; Ghosh, A

    2014-10-28

    We have studied the mixed network former effect on the dynamics of lithium ions in borotellurite glasses in wide composition and temperature ranges. The length scales of ion dynamics, such as characteristic mean square displacement and spatial extent of sub-diffusive motion of lithium ions have been determined from the ac conductivity and dielectric spectra, respectively, in the framework of linear response theory. The relative concentrations of different network structural units have been determined from the deconvolution of the FTIR spectra. A direct correlation between the ion dynamics and the characteristic length scales and the relative concentration of BO4 units has been established for different compositions of the borotellurite glasses. PMID:25362322

  17. Time Resolved Correlation measurements of temporally heterogeneous dynamics

    E-print Network

    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.

  18. Spam Source Clustering by Constructing Spammer Network with Correlation Measure

    NASA Astrophysics Data System (ADS)

    Shin, Jeongkyu; Kim, Seunghwan

    Spam filtering is one of the most challenging problems in electric message systems. In general, recent studies on specifying real spam source are based on content filtering because spammers usually falsify their origin. We propose a method to specify spam source based on structural analysis with complex network. We assume that each spam sources either has the same victim list or uses the same spam-hosting program. We treat spam source - target relationship as a bipartite network and construct weighted spam source network by network projection using correlation measure. We find that community clustering methods are inappropriate with spammer network. We group spammers with gradient-based grouping, which uses correlations between nodes as gradient between nodes. We convert them into local minima, which helps to cluster spammers into a few spam source groups. We investigate the weblog spam data with the proposed method and validate it. The method that we propose can be applied to diverse categorization problems, such as multiple text categorization and network subunit clustering.

  19. 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.

  20. High-$p_{_{T}}$ Direct Photon Azimuthal Correlation Measurements

    E-print Network

    Ahmed M. Hamed

    2014-08-27

    The azimuthal correlations of direct photons ($\\gamma_{_{dir}}$) with high transverse momentum ($p_{_{T}}$), produced at mid-rapidity ($|\\eta^{\\gamma_{_{dir}}}|<1$) in Au+Au collisions at center-of-mass energy $\\sqrt{s_{_{NN}}}=200$~GeV, are measured and compared to those of neutral pions ($\\pi^{0}$) in the same kinematic range. The measured azimuthal elliptic anisotropy of direct photon, $v_{_{2}}^{\\gamma_{_{dir}}}(p_{_{T}})$, at high $p_{_{T}}$ ($8< p_{_{T}}^{\\gamma_{_{dir}}}<20$~GeV/$c$) is found to be smaller than that of $\\pi^{0}$ and consistent with zero when using the forward detectors ($2.4 <|\\eta|< 4.0$) in reconstructing the event plane. The associated charged hadron spectra recoiled from $\\gamma_{_{dir}}$ show more suppression than those recoiled from $\\pi^{0}$ $(I_{AA}^{\\gamma_{_{dir}}-h^{\\pm}} < I_{AA}^{\\pi^{0}-h^{\\pm}})$ in the new measured kinematic range $12< p_{_{T}}^{\\gamma_{_{dir}},\\pi^{0}}<24$~GeV/$c$ and $3< p_{_{T}}^{assoc}<24$~GeV/$c$.

  1. Multiple length and time scales of dynamic heterogeneities in model glass-forming liquids: A systematic analysis of multi-point and multi-time correlations

    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.

  2. An evaluation of deep-sea benthic megafauna length measurements obtained with laser and stereo camera methods

    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.

  3. Pharmacologically induced erect penile length and stretched penile length are both good predictors of post-inflatable prosthesis penile length.

    PubMed

    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

  4. openBEB: open biological experiment browser for correlative measurements

    PubMed Central

    2014-01-01

    Background New experimental methods must be developed to study interaction networks in systems biology. To reduce biological noise, individual subjects, such as single cells, should be analyzed using high throughput approaches. The measurement of several correlative physical properties would further improve data consistency. Accordingly, a considerable quantity of data must be acquired, correlated, catalogued and stored in a database for subsequent analysis. Results We have developed openBEB (open Biological Experiment Browser), a software framework for data acquisition, coordination, annotation and synchronization with database solutions such as openBIS. OpenBEB consists of two main parts: A core program and a plug-in manager. Whereas the data-type independent core of openBEB maintains a local container of raw-data and metadata and provides annotation and data management tools, all data-specific tasks are performed by plug-ins. The open architecture of openBEB enables the fast integration of plug-ins, e.g., for data acquisition or visualization. A macro-interpreter allows the automation and coordination of the different modules. An update and deployment mechanism keeps the core program, the plug-ins and the metadata definition files in sync with a central repository. Conclusions The versatility, the simple deployment and update mechanism, and the scalability in terms of module integration offered by openBEB make this software interesting for a large scientific community. OpenBEB targets three types of researcher, ideally working closely together: (i) Engineers and scientists developing new methods and instruments, e.g., for systems-biology, (ii) scientists performing biological experiments, (iii) theoreticians and mathematicians analyzing data. The design of openBEB enables the rapid development of plug-ins, which will inherently benefit from the “house keeping” abilities of the core program. We report the use of openBEB to combine live cell microscopy, microfluidic control and visual proteomics. In this example, measurements from diverse complementary techniques are combined and correlated. PMID:24666611

  5. Method and apparatus for measuring minority carrier lifetimes and bulk diffusion length in P-N junction solar cells

    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.

  6. Effect of Blending on High-Pressure Laminar Flame Speed Measurements, Markstein Lengths, and Flame Stability of Hydrocarbons

    E-print Network

    Lowry, William Baugh

    2012-02-14

    EFFECT OF BLENDING ON HIGH-PRESSURE LAMINAR FLAME SPEED MEASUREMENTS, MARKSTEIN LENGTHS, AND FLAME STABILITY OF HYDROCARBONS A Thesis by WILLIAM BAUGH LOWRY Submitted to the Office of Graduate Studies of Texas A...&M University in partial fulfillment of the requirements for the degree of MASTER OF SCIENCE December 2010 Major Subject: Mechanical Engineering Effect of Blending on High-Pressure Laminar Flame...

  7. Measurement of the imaginary part of the I = 1 N-barN S-wave scattering length

    SciTech Connect

    Mutchler, G.S.; Clement, J.; Kruk, J.; Moss, R.; Hungerford, E.V.; Kishimoto, T.; Mayes, B.; Pinsky, L.; Tang, L.; Xue, Y.; and others

    1988-11-20

    The survival time spectrum of slow antineutrons produced in a LH/sub 2/ target has been measured. From these data the imaginary part of the I = 1 spin averaged S-wave antineutron proton scattering length has been deduced to be Im a/sub 1/ = -0.83 +- 0.07 fm. The result lies within the range of values calculated from current potential models.

  8. Relationship between the surrogate anthropometric measures, foot length and chest circumference and birth weight among newborns of Sarlahi, Nepal

    Microsoft Academic Search

    L C Mullany; G L Darmstadt; S K Khatry; S C LeClerq; J M Tielsch

    2007-01-01

    Background:Classification of infants into low birth weight (LBW, <2500 g) or very low birth weight (VLBW, <2000 g) categories is a crucial step in targeting interventions to high-risk infants.Objective:To compare the validity of chest circumference and foot length as surrogate anthropometric measures for the identification of LBW and VLBW infants.Subjects and setting:Newborn infants (n=1640) born between March and June 2004

  9. Measurement of laminar burning speeds and Markstein lengths using a novel methodology

    SciTech Connect

    Tahtouh, Toni; Halter, Fabien; Mounaim-Rousselle, Christine [Institut PRISME, Universite d'Orleans, 8 rue Leonard de Vinci-45072, Orleans Cedex 2 (France)

    2009-09-15

    Three different methodologies used for the extraction of laminar information are compared and discussed. Starting from an asymptotic analysis assuming a linear relation between the propagation speed and the stretch acting on the flame front, temporal radius evolutions of spherically expanding laminar flames are postprocessed to obtain laminar burning velocities and Markstein lengths. The first methodology fits the temporal radius evolution with a polynomial function, while the new methodology proposed uses the exact solution of the linear relation linking the flame speed and the stretch as a fit. The last methodology consists in an analytical resolution of the problem. To test the different methodologies, experiments were carried out in a stainless steel combustion chamber with methane/air mixtures at atmospheric pressure and ambient temperature. The equivalence ratio was varied from 0.55 to 1.3. The classical shadowgraph technique was used to detect the reaction zone. The new methodology has proven to be the most robust and provides the most accurate results, while the polynomial methodology induces some errors due to the differentiation process. As original radii are used in the analytical methodology, it is more affected by the experimental radius determination. Finally, laminar burning velocity and Markstein length values determined with the new methodology are compared with results reported in the literature. (author)

  10. A volumetric approach to path-length measurements is essential when treating radiotherapy with modulated beams.

    PubMed

    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

  11. Extracting decay curves of the correlated fluorescence photons measured in fluorescence correlation spectroscopy

    NASA Astrophysics Data System (ADS)

    Ishii, Kunihiko; Tahara, Tahei

    2012-01-01

    We have developed a new method to extract the decay curves of the correlated fluorescence photons from the data of fluorescence correlation spectroscopy using time-correlated single photon counting. In this method, a two-dimensional correlation map of photon pairs is generated at an absolute delay time with reference to the excitation-emission delay of each photon. Using a dye-labeled DNA as an example, we have demonstrated that the decay curve of the correlated fluorescence photons is separated from the uncorrelated background signals simply by subtracting a two-dimensional correlation map at sufficiently long delay time without additional prior information.

  12. In situ multiproperty measurements of individual nanomaterials in SEM and correlation with their atomic structures

    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.

  13. Empirical correlations between Krafft temperature and tail length for amidosulfobetaine surfactants in the presence of inorganic salt.

    PubMed

    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

  14. Fatigue testing of high-density polyethylene and polycarbonate with crack length measurement using image processing techniques

    SciTech Connect

    Riemslag, A.C. (Delft Univ. of Technology (Netherlands). Lab. of Materials Science)

    1994-09-01

    A new automated method of measuring fatigue cracks in polymers is discussed. The new method is based on a video signal of the crack which is analyzed with image processing techniques. With this technique the crack length is measured every 20 s during a fatigue test. The accuracy of one single measurement is about 0.05 mm, but this can be increased by averaging a large number of measurements. The applied automated data collection and subsequent data processing is discussed in relation to the recommendations given in ASTM E 647, Test method for Measurement of Fatigue Crack Growth Rates. The use of the new technique is illustrated on the basis of fatigue tests performed on transparent polycarbonate (PC) and nontransparent polyethylene (PE). The fatigue behavior of PE and PC is briefly discussed.

  15. Second-harmonic microscopy of unstained living cardiac myocytes: measurements of sarcomere length with 20-nm accuracy

    NASA Astrophysics Data System (ADS)

    Boulesteix, Thierry; Beaurepaire, Emmanuel; Sauviat, Martin-Pierre; Schanne-Klein, Marie-Claire

    2004-09-01

    We extend second-harmonic generation (SHG) microscopy to the measurement of sarcomere length in unstained living cardiac myocytes with 20-nm accuracy. We quantify individual sarcomere shortening in the presence of saxitoxin and find that it is in agreement with mechanical measurements of atrial tissue contracture. This functional application of SHG microscopy is generally applicable to quantify the physiological effects of drugs on contractile tissue. Our data also suggest that packed myosin heads in sarcomere thick filaments are responsible for the large second-harmonic endogenous signal in muscle tissue.

  16. Characterizing acid diffusion lengths in chemically amplified resists from measurements of deprotection kinetics

    NASA Astrophysics Data System (ADS)

    Patil, Abhijit A.; Pandey, Yogendra Narayan; Doxastakis, Manolis; Stein, Gila E.

    2014-10-01

    The acid-catalyzed deprotection of glassy poly(4-hydroxystyrene-co-tertbutyl acrylate) films was studied with infrared absorbance spectroscopy and stochastic simulations. Experimental data were interpreted with a simple description of subdiffusive acid transport coupled to second-order acid loss. This model predicts key attributes of observed deprotection rates, such as fast reaction at short times, slow reaction at long times, and a nonlinear dependence on acid loading. Fickian diffusion is approached by increasing the postexposure bake temperature or adding plasticizing agents to the polymer resin. These findings demonstrate that acid mobility and overall deprotection kinetics are coupled to glassy matrix dynamics. To complement the analysis of bulk kinetics, acid diffusion lengths were calculated from the anomalous transport model and compared with nanopattern line widths. The consistent scaling between experiments and simulations suggests that the anomalous diffusion model could be further developed into a predictive lithography tool.

  17. Correlation lengths, porosity and water adsorption in TiO? thin films prepared by glancing angle deposition.

    PubMed

    González-García, Lola; Parra-Barranco, Julián; Sánchez-Valencia, Juan R; Barranco, Angel; Borrás, Ana; González-Elipe, Agustín R; García-Gutiérrez, Mari-Cruz; Hernández, Jaime J; Rueda, Daniel R; Ezquerra, Tiberio A

    2012-05-25

    This paper reports a thorough microstructural characterization of glancing angle deposited (GLAD) TiO(2) thin films. Atomic force microscopy (afm), grazing-incidence small-angle x-ray scattering (GISAXS) and water adsorption isotherms have been used to determine the evolution of porosity and the existence of some correlation distances between the nanocolumns constituting the basic elements of the film's nanostructure. It is found that the deposition angle and, to a lesser extent, the film thickness are the most important parameters controlling properties of the thin film. The importance of porosity and some critical dimensions encountered in the investigated GLAD thin films is highlighted in relation to the analysis of their optical properties when utilized as antireflective coatings or as hosts and templates for the development of new composite materials. PMID:22543422

  18. Calculation of Evolutionary Correlation between Individual Genes and Full-Length Genome: A Method Useful for Choosing Phylogenetic Markers for Molecular Epidemiology

    PubMed Central

    Wang, Shuai; Luo, Xuenong; Wei, Wei; Zheng, Yadong; Dou, Yongxi; Cai, Xuepeng

    2013-01-01

    Individual genes or regions are still commonly used to estimate the phylogenetic relationships among viral isolates. The genomic regions that can faithfully provide assessments consistent with those predicted with full-length genome sequences would be preferable to serve as good candidates of the phylogenetic markers for molecular epidemiological studies of many viruses. Here we employed a statistical method to evaluate the evolutionary relationships between individual viral genes and full-length genomes without tree construction as a way to determine which gene can match the genome well in phylogenetic analyses. This method was performed by calculation of linear correlations between the genetic distance matrices of aligned individual gene sequences and aligned genome sequences. We applied this method to the phylogenetic analyses of porcine circovirus 2 (PCV2), measles virus (MV), hepatitis E virus (HEV) and Japanese encephalitis virus (JEV). Phylogenetic trees were constructed for comparisons and the possible factors affecting the method accuracy were also discussed in the calculations. The results revealed that this method could produce results consistent with those of previous studies about the proper consensus sequences that could be successfully used as phylogenetic markers. And our results also suggested that these evolutionary correlations could provide useful information for identifying genes that could be used effectively to infer the genetic relationships. PMID:24312527

  19. Direct measurement of the phase-coherence length in a GaAs/GaAlAs square network.

    PubMed

    Ferrier, M; Angers, L; Rowe, A C H; Guéron, S; Bouchiat, H; Texier, C; Montambaux, G; Mailly, D

    2004-12-10

    The low temperature magnetoconductance of a large array of quantum coherent loops exhibits Altshuler-Aronov-Spivak oscillations with a periodicity corresponding to 1/2 flux quantum per loop. We show that the measurement of the harmonics content provides an accurate way to determine the electron phase-coherence length L(phi) in units of the lattice length with no adjustable parameters. We use this method to determine L(phi) in a square network realized from a 2D electron gas in a GaAs/GaAlAs heterojunction, with only a few conducting channels. The temperature dependence follows a power law T(-1/3) from 1.3 K to 25 mK with no saturation, as expected for 1D diffusive electronic motion and electron-electron scattering as the main decoherence mechanism. PMID:15697847

  20. The spin Hall angle and spin diffusion length of Pd measured by spin pumping and microwave photoresistance

    SciTech Connect

    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.

