For comprehensive and current results, perform a real-time search at Science.gov.

1

Bunch Length Measurements With Laser/SR Cross-Correlation

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.

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

2

CORRELATIONS OF WEIGHT, LENGTH, AND OTHER BODY MEASUREMENTS IN THE WEAKFISH, CYNOSCION RECALlS

CORRELATIONS OF WEIGHT, LENGTH, AND OTHER BODY MEASUREMENTS IN THE WEAKFISH, CYNOSCION RECALl for pagination #12;CORRELATIONS OF WEIGHT, LENGTH, AND OTHER BODY MEASUREMENTS IN THE WEAKFISH, CYNOSCION REGALIS we are sure that none of the weights recorded are influenced by the ripening of the gonads

3

Measurement of the Correlation and Coherence Lengths in Boundary Layer Flight Data

NASA Technical Reports Server (NTRS)

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.

Palumbo, Daniel L.

2011-01-01

4

NASA Astrophysics Data System (ADS)

The supercooled N3 model exhibits an increasingly slow dynamics as density approaches the random closest packing density. Here, we present a direct measurement of the dynamical correlation function G4(r,t), showing the emergence of a growing length scale ?4 across which the dynamics is correlated. The correlation length measured, up to 120 lattice sites, power law diverges as the density approaches ?t, the density at which the fluid phase of the model is predicted to terminate. The four-point susceptibility, often used as an agent to estimate ?4, does not depend simply on the latter. Rather, it depends strongly on the short-range behavior of G4(r,t). Consequently, ?4 peaks before ?4 reaches its maximal value. The two quantities should therefore be studied independently.

Rotman, Z.; Eisenberg, E.

2010-11-01

5

Using terahertz (THz) transmission measurements through two-dimensional Fibonacci deterministic subwavelength hole arrays fabricated in metal foils, we find that the surface plasmon-polariton (SPP) correlation lengths for aperiodic resonances are smaller than those associated with the underlying grid. The enhanced transmission spectra associated with these arrays contain two groups of Fano-type resonances: those related to the two-dimensional Fibonacci structure and those related to the underlying hole grid array upon which the aperiodic Fibonacci array is built. For both groups the destructive interference frequencies at which transmission minima occur closely match prominent reciprocal vectors in the hole array (HA) structure-factor in reciprocal space. However the Fibonacci-related transmission resonances are much weaker than both their calculated Fourier intensity in k space and the grid-related resonances. These differences may arise from the complex, multi-fractal dispersion relations and scattering from the underlying grid arrays. We also systematically studied and compared the transmission resonance strength of Fibonacci HA and periodic HA lattices as a function of the number of holes in the array structure. We found that the Fibonacci-related resonance strengths are an order of magnitude weaker than that of the periodic HA, consistent with the smaller SPP correlation length for the aperiodic structure. PMID:22772220

Nguyen, Tho Duc; Nahata, Ajay; Vardeny, Z Valy

2012-07-01

6

Measuring Thermodynamic Length

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.

Crooks, Gavin E

2007-09-07

7

Introduction Hip axis length (HAL) has been reported to be an independent predictor of hip fracture. Significant ethnic differences in HAL have been noted, but no direct comparison has been made between African-American, Mexican-American, and non-Hispanic white women using the same protocol. Methods We compared 157 non-Hispanic white women from the Rancho Bernardo Study, 292 women from the Health Assessment Study of African-American Women, and 210 women from the Skeletal Health of Mexican-American Women Project. A standardized questionnaire was used to obtain medical history; height, weight, waist girth, and hip girth were measured; and percent body fat and HAL were obtained using dual energy x-ray absorptiometry. All HAL comparisons were adjusted for maximum hip girth to control for differences in size magnification by fan-beam absorptiometry. Results Though there were ethnic differences in the unadjusted HAL measurement, after adjusting for hip circumference, there were no residual differences in HAL by ethnicity: 10.7 cm in Mexican-American women vs. 10.8 in non-Hispanic white women and African-American women (p=0.61) Conclusions There were no ethnic differences in HAL in women from the 3 ethnic groups. Differences in fracture risk among these groups cannot be explained by ethnic differences in HAL. PMID:18301856

Clark, Patricia; Tesoriero, Linda J.; Morton, Deborah J.; Talavera, Juan O.; Karlamangla, Arun; Schneider, Diane L.; Wooten, Wilma J.; Barrett-Connor, Elizabeth

2009-01-01

8

Measuring Crack Length in Coarse Grain Ceramics

NASA Technical Reports Server (NTRS)

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.

Salem, Jonathan A.; Ghosn, Louis J.

2010-01-01

9

Exploitable length correlations in peptide nanofibres

NASA Astrophysics Data System (ADS)

Sequence-prescribed biomolecular assemblies find increasing use in the development of novel nanostructured materials. Critical requirements for emerging designs remain in matching form with function. Peptide assembly diversifies form and supports function, but lacks control over both. Herein we exploit length correlations in peptide nanoscale fibres (form) using a model helical template. We establish that different assembly patterns result from a synergistic interplay between peptide length, net charge and folding and supra-molecular cooperativity, while correlating with increases in cell proliferation (function) as a function of peptide length. The revealed correlations offer an efficient rationale for the programming of longitudinally finite and biologically active nanoscale fibres.Sequence-prescribed biomolecular assemblies find increasing use in the development of novel nanostructured materials. Critical requirements for emerging designs remain in matching form with function. Peptide assembly diversifies form and supports function, but lacks control over both. Herein we exploit length correlations in peptide nanoscale fibres (form) using a model helical template. We establish that different assembly patterns result from a synergistic interplay between peptide length, net charge and folding and supra-molecular cooperativity, while correlating with increases in cell proliferation (function) as a function of peptide length. The revealed correlations offer an efficient rationale for the programming of longitudinally finite and biologically active nanoscale fibres. Electronic supplementary information (ESI) available: Materials and methods together with additional tables and figures. See DOI: 10.1039/c4nr03328k

de Santis, Emiliana; Faruqui, Nilofar; Noble, James E.; Ryadnov, Maxim G.

2014-09-01

10

Antenatal measurement of scapula length using ultrasound.

In 76 fetuses from 14 weeks of gestation through to term, measurements of the scapula were made using ultrasound. Statistical analysis of the results revealed a highly significant correlation between scapula measurements and gestational age, biparietal diameter, fetal femur length and fetal abdominal circumference (r = 0.93, 0.91, 0.95, and 0.91, respectively). In particular, values related to length of the scapula were highly correlated with femur length. These findings show that this measurement is useful as an adjunct to assessing development as well as growth of the femur and dating parameters of the fetus in utero. PMID:2695411

Murao, F; Shibukawa, T; Takamiya, O; Yamamoto, K; Hasegawa, K

1989-01-01

11

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

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

2014-01-01

12

Fracture Roughness and Correlation Length in the Central Force Model

We measure the roughness exponent and the correlation length exponent of a stress-weighted percolation process in the central force model in 2D. The roughness exponent is found to be zeta = 0.75 \\\\pm 0.03 and the correlation length exponent is found to be nu = 1.7 \\\\pm 0.3. This result supports a conjecture that the fracture roughness for large scales

Jan Øystein Haavig Bakke; Thomas Ramstad; Alex Hansen

2005-01-01

13

An extended length digital correlator threshold circuit

NASA Astrophysics Data System (ADS)

An extended length digital correlator threshold circuit for (N * M)-bit correlation using N M-bit correlators is disclosed. For the exemplary case where N=2, the digital correlator threshold circuit comprises: a first circuit for storing a preselected code word having first and second digital code portions; a first correlator responsive to the first digital code portion and an input digital data stream passing there through for periodically producing a first multibit number representative of the number of bit agreements between the bits in the digital data stream and the bits in the first digital code portion; a second correlator responsive to the second digital code portion and the digital data stream passing there through from the first correlator for periodically producing a second multibit number representative of the number of bit agreements between the bits in the digital data stream from the first correlator and the bits in the second digital code portion; and a second circuit responsive to said first and second multibit numbers for generating an output signal when the combined number of bit agreements in both of the first and second multibit numbers is at least equal to a preselected threshold number.

Leibowitz, Leon M.; Mai, T.

1992-04-01

14

Telomere Length Correlations among Somatic Tissues in Adult Zebra Finches

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

Reichert, Sophie; Criscuolo, Francois; Verinaud, Elodie; Zahn, Sandrine; Massemin, Sylvie

2013-01-01

15

Dynamic Correlation Length Scales under Isochronal Conditions

The origin of the dramatic changes in the behavior of liquids as they approach their vitreous state - increases of many orders of magnitude in transport properties and dynamic time scales - is a major unsolved problem in condensed matter. These changes are accompanied by greater dynamic heterogeneity, which refers to both spatial correlation and spatial variation of molecular mobilities. The question is whether the changing dynamics is 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 to measure the third-order harmonic component of the susceptibility. We extract from this the number of dynamically correlated molecules for various state points, and find that the dynamic correlation volume depends primarily on the relaxation time, sensibly independent of temperature and pressure. This result, supported by molecular dynamic simulations, is consistent with dynamic heterogeneity serving as the principal control parameter for the slowing down of molecular motions in supercooled materials.

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

2014-10-02

16

Acyl Chain Length of Phosphatidylserine Is Correlated with Plant Lifespan

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

Tian, Xuejun; Li, Weiqi

2014-01-01

17

Scapula length measurement for assessment of fetal growth and development.

To determine the value of prenatal ultrasonographic scapula measurements for fetal growth and development as an adjunct to assessing in utero development, a prospective study of ultrasonography was conducted in 343 pregnant women with uneventful pregnancies with gestational ages from 16 to 41 weeks, and several biometric measurements were obtained. The relationships of scapula length with gestational age and with biparietal diameter, femur length, abdominal circumference and scapula length were examined. With the ultrasonographic examinations of 343 healthy pregnant women, a nomogram of scapula length measurements estimating gestational age and predicting the biparietal diameter, abdominal circumference, and femur length was generated. Linear relationships were found between the scapula length and the gestational age (R2 = 0.94, p < 0.0001), the biparietal diameter (R2 = 0.94, p < 0.0001), abdominal circumference (R2 = 0.94, p < 0.0001), and the femur length (R2 = 0.95, p < 0.0001). The rate of increase of scapula length was significantly higher before 28 weeks of gestation than in later pregnancy (p < 0.0001). The correlation coefficients between gestational age and scapula length were 0.95 before 28 weeks of gestation and 0.86 in later weeks. These results suggest that scapula length measurement is a valuable parameter for the assessment of fetal growth and development. PMID:7571122

Dilmen, G; Turhan, N O; Toppare, M F; Seçkin, N; Oztürk, M; Göksin, E

1995-01-01

18

Turbulent Radial Correlation Lengths in the DIII-D Tokamak

Measurements of the radial correlation length Ar of density fluctuations have been made on the DIII-D tokamak in a variety of L-mode discharges. These measurements span the radial region 0.5 < {rho} < 1 and are found to scale approximately as {rho}{sub {theta},s} or 5-10 {rho}{sub s}. Here {rho}{sub {theta},s} is the poloidal ion Larmor radius calculated using local T{sub e} and poloidal magnetic field and {rho}{sub s} is the same except calculated using the total magnetic field. The {Delta}r data were obtained from a heterodyne reflectometer system. Comparisons to published analytic formulas of Ar have been carried out for a particular discharge condition. The measurements are found to be comparable in magnitude and radial dependence with a slab type formulation of ion temperature gradient (ITG) driven turbulence as well as an electron drift wave turbulence type prediction. Predictions from toroidal ITG and a different slab ITG model were found to be outside the error bars of the measurements. In addition, a detailed comparison to a non-linear gyro-kinetic turbulence code has begun. These and other similar comparisons are believed to be important as they serve to test and benchmark theory and codes as well as to help identify the type(s) of turbulence involved.

T.L. Rhodes; J.-N. Leboeuf; R. Sydora; E.J. Doyle; R.A. Moyer; C.L. Rettig; K.H. Burrell; D.M. Thomas; G.R. McKee; W.A. Peebles

2000-08-01

19

Extracting the dynamic correlation length of actin networks from microrheology experiments

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.

Adar Sonn-Segev; Anne Bernheim-Groswasser; Yael Roichman

2014-08-21

20

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

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. PMID:25192175

Sonn-Segev, Adar; Bernheim-Groswasser, Anne; Roichman, Yael

2014-11-01

21

Determining Correlation and Coherence Lengths in Turbulent Boundary Layer Flight Data

NASA Technical Reports Server (NTRS)

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.

Palumbo, Dan

2012-01-01

22

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

ERIC Educational Resources Information Center

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…

Bavendam, James M.; Harper, Nancy L.

23

Measurements of mandibular length: a comparison of articulare vs condylion.

This study examines the validity of articulare for mandibular length measurements by exposing 3 lateral cephalograms on each of 60 consecutive patients. The radiographs were exposed with the patient in a closed-mouth position in habitual occlusion, a closed-mouth position with the patient in centric relation, and in an open-mouth position. The linear distances (mm) of articulare (Ar) to pogonion (Pog), Ar to gonion (Go), and Go to Pog were measured on the 2 closed-mouth cephalograms and compared with each other as well as the linear distances of condyle (Co) to Pog, Co to Go, and Go to Pog measured from the open-mouth cephalogram on each individual. Product-moment correlation coefficients were used to measure the linear associations among the mandibular measurements from the 3 techniques. Repeated measures analyses of variance were also fit to estimate the correlations between the 3 measurements adjusted for age and sex. The results of this study show that measurements taken from both closed-mouthed techniques agreed extremely well (intraclass correlation coefficient = 0.99). In addition, measurements from both closed-mouth techniques highly agreed with the corresponding measurements taken with the open-mouth technique (intraclass correlation coefficient = 0.94). This data suggests that measurements taken from Ar correlate very well with measurements taken from Co and that this correlation is not dependent on whether the patient is positioned in habitual occlusion or centric relation. PMID:11407774

Haas, D W; Martinez, D F; Eckert, G J; Diers, N R

2001-06-01

24

Torque correlation length and stochastic twist dynamics of DNA

NASA Astrophysics Data System (ADS)

We introduce a short correlation length for torque in twisting-stiff biomolecules, which is necessary for the physical property that torque fluctuations be finite in amplitude. We develop a nonequilibrium theory of dynamics of DNA twisting which predicts two crossover time scales for temporal torque correlations in single-molecule experiments. Bending fluctuations can be included, and at linear order we find that they do not affect the twist dynamics. However, twist fluctuations affect bending, and we predict the spatial inhomogeneity of twist, torque, and buckling arising in nonequilibrium "rotor-bead" experiments.

Banigan, Edward J.; Marko, John F.

2014-06-01

25

Bedside prediction of airway length by measuring upper incisor manubrio-sternal joint length

Background: Malpositioning of endotracheal tube may lead to serious complications like endobronchial intubation or accidental extubation. Using anatomical measurements for prediction of airway length would be more practical in resource constrained settings. Materials and Methods: One hundred adult patients of American Society of Anesthesiologists (ASA) grade 1 or 2, without any evidence of difficult airway, were randomly allocated to two cohorts — a model cohort of 70 (50 males) and test cohort of 30 (20 males) subjects. Height, the straight length from the upper incisor to manubrio-sternal joint in fully extended head position (IncManustL), the length from upper incisor to the carina in neutral head position (IncCarinaL), and degree of neck extension were measured in all subjects. Relationship between the two lengths in the model cohort was explored by Pearson's coefficient (r). Predictions were made for subjects in the test cohort and actual and predicted values assessed for agreement using intra-class correlation coefficient (ICC). Results: Good agreement was found between IncManustL and IncCarinaL for both male (r = 0.69) and female (r = 0.54) subjects. Multiple regression analysis suggested height to be another significant predictor, unlike age, weight, and neck extension. The gender-specific regression equations were used to predict IncCarinaL for the test cohort. ICC for absolute agreement between the actual and predicted values was 0.723 (95% CI 0.495-0.858). Conclusions: It is possible to predict airway length in adult Indian subjects by making two simple anatomical measurements, namely stature and incisor manubrio-sternal joint length. PMID:24803755

Mukherjee, Sudipta; Ray, Manjushree; Pal, Rita

2014-01-01

26

Correcting Correlation Function Measurements

Correlation functions measured as a function of $\\Delta \\eta, \\Delta \\phi$ have emerged as a powerful tool to study the dynamics of particle production in nuclear collisions at high energy. They are however subject, like any other observables, to instrumental effects which must be properly accounted for to extract meaningful physics results. We compare the merits of several techniques used towards measurement of these correlation functions in nuclear collisions. We discuss and distinguish the effects of finite acceptance, and detection efficiency that may vary with collision parameters such as the position of the event in the detector and the instantaneous luminosity of the beam. We focus in particular on instrumental effects which break the factorization of the particle pair detection efficiency, and describe a technique to recover the robustness of correlation observables. We finally introduce a multi-dimensional weight method to correct for efficiencies that vary simultaneously with particle pseudo rapidity, azimuthal angle, transverse momentum, and the collision vertex position. The method can be generalized to account for any number of "event variables" that may break the factorability of the pair efficiency.

Shantam Ravan; Prabhat Pujahari; Sidharth Prasad; Claude A. Pruneau

2013-11-15

27

Bunch Length Measurements using Coherent Radiation

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.

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

28

Local-hybrid functional based on the correlation length

NASA Astrophysics Data System (ADS)

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.

Johnson, Erin R.

2014-09-01

29

Length of adaptive walk on uncorrelated and correlated fitness landscapes

NASA Astrophysics Data System (ADS)

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.

Seetharaman, Sarada; Jain, Kavita

2014-09-01

30

Mask roughness induced LER: geometric model at long correlation lengths

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.

McClinton, Brittany M.; Naulleau, Patrick P.

2011-02-11

31

Relating Vegetation Aerodynamic Roughness Length to Interferometric SAR Measurements

NASA Technical Reports Server (NTRS)

In this paper, we investigate the feasibility of estimating aerodynamic roughness parameter from interferometric SAR (INSAR) measurements. The relation between the interferometric correlation and the rms height of the surface is presented analytically. Model simulations performed over realistic canopy parameters obtained from field measurements in boreal forest environment demonstrate the capability of the INSAR measurements for estimating and mapping surface roughness lengths over forests and/or other vegetation types. The procedure for estimating this parameter over boreal forests using the INSAR data is discussed and the possibility of extending the methodology over tropical forests is examined.

Saatchi, Sassan; Rodriquez, Ernesto

1998-01-01

32

The study is based on experimental work conducted in alpine snow. We made microwave radiometric and near-infrared reflectance measurements of snow slabs under different experimental conditions. We used an empirical relation to link near-infrared reflectance of snow to the specific surface area (SSA), and converted the SSA into the correlation length. From the measurements of snow radiances at 21 and 35 GHz, we derived the microwave scattering coefficient by inverting two coupled radiative transfer models (the sandwich and six-flux model). The correlation lengths found are in the same range as those determined in the literature using cold laboratory work. The technique shows great potential in the determination of the snow correlation length under field conditions. PMID:19104524

Toure, Ally Mounirou; Goïta, Kalifa; Royer, Alain; Mätzler, Christian; Schneebeli, Martin

2008-12-20

33

Automatic detection and measurement of femur length from fetal ultrasonography

NASA Astrophysics Data System (ADS)

Femur bone length is used in the assessment of fetal development and in the prediction of gestational age (GA). In this paper, we present a completely automated two-step method for identifying fetal femur and measuring its length from 2D ultrasound images. The detection algorithm uses a normalized score premised on the distribution of anatomical shape, size and presentation of the femur bone in clinically acceptable scans. The measurement process utilizes a polynomial curve fitting technique to determine the end-points of the bone from a 1D profile that is most distal from the transducer surface. The method has been tested with manual measurements made on 90 third trimester femur images by two radiologists. The measurements made by the experts are strongly correlated (Pearson's coefficient = 0.95). Likewise, the algorithm estimate is strongly correlated with expert measurements (Pearson's coefficient = 0.92 and 0.94). Based on GA estimates and their bounds specified in Standard Obstetric Tables, the GA predictions from automated measurements are found to be within +/-2SD of GA estimates from both manual measurements in 89/90 cases and within +/-3SD in all 90 cases. The method presented in this paper can be adapted to perform automatic measurement of other fetal limbs.

Mukherjee, Prateep; Swamy, Gokul; Gupta, Madhumita; Patil, Uday; Krishnan, Kajoli Banerjee

2010-03-01

34

X-ray Photon Correlation Spectroscopy (XPCS) is an emerging technique offering unprecedented sensitivity to dynamics of structural changes in materials. Existing XPCS facilities are limited to microstructure length scales less than 50 nm, eliminating large classes of important materials. Recently, the scale range has been extended dramatically by combining XPCS speckle measurements with ultrasmall-angle scattering (USAXS) studies at the Advanced Photon

Andrew Allen; Fan Zhang; Lyle Levine; Jan Ilavsky; Gabrielle Long

2010-01-01

35

Conductive Gage for Crack Length Measurement.

National Technical Information Service (NTIS)

The determination of crack lengths in an accurate and straight forward manner is very useful in studying and preventing load created flaws and cracks. A crack length sensor according to the present invention is fabricated in a rectangular or other geometr...

R. Prabhakaran, O. F. Lopez

1991-01-01

36

Direct measure of quantum correlation

The quantumness of the correlation known as quantum correlation is usually measured by quantum discord. So far various quantum discords can be roughly understood as indirect measure by some special discrepancy of two quantities. We present a direct measure of quantum correlation by revealing the difference between the structures of classically and quantum correlated states. Our measure explicitly includes the contributions of the inseparability and local nonorthogonality of the eigenvectors of a density matrix. Besides its relatively easy computability, our measure can provide a unified understanding of quantum correlation of all the present versions.

Yu, Chang-shui [School of Physics and Optoelectronic Technology, Dalian University of Technology, Dalian 116024 (China); H. H. Wills Physics Laboratory, University of Bristol, Tyndall Avenue, Bristol BS8 1TL (United Kingdom); Zhao, Haiqing [School of Science, Dalian Jiaotong University, Dalian 116028 (China)

2011-12-15

37

Coding Ropes For Length And Speed Measurements

NASA Technical Reports Server (NTRS)

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.

Rupp, Charles C.; Tiesenhausen, Georg Von

1988-01-01

38

Focal Length Measurements for the National Ignition Facility Large Lenses

The focal length of the spatial filter and final focus lenses for the National Ignition Facility are measured to < {+-} 0.01% using a combination of master lenses and production-oriented techniques for relative focal length.

Parham, T G; McCarville, T J; Johnson, M A; Kiikka, C

2002-01-25

39

Measurements of the Vertical Coherence Length in Neutron Interferometry

The study and use of macroscopic quantum coherence requires long coherence lengths. Here we describe an approach to measuring the vertical coherence length in neutron interferometry, along with improvements to the NIST interferometer that led to a measured coherence length of 790 A. The measurement is based on introducing a path separation and measuring the loss in contrast as this separation is increased. The measured coherence length is consistent with the momentum distribution of the neutron beam. Finally, we demonstrate that the loss in contrast with beam displacement in one leg of the interferometer can be recovered by introducing a corresponding displacement in the second leg.

Pushin, D. A.; Cory, D. G. [Department of Nuclear Science and Engineering, Massachusetts Institute of Technology, Cambridge, Massachusetts (United States); Arif, M. [National Institute of Standards and Technology, Gaithersburg, Maryland (United States); Huber, M. G. [Department of Physics, Tulane University, New Orleans, Louisiana (United States)

2008-06-27

40

Measuring and interpreting neuronal correlations

Mounting evidence suggests that understanding how the brain encodes information and performs computations will require studying correlations between neurons. The recent advent of recording techniques such as multielectrode arrays and two-photon imaging has made it easier to measure correlations, opening the door to detailed exploration of their properties and contributions to cortical processing. Studies to date, however, have reported discrepant findings, providing a confusing picture. Here, we briefly review these studies and conduct simulations to explore the influence of several experimental and physiological factors on correlation measurements. Differences in response strength, the time window over which spikes are counted, spike sorting conventions, and internal states can all dramatically affect measured correlations and systematically bias estimates. Given these complicating factors, we offer guidelines for interpreting correlation data and a discussion of how best to evaluate the impact of correlations on cortical processing. PMID:21709677

Cohen, Marlene R.; Kohn, Adam

2013-01-01

41

Genetic correlation between length of wattles and female body weight at sexual maturity in the foul

Genetic correlation between length of wattles and female body weight at sexual maturity in the foul in order to estimate phenotypic and genetic correlations between female body weight and their length in other strains and genetic correlation between female body weight and this trait. Material and methods

Paris-Sud XI, UniversitÃ© de

42

50 CFR Appendix C to Part 622 - Fish Length Measurements

Code of Federal Regulations, 2011 CFR

...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...

2011-10-01

43

50 CFR Appendix C to Part 622 - Fish Length Measurements

Code of Federal Regulations, 2010 CFR

...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...

2010-10-01

44

50 CFR Appendix C to Part 622 - Fish Length Measurements

Code of Federal Regulations, 2013 CFR

...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...

2013-10-01

45

50 CFR Appendix C to Part 622 - Fish Length Measurements

Code of Federal Regulations, 2012 CFR

...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...

2012-10-01

46

From Concrete to Abstract in the Measurement of Length

NASA Astrophysics Data System (ADS)

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.

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

2013-09-01

47

Objectives Accurate, objective measurement is important for understanding adolescents' physical activity (PA) behaviour. When using accelerometry to objectively measure PA, a decision must be made regarding how frequently data is recorded (i.e., epoch length). The purpose of this study was to examine i) PA bout length, and ii) the effect of variations in accelerometer epoch length on PA estimates during physical education (PE) and leisure time in adolescent boys. Design Cross-sectional study. Methods Year 9 boys (N?=?133; mean age ±SD ?=?14.36±0.48 years) wore accelerometers during two PE lessons, and for a period of seven consecutive days. Data were reintegrated from 1s into longer periods of 2, 5, 10, 30, and 60 seconds. ANOVAs were used to test for differences in PA estimates between epochs in leisure time and PE. Results The mean length of vigorous PA (VPA) bouts was 3.5±2.0 seconds for PE and 2.5±1.7 seconds for leisure time, and mean length of moderate PA (MPA) bouts was 2.3±0.5 seconds for PE and 2.9±0.5 seconds for leisure time. During PE, estimates of MVPA, MPA, and light PA (LPA) increased as epoch increased from 1 second to 60 seconds, while VPA and sedentary behaviour estimates decreased. During leisure time, estimates of all PA intensities decreased as epoch increased from 1 second to 60 seconds, with the exception of sedentary behaviour, which increased as epoch length increased. Conclusion The context in which PA occurs can influence PA bout length measurement and the effect of variations in epoch length on PA estimates. Researchers measuring PA with accelerometry should be conscious of the possible influence of context on PA estimates. PMID:24643129

Sanders, Taren; Cliff, Dylan P.; Lonsdale, Chris

2014-01-01

48

Surface Free Energies, Interfacial Tensions and Correlation Lengths of the ABF Models

Surface Free Energies, Interfacial Tensions and Correlation Lengths of the ABF Models David L. O. Abstract The surface free energies, interfacial tensions and correlation lengths of the Andrews been established there are various quan- tities of physical interest, such as the surface free energies

Pearce, Paul A.

49

Measurement of endodontic file lengths: calibrated versus uncalibrated digital images.

This in vitro study compared the accuracy of file length measurements made on calibrated and uncalibrated direct digital images. Endodontic files of known lengths and ISO sizes were used in 10 single-rooted, relatively straight teeth within cadaver specimens. The crowns of the teeth were ground flat and an orthodontic wire of known length was secured to the coronal surface. This wire was placed mesiodistally and perpendicular to the root and served as the reference point for the file measurement and as a calibration reference length. A #20 file was hand-measured to a length that reached the apical third of each tooth. It was inserted and a radiographic image was secured. The instrument was remeasured three additional times at different lengths on the same tooth and reinserted before each image acquisition. Thus 40 digital images were acquired using a GE X-ray unit and a Schick Computed Dental Radiography (CDR) #2 sensor. These images were placed in random order, and an independent, blinded investigator determined the file lengths using on-screen calibrated and uncalibrated measurement of the CDR image with a straight-line and multiple-line measuring technique. The experimental measurements were compared with each other and with the known clinical measurements. A two-way analysis of variance indicated that there was a statistically significant difference showing that the calibrated measurements were more accurate than the uncalibrated measurements (p = 0.0001), and there was no significant difference between the straight-line and multiple-line measuring techniques (p = 0.14). PMID:11771590

Loushine, R J; Weller, R N; Kimbrough, W F; Potter, B J

2001-12-01

50

Isometric Instructions: Measure the length from your shoulder to your elbow using the tape measure

Isometric Instructions: Part 1: Measure the length from your shoulder to your elbow using the tape measure provided. You will also need to measure the length from your elbow to your hand where you grip and the angle of the load cell. 6. Use the tape measure to measure the strap length and height from the point

Sniadecki, Nathan J.

51

NASA Astrophysics Data System (ADS)

Spatial coherence of thermal fields in far- and near-field zones generated by heated half-space into vacuum is studied at essentially different thermodynamical conditions. It is shown that correlation lengths of fields in any field zone are different in equilibrium and out of equilibrium systems. In wide range of distances from sample surface correlation functions are should be calculated using a total sum of evanescent and propagating contributions due to their mutual compensation at some conditions because of anticorrelations. It is demonstrated that correlation lengths as calculated with a proposed formula are in agreement with a behavior of correlation functions of thermal fields in spectral range of surface excitations

Dorofeyev, Illarion

2014-11-01

52

Telomere Length in Elderly Caucasians Weakly Correlates with Blood Cell Counts

Background. Age-related decrease in bone marrow erythropoietic capacity is often accompanied by the telomere length shortening in peripheral white blood cells. However, limited and conflicting data hamper the conclusive opinion regarding this relationship. Therefore, the aim of this study was to assess an association between telomere length and peripheral blood cell count parameters in the Polish elderly population. Material and Methods. The substudy included 1573 of 4981 subjects aged 65 years or over, participants of the population-based PolSenior study. High-molecular-weight DNA was isolated from blood mononuclear cells. Telomere length (TL) was measured by QRT-PCR as abundance of telomere template versus a single gene copy encoding acidic ribosomal phosphoprotein P0. Results. Only white blood count (WBC) was significantly different in TL tertile subgroups in all subjects (P = 0.02) and in men (P = 0.01), but not in women. Merely in men significant but weak positive correlations were found between TL and WBC (r = 0.11, P < 0.05) and RBC (r = 0.08, P < 0.05). The multiple regression analysis models confirmed a weak, independent contribution of TL to both RBC and WBC. Conclusions. In the elderly, telomere shortening limits hematopoiesis capacity to a very limited extent. PMID:24453794

Witecka, Joanna; Koscinska-Marczewska, Justyna; Szwed, Malgorzata; Owczarz, Magdalena; Mossakowska, Malgorzata; Milewicz, Andrzej; Zejda, Jan; Wiecek, Andrzej

2013-01-01

53

Correlation-length bounds, and estimates for intermittent islands in parabolic SPDEs

We consider the nonlinear stochastic heat equation in one dimension. Under some conditions on the nonlinearity, we show that the "peaks" of the solution are rare, almost fractal like. We also provide an upper bound on the length of the "islands," the regions of large values. These results are obtained by analyzing the correlation length of the solution.

Conus, Daniel; Khoshnevisan, Davar

2011-01-01

54

Correlation-length bounds, and estimates for intermittent islands in parabolic SPDEs

Correlation-length bounds, and estimates for intermittent islands in parabolic SPDEs Daniel Conus Abstract We consider the nonlinear stochastic heat equation in one dimension. Under some conditions bound on the length of the "islands," the regions of large values. These results are obtained

Khoshnevisan, Davar

55

CORRELATION OF H-MODE BARRIER WIDTH AND NEUTRAL PENTRATION LENGTH

OAK A271 CORRELATION OF H-MODE BARRIER WIDTH AND NEUTRAL PENTRATION LENGTH. Pedestal studies in DIII-D find a good correlation between the width of the region of steep gradient in the H-mode density and the neutral penetration length. These results are obtained by comparing experimental density profiles to the predictions of an analytic model for the profile, obtained from the particle continuity equations for electrons and deuterium atoms. In its range of validity (edge temperature between 40-500 eV), the analytic model quantitatively predicts the observed decrease of the width as the pedestal density increases, the observed strong increase of the gradient of the density as the pedestal density increases and the observation that L-mode and H-mode profiles with the same pedestal density have very similar shapes. The width of the density barrier, measured from the edge of the electron temperature barrier, is the lower limit for the observed width of the temperature barrier. These results support the hypothesis that particle fueling provides a dominant control for the size of the H-mode transport barrier.

GROEBNER,RJ; MAHDAVI,MA; LEONARD,AW; OSBORNE,TH; WOLF,NS; PORTER,GD; STANGEBY,PC; BROOKS,NH; COLCHIN,RJ; HEIDBRINK,WW; LUCE,TC; MCKEE,GR; OWEN,LW; WANG,G; WHYTE,DG

2002-09-01

56

CORRELATION OF H-MODE BARRIER WIDTH AND NEUTRAL PENETRATION LENGTH

OAK A271 CORRELATION OF H-MODE BARRIER WIDTH AND NEUTRAL PENETRATION LENGTH. Pedestal studies in DIII-D find a good correlation between the width of the H-mode density barrier and the neutral penetration length. These results are obtained by comparing experimental density profiles to the predictions of an analytic model for the profile, obtained from the particle continuity equations for electrons and deuterium atoms. In its range of validity (edge temperature between 40-500 eV), the analytic model quantitatively predicts the observed decrease of the width as the pedestal density increases, the observed strong increase of the gradient of the density as the pedestal density increases and the observation that L-mode and H-mode profiles with the same pedestal density have very similar shapes. The width of the density barrier, measured from the edge of the electron temperature barrier, is the lower limit for the observed width of the temperature barrier. These results support the hypothesis that particle fueling provides the dominant control for the size of the H-mode transport barrier.

