Science.gov

Sample records for angle measurement planes

  1. A Method for Measuring a Plane Angle.

    ERIC Educational Resources Information Center

    Roberts, George D.; Roberts, G. Gilbert

    1978-01-01

    Derivation of formulas and example problems for determining the size of a plane angle are given to help in drafting work. The authors state that a small hand calculator will provide greater accuracy in solving these problems than a protractor. (MF)

  2. Measuring Material Microstructure Under Flow Using 1-2 Plane Flow-Small Angle Neutron Scattering

    PubMed Central

    Gurnon, A. Kate; Godfrin, P. Douglas; Wagner, Norman J.; Eberle, Aaron P. R.; Butler, Paul; Porcar, Lionel

    2014-01-01

    A new small-angle neutron scattering (SANS) sample environment optimized for studying the microstructure of complex fluids under simple shear flow is presented. The SANS shear cell consists of a concentric cylinder Couette geometry that is sealed and rotating about a horizontal axis so that the vorticity direction of the flow field is aligned with the neutron beam enabling scattering from the 1-2 plane of shear (velocity-velocity gradient, respectively). This approach is an advance over previous shear cell sample environments as there is a strong coupling between the bulk rheology and microstructural features in the 1-2 plane of shear. Flow-instabilities, such as shear banding, can also be studied by spatially resolved measurements. This is accomplished in this sample environment by using a narrow aperture for the neutron beam and scanning along the velocity gradient direction. Time resolved experiments, such as flow start-ups and large amplitude oscillatory shear flow are also possible by synchronization of the shear motion and time-resolved detection of scattered neutrons. Representative results using the methods outlined here demonstrate the useful nature of spatial resolution for measuring the microstructure of a wormlike micelle solution that exhibits shear banding, a phenomenon that can only be investigated by resolving the structure along the velocity gradient direction. Finally, potential improvements to the current design are discussed along with suggestions for supplementary experiments as motivation for future experiments on a broad range of complex fluids in a variety of shear motions. PMID:24561395

  3. A Viewpoint on the Quantity "Plane Angle"

    NASA Astrophysics Data System (ADS)

    Eder, W. E.

    1982-01-01

    Properties of the quantity "plane angle" are explored under the hypothesis that it is a dimensional quantity. The exploration proceeds especially with respect to the physical concept, its mathematical treatment, vector concepts, measurement theory, units of related quantities, engineering pragmatism, and SI. An attempt is made to bring these different relations into a rational, logical and consistent framework, and thus to justify the hypothesis. Various types of vectorial quantities are recognized, and their properties described with an outline of the necessary algebraic manipulations. The concept of plane angle is amplified, and its interdependence with the circular arc is explored. The resulting units of plane angle form a class of similar scales of measurement. Consequences of the confirmed hypothesis are developed for mathematical expressions involving trigonometric functions, rotational volumes and areas, mathematical limits, differentiation and series expansion. Consequences for mechanical rotational quantities are developed, with proposals for revisions to a number of expressions for derived units within SI. A revised definition for the quantity "plane angle" is stated to take account of the developed insights. There is a clear need to reconsider the status of plane angle and some other quantities within the international framework of SI.

  4. From plane to spatial angles: PTB's spatial angle autocollimator calibrator

    NASA Astrophysics Data System (ADS)

    Kranz, Oliver; Geckeler, Ralf D.; Just, Andreas; Krause, Michael; Osten, Wolfgang

    2015-10-01

    Electronic autocollimators are utilised versatilely for non-contact angle measurements in applications like straightness measurements and profilometry. Yet, no calibration of the angle measurement of an autocollimator has been available when both its measurement axes are engaged. Additionally, autocollimators have been calibrated at fixed distances to the reflector, although its distance may vary during the use of an autocollimator. To extend the calibration capabilities of the Physikalisch-Technische Bundesanstalt (PTB) regarding spatial angles and variable distances, a novel calibration device has been set up: the spatial angle autocollimator calibrator (SAAC). In this paper, its concept and its mechanical realisation will be presented. The focus will be on the system's mathematical modelling and its application in spatial angle calibrations. The model considers the misalignments of the SAAC's components, including the non-orthogonalities of the measurement axes of the autocollimators and of the rotational axes of the tilting unit. It allows us to derive specific measurement procedures to determine the misalignments in situ and, in turn, to correct the measurements of the autocollimators. Finally, the realisation and the results of a traceable spatial angle calibration of an autocollimator will be presented. This is the first calibration of this type worldwide.

  5. Small-angle shubnikov-de haas measurements in a 2D electron system: the effect of a strong In-plane magnetic field

    PubMed

    Vitkalov; Zheng; Mertes; Sarachik; Klapwijk

    2000-09-01

    Measurements in magnetic fields applied at small angles relative to the electron plane in silicon MOSFETs indicate a factor of 2 increase of the frequency of Shubnikov-de Haas oscillations at H>H(sat). This signals the onset of full spin polarization above H(sat), the parallel field above which the resistivity saturates to a constant value. For H

  6. Interferometric measurement of angles.

    PubMed

    Malacara, D; Harris, O

    1970-07-01

    A new interferometric device for measuring small angles or rotations with high accuracy is described. This instrument works by counting fringes formed by the rotation of a flat-parallel plate of glass illuminated with a collimated beam from a gas laser. Some possible applications are given.

  7. Angle amplifying optics using plane and ellipsoidal reflectors

    DOEpatents

    Glass, Alexander J.

    1977-01-01

    An optical system for providing a wide angle input beam into ellipsoidal laser fusion target illumination systems. The optical system comprises one or more pairs of centrally apertured plane and ellipsoidal mirrors disposed to accept the light input from a conventional lens of modest focal length and thickness, to increase the angular divergence thereof to a value equivalent to that of fast lenses, and to direct the light into the ellipsoidal target illumination system.

  8. Azimuthal-Angle Dependence of Charged-Pion-Interferometry Measurements with Respect to Second- and Third-Order Event Planes in Au +Au Collisions at √sNN =200 GeV

    NASA Astrophysics Data System (ADS)

