Radial Correlation Length Measurements in ASDEX Upgrade
J. Schirmer; G. D. Conway; E. Holzhauer; H. Zohm; W. Suttrop
2006-01-01
Introduction Fluctuationsand turbulencearebelievedtoplay an importantroleinanoma- lous transport of heat and particles in magnetic fusion devices, and hence their characteriza- tion is important. Specifically, the radial and poloidal correlation lengths of turbulence (Lr and Lp) may be used to define the spatial size of turbulent eddies. Lr has been measured using a variety of diagnostics, the most common being correlation reflectometry.
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
NSDL National Science Digital Library
Miss Lerdahl
2010-01-26
Practice measuring length. Play this fun game to work on length. Measure the teddy Next, practice measuring to the nearest 1/2 inch. Measure to 1/2 inches If your ready for a challenge, practice this next game: Measure to 1/4 inches Play the Fish Tales game! *Once you have played all the games, have an adult sign your planner that you practiced these games! You'll ...
Nguyen, Tho Duc; Nahata, Ajay; Vardeny, Z Valy
2012-07-01
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
NASA Astrophysics Data System (ADS)
Proksch, Martin; Löwe, Henning; Schneebeli, Martin
2015-02-01
Precise measurements of snow structural parameters are crucial to understand the formation of snowpacks by deposition and metamorphism and to characterize the stratigraphy for many applications and remote sensing in particular. The area-wide acquisition of structural parameters at high spatial resolution from state-of-the-art methods is, however, still cumbersome, since the time required for a single profile is a serious practical limitation. As a remedy we have developed a statistical model to extract three major snow structural parameters: density, correlation length, and specific surface area (SSA) solely from the SnowMicroPen (SMP), a high-resolution penetrometer, which allows a meter profile to be measured with millimeter resolution in less than 1 min. The model was calibrated by combining SMP data with 3-D microstructural data from microcomputed tomography which was used to reconstruct full-depth snow profiles from different snow climates (Alpine, Arctic, and Antarctic). Density, correlation length, and SSA were derived from the SMP with a mean relative error of 10.6%, 16.4%, and 23.1%, respectively. For validation, we compared the density and SSA derived from the SMP to traditional measurements and near-infrared profiles. We demonstrate the potential of our method by the retrieval of a two-dimensional stratigraphy at Kohnen Station, Antarctica, from a 46 m long SMP transect. The result clearly reveals past depositional and metamorphic events, and our findings show that the SMP can be used as an objective, high-resolution tool to retrieve essential snow structural parameters efficiently in the field.
NASA Astrophysics Data System (ADS)
Singh, D.; Singh, K.; Herlin, I.
Retrieving the desired surface parameter of the soil is a matter of increasing interest in the application of microwave remote sensing. For the past several years, the problem of soil surface scattering has been of theoretical and practical interest. Several types of agricultural crops are commonly planted in parallel rows either in a rectangular format or in concentric rings. Therefore, it is the point of research to know the individual effect of periodic surface roughness and correlation length of bare soil on the scattering co-efficient ( 0 ). The scattering co-efficient of a surface is governed by both the dielectric properties and the roughness parameter of that surface. The roughness of the surface with one dimensional surface height profile h (x) can be characterized in terms of the standard deviation of surface height (h rms ) and the surface correlation length ( {}). So, in this paper, it is attempted to highlight these surface parameter effect on the0 at X- band ( 9.5 GHz) frequency. The angular and polarization dependence of roughness and correlation length has also been observed at X- band. For this purpose, an out door observation has been carried out by X- band scatterometer for various periodic surface roughness and correlation length. In this study, we have taken soil moisture as a constant. Experimentally observed data was utilized to provide a composite0 equation model accounting for individual effect in regression analysis. Experimentally observed co-polarized ratio (p= H H 0 / VV0 ) is compared with empirically obtained co-polarized ratio . A good agreement has been observed between experimentally observed p and empirically obtained p. The multiple and partial regression analyses have also been carried out for predicting the dependence of0 on h rms and {}more accurately. It was found that dependence of surface roughness is much more significant in comparison to correlation length at higher incidence angle for both like polarization and sensitivity of0 on surface roughness and correlation length depends upon polarization. VV-polarization is more sensitive than HH-polarization for observing the periodic surface roughness at X band. This type of results are- helpful to make an inversion technique to assess the surface roughness and correlation length by the air-borne or space borne sensor and propose the suitable angle of incidence and polarization to observe the surface roughness and correlation length at X-band.
Picosecond Bunch length and Energy-z correlation measurements at SLAC's A-Line and End Station A
Molloy, Stephen; Emma, P.; Frisch, J.C.; Iverson, R.H.; Ross, M.; McCormick, D.J.; Ross, Marc C.; Walston, S.; Blackmore, V.; /Oxford U.
2007-06-27
We report on measurements of picosecond bunch lengths and the energy-z correlation of the bunch with a high energy electron test beam to the A-line and End Station A (ESA) facilities at SLAC. The bunch length and the energy-z correlation of the bunch are measured at the end of the linac using a synchrotron light monitor diagnostic at a high dispersion point in the A-line and a transverse RF deflecting cavity at the end of the linac. Measurements of the bunch length in ESA were made using high frequency diodes (up to 100 GHz) and pyroelectric detectors at a ceramic gap in the beamline. Modeling of the beam's longitudinal phase space through the linac and A-line to ESA is done using the 2-dimensional tracking program LiTrack, and LiTrack simulation results are compared with data. High frequency diode and pyroelectric detectors are planned to be used as part of a bunch length feedback system for the LCLS FEL at SLAC. The LCLS also plans precise bunch length and energy-z correlation measurements using transverse RF deflecting cavities.
Measuring Thermodynamic Length
Crooks, Gavin E
2007-09-07
Thermodynamic length is a metric distance between equilibrium thermodynamic states. Among other interesting properties, this metric asymptotically bounds the dissipation induced by a finite time transformation of a thermodynamic system. It is also connected to the Jensen-Shannon divergence, Fisher information, and Rao's entropy differential metric. Therefore, thermodynamic length is of central interestin understanding matter out of equilibrium. In this Letter, we will consider how to denethermodynamic length for a small system described by equilibrium statistical mechanics and how to measure thermodynamic length within a computer simulation. Surprisingly, Bennett's classic acceptance ratio method for measuring free energy differences also measures thermodynamic length.
Measuring Crack Length in Coarse Grain Ceramics
NASA Technical Reports Server (NTRS)
Salem, Jonathan A.; Ghosn, Louis J.
2010-01-01
Due to a coarse grain structure, crack lengths in precracked spinel specimens could not be measured optically, so the crack lengths and fracture toughness were estimated by strain gage measurements. An expression was developed via finite element analysis to correlate the measured strain with crack length in four-point flexure. The fracture toughness estimated by the strain gaged samples and another standardized method were in agreement.
Enhancement of Quantum Correlation Length in Quenched Disordered Spin Chains
Debasis Sadhukhan; Sudipto Singha Roy; Debraj Rakshit; R. Prabhu; Aditi Sen De; Ujjwal Sen
2015-03-16
Classical correlations of ground states typically decay exponentially and polynomially, respectively for gapped and gapless short-ranged quantum spin systems. In such systems, entanglement decays exponentially even at the quantum critical points. However, quantum discord, an information-theoretic quantum correlation measure, survives long lattice distances. We investigate the effects of quenched disorder on quantum correlation lengths of quenched averaged entanglement and quantum discord, in the anisotropic XY and XYZ spin glass and random field chains. We find that there is virtually neither reduction nor enhancement in entanglement length while quantum discord length increases significantly with the introduction of the quenched disorder.
Overview of bunch length measurements.
Lumpkin, A. H.
1999-02-19
An overview of particle and photon beam bunch length measurements is presented in the context of free-electron laser (FEL) challenges. Particle-beam peak current is a critical factor in obtaining adequate FEL gain for both oscillators and self-amplified spontaneous emission (SASE) devices. Since measurement of charge is a standard measurement, the bunch length becomes the key issue for ultrashort bunches. Both time-domain and frequency-domain techniques are presented in the context of using electromagnetic radiation over eight orders of magnitude in wavelength. In addition, the measurement of microbunching in a micropulse is addressed.
Correlation of renal length with somatic variables in Indian children
R. Ganesh; T. Vasanthi; J. Lalitha; J. Rajkumar; S. Muralinath
2010-01-01
Mean kidney length in 230 Indian children without apparent renal disease were examined sonographically and correlated with,\\u000a age, body weight, length \\/ height, upper thigh (femur) length, head circumference and chest circumference. Mean kidney is\\u000a length best correlated with height, followed by upper thigh (femur) length and chest circumference.
Dynamic correlation length scales under isochronal conditions
NASA Astrophysics Data System (ADS)
Casalini, R.; Fragiadakis, D.; Roland, C. M.
2015-02-01
The origin of the dramatic changes in the behavior of liquids as they approach their vitreous state—increases of many orders of magnitude in dynamic time scales and transport properties—is a major unsolved problem in condensed matter. These changes are accompanied by greater dynamic heterogeneity, which refers to both spatial variation and spatial correlation of molecular mobilities. The question is whether the changing dynamics are coupled to this heterogeneity; that is, does the latter cause the former? To address this, we carried out the first nonlinear dielectric experiments at elevated hydrostatic pressures on two liquids, to measure the third-order harmonic component of their susceptibilities. We extract from this the number of dynamically correlated molecules for various state points and find that the dynamic correlation volume for non-associated liquids depends primarily on the relaxation time, sensibly independent of temperature and pressure. We support this result by molecular dynamic simulations showing that the maximum in the four-point dynamic susceptibility of density fluctuations is essentially invariant along isochrones for molecules that do not form hydrogen bonds. Our findings are consistent with dynamic cooperativity serving as the principal control parameter for the slowing down of molecular motions in supercooled materials.
Dynamic correlation length scales under isochronal conditions.
Casalini, R; Fragiadakis, D; Roland, C M
2015-02-14
The origin of the dramatic changes in the behavior of liquids as they approach their vitreous state-increases of many orders of magnitude in dynamic time scales and transport properties-is a major unsolved problem in condensed matter. These changes are accompanied by greater dynamic heterogeneity, which refers to both spatial variation and spatial correlation of molecular mobilities. The question is whether the changing dynamics are coupled to this heterogeneity; that is, does the latter cause the former? To address this, we carried out the first nonlinear dielectric experiments at elevated hydrostatic pressures on two liquids, to measure the third-order harmonic component of their susceptibilities. We extract from this the number of dynamically correlated molecules for various state points and find that the dynamic correlation volume for non-associated liquids depends primarily on the relaxation time, sensibly independent of temperature and pressure. We support this result by molecular dynamic simulations showing that the maximum in the four-point dynamic susceptibility of density fluctuations is essentially invariant along isochrones for molecules that do not form hydrogen bonds. Our findings are consistent with dynamic cooperativity serving as the principal control parameter for the slowing down of molecular motions in supercooled materials. PMID:25681920
Dynamic Correlation Length Scales under Isochronal Conditions
R. Casalini; D. Fragiadakis; C. M. Roland
2014-11-24
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 variation and spatial correlation 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 on two liquids, to measure the third-order harmonic component of their susceptibilities. We extract from this the number of dynamically correlated molecules for various state points, and find that the dynamic correlation volume for non-associated liquids depends primarily on the relaxation time, sensibly independent of temperature and pressure. We support this result by molecular dynamic simulations showing that the maximum in the four-point dynamic susceptibility of density fluctuations varies less than 10% for molecules that do not form hydrogen bonds. Our findings are consistent with dynamic heterogeneity serving as the principal control parameter for the slowing down of molecular motions in supercooled materials.
Environmental Correlates of Food Chain Length
Frederic Briand; Joel E. Cohen
1987-01-01
In 113 community food webs from natural communities, the average and maximal lengths of food chains are independent of primary productivity, contrary to the hypothesis that longer food chains should arise when more energy is available at their base. Environmental variability alone also does not appear to constrain average or maximal chain length. Environments that are three dimensional or solid,
Ozone Correlative Measurements Workshop
NASA Technical Reports Server (NTRS)
Hilsenrath, E. (editor)
1985-01-01
A study was conducted to determine the necessary parameters for the correlation of data on Earth ozone. Topics considered were: (1) measurement accuracy; (2) equipment considerations (SBUV); and (3) ground based measurements to support satellite data.
Drift wave transport scalings introduced by varying correlation length
Weiland, J.; Holod, I.
2005-01-01
Scalings of the correlation length of drift wave turbulence with magnetic current q, shear, elongation, and temperature ratio have been introduced into a drift wave transport model. The correlation length is calculated from linear scaling of the fastest growing mode. Such a procedure is supported by previous turbulence simulations with absorbing boundaries for short and long wavelengths. The resulting q and s scalings are now in better agreement with experimental scalings. In particular, the simulation results for transport barrier shots improve.
Extracting the dynamic correlation length of actin networks from microrheology experiments.
Sonn-Segev, Adar; Bernheim-Groswasser, Anne; Roichman, Yael
2014-11-01
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
Determining Correlation and Coherence Lengths in Turbulent Boundary Layer Flight Data
NASA Technical Reports Server (NTRS)
Palumbo, Dan
2012-01-01
Wall pressure data acquired during flight tests at several flight conditions are analysed and the correlation and coherence lengths of the data reported. It is found that the correlation and coherence lengths are influenced by the origin of the structure producing the pressure and the frequency bandwidth over which the analyses are performed. It is shown how the frequency bandwidth biases the correlation length and how the convection of the pressure field might reduce the coherence measured between sensors. A convected form of the cross correlation and cross spectrum is introduced to compensate for the effects of convection. Coherence lengths measured in the streamwise direction appear much longer than expected. Coherent structures detected using the convected cross correlation do not exhibit an exponential coherent power decay.
Telomere length correlates with life span of dog breeds.
Fick, Laura J; Fick, Gordon H; Li, Zichen; Cao, Eric; Bao, Bo; Heffelfinger, Doug; Parker, Heidi G; Ostrander, Elaine A; Riabowol, Karl
2012-12-27
Telomeric DNA repeats are lost as normal somatic cells replicate. When telomeres reach a critically short length, a DNA damage signal is initiated, inducing cell senescence. Some studies have indicated that telomere length correlates with mortality, suggesting that telomere length contributes to human life span; however, other studies report no correlation, and thus the issue remains controversial. Domestic dogs show parallels in telomere biology to humans, with similar telomere length, telomere attrition, and absence of somatic cell telomerase activity. Using this model, we find that peripheral blood mononuclear cell (PBMC) telomere length is a strong predictor of average life span among 15 different breeds (p < 0.0001), consistent with telomeres playing a role in life span determination. Dogs lose telomeric DNA ~10-fold faster than humans, which is similar to the ratio of average life spans between these species. Breeds with shorter mean telomere lengths show an increased probability of death from cardiovascular disease, which was previously correlated with short telomere length in humans. PMID:23260664
Distance and Cable Length Measurement System
Hernández, Sergio Elias; Acosta, Leopoldo; Toledo, Jonay
2009-01-01
A simple, economic and successful design for distance and cable length detection is presented. The measurement system is based on the continuous repetition of a pulse that endlessly travels along the distance to be detected. There is a pulse repeater at both ends of the distance or cable to be measured. The endless repetition of the pulse generates a frequency that varies almost inversely with the distance to be measured. The resolution and distance or cable length range could be adjusted by varying the repetition time delay introduced at both ends and the measurement time. With this design a distance can be measured with centimeter resolution using electronic system with microsecond resolution, simplifying classical time of flight designs which require electronics with picosecond resolution. This design was also applied to position measurement. PMID:22303169
Marine Bi 4iofy LENGTH MEASUREMENTS
Marine Bi 4iofy LENGTH MEASUREMENTS OF LAKE YELLOWSTONE TROUT WOODS HOLE, WASS SPECIAL SCIENTIFIC ;, Director LEI-IGTH MEASUREMEx^ITS OF LAKE YELLOWSTONE TROUT By Oliver B. Cope Fishery Biologist Special clarid lewisi) on Yellowstone Lake and its tributaries since 1936. Prior to that year, considerable
Measuring the orbit length of the Tevatron
Kerns, C.; Kerns, Q.; Miller, H.
1985-06-01
The orbit length in the Tevatron was measured when coasting beam was first obtained. The method was time-of-flight, using a vernier phase comparison between beam pickup signals and a synthesizer sine wave. Some effort was spent making a stable phase detector so that it would not be a limiting factor. The results exhibited a repeatability of a few Hz at 53 MHz, corresponding to a mean radius measurement to 0.1 mm. 5 refs., 4 figs.
Organizational Turnover: Correlates, Satisfaction, Opportunity, and Length of Service.
ERIC Educational Resources Information Center
Bavendam, James M.; Harper, Nancy L.
In a study of turnover in a midwest trucking firm, the files of 199 terminated drivers were used in a statistical analysis of 19 variables that might have been correlated to length of service. A series of interviews with drivers and key management personnel supplemented the statistical data. It was found that previously identified biographical…
Correlation Lengths in the Isotropic Phase of Nematic and Chiral Nematic Liquid Crystals
NASA Astrophysics Data System (ADS)
Krich, Jacob J.; Collings, Peter J.
2000-03-01
The correlation length for the fluctuations of short-range orientational order in the isotropic phase is measured for both a nematic and a chiral nematic liquid crystal using static light scattering. Although the dependence of scattering intensity on the scattering wavevector is weak, measurements with as much accuracy as in the past are possible. The nematic liquid crystal p-pentyl-p’-cyanobiphenyl (5CB) is a molecule that tends to form dimers, unlike the molecules studied in all previous correlation length measurements. In spite of this difference, the temperature dependence and bare correlation length for both types of molecules are similar. Similar measurements for a chiral nematic liquid crystal are more difficult, since the wavevector dependence of the scattering intensity depends on both the correlation length and the chirality of the fluctuations. For a mixture of chiral and racemic S-4'-(2-methylbutyl)phenyl-4-decyloxybenzoate (CE6), the results indicate a correlation length of the same magnitude as in nematic liquid crystals and a chirality close to the chirality of the chiral nematic phase.
Torque correlation length and stochastic twist dynamics of DNA
NASA Astrophysics Data System (ADS)
Banigan, Edward J.; Marko, John F.
2014-06-01
We introduce a short correlation length for torque in twisting-stiff biomolecules, which is necessary for the physical property that torque fluctuations be finite in amplitude. We develop a nonequilibrium theory of dynamics of DNA twisting which predicts two crossover time scales for temporal torque correlations in single-molecule experiments. Bending fluctuations can be included, and at linear order we find that they do not affect the twist dynamics. However, twist fluctuations affect bending, and we predict the spatial inhomogeneity of twist, torque, and buckling arising in nonequilibrium "rotor-bead" experiments.
Torque correlation length and stochastic twist dynamics of DNA.
Banigan, Edward J; Marko, John F
2014-06-01
We introduce a short correlation length for torque in twisting-stiff biomolecules, which is necessary for the physical property that torque fluctuations be finite in amplitude. We develop a nonequilibrium theory of dynamics of DNA twisting which predicts two crossover time scales for temporal torque correlations in single-molecule experiments. Bending fluctuations can be included, and at linear order we find that they do not affect the twist dynamics. However, twist fluctuations affect bending, and we predict the spatial inhomogeneity of twist, torque, and buckling arising in nonequilibrium "rotor-bead" experiments. PMID:25019813
A new ultrasonic stride length measuring system.
Maki, Hiromichi; Ogawa, Hidekuni; Yonezawa, Yoshiharu; Hahn, Allen W; Caldwell, W Morton
2012-01-01
We have developed a new ultrasonic stride length measuring system for analyzing the human gait. An ultrasonic transmitter, a radio transmitter, a pressure sensor and microcontroller are attached to the subject?s heel on the right shoe and in the direction of the left shoe. Two ultrasonic receivers, a radio receiver, a microcontroller and a 1GB SD memory card are installed on the left shoe. Ultrasonic receivers are attached to the toe and heel, in the direction of the right shoe. When the right foot contacts the ground, its heel-mounted ultrasonic and radio transmitters simultaneously transmit to the left shoe. However, radio propagation velocity is far faster than ultrasonic velocity. Therefore, the radio wave acts as a start signal to the radio receiver of the left shoe, indicating the start of ultrasound transmission from the right shoe. Upon receiving the start signal, the microcontroller timer starts to measure each ultrasound propagation time from the right shoe to the left shoe. Distance between right and left shoes is calculated with the time and ultrasound velocity and stored in the SD memory card. Stride length is calculated with a cosine function, by using the obtained distances and the distance between the toe and heel of the left shoe, by a conventional computer. The stride length can then be used for many characterizations of the subject?s gait. PMID:22846295
Is There Any Correlation Between Patient Height and Patellar Tendon Length?
Navali, Amir M; Jafarabadi, Mohammad Asghari
2015-01-01
Background: A potential specific problem of patellar tendon graft in ACL reconstruction is the possibility of graft-tunnel mismatch which could be more problematic with anatomic ACL reconstruction where the femoral tunnel is placed low on the lateral wall of the lateral femoral condyle. The occasional occurrence of this mismatch raises the question that whether a correlation exists between patient height and patellar tendon length. The purpose of the present study was to measure patellar tendon length as an anthropometric finding and to evaluate whether a correlation exists between patient height and patellar tendon length. Methods: Intra-operative measurement of patellar tendon length was carried out in 267 consecutive patients during bone-patellar tendon-bone (BTB) graft ACL reconstruction. Patient age, gender, height were recorded. The patellar tendon measurements were done independently by two surgeons and the possible inter-observer errors were checked. The data were analyzed using the Pearson correlation. Results: The mean length of the patellar tendon was 46.4 ± 4.8 mm (Mean ± SD) with a range of 32–61 mm. The mean patient height was 177 ± 7 cm (Mean ± SD) with a range of 159–197 cm. A weak positive correlations were found between patient height and patellar tendon length (Pearson r = 0.24, P< 0.001). The linear regression equation for patellar tendon length (y, in millimeters) as a function of patient height (x, in centimeters) can be expressed as y=16.54 + 0.17x. Conclusions: Our study showed a weak correlation between patellar tendon length and patient height. This finding is in contrast to the usual measurements in human anthropometry in which taller individuals have normally longer tendons and ligaments. The graft-tunnel mismatch may be the result of this variation. PMID:26110175
Crack length measurement with digital image processing
NASA Astrophysics Data System (ADS)
Wittkowsky, B.; Meyendorf, N.; Schwalbe, K. H.; Dogan, B.
1992-10-01
A method to measure crack length during fracture mechanics tests using digital analysis algorithms is presented. The process was designed for investigating crack propagation in probes submitted to high temperatures and monotonic loading. An optical test apparatus, using photography objectives and charge coupled device camera, was employed for testing the image processing system. A pointspread halogen/cold light source was used for illuminating the samples through the optical axis of the recording system. Results are presented for compact tensile samples of titanium alloys.
Relating Vegetation Aerodynamic Roughness Length to Interferometric SAR Measurements
NASA Technical Reports Server (NTRS)
Saatchi, Sassan; Rodriquez, Ernesto
1998-01-01
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.
Automatic detection and measurement of femur length from fetal ultrasonography
NASA Astrophysics Data System (ADS)
Mukherjee, Prateep; Swamy, Gokul; Gupta, Madhumita; Patil, Uday; Krishnan, Kajoli Banerjee
2010-03-01
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.
Bunch Length Measurements using Coherent Radiation
Ischebeck, Rasmus; Barnes, Christopher; Blumenfeld, Ian; Decker, Franz-Josef; Hogan, Mark; Iverson, Richard H.; Krejcik, Patrick; Siemann, Robert H.; Walz, Dieter; /SLAC; Kirby, Neil; /Stanford U., Phys. Dept.; Clayton, Chris; Huang, Chengkun; Johnson, Devon K.; Lu, Wei; Marsh, Ken; /UCLA; Deng, Suzhi; Oz, Erdem; /Southern California U.
2005-06-24
The accelerating field that can be obtained in a beam-driven plasma wakefield accelerator depends on the current of the electron beam that excites the wake. In the E-167 experiment, a peak current above 10 kA will be delivered at a particle energy of 28 GeV. The bunch has a length of a few ten micrometers and several methods are used to measure its longitudinal profile. Among these, autocorrelation of coherent transition radiation (CTR) is employed. The beam passes a thin metallic foil, where it emits transition radiation. For wavelengths greater than the bunch length, this transition radiation is emitted coherently. This amplifies the long-wavelength part of the spectrum. A scanning Michelson interferometer is used to autocorrelate the CTR. However, this method requires the contribution of many bunches to build an autocorrelation trace. The measurement is influenced by the transmission characteristics of the vacuum window and beam splitter. We present here an analysis of materials, as well as possible layouts for a single shot CTR autocorrelator.
Local-hybrid functional based on the correlation length
Johnson, Erin R.
2014-09-28
Local-hybrid functionals involve position-dependent mixing of Hartree-Fock and density-functional exchange, which should allow improved performance relative to conventional hybrids by reducing the inherent delocalization error and improving the long-range behaviour. Herein, the same-spin correlation length, obtained from the Fermi-hole radius, is used as the mixing parameter. The performance of the resulting local-hybrid functional is assessed for standard thermochemical and kinetics benchmarks. The local hybrid is shown to perform significantly better than the corresponding global hybrid in almost all cases.
In-vitro correlation between tension and length change in an anterior cruciate ligament substitute.
Good, L
1995-06-01
The length change and tension patterns from multiple insertion locations of an anterior cruciate ligament substitute were studied in 10 cadaver knees. Length change was measured with a spring-loaded isometer of low stiffness, and tension was measured with a piezoelectric load cell. In both instances a thin Kevlar test ligament was positioned in five different femoral and two different tibial ligament insertion locations, that were all located within the normal attachments of the anterior cruciate ligament. Differences were found regarding length changes and tension patterns from a simulated active extension between the central, posterior, and anterior femoral locations. All locations showed larger length change and tension values in extension than in flexion. The anterior femoral ligament insertion location showed length change and tension patterns with increasing values in flexion compared to the other femoral locations. The anterior tibial ligament insertion location showed smaller excursions of both length and tension, than did the central one, but the patterns of the curves were similar. A statistically significant correlation was found between length change and tension patterns throughout a 130-0 degrees range of motion. A statistically significant correlation was also found between the maximum length and tension values. No fixed relationship was found between the magnitude of the length and tension values, when different intervals of the range of motion were studied. RELEVANCE: The intraoperative employment of length change measurements of a test ligament in anterior cruciate ligament reconstruction gives information on where high tension can be expected in the range of motion of the knee, and how this can differ depending on the angle of graft fixation. The information gained can also be used to improve drill channel location. However, no predictions on the magnitude of tension can be made, mainly due to large biological variability. PMID:11415553
Bunch length and impedance measurements in SPEAR
Bane, K.; Donald, M.; Hofmann, A.; Jowett, J.; Lockman, W.; Morton, P.; Stege, R.; Spence, W.; Wilson, P.
1988-05-01
Subsequent to an extensive smoothing of the vacuum chamber a comprehensive study of the SPEAR impedance was undertaken. Bunch length, synchrotron quadrupole mode frequency, and parasitic mode loss were measured as functions of beam current. The results showed that, although the gross longitudinal impedance had indeed been reduced, the 'capacitive' component had also decreased relative to the 'inductive'--to the extent that previously compensated potential well distortion now induced bunch lengthening at low currents, and the turbulent threshold had actually been lowered. A specially designed multi-cell disc-loaded 'capacitor' cavity was shown to be capable of removing this effect by restoring the original compensation. A model of the new SPEAR impedance is also obtained. 7 refs., 6 figs.
Mask roughness induced LER: geometric model at long correlation lengths
McClinton, Brittany M.; Naulleau, Patrick P.
2011-02-11
Collective understanding of how both the resist and line-edge roughness (LER) on the mask affect the final printed LER has made significant advances. What is poorly understood, however, is the extent to which mask surface roughness couples to image plane LER as a function of illumination conditions, NA, and defocus. Recently, progress has been made in formulating a simplified solution for mask roughness induced LER. Here, we investigate the LER behavior at long correlation lengths of surface roughness on the mask. We find that for correlation lengths greater than 3/NA in wafer dimensions and CDs greater than approximately 0.75/NA, the previously described simplified model, which remains based on physical optics, converges to a 'geometric regime' which is based on ray optics and is independent of partial coherence. In this 'geometric regime', the LER is proportional to the mask slope error as it propagates through focus, and provides a faster alternative to calculating LER in contrast to either full 2D aerial image simulation modeling or the newly proposed physical optics model. Data is presented for both an NA = 0.32 and an NA = 0.5 imaging system for CDs of 22-nm and 50-nm horizontal-line-dense structures.
Direct Measure of Quantum Correlation
Chang-shui Yu; Heng Fan
2013-07-04
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 non-orthogonality of the eigenvectors of a density. Besides its relatively easy computability, our measure can provide a unified understanding of quantum correlation of all the present versions.
Epidemiologic correlates with menstrual cycle length in middle aged women.
Kato, I; Toniolo, P; Koenig, K L; Shore, R E; Zeleniuch-Jacquotte, A; Akhmedkhanov, A; Riboli, E
1999-10-01
While irregular menstruations have been associated with lower cumulative exposure to the ovarian steroids, shorter regular cycles have been postulated to increase the cumulative exposure. Epidemiological correlates with menstrual patterns were analyzed among 4900 premenopausal women aged 45 or younger from the New York University Women's Health Study. The length of regular menstrual cycles increased with increasing age at menarche, body mass index and parity, but decreased with age, nonwhite racial background and current smoking. The likelihood of irregular cycles increased with increasing age, body mass index and number of cigarettes smoked per day. With adjustment for age, body mass index and number of cigarettes smoked per day, the risk of irregular cycles was marginally positively associated with total fat intake. PMID:10608360
[Measurement of penile length in children and its significance].
Guo, Li-Li; Tang, Da-Xing
2013-09-01
Nowadays, more and more parents are paying increasing attention to the penile length of their children. At present, the methods of measuring penile length mainly include manual measurement and ultrasonography. The former can be used to measure the flaccid, stretched and erected penile lengths, and its use for measuring the stretched penile length has been internationally accepted for its precise definition, unified description, and high repeatability. The latter, as a new method, is being gradually accepted for its imaging visualization and measurement accuracy. This article reviews different measurements of penile length in the mainstream literature of recent years, with an analysis of their advantages and disadvantages. PMID:24386865
Correlations among height, leg length and arm span in growing Korean children.
Yun, D J; Yun, D K; Chang, Y Y; Lim, S W; Lee, M K; Kim, S Y
1995-01-01
A cross-sectional study was performed to find out if any specific correlations exist among height, leg length and arm span in growing Korean children. Height, leg length and arm span were measured in 10,322 healthy children (4740 males and 5582 females). Computed ratios of leg length to height, leg length to arm span and arm span to height for the 3rd, 25th, 50th, 75th and 97th percentiles were made. It was found that the ratios of leg length to height, leg length to arm span, and arm span to height were bigger in taller children in the same age group than the shorter ones in both sexes. All the ratios were bigger in older children in the same percentile than the younger ones in both sexes, showing that the growth rates of leg length and arm span were bigger than that of height in general. However, growth of leg length is faster in shorter children than in taller children until the onset of puberty, after which growth of leg length in taller children is faster than in shorter children. The first and most rapid growth of leg length is seen from birth to 2 years, the second growth spurt is seen during the pubertal period. An exceptional increment in leg length between ages from 10 to 15 is also noted in taller children. After puberty, arm span grows faster than height until 17 years of age in the tallest male child, and taller children have longer arm span than height, while arm span in the shortest children never exceeds height. PMID:8744998
NASA Astrophysics Data System (ADS)
Krich, Jacob J.
2001-03-01
Static light scattering was used to measure (1) the correlation length for the fluctuations of short-range orientational order in the isotropic phase of both nematic and chiral nematic liquid crystals, and (2) the chirality on both sides of the chiral nematic - isotropic transition. Although the dependence of the scattering intensity on the scattering wavevector is weak, correlation length measurements with as much accuracy as in the past are possible. The nematic liquid crystal p-pentyl-p'-cyanobiphenyl (5CB) is a short molecule that tends to form dimers, unlike the molecules studied in all previous correlation length measurements. The new measurements indicate that the correlation length is shorter in 5CB. Similar measurements for a chiral nematic liquid crystal are more difficult, since the wavevector dependence of the scattering intensity depends on both the correlation length and the chirality of the fluctuations. For a mixture of chiral and racemic S-4'-(2-methylbutyl)phenyl-4-decyloxybenzoate (CE6), the results indicate a correlation length slightly larger than in nematic liquid crystals and a chirality slightly higher than in the chiral nematic phase. This last finding of a small change in the chirality at this discontinuous transition disagrees markedly with simple extensions of the Landau-deGennes theory for chiral systems.
Forster, T.E.
EA Systems Examples Induction and Recursion Length Measuring the Universe Analysis Number systems of Mathematics University of Bristol April 21, 2008 Richard.Pettigrew@bris.ac.uk Natural number systems and infinitesimal analysis #12;EA Systems Examples Induction and Recursion Length Measuring the Universe Analysis
Entropic measures of nonclassical correlations
Matthias D. Lang; Carlton M. Caves; Anil Shaji
2015-02-16
A framework for categorizing entropic measures of nonclassical correlations in bipartite quantum states is presented. The measures are based on the difference between a quantum entropic quantity and the corresponding classical quantity obtained from measurements on the two systems. Three types of entropic quantities are used, and three different measurement strategies are applied to these quantities. Many of the resulting measures of nonclassical correlations have been proposed previously. Properties of the various measures are explored, and results of evaluating the measures for two-qubit quantum states are presented.
Two-color absolute length measuring method based on pulse repetition interval lengths
NASA Astrophysics Data System (ADS)
Wei, Dong; Aketagawa, Masato; Takamasu, Kiyoshi; Matsumoto, Hirokazu
2014-12-01
A unique absolute length measurement method is proposed and demonstrated for the first time. Since it takes advantage of both the high-accuracy measurement capability of a pulse train interference method and the ability of a two-color method to compensate for environmental changes, the present method is expected to be useful for high-precision length measurement for not only the purposes of laboratory science but also for satisfying the requirements of industry. A length measurement was performed to demonstrate the feasibility of the proposed method.
Measurements of Newton's gravitational constant and the length of day
John D. Anderson; Gerald Schubert; Virginia Trimble; Michael R. Feldman
2015-05-22
About a dozen measurements of Newton's gravitational constant, G, since 1962 have yielded values that differ by far more than their reported random plus systematic errors. We find that these values for G are oscillatory in nature, with a period of P = 5.899 +/- 0.062 yr, an amplitude of (1.619 +/- 0.103) x 10^{-14} m^3 kg^{-1} s^{-2}, and mean-value crossings in 1994 and 1997. However, we do not suggest that G is actually varying by this much, this quickly, but instead that something in the measurement process varies. Of other recently reported results, to the best of our knowledge, the only measurement with the same period and phase is the Length of Day (LOD - defined as a frequency measurement such that a positive increase in LOD values means slower Earth rotation rates and therefore longer days). The aforementioned period is also about half of a solar activity cycle, but the correlation is far less convincing. The 5.9 year periodic signal in LOD has previously been interpreted as due to fluid core motions and inner-core coupling. We report the G/LOD correlation, whose statistical significance is 0.99764 assuming no difference in phase, without claiming to have any satisfactory explanation for it. Least unlikely, perhaps, are currents in the Earth's fluid core that change both its moment of inertia (affecting LOD) and the circumstances in which the Earth-based experiments measure G. In this case, there might be correlations with terrestrial magnetic field measurements.
Measurements of Newton's gravitational constant and the length of day
NASA Astrophysics Data System (ADS)
Anderson, J. D.; Schubert, G.; Trimble, V.; Feldman, M. R.
2015-04-01
About a dozen measurements of Newton's gravitational constant, G, since 1962 have yielded values that differ by far more than their reported random plus systematic errors. We find that these values for G are oscillatory in nature, with a period of P = 5.899 +/- 0.062 \\text{yr} , an amplitude of (1.619 +/- 0.103) × 10-14 \\text{m}3 \\text{kg}-1 \\text{s}-2 , and mean-value crossings in 1994 and 1997. However, we do not suggest that G is actually varying by this much, this quickly, but instead that something in the measurement process varies. Of other recently reported results, to the best of our knowledge, the only measurement with the same period and phase is the Length of Day (LOD —defined as a frequency measurement such that a positive increase in LOD values means slower Earth rotation rates and therefore longer days). The aforementioned period is also about half of a solar activity cycle, but the correlation is far less convincing. The 5.9 year periodic signal in LOD has previously been interpreted as due to fluid core motions and inner-core coupling. We report the G/LOD correlation, whose statistical significance is 0.99764 assuming no difference in phase, without claiming to have any satisfactory explanation for it. Least unlikely, perhaps, are currents in the Earth's fluid core that change both its moment of inertia (affecting LOD) and the circumstances in which the Earth-based experiments measure G. In this case, there might be correlations with terrestrial-magnetic-field measurements.
Duration of diastole versus cycle length as correlates of left ventricular ejection time
NASA Technical Reports Server (NTRS)
Weisdorf, D.; Spodick, D. H.
1976-01-01
Studies were done on 82 normal subjects to evaluate cycle length vs duration of diastole as determinants of left ventricular ejection time. Cycle length and its reciprocal, heart rate, had the highest correlation with left ventricular ejection time. Removal of the self-correlation of left ventricular ejection time within cycle length reduces the correlation so that, of all intervals, duration of diastole had the highest correlation as a determinant of left ventricular ejection time. Cycle length and heart rate remain valuable as spuriously close but not misleading correlates for predicting or correcting left ventricular ejection time.
Electronic-Acoustic Instruments for Measuring Pipe Lengths
I. Yu. Zhiganov; B. V. Skvortsov; S. G. Sinnikov
2002-01-01
Block diagrams of electronic-acoustic instruments for measuring pipe lengths when there is only access from one end are considered. The principle of operation is based on determining the time taken for an acoustic pulse to propagate along the pipe, on being reflected from the open end. The range of pipe lengths that can be measured is 2–14 m and the
50 CFR Appendix C to Part 622 - Fish Length Measurements
Code of Federal Regulations, 2012 CFR
2012-10-01
...and Fisheries 12 2012-10-01 2012-10-01 false Fish Length Measurements C Appendix C to Part 622 Wildlife and...SOUTH ATLANTIC Pt. 622, App. C Appendix C to Part 622—Fish Length Measurements ER03JY96.000 Figure 1 of Appendix...
50 CFR Appendix C to Part 622 - Fish Length Measurements
Code of Federal Regulations, 2014 CFR
2014-10-01
...and Fisheries 12 2014-10-01 2014-10-01 false Fish Length Measurements C Appendix C to Part 622 Wildlife and...SOUTH ATLANTIC Pt. 622, App. C Appendix C to Part 622—Fish Length Measurements ER17AP13.000...
50 CFR Appendix C to Part 622 - Fish Length Measurements
Code of Federal Regulations, 2013 CFR
2013-10-01
...and Fisheries 12 2013-10-01 2013-10-01 false Fish Length Measurements C Appendix C to Part 622 Wildlife and...SOUTH ATLANTIC Pt. 622, App. C Appendix C to Part 622—Fish Length Measurements ER17AP13.000...
50 CFR Appendix C to Part 622 - Fish Length Measurements
Code of Federal Regulations, 2011 CFR
2011-10-01
...and Fisheries 10 2011-10-01 2011-10-01 false Fish Length Measurements C Appendix C to Part 622 Wildlife and...SOUTH ATLANTIC Pt. 622, App. C Appendix C to Part 622—Fish Length Measurements ER03JY96.000 Figure 1 of Appendix...
From Concrete to Abstract in the Measurement of Length
NASA Astrophysics Data System (ADS)
Stephanou, Andreas; Fisher, William P., Jr.
2013-09-01
The concatenation of units of length is widely viewed as the paradigmatic expression of fundamental measurement. Survey, assessment, and test scores in educational and psychological measurement are often interpreted in ways that assume a concatenation of units to have been established, even though these assumptions are rarely stated or tested. A concatenation model for measurement is shown to be equivalent to a Rasch model: any two units of measurement placed end to end must together be of the same length as either one of them added to itself. This additive principle and a concatenation model of measurement together serve as a heuristic guide for organizing two experimental approaches to calibrating instruments for measuring length. The capacity to reproduce the unit of measurement from theory with no need for repeated empirical calibration experiments, as in the geometrical bisection of the line and the resultant halving of the length measure, is highlighted as essential to demonstrating a thorough understanding of the construct.
Measurements of the aeolian sand transport saturation length
B. Andreotti; P. Claudin; O. Pouliquen
2008-06-24
The wavelength at which a dune pattern emerges from a flat sand bed is controlled by the sediment transport saturation length, which is the length needed for the sand flux to adapt to a change of wind strength. The influence of the wind shear velocity on this saturation length and on the subsequent dune initial wavelength has remained controversial. In this letter, we present direct measurements of the saturation length performed in a wind tunnel experiment. In complement, initial dune wavelengths are measured under different wind conditions -- in particular after storms. Using the linear stability analysis of dune formation, it is then possible to deduce the saturation length from field data. Both direct and indirect measurements agree that the saturation length is almost independent of the wind strength. This demonstrates that, in contrast with erosion, grain inertia is the dominant dynamical mechanism limiting sediment transport saturation.
Measurement: Which Unit of Length is Appropriate?
NSDL National Science Digital Library
2008-01-01
In this game, students are given an object such as a diving board or earthwork and are asked to select the appropriate unit for the measurement of the object, including yards, meters, centimeters, inches, and feet. Students select the correct answer from two possibilities. Their answers and the time taken are recorded. This is an excellent resource to help students understand the difference in units of measurement as well as beginning estimation skills.
Correlation Lengths, Disorder, and Dynamics of the Vortex Condensate as Heard Through the Noise
NASA Astrophysics Data System (ADS)
Rabin, Michael W.
1998-03-01
We have demonstrated a new method for probing correlated regions of vortices in type II superconductors.(M. W. Rabin, et al. Phys Rev B Rapid Comm 57 (2), 1 Jan 98) The heart of our measurement is the sensitivity of low frequency noise ( ~1Hz) to a higher frequency ( ~100 Hz) magnetic field perturbation (? H); ? H/H 10-4 substantially reduces the noise by inducing rapid switching among the metastable configurations present in the pinned state. Applied to the peak effect, where the critical current (I_c) increases as a function of either magnetic field (H) or temperature, ? H drops dramatically as H decreases from the peak value (H_p), implying an increasing correlation length (L_n). ? H reaches a minimum at the onset of the peak (H_pl), consistent with Ln reaching a sample-size limit. These measurements suggest a structural phase transition in the static, underlying vortex solid associated with the abrupt softening that causes the peak (Pippard scenario). The relationship among the collective-pinning theory correlation lengths (Lc and R_c, the Larkin lengths), the dynamic correlation length (L_v, based on transport measurements), and Ln will be discussed. For ? H to affect the vortex condensate's memory and reduce low frequency noise, ? H must change the number of vortices in a correlated region enough to force them to repin, hence (partially) scrambling their state, therefore ? H ? 1/L_n. Though voltage noise, like other transport properties, is only measured while the vortices are moving (i.e. when I>I_c), the noise in this regime reflects the pinned vortex configuration because (1) the noise power is comparable and spectral slope are the same for dc current and pulsed current and (2) because noise power is reduced by ? H even when ? H and I are out of sync, i.e. ? H is applied and removed while the current is zero and the vortices are pinned. All measurements were done on single crystals of 2H-NbSe2 with H||c at 4.2K in liquid He.
Computable measure of quantum correlation
NASA Astrophysics Data System (ADS)
Akhtarshenas, S. Javad; Mohammadi, Hamidreza; Karimi, Saman; Azmi, Zahra
2015-01-01
A general state of an system is a classical-quantum state if and only if its associated -correlation matrix (a matrix constructed from the coherence vector of the party , the correlation matrix of the state, and a function of the local coherence vector of the subsystem ), has rank no larger than . Using the general Schatten -norms, we quantify quantum correlation by measuring any violation of this condition. The required minimization can be carried out for the general -norms and any function of the local coherence vector of the unmeasured subsystem, leading to a class of computable quantities which can be used to capture the quantumness of correlations due to the subsystem . We introduce two special members of these quantifiers: The first one coincides with the tight lower bound on the geometric measure of discord, so that such lower bound fully captures the quantum correlation of a bipartite system. Accordingly, a vanishing tight lower bound on the geometric discord is a necessary and sufficient condition for a state to be zero-discord. The second quantifier has the property that it is invariant under a local and reversible operation performed on the unmeasured subsystem, so that it can be regarded as a computable well-defined measure of the quantum correlations. The approach presented in this paper provides a way to circumvent the problem with the geometric discord. We provide some examples to exemplify this measure.
Conductivity and the current-current correlation measure
J. M. Combes; F. Germinet; P. D. Hislop
2010-08-31
We review various formulations of conductivity for one-particle Hamiltonians and relate them to the current-current correlation measure. We prove that the current-current correlation measure for random Schr\\"odinger operators has a density at coincident energies provided the energy lies in a localization regime. The density vanishes at such energies and an upper bound on the rate of vanishing is computed. We also relate the current-current correlation measure to the localization length.
Measurements of Newton's gravitational constant and the length of day
Anderson, John D; Trimble, Virginia; Feldman, Michael R
2015-01-01
About a dozen measurements of Newton's gravitational constant, G, since 1962 have yielded values that differ by far more than their reported random plus systematic errors. We find that these values for G are oscillatory in nature, with a period of P = 5.899 +/- 0.062 yr, an amplitude of (1.619 +/- 0.103) x 10^{-14} m^3 kg^{-1} s^{-2}, and mean-value crossings in 1994 and 1997. However, we do not suggest that G is actually varying by this much, this quickly, but instead that something in the measurement process varies. Of other recently reported results, to the best of our knowledge, the only measurement with the same period and phase is the Length of Day (LOD - defined as a frequency measurement such that a positive increase in LOD values means slower Earth rotation rates and therefore longer days). The aforementioned period is also about half of a solar activity cycle, but the correlation is far less convincing. The 5.9 year periodic signal in LOD has previously been interpreted as due to fluid core motions ...
Patch-repetition correlation length in glassy systems
NASA Astrophysics Data System (ADS)
Cammarota, Chiara; Biroli, Giulio
2012-05-01
We obtain the patch-repetition entropy ? within the Random First-Order Transition (RFOT) theory and for the square plaquette system, a model related to the dynamical facilitation theory of glassy dynamics. We find that in both cases the entropy of patches of linear size l, ?(l), scales as scld+Ald- 1 down to length scales of the order of one, where A is a positive constant, sc is the configurational entropy density and d the spatial dimension. As a consequence, the only meaningful length that can be defined from patch-repetition is the crossover length ?=A/sc. We relate ? to the typical length scales already discussed in the literature and show that it is always of the order of the largest static length. Our results provide new insights, which are particularly relevant for RFOT theory, into the possible real-space structure of super-cooled liquids. They suggest that this structure differs from a mosaic of different patches having roughly the same size.
Measuring correlations in symbol sequences
NASA Astrophysics Data System (ADS)
Herzel, Hanspeter; Große, Ivo
1995-02-01
The paper is devoted to relations between correlation functions and mutual information. It is shown that, in sequences over an alphabet of ? symbols, statistical dependences are measured by ( ? - 1) 2 independent parameters. However, not all of them can be determined by autocorrelation functions. Appropriate sets of correlation functions (including crosscorrelations) are introduced, which allow the detection of all dependences. The results are exemplified for binary, ternary, and quaternary symbol sequences. As an application, it is discussed that a nonuniform codon usage in protein-coding DNA sequences introduces periodic correlations even at distances in the order of 1000 base pairs.
Correlation length in La{sub 1{minus}x}Ca{sub x}MnO{sub 3} (abstract)
Erwin, R.W.; Lynn, J.W.; Borchers, J.A.; Peng, J.L.; Greene, R.L.
1997-04-01
Small-angle neutron scattering (SANS) has been used to measure the ferromagnetic correlation length in La{sub 0.67}Ca{sub 0.33}MnO{sub 3}. This is of interest in these materials because the transport mechanism responsible for colossal magnetoresistivity involves valence fluctuation on the Mn sites, and thus, spin fluctuations. There should then be a direct relationship between the magnetoresistivity and the spin{endash}fluctuation correlation length. The magnetic SANS was determined by substracting 15 K data from the data at and above T{sub C} (250 K). When the quasistatic approximation is valid, the magnetic SANS measures the static equal-time two-spin correlation function. In an ideal isotropic ferromagnet, the fluctuations that drive the phase transition are the transverse (below T{sub C}) spin waves, which have a divergent correlation length at and below T{sub C}. Our measurements show that the magnetic scattering function for temperatures above T{sub C} is approximately Lorentzian. However, the extracted correlation length is anomalously small, starting at about 6 {Angstrom} at 400 K and increasing only to about 11 {Angstrom} at the nominal T{sub C}=250 K. The correlation length continues to increase below T{sub C} to about 14 {Angstrom} at 225 K. Inelastic scattering measurements suggest that there are significant diffusive fluctuations near T{sub C} in addition to the spin waves. We are performing SANS measurements in a magnetic field to try to separate the correlation lengths of these two types of fluctuations. {copyright} {ital 1997 American Institute of Physics.}
Far-from-equilibrium measurements of thermodynamic length
Feng, Edward H.; Crooks, Gavin E.
2008-11-05
Thermodynamic length is a path function that generalizes the notion of length to the surface of thermodynamic states. Here, we show how to measure thermodynamic length in far-from-equilibrium experiments using the work fluctuation relations. For these microscopic systems, it proves necessary to define the thermodynamic length in terms of the Fisher information. Consequently, the thermodynamic length can be directly related to the magnitude of fluctuations about equilibrium. The work fluctuation relations link the work and the free energy change during an external perturbation on a system. We use this result to determine equilibrium averages at intermediate points of the protocol in which the system is out-of-equilibrium. This allows us to extend Bennett's method to determine the potential of mean force, as well as the thermodynamic length, in single molecule experiments.
Correlations between Muscle Activities and Strap Length and Types of School Bag during Walking
Yoon, Jung-Gyu
2014-01-01
[Purpose] The purpose of this study was to examine correlations between muscle activities and strap length and type of the school bag during walking. [Subjects and Methods] The subjects of this study were 20 healthy students. An 8-channel electromyograph (8-EMG) (Pocket EMG, BTS, Italy) was used to measure the muscle activities of the right upper trapezius, left upper trapezius, right erector spinae and left erector spinae during walking with the bag. The collected data were analyzed using Kendall’s coefficient of concordance. [Results] The muscle activities of the right upper trapezius, left upper trapezius, right erector spinae and left erector spinae were significantly higher when walking with a shoulder bag than when walking with a backpack. No significant correlations were found between muscle activities and strap lengths of the bag. [Conclusion] While carrying a bag, the activities of the trunk muscles were influenced more by the type of the bag than by the strap length. These results indicate that a backpack is a better method of carrying a load than a shoulder bag. PMID:25540502
Correlations between Muscle Activities and Strap Length and Types of School Bag during Walking.
Yoon, Jung-Gyu
2014-12-01
[Purpose] The purpose of this study was to examine correlations between muscle activities and strap length and type of the school bag during walking. [Subjects and Methods] The subjects of this study were 20 healthy students. An 8-channel electromyograph (8-EMG) (Pocket EMG, BTS, Italy) was used to measure the muscle activities of the right upper trapezius, left upper trapezius, right erector spinae and left erector spinae during walking with the bag. The collected data were analyzed using Kendall's coefficient of concordance. [Results] The muscle activities of the right upper trapezius, left upper trapezius, right erector spinae and left erector spinae were significantly higher when walking with a shoulder bag than when walking with a backpack. No significant correlations were found between muscle activities and strap lengths of the bag. [Conclusion] While carrying a bag, the activities of the trunk muscles were influenced more by the type of the bag than by the strap length. These results indicate that a backpack is a better method of carrying a load than a shoulder bag. PMID:25540502
Coherent Transition Radiation to Measure the SLAC Electron Bunch Length
Muggli, P.; /Southern California U.; Hogan, M.J.; Barnes, C.D.; Walz, D.; Krejcik, P.; Siemann, R.H.; /SLAC
2005-05-13
Coherent transition radiation is used to measure the length of the ultra-short electron bunches available at the Stanford Linear Accelerator Center. The results and the limitations of the method are described.
Measuring the Length of a Captured Burmese Python
Skip Snow (National Park Service) measures the length of a captured Burmese python (Python molurus) at the South Florida Research Center, Everglades National Park. Photo courtesy of Lori Oberhofer, NPS. ...
Automated Defect and Correlation Length Analysis of Block Copolymer Thin Film Nanopatterns
Murphy, Jeffrey N.; Harris, Kenneth D.; Buriak, Jillian M.
2015-01-01
Line patterns produced by lamellae- and cylinder-forming block copolymer (BCP) thin films are of widespread interest for their potential to enable nanoscale patterning over large areas. In order for such patterning methods to effectively integrate with current technologies, the resulting patterns need to have low defect densities, and be produced in a short timescale. To understand whether a given polymer or annealing method might potentially meet such challenges, it is necessary to examine the evolution of defects. Unfortunately, few tools are readily available to researchers, particularly those engaged in the synthesis and design of new polymeric systems with the potential for patterning, to measure defects in such line patterns. To this end, we present an image analysis tool, which we have developed and made available, to measure the characteristics of such patterns in an automated fashion. Additionally we apply the tool to six cylinder-forming polystyrene-block-poly(2-vinylpyridine) polymers thermally annealed to explore the relationship between the size of each polymer and measured characteristics including line period, line-width, defect density, line-edge roughness (LER), line-width roughness (LWR), and correlation length. Finally, we explore the line-edge roughness, line-width roughness, defect density, and correlation length as a function of the image area sampled to determine each in a more rigorous fashion. PMID:26207990
Precisison neutron interferometric measurement of the nd coherent scattering length
NASA Astrophysics Data System (ADS)
Snow, W. M.; Black, T. C.; Arif, M.; Huffman, P. R.; Jacobson, D. L.; Werner, S. W.; Kaiser, H.; Schoen, K.; Lamoreaux, S.
2003-11-01
We have performed a high-precision neutron interferometric measurement of the coherent neutron-deuteron scattering length at the Center for Neutron Research at NIST, using a monochromatic cold neutron beam (En = 11.1 MeV, ? = 0.271 nm, ?? /? ? 0.5%) in a perfect single crystal silcon interferometer. After correcting for systematic effects, we obtained a bound coherent nd scattering length of (b_nd = 6.6649 ± 0.0020) fm. Combining our result with previous measurements yields a new world average free coherent scattering length of (a_nd = 4.443 ± 0.002) fm, which is inconsistent with most published theoretical calculations of the free coherent scattering length. The precision obtained in this measurement has the potential to distinguish between different nuclear force models even when 3N forces have been adjusted to replicate the triton binding energy.
A comparison of length-matching and length-fractionation measures of Müller-lyer distortions.
Predebon, John
2005-02-01
Two experiments were performed to evaluate the informational equivalence of length-matching (e.g., reproduction) and length-fractionation (e.g., bisection) procedures that are frequently used to quantify geometrical size distortions, such as the Müller-Lyer (M-L) illusion. In Experiment 1, the distortion in the apparent length of a horizontal test line was measured as a function of the angle between it and an abutting inducing line, and in Experiment 2 distortion was measured in the apparent length of the shaft of one-angle versions of the M-L illusion. Both procedures indexed the expansion of the obtuse-angle and the wings-out M-L illusion and the contraction of the acute-angle and the wings-in M-L illusion. However, whereas the reproduction measures indicated substantially greater expansion than contraction distortion, the bisection measures indicated greater contraction distortion. Some possible reasons for this difference, particularly the possibility that the reproduction and bisection procedures are unequally sensitive to the outputs of the mechanisms producing the M-L illusion, are discussed. PMID:15971690
Zohar Nussinov
2005-06-22
In this article, addressing large $n$ systems, we report that in numerous systems hosting long and short range interactions, multiple correlation lengths may appear. The largest correlation lengths often monotonically increase with temperature and diverge in the high temperature limit. Notwithstanding, the magnitude of the correlations themselves decreases with increasing temperature. We examine correlation function in the presence of competing interactions of long and short ranges. The behavior of the correlation and modulation lengths as a function of temperature provides us with selection rules on the possible underlying microscopic interactions. As a concrete example of these notions, we consider the correlations in a system of screened Coulomb interactions coexisting with attractive short range interactions.
Fiber Length Measurement In Pulp And Paper Industry
NASA Astrophysics Data System (ADS)
Piirainen, Raili A.
1986-10-01
For the pulp and paper maker, product quality and production costs are the major factors that determine profitability. Quality has to be high enough to satisfy the customer and costs low enough to maintain competitiveness. Accurate and readily available fiber length information is fast becoming one of the most important control factors to achieve these targets. Measurement of fiber length has been difficult and time consuming in the past --- appli-cation to production almost impossible due to the historical nature of the data. The Kajaani fiber length analyzer has revolutionized fiber length analysis. Even more accurate than the microscopic method and infinitely faster than mechanical classifiers, such as Bauer McNett or Clark classifiers, the Kajaani analyzer opens new horizons for the paper maker. The Kajaani method is an optical method and is based on the ability of fibers to change the direction of light polarization. With no critical sample preparation, the results are ready in a few minutes. During this time, the analyzer counts and measures over 3000 individual fibers. Results are printed out either in graphic or numerical form. Some of the typical applications of the Kajaani fiber length analyzer are to determine hardwood/softwood ratios in pulp and paper mills both in brownstock and stock preparation areas, to predict strength properties of mechanical pulp based on the fiber length information, to measure the coarseness of the fibers, to evaluate screening and refining processes and to check the quality of purchased pulp.