GROEBNER,RJ; MAHDAVI,MA; LEONARD,AW; OSBORNE,TH; WOLF,NS; PORTER,GD; STANGEBY,PC; BROOKS,NH; COLCHIN,RJ; HEIDBRINK,WW; LUCE,TC; MCKEE,GR; OWEN,LW; WANG,G; WHYTE,DG

2002-09-01

57

Electron bunch length measurement with a wakefield radiation decelerator

NASA Astrophysics Data System (ADS)

In this paper, we propose a novel method to measure the electron bunch length with a dielectric wakefield radiation (DWR) decelerator which is composed of two dielectric-lined waveguides (DLWs) and an electron spectrometer. When an electron beam passes through a DLW, the DWR is excited which leads to an energy loss of the electron beam. The energy loss is found to be largely dependent on the electron bunch length and can be easily measured by an electron spectrometer which is essential for a normal accelerator facility. Our study shows that this method has a high resolution and a great simplicity.

Li, Weiwei; He, Zhigang; Jia, Qika

2014-04-01

58

Measurement of Trap Length for an Optical Trap

NASA Technical Reports Server (NTRS)

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.

Wrbanek, Susan Y.

2009-01-01

59

Ruler measurements give space-time-transformation-independent invariant lengths

Two thought experiments are described in which ruler measurements of spatial intervals are performed in different reference frames. They demonstrate that such intervals are frame-independent as well as independent of the nature of the space-time transformation equations. As explained in detail elsewhere, the `length contraction' effect of conventional special relativity theory is therefore spurious and unphysical.

J. H. Field

2013-07-30

60

Determination of ?? scattering lengths from measurement of ?? atom lifetime

NASA Astrophysics Data System (ADS)

The DIRAC experiment at CERN has achieved a sizeable production of ?? atoms and has significantly improved the precision on its lifetime determination. From a sample of 21 227 atomic pairs, a 4% measurement of the S-wave ?? scattering length difference |a-a||syst-0.0073+0.0078)M?-1 has been attained, providing an important test of Chiral Perturbation Theory.

Adeva, B.; Afanasyev, L.; Benayoun, M.; Benelli, A.; Berka, Z.; Brekhovskikh, V.; Caragheorgheopol, G.; Cechak, T.; Chiba, M.; Chliapnikov, P. V.; Ciocarlan, C.; Constantinescu, S.; Costantini, S.; Curceanu (Petrascu), C.; Doskarova, P.; Dreossi, D.; Drijard, D.; Dudarev, A.; Ferro-Luzzi, M.; Fungueiriño Pazos, J. L.; Gallas Torreira, M.; Gerndt, J.; Gianotti, P.; Goldin, D.; Gomez, F.; Gorin, A.; Gorchakov, O.; Guaraldo, C.; Gugiu, M.; Hansroul, M.; Hons, Z.; Hosek, R.; Iliescu, M.; Karpukhin, V.; Kluson, J.; Kobayashi, M.; Kokkas, P.; Komarov, V.; Kruglov, V.; Kruglova, L.; Kulikov, A.; Kuptsov, A.; Kuroda, K. I.; Lamberto, A.; Lanaro, A.; Lapshin, V.; Lednicky, R.; Leruste, P.; Levi Sandri, P.; Lopez Aguera, A.; Lucherini, V.; Maki, T.; Manuilov, I.; Marin, J.; Narjoux, J. L.; Nemenov, L.; Nikitin, M.; Nunez Pardo, T.; Okada, K.; Olchevskii, V.; Pazos, A.; Pentia, M.; Penzo, A.; Perreau, J. M.; Plo, M.; Ponta, T.; Rappazzo, G. F.; Riazantsev, A.; Rodriguez, J. M.; Rodriguez Fernandez, A.; Romero Vidal, A.; Ronjin, V. M.; Rykalin, V.; Saborido, J.; Santamarina, C.; Schacher, J.; Schuetz, C.; Sidorov, A.; Smolik, J.; Takeutchi, F.; Tarasov, A.; Tauscher, L.; Tobar, M. J.; Trojek, T.; Trusov, S.; Utkin, V.; Vázquez Doce, O.; Vlachos, S.; Voskresenskaya, O.; Vrba, T.; Willmott, C.; Yazkov, V.; Yoshimura, Y.; Zhabitsky, M.; Zrelov, P.

2011-10-01

61

ADVANCES AND NEW TECHNIQUES IN LENGTH MEASUREMENTS BY OPTICAL INTERFEROMETRY

Studies of a long gauge block Kösters interferometer, performed at INMETRO, and the results of the CIPM Key Comparison CCL-2 show that the uncertainty in realization of the SI length unit achieved with this type of instrument in the range of 500 mm is ~1 part in 108. Basic advances in philosophy and techniques of high-precision temperature measurements, realized in

Alexandre Titov; Igor Malinovsky

62

Measurement of <20 fs bunch length using coherent transition radiation

NASA Astrophysics Data System (ADS)

By monitoring coherent transition radiation (CTR) with a Michelson interferometer, bunch length measurement was investigated. Less-than-20-fs electron bunches were generated by a photocathode-based linear accelerator (linac) and a magnetic bunch compressor. From the femtosecond electron bunch of 2.1 pC and 32 MeV, CTR was measured using a Michelson interferometer that had two detectors with different spectral ranges, which enhanced the detection spectral range of CTR (ranging from 3 to 50 THz) and enabled us to determine the bunch length of the electron bunch. A model based on the interferometer's frequency sensitivity was proposed and introduced to analyze the measured interferograms. The measured interferograms and the frequency spectra were explained using the model.

Nozawa, I.; Kan, K.; Yang, J.; Ogata, A.; Kondoh, T.; Gohdo, M.; Norizawa, K.; Kobayashi, H.; Shibata, H.; Gonda, S.; Yoshida, Y.

2014-07-01

63

How to Directly Measure a Kondo Cloud's Length

NASA Astrophysics Data System (ADS)

We propose a method to directly measure, by electrical means, the Kondo screening cloud formed by an Anderson impurity coupled to semi-infinite quantum wires, on which an electrostatic gate voltage is applied at distance L from the impurity. We show that the Kondo cloud, and hence the Kondo temperature and the electron conductance through the impurity, are affected by the gate voltage, as L decreases below the Kondo cloud length. Based on this behavior, the cloud length can be experimentally identified by changing L with a keyboard type of gate voltage or tuning the coupling strength between the impurity and the wires.

Park, Jinhong; Lee, S.-S. B.; Oreg, Yuval; Sim, H.-S.

2013-06-01

64

FEL Gain Length and Taper Measurements at LCLS

We present experimental studies of the gain length and saturation power level from 1.5 nm to 1.5 {angstrom} at the Linac Coherent Light Source (LCLS). By disrupting the FEL process with an orbit kick, we are able to measure the X-ray intensity as a function of undulator length. This kick method is cross-checked with the method of removing undulator sections. We also study the FEL-induced electron energy loss after saturation to determine the optimal taper of the undulator K values. The experimental results are compared to theory and simulations.

Ratner, Daniel; Brachmann, A.; Decker, F.J.; Ding, Y.; Dowell, D.; Emma, P.; Frisch, J.; Gilevich, S.; Hays, G.; Hering, P.; Huang, Z.; Iverson, R.; Loos, H.; Miahnahri, A.; Nuhn, H.D.; Turner, J.; Welch, J.; White, W.; Wu, J.; Xiang, D.; Yocky, G.; /SLAC /LBL, Berkeley; ,

2010-07-30

65

FEL GAIN LENGTH AND TAPER MEASUREMENTS AT LCLS

We present experimental studies of the gain length and saturation power level from 1.5 nm to 1.5 Angstroms at the Linac Coherent Light Source (LCLS). By disrupting theFEL process with an orbit kick, we are able to measure the X-ray intensity as a function of undulator length. This kick method is cross-checked with the method of removing undulator sections. We also study the FEL-induced electron energy loss after saturation to determine the optimal taper of the undulator K values. The experimental results are compared to theory and simulations.

Ratner, D.; Fawley, W. M.; Brachmann, A.; Decker, F.J.; Ding, Y.; Dowell, D.; Emma, P.; Frisch, J.; Gilevich, S.; Hays, G.; Hering, P.; Huang, Z.; Loos, H.; Miahnahri, A.; Nuhn, H.D.; Turner, J.; Welch, J.; White, W.; Wu, J.; Xiang, D.; Yocky, G.; Fawley, W. M.

2009-08-14

66

Negative correlation between age of subjects and length of the appendix in Bangladeshi males

Introduction The anatomy of the vermiform appendix shows variations in its macroscopic dimensions some of which have potential to influence the clinical aspects of the appendix. Anatomical studies on the appendix using people in Bangladesh as a sample are limited and fall short of producing any standardized anthropometric data. This study is predominantly a cross-sectional observational study which also uses some statistical analysis to understand the relationships amongst variables. Material and methods Fifty-six adult male postmortem appendices and adnexa were examined for macroscopic features. Possible interrelationships among the variables were assessed through statistical analysis. The age of the samples ranged from 18 to 67 years. The most common position of the appendix was retrocolic (53.57%) followed by pelvic (30.35%), postileal (12.5%), and subcaecal (3.5%). Results In most cases (62.5%) the mesoappendix did not reach the tip of the appendix. The appendicular length varied from 6.00 cm to 16.30 cm with mean (± SD) and median value of 10.21 ±2.50 cm and 10.00 cm respectively. The base of the appendix was 1.90 to 3.80 cm away from the ileocaecal junction. The other macroscopic measurements of the appendix were taken at the base, at the midzone and at the tip of the appendix and the mean of the three measurements was considered as the overall value. Thus, the overall external diameter varied between 0.32 cm and 0.83 cm. Assessment of possible correlations amongst different variables revealed a significant negative correlation between the age of the subjects and the length of the appendix. Conclusions The data of the present study may provide a baseline along with some previous data in the standardization of the anthropometric information regarding the vermiform appendix of Bangladeshi males. PMID:23515519

Bakar, Sheikh Muhammad Abu; Shamim, Manjare; Alam, Gazi Mahabubul

2013-01-01

67

Reducing trial length in force platform posturographic sleep deprivation measurements

NASA Astrophysics Data System (ADS)

Sleepiness correlates with sleep-related accidents, but convenient tests for sleepiness monitoring are scarce. The posturographic test is a method to assess balance, and this paper describes one phase of the development of a posturographic sleepiness monitoring method. We investigated the relationship between trial length and accuracy of the posturographic time-awake (TA) estimate. Twenty-one healthy adults were kept awake for 32 h and their balance was recorded, 16 times with 30 s trials, as a function of TA. The balance was analysed with regards to fractal dimension, most common sway amplitude and time interval for open-loop stance control. While a 30 s trial allows estimating the TA of individual subjects with better than 5 h accuracy, repeating the analysis using shorter trial lengths showed that 18 s sufficed to achieve the targeted 5 h accuracy. Moreover, it was found that with increasing TA, the posturographic parameters estimated the subjects' TA more accurately.

Forsman, P.; Hæggström, E.; Wallin, A.

2007-09-01

68

The electron-hole correlation length serves as an intrinsic length scale for analyzing excitonic interactions in semiconductor nanoparticles. In this work, the derivation of electron-hole correlation length using the two-particle reduced density is presented. The correlation length was obtained by first calculating the electron-hole cumulant from the pair density,and then transforming the cumulant into intracular coordinates, and finally then imposing exact sum-rule conditions on the radial integral of the cumulant. The excitonic wave function for the calculation was obtained variationally using the electron-hole explicitly correlated Hartree-Fock method. As a consequence, both the pair density and the cumulant were explicit functions of the electron-hole separation distance. The use of explicitly correlated wave function and the integral sum-rule condition are the two key features of this derivation. The method was applied to a series of CdSe quantum dots with diameters 1-20 nm and the effect of dot size on ...

Blanton, Christopher J

2014-01-01

69

Developing measurement concepts within context: Children's representations of length

NASA Astrophysics Data System (ADS)

This article presents data gathered from an investigation which focused on the experiences children have with measurement in the early years of schooling. The focus of this article is children's understandings of length at this early stage. 32 children aged 4-6 years at an Australian primary school were asked to draw a ruler and describe their drawing, once in February at the beginning of school, and again in November towards the end of their first year of school. The drawings and their accompanying descriptions are classified within a matrix which, informed by Bronfenbrenner's ecological theory and literature regarding the development of length concepts, considers conceptual understanding and contextual richness. The responses revealed that children have a good understanding of length at the start of school, but that as their ability to contextualise develops so too does their conceptual understanding. This article suggests that participation in tasks such as these allows children to create their own understandings of length in meaningful ways. Additionally, the task and its matrix of analysis provide an assessment strategy for identifying children's understandings about length and the contexts in which these understandings develop.

MacDonald, Amy; Lowrie, Tom

2011-03-01

70

Daily energy expenditure (DEE) of male barn swallows (Hirundo rustica), measured using the doubly labelled water technique, correlated with streamer length. Contrary to predictions derived from previous findings, neither a positive linear nor a u-shaped relationship was found between DEE and streamer length. Instead, an n-shaped curve showed that the highest DEE corresponded to an intermediate streamer length of 119 mm. A model incorporating estimates of resting metabolism and flight energy expenditure from aerodynamics models suggested that variation in individual tail dynamics was the most likely explanation for the observed DEE. We suggest that streamer length is coupled to foraging strategy, because tail dynamics control flight performance, which in turn influences flight behaviour. PMID:15252971

Nudds, Robert L; Spencer, Karen A

2004-05-01

71

Low-Temperature Series for the Correlation Length in $d=3$ Ising Model

We extend low-temperature series for the second moment of the correlation function in $d=3$ simple-cubic Ising model from $u^{15}$ to $u^{26}$ using finite-lattice method, and combining with the series for the susceptibility we obtain the low-temperature series for the second-moment correlation length to $u^{23}$. An analysis of the obtained series by inhomogeneous differential approximants gives critical exponents $ 2\

H. Arisue; K. Tabata

1994-07-28

72

Universal measurement of quantum correlations of radiation

A measurement technique is proposed which, in principle, allows one to observe the general space-time correlation properties of a quantized radiation field. Our method, called balanced homodyne correlation measurement, unifies the advantages of balanced homodyne detection with those of homodyne correlation measurements.

E. Shchukin; W. Vogel

2006-02-15

73

Effect of attractions on correlation length scales in a glass-forming liquid

NASA Astrophysics Data System (ADS)

There is growing evidence that slow dynamics and dynamic heterogeneity possess structural signatures in glass-forming liquids. However, even in the weakly frustrated glass-forming liquids, whether or not the dynamic heterogeneity has a structural origin is a matter of debate. Via molecular dynamics simulation, we present a study of examining the connection between dynamic heterogeneity and bond orientational order in a weakly frustrated glass-forming liquid in two dimensions by taking advantage of assessing the effect of attractions on the correlation length scales. We find that attractions can strongly affect relaxation dynamics, dynamic heterogeneity, and the associated dynamic correlation length of the liquid, but their influence on bond orientational order and the associated static correlation length shows a manner reminiscent of the effect of attractions on the thermodynamics of liquids. This implies that the growth of bond orientational order and static correlation length scale might be merely a manifestation of favoring the configurational entropy in weakly frustrated glass-forming liquids. Thus, our results provide strong evidence that bond orientational order cannot provide a complete description of dynamic heterogeneity even in weakly frustrated glass-forming systems.

Xu, Wen-Sheng; Sun, Zhao-Yan; An, Li-Jia

2012-10-01

74

An inverse correlation between loop length and stability in a four-helix-bundle protein

An inverse correlation between loop length and stability in a four-helix-bundle protein Athena D Nagi and Lynne Regan Background: The loops in proteins are less well characterized than the secondary structural elements that they connect. We have used the four-helix- bundle protein Rop as a model system

Mochrie, Simon

75

Correlation length exponent of the 2-d Z(4) model using an exact method

NASA Astrophysics Data System (ADS)

Using a recently suggested exact method to determine the partition function of a discrete model, the correlation length exponent v for the two-dimensional Z(4) spin model is estimated. This estimation is made from a study of the zeros of the partition function on finite lattices.

William, Peter

1990-05-01

76

Estimating the correlation length of inhomogeneities in a polycrystalline Igor Simonovski*

calculated from a finite-element model, which explicitly accounts for the selected mesoscopic features in the finite-element analysis. Different correlation lengths were obtained depending on whether the strain [13-15], continuum damage models [16,17] and stochastic finite-element approaches. A common feature

Cizelj, Leon

77

NASA Astrophysics Data System (ADS)

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.

Shaw, A.; Ghosh, A.

2013-09-01

78

Background Depression is associated with an unusually high rate of aging-related illnesses and early mortality. One aspect of “accelerated aging” in depression may be shortened leukocyte telomeres. When telomeres critically shorten, as often occurs with repeated mitoses or in response to oxidation and inflammation, cells may die. Indeed, leukocyte telomere shortening predicts early mortality and medical illnesses in non-depressed populations. We sought to determine if leukocyte telomeres are shortened in Major Depressive Disorder (MDD), whether this is a function of lifetime depression exposure and whether this is related to putative mediators, oxidation and inflammation. Methodology Leukocyte telomere length was compared between 18 unmedicated MDD subjects and 17 controls and was correlated with lifetime depression chronicity and peripheral markers of oxidation (F2-isoprostane/Vitamin C ratio) and inflammation (IL-6). Analyses were controlled for age and sex. Principal Findings The depressed group, as a whole, did not differ from the controls in telomere length. However, telomere length was significantly inversely correlated with lifetime depression exposure, even after controlling for age (p<0.05). Average telomere length in the depressed subjects who were above the median of lifetime depression exposure (?9.2 years' cumulative duration) was 281 base pairs shorter than that in controls (p<0.05), corresponding to approximately seven years of “accelerated cell aging.” Telomere length was inversely correlated with oxidative stress in the depressed subjects (p<0.01) and in the controls (p<0.05) and with inflammation in the depressed subjects (p<0.05). Conclusions These preliminary data indicate that accelerated aging at the level of leukocyte telomeres is proportional to lifetime exposure to MDD. This might be related to cumulative exposure to oxidative stress and inflammation in MDD. This suggest that telomere shortening does not antedate depression and is not an intrinsic feature. Rather, telomere shortening may progress in proportion to lifetime depression exposure. PMID:21448457

Wolkowitz, Owen M.; Mellon, Synthia H.; Epel, Elissa S.; Lin, Jue; Dhabhar, Firdaus S.; Su, Yali; Reus, Victor I.; Rosser, Rebecca; Burke, Heather M.; Kupferman, Eve; Compagnone, Mariana; Nelson, J. Craig; Blackburn, Elizabeth H.

2011-01-01

79

Recently a new approach to the determination of dynamic correlation lengths, {\\xi}, for supercooled liquids, based on the properties of the slow (picosecond) vibrational dynamics, was carried out [L. Hong, V.N. Novikov, and A.P. Sokolov, Phys. Rev. E 83, 061508 (2011)]. Although these vibrational measurements are typically conducted well below the glass transition temperature, Tg, the assumption is that the structure of the liquid is frozen at Tg, so that the {\\xi} characterize dynamic heterogeneity in the supercooled liquid state. We compare {\\xi} from this method to values calculated using an approximation to the four-point dynamic susceptibility. For 26 different materials we find good correlation between the two measures; moreover, the pressure dependences are consistent within the large experimental error. However, {\\xi} from Boson peak measurements above Tg have a different, and unrealistic, temperature dependence.

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

2011-09-01

80

Representative Elementary Length to Measure Soil Mass Attenuation Coefficient

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

Borges, J. A. R.; Pires, L. F.; Costa, J. C.

2014-01-01

81

Representative elementary length to measure soil mass attenuation coefficient.

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

Borges, J A R; Pires, L F; Costa, J C

2014-01-01

82

Single Molecule Measurements Using Correlation Force Spectroscopy

NASA Astrophysics Data System (ADS)

Thermal noise represents a fundamental limit in force measurements. We describe single molecule measurements using two AFM cantilevers that have lower thermal noise than single-cantilever measurements. We achieve this by measuring the correlated thermal motions of two closely spaced cantilevers. Because only correlated thermal noise is measured, there is lower noise. In addition, the use of two cantilevers produces both decreased hydrodynamic fluid damping and decreased van der Waals forces acting on an AFM probe, both of which are interferences in single molecule measurements. Analysis of the correlated motions reveals molecular damping, a parameter that is not sensed with conventional (pulling) AFM single molecule force spectroscopy. When a molecule is straddled between the two cantilevers, the correlation arises from the solvent coupling as well as stiffness and damping of the molecule. We will describe the technique of correlation force spectroscopy and measurements of the mechanical properties of single polymer chains such as dextran.

Radiom, Milad; Robbins, Brian; Walz, John; Paul, Mark; Ducker, William

2013-03-01

83

Measurement of the Length of an Optical Trap

NASA Technical Reports Server (NTRS)

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.

Wrbanek, Susan Y.

2010-01-01

84

Measurements of the Influence of Integral Length Scale on Stagnation Region Heat Transfer

NASA Technical Reports Server (NTRS)

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.

Vanfossen, G. James; Ching, Chang Y.

1994-01-01

85

Decaying turbulence: What happens when the correlation length varies spatially in two adjacent zones

NASA Astrophysics Data System (ADS)

We have imagined a numerical experiment to explore the onset of turbulent intermittency associated with a spatial perturbation of the correlation length. We place two isotropic regions, with different integral scales, inside a volume where the turbulent kinetic energy is initially uniform and leave them to interact and evolve in time. The different length scales produce different decay rates in the two regions. Since the smaller-scale region decays faster, a transient turbulent energy gradient is generated at the interface between the two regions. The transient is characterized by three phases in which the kinetic energy gradient across the interface grows, peaks and then slowly decays. The transient lifetime is almost proportional to the initial ratio of the correlation lengths. The direct numerical simulations also show that the interface width grows in time. The velocity moments inside this interaction zone are seen to depart from their initial isotropic values and, with a certain lag, the anisotropy is seen to spread to small scales. The longitudinal derivative moments also become anisotropic after a few eddy turnover times. This anisotropic behaviour is different from that observed in sheared homogeneous turbulent flows, where high transverse derivative moments are generated, but longitudinal moments almost maintain the isotropic turbulence values. Apart from the behaviour of the energy gradient transients, the results also show the timescaling of the interface diffusion width, and data on the anisotropy of the large and small scales, observed through one-point statistics determined inside the intermittency sublayer, which is associated with the interaction zone.

Tordella, Daniela; Iovieno, Michele

2012-02-01

86

Method for High Accuracy Multiplicity Correlation Measurements

Multiplicity correlation measurements provide insight into the dynamics of high energy collisions. Models describing these collisions need these correlation measurements to tune the strengths of the underlying QCD processes which influence all observables. Detectors, however, often possess limited coverage or reduced efficiency that influence correlation measurements in obscure ways. In this paper, the effects of non-uniform detection acceptance and efficiency on the measurement of multiplicity correlations between two distinct detector regions (termed forward-backward correlations) are derived. This result is transformed into a correction method. Verification of the presented correction method is provided through simulations using different event generators. The result of the method allows one to correct measurements in a simulation independent manner with high accuracy and thereby shed light on the underlying processes.

K. Gulbrandsen; C. Soegaard

2014-08-14

87

Method for High Accuracy Multiplicity Correlation Measurements

Multiplicity correlation measurements provide insight into the dynamics of high energy collisions. Models describing these collisions need these correlation measurements to tune the strengths of the underlying QCD processes which influence all observables. Detectors, however, often possess limited coverage or reduced efficiency that influence correlation measurements in obscure ways. In this paper, the effects of non-uniform detection acceptance and efficiency on the measurement of multiplicity correlations between two distinct detector regions (termed forward-backward correlations) are derived. This result is transformed into a correction method. Verification of the presented correction method is provided through simulations using different event generators. The result of the method allows one to correct measurements in a simulation independent manner with high accuracy and thereby shed light on the underlying processes.

Gulbrandsen, K

2014-01-01

88

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

NASA Astrophysics Data System (ADS)

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.

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

2014-11-01

89

Quantifying Precision of in Situ Length and Weight Measurements of Fish

We estimated and compared errors in field-made (in situ) measurements of lengths and weights of fish. We made three measurements of length and weight on each of 33 common carp Cyprinus carpio, and on each of a total of 34 bluegills Lepomis macrochirus and black crappies Pomoxis nigromaculatus. Maximum total lengths of all fish were measured to the nearest 1

Steve Gutreuter; Daniel J. Krzoska

1994-01-01

90

1. Heritabilities and genetic correlations in the base population of a closed strain of Muscovy duck, moderately selected for body weight at 10 weeks of age, have been estimated from the data of 9 successive generations for the following traits: male and female body weight at 10 and 18 weeks of age (BW10m, BW18m, BW10f, BW18f) and length of the 8th primary feather at 10 weeks of age (F110m, F110f). 2. Multivariate REML with an animal model was used, pooling data from the 9 generations (3283 and 3289 male and female offspring respectively). The same trait expressed in male and female was considered as 2 different traits. 3. The 8th primary feather was longer in females than in males by 6% to 22% at 10 weeks of age. Body weight was heavier in males than in females by 42% to 58% at 10 weeks of age and by 57% to 75% at 18 weeks of age. 3. The heritability estimates for body weight traits showed moderate values, being a little higher for females than for males at the same age, increasing with age from h2=0.24 at BW10m to h2=0.43 at BW18f. 4. The heritability estimates for feather length showed that a greater response would be obtained in selection for male feather length (h2=0.37) than for female length (h2=0.14). Both have high genetic correlations with body weight so they could be indirectly improved. 5. Heritabilities of the difference in body weights between males and females at 10 weeks (h2=0.07) and 18 weeks of age (h2=0.10) were small, as well as for feather length (h2=0.10). It would probably be difficult to modify sexual dimorphism in body weight through selection. 6. Genetic correlations between BW10m, BW18m and BW10f, BW18f were respectively r(g)=0.77 and r(g)=0.80. They were larger for body weight at the same ages between males and females, r(g)=0.90 (r(g)=0.88 between F110m and F110f). Body weight in males and females at the same age should be better considered as 2 different traits in a selection programme. 7. The cumulated predicted genetic gains expressed per unity of the genetic standard deviation (sigma(g)) over the 8 generations of selection were 1.3 sigma(g) and 1.4 sigma(g) respectively for the BW10m and BW10f. The predicted correlated responses were 1.2 sigma(g) for body weights at 18 weeks of age, 0.9 sigma(g) and 0.7 sigma(g) for F110f and F110m respectively. PMID:10670671

Hu, Y H; Poivey, J P; Rouvier, R; Wang, C T; Tai, C

1999-12-01

91

Quantum correlation cost of the weak measurement

Quantum correlation cost (QCC) characterizing how much quantum correlation is used in a weak-measurement process is presented based on the trace norm. It is shown that the QCC is related to the trace-norm-based quantum discord (TQD) by only a factor that is determined by the strength of the weak measurement, so it only catches partial quantumness of a quantum system compared with the TQD. We also find that the residual quantumness can be `extracted' not only by the further von Neumann measurement, but also by a sequence of infinitesimal weak measurements. As an example, we demonstrate our outcomes by the Bell-diagonal state.

Jun Zhang; Shao-xiong Wu; Chang-shui Yu

2014-09-14

92

Instrument for measuring thin-film belt lengths

NASA Technical Reports Server (NTRS)

Instrument consists of base, vernier height gauge, sliding block, and balance-beam assembly with tension weight. Pulley bracket is provided with three pulley mounting holes, 4 inches apart, to accommodate widely different belt lengths. Instrument is accurate to within 0.001 inch and is suitable for commercial production.

Casad, T. A.; Piggott, H.; Hoffman, J. K.

1974-01-01

93

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

Vlastimil Kunc; Barbara Frame; Ba Nghiep Nguyen; Charles L. Tucker; Gregorio Velez-Garcia

94

Measuring roughness with dichromatic speckle correlation

The most established way to inspect machined surfaces is measuring with profilometers. Roughness measurements by these methods take plenty of time and an on-line integration in production facilities is not feasible due to different reasons. Over two decades ago, Goodman and Parry discovered the correlation between laser speckles of different light wavelengths and surface roughness. Since then several authors have

Joerg Peters; Peter Lehmann; Armin Schoene

1996-01-01

95

From a postmortem study of the brains of 56 patients with schizophrenia and 56 controls, 38 cases whose clinical state had been objectively documented in life were examined to determine whether relations existed between features of the illness and postmortem findings. Decreased brain weight was significantly related (p < 0.05) to poor premorbid global function and to poor academic record, and decreased brain length was related to poorer premorbid global function (p < 0.05) and more severe negative symptoms. These relations are consistent with the view that morphological changes in the brain occur early in the course of the disease--that is, they are in some sense "developmental." An excess of "focal damage" in the patient group relative to controls was unrelated to the presence of morphological change or to features of illness, but was more common in female schizophrenic patients and was also correlated with evidence of cerebrovascular disease. This may possibly be due to a discrepancy between the groups in mode and cause of death. PMID:8163999

Johnstone, E C; Bruton, C J; Crow, T J; Frith, C D; Owens, D G

1994-01-01

96

Understanding the amplitudes of noise correlation measurements

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.

Tsai, Victor C.

2011-01-01

97

NASA Astrophysics Data System (ADS)

One of the challenges in developing catchment-scale models of hydrologic processes is accurately representing the spatial variation of subsurface properties. There is growing interest in the application of surface-based or borehole geophysical methods to obtain information about the correlation structure of hydrogeologic systems. It is well known, for all forms of measurement, that the support of the measurement impacts the derived estimates of correlation structure. Of interest in our work is the effect of the support of geophysical measurements on estimated correlation lengths. We define the support of a geophysical measurement as the presumed-homogeneous volume of the subsurface to which we can assign, given the methods of data acquisition and inversion, a single property. Accounting for the effect of the support becomes particularly important when integrating geophysical measurements of properties with other hydrologic measurements. The merged data sets are derived from measurements on scales that are rarely coincident with each other or the scale at which the properties are applied in hydrologic models. A number of previous studies have examined the impact of measurement scale on the estimated apparent correlation length for isotropic property fields. Most hydrologic property fields, however, are anisotropic at the catchment-scale. A further complicating factor is that geophysical measurements commonly have directionally-varying support dimensions. In this study we numerically generate both isotropic and anisotropic property fields and allow the orthogonal dimensions defining the measurement support to vary independently. When creating the anisotropic fields we define maximum and minimum correlation lengths, referred to as the underlying correlation lengths; these lengths are the same in the isotropic case. We initially estimate the apparent correlation length when the measurement support is equal to the grid size on which the field is defined. The increase in apparent correlation length relative to this initial estimate, or the error in apparent correlation length, is presented as a function of increasing measurement support, termed the error response curve. Our results show that the errors vary with both measurement support and the anisotropy of the measured property. In systems where the measurement support is equidimensional and the property field is anisotropic, the slope of the error response curve is consistently greater when calculated in the direction of minimum underlying correlation length. For isotropic property fields and non-equidimensional measurement support, the error response curve has a steeper slope when the direction of increased measurement support dimension is coincident with the direction in which we estimate the apparent correlation length. When the property field is anisotropic and the measurement support is non-equidimensional, three factors affect the behavior of the error response curve: the anisotropy of the property field, the direction of increasing measurement support, and the direction in which the apparent correlation length is estimated. The error response curve has a shallower slope when measurement support dimension increases in the perpendicular direction to that in which we estimate the apparent correlation length. This behavior is independent of the degree of anisotropy in the property field. However, as the anisotropy in the property field increases, the slope of the error response curve becomes even shallower. At large measurement supports, the error response curve flattens when increasing measurement support is perpendicular to the direction of estimation of the apparent correlation. The opposite is true when the measurement support increases in the same direction as we estimate the apparent correlation; the slope of the error response curve increases at large measurement supports. In both cases, the behavior of the error response curve is more sensitive to changes in measurement support when the underlying correlation length is smaller in the direction of estimated appare

Mitchell, V.; Gulati, J.; Knight, R.

2009-04-01

98

The collembolan, Folsomia candida, is widely used in soil ecotoxicology. In recent years, growth rate of collembolans has become as frequently used endpoint as reproduction rate in ecotoxicological studies. However, measuring collembolan body sizes to estimate growth rate is a complicated and time-consuming task. Here we present a new image analysis method, which facilitates and accelerates the body length measurement of the collembolan Folsomia candida. The new software package, called CollScope, consists of three elements: 1) an imaging device; 2) photographing software; 3) an ImageJ macro for image processing, measurement and data analysis. We give a complete description of the operation of the software, the image analyzing process and describe its accuracy and reliability. The software with a detailed usage manual is attached as Supplementary Material. We report a case study to demonstrate that the automated measurement of collembolan body sizes is highly correlated with the traditional manual measurements (estimated measuring accuracy 0.05 mm). Furthermore, we performed a dose-response ecotoxicity test using cadmium-sulfate by using CollScope as well as classical methods for size measurement. Size data measured by CollScope or manually did not differ significantly. Furthermore the new software package decreased time consumption of the measurements to 42% when tested on 35 animals. Consequently, methodological investigations performed in this study should be regarded as a recommendation for any other routine dose-response study where body growth is an endpoint. PMID:24901322

Banszegi, Oxana; Kosztolanyi, Andras; Bakonyi, Gabor; Szabo, Borbala; Dombos, Miklos

2014-01-01

99

Eddy Correlation Flux Measurement System (ECOR) Handbook

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.