  1. Maize Varieties Released in Different Eras Have Similar Root Length Density Distributions in the Soil, Which Are Negatively Correlated with Local Concentrations of Soil Mineral Nitrogen

    PubMed Central

    Ning, Peng; Li, Sa; White, Philip J.; Li, Chunjian

    2015-01-01

    Larger, and deeper, root systems of new maize varieties, compared to older varieties, are thought to have enabled improved acquisition of soil resources and, consequently, greater grain yields. To compare the spatial distributions of the root systems of new and old maize varieties and their relationships with spatial variations in soil concentrations of available nitrogen (N), phosphorus (P) and potassium (K), two years of field experiments were performed using six Chinese maize varieties released in different eras. Vertical distributions of roots, and available N, P and K in the 0–60 cm soil profile were determined in excavated soil monoliths at silking and maturity. The results demonstrated that new maize varieties had larger root dry weight, higher grain yield and greater nutrient accumulation than older varieties. All varieties had similar total root length and vertical root distribution at silking, but newer varieties maintained greater total root length and had more roots in the 30–60 cm soil layers at maturity. The spatial variation of soil mineral N (Nmin) in each soil horizon was larger than that of Olsen-P and ammonium-acetate-extractable K, and was inversely correlated with root length density (RLD), especially in the 0–20 cm soil layer. It was concluded that greater acquisition of mineral nutrients and higher yields of newer varieties were associated with greater total root length at maturity. The negative relationship between RLD and soil Nmin at harvest for all varieties suggests the importance of the spatial distribution of the root system for N uptake by maize. PMID:25799291

  2. Spring temperature, growing season length and carbon sequestration in North America: a flux measurement based analysis

    NASA Astrophysics Data System (ADS)

    Wu, C.; Chen, J.

    2011-12-01

    We present an analysis of spring temperature, GSL and carbon sequestration in North America using 24 flux sites (187 site-year in total) representing three plant functional types, including the evergreen forests (EF), deciduous forests (DF) and non-forests (NF) ecosystems. Spring temperature shows consistent positive impacts on GSL, irrespective of plant functions types and other ecoregional differences. GSL exhibits a clear latitudinal pattern and decreases at a speed of 5.2 day per decimal degree in latitudes for the overall dataset (R2=0.58, p<0.001). This speed differs substantially across plant functions types and values of 7.1, 5.0 and 3.3 day per decimal degree are observed for DF, NF and EF sites, respectively. Both spring temperature and GSL show positive correlations with annual gross primary production (GPP) and net ecosystem production (NEP), and the correlations also differ for different plant functional types. Further sensitivity comparison has shown a decrease trend (R2=0.54, p<0.001) in the slope of GSL to warmer spring temperature with increase of latitude, indicating existing latitudinal patterns in GPP could be strengthened with future increase in spring temperature. A surprising result is observed in the DF sites that most part (>85%) of the increased GPP due to warmer spring temperature and prolonged GSL can be retained in the annual NEP, suggesting a reconsideration of the functions of DF species in the context of future climate change.

  3. Noise Correction and Length Scale Estimation for Scalar Dissipation Rate Measurements in Turbulent Partially Premixed Flames

    Microsoft Academic Search

    Jian Cai; Robert S. Barlow; Adonis N. Karpetis; Chenning Tong

    2010-01-01

    A recently developed conditional sampling-based method for correcting noise effects in scalar dissipation rate measurements\\u000a and for estimating the extent of resolution of the dissipation rate is employed to analyze the data obtained in turbulent\\u000a partially premixed (Sandia) flames. The method uses conditional sampling to select instantaneous fully resolved local scalar\\u000a fields, which are analyzed to determine the measurement noise

  4. Clinical Correlates to Laboratory Measures for use in Non-Contact Anterior Cruciate Ligament Injury Risk Prediction Algorithm

    PubMed Central

    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

  5. Length scales in alloy dissolution and measurement of absolute interfacial free energy.

    PubMed

    Rugolo, J; Erlebacher, J; Sieradzki, K

    2006-12-01

    De-alloying is the selective dissolution of one or more of the elemental components of an alloy. In binary alloys that exhibit complete solid solubility, de-alloying of the less noble component results in the formation of nanoporous metals, a materials class that has attracted attention for applications such as catalysis, sensing and actuation. In addition, the occurrence of de-alloying in metallic alloy systems under stress is known to result in stress-corrosion cracking, a key failure mechanism in fossil fuel and nuclear plants, ageing aircraft, and also an important concern in the design of nuclear-waste storage containers. Central to the design of corrosion-resistant alloys is the identification of a composition-dependent electrochemical critical potential, Vcrit, above which the current rises dramatically with potential, signalling the onset of bulk de-alloying. Below Vcrit, the surface is passivated by the accumulation of up to several monolayers of the more noble component. The current understanding of the processes that control Vcrit is incomplete. Here, we report on de-alloying results of Ag/Au superlattices that clarify the role of pre-existing length scales in alloy dissolution. Our data motivated us to re-analyse existing data on critical potentials of Ag-Au alloys and develop a simple unifying picture that accounts for the compositional dependence of solid-solution alloy critical potentials. PMID:17099702

  6. Theoretical predictions for spatial covariance of the electroencephalographic signal during the anesthetic-induced phase transition: Increased correlation length and emergence of spatial self-organization

    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.

  7. Effectively classically correlated state of a measured system and a bosonic measurement apparatus

    SciTech Connect

    Camalet, S. [Laboratoire de Physique Theorique de la Matiere Condensee, UMR 7600, Universite Pierre et Marie Curie, 4, place Jussieu, F-75005 Paris (France)

    2011-04-15

    We consider a multilevel system coupled to a bosonic measurement apparatus. We derive exact expressions for the time-dependent expectation values of a large class of physically relevant observables that depend on degrees of freedom of both systems. We find that, for this class, though the two systems become entangled as a result of their interaction, they appear classically correlated for long enough times. The unique corresponding time-dependent separable state is determined explicitly. To better understand the physical parameters that control the time scale of this effective disentanglement process, we study a one-dimensional measurement apparatus.

  8. Measurement of viscoelastic properties at small length scales for heterogeneous and nonlinear materials

    NASA Astrophysics Data System (ADS)

    Wang, Fang

    In this dissertation, advances in linear and non-linear viscoelastic analysis and experimentation have been employed to investigate the properties of materials using nanoindentation. In the first study, a general linear-viscoelastic model was developed to measure the properties of polydimethylsiloxane (PDMS) using a flat punch indenter. Subsequently, linear viscoelastic nanoindentation was used to measure the young's relaxation modulus of a locally-heterogeneous thermally-aged bismaleimide resin using a Berkovich indenter. Nanoindentation measurements were conducted on both surface and cross section of aged bismaleimide resin specimens with different aging time at 200°C and 300°C respectively to extract the oxidation effect of sample under high temperatures. Finally, nanoindentation measurements were made on human tympanic membrane specimens with using a spherical nanoindenter tip in direct contact with the collagen fiber layer. Linear viscoelastic analysis was conducted to extract the Young's relaxation modulus distributions. The study also focused on the development of non-linear viscoelastic analysis of indentation experiments. Despite the fact that the nanoindentation technique is well established for the characterization of elasto-plastic materials, nanoindentation on viscoelastic materials is not fully understood especially in nonlinear viscoelastic region. In the dissertation, a nonlinear viscoelastic model was developed and implemented in Abaqus/Implicit Code to analyze the nonlinear visceoelastic behavior of polyvinyl acetate (PVA) under nanoindentation.

  9. Standard Intercepts for Calculating Lengths from Scale Measurements for Some Centrarchid and Percid Fishes

    Microsoft Academic Search

    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

  10. Evaluation of Length-of-Stain Gas Indicator Tubes for Measuring Carbon Monoxide in Air.

    ERIC Educational Resources Information Center

    Klaubert, Earl C.; And Others

    Techniques for detection and measurement of carbon monoxide (CO) in air are of interest and utility in many aspects of automotive safety. CO concentrations may range from less than 100 parts per million (ppm), or 0.01 percent, to about 10 percent by volume. Gas indicator tubes have been used for many years primarily as detectors of hazardous gases…

  11. Inter-ELM power decay length for JET and ASDEX upgrade: measurement and comparison with heuristic drift-based model.

    PubMed

    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

  12. Measurement of the spatial backscattering impulse-response at short length-scales with polarized enhanced backscattering (EBS)

    PubMed Central

    Radosevich, Andrew J.; Mutyal, Nikhil N.; Turzhitsky, Vladimir; Rogers, Jeremy D.; Yi, Ji; Taflove, Allen; Backman, Vadim

    2012-01-01

    In this Letter, we describe an easy to implement technique to measure the spatial backscattering impulse-response at length-scales shorter than a transport mean free path with resolution of better than 10 ?m using the enhanced backscattering (EBS) phenomenon. This technique enables spectroscopic measurements throughout the visible range and sensitivity to all polarization channels. Through a combination of Monte Carlo simulations and experimental measurements of latex microspheres, we explore the various sensitivities of our technique to both intrinsic sample properties and extrinsic instrumental properties. We conclude by demonstrating the extraordinary sensitivity of our technique to the shape of the scattering phase function, including higher order shape parameters than the anisotropy factor (or first moment). PMID:22179867

  13. Measurement of the Spatial Cross-Correlation Function of Damped Lyman Alpha Systems and Lyman Break Galaxies

    E-print Network

    J. Cooke; A. M. Wolfe; E. Gawiser; J. X. Prochaska

    2005-11-17

    We present the first spectroscopic measurement of the spatial cross-correlation function between damped Lyman alpha systems (DLAs) and Lyman break galaxies (LBGs). We obtained deep u'BVRI images of nine QSO fields with 11 known z ~ 3 DLAs and spectroscopically confirmed 211 R 2 LBGs. We find strong evidence for an overdensity of LBGs near DLAs versus random, the results of which are similar to that of LBGs near other LBGs. A maximum likelihood cross-correlation analysis found the best fit correlation length value of r_0 = 2.9^(+1.4)_(-1.5) h^(-1)Mpc using a fixed value of gamma = 1.6. The implications of the DLA-LBG clustering amplitude on the average dark matter halo mass of DLAs are discussed.

  14. Neutron interferometric measurement of the scattering length difference between the triplet and singlet states of n-$^3$He

    E-print Network

    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.

  15. Neutron interferometric measurement of the scattering length difference between the triplet and singlet states of n -3He

    NASA Astrophysics Data System (ADS)

    Huber, M. G.; Arif, M.; Chen, W. C.; Gentile, T. R.; Hussey, D. S.; Black, T. C.; Pushin, D. A.; Shahi, C. B.; Wietfeldt, F. E.; Yang, L.

    2014-12-01

    We report a determination of the n -3He scattering length difference ? b'=b1'-b0'=[-5.411 ±0.031 (statistical)±0.039 (systematic)] fm between the triplet and singlet states using a neutron interferometer. This revises our previous result ? b'=[-5.610 ±0.027 (statistical)±0.032 (systematic)] fm obtained using the same technique in 2008 [Huber et al., Phys. Rev. Lett. 102, 200401 (2009), 10.1103/PhysRevLett.102.200401; Huber et al., Phys. Rev. Lett. 103, 179903(E) (2009), 10.1103/PhysRevLett.103.179903]. This revision is attributable to a reanalysis of the 2008 experiment that now includes a systematic correction caused by magnetic-field gradients near the 3He cell which had been previously underestimated. Furthermore, we more than doubled our original data set from 2008 by acquiring 6 months of additional data in 2013. Both the new data set and a reanalysis 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 3He, aid in the interpretation of neutron scattering from quantum liquids. The difference ? b' was determined by measuring the relative phase shift between two incident neutron polarizations caused by the spin-dependent interaction with a polarized 3He target. The target 3He gas was sealed inside a small, flat-windowed glass cell that was placed in one beam path of the interferometer. The relaxation of 3He polarization was monitored continuously with neutron transmission measurements. The neutron polarization and spin-flipper efficiency were determined separately using 3He analyzers and two different polarimetry analysis methods. A summary of the measured scattering lengths for n -3He with a comparison to nucleon interaction models is given.

  16. An Evolutionarily Conserved Family of Virion Tail Needles Related to Bacteriophage P22 gp26: Correlation between Structural Stability and Length of the -Helical Trimeric Coiled Coil

    SciTech Connect

    Bhardwaj, A.; Walker-Kopp, N; Casjens, S; Cingolani, G

    2009-01-01

    Bacteriophages of the Podoviridae family use short noncontractile tails to inject their genetic material into Gram-negative bacteria. In phage P22, the tail contains a thin needle, encoded by the phage gene 26, which is essential both for stabilization and for ejection of the packaged viral genome. Bioinformatic analysis of the N-terminal domain of gp26 (residues 1-60) led us to identify a family of genes encoding putative homologues of the tail needle gp26. To validate this idea experimentally and to explore their diversity, we cloned the gp26-like gene from phages HK620, Sf6 and HS1, and characterized these gene products in solution. All gp26-like factors contain an elongated {alpha}-helical coiled-coil core consisting of repeating, adjacent trimerization heptads and form trimeric fibers with length ranging between about 240 to 300 {angstrom}. gp26 tail needles display a high level of structural stability in solution, with Tm (temperature of melting) between 85 and 95 C. To determine how the structural stability of these phage fibers correlates with the length of the {alpha}-helical core, we investigated the effect of insertions and deletions in the helical core. In the P22 tail needle, we identified an 85-residue-long helical domain, termed MiCRU (minimal coiled-coil repeat unit), that can be inserted in-frame inside the gp26 helical core, preserving the straight morphology of the fiber. Likewise, we were able to remove three quarters of the helical core of the HS1 tail needle, minimally decreasing the stability of the fiber. We conclude that in the gp26 family of tail needles, structural stability increases nonlinearly with the length of the {alpha}-helical core. Thus, the overall stability of these bacteriophage fibers is not solely dependent on the number of trimerization repeats in the {alpha}-helical core.

  17. Measurements of large scale-length plasmas produced from gas-filled targets

    SciTech Connect

    Back, C.A.; Berger, R.L.; Estabrook, K. [and others

    1995-06-30

    Apart from their intrinsic interest, plasma physics processes are important because they affect the coupling of the laser energy into laser-irradiated targets. Recently, new gas-filled targets have been developed to create large mm-size plasmas for the study of stimulated Brillouin scattering (SBS) and stimulated Raman scattering (SRS). We present x-ray images and x-ray spectra to characterize these targets, which show that the plasmas are homogeneous, have electron densities of {approximately}10{sup 21} cm{sup {minus}3}, and attain electron temperatures of {approximately}3 keV. We also present SBS measurements to demonstrate how systematic studies of physical phenomena can be performed using these targets.