    Adare, A.; Afanasiev, S.; Aidala, C.; Ajitanand, N. N.; Akiba, Y.; Al-Bataineh, H.; Alexander, J.; Aoki, K.; Aramaki, Y.; Atomssa, E. T.; Averbeck, R.; Awes, T. C.; Azmoun, B.; Babintsev, V.; Bai, M.; Baksay, G.; Baksay, L.; Barish, K. N.; Bassalleck, B.; Basye, A. T.; Bathe, S.; Baublis, V.; Baumann, C.; Bazilevsky, A.; Belikov, S.; Belmont, R.; Bennett, R.; Berdnikov, A.; Berdnikov, Y.; Bickley, A. A.; Bok, J. S.; Boyle, K.; Brooks, M. L.; Buesching, H.; Bumazhnov, V.; Bunce, G.; Butsyk, S.; Camacho, C. M.; Campbell, S.; Chen, C.-H.; Chi, C. Y.; Chiu, M.; Choi, I. J.; Choudhury, R. K.; Christiansen, P.; Chujo, T.; Chung, P.; Chvala, O.; Cianciolo, V.; Citron, Z.; Cole, B. A.; Connors, M.; Constantin, P.; Csanád, M.; Csörgő, T.; Dahms, T.; Dairaku, S.; Danchev, I.; Das, K.; Datta, A.; David, G.; Denisov, A.; Deshpande, A.; Desmond, E. J.; Dietzsch, O.; Dion, A.; Donadelli, M.; Drapier, O.; Drees, A.; Drees, K. A.; Durham, J. M.; Durum, A.; Dutta, D.; Edwards, S.; Efremenko, Y. V.; Ellinghaus, F.; Engelmore, T.; Enokizono, A.; En'yo, H.; Esumi, S.; Fadem, B.; Fields, D. E.; Finger, M.; Finger, M.; Fleuret, F.; Fokin, S. L.; Fraenkel, Z.; Frantz, J. E.; Franz, A.; Frawley, A. D.; Fujiwara, K.; Fukao, Y.; Fusayasu, T.; Garishvili, I.; Glenn, A.; Gong, H.; Gonin, M.; Goto, Y.; Granier de Cassagnac, R.; Grau, N.; Greene, S. V.; Grosse Perdekamp, M.; Gunji, T.; Gustafsson, H.-Å.; Haggerty, J. S.; Hahn, K. I.; Hamagaki, H.; Hamblen, J.; Han, R.; Hanks, J.; Hartouni, E. P.; Haslum, E.; Hayano, R.; He, X.; Heffner, M.; Hemmick, T. K.; Hester, T.; Hill, J. C.; Hohlmann, M.; Holzmann, W.; Homma, K.; Hong, B.; Horaguchi, T.; Hornback, D.; Huang, S.; Ichihara, T.; Ichimiya, R.; Ide, J.; Ikeda, Y.; Imai, K.; Inaba, M.; Isenhower, D.; Ishihara, M.; Isobe, T.; Issah, M.; Isupov, A.; Ivanischev, D.; Jacak, B. V.; Jia, J.; Jin, J.; Johnson, B. M.; Joo, K. S.; Jouan, D.; Jumper, D. S.; Kajihara, F.; Kametani, S.; Kamihara, N.; Kamin, J.; Kang, J. H.; Kapustinsky, J.; Karatsu, K.; Kawall, D.; Kawashima, M.; Kazantsev, A. V.; Kempel, T.; Khanzadeev, A.; Kijima, K. M.; Kim, B. I.; Kim, D. H.; Kim, D. J.; Kim, E.; Kim, E.-J.; Kim, S. H.; Kim, Y.-J.; Kinney, E.; Kiriluk, K.; Kiss, Á.; Kistenev, E.; Kochenda, L.; Komkov, B.; Konno, M.; Koster, J.; Kotchetkov, D.; Kozlov, A.; Král, A.; Kravitz, A.; Kunde, G. J.; Kurita, K.; Kurosawa, M.; Kwon, Y.; Kyle, G. S.; Lacey, R.; Lai, Y. S.; Lajoie, J. G.; Lebedev, A.; Lee, D. M.; Lee, J.; Lee, K.; Lee, K. B.; Lee, K. S.; Leitch, M. J.; Leite, M. A. L.; Leitner, E.; Lenzi, B.; Li, X.; Liebing, P.; Linden Levy, L. A.; Liška, T.; Litvinenko, A.; Liu, H.; Liu, M. X.; Love, B.; Luechtenborg, R.; Lynch, D.; Maguire, C. F.; Makdisi, Y. I.; Malakhov, A.; Malik, M. D.; Manko, V. I.; Mannel, E.; Mao, Y.; Masui, H.; Matathias, F.; McCumber, M.; McGaughey, P. L.; Means, N.; Meredith, B.; Miake, Y.; Mignerey, A. C.; Mikeš, P.; Miki, K.; Milov, A.; Mishra, M.; Mitchell, J. T.; Mohanty, A. K.; Morino, Y.; Morreale, A.; Morrison, D. P.; Moukhanova, T. V.; Murata, J.; Nagamiya, S.; Nagle, J. L.; Naglis, M.; Nagy, M. I.; Nakagawa, I.; Nakamiya, Y.; Nakamura, T.; Nakano, K.; Newby, J.; Nguyen, M.; Niida, T.; Nouicer, R.; Nyanin, A. S.; O'Brien, E.; Oda, S. X.; Ogilvie, C. A.; Oka, M.; Okada, K.; Onuki, Y.; Oskarsson, A.; Ouchida, M.; Ozawa, K.; Pak, R.; Pantuev, V.; Papavassiliou, V.; Park, I. H.; Park, J.; Park, S. K.; Park, W. J.; Pate, S. F.; Pei, H.; Peng, J.-C.; Pereira, H.; Peresedov, V.; Peressounko, D. Yu.; Pinkenburg, C.; Pisani, R. P.; Proissl, M.; Purschke, M. L.; Purwar, A. K.; Qu, H.; Rak, J.; Rakotozafindrabe, A.; Ravinovich, I.; Read, K. F.; Reygers, K.; Riabov, V.; Riabov, Y.; Richardson, E.; Roach, D.; Roche, G.; Rolnick, S. D.; Rosati, M.; Rosen, C. A.; Rosendahl, S. S. E.; Rosnet, P.; Rukoyatkin, P.; Ružička, P.; Sahlmueller, B.; Saito, N.; Sakaguchi, T.; Sakashita, K.; Samsonov, V.; Sano, S.; Sato, T.; Sawada, S.; Sedgwick, K.; Seele, J.; Seidl, R.; Semenov, A. Yu.; Seto, R.; Sharma, D.; Shein, I.; Shibata, T.-A.; Shigaki, K.; Shimomura, M.; Shoji, K.; Shukla, P.; Sickles, A.; Silva, C. L.; Silvermyr, D.; Silvestre, C.; Sim, K. S.; Singh, B. K.; Singh, C. P.; Singh, V.; Slunečka, M.; Soltz, R. A.; Sondheim, W. E.; Sorensen, S. P.; Sourikova, I. V.; Sparks, N. A.; Stankus, P. W.; Stenlund, E.; Stoll, S. P.; Sugitate, T.; Sukhanov, A.; Sziklai, J.; Takagui, E. M.; Taketani, A.; Tanabe, R.; Tanaka, Y.; Tanida, K.; Tannenbaum, M. J.; Tarafdar, S.; Taranenko, A.; Tarján, P.; Themann, H.; Thomas, T. L.; Todoroki, T.; Togawa, M.; Toia, A.; Tomášek, L.; Torii, H.; Towell, R. S.; Tserruya, I.; Tsuchimoto, Y.; Vale, C.; Valle, H.; van Hecke, H. W.; Vazquez-Zambrano, E.; Veicht, A.; Velkovska, J.; Vértesi, R.; Vinogradov, A. A.; Virius, M.; Vrba, V.; Vznuzdaev, E.; Wang, X. R.; Watanabe, D.; Watanabe, K.; Watanabe, Y.; Wei, F.; Wei, R.; Wessels, J.; White, S. N.; Winter, D.; Wood, J. P.; Woody, C. L.; Wright, R. M.; Wysocki, M.; Xie, W.; Yamaguchi, Y. L.; Yamaura, K.; Yang, R.; Yanovich, A.; Ying, J.; Yokkaichi, S.; You, Z.; Young, G. R.; Younus, I.; Yushmanov, I. E.; Zajc, W. A.; Zhang, C.; Zhou, S.; Zolin, L.; Phenix Collaboration

    2014-06-01

    Charged-pion-interferometry measurements were made with respect to the second- and third-order event plane for Au +Au collisions at √sNN =200 GeV. A strong azimuthal-angle dependence of the extracted Gaussian-source radii was observed with respect to both the second- and third-order event planes. The results for the second-order dependence indicate that the initial eccentricity is reduced during the medium evolution, which is consistent with previous results. In contrast, the results for the third-order dependence indicate that the initial triangular shape is significantly reduced and potentially reversed by the end of the medium evolution, and that the third-order oscillations are largely dominated by the dynamical effects from triangular flow.

  9. Azimuthal-angle dependence of charged-pion-interferometry measurements with respect to second- and third-order event planes in Au+Au collisions at √[S(NN)]=200  GeV.

    PubMed

    Adare, A; Afanasiev, S; Aidala, C; Ajitanand, N N; Akiba, Y; Al-Bataineh, H; Alexander, J; Aoki, K; Aramaki, Y; Atomssa, E T; Averbeck, R; Awes, T C; Azmoun, B; Babintsev, V; Bai, M; Baksay, G; Baksay, L; Barish, K N; Bassalleck, B; Basye, A T; Bathe, S; Baublis, V; Baumann, C; Bazilevsky, A; Belikov, S; Belmont, R; Bennett, R; Berdnikov, A; Berdnikov, Y; Bickley, A A; Bok, J S; Boyle, K; Brooks, M L; Buesching, H; Bumazhnov, V; Bunce, G; Butsyk, S; Camacho, C M; Campbell, S; Chen, C-H; Chi, C Y; Chiu, M; Choi, I J; Choudhury, R K; Christiansen, P; Chujo, T; Chung, P; Chvala, O; Cianciolo, V; Citron, Z; Cole, B A; Connors, M; Constantin, P; Csanád, M; Csörgő, T; Dahms, T; Dairaku, S; Danchev, I; Das, K; Datta, A; David, G; Denisov, A; Deshpande, A; Desmond, E J; Dietzsch, O; Dion, A; Donadelli, M; Drapier, O; Drees, A; Drees, K A; Durham, J M; Durum, A; Dutta, D; Edwards, S; Efremenko, Y V; Ellinghaus, F; Engelmore, T; Enokizono, A; En'yo, H; Esumi, S; Fadem, B; Fields, D E; Finger, M; Finger, M; Fleuret, F; Fokin, S L; Fraenkel, Z; Frantz, J E; Franz, A; Frawley, A D; Fujiwara, K; Fukao, Y; Fusayasu, T; Garishvili, I; Glenn, A; Gong, H; Gonin, M; Goto, Y; Granier de Cassagnac, R; Grau, N; Greene, S V; Grosse Perdekamp, M; Gunji, T; Gustafsson, H-Å; Haggerty, J S; Hahn, K I; Hamagaki, H; Hamblen, J; Han, R; Hanks, J; Hartouni, E P; Haslum, E; Hayano, R; He, X; Heffner, M; Hemmick, T K; Hester, T; Hill, J C; Hohlmann, M; Holzmann, W; Homma, K; Hong, B; Horaguchi, T; Hornback, D; Huang, S; Ichihara, T; Ichimiya, R; Ide, J; Ikeda, Y; Imai, K; Inaba, M; Isenhower, D; Ishihara, M; Isobe, T; Issah, M; Isupov, A; Ivanischev, D; Jacak, B V; Jia, J; Jin, J; Johnson, B M; Joo, K S; Jouan, D; Jumper, D S; Kajihara, F; Kametani, S; Kamihara, N; Kamin, J; Kang, J H; Kapustinsky, J; Karatsu, K; Kawall, D; Kawashima, M; Kazantsev, A V; Kempel, T; Khanzadeev, A; Kijima, K M; Kim, B I; Kim, D H; Kim, D J; Kim, E; Kim, E-J; Kim, S H; Kim, Y-J; Kinney, E; Kiriluk, K; Kiss, A; Kistenev, E; Kochenda, L; Komkov, B; Konno, M; Koster, J; Kotchetkov, D; Kozlov, A; Král, A; Kravitz, A; Kunde, G J; Kurita, K; Kurosawa, M; Kwon, Y; Kyle, G S; Lacey, R; Lai, Y S; Lajoie, J G; Lebedev, A; Lee, D M; Lee, J; Lee, K; Lee, K B; Lee, K S; Leitch, M J; Leite, M A L; Leitner, E; Lenzi, B; Li, X; Liebing, P; Linden Levy, L A; Liška, T; Litvinenko, A; Liu, H; Liu, M X; Love, B; Luechtenborg, R; Lynch, D; Maguire, C F; Makdisi, Y I; Malakhov, A; Malik, M D; Manko, V I; Mannel, E; Mao, Y; Masui, H; Matathias, F; McCumber, M; McGaughey, P L; Means, N; Meredith, B; Miake, Y; Mignerey, A C; Mikeš, P; Miki, K; Milov, A; Mishra, M; Mitchell, J T; Mohanty, A K; Morino, Y; Morreale, A; Morrison, D P; Moukhanova, T V; Murata, J; Nagamiya, S; Nagle, J L; Naglis, M; Nagy, M I; Nakagawa, I; Nakamiya, Y; Nakamura, T; Nakano, K; Newby, J; Nguyen, M; Niida, T; Nouicer, R; Nyanin, A S; O'Brien, E; Oda, S X; Ogilvie, C A; Oka, M; Okada, K; Onuki, Y; Oskarsson, A; Ouchida, M; Ozawa, K; Pak, R; Pantuev, V; Papavassiliou, V; Park, I H; Park, J; Park, S K; Park, W J; Pate, S F; Pei, H; Peng, J-C; Pereira, H; Peresedov, V; Peressounko, D Yu; Pinkenburg, C; Pisani, R P; Proissl, M; Purschke, M L; Purwar, A K; Qu, H; Rak, J; Rakotozafindrabe, A; Ravinovich, I; Read, K F; Reygers, K; Riabov, V; Riabov, Y; Richardson, E; Roach, D; Roche, G; Rolnick, S D; Rosati, M; Rosen, C A; Rosendahl, S S E; Rosnet, P; Rukoyatkin, P; Ružička, P; Sahlmueller, B; Saito, N; Sakaguchi, T; Sakashita, K; Samsonov, V; Sano, S; Sato, T; Sawada, S; Sedgwick, K; Seele, J; Seidl, R; Semenov, A Yu; Seto, R; Sharma, D; Shein, I; Shibata, T-A; Shigaki, K; Shimomura, M; Shoji, K; Shukla, P; Sickles, A; Silva, C L; Silvermyr, D; Silvestre, C; Sim, K S; Singh, B K; Singh, C P; Singh, V; Slunečka, M; Soltz, R A; Sondheim, W E; Sorensen, S P; Sourikova, I V; Sparks, N A; Stankus, P W; Stenlund, E; Stoll, S P; Sugitate, T; Sukhanov, A; Sziklai, J; Takagui, E M; Taketani, A; Tanabe, R; Tanaka, Y; Tanida, K; Tannenbaum, M J; Tarafdar, S; Taranenko, A; Tarján, P; Themann, H; Thomas, T L; Todoroki, T; Togawa, M; Toia, A; Tomášek, L; Torii, H; Towell, R S; Tserruya, I; Tsuchimoto, Y; Vale, C; Valle, H; van Hecke, H W; Vazquez-Zambrano, E; Veicht, A; Velkovska, J; Vértesi, R; Vinogradov, A A; Virius, M; Vrba, V; Vznuzdaev, E; Wang, X R; Watanabe, D; Watanabe, K; Watanabe, Y; Wei, F; Wei, R; Wessels, J; White, S N; Winter, D; Wood, J P; Woody, C L; Wright, R M; Wysocki, M; Xie, W; Yamaguchi, Y L; Yamaura, K; Yang, R; Yanovich, A; Ying, J; Yokkaichi, S; You, Z; Young, G R; Younus, I; Yushmanov, I E; Zajc, W A; Zhang, C; Zhou, S; Zolin, L