Cook, DR

2011-01-31

100

Chromatin fibers have been observed and measured in frozen hydrated sections of three types of cell (chicken erythrocytes and sperm of Patiria miniata and Thyone briareus) representing an approximately 20- bp range of nucleosomal repeat lengths. For sperm of the starfish P. miniata, it was possible to obtain images of chromatin fibers from cells that were swimming in seawater up to the moment of cryo- immobilization, thus providing a record of the native morphology of the chromatin of these cells. Glutaraldehyde fixation produced no significant changes in the ultrastructure or diameter of chromatin fibers, and fiber diameters observed in cryosections were similar to those recorded after low temperature embedding in Lowicryl K11M. Chromatin fiber diameters measured from cryosections of the three types of nuclei were similar, a striking contrast to the situation for chromatin isolated from these cell types, where a strong positive correlation between diameter and nucleosomal repeat length has been established. The demonstration of chromatin fibers in unfixed whole cells establishes an unequivocal baseline for the study of native chromatin and chromosome architecture. The significant differences between chromatin fibers in nucleo and after isolation supports a previous observation (P. J. Giannasca, R. A. Horowitz, and C. L. Woodcock. 1993. J. Cell Sci. 105:551-561), and suggests that structural studies on isolated material should be interpreted with caution until the changes that accompany chromatin isolation are understood. PMID:8138565

1994-01-01

101

NASA Astrophysics Data System (ADS)

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.

Sofia, Giulia; Marinello, Francesco; Tarolli, Paolo

2014-10-01

102

?-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 (L(e-e)) distributions respectively yielded values of persistence length (L(p)) of 41-46 nm, 40-45 nm, and 42-52 nm, corresponding to 1-1.3 molecular contour lengths (L(c)). We also demonstrate that a sufficiently large population, with at least 100 molecules, is required for a reliable L(p) measurement of ?Tm in single molecule studies. Our estimate that L(p) for ?Tm is only slightly longer than L(c) is consistent with a previous study showing there is little spread of cooperative activation into near-neighbor regulatory units of cardiac thin filaments. The L(p) 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

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

2012-01-01

103

Small-Angle Neutron Scattering Studies of Magnetic Correlation Lengths in Nanoparticle Assemblies

NASA Astrophysics Data System (ADS)

Small-angle neutron scattering (SANS) measurements of ordered arrays of surfactant-coated magnetic nanoparticle reveal characteristic length scales associated with interparticle and intraparticle magnetic ordering. The high degree of uniformity in the monodisperse nanoparticle size and spacing leads to a pronounced diffraction peak and allows for a straightforward determination of these length scales [1]. There are notable differences in these length scales depending on the particle moment, which depends on the material (Fe, Co, Fe3O4) and diameter, and also on whether the metal particle core is surrounded by an oxide shell. For 8.5 nm particles containing an Fe core and thick Fe3O4 shell, evidence of a spin flop phase is seen in the magnetite shell when a field is applied , but not when the shell thickness is ˜0.5 nm [2]. 8.0 nm particles with an e-Co core and 0.75 nm CoO shell show no exchange bias effects while similar particles with a 2 nm thick shell so significant training effects below 90 K. Polarized SANS studied of 7 nm Fe3O4 nanoparticle assemblies show the ability to resolve the magnetization components in 3D. [4pt] [1] M. Sachan, C. Bonnoit, S. A. Majetich, Y. Ijiri, P. O. Mensah-Bonsu, J. A. Borchers, and J. J. Rhyne, Appl. Phys. Lett. 92, 152503 (2008). [0pt] [2] Yumi Ijiri, Christopher V. Kelly, Julie A. Borchers, James J. Rhyne, Dorothy F. Farrell, Sara A. Majetich, Appl. Phys. Lett. 86, 243102-243104 (2005). [0pt] [3] K. L. Krycka, R. Booth, J. A. Borchers, W. C. Chen, C. Conlon, T. Gentile, C. Hogg, Y. Ijiri, M. Laver, B. B. Maranville, S. A. Majetich, J. Rhyne, and S. M. Watson, Physica B (submitted).

Majetich, Sara

2009-03-01

104

Quantum correlations and least disturbing local measurements

NASA Astrophysics Data System (ADS)

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.

Rossignoli, R.; Canosa, N.; Ciliberti, L.

2011-11-01

105

Quantum correlations and least disturbing local measurements

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 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 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.

Rossignoli, R; Ciliberti, L

2011-01-01

106

Quantum correlations and least disturbing local measurements

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 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 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.

R. Rossignoli; N. Canosa; L. Ciliberti

2011-12-07

107

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

Summary.-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

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

2014-10-01

108

Quantum Correlations and the Measurement Problem

NASA Astrophysics Data System (ADS)

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.

Bub, Jeffrey

2013-06-01

109

Quantum Correlations and the Measurement Problem

NASA Astrophysics Data System (ADS)

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.

Bub, Jeffrey

2014-10-01

110

Measuring roughness with dichromatic speckle correlation

NASA Astrophysics Data System (ADS)

The most established way to inspect machined surfaces is measuring with profilometers. Roughness measurements by these methods take plenty of time and an on-line integration in production facilities is not feasible due to different reasons. Over two decades ago, Goodman and Parry discovered the correlation between laser speckles of different light wavelengths and surface roughness. Since then several authors have been working on this topic. Nevertheless, industrial sensors based on the speckle correlation phenomenon measuring a roughness value are not available yet. In this article a new method is described, which is suitable for measuring the roughness of surfaces online under production conditions. The surface which is to be inspected is illuminated by a dichromatic laser beam. The scattered light is converted by lenses, and the far field speckles are detected in the Fourier plane of the lenses by a separate CCD-array for each wavelength. The CCD-data are captured by a frame grabber and stored for evaluation. A digital computer processes the data by calculating 2D-cross correlation functions of the two related speckle patterns for the different light wavelengths. The maximum values of the cross correlation function represents the correlation coefficient, which can then be translated into the root mean square of the surface heights of the workpiece. The main benefit of the method described is the feasibility of measuring roughness during processing. This is achieved by a time synchronous detection of speckle patterns of two different wavelengths, which are used to determine the roughness of a surface. The basic measuring time is determined by the shutter speed of the cameras, which is in the pilot project 1/10000 s. Therefore, only vibration frequencies above 1 kHz disturb the measuring results. A further reduction of the measuring time will be no major problem. Thus any realtime roughness measuring problem can be solved this way. This article describes the state of the art and the state of the experimental investigations measuring roughness by means of this new measuring process.

Peters, Joerg; Lehmann, Peter; Schoene, Armin

1996-09-01

111

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

Mayoral, E; Goicochea, A Gama

2014-10-30

112

Interfaces involving coexisting phases in condensed matter are essential in various examples of soft matter phenomena such as wetting, nucleation, morphology, phase separation kinetics, membranes, phase coexistence in nanomaterials, etc. Most analytical theories available use concepts derived from mean field theory which does not describe adequately these systems. Satisfactory numerical simulations for interfaces at atomistic to mesoscopic scales remains 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 mu = 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 the average critical exponent being nu = 0.67. Lastly, we show that the comparison of mu and nu for these binary mixtures constitutes the first test of Widom hyperscaling relation between these exponents in 3d, expressed as mu = nu (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.

E. Mayoral; A. Gama Goicochea

2014-10-07

113

Measuring magnetic correlations in nanoparticle assemblies

NASA Astrophysics Data System (ADS)

We illustrate how to extract correlations between magnetic moments in assemblies of nanoparticles from, e.g., electron holography data providing the combined knowledge of particle size distribution, inter-particle distances, and magnitude and orientation of each magnetic moment within a nanoparticle superstructure, We show, based on simulated data, how to build a radial/angular pair distribution function f(r,?) encoding the spatial and angular difference between every pair of magnetic moments. A scatter-plot of f(r,?) reveals the degree of structural and magnetic order present, and hence provides a measure of the strength and range of magnetic correlations.

Beleggia, M.; Frandsen, C.

2014-06-01

114

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.

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

115

The concept of the study was to find the correlation between the morphometry of the suprascapular notch and basic anthropometric measurements of the human scapula. The measurements of the human scapulae included: morphological length and width, maximal width and length projection of scapular spine, length of acromion, and maximal length of the coracoid process. The glenoid cavity was measured in two perpendicular directions to evaluate its width and length. The width-length scapular and glenoid cavity indexes were calculated for every bone. In addition to standard anthropometric measurements two other measurements were defined and evaluated for every suprascapular notch: maximal depth (MD) and superior transverse diameter (STD). The superior transverse suprascapular ligament was completely ossified in 7% of cases. Ten (11.6%) scapulae had a discrete notch. In the studied material, in 21 (24.4%) scapulae the MD was longer than the STD. Two (2.3%) scapulae had equal maximal depth and superior transverse diameter. In 47 (57.7%) scapulae the superior transverse diameter was longer than the maximal depth. There was no statistically significant difference between anthropometric measurements in the group with higher MD and the group with higher STD. The maximal depth of the suprascapular notch negatively correlated with the scapular width-length index. The maximal depth of the scapular notch correlated with the morphological length of the scapulae. PMID:21630232

Polguj, M; J?drzejewski, K S; Podgórski, M; Topol, M

2011-05-01

116

Bunch Length and Impedance Measurements at SPEAR3

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.

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

2011-11-02

117

Subpicometer Length Measurement Using Semiconductor Laser Tracking Frequency Gauge

NASA Technical Reports Server (NTRS)

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.

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

2011-01-01

118

Monitoring quantum transport: Backaction and measurement correlations

NASA Astrophysics Data System (ADS)

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.

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

2014-10-01

119

Background Various methods, including clinical and radiographic techniques, can be used to assess periodontal regeneration in interproximal areas. The goal of the present study was to compare the papilla length relative to the alveolar bone crest measured by clinical, intrasurgical, and radiographic techniques. Materials and methods The study sample included 250 interproximal papillae in 68 patients with generalized chronic periodontitis. The papilla length from the alveolar bone crest was measured clinically (as the actual papilla length, APL), intrasurgically (as the bone probing length, BPL), and radiographically (as the radiographic bone length, RBL). Measurements were standardized by using acrylic resin stents, XCP rinn, a paralleling technique, and/or a radiographic grid. Results The mean (± standard deviation) for RBL was 4.9 ± 0.8 mm, BPL was 5.1 ± 0.6 mm, and APL was 5.1 ± 0.6 mm. Correlations between RBL and APL and between BPL and APL were 0.918 and 0.943, respectively (both P < 0.01). Conclusions If the clinical recordings are appropriately standardized, then noninvasive radiographic methods can be used to evaluate the papilla length with good accuracy. PMID:24371382

Kolte, Rajashri A.; Kolte, Abhay P.; Ghodpage, Pallavi S.

2013-01-01

120

A tool for measuring the bending length in thin wires

NASA Astrophysics Data System (ADS)

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.

Lorenzini, M.; Cagnoli, G.; Cesarini, E.; Losurdo, G.; Martelli, F.; Piergiovanni, F.; Vetrano, F.; Viceré, A.

2013-03-01

121

High avidity antibodies to full-length VAR2CSA correlate with absence of placental malaria.

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 NH(4)SCN) 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

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

122

Estimating a Lagrangian Length Scale Using Measurements of CO2 in a Plant Canopy

NASA Astrophysics Data System (ADS)

Analytical Lagrangian equations capable of predicting concentration profiles from known source distributions offer the opportunity to calculate source/sink distributions through inverted forms of these equations. Inverse analytical Lagrangian equations provide a practical means of estimating source profiles using concentration and turbulence measurements. Uncertainty concerning estimates of the essentially immeasurable Lagrangian length scale ({{L}}), a key input, impedes the operational practicality of this method. The present study evaluates {{L}} within a corn canopy by using field measurements to constrain an analytical Lagrangian equation. Measurements of net CO2 flux, soil-to-atmosphere CO2 flux, and in-canopy profiles of CO2 concentration provided the information required to solve for {{L}} in a global optimization algorithm for 30-min time intervals. For days when the canopy was a strong CO2 sink, the optimization frequently located {{L}} profiles that follow a convex shape. A constrained optimization then fit the profile shape to a smooth sigmoidal equation. Inputting the optimized {{L}} profiles in the forward and inverse Lagrangian equations leads to strong correlations between measured and calculated concentrations and fluxes. Coefficients of the sigmoidal equation were specific to each 30-min period and did not scale with any measured variable. Plausible looking {{L}} profiles were associated with negative bulk Richardson number values. Once the canopy senesced, a simple eddy diffusivity profile sufficed to relate concentrations and sources in the analytical Lagrangian equations.

Brown, Shannon E.; Warland, Jon S.; Santos, Eduardo A.; Wagner-Riddle, Claudia; Staebler, Ralf; Wilton, Meaghan

2013-04-01

123

There is a controversy about the major determinants of the folding rate of small single-domain proteins. To shed light on this issue, we examined a possibility that the major determinants may change depending on temperature by conducting molecular dynamics simulations for 17 small single-domain proteins using an off-lattice Go-like model over a wide range of temperature. It was shown that the rank order of the folding rates is temperature dependent, which indicates that the major determinants are dependent on temperature. It was also found that as temperature is decreased, the correlation of the folding rate with the chain length becomes weakened, whereas that with the native topology becomes enhanced. Our simulation results, therefore, may provide a clue to reconcile the apparent controversy between the study by Plaxco based on experimental data and the previous theoretical and subsequent simulation studies: the former showed that the folding rate of two-state folders does not correlate with the chain length but correlates well with the native topology, whereas the latter showed that the folding rate does correlate with the chain length. We propose a possible scenario reconciling the controversy, explaining the reason why the correlation of the folding rate with the chain length became weakened and that with the native topology became enhanced with decreasing temperature. PMID:16089771

Nakamura, Hironori K; Takano, Mitsunori

2005-06-01

124

ERIC Educational Resources Information Center

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…

van den Boer, Madelon; de Jong, Peter F.; Haentjens-van Meeteren, Marleen M.

2013-01-01

125

Measuring the lens focal length by laser reflection-confocal technology.

A laser reflection-confocal focal-length measurement (LRCFM) is proposed for the high-accuracy measurement of lens focal length. LRCFM uses the peak points of confocal response curves to precisely identify the lens focus and vertex of the lens last surface. LRCFM then accurately measures the distance between the two positions to determine the lens focal length. LRCFM uses conic fitting, which significantly enhances measurement accuracy by inhibiting the influence of environmental disturbance and system noise on the measurement results. The experimental results indicate that LRCFM has a relative expanded uncertainty of less than 0.0015%. Compared with existing measurement methods, LRCFM has high accuracy and a concise structure. Thus, LRCFM is a feasible method for high-accuracy focal-length measurements. PMID:23736337

Yang, Jiamiao; Qiu, Lirong; Zhao, Weiqian; Shao, Rongjun; Li, Zhigang

2013-06-01

126

ATLAS-3 correlative measurement opportunities with UARS and surface observations

NASA Technical Reports Server (NTRS)

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.

Harrison, Edwin F.; Denn, Fred M.; Gibson, Gary G.

1995-01-01

127

On the dependence of the noise amplitude on the correlation length of inlet temperature University of Technology, Department of Nuclear Engineering, SE-412 96 GÃ¶teborg, Sweden b CEA, DEN, Cadarache effect Noise amplitude Moderator temperature fluctuation PWRs a b s t r a c t The dependence

DemaziÃ¨re, Christophe

128

agreement has been found between simulated backscatter and SAR images for incidence angles between ca. 20 in a semi-arid environment. The study compared backscattering coefficients simulated from the AIEM and retrieved from SAR imagery of a study site in Sardinia. Two treatments for correlation length were adopted

Boyer, Edmond

129

Quantifying precision of in situ length and weight measurements of fish

We estimated and compared errors in field-made (in situ) measurements of lengths and weights of fish. We made three measurements of length and weight on each of 33 common carp Cyprinus carpio, and on each of a total of 34 bluegills Lepomis macrochirus and black crappies Pomoxis nigromaculatus. Maximum total lengths of all fish were measured to the nearest 1 mm on a conventional measuring board. The bluegills and black crappies (85–282 mm maximum total length) were weighed to the nearest 1 g on a 1,000-g spring-loaded scale. The common carp (415–600 mm maximum total length) were weighed to the nearest 0.05 kg on a 20-kg spring-loaded scale. We present a statistical model for comparison of coefficients of variation of length (Cl ) and weight (Cw ). Expected Cl was near zero and constant across mean length, indicating that length can be measured with good precision in the field. Expected Cw decreased with increasing mean length, and was larger than expected Cl by 5.8 to over 100 times for the bluegills and black crappies, and by 3 to over 20 times for the common carp. Unrecognized in situ weighing errors bias the apparent content of unique information in weight, which is the information not explained by either length or measurement error. We recommend procedures to circumvent effects of weighing errors, including elimination of unnecessary weighing from routine monitoring programs. In situ weighing must be conducted with greater care than is common if the content of unique and nontrivial information in weight is to be correctly identified.

Gutreuter, S.; Krzoska, D.J.

1994-01-01

130

Probing Macroscopic Realism via Ramsey Correlation Measurements

NASA Astrophysics Data System (ADS)

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.

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

2014-05-01

131

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

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

2010-01-01

132

An inverse correlation between loop length and stability in a four-helix-bundle protein

Background: The loops in proteins are less well characterized than the secondary structural elements that they connect. We have used the four-helix- bundle protein Rop as a model system in which to explore the role of loop length in protein folding and stability. Results: A natural two-residue loop was replaced with a series of glycine linkers up to 10 residues

Athena D. Nagi; Lynne Regan

1997-01-01

133

The Length of a Pestle: A Class Exercise in Measurement and Statistical Analysis.

ERIC Educational Resources Information Center

Outlines the simple exercise of measuring the length of an object as a concrete paradigm of the entire process of making chemical measurements and treating the resulting data. Discusses the procedure, significant figures, measurement error, spurious data, rejection of results, precision and accuracy, and student responses. (TW)

O'Reilly, James E.

1986-01-01

134

GROUND VIBRATION AND COHERENCE LENGTH MEASUREMENTS FOR THE CLIC NANO-STABILIZATION STUDIES

GROUND VIBRATION AND COHERENCE LENGTH MEASUREMENTS FOR THE CLIC NANO-STABILIZATION STUDIES K requirements. For more than two decades, ground vibration measurements were made by different teams and at different CERN sites on the surface. The devices to measure nanometre sized vibrations, the analysis

Boyer, Edmond

135

ERIC Educational Resources Information Center

Prospective secondary mathematics teachers' pedagogical knowledge for teaching the estimation of length measurements was investigated by examining their personal benchmarks for measurement estimation. Benchmarks for measurement estimation are the meaningful representations of units that serve to increase one's understanding of…

Subramaniam, Karthigeyan

2014-01-01

136

The inner ear in the group of archosaurs (birds, crocodilians, and extinct dinosaurs) shows a high degree of structural similarity,\\u000a enabling predictions of their function in extinct species based on relationships among similar variables in living birds.\\u000a Behavioral audiograms and morphological data on the length of the auditory sensory epithelium (the basilar papilla) are available\\u000a for many avian species. By

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

2005-01-01

137

Research on the measurement technology of effective arm length of swing arm profilometer

NASA Astrophysics Data System (ADS)

When the swing arm profilometer(SAP) measuring the mirror, the effective arm length of SAP which haves an obvious influence on the measurement results of the mirror surface shape needs to be measured accurately. It requires the measurement uncertainty of the effective arm length to reach 10?m in order to meet the measurement requirements, in this paper, we present a kind of technology based on laser tracker to measure the effective arm length of SAP. When the swing arm rotates around the shaft axis of swing arm rotary stage, the probe and two laser tracker balls form three sections of circular arc around the shaft axis of swing arm rotary stage in space. Laser tracker tracks and measures the circular arcs of two laser tracker balls, the center coordinates of the circular plane of circular arc can be calculated by data processing. The linear equation that passes through the two center coordinates is the equation of the shaft axis of rotary stage, the vertical distance from the probe to the shaft axis of rotary stage which can be calculated refer to the equation from the point to the line is the effective arm length. After Matlab simulation, this measurement method can meet the measurement accuracy.

Chen, Lin; Jing, Hongwei; Wei, Zhongwei; Li, Jie; Cao, Xuedong

2014-09-01

138

This study aimed to investigate the correlations between the detection rate of mural coronary artery (MCA) by 128-slice CT and the MCA compression extent in systole with myocardial bridge (MB) length and thickness. A retrospective analysis was conducted for 580 patients receiving multislicespiral CT coronary angiography (MSCTCA). In addition, the MCA incidence rate and position were detected, and the MB length and thickness in the left anterior descending branch (LAD) and MCA compression extent in systole were measured to compare the differences between MB-MCA length and thickness among the mild, moderate and severe groups. A total of 140 cases of MB-MCA (24.14%) were involved in the study. Among them, 104 cases occurred in the middle segment of the LAD (74.3%), 16 cases (11.4%) occurred in the distal segment of the LAD, 8 cases (5.7%) occurred in the left circumflex-obtuse marginal branch (LCX-OM), 7 cases (5.0%) occurred in the first diagonal branch (1st D), 3 cases (2.1%) in the intermediate branch (M) and 2 cases (1.5%) occurred in the posterior descending branch of the right coronary artery (RCA-PD). The mean length of the MB in the LAD was 21.80±5.98 mm, the mean thickness was 2.15±0.74 mm and the mean compression extent was 38.5±19.6%. Among the different groups, there were no significant difference in MB length (P>0.05) but there were significant differences in MB thickness (P<0.05). In addition, the extent of MCA compression in systole was linearly and positively correlated with MB thickness (r=0.408, P<0.05) but was not correlated with MB length (r=0.076, P>0.05). 128-slice CT coronary angiography (SCTCA) is able to accurately detect MB-MCA and evaluate the correlations of MCA compression extent in systole with MB length and thickness which provides a basis for its clinical use. PMID:23408740

NIU, YU-JUN; ZHANG, XIANG-LIN; CAO, A-DAN; LENG, BING

2013-01-01

139

This study aimed to investigate the correlations between the detection rate of mural coronary artery (MCA) by 128-slice CT and the MCA compression extent in systole with myocardial bridge (MB) length and thickness. A retrospective analysis was conducted for 580 patients receiving multislicespiral CT coronary angiography (MSCTCA). In addition, the MCA incidence rate and position were detected, and the MB length and thickness in the left anterior descending branch (LAD) and MCA compression extent in systole were measured to compare the differences between MB-MCA length and thickness among the mild, moderate and severe groups. A total of 140 cases of MB-MCA (24.14%) were involved in the study. Among them, 104 cases occurred in the middle segment of the LAD (74.3%), 16 cases (11.4%) occurred in the distal segment of the LAD, 8 cases (5.7%) occurred in the left circumflex-obtuse marginal branch (LCX-OM), 7 cases (5.0%) occurred in the first diagonal branch (1st D), 3 cases (2.1%) in the intermediate branch (M) and 2 cases (1.5%) occurred in the posterior descending branch of the right coronary artery (RCA-PD). The mean length of the MB in the LAD was 21.80±5.98 mm, the mean thickness was 2.15±0.74 mm and the mean compression extent was 38.5±19.6%. Among the different groups, there were no significant difference in MB length (P>0.05) but there were significant differences in MB thickness (P<0.05). In addition, the extent of MCA compression in systole was linearly and positively correlated with MB thickness (r=0.408, P<0.05) but was not correlated with MB length (r=0.076, P>0.05). 128-slice CT coronary angiography (SCTCA) is able to accurately detect MB-MCA and evaluate the correlations of MCA compression extent in systole with MB length and thickness which provides a basis for its clinical use. PMID:23408740

Niu, Yu-Jun; Zhang, Xiang-Lin; Cao, A-Dan; Leng, Bing

2013-03-01

140

Slip Lengths on Hydrophobic and Hydrophilic Surfaces Measured by Quantum Dots

NASA Astrophysics Data System (ADS)

We report measurements of slip length obtained from tracking of individual quantum dots (QDs) within a few hundred nanometers of a surface using evanescent wave illumination. The measurements are obtained at different shear rates on a hydrophilic (quartz) and a hydrophobic (OTS-coated quartz) surface forming the wall of a rectangular microchannel nominally 300 micron in height. The shear rate is obtained independently by molecular tagging velocimetry (MTV) measurement of the in-situ velocity profile across the 300 micron height of the microchannel. Results indicate a larger slip length for the hydrophobic surface.

Koochesfahani, Manoochehr; Pouya, Shahram; Lum, Chee; Snee, Preston; Bawendi, Moungi; Nocera, Daniel

2006-11-01

141

We developed an on-line measurement system for the simultaneous measurement of the root-mean-square roughness and autocorrelation length which are the parameters of surface roughness. The measurement is based on the scattering theory of light on the rough surface. Computer simulation shows that the measurement range depends on the wavelength of the light source, and this is verified with the experiment.

Dalwoo Kim; Ki-Jang Oh; Choong-Soo Lim

1998-01-01

142

Effects of Text Length on Lexical Diversity Measures: Using Short Texts with Less than 200 Tokens

ERIC Educational Resources Information Center

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…

Koizumi, Rie; In'nami, Yo

2012-01-01

143

In this paper an algorithm is presented for estimating the maximum feasible penetration path length for neutron and synchrotron X-ray strain measurement instruments. This reflects the attenuation and scattering capability of the material under examination, the incident flux and detector arrangement, the likely background signal, the required strain measurement accuracy, the sampling volume and the diffracting geometry. Its validity and

Philip John Withers

2004-01-01

144

Rotation Curve Measurement using Cross-Correlation

Longslit spectroscopy is entering an era of increased spatial and spectral resolution and increased sample size. Improved instruments reveal complex velocity structure that cannot be described with a one-dimensional rotation curve, yet samples are too numerous to examine each galaxy in detail. Therefore, one goal of rotation curve measurement techniques is to flag cases in which the kinematic structure of the galaxy is more complex than a single-valued curve. We examine cross-correlation as a technique that is easily automated and works for low signal-to-noise spectra. We show that the technique yields well-defined errors which increase when the simple spectral model (template) is a poor match to the data, flagging those cases for later inspection. We compare the technique to the more traditional, parametric technique of simultaneous emission line fitting. When the line profile at a single slit position is non-Gaussian, the techniques disagree. For our model spectra with two well-separated velocity components...

Barton, E J; Kurtz, M J; Geller, M J; Barton, Elizabeth J.; Kannappan, Sheila J.; Kurtz, Michael J.; Geller, Margaret J.

2000-01-01

145

Rotation Curve Measurement using Cross-Correlation

Longslit spectroscopy is entering an era of increased spatial and spectral resolution and increased sample size. Improved instruments reveal complex velocity structure that cannot be described with a one-dimensional rotation curve, yet samples are too numerous to examine each galaxy in detail. Therefore, one goal of rotation curve measurement techniques is to flag cases in which the kinematic structure of the galaxy is more complex than a single-valued curve. We examine cross-correlation as a technique that is easily automated and works for low signal-to-noise spectra. We show that the technique yields well-defined errors which increase when the simple spectral model (template) is a poor match to the data, flagging those cases for later inspection. We compare the technique to the more traditional, parametric technique of simultaneous emission line fitting. When the line profile at a single slit position is non-Gaussian, the techniques disagree. For our model spectra with two well-separated velocity components, assigned velocities from the two techniques differ by up to ~52% of the velocity separation of the model components. However, careful use of the error statistics for either technique allows one to flag these non-Gaussian spectra.

Elizabeth J. Barton; Sheila J. Kannappan; Michael J. Kurtz; Margaret J. Geller

2000-06-20

146

Studies of telomeres and telomere biology often critically rely on the detection of telomeric DNA and measurements of the length of telomere repeats in either single cells or populations of cells. Several methods are available that provide this type of information and it is often not clear what method is most appropriate to address a specific research question. The major variables that need to be considered are the material that is or can be made available and the accuracy of measurements that is required. The goal of this review is to provide a comprehensive summary of the most commonly used methods and discuss the advantages and disadvantages of each. Methods that start with genomic DNA include telomere restriction fragment (TRF) length analysis, PCR amplification of telomere repeats relative to a single copy gene by Q-PCR or MMQPCR and single telomere length analysis (STELA), a PCR-based approach that accurately measures the full spectrum of telomere lengths from individual chromosomes. A different set of methods relies on fluorescent in situ hybridization (FISH) to detect telomere repeats in individual cells or chromosomes. By including essential calibration steps and appropriate controls these methods can be used to measure telomere repeat length or content in chromosomes and cells. Such methods include quantitative FISH (Q-FISH) and flow FISH which are based on digital microscopy and flow cytometry respectively. Here the basic principles of various telomere length measurement methods are described and their strengths and weaknesses are highlighted. Some recent developments in telomere length analysis are also discussed. The information in this review should facilitate the selection of the most suitable method to address specific research question about telomeres in either model organisms or human subjects. PMID:21663926

Aubert, Geraldine; Hills, Mark; Lansdorp, Peter M.

2012-01-01

147

parameters. We can in- terpret horizontal, but not vertical, correlation lengths and fractal dimensions from and fractal dimension interpretation from seismic data using variograms and power spectra Ken Mela and John N survey and analyzed it for the statistical parameters of correlation length and fractal dimension

148

Measurements of Correlation-Enhanced Collision Rates

modified by an equilibrium correlation factor g(), depending only on the correla- tion parameter e2 /a and temperature T, giving thermal ve- locity v (T/m)1/2, distance of closest approach b e2/T, and interparticle the nuclear reaction rate in dense correlated plasmas such as in giant planet interiors, brown dwarfs

California at San Diego, University of

149

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

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.

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

2006-05-01

150

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

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. 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. 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.

Evtushenko, P.; Coleman, J.; Jordan, K.; Klopf, J. Michael; Neil, G.; Williams, G. P. [Thomas Jefferson National Accelerator Facility, 12000 Jefferson Avenue, Newport News, VA 23606 (United States)

2006-11-20

151

NASA Astrophysics Data System (ADS)

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.

Kabi, S.; Ghosh, A.

2012-10-01

152

Measurement of bunch length in Indus-1 storage ring using fast photodiode

NASA Astrophysics Data System (ADS)

The length of electron bunches in a storage ring is an important parameter for both synchrotron radiation users and accelerator physicists. Several methods are used for measurements of bunch length using electronic and optical instruments. We have measured temporal profile of synchrotron radiation emitted from dipole magnet of Indus-1 by using fast photodiode. Bunch length is calculated by assuming gaussian profile for the particles inside bunch. The results show that bunch length is increasing with the decrease of gap voltage of RF cavity. These measurements were carried out at low beam current; at high voltage results are in close agreement with theory and the values estimated using ZAP code. In the second experiment, the results show that bunch length increases with the increase of beam current inside the bunch, and above threshold current, it follows Chao-Gareyte scaling law. The longitudinal broadband impedance for Indus-1 SRS was estimated using Keil-Schnell criterion and results were compared with theoretical estimated values using ZAP code.

Garg, Akash Deep; Nathwani, R. K.; Holikatti, A. C.; Kumar Karnewar, Akhilesh; Tyagi, Y.; Yadav, S.; Puntambekar, T. A.; Navathe, C. P.

2012-11-01

153

Subpicosecond beam length measurement study based on the TM010 mode

NASA Astrophysics Data System (ADS)

This article discusses a beam length measurement technique based on the TM010 modes of two cavities in frequency domain. Since the TM010 pickup monitor has a much better signal-to-noise ratio (SNR) than the other monitors, it can improve the measuring range and resolution limit of the beam length measurement in the frequency domain to achieve the real-time measurement of the pulse duration of the order of 1 ps or less with the resolution of about 10 fs. The root-mean-square length of a beam—which does not necessarily have a Gaussian distribution—can be obtained by choosing the working frequency of the cavity to be much less than the critical frequency of the beam. The modeling and analysis of the above theory were also made simultaneously. The resulting resolution was about 100 fs when the step size was chosen to be 200 fs in this simulation after the higher order mode coupling effect was eliminated and the beam offset was corrected by using the Bessel function. An efficient algorithm was also provided in case the measurement system would achieve the SNR of 112 dB when there could be some issue in signal processing. This algorithm can still provide the length result with the resolution of 3.5?m for a beam duration of 0.1 ps when the SNR of the difference signal is as low as 10 dB.

Chen, Zhichu; Zhou, Weimin; Leng, Yongbin; Yu, Luyang; Yuan, Renxian

2013-07-01

154

The spin-dependent nd scattering length - a proposed high-accuracy measurement

The understanding of few-nucleon systems at low energies is essential, e.g. for accurate predictions of element abundances in big-bang and stellar fusion. Novel effective field theories, taking only nucleons, or nucleons and pions as explicit degrees of freedom, provide a systematic approach, permitting an estimate of theoretical uncertainties. Basic constants parameterising the short range physics are derived from only a handful of experimental values. The doublet neutron scattering length a_2 of the deuteron is particularly sensitive to a three-nucleon contact interaction, but experimentally known with only 6% accuracy. It can be deduced from the two experimentally accessible parameters of the nd scattering length. We plan to measure the poorly known "incoherent" nd scattering length a_{i,d} with 10^{-3} accuracy, using a Ramsey apparatus for pseudomagnetic precession with a cold polarised neutron beam at PSI. A polarised target containing both deuterons and protons will permit a measurement relative to the...