  18. Precise Sound Velocity Measurements on Solids and Liquids at High Pressure and High Temperature with Direct Length Measurement

    SciTech Connect

    Li, B.

    2009-01-01

    Sound velocity measurements at pressure and/or temperature provide important information in the material's structural behavior and physical properties under extreme conditions. With the application of synchrotron X-radiation sources, new developments have emerged to facilitate the study properties and structures of crystalline and amorphous materials. In the last decade, we have developed a unique technique for measuring sound velocity in a cubic type multianvil apparatus installed at X-17B2, National Synchrotron Light Source (NSLS) of Brookhaven National Lab, which allows us to conduct precise velocity measurements on crystalline and noncrystalline materials at various pressure and temperature conditions by conducting simultaneous X-radiation and ultrasonic interferometry measurements. In this paper, sound velocities at high temperatures for some ceramics and metals are measured to study the behavior and property change of these materials undergoing compression/expansion as well as phase transition and structural instabilities. This technique opens new opportunities for the study of materials that are of interest to many disciplines, such as earth science, materials science, and condensed matter physics.

  19. Influence of FBG sensors length on temperature measures in laser-irradiated pancreas: theoretical and experimental evaluation.

    PubMed

    Saccomandi, P; Lupi, G; Schena, E; Polimadei, A; Caponero, M; Panzera, F; Martino, M; Di Matteo, F M; Sciuto, S; Silvestri, S

    2013-01-01

    Temperature distribution T(x,y,z,t) in tissue undergoing Laser-induced Interstitial Thermotherapy (LITT) plays a crucial role on treatment outcome. Theoretical and experimental assessment of temperature on ex vivo laser-irradiated pancreas is presented. The aim of this work is to assess the influence of thermometers dimensions on temperature measures during LITT. T(x,y,z,t) inside tissue is monitored by optical sensors, i.e., Fiber Bragg Gratings (FBGs): three FBGs with lengths of 10 mm and nine FBGs of 1 mm, at different distances (2 mm, 5 mm and 10 mm) and different quotes (0 mm, 2 mm and 4 mm) from the laser fiber tip are used. Theoretical punctual T(x,y,z,t) is averaged out on both 10 mm and 1 mm in order to compare numerical predictions with experimental data. Results demonstrate the influence of FBG length on T(x,y,z,t) measures. This phenomenon depends on the distance between sensor and applicator: it is particularly significant close to the applicator tip (2 mm) because of the high spatial T(x,y,z,t) gradient within the tissue. Both theoretical results and experimental ones show that just at a distance of 10 mm from the tip, differences between T(x,y,z,t) provided by FBGs of 10 mm and 1 mm are negligible. PMID:24110543

  20. Direct measurement of surface shape for validation of indentation deformation and plasticity length-scale effects: a comparison of methods

    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).

  1. Leaf vein length per unit area is not intrinsically dependent on image magnification: avoiding measurement artifacts for accuracy and precision.

    PubMed

    Sack, Lawren; Caringella, Marissa; Scoffoni, Christine; Mason, Chase; Rawls, Michael; Markesteijn, Lars; Poorter, Lourens

    2014-10-01

    Leaf vein length per unit leaf area (VLA; also known as vein density) is an important determinant of water and sugar transport, photosynthetic function, and biomechanical support. A range of software methods are in use to visualize and measure vein systems in cleared leaf images; typically, users locate veins by digital tracing, but recent articles introduced software by which users can locate veins using thresholding (i.e. based on the contrasting of veins in the image). Based on the use of this method, a recent study argued against the existence of a fixed VLA value for a given leaf, proposing instead that VLA increases with the magnification of the image due to intrinsic properties of the vein system, and recommended that future measurements use a common, low image magnification for measurements. We tested these claims with new measurements using the software LEAFGUI in comparison with digital tracing using ImageJ software. We found that the apparent increase of VLA with magnification was an artifact of (1) using low-quality and low-magnification images and (2) errors in the algorithms of LEAFGUI. Given the use of images of sufficient magnification and quality, and analysis with error-free software, the VLA can be measured precisely and accurately. These findings point to important principles for improving the quantity and quality of important information gathered from leaf vein systems. PMID:25096977

  2. Correlation

    NSDL National Science Digital Library

    Edwin P. Christmann

    2008-11-01

    This chapter will discuss the concept of correlation , which is used in later chapters that will explain the concepts of validity and reliability. Here, the authors introduce the Pearson correlation coefficient, a statistic that is used with ratio

  3. Resolving Dynamics Structure in the Mlt: Correlative Measurements with Tidi and Hrdi

    NASA Astrophysics Data System (ADS)

    Niciejewski, R.; Skinner, W. R.; Marshall, A.; Cooper, M.

    2011-12-01

    Undoubtedly, line of sight Doppler measurements of the terrestrial limb have and continue to provide the longest sequence of routine synoptic wind data of the mesosphere and lower thermosphere. To provide the community with basic information about global MLT winds, UARS/HRDI was launched in 1991 and later joined by TIMED/TIDI in 2001. Correlative observations of the MLT with the two instruments began in February 2002 and continued until April 2005 when battery problems aboard UARS forced the final turn-off of HRDI. TIDI continues observing the MLT to the present day with nearly a 100% duty cycle. On short time intervals (a few days), tidal frequencies are difficult to unambiguously identify from orbit by either HRDI or TIDI due to aliasing issues with single satellite observations. Combining measurements from the two platforms provides a significant improvement in understanding two-dimensional frequency wavenumber spectra for short data sets. This paper will describe the progress that has been made in characterizing migrating and non-migrating diurnal tides in the MLT. Short data sets of several days' length are necessary to identify planetary waves, such as the two-day wave, and its effect on MLT dynamics. These waves can transport water vapour exhaust from rocket launches over large distances providing a seed for enhancing noctilucent cloud formation at high latitudes.

  4. 23 CFR Appendix D to Part 658 - Devices That Are Excluded From Measurement of the Length or Width of a Commercial Motor Vehicle

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ...Measurement of the Length or Width of a Commercial Motor Vehicle D Appendix D to Part 658 Highways FEDERAL HIGHWAY ADMINISTRATION...DESIGNATIONS-LENGTH, WIDTH AND WEIGHT LIMITATIONS Pt. 658, App. D Appendix D to Part 658—Devices That Are Excluded...

  5. 23 CFR Appendix D to Part 658 - Devices That Are Excluded From Measurement of the Length or Width of a Commercial Motor Vehicle

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ...Measurement of the Length or Width of a Commercial Motor Vehicle D Appendix D to Part 658 Highways FEDERAL HIGHWAY ADMINISTRATION...DESIGNATIONS-LENGTH, WIDTH AND WEIGHT LIMITATIONS Pt. 658, App. D Appendix D to Part 658—Devices That Are Excluded...

  6. 23 CFR Appendix D to Part 658 - Devices That Are Excluded From Measurement of the Length or Width of a Commercial Motor Vehicle

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ...Measurement of the Length or Width of a Commercial Motor Vehicle D Appendix D to Part 658 Highways FEDERAL HIGHWAY ADMINISTRATION...DESIGNATIONS-LENGTH, WIDTH AND WEIGHT LIMITATIONS Pt. 658, App. D Appendix D to Part 658—Devices That Are Excluded...

  7. Measurements of Dihadron Correlations Relative to the Event Plane in Au+Au Collisions at $\\sqrt{s_{NN}}=200$ GeV

    E-print Network

    H. Agakishiev; M. M. Aggarwal; Z. Ahammed; A. V. Alakhverdyants; I. Alekseev; J. Alford; B. D. Anderson; C. D. Anson; D. Arkhipkin; G. S. Averichev; J. Balewski; D. R. Beavis; N. K. Behera; R. Bellwied; M. J. Betancourt; R. R. Betts; A. Bhasin; A. K. Bhati; H. Bichsel; J. Bielcik; J. Bielcikova; B. Biritz; L. C. Bland; W. Borowski; J. Bouchet; E. Braidot; A. V. Brandin; A. Bridgeman; S. G. Brovko; E. Bruna; S. Bueltmann; I. Bunzarov; T. P. Burton; X. Z. Cai; H. Caines; M. Calderón de la Barca Sánchez; D. Cebra; R. Cendejas; M. C. Cervantes; Z. Chajecki; P. Chaloupka; S. Chattopadhyay; H. F. Chen; J. H. Chen; J. Y. Chen; L. Chen; J. Cheng; M. Cherney; A. Chikanian; K. E. Choi; W. Christie; P. Chung; M. J. M. Codrington; R. Corliss; J. G. Cramer; H. J. Crawford; S. Dash; A. Davila Leyva; L. C. De Silva; R. R. Debbe; T. G. Dedovich; A. A. Derevschikov; R. Derradi de Souza; L. Didenko; P. Djawotho; S. M. Dogra; X. Dong; J. L. Drachenberg; J. E. Draper; J. C. Dunlop; L. G. Efimov; M. Elnimr; J. Engelage; G. Eppley; M. Estienne; L. Eun; O. Evdokimov; R. Fatemi; J. Fedorisin; R. G. Fersch; P. Filip; E. Finch; V. Fine; Y. Fisyak; C. A. Gagliardi; D. R. Gangadharan; A. Geromitsos; F. Geurts; P. Ghosh; Y. N. Gorbunov; A. Gordon; O. Grebenyuk; D. Grosnick; S. M. Guertin; A. Gupta; W. Guryn; B. Haag; O. Hajkova; A. Hamed; L-X. Han; J. W. Harris; J. P. Hays-Wehle; M. Heinz; S. Heppelmann; A. Hirsch; E. Hjort; G. W. Hoffmann; D. J. Hofman; B. Huang; H. Z. Huang; T. J. Humanic; L. Huo; G. Igo; P. Jacobs; W. W. Jacobs; C. Jena; F. Jin; J. Joseph; E. G. Judd; S. Kabana; K. Kang; J. Kapitan; K. Kauder; H. Ke; D. Keane; A. Kechechyan; D. Kettler; D. P. Kikola; J. Kiryluk; A. Kisiel; V. Kizka; A. G. Knospe; D. D. Koetke; T. Kollegger; J. Konzer; I. Koralt; L. Koroleva; W. Korsch; L. Kotchenda; V. Kouchpil; P. Kravtsov; K. Krueger; M. Krus; L. Kumar; P. Kurnadi; M. A. C. Lamont; J. M. Landgraf; S. LaPointe; J. Lauret; A. Lebedev; R. Lednicky; J. H. Lee; W. Leight; M. J. LeVine; C. Li; L. Li; N. Li; W. Li; X. Li; X. Li; Y. Li; Z. M. Li; M. A. Lisa; F. Liu; H. Liu; J. Liu; T. Ljubicic; W. J. Llope; R. S. Longacre; W. A. Love; Y. Lu; E. V. Lukashov; X. Luo; G. L. Ma; Y. G. Ma; D. P. Mahapatra; R. Majka; O. I. Mall; L. K. Mangotra; R. Manweiler; S. Margetis; C. Markert; H. Masui; H. S. Matis; Yu. A. Matulenko; D. McDonald; T. S. McShane; A. Meschanin; R. Milner; N. G. Minaev; S. Mioduszewski; A. Mischke; M. K. Mitrovski; B. Mohanty; M. M. Mondal; B. Morozov; D. A. Morozov; M. G. Munhoz; M. Naglis; B. K. Nandi; T. K. Nayak; P. K. Netrakanti; L. V. Nogach; S. B. Nurushev; G. Odyniec; A. Ogawa; Oh; Ohlson; V. Okorokov; E. W. Oldag; D. Olson; M. Pachr; B. S. Page; S. K. Pal; Y. Pandit; Y. Panebratsev; T. Pawlak; H. Pei; T. Peitzmann; C. Perkins; W. Peryt; S. C. Phatak; P. Pile; M. Planinic; M. A. Ploskon; J. Pluta; D. Plyku; N. Poljak; A. M. Poskanzer; B. V. K. S. Potukuchi; C. B. Powell; D. Prindle; C. Pruneau; N. K. Pruthi; P. R. Pujahari; J. Putschke; H. Qiu; R. Raniwala; S. Raniwala; R. L. Ray; R. Redwine; R. Reed; H. G. Ritter; J. B. Roberts; O. V. Rogachevskiy; J. L. Romero; A. Rose; L. Ruan; J. Rusnak; N. R. Sahoo; S. Sakai; I. Sakrejda; T. Sakuma; S. Salur; J. Sandweiss; E. Sangaline; A. Sarkar; J. Schambach; R. P. Scharenberg; A. M. Schmah; T. R. Schuster; J. Seele; J. Seger; I. Selyuzhenkov; P. Seyboth; E. Shahaliev; M. Shao; M. Sharma; S. S. Shi; Q. Y. Shou; E. P. Sichtermann; F. Simon; R. N. Singaraju; M. J. Skoby; N. Smirnov; H. M. Spinka; B. Srivastava; T. D. S. Stanislaus; D. Staszak; S. G. Steadman; J. R. Stevens; R. Stock; M. Strikhanov; B. Stringfellow; A. A. P. Suaide; M. C. Suarez; N. L. Subba; M. Sumbera; X. M. Sun; Y. Sun; Z. Sun; B. Surrow; D. N. Svirida; T. J. M. Symons; A. Szanto de Toledo; J. Takahashi; A. H. Tang; Z. Tang; L. H. Tarini; T. Tarnowsky; D. Thein; J. H. Thomas; J. Tian; A. R. Timmins; D. Tlusty; M. Tokarev; V. N. Tram; S. Trentalange; R. E. Tribble; Tribedy; O. D. Tsai; T. Ullrich; D. G. Underwood; G. Van Buren; G. van Nieuwenhuizen; J. A. Vanfossen, Jr.; R. Varma; G. M. S. Vasconcelos; A. N. Vasiliev; F. Videbæk; Y. P. Viyogi; S. Vokal; M. Wada; M. Walker; F. Wang; G. Wang; H. Wang; J. S. Wang; Q. Wang; X. L. Wang; Y. Wang; G. Webb; J. C. Webb; G. D. Westfall; C. Whitten Jr.; H. Wieman; S. W. Wissink; R. Witt; W. Witzke; Y. F. Wu; Xiao; W. Xie; H. Xu; N. Xu; Q. H. Xu; W. Xu; Y. Xu; Z. Xu; L. Xue; Y. Yang; P. Yepes; K. Yip; I-K. Yoo; M. Zawisza; H. Zbroszczyk; W. Zhan; J. B. Zhang; S. Zhang; W. M. Zhang; X. P. Zhang; Y. Zhang; Z. P. Zhang; J. Zhao; C. Zhong; W. Zhou; X. Zhu; Y. H. Zhu; R. Zoulkarneev; Y. Zoulkarneeva

    2013-05-16

    Dihadron azimuthal correlations containing a high transverse momentum ($\\pt$) trigger particle are sensitive to the properties of the nuclear medium created at RHIC through the strong interactions occurring between the traversing parton and the medium, i.e. jet-quenching. Previous measurements revealed a strong modification to dihadron azimuthal correlations in Au+Au collisions with respect to \\pp\\ and \\dAu\\ collisions. The modification increases with the collision centrality, suggesting a path-length dependence to the jet-quenching effect. This paper reports STAR measurements of dihadron azimuthal correlations in mid-central (20-60\\%) Au+Au collisions at $\\snn=200$~GeV as a function of the trigger particle's azimuthal angle relative to the event plane, $\\phis=|\\phit-\\psiEP|$. The azimuthal correlation is studied as a function of both the trigger and associated particle $\\pt$. The subtractions of the combinatorial background and anisotropic flow, assuming Zero Yield At Minimum (\\zyam), are described. The away-side correlation is strongly modified, and the modification varies with $\\phis$, which is expected to be related to the path-length that the away-side parton traverses. The pseudo-rapidity ($\\deta$) dependence of the near-side correlation, sensitive to long range $\\deta$ correlations (the ridge), is also investigated. The ridge and jet-like components of the near-side correlation are studied as a function of $\\phis$. The ridge appears to drop with increasing $\\phis$ while the jet-like component remains approximately constant. ...