    2014-06-01

    Charged-pion-interferometry measurements were made with respect to the second- and third-order event plane for Au+Au collisions at sqrt[s_{NN}]=200  GeV. A strong azimuthal-angle dependence of the extracted Gaussian-source radii was observed with respect to both the second- and third-order event planes. The results for the second-order dependence indicate that the initial eccentricity is reduced during the medium evolution, which is consistent with previous results. In contrast, the results for the third-order dependence indicate that the initial triangular shape is significantly reduced and potentially reversed by the end of the medium evolution, and that the third-order oscillations are largely dominated by the dynamical effects from triangular flow.

  10. Measuring Angles in Physical Therapy.

    ERIC Educational Resources Information Center

    Greeley, Nansee; Offerman, Theresa Reardon

    1997-01-01

    Features articles about physical therapy and its history as related to geometry through measurement of body angles. Includes open-ended worksheets for mathematics activities that introduce students to angle measurement, data analysis, and mathematical tools. Activities include: (1) Making Your Own Goniometer; (2) Range of Motion; (3) Active versus…

  11. Active correction of the tilt angle of the surface plane with respect to the rotation axis during azimuthal scan

    NASA Astrophysics Data System (ADS)

    Sereno, M.; Lupone, S.; Debiossac, M.; Kalashnyk, N.; Roncin, P.

    2016-09-01

    A procedure to measure the residual tilt angle τ between a flat surface and the azimuthal rotation axis of the sample holder is described. When the incidence angle θ and readout of the azimuthal angle ϕ are controlled by motors, an active compensation mechanism can be implemented to reduce the effect of the tilt angle during azimuthal motion. After this correction, the effective angle of incidence is kept fixed, and only a small residual oscillation of the scattering plane remains.

  12. Measurements of turbulent inclined plane dual jets

    NASA Astrophysics Data System (ADS)

    Wang, C. S.; Lin, Y. F.; Sheu, M. J.

    1993-11-01

    Measurements of mean velocities, flow direction, velocity fluctuations and Reynolds shear stress were made with a split film probe of hot wire anemometer to investigate the interactions created by two air jets issuing from two identical plane inclined nozzles. The reverse flow was detected by using the split film probe and observed by flow visualization. Experimental results with an inclined angle of 9° are presented in the paper. Some experimental results with an inclined angle of 27° are presented to investigate the effect of inclination on the flow field. Mean velocities approach self-preservation in both the converging region and the combining region. Velocity fluctuations and Reynolds shear stress approach self-preservation in the combining region only. The spreads of jet and the square of the decay of maximum mean velocity increase linearly as the distance from the nozzle exit increases.

  13. Robust angle-independent blood velocity estimation based on dual-angle plane wave imaging.

    PubMed

    Fadnes, Solveig; Ekroll, Ingvild Kinn; Nyrnes, Siri Ann; Torp, Hans; Lovstakken, Lasse

    2015-10-01

    Two-dimensional blood velocity estimation has shown potential to solve the angle-dependency of conventional ultrasound flow imaging. Clutter filtering, however, remains a major challenge for large beam-to-flow angles, leading to signal drop-outs and corrupted velocity estimates. This work presents and evaluates a compounding speckle tracking (ST) algorithm to obtain robust angle-independent 2-D blood velocity estimates for all beam-to-flow angles. A dual-angle plane wave imaging setup with full parallel receive beamforming is utilized to achieve high-frame-rate speckle tracking estimates from two scan angles, which may be compounded to obtain velocity estimates of increased robustness. The acquisition also allows direct comparison with vector Doppler (VD) imaging. Absolute velocity bias and root-mean-square (RMS) error of the compounding ST estimations were investigated using simulations of a rotating flow phantom with low velocities ranging from 0 to 20 cm/s. In a challenging region where the estimates were influenced by clutter filtering, the bias and RMS error for the compounding ST estimates were 11% and 2 cm/s, a significant reduction compared with conventional single-angle ST (22% and 4 cm/s) and VD (36% and 6 cm/s). The method was also tested in vivo for vascular and neonatal cardiac imaging. In a carotid artery bifurcation, the obtained blood velocity estimates showed that the compounded ST method was less influenced by clutter filtering than conventional ST and VD methods. In the cardiac case, it was observed that ST velocity estimation is more affected by low signal-to-noise (SNR) than VD. However, with sufficient SNR the in vivo results indicated that a more robust angle-independent blood velocity estimator is obtained using compounded speckle tracking compared with conventional ST and VD methods. PMID:26470038

  14. Robust angle-independent blood velocity estimation based on dual-angle plane wave imaging.

    PubMed

    Fadnes, Solveig; Ekroll, Ingvild Kinn; Nyrnes, Siri Ann; Torp, Hans; Lovstakken, Lasse

    2015-10-01

    Two-dimensional blood velocity estimation has shown potential to solve the angle-dependency of conventional ultrasound flow imaging. Clutter filtering, however, remains a major challenge for large beam-to-flow angles, leading to signal drop-outs and corrupted velocity estimates. This work presents and evaluates a compounding speckle tracking (ST) algorithm to obtain robust angle-independent 2-D blood velocity estimates for all beam-to-flow angles. A dual-angle plane wave imaging setup with full parallel receive beamforming is utilized to achieve high-frame-rate speckle tracking estimates from two scan angles, which may be compounded to obtain velocity estimates of increased robustness. The acquisition also allows direct comparison with vector Doppler (VD) imaging. Absolute velocity bias and root-mean-square (RMS) error of the compounding ST estimations were investigated using simulations of a rotating flow phantom with low velocities ranging from 0 to 20 cm/s. In a challenging region where the estimates were influenced by clutter filtering, the bias and RMS error for the compounding ST estimates were 11% and 2 cm/s, a significant reduction compared with conventional single-angle ST (22% and 4 cm/s) and VD (36% and 6 cm/s). The method was also tested in vivo for vascular and neonatal cardiac imaging. In a carotid artery bifurcation, the obtained blood velocity estimates showed that the compounded ST method was less influenced by clutter filtering than conventional ST and VD methods. In the cardiac case, it was observed that ST velocity estimation is more affected by low signal-to-noise (SNR) than VD. However, with sufficient SNR the in vivo results indicated that a more robust angle-independent blood velocity estimator is obtained using compounded speckle tracking compared with conventional ST and VD methods.

  15. Neutron spin echo scattering angle measurement (SESAME)

    SciTech Connect

    Pynn, R.; Fitzsimmons, M.R.; Fritzsche, H.; Gierlings, M.; Major, J.; Jason, A.

    2005-05-15

    We describe experiments in which the neutron spin echo technique is used to measure neutron scattering angles. We have implemented the technique, dubbed spin echo scattering angle measurement (SESAME), using thin films of Permalloy electrodeposited on silicon wafers as sources of the magnetic fields within which neutron spins precess. With 30-{mu}m-thick films we resolve neutron scattering angles to about 0.02 deg. with neutrons of 4.66 A wavelength. This allows us to probe correlation lengths up to 200 nm in an application to small angle neutron scattering. We also demonstrate that SESAME can be used to separate specular and diffuse neutron reflection from surfaces at grazing incidence. In both of these cases, SESAME can make measurements at higher neutron intensity than is available with conventional methods because the angular resolution achieved is independent of the divergence of the neutron beam. Finally, we discuss the conditions under which SESAME might be used to probe in-plane structure in thin films and show that the method has advantages for incident neutron angles close to the critical angle because multiple scattering is automatically accounted for.