Van den Brandt, B; Hautle, P; Kohlbrecher, J; Konter, J A; Zimmer, O

2004-01-01

155

An algorithm for retrieving the first two moments of the photon path length probability density function for both the oxygen A-band and the 0.820 mum water vapor band from measurements of the second generation Rotating Shadowband Spectrometer (RSS) is developed and applied to data from the Atmospheric Radiation Measurements (ARM) Program Southern Great Plains (SGP) site. In the algorithm, solar

Qilong Min; Eugene E. Clothiaux

2003-01-01

156

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.

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

157

Aims: This study was undertaken to establish correlation between intracholedochal cystic pressure (ICCP) with biochemical changes in bile, liver histology, cyst wall histology, length of common channel, and cyst volume. Materials and Methods: In this cross-sectional study, ICCP was measured after surgical access before any mobilization by direct cyst cannulation. Bile was then aspirated for biochemical estimation (bilirubin, amylase, lipase, pH, and electrolytes). Common channel length and cyst volume were determined by preoperative magnetic resonance cholangiopancreatography (MRCP). Liver histology was assessed under parenchymal, bile duct, and portal parameters. Cyst wall was examined for ulceration, inflammation, fibrosis, and metaplasia. Results: ICCP was recorded in 31 patients; mean and median ICCP were 15.64 and 14 mmHg, respectively (range = 6-30 mmHg). Cases with median ICCP < 14 had median cyst volume of 48 cc (range = 36-115) and amylase 2052 IU/L (range = 190-5052) whereas those with ICCP ? 15 had volume of 20 cc (range = 10-100) (P = 0.004) and amylase 36 IU/L (range = 0-2806) (P = 0.0004) suggesting inverse correlation. No significant correlation was found with bilirubin and electrolytes. ICCP directly correlated with parenchymal changes like hepatocellular damage (P = 0.002) and cholestasis (P = 0.001). It also correlated with bile duct changes. ICCP inversely correlated with cyst wall changes (P = 0.003, 0.0001, 0.023, 0.0013, respectively). High pressure cysts had normal pancreaticobiliary junction. Conclusion: High-pressure cysts tend to be smaller but have more severe backpressure changes in liver parenchyma. Low-pressure cysts have high volume and higher levels of amylase and lipase and therefore have more severe cyst wall changes. PMID:24604978

Sharma, Nitin; Bhatnagar, Veereshwar; Srinivas, M.; Agarwala, Sandeep; Singh, Manoj Kumar; Sharma, Raju

2014-01-01

158

NASA Astrophysics Data System (ADS)

One of the most accurate methods for measuring the compressibility of liquids is resonance measurement of sound velocity in a fixed-length interferometer. This method combines high sensitivity, accuracy, and small sample volume of the test liquid. The measuring principle is to study the resonance properties of a composite resonator that contains a test liquid sample. Ealier, the phase-locked loop (PLL) scheme was used for this. In this paper, we propose an alternative measurement scheme based on digital analysis of harmonic signals, describe the implementation of this scheme using commercially available data acquisition modules, and give examples of test measurements with accuracy evaluations of the results.

Astashev, M. E.; Belosludtsev, K. N.; Kharakoz, D. P.

2014-05-01

159

The Effect of Wire Length and Separation on X-Array Hot-Wire Anemometer Measurements

This paper describes a simple method for the calculation of errors due to the finite length and separation of X-array hot-wire anemometers. Results of computations for a typical wire array are presented for total and spectral turbulence measurements. Although the actual errors are slightly underestimated due to the simplifying assumptions used to reduce the computational effort, it is found that

Klaus Bremhorst

1972-01-01

160

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

Rose, Michael R.

161

Measurement of Optical Path Length for Cerebral Near-Infrared Spectroscopy in Newborn Infants

The time taken for an extremely short pulse of near-infrared laser light to traverse the heads of 6 preterm infants was measured after death. The values obtained were used to calculate a differential path length factor (DPF), defined as the mean distance travelled by the photons divided by the distance between the points where light entered and left the head.

J. S. Wyatt; M. Cope; D. T. Delpy; P. van der Zee; S. R. Arridge; A. D. Edwards; E. O. R. Reynolds

1990-01-01

162

Diffusion length measurements in solar cells: An analysis and comparison of techniques

NASA Technical Reports Server (NTRS)

A brief review of the major techniques for measuring minority carrier diffusion lengths in solar cells is given. Emphasis is placed on comparing limits of applicability for each method, especially as applied to silicon cells or to gallium arsenide cells, including the effects of radiation damage.

Woollam, J. A.; Khan, A. A.; Soukup, R. J.; Hermann, A. M.

1982-01-01

163

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

Acoustic method for measuring the sound speed of gases over small path lengths J. S. Olfert,a M. D, Canada Received 9 February 2007; accepted 8 April 2007; published online 9 May 2007 Acoustic "phase shift this method the discrete acoustic wave and phase detection DAWPD method. Experimental results show

164

NASA Astrophysics Data System (ADS)

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.

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

2014-06-01

165

The attenuation length measuring device was constructed by using oscilloscope and LabVIEW for signal acquisition and processing. The performance of the device has been tested with 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 gadolinium-loaded liquid scintillator (Gd-LS) was measured as 15.10 plus or minus 0.35 m where Gd-LS was heavily used in 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.

L. Gao; BX. Yu; YY. Ding; L. Zhou; LJ. Wen; YG. Xie; ZG. Wang; X. Cai; XL. Sun; J. Fang; Z. Xue; AW. Zhang; QW. LÜ; LJ. Sun; YS. Ge; YB. Liu; SL. Niu; T. Hu; J. Cao; JG. LÜ

2013-05-07

166

Focal length measurement of a microlens-array by grating shearing interferometry.

Based on grating shearing interferometry, a simple technique is introduced for focal length measurements of a microlens-array (MLA). The measurement system is composed of a He-Ne laser, condenser, collimator, the MLA under testing, a Ronchi grating, and CCD sensor. The plane wavefront from the collimator is transformed to a spherical wavefront by the MLA, while the curvature center is at the focus. Interference stripes appear at the overlap between the zero-order and first-order diffractive patterns of the grating and are detected by the CCD sensor. By analyzing the period change of stripes, the focal length is determined after the defocus of the grating is calculated. To validate the feasibility, an experiment is performed. The measurement uncertainty is discussed and measurement accuracy was determined to be 2%. PMID:25322367

Zhu, Xianchang; Hu, Song; Zhao, Lixin

2014-10-10

167

Measurements of photon scattering lengths in scintillator and a test of the linearity of light of light yield versus electron energy and measurements made to determine the scattering length of photons, particularly the scattering length of photons in the scintillator and the dependence of light yield on electron

Washington at Seattle, University of - Department of Physics, Electroweak Interaction Research Group

168

Measurement of leg length inequalities by Micro-Dose digital radiographs

New technology may, in time, supersede orthoroentgenograms for measurement of leg length inequalities. Micro-Dose digital scans are a new form of radiographs that require 1% of the radiation needed to produce conventional images. The Micro-Dose digital scan and orthoroentgenogram were compared in a clinical series of 25 children and in cadaveric femoral measurements. The accuracy of digital radiographs for this application was confirmed.

Altongy, J.F.; Harcke, H.T.; Bowen, J.R.

1987-05-01

169

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

Gutierrez-Rodrigues, Fernanda; Santana-Lemos, Bárbara A.; Scheucher, Priscila S.; Alves-Paiva, Raquel M.; Calado, Rodrigo T.

2014-01-01

170

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

Gutierrez-Rodrigues, Fernanda; Santana-Lemos, Bárbara A; Scheucher, Priscila S; Alves-Paiva, Raquel M; Calado, Rodrigo T

2014-01-01

171

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

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.

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

2012-09-05

172

Photoelectron track length distributions measured in a negative ion time projection chamber

We report photoelectron track length distributions between 3 and 8 keV in gas mixtures of Ne+CO2+CH3NO2 (260:80:10 Torr) and CO2+CH3NO2 (197.5: 15 Torr). The measurements were made using a negative ion time projection chamber (NITPC) at the National Synchrotron Light Source (NSLS) at the Brookhaven National Laboratory (BNL). We report the first quantitative analysis of photoelectron track length distributions in a gas. The distribution of track lengths at a given energy is best fit by a lognormal distribution. A powerlaw distribution of the form, f(E)=a(E/Eo)n, is found to fit the relationship between mean track length and energy. We find n=1.29 +/- 0.07 for Ne+CO2+CH3NO2 and n=1.20 +/- 0.09 for CO2+CH3NO2. Understanding the distribution of photoelectron track lengths in proportional counter gases is important for optimizing the pixel size and the dimensions of the active region in electron-drift time projection chambers (TPCs) and NITPC X-ray polarimeters.

Prieskorn, Z R; Kaaret, P E; Black, J K

2014-01-01

173

TRINAT: measuring ?-decay correlations with laser-trapped atoms

NASA Astrophysics Data System (ADS)

TRIUMF's neutral atom trap for ? decay (TRINAT) has been used to measure the most accurate ?- ? correlation. Plans include improving that measurement, and also carrying out a full program of spin-polarized ? decay correlation measurements complementary to the decay of the neutron

Behr, J. A.; Gorelov, A.; Jackson, K. P.; Pearson, M. R.; Anholm, M.; Kong, T.; Behling, R. S.; Fenker, B.; Melconian, D.; Ashery, D.; Gwinner, G.

2014-01-01

174

Correlating DSC and X-Ray Measurements Of Crystallinity

NASA Technical Reports Server (NTRS)

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.

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

1991-01-01

175

Vascular measurements correlate with estrogen receptor status

Background Breast carcinoma can be classified as either Estrogen Receptor (ER) positive or negative by immunohistochemical phenotyping, although ER expression may vary from 1 to 100% of malignant cells within an ER?+?tumor. This is similar to genetic variability observed in other tumor types and is generally viewed as a consequence of intratumoral evolution driven by random genetic mutations. Here we view cellular evolution within tumors as a classical Darwinian system in which variations in molecular properties represent predictable adaptations to spatially heterogeneous environmental selection forces. We hypothesize that ER expression is a successful adaptive strategy only if estrogen is present in the microenvironment. Since the dominant source of estrogen is blood flow, we hypothesized that, in general, intratumoral regions with higher blood flow would contain larger numbers of ER?+?cells when compared to areas of low blood flow and in turn necrosis. Methods This study used digital pathology whole slide image acquisition and advanced image analysis algorithms. We examined the spatial distribution of ER?+?and ER- cells, vascular density, vessel area, and tissue necrosis within histological sections of 24 breast cancer specimens. These data were correlated with the patients ER status and molecular pathology report findings. Results ANOVA analyses revealed a strong correlation between vascular area and ER expression and between high fractional necrosis and absent ER expression (R2?=?39%; p?correlate with tumor grade or size. Conclusion We conclude that ER expression can be understood as a Darwinian process and linked to variations in estrogen delivery by temporal and spatial heterogeneity in blood flow. This correlation suggests strategies to promote intratumoral blood flow or a cyclic introduction of estrogen in the treatment schedule could be explored as a counter-intuitive approach to increase the efficacy of anti-estrogen drugs. PMID:24755315

2014-01-01

176

Roughness Length as a Measure of the Effects of a Vegetative Windbreak

NASA Astrophysics Data System (ADS)

Vegetative windbreaks are often used as barriers to block the dispersion of particulate matter, particularly around agricultural facilities. Windbreaks and narrow forest strips alter the wind pattern and affect dispersion of particles and aerosols that are carried across. Our observations during two field campaigns, conducted near animal feeding lots where large flumes of dust are advected across edge-of-field windbreaks, suggest that sensible heat flux greatly affects the interaction between the flow and the windbreak. We used measurements at multiple heights upwind and downwind of the windbreak to calculate the background roughness length and the effective roughness length of the windbreak. While the flow is not fully adjusted at the wake of the windbreak, we use measurements at different times of the day as a sensitivity analysis to the strength of the buoyancy term within the theoretical surface similarity equation that includes the effects of the wind break. Clearly, calculated roughness length downwind of the windbreak is much greater than upwind of the windbreak, but as SHF increases, the difference in roughness length across the windbreak decreases indicating a decrease in the overall effect of the windbreak on flow. Our findings indicate that as SHF increases, windbreaks may not be able to play much of a role in affecting the dispersion of particulate matter, as the overall effects of windbreaks diminish.

Kenny, W.; Maurer, K.; Bohrer, G.

2012-12-01

177

The spin-dependent nd scattering length - a proposed high-accuracy measurement

The understanding of few-nucleon systems at low energies is essential, e.g. for accurate predictions of element abundances in big-bang and stellar fusion. Novel effective field theories, taking only nucleons, or nucleons and pions as explicit degrees of freedom, provide a systematic approach, permitting an estimate of theoretical uncertainties. Basic constants parameterising the short range physics are derived from only a handful of experimental values. The doublet neutron scattering length a_2 of the deuteron is particularly sensitive to a three-nucleon contact interaction, but experimentally known with only 6% accuracy. It can be deduced from the two experimentally accessible parameters of the nd scattering length. We plan to measure the poorly known "incoherent" nd scattering length a_{i,d} with 10^{-3} accuracy, using a Ramsey apparatus for pseudomagnetic precession with a cold polarised neutron beam at PSI. A polarised target containing both deuterons and protons will permit a measurement relative to the incoherent np scattering length, which is know experimentally with an accuracy of 2.4\\times 10^{-4}.

B. van den Brandt; H. W. Griesshammer; P. Hautle; J. Kohlbrecher; J. A. Konter; O. Zimmer

2004-01-23

178

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

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

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

2013-01-01

179

Long focal-length measurement using divergent beam and two gratings of different periods.

A new accurate method for long focal-length measurement based on Talbot interferometry is proposed. A divergent beam and two Ronchi gratings of different periods are employed, as the alternative of the collimated beam and two identical gratings, to achieve higher measurement accuracy. Moreover, with divergent beam, lenses of large aperture can be easily measured without scanning, which is required when it comes to traditional collimated beam. Numerical analysis and experiments were carried out. The results demonstrate the proposed method features remarkably high accuracy and repeatability. PMID:25402033

Luo, Jia; Bai, Jian; Zhang, Jinchun; Hou, Changlun; Wang, Kaiwei; Hou, Xiyun

2014-11-17

180

Spectral-domain measurement of beat length in polarization-maintaining fibers

NASA Astrophysics Data System (ADS)

A spectral white-light interferometric (WLI) method for measuring the beat length in high birefringence polarization-maintaining fibers (PMFs) is presented. The approach is based on the stress-induced polarization mode coupling between the two polarization eigenmodes and utilizes their spectral interferograms. By recording the spectral interferograms before and after the displacement of the force, the beat length can be obtained by the displacement of the force and the relative phase variation retrieved from the two spectral interferograms. According to the principle that the phase difference between adjacent fringes peaks is 2?, the phase can be retrieved from the interferograms simply. The factors affecting the measurement precision of this method and the main source of errors are investigated in detail.

Chen, Xinwei; Liu, Tiegen; Zhang, Hongxia; Lu, Wei; Huang, Lichang; Cheng, Liang; Zhang, Yimo

2012-12-01

181

We explain why in our view an extrapolation from small lattices containing only perturbative information cannot be sufficient to determine nonperturbative qunatities and therefore cannot lead to a trustworthy determination of the correlation length.

A. Patrascioiu; E. Seiler

1995-02-24

182

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

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.

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

183

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

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.

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

2011-12-21

184

Ultrasonic measurement of stress in railroad wheels and in long lengths of welded rail

NASA Technical Reports Server (NTRS)

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.

Clotfelter, W. N.; Risch, E. R.

1974-01-01

185

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

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.

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

186

Measuring correlations between non-stationary series with DCCA coefficient

NASA Astrophysics Data System (ADS)

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.

Kristoufek, Ladislav

2014-05-01

187

Correlation lidar methods of wind-velocity measurement

The work presents the basic principles for the design of correlation lidar instruments for wind measurement. The space-time structure of aerosol inhomogeneities is studied theoretically and experimentally, and requirements on the parameters of correlation lidars are given. The appropriate signal-processing algorithms are examined, and different types of measurement errors are analyzed. Attention is given to examples of the application of

G. G. Matvienko; G. O. Zadde; E. S. Ferdinandov; I. N. Kolev; R. P. Avramova

1985-01-01

188

Experimental techniques have been developed to directly measure the concentration of fluorine atoms, the gain length and the small signal gain in a hydrogen fluoride 5 cm slit nozzle laser. A gas phase titration technique was utilized to measure the fluorine atom concentration using HCl as the titrant. The gain length was measured using a pitot probe to locate the

Charles F Wisniewski; Kevin B Hewett; Gerald C Manke II; C Randall Truman; Gordon D Hager

2003-01-01

189

Standard Length versus Total Length

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.

William F. Royce

1942-01-01

190

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

NASA Astrophysics Data System (ADS)

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

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

2012-09-01

191

Measurement of the axial eye length by wavelength-tuning interferometry

NASA Astrophysics Data System (ADS)

An alternative approach to measure intraocular optical distances in vivo is wavelength tuning interferometry. The principle of this technique is that every wavelength shift of a laser diode is associated with a phase shift of the waves reflected at the cornea and the retina. This results in a change of the interference order of the fringe system that will occur when the two wavefronts interfere. By Fourier transform of the intensity data, we cannot only measure the axial eye length but also other intraocular distances. In our approach we used an external cavity, single mode laser diode at a center wavelength of 780 nm which is tunable over 15 nm. First measurements were carried out in a model eye using the mode hop free tuning range of 9 nm, at the maximum tuning rate of 0.33 nm/s. The precision we obtained for the axial eye length was 0.04 mm. The large tuning range cannot be used of in vivo measurements because of the slow scanning rate of 0.33 nm/s. With this scanning rate the signal frequency corresponding to the axial eye length is on the order of 30 Hz. This is within the frequency range of the intensity modulations caused by fundus pulsations due to the heart beat and can therefore not be separated from them. The in vivo measurements have to be performed by tuning the wavelength of the laser with a piezoelectric transducer to achieve signal frequencies in the kHz range. Since the tuning range in this case in only 0.18 nm the resolution is about 50 times worse than that achieved in the model eye.

Lexer, Franz; Hitzenberger, Christoph K.; Kulhavy, Manfred; Fercher, Adolf F.

1996-12-01

192

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

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

193

NASA Astrophysics Data System (ADS)

We have investigated the ultracold interspecies scattering properties of metastable triplet He and Rb. We performed state-of-the-art ab initio calculations of the relevant interaction potential, and measured the interspecies elastic cross section for an ultracold mixture of metastable triplet He4 and Rb87 in a quadrupole magnetic trap at a temperature of 0.5 mK. Our combined theoretical and experimental study gives an interspecies scattering length a4+87=+17-4+1a0, which prior to this work was unknown. More general, our work shows the possibility of obtaining accurate scattering lengths using ab initio calculations for a system containing a heavy, many-electron atom, such as Rb.

Knoop, S.; ?uchowski, P. S.; KÈ©dziera, D.; Mentel, ?.; Puchalski, M.; Mishra, H. P.; Flores, A. S.; Vassen, W.

2014-08-01

194

Measurement and Correlation of Ice Accretion Roughness

NASA Technical Reports Server (NTRS)

Measurements were taken of the roughness characteristics of ice accreted on NACA 0012 airfoils in the NASA Glenn Icing Research Tunnel (IRT). Tests were conducted with size scaled, using models with chords of 26.7, 53.3, and 80.0 cm, and with liquid-water content scaled, both according to previously-tested scaling methods. The width of the smooth zone which forms on either side of the leading edge of the airfoil and the diameter of the roughness elements are presented in non-dimensional form as functions of the accumulation parameter. The smooth-zone width was found to decrease with increasing accumulation parameter. The roughness-element diameter increased with accumulation parameter until a plateau was reached. This maximum diameter was about 0.06 times twice the model leading-edge radius. Neither smooth-zone width nor element diameter were affected by a change in freezing fraction from 0.2 to 0.4. Both roughness characteristics appeared to scale with model size and with liquid-water content.

Anderson, David N.; Hentschel, Daniel B.; Ruff, Gary A.

2003-01-01

195

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

Saharkhiz, Nasrin; Nikbakht, Roshan; Salehpour, Saghar

2014-01-01

196

NASA Astrophysics Data System (ADS)

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.

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

2012-05-01

197

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{sup '} rms normalized emittance values smaller than 0.2{pi} 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.

Miracoli, R. [ESS Bilbao, Vizcaya (Spain); INFN - Laboratori Nazionali del Sud, via S. Sofia 62, 95123 Catania (Italy); Gammino, S.; Celona, L.; Mascali, D. [INFN - Laboratori Nazionali del Sud, via S. Sofia 62, 95123 Catania (Italy); Castro, G. [INFN - Laboratori Nazionali del Sud, via S. Sofia 62, 95123 Catania (Italy); Universita degli studi di Catania, Dipartimento di Fisica e Astronomia, V. S. Sofia 64, 95123 Catania (Italy); Gobin, R.; Delferriere, O.; Adroit, G.; Senee, F. [CEA-IRFU, Gif sur Yvette Cedex (France); Ciavola, G. [INFN - Laboratori Nazionali del Sud, via S. Sofia 62, 95123 Catania (Italy); CNAO, Str. Pr. Campeggi, Pavia (Italy)

2012-05-15

198

Measurement and analysis of two- and three-particle correlations

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.

M. Csanad

2005-09-30

199

This work addresses the difficulties in the measurements of the nonlinear medium parameter B/A and presents a modification of the finite amplitude method (FAM), one of the accepted procedures to determine this parameter. The modification is based on iterative, hybrid approach and entails the use of the versatile and comprehensive model to predict distortion of the pressure-time waveform and its subsequent comparison with the one experimentally determined. The measured p-t waveform contained at least 18 harmonics generated by 2.25 MHz, 29 mm effective diameter, single element, focused PZT source (f-number 3.5) and was recorded by Sonora membrane hydrophone calibrated in the frequency range 1-40 MHz. The hydrophone was positioned coaxially at the distal end of the specially designed, two-section assembly comprising of one, fixed length (60mm), water-filled cylindrical container and the second, variable length (60-120 mm) container that was filled with unknown medium. The details of the measurement chamber are described and the reasons for this specific design are analyzed. The data were collected with the variable length chamber filled with 1.3-butanediol, which was used as a close approximation of tissue mimicking phantom. The results obtained provide evidence that a novel combination of the FAM with the semi-empirical nonlinear propagation model based on the hyperbolic operator is capable of reducing the overall uncertainty of the B/A measurements as compared to those reported in the literature. The overall uncertainty of the method reported here was determined to be ±2%, which enhances the confidence in the numerical values of B/A measured for different, clinically relevant media. Optimization of the approach is also discussed and it is shown that it involves an iterative procedure that entails a careful selection of the acoustic source and its geometry and the axial distance over which the measurements need to be performed. The optimization also depends critically on the experimental determination of the source surface pressure amplitude. PMID:21722932

Kujawska, Tamara; Nowicki, Andrzej; Lewin, Peter A

2011-12-01

200

Measurement of s-wave scattering lengths in a two-component Bose-Einstein condensate

NASA Astrophysics Data System (ADS)

We use collective oscillations of a two-component Bose-Einstein condensate (2CBEC) of 87Rb atoms prepared in the internal states |1>?|F=1,mF=-1> and |2>?|F=2,mF=1> for the precision measurement of the interspecies scattering length a12 with a relative uncertainty of 1.6×10-4. We show that in a cigar-shaped trap the three-dimensional (3D) dynamics of a component with a small relative population can be conveniently described by a one-dimensional (1D) Schrödinger equation for an effective harmonic oscillator. The frequency of the collective oscillations is defined by the axial trap frequency and the ratio a12/a11, where a11 is the intraspecies scattering length of a highly populated component 1 and is largely decoupled from the scattering length a22, the total atom number and loss terms. By fitting numerical simulations of the coupled Gross-Pitaevskii equations to the recorded temporal evolution of the axial width we obtain the value a12=98.006(16)a0, where a0 is the Bohr radius. Our reported value is in reasonable agreement with the theoretical prediction a12=98.13(10)a0 but deviates significantly from the previously measured value a12=97.66a0 [Phys. Rev. Lett.PRLTAO0031-900710.1103/PhysRevLett.99.190402 99, 190402 (2007)] which is commonly used in the characterization of spin dynamics in degenerate 87Rb atoms. Using Ramsey interferometry of the 2CBEC we measure the scattering length a22=95.44(7)a0 which also deviates from the previously reported value a22=95.0a0 [Phys. Rev. Lett.PRLTAO0031-900710.1103/PhysRevLett.99.190402 99, 190402 (2007)]. We characterize two-body losses for component 2 and obtain the loss coefficients ?12=1.51(18)×10-14cm3/s and ?22=8.1(3)×10-14cm3/s.

Egorov, M.; Opanchuk, B.; Drummond, P.; Hall, B. V.; Hannaford, P.; Sidorov, A. I.

2013-05-01

201

This study evaluated segmental measurement techniques for predicting immediate post-deployment intraluminal tracheal stent length in dogs with naturally occurring tracheal collapse. Radiographs of 12 client-owned dogs that underwent intraluminal tracheal stent placement were retrospectively reviewed. Tracheal lengths were divided into 1, 2, 3, or 4 equal segments. Stent lengths were predicted using the widest dorsoventral height of each segment, with and without the addition of 10%, and an accompanying foreshortening chart. Techniques were compared for intra- and inter-observer reliability, and post-deployment stent length predictability. There was good to high intra- and inter-observer reliability for all segmental measurements; median intra-class correlation coefficients were 0.98 and 0.92, respectively. Measuring 2 segments without the addition of 10% to the widths was significantly more accurate in predicting immediate post-deployment stent length in terms of percent (P = 0.03) and absolute difference (P = 0.02). Segmental measuring techniques are repeatable amongst observers and may help guide stent selection. PMID:24790228

Monaco, Thomas A.; Taylor, Jim A.; Langenbach, Anke; Gordon, Sebastian; Vance, Eric

2014-01-01

202

NASA Technical Reports Server (NTRS)

Diffusion lengths and surface recombination velocities were measured in GaAs diodes and InP finished solar cells. The basic technique used was charge collection microscopy, also known as electron beam induced current (EBIC). The normalized currents and distances from the pn junction were read directly from the calibrated curves obtained while using the line-scan mode in an SEM. These values were then equated to integral and infinite series expressions resulting from the solution of the diffusion equation with both extended-generation and point-generation functions. This expands previous work by examining both thin and thick samples. The surface recombination velocity was either treated as an unknown in a system of two equations or measured directly using low e(-) beam accelerating voltages. These techniques give accurate results by accounting for the effects of surface recombination and the finite size of the generation volume.

Leon, R. P.

1987-01-01

203

NASA Technical Reports Server (NTRS)

Diffusion lengths and surface recombination velocities were measured in GaAs diodes and InP finished solar cells. The basic techniques used was charge collection microscopy also known as electron beam induced current (EBIC). The normalized currents and distances from the pn junction were read directly from the calibrated curves obtained while using the line scan mode in an SEM. These values were then equated to integral and infinite series expressions resulting from the solution of the diffusion equation with both extended generation and point generation functions. This expands previous work by examining both thin and thick samples. The surface recombination velocity was either treated as an unknown in a system of two equations, or measured directly using low e(-) beam accelerating voltages. These techniques give accurate results by accounting for the effects of surface recombination and the finite size of the generation volume.

Leon, R. P.

1987-01-01

204

Measuring the superconducting coherence length in thin films using a two-coil experiment

NASA Astrophysics Data System (ADS)

We present measurements of the superconducting coherence length ? in thin (d?100-Å) films of MoGe and Nb using a combination of linear and nonlinear mutual inductance techniques. As the alternating current in the drive coil is increased at a fixed temperature, we see a crossover from linear to nonlinear coupling to the pickup coil, consistent with the unbinding of vortex-antivortex pairs as the peak pair momentum nears ?/? and the unbinding barrier vanishes. We compare measurements of ? performed by this mutual inductance technique to values determined from the films' upper critical fields, thereby confirming the applicability of a recent calculation of the upper limit on a vortex-free state in our experiment.

Draskovic, John; Lemberger, Thomas R.; Peters, Brian; Yang, Fengyuan; Ku, Jaseung; Bezryadin, Alexey; Wang, Song

2013-10-01

205

NASA Technical Reports Server (NTRS)

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.

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

1976-01-01

206

Measurement of femtosecond electron pulse length and the temporal broadening due to space charge.

The temporal width of ultrashort electron pulses as a function of beam intensity was measured on the femtosecond time scale with a customized streak camera. The results show that the temporal profile of an electron pulse is Gaussian at low beam intensity and progressively evolves to a top-hat shape due to space charge broadening as the beam intensity increases. The strong correlation between the pulse width and beam intensity observed in our streaking measurements agrees very well with the mean-field calculation and supports the main conclusion of previous theoretical studies that the space charge broadening plays a determinant role. PMID:19191442

Wang, Xuan; Nie, Shouhua; Park, Hyuk; Li, Junjie; Clinite, Rick; Li, Renkai; Wang, Xijie; Cao, Jianming

2009-01-01

207

Simple Estimation of Hidden Correlation in Repeated Measures

In medical and social studies, it is often desirable to assess the correlation between characteristics of interest that are not directly observable. In such cases, repeated measures are often available, but the correlation between the repeated measures is not the same as that between the true characteristics that are confounded with the measurement errors. The latter is called the hidden correlation. Previously, the problem has been treated by assuming prior knowledge about the measurement errors, or by using relatively complex statistical models, such as the mixed effects models, with no closed-form expression for the estimated hidden correlation. We propose a simple estimator of the hidden correlation that is very much like the Pearson correlation coefficient, with a closed-form expression, under assumptions much weaker than the mixed effects model. Simulation results show that the proposed simple estimator performs similarly as the restricted maximum likelihood (REML) estimator in mixed models, but is computationally much more efficient than REML. Simulation comparison with the Pearson correlation is also made. A real data example is considered. PMID:21997471

Nguyen, Thuan; Jiang, Jiming

2013-01-01

208

ERIC Educational Resources Information Center

This meta-analysis summarized the correlational evidence of the association between the CBM Oral Reading measure (R-CBM) and other standardized measures of reading achievement for students in grades 1-6. Potential moderating variables were also examined (source of criterion test, administration format, grade level, length of time, and type of…

Reschly, Amy L.; Busch, Todd W.; Betts, Joseph; Deno, Stanley L.; Long, Jeffrey D.

2009-01-01

209

Effect of a magnetic field on crack length measurement of 9NI steel by unloading compliance method

NASA Astrophysics Data System (ADS)

In the fracture toughness measurement of ferro-magnetic materials in high magnetic fields, it has not been clarified whether we can use the same formulas as ones used in a non-magnetic field. Therefore, it is necessary to understand the magnetic effect in the fracture toughness measurement of ferro-magnetic materials. As the first step, crack length was measured at 4 K by unloading compliance method in the testing of CT specimen of 9% nickel steel. The same formula was used in the magnetic field of 0 and 8 Tesla. They were compared with the length measured by optical fractography. The magnetic field had little effect on the crack length measurement by the unloading compliance method. The small amount of retained austenite in Q T heat-treated specimen did not exhibit a magnetic effect on the crack length measurement by the unloading compliance method.

Nagasaki, C.; Matsui, K.; Shibata, K.

2002-05-01

210

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.

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

2013-08-01

211

Asynchronous quantum correlation: measurement acting as a beamsplitter

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.

F. V. Kowalski; R. S. Browne

2014-04-30

212

The Measurement and Correlates of Career Decision Making.

ERIC Educational Resources Information Center

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…

Harren, Vincent A.; Kass, Richard A.

213

Measurement of the neutron-neutron scattering length using the ?-d capture reaction

NASA Astrophysics Data System (ADS)

We have determined a value for the 1S0 neutron-neutron scattering length (ann) from high-precision measurements of time-of-flight spectra of neutrons from the H2(?-,n?)n capture reaction. The measurements were done at the Los Alamos Meson Physics Facility by the E1286 Collaboration. The high spatial resolution of our ?-ray detector enabled us to make a detailed assessment of the systematic uncertainties in our techniques. The value obtained in the present work is ann=-18.63±0.10 (statistical) ± 0.44 (systematic) ± 0.30 (theoretical) fm. This result is consistent with previous determinations of ann from the ?-d capture reaction. We found that the analysis of the data with calculations that use a relativistic phase-space factor gives a more negative value for ann by 0.33 fm over the analysis done using a nonrelativistic phase-space factor. Combining the present result with the previous ones from ?-d capture gives ann=-18.63±0.27(expt)±0.30 fm (theory). For the first time the combined statistical and systematic experimental uncertainty in ann is smaller than the theoretical uncertainty and comparable to the uncertainty in the proton-proton 1S0 scattering length (app). This average value of ann when corrected for the magnetic-moment interaction of the two neutrons becomes -18.9 ± 0.4 fm, which is 1.6 ± 0.5 fm different from the recommended value of app, thereby confirming charge symmetry breaking at the 1% confidence level.