  8. Quantum correlation evolution of GHZ and states under noisy channels using ameliorated measurement-induced disturbance

    NASA Astrophysics Data System (ADS)

    Espoukeh, Pakhshan; Pedram, Pouria

    2015-01-01

    We study quantum correlation of Greenberger-Horne-Zeilinger (GHZ) and W states under various noisy channels using measurement-induced disturbance approach and its optimized version. Although these inequivalent maximal entangled states represent the same quantum correlation in the absence of noise, it is shown that the W state is more robust than the GHZ state through most noisy channels. Also, using measurement-induced disturbance measure, we obtain the analytical relations for the time evolution of quantum correlations in terms of the noisy parameter and remove its overestimating quantum correlations upon implementing the ameliorated measurement-induced disturbance.

  9. Joint radius-length distribution as a measure of anisotropic pore eccentricity: An experimental and analytical framework

    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.

  10. Chaotic classification of electromyographic (EMG) signals via correlation dimension measurement

    Microsoft Academic Search

    M. Bodruzzaman; S. Devgan; S. Kari

    1992-01-01

    A set of intramuscular electromyographic signals were collected from various patient groups during ramp muscle contraction. The signals were collected using a real-time data acquisition system. The signals were tested for their chaotic behavior using spectral analysis and Poincare map techniques. MATLAB based software tools were developed to compute and plot the correlation function for each data set to determine

  11. Benefits of Time Correlation Measurements for Passive Screening

    NASA Astrophysics Data System (ADS)

    Murer, David; Blackie, Douglas; Peerani, Paolo

    2014-02-01

    The “FLASH Portals Project” is a collaboration between Arktis Radiation Detectors Ltd (CH), the Atomic Weapons Establishment (UK), and the Joint Research Centre (European Commission), supported by the Technical Support Working Group (TSWG). The program's goal was to develop and demonstrate a technology to detect shielded special nuclear materials (SNM) more efficiently and less ambiguously by exploiting time correlation. This study presents experimental results of a two-sided portal monitor equipped with in total 16 4He fast neutron detectors as well as four polyvinyltoluene (PVT) plastic scintillators. All detectors have been synchronized to nanosecond precision, thereby allowing the resolution of time correlations from timescales of tens of microseconds (such as (n, ?) reactions) down to prompt fission correlations directly. Our results demonstrate that such correlations can be detected in a typical radiation portal monitor (RPM) geometry and within operationally acceptable time scales, and that exploiting these signatures significantly improves the performance of the RPM compared to neutron counting. Furthermore, the results show that some time structure remains even in the presence of heavy shielding, thus significantly improving the sensitivity of the detection system to shielded SNM.

  12. Atmospheric pollution measurement by optical cross correlation methods - A concept

    NASA Technical Reports Server (NTRS)

    Fisher, M. J.; Krause, F. R.

    1971-01-01

    Method combines standard spectroscopy with statistical cross correlation analysis of two narrow light beams for remote sensing to detect foreign matter of given particulate size and consistency. Method is applicable in studies of generation and motion of clouds, nuclear debris, ozone, and radiation belts.

  13. Correlations between force plate measures for assessment of balance

    Microsoft Academic Search

    Annica Karlsson; Gunilla Frykberg

    2000-01-01

    Objective. To compare different force plate measures for assessment of postural stability during normal standing. Five types of measures were analysed: (1) The standard deviation of the horizontal ground reaction force, (2) the standard deviation of the centre of pressure, (3) the mean velocity of the centre of pressure, (4) movement strategy measures, and (5) the standard deviation of the

  14. Correlation Between Immersion Profile and Measured Value of Fixed-Point Temperature

    NASA Astrophysics Data System (ADS)

    Shulgat, O. S.; Fuksov, V. M.; Ivanova, A. G.; Gerasimov, S. F.; Pokhodun, A. I.

    2014-04-01

    Assessment of thermal immersion effects in the melting and freezing points defined by the International Temperature Scale of 1990 is one of the vital issues of modern thermometry. In documents of the Consultative Committee for Thermometry, the deviation of the experimental immersion profile from the theoretical value of the hydrostatic effect at a height of about 3 cm to 5 cm from the thermometer well bottom is used for the estimation of the uncertainty due to unwanted thermal effects. This estimation assumes the occurrence of solely the hydrostatic effect all along the height of the well inner wall. Real distortions of the temperature gradient at the bottom and at the top part of the well caused by the change of heat-exchange conditions are not taken into account. To define more precisely the temperature gradient along the height of the well, a miniature PRT with a 30 mm sensitive element and a sheath length and diameter of about 60 mm and 6 mm, respectively, were used. Also, the measurements of fixed-points temperature at noticeably different slopes of immersion profiles due to variations of the thermometer heat exchange and phase transition realization conditions were produced by means of a standard platinum resistance thermometer (SPRT). The measurements were carried out at the tin and zinc freezing points. The immersion curves measured with a miniature thermometer demonstrated an increase of the temperature during its lifting in the first 1 cm to 3 cm above the bottom of the well. The measurement results at the zinc freezing point by means of the SPRT have not confirmed the correlation between the immersion curves, the received value of the Zn freezing temperature, and the estimation of its uncertainty.

  15. Direct measurement of the twist penetration length in a single smectic A layer of colloidal virus particles

    PubMed Central

    Barry, Edward; Dogic, Zvonimir; Meyer, Robert B.; Pelcovits, Robert A.; Oldenbourg, Rudolf

    2010-01-01

    In the 1970s deGennes discussed the fundamental geometry of smectic liquid crystals and established an analogy between the smectic A phase and superconductors. It follows that smectic layers expel twist deformations in the same way that superconductors expel magnetic field. We make a direct observation of the penetration of twist at the edge of a single isolated smectic A layer composed of chiral fd virus particles subjected to a depletion interaction. Using the LC-PolScope we make quantitative measurements of the spatial dependence of the birefringence due to molecular tilt near the layer edges. We match data to theory for the molecular tilt penetration profile and determine the twist penetration length for this system. PMID:18975886

  16. Correlation measure to detect time series distances, whence economy globalization

    NASA Astrophysics Data System (ADS)

    Mi?kiewicz, Janusz; Ausloos, Marcel

    2008-11-01

    An instantaneous time series distance is defined through the equal time correlation coefficient. The idea is applied to the Gross Domestic Product (GDP) yearly increments of 21 rich countries between 1950 and 2005 in order to test the process of economic globalisation. Some data discussion is first presented to decide what (EKS, GK, or derived) GDP series should be studied. Distances are then calculated from the correlation coefficient values between pairs of series. The role of time averaging of the distances over finite size windows is discussed. Three network structures are next constructed based on the hierarchy of distances. It is shown that the mean distance between the most developed countries on several networks actually decreases in time, -which we consider as a proof of globalization. An empirical law is found for the evolution after 1990, similar to that found in flux creep. The optimal observation time window size is found ?15 years.

  17. 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.

  18. Correlated optical measurements and plasmon mapping of silver nanorods

    SciTech Connect

    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.

  19. Precision and Accuracy Studies with Kajaani Fiber Length Analyzers

    NASA Astrophysics Data System (ADS)

    Copur, Yalcin; Makkonen, Hannu

    The aim of this study was to test the measurement precision and accuracy of the Kajaani FS-100 giving attention to possible machine error in the measurements. Fiber length of pine pulps produced using polysulfide, kraft, biokraft and soda methods were determined using both FS-100 and FiberLab automated fiber length analyzers. The measured length values were compared for both methods. The measurement precision and accuracy was tested by replicated measurements using rayon stable fibers. Measurements performed on pulp samples showed typical length distributions for both analyzers. Results obtained from Kajaani FS-100 and FiberLab showed a significant correlation. The shorter length measurement with FiberLab was found to be mainly due to the instrument calibration. The measurement repeatability tested for Kajaani FS-100 indicated that the measurements are precise.

  20. Estimating age from recapture data: integrating incremental growth measures with ancillary data to infer age-at-length.

    PubMed

    Eaton, Mitchell J; Link, William A

    2011-10-01

    Estimating the age of individuals in wild populations can be of fundamental importance for answering ecological questions, modeling population demographics, and managing exploited or threatened species. Significant effort has been devoted to determining age through the use of growth annuli, secondary physical characteristics related to age, and growth models. Many species, however, either do not exhibit physical characteristics useful for independent age validation or are too rare to justify sacrificing a large number of individuals to establish the relationship between size and age. Length-at-age models are well represented in the fisheries and other wildlife management literature. Many of these models overlook variation in growth rates of individuals and consider growth parameters as population parameters. More recent models have taken advantage of hierarchical structuring of parameters and Bayesian inference methods to allow for variation among individuals as functions of environmental covariates or individual-specific random effects. Here, we describe hierarchical models in which growth curves vary as individual-specific stochastic processes, and we show how these models can be fit using capture-recapture data for animals of unknown age along with data for animals of known age. We combine these independent data sources in a Bayesian analysis, distinguishing natural variation (among and within individuals) from measurement error. We illustrate using data for African dwarf crocodiles, comparing von Bertalanffy and logistic growth models. The analysis provides the means of predicting crocodile age, given a single measurement of head length. The von Bertalanffy was much better supported than the logistic growth model and predicted that dwarf crocodiles grow from 19.4 cm total length at birth to 32.9 cm in the first year and 45.3 cm by the end of their second year. Based on the minimum size of females observed with hatchlings, reproductive maturity was estimated to be at nine years. These size benchmarks are believed to represent thresholds for important demographic parameters; improved estimates of age, therefore, will increase the precision of population projection models. The modeling approach that we present can be applied to other species and offers significant advantages when multiple sources of data are available and traditional aging techniques are not practical. PMID:22073638

  1. IEEE TRANSACTIONS ON INSTRUMENTATION AND MEASUREMENT, VOL. 50, NO. 3, JUNE 2001 697 Robust Sensing of Arc Length

    E-print Network

    Zhang, YuMing

    tungsten arc welding (GTAW) with argon shield. To this end, effects of welding parame- ters on spectral of Arc Length Pengjiu Li and YuMing Zhang, Senior Memeber, IEEE Abstract--During arc welding, the arc length are fun- damental in robotic and automated welding operations. Length of welding arc determines

  2. Effect of Crystal Defects on Minority Carrier Diffusion Length in 6H SiC Measured Using the Electron Beam Induced Current Method

    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.

  3. Optical Design of a Broadband Infrared Spectrometer for Bunch Length Measurement at the Linac Coherent Light Source

    SciTech Connect

    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.

  4. The heritabilities, phenotypic correlations, and genetic correlations of lean color and palatability measures from longissimus muscle in beef cattle.

    PubMed

    Pratt, P J; Moser, D W; Thompson, L D; Jackson, S P; Johnson, B J; Garmyn, A J; Miller, M F

    2013-06-01

    Data from a study conducted over 5 yr were analyzed to determine heritability estimates of LM lean color, as measured by subjective scoring and Hunter Colorimeter readings, and palatability, as measured by trained sensory panelists and Warner-Bratzler shear force (WBSF). Phenotypic and genetic correlations were determined between each of the measures of palatability and color. There were 1,066 cattle representing 12 different breeds in the study. Subjective lean color and a* (redness) and b* (yellowness) values were moderately heritable, 0.34 ± 0.122, 0.29 ± 0.115 and 0.28 ± 0.120, respectively, whereas the L* (lightness) was lowly heritable, 0.09 ± 0.087. The heritability of WBSF was moderately heritable ranging from 0.23 ± 0.114 (3 d) to 0.42 ± 0.148 (21 d). Sustained tenderness, as measured by sensory panelists, was found to be moderately heritable ranging from 0.16 ± 0.108 (21 d) to 0.33 ± 0.135 (14 d). Sustained juiciness and beef flavor, as measured by sensory panelists, were found to be lowly to moderately heritable ranging from 0.00 ± 0.089 (21 d) to 0.18 ± 0.105 (14 d) and 0.00 ± 0.080 (7 d) to 0.18 ± 0.110 (21 d), respectively. The significant phenotypic correlations were those between WBSF and subjective lean color, L* value, and a* value; both initial and sustained tenderness as well as beef flavor were correlated with subjective lean color and L* value. Flavor intensity and overall mouthfeel were associated with subjective lean color, L* value, a* value, and b* value. Both a* and b* values were highly correlated genetically with WBSF, -0.71 and -0.72, respectively, and subjective lean color was moderately correlated with WBSF, -0.46. The genetic correlation between subjective lean color and initial tenderness was also high, 0.56, whereas that between a* value and initial tenderness was 0.43, which was similar to that found between b* value and initial tenderness, 0.44. The genetic correlations between subjective lean color, a* value, and b* value with sustained tenderness were all high at 0.58, 0.70, and 0.58, respectively. The genetic correlations between a* value and b* value with beef flavor were low to moderate at 0.12 and 0.19, respectively, whereas that between subjective lean color and beef flavor was high, 0.64. The genetic correlations between a* value, b* value, and lean color with sustained juiciness were all moderate correlations at -0.35, -0.23, and -0.45, respectively. The genetic correlations between a* value and b* value with overall mouthfeel were high at 0.80 and 0.79, respectively, whereas that between subjective lean color and overall mouthfeel was moderate, 0.46. In conclusion, regardless of measurement technique of lean color, it was not only heritable but was also moderately to highly correlated with measurements of palatability in beef from LM. PMID:23508032

  5. A correlation force spectrometer for single molecule measurements under tensile load

    E-print Network

    Paul, Mark

    .15­20 Comparing the dual trap technique with atomic force microscopy (AFM) single molecule forceA correlation force spectrometer for single molecule measurements under tensile load Milad Radiom,1-correlation measurements is less than one third of the value for single-cantilever force microscopy. The dynamics

  6. Ultrasonic attenuation measurements at very high SNR: Correlation, information theory and performance

    NASA Astrophysics Data System (ADS)

    Challis, Richard; Ivchenko, Vladimir; Al-Lashi, Raied

    2013-08-01

    This paper describes a system for ultrasonic wave attenuation measurements which is based on pseudo-random binary codes as transmission signals combined with on-the-fly correlation for received signal detection. The apparatus can receive signals in the nanovolt range against a noise background in the order of hundreds of microvolts and an analogue to digital convertor (ADC) bit-step also in the order of hundreds of microvolts. Very high signal to noise ratios (SNRs) are achieved without recourse to coherent averaging with its associated requirement for high sampling times. The system works by a process of dithering - in which very low amplitude received signals enter the dynamic range of the ADC by 'riding' on electronic noise at the system input. The amplitude of this 'useful noise' has to be chosen with care for an optimised design. The process of optimisation is explained on the basis of classical information theory and is achieved through a simple noise model. The performance of the system is examined for different transmitted code lengths and gain settings in the receiver chain. Experimental results are shown to verify the expected operation when the system is applied to a very highly attenuating material - an aerated slurry.