  16. Hysteresis during contact angles measurement.

    PubMed

    Diaz, M Elena; Fuentes, Javier; Cerro, Ramon L; Savage, Michael D

    2010-03-15

    A theory, based on the presence of an adsorbed film in the vicinity of the triple contact line, provides a molecular interpretation of intrinsic hysteresis during the measurement of static contact angles. Static contact angles are measured by placing a sessile drop on top of a flat solid surface. If the solid surface has not been previously in contact with a vapor phase saturated with the molecules of the liquid phase, the solid surface is free of adsorbed liquid molecules. In the absence of an adsorbed film, molecular forces configure an advancing contact angle larger than the static contact angle. After some time, due to an evaporation/adsorption process, the interface of the drop coexists with an adsorbed film of liquid molecules as part of the equilibrium configuration, denoted as the static contact angle. This equilibrium configuration is metastable because the droplet has a larger vapor pressure than the surrounding flat film. As the drop evaporates, the vapor/liquid interface contracts and the apparent contact line moves towards the center of the drop. During this process, the film left behind is thicker than the adsorbed film and molecular attraction results in a receding contact angle, smaller than the equilibrium contact angle.

  17. Large angle measurement by interferometry

    NASA Astrophysics Data System (ADS)

    Apostol, Dan; Blanaru, Constantin; Damian, Victor S.; Logofatu, Petre-Catalin; Tumbar, R.; Dobroiu, Adrian

    1995-03-01

    An interferometric set-up able to measure angles as large as +180 degree(s) is presented. The principle of the method is to measure a linear displacement (translation) produced by a crank-gear mechanism which converts the angular movement of a rotating table. The optical scheme and consideration on the accuracy of the method are presented.

  18. Precision issues in angle measurements by means of autocollimator

    NASA Astrophysics Data System (ADS)

    Filatov, Yuri V.; Larichev, Roman A.

    2014-11-01

    Ambiguity in plane angle definition is considered. Autocollimator performance is regarded from geometric ray optics and wave diffraction optics points of view. Few typical aberrations and their influence on image formation in autocollimator are presented. Modeling estimates of aberration influence on angle measurements are outlined.

  19. Non-contact measurement of rotation angle with solo camera

    NASA Astrophysics Data System (ADS)

    Gan, Xiaochuan; Sun, Anbin; Ye, Xin; Ma, Liqun

    2015-02-01

    For the purpose to measure a rotation angle around the axis of an object, a non-contact rotation angle measurement method based on solo camera was promoted. The intrinsic parameters of camera were calibrated using chessboard on principle of plane calibration theory. The translation matrix and rotation matrix between the object coordinate and the camera coordinate were calculated according to the relationship between the corners' position on object and their coordinates on image. Then the rotation angle between the measured object and the camera could be resolved from the rotation matrix. A precise angle dividing table (PADT) was chosen as the reference to verify the angle measurement error of this method. Test results indicated that the rotation angle measurement error of this method did not exceed +/- 0.01 degree.

  20. Hip rotation angle is associated with frontal plane knee joint mechanics during running.

    PubMed

    Sakaguchi, Masanori; Shimizu, Norifumi; Yanai, Toshimasa; Stefanyshyn, Darren J; Kawakami, Yasuo

    2015-02-01

    Inability to control lower extremity segments in the frontal and transverse planes resulting in large knee abduction angle and increased internal knee abduction impulse has been associated with patellofemoral pain (PFP). However, the influence of hip rotation angles on frontal plane knee joint kinematics and kinetics remains unclear. The purpose of this study was to explore how hip rotation angles are related to frontal plane knee joint kinematics and kinetics during running. Seventy runners participated in this study. Three-dimensional marker positions and ground reaction forces were recorded with an 8-camera motion analysis system and a force plate while subjects ran along a 25-m runway at a speed of 4m/s. Knee abduction, hip rotation and toe-out angles, frontal plane lever arm at the knee, internal knee abduction moment and impulse, ground reaction forces and the medio-lateral distance from the ankle joint center to the center of pressure (AJC-CoP) were quantified. The findings of this study indicate that greater hip external rotation angles were associated with greater toe-out angles, longer AJC-CoP distances, smaller internal knee abduction impulses with shorter frontal plane lever arms and greater knee abduction angles. Thus, there appears to exist a conflict between kinematic and kinetic risk factors of PFP, and hip external rotation angle may be a key factor to control frontal plane knee joint kinematics and kinetics. These results may help provide an appropriate manipulation and/or intervention on running style to reduce the risk of PFP.

  1. Determination of isocentric machine parameters for inclined treatment volumes: a single solution for angled transverse or coronal treatment planes.

    PubMed

    Bradley, F L

    2001-01-01

    The derivation of the trigonometric equations necessary to calculate gantry, floor and collimator settings for a treatment plane at an angle phi to the transverse plane of the patient has been described previously. The derivation of a second set of equations to facilitate treatment in a plane at an angle phi to the coronal plane has also been described previously. This work reinterprets the geometry of inclined volumes and shows that essentially only one set of equations is required to determine the settings for treatment planes at an angle phi to either the transverse or coronal planes of the patient.

  2. Dynamic contact angle measurements on superhydrophobic surfaces

    NASA Astrophysics Data System (ADS)

    Kim, Jeong-Hyun; Kavehpour, H. Pirouz; Rothstein, Jonathan P.

    2015-03-01

    In this paper, the dynamic advancing and receding contact angles of a series of aqueous solutions were measured on a number of hydrophobic and superhydrophobic surfaces using a modified Wilhelmy plate technique. Superhydrophobic surfaces are hydrophobic surfaces with micron or nanometer sized surface roughness. These surfaces have very large static advancing contact angles and little static contact angle hysteresis. In this study, the dynamic advancing and dynamic receding contact angles on superhydrophobic surfaces were measured as a function of plate velocity and capillary number. The dynamic contact angles measured on a smooth hydrophobic Teflon surface were found to obey the scaling with capillary number predicted by the Cox-Voinov-Tanner law, θD3 ∝ Ca. The response of the dynamic contact angle on the superhydrophobic surfaces, however, did not follow the same scaling law. The advancing contact angle was found to remain constant at θA = 160∘, independent of capillary number. The dynamic receding contact angle measurements on superhydrophobic surfaces were found to decrease with increasing capillary number; however, the presence of slip on the superhydrophobic surface was found to result in a shift in the onset of dynamic contact angle variation to larger capillary numbers. In addition, a much weaker dependence of the dynamic contact angle on capillary number was observed for some of the superhydrophobic surfaces tested.

  3. Implications of adopting plane angle as a base quantity in the SI

    NASA Astrophysics Data System (ADS)

    Quincey, Paul; Brown, Richard J. C.

    2016-06-01

    The treatment of angles within the SI is anomalous compared with other quantities, and there is a case for removing this anomaly by declaring plane angle to be an additional base quantity within the system. It is shown that this could bring several benefits in terms of treating angle on an equal basis with other metrics, removing potentially harmful ambiguities, and bringing SI units more in line with concepts in basic physics, but at the expense of significant upheaval to familiar equations within mathematics and physics. This paper sets out the most important of these changes so that an alternative unit system containing angle as a base quantity can be seen in the round, irrespective of whether it is ever widely adopted. The alternative formulas and units can be treated as the underlying, more general equations of mathematical physics, independent of the units used for angle, which are conventionally simplified by implicitly assuming that the unit used for angle is the radian.

  4. Free-form lens for rectangular illumination with the target plane rotating at a certain angle.

    PubMed

    Liu, Dianhong; Zhang, Xiaohui; Chen, Chen

    2015-11-01

    We have proposed a method for rectangular illumination in a (u, v) coordinate system with high collection efficiency and favorable uniformity. In our proposed approach, with the target plane rotating at a certain angle around the z axis, one of the diagonals on the rectangular target plane moves to the coordinate axis; then, we partition the light source and target plane into grids. The intersection points of the grids are in one-to-one correspondence from the source to the target plane. This improved method will avoid the one-to-many correspondence topological relationship in the traditional (u, v) mapping method; uniformity of the illuminance pattern will be promoted. Based on this method, lenses are designed for rectangular target plane illumination; uniformity over 0.83 and efficiency of about 0.92 are obtained with a 1  mm×1  mm LED Lambertian source. PMID:26560910

  5. Measurement of two-dimensional small angle deviation with a prism interferometer

    SciTech Connect

    Chatterjee, Sanjib; Kumar, Y. Pavan

    2008-09-20

    A new technique for the measurement of two-dimensional small angular deviation is presented. A compound prism, which effectively produces a combination of two right-angled prisms in orthogonal directions, and plane reference surfaces have been utilized for the measurement of the orthogonal components of the angular tilt of an incident plane wavefront. Each orthogonal component of the angular tilt is separately measured from the angular rotation of the resultant wedge fringes between two plane wavefronts generated due to splitting of the incident plane wavefront by the corresponding set of right-angled prism and plane reference surface. The technique is shown to have high sensitivity for the measurement of small angle deviation. A monolithic prism interferometer, which is practically insensitive to vibration, is also proposed. Results obtained for the measurement of a known tilt angle are presented.

  6. Combined effects of the in-plane orientation angle and the loading angle on the dynamic enhancement of honeycombs under mixed shear-compression loading

    NASA Astrophysics Data System (ADS)

    Tounsi, R.; Markiewicz, E.; Haugou, G.; Chaari, F.; Zouari, B.

    2016-05-01

    The combined effect of the loading angle (ψ) and the in-plane orientation angle (β) on the dynamic enhancement of aluminium alloy honeycombs is investigated. Experimental results are analysed on the crushing surfaces (initial peak and average crushing forces). A significant effect of the loading angle is reported. The dynamic enhancement rate depends on the loading angle until a critical loading angle (ψcritical). Beyond, a negative dynamic enhancement rate is observed. Concerning the in-plane orientation angle β effect, it depends on the loading angle ψ under quasi-static conditions. Under dynamic conditions, a significant effect is reported independently of the loading angle ψ. Therefore, the dynamic enhancement rate depends on the combined effects of ψ and β angles. A global analysis of the buckling mechanisms allowed us to explain the combined effect of ψ and β angles on the initial peak force. The collapse mechanisms analysis explain the negative dynamic enhancement rate for large loading angles.