Telomere Length: A Review of Methods for Measurement
Montpetit, Alison J.; Alhareeri, Areej A.; Montpetit, Marty; Starkweather, Angela R.; Elmore, Lynne W.; Filler, Kristin; Mohanraj, Lathika; Burton, Candace W.; Menzies, Victoria S.; Lyon, Debra E.; Collins, Judith B.; Teefey, Joseph M.; Jackson-Cook, Colleen K.
2014-01-01
Background The exciting discovery that telomere shortening is associated with many health conditions, and that telomere lengths can be altered in response to social and environmental exposures, has underscored the need for methods to accurately and consistently quantify telomere length. Objectives The purpose of this paper is to provide a comprehensive summary that compares and contrasts the current technologies used to assess telomere length. Discussion Multiple methods have been developed for the study of telomeres. These techniques include quantification of telomere length by terminal restriction fragmentation—which was one of the earliest tools used for length assessment—making it the gold standard in telomere biology. Quantitative-PCR provides the advantage of being able to use smaller amounts of DNA, thereby making it amenable to epidemiology studies involving large numbers of people. An alternative method uses fluorescent probes to quantify not only mean telomere lengths, but also chromosome-specific telomere lengths; however, the downside of this approach is that it can only be used on mitotically active cells. Additional methods that permit assessment of the length of a subset of chromosome-specific telomeres, or the subset of telomeres that demonstrate shortening, are also reviewed. Conclusion Given the increased utility for telomere assessments as a biomarker in physiological, psychological and biobehavioral research, it is important that investigators become familiar with the methodological nuances of the various procedures used for measuring telomere length. This will ensure that they are empowered to select an optimal assessment approach to meet the needs of their study designs. Gaining a better understanding of the benefits and drawbacks of various measurement techniques is important not only in individual studies, but also to further establish the science of telomere associations with biobehavioral phenomena. PMID:24977726
NASA Astrophysics Data System (ADS)
Slobodda, J.; Hünerbein, A.; Lindstrot, R.; Preusker, R.; Ebell, K.; Fischer, J.
2015-02-01
Images of measured radiance in different channels of the geostationary Meteosat-9 SEVIRI instrument are analysed with respect to the representativeness of the observations of eight cloud observatories in Europe (e.g. measurements from cloud radars or microwave radiometers). Cloudy situations are selected to get a time series for every pixel in a 300 km × 300 km area centred around each ground station. Then a cross correlation of each time series to the pixel nearest to the corresponding ground site is calculated. In the end a correlation length is calculated to define the representativeness. It is found that measurements in the visible and near infrared channels, which respond to cloud physical properties, are correlated in an area with a 1 to 4 km radius, while the thermal channels, that correspond to cloud top temperature, are correlated to a distance of about 20 km. This also points to a higher variability of the cloud microphysical properties inside a cloud than of the cloud top temperature. The correlation length even increases for the channels at 6.2, 7.3 and 9.7 ?m. They respond to radiation from the upper atmospheric layers emitted by atmospheric gases and higher level clouds, which are more homogeneous than low-level clouds. Additionally, correlations at different distances, corresponding to the grid box sizes of forecast models, were compared. The results suggest the possibility of comparisons between instantaneous cloud observations from ground sites and regional forecast models and ground-based measurements. For larger distances typical for global models the correlations decrease, especially for short-wave measurements and corresponding cloud products. By comparing daily means, the correlation length of each station is increased to about 3 to 10 times the value of instantaneous measurements and also the comparability to models grows.
Critical point coupling in liquid helium and the significance of the correlation length
NASA Astrophysics Data System (ADS)
Perron, Justin K.; Thomson, Stephen R. D.; Gasparini, Francis M.
2012-02-01
[1]( #1 ?m )^3 Recent measurements of liquid helium confined to 2 boxes connected through a 33 nm film have shown coupling effects between boxes spaced distances much larger than the correlation length ?(t,L)[1,2] and proximity effects on the connecting film[3]. An analysis of data suggests that ?(t,L) is the relevant parameter in these effects. This dependence on ?(t,L) is used to argue that the enhancement in the specific heat due to coupling is a reflection of the finite-size correlation length in the boxes and hence its scaling function. All this raises some profound questions about our physical understanding of ?(t,L). [4pt] [1] Perron J K, Kimball M O, Mooney K P and Gasparini F M 2010 Nat. Phys./ 6 499--502[0pt] [2] Perron J K, and Gasparini F M 2011 submitted to PNAS/[0pt] [3] Perron J K, and Gasparini F M 2011 to be published in JPCS/
Measurement of Trap Length for an Optical Trap
NASA Technical Reports Server (NTRS)
Wrbanek, Susan Y.
2009-01-01
The trap length along the beam axis for an optical trap formed with an upright, oil-immersion microscope was measured. The goals for this effort were twofold. It was deemed useful to understand the depth to which an optical trap can reach for purposes of developing a tool to assist in the fabrication of miniature devices. Additionally, it was desired to know whether the measured trap length favored one or the other of two competing theories to model an optical trap. The approach was to trap a microsphere of known size and mass and raise it from its initial trap position. The microsphere was then dropped by blocking the laser beam for a pre-determined amount of time. Dropping the microsphere in a free-fall mode from various heights relative to the coverslip provides an estimate of how the trapping length changes with depth in water in a sample chamber on a microscope slide. While it was not possible to measure the trap length with sufficient precision to support any particular theory of optical trap formation, it was possible to find regions where the presence of physical boundaries influenced optical traps, and determine that the trap length, for the apparatus studied, is between 6 and 7 m. These results allow more precise control using optical micromanipulation to assemble miniature devices by providing information about the distance over which an optical trap is effective.
Ludington, William B; Ishikawa, Hiroaki; Serebrenik, Yevgeniy V; Ritter, Alex; Hernandez-Lopez, Rogelio A; Gunzenhauser, Julia; Kannegaard, Elisa; Marshall, Wallace F
2015-03-24
Cells control organelle size with great precision and accuracy to maintain optimal physiology, but the mechanisms by which they do so are largely unknown. Cilia and flagella are simple organelles in which a single measurement, length, can represent size. Maintenance of flagellar length requires an active transport process known as intraflagellar transport, and previous measurements suggest that a length-dependent feedback regulates intraflagellar transport. But the question remains: how is a length-dependent signal produced to regulate intraflagellar transport appropriately? Several conceptual models have been suggested, but testing these models quantitatively requires that they be cast in mathematical form. Here, we derive a set of mathematical models that represent the main broad classes of hypothetical size-control mechanisms currently under consideration. We use these models to predict the relation between length and intraflagellar transport, and then compare the predicted relations for each model with experimental data. We find that three models-an initial bolus formation model, an ion current model, and a diffusion-based model-show particularly good agreement with available experimental data. The initial bolus and ion current models give mathematically equivalent predictions for length control, but fluorescence recovery after photobleaching experiments rule out the initial bolus model, suggesting that either the ion current model or a diffusion-based model is more likely correct. The general biophysical principles of the ion current and diffusion-based models presented here to measure cilia and flagellar length can be generalized to measure any membrane-bound organelle volume, such as the nucleus and endoplasmic reticulum. PMID:25809250
Cytosine Usage Modulates the Correlation between CDS Length and CG Content in Prokaryotic Genomes
Xia, Xuhua
Cytosine Usage Modulates the Correlation between CDS Length and CG Content in Prokaryotic Genomes empirically by prokaryotic genomes. How- ever, the correlation is weak for a number of species, with 4 species abundant nucleotide in the cell, and a long CDS should have fewer Cs to increase transcription efficiency
Ruler measurements give space-time-transformation-independent invariant lengths
J. H. Field
2013-07-30
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.
Radiofrequency sensors for on-line metal tube length measurement
A. R. Bushel; A. S. Sovlukov; V. A. Viktorov
2002-01-01
Radiofrequency sensors are suggested and applied for length measurement of elongated metal articles (tubes, rods). According to principles of such sensor design each produced or ready article is considered as one of the conductors of TEM-line. Another elongated conductor (screen) that is parallel to a monitored article is used as the other conductor of such TEM-line. In most cases, section
Measurement of <20 fs bunch length using coherent transition radiation
NASA Astrophysics Data System (ADS)
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
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.
Driscoll, J.F.; Huh, H.; Yoon, Y.; Donbar, J. [Univ. of Michigan, Ann Arbor, MI (United States). Dept. of Aerospace Engineering] [Univ. of Michigan, Ann Arbor, MI (United States). Dept. of Aerospace Engineering
1996-10-01
Measurements of flame length are reported that help to quantify the overall fuel-air mixing process that occurs within a jet-like flame in the supersonic regime. A nonpremixed, turbulent, hydrogen-air jet flame is stabilized along the axis of a Mach 2.2 coflowing air stream. Supersonic flame lengths are compared to measured lengths of subsonic hydrogen-air flames with coflow that were stabilized on the axis of a subsonic wind tunnel for a range of fuel/air velocity and density ratios. The supersonic flames are found to be significantly shorter than (i.e., typically half as long as) corresponding subsonic flames,providing that both the velocity and density ratios are matched for the two cases. This difference implies that for axisymmetric jet geometries with combustion, mixing rates are larger in the supersonic case. Compressibility effects are not believed to be significant since typical convective Mach numbers are less than 0.45. One possible reason why the supersonic flames are relatively short is that the radial velocity, which controls entrainment, can be altered by compression/expansion waves that are inherent to the jet geometry. Both subsonic and supersonic flame lengths increase as the normalized fuel mass flux increases, which is predicted to occur by a scaling analysis. The density of the supersonic airstream was decreased in order to simulate an increase in altitude, and the supersonic flames became longer, as predicted by the analysis. Increasing the air stagnation temperature to 600 K shortens the supersonic flames, which is not explained by the mixing-limited scaling analysis and may be due to finite-rate chemistry or partially premixed combustion, both of which are temperature dependent processes.
How to Directly Measure a Kondo Cloud's Length
NASA Astrophysics Data System (ADS)
Park, Jinhong; Lee, S.-S. B.; Oreg, Yuval; Sim, H.-S.
2013-06-01
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.
FEL Gain Length and Taper Measurements at LCLS
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
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.
FEL GAIN LENGTH AND TAPER MEASUREMENTS AT LCLS
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
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.
Reducing trial length in force platform posturographic sleep deprivation measurements
NASA Astrophysics Data System (ADS)
Forsman, P.; Hæggström, E.; Wallin, A.
2007-09-01
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.
Effective crack lengths by compliance measurement for ARALL-2 laminates
NASA Technical Reports Server (NTRS)
Wilson, Christopher D.; Wilson, Dale A.
1991-01-01
As a means of determining a stress intensity factor solution, the compliance properties of an ARALL-2 laminated-sheet composite were investigated. Fatigue crack growth rate (FCGR) tests were conducted on middle crack tension (MT) specimens fabricated from a layup consisting of three sheets of 2024-T3 aluminum bonded together with unidirectional aramid fibers embedded in epoxy. Excellent fatigue crack growth properties are obtained by the presence of unbroken aramid fibers in the wake of the crack tip. These unbroken fibers act as a bridging mechanism to inhibit further crack growth. To quantify the effect of maximum fatigue load on compliance, a series of FCGR tests were performed. Effective crack lengths were determined to be at least 10 mm shorter than surface measured crack lengths for a 76-mm-wide specimen. The bridging zone was estimated to be at least 5 mm. Compliance and stress intensity factor as functions of effective crack length were determined.
Developing measurement concepts within context: Children's representations of length
NASA Astrophysics Data System (ADS)
MacDonald, Amy; Lowrie, Tom
2011-03-01
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.
An ultrasonic stride length measuring system employing two digital compasses.
Maki, Hiromichi; Ogawa, Hidekuni; Yonezawa, Yoshiharu; Hahn, Allen W; Caldwell, W Morton
2014-01-01
We have developed an ultrasonic stride length measuring system for analyzing the human gait. All elements of the system are quite small and each fit into an appropriate package. An ultrasonic transmitter, a digital compass, a radio transmitter and a microcontroller are attached to the subject?s heel on the right shoe and in the direction of the left shoe. Two ultrasonic receivers, a digital compass, a radio receiver, a microcontroller and a 1GB SD memory card are installed on the left shoe. The ultrasonic receivers are attached to the toe and heel in the direction of the right shoe. The walking direction is thus detected by the compass attached on the right and left shoes, respectively. The stride length is detected by the difference between the radio wave and ultrasonic propagation velocities. The stride length is corrected by the detected walking direction, and then the corrected stride length is stored in the SD memory card. When downloaded, the memory card gives the accurate stride length which then is used to characterize the subject?s gait during daily activity. PMID:25405450
Universal measurement of quantum correlations of radiation.
Shchukin, E; Vogel, W
2006-05-26
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. PMID:16803157
Interaural correlations in normal and traumatized cochleas: length and sensory cell loss
Bohne, B.A.; Bozzay, D.G.; Harding, G.W.
1986-12-01
Sizable intraspecies variations have been found in both the length of the organ of Corti (OC) and the amount of damage resulting from exposure to a particular ototraumatic agent. These variations have made it difficult to address certain research questions such as the susceptibility of the previously injured ear to further damage. If intra-animal correlation is high, the variability problem could be circumvented by using the two ears from a given animal for different aspects of the same study. Therefore, correlation coefficients were calculated for OC length and for percentage of missing inner (IHCs) and outer hair cells (OHCs) in a large sample of chinchillas which included controls and animals which had been exposed to noise or treated with ionizing radiation. The correlation coefficients were +0.96 for OC length, +0.93 for IHC loss, and +0.97 for OHC loss.
Absolute Bunch Length Measurements by Incoherent Radiation Fluctuation Analysis
Sannibale, F.; /LBL, Berkeley; Stupakov, G.V.; /SLAC; Zolotorev, M.S.; /LBL, Berkeley; Filippetto, D.; /INFN, Rome; Jagerhofer, L.; /Vienna, Tech. U.
2009-12-09
By analyzing the pulse to pulse intensity fluctuations of the radiation emitted by a charge particle in the incoherent part of the spectrum, it is possible to extract information about the spatial distribution of the beam. At the Advanced Light Source (ALS) of the Lawrence Berkeley National Laboratory, we have developed and successfully tested a simple scheme based on this principle that allows for the absolute measurement of the rms bunch length. A description of the method and the experimental results are presented.
Xu, Wen-Sheng; Sun, Zhao-Yan; An, Li-Jia
2012-08-15
We numerically study dynamics and correlation length scales of a colloidal liquid in both quiescent and sheared conditions to further understand the origin of slow dynamics and dynamic heterogeneity in glass-forming systems. The simulation is performed in a weakly frustrated two-dimensional liquid, where locally preferred order is allowed to develop with increasing density. The four-point density correlations and bond-orientation correlations, which have been frequently used to capture dynamic and static length scales ? in a quiescent condition, can be readily extended to a system under steady shear in this case. In the absence of shear, we confirmed the previous findings that the dynamic slowing down accompanies the development of dynamic heterogeneity. The dynamic and static length scales increase with ?-relaxation time ?(?) as a power law [Formula: see text], with ? > 0. In the presence of shear, both viscosity and ?(?) have power-law dependences on shear rate in the marked shear-thinning regime. However, the dependence of correlation lengths cannot be described by power laws in the same regime. Furthermore, the relation [Formula: see text] between length scales and dynamics holds for not too strong shear where thermal fluctuations and external forces are both important in determining the properties of dense liquids. Thus, our results demonstrate a link between slow dynamics and structure in glass-forming liquids even under nonequilibrium conditions. PMID:22647845
Correlation length and negative phase velocity in isotropic dielectric-magnetic materials
NASA Astrophysics Data System (ADS)
Mackay, Tom G.; Lakhtakia, Akhlesh
2006-09-01
A composite material comprising randomly distributed spherical particles of two different isotropic dielectric-magnetic materials is homogenized using the second-order strong-property-fluctuation theory in the long-wavelength approximation. Whereas neither of the two constituent materials by itself supports plane wave propagation with negative phase velocity (NPV), the homogenized composite material (HCM) can. The propensity of the HCM to support NPV propagation is sensitive to the distributional statistics of the constituent material particles, as characterized by a two-point covariance function and its associated correlation length. The scope for NPV propagation diminishes as the correlation length increases.
James F. Driscoll; Hwanil Huh; Youngbin Yoon; Jeffrey Donbar
1996-01-01
Measurements of flame length are reported that help to quantify the overall fuel-air mixing process that occurs within a jet-like flame in the supersonic regime. A nonpremixed, turbulent, hydrogen-air jet flame is stabilized along the axis of a Mach 2.2 coflowing air stream. Supersonic flame lengths are compared to measured lengths of subsonic hydrogen-air flames with coflow that were stabilized
Direct calculation of correlation length based on quasi-cumulant method
NASA Astrophysics Data System (ADS)
Fukushima, Noboru
2014-03-01
We formulate a method of directly obtaining a correlation length without full calculation of correlation functions, as a high-temperature series. The method is based on the quasi-cumulant method, which was formulated by the author in J. Stat. Phys. 111, 1049-1090 (2003) as a complementary method for the high-temperature series expansion originally for an SU(n) Heisenberg model, but is applicable to general spin models according to our recent reformulation. A correlation function divided by its lowest-order nonzero contribution has properties very similar to a generating function of some kind of moments, which we call quasi-moments. Their corresponding quasi-cumulants can be also derived, whose generating function is related to the correlation length. In addition, applications to other numerical methods such as the quantum Monte Carlo method are also discussed. JSPS KAKENHI Grant Number 25914008.
An easy measure of quantum correlation
NASA Astrophysics Data System (ADS)
Cao, Hui; Wu, Zhao-Qin; Hu, Li-Yun; Xu, Xue-Xiang; Huang, Jie-Hui
2015-08-01
To measure the quantum correlation of a bipartite state, a test matrix is constructed through the commutations among the blocks of its density matrix, which turns out to be a zero matrix for a classical state with zero quantum correlation, and a nonzero one for a quantum state with positive quantum correlation. The Frobenius norm of the test matrix is used to measure the quantum correlation, which satisfies the basic requirements for a good measure and coincides with Wootters concurrence for two-qubit pure states. Since no optimization is involved in the definition, this measure of quantum correlation is easy to compute and even can be calculated manually.
Measuring the length of poly(A) tails.
Nilsen, Timothy W
2015-04-01
Adenylation status has an important role in the regulation of mRNA metabolism: mRNAs are deadenylated before degradation, microRNAs (miRNAs) can cause deadenylation, and the poly(A) length of certain mRNAs is regulated during development. This protocol describes methods that can be used to measure the poly(A) tail length of specific mRNAs. These include, in the order of increasing sensitivity, (1) northern blotting of intact and experimentally deadenylated mRNAs and (2) northern blotting of intact and experimentally deadenylated mRNA fragments that have been cleaved near the 3' end with RNase H. Highly sensitive polymerase chain reaction (PCR)-based approaches are also discussed. PMID:25834263
Real time bunch length measurements in the SLC linac
Sheppard, J.C.; Clendenin, J.E.; James, M.B.; Miller, R.H.; Ross, M.C.
1985-02-01
The longitudinal charge distribution of bunches accelerated in the Stanford Linear Collider (SLC) linac will strongly affect the performance of the Collider. Bunch lengths are chosen in a balance between the deleterious effects of longitudinal and transverse wakefields. The former impacts on the beam energy spread whereas the latter is important to the transverse emittance. Two bunch length measurement ports have been installed in the SLC linac: one in the injector region and one after the emittance damping ring to linac reinjection point. These ports utilize a fused quartz Cerenkov radiator in conjunction with an electrooptic streak camera to permit real time monitoring of single s-band buckets with a resolution of several picoseconds. The design of the radiators and light collection optics is discussed with an emphasis on those issues important to high resolution. Experimental results are presented. 7 refs., 4 figs.
NASA Astrophysics Data System (ADS)
Goldfinger, C.; Morey, A. E.; Erhardt, M.; Nelson, C. H.; Johnson, J. E.; Gutierrez-Pastor, J.
2005-12-01
We are continuing to test correlation methods for a series of offshore cores along the Cascadia subduction margin. We are applying multiple proxies, including XRF analysis, to the determination of hemipelagic thickness between turbidite events. With improved sedimentation rates, and time intervals represented by inter-event sedimentation, we use Bayesian statistical methods to combine and constrain radiocarbon ages. Using OxCal we incorporate limiting ages with known criteria including ash ages, hemipelagic sedimentation rates, and historical data to refine the error ranges for a given event. Multiple ages for the same event are also given `credit' for this, and rather than averaging, iterative Bayesian models are used to reduce the error range for events that are known to correlate, and or have independent constraints. This method significantly reduces 14C variability between along strike events that are thought to correlate. We also continue to refine inter-site physical property correlation methods in parallel with 14C ages. Depositional patterns within events, recorded as magnetic susceptibility, chemical, and density patterns, match at widely separated sites in surprising detail. 16 individual event density-magnetic signatures between JDF and Cascadia Channel have correlate with coefficients of 0.6-0.9, with two scores (0.16 and 0.32) for events with similar, but out of phase characteristics. The character of each event is clearly evident in the cores. For example, T5 is a small doublet at all sites; T6 is a triplet at most sites, T8 is a large triplet at most sites, T17 is a couplet at all sites, T11 is a large flat topped peak at all sites. In some cases, correlation of events hundreds of km apart is almost as robust as the correlation between piston and trigger core pairs only one meter apart. Numerical tests of the correlation patterns strongly support this conclusion. Values for other measures include: the number of sandy pulses per event down core(r=0.84-0.92), relative thickness pattern downcore (r=0.70-0.89), and whether these values could have come from a random sample of a normal distribution (rejected with 99% confidence). Thus, both individual event signatures, and the downcore stratigraphy are both highly unique and strongly comparable from site. Strengthened correlations, refined 14C ages, and closer correlation with land events support long rupture lengths for at least 16 great earthquakes in the Holocene, extending at least from 42N to 48N. Several partial ruptures are evident, four limited to southern Oregon, one from central Oregon Northward, and one from central Oregon southward. The penultimate event at ~ 1500 AD, is recorded at all offshore sites as a thin turbidite, and only recorded at a few land sites, suggesting a small event.
E Widjaja; J W OXTOBY; T L HALE; P W JONES; P N HARDEN
2004-01-01
Ultrasound measured renal length and CT measured renal volume are potential surrogate markers for single kidney glomerular filtration rate (SKGFR). The aims of this study are to determine: (1) the repeatability of ultrasound measured length and low radiation dose spiral CT measured volume; (2) the relationship between renal length and volume; and (3) whether length and\\/or volume is a predictor
Effect of attractions on correlation length scales in a glass-forming liquid
Wen-Sheng Xu; Zhao-Yan Sun; Li-Jia An
2012-10-06
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 lead strong evidence that bond orientational order cannot provide a complete description of dynamic heterogeneity even in weakly frustrated glass-forming systems.
Decoherence and measurement-induced correlations
Luo Shunlong; Li Nan [Academy of Mathematics and Systems Science, Chinese Academy of Sciences, 100190 Beijing (China)
2011-11-15
Decoherence arises from the interaction of a quantum system with the environment or, more precisely, from the measurement in which the environment ''measures'' the quantum system and establishes correlations with it. In this work, we first quantify measurement-induced correlations from both classical and quantum perspectives. Then we quantify decoherence via measurement-induced classical correlations. By virtue of an intrinsic and powerful link between entanglement (as quantified by entanglement of formation) and classical correlations (as quantified by the difference between the total correlations and quantum discord) in pure tripartite systems, we present general analytical formulas for measurement-induced correlations and decoherence measures for qubit systems and, furthermore, reveal a conservation relation for the information-disturbance tradeoff.
Precision Neutron Scattering Length Measurements Using Neutron Interferometry
NASA Astrophysics Data System (ADS)
Wietfeldt, Fred
2008-10-01
The neutron interferometer, pioneered by Werner and Rauch in the 1970's, splits the neutron matter wave into two paths by Bragg diffraction in a perfect silicon crystal, then recombines them coherently to produce a interference signal measured by a neutron counter, thereby directly obtaining an interaction amplitude via the phase shift. It has been used to make famous demonstrations of quantum phenomena that are now found in many textbooks. It is also an ideal instrument for precision measurement of low-energy neutron scattering lengths that are important for developing and testing nuclear potential models and effective field theories, and probing neutron substructure. I will describe previous experiments and the current program at the NIST Neutron Interferometry and Optics Facility.
Leg length and offset measures with a pinless femoral reference array during THA.
Renkawitz, Tobias; Schuster, Tibor; Grifka, Joachim; Kalteis, Thomas; Sendtner, Ernst
2010-07-01
The bony fixation of reference marker arrays used for computer-assisted navigation during total hip arthroplasty (THA) theoretically involves the risk of fracture, infection, and/or pin loosening. We asked whether intraoperative assessment of leg length (LL) and offset (OS) changes would be accurate using a novel pinless femoral reference system in conjunction with an imageless measurement algorithm based on specific realignment of the relationship between a dynamic femoral and pelvis reference array. LL/OS measurements were recorded during THA in 17 cadaver specimen hips. Preoperatively and postoperatively, specimens were scanned using CT. Linear radiographic LL/OS changes were determined by two investigators using visible fiducial landmarks and image processing software. We found a high correlation of repeated measurements within and between (both 0.95 or greater) the two examiners who did the CT assessments. Pinless LL/OS values showed mean differences less than 1 mm and correlations when compared with CT measurements. PMID:19768517
Influence of tapered thermowell length on temperature measurement
Zhou, Z.J.; Motriuk, R.W. [Nova Gas Transmission Ltd., Calgary, Alberta (Canada)
1996-12-01
Temperature probe assemblies are frequently subjected to vibrations at their natural frequencies. Centrifugal compressor generated acoustic energy is large enough to excite piping and the temperature probe assemblies attached to it. Vibration of the assemblies leads to their component failures. The thermowell is a main mechanical component of such an assembly and it often fails due to fatigue phenomena. Incidents of thermowell failures at Nova Gas Transmission Limited (NGTL) piping system triggered a complete review of the company standard defining design of a temperature probe assembly. The proposed new standard recommends a reduction of the thermowell insertion length from six to three inches. Implementation of this recommendation changes the mechanical natural frequencies (MNFs) of the temperature probe assembly. To ensure that the modified temperature probe assembly has an adequate temperature measurement accuracy and acceptable response time, a number of heat transfer analyses have been performed. This paper summarizes the analytical results taking into account the following factors: (i) the effects of gas pressure, velocity, and material properties on the accuracy of measurement, (ii) the time required to obtain a reasonable measurement accuracy, and (iii) implications of design changes on the measurement procedure.
The generalized localization lengths in one-dimensional systems with correlated disorder
NASA Astrophysics Data System (ADS)
Varga, Imre; Pipek, János
1998-01-01
The scale-invariant properties of wave functions in finite samples of one-dimensional random systems with correlated disorder are analysed. The random-dimer model and its generalizations are considered and the wave functions are compared. Generalized entropic localization lengths are introduced in order to characterize the states and compared with their behaviour for exponential localization. An acceptable agreement is obtained; however, the exponential form seems to be an oversimplification in the presence of correlated disorder. According to our analysis, in the case of the random-dimer model and the two new models the possibility of power-law localization cannot be ruled out.
Aulinas, Anna; Ramírez, María-José; Barahona, María-José; Valassi, Elena; Resmini, Eugenia; Mato, Eugènia; Santos, Alicia; Crespo, Iris; Bell, Olga; Surrallés, Jordi; Webb, Susan M.
2015-01-01
Introduction Cushing’s syndrome (CS) increases cardiovascular risk (CVR) and adipocytokine imbalance, associated with an increased inflammatory state. Telomere length (TL) shortening is a novel CVR marker, associated with inflammation biomarkers. We hypothesized that inflammatory state and higher CVR in CS might be related to TL shortening, as observed in premature aging. Aim To evaluate relationships between TL, CVR and inflammation markers in CS. Methods In a cross-sectional study, 77 patients with CS (14 males, 59 pituitary-, 17 adrenal- and 1 ectopic-origin; 21 active disease) and 77 age-, gender-, smoking-matched controls were included. Total white blood cell TL was measured by TRF-Southern technique. Clinical data and blood samples were collected (lipids, adrenal function, glucose). Adiponectin, interleukin-6 (IL6) and C-reactive protein (CRP) were available in a subgroup of patients (n=32). Correlations between TL and clinical features were examined and multiple linear regression analysis was performed to investigate potential predictors of TL. Results Dyslipidemic CS had shorter TL than non-dyslipidemic subjects (7328±1274 vs 7957±1137 bp, p<0.05). After adjustment for age and body mass index, cured and active CS dyslipidemic patients had shorter TL than non-dyslipidemic CS (cured: 7187±1309 vs 7868±1104; active: 7203±1262 vs 8615±1056, respectively, p<0.05). Total cholesterol and triglycerides negatively correlated with TL (r-0.279 and -0.259, respectively, p<0.05), as well as CRP and IL6 (r-0.412 and -0.441, respectively, p<0.05). No difference in TL according the presence of other individual CVR factors (hypertension, diabetes mellitus, obesity) were observed in CS or in the control group. Additional TL shortening was observed in dyslipidemic obese patients who were also hypertensive, compared to those with two or less CVR factors (6956±1280 vs 7860±1180, respectively, p<0.001). Age and dyslipidemia were independent negative predictors of TL. Conclusion TL is shortened in dyslipidemic CS patients, further worse if hypertension and/or obesity coexist and is negatively correlated with increased inflammation markers. Increased lipids and a “low” grade inflammation may contribute to TL shortening and consequently to premature ageing and increased morbidity in CS. PMID:25799396
Method for High Accuracy Multiplicity Correlation Measurements
NASA Astrophysics Data System (ADS)
Søgaard, C.; Gulbrandsen, K.
2015-03-01
A novel method for measuring particle multiplicity correlations is presented. The method takes reduced acceptance and detection efficiency into account, in a purely statistical manner. The method does therefore not require any information from simulations - only knowledge of the detectors capability. The method provides the ability to measure forward-backward particle multiplicity correlations with high accuracy and negligible bias. The validity of the method is provided through numerous simulations. The correlation values calculated from carefully selected detection acceptances and efficiencies are compared to the correlation values at the event-generator level. Further validity to the method is given by incorporating different event generators into the simulations. Although the emphasis is on fwd-bwd correlations, the method can be extended to other multiplicity correlation measurements.
NASA Astrophysics Data System (ADS)
Gleich, Otto; Dooling, Robert J.; Manley, Geoffrey A.
2005-12-01
The inner ear in the group of archosaurs (birds, crocodilians, and extinct dinosaurs) shows a high degree of structural similarity, enabling predictions of their function in extinct species based on relationships among similar variables in living birds. Behavioral audiograms and morphological data on the length of the auditory sensory epithelium (the basilar papilla) are available for many avian species. By bringing different data sets together, we show that body mass and the size of the basilar papilla are significantly correlated, and the most sensitive frequency in a given species is inversely related to the body mass and the length of the basilar papilla. We also demonstrate that the frequency of best hearing is correlated with the high-frequency limit of hearing. Small species with a short basilar papilla hear higher frequencies compared with larger species with a longer basilar papilla. Based on the regression analysis of two significant correlations in living archosaurs (best audiogram frequency vs body mass and best audiogram frequency vs papillar length), we suggest that hearing in large dinosaurs was restricted to low frequencies with a high-frequency limit below 3 kHz.
NASA Astrophysics Data System (ADS)
St. Martin, Clara M.; Lundquist, Julie K.; Handschy, Mark A.
2015-04-01
The variability in wind-generated electricity complicates the integration of this electricity into the electrical grid. This challenge steepens as the percentage of renewably-generated electricity on the grid grows, but variability can be reduced by exploiting geographic diversity: correlations between wind farms decrease as the separation between wind farms increases. But how far is far enough to reduce variability? Grid management requires balancing production on various timescales, and so consideration of correlations reflective of those timescales can guide the appropriate spatial scales of geographic diversity grid integration. To answer ‘how far is far enough,’ we investigate the universal behavior of geographic diversity by exploring wind-speed correlations using three extensive datasets spanning continents, durations and time resolution. First, one year of five-minute wind power generation data from 29 wind farms span 1270 km across Southeastern Australia (Australian Energy Market Operator). Second, 45 years of hourly 10 m wind-speeds from 117 stations span 5000 km across Canada (National Climate Data Archive of Environment Canada). Finally, four years of five-minute wind-speeds from 14 meteorological towers span 350 km of the Northwestern US (Bonneville Power Administration). After removing diurnal cycles and seasonal trends from all datasets, we investigate dependence of correlation length on time scale by digitally high-pass filtering the data on 0.25–2000 h timescales and calculating correlations between sites for each high-pass filter cut-off. Correlations fall to zero with increasing station separation distance, but the characteristic correlation length varies with the high-pass filter applied: the higher the cut-off frequency, the smaller the station separation required to achieve de-correlation. Remarkable similarities between these three datasets reveal behavior that, if universal, could be particularly useful for grid management. For high-pass filter time constants shorter than about ? = 38 h, all datasets exhibit a correlation length ? that falls at least as fast as {{? }-1} . Since the inter-site separation needed for statistical independence falls for shorter time scales, higher-rate fluctuations can be effectively smoothed by aggregating wind plants over areas smaller than otherwise estimated.
Gray scale inversion in digital image for measurement of tooth length.
Oliveira, Matheus Lima; Vieira, Marcela Lacerda; Cruz, Adriana Dibo; Bóscolo, Frab Norberto; DE Almeida, Solange Maria
2012-01-01
The aim of this study was to assess the applicability of gray scale inversion in performing digital linear endodontic measurements. Standardized digital images were taken of 40 extracted human permanent single-rooted teeth with K-files size 15 placed at different lengths in the root canal, using the CDR Wireless(®) digital system. All images were treated with Positive, a digital tool that inverts the grayscale value. Eight radiologists measured the distance between the lower limit of the rubber stop and the tip of the file on both original and positive images. After 15 days, they repeated this procedure in 50% of the image samples. The intra- and inter-examiner agreement was analyzed by intraclass correlation test, and the comparison between the two image groups and the actual lengths by the Student's t-test (?=0.05). Intra- and inter-examiner evaluation showed high reproducibility (r>0.95) of both original and positive images. No statistically significant differences (p>0.05) were found between measurements performed on original and positive images, but both differed significantly from the actual lengths (p<0.05). Gray scale inversion has low applicability in measuring endodontic files, since it did not improve the accuracy of measurements. PMID:23338264
On increase of earthquake correlation length prior to large earthquakes in California
I. Zaliapin; Z. Liu; G. Zöller; V. Keilis-Borok; D. Turcotte
It is well established that earthquakes are correlated over distances greatly exceeding their source dimension. Recent studies hypothesize for important associated phenomenon: The area over which earthquake activity is correlated varies in time and might grow prior to a large earthquake. This hypothesis is supported by a wealth of observations, computer simulation, and has theoretical interpretations. Several measures of earthquake
Cavity length measurement: bias from misalignment and mismatching.
Reasenberg, Robert D
2013-11-20
SR-POEM, the sounding rocket principle of equivalence measurement, uses a set of six tracking-frequency laser gauges operating in Fabry-Perot cavities to determine the relative acceleration of two test masses (TMs) that are chemically different. One end of each cavity is a flat mirror on a TM; the other end is a concave coupling mirror mounted to a common reference plate. The tracking-frequency laser gauges work by locking a variable frequency laser to the cavity by the method of Pound, Drever, and Hall. Because the TMs are unconstrained, they are expected to rotate slightly during measurement. Although the distance measurements are intended to be based on the TEM?? cavity mode, any misalignment will couple into higher-order transverse modes, particularly the TEM?? and TEM??. Light thus coupled will contribute a spurious signal to the cavity locking servo that causes a bias (i.e., a systematic error) in the length determination. The spurious signal proportional to the misalignment has an antisymmetric distribution at the detector and thus has a zero average, but causes a distance bias because of the inhomogeneity of the detector responsivity. To prevent such bias, SR-POEM includes a servo to keep the incoming laser beam aligned with the cavity. The required performance of that alignment servo is less stringent than has already been achieved by other projects. There is also a spurious signal proportional to the square of the misalignment that produces a symmetric distribution at the detector. This signal is also made unimportant by the operation of an alignment servo, even when operating well above the shot noise limit. We also look at the locking of a laser to a high finesse cavity and conclude that the alignment quality sets a bound on the ratio of measurement accuracy to cavity linewidth. PMID:24513772
Norm-based measurement of quantum correlation
Wu Yuchun; Guo Guangcan [Key Laboratory of Quantum Information, University of Science and Technology of China, 230026 Hefei (China)
2011-06-15
In this paper we derived a necessary and sufficient condition for classical correlated states and proposed a norm-based measurement Q of quantum correlation. Using the max norm of operators, we gave the expression of the quantum correlation measurement Q and investigated the dynamics of Q in Markovian and non-Markovian cases, respectively. Q decays exponentially and vanishes only asymptotically in the Markovian case and causes periodical death and rebirth in the non-Markovian case. In the pure state, the quantum correlation Q is always larger than the entanglement, which was different from other known measurements. In addition, we showed that locally broadcastable and broadcastable are equivalent and reproved the density of quantum correlated states.
Hierarchy of Correlations via LÜDERS Measurements
NASA Astrophysics Data System (ADS)
Luo, Shunlong; Fu, Shuangshuang
2012-04-01
The classification and quantification of correlations (classical and quantum) in composite quantum systems are of fundamental significance for quantum information processing. While the paradigm of separability versus entanglement has been intensively studied, the scenario of classicality versus quantumness, with focus on the quantum discord, has also attracted many recent interests. In this paper, pursuing further the latter scenario and exploiting the intrinsic structure of bipartite quantum states via local projective measurements, we introduce the notion of coherent dimension of correlations in terms of the Lüders measurements. The coherent dimension can alternatively be regarded as a generalization of the Schmidt number of a pure state. Furthermore, we propose some families of measures for correlations, which extend naturally both the quantum discord and the quantum mutual information (total correlations), and furthermore interpolate between them. These quantities reveal some hierarchial structures, and provide a more complete description, of both classical and quantum correlations in the quantum realm.
Hierarchy of Correlations via LÜDERS Measurements
NASA Astrophysics Data System (ADS)
Luo, Shunlong; Fu, Shuangshuang
2013-01-01
The classification and quantification of correlations (classical and quantum) in composite quantum systems are of fundamental significance for quantum information processing. While the paradigm of separability versus entanglement has been intensively studied, the scenario of classicality versus quantumness, with focus on the quantum discord, has also attracted many recent interests. In this paper, pursuing further the latter scenario and exploiting the intrinsic structure of bipartite quantum states via local projective measurements, we introduce the notion of coherent dimension of correlations in terms of the Lüders measurements. The coherent dimension can alternatively be regarded as a generalization of the Schmidt number of a pure state. Furthermore, we propose some families of measures for correlations, which extend naturally both the quantum discord and the quantum mutual information (total correlations), and furthermore interpolate between them. These quantities reveal some hierarchial structures, and provide a more complete description, of both classical and quantum correlations in the quantum realm.
Length measurement of a moving rod by a single observer without assumptions concerning its magnitude
Bernhard Rothenstein; Ioan Damian
2005-07-03
We extend the results presented by Weinstein concerning the measurement of the length of a moving rod by a single observer, without making assumptions concerning the distance between the moving rod and the observer who measures its length.
Complexity measures, emergence, and multiparticle correlations.
Galla, Tobias; Gühne, Otfried
2012-04-01
We study correlation measures for complex systems. First, we investigate some recently proposed measures based on information geometry. We show that these measures can increase under local transformations as well as under discarding particles, thereby questioning their interpretation as a quantifier for complexity or correlations. We then propose a refined definition of these measures, investigate its properties, and discuss its numerical evaluation. As an example, we study coupled logistic maps and study the behavior of the different measures for that case. Finally, we investigate other local effects during the coarse graining of the complex system. PMID:22680558
On the measurability of quantum correlation functions
NASA Astrophysics Data System (ADS)
de Lima Bernardo, Bertúlio; Azevedo, Sérgio; Rosas, Alexandre
2015-05-01
The concept of correlation function is widely used in classical statistical mechanics to characterize how two or more variables depend on each other. In quantum mechanics, on the other hand, there are observables that cannot be measured at the same time; the so-called incompatible observables. This prospect imposes a limitation on the definition of a quantum analog for the correlation function in terms of a sequence of measurements. Here, based on the notion of sequential weak measurements, we circumvent this limitation by introducing a framework to measure general quantum correlation functions, in principle, independently of the state of the system and the operators involved. To illustrate, we propose an experimental configuration to obtain explicitly the quantum correlation function between two Pauli operators, in which the input state is an arbitrary mixed qubit state encoded on the polarization of photons.
Julia Tucker De Sanctis; Susan A. Connolly
OBJECTIVE. Renal length as measured on sonography is fundamental in the evaluation of renal disease in children. Understanding the effect of patient position and imaging plane on measured renal length is important for the appropriate use of the standards for interpretation. The goal of this study was to determine how measurement of renal length on sonograms is af- fected by
Scale and time dependence of serial correlations in word-length time series of written texts
NASA Astrophysics Data System (ADS)
Rodriguez, E.; Aguilar-Cornejo, M.; Femat, R.; Alvarez-Ramirez, J.
2014-11-01
This work considered the quantitative analysis of large written texts. To this end, the text was converted into a time series by taking the sequence of word lengths. The detrended fluctuation analysis (DFA) was used for characterizing long-range serial correlations of the time series. To this end, the DFA was implemented within a rolling window framework for estimating the variations of correlations, quantified in terms of the scaling exponent, strength along the text. Also, a filtering derivative was used to compute the dependence of the scaling exponent relative to the scale. The analysis was applied to three famous English-written literary narrations; namely, Alice in Wonderland (by Lewis Carrol), Dracula (by Bram Stoker) and Sense and Sensibility (by Jane Austen). The results showed that high correlations appear for scales of about 50-200 words, suggesting that at these scales the text contains the stronger coherence. The scaling exponent was not constant along the text, showing important variations with apparent cyclical behavior. An interesting coincidence between the scaling exponent variations and changes in narrative units (e.g., chapters) was found. This suggests that the scaling exponent obtained from the DFA is able to detect changes in narration structure as expressed by the usage of words of different lengths.
NASA Astrophysics Data System (ADS)
Estienne, B.; Regnault, N.; Bernevig, B. A.
2015-05-01
Using the newly developed matrix product state formalism for non-Abelian fractional quantum Hall (FQH) states, we address the question of whether a FQH trial wave function written as a correlation function in a nonunitary conformal field theory (CFT) can describe the bulk of a gapped FQH phase. We show that the nonunitary Gaffnian state exhibits clear signatures of a pathological behavior. As a benchmark we compute the correlation length of a Moore-Read state and find it to be finite in the thermodynamic limit. By contrast, the Gaffnian state has an infinite correlation length in (at least) the non-Abelian sector, and is therefore gapless. We also compute the topological entanglement entropy of several non-Abelian states with and without quasiholes. For the first time in the FQH effect the results are in excellent agreement in all topological sectors with the CFT prediction for unitary states. For the nonunitary Gaffnian state in finite size systems, the topological entanglement entropy seems to behave like that of the composite fermion Jain state at equal filling.
Partsakhashvili, J; Rtveliashvili, N; Philishvili, O; Kurdadze, R; Ukkat, J
2014-09-01
A consensus correlating the length of the internal carotid artery stenosis (short vs. long) to the preferred Endarterectomy (Conventional Vs. Eversion) and type of anesthesia (General Vs. cervical blockade) implemented has not yet been met. In a collaboration study between two hospitals in Germany and Georgia, 215 patients were analyzed and stratified into 3 groups according to length of stenosis, surgical technique and type of anesthesia used. In this series, for eversion endarterectomy with cervical blockade, non-neurological complications commenced at 1,78%. For conventional endarterectomy performed under general anesthesia, patients with a short stenosis had no postoperative complications whatsoever, whereas the incidence rate for various neurological deficits was 2,7% for long stenosis. In case of short stenosis of the internal carotid artery, eversion endarterectomy with cervical block, seems to be an optimal choice. Whereas for long stenosis, conventional endarterectomy under general anesthesia is a more suitable option. PMID:25341231
Quantum correlation cost of the weak measurement
Jun Zhang; Shao-xiong Wu; Chang-shui Yu
2014-09-14
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.
Bruno Milliard; Sebastien Heinis; Jeremy Blaizot; Stephane Arnouts; David Schiminovich; Tamas Budavari; Jose Donas; Marie Treyer; Michel Laget; Maurice Viton; Ted K. Wyder; Alex S. Szalay; Tom A. Barlow; Karl Forster; Peter G. Friedman; D. Christopher Martin; Patrick Morrissey; Susan G. Neff; Mark Seibert; Todd Small; Luciana Bianchi; Timothy M. Heckman; Young-Wook Lee; Barry F. Madore; R. Michael Rich; Barry Y. Welsh; Sukyoung K. Yi; C. K. Xu
2007-10-18
We present the first measurements of the angular correlation function of galaxies selected in the far (1530 A) and near (2310 A) Ultraviolet from the GALEX survey fields overlapping SDSS DR5 in low galactic extinction regions. The area used covers 120 sqdeg (GALEX - MIS) down to magnitude AB = 22, yielding a total of 100,000 galaxies. The mean correlation length is ~ 3.7 \\pm 0.6 Mpc and no significant trend is seen for this value as a function of the limiting apparent magnitude or between the GALEX bands. This estimate is close to that found from samples of blue galaxies in the local universe selected in the visible, and similar to that derived at z ~ 3 for LBGs with similar rest frame selection criteria. This result supports models that predict anti-biasing of star forming galaxies at low redshift, and brings an additional clue to the downsizing of star formation at z<1.
Reproducibility of Renal Length Measurements with 99mTc-DSMA SPECT
Eva Lin; Leonard P. Connolly; David Zurakowski; James DiCanzio; Laura Drubach; Karl Mitchell; Tracy Tetrault; Stephen P. Laffin; S. Ted Treves
2000-01-01
Renal length measurements are used in evaluating several abnormalities of the pediatric genitourinary tract. This study assesses reproducibility of renal length measurements obtained with 99m Tc-dimercaptosuccinic acid (DMSA) SPECT. Methods: The lengths of 98 kidneys of 51 children (age range, 1-16 y; mean age, 5.4 y) who underwent 99m Tc-DMSA SPECT were measured independently by 2 observers. Renal length was
Sonographic measurement of renal length in children: Variation associated with body position
Michiru Nakamura; Nobuyuki Taniguchi; Fukiko Kawai; Kyoko Yokota; Tomoko Ono; Yi Wang; Kouichiro Shigeta; Kiyoka Omoto; Harumi Koibuchi; Kouichi Itoh
2003-01-01
We ultrasonographically measured renal length in the major axis in children. Here we discuss the differences in measured lengths\\u000a in the supine and prone positions. In study 1, which included 214 children, more than 60 percent of the kidneys measured longer\\u000a in the supine than in the prone position. The difference (S-P: length in the supine position minus length in
Computable measure of the quantum correlation
S. Javad Akhtarshenas; Hamidreza Mohammadi; Saman Karimi; Zahra Azmi
2014-08-13
A general state of an $m\\otimes n$ system is a classical-quantum state if and only if its associated $A$-correlation matrix (a matrix constructed from the coherence vector of the party $A$, the correlation matrix of the state, and a function of the local coherence vector of the subsystem $B$), has rank no larger than $m-1$. Using the general Schatten $p$-norms, we quantify quantum correlation by measuring any violation of this condition. The required minimization can be carried out for the general $p$-norms and any function of the local coherence vector of the unmeasured subsystem, leading to a class of computable quantities which can be used to capture the quantumness of correlations due to the subsystem $A$. We introduce two special members of these quantifiers; The first one coincides with the tight lower bound on the geometric measure of discord, so that such lower bound fully captures the quantum correlation of a bipartite system. Accordingly, a vanishing tight lower bound on the geometric discord is a necessary and sufficient condition for a state to be zero-discord. The second quantifier has the property that it is invariant under a local and reversible operation performed on the unmeasured subsystem, so that it can be regarded as a computable well-defined measure of the quantum correlations. The approach presented in this paper provides a way to circumvent the problem with the geometric discord. We provide some examples to exemplify this measure.
NASA Astrophysics Data System (ADS)
Sütterlin, Daniel; Erni, Daniel; Schlott, Volker; Sigg, Hans; Jäckel, Heinz; Murk, Axel
2010-10-01
A spatial, electro-optical autocorrelation (EOA) interferometer using the vertically polarized lobes of coherent transition radiation (CTR) has been developed as a single-shot electron bunch length monitor at an optical beam port downstream the 100 MeV preinjector LINAC of the Swiss Light Source. This EOA monitor combines the advantages of step-scan interferometers (high temporal resolution) [D. Mihalcea et al., Phys. Rev. ST Accel. Beams 9, 082801 (2006) and T. Takahashi and K. Takami, Infrared Phys. Technol. 51, 363 (2008)] and terahertz-gating technologies [U. Schmidhammer et al., Appl. Phys. B: Lasers Opt. 94, 95 (2009) and B. Steffen et al., Phys. Rev. ST Accel. Beams 12, 032802 (2009)] (fast response), providing the possibility to tune the accelerator with an online bunch length diagnostics. While a proof of principle of the spatial interferometer was achieved by step-scan measurements with far-infrared detectors, the single-shot capability of the monitor has been demonstrated by electro-optical correlation of the spatial CTR interference pattern with fairly long (500 ps) neodymium-doped yttrium aluminum garnet (Nd:YAG) laser pulses in a ZnTe crystal. In single-shot operation, variations of the bunch length between 1.5 and 4 ps due to different phase settings of the LINAC bunching cavities have been measured with subpicosecond time resolution.
Knight, Rosemary J.; Irving, James D.; Tercier, Paulette; Freeman, Eugene J.; Murray, Christopher J.; Rockhold, Mark L.
2007-11-08
Surface-based ground-penetrating radar data were collected at the Hanford Site in Washington, U.S.A. to assess the use of radar reflection images as a means of quantifying the spatial variability of subsurface water content. Available at the selected test site were two sets of water content data derived from neutron probe measurements that had been made to a depth of ~18 m in 32 wells. The comparison of probe-derived water content data, synthetic radar data, and the acquired radar data indicated a good correspondence between the changes in probe-derived water content and the location of reflections in the radar data. Geostatistical analysis was conducted on the two sets of probe-derived water content values and the amplitudes of the reflections in the radar reflection image to determine the horizontal correlation length of water content. The experimental semivariograms for the water content data were fit with a single exponential model with a correlation length of 10 m. The semivariogram for the radar data was fit with a nested structure containing a dominant long-range structure with a correlation length of 14 m, and a smaller-scale structure with a correlation length of 0.3 m. Quantifying the scale triplet – the spacing, extent, and support – for the two forms of measurement provided a framework for comparing and assessing the derived correlation structures.
Understanding the amplitudes of noise correlation measurements
Tsai, Victor C.
2011-01-01
Cross correlation of ambient seismic noise is known to result in time series from which station-station travel-time measurements can be made. Part of the reason that these cross-correlation travel-time measurements are reliable is that there exists a theoretical framework that quantifies how these travel times depend on the features of the ambient noise. However, corresponding theoretical results do not currently exist to describe how the amplitudes of the cross correlation depend on such features. For example, currently it is not possible to take a given distribution of noise sources and calculate the cross correlation amplitudes one would expect from such a distribution. Here, we provide a ray-theoretical framework for calculating cross correlations. This framework differs from previous work in that it explicitly accounts for attenuation as well as the spatial distribution of sources and therefore can address the issue of quantifying amplitudes in noise correlation measurements. After introducing the general framework, we apply it to two specific problems. First, we show that we can quantify the amplitudes of coherency measurements, and find that the decay of coherency with station-station spacing depends crucially on the distribution of noise sources. We suggest that researchers interested in performing attenuation measurements from noise coherency should first determine how the dominant sources of noise are distributed. Second, we show that we can quantify the signal-to-noise ratio of noise correlations more precisely than previous work, and that these signal-to-noise ratios can be estimated for given situations prior to the deployment of seismometers. It is expected that there are applications of the theoretical framework beyond the two specific cases considered, but these applications await future work.
Correlation of interannual length-of-day variation with El Nino/Southern Oscillation, 1972-1986
NASA Technical Reports Server (NTRS)
Chao, B. Fong
1988-01-01
Correlation between interannual length-of-day (LOD) changes and an index representation of El Nino/Southern Oscillation (ENSO) for the period of 1972-1986 was examined in two ways: as the cross-correlation function in the time domain and as the complex coherence spectrum in the frequency domain. The ENSO representation was derived from barometric measurements from the Tahiti and Darwin, Australia, meteorological stations, as the difference of the sea-level pressure between the two locations. The cross correlation between this ENSO representation and LOD variation on the interannual time scale was found to have a maximum value of 0.68 and the LOD phase lag of 2 months, indicating that most of the interannual LOD variation is caused by ENSO, and that the transfer of ENSO's axial angular momentum to the solid earth lags behind the Tahiti-Darwin pressure variation by about 2 months. The corresponding coherence spectrum showed minimum correlation around biennial periods, indicating an influence of the stratospheric quasi-biennial oscillation on LOD variations.
Smirnova, Alexandra; Gamba, Riccardo; Khoriauli, Lela; Vitelli, Valerio; Nergadze, Solomon G; Giulotto, Elena
2013-01-01
Mammalian telomeres are transcribed into long non-coding telomeric repeat-containing RNA (TERRA) molecules that seem to play a role in the maintenance of telomere stability. In human cells, CpG-island promoters drive TERRA transcription and are regulated by methylation. It was suggested that the amount of TERRA may be related to telomere length. To test this hypothesis we measured telomere length and TERRA levels in single clones isolated from five human cell lines: HeLa (cervical carcinoma), BRC-230 (breast cancer), AKG and GK2 (gastric cancers), and GM847 (SV40 immortalized skin fibroblasts). However, these two parameters did not correlate with each other. Moreover, cell survival to ?-rays did not show a significant variation among the clones, suggesting that, in this cellular system, the intra-population variability in telomere length and TERRA levels does not influence sensitivity to ionizing radiation. This conclusion was supported by the observation that in a cell line in which telomeres were greatly elongated by the ectopic expression of telomerase, TERRA expression levels and radiation sensitivity were similar to the parental HeLa cell line. PMID:23717814
Wahlman, Judit; Hirst, Maurice; Roberts, J E; Prickett, Claire D; Trevithick, John R
2003-07-01
Hypericin is the ingredient used to standardize the popular over-the-counter antidepressant medication St. John's Wort. Because hypericin readily produces singlet oxygen and other excited state intermediates, it is a very efficient phototoxic agent in the eye that can potentially induce the development of the cataract photooxidative mechanism. Hypericin absorbs in the UV and visible ranges, binds to the lens crystallins (alpha, beta and gamma) and damages these proteins through a photooxidative mechanism. Effects were measured previously using fluorescence, UV and mass spectrometry. We report here two additional methods to monitor lens damage: (1) measuring focal length variability using a ScanTox instrument and (2) measuring protein leakage from the damaged lens. Because nonenzymic glycation results in free radical production, we chose to use elevated glucose concentrations as a convenient model for studying oxidative stress. To compare and contrast photooxidative damage against oxidative damage to the lens, we also measured the focal length variability and protein leakage induced by the presence of elevated glucose concentrations. We found that the total accumulated protein leakage was positively correlated (r = 0.9) with variability in focal length. Lenses treated with hypericin and irradiated with UVB had an increase in focal length variability as compared with the lenses that were only UVB-irradiated. Lenses without UVB irradiation had much lower focal length variability than irradiated lenses. For non-hypericin-treated lenses, UVB-irradiated lenses had a larger variability (4.58 mm) than the unirradiated lenses (1.78 mm). The lenses incubated in elevated glucose concentrations had a focal length variability (3.23 mm) equivalent to that of the unirradiated hypericin-treated lenses (3.54 mm). We conclude that photooxidative damage by hypericin results in changes in the optical properties of the lens, protein leakage and finally cataract formation. In contrast to this, high concentrations of glucose induced protein leakage but not changes in optical properties or the opacity associated with a cataract. This work provides further evidence that people should protect their eyes from intense sunlight when taking St. John's Wort. PMID:12929754
Generalized entropic measures of quantum correlations
Rossignoli, R.; Canosa, N.; Ciliberti, L. [Departamento de Fisica-IFLP, Universidad Nacional de La Plata, C.C. 67, 1900 La Plata (Argentina)
2010-11-15
We propose a general measure of nonclassical correlations for bipartite systems based on generalized entropic functions and majorization properties. Defined as the minimum information loss due to a local measurement, in the case of pure states it reduces to the generalized entanglement entropy, i.e., the generalized entropy of the reduced state. However, in the case of mixed states it can be nonzero in separable states, vanishing just for states diagonal in a general product basis, like the quantum discord. Simple quadratic measures of quantum correlations arise as a particular case of the present formalism. The minimum information loss due to a joint local measurement is also discussed. The evaluation of these measures in simple relevant cases is as well provided, together with comparison with the corresponding entanglement monotones.
Eddy Correlation Flux Measurement System (ECOR) Handbook
Cook, DR
2011-01-31
The eddy correlation (ECOR) flux measurement system provides in situ, half-hour measurements of the surface turbulent fluxes of momentum, sensible heat, latent heat, and carbon dioxide (CO2) (and methane at one Southern Great Plains extended facility (SGP EF) and the North Slope of Alaska Central Facility (NSA CF). The fluxes are obtained with the eddy covariance technique, which involves correlation of the vertical wind component with the horizontal wind component, the air temperature, the water vapor density, and the CO2 concentration.