  7. TURBULENT DYNAMICS IN SOLAR FLARE SHEET STRUCTURES MEASURED WITH LOCAL CORRELATION TRACKING

    SciTech Connect

    McKenzie, D. E., E-mail: mckenzie@physics.montana.edu [Department of Physics, Montana State University, P.O. Box 173840, Bozeman, MT 59717-3840 (United States)

    2013-03-20

    High-resolution observations of the Sun's corona in extreme ultraviolet and soft X-rays have revealed a new world of complexity in the sheet-like structures connecting coronal mass ejections (CMEs) to the post-eruption flare arcades. This article presents initial findings from an exploration of dynamic flows in two flares observed with Hinode/XRT and SDO/AIA. The flows are observed in the hot ({approx}> 10 MK) plasma above the post-eruption arcades and measured with local correlation tracking. The observations demonstrate significant shears in velocity, giving the appearance of vortices and stagnations. Plasma diagnostics indicate that the plasma {beta} exceeds unity in at least one of the studied events, suggesting that the coronal magnetic fields may be significantly affected by the turbulent flows. Although reconnection models of eruptive flares tend to predict a macroscopic current sheet in the region between the CME and the flare arcade, it is not yet clear whether the observed sheet-like structures are identifiable as the current sheets or 'thermal halos' surrounding the current sheets. Regardless, the relationship between the turbulent motions and the embedded magnetic field is likely to be complicated, involving dynamic fluid processes that produce small length scales in the current sheet. Such processes may be crucial for triggering, accelerating, and/or prolonging reconnection in the corona.

  8. Shrinkage of dental composite in simulated cavity measured with digital image correlation.

    PubMed

    Li, Jianying; Thakur, Preetanjali; Fok, Alex S L

    2014-01-01

    Polymerization shrinkage of dental resin composites can lead to restoration debonding or cracked tooth tissues in composite-restored teeth. In order to understand where and how shrinkage strain and stress develop in such restored teeth, Digital Image Correlation (DIC) was used to provide a comprehensive view of the displacement and strain distributions within model restorations that had undergone polymerization shrinkage. Specimens with model cavities were made of cylindrical glass rods with both diameter and length being 10 mm. The dimensions of the mesial-occlusal-distal (MOD) cavity prepared in each specimen measured 3 mm and 2 mm in width and depth, respectively. After filling the cavity with resin composite, the surface under observation was sprayed with first a thin layer of white paint and then fine black charcoal powder to create high-contrast speckles. Pictures of that surface were then taken before curing and 5 min after. Finally, the two pictures were correlated using DIC software to calculate the displacement and strain distributions. The resin composite shrunk vertically towards the bottom of the cavity, with the top center portion of the restoration having the largest downward displacement. At the same time, it shrunk horizontally towards its vertical midline. Shrinkage of the composite stretched the material in the vicinity of the "tooth-restoration" interface, resulting in cuspal deflections and high tensile strains around the restoration. Material close to the cavity walls or floor had direct strains mostly in the directions perpendicular to the interfaces. Summation of the two direct strain components showed a relatively uniform distribution around the restoration and its magnitude equaled approximately to the volumetric shrinkage strain of the material. PMID:25079865

  9. Measurement Uncertainty Evaluation Method Considering Correlation and its Application to Precision Centrifuge

    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.

  10. Plan View and Profile Relations: Measuring Correlation Between Channel Profile and Network Morphology

    NASA Astrophysics Data System (ADS)

    Shelef, E.; Hilley, G. E.

    2010-12-01

    In this research, we explore the relationships between channel network attributes and the corresponding channel profile geometries using high-resolution digital topography and model-generated synthetic topographies. This combined analysis addresses one of the long-standing questions in geomorphology relating to the mechanistic significance of various plan-view channel network geometry measures. Statistically based numerical studies suggest that Hortonian measures of channel network architecture (e.g. bifurcation ratio, area ratio, and length ratio) describe virtually all possible network geometries, and so are not diagnostic when evaluating the origins of the geometry of a particular network. We further explore this hypothesis by examining the correlation between Hack exponent, the channel profile characteristics, and process changes (i.e debris flow vs. fluvial flows) within the landscape. Analysis of high resolution DEMs as well as modeled landscapes, suggests that the Hack exponent is likewise insensitive to changes in the channel profile concavity. In contrast, we find that changes in the concavity of channel profiles apparently impacts the spatial distribution of plan-view junction angles of joining stream segments throughout a catchment. In the context of previous work, this angle might be expected to be a function of the ratio between the slopes of the adjoined channels. Channel concavity determines downstream change in this ratio for channel segments throughout the basin, and so such a metric might be used to explicitly link profile channel geometries to plan-view network geometries. Because profile geometries may change with different advective mass transport processes, such a metric may provide a link between the processes that transport material across a landscape, the profile geometry of channels through which these flows traverse, and the overall drainage network geometry. Additional numerical and field data based analysis are required to further explore the sensitivity of the junction angle, as well as other measures, to process changes along the channel network.

  11. Rapid, Accurate, and Non-Invasive Measurement of Zebrafish Axial Length and Other Eye Dimensions Using SD-OCT Allows Longitudinal Analysis of Myopia and Emmetropization

    PubMed Central

    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

  12. Measurement of the penetration depth and coherence length of MgB 2 in all directions using transmission electron microscopy

    NASA Astrophysics Data System (ADS)

    Loudon, J. C.; Yazdi, S.; Kasama, T.; Zhigadlo, N. D.; Karpinski, J.

    2015-02-01

    We demonstrate that images of flux vortices in a superconductor taken with a transmission electron microscope can be used to measure the penetration depth and coherence length in all directions at the same temperature and magnetic field. This is particularly useful for MgB 2, where these quantities vary with the applied magnetic field and values are difficult to obtain at low field or in the c direction. We obtained images of flux vortices from a MgB 2 single crystal cut in the a c plane by focused ion beam milling and tilted to 45? with respect to the electron beam about the crystallographic a axis. A new method was developed to simulate these images that accounted for vortices with a nonzero core in a thin, anisotropic superconductor and a simplex algorithm was used to make a quantitative comparison between the images and simulations to measure the penetration depths and coherence lengths. This gave penetration depths ?a b=100 ±35 nm and ?c=120 ±15 nm at 10.8 K in a field of 4.8 mT. The large error in ?a b is a consequence of tilting the sample about a and had it been tilted about c , the errors on ?a b and ?c would be reversed. Thus obtaining the most precise values requires taking images of the flux lattice with the sample tilted in more than one direction. In a previous paper [J. C. Loudon et al., Phys. Rev. B 87, 144515 (2013), 10.1103/PhysRevB.87.144515], we obtained a more precise value for ?a b using a sample cut in the a b plane. Using this value gives ?a b=107 ±8 nm, ?c=120 ±15 nm, ?a b=39 ±11 nm, and ?c=35 ±10 nm, which agree well with measurements made using other techniques. The experiment required two days to conduct and does not require large-scale facilities. It was performed on a very small sample, 30 ×15 ? m and 200-nm thick, so this method could prove useful for superconductors where only small single crystals are available, as is the case for some iron-based superconductors.

  13. Noninvasive Online Measurement of Genome Lengths of Mammalian Tissues in Bulk by 14 MeV Neutron Atometry

    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

  14. On using the levelling of the free surface of a Newtonian fluid to measure viscosity and Navier slip length

    PubMed Central

    Gilormini, P.; Teyssèdre, H.

    2013-01-01

    Measuring the relaxation time involved in the levelling of a free surface of a Newtonian fluid laid on a substrate can give access to material parameters. It is shown here how most favourable pattern geometries of the free surface and film thicknesses can be defined for the measures of viscosity and Navier slip length at the fluid–solid interface, respectively. Moreover, we put special emphasis on the conditions required to avoid shear thinning by controlling the maximum shear rate. For initially sinusoidal patterns with infinitesimal amplitudes, an analytical solution including slip at the fluid–solid interface is used, and numerical simulations based on the natural element method allow one to discuss the effect of finite amplitudes. This leads to the definition of a relevance domain for the analytical solution that avoids the need for numerical simulations in practical applications. It is also shown how these results can be applied to crenelated profiles, where Fourier series expansion can be used, but with caution. PMID:24353474

  15. Symplectic invariants, entropic measures and correlations of Gaussian states

    E-print Network

    Alessio Serafini; Fabrizio Illuminati; Silvio De Siena

    2003-12-16

    We present a derivation of the Von Neumann entropy and mutual information of arbitrary two--mode Gaussian states, based on the explicit determination of the symplectic eigenvalues of a generic covariance matrix. The key role of the symplectic invariants in such a determination is pointed out. We show that the Von Neumann entropy depends on two symplectic invariants, while the purity (or the linear entropy) is determined by only one invariant, so that the two quantities provide two different hierarchies of mixed Gaussian states. A comparison between mutual information and entanglement of formation for symmetric states is considered, remarking the crucial role of the symplectic eigenvalues in qualifying and quantifying the correlations present in a generic state.

  16. Expression of Telomeres in Astrocytoma WHO Grade 2 to 4: TERRA Level Correlates with Telomere Length, Telomerase Activity, and Advanced Clinical Grade12

    PubMed Central

    Sampl, Sandra; Pramhas, Sibylle; Stern, Christian; Preusser, Matthias; Marosi, Christine; Holzmann, Klaus

    2012-01-01

    Cancer cells bypass replicative senescence, the major barrier to tumor progression, by using telomerase or alternative lengthening of telomeres (ALT) as telomere maintenance mechanisms (TMMs). Correlation between ALT and patient survival was demonstrated for high-grade astrocytomas. Transcription from subtelomeres produces telomeric repeat-containing RNA (TERRA), a natural inhibitor of telomerase activity (TA). This led us to evaluate correlations of TERRA and TMM with tumor grade and outcome in astrocytoma patients. SYBR Green real-time reverse transcription-polymerase chain reaction assays for quantitation of total and chromosome 2p and 18p specific TERRA levels were developed. Tumor samples from 46 patients with astrocytoma grade 2 to 4, tissue controls, and cell lines were assessed. TMMs were evaluated by measuring TA and by detecting long telomeres due to ALT. In glioblastoma multiforme (GBM) grade 4, total TERRA levels were similar to cell lines but 14-, 31-, and 313-fold lower compared with grade 3, grade 2, and nonmalignant tissue, respectively. Total TERRA levels differed from chromosomal levels. Low 2p TERRA levels correlated with dense promoter methylation of subtelomeric CpG islands, indicating that TERRA expression in gliomas may be chromosome specific and epigenetically regulated. Total TERRA levels correlated with diagnosis, with low or absent TA and the presence of ALT, and were tentatively associated with favorable patient prognosis in our cohort (P = .06). TA and short telomeres identified a subset of GBM with a median survival of only 14.8 months. TERRA and TA may be prognostic in astrocytic tumors. PMID:22348177

  17. Measurement of ultrasonic velocity using phase-slope and cross-correlation methods

    NASA Technical Reports Server (NTRS)

    Hull, D. R.; Kautz, H. E.; Vary, A.

    1985-01-01

    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 magahertz range.

  18. 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.

  19. Correlation of Scan and Sample Measurements Using Appropriate Sample Size

    Microsoft Academic Search

    Lux

    2008-01-01

    At a former nuclear fuel cycle facility, radiological site characterization performed in the 1990's relied on surface soil samples collected and analyzed on a systematic sampling grid, supplemented by 100% scans of the property to identify soil exceeding decommissioning criteria. Biased sampling was performed as indicated by these measurements to provide more precise delineation of material exceeding the decommissioning criteria

  20. Generic measure for the quantum correlation of the two-qubit systems: the average of the spin-correlation elements

    E-print Network

    El-Orany, Faisal A A

    2012-01-01

    Based on the Pauli spin operators we develop the notion of the spin-correlation matrix for the two-qubit system. If this matrix is non-zero, the measure of the correlation between the qubits is the average of the non-zero elements. Trivially, for zero matrix the bipartite is uncorrelated. This criterion turns out to be a necessary and sufficient condition for the full correlation, where it includes information on both entanglement and correlation other than entanglement. Moreover, we discuss to what extent this criterion can give information on the entanglement of the system. The criterion is generic in the sense that it can be applied to mixed and pure systems. Also, it can be easily extended to treat the correlation of multipartite systems. We compare the results obtained from this criterion to those from concurrence for various examples and we gain agreement regarding entanglement. We believe that this criterion may have a wide range of potential applications in quantum information theory.

  1. Kronecker Product Linear Exponent AR(1) Correlation Structures for Multivariate Repeated Measures

    PubMed Central

    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

  2. Relationship between the stature and the length of long bones measured from the X-rays; modified trotter and gleser formulae in iranian population: A preliminary report.

    PubMed

    Farsinejad, Mohammadreza; Rasaneh, Samira; Zamani, Nasim; Jamshidi, Farkhondeh

    2014-01-01

    Background: We aimed to determine specific formulae by which we are able to estimate the body stature from the length of ulna and tibia calculated from the X-rays in order to be a reference for skeletal remains-based identification in Iranian population.Methods: The length of right ulna and tibia of 49 male and 52 female adults, who were anatomically healthy, were measured on the antero-posterior X-rays. Body height of each subject was also recorded. Results: Mean stature of the male and female adults was reported to be 171 ± 3.6 and 160 ± 3.9 centimeters (cm), respectively. Four single linear regression equations and 2 multiple regression equations were obtained. Conclusions: Lengths of ulna and tibia measured on the X-rays may be useful for estimation of the stature in cases of forensic personal identification. Keywords: stature - length of long bones - ulna - tibia - radiological evaluation - skeletal remains. PMID:24754371

  3. Correlation of subjective and objective measures of speech intelligibility

    NASA Astrophysics Data System (ADS)

    Bowden, Erica E.; Wang, Lily M.; Palahanska, Milena S.

    2003-10-01

    Currently there are a number of objective evaluation methods used to quantify the speech intelligibility in a built environment, including the Speech Transmission Index (STI), Rapid Speech Transmission Index (RASTI), Articulation Index (AI), and the Percentage Articulation Loss of Consonants (%ALcons). Many of these have been used for years; however, questions remain about their accuracy in predicting the acoustics of a space. Current widely used software programs can quickly evaluate STI, RASTI, and %ALcons from a measured impulse response. This project compares subjective human performance on modified rhyme and phonetically balanced word tests with objective results calculated from impulse response measurements in four different spaces. The results of these tests aid in understanding performance of various methods of speech intelligibility evaluation. [Work supported by the Univ. of Nebraska Center for Building Integration.] For Speech Communication Best Student Paper Award.

  4. Measurement of N-Type 6H SiC Minority-Carrier Diffusion Lengths by Electron Bombardment of Schottky Barriers

    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.