  7. Observation angle and plane characterisation for ISAR imaging of LEO space objects

    NASA Astrophysics Data System (ADS)

    Chen, Jin; Fu, Tuo; Chen, Defeng; Gao, Meiguo

    2016-07-01

    For inverse synthetic aperture radar (ISAR) imaging of low Earth orbit (LEO) space objects, examining the variations in the image plane of the object over the entire visible arc period allows more direct characterisation of the variations in the object imaging. In this study, the ideal turntable model was extended to determine the observation geometry of near-circular LEO objects. Two approximations were applied to the observation model to calculate the image plane's normal and observation angles for near-circular orbit objects. One approximation treats the orbit of the space object as a standard arc relative to the Earth during the radar observation period, and the other omits the effect of the rotation of the Earth on the observations. First, the closed-form solution of the image plane normal in various attitude-stabilisation approaches was determined based on geometric models. The characteristics of the image plane and the observation angle of the near-circular orbit object were then analysed based on the common constraints of the radar line-of-sight (LOS). Subsequently, the variations in the image plane and the geometric constraints of the ISAR imaging were quantified. Based on the image plane's normal, the rotational angular velocity of the radar LOS was estimated. The cross-range direction of the ISAR image was then calibrated. Three-dimensional imaging was then reconstructed based on dual station interferometry. Finally, simulations were performed to verify the result of the three-dimensional interferometric reconstruction and to calculate the reconstruction's precision errors.

  8. Automatic star-horizon angle measurement system

    NASA Technical Reports Server (NTRS)

    Koerber, K.; Koso, D. A.; Nardella, P. C.

    1969-01-01

    Automatic star horizontal angle measuring aid for general navigational use incorporates an Apollo type sextant. The eyepiece of the sextant is replaced with two light detectors and appropriate circuitry. The device automatically determines the angle between a navigational star and a unique point on the earths horizon as seen on a spacecraft.

  9. The range of options for handling plane angle and solid angle within a system of units

    NASA Astrophysics Data System (ADS)

    Quincey, Paul

    2016-04-01

    The radian and steradian are unusual units within the SI, originally belonging to their own category of ‘supplementary units’, with this status being changed to dimensionless ‘derived units’ in 1995. Recent papers have suggested that angles could be handled in two different ways within the SI, both differing from the present system. The purpose of this paper is to provide a framework for putting such suggestions into context, outlining the range of options that is available, together with the advantages and disadvantages of these options. Although less rigorously logical than some alternatives, the present SI approach is generally supported, but with some changes to the SI brochure to make the position clearer, in particular with regard to the designation of the radian and steradian as derived units.

  10. [Correlations between the occlusal plane angle and the risk of relapse after surgical orthodontic treatment of Angle Class III anomalies].

    PubMed

    Popescu, M; Dincă, O; Bucur, A

    2010-01-01

    An important criterion in the diagnostic and therapeutic assessment of severe true mandibular prognathia (characterized by excessive growth of the mandible and hiperdivergent facial growth pattern) is the orientation of the occlusal plane compared with the facial benchmark represented by the Frankfurt horizontal line. This is because orthognatic surgery in this pathology (sagittal bilateral osteotomy) envisages not only the shortening of the mandible, but also the counterclockwise rotation of the mandible to restore facial and dento-alveolar harmony in the three planes (sagittal, transverse, vertical). The aim of the study is the analysis of the evolution of the maxillo-mandibular complex in relation to the occlusal plane after orthognatic surgery (sagittal osteotomy of the mandible and bilateral Le Fort I of the maxilla), in a group of 15 patients with a mean age 22+3 years diagnosed with skeletal class III malocclusion, hiperdivergent facial pattern, initial average value of the occlusal plane angle 130+0.60. t test applied for comparative statistical analysis for the linear and angular parameters considered in four therapeutic stages (initial presurgical, post surgical, one year post surgical) show statistically significant changes in parameters related to the mandibular length and rotation, without significant variations one year after the surgical phase.

  11. An ultra-high vacuum chamber for scattering experiments featuring in-vacuum continuous in-plane variation of the angle between entrance and exit vacuum ports

    SciTech Connect

    Englund, Carl-Johan; Agåker, Marcus Fredriksson, Pierre; Olsson, Anders; Johansson, Niklas; Rubensson, Jan-Erik; Nordgren, Joseph

    2015-09-15

    A concept that enables in-vacuum continuous variation of the angle between two ports in one plane has been developed and implemented. The vacuum chamber allows for measuring scattering cross sections as a function of scattering angle and is intended for resonant inelastic X-ray scattering experiments. The angle between the ports can be varied in the range of 30°-150°, while the pressure change is less than 2 × 10{sup −10} mbars.

  12. Patellar Tendon–Trochlear Groove Angle Measurement

    PubMed Central

    Hinckel, Betina B.; Gobbi, Riccardo G.; Kihara Filho, Eduardo N.; Demange, Marco K.; Pécora, José Ricardo; Camanho, Gilberto Luis

    2015-01-01

    Background: The tibial tubercle–trochlear groove (TT-TG) is used as the gold standard for patellofemoral malalignment. Purpose: To assess 3 patellar tendon–trochlear groove (PT-TG) angle measurement techniques and the PT-TG distance measurement (tendinous cartilaginous TT-TG) as predictors of patellar instability. Study Design: Cohort study (diagnosis); Level of evidence, 3. Methods: Three PT-TG angle measurements and the PT-TG distance were measured in 82 participants with patellar instability and 100 controls using magnetic resonance imaging (MRI). Measurement landmarks were the line tangent to the posterior femoral condyles, the deepest point of the trochlea, the transepicondylar line, and the patellar tendon center. All measurements were recorded once by 1 examiner, and the measurements were recorded twice by 2 examiners in a random group of 100 knees. Mean values and standard deviations (SDs) were obtained. Normality cutoff values were defined as 2 and 3 SDs above the mean in the control group. The sensitivity, specificity, and positive likelihood ratio (LR+) were calculated. Inter- and intrarater reliability were assessed based on the intraclass correlation coefficient (ICC). Results: The measurements from the patellar instability and control groups, respectively, for angle 1 (16.4° and 8.4°), angle 2 (31° and 15.6°), angle 3 (30.8° and 15.7°), PT-TG distance (14.5 and 8.4 mm), and patellar tilt (21.1° and 7.5°) were significantly different (P < .05). The angle measurements showed greater sensitivity, specificity, and LR+ than the PT-TG distance. Inter- and intrarater ICC values were >0.95 for all measurements. Conclusion: The PT-TG angle and the PT-TG distance are reliable and are different between the patellar instability and control groups. PT-TG angles are more closely associated with patellar instability than PT-TG distance. Clinical Relevance: PT-TG angle measurements show high reliability and association with patellar instability and can

  13. Approximate heating analysis for the windward-symmetry plane of Shuttle-like bodies at large angle of attack

    NASA Technical Reports Server (NTRS)

    Zoby, E. V.

    1981-01-01

    An engineering method has been developed for computing the windward-symmetry plane convective heat-transfer rates on Shuttle-like vehicles at large angles of attack. The engineering code includes an approximate inviscid flowfield technique, laminar and turbulent heating-rate expressions, an approximation to account for the variable-entropy effects on the surface heating and the concept of an equivalent axisymmetric body to model the windward-ray flowfields of Shuttle-like vehicles at angles of attack from 25 to 45 degrees. The engineering method is validated by comparing computed heating results with corresponding experimental data measured on Shuttle and advanced transportation models over a wide range of flow conditions and angles of attack from 25 to 40 degrees and also with results of existing prediction techniques. The comparisons are in good agreement.

  14. Failure-plane angle in Bentheim sandstone subjected to true triaxial stresses: experimental results and theoretical prediction

    NASA Astrophysics Data System (ADS)

    Ma, Xiaodong; Rudnicki, John; Haimson, Bezalel

    2014-05-01

    We conducted true triaxial tests in the high-porosity (n = 24%), quartz-rich (95%), Bentheim sandstone. An important objective was to investigate the dependence of failure-plane angle θ (angle between the normal to the plane and σ1 direction) on the prevailing stress conditions. We employed two distinct loading paths, and seven σ3 magnitudes (between 0 and 150 MPa). In tests using the common loading path, σ2 and σ3 were fixed, while σ1 was raised monotonically to failure. In tests using the novel loading path (which facilitate comparison with theoretical predictions), σ3 was fixed, and the Lode angle, Θ (= tan-1 [(σ1 - 2σ2 + σ3) / 30.5(σ1 - σ3)]) was kept constant by raising σ1 and σ2 simultaneously at a set ratio b [= (σ2 -σ3)/(σ1 -σ3)] until failure occurred. Six stress ratios b (= 0, 1/6, 1/3, 1/2, 3/4, 1), i.e. six Θ (= tan-1 [(1-2b) / 30.5]) values from +π/6 (axisymmetric compression) to -π/6 (axisymmetric extension) were used. In axisymmetric common loading path tests, failure-plane angle θ generally declined as the applied σ3 = σ2 increased from about 80° at σ3 = σ2 = 0 MPa to 0° at σ3 = σ2 = 150 MPa (forming compaction bands). In tests where σ3 ≠ σ2, the resulting failure-plane strike was consistently parallel to σ2 direction. For low σ3, θ typically rose by up to 12° as σ2 rose from σ2 = σ3 to σ2 = σ1. However, the rise in θ with σ2 tended to diminish at higher σ3. A limiting case occurred at σ3 = 150 MPa, where failure plane remained at 0° , regardless of the rise in σ2. In the novel loading path tests, failure-plane angle θ declined monotonically for any given Lode angle Θ, from roughly 80° to 0° , as the mean stress at failure (σoct,f) rose from about 20 MPa to around 220 MPa; for a constant σoct,f, θ typically increased from 10° (at σoct,f = 20 MPa) to 30° (at σoct,f = 220 MPa) as Θ dropped from +π/6 (σ2 = σ3) to -π/6 (σ2 = σ1). We compared the measured θ with that predicted using

  15. Uncertainties in Small-Angle Measurement Systems Used to Calibrate Angle Artifacts.

    PubMed

    Stone, Jack A; Amer, Mohamed; Faust, Bryon; Zimmerman, Jay

    2004-01-01

    We have studied a number of effects that can give rise to errors in small-angle measurement systems when they are used to calibrate artifacts such as optical polygons. Of these sources of uncertainty, the most difficult to quantify are errors associated with the measurement of imperfect, non-flat faces of the artifact, causing the instrument to misinterpret the average orientation of the surface. In an attempt to shed some light on these errors, we have compared autocollimator measurements to angle measurements made with a Fizeau phase-shifting interferometer. These two instruments have very different operating principles and implement different definitions of the orientation of a surface, but (surprisingly) we have not yet seen any clear differences between results obtained with the autocollimator and with the interferometer. The interferometer is in some respects an attractive alternative to an autocollimator for small-angle measurement; it implements an unambiguous and robust definition of surface orientation in terms of the tilt of a best-fit plane, and it is easier to quantify likely errors of the interferometer measurements than to evaluate autocollimator uncertainty.