Chen, Q.; Howell, C. R.; Carman, T. S.; Gibbs, W. R.; Gibson, B. F.; Hussein, A.; Kiser, M. R.; Mertens, G.; Moore, C. F.; Morris, C.; Obst, A.; Pasyuk, E.; Roper, C. D.; Salinas, F.; Setze, H. R.; Slaus, I.; Sterbenz, S.; Tornow, W.; Walter, R. L.; Whiteley, C. R.; Whitton, M.

2008-05-01

214

Photocathode rf gun emittance measurements using variable-length laser pulses

NASA Astrophysics Data System (ADS)

The Gun Test Facility (GTF) at the Stanford Linear Accelerator Center (SLAC) was created to develop an appropriate injector for the proposed Linac Coherent Light Source (LCLS) at SLAC. The LCLS design requires the injector to produce a beam with at least 1 nC of charge in a 10 ps or shorter pulse with no greater than 1 (pi) mm-mrad normalized rms emittance. The first photoinjector under study at the GTF is a 1.6 cell S-band symmetrized gun with an emittance compensation solenoid. Emittance measurements, reported here, were made as function of the transverse laser pulse shape and the Gaussian longitudinal laser pulse length. The lowest achieved emittance to data with 1 nC of charge is 5.6 (pi) mm-mrad and was obtained with both a Gaussian longitudinal and transverse pulse shape with 5 ps FWHM and 2.4 mm FWHM respectively. The measurement is in agreement with a PARMELA simulation using measured beam parameters. There are indications that the accelerator settings used in the results presented here were not optimal. Simulations indicate that a normalized emittance meeting the LCLS requirement can be obtained using appropriately shaped transverse and temporal laser/electron beam pulses. Work has begun on producing temporal flat top laser pulses which combined with transverse clipping of the laser is expected to lower the emittance to approximately 1 (pi) mm-mrad for 1 nC beams with optimal accelerator settings.

Schmerge, John F.; Hernandez, Mike; Hogan, Mark J.; Reis, David A.; Winick, Herman

1999-07-01

215

Simple and low-cost implementation of three-dimensional (3D) particle measurement is vital for designing and characterizing microfluidic devices that show spatiotemporally varying characteristics in three dimensions. However, the conventional 3D particle image velocimetry or particle streak velocimetry has proven difficult to address the needs, requiring complex and expensive equipment, precise alignment between optical components, and specialized image-processing algorithms. Here, we report mirror-embedded microchannels and a method of optical path-length (OPL) modulation for 3D particle measurement in the channels. The mirror, ideally at 45 degrees, reflects the side view of the channels and enables 3D positional information to be obtained easily from two different orthogonal-axis images with different optical paths. To offset the optical path difference between two image views, we utilized a cover glass as a medium of high refractive index and placed it in the light path through which the side-view image propagates, thereby prolonging the OPL of the side view and simultaneously shifting its depth of field (DOF) range. This modulation ensures imaging of in-focus side view as well as top view. This 3D imaging principle was verified by observing 3D positions of 6 mum-sized beads in the linear and grooved microchannels. The mirror-embedded scheme can be readily fabricated with existing microfluidic designs, and offer easy and simple implementation of 3D particle measurement. PMID:20091005

Choi, Sungyoung; Kim, Seung-Hoon; Park, Je-Kyun

2010-02-01

216

Enhancing robustness of multiparty quantum correlations using weak measurement

NASA Astrophysics Data System (ADS)

Multipartite quantum correlations are important resources for the development of quantum information and computation protocols. However, the resourcefulness of multipartite quantum correlations in practical settings is limited by its fragility under decoherence due to environmental interactions. Though there exist protocols to protect bipartite entanglement under decoherence, the implementation of such protocols for multipartite quantum correlations has not been sufficiently explored. Here, we study the effect of local amplitude damping channel on the generalized Greenberger-Horne-Zeilinger state, and use a protocol of optimal reversal quantum weak measurement to protect the multipartite quantum correlations. We observe that the weak measurement reversal protocol enhances the robustness of multipartite quantum correlations. Further it increases the critical damping value that corresponds to entanglement sudden death. To emphasize the efficacy of the technique in protection of multipartite quantum correlation, we investigate two proximately related quantum communication tasks, namely, quantum teleportation in a one sender, many receivers setting and multiparty quantum information splitting, through a local amplitude damping channel. We observe an increase in the average fidelity of both the quantum communication tasks under the weak measurement reversal protocol. The method may prove beneficial, for combating external interactions, in other quantum information tasks using multipartite resources.

Singh, Uttam; Mishra, Utkarsh; Dhar, Himadri Shekhar

2014-11-01

217

Enhancing robustness of multiparty quantum correlations using weak measurement

Multipartite quantum correlations are important resources for the development of quantum information and computation protocols. However, the resourcefulness of multipartite quantum correlations in practical settings is limited by its fragility under decoherence due to environmental interactions. Though there exist protocols to protect bipartite entanglement under decoherence, the implementation of such protocols for multipartite quantum correlations has not been sufficiently explored. Here, we study the effect of local amplitude damping channel on the generalized Greenberger-Horne-Zeilinger state, and use a protocol of optimal reversal quantum weak measurement to protect the multipartite quantum correlations. We observe that the weak measurement reversal protocol enhances the robustness of multipartite quantum correlations. Further it increases the critical damping value that corresponds to entanglement sudden death. To emphasize the efficacy of the technique in protection of multipartite quantum correlation, we investigate two proximately related quantum communication tasks, namely, quantum teleportation in a one sender, many receivers setting and multiparty quantum information splitting, through a local amplitude damping channel. We observe an increase in the average fidelity of both the quantum communication tasks under the weak measurement reversal protocol. The method may prove beneficial, for combating external interactions, in other quantum information tasks using multipartite resources.

Uttam Singh; Utkarsh Mishra; Himadri Shekhar Dhar

2014-03-12

218

National Technical Information Service (NTIS)

Electron Beam Induced Current (EBIC) measurements were performed on GaN nanowires to determine minority charge carrier diffusion length, Ld. Although EBIC has been used to characterize bulk and thin film materials, very little is known about near contact ...

C. P. Ong

2009-01-01

219

Generalized information theoretic measure to discern the quantumness of correlations

A novel measure, quantumness of correlations is introduced here for bipartite states, by incorporating the required measurement scheme crucial in defining any such quantity. Quantumness coincides with the previously proposed measures in special cases and it vanishes for separable states - a feature not captured by the measures proposed earlier. It is found that an optimal generalized measurement on one of the parts leaves the overall state in its closest separable form, which shares the same marginal for the other part, implying that quantumness is non-zero for all entangled bipartite states and it serves as an upper bound to the relative entropy of entanglement.

A. R. Usha Devi; A. K. Rajagopal

2007-07-15

220

The transverse correlation length, ?, in the nematic and smectic C phases of heptyloxyazoxybenzene (HAB) have been determined from neutron scattering and x-ray diffraction techniques. The experimental intensity values I(q) are fitted using least squares method to a Lorenztian function. The ? values diverges near the smectic C to nematic transition indicating second order phase transition. The intermolecular distance throughout

M. K. Das; B. Adhikari; R. Paul; S. Paul; K. Usha Deniz; S. K. Paranjpe

1999-01-01

221

Statistical measure of complexity and correlated behavior of Fermi systems.

We apply the statistical measure of complexity, introduced by López-Ruiz, Mancini, and Calbet (LMC), to uniform Fermi systems. We investigate the connection between information and complexity measures with the strongly correlated behavior of various Fermi systems as nuclear matter, electron gas, and liquid helium. We examine the possibility that LMC complexity can serve as an index quantifying correlations in the specific system and to which extent could be related with experimental quantities. Moreover, we concentrate on thermal effects on the complexity of ideal Fermi systems. We find that complexity behaves, both at low and high values of temperature, in a similar way as the specific heat. PMID:20365320

Moustakidis, Ch C; Psonis, V P; Chatzisavvas, K Ch; Panos, C P; Massen, S E

2010-01-01

222

Avian hind-limb digit length ratios measured from radiographs are sexually dimorphic

Sexual dimorphism in digit length ratios is well established in humans, and has been reported in other vertebrate species as well, including birds. The sign of sexual dimorphism in digit ratios may, however, vary both within and between vertebrate classes. It has been hypothesized that sex differences in digit ratios arise via differential prenatal exposure of the two sexes to steroids, which may affect the expression of the Hox genes controlling the osteometric development of digits and appendices. Among birds, the evidence for sex dimorphism in hind-limb digit ratios is conflicting, though all previous studies were based on measurements of undissected digits, implying that results could be confounded by sex-related variation in soft tissues. Here we report that digit ratios derived from radiographs of both feet of a large passerine bird, the hooded crow (Corvus corone), are sexually dimorphic, males showing larger 2D : 3D (effect size, r = 0.33) and 2D : 4D than females (effect size, r = 0.28). We also observed a good agreement (r = 0.45) between radiographic estimates of digit ratios and digit ratios calculated based on undissected digit measurements (thus including soft tissues). Importantly, we found that the patterns of sex and side differences were largely coherent between the two methods. Therefore, our findings show for the first time in avian species that sex differences in digit ratios have an osteometric basis, a fundamental prerequisite for a role of Hox genes in originating such dimorphism. PMID:18691377

Leoni, Barbara; Rubolini, Diego; Romano, Maria; di Giancamillo, Mauro; Saino, Nicola

2008-01-01

223

Acoustic ship signature measurements by cross-correlation method.

Cross-correlation methods were applied for the estimation of the power spectral density and modulation spectrum of underwater noise generated by moving vessels. The cross-correlation of the signal from two hydrophones allows the separation of vessel acoustic signatures in a busy estuary. Experimental data recorded in the Hudson River are used for demonstration that cross-correlation method measured the same ship noise and ship noise modulation spectra as conventional methods. The cross-correlation method was then applied for the separation of the acoustic signatures of two ships present simultaneously. Presented methods can be useful for ship traffic monitoring and small ship classification, even in noisy harbor environments. PMID:21361436

Fillinger, Laurent; Sutin, Alexander; Sedunov, Alexander

2011-02-01

224

Background Recently, multi-planar reconstruction of the three-dimensional (3D) spiral chest CT scan has demonstrated superiority in the evaluation of the tracheobronchial tree. The goal of this study was to measure the lengths of the right and left main bronchi and their anteroposterior (AP) and transverse (TR) diameters using the 3D and two-dimensional (2D) images in the same adult respectively, and to evaluate the degree of correlation between them. Methods We measured the lengths of the right and left main bronchi from the carina to the first of their branches and the AP and TR diameters at the mid-portion of the right main bronchus and 2 cm below the carina in the left main bronchus. We determined the size of the left-sided double-lumen tube (DLT) based on the measured AP diameter of the left main bronchus from the 3D and 2D images, respectively. Results There was moderate correlation between the lengths of both main bronchi obtained from the 3D images and the 2D images, and between the AP diameter of the left main bronchus obtained from the 3D images and the 2D images. Same sized DLTs were estimated in 69% of the men and 34% of the women. Conclusions The lengths of the right and left main bronchi and their AP and TR diameters obtained from 3D images were not strongly correlated with those from 2D images. Therefore, a further study is needed to verify the superiority of 3D images in selecting the appropriate size of left-sided DLT. PMID:24729839

Lee, Jeong Woo; Choi, Jin-Wook; Han, Young-Jin; Lee, Jun-Rae

2014-01-01

225

Three-dimensional deformation field measurement with digital speckle correlation

NASA Astrophysics Data System (ADS)

Digital speckle correlation is based on a detailed analysis of changes in speckle images that are recorded from laser-illuminated rough surfaces. The two in-plane components are obtained by cross-correlation of corresponding subimages, a method also known as digital speckle photography. The local gradient of the hitherto inaccessible out-of-plane component is determined from the characteristic dependence of the speckle correlation on the spatial frequency. A detailed experimental study is carried out to analyze the new technique for systematic and random measuring errors. For moderate decorrelation the accuracy of the out-of-plane measurement is better than ?/10 and thus comparable with interferometric techniques. Yet the extremely simple and robust optical setup is suited to nondestructive-testing applications in harsh environments. The quality of the deformation maps is demonstrated in a practical application.

Fricke-Begemann, Thomas

2003-12-01

226

Degree of polarization as a cross-correlation detector for absolute distance measurement

NASA Astrophysics Data System (ADS)

We present an absolute distance measurement concept based on pulse frequency repetition (PRF) sweep with a mode-locked laser diode. This technique requires a Michelson interferometer, a mode-locked laser source and a cross-correlation detector. The role of the cross-correlator is to analyze the state of superposition of a pair of pulses, one travelling over the reference arm of the interferometer, the other, corresponding to the measuring arm, travelling from the apparatus to the target and reflected back. Using two distinct laser pulse repetition frequency and knowing the cross-correlation peak position at reference arm of the interferometer for each frequency, it's possible to obtain the length of the measuring arm, i.e., a distance measuring. The main techniques for performing pulse correlation are based in 2nd order effects over second harmonic crystal (SHG) or a two-photon absorption (TPA) process in a semiconductor junction. Both SHG and TPA methods require reasonably high pulse energies to achieve fair signal to noise ratios. The use Degree of Polarization (DOP) technique for cross-correlation detection allows the use of optical powers as low as -60 dBm. Such high sensitivity can be very convenient for low energy pulse sources such is the case of high frequency mode-locked laser diodes. The DOP technique can however limit the maximum measurement range, constrained by the loss of coherence of the laser source for longer distances. In this paper we present the first results of this measurement concept, based in the DOP correlator, discussing the main limitations of this technique for long distance measurements.

Castro Alves, D.; Abreu, Manuel; Cabral, Alexandre; Rebordão, J. M.

2013-11-01

227

Clove oil as a fish anaesthetic for measuring length and weight of rabbitfish ( Siganus lineatus)

The successful use of clove oil as a fish anaesthetic is described. Juvenile rabbitfish, Siganus lineatus, from the same cohort ranging in size from 5 to 23 cm in total length (TL) were anaesthetized, and their length and weight were recorded on three separate occasions. Fish fed shortly afterward, and no mortality was observed. Clove oil appears to be highly

Cristina G. Soto; Burhanuddin

1995-01-01

228

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

NASA Technical Reports Server (NTRS)

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.

Panda, Jayanta

2006-01-01

229

We have performed the first high precision measurement of the coherent neutron scattering length of deuterium in a pure sample using neutron interferometry. We find b_nd = (6.665 +/- 0.004) fm in agreement with the world average of previous measurements using different techniques, b_nd = (6.6730 +/- 0.0045) fm. We compare the new world average for the nd coherent scattering length b_nd = (6.669 +/- 0.003) fm to calculations of the doublet and quartet scattering lengths from several modern nucleon-nucleon potential models with three-nucleon force (3NF) additions and show that almost all theories are in serious disagreement with experiment. This comparison is a more stringent test of the models than past comparisons with the less precisely-determined nuclear doublet scattering length of a_nd = (0.65 +/- 0.04) fm.

T. C. Black; P. R. Huffman; D. L. Jacobson; W. M. Snow; K. Schoen; M. Arif; H. Kaiser; S. K. Lamoreaux; S. A. Werner

2003-05-21

230

The authors conducted experiments on DCB specimens 10 and 20 mm thick made of 15Kh2NMFA and 15 Kh2NMFAA steels in the embrittled state at room and liquid nitrogen temperatures. Fatigue cracks of various length were induced in the specimens. The dimensions of these cracks were determined more accurately after final fracture of the specimens. The compliance of the specimens was determined from the slope of the linear section of the P-V diagram. The effect of temperature of fictitious beam length was measured, and indicates that the fictitious beam length decreases with decreasing temperature.

Kashtalyan, Yu. A.; Orynyak, I.V.; Torop, V.M.

1986-07-01

231

Previous studies have reported that renal size may change when the function is compromised. However, it is not known whether sonographically measured renal size reflects the residual renal function (RRF) in patients undergoing chronic hemodialysis. A total of 140 patients undergoing chronic hemodialysis (?3 months) were investigated in the present study. The patients were divided into two groups according to the daily urine volume: Individuals with RRF (RRF+ group; ?200 ml; n=65) and without RRF (RRF? group; <200 ml; n=75). Renal sizes were measured using sonography and renal volumes were calculated with the ellipsoid formula. Univariable and multivariable stepwise forward logistic regression analyses were performed to examine the correlation between the presence of RRF and various variables. The results indicated that there were statistically significant differences (P<0.001) between the RRF+ and RRF? groups with regard to renal length, width, thickness and volume of the left (length, 7.9±1.2 vs. 6.8±1.2 cm; volume, 60.0±26.7 vs. 40.2±18.1 ml, respectively) and right (length, 7.6±1.2 vs. 6.7±1.2 cm; volume, 50.2±26.5 vs. 33.9±15.3 ml, respectively) sides of the kidney. Multivariable stepwise forward logistic regression analyses showed that the mean renal length or volume and hemodialysis duration were independent predictors of the presence of RRF. Therefore, renal size assessment by ultrasonography may be useful for RRF evaluation in patients undergoing chronic hemodialysis. PMID:24940422

ZHANG, WU-XING; ZHANG, ZHI-MIN; CAO, BING-SHENG; ZHOU, WEI

2014-01-01

232

NASA Astrophysics Data System (ADS)

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.

Shaw, A.; Ghosh, A.

2014-10-01

233

Rheology of fluids measured by correlation force spectroscopy

NASA Astrophysics Data System (ADS)

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.

Radiom, Milad; Robbins, Brian; Honig, Christopher D. F.; Walz, John Y.; Paul, Mark R.; Ducker, William A.

2012-04-01

234

A specialized fast cross-correlation for acoustical measurements using coded sequences.

In acoustics applications, binary maximal-length sequences and related sequences are increasingly used for acoustics system identification tasks. A number of coded sequences, such as binary maximal-length related sequences and ternary sequences possess two-valued or pulselike autocorrelation functions. It is this correlation property that is exploited in most of acoustical applications. However, the length of some of these sequences is not directly suitable for FFT-based cross-correlation algorithms. This paper explores using standard FFTs to calculate the cross-correlation between two periodic finite-length sequences of equal length, where the lengths of the sequences are not a power of 2. We apply our specialized correlation algorithm to analyze data collected in a room-acoustic environment to simultaneously obtain impulse responses between multiple sources and multiple receivers. PMID:16454288

Daigle, John N; Xiang, Ning

2006-01-01

235

ERIC Educational Resources Information Center

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…

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

2012-01-01

236

Topography measurements for correlations of standard cartridge cases

NASA Astrophysics Data System (ADS)

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.

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

237

Measurement of angular correlations based on secondary vertex reconstruction at

A measurement of the angular correlations between beauty and anti-beauty hadrons () produced in pp collisions at a centre-of-mass energy of 7 TeV at the CERN LHC is presented, probing for the first time the\\u000a region of small angular separation. The B hadrons are identified by the presence of displaced secondary vertices from their\\u000a decays. The B hadron angular separation

V. Khachatryan; A. M. Sirunyan; A. Tumasyan; W. Adam; T. Bergauer; M. Dragicevic; J. Erö; C. Fabjan; M. Friedl; R. Frühwirth; V. M. Ghete; J. Hammer; S. Hänsel; C. Hartl; M. Hoch; N. Hörmann; J. Hrubec; M. Jeitler; G. Kasieczka; W. Kiesenhofer; M. Krammer; D. Liko; I. Mikulec; M. Pernicka; H. Rohringer; R. Schöfbeck; J. Strauss; A. Taurok; F. Teischinger; P. Wagner; W. Waltenberger; G. Walzel; E. Widl; C.-E. Wulz; V. Mossolov; N. Shumeiko; J. Suarez Gonzalez; L. Benucci; K. Cerny; E. A. De Wolf; X. Janssen; T. Maes; L. Mucibello; S. Ochesanu; B. Roland; R. Rougny; M. Selvaggi; H. Van Haevermaet; P. Van Mechelen; N. Van Remortel; S. Beauceron; F. Blekman; S. Blyweert; J. D’Hondt; O. Devroede; R. Gonzalez Suarez; A. Kalogeropoulos; J. Maes; M. Maes; S. Tavernier; W. Van Doninck; P. Van Mulders; G. P. Van Onsem; I. Villella; O. Charaf; B. Clerbaux; G. De Lentdecker; V. Dero; A. P. R. Gay; G. H. Hammad; T. Hreus; P. E. Marage; L. Thomas; C. Vander Velde; P. Vanlaer; J. Wickens; V. Adler; S. Costantini; M. Grunewald; B. Klein; A. Marinov; J. Mccartin; D. Ryckbosch; F. Thyssen; M. Tytgat; L. Vanelderen; P. Verwilligen; S. Walsh; N. Zaganidis; S. Basegmez; G. Bruno; J. Caudron; L. Ceard; J. De Favereau De Jeneret; C. Delaere; P. Demin; D. Favart; A. Giammanco; G. Grégoire; J. Hollar; V. Lemaitre; J. Liao; O. Militaru; S. Ovyn; D. Pagano; A. Pin; K. Piotrzkowski; N. Schul; N. Beliy; T. Caebergs; E. Daubie; G. A. Alves; D. De Jesus Damiao; M. E. Pol; M. H. G. Souza; W. Carvalho; E. M. Da Costa; C. De Oliveira Martins; S. Fonseca De Souza; L. Mundim; H. Nogima; V. Oguri; W. L. Prado Da Silva; A. Santoro; S. M. Silva Do Amaral; A. Sznajder; F. Torres Da Silva De Araujo; F. A. Dias; M. A. F. Dias; T. R. Fernandez Perez Tomei; E. M. Gregores; F. Marinho; S. F. Novaes; Sandra S. Padula; N. Darmenov; L. Dimitrov; V. Genchev; P. Iaydjiev; S. Piperov; M. Rodozov; S. Stoykova; G. Sultanov; V. Tcholakov; R. Trayanov; I. Vankov; M. Dyulendarova; R. Hadjiiska; V. Kozhuharov; L. Litov; E. Marinova; M. Mateev; B. Pavlov; P. Petkov; J. G. Bian; G. M. Chen; H. S. Chen; C. H. Jiang; D. Liang; S. Liang; J. Wang; X. Wang; Z. Wang; M. Xu; M. Yang; J. Zang; Z. Zhang; Y. Ban; S. Guo; Y. Guo; W. Li; Y. Mao; S. J. Qian; H. Teng; L. Zhang; B. Zhu; W. Zou; A. Cabrera; B. Gomez Moreno; A. A. Ocampo Rios; A. F. Osorio Oliveros; J. C. Sanabria; N. Godinovic; D. Lelas; K. Lelas; R. Plestina; D. Polic; I. Puljak; Z. Antunovic; M. Dzelalija; V. Brigljevic; S. Duric; K. Kadija; S. Morovic; A. Attikis; M. Galanti; J. Mousa; C. Nicolaou; F. Ptochos; P. A. Razis; H. Rykaczewski; M. Finger; Y. Assran; M. A. Mahmoud; A. Hektor; M. Kadastik; K. Kannike; M. Müntel; M. Raidal; L. Rebane; V. Azzolini; P. Eerola; S. Czellar; J. Härkönen; A. Heikkinen; V. Karimäki; R. Kinnunen; J. Klem; M. J. Kortelainen; T. Lampén; K. Lassila-Perini; S. Lehti; T. Lindén; P. Luukka; T. Mäenpää; E. Tuominen; J. Tuominiemi; E. Tuovinen; D. Ungaro; L. Wendland; K. Banzuzi; A. Korpela; T. Tuuva; D. Sillou; M. Besancon; S. Choudhury; M. Dejardin; D. Denegri; B. Fabbro; J. L. Faure; F. Ferri; S. Ganjour; F. X. Gentit; A. Givernaud; P. Gras; G. Hamel de Monchenault; P. Jarry; E. Locci; J. Malcles; M. Marionneau; L. Millischer; J. Rander; A. Rosowsky; I. Shreyber; M. Titov; P. Verrecchia; S. Baffioni; F. Beaudette; L. Bianchini; M. Bluj; C. Broutin; P. Busson; C. Charlot; T. Dahms; L. Dobrzynski; R. Granier de Cassagnac; M. Haguenauer; P. Miné; C. Mironov; C. Ochando; P. Paganini; D. Sabes; R. Salerno; Y. Sirois; C. Thiebaux; B. Wyslouch; A. Zabi; J.-L. Agram; J. Andrea; A. Besson; D. Bloch; D. Bodin; J.-M. Brom; M. Cardaci; E. C. Chabert; C. Collard; E. Conte; F. Drouhin; C. Ferro; J.-C. Fontaine; D. Gelé; U. Goerlach; S. Greder; P. Juillot; M. Karim; A.-C. Le Bihan; Y. Mikami; P. Van Hove; F. Fassi; D. Mercier; C. Baty; N. Beaupere; M. Bedjidian; O. Bondu; G. Boudoul; D. Boumediene; H. Brun; N. Chanon; R. Chierici; D. Contardo; P. Depasse; H. El Mamouni; A. Falkiewicz; J. Fay; S. Gascon; B. Ille; T. Kurca; T. Le Grand; M. Lethuillier; L. Mirabito; S. Perries; V. Sordini; S. Tosi; Y. Tschudi; P. Verdier; H. Xiao; L. Megrelidze; V. Roinishvili; D. Lomidze; G. Anagnostou; M. Edelhoff; L. Feld; N. Heracleous; O. Hindrichs; R. Jussen; K. Klein; J. Merz; N. Mohr; A. Ostapchuk; A. Perieanu; F. Raupach; J. Sammet; S. Schael; D. Sprenger; H. Weber; M. Weber; B. Wittmer; M. Ata; W. Bender; M. Erdmann; J. Frangenheim; T. Hebbeker; A. Hinzmann; K. Hoepfner; C. Hof; T. Klimkovich; D. Klingebiel; P. Kreuzer; D. Lanske; C. Magass; G. Masetti; M. Merschmeyer; A. Meyer; P. Papacz; H. Pieta; H. Reithler; S. A. Schmitz; L. Sonnenschein; J. Steggemann; D. Teyssier; M. Bontenackels; M. Davids; M. Duda; G. Flügge; H. Geenen; M. Giffels; W. Haj Ahmad; D. Heydhausen; T. Kress; Y. Kuessel; A. Linn; A. Nowack; L. Perchalla; O. Pooth; J. Rennefeld

2011-01-01

238

A quantitative measure of phase correlations in density fields

NASA Technical Reports Server (NTRS)

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.

Scherrer, Robert J.; Melott, Adrian L.; Shandarin, Sergei F.

1991-01-01

239

Correlates of Objectively Measured Physical Activity in Obese Children

The aim of this study was to identify potential correlates of objectively measured physical activity in a sample of obese children. A cross-sectional design was used to assess 137 5–9-year-old obese children (mean ± s.d. age = 8.3 ± 1.1 years; mean BMI z-score = 2.76 ± 0.70; 58% girls) from two regional cities in New South Wales, Australia, before

Philip J. Morgan; Anthony D. Okely; Dylan P. Cliff; Rachel A. Jones; Louise A. Baur

2008-01-01

240

Correlates of objectively measured physical activity in preadolescent youth

Objective: The purpose of this study was to identify the psychosocial and environmental correlates of objectively measured physical activity behavior in a diverse sample of sixth-grade students.Design: Cross-sectional.Participants and Setting: One hundred ninety-eight sixth-grade students from 4 public middle schools in Columbia, South Carolina. The study group was 52.0% female, 55.1% African-American, with a mean age of 11.4 ± 0.6

Stewart G Trost; Russell R Pate; Dianne S Ward; Ruth Saunders; William Riner

1999-01-01

241

A correlation study between two color-measuring spectrophotometers

NASA Astrophysics Data System (ADS)

The U.S. Army recently completed a four phase effort to develop an objective computerized method for evaluating shade acceptability of dyed and printed textiles for the government quality assurance program. Rapidly emerging developments in the field of optics and computers have made older instruments obsolete. This study evaluates the repeatability and correlation between two spectrophotometers manufactured 8 years apart by Applied Color Systems of Princeton, New Jersey. The samples (20 fabric swatches, 22 porcelain tiles, and a color difference pair) were measured for short- and long-term repeatability. Each instrument was found to show a repeatability of 0.12 CIELAB color difference units or less for the two time periods studied. The largest color difference observed between the two instruments for these samples was 0.5 CIELAB color difference units. The color difference pair correlation measurements and repeatability of the instruments data were very good. Measurements in the infrared region (up to 900 nm) for the two instruments demonstrated very good repeatability and correlation results.

St. Pere, Robin R.

1991-01-01

242

Measurement of ultraviolet radiation and correlation to direct normal irradiance

The DLR operates a solar furnace at the site near Cologne for experiments in material research and solar chemistry. For these activities that make use of concentrating systems the direct normal irradiances are of main importance. Especially for the photochemistry the shorter wavelengths in the visible part of the solar spectrum and the ultraviolet region are important. for collecting operational data, for statistical purpose, and for measuring the solar furnace input power the DLR operates also a meteorological station that besides temperature, rain, and wind data records several important irradiance parameters like direct normal or direct normal narrowband UVA and UVB. In order to compare measured data to model predictions the authors performed a correlation analysis between LOWTRAN results and direct normal irradiance and measurements of UVA at 368 nm and UVB at 306 nm. It shows that on clear summer days and high direct normal irradiances of about 800 W/m{sup 2} the model data agree well with the UVA measurements. In the UVB the deviation is larger. On sunny days with thin cloud coverage the data show more scattering and higher UV intensities compared to the model at similar elevation angles. Empirical correlation functions are proposed for modeling the UVA and UVB measurements.

Neumann, A.

1999-07-01

243

A Nonlocal Strain Measure for Digital Image Correlation

We propose a nonlocal strain measure for use with digital image correlation (DIC). Whereas the traditional notion of compatibility (strain as the derivative of the displacement field) is problematic when the displacement field varies substantially either because of measurement noise or material irregularity, the proposed measure remains robust, well-defined and invariant under rigid body motion. Moreover, when the displacement field is smooth, the classical and nonlocal strain are in agreement. We demonstrate, via several numerical examples, the potential of this new strain measure for problems with steep gradients. We also show how the nonlocal strain provides an intrinsic mechanism for filtering high frequency content from the strain profile and so has a high signal to noise ratio. This is a convenient feature considering image noise and its impact on strain calculations.

Lehoucq, R B; Turner, D Z

2014-01-01

244

Direct Photon-Hadron Correlations Measured with PHENIX

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.

Megan Connors; for the PHENIX Collaboration

2009-07-27

245

length dependence of single polymers Shilong Yang and Jianshu Caoa) Department of Chemistry, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139 Received 9 March 2004; accepted 6 April. The WilemskiÂFixman rate is used in combination with scaling arguments to predict the dependence

Cao, Jianshu

246

ERIC Educational Resources Information Center

Stuttered sentences pronounced by 12 4- to 6-year-old children in spontaneous conversation were analyzed for length and grammatical complexity. Results indicated that sentences in which stuttering occurred within the first three words were significantly longer and more complex than sentences where no fluency failure was found. Implications for…

Gaines, Natalie D.; And Others

1991-01-01

247

Telomere lengths at birth in trisomies 18 and 21 measured by Q-FISH.

Trisomies 18 and 21 are genetic disorders in which cells possess an extra copy of each of the relevant chromosomes. Individuals with these disorders who survive birth generally have a shortened life expectancy. As telomeres are known to play an important role in the maintenance of genomic integrity by protecting the chromosomal ends, we conducted a study to determine whether there are differences in telomere length at birth between individuals with trisomy and diploidy, and between trisomic chromosomes and normal chromosomes. We examined samples of peripheral blood lymphocytes (PBLs) from 31 live neonates (diploidy: 10, trisomy 18: 10, trisomy 21: 11) and estimated the telomere length of each chromosome arm using Q-FISH. We observed that the telomeres of trisomic chromosomes were neither shorter nor longer than the mean telomere length of chromosomes as a whole among subjects with trisomies 18 and 21 (intra-cell comparison), and we were unable to conclude that there were differences in telomere length between 18 trisomy and diploid subjects, or between 21 trisomy and diploid subjects (inter-individual comparison). Although it has been reported that telomeres are shorter in older individuals with trisomy 21 and show accelerated telomere shortening with age, our data suggest that patients with trisomies 18 and 21 may have comparably sized telomeres. Therefore, it would be advisable for them to avoid lifestyle habits and characteristics such as obesity, cigarette smoking, chronic stress, and alcohol intake, which lead to marked telomere shortening. PMID:24080483

Nakamura, Ken-Ichi; Ishikawa, Naoshi; Izumiyama, Naotaka; Aida, Junko; Kuroiwa, Mie; Hiraishi, Naoki; Fujiwara, Mutsunori; Nakao, Atsushi; Kawakami, Tadashi; Poon, Steven S S; Matsuura, Masaaki; Sawabe, Motoji; Arai, Tomio; Takubo, Kaiyo

2014-01-01

248

Measurement of fluid velocity fields using digital correlation techniques

NASA Technical Reports Server (NTRS)

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.

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

1990-01-01

249

Displacement measurements of highway bridges using digital image correlation methods

NASA Astrophysics Data System (ADS)

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.