  5. Digital image correlation method for measuring thermal deformation of composite materials

    NASA Astrophysics Data System (ADS)

    Jiang, Li; He, Yan; Wang, Dong-wei; Liu, Ke; Wu, Wei-ren

    2013-10-01

    Thermal deformation measurement of the high-speed aircrafts under the high temperature is significant for reliability assessment, life prediction, and safety design for the materials and structures. This paper presents a digital image correlation method to accurately measure the full-field thermal deformation of composites under the environment of high temperature. First, real-time deformation images of experimental objects under different loads are acquired with CCD cameral. Based on the digital speckle correlation theory, the bilinear interpolation algorithm is employed to measure the thermal deformation. Last, the comparative analyses on measurement results by the proposed and traditional methods are conducted, as well as factors impacting measurement errors are analyzed.

  6. Surface measurements of solar irradiance: A study of the spatial correlation between simultaneous measurements at separated sites

    NASA Technical Reports Server (NTRS)

    Long, Charles N.; Ackerman, Thomas P.

    1995-01-01

    Pyranometers have been used for many years to measure broadband surface incoming solar irradiance, data that is necessary for surface energy budget, cloud forcing, and satellite validation research. Because such measurements are made at a specific location, it is unclear how representative they may be of a larger area. This study attempts to determine a reasonable spacing between measurement sites for such research by computing the correlation, and standard deviation from perfect correlation, between simultaneous measurements of incoming solar irradiance for a network of surface measurement sites covering a 75 km x 75 km area. Using 1-min data collected from this network of 11 sites during the NASA First ISSCP Radiation Experiment/Surface Radiation Budget (FIRE/SRB) Project temporal averages were calculated. The correlation between any two of these sites was determined by comparing simultaneous measurement averages for the 55 possible combinations of site pairs, along with the distances between them. In an attempt to remove the effect of the diurnal cycle, thus leaving clouds as the primary influence on correlation of the radiation field, model results for a clear day were used to normalize measured irradiances and correlations were again calculated.

  7. Surface roughness measurement on a wing aircraft by speckle correlation.

    PubMed

    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

  8. Surface Roughness Measurement on a Wing Aircraft by Speckle Correlation

    PubMed Central

    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

  9. CORRELATION BETWEEN CLINICAL ASSESSMENT AND FORCE PLATE MEASUREMENT OF POSTURAL CONTROL AFTER STROKE

    Microsoft Academic Search

    Gunilla Elmgren Frykberg; Birgitta Lindmark; Håkan Lanshammar; Jörgen Borg

    2007-01-01

    Objectives: To explore the correlation between clinical as- sessment and force plate measurement of postural control after stroke when selected balance tasks are performed un- der similar spatial and temporal conditions, and to examine the inter-rater agreement of assessment of weight distribu- tion during quiet stance in subjects with stroke. Design: A descriptive and correlational study. Methods: Clinical assessment of

  10. Measurement of the Vaporization Enthalpy of Complex Mixtures by Correlation-Gas Chromatography. The

    E-print Network

    Chickos, James S.

    Measurement of the Vaporization Enthalpy of Complex Mixtures by Correlation-Gas Chromatography April 21, 2005. Revised Manuscript Received June 2, 2005 The use of correlation-gas chromatography using gas chromatography. Some variance in composition with the literature values has been observed

  11. MMPI2 Correlates of Sexual Preoccupation as Measured by the Sexuality Scale in a College Setting

    Microsoft Academic Search

    Tayla Lee; Johnathan D. Forbey

    2010-01-01

    The current study explored associations between MMPI-2 scales and a measure of sexual preoccupation college students. Participants were 846 undergraduate students at a Midwestern university who completed the MMPI-2 and Sexuality Scale. Correlational analyses were conducted by gender to identify significant relations, which were then examined for potential gender differences. Results indicated significant correlations between sexual preoccupation scores and a

  12. Phase noise measurement of mode locked lasers using guided wave PPKTP balanced cross correlators

    Microsoft Academic Search

    Amir H. Nejadmalayeri; Jonathan A. Cox; Jungwon Kim; Franco N. C. Wong; Tony D. Roberts; Philip Battle; Franz X. Kartner

    2010-01-01

    Channel waveguides in PPKTP are used to demonstrate a guided wave balanced cross correlator in the telecom band. The device is used to measure the relative timing jitter between two 200 MHz fiber lasers.

  13. Variation and pearson correlation coefficients of warner-bratzler shear force measurements within broiler breast fillets

    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...

  14. 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.

  15. 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.

  16. Self-reported childhood trauma correlates with schizotypal measures in schizophrenia but not bipolar pedigrees

    E-print Network

    Paris-Sud XI, Université de

    Self-reported childhood trauma correlates with schizotypal measures in schizophrenia between childhood trauma and schizotypal dimensions in subjects at high genetic risk for schizophrenia suggests that susceptibility genes for schizophrenia may interact with childhood trauma to induce

  17. [Ammonia gas concentration and velocity measurement using tunable diode laser absorption spectroscopy and optical signal cross-correlation method].

    PubMed

    Zhang, Chun-Xiao; Wang, Fei; Li, Ning; Yan, Jian-Hua; Chi, Yong; Cen, Ke-Fa

    2009-10-01

    Simultaneous online measurement of gas concentration and velocity can be realized by tunable diode laser absorption spectroscopy (TDLAS) technique and optical signal cross-correlation method. The fundamental and relative factors of gas concentration and velocity measurement are described in the present paper. The spectral lines of NH3 used for gas sensing at communication band in near infrared range were selected and analyzed by the calculation based on the HITRAN database. In the verification experiment, NH3 and N2 were mixed by two mass flow meters and sent to flow through the quartz tube 0. 016 m in inner diameter and 1 m in length at normal temperature and pressure. The spectral line located at 6,548.7 cm(-1) was scanned at high frequency by the diode laser of 15 MHz linewidth and 1 cm' tunable range with no mode hoppings. The instantaneous NH3 absorbance was obtained using direct absorption method and the gas concentration was calculated. At the same time, the non-intrusive optical absorption signal cross-correlation method was utilized to obtain two concentration signals from two adjacent detectors mounted along the gas tube. The corresponding transit time of gas passing through the detectors was calculated by cross-correlation algorithm, and the average gas velocity was inferred according to the distance between the two detectors and the transit time. The relative errors were less than 7% for the gas concentration measurement, and less than 10% for the gas velocity measurement. Experimental results were proved to be of high precision and good repeatability in the lab. The feature of fast response and capacity immune to the in situ disturbance would lead to a potential in industry application for the real time measurement and control of gas pollutant emission in the future. PMID:20038016

  18. 3D topography measurements on correlation cells—a new approach to forensic ballistics identifications

    NASA Astrophysics Data System (ADS)

    Song, John; Chu, Wei; Tong, Mingsi; Soons, Johannes

    2014-06-01

    Based on three-dimensional (3D) topography measurements on correlation cells, the National Institute of Standards and Technology (NIST) has developed the ‘NIST Ballistics Identification System (NBIS)’ aimed at accurate ballistics identifications and fast ballistics evidence searches. The 3D topographies are divided into arrays of correlation cells to identify ‘valid correlation areas’ and eliminate ‘invalid correlation areas’ from the matching and identification procedure. A ‘congruent matching cells’ (CMC)’ method using three types of identification parameters of the paired correlation cells (cross correlation function maximum CCFmax, spatial registration position in x-y and registration angle ?) is used for high accuracy ballistics identifications. ‘Synchronous processing’ is proposed for correlating multiple cell pairs at the same time to increase the correlation speed. The proposed NBIS can be used for correlations of both geometrical topographies and optical intensity images. All the correlation parameters and algorithms are in the public domain and subject to open tests. An error rate reporting procedure has been developed that can greatly add to the scientific support for the firearm and toolmark identification specialty, and give confidence to the trier of fact in court proceedings. The NBIS is engineered to employ transparent identification parameters and criteria, statistical models and correlation algorithms. In this way, interoperability between different ballistics identification systems can be more easily achieved. This interoperability will make the NBIS suitable for ballistics identifications and evidence searches with large national databases, such as the National Integrated Ballistic Information Network in the United States.

  19. Measurement of two-dimensional fluid flow by digital correlation of scattered light

    NASA Technical Reports Server (NTRS)

    Matthys, Donald R.; Gilbert, John A.; Wang, Jidong

    1992-01-01

    Digital correlation is a pattern matching procedure. This procedure has recently been used in two-dimensional fluid flow measurements. Two images of a seeded fluid are taken and the intensity distribution of a small window in the first image is matched in the second image using a statistical correlation method. A series of structure functions have been implemented to improve the accuracy and reliability of the correlation method and new algorithms have been developed to reduce the time required for the correlation computations.

  20. 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.

  1. Progress towards precision measurements of beta-decay correlation parameters using atom and ion traps

    E-print Network

    D. Melconian; R. S. Behling; B. Fenker; M. Mehlman; P. D. Shidling; M. Anholm; D. Ashery; J. A. Behr; A. Gorelov; G. Gwinner; K. Olchankski; S. Smale

    2014-08-07

    The correlations of the decay products following the beta decay of nuclei have a long history of providing a low-energy probe of the fundamental symmetries of our universe. Over half a century ago, the correlation of the electrons following the decay of polarized 60Co demonstrated that parity is not conserved in weak interactions. Today, the same basic idea continues to be applied to search for physics beyond the standard model: make precision measurements of correlation parameters and look for deviations compared to their standard model predictions. Efforts to measure these parameters to the 0.1% level utilizing atom and ion trapping techniques are described.

  2. Particle image velocimetry correlation signal-to-noise ratio metrics and measurement uncertainty quantification

    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.

  3. Comparison of spring measures of length, weight, and condition factor for predicting metamorphosis in two populations of sea lamprey (Petromyzon marinus) larvae

    USGS Publications Warehouse

    Henson, M.P.; Bergstedt, R.A.; Adams, J.V.

    2003-01-01

    The ability to predict when sea lampreys (Petromyzon marinus) will metamorphose from the larval phase to the parasitic phase is essential to the operation of the sea lamprey control program. During the spring of 1994, two populations of sea lamprey larvae from two rivers were captured, measured, weighed, implanted with coded wire tags, and returned to the same sites in the streams from which they were taken. Sea lampreys were recovered in the fall, after metamorphosis would have occurred, and checked for the presence of a tag. When the spring data were compared to the fall data it was found that the minimum requirements (length ??? 120 mm, weight ??? 3 g, and condition factor ??? 1.50) suggested for metamorphosis did define a pool of larvae capable of metamorphosing. However, logistic regressions that relate the probability of metamorphosis to size are necessary to predict metamorphosis in a population. The data indicated, based on cross-validation, that weight measurements alone predicted metamorphosis with greater precision than length or condition factor in both the Marengo and Amnicon rivers. Based on the Akaike Information Criterion, weight alone was a better predictor in the Amnicon River, but length and condition factor combined predicted metamorphosis better in the Marengo River. There would be no additional cost if weight alone were used instead of length. However, if length and weight were measured the gain in predictive power would not be enough to justify the additional cost.

  4. Comparison of spring measures of length, weight, and condition factor for predicting metamorphosis in two populations of sea lampreys (Petromyzon marinus) larvae

    USGS Publications Warehouse

    Henson, Mary P.; Bergstedt, Roger A.; Adams, Jean V.

    2003-01-01

    The ability to predict when sea lampreys (Petromyzon marinus) will metamorphose from the larval phase to the parasitic phase is essential to the operation of the sea lamprey control program. During the spring of 1994, two populations of sea lamprey larvae from two rivers were captured, measured, weighed, implanted with coded wire tags, and returned to the same sites in the streams from which they were taken. Sea lampreys were recovered in the fall, after metamorphosis would have occurred, and checked for the presence of a tag. When the spring data were compared to the fall data it was found that the minimum requirements (length a?Y 120 mm, weight a?Y 3 g, and condition factor a?Y 1.50) suggested for metamorphosis did define a pool of larvae capable of metamorphosing. However, logistic regressions that relate the probability of metamorphosis to size are necessary to predict metamorphosis in a population. The data indicated, based on cross-validation, that weight measurements alone predicted metamorphosis with greater precision than length or condition factor in both the Marengo and Amnicon rivers. Based on the Akaike Information Criterion, weight alone was a better predictor in the Amnicon River, but length and condition factor combined predicted metamorphosis better in the Marengo River. There would be no additional cost if weight alone were used instead of length. However, if length and weight were measured the gain in predictive power would not be enough to justify the additional cost.

  5. In vivo measurement of fascicle length and pennation of the human anconeus muscle at several elbow joint angles.

    PubMed

    Stevens, Daniel E; Smith, Cameron B; Harwood, Brad; Rice, Charles L

    2014-11-01

    Ultrasound imaging has facilitated the reliable measure of the architectural variables fascicle length (LF ) and pennation angle (PA), at rest and during static and dynamic contractions in many human skeletal muscles in vivo. Despite its small size and very modest contribution to elbow extension torque, the anconeus muscle has proven a useful model for the study of neuromuscular function in health and disease. Recent single motor unit (MU) studies in the anconeus have reported discrete and identifiable individual trains of MU potentials from intramuscular electromyography (EMG) recordings during dynamic elbow extensions. It is unknown whether the anconeus has unique architectural features related to alterations in LF and PA throughout the elbow joint range of motion that may help explain these high-quality recordings. Previous anatomical studies have investigated this muscle in cadavers and at mainly one elbow joint angle. The purpose of this study was to measure in vivo PA and LF of the anconeus muscle in a relaxed state at different degrees of elbow flexion using ultrasonography. Ultrasound images were collected from 10 healthy males (25 ± 3 years) at 135°, 120°, 90°, 45°, and 0° of elbow flexion. Average values of LF decreased by 6 mm (10%), 6 mm (12%), and 4 mm (9%) from 135-120°, 120-90°, and 90-45° of elbow flexion, respectively, whereas average PA values increased by 1° (9%), 1° (8%), and 2° (14%) from 135-120°, 120-90°, and 45-0°, respectively. The results indicate that anconeus muscle architecture is dynamic, undergoing moderate changes with elbow joint excursion that are similar to other limb muscles reported elsewhere. The data obtained here are more comprehensive and representative of architectural changes at various elbow joint positions than those data reported in cadaveric studies. Furthermore, the results of this study indicate that despite experiencing similar relative changes in muscle architecture to other skeletal muscles about the elbow joint, the minimal absolute changes in LF of the anconeus likely contribute to the clarity of intramuscular EMG previously reported in this muscle. PMID:25223934

  6. AIR POLLUTION EXPOSURE AND TELOMERE LENGTH IN HIGHLY EXPOSED SUBJECTS IN BEIJING, CHINA: A REPEATED-MEASURE STUDY

    PubMed Central

    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

  7. Measurement of sub-pixel image motion based on joint transform correlator

    NASA Astrophysics Data System (ADS)

    Hong, Xue-ting; Qian, Yi-xian; Shi, Xiao-wei; Li, Deng-hui

    2014-11-01

    An effective approach to measure image motion is presented based on joint transform correlator(JTC), in order to measure the sub-pixel image motion caused by satellite attitude instability or vibration. Firstly, the high-speed CCD is used to capture image sequences, which are preprocessed by wavelet edge detection. Next the acquired image edge sequences are optically calculated by JTC, and an improved correlation peak is obtained. Lastly a modified centroid algorithm is proposed to get more accurate motion measurement. Motion measurement based on optical correlation is discussed, and the optical experiment system is also set up. The experimental results show that the measurement error is as low as 0.02 pixels, the accuracy is improved greatly.