  16. Uncertainties in Small-Angle Measurement Systems Used to Calibrate Angle Artifacts

    PubMed Central

    Stone, Jack A.; Amer, Mohamed; Faust, Bryon; Zimmerman, Jay

    2004-01-01

    We have studied a number of effects that can give rise to errors in small-angle measurement systems when they are used to calibrate artifacts such as optical polygons. Of these sources of uncertainty, the most difficult to quantify are errors associated with the measurement of imperfect, non-flat faces of the artifact, causing the instrument to misinterpret the average orientation of the surface. In an attempt to shed some light on these errors, we have compared autocollimator measurements to angle measurements made with a Fizeau phase-shifting interferometer. These two instruments have very different operating principles and implement different definitions of the orientation of a surface, but (surprisingly) we have not yet seen any clear differences between results obtained with the autocollimator and with the interferometer. The interferometer is in some respects an attractive alternative to an autocollimator for small-angle measurement; it implements an unambiguous and robust definition of surface orientation in terms of the tilt of a best-fit plane, and it is easier to quantify likely errors of the interferometer measurements than to evaluate autocollimator uncertainty. PMID:27366616

  17. Probe Without Moving Parts Measures Flow Angle

    NASA Technical Reports Server (NTRS)

    Corda, Stephen; Vachon, M. Jake

    2003-01-01

    The measurement of local flow angle is critical in many fluid-dynamic applications, including the aerodynamic flight testing of new aircraft and flight systems. Flight researchers at NASA Dryden Flight Research Center have recently developed, flight-tested, and patented the force-based flow-angle probe (FLAP), a novel, force-based instrument for the measurement of local flow direction. Containing no moving parts, the FLAP may provide greater simplicity, improved accuracy, and increased measurement access, relative to conventional moving vane-type flow-angle probes. Forces in the FLAP can be measured by various techniques, including those that involve conventional strain gauges (based on electrical resistance) and those that involve more advanced strain gauges (based on optical fibers). A correlation is used to convert force-measurement data to the local flow angle. The use of fiber optics will enable the construction of a miniature FLAP, leading to the possibility of flow measurement in very small or confined regions. This may also enable the tufting of a surface with miniature FLAPs, capable of quantitative flow-angle measurements, similar to attaching yarn tufts for qualitative measurements. The prototype FLAP was a small, aerodynamically shaped, low-aspect-ratio fin about 2 in. (approximately equal to 5 cm) long, 1 in. (approximately equal to 2.5 cm) wide, and 0.125 in. (approximately equal to 0.3 cm) thick (see Figure 1). The prototype FLAP included simple electrical-resistance strain gauges for measuring forces. Four strain gauges were mounted on the FLAP; two on the upper surface and two on the lower surface. The gauges were connected to form a full Wheatstone bridge, configured as a bending bridge. In preparation for a flight test, the prototype FLAP was mounted on the airdata boom of a flight-test fixture (FTF) on the NASA Dryden F-15B flight research airplane.

  18. Spirality: Spiral arm pitch angle measurement

    NASA Astrophysics Data System (ADS)

    Shields, Douglas W.; Boe, Benjamin; Pfountz, Casey; Davis, Benjamin L.; Hartley, Matthew; Pour Imani, Hamed; Slade, Zac; Kennefick, Daniel; Kennefick, Julia

    2015-12-01

    Spirality measures spiral arm pitch angles by fitting galaxy images to spiral templates of known pitch. Written in MATLAB, the code package also includes GenSpiral, which produces FITS images of synthetic spirals, and SpiralArmCount, which uses a one-dimensional Fast Fourier Transform to count the spiral arms of a galaxy after its pitch is determined.

  19. On the units radian and cycle for the quantity plane angle

    NASA Astrophysics Data System (ADS)

    Mills, Ian

    2016-06-01

    This paper is concerned with the names and symbols for quantities used to describe oscillatory motion such as for a harmonic oscillator, and the units to be used for the quantity plane angle and phase angle for an oscillator, and related quantities. I draw attention to the need to carefully distinguish the names and symbols for quantities from the names and symbols for their numerical values in any application, and the significance of including units such as radian and cycle for the quantity plane angle. The familiar equations for a harmonic oscillator such as ω  =  2πν, and the relation ħ  =  h/2π for the Planck constant, are shown to hold only if the symbols are taken to represent the dimensionless numerical values of the quantities concerned in particular units, rather than the actual values which are not dimensionless as generally used in the equations of physics. Alternative ways of handling these quantities and units are discussed.

  20. Light's bending angle in the equatorial plane of a Kerr black hole

    SciTech Connect

    Iyer, S. V.; Hansen, E. C.

    2009-12-15

    We present here a detailed derivation of an explicit spin-dependent expression for the bending angle of light as it traverses in the equatorial plane of a spinning black hole. We show that the deflection produced in the presence of the black hole angular momentum explicitly depends on whether the motion of the light ray is in the direction, or opposite to the spin. Compared to the zero-spin Schwarzschild case, the bending angle is greater for direct orbits, and smaller for retrograde orbits, confirming our physical intuition about the loss of left-right symmetry from a lensing perspective. In addition, we show that for higher spins, the effect is more pronounced resulting in tighter winding of direct orbits with respect to the axis of rotation, and a higher degree of unwinding of retrograde orbits. A direct consequence of this effect is a shift in image positions in strong gravitational lensing.

  1. Measurements of Neutrino Oscillation Angle θ13

    NASA Astrophysics Data System (ADS)

    Kuze, Masahiro

    Neutrinos exhibit an interesting phenomenon called "neutrino oscillation", in which a neutrino changes its flavor after traveling some flight length. Many experiments measured the mixing angles and mass differences, but the angle θ13 had been unmeasured due to its smallness compared to others. During 2011 and 2012, series of new-generation neutrino experiments reported positive results in θ13 search, and its value has been determined to be just below the previous upper limit. The non-zero result of θ13 is a very good news for future of neutrino physics, since it opens a possibility of measuring the CP violation phase in the lepton sector. An introduction to neutrino oscillation and latest experimental results are presented. A detail is put on Double Chooz reactor experiment, in which the author is involved.

  2. Measurement of the angle alpha at BABAR

    SciTech Connect

    Perez, A.; /Orsay, LAL

    2009-06-25

    The authors present recent measurements of the CKM angle {alpha} using data collected by the BABAR detector at the PEP-II asymmetric-energy e{sup +}e{sup -} collider at the SLAC National Accelerator Laboratory, operating at the {Upsilon}(4S) resonance. They present constraints on {alpha} from B {yields} {pi}{pi}, B {yields} {rho}{rho} and B {yields} {rho}{pi} decays.

  3. Note: A novel integrated microforce measurement system for plane-plane contact research

    NASA Astrophysics Data System (ADS)

    Dong, W.; Rostoucher, D.; Gauthier, M.

    2010-11-01

    The evaluation of plane-plane contact force has become a big issue in micro-/nano research, for example in microassembly. However with the lack of effective experimental equipments, the research on plane-plane contact has been limited to theoretical formulations or virtual simulation. In this paper, a microforce sensor and precision parallel robot integrated system is proposed for the microforce measurement of plane-plane contact. In the proposed system, the two objects are fixed on the parallel robot end-platform and the microforce sensor probe tip, respectively, and the high precision robot system is employed to provide six degree-of-freedom motions between both objects. So it is convenient for the microforce measurement between the planar objects with different orientations. As a significant application, the proposed system is utilized for measurements of pull-off force between planar objects, in which the validation of the system is demonstrated in practice. The proposed microforce measurement system is generic, which can be extended to a variety of microforce measurements in plane-plane contact.

  4. Calculation Of Correction Angles Of 3-Dimensional Vertebral Rotations Based On Bi-Plane X-Ray Photogrammetry

    NASA Astrophysics Data System (ADS)

    Tamaki, Tamotsu; Umezaki, Eisaku; Yamagata, Masatsune; Inoue, Shun-ichi

    1984-10-01

    For the therapy of diseases of spinal deformity such as scoliosis, the data of 3-dimensional and correct spinal configuration are needed. Authors developed the system of spinal configuration analysis using bi-plane X-ray photogrammetry which is strong aid for this subject. The idea of correction angle of rotation of vertebra is introduced for this system. Calculated result under this idea has the clinical meaning because the correction angle is the angle which should be corrected on the treatment such as operation or wearing the equipment. Method of 30° oblique projection which gives the apparent X-ray image and eases the measurement of the anatomically characteristic points is presented. The anatomically characteristic bony points whose images should be measured on a- or b-film are of four points. These are centers of upper and lower end plates of each vertebra the center is calculated from two points which are most distant each other on the contour of vertebral end plate ), the lower end points of root of right and left pedicles. Some clinical applications and the effectiveness of this system are presented.