Bánszegi, Oxána; Kosztolányi, András; Bakonyi, Gábor; Szabó, Borbála; Dombos, Miklós
2014-01-01
The collembolan, Folsomia candida, is widely used in soil ecotoxicology. In recent years, growth rate of collembolans has become as frequently used endpoint as reproduction rate in ecotoxicological studies. However, measuring collembolan body sizes to estimate growth rate is a complicated and time-consuming task. Here we present a new image analysis method, which facilitates and accelerates the body length measurement of the collembolan Folsomia candida. The new software package, called CollScope, consists of three elements: 1) an imaging device; 2) photographing software; 3) an ImageJ macro for image processing, measurement and data analysis. We give a complete description of the operation of the software, the image analyzing process and describe its accuracy and reliability. The software with a detailed usage manual is attached as Supplementary Material. We report a case study to demonstrate that the automated measurement of collembolan body sizes is highly correlated with the traditional manual measurements (estimated measuring accuracy 0.05 mm). Furthermore, we performed a dose-response ecotoxicity test using cadmium-sulfate by using CollScope as well as classical methods for size measurement. Size data measured by CollScope or manually did not differ significantly. Furthermore the new software package decreased time consumption of the measurements to 42% when tested on 35 animals. Consequently, methodological investigations performed in this study should be regarded as a recommendation for any other routine dose-response study where body growth is an endpoint. PMID:24901322
Length scale dependence and reliability of x-ray strain measurements in metallic glasses
NASA Astrophysics Data System (ADS)
Vempati, Udaya K.
2011-12-01
There is a long history of using x-ray scattering techniques for measuring elastic strain in crystalline materials. Only recently have these techniques been applied to metallic glasses. Results emerging from this work indicate that the elastic strain in metallic glasses varies with the distance from an average atom r in an asymptotic fashion. The reason for such anomalous length-scale behavior of elastic strain in these materials remains unclear. To investigate the origins of this behavior, high energy x-ray scattering experiments were carried out in this work on zirconium and palladium based metallic glass specimens subject to mechanical loading. In both these alloys, the elastic strain obtained from pair correlation function position shifts was found to approach the imposed strain asymptotically. This behavior was found to be independent of the uniaxial compression, uniaxial tension, or pure shear loading geometries. To further investigate the length-scale behavior, molecular dynamics simulations were carried out on a binary Lennard-Jones glass. Elastic strain in this model binary glass, when subject to uniaxial tensile deformation, qualitatively reproduced the length-scale behavior observed in the experiments when the strain was calculated from pair correlation function positions shifts. Other techniques for calculating strain, however, gave different results. Also, independent of the calculation methodology, imposing hydrostatic deformation resulted in nearly length-scale independent strain. These results seem to indicate that the presence of resolved shear stresses and non-affine displacements are central to the length-scale effect. Besides the anomalous length-scale behavior, recent data also suggest that the x-ray technique usually underestimates the elastic strain (with respect to macroscopic value), or overestimates the elastic modulus, in metallic glasses. To investigate this modulus discrepancy, a two-phase model, containing low density liquid-like regions and high density relaxed regions, was investigated. This model was found to be unsuitable because the density difference required to explain the observed discrepancy was too large to be physically meaningful. However, assuming presence of voids, as an extreme of the two phase model, was found to explain the observed discrepancy.
Nonclassical correlations from randomly chosen local measurements.
Liang, Yeong-Cherng; Harrigan, Nicholas; Bartlett, Stephen D; Rudolph, Terry
2010-02-01
We show that correlations inconsistent with any locally causal description can be a generic feature of measurements on entangled quantum states. Specifically, spatially separated parties who perform local measurements on a maximally entangled state using randomly chosen measurement bases can, with significant probability, generate nonclassical correlations that violate a Bell inequality. For n parties using a Greenberger-Horne-Zeilinger state, this probability of violation rapidly tends to unity as the number of parties increases. We also show that, even with both a randomly chosen two-qubit pure state and randomly chosen measurement bases, a violation can be found about 10% of the time. Among other applications, our work provides a feasible alternative for the demonstration of Bell inequality violation without a shared reference frame. PMID:20366749
Quantum correlations and least disturbing local measurements
Rossignoli, R.; Canosa, N.; Ciliberti, L. [Departamento de Fisica-IFLP, Universidad Nacional de La Plata, C.C. 67, La Plata (1900) (Argentina)
2011-11-15
We examine the evaluation of the minimum information loss due to an unread local measurement in mixed states of bipartite systems, for a general entropic form. Such a quantity provides a measure of quantum correlations, reducing for pure states to the generalized entanglement entropy, while in the case of mixed states it vanishes just for classically correlated states with respect to the measured system, as the quantum discord. General stationary conditions are provided, together with their explicit form for general two-qubit states. Closed expressions for the minimum information loss as measured by quadratic and cubic entropies are also derived for general states of two-qubit systems. As an application, we analyze the case of states with maximally mixed marginals, where a general evaluation is provided, as well as X states and the mixture of two aligned states.
Lenhart, Phoebe D.; Hutchinson, Amy K.; Lynn, Michael J.; Lambert, Scott R.
2010-01-01
PURPOSE To determine whether measurements obtained by partial coherence interferometry (PCI) correlate well with measurements obtained using immersion ultrasound (US) in children. SETTING Department of Ophthalmology, Emory University School of Medicine, Atlanta, Georgia, USA. DESIGN Evaluation of a diagnostic test or technology. METHODS The charts of pediatric patients who had cataract surgery from August 2008 to September 2009 were reviewed. Axial length (AL) measurements in the operative eye were obtained using PCI at the preoperative clinic visit and then using immersion US in the operating room before surgery. The data were compared to determine the degree of agreement. RESULTS The charts of 18 patients (27 eyes) were reviewed. Preoperative AL measurements by PCI were obtained in 21 eyes (78%). On average, the PCI-measured ALs were 0.1 mm less than the immersion US values (95% confidence interval, ?0.2 to ?0.1; P = .002). All eyes with an AL of 23.5 mm or less had lower PCI values than immersion US values. There was no systematic pattern of 1 measurement being greater or less than the other in eyes with an AL longer than 23.5 mm. CONCLUSIONS There is a systematic difference in AL measurement between PCI and immersion US, with PCI tending to give lower values, particularly in eyes with an AL longer than 23.5 mm. Depending on the length of the eye, a 0.1 mm error in AL measurement could result in a 0.25 to 0.75 diopter difference in intraocular lens calculation that could be clinically significant in some patients. PMID:21111313
Measurements of Energy-Energy-Correlations
Erdmann, Martin
of these mysteries are connected with the cosmic rays reaching ex- treme high energies of over 100 EeMeasurements of Energy-Energy-Correlations of Ultra-High-Energy Cosmic Rays with the Pierre Auger A RWTH Aachen RWTH Aachen #12;#12;Contents 1 Introduction 1 2 Physics of Ultra-High-Energy Cosmic Rays 3
Computer Anxiety: Definition, Measurement, and Correlates.
ERIC Educational Resources Information Center
Cambre, Marjorie A.; Cook, Desmond L.
This review examines the definition, measurement, and correlates of computer anxiety as provided in available research. The concept of computer anxiety reflects an anxiety state, rather than an anxiety trait, thus rendering it susceptible to change over time. Computer anxiety is similar in nature to math anxiety and test anxiety. Two approaches to…
NASA Technical Reports Server (NTRS)
Johnson, R. A.; Wehrly, T.
1976-01-01
Population models for dependence between two angular measurements and for dependence between an angular and a linear observation are proposed. The method of canonical correlations first leads to new population and sample measures of dependence in this latter situation. An example relating wind direction to the level of a pollutant is given. Next, applied to pairs of angular measurements, the method yields previously proposed sample measures in some special cases and a new sample measure in general.
Correlates of rehabilitation hospital length of stay among older African-American patients.
Mills, Terry L.; Lichtenberg, Peter A.; Wakeman, Melanie A.; Scott-Okafor, Hellena
2002-01-01
This study addresses a gap in the current literature on the correlates of rehabilitation hospital length of stay for older African Americans. Using data from 616 consecutively admitted rehabilitation patients who ranged in age from 50 to 103 years old, we tested the effect of patient's primary medical impairment; structural factors such as admit and discharge setting; level of depression (Geriatric Depression Scale); functional ability upon hospital admission (FIM score); and other control variables. Hierarchical linear regression models show that medical impairment alone was not a robust predictor of LOS. However, when controlling for structural and psychosocial factors, and medical condition, then circulation/amputation impairment was directly associated with longer LOS. Being unmarried or at risk for depression were also directly related to longer LOS. Consequently, rehabilitation administrators and hospital staff should note these findings to determine whether and how these factors affect discharge outcomes in their particular rehabilitative environments. PMID:12392049
Is severity of family burden a correlate of length of stay?
He, Hongbo; Ning, Yuping; Rosenheck, Robert; Sun, Bin; Zhang, Jie; Zhou, Yanling
2015-11-30
It has been difficult to identify relevant correlates of inpatient psychiatric length of stay (LOS), but few have examined family burden as a potential factor. The present study investigated the association of several dimensions of family burden with LOS net of other factors. Dimensions of burden experienced by primary caregivers were evaluated in a sample of 602 psychiatric inpatients in a large hospital in Guangzhou, China within 1 week of admission. Factor analysis reduced the burden data to five factors. Bivariate association and multiple linear regression analyzes were used to investigate burden and other factors associated with LOS (average LOS=58.8 days, SD=44.3). Multiple regression analysis showed that in addition to having health insurance coverage, being diagnosed with schizophrenia, being unmarried, and not being employed; being perceived by family members as showing more violent behavior and causing higher levels of caregiver distress were independently associated with longer LOS. PMID:26321126
Automated path length and M{sub 56} measurements at Jefferson Lab
Hardy, D.; Tang, J.; Legg, R.
1997-08-01
Accurate measurement of path length and path length changes versus momentum (M{sub 56}) are critical for maintaining minimum beam energy spread in the CEBAF (Continuous Electron Beam Accelerator Facility) accelerator at the Thomas Jefferson National Accelerator Facility (Jefferson Lab). The relative path length for each circuit of the beam (1256m) must be equal within 1.5 degrees of 1497 MHz RF phase. A relative path length measurement is made by measuring the relative phases of RF signals from a cavity that is separately excited for each pass of a 4.2 {mu}s pulsed beam. This method distinguishes the path length to less than 0.5 path length error. The development of a VME based automated measurement system for path length and M{sub 56} has contributed to faster machine setup time and has the potential for use as a feedback parameter for automated control.
Quantum Correlations and the Measurement Problem
NASA Astrophysics Data System (ADS)
Bub, Jeffrey
2014-10-01
The transition from classical to quantum mechanics rests on the recognition that the structure of information is not what we thought it was: there are operational, i.e., phenomenal, probabilistic correlations that lie outside the polytope of local correlations. Such correlations cannot be simulated with classical resources, which generate classical correlations represented by the points in a simplex, where the vertices of the simplex represent joint deterministic states that are the common causes of the correlations. The `no go' hidden variable theorems tell us that we can't shoe-horn phenomenal correlations outside the local polytope into a classical simplex by supposing that something has been left out of the story. The replacement of the classical simplex by the quantum convex set as the structure representing probabilistic correlations is the analogue for quantum mechanics of the replacement of Newton's Euclidean space and time by Minkowski spacetime in special relativity. The nonclassical features of quantum mechanics, including the irreducible information loss on measurement, are generic features of correlations that lie outside the classical simplex. This paper is an elaboration of these ideas, which have their source in work by Pitowsky (J. Math. Phys. 27:1556, 1986; Math. Program. 50:395, 1991; Phys. Rev. A 77:062109, 2008), Garg and Mermin (Found. Phys. 14:1-39, 1984), Barrett (Phys. Rev. A 75:032304, 2007; Phys. Rev. A 7:022101, 2005) and others, e.g., Brunner et al. (arXiv:1303.2849, 2013), but the literature goes back to Boole (An Investigation of the Laws of Thought, Dover, New York, 1951). The final section looks at the measurement problem of quantum mechanics in this context. A large part of the problem is removed by seeing that the inconsistency in reconciling the entangled state at the end of a quantum measurement process with the definiteness of the macroscopic pointer reading and the definiteness of the correlated value of the measured micro-observable depends on a stipulation that is not required by the structure of the quantum possibility space. Replacing this stipulation by an alternative consistent stipulation is the first step to resolving the problem.
NON-DESTRUCTIVE SINGLE SHOT BUNCH LENGTH MEASUREMENTS FOR THE CLIC TEST FACILITY 3
NON-DESTRUCTIVE SINGLE SHOT BUNCH LENGTH MEASUREMENTS FOR THE CLIC TEST FACILITY 3 A. Dabrowski, M and P. Urschütz, CERN, Geneva, Switzerland Abstract A non-destructive bunch length detector has been has been made at CTF3 to develop a non destructive single shot bunch length monitor. This device
Rémy Colin; Ahmed Alsayed; Cyprien Gay; Bérengère Abou
2015-03-13
Clusters of fast and slow correlated particles, identified as dynamical heterogeneities (DHs), constitute a central aspect of glassy dynamics. A key ingredient of the glass transition scenario is a significant increase of the cluster size $\\xi$4 as the transition is approached. In need of easy-to-compute tools to measure $\\xi$4, the dynamical susceptibility $\\chi$4 was introduced recently. Here, we investigate DHs in dense microgel suspensions using image correlation, and compute both $\\chi$4 and the four-point correlation function G4. The spatial decrease of G4 provides a direct access to $\\xi$4, which is found to grow significantly with increasing volume fraction. However, this increase is not captured by $\\chi$4. We show that the assumptions that validate the connection between $\\chi$4 and $\\xi$4 are not fulfilled in our experiments. Our findings question the relevance of the broadly used $\\chi$4 in describing DHs.
NASA Astrophysics Data System (ADS)
Sofia, Giulia; Marinello, Francesco; Tarolli, Paolo
2014-10-01
This work presents the potential for high-resolution remote sensing data (LiDAR digital terrain models) to determine the spatial heterogeneity of terraced landscapes. The study objective is achieved through the identification of a new parameter that distinguishes this unique landscape form from more natural land formations. The morphological indicator proposed is called the Slope Local Length of Auto-Correlation (SLLAC), and it is derived from the local analysis of slope self-similarity. The SLACC is obtained over two steps: (i) calculating the correlation between a slope patch and a defined surrounding area and (ii) identifying the characteristic length of correlation for each neighbourhood. The SLLAC map texture can be measured using a surface metrology metric called the second derivative of peaks, or Spc. For the present study, we tested the algorithm for two types of landscapes: a Mediterranean and an Alpine one. The research method involved an examination of both real LiDAR DTMs and simulated ones, in which it was possible to control terrace shapes and the percentage of area covered by terraces. The results indicate that SLLAC maps exhibit a random aspect for natural surfaces. In contrast, terraced landscapes demonstrate a higher degree of order, and this behaviour is independent of the morphological context and terracing system. The outcomes of this work also prove that Spc values decrease as the area of terraced surfaces increases within the investigated region: the Spc for terraced areas is significantly different from the Spc of a natural landscape. In areas of smooth natural morphology, the Spc identifies terraced areas with a 20% minimum height range covered in terraces. In contrast, in areas of steep morphologies and vertical cliffs, the algorithm performs well when terraces cover at least 50% of the investigated surface. Given the increasing importance of terraced landscapes, the proposed procedure offers a significant and promising tool for the exploration of spatial heterogeneity in terraced sites.
Sonographic measurement of renal length in children: Does the position of the patient matter?
Caroline W. T. Carrico; J. Michael Zerin
1996-01-01
Purpose. This prospective study was designed to determine the effect of patient positioning on sonographic measurements of renal length in children.Materials and methods. Two dedicated pediatric ultrasonographers (observers A and B) measured the sonographic lengths of 48 kidneys in 25 children (two had unilateral renal agenesis). Each observer obtained the two “longest possible” measurements for each kidney with the patient
Evolution equation for geometric quantum correlation measures
NASA Astrophysics Data System (ADS)
Hu, Ming-Liang; Fan, Heng
2015-05-01
A simple relation is established for the evolution equation of quantum-information-processing protocols such as quantum teleportation, remote state preparation, Bell-inequality violation, and particularly the dynamics of geometric quantum correlation measures. This relation shows that when the system traverses the local quantum channel, various figures of merit of the quantum correlations for different protocols demonstrate a factorization decay behavior for dynamics. We identified the family of quantum states for different kinds of quantum channels under the action of which the relation holds. This relation simplifies the assessment of many quantum tasks.
NASA Astrophysics Data System (ADS)
Venkatakrishnan, P.
1987-12-01
A physical length scale in the wavefront corresponding to the parameter (r0) characterizing the loss in detail in a long exposure image is identified, and the influence of the correlation scale of turbulence as r0 approaches this scale is shown. Allowing for the effect of 2-point correlations in the fluctuations of the refractive index, Venkatakrishnan and Chatterjee (1987) proposed a modified law for the phase structure function. It is suggested that the departure of the phase structure function from the 5/3 power law for length scales in the wavefront approaching the correlation scale of turbulence may lead to better 'seeing' at longer wavelengths.
NASA Astrophysics Data System (ADS)
Manske, E.; Fröhlich, T.; Füßl, R.
2015-02-01
The requirements on the precision lengths and precision load measurement rise due to the rapid technical development, in particular of nanotechnologies and precision optics. According to the roadmap "Dimensional metrology for micro- and nanotechnology" of the European National Metrology Institutes (iMERA)2 in the next few years "traceable 2D (3D) metrology at (sub)-nm accuracy over several 100 mm range" will be required.
Neutrino mass measurement from correlation dipoles
NASA Astrophysics Data System (ADS)
Chen, Xuelei
2015-08-01
The large scale structure measurement can be used as a precision probe for neutrinos. It is well known that the power spectrum is suppressed at relatively small scales by the free-streaming of neutrinos, and this is used to measure the neutrino mass. However, this method is prone to scale-dependent galaxy bias, which can lead to significant system error in the measurement. We proposed a new method to measure the neutrino mass which is free of this problem. Due to their smaller masses, the neutrinos can develop large relative velocities with respect to the dark matter, the neutrino distribution can then affect the structure formation process. Although the effect is very small, it may generate significant dipole in the galaxy cross-correlation function or the galaxy lensing. The neutrino mass may by determined by such observations. We present the feasibility for such measurement.
Small-Angle Neutron Scattering Studies of Magnetic Correlation Lengths in Nanoparticle Assemblies
NASA Astrophysics Data System (ADS)
Majetich, Sara
2009-03-01
Small-angle neutron scattering (SANS) measurements of ordered arrays of surfactant-coated magnetic nanoparticle reveal characteristic length scales associated with interparticle and intraparticle magnetic ordering. The high degree of uniformity in the monodisperse nanoparticle size and spacing leads to a pronounced diffraction peak and allows for a straightforward determination of these length scales [1]. There are notable differences in these length scales depending on the particle moment, which depends on the material (Fe, Co, Fe3O4) and diameter, and also on whether the metal particle core is surrounded by an oxide shell. For 8.5 nm particles containing an Fe core and thick Fe3O4 shell, evidence of a spin flop phase is seen in the magnetite shell when a field is applied , but not when the shell thickness is ˜0.5 nm [2]. 8.0 nm particles with an e-Co core and 0.75 nm CoO shell show no exchange bias effects while similar particles with a 2 nm thick shell so significant training effects below 90 K. Polarized SANS studied of 7 nm Fe3O4 nanoparticle assemblies show the ability to resolve the magnetization components in 3D. [4pt] [1] M. Sachan, C. Bonnoit, S. A. Majetich, Y. Ijiri, P. O. Mensah-Bonsu, J. A. Borchers, and J. J. Rhyne, Appl. Phys. Lett. 92, 152503 (2008). [0pt] [2] Yumi Ijiri, Christopher V. Kelly, Julie A. Borchers, James J. Rhyne, Dorothy F. Farrell, Sara A. Majetich, Appl. Phys. Lett. 86, 243102-243104 (2005). [0pt] [3] K. L. Krycka, R. Booth, J. A. Borchers, W. C. Chen, C. Conlon, T. Gentile, C. Hogg, Y. Ijiri, M. Laver, B. B. Maranville, S. A. Majetich, J. Rhyne, and S. M. Watson, Physica B (submitted).
ATLAS-3 correlative measurement opportunities with UARS and surface observations
NASA Technical Reports Server (NTRS)
Harrison, Edwin F.; Denn, Fred M.; Gibson, Gary G.
1995-01-01
The third ATmospheric Laboratory for Applications and Science (ATLAS-3) mission was flown aboard the Space Shuttle launched on November 3, 1994. The mission length was approximately 10 days and 22 hours. The ATLAS-3 Earth-viewing instruments provided a large number of measurements which were nearly coincident with observations from experiments on the Upper Atmosphere Research Satellite (UARS). Based on ATLAS-3 instrument operating schedules, simulations were performed to determine when and where correlative measurements occurred between ATLAS and UARS instruments, and between ATLAS and surface observations. Results of these orbital and instrument simulations provide valuable information for scientists to compare measurements between various instruments on the two satellites and at selected surface sites.
Michael A. Terry; Jennifer J. Winell; Daniel W. Green; Robert Schneider; Margaret Peterson; Robert G. Marx; Roger F. Widmann
The purpose of this study was to assess interobserver and intraobserver variability in the assessment of clinical and radio- graphic measurement of lower limb length discrepancy. Clinical measurements included direct measurement with a tape measure from anterior superior iliac spine (ASIS) to lateral malleolus and ASIS to medial malleolus as well as block measurement. Slit scanogram radiographic measurement was also
Correlative stitching technique for measuring flatness
NASA Astrophysics Data System (ADS)
Yu, Yingjie
2000-10-01
In flatness measuring by correlative stitching technique, a bigger scale's measurement can be realized by the system witha smaller measurement caliber. At the same time, high measurement precision, high spatial resolution and low price can be maintained. In this technique, mode building and solving are especially important. Aiming at some problems in common mode building and solving, the paper presents a new solving method. The iterative least-squares technique is applied in the method and it considers not only the information in height, but also the influence of the parameters in other directions which are usually predigested in common modes. By this solving method, the demand for rail of systems is decreased. Some simitations are done to testify the presented method.
Photoluminescence-based measurements of the energy gap and diffusion length of Zn3P2
Kimball, Gregory
Photoluminescence-based measurements of the energy gap and diffusion length of Zn3P2 Gregory M 2009; accepted 20 August 2009; published online 14 September 2009 The steady-state photoluminescence-resolved photoluminescence decay measurements, implying minority-carrier diffusion lengths of 7 m. © 2009 American Institute
Rémy Colin; Ahmed Alsayed; Cyprien Gay; Bérengère Abou
2015-09-10
Clusters of fast and slow correlated particles, identified as dynamical heterogeneities (DHs), con-stitute a central aspect of glassy dynamics. A key ingredient of the glass transition scenario is asignificant increase of the cluster size $\\xi$4 as the transition is approached. In need of easy-to-computetools to measure $\\xi$4 , the dynamical susceptibility $\\chi$4 was introduced recently, and used in various ex-perimental works to probe DHs. Here, we investigate DHs in dense microgel suspensions using imagecorrelation analysis, and compute both $\\chi$4 and the four-point correlation function G4 . The spatialdecrease of G4 provides a direct access to $\\xi$4 , which is found to grow significantly with increasingvolume fraction. However, this increase is not captured by $\\chi$4 . We show that the assumptions thatvalidate the connection between $\\chi$4 and $\\xi$4 are not fulfilled in our experiments.
DCM: device correlated metrology for overlay measurements
NASA Astrophysics Data System (ADS)
Chen, Charlie; Huang, George K. C.; Pai, Yuan Chi; Wu, Jimmy C. H.; Cheng, Yu Wei; Hsu, Simon C. C.; Yu, Chun Chi; Amir, Nuriel; Choi, Dongsub; Itzkovich, Tal; Tarshish-Shapir, Inna; Tien, David C.; Huang, Eros; Kuo, Kelly T. L.; Kato, Takeshi; Inoue, Osamu; Kawada, Hiroki; Okagawa, Yutaka; Huang, Luis; Hsu, Matthew; Su, Amei
2013-04-01
One of the main issues with overlay error metrology accuracy is the bias between results based on overlay (OVL) targets and actual device overlay error. In this study, we introduce the concept of Device Correlated Metrology (DCM), which is a systematic approach to quantifying and overcoming the bias between target-based overlay results and device overlay issues. For systematically quantifying the bias components between target and device, we introduce a new hybrid target integrating an optical OVL target with a device mimicking CD-SEM (Critical Dimension - Scanning Electron Microscope) target. The hybrid OVL target is designed to accurately represent the process influence found on the real device. In the general case, the CD-SEM can measure the bias between target and device on the same layer at AEI (After Etch Inspection) for all layers, the OVL between layers at AEI for most cases and at ADI (After Develop Inspection) for limited cases such as DPL (Double Patterning Lithography). The results shown demonstrate that for the new process compatible hybrid targets the bias between target and device is small, of the order of CD-SEM measurement uncertainty. Direct OVL measurements by CD-SEM show excellent correlation with optical OVL measurements in certain conditions. This correlation helps verify the accuracy of the optical measurement results and is applicable for imaging based OVL metrology methods using AIM or AIMid OVL targets, and scatterometry-based overlay methods such as SCOL (Scatterometry OVL). Future plans include broadening the hybrid target design to better mimic each layer's process conditions such as pattern density. We are also designing hybrid targets for memory devices.
Large-aperture laser differential confocal ultra-long focal length measurement and its system.
Zhao, Weiqian; Li, Zhigang; Qiu, Lirong; Ren, Huan; Shao, Rongjun
2015-06-29
A new laser differential confocal ultra-long focal length measurement (LDCFM) method is proposed with the capability to self-calibrate the reference lens (RL) focal length and the axial space between the test lens and RL. Using the property that the focus of laser differential confocal ultra-long focal length measurement system (LDCFS) precisely corresponds to the null point of the differential confocal axial intensity curve, the proposed LDCFM measures the RL focal length f_{R}' by precisely identifying the positions of the focus and last surface of RL, measures the axial space d_{0} between RL and test ultra-long focal length lens (UFL) by identifying the last surface of RL and the vertex of UFL last surface, and measures the variation l in focus position of LDCFS with and without test UFL, and then calculates the UFL focal length f_{T}' by the above measured f_{R}', d_{0} and l. In addition, a LDCFS based on the proposed method is developed for a large aperture lens. The experimental results indicate that the relative uncertainty is less than 0.01% for the test UFL, which has an aperture of 610 mm and focal length of 31,000 mm. LDCFM provides a novel approach for the high-precision focal-length measurement of large-aperture UFL. PMID:26191747
E. Mayoral; A. Gama Goicochea
2014-10-07
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.
NASA Astrophysics Data System (ADS)
Dugave, Maxime; Göhmann, Frank; Kozlowski, Karol K.; Suzuki, Junji
2015-08-01
We consider the spectrum of correlation lengths of the spin?\\displaystyle \\frac{1}{2} XXZ chain in the antiferromagnetic massive regime. These are given as ratios of eigenvalues of the quantum transfer matrix of the model. The eigenvalues are determined by integrals over certain auxiliary functions and by their zeros. The auxiliary functions satisfy nonlinear integral equations. We analyse these nonlinear integral equations in the low-temperature limit. In this limit we can determine the auxiliary functions and the expressions for the eigenvalues as functions of a finite number of parameters which satisfy finite sets of algebraic equations, the so-called higher-level Bethe ansatz equations. The behaviour of these equations, if we send the temperature T to zero, is different for zero and non-zero magnetic field h. If h is zero the situation is much like in the case of the usual transfer matrix. Non-trivial higher-level Bethe ansatz equations remain which determine certain complex excitation parameters as functions of hole parameters which are free on a line segment in the complex plane. If h is non-zero, on the other hand, a remarkable restructuring occurs, and all parameters which enter the description of the quantum transfer matrix eigenvalues can be interpreted entirely in terms of particles and holes which are freely located on two curves when T goes to zero. Dedicated to Professor Baxter on the occasion of his 75th birthday.
NASA Astrophysics Data System (ADS)
Kubica, Aleksander; Yoshida, Beni
2014-03-01
We invent a novel real-space renormalization group (RG) scheme which accurately estimates correlation length exponents ? near criticality of quantum Ising and clock models in higher dimensions. The method, based on a recent proposal by Miyazaki et al., Phys. Rev. E 83, 051103 (2011), is remarkably simple (often analytical), grouping only a few spins into a block spin so that renormalized Hamiltonian has a closed form. A previous difficulty of spatial anisotropy and unwanted terms arising in higher-dimensional RG schemes is avoided by incorporating rotational invariance and internal Zq symmetries of the Hamiltonian. By applying this scheme to (2+1)-dim Ising model on a triangular lattice, we obtained ? = 0 . 6300 which is within statistical error of the current best Monte-Carlo result and ?4 theory estimation with seven-loop corrections. We also apply the scheme to higher-dimensional clock (Potts) models for which ordinary Monte-Carlo methods are not efficient due to suppression of quantum fluctuation in first-order phase transition.
HIRASAWA, Shun; SHIMIZU, Miki; MARUI, Yuumi; KISHIMOTO, Miori; OKUNO, Seiichi
2014-01-01
We designed a new method of measuring the length of the ulnar nerve and determining standard values for F-wave parameters of the ulnar nerve in clinically normal beagles. Nerve length must be precisely measured to determine F-wave latency and conduction velocity. The length of the forelimb has served as the length of the ulnar nerve for F-wave assessments, but report indicates that F-wave latency is proportional to the length of the pathway traveled by nerve impulses. Therefore, we measured the surface distance from a stimulus point to the spinous process of the first thoracic vertebra (nerve length 1) and the anterior horn of the scapula (nerve length 2) as landmarks through the olecranon and the shoulder blade acromion. The correlation coefficients between the shortest F-wave latency and the length of nerves 1, 2 or the forelimb were 0.61, 0.7 and 0.58. Nerve length 2 generated the highest value. Furthermore, the anterior horn of the scapula was easily palpated in any dog regardless of well-fed body. We concluded that nerve length 2 was optimal for measuring the length of the ulnar nerve. PMID:25649942
Device-correlated metrology for overlay measurements
NASA Astrophysics Data System (ADS)
Chen, Charlie; Huang, George K. C.; Pai, Yuan Chi; Wu, Jimmy C. H.; Cheng, Yu Wei; Hsu, Simon C. C.; Yu, Chun Chi; Amir, Nuriel; Choi, Dongsub; Itzkovich, Tal; Tarshish-Shapir, Inna; Tien, David C.; Huang, Eros; Kuo, Kelly T. L.; Kato, Takeshi; Inoue, Osamu; Kawada, Hiroki; Okagawa, Yutaka; Huang, Luis; Hsu, Matthew; Su, Amei
2014-10-01
One of the main issues with accuracy is the bias between the overlay (OVL) target and actual device OVL. In this study, we introduce the concept of device-correlated metrology (DCM), which is a systematic approach to quantify and overcome the bias between target-based OVL results and device OVL values. In order to systematically quantify the bias components between target and device, we introduce a new hybrid target integrating an optical OVL target with a device mimicking critical dimension scanning electron microscope (CD-SEM) target. The hybrid OVL target is designed to accurately represent the process influence on the actual device. In the general case, the CD-SEM can measure the bias between the target and device on the same layer after etch inspection (AEI) for all layers, the OVL between layers at AEI for most cases and after develop inspection for limited cases such as double-patterning layers. The results have shown that for the innovative process compatible hybrid targets the bias between the target and device is small, within the order of CD-SEM noise. Direct OVL measurements by CD-SEM show excellent correlation between CD-SEM and optical OVL measurements at certain conditions. This correlation helps verify the accuracy of the optical measurement results and is applicable for the imaging base OVL method using several target types advance imaging metrology, advance imaging metrology in die OVL, and the scatterometrybase OVL method. Future plans include broadening the hybrid target design to better mimic each layer process conditions such as pattern density. Additionally, for memory devices we are developing hybrid targets which enable other methods of accuracy verification.
ERIC Educational Resources Information Center
Tan-Sisman, Gulcin; Aksu, Meral
2012-01-01
"Knowing and doing measurement" is a fundamental competency in real life since measuring attributes of objects in appropriate units and using measuring tools assist students to quantify and understand the world. For this reason, the study of measurement has a special place in every mathematics curriculum. Among the domains of measurement, length…
Eddy correlation measurements of submarine groundwater discharge
Crusius, J.; Berg, P.; Koopmans, D.J.; Erban, L.
2008-01-01
This paper presents a new, non-invasive means of quantifying groundwater discharge into marine waters using an eddy correlation approach. The method takes advantage of the fact that, in virtually all aquatic environments, the dominant mode of vertical transport near the sediment-water interface is turbulent mixing. The technique thus relies on measuring simultaneously the fluctuating vertical velocity using an acoustic Doppler velocimeter and the fluctuating salinity and/or temperature using rapid-response conductivity and/or temperature sensors. The measurements are typically done at a height of 5-15??cm above the sediment surface, at a frequency of 16 to 64??Hz, and for a period of 15 to 60??min. If the groundwater salinity and/or temperature differ from that of the water column, the groundwater specific discharge (cm d- 1) can be quantified from either a heat or salt balance. Groundwater discharge was estimated with this new approach in Salt Pond, a small estuary on Cape Cod (MA, USA). Estimates agreed well with previous estimates of discharge measured using seepage meters and 222Rn as a tracer. The eddy correlation technique has several desirable characteristics: 1) discharge is quantified under in-situ hydrodynamic conditions; 2) salinity and temperature can serve as two semi-independent tracers of discharge; 3) discharge can be quantified at high temporal resolution, and 4) long-term records of discharge may be possible, due to the low power requirements of the instrumentation. ?? 2007 Elsevier B.V. All rights reserved.
Measuring system for cable length and diameter based on photoelectric technology
NASA Astrophysics Data System (ADS)
Zhu, WeiMin; Zhou, Zhou; Wei, Ping; Qi, Fang
2012-10-01
Precise online measurement of cable diameter and length will ensure stability of quality production and production speed. This paper describes a measuring device to measure cable length and diameter simultaneously, accomplish online production process control. The device consists mainly of a synchronous sampling part, calculation and control part. The synchronous sampling part consists of two parallel rollers one meter far from each other. A measuring band cinctures the rollers and move together with them. There are two electromagnetic chucks on the measuring band which are controlled by two photoelectric position switches to hold or release a cable, in order to make the cable move with measuring system synchronously. An optical encoder is connected to one of the rollers coaxially to measure cable length. For cable diameter measurement, two orthogonal CCD sensors are used. Accuracy of online diameter measurement is mainly affected by vibration of cable movement. In order to reduce the cable diameter measurement error caused by vibration, measuring system uses a mechanical damping device and high-speed CCD sensors which exposure time is up to microseconds. The calculation and control part of measuring device can filter, amplify and binarizate electrical signals from synchronous sampling part, then they are processed by microcontroller 8051 to complete cable length and diameter measurement. As well, the measuring device can set error limits and detect online whether cable length and diameter size are in default range , if not it would give corresponding alarm.
Diffusion length measurements using the scanning electron microscope. [in semiconductor devices
NASA Technical Reports Server (NTRS)
Weizer, V. G.
1975-01-01
A measurement technique employing the scanning electron microscope is described in which values of the true bulk diffusion length are obtained. It is shown that surface recombination effects can be eliminated through the application of highly doped surface field layers. The influence of high injection level effects and low-high junction current generation on the resulting measurement was investigated. Close agreement is found between the diffusion lengths measured by this method and those obtained using a penetrating radiation technique.
Subpicometer Length Measurement Using Semiconductor Laser Tracking Frequency Gauge
NASA Technical Reports Server (NTRS)
Thapa, Rajesh; Phillips, James D.; Rocco, Emanuele; Reasenburg, Robert D.
2011-01-01
We have demonstrated heretofore unattained distance precision of 0:14pm (2pm) incremental and 14nm (2.9 micrometers) absolute in a resonant (nonresonant) interferometer at an averaging time of 1 s, using inexpensive telecommunications diode lasers. We have controlled the main source of error, that due to spurious reflection and the resulting amplitude modulation. In the resonant interferometer, absolute distance precision is well under lambda/6. Therefore, after an interruption, an absolute distance measurement can be used to return to the same interferometer order.
A tool for measuring the bending length in thin wires.
Lorenzini, M; Cagnoli, G; Cesarini, E; Losurdo, G; Martelli, F; Piergiovanni, F; Vetrano, F; Viceré, A
2013-03-01
Great effort is currently being put into the development and construction of the second generation, advanced gravitational wave detectors, Advanced Virgo and Advanced LIGO. The development of new low thermal noise suspensions of mirrors, based on the experience gained in the previous experiments, is part of this task. Quasi-monolithic suspensions with fused silica wires avoid the problem of rubbing friction introduced by steel cradle arrangements by directly welding the wires to silica blocks bonded to the mirror. Moreover, the mechanical loss level introduced by silica (?fs ? 10(-7) in thin fused silica wires) is by far less than the one associated with steel. The low frequency dynamical behaviour of the suspension can be computed and optimized, provided that the wire bending shape under pendulum motion is known. Due to the production process, fused silica wires are thicker near the two ends (necks), so that analytical bending computations are very complicated. We developed a tool to directly measure the low frequency bending parameters of fused silica wires, and we tested it on the wires produced for the Virgo+ monolithic suspensions. The working principle and a set of test measurements are presented and explained. PMID:23556827
A tool for measuring the bending length in thin wires
NASA Astrophysics Data System (ADS)
Lorenzini, M.; Cagnoli, G.; Cesarini, E.; Losurdo, G.; Martelli, F.; Piergiovanni, F.; Vetrano, F.; Viceré, A.
2013-03-01
Great effort is currently being put into the development and construction of the second generation, advanced gravitational wave detectors, Advanced Virgo and Advanced LIGO. The development of new low thermal noise suspensions of mirrors, based on the experience gained in the previous experiments, is part of this task. Quasi-monolithic suspensions with fused silica wires avoid the problem of rubbing friction introduced by steel cradle arrangements by directly welding the wires to silica blocks bonded to the mirror. Moreover, the mechanical loss level introduced by silica (?fs ˜ 10-7 in thin fused silica wires) is by far less than the one associated with steel. The low frequency dynamical behaviour of the suspension can be computed and optimized, provided that the wire bending shape under pendulum motion is known. Due to the production process, fused silica wires are thicker near the two ends (necks), so that analytical bending computations are very complicated. We developed a tool to directly measure the low frequency bending parameters of fused silica wires, and we tested it on the wires produced for the Virgo+ monolithic suspensions. The working principle and a set of test measurements are presented and explained.
Body length measurement is an im-portant part of growth, condition,
with 95% ethyl alcohol. The fish were remeasured 3, 20, and 90 days after preservation. Repeated measures% alcohol. A length correction formula is presented that allows live standard length to be calculated from tyrannus) after preservation in alcohol Dariusz P. Fey Sea Fisheries Institute Dept. of Fisheries
Direct measurement of the plasma screening length and surface potential near the lunar terminator
NASA Technical Reports Server (NTRS)
Benson, J.
1977-01-01
Direct measurement of the lunar dayside surface potential and screening length has been made by the suprathermal ion detector experiment (Side) near the terminator. In a region 20-30 deg from the terminator at the Apollo 14 and 15 sites the surface potential is found to be approximately 50 V negative, and the screening length to be about 1 km. This value of the screening length is more than 2 orders of magnitude greater than the solar wind 'Debye' length. The strong negative surface potential in this region may be due to enhanced temperature and density of the solar wind plasma.
ERIC Educational Resources Information Center
van den Boer, Madelon; de Jong, Peter F.; Haentjens-van Meeteren, Marleen M.
2013-01-01
Beginning readers' reading latencies increase as words become longer. This length effect is believed to be a marker of a serial reading process. We examined the effects of visual and phonological skills on the length effect. Participants were 184 second-grade children who read 3- to 5-letter words and nonwords. Results indicated that reading…
Daly, Samantha
in Part 2 was digital image correlation (DIC). Here, we will discuss how to apply DIC measurement length. We will start with some background and funda- mentals of DIC, describe the setup and specimen-conditioned SM wire and one on SE wire. 2. Digital Image Correlation Fundamentals Digital Image Correlation (DIC
Cesium oscillator strengths measured with a multiple-path-length absorption cell
NASA Technical Reports Server (NTRS)
Exton, R. J.
1976-01-01
Absorption-oscillator-strength measurements for the principal series in cesium were measured using a multiple-path-length cell. The optical arrangement included a movable transverse path for checking the uniformity of the alkali density along the length of the cell and which also allowed strength measurements to be made simultaneously on both strong and weak lines. The strengths measured on the first 10 doublets indicate an increasing trend in the doublet ratio. The individual line strengths are in close agreement with the high resolution measurements of Pichler (1974) and with the calculations of Norcross (1973).
Correlating Beauty and Two Measures of Pleasure.
Vale, Lauren; Gerger, Gernot; Leder, Helmut; Pelli, Denis
2015-09-01
When you look at your beauty and I look at mine, do we have the same feeling? Kant (1764) and Santayana (1896) say that the experience of beauty is pleasure, with qualifications. So we measure pleasure. Observers use Google Images to find an image that is beautiful to them. The observer is asked to look at that image and rate pleasure by continually adjusting the spread of two fingers to track the decaying pleasure they feel from the image. We record both the finger spread rating (on smartphone screen using our emotiontracker.net) and facial muscle activity (fEMG, facial electromyography of M. corrugator supercilii and M. zygomaticus major). We find a high correlation between the feeling of beauty (or liking) and fEMG and finger-rating responses. The rating correlation is 80% until 90 s after stimulus offset. This consistent finding across observers suggests that the two physiological responses, one overt and the other automatic, both track the pleasure of beauty. Meeting abstract presented at VSS 2015. PMID:26325934
Correlation measurements of fission-fragment properties
NASA Astrophysics Data System (ADS)
Oberstedt, S.; Belgya, T.; Billnert, R.; Borcea, R.; Cano-Ott, D.; Göök, A.; Hambsch, F.-J.; Karlsson, J.; Kis, Z.; Martinez, T.; Oberstedt, A.; Szentmiklosi, L.; Takác, K.
2010-10-01
For the development of future nuclear fission applications and for a responsible handling of nuclear waste the a-priori assessment of the fission-fragments' heat production and toxicity is a fundamental necessity. The success of an indispensable modelling of the fission process strongly depends on a good understanding of the particular mechanism of scission, the mass fragmentation and partition of excitation energy. Experimental observables are fission-fragment properties like mass- and energy-distributions, and the prompt neutron as well as ?-ray multiplicities and emission spectra. The latter quantities should preferably be known as a function of fragment mass and excitation energy. Those data are highly demanded as published by the OECD-NEA in its high priority data request list. With the construction of the double (v, E) spectrometer VERDI we aim at measuring pre- and post-neutron masses directly and simultaneously to avoid prompt neutron corrections. From the simultaneous measurement of pre- and post-neutron fission-fragment data the prompt neutron multiplicity may then be inferred fully correlated with fragment mass yield and total kinetic energy. Using an ultra-fast fission event trigger spectral prompt fission ?-ray measurements may be performed. For that purpose recently developed lanthanum-halide detectors, with excellent timing characteristics, were coupled to the VERDI spectrometer allowing for a very good discrimination of fission ?-rays and prompt neutrons due to their different time-of-flight.
Bunch length measurements at the Advanced Photon Source (APS) linear accelerator
N. S. Sereno; R. Fuja; C. Gold; A. E. Grelick; A. Nassiri; J. J. Song; M. White
1995-01-01
Measurements of the APS linac micro-bunch length are performed by backphasing a single 2856-MHz, S-band linac waveguide and using a downstream spectrometer to observe the beam. By measuring the beam width in the dispersive plane as a function of RF power into the linac waveguide, the bunch length can be determined absolutely provided the beam energy and dispersion at the
Polarization gating enables sarcomere length measurements by laser diffraction in fibrotic muscle
NASA Astrophysics Data System (ADS)
Young, Kevin W.; Dayanidhi, Sudarshan; Lieber, Richard L.
2014-11-01
Sarcomere length is a key parameter commonly measured in muscle physiology since it dictates striated muscle active force. Laser diffraction (LD)-based measurements of sarcomere length are time-efficient and sample a greater number of sarcomeres compared with traditional microscopy-based techniques. However, a limitation to LD techniques is that signal quality is severely degraded by scattering events as photons propagate through tissue. Consequently, sarcomere length measurements are unattainable when the number of scattering events is sufficiently large in muscle tissue with a high scattering probability. This occurs in fibrotic skeletal muscle seen in muscular dystrophies and secondary to tissue trauma, thus eliminating the use of LD to study these skeletal muscle ailments. Here, we utilize polarization gating to extract diffracted signals that are buried in noise created by scattering. Importantly, we demonstrate that polarization-gated laser diffraction (PGLD) enables sarcomere length measurements in muscles from chronically immobilized mice hind limbs; these muscles have a substantial increase of intramuscular connective tissue that scatter light and disable sarcomere length measurements by traditional LD. Further, we compare PGLD sarcomere lengths to those measured by bright field (BF) and confocal microscopy as positive controls and reveal a significant bias of BF but not of confocal microscopy.
CORRELATION COEFFICIENT Correlation coefficient is a measure of association
Chung, Moo K.
degrees of freedom, which is 1.71. Since the t value is larger than the quantile point, we reject the null. The case study gives This t value is compared with the 95% quantile point of the t distribution with n2 hypothesis and conclude that there is correlation between the smok- ing index and the lung cancer mortality
ERIC Educational Resources Information Center
Subramaniam, Karthigeyan
2014-01-01
Prospective secondary mathematics teachers' pedagogical knowledge for teaching the estimation of length measurements was investigated by examining their personal benchmarks for measurement estimation. Benchmarks for measurement estimation are the meaningful representations of units that serve to increase one's understanding of…
NASA Astrophysics Data System (ADS)
Sofia, Giulia; Marinello, Francesco; Tarolli, Paolo
2014-05-01
Terraces represent an outstanding example that displays centuries of a ubiquitous human-Earth interaction, in a very specific and productive way, and they are a significant part of numerous local economies. They, in fact, optimise the local resources for agricultural purposes, but also exploit marginal landscapes, expanding local populations. The ubiquity, variety, and importance of terraces have motivated studies designed to understand them better both as cultural and ecological features, but also as elements that can deeply influence runoff generation and propagation, contributing to local instabilities, and triggering or aggravating land degradation processes. Their vulnerability in the face of fast-growing urban settlements and the changes in agricultural practices is also well known, prompting protection measures strongly supported by local communities, but also by national and international projects. This work explores the spatial heterogeneity of terraced landscapes, identifying a proper indicator able to discriminate a terraced landscape respect to a more natural one. Recognizing and characterizing terraced areas can offer important multi-temporal insights into issues such as agricultural sustainability, indigenous knowledge systems, human-induced impact on soil degradation or erosive and landslide processes, geomorphological and pedologic processes that influence soil development, and climatic and biodiversity changes. More in detail, the present work introduces a new morphological indicator from LiDAR, effectively implementable for the automatic characterization of terraced landscapes. For the study, we tested the algorithm for environments that differ in term of natural morphology and terracing system. Starting from a LiDAR Digital Terrain Models (DTM), we considered the local auto-correlation (~local self-similarity) of the slope, calculating the correlation between a slope patch and its surrounding areas. We define the resulting map as the "Slope Local Length of Auto-Correlation", or SLLAC map. The SLLAC map texture is characterized by the presence of peculiar elongated fibers that change depending on the landscape morphology, and on the type of terracing system. The differences in texture can be measured, and they can be used to discriminate terraced areas from more natural ones. Given the raising importance of these landscapes, the proposed procedure can offer an important and promising tool to explore the spatial heterogeneity of terraced sites.
Passos, Ana Paula; Araujo Júnior, Edward; Bruns, Rafael Frederico; Nardozza, Luciano Marcondes Machado; Moron, Antonio Fernandes
2015-02-01
This study aimed to establish reference values for the length and area of the fetal cisterna magna using the multiplanar mode of 3-dimensional ultrasonography. A cross-sectional study including 224 normal pregnant women between 17 weeks 0 days and 29 weeks 6 days of gestation was carried out. The area and length of the fetal cisterna magna were measured in the axial plane at the level of the cerebellar transverse diameter. Reliability was determined by intraclass correlation coefficient. The mean length and area of the fetal cisterna magna ranged from 0.50 ± 0.10 to 0.79 ± 0.18 cm and 0.95 ± 0.18 to 3.09 ± 0.62 cm(2), respectively. Intraobserver reliability for the length and area (intraclass coefficients: 0.86 and 0.91, respectively) and interobserver reliability (intraclass coefficients: 0.64 and 0.82, respectively) were good. Three-dimensional ultrasonography using the multiplanar mode is a reliable method for the determination of reference values for the length and area of the fetal cisterna magna. PMID:24846899
A Precision Measurement of the n-D Coherent Scattering Length
NASA Astrophysics Data System (ADS)
Schoen, K.; Black, T.; Snow, W. M.; Huffman, P.; Arif, M.; Kaiser, H.; Jacobson, D.; Werner, S.
2001-04-01
Theoretical calculations of the properties of few-nucleon systems starting from the NN interaction potential have been improved qualitatively over the last few years. The issue of the nature and origin of three-nucleon (3N) forces in particular has received special interest. The triton binding energy and the doublet n-D scattering length are the two zero-energy observables for which calculations of the effects of 3N forces are uncomplicated by Coulomb corrections. Since the quartet n-D scattering length is sensitive mainly to the long-range part of the NN interaction and is therefore determined essentially by the properties of the deuteron, a precision measurement of the coherent n-D scattering length (which is a linear combination of the doublet and quartet lengths) can be used to gain information on the n-D doublet scattering length. We will present new measurements of the n-D coherent scattering length using the NIST neutron interferometer facility with almost an order-of-magnitude improvement in sensitivity relative to existing measurements. We will also discuss the possibility of improving the accuracy of the coherent n-H scattering length.
NASA Astrophysics Data System (ADS)
Mandadapu, Kranthi; Hudson, Alexander; Chandler, David
2015-03-01
Dynamical facilitation theory predicts the emergence of a non-trivial correlation length from the cooling process that transforms the reversible melt to the irreversible glass. A decrease in cooling rate produces an increase in correlation length, and an increase in correlation length coincides with an increase in stability and aging rate of the glass. Here, we present results from a large-scale non-equilibrium numerical simulation that provide the first demonstration of the emergent nonequilbrium correlation length for an atomistic model. The study also tests the ability of the theory to predict the value of the nonequilibrium length and its corresponding glass transition temperature in terms of material properties and cooling protocols. Nontrivial correlation length distinguishes melt from glass in a large-scale atomistic non-equilibrium simulation of a glass transition
Correlations of telomere length, P53 mutation, and chromosomal translocation in soft tissue sarcomas
Liu, Chunxia; Li, Bingcheng; Li, Li; Zhang, Haijun; Chen, Yunzhao; Cui, Xiaobin; Hu, Jianming; Jiang, Jingfang; Qi, Yan; Li, Feng
2015-01-01
Background: Soft tissue sarcomas (STSs) are a heterogeneous group of malignant tumors that can be divided into specific reciprocal translocation associated in STSs (SRTSs) and nonspecific reciprocal translocation associated in STSs (NRTSs). Telomeres play a key role in maintaining chromosomal stability; pathological telomere elongation is found in a number of cancers. In this study, we aimed to assess telomere lengths in the two types of sarcomas. Twenty formalin-fixed paraffin-embedded (FFPE) archival tissues, namely, 10 sarcomas with characteristic translocations and 10 without characteristic translocations, were included in this study. Expression levels of special fusion gene transcripts were detected in these tumors by reverse transcription polymerase chain reaction. Telomere lengths were assessed by fluorescence in situ hybridization. Results showed that in 10 of the 10 cases of SRTSs, telomere lengths were similar to or reduced compared with the surrounding normal cells. Telomere lengths were elongated in eight of 10 cases of NRTSs, but reduced in two cases. The difference in telomere length was statistically significant in the two types of sarcomas (P = 0.001). Upon combining the P53 mutation status, we found that the telomere length was short in eight cases, and only one case demonstrated p53 mutation. However, the telomere length was long in eight cases, and p53 mutation was observed in five cases. These data suggested that p53 mutation was accompanied with long telomeres, and telomeres possibly play an important role in NRTSs. Therefore, telomere-targeting therapy may lead to novel therapeutic strategies to improve treatment of NRTS patients. PMID:26191279
Tyre contact length on dry and wet road surfaces measured by three-axial accelerometer
NASA Astrophysics Data System (ADS)
Matilainen, Mika; Tuononen, Ari
2015-02-01
We determined the tyre contact length on dry and wet roads by measuring the accelerations of the inner liner with a three-axial accelerometer. The influence of the tyre pressure, driving velocity, and tread depth on the contact length was studied in both types of road surface conditions. On dry asphalt the contact length was almost constant, regardless of the driving velocity. On wet asphalt the presence of water could be detected even at low driving velocities (e.g. 20 km/h for a worn tyre) as the contact length began to decrease from that found in the dry asphalt situation. In addition to improving the performance of active safety systems and driver warning systems, the contact length information could be beneficial for classifying and studying the aquaplaning behaviour of tyres.
Large-aperture ultra-long focal length measurement and its system by laser confocal techniques
NASA Astrophysics Data System (ADS)
Li, Zhigang; Qiu, Lirong; Zhao, Weiqian; Guo, Yongkui; Yuan, Quan
2015-09-01
A new laser confocal ultralong focal length measurement method (LCFM) is proposed with the capability to self-calibrate the reference lens (RL) focal length and the axial space between the test lens and the RL. Using the property that the focus of a laser confocal ultralong focal length measurement system (LCFS) precisely corresponds to the peak point of the confocal axial intensity curve, the proposed LCFM measures the RL focal length f\\text{R}\\prime by precisely identifying the positions of the focus and the last surface of the RL, measures the axial space d0 between the RL and the test ultra-long focal-length lens (UFL) by identifying the last surface of the RL and the vertex of the UFL last surface, measures the variation l in focus position of the LCFS with and without the test UFL, and then calculates the UFL focal length f\\text{T}\\prime using the above-measured f\\text{R}\\prime , d0, and l. Furthermore, the LCFM uses conic fitting, which obviously enhances the measurement accuracy by reducing the influences of random disturbances. In addition, an LCFS based on the proposed method is developed for large aperture lens. The experimental results indicate that the relative uncertainty is less than 0.015% for the test UFL, which has an aperture of 610?mm and a focal length of 31?000?mm. Compared with existing methods, the LCFM utilizes a concise structure and has good stability, making it especially suitable for practical engineering applications.
Focal length measurement of microlens array for Shack-Hartmann wavefront sensor using interferometer
NASA Astrophysics Data System (ADS)
Kumar, M. Senthil; Narayanamurthy, C. S.; Kumar, A. S. Kiran
2013-12-01
We have proposed a method to determine the focal length of microlens array (MLA) based on the measurement of transverse displacement of image spot in the focal plane for a change of angle of incidence of plane wavefront. An existing interferometer test setup, meant for the surface figure measurement of MLA substrate, along with a charge-coupled device (CCD) is used for this purpose. The interferometer generates as well as measures the angle of incidence of plane wavefront at the MLA, and the transverse displacement of the image spot is determined from images recorded with the CCD. We have also discussed the theory of estimation of the focal length of MLA with spherical wavefront. Error analysis is carried out for both methods and is compared. The proposed plane wavefront method is experimentally demonstrated with an off-the-shelf MLA, and the measured focal length is within 1% of catalogue value.
Technique for the focal-length measurement of positive lenses using Fizeau interferometry
Pavan Kumar, Yeddanapudi; Chatterjee, Sanjib
2009-02-01
We present what we believe is a new technique for the focal-length measurement of positive lenses using Fizeau interferometery. The technique utilizes the Gaussian lens equation. The image distance is measured interferometrically in terms of the radius of curvature of the image-forming wavefront emerging from the lens. The radii of curvature of the image-forming wavefronts corresponding to two different axial object positions of known separation are measured. The focal length of the lens is determined by solving the equations obtained using the Gaussian lens equation for the two object positions. Results obtained for a corrected doublet lens of a nominal focal length of 200.0 mm with a measurement uncertainty of {+-}2.5% is presented.
Measurement of the Bunch Length at the TESLA Test Facility Linac
Hanke, K.
1996-04-01
An autocorrelation method is proposed to measure the bunch length at the TESLA Test Facility linac. The coherent part of the spectrum of transition radiation is to be examined using a quasioptical setup and a Golay Cell (1). The experimental setup is presented and the proposed measurements are discussed. {copyright} {ital 1996 American Institute of Physics.}
Possible methods of measuring the length of sub-picosecond electron bunches in the frequency domain
Jackson, G.P.
1992-12-01
The traditional method of measuring extremely short electron beams using streak cameras begins to become problematic and expensive at bunch lengths at a picosecond and below. In this paper a few alternatives, based on the differential measurement of the Fourier spectrum of the longitudinal charge distribution of a bunch are suggested and evaluated.
Far-from-equilibrium measurements of thermodynamic length Edward H. Feng
the manipulation of single molecules and the measurement of the thermody- namic properties of microscopic systems 1 function that measures the distance along a path in ther- modynamic state space. This is in contrast, the thermodynamic length bounds the dissipation of slow, but finite time transformations 12,14 . Moreover
NASA Astrophysics Data System (ADS)
Schödel, R.