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

2011-12-01

250

Measuring capital market efficiency: Global and local correlations structure

NASA Astrophysics Data System (ADS)

We introduce a new measure for capital market efficiency. The measure takes into consideration the correlation structure of the returns (long-term and short-term memory) and local herding behavior (fractal dimension). The efficiency measure is taken as a distance from an ideal efficient market situation. The proposed methodology is applied to a portfolio of 41 stock indices. We find that the Japanese NIKKEI is the most efficient market. From a geographical point of view, the more efficient markets are dominated by the European stock indices and the less efficient markets cover mainly Latin America, Asia and Oceania. The inefficiency is mainly driven by a local herding, i.e. a low fractal dimension.

Kristoufek, Ladislav; Vosvrda, Miloslav

2013-01-01

251

Many lake whitefish stocks in Lake Michigan have experienced substantial declines in growth and condition since the 1990s. Reduced growth and condition could result in reduced quality or quantity of eggs produced by spawning females, which in turn could negatively impact recruitment. We evaluated the potential for reduced recruitment by measuring early life stage density and length, and we discuss

Randall M. Claramunt; Andrew M. Muir; Trent M. Sutton; Paul J. Peeters; Mark P. Ebener; John D. Fitzsimons; Marten A. Koops

2010-01-01

252

National Technical Information Service (NTIS)

A microcircuit grid technique was investigated and used to measure crack lengths in fatigue crack growth test specimens of an aluminum alloy (7075-T6) at room temperature and a nickel-based superalloy (Inconel 718) at 650 C as part of a Phase I SBIR progr...

A. V. Virkar, D. K. Shetty, K. Stuffle, R. A. Cutler

1988-01-01

253

Measurement of the Minority Carrier Diffusion Length and Edge Surface-Recombination Velocity in InP.

National Technical Information Service (NTIS)

A scanning electron microscope (SEM) was used to measure the electron (minority carrier) diffusion length (L(sub n)) and the edge surface-recombination velocity (V(sub s)) in zinc-doped Czochralski-grown InP wafers. Electron-beam-induced current (EBIC) pr...

S. G. Bailey, R. Hakimzadeh

1993-01-01

254

A combination of surface wind speed (SWS) and sea state variables, derived from quasi-simultaneous airborne lidar and radar measurements, made in the framework of the Flux, État de mer et Télédétection en Condition de fetcH variable (FETCH) experiment, is used to analyze the evolution of surface roughness length, neutral drag coefficient, and friction velocity coefficient with fetch in the first

Cyrille Flamant; Jacques Pelon; Danièle Hauser; Céline Quentin; William M. Drennan; Francis Gohin; Bertrand Chapron; Jrome Gourrion

2003-01-01

255

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

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

2011-01-01

256

The interface failure sequence was observed during fiber pushout tests on several model composites. The pushout experiments indicated that only composites with an Esbf\\/Esbm ratio less than 3 and with negligible to moderate residual stresses can be expected to debond from the top. The debond length as a function of force and displacement was also measured in a polariscope for

Vernon Thomas Bechel

1997-01-01

257

NASA Astrophysics Data System (ADS)

A new experimental technique is developed to simultaneously measure the wave propagation direction and the effective length of a small (L value much smaller than wavelength) electric dipole antenna on a spin-stabilized satellite in the magnetosphere. The technique relies on the near simultaneous measurement of single components of the electric and magnetic fields of a coherent VLF signal injected into the medium from a ground-based source. The spin fading characteristics of the signal received by the electric dipole and the magnetic loop antenna permit the measurement of the wave normal direction assuming whistler-mode propagation. In-situ and remote measurements of the local cold plasma density are used to determine the refractive index. The wave electric field is then inferred from the wave magnetic field as measured on the loop antenna, the refractive index and the direction of propagation. Comparing this electric field with the measured voltage across the dipole antenna leads to the determination of the effective length of the receiving electric dipole. The technique is applied to data from the Dynamics Explorer 1 satellite observations of whistler mode signals injected into the magnetosphere from the Siple, Antarctica, VLF transmitter. In one case, with the measured background cold plasma density being 15 el/cu cm, the effective length of the 200 m-long electric dipole antenna is found to be 222 + or - 56 m, i.e., about twice the conventional value.

Sonwalker, V. S.; Inan, U. S.

1986-01-01

258

NASA Astrophysics Data System (ADS)

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.

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

259

Directional correlation measurements for gamma transitions in /sup 127/Te

The directional correlation of coincident ..gamma.. transitions in /sup 127/Te has been measured following the ..beta../sup -/ decay of /sup 127/Sb (T/sub 1/2/ = 3.9 d) using Ge(Li)-Ge(Li) and Ge(Li)-NaI(T1) gamma spectrometers. Measurements have been carried out for 14 gamma cascades resulting in the determination of multipole mixing ratios delta(E2/M1) for 15 ..gamma.. transitions. The present results permitted a definite spin assignment of (7/2) for the 785 keV level and confirmation of several previous assignments to other levels in /sup 127/Te. The g factor of the 340 keV ((9/2)/sup -/) level has also been measured using the integral perturbed angular correlation method in the hyperfine magnetic field of a Te in Ni matrix. The results of the g factor as well as the mixing ratio for the 252 keV ((9/2)/sup -/..-->..(11/2)/sup -/) transition support the earlier interpretation of this state as an anomalous coupling state.

de Souza, M.O.M.D.; Saxena, R.N.

1985-02-01

260

Correlates of objectively measured physical activity in cardiac patients

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.

Ozemek, Cemal; Riggin, Katrina; Strath, Scott; Kaminsky, Leonard

2014-01-01

261

NSDL National Science Digital Library

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.

American Association for the Advancement of Science (;)

2005-03-28

262

NASA Astrophysics Data System (ADS)

A method is proposed for measuring the diffusion length and surface recombination velocity of Interdigitated Back Contact (IBC) solar cells by means of a simple linear regression on experimental quantum efficiency values versus the inverse of the absorption coefficient. This method is extended to the case of Front Surface Field (FSF) solar cells. Under certain conditions, the real or the effective surface recombination velocity may be measured.

Verlinden, Pierre; Van de Wiele, Fernand

1985-03-01

263

The paper describes some new research results from designing analog-to-digital conversion for audio measurement system using MLS (maximum length sequence) algorithm. Evaluation version of USB audio measurement interface with two types of high quality analog-to-digital converters (ADC) has been presented in the paper. Comparison was subjected to 16 bit ADC with one bit sigma-delta (SD), fourth-order modulator and 16 bit

Daniel Król

2008-01-01

264

Silica, modified by esterification with linear alcohols having between 1 and 20 carbon atoms, is compacted into smooth discs. Their surface polarity, measured by contact angle techniques, decreases with increasing surface coverage and chain length of the grafts. For the longer chains, the surface energy of the grafted silicas reaches a value close to the one of poly(ethylene). The spreading pressures of water on the modified silicas were measured either by contact angle or vapor adsorption techniques. 13 references.

Kessaissia, Z. Papirer, E.; Donnet, J.B.

1981-08-01

265

Photoacoustic correlation spectroscopy for in vivo blood flow speed measurement

NASA Astrophysics Data System (ADS)

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.

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

2012-02-01

266

Three heterologous proteins were simultaneously expressed from a chimeric potyvirus Potato virus A (PVA) in Nicotiana benthamiana. The genes for green fluorescent protein of Aequoria victoriae ("G"; 714 nucleotides, nt), luciferase of Renilla reniformis ("L", 933 nt) and beta-glucuronidase of Escherichia coli ("U", 1806 nt) were inserted into the engineered cloning sites at the N-terminus of the P1 domain, the junction of P1 and helper component protein (HC-Pro), and the junction of the viral replicase (NIb) and coat protein (CP), respectively, in an infectious PVA cDNA. The proteins were expressed as part of the viral polyprotein and subsequently released by cleavage at the flanking proteolytic cleavage sites by P1 (one site) or the NIa-Pro proteinase (other sites). The engineered viral genome (pGLU, 13311 nt) was 39.2% larger than wild-type PVA (9565 nt) and infected plants of N. benthamiana systemically. pGLU was stable and expressed all three heterologous proteins, also following the second infection cycle initiated by sap-inoculation of new plants with the progeny viruses. The gene for GUS showed some inherent instabilities, as also reported in other studies. Accumulation of pGLU in infected leaves was lower by a magnitude as compared to the vector viruses pG0U and p0LU used to express two heterologous proteins. Hence, pGLU may have reached the maximum genome size that can still function and complete the PVA infection cycle. Examination of virions by electron microscopy indicated that the virion lengths of PVA chimera with various numbers of inserts were directly proportional to their genome lengths. PMID:18511144

Kelloniemi, Jani; Mäkinen, Kristiina; Valkonen, Jari P T

2008-08-01

267

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

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.

Weiland, Mark A.; Escher, Charles

2001-04-02

268

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

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

269

The Effect of Error Correlation on Interfactor Correlation in Psychometric Measurement

ERIC Educational Resources Information Center

This article shows how interfactor correlation is affected by error correlations. Theoretical and practical justifications for error correlations are given, and a new equivalence class of models is presented to explain the relationship between interfactor correlation and error correlations. The class allows simple, parsimonious modeling of error…

Westfall, Peter H.; Henning, Kevin S. S.; Howell, Roy D.

2012-01-01

270

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.

Hering, Marco; Koerner, Klaus; Jaehne, Bernd

2009-01-20

271

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

Shaw, A; Ghosh, A

2014-10-28

272

Oxygen measurement by multimode diode lasers employing gas correlation spectroscopy.

Multimode diode laser (MDL)-based correlation spectroscopy (COSPEC) was used to measure oxygen in ambient air, thereby employing a diode laser (DL) having an emission spectrum that overlaps the oxygen absorption lines of the A band. A sensitivity of 700 ppm m was achieved with good accuracy (2%) and linearity (R(2)=0.999). For comparison, measurements of ambient oxygen were also performed by tunable DL absorption spectroscopy (TDLAS) technique employing a vertical cavity surface emitting laser. We demonstrate that, despite slightly degraded sensitivity, the MDL-based COSPEC-based oxygen sensor has the advantages of high stability, low cost, ease-of-use, and relaxed requirements in component selection and instrument buildup compared with the TDLAS-based instrument. PMID:19209216

Lou, Xiutao; Somesfalean, Gabriel; Chen, Bin; Zhang, Zhiguo

2009-02-10

273

In this paper, we analyze the correlations between four clinical measures (Fugl-Meyer upper extremity scale, Motor Activity Log, Action Research Arm Test, and Jebsen-Taylor Hand Function Test) and four robotic measures (smoothness of movement, trajectory error, average number of target hits per minute, and mean tangential speed), used to assess motor recovery. Data were gathered as part of a hybrid

Ozkan Celik; Marcia K. O'Malley; Corwin Boake; Harvey S. Levin; Nuray Yozbatiran; Timothy A. Reistetter

2010-01-01

274

Automatic difference measure between movies using dissimilarity measure fusion and rank correlation dissimilarities. Subjective tests with human observers on the CITIA animation movie database have been carried out. In this paper, we work with the dataset used by Benoit & al. in [2]. It is composed of short animated movies

Paris-Sud XI, UniversitÃ© de

275

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

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.

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

2014-01-01

276

Accurate measurement of curvilinear shapes by Virtual Image Correlation

NASA Astrophysics Data System (ADS)

The proposed method allows the detection and the measurement, in the sense of metrology, of smooth elongated curvilinear shapes. Such measurements are required in many fields of physics, for example: mechanical engineering, biology or medicine (deflection of beams, fibers or filaments), fluid mechanics or chemistry (detection of fronts). Contrary to actual methods, the result is given in an analytical form of class C? (and not a finite set of locations or pixels) thus curvatures and slopes, often of great interest in science, are given with good confidence. The proposed Virtual Image Correlation (VIC) method uses a virtual beam, an image which consists in a lateral expansion of the curve with a bell-shaped gray level. This figure is deformed until it fits the best the physical image with a method issued from the Digital Image Correlation method in use in solid mechanics. The precision of the identification is studied in a benchmark and successfully compared to two state-of-the-art methods. Three practical examples are given: a bar bending under its own weight, a thin fiber transported by a flow within a fracture and a thermal front. The first allows a comparison with theoretical solution, the second shows the ability of the method to deal with complex shapes and crossings and the third deals with ill-defined image.

Semin, B.; Auradou, H.; François, M. L. M.

2011-10-01

277

Purpose To determine the axial length requiring adjustment of measured circumpapillary retinal nerve fiber layer (cpRNFL) thickness to account for ocular magnification during spectral-domain optical coherence tomography (SD-OCT). Methods In this prospective study, 148 eyes of 148 healthy student volunteers were imaged by two examiners using three-dimensional SD-OCT. In 54 randomly selected eyes, total cpRNFL thickness was measured with and without adjustment for ocular magnification to establish intra-examiner and inter-examiner measurement error. The 148 eyes were then divided into three groups according to the error values: control group (difference in the corrected and uncorrected total cpRNFL thickness was within the measurement error range), thinner group (the corrected total cpRNFL thickness was less than the uncorrected one), and thicker group (the corrected total cpRNFL thickness was more than the uncorrected one). The cutoff values of axial length between the control and the other groups were calculated by receiver operating characteristic analysis. Results Measurement error ranged from 4.2 to 5.3 µm; the threshold value was defined as 5.3 µm. The cutoff values of axial length between the thinner and the control groups and between the control and the thicker groups were 23.60 (area under the curve [AUC]?=?0.959) and 25.55 (AUC?=?0.944) mm, respectively. Conclusions Axial lengths shorter than 23.60 mm and longer than 25.55 mm require adjustment of measured cpRNFL thickness to account for ocular magnification during SD-OCT. Clinical Trial Registration UMIN Clinical Trials Registry (http://www.umin.ac.jp/) under unique trial number UMIN000013248 (date of registration: 02/24/2014) PMID:25215521

Hirasawa, Kazunori; Shoji, Nobuyuki; Yoshii, Yukako; Haraguchi, Shota

2014-01-01

278

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

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

279

Recent results and prospects for correlation ECE measurements on TCV

NASA Astrophysics Data System (ADS)

The Tokamak a Configuration Variable (TCV) has a two channel correlation electron cyclotron emission (CECE) radiometer with a line of sight perpendicular to the magnetic field. The antenna pattern of this radiometer limits resolution to k? < 112 m-1 or k??s < 0.3 at 500 kHz. It can access the region with minor radius ?vol < 0.7. A series of measurements has been made of the turbulence spectra at positive and negative triangularity and as a function of collisionality. Also, a series of measurements has been made as a function of poloidal angle, by varying the plasma vertical position with respect to the antenna, the measurements being made on the same flux surface. It is planned to extensively upgrade the diagnostic by integrating four more channels and acquiring a new front-end for the radiometer. This upgrade should reduce the required number of shots for a radial scan by a factor four and improve the signal-to-noise ratio. It is also planned to use a high gain antenna that will extend access to k? < 174m-1 or k??s < 0.5 at 500 kHz. The present system, measurements and the upgrade are described in this paper.

Porte, L.; Coda, S.; Goodman, T. P.; Pochelon, A.; Udintsev, V. S.; Vuille, V.

2012-09-01

280

NASA Astrophysics Data System (ADS)

We are using multiple proxies, including XRF analysis, to determine hemipelagic thickness between turbidite events recorded in cores along the offshore northern San Andreas margin. Inter-event times are calculated from these improved estimates of sediment thickness and regression-determined sedimentation rates, and used along with known stratigraphic information to constrain calibrated radiocarbon age ranges using Bayesian statistical methods within the program OxCal. OxCal can also be used to combine multiple ages for the same event. Multiple ages are given "credit" where age ranges overlap, resulting in reduced 1- or 2-sigma age ranges compared to averaging peak ages and propagating errors. These methods reduce calendar age variability of events along strike that are thought to correlate. We tested three methods of estimating calendar ages, using the most recent events in a Noyo Canyon core. These methods are: 1. unconstrained radiocarbon age calibration, 2. age determination using known dates and inter-event time calculated from hemipelagic thickness and the regression-determined sedimentation rate, and 3. (preferred method) use OxCal's sequence option to calibrate and constrain radiocarbon ages given all available stratigraphic information, including date of collection, historical or geological datums, inter-event times and radiocarbon ages. The upper-most event was chosen for these tests because it is known to be the 1906 earthquake and the 20th century reservoir correction is well known in this area. The penultimate event was chosen because it has been dated at multiple land sites. 1906 event: Unconstrained calibration: calibration of the radiocarbon age of the 1906 event yields an age of ~1913, (1?: 1898-1940). Sedimentation time: subtracting the time represented by the hemipelagic thickness above the 1906 event from the date of collection (1999) yields an age of ~1904. OxCal sequence: constrained calibration yields an age of ~1902 (1?: 1880-1910). Penultimate event: Unconstrained calibration: calibration of this radiocarbon age yields an age of ~1753 (1?: 1660-1840). Sedimentation time: subtracting the time represented by the hemipelagic thickness below the 1906 event from 1906 yields an age of ~1756. OxCal sequence: constrained calibration yields an age of ~1700 (1?: 1650-1735), in good agreement with adjacent northern SAF paleoseismic sites on land: Fort Ross = 1710 (1610-1810), Vedanta =1711 (1695-1720) (T. Niemi, K. Kelson, and T. Fumal pers. com. 2005). The close correspondence in time of our SAF penultimate event and the AD 1700 Cascadia event suggests the possibility that the Noyo Canyon site may have recorded the Cascadia event, ~ 130 km away, however we find that the penultimate event in Noyo Canyon is well correlated southward to at least Point Arena, too far to be related to the Cascadia event. We also continue to refine inter-site physical property correlation methods in parallel with radiocarbon ages. Depositional patterns within events, recorded as magnetic susceptibility, chemical, and density patterns, match at widely separated sites in surprising detail. Both individual event signatures, and the downcore stratigraphic patterns are both highly unique and strongly comparable from site.

Morey, A. E.; Goldfinger, C.; Erhardt, M.; Nelson, C. H.; Johnson, J. E.; Gutierrez-Pastor, J.

2005-12-01

281

Nanomechanical measurement of astrocyte stiffness correlated with cytoskeletal maturation.

Astrocytes are known to serve as scaffolding cells that shape the brain. The physical properties of astrocytes, such as stiffness, are important for their scaffolding function. These properties may be altered in certain pathological conditions, such as in brain cancer. However, actual stiffness of astrocytes is not yet well understood. Here, we report that the astrocyte stiffness is positively correlated with the density of cytoskeletal proteins, such as actin filaments, microtubules, and intermediate filaments. The value of the stiffness of astrocytes as measured by atomic force microscopy (AFM) increases 38-fold in five-week-old rats compared to postnatal-day zero pups. Using multicolor confocal microscopy, we found that the complexity of cytoskeletal proteins, such as actin filaments, microtubules, and intermediate filaments, increase as the animal gets older. Our findings indicate that the change of stiffness positively correlates with the maturation of cytoskeletal proteins, and suggest that AFM can be useful as an analytical and diagnostic tool for neuroscience. © 2014 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 103A: 365-370, 2015. PMID:24665040

Lee, Sang-Myung; Nguyen, Thi-Huong; Na, Kyounghwan; Cho, Il-Joo; Woo, Dong Ho; Oh, Jae-Eung; Lee, C Justin; Yoon, Eui-Sung

2015-01-01

282

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

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/$c$.

Ahmed M. Hamed

2014-08-04

283

Advances in Air-Sea Flux Measurement by Eddy Correlation

NASA Astrophysics Data System (ADS)

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.

Blomquist, Byron W.; Huebert, Barry J.; Fairall, Christopher W.; Bariteau, Ludovic; Edson, James B.; Hare, Jeffrey E.; McGillis, Wade R.

2014-09-01

284

Measurements of energy correlations in e + e -?hadrons

NASA Astrophysics Data System (ADS)

Energy-energy-correlations (EEC) have been measured with the JADE detector at c.m. energies of 14 GeV, 22 GeV and in the region 29 GeV< E cm<36 GeV. Corrected results are presented of EEC and their asymmetry, which can be directly compared to theoretical predictions. At < E cm>=34 GeV a comparison with second order QCD predictions yields good agreement for the string model fragmentation resulting in a value of the strong coupling constant ? s =0.165±0.01 (stat.). The independent fragmentation models, which yield values of ? s between 0.10 and 0.15 depending on the treatment of energy and momentum conservation and of the gluon splitting, do not provide a satisfactory description of the data over the full angular range.

Bartel, W.; Becker, L.; Bowdery, C.; Cords, D.; Felst, R.; Haidt, D.; Junge, H.; Knies, G.; Krehbiel, H.; Laurikainen, P.; Meinke, R.; Meissner, K.; Naroska, B.; Olsson, J.; Pietarinen, E.; Schmidt, D.; Steffen, P.; Warming, P.; Zachara, M.; Dietrich, G.; Elsen, E.; Heinzelmann, G.; Kado, H.; Kuhlen, M.; Mashimo, T.; Meier, K.; Petersen, A.; Schneekloth, U.; Weber, G.; Ambrus, K.; Bethke, S.; Dieckmann, A.; Heintze, J.; Hellenbrand, K. H.; Heuer, R. D.; Komaniya, S.; von Krogh, J.; Lennert, P.; Matsumura, H.; Rieseberg, H.; Spitzer, J.; Wagner, A.; Finch, A.; Foster, F.; Hughes, G.; Nozaki, T.; Nye, J.; Allison, J.; Baines, J.; Ball, A. H.; Barlow, R. J.; Chrin, J.; Duerdoth, I. P.; Greenshaw, T.; Hill, P.; Loebinger, F. K.; MacBeth, A. A.; McCann, H.; Mills, H. E.; Murphy, P. G.; Stephens, K.; Glasser, R. G.; Sechi-Zorn, B.; Skard, J. A. J.; Wagner, S.; Zorn, G. T.; Cartwright, S. L.; Clarke, D.; Marshall, R.; Whittaker, J. B.; Kanzaki, J.; Kawamoto, T.; Kobayashi, T.; Koshiba, M.; Minowa, M.; Nozaki, M.; Orito, S.; Sato, A.; Takeda, H.; Takeshita, T.; Totsuka, Y.; Yamada, S.

1984-09-01

285

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

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

2013-01-01

286

SPIN-DEPENDENT SCATTERING LENGTHS OF SLOW NEUTRONS WITH NUCLEI BY PSEUDOMAGNETIC MEASUREMENTS

- magnetic measurements may give precise information on the internal field seen by the nuclei. The scattering by the pseudomagnetic moments Â¡t* charac- teristic of the nuclei, such that M * = N Â¡t* P, where N is the number.913 the measure in nuclear magnetons of the magnetic moment ,un of the neutron. The nuclear polarization

Boyer, Edmond

287

Bin-Bin Correlation Measurement by the Bunching-Parameter Method

A new method for the experimental study of bin-bin correlations is proposed. It is shown that this method is able to reveal important additional information on bin-bin correlations, beyond that of factorial-correlator measurements.

S. V. Chekanov; W. Kittel; V. I. Kuvshinov

1996-05-23

288

openBEB: open biological experiment browser for correlative measurements

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

2014-01-01

289

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

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

Athena Xenikou; Adrian Furnham

1996-01-01

290

Along with the increasing need for living-donor liver transplantation (LDLT), the issue of organ shortage has become a serious problem. Therefore, the use of organs from elderly donors has been increasing. While the short-term results of LDLT have greatly improved, problems affecting the long-term outcome of transplant patients remain unsolved. Furthermore, since contradictory data have been reported with regard to the relationship between donor age and LT/LDLT outcome, the question of whether the use of elderly donors influences the long-term outcome of a graft after LT/LDLT remains unsettled. To address whether hepatocyte telomere length reflects the outcome of LDLT, we analyzed the telomere lengths of hepatocytes in informative biopsy samples from 12 paired donors and recipients (grafts) of pediatric LDLT more than 5 years after adult-to-child LDLT because of primary biliary atresia, using quantitative fluorescence in situ hybridization (Q-FISH). The telomere lengths in the paired samples showed a robust relationship between the donor and grafted hepatocytes (r?=?0.765, p?=?0.0038), demonstrating the feasibility of our Q-FISH method for cell-specific evaluation. While 8 pairs showed no significant difference between the telomere lengths for the donor and the recipient, the other 4 pairs showed significantly shorter telomeres in the recipient than in the donor. Multiple regression analysis revealed that the donors in the latter group were older than those in the former (p?=?0.001). Despite the small number of subjects, this pilot study indicates that donor age is a crucial factor affecting telomere length sustainability in hepatocytes after pediatric LDLT, and that the telomeres in grafted livers may be elongated somewhat longer when the grafts are immunologically well controlled. PMID:24727734

Kawano, Youichi; Ishikawa, Naoshi; Aida, Junko; Sanada, Yukihiro; Izumiyama-Shimomura, Naotaka; Nakamura, Ken-ichi; Poon, Steven S. S.; Matsumoto, Koshi; Mizuta, Koichi; Uchida, Eiji; Tajiri, Takashi; Kawarasaki, Hideo; Takubo, Kaiyo

2014-01-01

291

Measurement of the minority carrier diffusion length and edge surface-recombination velocity in InP

NASA Technical Reports Server (NTRS)

A scanning electron microscope (SEM) was used to measure the electron (minority carrier) diffusion length (L(sub n)) and the edge surface-recombination velocity (V(sub s)) in zinc-doped Czochralski-grown InP wafers. Electron-beam-induced current (EBIC) profiles were obtained in specimens containing a Schottky barrier perpendicular to the scanned (edge) surface. An independent technique was used to measure V(sub s), and these values were used in a theoretical expression for normalized EBIC. A fit of the experimental data with this expression enabled us to determine L(sub n).

Bailey, Sheila G.; Hakimzadeh, Roshanak

1993-01-01

292

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

of the leading measures (Resnik [11] and Wang et al. [15]). Our method showed impressive accuracy with results in the general English domain. For example, Resnik [11], Jiang and Conrath [5] and Lin [6] proposed information

Al-Mubaid, Hisham

293

New Measurement of ?-? Angular Correlation in ^22Na

NASA Astrophysics Data System (ADS)

We have measured the ?-? directional correlation in the hindered decay ^22 Na (3^+) arrow ^22Ne (2^+) using the Gammasphere array at LBNL. Our measurement contributes to determining a complete set of weak form factors for the ^22Na ? decay, testing corrections to allowed ? decay to second recoil order. The aim is to resolve a long-standing discrepancy between experiment and allowed-order theory in the electron capture to positron emission ratios. We used a 6 ?Ci source of ^22Na in the center of Gammasphere, a spherical array of 110 Ge detectors. The ?^+ is detected with a 3 mm thick plastic scintillator with 8% solid angle. The ?^+ decay is followed by a 1.275 MeV ? from the ^22Ne 2^+ state. We search for a directional dependence of the emitted ?'s detected in coincidence with a ? of form 1 + A\\cos^2 ?, with ? the angle between the ? and the individual Ge detectors, and A of order 10-3. Variable Ge detector efficiency is normalized by dividing coincident ? counts by single 1.275 MeV ?'s. Fitting the results versus ? - ? angle using gates on the ?^+ energy yields the energy-dependent A, which is sensitive to a linear combination of second-order form factors. Current data and analysis, and implications for ^22Na form factors will be presented.

Vetter, Paul; Bowers, Chris; Freedman, Stuart; Fujikawa, Brian; Reich, Jurgen; Shang, Song; Wasserman, Eric

1997-10-01

294

Reviews 16 publications (1913-1914) based on the problem of correlations. Correlation is viewed as a means of solving the problem of development and the traits that are affected. The uses of correlations are also discussed. A high correlation does not signify good quality of the two factors. A more intensive study of the factors influencing correlation is recommended. Cites a

James Burt Miner

1914-01-01

295

Reviews 38 studies on statistical correlation (1913-1916). Several studies have tried to explain and investigate Spearman's theory of general and specific mental factors in terms of correlation. The interpretation of correlation through heredity has also been discussed by investigators. A number of methods such as partial and multiple correlations, variant difference correlation method, and several others have been devised. The

James Burt Miner

1916-01-01

296

Picosecond electron bunch length measurement by electro-optic detection of the Wakefield

The longitudinal profile of an 10 nC electron bunch of a few picoseconds duration will be measured by electro-optic detection of the wakefield. The polarization of a short in-frared probe laser pulse (derived from the photocathode excitation laser) is modulated in a LiTaO3 crystal by the transient electric field of the bunch. The bunch profile is measured by scanning the delay between the laser and the bunch, and is sensitive to head/tail asymmetries. A single-shot extension of the technique is possible using a longer chirped laser pulse.

M. J. Fitch, A. C. Melissinos and P. L. Colestock

1999-05-17

297

NASA Astrophysics Data System (ADS)

A digital image correlation (DIC) algorithm for displacement measurements combining cross-correlation and a differential technique was validated through a set of experimental tests. These tests consisted of in-plane rigid-body translation and rotation tests, a tensile mechanical test, and a mode I fracture test. The fracture mechanical test, in particular, was intended to assess the accuracy of the method when dealing with discontinuous displacement fields, for which subset-based image correlation methods usually give unreliable results. The proposed algorithm was systematically compared with the Aramis® DIC-2D commercial code by processing the same set of images. When processing images from rigid-body and tensile tests (associated with continuous displacement fields), the two methods provided equivalent results. When processing images from the fracture mechanical test, however, the proposed method obtained a better qualitative description of the discontinuous displacements. Moreover, the proposed method gave a more reliable estimation of both crack length and crack opening displacement of the fractured specimen.©

Xavier, José; Sousa, António M. R.; Morais, José J. L.; Filipe, Vitor M. J.; Vaz, Mario

2012-04-01

298

Single-arm three-wave interferometer for measuring dispersion of short lengths of fiber

-coherence interferometry for light-scattering spectroscopy," Opt. Lett. 28, 1230-1232 (2003). 11. R. K. Hickernell, T by Fourier-transform spectroscopy", Opt. Lett. 18. 19-21 (1993). 12. P. Hlubina, "White-light spectral codes: (120.3180) Interferometry; (060.2300) Fiber measurements; (260.2030) Dispersion References

Qian, Li

299

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

Dan Ben-Yaakov,2 David Andelman,2 S. A. Safran,1 and Jacob Klein1,* 1 Department of Materials; published 11 September 2009) Using a surface force balance with fast video analysis, we have measured-Boltzmann (PB) theory, are used clas- sically to calculate the repulsive interactions between uniform

Andelman, David

300

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

Kenneth D. Carlander

1982-01-01

301

Compounds from Biomass Pyrolysis" Ross Kendall Faculty Mentor: Dr. Paul Dauenhauer, Chemical Engineering by using what he made to measure many of the compounds involved in biomass pyrolysis. If we can understand to retrieve diffusion coefficients of many intermediates of the biomass pyrolysis reaction. From this data

Mountziaris, T. J.

302

Length distributed measurement of temperature effects in Yb-doped fibers during pumping

NASA Astrophysics Data System (ADS)

We demonstrate a distributed measurement technique to observe temperature changes along pumped Yb-doped fibers. This technique is based on an array of fiber Bragg gratings acting as a temperature sensor line. The Bragg gratings are inscribed directly into the Yb-doped fiber core using high-intensity ultrashort laser pulses and an interferometric setup. We studied the temperature evolution in differently co-doped Yb fibers during optical pumping and identified different effects contributing to the observed temperature increase. We found that preloading of fibers with hydrogen supports the formation of Yb during UV irradiation and has a large impact on fiber temperature during pumping. The proposed technique can be applied to investigate the homogeneity of pump absorption in active fibers and to support spatially resolved photodarkening measurements.

Leich, Martin; Fiebrandt, Julia; Schwuchow, Anka; Jetschke, Sylvia; Unger, Sonja; Jäger, Matthias; Rothhardt, Manfred; Bartelt, Hartmut

2014-06-01

303

Summary form only given. A conditioned 5 MeV, 20 kA, 40 ns FWHM intense relativistic electron beam produced by the SuperIBEX accelerator is injected into a 20-meter-diameter propagation tank at pressures in the 400-760 Torr range. The radial profile of the beam is measured using time-resolved optical diagnostics and a segmented concentric Faraday cup. Beam and net currents are recorded

M. C. Myers; J. A. Antoniades; R. F. Fernsler; R. F. Hubbard; D. P. Murphy; J. Santos; D. J. Weidman; R. A. Meger

1993-01-01

304

Herriott Cell Interferometer for Density Measurements in Small-Scale Length Plasmas

NASA Astrophysics Data System (ADS)

The introduction of a Herriott cell into a standard quadrature heterodyne interferometer is evaluated and demonstrated to increase the resolution of the system. Measurements of electron and neutral density during and after the current pulse are sought for modeling purposes for spacecraft contamination from Pulsed Plasma Thrusters. Testing is performed on the UIUC PPT-4, a coaxial electrothermal Pulsed Plasma Thruster pulsing at 20 J. Analytical and experimental analysis is conducted to determine the integrity of the phase front and the effect of multiple passes on the density measurements taken. The phase front quality is found to be acceptable for interferometric purposes and density measurements are taken for 2, 6, 14, and 18 passes in the Herriott cell. The advantage of the cell is obvious at late times when the external room vibrations induce an apparent phase shift in the same direction as neutral particles. Due to the same dependence on wavelength, 2 laser frequencies cannot be used to separate neutral and vibration contributions. The Herriott cell allows a density resolution increase linear with the number of passes that does not increase the vibrational component. Uncertainties from both vibrational sources and shot-to-shot variations of the thruster itself are investigated and characterized for this system. Due to variations in room vibrations on a day to day basis, the cell was unable to characterize the neutral density of the thruster. However, for single tests, neutral density measurements were acquired. The Herriott cell with 18 passes introduced a 9-fold increase in resolution over the standard 2-pass interferometric setup. At 200 microseconds for single tests at 14 and 18 passes (^20 shots averaged) neutral density at the exit plane was shown to be no more than 1*1016/cu cm. Peak electron density (4 microseconds) was shown to be 5.0*1015 +/- 1.1*1015/cu cm.