  8. Open-path tunable diode laser absorption for eddy correlation flux measurements of atmospheric trace gases

    NASA Astrophysics Data System (ADS)

    Anderson, Stuart M.; Zahniser, Mark S.

    1991-05-01

    Biogenic emissions from and dry deposition to terrestrial surfaces are important processes determining the trace gas composition of the atmosphere. We have developed an instrument 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 (approximately equals 0.1 s) and short base pathlength (0.6 m) 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.

  9. Correlation

    NSDL National Science Digital Library

    Pennilyn Higgins

    Three hypothetical rock sections along an East-West transect are provided. Students correlate the three sections using the biostratigraphy of planktic forams (as a proxy for age), benthic forams (as a proxy of depth), and lithology (as a proxy of environment). Students are asked to provide an interpretation of the history of this depositional basin. An ash bed of known age is added and students are asked to determine if this new information affects their interpretation. Finally, an interesting lithologic feature is added, and students are asked to provide a geological explanation.

  10. Pharmacologically induced erect penile length and stretched penile lengh are both good predictors of post-inflatable prosthesis penile length

    PubMed Central

    Osterberg, EC; Maganty, A; Ramasamy, R; Eid, JF

    2015-01-01

    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

  11. A critical window of CAG repeat-length correlates with phenotype severity in the R6/2 mouse model of Huntington's disease

    PubMed Central

    Cummings, Damian M.; Alaghband, Yasaman; Hickey, Miriam A.; Joshi, Prasad R.; Hong, S. Candice; Zhu, Chunni; Ando, Timothy K.; André, Véronique M.; Cepeda, Carlos; Watson, Joseph B.

    2012-01-01

    The R6/2 mouse is the most frequently used model for experimental and preclinical drug trials in Huntington's disease (HD). When the R6/2 mouse was first developed, it carried exon 1 of the huntingtin gene with ?150 cytosine-adenine-guanine (CAG) repeats. The model presented with a rapid and aggressive phenotype that shared many features with the human condition and was particularly similar to juvenile HD. However, instability in the CAG repeat length due to different breeding practices has led to both decreases and increases in average CAG repeat lengths among colonies. Given the inverse relationship in human HD between CAG repeat length and age at onset and to a degree, the direct relationship with severity of disease, we have investigated the effect of altered CAG repeat length. Four lines, carrying ?110, ?160, ?210, and ?310 CAG repeats, were examined using a battery of tests designed to assess the basic R6/2 phenotype. These included electrophysiological properties of striatal medium-sized spiny neurons, motor activity, inclusion formation, and protein expression. The results showed an unpredicted, inverted “U-shaped” relationship between CAG repeat length and phenotype; increasing the CAG repeat length from 110 to 160 exacerbated the R6/2 phenotype, whereas further increases to 210 and 310 CAG repeats greatly ameliorated the phenotype. These findings demonstrate that the expected relationship between CAG repeat length and disease severity observed in humans is lost in the R6/2 mouse model and highlight the importance of CAG repeat-length determination in preclinical drug trials that use this model. PMID:22072510

  12. Penile length-somatometric parameters relationship in healthy Egyptian men.

    PubMed

    Shalaby, M E; Almohsen, A E-R M; El Shahid, A R; Abd Al-Sameaa, M T; Mostafa, T

    2015-05-01

    This study aimed to assess the penile length-somatometric parameters relationship in healthy Egyptian men. Two thousand physically normal men (22-40 years) were subjected to measurement of stretched penile length, glans penis, testis size, index finger, weight, height, span, body mass index (BMI), waist circumference, hip circumference and waist/hip ratio. The mean stretched penile length of the studied subjects was 13.84 ± 1.35 cm (range 12-19 cm), and the mean glans penis length was 2.6 ± 0.4 cm (range 1.7-3.8 cm). Penile length demonstrated positive significant correlation with glans penis length, index finger length, BMI and significant negative correlation with waist/hip ratio. On the other hand, penile length demonstrated nonsignificant correlation with age, weight, height, waist circumference, span or testicular size. It is concluded that the penile length-somatometric parameters relationship in healthy Egyptian men is mostly related to glans penis and index finger lengths. PMID:24698122

  13. Correlating aerosol optical thickness measurement with PM10 mass concentration in Wuhan area

    NASA Astrophysics Data System (ADS)

    Wang, Chensheng; Zhang, Zhijie; Yue, Song

    2011-11-01

    This paper aims at developing a method to use satellite retrievals aerosol optical thickness (AOT) and filed measured AOT to monitor air particulate pollution. This work is applied during the entire year of 2009, on Wuhan area, central China. The ground level daily mean PM10 mass concentration is measured by tapered element oscillating microbalance. Meanwhile, local daily mean AOT is obtained by using field spectrometer. After that, the correlations between local daily mean AOT and PM10 concentrations are calculated. As the AOT MODIS retrieval AOT has good agreement with field measured ones, the good correlation between MODIS AOT and PM10 mass concentration is demonstrated, and the correlation coefficients range from 0.67 to 0.77. This correlation coefficient has strong season dependence which indicates that the correlation in spring and summer is high, while it is much lower in winter. Then the correlation is improved according to the impact of relative humidity. Based on the good correlation condition, the linear regression analysis is completed with the help of SPSS Statistics.

  14. Accurate measurement of wall skin friction by single-pixel ensemble correlation

    NASA Astrophysics Data System (ADS)

    Shen, JunQi; Pan, Chong; Wang, JinJun

    2014-07-01

    The present work deals with accurately estimating wall-skin friction from near-wall mean velocity by means of PIV measurement. The estimation accuracy relies on the spatial resolution and the precision of the resolved velocity profile inside the viscous sublayer, which is a big challenge for conventional window-based correlation method (Kähler C J, et al. Exp Fluids, 2012, 52: 1641-1656). With the help of single-pixel ensemble correlation, the ensemble-averaged velocity vector can be resolved at significant spatial resolution, thus improving the measurement accuracy. To demonstrate the feasibility of this single-pixel ensemble correlation method, we first study the velocity estimation precision in a case of steady near-wall flow. Synthetic particle images are used to investigate the effect of different image parameters. It is found that the velocity RMS-uncertainty level of the single-pixel ensemble correlation method can be equivalent to the conventional window correlation method once the effective particle number used for the ensemble correlation is large enough. Furthermore, a canonical turbulent boundary layer is synthetically simulated based on velocity statistics resolved by previous Direct Numerical Simulation (DNS) work (Schlatter P, et al. J Fluid Mech, 2010, 659: 116-126). The relative error of wall skin friction coefficient is shown to be one-order smaller than that of the window correlation method. And the optimization strategy to further minimize the measurement uncertainty is discussed in the last part.

  15. Discrete EKF with pairwise Time Correlated Measurement Noise for Image-Aided Inertial Integrated Navigation

    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.

  16. 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.

  17. A new interpretation and validation of variance based importance measures for models with correlated inputs

    NASA Astrophysics Data System (ADS)

    Hao, Wenrui; Lu, Zhenzhou; Li, Luyi

    2013-05-01

    In order to explore the contributions by correlated input variables to the variance of the output, a novel interpretation framework of importance measure indices is proposed for a model with correlated inputs, which includes the indices of the total correlated contribution and the total uncorrelated contribution. The proposed indices accurately describe the connotations of the contributions by the correlated input to the variance of output, and they can be viewed as the complement and correction of the interpretation about the contributions by the correlated inputs presented in "Estimation of global sensitivity indices for models with dependent variables, Computer Physics Communications, 183 (2012) 937-946". Both of them contain the independent contribution by an individual input. Taking the general form of quadratic polynomial as an illustration, the total correlated contribution and the independent contribution by an individual input are derived analytically, from which the components and their origins of both contributions of correlated input can be clarified without any ambiguity. In the special case that no square term is included in the quadratic polynomial model, the total correlated contribution by the input can be further decomposed into the variance contribution related to the correlation of the input with other inputs and the independent contribution by the input itself, and the total uncorrelated contribution can be further decomposed into the independent part by interaction between the input and others and the independent part by the input itself. Numerical examples are employed and their results demonstrate that the derived analytical expressions of the variance-based importance measure are correct, and the clarification of the correlated input contribution to model output by the analytical derivation is very important for expanding the theory and solutions of uncorrelated input to those of the correlated one.

  18. Linear smoothing using measurements containing correlated noise with an application to inertial navigation

    Microsoft Academic Search

    R. Mehra

    1968-01-01

    Kalman and Bucy [1] derived the maximum likelihood filter for continuous linear dynamic systems where all measurements contain white noise, i.e., noise with short correlation times compared to response times of the dynamic system. The corresponding maximum likelihood smoother was described in [2]. The maximum likelihood filter was presented in [3] for the case in which some measurements contain either

  19. Measurement of the Wiener Kernels of a Non-linear System by Cross-correlation

    Microsoft Academic Search

    Y. W. LEE; M. SCHETZEN

    1965-01-01

    A practical and relatively simple method of measuring the Wiener kernels of a non-linear system is presented. The method is based upon cross-correlation techniques and avoids orthogonal expansions such as those of the Wiener method of measurement. The application of this method to the experimental characterization of a non-linear system is discussed.

  20. 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...

  1. Chemical oxygen diffusion coefficient measurement by conductivity relaxation--correlation between tracer diffusion

    E-print Network

    Paris-Sud XI, Université de

    Chemical oxygen diffusion coefficient measurement by conductivity relaxation--correlation between J. P., Grenier J. C., Loup J. P. ABSTRACT Chemical oxygen diusion coecient ¯(D)was measured the oxygen partial pressure in the surrounding atmosphere of the sample. The consequent evolution

  2. Chemometric correlation of shelf life, quality measurements, and visible-near infrared spectra of pasteurized eggs

    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...

  3. Single Turnover Measurements of Nanoparticle Catalysis Analyzed with Dwell Time Correlation Functions and Constrained Mean Dwell

    E-print Network

    Chen, Peng

    -turnover study of a fluorogenic reaction to catalysis by gold and platinum nanoparticles. The nanoparticlesSingle Turnover Measurements of Nanoparticle Catalysis Analyzed with Dwell Time Correlation-molecule measurements of enzyme catalysis1-9 have the capacity to discern the differing enzymatic activity of distinct

  4. Correlation measurements in Z-->tau+tau- and the tau neutrino helicity

    Microsoft Academic Search

    D. Buskulic; I. de Bonis; D. Decamp; P. Ghez; C. Goy; J.-P. Lees; M.-N. Minard; B. Pietrzyk; F. Ariztizabal; P. Comas; J. M. Crespo; M. Delfino; I. Efthymiopoulos; E. Fernandez; M. Fernandez-Bosman; V. Gaitan; Ll. Garrido; T. Mattison; A. Pacheco; C. Padilla; A. Pascual; D. Creanza; M. de Palma; A. Farilla; G. Iaselli; G. Maggi; N. Marinelli; S. Natali; S. Nuzzo; A. Ranieri; G. Raso; F. Romano; F. Ruggieri; G. Selvaggi; L. Silvestris; P. Tempesta; G. Zito; Y. Chai; H. Hu; D. Huang; X. Huang; J. Lin; T. Wang; Y. Xie; D. Xu; R. Xu; J. Zhang; L. Zhang; W. Zhao; G. Bonvicini; J. Boudreau; D. Casper; H. Drevermann; R. W. Forty; G. Ganis; C. Gay; M. Girone; R. Hagelberg; J. Harvey; J. Hilgart; R. Jacobsen; B. Jost; J. Knobloch; I. Lehraus; M. Maggi; C. Markou; M. Martinez; P. Mato; H. Meinhard; A. Minten; R. Miquel; H.-G. Moser; P. Palazzi; J. R. Pater; J. A. Perlas; P. Perrodo; J.-F. Pusztaszeri; F. Ranjard; L. Rolandi; J. Rothberg; T. Ruan; M. Saich; D. Schlatter; M. Schmelling; F. Sefkow; W. Tejessy; I. R. Tomalin; R. Veenhof; H. Wachsmuth; S. Wasserbaech; W. Wiedenmann; T. Wildish; W. Witzeling; J. Wotschack; Z. Ajaltouni; M. Bardadin-Otwinowska; A. Barres; C. Boyer; A. Falvard; P. Gay; C. Guicheney; P. Henrard; J. Jousset; B. Michel; J.-C. Montret; D. Pallin; P. Perret; F. Podlyski; J. Proriol; F. Saadi; T. Fearnley; J. B. Hansen; J. D. Hansen; P. H. Hansen; R. Møllerud; B. S. Nilsson; A. Kyriakis; E. Simopoulou; I. Siotis; A. Vayaki; K. Zachariadou; J. Badier; A. Blondel; G. Bonneaud; J. C. Brient; P. Bourdon; G. Fouque; S. Orteu; A. Rougé; M. Rumpf; R. Tanaka; M. Verderi; H. Videau; D. J. Candlin; M. I. Parsons; E. Veitch; E. Focardi; L. Moneta; G. Parrini; M. Corden; C. Georgiopoulos; D. E. Jaffe; D. Levinthal; A. Antonelli; R. Baldini; G. Bencivenni; G. Bologna; F. Bossi; P. Campana; G. Capon; F. Cerutti; V. Chiarella; G. Felici; P. Laurelli; G. Mannocchi; F. Murtas; G. P. Murtas; L. Passalacqua; M. Pepe-Altarelli; P. Colrain; I. Ten Have; J. G. Lynch; W. Maitland; W. T. Morton; C. Raine; P. Reeves; J. M. Scarr; K. Smith; M. G. Smith; A. S. Thompson; R. M. Turnbull; B. Brandl; O. Braun; C. Geweniger; P. Hanke; V. Hepp; E. E. Kluge; Y. Maumary; A. Putzer; B. Rensch; A. Stahl; K. Tittel; M. Wunsch; R. Beuselinck; D. M. Binnie; W. Cameron; M. Cattaneo; D. J. Colling; P. J. Dornan; J. F. Hassard; N. M. Lieske; A. Moutoussi; J. Nash; S. Patton; D. G. Payne; M. J. Phillips; G. San Martin; J. K. Sedgbeer; A. G. Wright; P. Girtler; D. Kuhn; G. Rudolph; R. Vogl; C. K. Bowdery; T. J. Brodbeck; A. J. Finch; F. Foster; G. Hughes; D. Jackson; N. R. Keemer; M. Nuttall; A. Patel; T. Sloan; S. W. Snow; E. P. Whelan; A. M. Greene; K. Kleinknecht; J. Raab; B. Renk; H.-G. Sander; H. Schmidt; S. M. Walther; R. Wanke; B. Wolf; A. Zimmermann; A. M. Bencheikh; C. Benchouk; A. Bonissent; D. Calvet; J. Carr; P. Coyle; C. Diaconu; J. Drinkard; F. Etienne; D. Nicod; P. Payre; L. Roos; D. Rousseau; P. Schwemling; M. Talby; S. Adlung; R. Assmann; C. Bauer; W. Blum; D. Brown; P. Cattaneo; B. Dehning; H. Dietl; F. Dydak; M. Frank; A. W. Halley; K. Jakobs; J. Lauber; G. Lütjens; G. Lutz; W. Männer; R. Richter; J. Schröder; A. S. Schwarz; R. Settles; H. Seywerd; U. Stierlin; U. Stiegler; R. St. Denis; G. Wolf; R. Alemany; J. Boucrot; O. Callot; A. Cordier; M. Davier; L. Duflot; J.-F. Grivaz; Ph. Heusse; P. Janot; D. W. Kimfn; F. Le Diberder; J. Lefrançois; A.-M. Lutz; M.-H. Schune; J.-J. Veillet; I. Videau; Z. Zhang; D. Abbaneo; G. Bagliesi; G. Batignani; U. Bottigli; C. Bozzi; G. Calderini; M. Carpinelli; M. A. Ciocci; V. Ciulli; R. dell'Orso; I. Ferrante; F. Fidecaro; L. Foà; F. Forti; A. Giassi; M. A. Giorgi; A. Gregorio; F. Ligabue; A. Lusiani; E. B. Mannelli; P. S. Marrocchesi; A. Messineo; F. Palla; G. Rizzo; G. Sanguinetti; P. Spagnolo; J. Steinberger; R. Tenchini; G. Tonelli; G. Triggiani; A. Valassi; C. Vannini; A. Venturi; P. G. Verdini; J. Walsh; A. P. Betteridge; Y. Gao; M. G. Green; D. L. Johnson; P. V. March; T. Medcalf; Ll. M. Mir; I. S. Quazi; J. A. Strong; D. R. Botterill; R. W. Clifft; T. R. Edgecock; S. Haywood; P. R. Norton; J. C. Thompson; B. Bloch-Devaux; P. Colas; H. Duarte; S. Emery; W. Kozanecki; E. Lançon; M. C. Lemaire; E. Locci; B. Marx; P. Perez; J. Rander; J.-F. Renardy; A. Rosowsky; A. Roussarie; J.-P. Schuller; J. Schwindling; D. Si Mohand; B. Vallage; R. P. Johnson; A. M. Litke; G. Taylor; J. Wear; W. Babbage; C. N. Booth; C. Buttar; S. Cartwright; F. Combley; I. Dawson; L. F. Thompson; E. Barberio; A. Böhrer; S. Brandt; G. Cowan; C. Grupen; G. Lutters; F. Rivera; U. Schäfer; L. Smolik; L. Bosisio; R. della Marina; G. Giannini; B. Gobbo; L. Pitis; F. Ragusa; L. Bellantoni; W. Chen; J. S. Conway; Z. Feng; D. P. S. Ferguson; J. Grahl; J. L. Harton; O. J. Hayes; J. M. Nachtman; Y. B. Pan; Y. Saadi; M. Schmitt; I. Scott; V. Sharma; Z. H. Shi; J. D. Turk; A. M. Walsh; F. V. Weber