2015-08-01
Traceability of length measurements to the international system of units (SI) can be realized by using optical interferometry making use of well-known frequencies of monochromatic light sources mentioned in the Mise en Pratique for the realization of the metre. At some national metrology institutes, such as Physikalisch-Technische Bundesanstalt (PTB) in Germany, the absolute length of prismatic bodies (e.g. gauge blocks) is realized by so-called gauge-block interference comparators. At PTB, a number of such imaging phase-stepping interference comparators exist, including specialized vacuum interference comparators, each equipped with three highly stabilized laser light sources. The length of a material measure is expressed as a multiple of each wavelength. The large number of integer interference orders can be extracted by the method of exact fractions in which the coincidence of the lengths resulting from the different wavelengths is utilized as a criterion. The unambiguous extraction of the integer interference orders is an essential prerequisite for correct length measurements. This paper critically discusses coincidence criteria and their validity for three modes of absolute length measurements: 1) measurements under vacuum in which the wavelengths can be identified with the vacuum wavelengths, 2) measurements under air in which the air refractive index is obtained from environmental parameters using an empirical equation, and 3) measurements under air in which the air refractive index is obtained interferometrically by utilizing a vacuum cell placed along the measurement pathway. For case 3), which corresponds to PTB’s Kösters-Comparator for long gauge blocks, the unambiguous determination of integer interference orders related to the air refractive index could be improved by about a factor of ten when an ‘overall dispersion value,’ suggested in this paper, is used as coincidence criterion.
Toyoki Maeda; Jun-ichi Oyama; Yoshihiro Higuchi; Yasuhiro Nishiyama; Yoshihiro Kudo; Tomoko Yamori; Takashi Nakazono; Takahiro Arima; Koshi Mimori; Naoki Makino
2011-01-01
Background: The telomere length and subtelomeric methylated status of peripheral blood leukocytes have been reported to be correlated with many kinds of pathophysiological conditions. However, the correlation between the telomeric parameters and patients’ physical ability is not known. Objective: This study aims to study how telomeric parameters, including telomere length and the subtelomeric methylation status of peripheral blood leukocytes, are
Zhang, YuMing
of Arc Length Pengjiu Li and YuMing Zhang, Senior Memeber, IEEE Abstract--During arc welding, the arc and the intensity of the heat flux are determined by the length of the arc. The measurement and control of the arc length are fun- damental in robotic and automated welding operations. Length of welding arc determines
Radial correlation reflectometry measurements on the JET tokamak
NASA Astrophysics Data System (ADS)
Fonseca, A.; Alper, B.; Budny, R.; Cupido, L.; Fessey, J.; Figueiredo, A.; Hacquin, S.; Manso, M. E.; Mazzucato, E.; Meneses, L.; Sirinelli, A.; Walsh, M.
2007-11-01
Fluctuations and turbulence are believed to play an important role in anomalous transport of heat and particles in magnetic fusion devices. It is of vital importance to characterize transport mechanism in order to understand and control it. In correlation reflectometry (CR), two microwave beams with different frequencies are launched into the plasma from which the turbulence correlation length, Lr, and the density fluctuation level, 0.7exn / n n.- 0.7exn can be deduced; quantities that are important for the study of plasma turbulence and transport. In this paper, some results of Lr obtained with the four X-mode CR systems installed at Joint European Torus (JET) are reported. Experimentally, it was observed that Lr increases from the plasma edge to the plasma core. Also, Lr decreases inside the Internal Transport Barriers (ITB) [1]. The results obtained at JET agree quiet well with the Lr dependence measured in other tokamak machines. [1] - A.C.A. Figueiredo, et.al., in the 34^th EPS Conference on Plasma Physics, Warsaw, Poland, 2-7 July, (2007).
Oshima, Shiori; Sankai, Yoshiyuki
2009-09-01
Optical techniques have been developed to acquire blood information (e.g., hematocrit [Hct], saturation of oxygen, thrombus) noninvasively and continuously in an artificial heart. For the practical use of an optical Hct measurement, Twersky's theory has been shown to be useful and have a good agreement in forward-scattered measurements. However, it was not applied to backward-scattered measurements, which can provide the measurement with a less demanding spatial requirement. Additionally, optimal measurement for accuracy is not well examined. Therefore, we developed an accurate Hct measurement in an artificial heart using current optical devices. To this end, we focused on optimizing an emitter-detector distance to provide a maximum optical path length. We attached optical emitter and detector fibers on Tygon tubing at various distances to measure forward- and backward-scattered light. Fresh bovine blood (Hct: 30-50%) was circulated in the tubing by a nonpulsatile artificial heart. We calculated the optical path length at various emitter-detector distances by fitting the measured optical outputs and the reference Hcts to Twersky's theory. Then, we performed Hct measurements. As a result, Twersky's theory is applicable not only to forward- but also to backward-scattered measurements in the physiogical Hct range. In both forward- and backward-scattered measurements, calculated optical path lengths become maximum at the same emitter-detector distance. The accuracy of Hct measurement is improved two to three times with the emitter-detector distance compared with other distances. The mean error is less than 1 Hct%. This result shows that an accurate Hct measurement is realized by selecting the optimal emitter-detector distance, which provides maximum optical path length defined by Twersky's theory. Our study provides a framework for the practical and less restrictive application of the optical Hct measurement to patients with an artificial heart. PMID:19775267
NASA Astrophysics Data System (ADS)
Shojania Feizabadi, Mitra; Winton, Carly; Barrientos, Jimmy
2012-02-01
Recent studies on microtubules composed of different ? tubulin isotypes indicate their different functionality in terms of their dynamical behavior or the mechanism of their interaction with chemotherapeutic drugs. Along these lines, the result of our recent study measuring the rigidity of neural and non-neural samples of microtubules with different ? tubulin isotype compositions suggests that the distinguished mechanical properties of microtubules, such as rigidity, may also be associated with the different distribution of their ? tubulin isotypes. In our current study, we have reported the persistence length of a single soybean microtubule. This plant microtubule has a structural composition different from that of mammalian microtubules. Under the same experimental methods of measurement, the soybean microtubules showed a different persistence length as compared to the value of the persistence length that we estimated in the study of both single Bovine Brain and MCF7 microtubules.
Chen, Qianghua; Luo, Huifu; Wang, Sumei; Wang, Feng; Chen, Xinhua
2012-09-01
A measurement method based on interferometry with two different reference cavity lengths is presented and applied in air refractive index measurement in which the two cavity lengths and a laser wavelength are combined to generate two wavelength equivalents of cavity. Corresponding calculation equations are derived, and the optical path configuration is designed, which is inspired by the traditional synthetic wavelength method. Theoretical analyses indicate that the measurement uncertainty of the determined index of refraction is about 2.3×10(-8), which is mainly affected by the length precision of the long vacuum cavity and the ellipticity of polarization components of the dual-frequency laser, and the range of nonambiguity is 3.0×10(-5), which is decided by the length difference of the two cavities. Experiment results show that the accuracy of air refractive index measurement is better than 5.0×10(-8) when the laboratory conditions changes slowly. The merit of the presented method is that the classical refractometry can be also used without evacuation of the gas cavity during the experiment. Furthermore, the application of the traditional synthetic wavelength method may be extended by using the wavelength equivalents of cavity, any value of which can be easily acquired by changing cavity length rather than using actual wavelengths whose number is limited. PMID:22945157
Connection between measurement disturbance relation and multipartite quantum correlation
NASA Astrophysics Data System (ADS)
Li, Jun-Li; Du, Kun; Qiao, Cong-Feng
2015-01-01
It is found that the measurement disturbance relation (MDR) determines the strength of quantum correlation and hence is one of the essential facets of the nature of quantum nonlocality. In reverse, the exact form of MDR may be ascertained through measuring the correlation function. To this aim, an optical experimental scheme is proposed. Moreover, by virtue of the correlation function, we find that the quantum entanglement, the quantum nonlocality, and the uncertainty principle can be explicitly correlated.
Bunch Length Measurements at the JLab FEL Using Coherent Transition and Synchrotron Radiation
Pavel Evtushenko; James Coleman; Kevin Jordan; J. Michael Klopf; George Neil; Gwyn Williams
2006-05-01
The JLab FEL is routinely operated with sub-picosecond bunches. The short bunch length is important for high gain of the FEL. Coherent transition radiation has been used for the bunch length measurements for many years [1]. This diagnostic can be used only in the pulsed beam mode. It is our goal to run the FEL with CW beam and a 74.85 MHz micropulse repetition rate, which, with the 135 pC nominal bunch charge corresponds to the beam average current of 10 mA. Hence it is very desirable to have the possibility of making bunch length measurements when running CW beam with any micropulse frequency. We use a Fourier transform infrared (FTIR) interferometer, which is essentially a Michelson interferometer, to measure the spectrum of the coherent synchrotron radiation generated in the last dipole of the magnetic bunch compressor upstream of the FEL wiggler. This noninvasive diagnostic provides bunch length measurements for CW beam operation at any micropulse frequency. We also compare the measurements made with the help of the FTIR interferometer with data obtained using the Martin-Puplett interferometer [1]. Results of the two diagnostics agree within 15 %. Here we present a description of the experimental setup, data evaluation procedure and results of the beam measurements.
Longitudinal-to-Transverse Mapping for Femtosecond Electron Bunch Length Measurement
Xiang, Dao; Ding, Yuantao; /SLAC
2010-08-25
A longitudinal-to-transverse mapping technique is proposed to measure the length and temporal profile of ultrashort electron bunches. In this scheme a special chicane and a radio-frequency deflecting cavity are used to transform the beam's longitudinal distribution into angular distribution which is further converted to transverse distribution after a parallel-to-point imaging beam line. With this technique, the temporal profile of the electron beam is exactly mapped to the transverse profile. This makes it possible to measure ultrashort electron bunch length with a resolution well beyond 1 femtosecond.
NASA Technical Reports Server (NTRS)
Flat, A.; Milnes, A. G.
1978-01-01
In scanning electron microscope (SEM) injection measurements of minority carrier diffusion lengths some uncertainties of interpretation exist when the response current is nonlinear with distance. This is significant in epitaxial layers where the layer thickness is not large in relation to the diffusion length, and where there are large surface recombination velocities on the incident and contact surfaces. An image method of analysis is presented for such specimens. A method of using the results to correct the observed response in a simple convenient way is presented. The technique is illustrated with reference to measurements in epitaxial layers of GaAs. Average beam penetration depth may also be estimated from the curve shape.
2013-01-01
Background Esophageal cancer is the sixth leading cause of cancer death worldwide; current early detection screening tests are inadequate. Esophageal balloon cytology successfully retrieves exfoliated and scraped superficial esophageal epithelial cells, but cytologic reading of these cells has poor sensitivity and specificity for detecting esophageal squamous dysplasia (ESD), the precursor lesion of esophageal squamous cell carcinoma (ESCC). Measuring telomere length, a marker for chromosomal instability, may improve the utility of balloon cytology for detecting ESD and early ESCC. Methods We examined balloon cytology specimens from 89 asymptomatic cases of ESD (37 low-grade and 52 high-grade) and 92 age- and sex-matched normal controls from an esophageal cancer early detection screening study. All subjects also underwent endoscopy and biopsy, and ESD was diagnosed histopathologically. DNA was extracted from the balloon cytology cells, and telomere length was measured by quantitative PCR. A receiver operating characteristic (ROC) curve was plotted for telomere length as a diagnostic marker for high-grade dysplasia. Results Telomere lengths were comparable among the low- and high-grade dysplasia cases and controls, with means of 0.96, 0.96, and 0.92, respectively. The area under the ROC curve was 0.55 for telomere length as a diagnostic marker for high-grade dysplasia. Further adjustment for subject characteristics, including sex, age, smoking, drinking, hypertension, and body mass index did not improve the use of telomere length as a marker for ESD. Conclusions Telomere length of esophageal balloon cytology cells was not associated with ESCC precursor lesions. Therefore, telomere length shows little promise as an early detection marker for ESCC in esophageal balloon samples. PMID:24308314
Research on all fiber beat length measurement system for polarization-maintaining fibers
NASA Astrophysics Data System (ADS)
Peng, Li; Feng, Lishuang; Zhang, Xiaoqing; Hong, Lingfei
2010-12-01
Polarization-maintaining fiber (PMF) has attracted great attentions not only due to its ability to realize coherent optic communication with ultrahigh-capacity, but also because it can be widely employed in high-precise fiber-optic sensors and optic information processors, e.g., fiber-optic gyroscope and fiber-optic amperemeter. Distinct with common monomode optic fibers, additional birefringence is introduced in the PMF, minimizing the effect of mode coupling between two orthogonal polarization modes in optic fibers. Thus, light polarization can be maintained after long distance transmission in the PMF. However, beat-length, which reflects the characteristic of induced birefringence and evaluates the ability of polarization maintaining, is one of the most important parameters for PMF. Accurate measurement of PMF beat length becomes more and more important along with the expanding of its application field. The uniqueness of the measurement results determines the identity of PMF fabrication and the resolution of fiber-optic sensors. The existing measurement methods for PMF beat length are introduced first. Most testing setups are established by several individual components, which lead to complicated setup, inconvenient testing, and unsteady measurement. In this paper, a novel all fiber beat length measurement system is presented, where optic source, integrated optic modulator, stress apply structure, polarization detector, and polarization indicator of output light are included. The configuration and working principle of the whole system, and the designing and realization of each components, are addressed in the paper. Furthermore, the influence on measurement results by the relative direction between applied stress and principal axis of the optic fiber is analyzed. Moreover, optimized designs, including polarized light incidence, pressure apply, and precise movement systems, are performed, which ensure the identical pressure apply direction in the moving process. Finally, measurement of PMF samples is carried out on experimental setup. In comparison with the other existing system, due to its all fiber light incidence structure, the novel beat length measurement system represents great stability and high reliability.
Research on all fiber beat length measurement system for polarization-maintaining fibers
NASA Astrophysics Data System (ADS)
Peng, Li; Feng, Lishuang; Zhang, Xiaoqing; Hong, Lingfei
2011-05-01
Polarization-maintaining fiber (PMF) has attracted great attentions not only due to its ability to realize coherent optic communication with ultrahigh-capacity, but also because it can be widely employed in high-precise fiber-optic sensors and optic information processors, e.g., fiber-optic gyroscope and fiber-optic amperemeter. Distinct with common monomode optic fibers, additional birefringence is introduced in the PMF, minimizing the effect of mode coupling between two orthogonal polarization modes in optic fibers. Thus, light polarization can be maintained after long distance transmission in the PMF. However, beat-length, which reflects the characteristic of induced birefringence and evaluates the ability of polarization maintaining, is one of the most important parameters for PMF. Accurate measurement of PMF beat length becomes more and more important along with the expanding of its application field. The uniqueness of the measurement results determines the identity of PMF fabrication and the resolution of fiber-optic sensors. The existing measurement methods for PMF beat length are introduced first. Most testing setups are established by several individual components, which lead to complicated setup, inconvenient testing, and unsteady measurement. In this paper, a novel all fiber beat length measurement system is presented, where optic source, integrated optic modulator, stress apply structure, polarization detector, and polarization indicator of output light are included. The configuration and working principle of the whole system, and the designing and realization of each components, are addressed in the paper. Furthermore, the influence on measurement results by the relative direction between applied stress and principal axis of the optic fiber is analyzed. Moreover, optimized designs, including polarized light incidence, pressure apply, and precise movement systems, are performed, which ensure the identical pressure apply direction in the moving process. Finally, measurement of PMF samples is carried out on experimental setup. In comparison with the other existing system, due to its all fiber light incidence structure, the novel beat length measurement system represents great stability and high reliability.
Belew, W.L.; Cooley, J.N.; Whitaker, J.M.
1992-07-17
The activities performed in verification of reactor fuel rods and assemblies by International Atomic Energy Agency (IAEA) safeguards inspectors include measurements of the length of the enriched uranium sections in fuel assemblies and fuel rods. These measurements are normally made with the IAEA hand-held gamma monitor (HM-4) on fuel elements containing only enriched uranium. Many fuel rods currently in use contain natural uranium end sections and several different {sup 235}U enrichment zones. To support development of standard procedures for IAEA nondestructive assay (NDA) measurements, a field measurement campaign was carried out to evaluate the FM-4 measurements and to investigate the feasibility of extending the HM-4 measurements to fuel rods and assemblies containing both natural and enriched uranium sections. The results show that the enriched fuel length can be measured to within {plus_minus} 1 to 2 cm in the presence of natural uranium sections and to within {plus_minus} 0.5 = when only enriched uranium is present. Based on the results from these measurements, a standard procedure, ``Measurement of Active Fuel Length in Fuel Assemblies and Fuel Rods Using the HM-4,`` has been drafted for review by the IAEA.
Belew, W.L.; Cooley, J.N.; Whitaker, J.M.
1992-07-17
The activities performed in verification of reactor fuel rods and assemblies by International Atomic Energy Agency (IAEA) safeguards inspectors include measurements of the length of the enriched uranium sections in fuel assemblies and fuel rods. These measurements are normally made with the IAEA hand-held gamma monitor (HM-4) on fuel elements containing only enriched uranium. Many fuel rods currently in use contain natural uranium end sections and several different [sup 235]U enrichment zones. To support development of standard procedures for IAEA nondestructive assay (NDA) measurements, a field measurement campaign was carried out to evaluate the FM-4 measurements and to investigate the feasibility of extending the HM-4 measurements to fuel rods and assemblies containing both natural and enriched uranium sections. The results show that the enriched fuel length can be measured to within [plus minus] 1 to 2 cm in the presence of natural uranium sections and to within [plus minus] 0.5 = when only enriched uranium is present. Based on the results from these measurements, a standard procedure, Measurement of Active Fuel Length in Fuel Assemblies and Fuel Rods Using the HM-4,'' has been drafted for review by the IAEA.
Khatami, Saeid Reza; Galehdari, Hamid; Rasekh, Abdorrahman; Mombeini, Hayat; Konar, Elham
2015-01-01
Background The androgen receptor (AR) gene contains a polymorphic trinucleotide repeat that encodes a polyglutamine tract in its N-terminal transactivation domain (N- TAD). We aimed to find a correlation between the length of this polymorphic tract and azoospermia or oligozoospermia in infertile men living in Khuzestan, Iran. Materials and Methods In this case-control study during two years till 2010, we searched for microdeletions in the Y chromosome in 84 infertile male patients with normal karyotype who lived in Khuzestan Province, Southwest of Iran. All cases (n=12) of azoospermia or oligozoospermia resulting from Y chromosome microdele- tions were excluded from our study. The number of CAG repeats in exon 1 of the AR gene was determined in 72 patients with azoospermia or oligozoospermia and in 72 fertile controls, using the polymerase chain reaction (PCR) and polyacrylamide gel electrophoresis. Results Microdeletions were detected in 14.3% (n=12) patients suffering severe oligozoospermia. The mean CAG repeat length was 18.99 ± 0.35 (range, 11-26) and 19.96 ± 0.54 (range, 12-25) in infertile males and controls, respectively. Also in the infertile group, the most common allele was 19 (26.38%), while in controls, it was 25 (22.22%). Conclusion Y chromosome microdeletions could be one of the main reasons of male infertility living in Khuzestan Province, while there was no correlation between CAG length in AR gene with azoospermia or oligozoospermia in infertile men living in Khuzestan, Iran.
ERIC Educational Resources Information Center
Krus, Patricia H.; And Others
Field testing of the Length Unit of the Money, Measurement and Time Program was conducted with 23 elementary school classes of educable mentally handicapped (EMH) children. The 218 Ss were assigned to the experimental group, the Hawthorne group, or the control group. Two criterion referenced tests were administered to evaluate Ss' measuring skills…
Measurement of bunch length in Indus-1 storage ring using fast photodiode
Garg, Akash Deep; Nathwani, R. K.; Holikatti, A. C.; Kumar Karnewar, Akhilesh; Tyagi, Y.; Yadav, S.; Puntambekar, T. A.; Navathe, C. P.
2012-11-15
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.
Focal length measurement of microlens-array by the clarity function of digital image
NASA Astrophysics Data System (ADS)
Zhu, Xianchang; Wu, Fan; Cao, Xuedong; Wu, Shibin; Zhang, Peng; Jing, Hongwei
2012-10-01
In this paper, a method for the focal length measurement of Microlens-array (MLA) is introduced. The measuring setup is composed by monochromatic, condenser, collimator, MLA, microscope and CCD sensor. An experiment was performed using a MLA whose focal length is about 8 mm and a GUI based on Matlab software was developed to analyze the image gathered at the vertex and the focus by the clarity of digital image processing technology. The measuring uncertainty of this method is about 0.8% and this method introduced in this paper can finish tens of microlens array measurement at a single shot. Compared with traditional technology for MLA measuring, this method not only has a preferable precision but also super efficiency.
J Murray Gibson
2007-01-01
We explore the ability of the pair-distribution function (pdf) to accurately measure medium-range correlation lengths in nanoscale crystalline materials. Through simple computer simulations of disordered fcc metals, we find that the presence of quadratic displacement fields is sufficient to mask topological order (mro) at the medium-range (1–3nm). This reconciles previous measurements and modeling on amorphous silicon—which showed that paracrystalline structures
Correlation of atmospheric optical turbulence and meteorological measurements
Gail M. Tirrell Vaucher
1989-01-01
The correlation of meteorological events such as the jet stream, gravity waves and boundary layer circulation with the optical turbulence parameters, the transverse coherence length r sub o and the isoplanatic angle is essential for interpreting and forecasting imaging and laser systems performance. In support of the United States Air Force Relay Mirror Experiment, the Naval Postgraduate School performed a
Lifetime and diffusion length measurements on silicon material and solar cells
NASA Technical Reports Server (NTRS)
Othmer, S.; Chen, S. C.
1978-01-01
Experimental methods were evaluated for the determination of lifetime and diffusion length in silicon intentionally doped with potentially lifetime-degrading impurities found in metallurgical grade silicon, impurities which may be residual in low-cost silicon intended for use in terrestrial flat-plate arrays. Lifetime measurements were made using a steady-state photoconductivity method. Diffusion length determinations were made using short-circuit current measurements under penetrating illumination. Mutual consistency among all experimental methods was verified, but steady-state photoconductivity was found preferable to photoconductivity decay at short lifetimes and in the presence of traps. The effects of a number of impurities on lifetime in bulk material, and on diffusion length in cells fabricated from this material, were determined. Results are compared with those obtained using different techniques. General agreement was found in terms of the hierarchy of impurities which degrade the lifetime.
The CEBAF Injector RF Distribution and Bunch-Length Measurement System
Bowling, Bruce; Krafft, Geoffrey; Hovater, J.; Crofford, Mark; Abbott, Richard
1992-08-01
The CEBAF injector includes 22 RF control modules which require an intermediate frequency (IF) of 70 MHz and a local oscillator (LO) frequency of 1427 MHz. A STAR network distributes the signals over coaxial cables that are of equal length so that all systems see the same phase drifts due to ambient temperature changes. To obtain the signal levels required by the individual RF control modules, amplifiers are used in both the LO and IF distribution. Temperature-dependent phase drifts associated with the amplifiers are minimized by a phase-lock loop around each amplifier. In addition to the frequency distributio, an automated beam bunch-length measurement is incorporated in the chopper cavities' intermediate frequency. This allows the phase of the chopper cavities to be modulated and bunch-length measurements to be performed on the electron beam downstream.
NASA Astrophysics Data System (ADS)
Kabi, S.; Ghosh, A.
2012-10-01
We have presented conductivity spectra at different temperatures for mixed network former silver borophosphate glasses. By mapping the conductivity spectra onto time dependence of the mean square displacement of mobile ions in the framework of linear response theory, we have obtained two characteristic lengths of ion dynamics viz characteristic mean square displacement at which crossover from diffusive to subdiffusive ion dynamics and spatial extent of localized motion of mobile silver ions occur. We have shown that the mixed network effect in these glasses is correlated to these characteristic lengths which are strongly influenced by the Coulomb repulsion between the mobile silver ions as well as the interaction between the mobile ions and the glass network.
Benwell, Christopher S Y; Harvey, Monika; Thut, Gregor
2014-02-01
Healthy participants tend to show systematic biases in spatial attention, usually to the left. However, these biases can shift rightward as a result of a number of experimental manipulations. Using electroencephalography (EEG) and a computerized line bisection task, here we investigated for the first time the neural correlates of changes in spatial attention bias induced by line-length (the so-called line-length effect). In accordance with previous studies, an overall systematic left bias (pseudoneglect) was present during long line but not during short line bisection performance. This effect of line-length on behavioral bias was associated with stronger right parieto-occipital responses to long as compared to short lines in an early time window (100-200ms) post-stimulus onset. This early differential activation to long as compared to short lines was task-independent (present even in a non-spatial control task not requiring line bisection), suggesting that it reflects a reflexive attentional response to long lines. This was corroborated by further analyses source-localizing the line-length effect to the right temporo-parietal junction (TPJ) and revealing a positive correlation between the strength of this effect and the magnitude by which long lines (relative to short lines) drive a behavioral left bias across individuals. Therefore, stimulus-driven left bisection bias was associated with increased right hemispheric engagement of areas of the ventral attention network. This further substantiates that this network plays a key role in the genesis of spatial bias, and suggests that post-stimulus TPJ-activity at early information processing stages (around the latency of the N1 component) contributes to the left bias. PMID:24128738
Khan, A O
2006-01-01
Aim To compare paediatric axial length values estimated from the aphakic refraction alone with axial length values measured by ultrasound. Methods Retrospective institutional medical record review of paediatric aphakic patients 12?years of age and younger with documented ultrasonic axial length and objective refraction (retinoscopy) within 3?months of each other. An estimate of axial length was made from the aphakic refraction alone (with an assumed average keratometry value of 44?dioptres) for all patients. Results 149 eyes of 102 paediatric aphakic patients were identified. The ultrasonic axial length values (mean 22.47?mm, SD 1.69, 95% confidence interval (CI) 0.27) and estimated axial length values (mean 22.41?mm, SD 1.53, 95% CI 0.25) had an average difference of 0.05?mm (SD 1.04, 95% CI 0.17) and were not significantly different (p?=?0.56) by the two tailed paired t test. A histogram of the differences that did exist between the two values resembled a normal distribution. The nine eyes with the largest differences between the two values had either low hyperopic aphakic refractions or abnormal average keratometry values. Conclusions There was no significant difference between the two groups of axial length values, and the distribution of differences that did exist seemed random. The greatest differences between the two values occurred in longer (less hyperopic) eyes and in eyes with abnormally steep or flat keratometry. Estimation of axial length from the aphakic refraction alone seems to be a useful technique in the average paediatric eye, especially if biometry is unavailable. PMID:16707524
Technology Transfer Automated Retrieval System (TEKTRAN)
Hydrologic and morphological properties of claypan landscapes cause variability in soybean root and shoot biomass. This study was conducted to develop predictive models of soybean root length density distribution (RLDd) using direct measurements and sensor based estimators of claypan morphology. A c...
ERIC Educational Resources Information Center
Smith, John P., III; Males, Lorraine M.; Dietiker, Leslie C.; Lee, KoSze; Mosier, Aaron
2013-01-01
Extensive research has shown that elementary students struggle to learn the basic principles of length measurement. However, where patterns of errors have been documented, the origins of students' difficulties have not been identified. This study investigated the hypothesis that written elementary mathematics curricula contribute to the…
The results are shown in Tables 1 and 2. For line-length measurements, using
Zhang, Yanli
significantly with the inclusion of GLONASS and ranged from 5.04 percent with a GPS + GLONASS combination and 3.66 percent with a GPS + GLONASS + WAAS combination. Why might the accuracy of the length and area measurements decline when GLONASS is used? One possible expla- nation is that the GLONASS signal is not being
A New Path Length Measure Based on GO for Gene Similarity with Evaluation Using SGD Pathways
Al-Mubaid, Hisham
A New Path Length Measure Based on GO for Gene Similarity with Evaluation Using SGD Pathways Anurag methods in certain cases. Keywords: Gene similarity, GO term similarity, Gene similarity in SGD. 1. Introduction One of the greatest projects in bioinformatics is the Gene Ontology (GO) [2]. GO is a controlled
Diffusion length measurements in solar cells: An analysis and comparison of techniques
NASA Technical Reports Server (NTRS)
Woollam, J. A.; Khan, A. A.; Soukup, R. J.; Hermann, A. M.
1982-01-01
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.
A COMPARISON OF CALCULATED AND MEASURED DEBOND LENGTHS FROM FIBER PUSH-OUT TESTS
Sottos, Nancy R.
A COMPARISON OF CALCULATED AND MEASURED DEBOND LENGTHS FROM FIBER PUSH-OUT TESTS V. T. Bechela the progressive debonding load/de¯ection data from ®ber push-out tests conducted on a polyester/epoxy model, C. ®nite-element analysis 1 INTRODUCTION The ®ber push-out test has become a popular method
Measuring the effects of geographical distance on stock market correlation
Schmidt, Volker
Measuring the effects of geographical distance on stock market correlation Stefanie Eckela , Gunter, Germany Abstract Recent studies suggest that the correlation of stock returns increases with decreasing it with an approach from spatial statistics, the mark correlation function. For the stocks contained in the S&P 500
NASA Astrophysics Data System (ADS)
Wei, Guo-Qing; Qian, JianZhong; Chen, Eric; Engdahl, John
2000-06-01
Body motion and heart upward creep are among the most frequent sources of artifacts in the single-photon emission computed tomography (SPECT) of nuclear medicine. This paper provides a new method for automatic correction of such motions. Under the formulation of a variable length correlation, abrupt body motions, gradual body motions, and heart upward creep are corrected in sequential passes. An affine transformation is used to compensate for changes in heart appearance caused by varying view angles in image acquisition. Additionally, a method is proposed for automatic exclusion of non-cardiac organs. The effectiveness of the method has been demonstrated with experimental results.
Hogan, Conor; Palummo, Maurizia; Gierschner, Johannes; Rubio, Angel
2013-01-14
Excited states of ethylene-linked free-base porphyrin oligomers and polymer are studied using many-body perturbation theory (MBPT) within the GW approximation and the Bethe-Salpeter equation. Trends in the electronic levels with oligomer length are analysed and the correct long-range behaviour in the band gap is obtained. High polarizabilities and strong redshifts in the optical absorption peaks are predicted in agreement with observations on other strongly conjugated oligoporphyrins. We explain these trends by means of spatial and spectral analyses of the exciton character. Although Wannier-Mott and charge-transfer excitons are identified in the optical spectra, the strongest polarizabilities are actually associated with small, tightly bound excitons (Frenkel-like), in contrast to expectations. Furthermore, the common procedure of extrapolating polymer properties from oligomer calculations is examined from a MBPT perspective. PMID:23320688
Spatial correlation of measured unsteady surface pressure behind a backward-facing step
NASA Astrophysics Data System (ADS)
Bilka, Michael J.; Paluta, Mark R.; Silver, Jonathan C.; Morris, Scott C.
2015-02-01
The spatial correlations of the unsteady surface pressure for a backward-facing step were studied experimentally. The measurements were acquired using an array of surface pressure sensors within an anechoic wind tunnel which was designed to minimize acoustic contamination. The maximum Reynolds number based on the step height was 59,200. The spatial characteristics of the surface pressure were studied in two parts. First, a linear array of microphones oriented in the streamwise direction was used to obtain the evolution of the pressure spectra, length scale, and phase speed. Second, an array oriented in the spanwise direction was used to provide the coherence and integral length scales in that direction. The correlation length functions were found to vary with downstream location in the separated region behind the step. After reattachment, the integral scales of the surface pressure continued to increase in magnitude as far as 18 step heights downstream of the step.
NASA Astrophysics Data System (ADS)
Ketter, W.; Heil, W.; Badurek, G.; Baron, M.; Jericha, E.; Loidl, R.; Rauch, H.
2006-02-01
Improved knowledge of the real part of the neutron scattering length of 3He is important for further development of nuclear few-body theory, as well as for a thorough understanding of neutron scattering off quantum liquids. The real part of the bound incoherent neutron scattering length b i' has recently been measured directly with an experimental uncertainty of better than 1% by means of spin echo spectrometry. The uncertainty of the more fundamental bound multiplet scattering lengths b ±' is thus limited by today's 1.2% uncertainty of the spin-independent coherent part b c'. Employing the skew-symmetric perfect crystal Si-interferometer at the S18 experimental site at ILL, Grenoble, we have re-measured the real part of the bound coherent neutron scattering length b c' of 3He. Our result b c' = 6.010(21)fm exhibits a significant deviation compared to the latest accepted value b c' = 5.74(7)fm (H. Kaiser, H. Rauch, G. Badurek, W. Bauspiess, U. Bonse, Z. Phys. A 291, 231 (1979)). Including the known value of the incoherent neutron scattering length, we obtain new values for the real parts of the free singlet and triplet scattering lengths, a -' = 7.573(30)fm and a +' = 3.480(18)fm. Our result contravenes by more than 7 standard deviations the measurement of the same physical quantity that has recently been performed by a group at NIST in a very similar experiment (P.R. Huffman, D.L. Jacobson, K. Schoen, M. Arif, T.C. Black, W.M. Snow, S.A. Werner, Phys. Rev. C 70, 014004 (2004)) which yielded b c' = 5.853(7)fm.
Quantum discord and other measures of quantum correlation
Modi, Kavan; Cable, Hugo; Paterek, Tomasz; Vedral, Vlatko
2011-01-01
One of the best signatures of nonclassicality in a quantum system is the existence of correlations that have no classical counterpart. Different methods for quantifying the quantum and classical parts of the correlations are amongst the most actively-studied topics of quantum information theory in the past decade. Entanglement is the most prominent of these correlations, but in many cases unentangled states exhibit nonclassical behavior. Thus distinguishing quantum correlation other than entanglement provides a better division between the quantum and classical worlds, especially when considering mixed states. Here we review different notions of classical and quantum correlations quantified by quantum discord and other related measures. In the first half we review the mathematical properties of the measures of quantum correlation, relate them to each other, and discuss the classical-quantum division that is common among them. In the second half, we show that the measures quantum correlation identify and quanti...
A class of repeated measures concordance correlation coefficients.
King, Tonya S; Chinchilli, Vernon M; Wang, Kai-Ling; Carrasco, Josep L
2007-01-01
The repeated measures concordance correlation coefficient was proposed for measuring agreement between two raters or two methods of measuring a response in the presence of repeated measurements (King et al., 2007). This paper proposes a class of repeated measures concordance correlation coefficients that are appropriate for both continuous and categorical data. We illustrate the methodology with examples comparing (1) 1-hour vs. 2-hour blood draws for measuring cortisol in an asthma clinical trial, (2) two measurements of percentage body fat, from skinfold calipers and dual energy x-ray absorptiometry, and (3) two binary measures of quality of health from an asthma clinical trial. PMID:17613646
Park, So Yeong; Hong, Chung Ki [Department of Physics, POSTECH, Pohang 790-784 (Korea, Republic of)] [Department of Physics, POSTECH, Pohang 790-784 (Korea, Republic of); Lim, Jun, E-mail: limjun@postech.ac.kr [Pohang Accelerator Laboratory, POSTECH, Pohang 790-784 (Korea, Republic of)] [Pohang Accelerator Laboratory, POSTECH, Pohang 790-784 (Korea, Republic of)
2014-04-15
We measured the spatial coherence length and incoherent source size of a hard x-ray undulator beamline at Pohang Light Source-II, the stored electron energy of which has been increased from 2.5 GeV to 3 GeV. The coherence length was determined by single-slit measurement of the visibility of the Fresnel diffraction pattern. The correlated incoherent source size was cross-checked for three different optics: the single slit, beryllium parabolic compound refractive lenses, and the Fresnel zone plate. We concluded that the undulator beamline has an effective incoherent source size (FWHM) of 540 ?m (horizontal) × 50 ?m (vertical)
NASA Technical Reports Server (NTRS)
Pandey, P. C.; Kakar, R. K.
1983-01-01
Numerical experiments using regressions by leaps and bounds have been performed to determine the optimum frequencies for satellite-borne microwave radiometers to estimate atmospheric electrical path length over the sea. The frequency range 5-40 GHz was searched. The effect of surface wind speed, sea surface temperature, and clouds was considered in the optimum frequency selection. The analysis indicates that approximately 0.6-cm rms accuracy is possible for one-way path length measurement using a proper pair of frequencies. The best two-channel subset selected by the leaps and bounds techniques is (16.0, 21.0) GHz.
On the irreversibility of measurements of correlations
NASA Astrophysics Data System (ADS)
Koashi, Masato
2009-12-01
Measurements on a bipartite system AB are classified into ones that are freely implementable with only classical communication between A and B (LOCC measurements), and the others that require consumption of entanglement if they are to be implemented with classical communication. When we notice that measurements on a bipartite system can also be used to create entanglement, we have another natural classification: measurements that are capable of creating entanglement, and the others that have no ability of producing entanglement (separable measurements). Interestingly, there exists a separable measurement that is not an LOCC measurement, namely, a measurement that requires entanglement to implement, but is not capable of creating entanglement at all. Such an example was found for a pair of three-level systems, in conjunction with a discrimination task of an intricate set of eight or nine states. Here we show an example of such a measurement on a pair of two-level systems (qubits), which arises in a discrimination task of just two states that look quite simple and have little intricacy. Such an example suggests that this kind of irreversibility is not only shown by a limited set of cleverly constructed measurements, but is also exhibited by a much larger class of measurements than we had expected.
Correlation measures in bipartite states and entanglement irreversibility
Shengjun Wu
2012-07-24
We derive quantitative relations among several naturally defined measures of classical and nonclassical correlations in a bipartite quantum state. We also obtain an upper bound of entanglement irreversibility and a sufficient condition for reversible entanglement. The additivity of entanglement of formation is directly related to the additivity of quantum discord as well as a certain measure of classical correlation.
Measurement of Two-Plasmon-Decay Dependence on Plasma Density Scale Length
NASA Astrophysics Data System (ADS)
Haberberger, D.
2013-10-01
An accurate understanding of the plasma scale-length (Lq) conditions near quarter-critical density is important in quantifying the hot electrons generated by the two-plasmon-decay (TPD) instability in long-scale-length plasmas. A novel target platform was developed to vary the density scale length and an innovative diagnostic was implemented to measure the density profiles above 1021 cm-3 where TPD is expected to have the largest growth. A series of experiments was performed using the four UV (351-nm) beams on OMEGA EP that varied the Lq by changing the radius of curvature of the target while maintaining a constant Iq/Tq. The fraction of laser energy converted to hot electrons (fhot) was observed to increase rapidly from 0.005% to 1% by increasing the plasma scale length from 130 ?m to 300 ?m, corresponding to target diameters of 0.4 mm to 8 mm. A new diagnostic was developed based on refractometry using angular spectral filters to overcome the large phase accumulation in standard interferometric techniques. The angular filter refractometer measures the refraction angles of a 10-ps, 263-nm probe laser after propagating through the plasma. An angular spectral filter is used in the Fourier plane of the probe beam, where the refractive angles of the rays are mapped to space. The edges of the filter are present in the image plane and represent contours of constant refraction angle. These contours are used to infer the phase of the probe beam, which are used to calculate the plasma density profile. In long-scale-length plasmas, the diagnostic currently measures plasma densities from ~1019 cm-3 to ~2 × 1021 cm-3. This material is based upon work supported by the Department of Energy National Nuclear Security Administration under Award Number DE-NA0001944. An accurate understanding of the plasma scale-length (Lq) conditions near quarter-critical density is important in quantifying the hot electrons generated by the two-plasmon-decay (TPD) instability in long-scale-length plasmas. A novel target platform was developed to vary the density scale length and an innovative diagnostic was implemented to measure the density profiles above 1021 cm-3 where TPD is expected to have the largest growth. A series of experiments was performed using the four UV (351-nm) beams on OMEGA EP that varied the Lq by changing the radius of curvature of the target while maintaining a constant Iq/Tq. The fraction of laser energy converted to hot electrons (fhot) was observed to increase rapidly from 0.005% to 1% by increasing the plasma scale length from 130 ?m to 300 ?m, corresponding to target diameters of 0.4 mm to 8 mm. A new diagnostic was developed based on refractometry using angular spectral filters to overcome the large phase accumulation in standard interferometric techniques. The angular filter refractometer measures the refraction angles of a 10-ps, 263-nm probe laser after propagating through the plasma. An angular spectral filter is used in the Fourier plane of the probe beam, where the refractive angles of the rays are mapped to space. The edges of the filter are present in the image plane and represent contours of constant refraction angle. These contours are used to infer the phase of the probe beam, which are used to calculate the plasma density profile. In long-scale-length plasmas, the diagnostic currently measures plasma densities from ~1019 cm-3 to ~2 × 1021 cm-3. This material is based upon work supported by the Department of Energy National Nuclear Security Administration under Award Number DE-NA0001944. In collaboration with D. H. Edgell, S. X. Hu, S. Ivancic, R. Boni, C. Dorrer, and D. H. Froula (Laboratory for Laser Energetics, U. of Rochester).
Family-portraits for daphnids: scanning living individuals and populations to measure body length.
Agatz, Annika; Hammers-Wirtz, Monika; Gergs, Andre; Mayer, Tanja; Preuss, Thomas G
2015-08-01
A method has been developed and tested to determine the body length of living daphnids. The purpose of the method was the simple, accurate, repeatable, quick, and to the living organism, harmless measurement of body length of all individuals in a population to enhance the capability of observing population development over time. Generally, organisms are transferred to a petri dish and temporarily fixed by removing access medium. A picture of the petri dish is taken using an ordinary flatbed scanner. Pictures are manually analysed with purposely developed software. We found no significant impact of the method on either individual performance (growth and reproduction) or population development (abundance and structure) of daphnids in comparison to the previously used method for data gathering (sieving, counting and length measurement of a subsample via microscopy). The disadvantage of our method, an increased demand in time for picture analysis, is negligible compared to the advantages this method has. Data generated with the new method do represent the population structure more accurately than those data generated with the previously used method. Scanning organisms does also allow a retrospective quality control for generated data as pictures can securely be stored. The quality of the pictures is furthermore sufficient to include additional endpoints to the analysis (e.g., number and size of aborts, number and size of eggs in the brood pouch, spine length). Here, we present, test and discuss an alternative approach to automated image analysis for data gathering in single and multiple individual and species experiments. PMID:26048239
Precision measurement of the n-4He scattering length using neutron interferometry
NASA Astrophysics Data System (ADS)
Huber, M. G.; Arif, M.; Jacobson, D. L.; Pushin, D. A.; Abutaleb, M. O.; Black, T. C.; Shahi, C. B.; Wietfeldt, F. E.
2010-11-01
The NIST neutron interferometer and optics facility (NIOF) is currently performing a precision measurement of the n-4He scattering length to less than 0.3% relative uncertainty. A neutron interferometer consists of a perfect silicon crystal machined such that there are three separate blades on a common base. Neutrons entering the interferometer are Bragg diffracted in the blades to produce two spatially separate yet coherent beam paths much like an optical Mach-Zehnder interferometer. A sample placed in one of the beam paths of the interferometer causes a phase difference between the two paths. This phase difference is directly related to the sample's scattering length. Neutron scattering lengths are one parameter that can be predicted using advanced theoretical models describing two and three nucleon interactions. In an effort to provide tests and/or benchmarks of these theoretical models, the NIOF has already performed precision measurements of neutron scattering lengths to less than 1% relative uncertainty in several low Z gases: H, D, 3He, and polarized 3He. A preliminary result of this work will be given.
Increasing the length of tubular objects that can be measured using acoustic pulse reflectometry
NASA Astrophysics Data System (ADS)
Sharp, D. B.
1998-09-01
Acoustic pulse reflectometry is a non-invasive technique for measuring the internal dimensions of tubular objects. A sound pulse is produced using a loudspeaker and injected into the object under investigation via a source tube. The resultant object reflections are recorded by a microphone embedded in the wall of the source tube. Analysis of the reflections yields information about the bore profile of the object. At present, there is a restriction on the length of object that can be measured using the standard reflectometer. This restriction arises because after the object reflections pass the microphone they undergo further reflection at the loudspeaker. These source reflections return to the microphone as unwanted signal. Hence, there is only a finite time over which the object reflections can be accurately recorded which, in turn, limits the length of object that can be measured. In this paper, a method for removing the length restriction is described. The method involves the cancellation of the incoming object reflections at the loudspeaker, thus preventing the formation of source reflections. The results achieved indicate the potential of the method for accurate measurement of longer objects.
Adherence to Criteria for Transvaginal Ultrasound Imaging and Measurement of Cervical Length
Iams, JD; Grobman, WA; Lozitska, A; Spong, CY; Saade, G; Mercer, BM; Tita, AN; Rouse, DJ; Sorokin, Y; Wapner, RJ; Leveno, KJ; Esplin, MS; Tolosa, JE; Thorp, JM; Caritis, SN; Van Dorsten, JP
2014-01-01
Background Adherence to published criteria for transvaginal imaging and measurement of cervical length is uncertain. We sought to assess adherence by evaluating images submitted to certify research sonographers for participation in a clinical trial. Study Design We reviewed qualifying test results of sonographers seeking certification to image and measure cervical length in a clinical trial. Participating sonographers were required to access training materials and submit 15 images, three each from five pregnant women not enrolled in the trial. One of two sonologists reviewed all qualifying images. We recorded the proportion of images that did not meet standard criteria (excess compression, landmarks not seen, improper image size, or full maternal bladder) and the proportion in which the cervical length was measured incorrectly. Failure for a given patient was defined as more than one unacceptable image, or more than two acceptable images with incorrect caliper placement or erroneous choice of the “shortest best” cervical length. Certification required satisfactory images and cervical length measurement from four or more patients. Results 327 sonographers submitted 4905 images. 271 sonographers (83%) were certified on the first, 41 (13%) on the second, and 2 (0.6%) on the third submission. 13 never achieved certification. Of 314 who passed, 196 submitted 15 acceptable images that were appropriately measured for all five women. There were 1277 deficient images: 493 were acceptable but incorrectly measured images from sonographers who passed certification because mis-measurement occurred no more than twice. Of 784 deficient images submitted by sonographers who failed the certification, 471 were rejected because of improper measurement (caliper placement and/or failure to identify the shortest best image), and 313 because of failure to obtain a satisfactory image (excessive compression, required landmarks not visible, incorrect image size, brief examination, and/or full maternal bladder) Conclusion Although 83% of sonographers were certified on their first submission, more than one in four ultrasound images submitted did not meet published quality criteria. Increased attention to standardized education and credentials is warranted for persons who perform ultrasound examinations of the cervix in pregnancy. PMID:23958649
Kim, Jin-Woo; Lee, Dong-Gi
2014-10-01
During the compression molding of fiber-reinforced plastic composites, there are two issues: one is separation of fiber and matrix because of the different flow state and fiber orientation. Due to separation and orientation, moldings become nonhomogeneous, and show anisotropy. Therefore, separation and orientation should be closely corresponded to molding condition and fiber structure. If fiber shows strong agglomeration, it increases the separation, but fiber orientation will be limited. That is, separation and orientation of fiber is closely related, and the relationship should be clearly defined. In this study, fiber content and length is varied for stacked laminates, and primary sheet is fabricated with thermal compression press. Primary sheet is heated and molded with 30-ton hydraulic press. Nonhomogeneity, one of indicators for separation, is measured from one-dimensional rectangular plate after compression. Orientation function is calculated using X-ray image on moldings and image scanner for processing imagery data. From the correlation between the separation and the orientation of fiber and matrix, the correlation coefficient is defined, and the impact of fiber length on the coefficient is evaluated. PMID:25942851
Homodyne detection for measuring internal quantum correlations of optical pulses
T. Opatrny; D. -G. Welsch; W. Vogel
1996-03-28
A new method is described for determining the quantum correlations at different times in optical pulses by using balanced homodyne detection. The signal pulse and sequences of ultrashort test pulses are superimposed, where for chosen distances between the test pulses their relative phases and intensities are varied from measurement to measurement. The correlation statistics of the signal pulse is obtained from the time-integrated difference photocurrents measured.
Diffusion length measurements of thin GaAs solar cells by means of energetic electrons
NASA Technical Reports Server (NTRS)
Vonross, O.
1980-01-01
A calculation of the short circuit current density (j sub sc) of a thin GaAs solar cell induced by fast electrons is presented. It is shown that in spite of the disparity in thickness between the N-type portion of the junction and the P-type portion of the junction, the measurement of the bulk diffusion length L sub p of the N-type part of the junction is seriously hampered due to the presence of a sizable contribution to the j sub sc from the P-type region of the junction. Corrections of up to 50% had to be made in order to interpret the data correctly. Since these corrections were not amenable to direct measurements it is concluded that the electron beam method for the determination of the bulk minority carrier diffusion length, which works so well for Si solar cells, is a poor method when applied to thin GaAs cells.
Direct measurements of in-cylinder integral length scales of a transparent engine
NASA Astrophysics Data System (ADS)
Hong, C. W.; Chen, D. G.
This paper presents a hardware technology and its accompanying software developed to measure the in-cylinder integral length scales of the flow inside a transparent four-stroke engine directly, using a fiber laser Doppler velocimeter (LDV). A traverse table was designed to combine two 1-component fiber optical probes to form an LDV system with the capability of both 2-component single-point and 1-component two-point simultaneous measurements for velocities. This paper demonstrates the evaluation of radially separated lateral and longitudinal integral length scales. The location was at a mid-plane of the top dead center (TDC) clearance height, and the engine was motored at a speed of 500 rpm. Data analysis was processed using statistical techniques and the physical meaning of the results was explained.
Measurement of the KL nuclear interaction length in the NaI(Tl) calorimeter
NASA Astrophysics Data System (ADS)
Achasov, M. N.; Beloborodov, K. I.; Berdyugin, A. V.; Bogdanchikov, A. G.; Vasiljev, A. V.; Golubev, V. B.; Dimova, T. V.; Druzhinin, V. P.; Korol, A. A.; Koshuba, S. V.; Pakhtusova, E. V.; Serednyakov, S. I.; Silagadze, Z. K.; Usov, Yu. V.
2015-09-01
In the study of the reaction e+e?? KSKL at the VEPP-2M e+e? collider with the SND detector the nuclear interaction length of KL meson in NaI(Tl) has been measured. Its value is found to be 30–50 cm in the KL momentum range 0.11–0.48 GeV/c. The results are compared with the values used in the simulation programs GEANT4 and UNIMOD.
Minority carrier diffusion length measurements - A review and comparison of techniques
NASA Technical Reports Server (NTRS)
Khan, A. A.; Woollam, J. A.; Hermann, A. M.
1982-01-01
A review of the major techniques for measuring minority carrier diffusion lengths in solar cells is given. Limits of applicability are indicated for each method, as relevant to indirect bandgap materials such as silicon, and direct bandgap materials like gallium arsenide. A discussion and bibliography is presented for the following techniques: uniform generation, electron beam induced current, Schottky barrier (and other steady-state) photocurrent, surface photovoltage, transient decay, and luminescence.
Filippetto, D.; /Frascati; Sannibale, F.; Zolotorev, Max Samuil; /LBL, Berkeley; Stupakov, G.V.; /SLAC
2008-01-24
By analyzing the pulse to pulse intensity fluctuations of the radiation emitted by a charge particle in the incoherent part of the spectrum, it is possible to extract information about the spatial distribution of the beam. At the Advanced Light Source (ALS) of the Lawrence Berkeley National Laboratory, we have developed and tested a simple scheme based on this principle that allows for the absolute measurement of the bunch length. A description of the method and the experimental results are presented.
Ultrasonic measurement of stress in railroad wheels and in long lengths of welded rail
NASA Technical Reports Server (NTRS)
Clotfelter, W. N.; Risch, E. R.
1974-01-01
The failure of high speed emergency braking is discussed for railroad wheels and track. It is shown that high compressive residual stresses exist in the rims of new wheels which generate excessive heat, reducing the stress levels. Thermal stresses that build up in continuous lengths of welded track are reported and nondestructive methods of measuring stresses in thick steel are presented for identification, replacement, or adjustment before hazardous failures occur.
Isotopic fractionation in proteins as a measure of hydrogen bond length
NASA Astrophysics Data System (ADS)
McKenzie, Ross H.; Athokpam, Bijyalaxmi; Ramesh, Sai G.
2015-07-01
If a deuterated molecule containing strong intramolecular hydrogen bonds is placed in a hydrogenated solvent, it may preferentially exchange deuterium for hydrogen. This preference is due to the difference between the vibrational zero-point energy for hydrogen and deuterium. It is found that the associated fractionation factor ? is correlated with the strength of the intramolecular hydrogen bonds. This correlation has been used to determine the length of the H-bonds (donor-acceptor separation) in a diverse range of enzymes and has been argued to support the existence of short low-barrier H-bonds. Starting with a potential energy surface based on a simple diabatic state model for H-bonds, we calculate ? as a function of the proton donor-acceptor distance R. For numerical results, we use a parameterization of the model for symmetric O-H⋯O bonds [R. H. McKenzie, Chem. Phys. Lett. 535, 196 (2012)]. We consider the relative contributions of the O-H stretch vibration, O-H bend vibrations (both in plane and out of plane), tunneling splitting effects at finite temperature, and the secondary geometric isotope effect. We compare our total ? as a function of R with NMR experimental results for enzymes, and in particular with an earlier model parametrization ?(R), used previously to determine bond lengths.
Isotopic fractionation in proteins as a measure of hydrogen bond length.
McKenzie, Ross H; Athokpam, Bijyalaxmi; Ramesh, Sai G
2015-07-28
If a deuterated molecule containing strong intramolecular hydrogen bonds is placed in a hydrogenated solvent, it may preferentially exchange deuterium for hydrogen. This preference is due to the difference between the vibrational zero-point energy for hydrogen and deuterium. It is found that the associated fractionation factor ? is correlated with the strength of the intramolecular hydrogen bonds. This correlation has been used to determine the length of the H-bonds (donor-acceptor separation) in a diverse range of enzymes and has been argued to support the existence of short low-barrier H-bonds. Starting with a potential energy surface based on a simple diabatic state model for H-bonds, we calculate ? as a function of the proton donor-acceptor distance R. For numerical results, we use a parameterization of the model for symmetric O-H?O bonds [R. H. McKenzie, Chem. Phys. Lett. 535, 196 (2012)]. We consider the relative contributions of the O-H stretch vibration, O-H bend vibrations (both in plane and out of plane), tunneling splitting effects at finite temperature, and the secondary geometric isotope effect. We compare our total ? as a function of R with NMR experimental results for enzymes, and in particular with an earlier model parametrization ?(R), used previously to determine bond lengths. PMID:26233131
NASA Astrophysics Data System (ADS)
Hu, Q.; Qiu, J.; Krucker, S.; Wang, L.; Wang, B.; Chen, Y.; Moestl, C.
2014-12-01
We report on the detailed and systematic study of field-line twist and length distributions within magnetic flux ropes embedded in Interplanetary Coronal Mass Ejections (ICMEs). In particular we will utilize energetic electron burst observations at 1 AU together with associated type III radio emissions detected by the Wind spacecraft to provide unique measurements of magnetic field-line lengths within selected ICME events. These direct measurements will be compared with flux-rope model calculations to help assess the fidelity of different models and to provide diagnostics of internal structures. The Grad-Shafranov reconstruction method will be utilized together with a constant-twist nonlinear force-free (Gold-Hoyle) flux rope model and the commonly known Lundquist (linear force-free) model to reveal the close relation between the field-line twist and length in cylindrical flux ropes, based on in-situ Wind spacecraft magnetic field and plasma measurements. We show that our initial analysis of field-line twist indicates clear deviation from the Lundquist model, but better consistency with the Gold-Hoyle model. We will also discuss the implications of our analysis of flux-rope structures on the origination and evolution processes in their corresponding solar source regions.
Zhou, Guang-Quan; Chan, Phoebe; Zheng, Yong-Ping
2015-03-01
Muscle imaging is a promising field of research to understand the biological and bioelectrical characteristics of muscles through the observation of muscle architectural change. Sonomyography (SMG) is a technique which can quantify the real-time architectural change of muscles under different contractions and motions with ultrasound imaging. The pennation angle and fascicle length are two crucial SMG parameters to understand the contraction mechanics at muscle level, but they have to be manually detected on ultrasound images frame by frame. In this study, we proposed an automatic method to quantitatively identify pennation angle and fascicle length of gastrocnemius (GM) muscle based on multi-resolution analysis and line feature extraction, which could overcome the limitations of tedious and time-consuming manual measurement. The method started with convolving Gabor wavelet specially designed for enhancing the line-like structure detection in GM ultrasound image. The resulting image was then used to detect the fascicles and aponeuroses for calculating the pennation angle and fascicle length with the consideration of their distribution in ultrasound image. The performance of this method was tested on computer simulated images and experimental images in vivo obtained from normal subjects. Tests on synthetic images showed that the method could identify the fascicle orientation with an average error less than 0.1°. The result of in vivo experiment showed a good agreement between the results obtained by the automatic and the manual measurements (r=0.94±0.03; p<0.001, and r=0.95±0.02, p<0.001). Furthermore, a significant correlation between the ankle angle and pennation angle (r=0.89±0.05; p<0.001) and fascicle length (r=-0.90±0.04; p<0.001) was found for the ankle plantar flexion. This study demonstrated that the proposed method was able to automatically measure the pennation angle and fascicle length of GM ultrasound images, which made it feasible to investigate muscle-level mechanics more comprehensively in vivo. PMID:25465963
Parikh, Harsh; Singh, Apoorvi; Krishnamachari, Annangarachari; Shah, Kushal
2015-02-01
We have carried out an analysis on 500 bacterial genomes and found that the de-facto GC skew method could predict the replication origin site only for 376 genomes. We also found that the auto-correlation and cross-correlation based methods have a similar prediction performance. In this paper, we propose a new measure called correlated entropy measure (CEM) which is able to predict the replication origin of all these 500 bacterial genomes. The proposed measure is context sensitive and thus a promising tool to identify functional sites. The process of identifying replication origins from the output of CEM and other methods has been automated to analyze a large number of genomes in a faster manner. We have also explored the applicability of SVM based classification of the workability of each of these methods on all the 500 bacterial genomes based on its length and GC content. PMID:25576764
Dogandži?, Tamara; Braun, David R.; McPherron, Shannon P.