  5. Effects of a functional foot orthosis on the knee angle in the sagittal plane of college students in their 20s with flatfoot

    PubMed Central

    Park, KwangYong; Seo, KyoChul

    2015-01-01

    [Purpose] The purpose of this study was to examine the effects of a functional foot orthosis on the knee angle in the sagittal plane of college students in their 20s who had flatfoot. [Subjects and Methods] The subjects of this study were 20 college students diagnosed as having flatfoot. The variations of their knee angle (Q-angle) in the sagittal plane during the stance phase were measured using the VICON Motion System (Vicon, Hansung, Korea) before and while wearing a foot orthosis. The experimental data were analyzed using SPSS 12.0 for Windows. [Results] The Q-angle in the test group during the stance phase showed statistically significant declines on the right and left sides while wearing the foot orthosis during the gait-phases of loading response and midstance. During initial contact, terminal stance, and preswing, the Q-angle also decreased on the right and left sides after wearing the foot orthosis, but the changes were not statistically significant. [Conclusion] The college students with flatfoot exhibited declines in the Q-angle in the sagittal plane while wearing a foot orthosis. In this regard, the application of active gait training using orthotic shoes for long hours is likely to help individuals with flatfoot to achieve normal gait. PMID:25995591

  6. Effects of a functional foot orthosis on the knee angle in the sagittal plane of college students in their 20s with flatfoot.

    PubMed

    Park, KwangYong; Seo, KyoChul

    2015-04-01

    [Purpose] The purpose of this study was to examine the effects of a functional foot orthosis on the knee angle in the sagittal plane of college students in their 20s who had flatfoot. [Subjects and Methods] The subjects of this study were 20 college students diagnosed as having flatfoot. The variations of their knee angle (Q-angle) in the sagittal plane during the stance phase were measured using the VICON Motion System (Vicon, Hansung, Korea) before and while wearing a foot orthosis. The experimental data were analyzed using SPSS 12.0 for Windows. [Results] The Q-angle in the test group during the stance phase showed statistically significant declines on the right and left sides while wearing the foot orthosis during the gait-phases of loading response and midstance. During initial contact, terminal stance, and preswing, the Q-angle also decreased on the right and left sides after wearing the foot orthosis, but the changes were not statistically significant. [Conclusion] The college students with flatfoot exhibited declines in the Q-angle in the sagittal plane while wearing a foot orthosis. In this regard, the application of active gait training using orthotic shoes for long hours is likely to help individuals with flatfoot to achieve normal gait.

  7. Simultaneous quantification of flow and tissue velocities based on multi-angle plane wave imaging.

    PubMed

    Ekroll, Ingvild Kinn; Swillens, Abigail; Segers, Patrick; Dahl, Torbjørn; Torp, Hans; Lovstakken, Lasse

    2013-04-01

    A quantitative angle-independent 2-D modality for flow and tissue imaging based on multi-angle plane wave acquisition was evaluated. Simulations of realistic flow in a carotid artery bifurcation were used to assess the accuracy of the vector Doppler (VD) technique. Reduction in root mean square deviation from 27 cm/s to 6 cm/s and 7 cm/s to 2 cm/s was found for the lateral (vx) and axial (vz) velocity components, respectively, when the ensemble size was increased from 8 to 50. Simulations of a Couette flow phantom (vmax = 2.7 cm/s) gave promising results for imaging of slowly moving tissue, with root mean square deviation of 4.4 mm/s and 1.6 mm/s for the x- and z-components, respectively. A packet acquisition scheme providing both B-mode and vector Doppler RF data was implemented on a research scanner, and beamforming and further post-processing was done offline. In vivo results of healthy volunteers were in accordance with simulations and gave promising results for flow and tissue vector velocity imaging. The technique was also tested in patients with carotid artery disease. Using the high ensemble vector Doppler technique, blood flow through stenoses and secondary flow patterns were better visualized than in ordinary color Doppler. Additionally, the full velocity spectrum could be obtained retrospectively for arbitrary points in the image.

  8. Magnetic measurements with atomic-plane resolution.

    PubMed

    Rusz, Ján; Muto, Shunsuke; Spiegelberg, Jakob; Adam, Roman; Tatsumi, Kazuyoshi; Bürgler, Daniel E; Oppeneer, Peter M; Schneider, Claus M

    2016-01-01

    Rapid development of magnetic nanotechnologies calls for experimental techniques capable of providing magnetic information with subnanometre spatial resolution. Available probes of magnetism either detect only surface properties, such as spin-polarized scanning tunnelling microscopy, magnetic force microscopy or spin-polarized low-energy electron microscopy, or they are bulk probes with limited spatial resolution or quantitativeness, such as X-ray magnetic circular dichroism or classical electron magnetic circular dichroism (EMCD). Atomic resolution EMCD methods have been proposed, although not yet experimentally realized. Here, we demonstrate an EMCD technique with an atomic size electron probe utilizing a probe-corrected scanning transmission electron microscope in its standard operation mode. The crucial element of the method is a ramp in the phase of the electron beam wavefunction, introduced by a controlled beam displacement. We detect EMCD signals with atomic-plane resolution, thereby bringing near-atomic resolution magnetic circular dichroism spectroscopy to hundreds of laboratories worldwide. PMID:27578421

  9. Magnetic measurements with atomic-plane resolution

    NASA Astrophysics Data System (ADS)

    Rusz, Ján; Muto, Shunsuke; Spiegelberg, Jakob; Adam, Roman; Tatsumi, Kazuyoshi; Bürgler, Daniel E.; Oppeneer, Peter M.; Schneider, Claus M.

    2016-08-01

    Rapid development of magnetic nanotechnologies calls for experimental techniques capable of providing magnetic information with subnanometre spatial resolution. Available probes of magnetism either detect only surface properties, such as spin-polarized scanning tunnelling microscopy, magnetic force microscopy or spin-polarized low-energy electron microscopy, or they are bulk probes with limited spatial resolution or quantitativeness, such as X-ray magnetic circular dichroism or classical electron magnetic circular dichroism (EMCD). Atomic resolution EMCD methods have been proposed, although not yet experimentally realized. Here, we demonstrate an EMCD technique with an atomic size electron probe utilizing a probe-corrected scanning transmission electron microscope in its standard operation mode. The crucial element of the method is a ramp in the phase of the electron beam wavefunction, introduced by a controlled beam displacement. We detect EMCD signals with atomic-plane resolution, thereby bringing near-atomic resolution magnetic circular dichroism spectroscopy to hundreds of laboratories worldwide.

  10. Magnetic measurements with atomic-plane resolution

    PubMed Central

    Rusz, Ján; Muto, Shunsuke; Spiegelberg, Jakob; Adam, Roman; Tatsumi, Kazuyoshi; Bürgler, Daniel E.; Oppeneer, Peter M.; Schneider, Claus M.

    2016-01-01

    Rapid development of magnetic nanotechnologies calls for experimental techniques capable of providing magnetic information with subnanometre spatial resolution. Available probes of magnetism either detect only surface properties, such as spin-polarized scanning tunnelling microscopy, magnetic force microscopy or spin-polarized low-energy electron microscopy, or they are bulk probes with limited spatial resolution or quantitativeness, such as X-ray magnetic circular dichroism or classical electron magnetic circular dichroism (EMCD). Atomic resolution EMCD methods have been proposed, although not yet experimentally realized. Here, we demonstrate an EMCD technique with an atomic size electron probe utilizing a probe-corrected scanning transmission electron microscope in its standard operation mode. The crucial element of the method is a ramp in the phase of the electron beam wavefunction, introduced by a controlled beam displacement. We detect EMCD signals with atomic-plane resolution, thereby bringing near-atomic resolution magnetic circular dichroism spectroscopy to hundreds of laboratories worldwide. PMID:27578421

  11. A new procedure for measuring contact angle

    SciTech Connect

    Concus, P.; Finn, R.

    1994-05-01

    Described here are some recent work regarding the mathematic design of apparatus that exploits microgravity conditions for accurate experimental determination of contact angle. The underlying motivation for the procedures rests on a discontinuous dependence of the capillary free surface interface S on the contact angle {gamma}, in a cylindrical capillary tube whose section (base) {Omega} contains a protruding corner with opening angle 2{alpha}.

  12. Soil-water contact angle of some soils of the Russian Plane

    NASA Astrophysics Data System (ADS)

    Bykova, Galina; Tyugai, Zemfira; Milanovskiy, Evgeny; Shein, Evgeny

    2016-04-01

    INTRODUCTION Soil wettability affects the aggregate water resistance, the movement of moisture and dissolved substances, preferential flows, etc. There are many factors affecting the soil's wettability (the content of organic matter (OM), soil's mineralogical composition, particle size distribution), so it can reflect changes in the soil, including results of human impact. The quantitative characteristic of soil wettability is a contact angle (CA), its measurement is a new and difficult problem because of the complexity, heterogeneity and polydispersity of the object of investigation. The aim of this work is to study soil-water CA of some soils of the Russian Plane. MATERIALS AND METHODS The objects of study were sod-podzolic (Umbric Albeluvisols Abruptic, Eutric Podzoluvisols), grey forest non-podzolised (Greyic Phaeozems Albic, Haplic Greyzems), typical Chernozems (Voronic Chernozems pachic, Haplic Chernozems) - profiles under the forest and the arable land, and the chestnut (Haplic Kastanozems Chromic, Haplic Kastanozems) soils. The CA's determination was performed by a Drop Shape Analyzer DSA100 by the static sessile drop method. For all samples was determined the content of total and organic carbon (OC and TC) by dry combustion in oxygen flow. RESULTS AND DISCUSSION There is CA increasing from 85,1° (5 cm) to 40-45° (deeper, than 45 cm) in the sod-podzolic soil; OC content is changed at the same depths from 1,44 to 0.22%. We can see the similar picture in profiles of chernozems. In the forest profile the highest OC content and CA value are achieved on the surface of profile (6,41% and 78,1°), and by 90 cm these values are 1.9% and 50.2°. In the chernozem under the arable land the OC content is almost two times less and the profile is more wettable (from 50° to 19° at 5 and 100 cm). Corresponding with the OC content, the curve describing changes of CA in the profile of grey forest soil is S-shaped with peaks at 20 and 150 cm (81,3° and 70° respectively

  13. Realizing in-plane surface diffraction by x-ray multiple-beam diffraction with large incidence angle

    SciTech Connect

    Huang, Xian-Rong Gog, Thomas; Assoufid, Lahsen; Peng, Ru-Wen; Siddons, D. P.