    1994-01-01

    Using data collected with the ALEPH detector at LEP correlations between the decay products of the tau+ and tau- produced in the decay of the Z have been measured. The measurements performed in the decays tau-->pinu and tau-->varrhonu place limits on deviations from the Standard Model. These are given by the parameter zeta with zeta = -1 for the Standard

  5. Shear Strength Correlations for Kaolin/Water Slurries: A Comparison of Recent Measurements with Historical Data

    SciTech Connect

    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.

  6. 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.

  7. Validation of lactate measurement in American flamingo (Phoenicopterus ruber) plasma and correlation with duration and difficulty of capture.

    PubMed

    Burgdorf-Moisuk, Anne; Wack, Raymund; Ziccardi, Michael; Larsen, R Scott; Hopper, Kate

    2012-09-01

    Capture myopathy and associated death have been reported with capture and restraint of greater flamingos (Phoenicopterus ruber roseus) and lesser flamingos (Phoeniconaias minor). In chickens (Gallus gallus), blood lactate concentration levels have been used as indicators of muscle damage. Lactate has also been used to predict survival in humans and dogs. The goals of this study were to validate two common methods for measuring lactate (i-STAT and VetTest analyzers) in flamingo plasma by comparing measurements to a reference analyzer; and to correlate blood lactate concentration levels in captured flamingos with the duration and difficulty of capture as a possible indicator of capture myopathy. Twenty-seven banked flamingo plasma samples were run in triplicate on each of the three blood analyzers. Values from the i-STAT analyzer were consistently lower than those from the ABL analyzer, while values from the VetTest were consistently higher than those from the ABL analyzer. However, there was a good level of correlation between all three analyzers. Two of the three analyzers were determined to have acceptable total allowable error levels, calculated at 3.6% for the ABL and 10.7% for the VetTest. For clinical purposes, both the i-STAT and the VetTest analyzers provide adequate evaluation of lactate levels when serial samples are measured on the same analyzer. After validating the assay, 34 captive flamingos were captured for routine examinations. Blood lactate concentration levels were positively correlated with the length of time of the individual capture, but lactate did not increase significantly as capture difficulty increased. Only one animal was considered to have a difficult capture. No flamingos demonstrated clinical signs of capture myopathy during this study. Further research is required to determine if blood lactate concentration is a useful indicator of capture myopathy. PMID:23082507

  8. Supplementary material for "Measuring and interpreting neuronal correlations" by Cohen Spike count correlation depends on measurement window in a correlated rate model

    E-print Network

    Pillow, Jonathan

    Appendix 2 of Bair et al. (2001) for a similar derivation. Overly stringent spike sorting criteria reduces measured rSC We showed through simulations that overly stringent spike sorting criteria reduces spikes are discarded with probability p1 and p2. The spikes kept from each neuron during spike sorting

  9. Design, fabrication, and calibration of curved integral coils for measuring transfer function, uniformity, and effective length of LBL ALS (Lawrence Berkeley Laboratory Advanced Light Source) Booster Dipole Magnets

    SciTech Connect

    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.

  10. 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.

  11. Submaximal delayed-onset muscle soreness: correlations between MR imaging findings and clinical measures

    NASA Technical Reports Server (NTRS)

    Evans, G. F.; Haller, R. G.; Wyrick, P. S.; Parkey, R. W.; Fleckenstein, J. L.; Blomqvist, C. G. (Principal Investigator)

    1998-01-01

    PURPOSE: To assess correlations between muscle edema on magnetic resonance (MR) images and clinical indexes of muscle injury in delayed-onset muscle soreness (DOMS) produced by submaximal exercise protocols. MATERIALS AND METHODS: Sixteen subjects performed 36 elbow flexions ("biceps curls") at one of two submaximal workloads that emphasized eccentric contractions. Changes in MR imaging findings, plasma levels of creatine kinase, and pain scores were correlated. RESULTS: Both exercise protocols produced DOMS in all subjects. The best correlation was between change in creatine kinase level and volume of muscle edema on MR images, regardless of the workload. Correlations tended to be better with the easier exercise protocol. CONCLUSION: Whereas many previous studies of DOMS focused on intense exercise protocols to ensure positive results, the present investigation showed that submaximal workloads are adequate to produce DOMS and that correlations between conventionally measured indexes of injury may be enhanced at lighter exercise intensities.

  12. Why do measures of normal and disordered personality correlate? A study of genetic comorbidity.

    PubMed

    Jang, K L; Livesley, W J

    1999-01-01

    The genetic and environmental correlations between measures of normal (NEO-FFI) and abnormal personality (Dimensional Assessment of Personality Pathology: DAPP-BQ) were estimated in a sample of 545 volunteer general population twin pairs (269 monozygotic and 276 dizygotic pairs). The largest genetic correlations were observed between the 18 DAPP-BQ dimensions and NEO-FFI neuroticism (range = .05 to .81; median = .48), extraversion (range = -.65 to .33; median = -.28), agreeableness (range = -.65 to .00; median = -.38), and conscientiousness (range = -.76 to .52; median = -.31). The smallest genetic correlations were found between the DAPP-BQ dimensions and NEO-FFI openness (range = -.17 to .20; median = -.04). The environmental correlations are lower in magnitude but show the same pattern of correlations between DAPP-BQ and NEO-FFI scales. These results indicate that these two scales share a common broad-based genetic architecture, whereas the environmental influences show greater scale specificity. PMID:10228923

  13. Growth in the first four years: IV. Correlations with parental measures in small-for-dates and large-for-dates babies.

    PubMed

    Ounsted, M; Moar, V; Scott, A

    1982-12-01

    Parent-child correlations for weight, height and head circumference on eight occasions between birth and 4 years were estimated within groups of 212 small-for-dates (SFD), 208 average-for-dates (AFD) and 221 large-for-dates (LFD) children. For mothers and fathers in the SFD and AFD groups, and fathers in the LFD group, correlations for weight were generally low in the first year, with moderate increases up to 4 years. No correlations for weight at any age were found between mothers and LFD children. There was a gradual rise in correlations for length in all three groups for both mothers and fathers between birth and 4 years. Head circumference correlations in the AFD and LFD groups were relatively high at birth and showed little change thereafter. Mother-child correlations for head circumference in the SFD group were absent at birth, but then rose sharply to a value comparable with the AFD parents' correlations at 18 months, with the little change thereafter. No SFD father-child correlations for head circumference were found at any age. Children's standards of weight and head circumference adjusted for mid-parental measures would, in some cases, be misleading. PMID:7169031

  14. Hydroxyl space-time correlation measurements in partially premixed turbulent opposed-jet flames

    NASA Astrophysics Data System (ADS)

    Venkatesan, K. K.; Zhang, J.; King, G. B.; Laurendeau, N. M.; Renfro, M. W.

    2007-10-01

    A high repetition-rate, two-point, time-resolved, laser-induced fluorescence technique is used to perform simultaneous two-point OH time-series measurements in a series of turbulent opposed-jet partially premixed flames with varying fuel-side equivalence ratio and bulk Reynolds number. Time scales of OH in these flames have previously been reported; however, the extension to two-point detection permits measurements of new spatial and temporal statistics previously unavailable in such flames. In particular, the simultaneous OH time series are used here to compute spatial and temporal autocorrelation functions. Filtered OH length scales (lr,OH), corresponding to radial OH fluctuations in turbulent stagnation flames, are obtained from the spatial autocorrelation function, including their variation across the stagnation plane. In general, maximum OH fluctuations occur at the stagnation plane, thus minimizing the OH integral length scale at the axial location of peak OH. For all flames of this study, trends in OH length scale follow those of axial time scale (?I,OH). For flames with constant Re, lr,OH decreases with less partial premixing. However, this change in integral length scale appears to be more significant for flames at lower Re in comparison to those at higher Re. Similar to OH integral time scales, for flames with the same fuel composition, lr,OH decreases with increasing Re. Moreover, fuel-lean mixtures appear to be more sensitive to Re variations as compared to fuel-rich mixtures.

  15. A correlation force spectrometer for single molecule measurements under tensile load

    NASA Astrophysics Data System (ADS)

    Radiom, Milad; Honig, Christopher D. F.; Walz, John Y.; Paul, Mark R.; Ducker, William A.

    2013-01-01

    The dynamical-mechanical properties of a small region of fluid can be measured using two closely spaced thermally stimulated micrometer-scale cantilevers. We call this technique correlation force spectroscopy (CFS). We describe an instrument that is designed for characterizing the extensional properties of polymer molecules that straddle the gap between the two cantilevers and use it to measure the stiffness and damping (molecular friction) of a dextran molecule. The device is based on a commercial atomic force microscope, into which we have incorporated a second antiparallel cantilever. The deflection of each cantilever is measured in the frequency range dc-1 MHz and is used to generate the cross-correlation at equilibrium. The main advantage of cross-correlation measurements is the reduction in thermal noise, which sets a fundamental noise limit to force resolution. We show that the thermal noise in our cross-correlation measurements is less than one third of the value for single-cantilever force microscopy. The dynamics of the cantilever pair is modeled using the deterministic motion of a harmonic oscillator initially displaced from equilibrium, which yields the equilibrium auto and cross-correlations in cantilever displacement via the fluctuation-dissipation theorem. Fitted parameters from the model (stiffness and damping) are used to characterize the fluid at equilibrium, including any straddling molecules.

  16. Focusing in Arthurs-Kelly-type Joint Measurements with Correlated Probes

    E-print Network

    Thomas J Bullock; Paul Busch

    2014-09-16

    Joint approximate measurement schemes of position and momentum provide us with a means of inferring pieces of complementary information if we allow for the irreducible noise required by quantum theory. One such scheme is given by the Arthurs-Kelly model, where information about a system is extracted via indirect probe measurements. So far, only separable uncorrelated probes have been considered. Here, following Di Lorenzo (PRL 110, 120403 (2013)), we extend this model to both entangled and classically correlated probes, achieving full generality. We find the measured observable of the system under consideration to be covariant under phase space translations, and show that correlated probes can produce more precise joint measurement outcomes of position and momentum than the same probes can achieve if applied alone to realize a position or momentum measurement. Contrary to Di Lorenzo's claim, we find that nevertheless there are no violations of Heisenberg's measurement uncertainty relations in these generalized Arthurs-Kelly models.

  17. Measurement of carotid artery stenosis: correlation analysis between B-mode ultrasonography and contrast arteriography

    PubMed Central

    Lee, Kyo Won; Park, Yang Jin; Rho, Young-Nam; Kim, Dong-Ik

    2011-01-01

    Purpose To evaluate the efficacy of B-mode ultrasonography (US) in measurement of carotid stenosis% (CS%). Methods One hundred and thirth-three carotid arteries in 96 patients who underwent both carotid US and carotid arteriography (CA) were included in this retrospective study. To measure CS% on US, a cross sectional view of the most stenotic segment of the internal carotid artery was captured and residual diameter and original diameter of that segment were measured with electronic caliper on the same plane and in the same direction. To measure CS% on an angiogram, we used European Carotid Surgery Trial (ECST) and the North American Symptomatic Carotid Endarterectomy Trial (NASCET) methods. Pearson's correlation analysis and linear regression analysis were used to determine the correlation between CS% on an US and angiogram. Results Pearson's correlation coefficient (R) between CS% measured in US and CA were 0.853 (ECST method, P < 0.001) and 0.828 (NASCET method, P < 0.001). Accuracies of B-mode US were 93.2%, 88.0%, and 81.2% for estimating CS% by ECST method and 86.5%, 82.7%, and 82% for estimating CS% by NASCET method. Conclusion CS% measured in B-mode US was simpler and showed a strong positive correlation with that measured on an arteriogram either ECST or NASCET method. PMID:22066059

  18. TeloTool: a new tool for telomere length measurement from terminal restriction fragment analysis with improved probe intensity correction

    PubMed Central

    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

  19. TeloTool: a new tool for telomere length measurement from terminal restriction fragment analysis with improved probe intensity correction.

    PubMed

    Göhring, Janett; Fulcher, Nick; Jacak, Jaroslaw; Riha, Karel

    2014-02-01

    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

  20. Correlation of combustor acoustic power levels inferred from internal fluctuating pressure measurements

    NASA Technical Reports Server (NTRS)

    Vonglahn, U. H.

    1978-01-01

    Combustion chamber acoustic power levels inferred from internal fluctuating pressure measurements are correlated with operating conditions and chamber geometries over a wide range. The variables include considerations of chamber design (can, annular, and reverse-flow annular) and size, number of fuel nozzles, burner staging and fuel split, airflow and heat release rates, and chamber inlet pressure and temperature levels. The correlated data include those obtained with combustion component development rigs as well as engines.