2015-01-01
Blank size and form represent one of the main sources of variation in lithic assemblages. They reflect economic properties of blanks and factors such as efficiency and use life. These properties require reliable measures of size, namely edge length and surface area. These measures, however, are not easily captured with calipers. Most attempts to quantify these features employ estimates; however, the efficacy of these estimations for measuring critical features such as blank surface area and edge length has never been properly evaluated. In addition, these parameters are even more difficult to acquire for retouched implements as their original size and hence indication of their previous utility have been lost. It has been suggested, in controlled experimental conditions, that two platform variables, platform thickness and exterior platform angle, are crucial in determining blank size and shape meaning that knappers can control the interaction between size and efficiency by selecting specific core angles and controlling where fracture is initiated. The robustness of these models has rarely been tested and confirmed in context other than controlled experiments. In this paper, we evaluate which currently employed caliper measurement methods result in the highest accuracy of size estimations of blanks, and we evaluate how platform variables can be used to indirectly infer aspects of size on retouched artifacts. Furthermore, we investigate measures of different platform management strategies that control the shape and size of artifacts. To investigate these questions, we created an experimental lithic assemblage, we digitized images to calculate 2D surface area and edge length, which are used as a point of comparison for the caliper measurements and additional analyses. The analysis of aspects of size determinations and the utility of blanks contributes to our understanding of the technological strategies of prehistoric knappers and what economic decisions they made during process of blank production. PMID:26332773
Dogandži?, Tamara; Braun, David R; McPherron, Shannon P
2015-01-01
Blank size and form represent one of the main sources of variation in lithic assemblages. They reflect economic properties of blanks and factors such as efficiency and use life. These properties require reliable measures of size, namely edge length and surface area. These measures, however, are not easily captured with calipers. Most attempts to quantify these features employ estimates; however, the efficacy of these estimations for measuring critical features such as blank surface area and edge length has never been properly evaluated. In addition, these parameters are even more difficult to acquire for retouched implements as their original size and hence indication of their previous utility have been lost. It has been suggested, in controlled experimental conditions, that two platform variables, platform thickness and exterior platform angle, are crucial in determining blank size and shape meaning that knappers can control the interaction between size and efficiency by selecting specific core angles and controlling where fracture is initiated. The robustness of these models has rarely been tested and confirmed in context other than controlled experiments. In this paper, we evaluate which currently employed caliper measurement methods result in the highest accuracy of size estimations of blanks, and we evaluate how platform variables can be used to indirectly infer aspects of size on retouched artifacts. Furthermore, we investigate measures of different platform management strategies that control the shape and size of artifacts. To investigate these questions, we created an experimental lithic assemblage, we digitized images to calculate 2D surface area and edge length, which are used as a point of comparison for the caliper measurements and additional analyses. The analysis of aspects of size determinations and the utility of blanks contributes to our understanding of the technological strategies of prehistoric knappers and what economic decisions they made during process of blank production. PMID:26332773
Multifunctional optical correlator for picosecond ultraviolet laser pulse measurement.
Rakhman, Abdurahim; Wang, Yang; Garcia, Frances; Long, Cary; Huang, Chunning; Takeda, Yasuhiro; Liu, Yun
2014-11-01
A compact multifunctional optical correlator system for pulse width measurement of ultrashort ultraviolet (UV) pulses has been designed and experimentally demonstrated. Both autocorrelation and cross-correlation functions are measured using a single nonlinear crystal, and the switching between two measurements requires no adjustment of phase matching and detector. The system can measure UV pulse widths from sub-picoseconds to 100 ps, and it involves no auxiliary pulse in the measurement. The measurement results on a burst-mode picosecond UV laser show a high-quality performance on speed, accuracy, resolution, and dynamic range. The proposed correlator can be applied to measure any ultrashort UV pulses produced through sum-frequency generation or second-harmonic generation. PMID:25402928
A multifunctional optical correlator for picosecond UV laser pulse measurement
Abudureyimu, Reheman; Wang, Yang; Garcia, Frances; Long, Cary D; Huang, Chunning; Takeda, Yasuhiro; Liu, Yun
2014-01-01
A compact optical correlator system that measures both the autocorrelation between two infrared (IR) lights and the cross-correlation between an IR and an ultraviolet (UV) light using a single nonlinear optical crystal has been designed and experimentally demonstrated. The rapid scanning of optical delay line, switching between auto and cross-correlations, crystal angle tuning, and data acquisition and processing are all computer controlled. Pulse widths of an IR light from a mode-locked laser are measured by the correlator and the results are compared with a direct measurement using a high-speed photodetector system. The correlator has been used to study the parameter dependence of the pulse width of a macropulse UV laser designed for laser-assisted hydrogen ion (H-) beam stripping for the Spallation Neutron Source at Oak Ridge National Laboratory.
Continuous Quantum Measurement with Independent Detector Cross Correlations
NASA Astrophysics Data System (ADS)
Jordan, Andrew N.; Büttiker, Markus
2005-11-01
We investigate the advantages of using two independent, linear detectors for continuous quantum measurement. For single-shot measurement, the detection process may be quantum limited if the detectors are twins. For weak continuous measurement, cross correlations allow a violation of the Korotkov-Averin bound for the detector’s signal-to-noise ratio. The joint weak measurement of noncommuting observables is also investigated, and we find the cross correlation changes sign as a function of frequency, reflecting a crossover from incoherent relaxation to coherent, out of phase oscillations. Our results are applied to a double quantum-dot charge qubit, simultaneously measured by two quantum point contacts.
NASA Astrophysics Data System (ADS)
Duminil-Copin, H.
2012-12-01
Parafermionic observables were introduced by Smirnov for planar Fortuin-Kasteleyn (FK) percolation in order to study the critical phase (p, q) = (pc(q), q). This paper gathers several known properties of these observables. Some of these properties are used to prove the divergence of the correlation length when approaching the critical point for FK percolation when 1 ? q ? 4. A crucial step is to consider FK percolation on the universal cover of the punctured plane. We also mention several conjectures on FK percolation with arbitrary cluster weight q > 0. This article is part of ‘Lattice models and integrability’, a special issue of Journal of Physics A: Mathematical and Theoretical in honour of F Y Wu's 80th birthday.
Correlative measurements of the stratospheric aerosols
NASA Astrophysics Data System (ADS)
Santer, R.; Brogniez, C.; Herman, M.; Diallo, S.; Ackerman, M.
1992-12-01
Joint experiments were organized or available during stratospheric flights of a photopolarimeter, referred to as RADIBAL (radiometer balloon). In May 1984, RADIBAL flew simultaneously with another balloonborne experiment conducted by the Institut d'Aeronomie Spatiale de Belgique (IASB), which provides multiwavelength vertical profiles of the aerosol scattering coefficient. At this time, the El Chichon layer was observable quite directly from mountain sites. A ground-based station set up at Pic du Midi allowed an extensive description of the aerosol optical properties. The IASB and the Pic du Midi observations are consistent with the aerosol properties derived from the RADIBAL measurement analysis.
Entanglement as measure of electronelectron correlation in quantum chemistry calculations
Kais, Sabre
Entanglement as measure of electronelectron correlation in quantum chemistry calculations ZhenÕ to a correlation of quantum nature. He stated that for an entangled state Ôthe best possible knowledge of the whole] there has been a quest for generating entanglement between quantum particles [10,17]. Investigation
Measurement of the transverse spin correlation in Z ? ? + ? - decays
NASA Astrophysics Data System (ADS)
Abreu, P.; Adam, W.; Adye, T.; Ajinenko, I.; Alekseev, G. D.; Alemany, R.; Allport, P. P.; Almehed, S.; Amaldi, U.; Amato, S.; Andersson, P.; Andreazza, A.; Antilogus, P.; Apel, W.-D.; Åsman, B.; Augustin, J.-E.; Augustinus, A.; Baillon, P.; Bambade, P.; Barao, F.; Barbi, M.; Bardin, D. Y.; Barker, G.; Baroncelli, A.; Barring, O.; Bates, M. J.; Battaglia, M.; Baubillier, M.; Baudot, J.; Becks, K.-H.; Begalli, M.; Beilliere, P.; Belokopytov, Yu.; Belous, K.; Benvenuti, A. C.; Berggren, M.; Bertini, D.; Bertrand, D.; Besancon, M.; Bianchi, F.; Bigi, M.; Bilenky, M. S.; Billoir, P.; Bizouard, M.-A.; Bloch, D.; Blume, M.; Bonesini, M.; Bonivento, W.; Booth, P. S. L.; Borgland, A. W.; Borisov, G.; Bosio, C.; Botner, O.; Boudinov, E.; Bouquet, B.; Bourdarios, C.; Bowcock, T. J. V.; Bozovic, I.; Bozzo, M.; Branchini, P.; Brand, K. D.; Brenke, T.; Brenner, R. A.; Bricman, C.; Brown, R. C. A.; Bruckman, P.; Brunet, J.-M.; Bugge, L.; Buran, T.; Burgsmueller, T.; Buschmann, P.; Cabrera, S.; Caccia, M.; Calvi, M.; Camacho Rozas, A. J.; Camporesi, T.; Canale, V.; Canepa, M.; Cao, F.; Carena, F.; Carroll, L.; Caso, C.; Castillo Gimenez, M. V.; Cattai, A.; Cavallo, F. R.; Chabaud, V.; Charpentier, Ph.; Chaussard, L.; Checchia, P.; Chelkov, G. A.; Chen, M.; Chierici, R.; Chliapnikov, P.; Chochula, P.; Chorowicz, V.; Cindro, V.; Collins, P.; Contri, R.; Cortina, E.; Cosme, G.; Cossutti, F.; Cowell, J.-H.; Crawley, H. B.; Crennell, D.; Crosetti, G.; Cuevas Maestro, J.; Czellar, S.; Dahm, J.; Dalmagne, B.; Dam, M.; Damgaard, G.; Dauncey, P. D.; Davenport, M.; da Silva, W.; Deghorain, A.; Della Ricca, G.; Delpierre, P.; Demaria, N.; de Angelis, A.; de Boer, W.; de Brabandere, S.; de Clercq, C.; de La Vaissiere, C.; de Lotto, B.; de Min, A.; de Paula, L.; Dijkstra, H.; di Ciaccio, L.; di Diodato, A.; Djannati, A.; Dolbeau, J.; Doroba, K.; Dracos, M.; Drees, J.; Drees, K.-A.; Dris, M.; Durand, J.-D.; Edsall, D.; Ehret, R.; Eigen, G.; Ekelof, T.; Ekspong, G.; Elsing, M.; Engel, J.-P.; Erzen, B.; Espirito Santo, M.; Falk, E.; Fanourakis, G.; Fassouliotis, D.; Feindt, M.; Ferrari, P.; Ferrer, A.; Fichet, S.; Filippas, T. A.; Firestone, A.; Fischer, P.-A.; Foeth, H.; Fokitis, E.; Fontanelli, F.; Formenti, F.; Franek, B.; Frodesen, A. G.; Fruhwirth, R.; Fulda-Quenzer, F.; Fuster, J.; Galloni, A.; Gamba, D.; Gandelman, M.; Garcia, C.; Garcia, J.; Gaspar, C.; Gasparini, U.; Gavillet, Ph.; Gazis, E. N.; Gele, D.; Gerber, J.-P.; Gokieli, R.; Golob, B.; Goncalves, P.; Gopal, G.; Gorn, L.; Gorski, M.; Gouz, Yu.; Gracco, V.; Graziani, E.; Green, C.; Grefrath, A.; Gris, P.; Grosdidier, G.; Grzelak, K.; Gumenyuk, S.; Gunther, M.; Guy, J.; Hahn, F.; Hahn, S.; Hajduk, Z.; Hallgren, A.; Hamacher, K.; Harris, F. J.; Hedberg, V.; Henriques, R.; Hernandez, J. J.; Herquet, P.; Herr, H.; Hessing, T. L.; Heuser, J.-M.; Higon, E.; Hilke, H. J.; Holmgren, S.-O.; Holt, P. J.; Holthuizen, D.; Hoorelbeke, S.; Houlden, M.; Hrubec, J.; Huet, K.; Hultqvist, K.; Jackson, J. N.; Jacobsson, R.; Jalocha, P.; Janik, R.; Jarlskog, Ch.; Jarlskog, G.; Jarry, P.; Jean-Marie, B.; Johansson, E. K.; Jonsson, L.; Jonsson, P.; Joram, C.; Juillot, P.; Kaiser, M.; Kapusta, F.; Karafasoulis, K.; Karlsson, M.; Katsanevas, S.; Katsoufis, E. C.; Keranen, R.; Khokhlov, Yu.; Khomenko, B. A.; Khovanski, N. N.; King, B.; Kjaer, N. J.; Klapp, O.; Klein, H.; Kluit, P.; Knoblauch, D.; Koene, B.; Kokkinias, P.; Konopliannikov, A.; Koratzinos, M.; Korcyl, K.; Kostioukhine, V.; Kourkoumelis, C.; Kouznetsov, O.; Krammer, M.; Kreuter, C.; Kronkvist, I.; Krumstein, Z.; Krupinski, W.; Kubinec, P.; Kucewicz, W.; Kurvinen, K.; Lacasta, C.; Laktineh, I.; Lamsa, J. W.; Lanceri, L.; Lane, D. W.; Langefeld, P.; Laugier, J.-P.; Lauhakangas, R.; Leder, G.; Ledroit, F.; Lefebure, V.; Legan, C. K.; Leisos, A.; Leitner, R.; Lemonne, J.; Lenzen, G.; Lepeltier, V.; Lesiak, T.; Libby, J.; Liko, D.; Lindner, R.; Lipniacka, A.; Lippi, I.; Loerstad, B.; Loken, J. G.; Lopez, J. M.; Loukas, D.; Lutz, P.; Lyons, L.; MacNaughton, J.; Maehlum, G.; Mahon, J. R.; Maio, A.; Malmgren, T. G. M.; Malychev, V.; Mandl, F.; Marco, J.; Marco, R.; Marechal, B.; Margoni, M.; Marin, J.-C.; Mariotti, C.; Markou, A.; Martinez-Rivero, C.; Martinez-Vidal, F.; Marti I Garcia, S.; Matorras, F.; Matteuzzi, C.; Matthiae, G.; Mazzucato, M.; Mc Cubbin, M.; Mc Kay, R.; Mc Nulty, R.; Medbo, J.; Merk, M.; Meroni, C.; Meyer, S.; Meyer, W. T.; Miagkov, A.; Michelotto, M.; Migliore, E.; Mirabito, L.; Mitaroff, W. A.; Mjoernmark, U.; Moa, T.; Moeller, R.; Moenig, K.; Monge, M. R.; Morettini, P.; Mueller, H.; Muenich, K.; Mulders, M.; Mundim, L. M.; Murray, W. J.; Muryn, B.; Myatt, G.; Naraghi, F.; Navarria, F. L.; Navas, S.; Nawrocki, K.; Negri, P.; Nemecek, S.; Neumann, W.; Neumeister, N.; Nicolaidou, R.; Nielsen, B. S.
1997-02-01
The measurement of the correlation between the transverse spin components of ? + ? - pairs collected during 1992 to 1994 with the DELPHI detector at LEPI is presented. A value C ? = 0.87 ± 0.20 (stat.) -0.12+0.10 (syst.) was obtained for the correlation parameter, in agreement with the Standard Model expectation.
Measurement and analysis of two- and three-particle correlations
M. Csanad
2006-02-17
Allowed regions of core fraction versus partial coherence are obtained from analysis of both two- and three-pion Bose-Einstein correlations measured at PHENIX in $\\sqrt{s_{NN}}=200$ GeV Au+Au collisions. Two-pion Bose-Einstein correlation functions for different average transverse momenta are used to analyze chiral symmetry restoration.
A precision length measuring system for a variety of linear artefacts
NASA Astrophysics Data System (ADS)
Eom, Tae Bong; Han, Jin Wan
2001-06-01
To calibrate precision length standards and length measuring transducers, the Korea Research Institute of Standards and Science (KRISS) has built a new linear measuring machine. The main requirement on the machine is to achieve sufficient flexibility to be able to calibrate a variety of standards such as step gauges, long-range linear transducers, industrial line scales and end bars with high accuracy. This system is not designed for calibrating primary standards such as a gauge block or a primary standard line scale, which are usually measured by specially designed precise interferometers. The main parts of the system are a precision stage and a laser interferometer. For smooth motion and precise positioning, we have built double stages, which consist of a global stage with an air bearing and a micro-stage with a flexure structure. Furthermore, two tilting stages are used for compensating for the pitch motion and the yaw motion of the global stage. Two double-pass plane mirror interferometers based on the heterodyne technique measure the displacement of the stage. The Abbe offset error is minimized by two interferometers with double-pass arrangements and two servo-controlled tilting stages. The measuring range of the system is 2500 mm and the expanded uncertainty for 1000 mm end bar calibration is 0.8 µm at the 95% confidence level.
Zhang, J.; Chowdhury, S.; Messac, A.; Hodge, B. M.
2013-08-01
This paper significantly advances the hybrid measure-correlate-predict (MCP) methodology, enabling it to account for variations of both wind speed and direction. The advanced hybrid MCP method uses the recorded data of multiple reference stations to estimate the long-term wind condition at a target wind plant site. The results show that the accuracy of the hybrid MCP method is highly sensitive to the combination of the individual MCP algorithms and reference stations. It was also found that the best combination of MCP algorithms varies based on the length of the correlation period.
Measuring absolute infrared spectral radiance with correlated photons: new arrangements
Migdall, Alan
metrologia Measuring absolute infrared spectral radiance with correlated photons: new arrangements. Sergienko Abstract. New experimental configurations of a system to measure absolute infrared (IR) spectral spectral radiance to be measured in the IR in an intrinsically absolute manner, using only uncalibrated
The quantumness of correlations revealed in local measurements exceeds entanglement
Marco Piani; Gerardo Adesso
2012-01-16
We analyze a family of measures of general quantum correlations for composite systems, defined in terms of the bipartite entanglement necessarily created between systems and apparatuses during local measurements. For every entanglement monotone $E$, this operational correspondence provides a different measure $Q_E$ of quantum correlations. Examples of such measures are the relative entropy of quantumness, the quantum deficit, and the negativity of quantumness. In general, we prove that any so defined quantum correlation measure is always greater than (or equal to) the corresponding entanglement between the subsystems, $Q_E \\ge E$, for arbitrary states of composite quantum systems. We analyze qualitatively and quantitatively the flow of correlations in iterated measurements, showing that general quantum correlations and entanglement can never decrease along von Neumann chains, and that genuine multipartite entanglement in the initial state of the observed system always gives rise to genuine multipartite entanglement among all subsystems and all measurement apparatuses at any level in the chain. Our results provide a comprehensive framework to understand and quantify general quantum correlations in multipartite states.
S. R. Mirfayzi
2013-01-08
Neutron diffusion length in reactor grade graphite is measured both experimentally and theoretically. The experimental work includes Monte Carlo (MC) coding using 'MCNP' and Finite Element Analysis (FEA) coding suing 'COMSOL Multiphysics' and Matlab. The MCNP code is adopted to simulate the thermal neutron diffusion length in a reactor moderator of 2m x 2m with slightly enriched uranium ($^{235}U$), accompanied with a model designed for thermal hydraulic analysis using point kinetic equations, based on partial and ordinary differential equation. The theoretical work includes numerical approximation methods including transcendental technique to illustrate the iteration process with the FEA method. Finally collision density of thermal neutron in graphite is measured, also specific heat relation dependability of collision density is also calculated theoretically, the thermal neutron diffusion length in graphite is evaluated at $50.85 \\pm 0.3cm$ using COMSOL Multiphysics and $50.95 \\pm 0.5cm$ using MCNP. Finally the total neutron cross-section is derived using FEA in an inverse iteration form.
NASA Astrophysics Data System (ADS)
Yang, Shilong; Cao, Jianshu
2004-07-01
Fluorescence lifetime measurements in a polymer chain are modeled using a memory function expansion, computer simulations, and simple scaling arguments. Unless the quenching rate is localized and infinitely fast, the fluorescence lifetime is generally not equivalent to the first passage time. The fluorescence lifetime distribution is decomposed into memory functions that can be measured separately in single-molecule experiments. The leading order of the expansion gives the Wilemski-Fixman (WF) approximation, and the convergence of higher order terms determines its validity. Simulations of the fluorescence quenching on a Rouse chain verify the accuracy of the WF approximation at small contact radii, short contour lengths, and small quenching rates. Detailed investigation of the average fluorescence lifetime reveals two competing mechanisms: the independent motion of end-to-end vector, which dominates at small contact radius, and the slowest relaxation of polymer, which dominates at large contact radius. The Wilemski-Fixman rate is used in combination with scaling arguments to predict the dependence of fluorescence lifetime on the contour length. Our predictions for the scaling of the average lifetime with the contour length are in good agreement with both simulations and recent experiments by Eaton and his group [L. J. Lapidus, W. A. Eaton, and J. Hofrichter, Proc. Natl. Acad. Sci. U.S.A. 97, 7220 (2000)].
Torsten Gogolla; Katerina Krebber
2000-01-01
We present a method for distributed measurement of beat length, differential group delay, strain, and temperature in long length single-mode optical fibers. Toward this aim, we employ the polarization state sensitive effect of stimulated Brillouin scattering (SBS). The distributed measurement is realized by applying frequency-domain analysis. We present the analytical relationships between the Brillouin interaction of two counterpropagating waves in
A set-up to measure the optical attenuation length of scintillating fibres
Alfieri, C; Joram, C
2015-01-01
The optical attenuation length of a scintillating fibre characterizes the quality of light transport through the fibre. It relates directly to the quantity of detectable light at the readout end of the fibre. An optical bench has been constructed, which allows excitation of the fibre at various distances from the photodetector. Depending on the choice of the photodetector – Si-PIN photodiode or grating spectrometer – the attenuation length is measured as weighted average over the sensitivity of the photodetector or as a spectral distribution. A few examples illustrate its operation and performance. The set-up serves for fibre optimisation in the R&D phase and is expected to be used for systematic checks during the series production phase of the LHCb SciFi tracker project.
NSDL National Science Digital Library
2012-01-01
This lesson introduces students to the measurable attribute of length and provides practice in measuring length using non-standard units. The lesson is launched using the story Ladybug on the Move by Richard Fowler. Lesson objectives, teaching ideas, and handouts are included.
Boardman, Lisa A.; Johnson, Ruth A.; Viker, Kimberly B.; Hafner, Kari A.; Jenkins, Robert B.; Riegert-Johnson, Douglas L.; Smyrk, Thomas C.; Litzelman, Kristin; Seo, Songwon; Gangnon, Ronald E.; Engelman, Corinne D.; Rider, David N.; Vanderboom, Russell J.; Thibodeau, Stephen N.; Petersen, Gloria M.; Skinner, Halcyon G.
2013-01-01
Introduction Colorectal cancer (CRC) tumor DNA is characterized by chromosomal damage termed chromosomal instability (CIN) and excessively shortened telomeres. Up to 80% of CRC is microsatellite stable (MSS) and is historically considered to be chromosomally unstable (CIN+). However, tumor phenotyping depicts some MSS CRC with little or no genetic changes, thus being chromosomally stable (CIN-). MSS CIN- tumors have not been assessed for telomere attrition. Experimental Design MSS rectal cancers from patients ?50 years old with Stage II (B2 or higher) or Stage III disease were assessed for CIN, telomere length and telomere maintenance mechanism (telomerase activation [TA]; alternative lengthening of telomeres [ALT]). Relative telomere length was measured by qPCR in somatic epithelial and cancer DNA. TA was measured with the TRAPeze assay, and tumors were evaluated for the presence of C-circles indicative of ALT. p53 mutation status was assessed in all available samples. DNA copy number changes were evaluated with Spectral Genomics aCGH. Results Tumors were classified as chromosomally stable (CIN-) and chromosomally instable (CIN+) by degree of DNA copy number changes. CIN- tumors (35%; n=6) had fewer copy number changes (<17% of their clones with DNA copy number changes) than CIN+ tumors (65%; n=13) which had high levels of copy number changes in 20% to 49% of clones. Telomere lengths were longer in CIN- compared to CIN+ tumors (p=0.0066) and in those in which telomerase was not activated (p=0.004). Tumors exhibiting activation of telomerase had shorter tumor telomeres (p=0.0040); and tended to be CIN+ (p=0.0949). Conclusions MSS rectal cancer appears to represent a heterogeneous group of tumors that may be categorized both on the basis of CIN status and telomere maintenance mechanism. MSS CIN- rectal cancers appear to have longer telomeres than those of MSS CIN+ rectal cancers and to utilize ALT rather than activation of telomerase. PMID:24278232
Asynchronous quantum correlation: measurement acting as a beamsplitter
F. V. Kowalski; R. S. Browne
2015-06-23
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.
Measurements of Roughness Length and Displacement Heights in Model Urban Canopies
NASA Astrophysics Data System (ADS)
Rahman, Auvi; Huq, Pablo; Camelli, Fernando; UD-GMU Collaboration
2013-11-01
We present the results of roughness length and displacement height based on PIV velocity measurements in a water tunnel experiment of flow over idealized models of urban canopies. Experiments were conducted with large roughness elements of regular arrays of buildings of uniform height with aspect ratios of 1 and 3. Mean velocity profile above the canopy is described by the log law and a simple optimization procedure to compute the roughness length and displacement height has been developed. Laterally averaged values of displacement height d/H increase from 0 to 1 with plan area density ?p of the urban canopy. In contrast, laterally averaged roughness height z0/H increases to a maximum value (as ?f approaches a value of 0.2) and then decreases to zero. We present data for effective roughness heights (z0 + d)/H as a function of aspect ratio H/wb of buildings. This also reveals three categories of values: street canyon, building wake, and laterally averaged values. Measurements taken at the centerline of canyons form a lower bound on the effective roughness height whereas measurements behind building wakes form an upper bound. Laterally averaged values of friction velocity u*/UH varied inversely with the aspect ratio (UH is the mean velocity at the building height).
Measurement of the $K_L$ nuclear interaction length in the NaI(Tl) calorimeter
Achasov, M N; Berdyugin, A V; Bogdanchikov, A G; Vasiljev, A V; Golubev, V B; Dimova, T V; Druzhinin, V P; Korol, A A; Koshuba, S V; Pakhtusova, E V; Serednyakov, S I; Silagadze, Z K; Usov, Yu V
2015-01-01
In the study of the reaction $e^+e^-\\to K_{S}K_{L}$ at the VEPP-2M $e^+e^-$ collider with the SND detector the nuclear interaction length of $K_{L}$ meson in NaI(Tl) has been measured. Its value is found to be 30--50 cm in the $K_{L}$ momentum range 0.11--0.48 GeV/$c$. The results are compared with the values used in the simulation programs GEANT4 and UNIMOD.
Mechanical measurements of heterogeneity and length scale effects in PEG-based hydrogels
Bush, Brian G.; Shapiro, Jenna M.; DelRio, Frank W.; Cook, Robert F.; Oyen, Michelle L.
2015-01-01
.rsc.org/ Mechanical measurements of heterogeneity and length scale effects in PEG-based hydrogels Brian G. Bush,a Jenna M. Shapiro,b,c Frank W. DelRio,a Robert F. Cook,a and Michelle L. Oyenc Colloidal-probe spherical indentation load-relaxation experiments with a... persulfate (APS), N,N,N’,N’- tetramethylethylene-diamine (TEMED), and 3- aminopropyltriethoxysilane (APTES) were purchased from Sigma-Aldrich (St. Louis, MO). PEGDMA cross-links through free-radical polymerization of the methacrylate groups with APS...
Diffusion length measurement using the scanning electron microscope. [for silicon solar cell
NASA Technical Reports Server (NTRS)
Weizer, V. G.
1975-01-01
The present work describes a measuring technique employing the scanning electron microscope in which values of the true bulk diffusion length are obtained. It is shown that surface recombination effects can be eliminated through application of highly doped surface field layers. The effects of high injection level and low-high junction current generation are investigated. Results obtained with this technique are compared to those obtained by a penetrating radiation (X-ray) method, and a close agreement is found. The SEM technique is limited to cells that contain a back surface field layer.
Measurement of the $K_L$ nuclear interaction length in the NaI(Tl) calorimeter
M. N. Achasov; K. I. Beloborodov; A. V. Berdyugin; A. G. Bogdanchikov; A. V. Vasiljev; V. B. Golubev; T. V. Dimova; V. P. Druzhinin; A. A. Korol; S. V. Koshuba; E. V. Pakhtusova; S. I. Serednyakov; Z. K. Silagadze; Yu. V. Usov
2015-09-07
In the study of the reaction $e^+e^-\\to K_{S}K_{L}$ at the VEPP-2M $e^+e^-$ collider with the SND detector the nuclear interaction length of $K_{L}$ meson in NaI(Tl) has been measured. Its value is found to be 30--50 cm in the $K_{L}$ momentum range 0.11--0.48 GeV/$c$. The results are compared with the values used in the simulation programs GEANT4 and UNIMOD.
The Measurement and Correlates of Career Decision Making.
ERIC Educational Resources Information Center
Harren, Vincent A.; Kass, Richard A.
This paper presents a theoretical framework for understanding career decision making (CDM); introduces an instrument, Assessment of Career Decision Making (ACDM) to measure CDM with college students; and presents correlational data on sex role and cognitive style factors hypothesized to influence CDM. The ACDM, designed to measure the Tiedeman and…
Image scale measurement with correlation filters in a volume holographic optical correlator
NASA Astrophysics Data System (ADS)
Zheng, Tianxiang; Cao, Liangcai; He, Qingsheng; Jin, Guofan
2013-08-01
A search engine containing various target images or different part of a large scene area is of great use for many applications, including object detection, biometric recognition, and image registration. The input image captured in realtime is compared with all the template images in the search engine. A volume holographic correlator is one type of these search engines. It performs thousands of comparisons among the images at a super high speed, with the correlation task accomplishing mainly in optics. However, the inputted target image always contains scale variation to the filtering template images. At the time, the correlation values cannot properly reflect the similarity of the images. It is essential to estimate and eliminate the scale variation of the inputted target image. There are three domains for performing the scale measurement, as spatial, spectral and time domains. Most methods dealing with the scale factor are based on the spatial or the spectral domains. In this paper, a method with the time domain is proposed to measure the scale factor of the input image. It is called a time-sequential scaled method. The method utilizes the relationship between the scale variation and the correlation value of two images. It sends a few artificially scaled input images to compare with the template images. The correlation value increases and decreases with the increasing of the scale factor at the intervals of 0.8~1 and 1~1.2, respectively. The original scale of the input image can be measured by estimating the largest correlation value through correlating the artificially scaled input image with the template images. The measurement range for the scale can be 0.8~4.8. Scale factor beyond 1.2 is measured by scaling the input image at the factor of 1/2, 1/3 and 1/4, correlating the artificially scaled input image with the template images, and estimating the new corresponding scale factor inside 0.8~1.2.
Statistical Measures of Planck Scale Signal Correlations in Interferometers
Craig J. Hogan; Ohkyung Kwon
2015-08-30
A model-independent statistical framework is presented to interpret data from systems where the mean time derivative of positional cross correlation between world lines, a measure of spreading in a quantum geometrical wave function, is measured with a precision smaller than the Planck time. The framework provides a general way to constrain possible departures from perfect independence of classical world lines, associated with Planck scale bounds on positional information. A parametrized candidate set of possible correlation functions is shown to be consistent with the known causal structure of the classical geometry measured by an apparatus, and the holographic scaling of information suggested by gravity. Frequency-domain power spectra are derived that can be compared with interferometer data. Simple projections of sensitivity for specific experimental set-ups suggests that measurements will directly yield constraints on a universal time derivative of the correlation function, and thereby confirm or rule out a class of Planck scale departures from classical geometry.
Statistical Measures of Planck Scale Signal Correlations in Interferometers
Craig J. Hogan; Ohkyung Kwon
2015-08-04
A model-independent statistical framework is presented to interpret data from systems where the mean time derivative of positional cross correlation between world lines, a measure of spreading in a quantum geometrical wave function, is measured with a precision smaller than the Planck time. The framework provides a general way to constrain possible departures from perfect independence of classical world lines, associated with Planck scale bounds on positional information. A parametrized candidate set of possible correlation functions is shown to be consistent with the known causal structure of the classical geometry measured by an apparatus, and the holographic scaling of information suggested by gravity. Frequency-domain power spectra are derived that can be compared with interferometer data. Simple projections of sensitivity for specific experimental set-ups suggests that measurements will directly yield constraints on a universal time derivative of the correlation function, and thereby confirm or rule out a class of Planck scale departures from classical geometry.
J. M. Pilcher; U. Patel
2002-01-01
AIM: To evaluate a formula based on the patient's height for choosing the correct length of ureteric stent and to compare its accuracy with that of direct ureteric length measurement.METHODS: Thirty-five patients (41 ureters) with ureteric obstruction were prospectively studied. All received Percuflex 8F double pigtail ureteric stents. Stent lengths were chosen according to patient height:<5ft 10in (<178cm)=22cm; 5ft 10in
Accurate Measurement of Canal Length during Root Canal Treatment: An In Vivo Study
Sadaf, Durre; Ahmad, Muhammad Zubair
2015-01-01
Objectives: To assess the consistency and accuracy of Electronic Apex Locator (EAL) (Root ZXII) in individual canals and its association with other clinical variables. Study Design: Cross-Sectional study. Place of study: Dental section of the Aga Khan University Hospital, Karachi, Pakistan. Materials and Methods: Working length was measured by EAL in 180 patients requiring endodontic therapy in molar and premolar teeth. The effects of clinical variables e.g. gender and pulpal status on the consistency and accuracy of EAL were recorded. Performance of apex locator was considered “Consistent” when the scale bar was stable and moved only in correspondence to the movement of file in the root canal. Accuracy was determined by inserting the file at the working length determined by the EAL and periapical view of radiograph was taken using paralleling technique. Estimated working length was considered accurate when the file tip was located 0-2mm short of the radiographic apex. If the file was overextended from the radiographic apex, it showed dysfunction of the EAL. Results: Consistency of EAL was found 97.6% in distobuccal canals, 91.1% in palatal canals, 73.7% in mesiolingual canals, 83.3% in mesiobuccal and 80.2% in distal canals. Accuracy of EAL was 91.4% in mesiolingual canal, 92% in mesiobuccal, and 90.2% in Palatal and 93.2% in distal canal. Conclusion: Consistency of electronic apex locator vary in different canals, however consistent measurements are highly accurate. No significant association was found between other clinical variables with the consistency and accuracy of EAL.
NASA Astrophysics Data System (ADS)
Shi, Zhi-Dong; Lin, Jian-Qiang; Bao, Huan-Huan; Liu, Shu; Xiang, Xue-Nong
2008-03-01
A photoelectric measurement system for measuring the beat length of birefringence fiber is set up including a set of rotating-wave-plate polarimeter using single photodiode. And two improved cutback methods suitable for measuring beat-length within millimeter range of high birefringence fiber are proposed through data processing technique. The cut length needs not to be restricted shorter than one centimeter so that the auto-cleaving machine is freely used, and no need to carefully operate the manually cleaving blade with low efficiency and poor success. The first method adopts the parameter-fitting to a saw-tooth function of tried beat length by the criterion of minimum square deviations, without special limitation on the cut length. The second method adopts linear-fitting in the divided length ranges, only restrict condition is the increment between different cut lengths less than one beat-length. For a section of holey high-birefringence fiber, we do experiments respectively by the two methods. The detecting error of beat-length is discussed and the advantage is compared.
Measurements of Bose-Einstein correlations with the ATLAS detector
Sykora, Ivan; The ATLAS collaboration
2015-01-01
The Bose-Einstein correlations provide a unique opportunity for detailed understanding of space-time characteristics of the hadronization region, for determining the size and shape of the source from which particles are emitted and for interpreting quark confinement effects. The correlations lead to enhancement in production of identical bosons that are close in phase space. The ATLAS collaboration has performed a measurement of Bose-Einstein correlations of pairs of charged particles with transverse momentum greater than 100 MeV in p-p collisions at 900 GeV and 7 TeV. Bose-Einstein correlation parameters are investigated up to very high charged-particle multiplicities. The dependence of the Bose-Einstein correlation parameters on the average transverse momentum per pair is also investigated.
Modeling work zone crash frequency by quantifying measurement errors in work zone length.
Yang, Hong; Ozbay, Kaan; Ozturk, Ozgur; Yildirimoglu, Mehmet
2013-06-01
Work zones are temporary traffic control zones that can potentially cause safety problems. Maintaining safety, while implementing necessary changes on roadways, is an important challenge traffic engineers and researchers have to confront. In this study, the risk factors in work zone safety evaluation were identified through the estimation of a crash frequency (CF) model. Measurement errors in explanatory variables of a CF model can lead to unreliable estimates of certain parameters. Among these, work zone length raises a major concern in this analysis because it may change as the construction schedule progresses generally without being properly documented. This paper proposes an improved modeling and estimation approach that involves the use of a measurement error (ME) model integrated with the traditional negative binomial (NB) model. The proposed approach was compared with the traditional NB approach. Both models were estimated using a large dataset that consists of 60 work zones in New Jersey. Results showed that the proposed improved approach outperformed the traditional approach in terms of goodness-of-fit statistics. Moreover it is shown that the use of the traditional NB approach in this context can lead to the overestimation of the effect of work zone length on the crash occurrence. PMID:23563145
Rule, D. W.; Fiorito, R. B.; Kimura, W. D.
1999-07-12
We present an analysis on the effect of the finite bandwidth of a detector on the observed intensity of coherent transition radiation (CTR) produced by a long train of microbunches. The parameters of the planned CTR bunch length measurement for the Staged Electron Laser Acceleration (STELLA) experiment on the ATF linac at Brookhaven National Laboratory (BNL) are used as an illustrative example. We show how the effective number of bunches contributing to the observed coherent radiation depends on the band width of the detector. We conclude that meaningful CTR bunch length measurements on the STELLA experiment are possible using fairly wide band pass filters, e.g., {approx}5%. Micropulse widths of {approx}1-3 {mu}m (3-10 fs) FWHM can easily be distinguished by observing up to 5-6 harmonics of the 10.6-{mu}m bunch spacing. This analysis should also be applicable to other radiation produced by microbunches, such as coherent Cerenkov and synchrotron radiation.
NASA Technical Reports Server (NTRS)
Norgren, C. T.; Ingebo, R. D.
1976-01-01
Radiometric data were obtained over a range of parametric test conditions at three positions along the length of an experimental combustor segment corresponding to the primary, intermediate, and dilution zones. The concentration of soot entrained in the combustion gases was calculated by a technique using spectral radiance measurements. Tests were conducted primarily with Jet A fuel, although limited data were taken with two fuels having higher aromatic content, diesel oil number 2 and a blend of 40 percent tetralin in Jet A fuel. Radiometric observation of the combustion gases indicated that the maximum total radiance peaked at the intermediate zone, which was located immediately upstream of the dilution holes. Soot concentrations calculated from optical measurements in the dilution zone compared favorably with those obtained by in situ gas sampling at the exhaust. The total radiance increased with the higher aromatic content fuels.
NASA Technical Reports Server (NTRS)
Leon, R. P.
1987-01-01
Diffusion lengths and surface recombination velocities were measured in GaAs diodes and InP finished solar cells. The basic technique used was charge collection microscopy, also known as electron beam induced current (EBIC). The normalized currents and distances from the pn junction were read directly from the calibrated curves obtained while using the line-scan mode in an SEM. These values were then equated to integral and infinite series expressions resulting from the solution of the diffusion equation with both extended-generation and point-generation functions. This expands previous work by examining both thin and thick samples. The surface recombination velocity was either treated as an unknown in a system of two equations or measured directly using low e(-) beam accelerating voltages. These techniques give accurate results by accounting for the effects of surface recombination and the finite size of the generation volume.
NASA Technical Reports Server (NTRS)
Leon, R. P.
1987-01-01
Diffusion lengths and surface recombination velocities were measured in GaAs diodes and InP finished solar cells. The basic techniques used was charge collection microscopy also known as electron beam induced current (EBIC). The normalized currents and distances from the pn junction were read directly from the calibrated curves obtained while using the line scan mode in an SEM. These values were then equated to integral and infinite series expressions resulting from the solution of the diffusion equation with both extended generation and point generation functions. This expands previous work by examining both thin and thick samples. The surface recombination velocity was either treated as an unknown in a system of two equations, or measured directly using low e(-) beam accelerating voltages. These techniques give accurate results by accounting for the effects of surface recombination and the finite size of the generation volume.
NASA Astrophysics Data System (ADS)
Piehler, G.; Kegel, W. H.
1995-05-01
We investigated the formation of interstellar molecular lines in a turbulent velocity field with finite correlation length, extending previous work (Albrecht & Kegel 1987; Kegel et al. 1992) to isothermal spheres in hydrostatic equilibrium as cloud models with ?>>v_ therm _. For this we use the transformed generalized radiative transfer equation (Kegel et al. 1992). We concentrate our calculations on the CO-molecule with up to 12 energy levels. We give numerical results for models with T_kin_=50K, ?=3.9km/sec (?/v_ therm _=22), and different values of the central H_2_ density and different values of the correlation length. As our results show, accounting for a velocity field with a finite correlation length affects the line profiles, the center-to-limb variation, and the intensity ratios. We find that the higher transitions are more strongly affected than the J=1-0 transition.
First Measurements of Pion Correlations by the PHENIX Experiment
Johnson, S C
2001-04-11
First identical-pion correlations measured at RHIC energies by PHENIX are presented. Two analyses with separate detectors, systematics, and statistics provide consistent results. The resulting HBT radii are moderately larger than those measured at lower energies. The k{sub t} dependence of the Bertsch-Pratt HBT radii is also similar to previous measures and is consistent with the conjecture of an expanding source.
Displacement measurements in microregion with generalized digital speckle correlation method
NASA Astrophysics Data System (ADS)
Li, Xide; Deng, Bing; Shi, Huiji
2002-05-01
High magnifying optics is now widely used in micro-region imaging, which leads to the special image structures on the recording plane, such as continue-gray distributions, large granules and spread structures. As a result, the deformation analyses are unreliable and divergent by using the conventional speckle correlation methods and these generalized speckle patterns. A new correlation algorithm, high-order gradient digital correlation method, has been proposed in this paper to measure the displacements in a micro-region. The performance of the proposed algorithm is illustrated using the generalized speckle patterns captured from the micro-regions.
Direct measurement of correlation functions in a lattice Lorentz gas
NASA Technical Reports Server (NTRS)
Binder, P.-M.; Frenkel, D.
1990-01-01
Simulations of a two-dimensional ballistic Lorentz gas on a lattice are reported. A moment-propagation technique allows direct measurements of the velocity correlation function and its moments with low relative errors for all times. The predicted 1/t-sq algebraic tails in the velocity correlation function are observed at all studied scatterer densities, unlike what has been reported for continuous systems. In the square lattice a fast oscillation is observed, consistent with the existence of staggered density modes. For the second-rank tensor correlation function, an extremely slow approach to the expected 1/t exp 3 tail is found.
Enhancing robustness of multiparty quantum correlations using weak measurement
NASA Astrophysics Data System (ADS)
Singh, Uttam; Mishra, Utkarsh; Dhar, Himadri Shekhar
2014-11-01
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.
Direct measurements of hydrophobic slippage using double-focus fluorescence cross-correlation
Olga I. Vinogradova; Kaloian Koynov; Andreas Best; François Feuillebois
2008-02-04
We report results of direct measurements of velocity profiles in a microchannel with hydrophobic and hydrophilic walls, using a new high precision method of double-focus spacial fluorescence cross-correlation under a confocal microscope. In the vicinity of both walls the measured velocity profiles do not turn to zero by giving a plateau of constant velocity. This apparent slip is proven to be due to a Taylor dispersion, an augmented by shear diffusion of nanotracers in the direction of flow. Comparing the velocity profiles near the hydrophobic and hydrophilic walls for various conditions shows that there is a true slip length due to hydrophobicity. This length, of the order of several tens of nanometers, is independent on electrolyte concentration and shear rate.
2011-01-01
Background Surprisingly, in several multi-cellular eukaryotes optimal codon use correlates negatively with gene length. This contrasts with the expectation under selection for translational accuracy. While suggested explanations focus on variation in strength and efficiency of translational selection, it has rarely been noticed that the negative correlation is reported only in organisms whose optimal codons are biased towards codons that end with G or C (-GC). This raises the question whether forces that affect base composition - such as GC-biased gene conversion - contribute to the negative correlation between optimal codon use and gene length. Results Yeast is a good organism to study this as equal numbers of optimal codons end in -GC and -AT and one may hence compare frequencies of optimal GC- with optimal AT-ending codons to disentangle the forces. Results of this study demonstrate in yeast frequencies of GC-ending (optimal AND non-optimal) codons decrease with gene length and increase with recombination. A decrease of GC-ending codons along genes contributes to the negative correlation with gene length. Correlations with recombination and gene expression differentiate between GC-ending and optimal codons, and also substitution patterns support effects of GC-biased gene conversion. Conclusion While the general effect of GC-biased gene conversion is well known, the negative correlation of optimal codon use with gene length has not been considered in this context before. Initiation of gene conversion events in promoter regions and the presence of a gene conversion gradient most likely explain the observed decrease of GC-ending codons with gene length and gene position. PMID:21481245
Full Wave Simulation of Reflectometer Correlation Measurements in the Core of Fusion Plasmas
NASA Astrophysics Data System (ADS)
Valeo, E. J.; Nazikian, R.
2000-10-01
A fundamental issue in reflectometry is whether the measured correlation length is the same as that of the turbulent density fluctuations.(B. I. Cohen, etal.), Phys. of Plasmas, 6, 1732 (1999); M. Gilmore, etal., Plasma Phys. Control. Fusion, 42, L1 (2000). Consideration of wave propagation in fusion plasmas would suggest that the two should not coincide except under special conditions. On the other hand, extensive measurements in laboratory plasmas and in the edge of tokamak plasmas have shown that the reflectometer correlation length agrees with probe measurements and with 1-D full wave analysis. We investigate via 2-D full-wave simulations whether this equivalence can generally be extrapolated to conditions typical of core fusion plasmas, especially those where where an internal transport barrier is established. In order to perform the correlation analysis on realistic sized plasmas the code uses a line-jacobi algorithm which allows the Courant condition to be exceeded,(H. X. Vu, J. Comp. Phys., 144, 257 (1998).) and has been implemented on a parallel computer at PPPL.
Measurements of $t\\bar{t}$ spin correlations in CMS
Kelly Beernaert
2014-11-26
We present an overview of the measurements of $t\\bar{t}$ spin correlations in the CMS Collaboration. We present two analyses both in the dilepton channel using proton-proton collisions at $\\sqrt{s}\\, =\\, 7$ TeV based on an integrated luminosity of 5.0 fb$^{-1}$. The spin correlations and polarization are measured using angular asymmetries. The results are consistent with unpolarized top quarks and Standard Model spin correlation. The second analysis sets a limit on the real part of the top-quark chromo-magnetic dipole moment of $-0.043\\, <\\, Re({\\hat{\\mu}}_{t})\\, <\\, 0.117$ at $95\\,%$ confidence level through the measured azimuthal angle difference between the two charged leptons from $t\\bar{t}$ production.
Scattering Corrections in Neutron ?-decay Angular Correlation Measurements
NASA Astrophysics Data System (ADS)
Pattie, Robert
2010-11-01
Measurements of angular correlations in neutron ?-decay, such as the electron momentum-neutron spin correlation A, require precise knowledge of the energy and momentum of the emitted electron and or proton. However, accurate determination of these observables is often limited by our understanding of scattering from materials before detection. Over the past decade, the UCNA experiment has developed a PENELOPE-based Monte Carlo simulation to estimate this systematic effect on the measured ? asymmetry A. Other experiments, proposed and active, will measure angular correlations using similar detection methods. We will discuss our results as well as the general implications of these simulations as they apply to other detector geometries and electric/magnetic field profiles.
Two Point Space-Time Correlation of Density Fluctuations Measured in High Velocity Free Jets
NASA Technical Reports Server (NTRS)
Panda, Jayanta
2006-01-01
Two-point space-time correlations of air density fluctuations in unheated, fully-expanded free jets at Mach numbers M(sub j) = 0.95, 1.4, and 1.8 were measured using a Rayleigh scattering based diagnostic technique. The molecular scattered light from two small probe volumes of 1.03 mm length was measured for a completely non-intrusive means of determining the turbulent density fluctuations. The time series of density fluctuations were analyzed to estimate the integral length scale L in a moving frame of reference and the convective Mach number M(sub c) at different narrow Strouhal frequency (St) bands. It was observed that M(sub c) and the normalized moving frame length scale L*St/D, where D is the jet diameter, increased with Strouhal frequency before leveling off at the highest resolved frequency. Significant differences were observed between data obtained from the lip shear layer and the centerline of the jet. The wave number frequency transform of the correlation data demonstrated progressive increase in the radiative part of turbulence fluctuations with increasing jet Mach number.
Axial Length Measurement Failure Rates with the IOLMaster and Lenstar LS 900 in Eyes with Cataract
Pesudovs, Konrad; Yang, Xin; Bao, Fangjun; Yu, Ayong; Lin, Shishi; Feng, Yifan; Huang, Jinhai
2015-01-01
Purpose To evaluate axial length (AL) measurement failure rate with the IOLMaster (Carl Zeiss AG, Germany) and Lenstar LS 900 (Haag-Streit AG, Switzerland) in eyes with cataract. Methods Two hundred and ninety-six eyes of 170 patients with cataract were enrolled. Cataract type and severity were graded using the Lens Opacities Classification System III (LOCS III) and AL measurements were attempted with IOLMaster (version 5.4) and Lenstar LS 900 (version 1.1). Chi-squared analysis was used to assess if the difference in AL measurement acquisition rate was statistically significant between the two devices. The association of the different cataract types and severity with the AL measurement acquisition rate was evaluated with logistic regression analysis. Results AL measurements were obtained in 184 eyes (62.16%) using the IOLMaster and 191 eyes (64.53%) using the Lenstar, which corresponds to a failure rate of 37.84% and 35.47% respectively. Chi-square analysis indicated no significant difference between the Lenstar and IOLMaster for AL measurement failure rate (x2 = 0.356, P = 0.550). Logistic regression analysis indicated no association between acquisition rates and cortical or nuclear cataracts with either device. There was a statistically significant association between acquisition rates and increasing severity of posterior subcapsular cataracts with the IOLMaster (? = -1.491, P<0.001) and Lenstar LS 900 (? = -1.507, P<0.001). Conclusion The IOLMaster and Lenstar LS 900 have similar AL measurement failure rates (35–38%) for Chinese public hospital cataract patients. Increasing severity of posterior subcapsular cataracts was problematic for both devices. PMID:26061554
Diffraction effects in coherent transition radiation diagnostics for sub-mm bunch length measurement
Maxwell, T.J.; Mihalcea, D.; Piot, P.; /Northern Illinois U. /Fermilab
2008-09-01
Electrons crossing the boundary between different media generate bursts of transition radiation. In the case of bunches of N electrons, the radiation is coherent and has an N-squared enhancement at wavelengths related to the longitudinal bunch distribution. This coherent transition radiation has therefore attracted attention as an interceptive charged particle beam diagnostic technique. Many analytical descriptions have been devised describing the spectral distribution generated by electron bunches colliding with thin metallic foils making different simplifying assumptions. For typical bunches having lengths in the sub-millimeter range, measurable spectra are generated up into the millimeter range. Analysis of this THz radiation is performed using optical equipment tens of millimeters in size. This gives rise to concern that optical diffraction effects may spread the wavefront of interest into regions larger than the optical elements and partially escape detection, generating a wavelength-dependent instrument response. In this paper we present a model implementing vector diffraction theory to analyze these effects in bunch length diagnostics based on coherent transition radiation.
Turbulent transport and length scale measurement experiments with comfined coaxial jets
NASA Technical Reports Server (NTRS)
Johnson, B. V.; Roback, R.
1984-01-01
A three phase experimental study of mixing downstream of swirling and nonswirling confined coaxial jets was conducted to obtain data for the evaluation and improvement of turbulent transport models currently employed in a variety of computational procedures. The present effort was directed toward the acquisition of length scale and dissipation rate data that provide more accurate inlet boundary conditions for the computational procedures and a data base to evaluate the turbulent transport models in the near jet region where recirculation does not occur, and the acquisition of mass and momentum turbulent transport data for a nonswirling flow condition with a blunt inner jet inlet configuration rather than the tapered inner jet inlet. A measurement technique, generally used to obtain approximate integral length and microscales of turbulence and dissipation rates, was computerized. Results showed the dissipation rate varied by 2 1/2 orders of magnitude across the inlet plane, by 2 orders of magnitude 51 mm from the inlet plane, and by 1 order of magnitude at 102 mm from the inlet plane for a nonswirling flow test conditions.
Kim, Do-Hyun; Shi, Dexiu; Ilev, Ilko K
2011-09-10
We present a simple method for measuring the effective focal length without determining the location of principle plane of the lens. The method is based on the measurement of confocal backreflection axial responses from the front and back surfaces of a reference plate with known refractive index and thickness. We proved the concept by measuring the effective focal lengths of thin singlet lenses and complex microscope objectives. The theoretical limit of measurement precision varies depending on the numerical aperture of the lens. This method can provide an alternative focal length measurement method for complex lenses or lenses that are permanently attached to other structures. Measurement errors were analyzed theoretically and improvements in measurement accuracy were discussed. PMID:21946999
Wada, Kenji; Matsukura, Satoru; Tanaka, Amaka; Matsuyama, Tetsuya; Horinaka, Hiromichi
2015-09-01
A simple method to measure single-mode optical fiber lengths is proposed and demonstrated using a gain-switched 1.55-?m distributed feedback laser without a fast photodetector or an optical interferometer. From the variation in the amplified spontaneous emission noise intensity with respect to the modulation frequency of the gain switching, the optical length of a 1-km single-mode fiber immersed in water is found to be 1471.043915 m ± 33 ?m, corresponding to a relative standard deviation of 2.2 × 10^{-8}. This optical length is an average value over a measurement time of one minute under ordinary laboratory conditions. PMID:26368406
Kyrala, G.A.
1987-01-01
A two-source shear pattern recording is proposed as a method for single-shot measurement of the pulse shape from nearly monochromatic sources whose pulse lengths are shorter than their coherence times. The basis of this method relies on the assertion that if two identical electromagnetic pulses are recombined with a time delay greater than the sum of their pulse widths, the recordable spatial pattern has no fringes in it. At an arbitrary delay, translated into an actual spatial recording position, the recorded modulated intensity will sample the corresponding laser intensity at that delay time, but with a modulation due to the coherence function of the electromagnetic pulse. Two arrangements are proposed for recording the pattern. The principles, the design parameters, and the methodologies of these arrangements will be presented. Resolutions of the configurations and their limitations will be given as well.
Precision Measurements of the n-H, n-D, and n-3He Coherent Scattering Lengths
NASA Astrophysics Data System (ADS)
Schoen, K.; Black, T.; Snow, W. M.; Huffman, P.; Arif, M.; Kaiser, H.; Jacobson, D.; Werner, S.; Lamoreaux, S.
2002-04-01
Theoretical calculations of the properties of few-nucleon systems starting from the nucleon-nucleon (NN) interaction potential have been improved qualitatively over the last few years. The issue of the nature and origin of three- and four-nucleon (3N and 4N) forces in particular has received special attention. The triton binding energy and the doublet n-D scattering length are the two zero-energy observables for which calculations of the effects of 3N forces are uncomplicated by Coulomb corrections. Since the quartet n-D scattering length is mainly due to the long-range part of the NN interaction and is therefore determined essentially by the properties of the deuteron, a precision measurement of the coherent n-D scattering length (which is a linear combination of the doublet and quartet lengths) can be used to gain information on the n-D doublet scattering length. In measuring n-H and n-3He scattering lengths, one can theoretically extract n-n and n-p interactions, which can then be used to examine the residual few-nucleon forces and deviations from theory. We will present new measurements of the n-D, n-H, and n-3He coherent scattering lengths using the NIST neutron interferometer facility with comparable sensitivity for n-D and n-H and almost an order-of-magnitude improvement in sensitivity for n-3He, relative to existing measurements.
Correlative studies in optical reflectance measurements of cerebral blood oxygenation
NASA Astrophysics Data System (ADS)
Kan Wan, Siew; Guo, Zhixiong
2006-03-01
A numerical study is made of correlation development for measuring cerebral blood oxygen saturation (StO) noninvasively using optical reflectance ratio of dual wavelengths. The Monte Carlo (MC) method was used for simulating reflectance measurements in a model neck tissue, where the cerebral blood oxygenation was monitored through the blood flows in the common carotid artery (CCA) and jugular vein. Reflectance ratios between two wavelengths at 633 and 800 nm were obtained under different blood vessel conditions. The results revealed a quantifiable correlation between the reflectance ratio and the cerebral StO level. Correlations for each of the blood vessel parameters such as the location, size, and hemoglobin concentration of the CCA or jugular vein (JV) were developed.