Antonsen, Erik; Burton, Rodney; Engelman, Scott; Spanjers, Greg

2000-06-01

305

NASA Technical Reports Server (NTRS)

Measurements of stratospheric ozone, temperature, and aerosols were made by the NASA/GSFC mobile stratospheric lidar during the UARS (Upper Atmospheric Research Satellite) Correlative Measurement Campaign at the JPL-Table Mountain Facility in Feb. and Mar. 1992. Due to the presence of substantial amounts of residual volcanic aerosol from the eruption of Mt. Pinatubo, the GSFC lidar system was modified for an accurate measurement of ozone concentration in the stratosphere. While designed primarily for the measurement of stratospheric ozone, this lidar system was also used to measure middle atmosphere temperature and density from 30 to 65 km and stratospheric aerosol from 15 to 35 km. In the following sections, we will briefly describe and present some typical measurements made during this campaign. Stratospheric ozone, temperature, and aerosols profiles derived from data taken between 15 Feb. and 20 Mar., 1992 will be presented at the conference.

Mcgee, Thomas J.; Singh, Upendra N.; Gross, Michael; Heaps, William S.; Ferrare, Richard

1992-01-01

306

Background The prevalence of obesity in U.S. has been rising at an alarming rate, particularly among Hispanic, African, and Asian minority groups. This trend is due in part to excessive calorie consumption and sedentary lifestyle. We sought to investigate whether parental origins influence eating behaviors in healthy urban middle school students. Methods A multiethnic/racial population of students (N?=?182) enrolled in the ROAD (Reduce Obesity and Diabetes) Study, a school-based trial to assess clinical, behavioral, and biochemical risk factors for adiposity and its co-morbidities completed questionnaires regarding parental origins, length of US residency, and food behaviors and preferences. The primary behavioral questionnaire outcome variables were nutrition knowledge, attitude, intention and behavior, which were then related to anthropometric measures of waist circumference, BMI z-scores, and percent body fat. Two-way analysis of variance was used to evaluate the joint effects of number of parents born in the U.S. and ethnicity on food preference and knowledge score. The Tukey-Kramer method was used to compute pairwise comparisons to determine where differences lie. Analysis of covariance (ANCOVA) was used to analyze the joint effects of number of parents born in the US and student ethnicity, along with the interaction term, on each adiposity measure outcome. Pearson correlation coefficients were used to examine the relationships between maternal and paternal length of residency in the US with measures of adiposity, food preference and food knowledge. Results African Americans had significantly higher BMI, waist circumference and body fat percentage compared to other racial and ethnic groups. Neither ethnicity/race nor parental origins had an impact on nutrition behavior. Mothers’ length of US residency positively correlated with students’ nutrition knowledge, but not food attitude, intention or behavior. Conclusions Adiposity measures in children differ according to ethnicity and race. In contrast, food behaviors in this middle school sample were not influenced by parental origins. Longer maternal US residency benefited offspring in terms of nutrition knowledge only. We suggest that interventions to prevent obesity begin in early childhood. PMID:24134822

2013-01-01

307

Interactions between membranes and molecules are important for many biological processes, e.g., transport of molecules across cell membranes. However, the detailed physical description of the membrane-biomolecule system remains a challenge and simplified schemes allow capturing its main intrinsic features. In this work, by means of Monte Carlo computer simulations, we systematically study the distribution of uncharged spherical molecules in contact with a flexible surface. Our results show that the distribution for finite size particles has the same simple functional form as the one obtained for point-like particles and depends only on the ratio of the lateral correlation length of the membrane and the radius of the molecules. PMID:25238488

Córdoba-Valdés, Fidel; Castañeda-Priego, Ramón; Timmer, Jens; Fleck, Christian

2014-10-01

308

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.

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

309

Reviews 7 studies in the area of interpretation of correlation from the psychological point of view. The limitations and meanings of correlation methods have also been given. The statistical methods of calculating correlation, as given by 8 psychologists have been reported. Presents 22 reports, given by various psychologists, who have evaluated the tests using various correlation methods. Six studies were

James Burt Miner

1919-01-01

310

A subtilisin-like enzyme, soybean protease C1 (EC 3.4.21.25), initiates the degradation of the ?-conglycinin storage proteins in early seedling growth. Previous kinetic studies revealed a nine-residue (P5-P4') length requirement for substrate peptides to attain optimum cleavage rates. This modeling study used the crystal structure of tomato subtilase (SBT3) as a starting model to explain the length requirement. The study also correlates structure to kinetic studies that elucidated the amino acid preferences of soybean protease C1 for P1, P1' and P4' locations of the cleavage sequence. The interactions of a number of protease C1 residues with P5, P4 and P4' residues of its substrate elucidated by this analysis can explain why the enzyme only hydrolyzes peptide bonds outside of soybean storage protein's core double ?-barrel cupin domains. The findings further correlate with the literature-reported hypothesis for the subtilisin-specific protease-associated (PA) domain to play a critical role. Residues of the SBT3 PA domain also interact with the P2' residue on the substrate's carboxyl side of the scissile bond, while those on protease C1 interact with its substrate's P4' residue. This stands in contrast with the subtilisin BPN' that has no PA domain, and where the enzyme makes stronger interaction with residues on the amino side of the cleaved bond. The variable patterns of interactions between the substrate models and PA domains of tomato SBT3 and soybean protease C1 illustrate a crucial role for the PA domain in molecular recognition of their substrates. PMID:22285412

Tan-Wilson, Anna; Bandak, Basel; Prabu-Jeyabalan, Moses

2012-04-01

311

Adolescence is a period which is characterized by rapid physical growth and development of secondary sex characteristics. Male adolescence begins at 11-12 years of age and lasts approximately 5 years. During this interval, there is a growth spurt period which is observed any time between 11 and 16 years of age, lasting 2-3 years. Some authors claim that a male may have nearly 20-25% of his adult height and 50% of his adult weight during adolescence. When evaluating the maturational aspects of adolescence, it is essential to consider bone age (BA) as well as chronological age (CA). Bone age is the mean CA at which the skeletal maturation is normally attained. It is influenced by genetic, endocrinological and nutritional factors. An adolescent may not demonstrate the expected maturational steps if his BA is retarded. This report examines the relationship between CA, biological maturation and some anthropometrical measurements. PMID:8165916

Büyükgebiz, A; Eroglu, Y; Karaman, O; Kinik, E

1994-02-01

312

Transverse emittance measurements from a photocathode RF gun with variable laser pulse length

NASA Astrophysics Data System (ADS)

The gun test facility (GTF) at SSRL was started in 1996 to develop an appropriate injector for the proposed linac coherent light source (LCLS) at SLAC. The LCLS design requires the injector to produce a beam with at least 1 nC of charge in a 10 ps or shorter pulse with no greater than 1? mm mrad normalized rms emittance. The photoinjector at the GTF is 1.6 cell S-band symmetrized gun and emittance compensation solenoid. Emittance measurements, reported here, were made as function of laser pulse width using Gaussian longitudinal pulses. The lowest achieved emittance to date with 1 nC of charge is 5.6? mm mrad and was obtained with a pulse width of 5 ps (FWHM) and is in agreement with simulation. There are indications that the accelerator settings for these results may not have been optimal. Simulations also indicate that a normalized emittance meeting the LCLS requirement can be obtained using appropriately shaped transverse and temporal laser/electron beam pulses. Work has begun on producing temporal flat top laser pulses which combined with transverse clipping of the laser is expected to lower the emittance to approximately 1? mm mrad for 1 nC with optimal accelerator settings.

Reis, D. A.; Hernandez, M.; Schmerge, J. F.; Winick, H.; Hogan, M. J.

1999-06-01

313

Boundary Curvature Effect on Thin-film Drainage and Slip Length Measurements

The thin-liquid film drainage between two curved surfaces is a fundamental process for many hydrodynamic measurements, for which Vinogradova's formula has played a central role when flow slip occurs at fluid-solid interfaces. By performing a rigorous order-of-magnitude analysis, we reveal the importance of the curvature contribution to boundary flow, neglected sofar. Vinogradova's result is found to considerably underestimate the slip-induced reduction of the hydrodynamic drainage force. Our theory can play a crucial role in distinguishing finite-slip from no-slip and quantifying the degree of flow slip at fluid-solid surfaces, which is a fundamental but controversial issue in fluid dynamics. Moreover, qualitatively different from previous theories, our theory predicts a finite hydrodynamic repulsive force for two hydrophobic particles in touch, thus allowing particle collision to occur in a finite time without any additional attractive surface forces. This finding has deep and immediate implications on particle coagulation, adsorption and sedimentation processes relevant for numerous industrial technologies as well as natural phenomena on the earth.

Angbo Fang

2014-07-20

314

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

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.

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

315

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

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

316

The degree of correlation between ISEE 1 and ISEE 3 IMF measurements is highly variable. Approximately 200 two-hour periods when the correlation was good and 200 more when the correlation was poor are used to determine the relative control of several factors over the degree of correlation. Both IMF variance and spacecraft separation distance in the plane perpendicular to the

N. U. Crooker; G. L. Siscoe; C.T. Russell; E. J. Smith

1982-01-01

317

NSDL National Science Digital Library

The applets, created by Virginia Tech's Department of Statistics, allow you to see how different bivariate data look under different correlation structures. The "Movie" applet either creates data for a particular correlation or animates a multitude data sets ranging correlations from -1 to 1. The "Creation" applet allows the user to create a data set by adding or deleting points from the screen.

Anderson-Cook, C.; Dorai-Raj, S.; Robinson, T.

2009-09-14

318

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

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

2014-10-01

319

The correlation-optical method measuring time of thrombus formation

NASA Astrophysics Data System (ADS)

The method of laser express diagnostics of thrombus formation process in a blood plasma is presented. This method is based on analysis of image correlation of blood plasma during thrombus formation process. The technique of experimental researches of scattering laser radiation by blood plasma is shown. It is established that the dynamic of intensity fluctuations of radiation of scattered by blood plasma decreases under the influence of thrombin that causes increasing correlation coefficient and gives the possibility to estimate continuance of thrombus formation process. It was discovered that time of thrombus formation of healthy people is smaller than of asthmatics.

Gavrylyak, M. S.; Grygoryshyn, P. M.

2013-12-01

320

Non-Markovianity: initial correlations and nonlinear optical measurements

By extending the response function approach developed in nonlinear optics, we analytically derive an expression for the non-Markovianity in the time evolution of a system in contact with a quantum mechanical bath, and find a close connection with the directly observable nonlinear optical response. The result indicates that memory in the bath-induced fluctuations rather than in the dissipation causes non-Markovianity. Initial correlations between states of the system and the bath are shown to be essential for a correct understanding of the non-Markovianity. These correlations are included in our treatment through a preparation function. PMID:22753819

Dijkstra, Arend G.; Tanimura, Yoshitaka

2012-01-01

321

National Technical Information Service (NTIS)

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...

M. Tabib-Azar

1997-01-01

322

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

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

2009-03-26

323

NASA Astrophysics Data System (ADS)

The current density of the noontime equatorial electrojet (EEJ) as determined from CHAMP data is highly variable between successive passes of the satellite, which are separated by 23° in distance and 93 min in time. An open question is to which extent this variability is caused by temporal or spatial variations in the ionosphere. Another important question is the connection between EEJ and global solar-quiet (Sq) current systems. We try to answer these questions by comparing the EEJ current density estimated from high-quality scalar magnetic field measurements of the CHAMP satellite with the magnetic horizontal intensity variations at six equatorial observatory pairs distributed across the globe. Data taken during the period 2000-2002 were used for the present study. We apply corrections for the effect of local time (LT) and Sq fields. By estimating the correlation coefficients between the ground and satellite data as a function of distances between measurements, new insights into the spatial structure of the EEJ have been obtained. The high correlation, when CHAMP passes directly over an observatory, decays quickly in eastern and western directions. Typically, within ±15° of longitudinal separation between satellite and observatory, the correlation falls well below the statistical significance level. This observation holds for all longitude sectors. Interestingly, the correlation between CHAMP-inferred EEJ strength and observatory differences breaks down for the observatory pairs, outside of a ±4° latitudinal band. This implies that the EEJ and Sq variations are uncorrelated for periods up to 1 hour. Additionally, it was found that monitoring of the EEJ can be performed best if the reference observatory is 4° to 5° apart from the dip equator.

Manoj, C.; Lühr, H.; Maus, S.; Nagarajan, N.

2006-11-01

324

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. ?? 2011 by the Ecological Society of America.

Eaton, M.J.; Link, W.A.

2011-01-01

325

Enhanced sensitivity cross-correlation method for voltage noise measurements

Ultralow noise measurements often require the application of signal processing and correction techniques to go beyond the noise performances of front-end amplifiers. In this paper, a new method for the voltage noise measurement is proposed, which allows, at least in principle, the complete elimination of the noise introduced by the amplifiers used for the measurements. This is obtained by resorting

Felice Crupi; Gino Giusi; Carmine Ciofi; Calogero Pace

2006-01-01

326

Reviews 32 papers on correlation its methods, interpretation and application. Highlights the contributions of K. Pearson, B. Hart and C. Spearman, and W. H. Winch. W. Betz's publications concludes that correlation alone does not demonstrate a functional connection and serves the purpose of (1) describing educational or social descriptions of Large groups, and (2) discovering functional connections when used with

James Burt Miner

1912-01-01

327

Discusses: (1) the need for a general factor to explain the correlation between tested psychophysical processes and (2) the importance of multiple correlation in solving the complex problems. Reports the contributions of Thurstone, Ruml and Kelley to the methods of calculation of coefficients. Doll offers new ways of using corrections. Applications of this method in new fields other than applied

James Burt Miner

1917-01-01

328

What is the order of the nematic--smectic-[ital A] ([ital NA]) transition The answer to this question has flip-flopped over the years as ever more sophisticated theories and ever more careful experiments have addressed the issue. The Landau theory predicts that the transition can be either first or second order, depending on material parameters. de Gennes and McMillan [Solid State Commun. 10, 753 (1972); Phys. Rev. A 14, 1238 (1971)] showed that nematic fluctuations would drive the transition to first order as the temperature of the [ital NA] transition approached that of the nematic-isotropic transition. Halperin, Lubensky, and Ma [Phys. Rev. Lett. 32, 292 (1974)] (HLM) then argued that the effect of nematic fluctuations is more subtle and concluded that the transition is always at least weakly first order. Monte Carlo simulations indicate, however, that for a large enough nematic range, the transition becomes second order. We investigate the order of the [ital NA] transition experimentally by measuring the capillary length (ratio of the surface tension to the latent heat) near an apparent tricritical point in a binary liquid-crystal mixture. Our measurements confirm the existence of the extra free-energy term predicted by the HLM theory and yield, as a by-product, surface-tension measurements of the [ital NA] interface. Although we cannot currently detect the tricritical point suggested by numerical work, we have not approached any fundamental sensitivity limits either.

Tamblyn, N. (Department of Physics, Simon Fraser University, Burnaby, British Columbia, V5A 1S6 (Canada)); Oswald, P. (Laboratoire de Physique, Ecole Normale Superieure de Lyon, 46, allee d'Italie, 69364 Lyon Cedex 07 (France)); Miele, A. (Department of Physics, Simon Fraser University, Burnaby, British Columbia, V5A 1S6 (Canada)); Bechhoefer, J. (Department of Physics, Simon Fraser University, Burnaby, British Columbia, V5A 1S6 (Canada))

1995-03-01

329

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 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. The SNR metrics and corresponding models presented herein are expanded to be applicable to both standard and filtered correlations. 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 ...

Xue, Zhenyu; Vlachos, Pavlos P

2014-01-01

330

Accurate measurement of curvilinear shapes by Virtual Image Correlation

The proposed method allows the detection and the measurement, in the sense of metrology, of smooth elongated curvilinear shapes. Such measurements are required in many fields of physics, for example: mechanical engineering, biology or medicine (deflection of beams, fibers or filaments), fluid mechanics or chemistry (detection of fronts). Contrary to actual methods, the result is given in an analytical form

B. Semin; H. Auradou; M. L. M. François

2011-01-01

331

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

Sampl, Sandra; Pramhas, Sibylle; Stern, Christian; Preusser, Matthias; Marosi, Christine; Holzmann, Klaus

2012-01-01

332

Examines the use of various methods of correlations, for determining the diagnostic value of tests, used in analysis of abilities, in business psychology, mental development and school records. Also reviews a number of studies done in this regard.

James Burt Miner

1918-01-01

333

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

NASA Astrophysics Data System (ADS)

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.

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

2014-04-01

334

Spot size and effective focal length measurements for a fast axial flow CO{sub 2} laser

An evaluation of the variation in focal plane position and spot size for a 1,650 W fast axial flow CO{sub 2} laser was performed. Multiple measurements of the focused beam were taken at stepped intervals along the beam axis to create a composite representation of the focus region. Measurements were made at several power levels from low to full power for each of five nominally identical lenses. It was found that as laser output power increases, the minimum focused spot radius increases, and the position of minimum focus shifts toward the laser resonator. These effects were attributed to observed variations in the diameter of the beam entering the focusing lens. For the ZnSe (f = 127 mm) lenses examined, variations in spot radius and focal plane position were seen. Lenses with high rated absorption had a larger variation in spot size and effective focal length than those with low absorption. Lenses that had previously been degraded by welding had the greatest variation.

Steele, R.J. [Naval Air Warfare Center, China Lake, CA (United States); Fuerschbach, P.W.; MacCallum, D.O. [Sandia National Labs., Albuquerque, NM (United States)

1997-12-31

335

It remains to be established to what degree titin and the extracellular matrix (ECM) contribute to passive pressure in the left ventricle (LV). Thus, we aimed to elucidate the contribution of major molecular determinants of passive pressure in the normal mouse LV. Furthermore, we determined the working sarcomere length (SL) range of the LV to bridge our findings to earlier work in skinned muscle fibers. We utilized Frank-Starling type protocols to obtain diastolic pressure-volume relationships (PVR) in Langendorff perfused isolated LVs. To quantify the molecular contribution of titin and ECM, we innovated on methods of fiber mechanics to chemically permeabilize intact LVs and measure a fully passive PVR. To differentially dissect the contributions of the ECM and titin, we utilized myofilament extraction techniques in permeabilized LVs, measuring passive PVRs at each stage in the protocol. Myofilament extraction suggests that titin contributes ~80% of passive pressures in the heart. Langendorff perfusion was also used to chemically fix passive and BaCl2 activated hearts at specific volumes to determine that the maximal working SL range of the midwall LV fibers is approximately 1.8-2.2 ?m. A model of the passive SL-Volume relationship was then used to estimate the pressure-SL relationships, indicating that the ECM contribution does not exceed titin's contribution until large volumes with SLs>~2.2?m. In conclusion, within physiological volumes titin is the dominant contributor to LV passive pressure, and ECM-based pressures dominates at larger volumes. PMID:21255582

Chung, Charles S; Granzier, Henk L

2011-01-01

336

Electrical conductivity measurements of nanofluids and development of new correlations.

In this study the electrical conductivity of aluminum oxide (Al2O3), silicon dioxide (SiO2) and zinc oxide (ZnO) nanoparticles dispersed in propylene glycol and water mixture were measured in the temperature range of 0 degrees C to 90 degrees C. The volumetric concentration of nanoparticles in these fluids ranged from 0 to 10% for different nanofluids. The particle sizes considered were from 20 nm to 70 nm. The electrical conductivity measuring apparatus and the measurement procedure were validated by measuring the electrical conductivity of a calibration fluid, whose properties are known accurately. The measured electrical conductivity values agreed within +/- 1% with the published data reported by the manufacturer. Following the validation, the electrical conductivities of different nanofluids were measured. The measurements showed that electrical conductivity of nanofluids increased with an increase in temperature and also with an increase in particle volumetric concentration. For the same nanofluid at a fixed volumetric concentration, the electrical conductivity was found to be higher for smaller particle sizes. From the experimental data, empirical models were developed for three nanofluids to express the electrical conductivity as functions of temperature, volumetric concentration and the size of the nanoparticles. PMID:22103081

Konakanchi, Hanumantharao; Vajjha, Ravikanth; Misra, Debasmita; Das, Debendra

2011-08-01

337

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

Collery, Ross F.; Veth, Kerry N.; Dubis, Adam M.; Carroll, Joseph; Link, Brian A.

2014-01-01

338

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. ...

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

2010-10-04

339

Helium production measurements for neutron dosimetry and damage correlations

Helium accumulation fluence monitors (HAFM's), consisting of miniature vanadium capsules containing small, accurately-known amounts of Â¹Â°B or â¶Li, are being used routinely for neutron dosimetry measurements in breeder reactor environments. Additionally, solid wires of Al, Fe and Cu have been irradiated by 14.8-MeV neutrons from the d-T reaction, and measurements of the helium production along these wires have given detailed

H. IV Farrar; E. P. Lippincott

1978-01-01

340

This study was designed to estimate the risk of developing diabetes in relation to adult height components, namely leg length\\u000a and leg length\\/height ratio. Data on 12,800 individuals without diabetes were obtained at the baseline examination from the\\u000a ARIC cohort. Cox proportional hazard models were used to estimate hazard rate ratios of diabetes for each 5-cm difference\\u000a in leg length

Shimon Weitzman; Chin-Hua Wang; James S. Pankow; Maria I. Schmidt; Frederic L. Brancati

2010-01-01

341

Measuring blood velocity using correlative spectrally encoded flow cytometry.

Spectrally encoded flow cytometry (SEFC) is a promising technique for imaging blood in the microcirculation. Yet, the dependency of one of the axes of the image on time prevents effective quantification of essential clinical parameters. Here, we address this challenge by splitting the optical path in an SEFC system into two parallel imaging lines, followed by straightforward data analysis for recovering the flow speed from the multiplexed data. The method is demonstrated by measuring the flow velocity of latex beads and blood cells in vitro. The system allows real-time velocity measurements of up to 11.7??mm/s at high spatial resolution, and could be integrated into existing SEFC systems for effectively measuring blood parameters in small capillary vessels. PMID:25078193

Elhanan, Tal; Yelin, Dvir

2014-08-01

342

Analysis of hard two-photon correlations measured in heavy-ion reactions at intermediate energies

hypersurfaces, e.g., one describes the correlation as function of the quantities q q1 q2 , q0 E1 E2 1 , or QinvAnalysis of hard two-photon correlations measured in heavy-ion reactions at intermediate energies H Recently reported measurements of hard photon correlations in the reactions 36 Ar on 27 Al at 95A MeV, 86

Bauer, Wolfgang

343

TURBULENT DYNAMICS IN SOLAR FLARE SHEET STRUCTURES MEASURED WITH LOCAL CORRELATION TRACKING

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.

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

344

SUMMARY: Arslan N, Büyükgebiz B, Öztürk Y. Fatty liver in obese children: prevalence and correlation with anthropometric measurements and hyperlipidemia. Turk J Pediatr 2005; 47: 23-27. The aim of this study was to evaluate the correlation of ultrasonography-proven fatty liver with liver functions, serum lipid levels and anthropometric measurements in children with exogenous obesity. Three hundred and twenty- two patients

Nur Arslan; Benal Büyükgebiz; Yeþim Öztürk; Handan Çakmakçý

2005-01-01

345

The purpose of this report is to demonstrate how to measure the magnitude of expression of the 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

SUSAN J. ASTLEY; STERLING K. CLARREN

2001-01-01

346

First Measurements of Spin Correlation Using Semi-leptonic $t\\bar{t}$ Events at ATLAS

This poster presents the results of the first measurement of $t\\bar{t}$ spin correlations in the lepton+jets channel at ATLAS. By using a dedicated up/down type quark separation in the reconstruction, two hadronic spin analyzers were used to measure spin correlations.

Lemmer, Boris; The ATLAS collaboration

2014-01-01

347

Impulsive noise of printers: measurement metrics and their subjective correlation

In the office and home computing environments, printer impulsive noise has become a significant contributor to user perceived quality or lack thereof, and can affect the user's comfort level and ability to concentrate. Understanding and quantifying meaningful metrics for printer impulsivity is becoming an increasingly important goal for printer manufacturers. Several methods exist in international standards for measuring the impulsivity

Terrence Baird; Norman Otto; Wade Bray; Mike Stephan

2005-01-01

348

Measurement of intracellular strain on deformable substrates with texture correlation.

Mechanical stimuli are important factors that regulate cell proliferation, survival, metabolism and motility in a variety of cell types. The relationship between mechanical deformation of the extracellular matrix and intracellular deformation of cellular sub-regions and organelles has not been fully elucidated, but may provide new insight into the mechanisms involved in transducing mechanical stimuli to biological responses. In this study, a novel fluorescence microscopy and image analysis method was applied to examine the hypothesis that mechanical strains are fully transferred from a planar, deformable substrate to cytoplasmic and intranuclear regions within attached cells. Intracellular strains were measured in cells derived from the anulus fibrosus of the intervertebral disc when attached to an elastic silicone membrane that was subjected to tensile stretch. Measurements indicated cytoplasmic strains were similar to those of the underlying substrate, with a strain transfer ratio (STR) of 0.79. In contrast, nuclear strains were much smaller than those of the substrate, with an STR of 0.17. These findings are consistent with previous studies indicating nuclear stiffness is significantly greater than cytoplasmic stiffness, as measured using other methods. This study provides a novel method for the study of cellular mechanics, including a new technique for measuring intranuclear deformations, with evidence of differential magnitudes and patterns of strain transferred from the substrate to cell cytoplasm and nucleus. PMID:16698026

Gilchrist, Christopher L; Witvoet-Braam, Sietske W; Guilak, Farshid; Setton, Lori A

2007-01-01

349

A Binomial Test of Group Differences with Correlated Outcome Measures

ERIC Educational Resources Information Center

Building on previous arguments for why educational researchers should not provide effect-size estimates in the face of statistically nonsignificant outcomes (Robinson & Levin, 1997), Onwuegbuzie and Levin (2005) proposed a 3-step statistical approach for assessing group differences when multiple outcome measures are individually analyzed within…

Onwuegbuzie, Anthony J.; Levin, Joel R.; Ferron, John M.

2011-01-01

350

Chromosomal and genomic instability due to telomere dysfunction is known to play an important role in carcinogenesis. To study telomere shortening in the epidermis surrounding actinic keratosis, we measured telomere lengths of basal, parabasal, and suprabasal cells in epidermis with actinic keratosis (actinic keratosis group, n = 18) and without actinic keratosis (sun-protected, n = 15, and sun-exposed, n = 13 groups) and in actinic keratosis itself as well as in dermal fibroblasts in the 3 groups, using quantitative fluorescence in situ hybridization. Among the 3 cell types, telomeres of basal cells were not always the longest, suggesting that tissue stem cells are not necessarily located among basal cells. Telomeres of basal cells in the sun-exposed group were shorter than those in the sun-protected group. Telomeres in the background of actinic keratosis and in actinic keratosis itself and those of fibroblasts in actinic keratosis were significantly shorter than those in the controls. Our findings demonstrate that sun exposure induces telomere shortening and that actinic keratosis arises from epidermis with shorter telomeres despite the absence of any histologic atypia. PMID:24411948

Ikeda, Hiroyuki; Aida, Junko; Hatamochi, Atsushi; Hamasaki, Yoichiro; Izumiyama-Shimomura, Naotaka; Nakamura, Ken-Ichi; Ishikawa, Naoshi; Poon, Steven S; Fujiwara, Mutsunori; Tomita, Ken-Ichiro; Hiraishi, Naoki; Kuroiwa, Mie; Matsuura, Masaaki; Sanada, Yukihiro; Kawano, Youichi; Arai, Tomio; Takubo, Kaiyo

2014-03-01

351

NASA Astrophysics Data System (ADS)

Ozone measurements made by the Cryogenic Limb Array Etalon Spectrometer (CLAES) aboard the NASA Upper Atmosphere Research Satellite (UARS) are compared to nearly coincident correlative measurements taken in 1992 and 1993 and to mean ozone distributions observed by other satellite instruments during past missions. This paper describes the CLAES measurement characteristics, uncertainties, predicted, and observed precisions and compares the observations with independent measurements both qualitatively and statistically. Satellite- and ground-based remote sensing as well as balloon-borne in situ measurements are represented in the correlative data set. The CLAES data are shown to be within ±20% of all correlative measurements between 0.5 and 30 mbar. Differences at lower altitudes may be related to effects of the Pinatubo aerosol on certain of the correlative measurements and the CLAES retrieval. Comparisons with historical data from the LIMS, SAGE II, and SBUV instruments indicate good agreement with the spatial and seasonal ozone distributions seen by CLAES.

Bailey, P. L.; Edwards, D. P.; Gille, J. C.; Lyjak, L. V.; Massie, S. T.; Roche, A. E.; Kumer, J. B.; Mergenthaler, J. L.; Connor, B. J.; Gunson, M. R.; Margitan, J. J.; McDermid, I. S.; McGee, T. J.

1996-04-01

352

A spirit of conservatism and caution in regard to intelligence test correlations animates numerous papers. Several writers urge the use of units of rank orders, in the estimating of mental abilities. (See, Boring, McEwen, Michael and the Scott Laboratory). Several others like Ruml, Myers, Mitchell, Thorndike and Thompson hold various views in favor of or in criticism against numerous concepts

J. B. Miner

1920-01-01

353

The Belt voice: Acoustical measurements and esthetic correlates

NASA Astrophysics Data System (ADS)

This dissertation explores the esthetic attributes of the Belt voice through spectral acoustical analysis. The process of understanding the nature and safe practice of Belt is just beginning, whereas the understanding of classical singing is well established. The unique nature of the Belt sound provides difficulties for voice teachers attempting to evaluate the quality and appropriateness of a particular sound or performance. This study attempts to provide answers to the question "does Belt conform to a set of measurable esthetic standards?" In answering this question, this paper expands on a previous study of the esthetic attributes of the classical baritone voice (see "Vocal Beauty", NATS Journal 51,1) which also drew some tentative conclusions about the Belt voice but which had an inadequate sample pool of subjects from which to draw. Further, this study demonstrates that it is possible to scientifically investigate the realm of musical esthetics in the singing voice. It is possible to go beyond the "a trained voice compared to an untrained voice" paradigm when evaluating quantitative vocal parameters and actually investigate what truly beautiful voices do. There are functions of sound energy (measured in dB) transference which may affect the nervous system in predictable ways and which can be measured and associated with esthetics. This study does not show consistency in measurements for absolute beauty (taste) even among belt teachers and researchers but does show some markers with varying degrees of importance which may point to a difference between our cognitive learned response to singing and our emotional, more visceral response to sounds. The markers which are significant in determining vocal beauty are: (1) Vibrancy-Characteristics of vibrato including speed, width, and consistency (low variability). (2) Spectral makeup-Ratio of partial strength above the fundamental to the fundamental. (3) Activity of the voice-The quantity of energy being produced. (4) Consistency of the voice-How low is the variability in the energy patterns of the voice.

Bounous, Barry Urban

354

NASA Technical Reports Server (NTRS)

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.

Hubbard, S. M.; Tabib-Azar, M.; Balley, S.; Rybickid, G.; Neudeck, P.; Raffaelle, R.

2004-01-01

355

NSDL National Science Digital Library

This lesson plan for teachers of kindergarten students involves activities that introduce the concepts of using a non-standard unit to measure length and associating a measurement with a number. After introducing the lesson with a literature connection, students cut out their own measuring cards and use them to compare lengths, and measure distance along a path using a line of ladybug beans and a non-standard tape. Materials, handouts, and suggestions for extensions and parental involvement are included.

Lessonplans, Utah

2006-06-24

356

A third-order correlator with a single-shot time window and a full dynamic range of 108 is developed. The time contrast of radiation from the front-end system of a petawatt femtosecond laser complex measured with the correlator within time windows ±1 ps and ±100 ps was 104 and more than 108, respectively. Based on the theoretical analysis of the cross-correlator operation,

V. N. Ginzburg; N. V. Didenko; Aleksandr V. Konyashchenko; V. V. Lozhkarev; G. A. Luchinin; Andrei P. Lutsenko; S. Yu Mironov; Efim A. Khazanov; I. V. Yakovlev

2008-01-01

357

We discuss the effect of large positive correlations in the combinations of several measurements of a single physical quantity using the Best Linear Unbiased Estimate (BLUE) method. We suggest a new approach for comparing the relative weights of the different measurements in their contributions to the combined knowledge about the unknown parameter, using the well-established concept of Fisher information. We argue, in particular, that one contribution to information comes from the collective interplay of the measurements through their correlations and that this contribution cannot be attributed to any of the individual measurements alone. We show that negative coefficients in the BLUE weighted average invariably indicate the presence of a regime of high correlations, where the effect of further increasing some of these correlations is that of reducing the error on the combined estimate. In these regimes, we stress that the correlations provided as input to BLUE combinations need to be assessed with extreme ca...

Valassi, A

2014-01-01

358

Ultrasonic velocity measurement using phase-slope cross-correlation methods

NASA Technical Reports Server (NTRS)

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.

Hull, D. R.; Kautz, H. E.; Vary, A.

1984-01-01

359

Surface roughness measurement on a wing aircraft by speckle correlation.