Static Laboratory Earthquake Measurements with the Digital Image Correlation Method
Avouac, Jean-Philippe
Static Laboratory Earthquake Measurements with the Digital Image Correlation Method V. Rubino & N on the Earth's surface following an earthquake is of paramount importance to enhance our understanding of earthquake mechan- ics. Currently, aerial and satellite images taken pre- and post- earthquake can
Averaging Measurements with Hidden Correlations and Asymmetric Errors
Michael Schmelling
2000-06-02
Properties of weighted averages are studied for the general case that the individual measurements are subject to hidden correlations and have asymmetric statistical as well as systematic errors. Explicit expressions are derived for an unbiased average with a well defined error estimate.
Averaging Measurements with Hidden Correlations and Asymmetric Errors
Michael Schmelling
2000-01-01
Properties of weighted averages are studied for the general case that the individual measurements are subject to hidden correlations and have asymmetric statistical as well as systematic errors. Explicit expressions are derived for an unbiased average with a well defined error estimate.
PROTOTYPE CORRELATION MASK FLAME PHOTOMETRIC DETECTOR FOR MEASURING SULFUR DIOXIDE
A prototype flame photometric detector system (FPD) to measure gaseous sulfur compounds was fabricated using a previously developed correlation mask optical system and a new flame housing. Also, a new burner for the FPD system was optimized to view the excited molecular sulfur em...
CORRELATION OF EGG PHYSICAL QUALITY MEASUREMENTS AND FUNCTIONAL DETERMINATIONS
Technology Transfer Automated Retrieval System (TEKTRAN)
Both physical and functional determinations have served as a means for determining shell egg quality. A study was conducted to determine if correlations exist between these types of egg quality measurements. Shell eggs were collected weekly after processing from a U.S. inline processing facility f...
Measuring telomere length and telomere dynamics in evolutionary biology and ecology
Nussey, Daniel H; Baird, Duncan; Barrett, Emma; Boner, Winnie; Fairlie, Jennifer; Gemmell, Neil; Hartmann, Nils; Horn, Thorsten; Haussmann, Mark; Olsson, Mats; Turbill, Chris; Verhulst, Simon; Zahn, Sandrine; Monaghan, Pat
2014-01-01
Telomeres play a fundamental role in the protection of chromosomal DNA and in the regulation of cellular senescence. Recent work in human epidemiology and evolutionary ecology suggests adult telomere length (TL) may reflect past physiological stress and predict subsequent morbidity and mortality, independent of chronological age. Several different methods have been developed to measure TL, each offering its own technical challenges. The aim of this review is to provide an overview of the advantages and drawbacks of each method for researchers, with a particular focus on issues that are likely to face ecologists and evolutionary biologists collecting samples in the field or in organisms that may never have been studied in this context before. We discuss the key issues to consider and wherever possible try to provide current consensus view regarding best practice with regard to sample collection and storage, DNA extraction and storage, and the five main methods currently available to measure TL. Decisions regarding which tissues to sample, how to store them, how to extract DNA, and which TL measurement method to use cannot be prescribed, and are dependent on the biological question addressed and the constraints imposed by the study system. What is essential for future studies of telomere dynamics in evolution and ecology is that researchers publish full details of their methods and the quality control thresholds they employ. PMID:25834722
Zhang, H.; Lynn, J.W.; Majkrzak, C.F.; Satija, S.K.; Kang, J.H.; Wu, X.D.
1995-10-01
Polarized neutron reflectivity measurements have been performed on two polycrystalline niobium films grown on silicon substrates. The samples were characterized with x-ray diffraction and reflection, electrical resistivity, and unpolarized neutron reflection measurements. For the film of 310 nm thickness, polarized neutron reflectivity measurements were carried out on both the Si side as well as the vacuum side, and we found that substantially higher quality data could be obtained from the Si side due to the enhanced contrast between the weak diamagnetic scattering and the nuclear scattering from the films. A large number of interference fringes from the waves reflected from the front and back surfaces of the film could be observed, attesting to the high quality and flatness of the sample. The vacuum-Nb interface had a surface roughness of {sigma}{similar_to}3.4 nm, while the Nb-Si interface was nearly atomically smooth. We also carried out an experiment on a 300 nm-thick film of YBa{sub 2}Cu{sub 3}O{sub 7}, but the roughness was so severe that no interference fringes could be observed, and reliable measurements of {lambda} could not be obtained. The magnetic screening length for the Nb films was measured to be {lambda}=110{plus_minus}2 nm for the sample with an electron mean free path {ital l}=10 nm, and {lambda}=55{plus_minus}2 nm for the sample with {ital l}=35 nm. Taking into account the effects of crystalline defects and impurities, we obtain the intrinsic London penetration depth in superconducting Nb to be {lambda}{sub {ital L}}=43{plus_minus}8 nm at {ital T}=4.5 K. This result is in good agreement with that of Felcher {ital et} {ital al}.
Pislaru, Cristina; Urban, Matthew W.; Pislaru, Sorin V.; Kinnick, Randall R.; Greenleaf, James F.
2014-01-01
Our aims were (i) to compare in vivo measurements of myocardial elasticity by shear wave dispersion ultrasound vibrometry (SDUV) with those by the conventional pressure-segment length method, and (ii) to quantify changes in myocardial viscoelasticity during systole and diastole after reperfused acute myocardial infarction. The shear elastic modulus (?1) and viscous coefficient (?2) of left ventricular myocardium were measured by SDUV in 10 pigs. Young’s elastic modulus was independently measured by the pressure-segment length method. Measurements made with the SDUV and pressure-segment length methods were strongly correlated. At reperfusion, ?1 and ?2 in end-diastole were increased. Less consistent changes were found during systole. In all animals, ?1 increased linearly with left ventricular pressure developed during systole. Preliminary results suggest that m1 is preload dependent. This is the first study to validate in vivo measurements of myocardial elasticity by a shear wave method. In this animal model, the alterations in myocardial viscoelasticity after a myocardial infarction were most consistently detected during diastole. PMID:24814645
Correlation measurements with {sup 252}Cf to characterize fissile material
Mattingly, J.K.; Mihalczo, J.T.; Valentine, T.E.; Mullens, J.A.; March-Leuba, J.; Uckan, T.
2000-07-01
Measurements using {sup 252}Cf as a timed source of neutrons and gammas have in recent years undergone significant maturation. These methods use {sup 252}Cf as an observable source of spontaneous fission neutrons and gammas in conjunction with one or more neutron-sensitive and/or gamma-sensitive detectors to measure the time distribution of correlated detector counts following (a) an observed {sup 252}Cf-fission event and/or (b) a counting event in another detector. Detection of {sup 252}Cf spontaneous fission is frequently achieved via use of a small ionization chamber in which the {sup 252}Cf is contained; in this case, the timing of source emission events is random. However, one application subsequently described uses a neutron-absorbent shutter to modulate {sup 252}Cf emissions to produce a neutron source with deterministic timing. Other applications, frequently termed noise-analysis measurements, transform the time distributions to the frequency domain. Collectively, these correlation methods use {sup 252}Cf to excite the fissile ray of detectors and analyzed using standard time-correlation and/or frequency-analysis techniques. In recent years, numerous advances have been made in the application of these methods to in situ or field measurements directed at characterizing various configurations of fissile material in operational facilities. Applications include reactor physics measurements, nuclear criticality safety, nondestructive analysis and nonintrusive monitoring of enrichment (or deenrichment) processes, and inventory tracking for nuclear materials control and accountability.
Measurement-induced disturbances and nonclassical correlations of Gaussian states
Mista, Ladislav Jr. [Department of Optics, Palacky University, 17. listopadu 12, CZ-771 46 Olomouc (Czech Republic); School of Physics and Astronomy, University of St. Andrews, North Haugh, St. Andrews, Fife, KY16 9SS, Scotland (United Kingdom); Tatham, Richard; Korolkova, Natalia [School of Physics and Astronomy, University of St. Andrews, North Haugh, St. Andrews, Fife, KY16 9SS, Scotland (United Kingdom); Girolami, Davide; Adesso, Gerardo [School of Mathematical Sciences, University of Nottingham, University Park, Nottingham NG7 2RD (United Kingdom)
2011-04-15
We study quantum correlations beyond entanglement in two-mode Gaussian states of continuous-variable systems by means of the measurement-induced disturbance (MID) and its ameliorated version (AMID). In analogy with the recent studies of the Gaussian quantum discord, we define a Gaussian AMID by constraining the optimization to all bi-local Gaussian positive operator valued measurements. We solve the optimization explicitly for relevant families of states, including squeezed thermal states. Remarkably, we find that there is a finite subset of two-mode Gaussian states comprising pure states where non-Gaussian measurements such as photon counting are globally optimal for the AMID and realize a strictly smaller state disturbance compared to the best Gaussian measurements. However, for the majority of two-mode Gaussian states the unoptimized MID provides a loose overestimation of the actual content of quantum correlations, as evidenced by its comparison with Gaussian discord. This feature displays strong similarity with the case of two qubits. Upper and lower bounds for the Gaussian AMID at fixed Gaussian discord are identified. We further present a comparison between Gaussian AMID and Gaussian entanglement of formation, and classify families of two-mode states in terms of their Gaussian AMID, Gaussian discord, and Gaussian entanglement of formation. Our findings provide a further confirmation of the genuinely quantum nature of general Gaussian states, yet they reveal that non-Gaussian measurements can play a crucial role for the optimized extraction and potential exploitation of classical and nonclassical correlations in Gaussian states.
Correlation of Spatially Filtered Dynamic Speckles in Distance Measurement Application
Semenov, Dmitry V.; Nippolainen, Ervin; Kamshilin, Alexei A. [Department of Physics, University of Kuopio, P.O.B. 1627, FI-70211 Kuopio (Finland); Miridonov, Serguei V. [Optics Department, CICESE, Carr. Tijuana-Ensenada km 107, C.P. 22860, A.P. 360, Ensenada, B.C. (Mexico)
2008-04-15
In this paper statistical properties of spatially filtered dynamic speckles are considered. This phenomenon was not sufficiently studied yet while spatial filtering is an important instrument for speckles velocity measurements. In case of spatial filtering speckle velocity information is derived from the modulation frequency of filtered light power which is measured by photodetector. Typical photodetector output is represented by a narrow-band random noise signal which includes non-informative intervals. Therefore more or less precious frequency measurement requires averaging. In its turn averaging implies uncorrelated samples. However, conducting research we found that correlation is typical property not only of dynamic speckle patterns but also of spatially filtered speckles. Using spatial filtering the correlation is observed as a response of measurements provided to the same part of the object surface or in case of simultaneously using several adjacent photodetectors. Found correlations can not be explained using just properties of unfiltered dynamic speckles. As we demonstrate the subject of this paper is important not only from pure theoretical point but also from the point of applied speckle metrology. E.g. using single spatial filter and an array of photodetector can greatly improve accuracy of speckle velocity measurements.
Absolute Measurement Of Laminar Shear Rate Using Photon Correlation Spectroscopy
Elliot Jenner; Brian D'Urso
2015-05-11
An absolute measurement of the components of the shear rate tensor $\\mathcal{S}$ in a fluid can be found by measuring the photon correlation function of light scattered from particles in the fluid. Previous methods of measuring $\\mathcal{S}$ involve reading the velocity at various points and extrapolating the shear, which can be time consuming and is limited in its ability to examine small spatial scale or short time events. Previous work in Photon Correlation Spectroscopy has involved only approximate solutions, requiring free parameters to be scaled by a known case, or different cases, such as 2-D flows, but here we present a treatment that provides quantitative results directly and without calibration for full 3-D flow. We demonstrate this treatment experimentally with a cone and plate rheometer.
Optimizing quantum correlation dynamics by weak measurement in dissipative environment
NASA Astrophysics Data System (ADS)
Du, Shao-Jiang; Xia, Yun-Jie; Duan, De-Yang; Zhang, Lu; Gao, Qiang
2015-04-01
We investigate the protection of quantum correlations of two qubits in independent vacuum reservoirs by means of weak measurements. It is found that the weak measurement can reduce the amount of quantum correlation for one type of initial state at the beginning in a non-Markovian environment and meanwhile it can reduce the occurrence time of entanglement sudden death (ESD) in the process of time evolution. In a Markovian environment, the quantum entanglements of the two kinds of initial states decay rapidly and the weak measurement can further weaken the quantum entanglement, therefore in this case the entanglement cannot be optimized in the evolution process. Project supported by the National Natural Science Foundation of China (Grant Nos. 61178012 and No.11147019).
Soft defect printability: correlation to optical flux-area measurements
NASA Astrophysics Data System (ADS)
Taylor, Darren; Fiekowsky, Peter
2001-01-01
Soft defects on photomasks have, historically, been difficult to measure, and predict how the measured size of a soft defect will correlate to what prints, if at all. Over the past few years KLA-Tencor STARlight surface inspection has become the inspection of choice for soft defects. Though the capture rate of this tool is exceptional, the defect sizing capability has lacked in accuracy. Customer specifications have traditionally been built around defect size and transmission. If a given defect cannot be accurately sized then it cannot be accurately dispositioned. In this study we are attempting to show a correlation between the AVI defect measurement tool sizing and what actually prints on the wafer. We will show defect sizing both from the KLA-Tencor STARlight and pattern tools, the AVI tool, AIMS and VSS printability data.
Correlation techniques and measurements of wave-height statistics
NASA Technical Reports Server (NTRS)
Guthart, H.; Taylor, W. C.; Graf, K. A.; Douglas, D. G.
1972-01-01
Statistical measurements of wave height fluctuations have been made in a wind wave tank. The power spectral density function of temporal wave height fluctuations evidenced second-harmonic components and an f to the minus 5th power law decay beyond the second harmonic. The observations of second harmonic effects agreed very well with a theoretical prediction. From the wave statistics, surface drift currents were inferred and compared to experimental measurements with satisfactory agreement. Measurements were made of the two dimensional correlation coefficient at 15 deg increments in angle with respect to the wind vector. An estimate of the two-dimensional spatial power spectral density function was also made.
Measurement and correlation of mutual solubilities in 2-butanol + water
Ochi, Kenji; Saito, Tohru; Kojima, Kazuo
1996-03-01
A newly developed laser scattering technique was tested for the determination of mutual solubilities in the 2-butanol + water system at moderate pressures. The liquid-liquid solubility data were measured from the region of solid-liquid equilibria to the upper critical solution temperature. Freezing points in this system were determined by a cooling curve method. A concave curvature of the liquid-liquid line was observed in the vicinity of the freezing points. The solubility data were satisfactorily correlated with Hiranuma`s modification of the Wilson equation. The newly measured data compare favorably with previous measurements.
Length, width and centroid distance as measures of teams tactical performance in youth football.
Folgado, Hugo; Lemmink, Koen A P M; Frencken, Wouter; Sampaio, Jaime
2014-01-01
Small-sided games are commonly used in training and teaching contexts of football. However, few studies have focused on the tactical implications of this type of drills. The aim of this study is to identify how tactical collective behaviour varies with age in different small-sided game formats. We investigated the in-game field position in three different age groups of youth football players [under-9 (n=10; age = 8.5 ± 0.53), under-11 (n=10; age = 10.4 ± 0.52) and under-13 (n=10; age = 12.7 ± 0.48)], participating in two different small-sided game conditions (GK + 3 × 3 + GK and GK + 4 × 4 + GK). A team variable was created based on the players' length per width ratio (lpwratio), and a match variable was calculated as the distance between the centroid of the two teams. Results show that team variable values were influenced by the age of the players, as younger teams tend to present a higher value of lpwratio in their dispersion on the pitch. The variability of this variable also showed a decrease for teams with older players, suggesting a more consistent application of the width (stretching and creating space) and concentration (compressing into a confined area) principles of play and reflecting a higher level of collective tactical behaviour. Match variable showed a larger centroid distance for the older age groups in comparison with the younger players in the GK + 3 × 3 + GK, while all age groups demonstrated similar large centroid distances in the GK + 4 × 4 + GK game format. These results suggest that length and width ratio and centroid distance are useful measures of tactical performance in small-sided games in youth football. PMID:24444244
Comparative Study of Bunch Length And Arrival Time Measurements at FLASH
Schlarb, H.; Azima, A.; Dusterer, S.; Huning, M.; Knabbe, E.A.; Roehrs, M.; Rybnikov, V.; Schmidt, B.; Steffen, B.; /DESY; Ross, M.C.; /SLAC; Schmueser, P.; Winter, A.; /Hamburg U.
2007-04-16
Diagnostic devices to precisely measure the longitudinal electron beam profile and the bunch arrival time require elaborate new instrumentation techniques. At FLASH, two entirely different methods are used. The bunch profile can be determined with high precision by a transverse deflecting RF structure, but the method is disruptive and does not allow to monitor multiple bunches in a macro-pulse train. It is therefore complemented by two non-disruptive electrooptical devices, called EO and TEO. The EO setup uses a dedicated diagnostic laser synchronized to the machine RF. The longitudinal electron beam profile is encoded in the intensity profile of a chirped laser pulse and analyzed by looking at the spectral composition of the pulse. The second setup, TEO, utilizes the TiSa-based laser system used for pump-probe experiments. Here, the temporal electron shape is encoded into the spatial dimension of the laser pulse by an intersection angle between the laser and the electron beam at the EO-crystal. In this paper, we present a comparative study of bunch length and arrival time measurements performed simultaneously with all three experimental techniques.
Knafo, A; Israel, S; Darvasi, A; Bachner-Melman, R; Uzefovsky, F; Cohen, L; Feldman, E; Lerer, E; Laiba, E; Raz, Y; Nemanov, L; Gritsenko, I; Dina, C; Agam, G; Dean, B; Bornstein, G; Ebstein, R P
2008-04-01
Human altruism is a widespread phenomenon that puzzled evolutionary biologists since Darwin. Economic games illustrate human altruism by showing that behavior deviates from economic predictions of profit maximization. A game that most plainly shows this altruistic tendency is the Dictator Game. We hypothesized that human altruistic behavior is to some extent hardwired and that a likely candidate that may contribute to individual differences in altruistic behavior is the arginine vasopressin 1a (AVPR1a) receptor that in some mammals such as the vole has a profound impact on affiliative behaviors. In the current investigation, 203 male and female university students played an online version of the Dictator Game, for real money payoffs. All subjects and their parents were genotyped for AVPR1a RS1 and RS3 promoter-region repeat polymorphisms. Parents did not participate in online game playing. As variation in the length of a repetitive element in the vole AVPR1a promoter region is associated with differences in social behavior, we examined the relationship between RS1 and RS3 repeat length (base pairs) and allocation sums. Participants with short versions (308-325 bp) of the AVPR1a RS3 repeat allocated significantly (likelihood ratio = 14.75, P = 0.001, df = 2) fewer shekels to the 'other' than participants with long versions (327-343 bp). We also implemented a family-based association test, UNPHASED, to confirm and validate the correlation between the AVPR1a RS3 repeat and monetary allocations in the dictator game. Dictator game allocations were significantly associated with the RS3 repeat (global P value: likelihood ratio chi(2) = 11.73, df = 4, P = 0.019). The association between the AVPR1a RS3 repeat and altruism was also confirmed using two self-report scales (the Bardi-Schwartz Universalism and Benevolence Value-expressive Behavior scales). RS3 long alleles were associated with higher scores on both measures. Finally, long AVPR1a RS3 repeats were associated with higher AVPR1a human post-mortem hippocampal messenger RNA levels than short RS3 repeats (one-way analysis of variance (ANOVA): F = 15.04, P = 0.001, df = 14) suggesting a functional molecular genetic basis for the observation that participants with the long RS3 repeats allocate more money than participants with the short repeats. This is the first investigation showing that a common human polymorphism, with antecedents in lower mammals, contributes to decision making in an economic game. The finding that the same gene contributing to social bonding in lower animals also appears to operate similarly in human behavior suggests a common evolutionary mechanism. PMID:17696996
Reliability-guided digital image correlation for image deformation measurement
Pan Bing
2009-03-10
A universally applicable reliability-guided digital image correlation (DIC) method is proposed for reliable image deformation measurement. The zero-mean normalized cross correlation (ZNCC) coefficient is used to identify the reliability of the point computed. The correlation calculation begins with a seed point and is then guided by the ZNCC coefficient. That means the neighbors of the point with the highest ZNCC coefficient in a queue for computed points will be processed first. Thus the calculation path is always along the most reliable direction, and possible error propagation of the conventional DIC method can be avoided. The proposed novel DIC method is universally applicable to the images with shadows, discontinuous areas, and deformation discontinuity. Two image pairs were used to evaluate the performance of the proposed technique, and the successful results clearly demonstrate its robustness and effectiveness.
Technology Transfer Automated Retrieval System (TEKTRAN)
Genetic parameters for length of productive life given the opportunity (LPL|O), measured as days between first calving and disposal conditioned on one of six opportunity groups, (e.g., L2 is length of productive life in days given the opportunity to live 2 yr after first calving), and lifetime produ...
NASA Astrophysics Data System (ADS)
Black, T. C.; Huffman, P. R.; Jacobson, D. L.; Snow, W. M.; Schoen, K.; Arif, M.; Kaiser, H.; Lamoreaux, S. K.; Werner, S. A.
2003-05-01
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 bnd=(6.665±0.004) fm in agreement with the world average of previous measurements using different techniques, bnd=(6.6730±0.0045) fm. We compare the new world average for the nd coherent scattering length bnd=(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 doublet scattering length of 2and=(0.65±0.04) fm.
Improved extended digital image correlation for crack tip deformation measurement
NASA Astrophysics Data System (ADS)
Chen, Jinlong; Zhan, Nan; Zhang, Xiaochuan; Wang, Jixiao
2015-02-01
The objective is to find an appropriate shape function which can enhance the performance of Extended Digital Image Correlation (X-DIC). This paper presents an improved X-DIC methodology to measure the discontinuous deformation across the crack. After simplifying the shape function of crack tip element based on the linear elastic fracture mechanics, non-rectangular subset is proposed to eliminate the effect of the crack width on the measurement accuracy. Then, the work verifies the performance of improved X-DIC by measuring the deformation of a specimen with a mode I crack. Experimental results show that the proposed method is effective at improving the measurement accuracy and enhancing the computational efficiency of X-DIC. In the end, the thesis provides a practical application of improved X-DIC to crack tip deformation measurement.
Correlation between rhinometric measurement methods in healthy young adults.
Numminen, Jura; Ahtinen, Mikko; Huhtala, Heini; Laranne, Jussi; Rautiainen, Markus
2002-01-01
The most common rhinometric measurement methods used in modern rhinology are acoustic rhinometry, rhinomanometry, and nasal peak expiratory flow (PEF) rate. In this prospective study, we wanted to clarifiy whether the parameters given by these three methods in the same subject support each other and can be used simultaneously in clinical practice. We also wanted to define the dimensions of normal nasal geometry and function based on these three methods. The rhinometric measurements were done in 249 healthy white subjects consisting of 171 women and 78 men. The geometry was analyzed with regard to body mass index (BMI) and smoking habits. The result could he used as some kind of reference value for the same kind of patient cohort as when rhinological pathology is investigated. The measurements obtained by acoustic rhinometry showed only statistically significant correlations between the measured volume and minimal cross-sectional area in the nasal cavities (r = 0.959). Rhinomanometry showed only a statistically significant correlation between the measured resistance in expiration and inspiration (r = 0.977). Acoustic rhinometry, rhinomanometry, and nasal PEF did not show any correlations and the BMI did not have any effect on the results. Although the smoking group was relatively small in this cohort, the rhinometric methods showed smaller nasal cavity volume, higher resistance, and lower nasal PEF values. Based on these results, we recommend the use of these three rhinometric methods as independent instruments in rhinological examinations. However, in the pathological nose, e.g., smokers, the methods show equal changes in measurements. It is important to measure at least acoustic rhinometry and rhinomanometry at the same time in clinical practice to achieve good quality of examinations. PMID:12222945
NASA Astrophysics Data System (ADS)
Schoen, K.; Jacobson, D. L.; Arif, M.; Huffman, P. R.; Black, T. C.; Snow, W. M.; Lamoreaux, S. K.; Kaiser, H.; Werner, S. A.
2003-04-01
We have performed high-precision measurements of the coherent neutron scattering lengths of gas phase molecular hydrogen and deuterium using neutron interferometry. After correcting for molecular binding and multiple scattering from the molecule, we find bnp=(-3.7384±0.0020) fm and bnd=(6.6649±0.0040) fm. Our results are in agreement with the world average of previous measurements, bnp=(-3.7410±0.0010) fm and bnd=(6.6727±0.0045) fm. The new world averages for the n-p and n-d coherent scattering lengths, including our new results, are bnp=(-3.7405±0.0009) fm and bnd=(6.6683±0.0030) fm. We compare bnd with the calculations of the doublet and quartet scattering lengths of several nucleon-nucleon potential models and show that almost all known calculations are in disagreement with the precisely measured linear combination corresponding to the coherent scattering length. Combining the world data on bnd with the modern high-precision theoretical calculations of the quartet n-d scattering lengths recently summarized by Friar et al., we deduce a new value for the doublet scattering length of 2and=[0.645±0.003(expt)±0.007(theory)] fm. This value is a factor of 4, more precise than the previously accepted value of 2and=[0.65±0.04(expt)] fm. The current state of knowledge of scattering lengths in the related p-d system, ideas for improving by a factor of 5 the accuracy of the bnp and bnd measurements using neutron interferometry, and possibilities for further improvement of our knowledge of the coherent neutron scattering lengths of 3H, 3He, and 4He are discussed.
Kawashima, Kazuko; Shikama, Hiroshi; Imoto, Kazuhiko; Izawa, Mitsuo; Nishimura, Susumu ); Naruke, Tsuguo; Okabayashi, Kenzo )
1988-04-01
Restriction length fragment polymorphism of the L-MYC gene was examined in DNAs from lung cancer tissues and normal tissues of 51 Japanese patients with lung cancer. In individual patients, no difference was seen between the restriction length fragments of the two alleles of L-MYC (6-kilobase (kb)) and 10-kb fragments in EcoRI digests in lung cancer tissues and normal tissues. But a striking correlation was found between the restriction length fragment polymorphism pattern of L-MYC and the extent of metastasis, particularly to the lymph nodes at the time of surgery: Patients with only the L band (10 kb) had few lymph node metastatic lesions, whereas patients with either the S band (6 kb) or the S and L bands almost always had lymph node metastatic lesion. A similar correlation was found between the presence of the S band and metastases to other organs. This correlation was particularly marked in cases of adenocarcinoma. These results indicate a clear genetic influence on metastases and a consequent poor prognosis for certain patients of lung cancer; L-MYC restriction length fragment polymorphism is thus shown to be a useful marker for predicting the metastatic potential of human lung cancer.
Interplay between computable measures of entanglement and other quantum correlations
Girolami, Davide; Adesso, Gerardo [School of Mathematical Sciences, University of Nottingham, University Park, Nottingham NG7 2RD (United Kingdom)
2011-11-15
Composite quantum systems can be in generic states characterized not only by entanglement but also by more general quantum correlations. The interplay between these two signatures of nonclassicality is still not completely understood. In this work we investigate this issue, focusing on computable and observable measures of such correlations: entanglement is quantified by the negativity N, while general quantum correlations are measured by the (normalized) geometric quantum discord D{sub G}. For two-qubit systems, we find that the geometric discord reduces to the squared negativity on pure states, while the relationship D{sub G}{>=}N{sup 2} holds for arbitrary mixed states. The latter result is rigorously extended to pure, Werner, and isotropic states of two-qudit systems for arbitrary d, and numerical evidence of its validity for arbitrary states of a qubit and a qutrit is provided as well. Our results establish an interesting hierarchy, which we conjecture to be universal, between two relevant and experimentally friendly nonclassicality indicators. This ties in with the intuition that general quantum correlations should at least contain and in general exceed entanglement on mixed states of composite quantum systems.
GONOME: measuring correlations between GO terms and genomic positions
Stanley, Stefan M; Bailey, Timothy L; Mattick, John S
2006-01-01
Background: Current methods to find significantly under- and over-represented gene ontology (GO) terms in a set of genes consider the genes as equally probable "balls in a bag", as may be appropriate for transcripts in micro-array data. However, due to the varying length of genes and intergenic regions, that approach is inappropriate for deciding if any GO terms are correlated with a set of genomic positions. Results: We present an algorithm – GONOME – that can determine which GO terms are significantly associated with a set of genomic positions given a genome annotated with (at least) the starts and ends of genes. We show that certain GO terms may appear to be significantly associated with a set of randomly chosen positions in the human genome if gene lengths are not considered, and that these same terms have been reported as significantly over-represented in a number of recent papers. This apparent over-representation disappears when gene lengths are considered, as GONOME does. For example, we show that, when gene length is taken into account, the term "development" is not significantly enriched in genes associated with human CpG islands, in contradiction to a previous report. We further demonstrate the efficacy of GONOME by showing that occurrences of the proteosome-associated control element (PACE) upstream activating sequence in the S. cerevisiae genome associate significantly to appropriate GO terms. An extension of this approach yields a whole-genome motif discovery algorithm that allows identification of many other promoter sequences linked to different types of genes, including a large group of previously unknown motifs significantly associated with the terms 'translation' and 'translational elongation'. Conclusion: GONOME is an algorithm that correctly extracts over-represented GO terms from a set of genomic positions. By explicitly considering gene size, GONOME avoids a systematic bias toward GO terms linked to large genes. Inappropriate use of existing algorithms that do not take gene size into account has led to erroneous or suspect conclusions. Reciprocally GONOME may be used to identify new features in genomes that are significantly associated with particular categories of genes. PMID:16504139
Measurement and correlation of jet fuel viscosities at low temperatures
NASA Technical Reports Server (NTRS)
Schruben, D. L.
1985-01-01
Apparatus and procedures were developed to measure jet fuel viscosity for eight current and future jet fuels at temperatures from ambient to near -60 C by shear viscometry. Viscosity data showed good reproducibility even at temperatures a few degrees below the measured freezing point. The viscosity-temperature relationship could be correlated by two linear segments when plotted as a standard log-log type representation (ASTM D 341). At high temperatures, the viscosity-temperature slope is low. At low temperatures, where wax precipitation is significant, the slope is higher. The breakpoint between temperature regions is the filter flow temperature, a fuel characteristic approximated by the freezing point. A generalization of the representation for the eight experimental fuels provided a predictive correlation for low-temperature viscosity, considered sufficiently accurate for many design or performance calculations.
Franchignoni, F; Tesio, L; Martino, M T; Benevolo, E; Castagna, M
1998-01-01
A model for prediction of length of stay (LOS, in days) of stroke rehabilitation inpatients was developed, based on patients' age (years) and function at admission (scored on the Functional Independence Measure, FIMSM). One hundred and twenty-nine cases, consecutively admitted to three free-standing rehabilitation centres in Italy, were analyzed. A multiple linear regression using forward stepwise selection procedure was adopted. Median admission and discharge scores were: 57 and 75 for the total FIM score, 29 and 48 for the 13-item motor FIM subscore, 29 and 30 for the 5-item cognitive FIM subscore (potential range: 18-126, 13-91, 5-35, respectively). Median LOS was 44 days (interquartile range 30-62). The logLOS predictive model included three FIM items ("toilet transfer", TTr; "social interaction"; "expression") and patient's age (R2 = 0.48). TTr alone explained 31.3% of the variance of logLOS. These results are consistent with previous American studies, showing that FIM scores at admission are strong predictors of patients' LOS, with the transfer items having the greatest predictive power. PMID:10234877
Measurement of correlated b quark cross sections at CDF
Gerdes, D.; CDF Collaboration
1994-09-01
Using data collected during the 1992--93 collider run at Fermilab, CDF has made measurements of correlated b quark cross section where one b is detected from a muon from semileptonic decay and the second b is detected with secondary vertex techniques. We report on measurements of the cross section as a function of the momentum of the second b and as a function of the azimuthal separation of the two b quarks, for transverse momentum of the initial b quark greater than 15 GeV. Results are compared to QCD predictions.
Collinge, Cory A; Koerner, John D; Yoon, Richard S; Beltran, Michael J; Liporace, Frank A
2015-10-01
Insertion of locking screws through the proximal thigh while locking retrograde femoral nails is arguably more difficult and traumatic to local tissues than locking at other intramedullary nail sites. The purpose of this study was to evaluate whether a "standard" screw length for proximal interlocking of retrograde nails is possible, therefore assessing whether the act of measuring for these screws can be omitted. This article retrospective evaluates screw position and estimated proximal locking screw length in patients undergoing retrograde nailing using a large radiographically measured computed tomography cohort, with validation through a smaller clinical cohort. According to these data, it seems reasonable to skip depth gauge measurement during anteroposterior interlocking of retrograde femoral nails and insert a standard length screw based on location relative to the lesser trochanter. This should decrease the amount of local trauma to the patient at the locking screw site while increasing operating room efficiency by avoiding what can often become a difficult step during the procedure. PMID:25946415
Direct Photon-Hadron Correlations Measured with PHENIX
Megan Connors; for the PHENIX Collaboration
2009-09-24
Direct photon-hadron correlations greatly improve our ability to perform jet tomography in heavy-ion collisions because the momentum of the direct photon can be used to constrain the initial momentum of the opposing jet. By comparing the spectrum of away-side hadrons observed in heavy ion collisions to the spectrum seen in nucleon collisions we can quantify the medium modification to the fragmentation function due to energy loss of the away-side parton. High $p_{T}$ direct photon-hadron correlations have been measured with the PHENIX detector using a statistical subtraction method to remove the photon contribution from meson decays. The increased integrated luminosity in the most recent Au+Au RHIC run at $\\sqrt{s_{NN}}$ = 200 GeV provides substantially improved statistical precision and enhances the kinematic reach. These measurements are compared to PHENIX p+p results and several theoretical models of energy loss. In addition, we compare direct photon-hadron and $\\pi^{0}$-hadron correlations.
Babichenko, V. S., E-mail: vsbabichenko@hotmail.com; Kagan, Yu. [National Research Centre Kurchatov Institute (Russian Federation)
2012-11-15
The influence of multiparticle correlation effects and Cooper pairing in an ultracold Fermi gas with a negative scattering length on the formation rate of molecules is investigated. Cooper pairing is shown to cause the formation rate of molecules to increase, as distinct from the influence of Bose-Einstein condensation in a Bose gas on this rate. This trend is retained in the entire range of temperatures below the critical one.
Single-Molecule Measurements of the Persistence Length of Double-Stranded RNA
Dekker, Cees
persistence length, which is the basic mechanical property that quantifies its stiffness. The persistence is the cycli- zation of plasmids (Shore et al., 1981). Estimates of both the stretching and torsional
Offset balancing in pseudo-correlation radiometers for CMB measurements
Aniello Mennella; Marco Bersanelli; Michael Seiffert; Danielle Kettle; Neil Roddis; Althea Wilkinson; Peter Meinhold
2003-08-25
Radiometeric CMB measurements need to be highly stable and this stability is best obtained with differential receivers. The residual 1/f noise in the differential output is strongly dependent on the radiometer input offset which can be cancelled using various balancing strategies. In this paper we discuss a software method implemented in the Planck-LFI pseudo-correlation receivers which uses a tunable "gain modulation factor, r, in the sky-load difference. Numerical simulations and experimental data show how proper tuning of the parameter r ensures a very stable differential output with knee frequencies of the order of few mHz. Various approaches to calculate r using the radiometer total power data are discussed with some examples relevant to Planck-LFI. Although the paper focuses on pseudo-correlation receivers and the examples are relative to Planck-LFI, the proposed method and its analysis is general and can be applied to a large class of differential radiometric receivers.
ERIC Educational Resources Information Center
Steinbrink, Claudia; Groth, Katarina; Lachmann, Thomas; Riecker, Axel
2012-01-01
This fMRI study investigated phonological vs. auditory temporal processing in developmental dyslexia by means of a German vowel length discrimination paradigm (Groth, Lachmann, Riecker, Muthmann, & Steinbrink, 2011). Behavioral and fMRI data were collected from dyslexics and controls while performing same-different judgments of vowel duration in…
Jens Jorgen Hyldig-Nielsen; Niels Morling; Niels Odum; Lars P. Ryder; Per Platz; Bodil Jakobsen; Arne Svejgaard
1987-01-01
The restriction fragment length polymorphism (RFLP) of the class II HLA-DP subregion of the major histocompatibility complex (MHC) of humans has been unraveled by Southern blotting using DPalpha and DPbeta probes in a study of 46 unrelated individuals with known HLA-DP types. Contrary to earlier preliminary findings with a limited number of enzymes, the RFLP appears to be quite extensive
Vasileiou, Alexandros A; Kontopoulou, Marianna; Gui, Hua; Docoslis, Aristides
2015-01-28
The objectives of this work are to quantify the degree of multiwalled carbon nanotube (MWCNT) length reduction upon melt compounding and to demonstrate unambiguously that the length reduction is mainly responsible for the increase in electrical percolation threshold of the resulting composites. Polyolefin matrices of varying viscosities and different functional groups are melt compounded with MWCNTs. A simple method is developed to solubilize the polymer matrix and isolate the MWCNTs, enabling detailed imaging analysis. In spite of the perceived strength of the MWCNTs, the results demonstrate that the shear forces developed during melt mixing are sufficient to cause significant nanotube breakage and length reduction. Breakage is promoted when higher MWCNT contents are used, due to increased probability of particle collisions. Furthermore, the higher shear forces transmitted to the nanotubes in the presence of higher matrix viscosities and functional groups that promote interfacial interactions, shift the nanotube distribution toward smaller sizes. The length reduction of the MWCNTs causes significant increases in the percolation threshold, due to the loss of interconnectivity, which results in fewer conductive pathways. These findings are validated by comparing the experimental percolation threshold values with those predicted by the improved interparticle distance theoretical model. PMID:25548884
NASA Astrophysics Data System (ADS)
Lou, X. T.; Somesfalean, G.; Zhang, Z. G.; Svanberg, S.
2009-03-01
The important air pollutant sulfur dioxide has a strong structured absorption band in the ultraviolet (UV) region around 300 nm. Recently, light-emitting diodes (LEDs) with structureless emission in a band about 15-nm wide in the UV region have become available. We demonstrate that they can be ideal sources for gas absorption measurements combined with the gas correlation technique, where an absorption cell with an optically thick column of the gas under investigation is used for analysing the target gas contents in a path between the LED and the measurement device. A sensitivity of 0.4 ppm sulfur dioxide was obtained with a 19-cm optical path length and 60-s integration time. Particularly compact and cost-effective monitors especially for industrial emissions can be envisaged.
Some measurements of time and space correlation in wind tunnel
NASA Technical Reports Server (NTRS)
Favre, A; Gaviglio, J; Dumas, R
1955-01-01
Results are presented of research obtained by means of an apparatus for measurement of time and space correlation and of a spectral analyzer in the study of the longitudinal component of turbulence velocities in a wind tunnel downstream of a grid of meshes. Application to the case of a flat-plate boundary layer is illustrated. These researches were made at the Laboratoire de Mecanique de l'Atmosphere de l'I.M.F.M. for the O.N.E.R.A.
Z KESSAISSIA; E. Z. Papirer; J. B. Donnet
1981-01-01
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
F. Tamura; H. Mizuno
1997-01-01
In order to control the driving RF phase at the input of the accelerating structure of X-band linear collider main linacs, it is necessary to measure the length of the long TE01 mode delay lines of 40-80 m. A new measurement scheme by using the low frequency resonant mode of the TE01 mode delay line was proposed. The delay lines
Kessaissia, Z. Papirer, E.; Donnet, J.B.
1981-08-01
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.
Strongly correlated two-dimensional plasma explored from entropy measurements.
Kuntsevich, A Y; Tupikov, Y V; Pudalov, V M; Burmistrov, I S
2015-01-01
Charged plasma and Fermi liquid are two distinct states of electronic matter intrinsic to dilute two-dimensional electron systems at elevated and low temperatures, respectively. Probing their thermodynamics represents challenge because of lack of an adequate technique. Here, we report a thermodynamic method to measure the entropy per electron in gated structures. Our technique appears to be three orders of magnitude superior in sensitivity to a.c. calorimetry, allowing entropy measurements with only 10(8) electrons. This enables us to investigate the correlated plasma regime, previously inaccessible experimentally in two-dimensional electron systems in semiconductors. In experiments with clean two-dimensional electron system in silicon-based structures, we traced entropy evolution from the plasma to Fermi liquid regime by varying electron density. We reveal that the correlated plasma regime can be mapped onto the ordinary non-degenerate Fermi gas with an interaction-enhanced temperature-dependent effective mass. Our method opens up new horizons in studies of low-dimensional electron systems. PMID:26099565
Grütter, Peter
Detection and Correction of Blinking Bias in Image Correlation Transport Measurements of Quantum in the measurements due to blinking. Image correlation mea- surements of the diffusing QD samples measured demonstrate application of the image correlation methods for measurement of the diffusion coefficient
Masahiro Daibo; Toshio Kikuchi; Masahito Yoshizawa
2003-01-01
We evaluated single crystal silicon wafers with a p-n junction structure using a laser superconducting quantum interference device (SQUID) microscope. A high temperature superconductor SQUID magnetometer was used to detect photogenerated magnetic signals with an amplitude of several pico-tesla. The relationship between the photogenerated magnetic fields and the wavelengths of the excitation light was investigated. The minority carrier diffusion length
Measurements of the aeolian sand transport saturation length B. Andreotti a
is the length needed for the sand flux to adapt to a change in wind strength. The influence of the wind shear. In particular, a situation in which external parameters (e.g. the basal shear stress or the bed roughness) vary is almost independent of the wind strength. This result supports the idea that grain inertia is the dominant
Measurement of the imaginary part of the I = 1 N-barN S-wave scattering length
Mutchler, G.S.; Clement, J.; Kruk, J.; Moss, R.; Hungerford, E.; Kishimoto, T.; Mayes, B.; Pinsky, L.; Tang, L.; Xue, Y.; and others
1988-08-01
The survival time spectrum of slow antineutrons produced in a liquid-hydrogen target has been measured. From these data the imaginary part of the I = 1 spin-averaged S-wave antineutron proton scattering length has been deduced to be Ima/sub 1/ = -0.83 +- 0.07 fm. The result lies within the range of values calculated from current potential models. In addition, by combining a/sub 1/ with the antiproton-proton scattering length deduced from antiprotonic atoms, the imaginary part of the I = 0 spin-averaged N-barN scattering length was calculated to be Ima/sub 0/ = -1.07 +- 0.16 fm.
Gonzalez Trotter, D.E.; Salinas, F.; Chen, Q.; Crowell, A.S.; Howell, C.R.; Roper, C.D.; Tornow, W.; Walter, R.L. [Duke University and Triangle Universities Nuclear Laboratory, Durham, North Carolina 27708 (United States)] [Duke University and Triangle Universities Nuclear Laboratory, Durham, North Carolina 27708 (United States); Gloeckle, W. [Institut fuer Theoretische Physik, Ruhr-Universitaet Bochum, D-44780 Bochum (Germany)] [Institut fuer Theoretische Physik, Ruhr-Universitaet Bochum, D-44780 Bochum (Germany); Schmidt, D. [Physikalisch-Technische Bundesanstalt, D-38116 Braunschweig (Germany)] [Physikalisch-Technische Bundesanstalt, D-38116 Braunschweig (Germany); Slaus, I. [Rudjer Boskovic Institute, Zagreb (Croatia)] [Rudjer Boskovic Institute, Zagreb (Croatia); Tang, H.; Zhou, Z. [Chinese Institute for Atomic Energy, Beijing, People`s Republic of (China)] [Chinese Institute for Atomic Energy, Beijing, People`s Republic of (China); Witala, H. [Institute of Physics, Jagellonian University, PL-30059 Cracow (Poland)] [Institute of Physics, Jagellonian University, PL-30059 Cracow (Poland)
1999-11-01
This paper reports high-accuracy cross-section data taken for identical kinematic conditions of the neutron-proton (np) and neutron-neutron (nn) final-state interactions in the {sup 2}H( n,thinspnnp) reaction at an incident mean neutron energy of 13.0thinspthinspMeV. These data were analyzed with rigorous three-nucleon calculations to determine the {sup 1}S{sub 0} np and nn scattering lengths, a{sub np} and a{sub nn} . Our results are a{sub nn}={minus}18.7{plus_minus}0.6 fm and a{sub np}={minus}23.5{plus_minus}0.8 fm . The value obtained for a{sub nn} in the present work is in agreement with that from {pi}{sup {minus}}d measurements but disagrees with values obtained from earlier neutron-deuteron breakup studies. {copyright} {ital 1999} {ital The American Physical Society}
NSDL National Science Digital Library
American Association for the Advancement of Science (; )
2005-03-28
This Science Update explores male agression patterns and their correlation to pre-natal testosterone exposure. Although life experience plays a huge role in shaping who we are, the foundations of our personality begin in the womb. One recent study looks to finger length for signs of a man's pre-natal exposure to testosterone.n women, the index and ring finger are roughly equal in length. But in most men, the ring finger is longer. That's a result of fetal exposure to testosterone. Psychologists Alison Bailey and Pete Hurd, of the University of Alberta in Canada, studied these finger ratios in male college students. And they found that men with more dramatic differences tended to be more aggressive. Additional links to resources are given for further inquiry.
Correlates of objectively measured physical activity in obese children.
Morgan, Philip J; Okely, Anthony D; Cliff, Dylan P; Jones, Rachel A; Baur, Louise A
2008-12-01
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 commencement in a treatment trial. Correlates examined included age, BMI z, parental BMI, perceived competence, health-related quality of life, daily minutes spent in small screen recreation (SSR), and fundamental motor skill (FMS) proficiency. Physical activity was assessed using accelerometers and values were calculated for % of monitored time spent in moderate- (MPA) and vigorous (VPA)-intensity physical activity and mean counts per minute (CPM). Analyses were conducted separately for boys and girls. Motor skill proficiency was significantly correlated with a number of physical activity variables for boys and girls. For boys, regression analysis revealed object-control proficiency predicted CPM (R(2) = 0.25) and age was a predictor of %MPA (R(2) = 0.56). Age and object-control skill proficiency were salient predictors of %VPA (R(2) = 0.34). For girls, age and daily minutes of SSR were the only significant predictors for CPM (R(2) = 0.13). Age was the sole predictor of %MPA (R(2) = 0.38) and %VPA (R(2) = 0.15). The targeting of FMSs at an early age should be tested in experimental studies as potential strategies to increase physical activity among obese children, particularly for boys. Interventions aimed at reducing sedentary behaviors among obese girls should also be considered. PMID:18927553
Shaw, A.; Ghosh, A.
2014-10-28
We have studied the mixed network former effect on the dynamics of lithium ions in borotellurite glasses in wide composition and temperature ranges. The length scales of ion dynamics, such as characteristic mean square displacement and spatial extent of sub-diffusive motion of lithium ions have been determined from the ac conductivity and dielectric spectra, respectively, in the framework of linear response theory. The relative concentrations of different network structural units have been determined from the deconvolution of the FTIR spectra. A direct correlation between the ion dynamics and the characteristic length scales and the relative concentration of BO{sub 4} units has been established for different compositions of the borotellurite glasses.
Measurements of 3D slip velocities and plasma column lengths of a gliding arc discharge
NASA Astrophysics Data System (ADS)
Zhu, Jiajian; Gao, Jinlong; Ehn, Andreas; Aldén, Marcus; Li, Zhongshan; Moseev, Dmitry; Kusano, Yukihiro; Salewski, Mirko; Alpers, Andreas; Gritzmann, Peter; Schwenk, Martin
2015-01-01
A non-thermal gliding arc discharge was generated at atmospheric pressure in an air flow. The dynamics of the plasma column and tracer particles were recorded using two synchronized high-speed cameras. Whereas the data analysis for such systems has previously been performed in 2D (analyzing the single camera image), we provide here a 3D data analysis that includes 3D reconstructions of the plasma column and 3D particle tracking velocimetry based on discrete tomography methods. The 3D analysis, in particular, the determination of the 3D slip velocity between the plasma column and the gas flow, gives more realistic insight into the convection cooling process. Additionally, with the determination of the 3D slip velocity and the 3D length of the plasma column, we give more accurate estimates for the drag force, the electric field strength, the power per unit length, and the radius of the conducting zone of the plasma column.
Pourmand, Nader; Caramuta, Stefano; Villablanca, Andrea; Mori, Silvia; Karhanek, Miloslav; Wang, Shan X; Davis, Ronald W
2007-04-10
The analysis of short tandem repeats (STRs) plays an important role in forensic science, human identification, genetic mapping, and disease diagnostics. Traditional STR analysis utilizes gel- or column-based approaches to analyze DNA repeats. Individual STR alleles are separated and distinguished according to fragment length; thus the assay is generally hampered by its low multiplex capacity. However, use of DNA microarray would employ a simple hybridization and detection for field forensics and biology. Here we demonstrate a rapid, highly sensitive method for STR analysis that utilizes DNA microarray technology. We describe two adaptations to accomplish this: the use of competitive hybridization to remove unpaired ssDNA from an array and the use of neural network classification to automate the analysis. The competitive displacement technique mimics the branch migration process that occurs during DNA recombination. Our technique will facilitate the rapid deduction of identity, length, and number of repeats for the multiple STRs in an unknown DNA sample. PMID:17389407
Du, Hong-Yan; Pumbo, Elena; Ivanovich, Jennifer; An, Ping; Maziarz, Richard T.; Reiss, Ulrike M.; Chirnomas, Deborah; Shimamura, Akiko; Vlachos, Adrianna; Lipton, Jeffrey M.; Goyal, Rakesh K.; Goldman, Frederick; Wilson, David B.; Mason, Philip J.
2009-01-01
Dyskeratosis congenita (DC) is a rare inherited form of bone marrow failure (BMF) caused by mutations in telomere maintaining genes including TERC and TERT. Here we studied the prevalence of TERC and TERT gene mutations and of telomere shortening in an unselected population of patients with BMF at our medical center and in a selected group of patients referred from outside institutions. Less than 5% of patients with BMF had pathogenic mutations in TERC or TERT. In patients with BMF, pathogenic TERC or TERT gene mutations were invariably associated with marked telomere shortening (? 1st percentile) in peripheral blood mononuclear cells (PBMCs). In asymptomatic family members, however, telomere length was not a reliable predictor for the presence or absence of a TERC or TERT gene mutation. Telomere shortening was not pathognomonic of DC, as approximately 30% of patients with BMF due to other causes had PBMC telomere lengths at the 1st percentile or lower. We conclude that in the setting of BMF, measurement of telomere length is a sensitive but nonspecific screening method for DC. In the absence of BMF, telomere length measurements should be interpreted with caution. PMID:18931339
Water Velocity Measurement on an Extended-Length Submerged Bar Screen at John Day Dam
Weiland, Mark A.; Escher, Charles
2001-04-02
This report describes a study of water velocity around an extended-length submerged bar screen (ESBS) at John Day Dam. The study was conducted for the U.S. Army Corps of Engineers by AScI Corporation and MEVATEC Corporation in March of 2000. This report was prepared by Pacific Northwest National Laboratory. ESBS are being studied as one method for diverting juvenile migrating fish from the dam's turbine intakes into the gate well and through the juvenile fish bypass channels.
Sannibale, Fernando; Zolotorev, Max S.; Filippetto, Daniele; Stupakov, Gennady V.
2007-06-22
By analysing the pulse to pulse intensity fluctuations ofthe radiation emitted by a charge particle in the incoherent part of thespectrum, it is possible to extract information about the spatialdistribution of the beam. At the Advanced Light Source (ALS) of theLawrence Berkeley National Laboratory, we have developed and tested asimple scheme based on this principle that allows for the absolutemeasurement of the bunch length. A description of the method and theexperimental results are presented.
Measuring the first two statistics moments using the Correlator resources
NASA Astrophysics Data System (ADS)
Saez, A.; Herrera, D.; Sepulveda, Jorge
2014-07-01
The ALMA telescope is composed of 66 high precision antennas, each antenna having 8 high bandwidth digitizers (4Gsamples/Second). It is a critical task to determine the well functioning of those digitizers prior to starting a round of observations. Since observation time is a valuable resource, it is germane that a tool be developed which can provide a quick and reliable answer regarding the digitizer status. Currently the digitizer output statistics are measured by using comparators and counters. This method introduced uncertainties due to the low amount of integration, in addition to going through all the possible states for all available digitizer time which all resulted in the antennas taking a considerable amount of time. In order to avoid the aforementioned described problems, a new method based on correlator resources is hereby presented.
Measure Factors, Tension, and Correlations of Fluid Membranes
W. Cai; T. C. Lubensky; P. Nelson; T. Powers
1994-01-20
We study two geometrical factors needed for the correct construction of statistical ensembles of surfaces. Such ensembles appear in the study of fluid bilayer membranes, though our results are more generally applicable. The naive functional measure over height fluctuations must be corrected by these factors in order to give correct, self-consistent formulas for the free energy and correlation functions of the height. While one of these corrections -- the Faddeev-Popov determinant -- has been studied extensively, our derivation proceeds from very simple geometrical ideas, which we hope removes some of its mystery. The other factor is similar to the Liouville correction in string theory. Since our formulas differ from those of previous authors, we include some explicit calculations of the effective frame tension and two-point function to show that our version indeed secures coordinate-invariance and consistency to lowest nontrivial order in a temperature expansion.
NASA Astrophysics Data System (ADS)
Debartolo, Janae; Karunaratne, V. N. C.; Berry, Justin; Lurio, Laurence; Thurston, George; Sandy, Alec; Narayanan, Suresh; Weizeorick, John
2010-03-01
X-ray photon correlation spectroscopy (XPCS) has been applied in recent years to the study of dynamics within a wide range of soft materials. Its application to protein diffusion has been hindered by the weak scattering and the susceptibility of proteins to damage. We report the first application of XPCS to study the dynamics of concentrated suspensions of alpha and gamma crystallin proteins extracted from bovine eye-lens. The limitations of low flux and x-ray damage were overcome through a combination of a fast, high efficiency CCD, a kinoform lens and by limiting exposures to short intervals. Dynamics were measured both for alpha crystallin suspended in a concentrated matrix of gamma crystallin and concentrated alpha crystallin suspensions, showing time constants of a few tens of milliseconds at length scales corresponding to the protein diameter.
NASA Astrophysics Data System (ADS)
Ray, Suman; Chakrabarti, Sandip Kumar; Sasmal, Sudipta
We present results of year-long analysis of VLF signals, both for VTX-Malda (`west-east' propagation path) and VTX-Pune (`east-west' propagation path). We analyzed whole year data of 2008 and 2009 for VTX-Malda and VTX-Pune propagation path, respectively. In both the cases we found that `VLF day-length' (defined as time difference between sunset terminator time and sunrise terminator time) became anomalously high 1-2 days before an earthquake. Besides this year-long study we have also done some case by case analysis. On 9th January, 2009 an earthquake of magnitude 5.5 occurred at Carlsberg Ridge (latitude 10.3(°) N, longitude 57.1(°) E). In a separate incident, on 3rd November, 2009, another earthquake of magnitude 5.4 occurred at Andaman Islands (latitude 14.1(°) N, longitude 93.1(°) E). We analyze VLF signals for VTX-Pune (`east-west’ propagation path) propagation path around these two earthquake days and found that for both of these cases, the `VLF-day-length' became anomalously high two days before the event. This agrees well with statistical analysis based on year-long data for VTX-Pune path. Furthermore, during time period of June, 2010, two major earthquakes of low-depth ( 10Km) and high magnitude (M>5) occurred near NWC-Salt Lake (east-west propagation path) propagation paths. First one occurred on 13th June, 2010 at Nicobar Islands, India (latitude 7.8(°) N, longitude 92.0(°) E). Its magnitude was 5.1 (in Richter scale). The second one of magnitude 6.0 (in Richter Scale) occurred on 19th June, 2010 at Andaman Islands, India (latitude 13.4(°) N, longitude 93.0(°) E). For both of these two earthquakes, we found that VLF-day-length, became anomalously high one day before earthquakes. We claim that these were pre-cursors of the earthquakes which occurred in Andaman and Nicober Islands.
Real-time pulse length measurement of few-cycle laser pulses using above-threshold ionization.
Sayler, A M; Rathje, Tim; Müller, W; Kürbis, Ch; Rühle, Klaus; Stibenz, Gero; Paulus, G G
2011-02-28
The pulse lengths of intense few-cycle (4-10 fs) laser pulses at 790 nm are determined in real-time using a stereographic above-threshold ionization (ATI) measurement of Xe, i.e. the same apparatus recently shown to provide a precise, real-time, every-single-shot, carrier-envelope phase measurement of ultrashort laser pulses. The pulse length is calibrated using spectral-phase interferometry for direct electric-field reconstruction (SPIDER) and roughly agrees with calculations done using quantitative rescattering theory (QRS). This stereo-ATI technique provides the information necessary to characterize the waveform of every pulse in a kHz pulse train, within the Gaussian pulse approximation, and relies upon no theoretical assumptions. Moreover, the real-time display is a highly effective tool for tuning and monitoring ultrashort pulse characteristics. PMID:21369278
NASA Astrophysics Data System (ADS)
Michel, D. T.; Davis, A. K.; Goncharov, V. N.; Sangster, T. C.; Hu, S. X.; Igumenshchev, I. V.; Meyerhofer, D. D.; Seka, W.; Froula, D. H.
2015-04-01
Measurements of the conduction-zone length (110 ±20 ? m at t =2.8 ns ), the averaged mass ablation rate of the deuterated plastic (7.95 ±0.3 ? g /ns ), shell trajectory, and laser absorption are made in direct-drive cryogenic implosions and are used to quantify the electron thermal transport through the conduction zone. Hydrodynamic simulations that use nonlocal thermal transport and cross-beam energy transfer models reproduce these experimental observables. Hydrodynamic simulations that use a time-dependent flux-limited model reproduce the measured shell trajectory and the laser absorption but underestimate the mass ablation rate by ˜10 % and the length of the conduction zone by nearly a factor of 2.
NASA Astrophysics Data System (ADS)
Rajon, D. A.; Jokisch, D. W.; Patton, P. W.; Shah, A. P.; Watchman, C. J.; Bolch, W. E.
2002-05-01
Chord-length distributions through the trabecular regions of the skeleton have been investigated since the early 1960s. These distributions have become important features for bone marrow dosimetry; as such, current models rely on the accuracy of their measurements. Recent techniques utilize nuclear magnetic resonance (NMR) microscopy to acquire 3D images of trabecular bone that are then used to measure 3D chord-length distributions by Monte Carlo methods. Previous studies have shown that two voxel effects largely affect the acquisition of these distributions within digital images. One is particularly pertinent as it dramatically changes the shape of the distribution and reduces its mean. An attempt was made to reduce this undesirable effect and good results were obtained for a single-sphere model using minimum acceptable chord (MAC) methods (Jokisch et al 2001 Med. Phys. 28 1493-504). The goal of the present work is to extend the study of these methods to more general models in order to better quantify their consequences. First, a mathematical model of a trabecular bone sample was used to test the usefulness of the MAC methods. The results showed that these methods were not efficient for this simulated bone model. These methods were further tested on a single voxelized sphere over a large range of voxel sizes. The results showed that the MAC methods are voxel-size dependent and overestimate the mean chord length for typical resolutions used with NMR microscopy. The study further suggests that bone and marrow chord-length distributions currently utilized in skeletal dosimetry models are most likely affected by voxel effects that yield values of mean chord length lower than their true values.
Rajon, D A; Jokisch, D W; Patton, P W; Shah, A P; Watchman, C J; Bolch, W E
2002-05-21
Chord-length distributions through the trabecular regions of the skeleton have been investigated since the early 1960s. These distributions have become important features for bone marrow dosimetry; as such, current models rely on the accuracy of their measurements. Recent techniques utilize nuclear magnetic resonance (NMR) microscopy to acquire 3D images of trabecular bone that are then used to measure 3D chord-length distributions by Monte Carlo methods. Previous studies have shown that two voxel effects largely affect the acquisition of these distributions within digital images. One is particularly pertinent as it dramatically changes the shape of the distribution and reduces its mean. An attempt was made to reduce this undesirable effect and good results were obtained for a single-sphere model using minimum acceptable chord (MAC) methods (Jokisch et al 2001 Med. Phys. 28 1493-504). The goal of the present work is to extend the study of these methods to more general models in order to better quantify their consequences. First, a mathematical model of a trabecular bone sample was used to test the usefulness of the MAC methods. The results showed that these methods were not efficient for this simulated bone model. These methods were further tested on a single voxelized sphere over a large range of voxel sizes. The results showed that the MAC methods are voxel-size dependent and overestimate the mean chord length for typical resolutions used with NMR microscopy. The study further suggests that bone and marrow chord-length distributions currently utilized in skeletal dosimetry models are most likely affected by voxel effects that yield values of mean chord length lower than their true values. PMID:12069091
Correlated Protein Motion Measurements of Dihydrofolate Reductase Crystals
NASA Astrophysics Data System (ADS)
Xu, Mengyang; Niessen, Katherine; Pace, James; Cody, Vivian; Markelz, Andrea
2014-03-01
We report the first direct measurements of the long range structural vibrational modes in dihydrofolate reductase (DHFR). DHFR is a universal housekeeping enzyme that catalyzes the reduction of 7,8-dihydrofolate to 5,6,7,8-tetra-hydrofolate, with the aid of coenzyme nicotinamide adenine dinucleotide phosphate (NADPH). This crucial enzymatic role as the target for anti-cancer [methotrexate (MTX)], and other clinically useful drugs, has made DHFR a long-standing target of enzymological studies. The terahertz (THz) frequency range (5-100 cm-1), corresponds to global correlated protein motions. In our lab we have developed Crystal Anisotropy Terahertz Microscopy (CATM), which directly measures these large scale intra-molecular protein vibrations, by removing the relaxational background of the solvent and residue side chain librational motions. We demonstrate narrowband features in the anisotropic absorbance for mouse DHFR with the ligand binding of NADPH and MTX single crystals as well as Escherichia coli DHFR with the ligand binding of NADPH and MTX single crystals. This work is supported by NSF grant MRI2 grant DBI2959989.
Robinson, M.A. )
1989-12-01
Direct sequence analysis of the human T-cell antigen receptor (TCR) V{sub {beta}1} variable gene identified a single base-pair allelic variation (C/G) located within the coding region. This change results in substitution of a histidine (CAC) for a glutamine (CAG) at position 48 of the TCR {beta} chain, a position predicted to be in the TCR antigen binding site. The V{sub {beta}1} polymorphism was found by DNA sequence analysis of V{sub {beta}1} genes from seven unrelated individuals; V{sub {beta}1} genes were amplified by the polymerase chain reaction, the amplified fragments were cloned into M13 phage vectors, and sequences were determined. To determined the inheritance patterns of the V{sub {beta}1} substitution and to test correlation with V{sub {beta}1} restriction fragment length polymorphism detected with Pvu II and Taq I, allele-specific oligonucleotides were constructed and used to characterize amplified DNA samples. Seventy unrelated individuals and six families were tested for both restriction fragment length polymorphism and for the V{sub {beta}1} substitution. The correlation was also tested using amplified, size-selected, Pvu II- and Taq I-digested DNA samples from heterozygotes. Pvu II allele 1 (61/70) and Taq I allele 1 (66/70) were found to be correlated with the substitution giving rise to a histidine at position 48. Because there are exceptions to the correlation, the use of specific probes to characterize allelic forms of TCR variable genes will provide important tools for studies of basic TCR genetics and disease associations.
Measurement of laminar burning speeds and Markstein lengths using a novel methodology
Tahtouh, Toni; Halter, Fabien; Mounaim-Rousselle, Christine
2009-09-15
Three different methodologies used for the extraction of laminar information are compared and discussed. Starting from an asymptotic analysis assuming a linear relation between the propagation speed and the stretch acting on the flame front, temporal radius evolutions of spherically expanding laminar flames are postprocessed to obtain laminar burning velocities and Markstein lengths. The first methodology fits the temporal radius evolution with a polynomial function, while the new methodology proposed uses the exact solution of the linear relation linking the flame speed and the stretch as a fit. The last methodology consists in an analytical resolution of the problem. To test the different methodologies, experiments were carried out in a stainless steel combustion chamber with methane/air mixtures at atmospheric pressure and ambient temperature. The equivalence ratio was varied from 0.55 to 1.3. The classical shadowgraph technique was used to detect the reaction zone. The new methodology has proven to be the most robust and provides the most accurate results, while the polynomial methodology induces some errors due to the differentiation process. As original radii are used in the analytical methodology, it is more affected by the experimental radius determination. Finally, laminar burning velocity and Markstein length values determined with the new methodology are compared with results reported in the literature. (author)
Riemslag, A.C. . Lab. of Materials Science)
1994-09-01
A new automated method of measuring fatigue cracks in polymers is discussed. The new method is based on a video signal of the crack which is analyzed with image processing techniques. With this technique the crack length is measured every 20 s during a fatigue test. The accuracy of one single measurement is about 0.05 mm, but this can be increased by averaging a large number of measurements. The applied automated data collection and subsequent data processing is discussed in relation to the recommendations given in ASTM E 647, Test method for Measurement of Fatigue Crack Growth Rates. The use of the new technique is illustrated on the basis of fatigue tests performed on transparent polycarbonate (PC) and nontransparent polyethylene (PE). The fatigue behavior of PE and PC is briefly discussed.
Chu, Zonglin; Feng, Yujun
2012-01-17
Long-chain amidosulfobetaine surfactants, 3-(N-fattyamidopropyl-N,N-dimethyl ammonium) propanesulfonates (n-DAS, n > 18), are insoluble in pure water due to their high Krafft temperature (T(K)), while they are soluble when inorganic salt is added to the surfactant solution as the T(K) of these zwitterionic surfactants is decreased. The influence of the salt content and ionic species of the added electrolytes on the T(K) of the series of amidosulfobetaine surfactants was examined by means of UV-vis spectrophometry and visual inspection. It was found that the T(K) of these surfactants depends strongly on not only the hydrophobic alkyl length (n), but also the salinity of the aqueous environment. When the salt concentration is increased from 0 to 100 mM, the T(K) shows a sharp decrease; when the salinity is fixed between 100 and 2000 mM, the T(K) varies linearly with n with a slope of ~7.7 irrespective of the salt species and the salt content. When the salt concentration is further increased above 2000 mM, a linear function is still observed, but the slope increases slightly. PMID:22149531
NASA Astrophysics Data System (ADS)
Kegel, W. H.; Piehler, G.; Albrecht, M. A.
1993-03-01
We investigated the formation of interstellar molecular lines in a turbulent velocity field with finite correlation length, extending previous work (Albrecht and Kegel, 1987) to the regime sigma much greater than V(therm). For this we transformed the generalized transfer equation by introducing a new, Delta(nu)-dependent velocity coordinate the origin of which corresponds to the center of the profile of the absorption coefficient. This transformation allows in the case of sigma much greater than V(therm) to reduce the numerical effort considerably. We give numerical results for NLTE-calculations for a 10-level CO molecule for (sigma/v(therm)) = 20 as well as for comparison for sigma = v(therm). Our results show that a finite correlation length affects strongly the line profiles, the line width, and the intensity ratios. At low densities also the excitation conditions are effected, i.e., the NLTE-effects are modified. These effects increase with inceasing ratio sigma/v(therm).
Measurement of the minority carrier diffusion length and edge surface-recombination velocity in InP
NASA Technical Reports Server (NTRS)
Bailey, Sheila G.; Hakimzadeh, Roshanak
1993-01-01
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).
Parker, A J; Davies, P; Newton, J R
1982-10-01
Two populations of pregnant Asian and European women were scanned using linear array real-time ultrasound machines. Measurements were made of fetal crown-rump length (CRL) up to 14 weeks gestational age and of biparietal diameter (BPD) up to 20 weeks gestational age. Polynomial growth curves relating CRL and BPD measurements to their gestational ages were fitted to the data by the method of unweighted least squares. There were no significant differences between the Asian and European parameters for the CRL and BPD curves. European nomograms may be used to establish Asian fetal gestational age up to 20 weeks. PMID:7126504
Brown, Dean P; Brown, Thomas G
2008-12-01
Correlations in the illumination field have a profound impact on the image contrast for features near the resolution limit. The pupil polarization affects these correlations. We show that a polarization vortex has a particularly dramatic effect. A theoretical model is given for the correlation matrix of a partially correlated source created by placing an azimuthal polarization vortex mode converter in the pupil plane of a critical illumination system. We then validate this model experimentally using a reversed-wavefront Young interferometer, directly show the impact that the phase of the correlation function has on image contrast. PMID:19065180
Ning, Peng; Li, Sa; White, Philip J.; Li, Chunjian
2015-01-01
Larger, and deeper, root systems of new maize varieties, compared to older varieties, are thought to have enabled improved acquisition of soil resources and, consequently, greater grain yields. To compare the spatial distributions of the root systems of new and old maize varieties and their relationships with spatial variations in soil concentrations of available nitrogen (N), phosphorus (P) and potassium (K), two years of field experiments were performed using six Chinese maize varieties released in different eras. Vertical distributions of roots, and available N, P and K in the 0–60 cm soil profile were determined in excavated soil monoliths at silking and maturity. The results demonstrated that new maize varieties had larger root dry weight, higher grain yield and greater nutrient accumulation than older varieties. All varieties had similar total root length and vertical root distribution at silking, but newer varieties maintained greater total root length and had more roots in the 30–60 cm soil layers at maturity. The spatial variation of soil mineral N (Nmin) in each soil horizon was larger than that of Olsen-P and ammonium-acetate-extractable K, and was inversely correlated with root length density (RLD), especially in the 0–20 cm soil layer. It was concluded that greater acquisition of mineral nutrients and higher yields of newer varieties were associated with greater total root length at maturity. The negative relationship between RLD and soil Nmin at harvest for all varieties suggests the importance of the spatial distribution of the root system for N uptake by maize. PMID:25799291
Acoustic method for measuring the sound speed of gases over small path lengths
speeds have a number of useful applications in industry such as measuring gas composition, temperature in automotive applications, such as measuring the ex- haust gas recirculation EGR in combustion engines . In automotive appli- cations, sensors must be compact, robust, fast, and cost effective. Various acoustic
Quantifying Path Length: Fourth-Grade Children's Developing Abstractions for Linear Measurement
ERIC Educational Resources Information Center
Barrett, Jeffrey E.; Clements, Douglas H.
2003-01-01
This article describes how children build increasingly abstract knowledge of linear measurement, emphasizing ways they relate space and number. Assessments indicate children struggle to understand measurement, especially concepts related to complex paths as in perimeter tasks. This article draws on developmental accounts of children's knowledge of…
Direct Measurement of the Phase-Coherence Length in a GaAs/GaAlAs Square Network
NASA Astrophysics Data System (ADS)
Ferrier, M.; Angers, L.; Rowe, A. C.; Guéron, S.; Bouchiat, H.; Texier, C.; Montambaux, G.; Mailly, D.
2004-12-01
The low temperature magnetoconductance of a large array of quantum coherent loops exhibits Altshuler-Aronov-Spivak oscillations with a periodicity corresponding to 1/2 flux quantum per loop. We show that the measurement of the harmonics content provides an accurate way to determine the electron phase-coherence length L? in units of the lattice length with no adjustable parameters. We use this method to determine L? in a square network realized from a 2D electron gas in a GaAs/GaAlAs heterojunction, with only a few conducting channels. The temperature dependence follows a power law T-1/3 from 1.3K to 25mK with no saturation, as expected for 1D diffusive electronic motion and electron-electron scattering as the main decoherence mechanism.
Tao, X. D.; Feng, Z.; Miao, B. F.; Sun, L.; You, B.; Wu, D.; Du, J.; Zhang, W.; Ding, H. F.
2014-05-07
We present the experimental study of the spin Hall angle (SHA) and spin diffusion length of Pd with the spin pumping and microwave photoresistance effects. The Py/Pd bilayer stripes are excited with an out-of-plane microwave magnetic field. The pure spin current is thus pumped and transforms into charge current via the inverse spin Hall effect (ISHE) in Pd layer, yielding an ISHE voltage. The ISHE voltage can be distinguished from the unwanted signal caused by the anisotropic magnetoresistance according to their different symmetries. Together with Pd thickness dependent measurements of in and out-of-plane precessing angles and effective spin mixing conductance, the SHA and spin-diffusion length of Pd are quantified as 0.0056?±?0.0007 and 7.3?±?0.7?nm, respectively.
NASA Astrophysics Data System (ADS)
Loudon, James; Yazdi, S.; Kasama, T.; Zhigadlo, N. D.; Karpinski, J.
2015-03-01
We demonstrate that images of flux vortices in a superconductor taken with a transmission electron microscope can be used to measure simultaneously the penetration depth and coherence length in all directions at the same temperature and magnetic field. This is particularly useful for MgB2 where these quantities vary with the applied magnetic field and values are difficult to obtain at low field or in the c direction. We obtained images of flux vortices from a sample cut in the ac plane by focussed ion beam milling and compared these with simulations which accounted for flux vortices with a non-zero core in a thin, anisotropic superconductor. This gave penetration depths ?ab = 100 +/- 35 nm, ?c = 120 +/- 15 nm and coherence lengths ?ab = 41 +/- 13 nm and ?c = 34 +/- 10 nm at 10.8 K in a field of 4.8 mT. The implications of these values for type-1.5 superconductivity will be discussed.
A New Measurement Method of the Delay Line Length in the X-band Delay Line Distribution System(DLDS)
NASA Astrophysics Data System (ADS)
Tamura, F.; Mizuno, H.
1997-05-01
In order to control the driving RF phase at the input of the accelerating structure of X-band linear collider main linacs, it is necessary to measure the length of the long TE01 mode delay lines of 40-80m. A new measurement scheme by using the low frequency resonant mode of the TE01mode delay line was proposed. The delay lines have the tapered guide on its both ends, thus the low frequency resonant mode around 2GHz can be the measure of the delay line dimensions. The operational principle and the elementary characteristics of this measurement method such as, sensitivity, S/N ratio and other basic design parameters are presented.
NASA Astrophysics Data System (ADS)
Igawa, Hirotaka; Murayama, Hideaki; Nakamura, Toshiya; Yamaguchi, Isao; Kageyama, Kazuro; Uzawa, Kiyoshi; Wada, Daichi; Ohsawa, Isamu; Kanai, Makoto; Omichi, Koji
2009-10-01
High spatial resolution and sensitivity are required in distributed strain measurements for structural health monitoring. We have developed a distributed strain sensing technique with long gauge FBG sensors, which enables to measure strain at an arbitrary position along the FBG sensors with the high spatial resolution less than 1 mm based on optical frequency domain reflectometry (OFDR). In this paper this technique with a 1500 mm gauge length FBG was applied to monitoring strain distributions of a simply supported beam subjected to bending loads. The agreement between the measured strain and the theoretical one is excellent. Also we succeeded to identify the applied load by the inverse analysis from the measured strain distribution data, and confirmed the validity of these methods.
NASA Astrophysics Data System (ADS)
Steyn-Ross, Moira L.; Steyn-Ross, D. A.; Sleigh, J. W.; Whiting, D. R.
2003-08-01
In a recent series of papers, the authors have developed a stochastic theory to describe the electrical response of a spatially homogeneous cerebral cortex to infusion of a general anesthetic agent. We showed that by modeling the GABAergic (propofol-like) drug effect as a prolongation of the inhibitory postsynaptic impulse response, we obtain a prediction that there will be a hysteretically separated pair of first-order phase transitions in the population-average excitatory soma voltage, the first occurring at the point of induction of unconsciousness, and the second at the point of emergence from unconsciousness. In the present paper we generalize our earlier “zero-dimensional” homogeneous cortex to a one-dimensional (1D) line of cortical “mass,” thus allowing for the possibility of spatial inhomogeneities in neural activity. Following the spirit of our earlier adiabatic (“slow membrane”) philosophy, we impose a spatioadiabatic approximation that permits us to compute analytic expressions for changes in EEG (electroencephalographic) correlation length and EEG spatial covariance as a function of anesthetic effect. We establish that the correlation length of the EEG fluctuations is expected to increase at the approach to the transition points, and this finding is consistent with both the homogeneous-cortex prediction of increased correlation time (“critical slowing down”) near transition, and the recent, comprehensive anesthetic study by John et al.?[Conscious. Cogn. 10, 165 (2001)] reporting an increase in EEG coherence near the points of loss and recovery of consciousness. In addition, we find that if the long-range (corticocortical) excitatory-to-inhibitory connectivity in the 1D cortex is stronger than the long-range excitatory-to-excitatory connectivity, then the spatioadiabatic system can organize itself into large-amplitude spatial patterns (“dissipative structures”) consisting of giant stationary quasiperiodic voltage fluctuations distributed along the cortical rod.
Stasyszyn, F; Dolag, K; Beck, R; Donnert, J
2010-01-01
Using cosmological MHD simulations of the magnetic field in galaxy clusters and filaments we evaluate the possibility to infer the magnetic field strength in filaments by measuring cross-correlation functions between Faraday Rotation Measures (RM) and the galaxy density field. We also test the reliability of recent estimates considering the problem of data quality and Galactic foreground (GF) removal in current datasets. Besides the two self-consistent simulations of cosmological magnetic fields based on primordial seed fields and galactic outflows analyzed here, we also explore a larger range of models scaling up the resulting magnetic fields of one of the simulations. We find that, if an unnormalized estimator for the cross-correlation functions and a GF removal procedure is used, the detectability of the cosmological signal is only possible for future instruments (e.g. SKA and ASKAP). However, mapping of the observed RM signal to the underlying magnetization of the Universe (both in space and time) is an e...
Effectively classically correlated state of a measured system and a bosonic measurement apparatus
Camalet, S.
2011-04-15
We consider a multilevel system coupled to a bosonic measurement apparatus. We derive exact expressions for the time-dependent expectation values of a large class of physically relevant observables that depend on degrees of freedom of both systems. We find that, for this class, though the two systems become entangled as a result of their interaction, they appear classically correlated for long enough times. The unique corresponding time-dependent separable state is determined explicitly. To better understand the physical parameters that control the time scale of this effective disentanglement process, we study a one-dimensional measurement apparatus.
Water equivalent path length measurement in proton radiotherapy using time resolved diode dosimetry
Gottschalk, B.; Tang, S.; Bentefour, E. H.; Cascio, E. W.; Prieels, D.; Lu, H.-M.
2011-04-15
Purpose: To verify water equivalent path length (WEPL) before treatment in proton radiotherapy using time resolved in vivo diode dosimetry. Methods: Using a passively scattered range modulated proton beam, the output of a diode driving a fast current-to-voltage amplifier is recorded at a number of depths in a water tank. At each depth, a burst of overlapping single proton pulses is observed. The rms duration of the burst is computed and the resulting data set is fitted with a cubic polynomial. Results: When the diode is subsequently set to an arbitrary depth and the polynomial is used as a calibration curve, the ''unknown'' depth is determined within 0.3 mm rms. Conclusions: A diode or a diode array, placed (for instance) in the rectum in conjunction with a rectal balloon, can potentially determine the WEPL at that point, just prior to treatment, with submillimeter accuracy, allowing the beam energy to be adjusted. The associated unwanted dose is about 0.2% of a typical single fraction treatment dose.
PRIOR GENETIC CORRELATIONS AND NON-MEASURED TRAITS
Technology Transfer Automated Retrieval System (TEKTRAN)
Current international genetic evaluations are based on how related country populations are genetically (across-country genetic correlations). Those correlations may be influenced strongly by prior expectations that were not based on sound scientific principles. Objective methods to predict prior cor...
Measurement and modification of biexciton-exciton time correlations.
Huber, Tobias; Predojevi?, Ana; Zoubi, Hashem; Jayakumar, Harishankar; Solomon, Glenn S; Weihs, Gregor
2013-04-22
Photons which are generated in a two-photon cascade process have an underlying time correlation since the spontaneous emission of the upper level populates the intermediate state. This correlation leads to a reduction of the purity of the photon emitted from the intermediate state. Here we characterize this time correlation for the biexciton-exciton cascade of an InAs/GaAs quantum dot. We show that the correlation can be reduced by tuning the biexciton transition in resonance to a planar distributed Bragg reflector cavity. The enhanced and inhibited emission into the cavity accelerates the biexciton emission and slows down the exciton emission thus reduces the correlation and increases the purity of the exciton photon. This is essential for schemes like creating time-bin entangled photon pairs from quantum dot systems. PMID:23609694
Eich, T; Sieglin, B; Scarabosio, A; Fundamenski, W; Goldston, R J; Herrmann, A
2011-11-18
Experimental measurements of the SOL power decay length (?(q)) estimated from analysis of fully attached divertor heat load profiles from two tokamaks, JET and ASDEX Upgrade, are presented. Data was measured by means of infrared thermography. An empirical scaling reveals parametric dependency ?(q) in mm = 0.73B(T)(-0.78)q(cyl)(1.2)P(SOL)(0.1)R(geo)(0), where B(T)(T) describes the toroidal magnetic field, q(cyl) the cylindrical safety factor, P(SOL)(MW) the power crossing the separatrix and R(geo)(m) the major radius of the device. A comparison of these measurements to a heuristic particle drift-based model shows satisfactory agreement in both absolute magnitude and scaling. Extrapolation to ITER gives ?(q) ? 1 mm. PMID:22181888
M. G. Huber; M. Arif; W. C. Chen; T. R. Gentile; D. S. Hussey; T. C. Black; D. A. Pushin; C. B. Shahi; F. E. Wietfeldt; L. Yang
2014-09-30
We report a determination of the n-$^3$He scattering length difference $\\Delta b^{\\prime} = b_{1}^{\\prime}-b_{0}^{\\prime} = $ ($-5.411$ $\\pm$ $0.031$ (statistical) $\\pm$ $0.039$ (systematic)) fm between the triplet and singlet states using a neutron interferometer. This revises our previous result $\\Delta b^{\\prime} = $ (-5.610 $\\pm$ $0.027$ (statistical) $\\pm$ $0.032$ (systematic) fm obtained using the same technique in 2008. This revision is due to a re-analysis of the 2008 experiment that includes a more robust treatment of the phase shift caused by magnetic field gradients near the $^3$He cell. Furthermore, we more than doubled our original data set from 2008 by acquiring six months of additional data in 2013. Both the new data set and a re-analysis of the older data are in good agreement. Scattering lengths of low Z isotopes are valued for use in few-body nuclear effective field theories, provide important tests of modern nuclear potential models and in the case of $^3$He aid in the interpretation of neutron scattering from quantum liquids. The difference $\\Delta b^{\\prime}$ was determined by measuring the relative phase shift between two incident neutron polarizations caused by the spin-dependent interaction with a polarized $^3$He target. The target $^3$He gas was sealed inside a small, flat windowed glass cell that was placed in one beam path of the interferometer. The relaxation of $^3$He polarization was monitored continuously with neutron transmission measurements. The neutron polarization and spin flipper efficiency were determined separately using $^3$He analyzers and two different polarimetry analysis methods. A summary of the measured scattering lengths for n-$^3$He with a comparison to nucleon interaction models is given.
NASA Astrophysics Data System (ADS)
Huber, M. G.; Arif, M.; Chen, W. C.; Gentile, T. R.; Hussey, D. S.; Black, T. C.; Pushin, D. A.; Shahi, C. B.; Wietfeldt, F. E.; Yang, L.
2014-12-01
We report a determination of the n -3He scattering length difference ? b'=b1'-b0'=[-5.411 ±0.031 (statistical)±0.039 (systematic)] fm between the triplet and singlet states using a neutron interferometer. This revises our previous result ? b'=[-5.610 ±0.027 (statistical)±0.032 (systematic)] fm obtained using the same technique in 2008 [Huber et al., Phys. Rev. Lett. 102, 200401 (2009), 10.1103/PhysRevLett.102.200401; Huber et al., Phys. Rev. Lett. 103, 179903(E) (2009), 10.1103/PhysRevLett.103.179903]. This revision is attributable to a reanalysis of the 2008 experiment that now includes a systematic correction caused by magnetic-field gradients near the 3He cell which had been previously underestimated. Furthermore, we more than doubled our original data set from 2008 by acquiring 6 months of additional data in 2013. Both the new data set and a reanalysis of the older data are in good agreement. Scattering lengths of low-Z isotopes are valued for use in few-body nuclear effective field theories, provide important tests of modern nuclear potential models, and, in the case of 3He, aid in the interpretation of neutron scattering from quantum liquids. The difference ? b' was determined by measuring the relative phase shift between two incident neutron polarizations caused by the spin-dependent interaction with a polarized 3He target. The target 3He gas was sealed inside a small, flat-windowed glass cell that was placed in one beam path of the interferometer. The relaxation of 3He polarization was monitored continuously with neutron transmission measurements. The neutron polarization and spin-flipper efficiency were determined separately using 3He analyzers and two different polarimetry analysis methods. A summary of the measured scattering lengths for n -3He with a comparison to nucleon interaction models is given.
NASA Astrophysics Data System (ADS)
Yamamoto, Tetsuya T.; Shiota, Daikou; Sakajiri, Takuma; Akiyama, Sachiko; Isobe, Hiroaki; Shibata, Kazunari
2002-11-01
We analyze 17 arcades to study the relations between solar flares and arcades. Soft X-ray images taken with Yohkoh's soft X-ray telescope are used to derive T0, EM0, and temporal variation of Tarc and EMarc, where Tarc and T0 are the temperatures of an arcade and prearcade region and EMarc and EM0 are the volume emission measures of an arcade and prearcade region. It is found that T0~2 MK and Tarc~4 MK. We also estimate prearcade coronal electron density n0 and arcade electron density narc to find that narc is comparable to n0 (narc~n0~108 cm-3). Using these observed EM, T, and n0, we calculate the theoretical loop length Ltheor based on the scaling law for solar and stellar flares derived by Shibata & Yokoyama and compare it with observed flare/arcade loop length Lobs. The result shows a good correlation between them (Ltheor~Lobs) and indicates the need of plasma ? for the scaling law (Ltheor~EM3/5T-8/5n- 2/50?-6/5). This supports the theory of the scaling law and is indirect evidence that flares and arcades are heated by the same magnetic reconnection mechanism.
Buxton, Jessica L; Das, Shikta; Rodriguez, Alina; Kaakinen, Marika; Couto Alves, Alexessander; Sebert, Sylvain; Millwood, Iona Y; Laitinen, Jaana; O'Reilly, Paul F; Jarvelin, Marjo-Riitta; Blakemore, Alexandra I F
2014-01-01
Studies of leukocyte telomere length (LTL) and adiposity have produced conflicting results, and the relationship between body mass index (BMI) and telomere length throughout life remains unclear. We therefore tested association of adult LTL measured in 5,598 participants with: i) childhood growth measures (BMI and age at adiposity rebound (AR)); ii) change in BMI from childhood to adulthood and iii) adult BMI, waist-to-hip ratio (WHR), body adiposity index (BAI). Childhood BMI at AR was positively associated with LTL at 31 years in women (P = 0.041). Adult BMI and WHR in both men (P = 0.025 and P = 0.049, respectively) and women (P = 0.029 and P = 0.008, respectively), and BAI in women (P = 0.021) were inversely associated with LTL at 31 years. An increase in standardised BMI between early childhood and adulthood was associated with shorter adult LTL in women (P = 0.008). We show that LTL is inversely associated with multiple measures of adiposity in both men and women. Additionally, BMI increase in women from childhood to adulthood is associated with shorter telomeres at age 31, potentially indicating accelerated biological ageing. PMID:24919187
NASA Astrophysics Data System (ADS)
Bai, M.; Taub, H.; Knorr, K.; Volkmann, U. G.; Hansen, F. Y.
2007-03-01
We have recently discovered that films of intermediate-length alkanes (n-CnH2n+2; 24 < n < 40) do not completely wet a SiO2 surface on a nanometer length scale [2]. In a narrow temperature range near the bulk melting point Tb, we observe a single layer of molecules oriented with their long axis perpendicular to the surface. On heating just above Tb, these molecules undergo a delayering transition to three-dimensional droplets that remain present up to their evaporation point. Here we report measurements by noncontact Atomic Force Microscopy of the contact angle of these droplets for a film of hexatriacontane (n-C36H74 or C36). Our preliminary measurements indicate that there is a weak maximum in the contact angle at ˜Tb + 3 C. Further measurements are planned to investigate whether the weak maximum in the contact angle is consistent with the droplets supporting a surface freezing effect as at the bulk fluid/air interface. ^2M. Bai, K. Knorr, M. J. Simpson, S. Trogisch, H. Taub, S. N. Ehrlich, H. Mo, U. G. Volkmann, F. Y. Hansen, cond-mat/0611497.
Conductance measurement of a single molecular chain as a continuous function of its length
Leif Lafferentz; Francisco Ample; Christian Joachim; Hao Yu; Stefan Hecht; Leonhard Grill
2010-01-01
One prerequisite for the realization of molecular electronics is a fundamental understanding of charge transport through single molecules. We have conducted experiments with a low temperature scanning tunneling microscope (STM) that allow to measure currents going through a single long molecular wire as a continuous function of the distance between the two contacts on one and the same molecule (Science
Evaluation of Length-of-Stain Gas Indicator Tubes for Measuring Carbon Monoxide in Air.
ERIC Educational Resources Information Center
Klaubert, Earl C.; And Others
Techniques for detection and measurement of carbon monoxide (CO) in air are of interest and utility in many aspects of automotive safety. CO concentrations may range from less than 100 parts per million (ppm), or 0.01 percent, to about 10 percent by volume. Gas indicator tubes have been used for many years primarily as detectors of hazardous gases…
NASA Astrophysics Data System (ADS)
Wang, Fang
In this dissertation, advances in linear and non-linear viscoelastic analysis and experimentation have been employed to investigate the properties of materials using nanoindentation. In the first study, a general linear-viscoelastic model was developed to measure the properties of polydimethylsiloxane (PDMS) using a flat punch indenter. Subsequently, linear viscoelastic nanoindentation was used to measure the young's relaxation modulus of a locally-heterogeneous thermally-aged bismaleimide resin using a Berkovich indenter. Nanoindentation measurements were conducted on both surface and cross section of aged bismaleimide resin specimens with different aging time at 200°C and 300°C respectively to extract the oxidation effect of sample under high temperatures. Finally, nanoindentation measurements were made on human tympanic membrane specimens with using a spherical nanoindenter tip in direct contact with the collagen fiber layer. Linear viscoelastic analysis was conducted to extract the Young's relaxation modulus distributions. The study also focused on the development of non-linear viscoelastic analysis of indentation experiments. Despite the fact that the nanoindentation technique is well established for the characterization of elasto-plastic materials, nanoindentation on viscoelastic materials is not fully understood especially in nonlinear viscoelastic region. In the dissertation, a nonlinear viscoelastic model was developed and implemented in Abaqus/Implicit Code to analyze the nonlinear visceoelastic behavior of polyvinyl acetate (PVA) under nanoindentation.
Bhardwaj, A.; Walker-Kopp, N; Casjens, S; Cingolani, G
2009-01-01
Bacteriophages of the Podoviridae family use short noncontractile tails to inject their genetic material into Gram-negative bacteria. In phage P22, the tail contains a thin needle, encoded by the phage gene 26, which is essential both for stabilization and for ejection of the packaged viral genome. Bioinformatic analysis of the N-terminal domain of gp26 (residues 1-60) led us to identify a family of genes encoding putative homologues of the tail needle gp26. To validate this idea experimentally and to explore their diversity, we cloned the gp26-like gene from phages HK620, Sf6 and HS1, and characterized these gene products in solution. All gp26-like factors contain an elongated {alpha}-helical coiled-coil core consisting of repeating, adjacent trimerization heptads and form trimeric fibers with length ranging between about 240 to 300 {angstrom}. gp26 tail needles display a high level of structural stability in solution, with Tm (temperature of melting) between 85 and 95 C. To determine how the structural stability of these phage fibers correlates with the length of the {alpha}-helical core, we investigated the effect of insertions and deletions in the helical core. In the P22 tail needle, we identified an 85-residue-long helical domain, termed MiCRU (minimal coiled-coil repeat unit), that can be inserted in-frame inside the gp26 helical core, preserving the straight morphology of the fiber. Likewise, we were able to remove three quarters of the helical core of the HS1 tail needle, minimally decreasing the stability of the fiber. We conclude that in the gp26 family of tail needles, structural stability increases nonlinearly with the length of the {alpha}-helical core. Thus, the overall stability of these bacteriophage fibers is not solely dependent on the number of trimerization repeats in the {alpha}-helical core.
Length distributed measurement of temperature effects in Yb-doped fibers during pumping
NASA Astrophysics Data System (ADS)
Leich, Martin; Fiebrandt, Julia; Schwuchow, Anka; Jetschke, Sylvia; Unger, Sonja; Jäger, Matthias; Rothhardt, Manfred; Bartelt, Hartmut
2014-06-01
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.
Abdel-Baset A. Mohamed
2013-01-30
The quantum correlations, including entanglement and discord with its geometric measure, and classical correlation are studied for a bipartite partition of a open or closed quantum system. It is found that the purity of the initial state plays an important role in the dynamics of quantum and classical correlations. In the dephasing model, the quantum correlations loss and the classical correlation gain are instantaneously happen. While, the purity of the initial state destroys the quantum correlations which is resulted by the unitary interaction. Therefore, with the purity parameter, a particular region in which there is no state have quantum correlations can be determined.
Measuring spin correlations in optical lattices using superlattice potentials
Pedersen, K. G. L.; Andersen, B. M.; Soerensen, A. S.; Bruun, G. M.; Syljuaasen, O. F.
2011-10-15
We suggest two experimental methods for probing both short- and long-range spin correlations of atoms in optical lattices using superlattice potentials. The first method involves an adiabatic doubling of the periodicity of the underlying lattice to probe neighboring singlet (triplet) correlations for fermions (bosons) by the occupation of the resulting vibrational ground state. The second method utilizes a time-dependent superlattice potential to generate spin-dependent transport by any number of prescribed lattice sites, and probes correlations by the resulting number of doubly occupied sites. For experimentally relevant parameters, we demonstrate how both methods yield large signatures of antiferromagnetic correlations of strongly repulsive fermionic atoms in a single shot of the experiment. Lastly, we show how this method may also be applied to probe d-wave pairing, a possible ground-state candidate for the doped repulsive Hubbard model.
H. Agakishiev; M. M. Aggarwal; Z. Ahammed; A. V. Alakhverdyants; I. Alekseev; J. Alford; B. D. Anderson; C. D. Anson; D. Arkhipkin; G. S. Averichev; J. Balewski; D. R. Beavis; N. K. Behera; R. Bellwied; M. J. Betancourt; R. R. Betts; A. Bhasin; A. K. Bhati; H. Bichsel; J. Bielcik; J. Bielcikova; B. Biritz; L. C. Bland; W. Borowski; J. Bouchet; E. Braidot; A. V. Brandin; A. Bridgeman; S. G. Brovko; E. Bruna; S. Bueltmann; I. Bunzarov; T. P. Burton; X. Z. Cai; H. Caines; M. Calderón de la Barca Sánchez; D. Cebra; R. Cendejas; M. C. Cervantes; Z. Chajecki; P. Chaloupka; S. Chattopadhyay; H. F. Chen; J. H. Chen; J. Y. Chen; L. Chen; J. Cheng; M. Cherney; A. Chikanian; K. E. Choi; W. Christie; P. Chung; M. J. M. Codrington; R. Corliss; J. G. Cramer; H. J. Crawford; S. Dash; A. Davila Leyva; L. C. De Silva; R. R. Debbe; T. G. Dedovich; A. A. Derevschikov; R. Derradi de Souza; L. Didenko; P. Djawotho; S. M. Dogra; X. Dong; J. L. Drachenberg; J. E. Draper; J. C. Dunlop; L. G. Efimov; M. Elnimr; J. Engelage; G. Eppley; M. Estienne; L. Eun; O. Evdokimov; R. Fatemi; J. Fedorisin; R. G. Fersch; P. Filip; E. Finch; V. Fine; Y. Fisyak; C. A. Gagliardi; D. R. Gangadharan; A. Geromitsos; F. Geurts; P. Ghosh; Y. N. Gorbunov; A. Gordon; O. Grebenyuk; D. Grosnick; S. M. Guertin; A. Gupta; W. Guryn; B. Haag; O. Hajkova; A. Hamed; L-X. Han; J. W. Harris; J. P. Hays-Wehle; M. Heinz; S. Heppelmann; A. Hirsch; E. Hjort; G. W. Hoffmann; D. J. Hofman; B. Huang; H. Z. Huang; T. J. Humanic; L. Huo; G. Igo; P. Jacobs; W. W. Jacobs; C. Jena; F. Jin; J. Joseph; E. G. Judd; S. Kabana; K. Kang; J. Kapitan; K. Kauder; H. Ke; D. Keane; A. Kechechyan; D. Kettler; D. P. Kikola; J. Kiryluk; A. Kisiel; V. Kizka; A. G. Knospe; D. D. Koetke; T. Kollegger; J. Konzer; I. Koralt; L. Koroleva; W. Korsch; L. Kotchenda; V. Kouchpil; P. Kravtsov; K. Krueger; M. Krus; L. Kumar; P. Kurnadi; M. A. C. Lamont; J. M. Landgraf; S. LaPointe; J. Lauret; A. Lebedev; R. Lednicky; J. H. Lee; W. Leight; M. J. LeVine; C. Li; L. Li; N. Li; W. Li; X. Li; X. Li; Y. Li; Z. M. Li; M. A. Lisa; F. Liu; H. Liu; J. Liu; T. Ljubicic; W. J. Llope; R. S. Longacre; W. A. Love; Y. Lu; E. V. Lukashov; X. Luo; G. L. Ma; Y. G. Ma; D. P. Mahapatra; R. Majka; O. I. Mall; L. K. Mangotra; R. Manweiler; S. Margetis; C. Markert; H. Masui; H. S. Matis; Yu. A. Matulenko; D. McDonald; T. S. McShane; A. Meschanin; R. Milner; N. G. Minaev; S. Mioduszewski; A. Mischke; M. K. Mitrovski; B. Mohanty; M. M. Mondal; B. Morozov; D. A. Morozov; M. G. Munhoz; M. Naglis; B. K. Nandi; T. K. Nayak; P. K. Netrakanti; L. V. Nogach; S. B. Nurushev; G. Odyniec; A. Ogawa; Oh; Ohlson; V. Okorokov; E. W. Oldag; D. Olson; M. Pachr; B. S. Page; S. K. Pal; Y. Pandit; Y. Panebratsev; T. Pawlak; H. Pei; T. Peitzmann; C. Perkins; W. Peryt; S. C. Phatak; P. Pile; M. Planinic; M. A. Ploskon; J. Pluta; D. Plyku; N. Poljak; A. M. Poskanzer; B. V. K. S. Potukuchi; C. B. Powell; D. Prindle; C. Pruneau; N. K. Pruthi; P. R. Pujahari; J. Putschke; H. Qiu; R. Raniwala; S. Raniwala; R. L. Ray; R. Redwine; R. Reed; H. G. Ritter; J. B. Roberts; O. V. Rogachevskiy; J. L. Romero; A. Rose; L. Ruan; J. Rusnak; N. R. Sahoo; S. Sakai; I. Sakrejda; T. Sakuma; S. Salur; J. Sandweiss; E. Sangaline; A. Sarkar; J. Schambach; R. P. Scharenberg; A. M. Schmah; T. R. Schuster; J. Seele; J. Seger; I. Selyuzhenkov; P. Seyboth; E. Shahaliev; M. Shao; M. Sharma; S. S. Shi; Q. Y. Shou; E. P. Sichtermann; F. Simon; R. N. Singaraju; M. J. Skoby; N. Smirnov; H. M. Spinka; B. Srivastava; T. D. S. Stanislaus; D. Staszak; S. G. Steadman; J. R. Stevens; R. Stock; M. Strikhanov; B. Stringfellow; A. A. P. Suaide; M. C. Suarez; N. L. Subba; M. Sumbera; X. M. Sun; Y. Sun; Z. Sun; B. Surrow; D. N. Svirida; T. J. M. Symons; A. Szanto de Toledo; J. Takahashi; A. H. Tang; Z. Tang; L. H. Tarini; T. Tarnowsky; D. Thein; J. H. Thomas; J. Tian; A. R. Timmins; D. Tlusty; M. Tokarev; V. N. Tram; S. Trentalange; R. E. Tribble; Tribedy; O. D. Tsai; T. Ullrich; D. G. Underwood; G. Van Buren; G. van Nieuwenhuizen; J. A. Vanfossen, Jr.; R. Varma; G. M. S. Vasconcelos; A. N. Vasiliev; F. Videbæk; Y. P. Viyogi; S. Vokal; M. Wada; M. Walker; F. Wang; G. Wang; H. Wang; J. S. Wang; Q. Wang; X. L. Wang; Y. Wang; G. Webb; J. C. Webb; G. D. Westfall; C. Whitten Jr.; H. Wieman; S. W. Wissink; R. Witt; W. Witzke; Y. F. Wu; Xiao; W. Xie; H. Xu; N. Xu; Q. H. Xu; W. Xu; Y. Xu; Z. Xu; L. Xue; Y. Yang; P. Yepes; K. Yip; I-K. Yoo; M. Zawisza; H. Zbroszczyk; W. Zhan; J. B. Zhang; S. Zhang; W. M. Zhang; X. P. Zhang; Y. Zhang; Z. P. Zhang; J. Zhao; C. Zhong; W. Zhou; X. Zhu; Y. H. Zhu; R. Zoulkarneev; Y. Zoulkarneeva
2013-05-16
Dihadron azimuthal correlations containing a high transverse momentum ($\\pt$) trigger particle are sensitive to the properties of the nuclear medium created at RHIC through the strong interactions occurring between the traversing parton and the medium, i.e. jet-quenching. Previous measurements revealed a strong modification to dihadron azimuthal correlations in Au+Au collisions with respect to \\pp\\ and \\dAu\\ collisions. The modification increases with the collision centrality, suggesting a path-length dependence to the jet-quenching effect. This paper reports STAR measurements of dihadron azimuthal correlations in mid-central (20-60\\%) Au+Au collisions at $\\snn=200$~GeV as a function of the trigger particle's azimuthal angle relative to the event plane, $\\phis=|\\phit-\\psiEP|$. The azimuthal correlation is studied as a function of both the trigger and associated particle $\\pt$. The subtractions of the combinatorial background and anisotropic flow, assuming Zero Yield At Minimum (\\zyam), are described. The away-side correlation is strongly modified, and the modification varies with $\\phis$, which is expected to be related to the path-length that the away-side parton traverses. The pseudo-rapidity ($\\deta$) dependence of the near-side correlation, sensitive to long range $\\deta$ correlations (the ridge), is also investigated. The ridge and jet-like components of the near-side correlation are studied as a function of $\\phis$. The ridge appears to drop with increasing $\\phis$ while the jet-like component remains approximately constant. ...
Resolving Dynamics Structure in the Mlt: Correlative Measurements with Tidi and Hrdi
NASA Astrophysics Data System (ADS)
Niciejewski, R.; Skinner, W. R.; Marshall, A.; Cooper, M.
2011-12-01
Undoubtedly, line of sight Doppler measurements of the terrestrial limb have and continue to provide the longest sequence of routine synoptic wind data of the mesosphere and lower thermosphere. To provide the community with basic information about global MLT winds, UARS/HRDI was launched in 1991 and later joined by TIMED/TIDI in 2001. Correlative observations of the MLT with the two instruments began in February 2002 and continued until April 2005 when battery problems aboard UARS forced the final turn-off of HRDI. TIDI continues observing the MLT to the present day with nearly a 100% duty cycle. On short time intervals (a few days), tidal frequencies are difficult to unambiguously identify from orbit by either HRDI or TIDI due to aliasing issues with single satellite observations. Combining measurements from the two platforms provides a significant improvement in understanding two-dimensional frequency wavenumber spectra for short data sets. This paper will describe the progress that has been made in characterizing migrating and non-migrating diurnal tides in the MLT. Short data sets of several days' length are necessary to identify planetary waves, such as the two-day wave, and its effect on MLT dynamics. These waves can transport water vapour exhaust from rocket launches over large distances providing a seed for enhancing noctilucent cloud formation at high latitudes.
NSDL National Science Digital Library
Edwin P. Christmann
2008-11-01
This chapter will discuss the concept of correlation , which is used in later chapters that will explain the concepts of validity and reliability. Here, the authors introduce the Pearson correlation coefficient, a statistic that is used with ratio
NASA Astrophysics Data System (ADS)
Espoukeh, Pakhshan; Pedram, Pouria
2015-01-01
We study quantum correlation of Greenberger-Horne-Zeilinger (GHZ) and W states under various noisy channels using measurement-induced disturbance approach and its optimized version. Although these inequivalent maximal entangled states represent the same quantum correlation in the absence of noise, it is shown that the W state is more robust than the GHZ state through most noisy channels. Also, using measurement-induced disturbance measure, we obtain the analytical relations for the time evolution of quantum correlations in terms of the noisy parameter and remove its overestimating quantum correlations upon implementing the ameliorated measurement-induced disturbance.
Role of Weak Measurements on States Ordering and Monogamy of Quantum Correlation
NASA Astrophysics Data System (ADS)
Hu, Ming-Liang; Fan, Heng; Tian, Dong-Ping
2015-01-01
The information-theoretic definition of quantum correlation, e.g., quantum discord, is measurement dependent. By considering the more general quantum measurements, weak measurements, which include the projective measurement as a limiting case, we show that while weak measurements can enable one to capture more quantumness of correlation in a state, it can also induce other counterintuitive quantum effects. Specifically, we show that the general measurements with different strengths can impose different orderings for quantum correlations of some states. It can also modify the monogamous character for certain classes of states as well which may diminish the usefulness of quantum correlation as a resource in some protocols. In this sense, we say that the weak measurements play a dual role in defining quantum correlation.
Mechanical measurements of heterogeneity and length scale effects in PEG-based hydrogels.
Bush, Brian G; Shapiro, Jenna M; DelRio, Frank W; Cook, Robert F; Oyen, Michelle L
2015-09-28
Colloidal-probe spherical indentation load-relaxation experiments with a probe radius of 3 ?m are conducted on poly(ethylene glycol) (PEG) hydrogel materials to quantify their steady-state mechanical properties and time-dependent transport properties via a single experiment. PEG-based hydrogels are shown to be heterogeneous in both morphology and mechanical stiffness at this scale; a linear-harmonic interpolation of hyperelastic Mooney-Rivlin and Boussinesq flat-punch indentation models was used to describe the steady-state response of the hydrogels and determine upper and lower bounds for indentation moduli. Analysis of the transient load-relaxation response during displacement-controlled hold periods provides a means of extracting two time constants ?1 and ?2, where ?1 and ?2 are assigned to the viscoelastic and poroelastic properties, respectively. Large ?2 values at small indentation depths provide evidence of a non-equilibrium state characterized by a phenomenon that restricts poroelastic fluid flow through the material; for larger indentations, the variability in ?2 values decreases and pore sizes estimated from ?2via indentation approach those measured via macroscopic swelling experiments. The contact probe methodology developed here provides a means of assessing hydrogel heterogeneity, including time-dependent mechanical and transport properties, and has potential implications in hydrogel biomedical and engineering applications. PMID:26255839
Correlation Between Immersion Profile and Measured Value of Fixed-Point Temperature
NASA Astrophysics Data System (ADS)
Shulgat, O. S.; Fuksov, V. M.; Ivanova, A. G.; Gerasimov, S. F.; Pokhodun, A. I.
2014-04-01
Assessment of thermal immersion effects in the melting and freezing points defined by the International Temperature Scale of 1990 is one of the vital issues of modern thermometry. In documents of the Consultative Committee for Thermometry, the deviation of the experimental immersion profile from the theoretical value of the hydrostatic effect at a height of about 3 cm to 5 cm from the thermometer well bottom is used for the estimation of the uncertainty due to unwanted thermal effects. This estimation assumes the occurrence of solely the hydrostatic effect all along the height of the well inner wall. Real distortions of the temperature gradient at the bottom and at the top part of the well caused by the change of heat-exchange conditions are not taken into account. To define more precisely the temperature gradient along the height of the well, a miniature PRT with a 30 mm sensitive element and a sheath length and diameter of about 60 mm and 6 mm, respectively, were used. Also, the measurements of fixed-points temperature at noticeably different slopes of immersion profiles due to variations of the thermometer heat exchange and phase transition realization conditions were produced by means of a standard platinum resistance thermometer (SPRT). The measurements were carried out at the tin and zinc freezing points. The immersion curves measured with a miniature thermometer demonstrated an increase of the temperature during its lifting in the first 1 cm to 3 cm above the bottom of the well. The measurement results at the zinc freezing point by means of the SPRT have not confirmed the correlation between the immersion curves, the received value of the Zn freezing temperature, and the estimation of its uncertainty.
NASA Astrophysics Data System (ADS)
Benjamini, Dan; Basser, Peter J.
2014-12-01
In this work, we present an experimental design and analytical framework to measure the nonparametric joint radius-length (R-L) distribution of an ensemble of parallel, finite cylindrical pores, and more generally, the eccentricity distribution of anisotropic pores. Employing a novel 3D double pulsed-field gradient acquisition scheme, we first obtain both the marginal radius and length distributions of a population of cylindrical pores and then use these to constrain and stabilize the estimate of the joint radius-length distribution. Using the marginal distributions as constraints allows the joint R-L distribution to be reconstructed from an underdetermined system (i.e., more variables than equations), which requires a relatively small and feasible number of MR acquisitions. Three simulated representative joint R-L distribution phantoms corrupted by different noise levels were reconstructed to demonstrate the process, using this new framework. As expected, the broader the peaks in the joint distribution, the less stable and more sensitive to noise the estimation of the marginal distributions. Nevertheless, the reconstruction of the joint distribution is remarkably robust to increases in noise level; we attribute this characteristic to the use of the marginal distributions as constraints. Axons are known to exhibit local compartment eccentricity variations upon injury; the extent of the variations depends on the severity of the injury. Nonparametric estimation of the eccentricity distribution of injured axonal tissue is of particular interest since generally one cannot assume a parametric distribution a priori. Reconstructing the eccentricity distribution may provide vital information about changes resulting from injury or that occurred during development.
Benefits of Time Correlation Measurements for Passive Screening
NASA Astrophysics Data System (ADS)
Murer, David; Blackie, Douglas; Peerani, Paolo
2014-02-01
The “FLASH Portals Project” is a collaboration between Arktis Radiation Detectors Ltd (CH), the Atomic Weapons Establishment (UK), and the Joint Research Centre (European Commission), supported by the Technical Support Working Group (TSWG). The program's goal was to develop and demonstrate a technology to detect shielded special nuclear materials (SNM) more efficiently and less ambiguously by exploiting time correlation. This study presents experimental results of a two-sided portal monitor equipped with in total 16 4He fast neutron detectors as well as four polyvinyltoluene (PVT) plastic scintillators. All detectors have been synchronized to nanosecond precision, thereby allowing the resolution of time correlations from timescales of tens of microseconds (such as (n, ?) reactions) down to prompt fission correlations directly. Our results demonstrate that such correlations can be detected in a typical radiation portal monitor (RPM) geometry and within operationally acceptable time scales, and that exploiting these signatures significantly improves the performance of the RPM compared to neutron counting. Furthermore, the results show that some time structure remains even in the presence of heavy shielding, thus significantly improving the sensitivity of the detection system to shielded SNM.
The Internal Structure and Correlates of Some School Climate Measures.
ERIC Educational Resources Information Center
Gottfredson, Gary D.
J. M. Richards (1989) has demonstrated that when individuals' reports about environments are aggregated to create environmental measures, the use of coefficient alpha to estimate single occasion reliability can be misleadingly elevated and that alpha cannot distinguish an environmental measure from a "disguised measure of individual differences."…
Characterization of S -T+ transition dynamics via correlation measurements
NASA Astrophysics Data System (ADS)
Dickel, Christian; Foletti, Sandra; Umansky, Vladimir; Bluhm, Hendrik
2015-09-01
Nuclear spins are an important source of dephasing for electron spin qubits in GaAs quantum dots. Most studies of their dynamics have focused on the relatively slow longitudinal polarization. We present a semiclassical model and experimental data showing that the dynamics of the transverse hyperfine field can be probed by correlating individual Landau-Zener sweeps across the S -T+ transition of a two-electron spin qubit. The relative Larmor precession of different nuclear spin species leads to oscillations in these correlations, which decay due to dephasing of the nuclei. In the presence of spin-orbit coupling, oscillations with the absolute Larmor frequencies whose amplitude depends on the spin-orbit coupling strength are expected. These oscillations reflect rapid dynamics of the transverse hyperfine field, which are relevant for several qubit control schemes.
Correlation measure to detect time series distances, whence economy globalization
NASA Astrophysics Data System (ADS)
Mi?kiewicz, Janusz; Ausloos, Marcel
2008-11-01
An instantaneous time series distance is defined through the equal time correlation coefficient. The idea is applied to the Gross Domestic Product (GDP) yearly increments of 21 rich countries between 1950 and 2005 in order to test the process of economic globalisation. Some data discussion is first presented to decide what (EKS, GK, or derived) GDP series should be studied. Distances are then calculated from the correlation coefficient values between pairs of series. The role of time averaging of the distances over finite size windows is discussed. Three network structures are next constructed based on the hierarchy of distances. It is shown that the mean distance between the most developed countries on several networks actually decreases in time, -which we consider as a proof of globalization. An empirical law is found for the evolution after 1990, similar to that found in flux creep. The optimal observation time window size is found ?15 years.
Reduction of Gun Erosion and Correlation of Gun Erosion Measurements
NASA Technical Reports Server (NTRS)
Bogdanoff, Dave; Wercinski, Paul (Technical Monitor)
1997-01-01
Gun barrel erosion is serious problem with two-stage light gas guns. Excessive barrel erosion can lead to poor or failed launches and frequent barrel changes, with the corresponding down time. Also, excessive barrel erosion can limit the maximum velocity obtainable by loading down the hydrogen working gas with eroded barrel material. Guided by a CFD code, the operating conditions of the Ames 0.5-inch gun were modified to reduce barrel erosion. The changes implemented included: (1) reduction in the piston mass, powder mass and hydrogen fill pressure; and (2) reduction in pump tube volume, while maintaining hydrogen mass. The latter change was found, in particular, to greatly reduce barrel erosion. For muzzle velocity ranges of 6.1 - 6.9 km/sec, the barrel erosion was reduced by a factor of 10. Even for the higher muzzle velocity range of 7.0 - 8.2 km/sec, the barrel erosion was reduced by a factor of 4. Gun erosion data from the Ames 0.5-inch, 1.0-inch, and 1.5-inch guns operated over a wide variety of launch conditions was examined and it was found that this data could be correlated using four different parameters: normalized powder charge energy, normalized hydrogen energy density, normalized pump tube volume and barrel diameter. The development of the correlation and the steps used to collapse the experimental data are presented. Over a certain parameter range in the correlation developed, the barrel erosion per shot is found to increase very rapidly. The correlation should prove useful in the selection of gun operating conditions and the design of new guns. Representative shapes of eroded gun barrels are also presented.