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

Salazar, Félix; Barrientos, Alberto

2013-01-01

360

Comparison of co-expression measures: mutual information, correlation, and model based indices

Background Co-expression measures are often used to define networks among genes. Mutual information (MI) is often used as a generalized correlation measure. It is not clear how much MI adds beyond standard (robust) correlation measures or regression model based association measures. Further, it is important to assess what transformations of these and other co-expression measures lead to biologically meaningful modules (clusters of genes). Results We provide a comprehensive comparison between mutual information and several correlation measures in 8 empirical data sets and in simulations. We also study different approaches for transforming an adjacency matrix, e.g. using the topological overlap measure. Overall, we confirm close relationships between MI and correlation in all data sets which reflects the fact that most gene pairs satisfy linear or monotonic relationships. We discuss rare situations when the two measures disagree. We also compare correlation and MI based approaches when it comes to defining co-expression network modules. We show that a robust measure of correlation (the biweight midcorrelation transformed via the topological overlap transformation) leads to modules that are superior to MI based modules and maximal information coefficient (MIC) based modules in terms of gene ontology enrichment. We present a function that relates correlation to mutual information which can be used to approximate the mutual information from the corresponding correlation coefficient. We propose the use of polynomial or spline regression models as an alternative to MI for capturing non-linear relationships between quantitative variables. Conclusion The biweight midcorrelation outperforms MI in terms of elucidating gene pairwise relationships. Coupled with the topological overlap matrix transformation, it often leads to more significantly enriched co-expression modules. Spline and polynomial networks form attractive alternatives to MI in case of non-linear relationships. Our results indicate that MI networks can safely be replaced by correlation networks when it comes to measuring co-expression relationships in stationary data. PMID:23217028

2012-01-01

361

Kronecker Product Linear Exponent AR(1) Correlation Structures for Multivariate Repeated Measures

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

Simpson, Sean L.; Edwards, Lloyd J.; Styner, Martin A.; Muller, Keith E.

2014-01-01

362

In near-infrared spectroscopy (NIRS), concentration changes in oxy- and deoxyhemoglobin are calculated using an attenuation change of the measurement light and by solving a linear equation based on the modified Lambert-Beer law. While solving this equation, we need to know the wavelength-dependent mean optical path lengths of the measurement lights. However, it is very difficult to know these values by a continuous-wave-type (CW-type) system. We propose a new method of estimating wavelength-dependent optical path length ratios of the measurement lights based on the data obtained by a triple wavelength CW-type NIRS instrument. The proposed method does not give a path length itself, but it gives a path length ratio. Thus, it is possible to obtain the accurate hemoglobin concentration changes without cross talk, although the method cannot contribute to the quantification of the absolute magnitude of hemoglobin changes. The method is based on the principle that two possible estimations of hemoglobin concentration changes calculated using a triple-wavelength measurement system should be identical. The method was applied to the experimental data of human subjects' foreheads. The estimated path length ratios were very similar to literature values obtained by using picosecond laser pulses and a streak camera detector [M. Essenpreis et al., Appl. Opt. 32(4), 418-425 (1993)]. PMID:19895139

Umeyama, Shinji; Yamada, Toru

2009-01-01

363

Angular correlations measured in pp collisions by ALICE at the LHC

We report on studies of untriggered two-particle angular correlations of identified particles (pions, kaons and protons) measured in proton-proton collisions at center-of-mass energy sqrt{s}=7 TeV recorded by ALICE at the LHC. These type of studies are sensitive to a wide range of correlations which arise from different physics mechanisms, each of them having a unique structure in DeltaEta-DeltaPhi space. The correlations of particles with different quark content and flavor are sensitive to various conservation laws. The study of these correlations is the main goal of this analysis. The results confirm that these laws strongly influence the shape of the correlation functions for different particle types and must be taken into account while analysing the data. Moreover, we verify their implementation using two Monte Carlo event generators and we found that the analyzed models do not reproduce the measured correlations for protons.

?ukasz Kamil Graczykowski; Ma?gorzata Anna Janik

2014-01-17

364

Angular correlations measured in pp collisions by ALICE at the LHC

We report on studies of untriggered two-particle angular correlations of identified particles (pions, kaons and protons) measured in proton-proton collisions at center-of-mass energy sqrt{s}=7 TeV recorded by ALICE at the LHC. These type of studies are sensitive to a wide range of correlations which arise from different physics mechanisms, each of them having a unique structure in DeltaEta-DeltaPhi space. The correlations of particles with different quark content and flavor are sensitive to various conservation laws. The study of these correlations is the main goal of this analysis. The results confirm that these laws strongly influence the shape of the correlation functions for different particle types and must be taken into account while analysing the data. Moreover, we verify their implementation using two Monte Carlo event generators and we found that the analyzed models do not reproduce the measured correlations for protons.

Graczykowski, ?ukasz Kamil

2014-01-01

365

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

Hou, Lifang; Wang, Sheng; Dou, Chang; Zhang, Xiao; Yu, Yue; Zheng, Yinan; Avula, Umakanth; Hoxha, Mirjam; Diaz, Anaite; McCracken, John; Barretta, Francesco; Marinelli, Barbara; Bertazzi, Pier Alberto; Schwartz, Joel; Baccarelli, Andrea A.

2013-01-01

366

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

Stevens, Daniel E; Smith, Cameron B; Harwood, Brad; Rice, Charles L

2014-11-01

367

The recently developed concept of a correlation entropy, S, as a quantitative measure of the correlation strength present in a correlated quantum many-body state is applied to the ground states of the He isoelectronic series He(Z) with varying nuclear charge Z and of the Hooke's law model HLM(omega) with varying oscillator frequency omega. S is constructed from the natural orbital

Paul Ziesche; Vedene H. Smith; Minhhuy Hô; Sven P. Rudin; Peter Gersdorf; Manfred Taut

1999-01-01

368

NASA Technical Reports Server (NTRS)

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.

Long, Charles N.; Ackerman, Thomas P.

1995-01-01

369

Correlation Attenuation Due to Measurement Error: A New Approach Using the Bootstrap Procedure

ERIC Educational Resources Information Center

Issues with correlation attenuation due to measurement error are well documented. More than a century ago, Spearman proposed a correction for attenuation. However, this correction has seen very little use since it can potentially inflate the true correlation beyond one. In addition, very little confidence interval (CI) research has been done for…

Padilla, Miguel A.; Veprinsky, Anna

2012-01-01

370

Point-to-Set as a measure of Correlations during Unjamming in Granular Systems

NASA Astrophysics Data System (ADS)

There is evidence indicating that the unjamming of frictionless, soft grain packings occurs at a critrical point, however, no correlation function associated with a diverging, static length scale has been identified. To better understand the nature of this transition, we consider the soft grain packing problem as a constraint satisfaction problem [1]. Jammed configurations are mechanically stable packings with non-zero pressure. Contact forces on each grain therefore satisfy the equations of mechanical equilibrium, which are a set of local constraints, as well as a global constraint from the pressure. In general when jammed, there are more contact forces than constraints, so that an ensemble of force networks exists [2] which satisfy the constraints. These force networks make up a high-dimensional solution space that shrinks to a point at the unjamming transition, suggesting that the unjamming transition can be considered an entropy vanishing transition. We explore a new type of "point-to-set" correlation function which has been used to identify non-obvious length scales in other constraint satisfaction problems [3], and show that it exhibits a diverging length scale. We compare and contrast this length scale with the well established "isostatic length" of Wyart et. al [4].[4pt] [1] F. Krzakala and J. Kurchan, PRE 76, 021122 (2007)[0pt] [2] J.H. Snoeijer et. al, PRE 70, 061306 (2004)[0pt] [3] A. Montanari and G. Semerjain, Journal of Stat. Phys, 125, 1 (2006)[0pt] [4] M. Wyart et. al, PRE 72, 051306 (2005)

Mailman, Mitch

2011-03-01

371

Coherence and correlations in multitime quantum measurements of stochastic quantum trajectories

be carried out without perturbing the system. Quantum measurements, in contrast, are accompanied by a wave and their moments--the equilibrium correlations functions. A quan- tum measurement, in contrast, is a nonequilibrium linearly coupled to a bath and compare classical measurements with von Neumann's wave function collapse

Mukamel, Shaul

372

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.

Henson, M. P.; Bergstedt, R. A.; Adams, J. V.

2003-01-01

373

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.

Henson, Mary P.; Bergstedt, Roger A.; Adams, Jean V.

2003-01-01

374

NSDL National Science Digital Library

Although life experience plays a huge role in shaping who we are, the foundations of our personality begin in the womb. This Science Update describes a recent study that looks to finger length for signs of a man's pre-natal exposure to testosterone.

Science Update;

2005-03-28

375

correlation Measure of Parent/Family Functioning Mean score (SD) r p

Pearson's correlation Measure of Parent/Family Functioning Mean score (SD) r p Global Severity) Â· Affected 69,184 children in 2009. Â· Affects around 20% of girls and 8% of boys. Â· Those who experience CSA

Farritor, Shane

376

Identification of Noise Sources in High Speed Jets via Correlation Measurements: A Review

NASA Technical Reports Server (NTRS)

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.

Bridges, James (Technical Monitor); Panda, Jayanta

2005-01-01

377

Field methods to measure surface displacement and strain with the Video Image Correlation method

NASA Technical Reports Server (NTRS)

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.

Maddux, Gary A.; Horton, Charles M.; Mcneill, Stephen R.; Lansing, Matthew D.

1994-01-01

378

NASA Astrophysics Data System (ADS)

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.

Song, John; Chu, Wei; Tong, Mingsi; Soons, Johannes

2014-06-01

379

A robust measure of correlation between two genes on a microarray

Background The underlying goal of microarray experiments is to identify gene expression patterns across different experimental conditions. Genes that are contained in a particular pathway or that respond similarly to experimental conditions could be co-expressed and show similar patterns of expression on a microarray. Using any of a variety of clustering methods or gene network analyses we can partition genes of interest into groups, clusters, or modules based on measures of similarity. Typically, Pearson correlation is used to measure distance (or similarity) before implementing a clustering algorithm. Pearson correlation is quite susceptible to outliers, however, an unfortunate characteristic when dealing with microarray data (well known to be typically quite noisy.) Results We propose a resistant similarity metric based on Tukey's biweight estimate of multivariate scale and location. The resistant metric is simply the correlation obtained from a resistant covariance matrix of scale. We give results which demonstrate that our correlation metric is much more resistant than the Pearson correlation while being more efficient than other nonparametric measures of correlation (e.g., Spearman correlation.) Additionally, our method gives a systematic gene flagging procedure which is useful when dealing with large amounts of noisy data. Conclusion When dealing with microarray data, which are known to be quite noisy, robust methods should be used. Specifically, robust distances, including the biweight correlation, should be used in clustering and gene network analysis. PMID:17592643

Hardin, Johanna; Mitani, Aya; Hicks, Leanne; VanKoten, Brian

2007-01-01

380

NASA Technical Reports Server (NTRS)

Accurate evaluations of diffusion lengths for heavily to moderately doped III-V semiconductors and/or radiation damaged solar cells have been made possible by using experimental and numerical techniques. The techniques employed were electron beam induced current and low voltage electron microscopy.

Leon, R. P.

1987-01-01

381

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

Zhang, Chun-Xiao; Wang, Fei; Li, Ning; Yan, Jian-Hua; Chi, Yong; Cen, Ke-Fa

2009-10-01

382

NASA Astrophysics Data System (ADS)

There are several methods for correlating thin film thickness measurement equipment. The most commonly used method is to program in an offset that gets systematically added to or subtracted from the thickness calculation. Measurement errors can occur using this 'fudge factor' method because the relationship between the reference thicknesses and the measured thicknesses is not, in general, a fixed constant or simple function. A better method for correlating thin film thickness measurement equipment is to tune the instruments to the process by refining the internal optical constants.

Kaiser, Anne M.

1991-07-01

383

NASA Astrophysics Data System (ADS)

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.

Xue, Zhenyu; Charonko, John J.; Vlachos, Pavlos P.

2014-11-01

384

NASA Astrophysics Data System (ADS)

We discuss the effect of large positive correlations in the combinations of several measurements of a single physical quantity using the Best Linear Unbiased Estimate (BLUE) method. We suggest a new approach for comparing the relative weights of the different measurements in their contributions to the combined knowledge about the unknown parameter, using the well-established concept of Fisher information. We argue, in particular, that one contribution to information comes from the collective interplay of the measurements through their correlations and that this contribution cannot be attributed to any of the individual measurements alone. We show that negative coefficients in the BLUE weighted average invariably indicate the presence of a regime of high correlations, where the effect of further increasing some of these correlations is that of reducing the error on the combined estimate. In these regimes, we stress that assuming fully correlated systematic uncertainties is not a truly conservative choice, and that the correlations provided as input to BLUE combinations need to be assessed with extreme care instead. In situations where the precise evaluation of these correlations is impractical, or even impossible, we provide tools to help experimental physicists perform more conservative combinations.

Valassi, Andrea; Chierici, Roberto

2014-03-01

385

National Technical Information Service (NTIS)

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 ...

S. M. Hubbard, M. Tabib-Azar, S. Balley, G. Rybickid, P. Neudeck, R. Raffaelle

2004-01-01

386

ERIC Educational Resources Information Center

The aim was to develop a new instrument for measuring length of sleep as well as television and computer habits in school-age children. A questionnaire was constructed for use when children visit the school health care unit. Three aspects of the validity of the questionnaire were examined: its face validity, content validity, and construct…

Garmy, Pernilla; Jakobsson, Ulf; Nyberg, Per

2012-01-01

387

Accurate Measurement of Satellite Antenna Surface Using 3D Digital Image Correlation Technique

Application of the three-dimensional digital image correlation technique (3D DIC) to the accurate measurement of full-field surface profile of a 730 mm-diameter carbon fibre composite satellite antenna is investigated in this article. The basic principles of the 3D DIC technique are described. The measured profile was compared with the one measured with a three-dimensional coordinate measuring machine. The results clearly

B. Pan; H. Xie; L. Yang; Z. Wang

2009-01-01

388

The response of pions and protons in the energy range of 20–180GeV, produced at CERN's SPS H8 test-beam line in the ATLAS iron–scintillator Tile hadron calorimeter, has been measured. The test-beam configuration allowed the measurement of the longitudinal shower development for pions and protons up to 20 nuclear interaction lengths. It was found that pions penetrate deeper in the calorimeter

P. Adragna; C. Alexa; K. Anderson; A. Antonaki; A. Arabidze; L. Batkova; V. Batusov; H. P. Beck; E. Bergeaas Kuutmann; C. Biscarat; G. Blanchot; A. Bogush; C. Bohm; V. Boldea; M. Bosman; C. Bromberg; J. Budagov; D. Burckhart-Chromek; M. Caprini; L. Caloba; D. Calvet; T. Carli; J. Carvalho; M. Cascella; J. Castelo; M. V. Castillo; M. Cavalli-Sforza; V. Cavasinni; A. S. Cerqueira; C. Clement; M. Cobal; F. Cogswell; S. Constantinescu; D. Costanzo; A. Corso-Radu; C. Cuenca; D. O. Damazio; T. Davidek; K. de; T. Del Prete; B. Di Girolamo; S. Dita; T. Djobava; M. Dobson; A. Dotti; R. Downing; I. Efthymiopoulos; D. Eriksson; D. Errede; S. Errede; A. Farbin; D. Fassouliotis; R. Febbraro; A. Fenyuk; C. Ferdi; A. Ferrer; V. Flaminio; D. Francis; E. Fullana; S. Gadomski; S. Gameiro; V. Garde; K. Gellerstedt; V. Giakoumopoulou; O. Gildemeister; V. Gilewsky; N. Giokaris; N. Gollub; A. Gomes; V. Gonzalez; B. Gorini; P. Grenier; P. Gris; M. Gruwe; V. Guarino; C. Guicheney; A. Gupta; C. Haeberli; H. Hakobyan; M. Haney; S. Hellman; A. Henriques; E. Higon; S. Holmgren; M. Hurwitz; J. Huston; C. Iglesias; A. Isaev; I. Jen-La Plante; M. Joos; T. Junk; A. Karyukhin; A. Kazarov; H. Khandanyan; J. Khramov; J. Khubua; S. Kolos; I. Korolkov; P. Krivkova; Y. Kulchitsky; Yu. Kurochkin; P. Kuzhir; T. Le Compte; R. Lefevre; G. Lehmann; R. Leitner; M. Lembesi; J. Lesser; J. Li; M. Liablin; M. Lokajicek; Y. Lomakin; A. Lupi; C. Maidanchik; A. Maio; M. Makouski; S. Maliukov; A. Manousakis; L. Mapelli; C. Marques; F. Marroquim; F. Martin; E. Mazzoni; F. Merritt; A. Miagkov; R. Miller; I. Minashvili; L. Miralles; G. Montarou; M. Mosidze; A. Myagkov; S. Nemecek; M. Nessi; L. Nodulman; B. Nordkvist; O. Norniella; J. Novakova; A. Onofre; M. Oreglia; D. Pallin; D. Pantea; J. Petersen; J. Pilcher; J. Pina; J. Pinhão; F. Podlyski; X. Portell; J. Poveda; L. Pribyl; L. E. Price; J. Proudfoot; M. Ramstedt; R. Richards; C. Roda; V. Romanov; P. Rosnet; P. Roy; A. Ruiz; V. Rumiantsev; N. Russakovich; O. Saltó; B. Salvachua; E. Sanchis; H. Sanders; C. Santoni; J. G. Saraiva; F. Sarri; I. Satsunkevitch; L.-P. Says; G. Schlager; J. Schlereth; J. M. Seixas; B. Selldèn; N. Shalanda; P. Shevtsov; M. Shochet; J. Silva; P. Da Silva; V. Simaitis; M. Simonyan; A. Sissakian; J. Sjölin; C. Solans; A. Solodkov; I. Soloviev; O. Solovyanov; M. Sosebee; F. Spanò; R. Stanek; E. Starchenko; P. Starovoitov; P. Stavina; M. Suk; I. Sykora; F. Tang; P. Tas; R. Teuscher; S. Tokar; N. Topilin; J. Torres; L. Tremblet; P. Tsiareshka; M. Tylmad; D. Underwood; G. Unel; G. Usai; A. Valero; S. Valkar; J. A. Valls; A. Vartapetian; F. Vazeille; I. Vichou; V. Vinogradov; I. Vivarelli; M. Volpi; A. White; A. Zaitsev; A. Zenine; T. Zenis

2010-01-01

389

NASA Astrophysics Data System (ADS)

We have studied the influence of molecular beam epitaxy (MBE) of ?- FeSi films on minority-carrier diffusion length of an n-type Si(111) substrate. It was found from electron beam induced current technique that the diffusion length was less influenced in sample formed with a ?- FeSi template prior to the MBE growth than that in sample grown without the template. The size of ?- FeSi grains measured by electron back-scatter diffraction was also discussed.

Kawakami, H.; Suzuno, M.; Akutsu, K.; Chen, J.; Fuxing, Y.; Sekiguchi, T.; Suemasu, T.

390

The authors conducted experiments on DCB specimens 10 and 20 mm thick made of 15Kh2NMFA and 15 Kh2NMFAA steels in the embrittled state at room and liquid nitrogen temperatures. Fatigue cracks of various length were induced in the specimens. The dimensions of these cracks were determined more accurately after final fracture of the specimens. The compliance of the specimens was

Yu. A. Kashtalyan; I. V. Orynyak; V. M. Torop

1986-01-01

391

The mean total length of young-of-the-year paddlefish (Polyodon spathula) from Lewis and Clark Lake (a main-stem Missouri River reservoir at the Nebraska-South Dakota border) was 215 mm on 31 August of the first summer of life and estimated to be 296 mm by the end of the first growing season; average growth rate was 2.7 mm\\/day. The diet in 1972

Richard Ruelle; Patrick L. Hudson

1977-01-01

392

We collected tissues from herring gulls (Larus argentatus) nesting within and outside of the Great Lakes basin. Genotoxin exposure was assessed as fluorescent aromatic compounds (FACs)\\u000a in bile and SOS Chromotest-inducing activity in muscle extracts. We determined whether these exposures were associated with\\u000a decreased erythrocyte DNA strand length and\\/or induction of hepatic ethoxyresorufin-O-deethylase (EROD) activity. FACs were detected in all

Glen A. Fox; Paul A. White; Suzanne Trudeau; Chris Theodorakis; Laird J. Shutt; Sean W. Kennedy; Kim J. Fernie

2005-01-01

393

Undulators in electron\\/positron accelerators are powerful sources of UV radiation and X-rays. The field-generating elements in classical undulators are either permanent magnets or electromagnets. For undulators with short periods, permanent magnets are used and the field strength (for a given period length and gap) is limited by the material properties. In this paper a novel concept is described which allows

Andreas Geisler; Achim Hobl; Detlef Krischel; Robert Rossmanith; Michael Schillo

2003-01-01

394

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 Approved by: Chair of Committee, Eric L. Petersen... Lengths, and Flame Stability of Hydrocarbons. (December 2010) William Baugh Lowry, B.S., Texas A&M University Chair of Advisory Committee: Dr. Eric L. Petersen Natural gas is the primary fuel used in industrial gas turbines for power generation...

Lowry, William Baugh

2012-02-14

395

The objective of this study is to evaluate the effect of anatomic urethral length on the relationship between descent at point\\u000a Aa of the pelvic organ prolapse quantification (POP-Q) system and the Q-tip straining angle. The records of 323 patients who\\u000a were evaluated for urinary incontinence were reviewed. Prolapse staging was performed using the POP-Q system. Urethrovesical\\u000a junction hypermobility defined

J. Robert Larrieux; Sunil Balgobin

2008-01-01

396

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

R. Mehra

1968-01-01

397

Personality Correlates of Self-Report, Role-Playing, and In Vivo Measures of Assertiveness.

ERIC Educational Resources Information Center

Undergraduates completed self-report inventories of assertiveness, participated in behavior role-playing tasks and in vivo measures of assertiveness, and completed the Personality Research Form E (PRF-E). Of 22 PRF-E scales, 11 had at least one significant correlation with assertiveness measures. Some composites of PRF-E scales were related to…

Green, Samuel B.; And Others

1979-01-01

398

Comment on "Measurement of 2- and 3-nucleon short range correlation probabilities in nuclei"

"Measurement of 2- and 3-nucleon short range correlation probabilities in nuclei" claimed to observe plateaus in the inclusive A/3He (e,e') ratios in the xB > 2 region; yet, a subsequent measurement at a higher momentum transfer did not observe xB > 2 plateaus. Herein we comment on a possible experimental explanation for this discrepancy.

Douglas W. Higinbotham; Or Hen

2014-09-10

399

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

Marco Hering; Klaus Koerner; Bernd Jaehne

2009-01-01

400

NASA Astrophysics Data System (ADS)

We study the time evolution of four distance measures in the presence of initial system-environment correlations. It is well known that the trace distance between two quantum states of an open system may increase due to initial correlations, which leads to a breakdown of the contractivity of the reduced dynamics. Here we compare and analyze, for two different models, the time evolution of the trace distance, the Bures metric, the Hellinger distance, and the Jensen-Shannon divergence regarding an increase above their initial values, witnessing initial correlations. This work generalizes, deepens, and corrects a part of the study performed by Dajka [Phys. Rev. APLRAAN1050-294710.1103/PhysRevA.84.032120 84, 032120 (2011)] and thereby reveals generic features of the considered distance measures with respect to the capability of detecting initial system-environment correlations.

Wißmann, S.; Leggio, B.; Breuer, H.-P.

2013-08-01

401

Optimizing the use of detector arrays for measuring intensity correlations of photon pairs

NASA Astrophysics Data System (ADS)

Intensity correlation measurements form the basis of many experiments based on spontaneous parametric down-conversion. In the most common situation, two single-photon avalanche diodes and coincidence electronics are used in the detection of the photon pairs, and the coincidence count distributions are measured by making use of some scanning procedure. Here we analyze the measurement of intensity correlations using multielement detector arrays. By considering the detector parameters such as the detection and noise probabilities, we found that the mean number of detected photons that maximizes the visibility of the two-photon correlations is approximately equal to the mean number of noise events in the detector array. We provide expressions predicting the strength of the measured intensity correlations as a function of the detector parameters and on the mean number of detected photons. We experimentally test our predictions by measuring far-field intensity correlations of spontaneous parametric down-conversion with an electron multiplying charge-coupled device camera, finding excellent agreement with the theoretical analysis.

Tasca, Daniel S.; Edgar, Matthew P.; Izdebski, Frauke; Buller, Gerald S.; Padgett, Miles J.

2013-07-01

402

Measuring the correlation of two optical frequencies using four-wave mixing.

We use the physics of four-wave mixing to study the decorrelation of two optical frequencies as they propagate through different fiber delays. The phase noise relationship between the four-wave mixing components is used to quantify and measure the correlation between the two optical frequencies using the correlation coefficient. We show the difference in the evolution of decorrelation between frequency-dependent and frequency-independent components of phase noise. PMID:25402993

Anthur, Aravind P; Watts, Regan T; Huynh, Tam N; Venkitesh, Deepa; Barry, Liam P

2014-11-10

403

Spatial Correlation of Solar-Wind Turbulence from Two-Point Measurements

Interplanetary turbulence, the best studied case of low frequency plasma turbulence, is the only directly quantified instance of astrophysical turbulence. Here, magnetic field correlation analysis, using for the first time only proper two-point, single time measurements, provides a key step in unraveling the space-time structure of interplanetary turbulence. Simultaneous magnetic field data from the Wind, ACE, and Cluster spacecraft are analyzed to determine the correlation (outer) scale, and the Taylor microscale near Earth's orbit.

Matthaeus, W.H.; Milano, L.J. [Bartol Research Institute, Department of Physics and Astronomy, University of Delaware, Newark, Delaware 19716 (United States); Dasso, S. [Instituto de Astronomia y Fisica del Espacio (IAFE) and Departamento de Fisica, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, 1428 Buenos Aires (Argentina); Weygand, J.M.; Kivelson, M.G. [IGPP, UCLA, Los Angeles, California 90095 (United States); Smith, C.W. [Institute for Earth, Oceans and Space, University of New Hampshire, Durham, New Hampshire 03824 (United States)

2005-12-02

404

Correlation of turbulence factor and hot wire turbulence measurements in subsonic flows of air

CORRELATION OF TURBULENCE FACTOR AND HOT WIRE TURBULENCE MEASUREMENTS IN SUBSONIC FLOWS OF AIR by CURTIS SINCIAIR WELISp JR. A Thesis Submitted to the Graduate School oi' the Agricultural and Mechanical College of Texas In Partial... Fulfillment of the Requirements for the Degree of MASTER OF SCIENCE August, 1959 Department of Aeronautical Engineering Smgor Sub/est: Aeronautical Engineering CORRELATION OF TURBULENCE FACTOR AND HOT WIRE TURBULENCE NEASUREMENI'S IN SUBSONIC FLOWS...

Wells, Curtis Sinclair

2012-06-07

405

NASA Technical Reports Server (NTRS)

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.

Vonglahn, U. H.

1978-01-01

406

We show that the complex-amplitude cross-correlation function between two beams can be obtained by the global Stokes parameters. We apply this approach to determine the topological charge of a Laguerre-Gaussian (LG) beam by performing power measurements only. Additionally, we study the connection of the cross-correlation function with the degree of polarization for nonuniformly polarized beams, and we obtain closed-form expressions of the cross correlation for LG vector modes and the generalized full Poincaré beams. PMID:24686641

Perez-Garcia, Benjamin; Lopez-Mago, Dorilian; Garcia-Gracia, Hipolito; Garza-Alanis, Jorge A; Hernandez-Aranda, Raul I; Gutiérrez-Vega, Julio C

2014-04-01

407

We investigate the value of the correlation function of an inhomogeneous hard-sphere fluid at contact. This quantity plays a critical role in Statistical Associating Fluid Theory (SAFT), which is the basis of a number of recently developed classical density functionals. We define two averaged values for the correlation function at contact, and derive formulas for each of them from the White Bear version of the Fundamental Measure Theory functional, using an assumption of thermodynamic consistency. We test these formulas, as well as two existing formulas against Monte Carlo simulations, and find excellent agreement between the Monte Carlo data and one of our averaged correlation functions.

Jeff Schulte; Patrick Kreitzberg; Chris Haglund; David Roundy

2012-08-31

408

NASA Astrophysics Data System (ADS)

We investigate the value of the correlation function of an inhomogeneous hard-sphere fluid at contact. This quantity plays a critical role in statistical associating fluid theory, which is the basis of a number of recently developed classical density functionals. We define two averaged values for the correlation function at contact and derive formulas for each of them from the White Bear version of the fundamental measure theory functional, using an assumption of thermodynamic consistency. We test these formulas, as well as two existing formulas, against Monte Carlo simulations and find excellent agreement between the Monte Carlo data and one of our averaged correlation functions.

Schulte, Jeff B.; Kreitzberg, Patrick A.; Haglund, Chris V.; Roundy, David

2012-12-01

409

MESFET cryogenic front-end for cross-correlation noise measurements

We present a dual-channel transimpedance amplifier for cross-correlation noise measurements with a MESFET cryogenic front-end and cooled feedback resistors. In order to test the noise performance of the system, devices with known noise power spectral density (i.e. resistors) have been measured. In particular, such a system has been able to reliably measure a noise current spectral density lower than 1

G. Fiori; L. Guidi; M. Macucci; G. Basso; I. Maione; B. Pellegrini

2007-01-01

410

A fast and robust methodology for identification of radioactive materials is of great interest for applications in the fields of homeland security and nuclear nonproliferation. For fissile materials in particular, several passive and active interrogation techniques are being investigated. These systems rely on the fact that the interrogated material emits correlated neutrons and gamma rays from each induced or spontaneous fission event. A convenient way to look at correlated events in a fissionable material is to study time-dependent detector cross-correlation functions. These functions are unique for a given material and geometry, representing a distinctive signature of the material-geometry configuration. In this work, we focus on the identification of plutonium samples in both metallic and oxide form. The simulation program used in this study is the MCNP-PoliMi code, an improved version of the standard MCNP code. This code allows the user to obtain event-by-event information about the simulated particles. This capability is essential for accurate simulations of cross-correlation events. The number of correlated events as a function of time is obtained from the MCNP-PoliMi output collision file by using appropriate postprocessing algorithms. We investigated several parameters, such as the sample composition and mass, the sample-detector distance, and the shielding between the detector and the sample. We then analyzed the simulated cross correlation functions to obtain relationships between features from the correlations and sample characteristics. To verify the simulations, the measured correlation function was compared with the simulated one.

Flaska, Marek [ORNL; Pozzi, Sara A [ORNL

2007-01-01

411

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 neu...

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

2014-01-01

412

We collected tissues from herring gulls (Larus argentatus) nesting within and outside of the Great Lakes basin. Genotoxin exposure was assessed as fluorescent aromatic compounds (FACs) in bile and SOS Chromotest-inducing activity in muscle extracts. We determined whether these exposures were associated with decreased erythrocyte DNA strand length and/or induction of hepatic ethoxyresorufin-O-deethylase (EROD) activity. FACs were detected in all bile samples. Most muscle extracts produced a positive or marginal SOS response in the presence of S9. SOS induction potentials were strongly associated with dietary trophic level. The median molecular length of DNA isolated from erythrocytes for 14 of 17 adult and 10 of 11 prefledgling collections was reduced compared to the modal class for their respective age group suggesting widespread DNA damage. DNA damage was greatest in gulls from Saginaw Bay, Lake Huron. Median EROD activity in both adults and prefledglings from remote locations was significantly lower than that of gulls from the lower Great Lakes and was not associated with concentrations of benzo[a]pyrene (B[a]P)-like FACs. Our results indicate Great Lakes herring gulls were exposed to genotoxins and Ah-receptor activating agents in biologically significant concentrations in the early 1990s. These agents appear to be persistent bioaccumulative compounds and/or their metabolites. PMID:16220360

Fox, Glen A; White, Paul A; Trudeau, Suzanne; Theodorakis, Chris; Shutt, Laird J; Kennedy, Sean W; Fernie, Kim J

2005-07-01

413

Estimating telomere length from whole genome sequence data

Telomeres play a key role in replicative ageing and undergo age-dependent attrition in vivo. Here, we report a novel method, TelSeq, to measure average telomere length from whole genome or exome shotgun sequence data. In 260 leukocyte samples, we show that TelSeq results correlate with Southern blot measurements of the mean length of terminal restriction fragments (mTRFs) and display age-dependent attrition comparably well as mTRFs. PMID:24609383

Ding, Zhihao; Mangino, Massimo; Aviv, Abraham; Spector, Tim; Durbin, Richard

2014-01-01

414

Measuring Quantum Correlations using Lossy Photon-Number-Resolving Detectors with Saturation

The variance of difference of photocounts is an established measure of quantum correlations for quantum states of light. It enables us to discriminate between the classical correlation of a two-mode coherent state and the quantum correlation of a twin-beam state. We study the effect of loss and saturation of the photon-number-resolving detector on the measurement of the variance of difference of photocounts. An analytic function is derived for this variance, both for the coherent and the twin-beam states. It is found that the variance of difference of photocounts is no longer a reliable entanglement measure in the non-linear regime of the detector response but it remains useful in some range of values of average photon numbers of the incident light. We also quantify the linear regime of the detector with saturation which will be useful for calibration of the detector quantum efficiency.

Si-Hui Tan; Leonid A. Krivitsky; Berthold-Georg Englert

2012-10-30

415