Correlated optical measurements and plasmon mapping of silver nanorods
Guiton, Beth S; Iberi, Vighter; Li, Shuzhou; Leonard, Donovan N; Parish, Chad M; Kotula, Paul G; Varela del Arco, Maria; Schatz, George C.; Pennycook, Stephen J; Camden, Jon P
2011-01-01
Plasmonics is a rapidly growing field, yet imaging of the plasmonic modes in complex nanoscale architectures is extremely challenging. Here we obtain spatial maps of the localized surface plasmon modes of high-aspect-ratio silver nanorods using electron energy loss spectroscopy (EELS) and correlate to optical data and classical electrodynamics calculations from the exact same particles. EELS mapping is thus demonstrated to be an invaluable technique for elucidating complex and overlapping plasmon modes.
Berthier, Etienne
present the methodology developed to measure glaciers surface displacement by image correlationMEASUREMENT OF GLACIER VELOCITY FIELDS USING VERY PRECISE MULTITEMPORAL CORRELATION ON HIGH RESOLUTION SPOT5 IMAGES Hélène Vadon 1 , Etienne Berthier 2 1 CNES, 18 Avenue Edouard Belin, 31401 Toulouse
NASA Astrophysics Data System (ADS)
Coppola, S.; Pozzi, D.; Candeloro De Sanctis, S.; Digman, M. A.; Gratton, E.; Caracciolo, G.
2013-03-01
Spatio-temporal image correlation spectroscopy (STICS) is a powerful technique for assessing the nature of particle motion in complex systems although it has been rarely used to investigate the intracellular dynamics of nanocarriers so far. Here we introduce a method for characterizing the mode of motion of nanocarriers and for quantifying their transport parameters on different length scales from single-cell to subcellular level. Using this strategy we were able to study the mechanisms responsible for the intracellular transport of DOTAP–DOPC/DNA (DOTAP: 1,2-dioleoyl-3-trimethylammonium-propane; DOPC: dioleoylphosphocholine) and DC-Chol–DOPE/DNA (DC-Chol: 3?-[N-(N,N-dimethylaminoethane)-carbamoyl] cholesterol; DOPE: dioleoylphosphatidylethanolamine) lipoplexes in CHO-K1 (CHO: Chinese hamster ovary) live cells. Measurement of both diffusion coefficients and velocity vectors (magnitude and direction) averaged over regions of the cell revealed the presence of distinct modes of motion. Lipoplexes diffused slowly on the cell surface (diffusion coefficient: D ? 0.003 ?m2 s?1). In the cytosol, the lipoplexes’ motion was characterized by active transport with average velocity v ? 0.03 ?m2 s?1 and random motion. The method permitted us to generate an intracellular transport map showing several regions of concerted motion of lipoplexes.
TURBULENT DYNAMICS IN SOLAR FLARE SHEET STRUCTURES MEASURED WITH LOCAL CORRELATION TRACKING
McKenzie, D. E., E-mail: mckenzie@physics.montana.edu [Department of Physics, Montana State University, P.O. Box 173840, Bozeman, MT 59717-3840 (United States)
2013-03-20
High-resolution observations of the Sun's corona in extreme ultraviolet and soft X-rays have revealed a new world of complexity in the sheet-like structures connecting coronal mass ejections (CMEs) to the post-eruption flare arcades. This article presents initial findings from an exploration of dynamic flows in two flares observed with Hinode/XRT and SDO/AIA. The flows are observed in the hot ({approx}> 10 MK) plasma above the post-eruption arcades and measured with local correlation tracking. The observations demonstrate significant shears in velocity, giving the appearance of vortices and stagnations. Plasma diagnostics indicate that the plasma {beta} exceeds unity in at least one of the studied events, suggesting that the coronal magnetic fields may be significantly affected by the turbulent flows. Although reconnection models of eruptive flares tend to predict a macroscopic current sheet in the region between the CME and the flare arcade, it is not yet clear whether the observed sheet-like structures are identifiable as the current sheets or 'thermal halos' surrounding the current sheets. Regardless, the relationship between the turbulent motions and the embedded magnetic field is likely to be complicated, involving dynamic fluid processes that produce small length scales in the current sheet. Such processes may be crucial for triggering, accelerating, and/or prolonging reconnection in the corona.
Shrinkage of dental composite in simulated cavity measured with digital image correlation.
Li, Jianying; Thakur, Preetanjali; Fok, Alex S L
2014-01-01
Polymerization shrinkage of dental resin composites can lead to restoration debonding or cracked tooth tissues in composite-restored teeth. In order to understand where and how shrinkage strain and stress develop in such restored teeth, Digital Image Correlation (DIC) was used to provide a comprehensive view of the displacement and strain distributions within model restorations that had undergone polymerization shrinkage. Specimens with model cavities were made of cylindrical glass rods with both diameter and length being 10 mm. The dimensions of the mesial-occlusal-distal (MOD) cavity prepared in each specimen measured 3 mm and 2 mm in width and depth, respectively. After filling the cavity with resin composite, the surface under observation was sprayed with first a thin layer of white paint and then fine black charcoal powder to create high-contrast speckles. Pictures of that surface were then taken before curing and 5 min after. Finally, the two pictures were correlated using DIC software to calculate the displacement and strain distributions. The resin composite shrunk vertically towards the bottom of the cavity, with the top center portion of the restoration having the largest downward displacement. At the same time, it shrunk horizontally towards its vertical midline. Shrinkage of the composite stretched the material in the vicinity of the "tooth-restoration" interface, resulting in cuspal deflections and high tensile strains around the restoration. Material close to the cavity walls or floor had direct strains mostly in the directions perpendicular to the interfaces. Summation of the two direct strain components showed a relatively uniform distribution around the restoration and its magnitude equaled approximately to the volumetric shrinkage strain of the material. PMID:25079865
Eaton, M.J.; Link, W.A.
2011-01-01
Estimating the age of individuals in wild populations can be of fundamental importance for answering ecological questions, modeling population demographics, and managing exploited or threatened species. Significant effort has been devoted to determining age through the use of growth annuli, secondary physical characteristics related to age, and growth models. Many species, however, either do not exhibit physical characteristics useful for independent age validation or are too rare to justify sacrificing a large number of individuals to establish the relationship between size and age. Length-at-age models are well represented in the fisheries and other wildlife management literature. Many of these models overlook variation in growth rates of individuals and consider growth parameters as population parameters. More recent models have taken advantage of hierarchical structuring of parameters and Bayesian inference methods to allow for variation among individuals as functions of environmental covariates or individual-specific random effects. Here, we describe hierarchical models in which growth curves vary as individual-specific stochastic processes, and we show how these models can be fit using capture-recapture data for animals of unknown age along with data for animals of known age. We combine these independent data sources in a Bayesian analysis, distinguishing natural variation (among and within individuals) from measurement error. We illustrate using data for African dwarf crocodiles, comparing von Bertalanffy and logistic growth models. The analysis provides the means of predicting crocodile age, given a single measurement of head length. The von Bertalanffy was much better supported than the logistic growth model and predicted that dwarf crocodiles grow from 19.4 cm total length at birth to 32.9 cm in the first year and 45.3 cm by the end of their second year. Based on the minimum size of females observed with hatchlings, reproductive maturity was estimated to be at nine years. These size benchmarks are believed to represent thresholds for important demographic parameters; improved estimates of age, therefore, will increase the precision of population projection models. The modeling approach that we present can be applied to other species and offers significant advantages when multiple sources of data are available and traditional aging techniques are not practical. ?? 2011 by the Ecological Society of America.
Eaton, Mitchell J.; Link, William A.
2011-01-01
Estimating the age of individuals in wild populations can be of fundamental importance for answering ecological questions, modeling population demographics, and managing exploited or threatened species. Significant effort has been devoted to determining age through the use of growth annuli, secondary physical characteristics related to age, and growth models. Many species, however, either do not exhibit physical characteristics useful for independent age validation or are too rare to justify sacrificing a large number of individuals to establish the relationship between size and age. Length-at-age models are well represented in the fisheries and other wildlife management literature. Many of these models overlook variation in growth rates of individuals and consider growth parameters as population parameters. More recent models have taken advantage of hierarchical structuring of parameters and Bayesian inference methods to allow for variation among individuals as functions of environmental covariates or individual-specific random effects. Here, we describe hierarchical models in which growth curves vary as individual-specific stochastic processes, and we show how these models can be fit using capture–recapture data for animals of unknown age along with data for animals of known age. We combine these independent data sources in a Bayesian analysis, distinguishing natural variation (among and within individuals) from measurement error. We illustrate using data for African dwarf crocodiles, comparing von Bertalanffy and logistic growth models. The analysis provides the means of predicting crocodile age, given a single measurement of head length. The von Bertalanffy was much better supported than the logistic growth model and predicted that dwarf crocodiles grow from 19.4 cm total length at birth to 32.9 cm in the first year and 45.3 cm by the end of their second year. Based on the minimum size of females observed with hatchlings, reproductive maturity was estimated to be at nine years. These size benchmarks are believed to represent thresholds for important demographic parameters; improved estimates of age, therefore, will increase the precision of population projection models. The modeling approach that we present can be applied to other species and offers significant advantages when multiple sources of data are available and traditional aging techniques are not practical.
Kumamoto, Yoshikazu; Noda, Yutaka; Sato, Yukio; Kanai, Tatsuaki; Murakami, Takeshi
2005-05-01
The effective doses and attenuation lengths for concrete and iron were measured for the design of heavy ion facilities. Neutrons were produced through the reaction of copper, carbon, and lead bombarded by carbon ions at 230 and 400 MeV.A, neon ions at 400 and 600 MeV.A, and silicon ions at 600 and 800 MeV.A. The detectors used were a Linus and a Andersson-Braun-type rem counter and a detector based on the activation of a plastic scintillator. Representative effective dose rates (in units of 10(-8) microSv h(-1) pps(-1) at 1 m from the incident target surface, where pps means particles per second) and the attenuation lengths (in units of m) were 9.4 x 10(4), 0.46 for carbon ions at 230 MeV.A; 8.9 x 10(5), 0.48 for carbon ions at 400 MeV.A; 9.3 x 10(5), 0.48 for neon ions at 400 MeV.A; 3.8 x 10(6), 0.50 for neon ions at 600 MeV.A; 3.9 x 10(6), 0.50 for silicon ions at 600 MeV.A; and 1.1 x 10(7), 0.51 for silicon ions at 800 MeV.A. The attenuation provided by an iron plate approximately 20 cm thick (nearly equal to the attenuation length) corresponded to that of a 50-cm block of concrete in the present energy range. Miscellaneous results, such as the angular distributions of the neutron effective dose, narrow beam attenuation experiments, decay of gamma-ray doses after the bombardment of targets, doses around an irradiation room, order effects in the multi-layer (concrete and iron) shielding, the doses from different targets, the doses measured with a scintillator activation detector, the gamma-ray doses out of walls and the ratio of the response between the Andersson-Braun-type and the Linus rem counters are also reported. PMID:15824595
NASA Astrophysics Data System (ADS)
Shelef, E.; Hilley, G. E.
2010-12-01
In this research, we explore the relationships between channel network attributes and the corresponding channel profile geometries using high-resolution digital topography and model-generated synthetic topographies. This combined analysis addresses one of the long-standing questions in geomorphology relating to the mechanistic significance of various plan-view channel network geometry measures. Statistically based numerical studies suggest that Hortonian measures of channel network architecture (e.g. bifurcation ratio, area ratio, and length ratio) describe virtually all possible network geometries, and so are not diagnostic when evaluating the origins of the geometry of a particular network. We further explore this hypothesis by examining the correlation between Hack exponent, the channel profile characteristics, and process changes (i.e debris flow vs. fluvial flows) within the landscape. Analysis of high resolution DEMs as well as modeled landscapes, suggests that the Hack exponent is likewise insensitive to changes in the channel profile concavity. In contrast, we find that changes in the concavity of channel profiles apparently impacts the spatial distribution of plan-view junction angles of joining stream segments throughout a catchment. In the context of previous work, this angle might be expected to be a function of the ratio between the slopes of the adjoined channels. Channel concavity determines downstream change in this ratio for channel segments throughout the basin, and so such a metric might be used to explicitly link profile channel geometries to plan-view network geometries. Because profile geometries may change with different advective mass transport processes, such a metric may provide a link between the processes that transport material across a landscape, the profile geometry of channels through which these flows traverse, and the overall drainage network geometry. Additional numerical and field data based analysis are required to further explore the sensitivity of the junction angle, as well as other measures, to process changes along the channel network.
NASA Astrophysics Data System (ADS)
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
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.
Williams, Kiel; /SLAC
2012-09-07
The electron pulses generated by the Linac Coherent Light Source at the SLAC National Accelerator Laboratory occur on the order of tens of femtoseconds and cannot be directly measured by conventional means. The length of the pulses can instead be reconstructed by measuring the spectrum of optical transition radiation emitted by the electrons as they move toward a conducting foil. Because the emitted radiation occurs in the mid-infrared from 0.6 to 30 microns a novel optical layout is required. Using a helium-neon laser with wavelength 633 nm, a series of gold-coated off-axis parabolic mirrors were positioned to direct a beam through a zinc selenide prism and to a focus at a CCD camera for imaging. Constructing this layout revealed a number of novel techniques for reducing the aberrations introduced into the system by the off-axis parabolic mirrors. The beam had a recorded radius of less than a millimeter at its final focus on the CCD imager. This preliminary setup serves as a model for the spectrometer that will ultimately measure the LCLS electron pulse duration.
NASA Astrophysics Data System (ADS)
Bowden, D. C.; Tsai, V. C.; Lin, F.
2013-12-01
Traditional ambient noise cross correlations between seismic stations have proven to be an effective means of extracting travel time information of surface waves. However, while the raw noise data is usually processed in a way which suppresses large amplitude earthquake events, it also distorts all relative amplitude information. Such information is the key to accurately retrieving attenuation and local site response measurements. Previous work using earthquake sources to track wave front propagation across the U.S. Array has been used to distinguish between effects on amplitude variation. Applying a similar approach to ambient noise studies offers potentially increased flexibility in such studies. We attempt a varied application of the methods which should preserve relative amplitudes in the Noise Correlation Function (NCF) across a given day or hour. Considering each station as a virtual source, a large number of travel time and relative amplitude maps can be constructed. By applying spatial differential operators to these maps, we track the effect of phase-front focusing and defocusing. By comparing amplitude variation for waves propagating in opposite directions, we attempt to independently infer the effects of seismic intrinsic attenuation and local site response. We have applied the approach on two datasets of vastly different scale. A dense array of single-component, broadband seismometers in Long Beach, CA (>4000 in an area around 100 sq-km) allows us to explore the higher frequency end of these measurements, up to 4Hz. In contrast, data collected over 4 years from the U.S. Array provide continental scale application, with useful periods of 8-30 seconds and depth sensitivities down to the uppermost mantle. We compare our results with previous studies based on earthquakes.
Intensity correlation measurements in stimulated Raman generation with a multimode laser
Westling, L.A.; Raymer, M.G.
1987-11-15
An experimental and theoretical study of the temporal correlations between the intensities of a broadband pump laser and Stokes light in stimulated Raman generation has been carried out. Direct measurements have been made of the pump laser and Stokes light intensity autocorrelation functions and of the intensity cross-correlation function between the two. Strong cross correlations are found. Nevertheless, the correlations are not perfect; that is, the Stokes intensity does not follow exactly the intensity variations of the laser. Transient effects and quantum fluctuations are shown, by theoretical modeling, to be responsible for the absence of perfect correlations.
Ultrasonic velocity measurement using phase-slope cross-correlation methods
NASA Technical Reports Server (NTRS)
Hull, D. R.; Kautz, H. E.; Vary, A.
1984-01-01
Computer implemented phase-slope and cross-correlation methods are introduced for measuring time delays between pairs of broadband ultrasonic pulse-echo signals for determining velocity in engineering materials. The phase-slope and cross-correlation methods are compared with the overlap method which is currently in wide use. Comparison of digital versions of the three methods shows similar results for most materials having low ultrasonic attenuation. However, the cross-correlation method is preferred for highly attenuating materials. An analytical basis for the cross-correlation method is presented. Examples are given for the three methods investigated to measure velocity in representative materials in the megahertz range.
NASA Astrophysics Data System (ADS)
Fiekowsky, Peter; Selassie, Daniel
1999-12-01
The search for the 'holy grail' of a fast, reliable, inexpensive predictor of defect printability has reached a new level. Taking images from several inspection tools (KLA-351, KLA-353, and KLA Starlight) during defect review, the AVI Photomask Metrology System provides measurement repeatability better than 5 nm, and significantly better correlation to printability than Scanning Electron Microscope (SEM) measurements. SEM measurements of printed defects are compared to various measurements of the defects on the mask. Analysis shows, as expected, that optical area measurements provide the best correlation to printability. Further, images from existing inspection tools are shown to be sufficient to produce these measurements using AVI's new 'Flux-area' technique.
NASA Astrophysics Data System (ADS)
Ullmann, V.; Emam, S.; Manske, E.
2015-08-01
For absolute length and form measurements at a large working distance (>150?mm) two special interferometers, a tandem interferometer and a Michelson interferometer with achromatic polarizing optics are constructed. In our experiments, both consist of a combination of one low-coherence interferometer and one laser interferometer. For the low-coherence interferometer part, a simple white-light source with less than 100?µW optical power output is chosen. It bases upon a low-cost fiber-coupled near-infrared LED with a large spectral width (FWHM?>?68?nm at 825?nm). The use of achromatic polarizing optics such as broadband polarizing beamsplitters and achromatic quarter-wave plates in the low-coherence interferometer parts increases the contrast level of the white-light signal fringe pattern to nearly 100%. Furthermore, the fringe pattern in a polarized interferometer has no subsignatures and is unique. Hence, different algorithms are tested for signal processing and automated zero-point detection of the white-light signature. The software for an automated measurement is tested in a standard room without thermal control and without damped oscillation. Therefore, in experiments with the tandem interferometer, it was possible to measure the zero-point position of a white-light signature with a peak-to-peak difference of 154?nm under uncontrolled environmental conditions without thermal stabilization. The white-light Michelson interferometer with polarizing achromatic optics allows zero-point detections with a standard deviation (mean value) of less than 15?nm. The drift is proved through measurement results.
Photon-correlation measurements of atomic-cloud temperature using an optical nanofiber
NASA Astrophysics Data System (ADS)
Grover, J. A.; Solano, P.; Orozco, L. A.; Rolston, S. L.
2015-07-01
We develop a temperature measurement of an atomic cloud based on the temporal correlations of fluorescence photons evanescently coupled into an optical nanofiber. We measure the temporal width of the intensity-intensity correlation function due to atomic transit time and use it to determine the most probable atomic velocity, hence the temperature. This technique agrees well with standard time-of-flight temperature measurements. We confirm our results with trajectory simulations.
Symplectic invariants, entropic measures and correlations of Gaussian states
Alessio Serafini; Fabrizio Illuminati; Silvio De Siena
2003-12-16
We present a derivation of the Von Neumann entropy and mutual information of arbitrary two--mode Gaussian states, based on the explicit determination of the symplectic eigenvalues of a generic covariance matrix. The key role of the symplectic invariants in such a determination is pointed out. We show that the Von Neumann entropy depends on two symplectic invariants, while the purity (or the linear entropy) is determined by only one invariant, so that the two quantities provide two different hierarchies of mixed Gaussian states. A comparison between mutual information and entanglement of formation for symmetric states is considered, remarking the crucial role of the symplectic eigenvalues in qualifying and quantifying the correlations present in a generic state.
Measuring blood velocity using correlative spectrally encoded flow cytometry.
Elhanan, Tal; Yelin, Dvir
2014-08-01
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
Sampl, Sandra; Pramhas, Sibylle; Stern, Christian; Preusser, Matthias; Marosi, Christine; Holzmann, Klaus
2012-01-01
Cancer cells bypass replicative senescence, the major barrier to tumor progression, by using telomerase or alternative lengthening of telomeres (ALT) as telomere maintenance mechanisms (TMMs). Correlation between ALT and patient survival was demonstrated for high-grade astrocytomas. Transcription from subtelomeres produces telomeric repeat-containing RNA (TERRA), a natural inhibitor of telomerase activity (TA). This led us to evaluate correlations of TERRA and TMM with tumor grade and outcome in astrocytoma patients. SYBR Green real-time reverse transcription-polymerase chain reaction assays for quantitation of total and chromosome 2p and 18p specific TERRA levels were developed. Tumor samples from 46 patients with astrocytoma grade 2 to 4, tissue controls, and cell lines were assessed. TMMs were evaluated by measuring TA and by detecting long telomeres due to ALT. In glioblastoma multiforme (GBM) grade 4, total TERRA levels were similar to cell lines but 14-, 31-, and 313-fold lower compared with grade 3, grade 2, and nonmalignant tissue, respectively. Total TERRA levels differed from chromosomal levels. Low 2p TERRA levels correlated with dense promoter methylation of subtelomeric CpG islands, indicating that TERRA expression in gliomas may be chromosome specific and epigenetically regulated. Total TERRA levels correlated with diagnosis, with low or absent TA and the presence of ALT, and were tentatively associated with favorable patient prognosis in our cohort (P = .06). TA and short telomeres identified a subset of GBM with a median survival of only 14.8 months. TERRA and TA may be prognostic in astrocytic tumors. PMID:22348177
Correlation between precision gravity and subsidence measurements at Cerro Prieto
Zelwer, R.; Grannell, R.B.
1982-10-01
Precision gravity measurements were made in the region of the Cerro Prieto geothermal field at yearly intervals from 1977 to 1981 to assess the feasibility of using gravity to determine subsurface reservoir changes with time. The extent of mass recharge in response to the continued production of fluids from this field was studied. Changes in gravity and ground elevation were observed throughout the region for the period of observation. Results indicate that the largest changes observed were the result of the Magnitude 6.1 (Caltech) Victoria earthquake of 8 June 1980. The epicenter of this earthquake was located 25 km southeast of the field on the Cerro Prieto Fault, which bounds the field on the southwest. Subsidence of up to 55 cm was measured east of the power plant, in the region between the northern end of the Cerro Prieto Fault and the southern end of the Imperial Fault. This area has been postulated to be the site of an active spreading center or pull-apart basin, and has been characterized by a high level of seismic activity during the last 10 years. Minor subsidence and small related gravity changes for the period preceeding the Victoria earthquake suggest that in spite of large fluid production rates, the reservoir is being almost completely recharged and that a measurable increase in subsurface density may be taking place. The results of measurements of horizontal ground motions made in this area are discussed in relation to the gravity and subsidence observations.
Intensive temperature and quantum correlations for refined quantum measurements
NASA Astrophysics Data System (ADS)
Ferraro, Alessandro; García-Saez, Artur; Acín, Antonio
2012-04-01
We consider the concept of temperature in a setting beyond the standard thermodynamics prescriptions. Namely, rather than restricting to standard coarse-grained measurements, we consider observers able to master any possible quantum measurement —a scenario that might be relevant at nanoscopic scales. In this setting, we focus on quantum systems of coupled harmonic oscillators and study the question of whether the temperature is an intensive quantity, in the sense that a block of a thermal state can be approximated by an effective thermal state at the same temperature as the whole system. Using the quantum fidelity as figure of merit, we identify instances in which this approximation is not valid, as the block state and the reference thermal state are distinguishable for refined measurements. Actually, there are situations in which this distinguishability even increases with the block size. However, we also show that the two states do become less distinguishable with the block size for coarse-grained measurements —thus recovering the standard picture. We then go further and construct an effective thermal state which provides a good approximation of the block state for any observables and sizes. Finally, we point out the role that entanglement plays in this scenario by showing that, in general, the thermodynamic paradigm of local intensive temperature applies whenever entanglement is not present in the system.
Correlation Curves: Measures of Association as Functions of Covariate Values
Steinar Bjerve; Kjell Doksum
1993-01-01
For experiments where the strength of association between a response variable $Y$ and a covariate $X$ is different over different regions of values for the covariate $X$, we propose local nonparametric dependence functions which measure the strength of association between $Y$ and $X$ as a function of $X = x$. Our dependence functions are extensions of Galton's idea of strength
NASA Technical Reports Server (NTRS)
Hubbard, S. M.; Tabib-Azar, M.; Balley, S.; Rybickid, G.; Neudeck, P.; Raffaelle, R.
2004-01-01
Minority-Carrier diffusion lengths of n-type 6H-SiC were measured using the electron-beam induced current (EBIC) technique. Experimental values of primary beam current, EBIC, and beam voltage were obtained for a variety of SIC samples. This data was used to calculate experimental diode efficiency vs. beam voltage curves. These curves were fit to theoretically calculated efficiency curves, and the diffusion length and metal layer thickness were extracted. The hole diffusion length in n-6H SiC ranged from 0.93 +/- 0.15 microns.
Angular correlations measured in pp collisions by ALICE at the LHC
?ukasz Kamil Graczykowski; Ma?gorzata Anna Janik
2014-09-09
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.
Angular correlations of identified charged particles measured in pp collisions by ALICE at the LHC
NASA Astrophysics Data System (ADS)
Graczykowski, ?ukasz Kamil; Janik, Ma?gorzata Anna
2014-06-01
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 ?{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 ???? 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 analyzing 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.
Dimension of quantum phase space measured by photon correlations
NASA Astrophysics Data System (ADS)
Leuchs, Gerd; Glauber, Roy J.; Schleich, Wolfgang P.
2015-06-01
We show that the different values 1, 2 and 3 of the normalized second-order correlation function {g}(2)(0) corresponding to a coherent state, a thermal state and a highly squeezed vacuum originate from the different dimensionality of these states in phase space. In particular, we derive an exact expression for {g}(2)(0) in terms of the ratio of the moments of the classical energy evaluated with the Wigner function of the quantum state of interest and corrections proportional to the reciprocal of powers of the average number of photons. In this way we establish a direct link between {g}(2)(0) and the shape of the state in phase space. Moreover, we illuminate this connection by demonstrating that in the semi-classical limit the familiar photon statistics of a thermal state arise from an area in phase space weighted by a two-dimensional Gaussian, whereas those of a highly squeezed state are governed by a line-integral of a one-dimensional Gaussian. We dedicate this article to Margarita and Vladimir Man’ko on the occasion of their birthdays. The topic of our contribution is deeply rooted in and motivated by their love for non-classical light, quantum mechanical phase space distribution functions and orthogonal polynomials. Indeed, through their articles, talks and most importantly by many stimulating discussions and intensive collaborations with us they have contributed much to our understanding of physics. Happy birthday to you both!
The Belt voice: Acoustical measurements and esthetic correlates
NASA Astrophysics Data System (ADS)
Bounous, Barry Urban
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.
J. W. Herbstreit; M. C. Thompson
1955-01-01
A system for the measurement of the variations in electrical lengths of radio propagation paths is described. The observed path-length instabilities are considered to be caused bythe same atmospheric turbulence responsible for the existence of very high frequency and ultra high frequency fields far beyond the radio horizon. Results obtained on 172.8 mc and 1,046 mc along 3½-, 10-, and
Reliability measures in item response theory: manifest versus latent correlation functions.
Milanzi, Elasma; Molenberghs, Geert; Alonso, Ariel; Verbeke, Geert; De Boeck, Paul
2015-02-01
For item response theory (IRT) models, which belong to the class of generalized linear or non-linear mixed models, reliability at the scale of observed scores (i.e., manifest correlation) is more difficult to calculate than latent correlation based reliability, but usually of greater scientific interest. This is not least because it cannot be calculated explicitly when the logit link is used in conjunction with normal random effects. As such, approximations such as Fisher's information coefficient, Cronbach's ?, or the latent correlation are calculated, allegedly because it is easy to do so. Cronbach's ? has well-known and serious drawbacks, Fisher's information is not meaningful under certain circumstances, and there is an important but often overlooked difference between latent and manifest correlations. Here, manifest correlation refers to correlation between observed scores, while latent correlation refers to correlation between scores at the latent (e.g., logit or probit) scale. Thus, using one in place of the other can lead to erroneous conclusions. Taylor series based reliability measures, which are based on manifest correlation functions, are derived and a careful comparison of reliability measures based on latent correlations, Fisher's information, and exact reliability is carried out. The latent correlations are virtually always considerably higher than their manifest counterparts, Fisher's information measure shows no coherent behaviour (it is even negative in some cases), while the newly introduced Taylor series based approximations reflect the exact reliability very closely. Comparisons among the various types of correlations, for various IRT models, are made using algebraic expressions, Monte Carlo simulations, and data analysis. Given the light computational burden and the performance of Taylor series based reliability measures, their use is recommended. PMID:24484622
Digital image correlation method for measuring thermal deformation of composite materials
NASA Astrophysics Data System (ADS)
Jiang, Li; He, Yan; Wang, Dong-wei; Liu, Ke; Wu, Wei-ren
2013-10-01
Thermal deformation measurement of the high-speed aircrafts under the high temperature is significant for reliability assessment, life prediction, and safety design for the materials and structures. This paper presents a digital image correlation method to accurately measure the full-field thermal deformation of composites under the environment of high temperature. First, real-time deformation images of experimental objects under different loads are acquired with CCD cameral. Based on the digital speckle correlation theory, the bilinear interpolation algorithm is employed to measure the thermal deformation. Last, the comparative analyses on measurement results by the proposed and traditional methods are conducted, as well as factors impacting measurement errors are analyzed.
Imaging of adult flatfoot: correlation of radiographic measurements with MRI.
Lin, Yu-Ching; Mhuircheartaigh, Jennifer Ni; Lamb, Joshua; Kung, Justin W; Yablon, Corrie M; Wu, Jim S
2015-02-01
OBJECTIVE. The purpose of this study is to determine whether radiographic foot measurements can predict injury of the posterior tibial tendon (PTT) and the supporting structures of the medial longitudinal arch as diagnosed on MRI. MATERIALS AND METHODS. After institutional review board approval, 100 consecutive patients with radiographic and MRI examinations performed within a 2-month period were enrolled. Thirty-one patients had PTT dysfunction clinically, and 69 patients had other causes of ankle pain. Talonavicular uncoverage angle, incongruency angle, calcaneal pitch angle, Meary angle, cuneiform-to-fifth metatarsal height, and talar tilt were calculated on standing foot or ankle radiographs. MRI was used to assess for abnormalities of the PTT (tenosynovitis, tendinosis, and tear) and supporting structures of the medial longitudinal arch (spring ligament, deltoid ligament, and sinus tarsi). Statistical analysis was performed using the chi-square and Fisher exact tests for categoric variables; the Student t test was used for continuous variables. RESULTS. There was a statistically significant association of PTT tear with abnormal talonavicular uncoverage angle, calcaneal pitch angle, Meary angle, and cuneiform-to-fifth metatarsal height. PTT tendinosis and isolated tenosynovitis had a poor association with most radiologic measurements. If both calcaneal pitch and Meary angles were normal, no PTT tear was present. An abnormal calcaneal pitch angle had the best association with injury to the supporting medial longitudinal arch structures. CONCLUSION. Radiographic measurements, especially calcaneal pitch and Meary angles, can be useful in detecting PTT tears. Calcaneal pitch angle provides the best assessment of injury to the supporting structures of the medial longitudinal arch. PMID:25615758
Measurement of the Vaporization Enthalpy of Complex Mixtures by Correlation-Gas Chromatography. The
Chickos, James S.
Measurement of the Vaporization Enthalpy of Complex Mixtures by Correlation-Gas Chromatography April 21, 2005. Revised Manuscript Received June 2, 2005 The use of correlation-gas chromatography using gas chromatography. Some variance in composition with the literature values has been observed
Martial Guillaud; Karen Adler-Storthz; Anais Malpica; Gregg Staerkel; Jasenka Matisic; Dirk Van Niekirk; Dennis Cox; Neal Poulin; Michele Follen; Calum MacAulay
2005-01-01
Objectives.In this study, we are testing the hypothesis that human papillomavirus (HPV) positivity is correlated with chromatin texture in the cell. Interim analyses are important since this study involves 2000 patients and generates 6000 biopsy specimens that will be subjected to quantitative histopathological analysis and correlated to HPV positivity as measured by the Hybrid Capture II test (Digene; Gaithersberg, MD)
Correlation Attenuation Due to Measurement Error: A New Approach Using the Bootstrap Procedure
ERIC Educational Resources Information Center
Padilla, Miguel A.; Veprinsky, Anna
2012-01-01
Issues with correlation attenuation due to measurement error are well documented. More than a century ago, Spearman proposed a correction for attenuation. However, this correction has seen very little use since it can potentially inflate the true correlation beyond one. In addition, very little confidence interval (CI) research has been done for…
Correlation between an in vitro and an in vivo measure of dioxin sensitivity in birds
Correlation between an in vitro and an in vivo measure of dioxin sensitivity in birds Jessica A to dioxin-like compounds in birds; induction of 7-ethoxyresorufin-O-de- ethylase (EROD) activity in cultured,3,7,8-tetrachlo- rodibenzo-p-dioxin (TCDD) and 6 polychlorinated biphe- nyls (PCBs) were strongly correlated
Thomas Chung; Stephen D. Bartlett; Andrew C. Doherty
2009-04-17
In measurement-based quantum computation (MBQC), local adaptive measurements are performed on the quantum state of a lattice of qubits. Quantum gates are associated with a particular measurement sequence, and one way of viewing MBQC is that such a measurement sequence prepares a resource state suitable for `gate teleportation'. We demonstrate how to quantify the performance of quantum gates in MBQC by using correlation functions on the pre-measurement resource state.
B. Mehrdadi; B. Kaghazchi; M. S. Beck
1982-01-01
An instrument has been developed for measuring the level of solid materials stored in a container in which ultrasound bursts with random durations are transmitted towards the solid\\/air interface. The acoustic transit time is measured by cross correlating the transmitted signals and received echoes. This technique overcomes erroneous measurement associated with conventional single pulse systems, caused by rogue reflections from
Ward, Daniel H
2015-07-01
Proportional smile design is a useful tool for evaluating and designing smiles that are in harmony with the face. Although not always observed in nature, the recurring esthetic dental proportion is preferred by dentists surveyed to the width proportions observed in nature with normal-length teeth. The width/length ratio of the central incisor is a key determinant in providing a smile that is pleasing to dentists. Using the desired tooth length while maintaining the preferred 78% width/length ratio of the central incisor in conjunction with the recommended recurring esthetic dental proportion is a good method for designing a smile balanced with the face. PMID:26140969
Vulliamy, T; Beswick, R; Kirwan, M J; Hossain, U; Walne, A J; Dokal, I
2012-01-01
Dyskeratosis congenita (DC) is a heterogeneous bone marrow failure syndrome with seven disease-causing genes identified to date, six of which are linked to telomere maintenance. Mutations in one of these genes (TINF2), which encodes a component of the shelterin complex, are associated with particularly short telomeres. Among the 224 consecutive patients with different forms of bone marrow failure (46 with DC, 122 with aplastic anaemia and 57 with some features of DC), we have identified 16 new families with variants in exon 6 of the TINF2 gene, eight of which are novel. We observe that the phenotype associated with these mutations extends to a severe early presentation, not always classified as DC. In addition, we see that some of the variants identified are not associated with short telomeres and are also found in asymptomatic individuals. In the absence of any direct functional assay, the data indicates that the telomere length measurement can inform us as to which variants in TINF2 are pathogenic and which may be non-pathogenic. PMID:21199492
The application of vision measurement in aerodynamic testing combined with speckle correlation
NASA Astrophysics Data System (ADS)
Chen, Ding; Zhang, Jin-guo; Zhang, Ye-hua; Wang, Wei; Ma, Hong-qiang; Zhang, Shang-bin; Feng, Jia-bo
2015-05-01
This paper presents a combination of visual measurement technique of speckle correlation method in aerodynamic test application. Modal analysis of aerodynamic testing and deformation measurement is often very important but very difficult to achieve, fortunately, the development of modern optical measurement techniques made it possible. First, we conduct the modal analysis on an airfoil model and its deformation analysis under certain conditions. Then, the above technique was used to verify it. The results of the aerodynamic test and finite element analysis agree well, The novel of the new method is combining the speckle correlation and the model deformation in the aerodynamic testing. This method using the speckle correlation to process the data, combining sub-pixel correlation can make the results achieve very high precision and realized the real planar measuring. This non-contact full-field optical metrology shows a lot of abstracting potentials in aerodynamic test applications.
Technology Transfer Automated Retrieval System (TEKTRAN)
Measurements of texture properties related to tenderness at different locations within deboned broiler breast fillets have been used to validate techniques for texture analysis and establish correlations between different texture evaluation methods. However, it has been demonstrated that meat text...
Field methods to measure surface displacement and strain with the Video Image Correlation method
NASA Technical Reports Server (NTRS)
Maddux, Gary A.; Horton, Charles M.; Mcneill, Stephen R.; Lansing, Matthew D.
1994-01-01
The objective of this project was to develop methods and application procedures to measure displacement and strain fields during the structural testing of aerospace components using paint speckle in conjunction with the Video Image Correlation (VIC) system.
Identification of Noise Sources in High Speed Jets via Correlation Measurements: A Review
NASA Technical Reports Server (NTRS)
Bridges, James (Technical Monitor); Panda, Jayanta
2005-01-01
Significant advancement has been made in the last few years to identify noise sources in high speed jets via direct correlation measurements. In this technique turbulent fluctuations in the flow are correlated with far field acoustics signatures. In the 1970 s there was a surge of work using mostly intrusive probes, and a few using Laser Doppler Velocimetry, to measure turbulent fluctuations. The later experiments established "shear noise" as the primary source for the shallow angle noise. Various interpretations and criticisms from this time are described in the review. Recent progress in the molecular Rayleigh scattering based technique has provided a completely non-intrusive means of measuring density and velocity fluctuations. This has brought a renewed interest on correlation measurements. We have performed five different sets of experiments in single stream jets of different Mach number, temperature ratio and nozzle configurations. The present paper tries to summarize the correlation data from these works.
Surface Roughness Measurement on a Wing Aircraft by Speckle Correlation
Salazar, Félix; Barrientos, Alberto
2013-01-01
The study of the damage of aeronautical materials is important because it may change the microscopic surface structure profiles. The modification of geometrical surface properties can cause small instabilities and then a displacement of the boundary layer. One of the irregularities we can often find is surface roughness. Due to an increase of roughness and other effects, there may be extra momentum losses in the boundary layer and a modification in the parasite drag. In this paper we present a speckle method for measuring the surface roughness on an actual unmanned aircraft wing. The results show an inhomogeneous roughness distribution on the wing, as expected according to the anisotropic influence of the winds over the entire wing geometry. A calculation of the uncertainty of the technique is given. PMID:24013488
Measurement of steel plate perforation tests with digital image correlation.
Cordova, Theresa Elena; Reu, Phillip L.; Vangoethem, Douglas J.
2009-03-01
The results of a series of punch-through tests performed on steel plates are presented. The geometry consisted of circular plates with welded boundary condition penetrated by a conical shaped punch with either a radiused or flat cylindrical end. After initial failure, the conical portion of the punch was driven through the plate to exercise tearing mechanics. Tests were performed quasi-statically with a hydraulic actuator and dynamically using a high-capacity drop table. Deformation and strain were measured with a stereo DIC system. The quasi-static tests utilized a conventional direct-view DIC technique while the dynamic tests required development of an indirect-view technique using a mirror. Experimental details used to conduct the test series will be presented along with test results. Methods of assessing test-to-test repeatability will be discussed. DIC results will also be synchronized and compared with transducer data (displacement and strain).
Surface roughness measurement on a wing aircraft by speckle correlation.
Salazar, Félix; Barrientos, Alberto
2013-01-01
The study of the damage of aeronautical materials is important because it may change the microscopic surface structure profiles. The modification of geometrical surface properties can cause small instabilities and then a displacement of the boundary layer. One of the irregularities we can often find is surface roughness. Due to an increase of roughness and other effects, there may be extra momentum losses in the boundary layer and a modification in the parasite drag. In this paper we present a speckle method for measuring the surface roughness on an actual unmanned aircraft wing. The results show an inhomogeneous roughness distribution on the wing, as expected according to the anisotropic influence of the winds over the entire wing geometry. A calculation of the uncertainty of the technique is given. PMID:24013488
Local deterministic model of singlet state correlations based on relaxing measurement independence.
Hall, Michael J W
2010-12-17
The derivation of Bell inequalities requires an assumption of measurement independence, related to the amount of free will experimenters have in choosing measurement settings. Violation of these inequalities by singlet state correlations brings this assumption into question. A simple measure of the degree of measurement independence is defined for correlation models, and it is shown that all spin correlations of a singlet state can be modeled via giving up just 14% of measurement independence. The underlying model is deterministic and no signaling. It may thus be favorably compared with other underlying models of the singlet state, which require maximum indeterminism or maximum signaling. A local deterministic model is also given that achieves the maximum possible violation of the well-known Bell-Clauser-Horne-Shimony-Holt inequality, at a cost of only 1/3 of measurement independence. PMID:21231566
NASA Astrophysics Data System (ADS)
Song, John; Chu, Wei; Tong, Mingsi; Soons, Johannes
2014-06-01
Based on three-dimensional (3D) topography measurements on correlation cells, the National Institute of Standards and Technology (NIST) has developed the ‘NIST Ballistics Identification System (NBIS)’ aimed at accurate ballistics identifications and fast ballistics evidence searches. The 3D topographies are divided into arrays of correlation cells to identify ‘valid correlation areas’ and eliminate ‘invalid correlation areas’ from the matching and identification procedure. A ‘congruent matching cells’ (CMC)’ method using three types of identification parameters of the paired correlation cells (cross correlation function maximum CCFmax, spatial registration position in x-y and registration angle ?) is used for high accuracy ballistics identifications. ‘Synchronous processing’ is proposed for correlating multiple cell pairs at the same time to increase the correlation speed. The proposed NBIS can be used for correlations of both geometrical topographies and optical intensity images. All the correlation parameters and algorithms are in the public domain and subject to open tests. An error rate reporting procedure has been developed that can greatly add to the scientific support for the firearm and toolmark identification specialty, and give confidence to the trier of fact in court proceedings. The NBIS is engineered to employ transparent identification parameters and criteria, statistical models and correlation algorithms. In this way, interoperability between different ballistics identification systems can be more easily achieved. This interoperability will make the NBIS suitable for ballistics identifications and evidence searches with large national databases, such as the National Integrated Ballistic Information Network in the United States.
Osterberg, EC; Maganty, A; Ramasamy, R; Eid, JF
2015-01-01
Inflatable penile prosthesis (IPP) remains the gold standard for the surgical treatment of refractory erectile dysfunction; however, current literature to aid surgeons on how best to counsel patients on their postoperative inflated penile length is lacking. The aim of this study was to identify preoperative parameters that could better predict postoperative penile length following insertion of an IPP. Twenty men were enrolled in a prospective study examining penile lengths before and after IPP surgery. Patients with Peyronie’s disease were excluded from this analysis. Baseline preoperative characteristics, including body mass index, history of hypertension, diabetes, Sexual Health Inventory for Men scores and/or prior radical prostatectomy were recorded. All patients underwent implantation with a three-piece inflatable Coloplast penile prosthesis. We compared stretched penile length to pharmacologically induced erect lengths. Postoperatively, we measured inflated penile lengths at 6 weeks and assessed patients’ perception of penile size at 12 weeks. The median (± interquartile range) stretched penile length and pharmacologically induced erect penile length was 15 (± 3) and 14.25 (± 2) cm, respectively (P = 0.5). Median post-prosthesis penile length (13.5 ± 2.13 cm) was smaller than preoperative pharmacologically induced length (P = 0.02) and preoperative stretched penile length (P = 0.01). The majority of patients (70%) had a decrease in penile length (median loss 0.5 ± 1.5 cm); however, this loss was perceptible by 43% of men. Stretched penile length and pharmacologically induced erect penile length were equally good predictors of postoperative inflated length (Spearman’s correlation 0.8 and 0.9, respectively). Pharmacologically induced erect penile length and stretched penile lengths are equal predictors of post-prosthesis penile length. The majority of men will experience some decrease in penile length following prosthesis implantation; however <50% report a subjective loss of penile length. PMID:24430278
NASA Astrophysics Data System (ADS)
Yan, Yan; Zou, Jian; Wang, Chao-Quan; Xu, Bao-Ming; Li, Hai; Shao, Bin
2015-06-01
We consider that two qubits interact with a common structured reservoir and initially there are correlations between the qubit system and the reservoir. By performing local measurements before and after the two qubits undergo decoherence, not only more entanglement can be produced between them at the beginning, but also the produced entanglement can decay more slowly. We focus on investigating the effects of different initial system-environment correlations on the entanglement of the two qubits, and in each case, we obtain the optimal pre- and post-measurement strength that give the maximum amount of entanglement of the two qubits. We also find that the initial quantum correlations would induce much more entanglement than the initial classical correlations, and the induced entanglement can preserve longer in the initial quantum correlation case. The enhancement of the entanglement depends on the evolution time, the decay rate and the initial state.
NASA Astrophysics Data System (ADS)
Xue, Zhenyu; Charonko, John J.; Vlachos, Pavlos P.
2014-11-01
In particle image velocimetry (PIV) the measurement signal is contained in the recorded intensity of the particle image pattern superimposed on a variety of noise sources. The signal-to-noise-ratio (SNR) strength governs the resulting PIV cross correlation and ultimately the accuracy and uncertainty of the resulting PIV measurement. Hence we posit that correlation SNR metrics calculated from the correlation plane can be used to quantify the quality of the correlation and the resulting uncertainty of an individual measurement. In this paper we extend the original work by Charonko and Vlachos and present a framework for evaluating the correlation SNR using a set of different metrics, which in turn are used to develop models for uncertainty estimation. Several corrections have been applied in this work. The SNR metrics and corresponding models presented herein are expanded to be applicable to both standard and filtered correlations by applying a subtraction of the minimum correlation value to remove the effect of the background image noise. In addition, the notion of a ‘valid’ measurement is redefined with respect to the correlation peak width in order to be consistent with uncertainty quantification principles and distinct from an ‘outlier’ measurement. Finally the type and significance of the error distribution function is investigated. These advancements lead to more robust and reliable uncertainty estimation models compared with the original work by Charonko and Vlachos. The models are tested against both synthetic benchmark data as well as experimental measurements. In this work, {{U}68.5} uncertainties are estimated at the 68.5% confidence level while {{U}95} uncertainties are estimated at 95% confidence level. For all cases the resulting calculated coverage factors approximate the expected theoretical confidence intervals, thus demonstrating the applicability of these new models for estimation of uncertainty for individual PIV measurements.
Super-quantum correlation and geometry for Bell-diagonal states with weak measurements
NASA Astrophysics Data System (ADS)
Wang, Yao-Kun; Ma, Teng; Fan, Heng; Fei, Shao-Ming; Wang, Zhi-Xi
2013-10-01
We propose "weak one-way deficit" by weak measurements as the generalization of one-way deficit defined for standard projective measurements. The weak one-way deficit for Werner state is obtained analytically. We find that weak one-way deficit is smaller than the standard one-way deficit, which contrasts with a straightforward expectation based on the known fact that super-quantum discord by weak measurement is always larger than the quantum discord defined by projective measurement. On the other hand, by tuning the weak measurement continuously to the projective measurement, both weak one-way deficit and super-quantum discord converge to the same value, which is either the one-way deficit or the quantum discord both quantifying quantum correlation. In this sense, weak measurement does not necessarily capture more quantumness of correlations. We also give the geometry of super-quantum discord of the Bell-diagonal states with explicit geometrical figures. As an application, the dynamic behavior of super-quantum correlation including super-quantum discord and weak one-way deficit under decoherence is investigated. We find that the order relation of the super-quantum correlation and the quantum correlation remained unchanged under the phase flipping channel for the Bell-diagonal states and the Werner states.
Reader, Simon
volumes. Innovation frequencies also correlated with laboratory measures of learning, increasing our confidence in the innovation measure, and with social learning frequencies, suggesting that innovation and social learning propensities have evolved together. Species range size did not correlate
Henson, M.P.; Bergstedt, R.A.; Adams, J.V.
2003-01-01
The ability to predict when sea lampreys (Petromyzon marinus) will metamorphose from the larval phase to the parasitic phase is essential to the operation of the sea lamprey control program. During the spring of 1994, two populations of sea lamprey larvae from two rivers were captured, measured, weighed, implanted with coded wire tags, and returned to the same sites in the streams from which they were taken. Sea lampreys were recovered in the fall, after metamorphosis would have occurred, and checked for the presence of a tag. When the spring data were compared to the fall data it was found that the minimum requirements (length ??? 120 mm, weight ??? 3 g, and condition factor ??? 1.50) suggested for metamorphosis did define a pool of larvae capable of metamorphosing. However, logistic regressions that relate the probability of metamorphosis to size are necessary to predict metamorphosis in a population. The data indicated, based on cross-validation, that weight measurements alone predicted metamorphosis with greater precision than length or condition factor in both the Marengo and Amnicon rivers. Based on the Akaike Information Criterion, weight alone was a better predictor in the Amnicon River, but length and condition factor combined predicted metamorphosis better in the Marengo River. There would be no additional cost if weight alone were used instead of length. However, if length and weight were measured the gain in predictive power would not be enough to justify the additional cost.
Henson, Mary P.; Bergstedt, Roger A.; Adams, Jean V.
2003-01-01
The ability to predict when sea lampreys (Petromyzon marinus) will metamorphose from the larval phase to the parasitic phase is essential to the operation of the sea lamprey control program. During the spring of 1994, two populations of sea lamprey larvae from two rivers were captured, measured, weighed, implanted with coded wire tags, and returned to the same sites in the streams from which they were taken. Sea lampreys were recovered in the fall, after metamorphosis would have occurred, and checked for the presence of a tag. When the spring data were compared to the fall data it was found that the minimum requirements (length a?Y 120 mm, weight a?Y 3 g, and condition factor a?Y 1.50) suggested for metamorphosis did define a pool of larvae capable of metamorphosing. However, logistic regressions that relate the probability of metamorphosis to size are necessary to predict metamorphosis in a population. The data indicated, based on cross-validation, that weight measurements alone predicted metamorphosis with greater precision than length or condition factor in both the Marengo and Amnicon rivers. Based on the Akaike Information Criterion, weight alone was a better predictor in the Amnicon River, but length and condition factor combined predicted metamorphosis better in the Marengo River. There would be no additional cost if weight alone were used instead of length. However, if length and weight were measured the gain in predictive power would not be enough to justify the additional cost.
NSDL National Science Digital Library
Pennilyn Higgins
Three hypothetical rock sections along an East-West transect are provided. Students correlate the three sections using the biostratigraphy of planktic forams (as a proxy for age), benthic forams (as a proxy of depth), and lithology (as a proxy of environment). Students are asked to provide an interpretation of the history of this depositional basin. An ash bed of known age is added and students are asked to determine if this new information affects their interpretation. Finally, an interesting lithologic feature is added, and students are asked to provide a geological explanation.
Stevens, Daniel E; Smith, Cameron B; Harwood, Brad; Rice, Charles L
2014-11-01
Ultrasound imaging has facilitated the reliable measure of the architectural variables fascicle length (LF ) and pennation angle (PA), at rest and during static and dynamic contractions in many human skeletal muscles in vivo. Despite its small size and very modest contribution to elbow extension torque, the anconeus muscle has proven a useful model for the study of neuromuscular function in health and disease. Recent single motor unit (MU) studies in the anconeus have reported discrete and identifiable individual trains of MU potentials from intramuscular electromyography (EMG) recordings during dynamic elbow extensions. It is unknown whether the anconeus has unique architectural features related to alterations in LF and PA throughout the elbow joint range of motion that may help explain these high-quality recordings. Previous anatomical studies have investigated this muscle in cadavers and at mainly one elbow joint angle. The purpose of this study was to measure in vivo PA and LF of the anconeus muscle in a relaxed state at different degrees of elbow flexion using ultrasonography. Ultrasound images were collected from 10 healthy males (25 ± 3 years) at 135°, 120°, 90°, 45°, and 0° of elbow flexion. Average values of LF decreased by 6 mm (10%), 6 mm (12%), and 4 mm (9%) from 135-120°, 120-90°, and 90-45° of elbow flexion, respectively, whereas average PA values increased by 1° (9%), 1° (8%), and 2° (14%) from 135-120°, 120-90°, and 45-0°, respectively. The results indicate that anconeus muscle architecture is dynamic, undergoing moderate changes with elbow joint excursion that are similar to other limb muscles reported elsewhere. The data obtained here are more comprehensive and representative of architectural changes at various elbow joint positions than those data reported in cadaveric studies. Furthermore, the results of this study indicate that despite experiencing similar relative changes in muscle architecture to other skeletal muscles about the elbow joint, the minimal absolute changes in LF of the anconeus likely contribute to the clarity of intramuscular EMG previously reported in this muscle. PMID:25223934
Correlating aerosol optical thickness measurement with PM10 mass concentration in Wuhan area
NASA Astrophysics Data System (ADS)
Wang, Chensheng; Zhang, Zhijie; Yue, Song
2011-11-01
This paper aims at developing a method to use satellite retrievals aerosol optical thickness (AOT) and filed measured AOT to monitor air particulate pollution. This work is applied during the entire year of 2009, on Wuhan area, central China. The ground level daily mean PM10 mass concentration is measured by tapered element oscillating microbalance. Meanwhile, local daily mean AOT is obtained by using field spectrometer. After that, the correlations between local daily mean AOT and PM10 concentrations are calculated. As the AOT MODIS retrieval AOT has good agreement with field measured ones, the good correlation between MODIS AOT and PM10 mass concentration is demonstrated, and the correlation coefficients range from 0.67 to 0.77. This correlation coefficient has strong season dependence which indicates that the correlation in spring and summer is high, while it is much lower in winter. Then the correlation is improved according to the impact of relative humidity. Based on the good correlation condition, the linear regression analysis is completed with the help of SPSS Statistics.
Accurate measurement of wall skin friction by single-pixel ensemble correlation
NASA Astrophysics Data System (ADS)
Shen, JunQi; Pan, Chong; Wang, JinJun
2014-07-01
The present work deals with accurately estimating wall-skin friction from near-wall mean velocity by means of PIV measurement. The estimation accuracy relies on the spatial resolution and the precision of the resolved velocity profile inside the viscous sublayer, which is a big challenge for conventional window-based correlation method (Kähler C J, et al. Exp Fluids, 2012, 52: 1641-1656). With the help of single-pixel ensemble correlation, the ensemble-averaged velocity vector can be resolved at significant spatial resolution, thus improving the measurement accuracy. To demonstrate the feasibility of this single-pixel ensemble correlation method, we first study the velocity estimation precision in a case of steady near-wall flow. Synthetic particle images are used to investigate the effect of different image parameters. It is found that the velocity RMS-uncertainty level of the single-pixel ensemble correlation method can be equivalent to the conventional window correlation method once the effective particle number used for the ensemble correlation is large enough. Furthermore, a canonical turbulent boundary layer is synthetically simulated based on velocity statistics resolved by previous Direct Numerical Simulation (DNS) work (Schlatter P, et al. J Fluid Mech, 2010, 659: 116-126). The relative error of wall skin friction coefficient is shown to be one-order smaller than that of the window correlation method. And the optimization strategy to further minimize the measurement uncertainty is discussed in the last part.
The classical-quantum boundary for correlations: discord and related measures
Kavan Modi; Aharon Brodutch; Hugo Cable; Tomasz Paterek; Vlatko Vedral
2012-11-27
One of the best signatures of nonclassicality in a quantum system is the existence of correlations that have no classical counterpart. Different methods for quantifying the quantum and classical parts of correlations are amongst the more actively-studied topics of quantum information theory over the past decade. Entanglement is the most prominent of these correlations, but in many cases unentangled states exhibit nonclassical behavior too. Thus distinguishing quantum correlations other than entanglement provides a better division between the quantum and classical worlds, especially when considering mixed states. Here we review different notions of classical and quantum correlations quantified by quantum discord and other related measures. In the first half, we review the mathematical properties of the measures of quantum correlations, relate them to each other, and discuss the classical-quantum division that is common among them. In the second half, we show that the measures identify and quantify the deviation from classicality in various quantum-information-processing tasks, quantum thermodynamics, open-system dynamics, and many-body physics. We show that in many cases quantum correlations indicate an advantage of quantum methods over classical ones.
Sharpe, Colin R.
1983-01-01
Leg length inequality, a common abnormality, can cause musculoskeletal pain, scoliosis, and osteoarthritis of the hip. Seven percent of the asymptomatic population has a leg length inequality greater than 12 mm; the incidence is considerably higher (13%-22%) in individuals complaining of low back pain. Correction can usually be accomplished by shoe modification, and can result in dramatic relief of pain. Leg length inequality of more than half an inch is considered clinically significant. Leg length measurement should be routine in all patients complaining of low back pain, hip pain, and atypical flank and lower quadrant pain. Correction might prove very cost-effective. PMID:21283327
Development of Standardized Mobile Tracer Correlation Approach for Large Area Emission Measurements
Work toward a standardized version of a mobile tracer correlation measurement method is discussed. The method used for assessment of methane emissions from 15 landfills in 56 field deployments from 2009 to 2013. This general area source measurement method uses advances in instrum...