    2014-11-03

    Based on rigorous dynamical-theory calculations, we demonstrate the principle of an x-ray multiple-beam diffraction (MBD) scheme that overcomes the long-lasting difficulties of high-resolution in-plane diffraction from crystal surfaces. This scheme only utilizes symmetric reflection geometry with large incident angles but activates the out-of-plane and in-plane diffraction processes simultaneously and separately in the continuous MBD planes. The in-plane diffraction is realized by detoured MBD, where the intermediate diffracted waves propagate parallel to the surface, which corresponds to an absolute Bragg surface diffraction configuration that is extremely sensitive to surface structures. A series of MBD diffraction and imaging techniques may be developed from this principle to study surface/interface (misfit) strains, lateral nanostructures, and phase transitions of a wide range of (pseudo)cubic crystal structures, including ultrathin epitaxial films and multilayers, quantum dots, strain-engineered semiconductor or (multi)ferroic materials, etc.

  14. Definition, transformation-formulae and measurements of tipvane angles

    NASA Astrophysics Data System (ADS)

    Bruining, A.

    1987-10-01

    The theoretical background of different angle systems used to define tipvane attitude in 3-D space is outlined. Different Euler equations are used for the various, wind tunnel, towing tank, and full scale tipvane models. The influence of rotor blade flapping angle on tipvane angles is described. The tipvane attitude measuring method is outlined in relationship to the Euler angle system. Side effects on the angle of attack of the tipvane due to rotation, translation, and curving of the tipvane are described.

  15. Out-of-plane ultrasonic velocity measurement

    DOEpatents

    Hall, M.S.; Brodeur, P.H.; Jackson, T.G.

    1998-07-14

    A method for improving the accuracy of measuring the velocity and time of flight of ultrasonic signals through moving web-like materials such as paper, paperboard and the like, includes a pair of ultrasonic transducers disposed on opposing sides of a moving web-like material. In order to provide acoustical coupling between the transducers and the web-like material, the transducers are disposed in fluid-filled wheels. Errors due to variances in the wheel thicknesses about their circumference which can affect time of flight measurements and ultimately the mechanical property being tested are compensated by averaging the ultrasonic signals for a predetermined number of revolutions. The invention further includes a method for compensating for errors resulting from the digitization of the ultrasonic signals. More particularly, the invention includes a method for eliminating errors known as trigger jitter inherent with digitizing oscilloscopes used to digitize the signals for manipulation by a digital computer. In particular, rather than cross-correlate ultrasonic signals taken during different sample periods as is known in the art in order to determine the time of flight of the ultrasonic signal through the moving web, a pulse echo box is provided to enable cross-correlation of predetermined transmitted ultrasonic signals with predetermined reflected ultrasonic or echo signals during the sample period. By cross-correlating ultrasonic signals in the same sample period, the error associated with trigger jitter is eliminated. 20 figs.

  16. Out-of-plane ultrasonic velocity measurement

    DOEpatents

    Hall, Maclin S.; Brodeur, Pierre H.; Jackson, Theodore G.

    1998-01-01

    A method for improving the accuracy of measuring the velocity and time of flight of ultrasonic signals through moving web-like materials such as paper, paperboard and the like, includes a pair of ultrasonic transducers disposed on opposing sides of a moving web-like material. In order to provide acoustical coupling between the transducers and the web-like material, the transducers are disposed in fluid-filled wheels. Errors due to variances in the wheel thicknesses about their circumference which can affect time of flight measurements and ultimately the mechanical property being tested are compensated by averaging the ultrasonic signals for a predetermined number of revolutions. The invention further includes a method for compensating for errors resulting from the digitization of the ultrasonic signals. More particularly, the invention includes a method for eliminating errors known as trigger jitter inherent with digitizing oscilloscopes used to digitize the signals for manipulation by a digital computer. In particular, rather than cross-correlate ultrasonic signals taken during different sample periods as is known in the art in order to determine the time of flight of the ultrasonic signal through the moving web, a pulse echo box is provided to enable cross-correlation of predetermined transmitted ultrasonic signals with predetermined reflected ultrasonic or echo signals during the sample period. By cross-correlating ultrasonic signals in the same sample period, the error associated with trigger jitter is eliminated.

  17. PHENIX Measurements of Reaction Plane Dependence of High-pT Photons and Pions

    SciTech Connect

    Pantuev, V. S.; Awes, Terry C; Batsouli, Sotiria; Cianciolo, Vince; Efremenko, Yuri; Read Jr, Kenneth F; Silvermyr, David O; Sorensen, Soren P; Stankus, Paul W; Young, Glenn R; Zhang, Chun; PHENIX, Collaboration

    2007-01-01

    Direct photon and neutral pion production with respect to the reaction plane at high-p{sub T} were measured with the PHENIX experiment in Au+Au collisions at {radical}s{sub NN}=200 GeV at mid-rapidity. The azimuthal asymmetry parameter v{sub 2} for direct photons was found to be consistent with zero for all centrality classes. We evaluate the dependence of {pi}{sub 0} suppression at high-p{sub T} on the emission angle {Delta}{phi} with respect to the event reaction plane for seven centrality bins. For the peripheral bins we observe no suppression for neutral pions aligned with the reaction plane while {pi}{sup 0}'s produced perpendicular to the reaction plane are suppressed by factor 2. We found that a simple geometric picture can explain the observed suppression pattern.

  18. Numerical phase retrieval from beam intensity measurements in three planes

    NASA Astrophysics Data System (ADS)

    Bruel, Laurent

    2003-05-01

    A system and method have been developed at CEA to retrieve phase information from multiple intensity measurements along a laser beam. The device has been patented. Commonly used devices for beam measurement provide phase and intensity information separately or with a rather poor resolution whereas the MIROMA method provides both at the same time, allowing direct use of the results in numerical models. Usual phase retrieval algorithms use two intensity measurements, typically the image plane and the focal plane (Gerschberg-Saxton algorithm) related by a Fourier transform, or the image plane and a lightly defocus plane (D.L. Misell). The principal drawback of such iterative algorithms is their inability to provide unambiguous convergence in all situations. The algorithms can stagnate on bad solutions and the error between measured and calculated intensities remains unacceptable. If three planes rather than two are used, the data redundancy created confers to the method good convergence capability and noise immunity. It provides an excellent agreement between intensity determined from the retrieved phase data set in the image plane and intensity measurements in any diffraction plane. The method employed for MIROMA is inspired from GS algorithm, replacing Fourier transforms by a beam-propagating kernel with gradient search accelerating techniques and special care for phase branch cuts. A fast one dimensional algorithm provides an initial guess for the iterative algorithm. Applications of the algorithm on synthetic data find out the best reconstruction planes that have to be chosen. Robustness and sensibility are evaluated. Results on collimated and distorted laser beams are presented.

  19. An evaluation of relation between the relative parallelism of occlusal plane to ala-tragal line and variation in the angulation of Po-Na-ANS angle in dentulous subjects: A cephalometric study

    PubMed Central

    Shetty, Sanath; Shenoy, K. Kamalakanth; Ninan, Justin; Mahaseth, Pranay

    2015-01-01

    Aims: The aim was to evaluate if any correlation exists between variation in angulation of Po-Na-ANS angle and relative parallelism of the occlusal plane to the different tragal levels of the ear in dentulous subjects. Methodology: A total of 200 subjects were selected for the study. A custom made occlusal plane analyzer was used to determine the posterior point of the ala-tragal line. The lateral cephalogram was shot for each of the subjects. The points Porion, Nasion, and Anterior Nasal Spine were located and the angle formed between these points was measured. Statistical Analysis Used: Fischer's exact test was used to find the correlation between Po-Na-ANS angle and relative parallelism of the occlusal plane to the ala-tragal line at different tragal levels. Results: Statistical analysis showed no significant correlation between Po-Na-ANS angle and relative parallelism of an occlusal plane at different tragal levels, and an inferior point on the tragus was the most common. Conclusion: Irrespective of variations in the Po-Na-ANS angle, no correlation exists between the variation in the angulations of Po-Na-ANS angle and the relative parallelism of occlusal plane to the ala-tragal line at different tragal levels. Furthermore, in a large number of subjects (54%), the occlusal plane was found parallel to a line joining the inferior border of the ala of the nose and the inferior part of the tragus. PMID:26929506

  20. Strength and muscle activities during the toe-gripping action: comparison of ankle angle in the horizontal plane between the sitting upright and standing positions

    PubMed Central

    Soma, Masayuki; Murata, Shin; Kai, Yoshihiro; Nakae, Hideyuki; Satou, Yousuke

    2016-01-01

    [Purpose] The aim of this study was to investigate whether toe grip strength and muscle activities are affected by the ankle angle in the horizontal plane in the sitting upright and standing positions. [Subjects] The subjects were 16 healthy young women. [Methods] We measured toe grip strength and the maximum voluntary contraction activities of the rectus femoris, biceps femoris, anterior tibialis, and medial head of the gastrocnemius. In addition, we calculated the percent integrated electromyography during foot gripping in 3 different ankle joint positions between the long axis of the foot and the line of progression on the horizontal plane, namely 10° of internal rotation, 0°, and 10° of external rotation. [Results] Two-way analysis of variance revealed significant differences. A significant main effect was observed in the measurement conditions for the percent integrated electromyography of the rectus femoris muscle and long head of the biceps femoris. However, two-way analysis of variance did not reveal any significant difference, and a significant main effect was not observed in toe grip strength. [Conclusion] These findings suggest that exerted toe grip strength is only slightly affected by the ankle angle in the horizontal plane in the sitting upright and standing positions. Therefore, the current measurement positions were shown to be optimal for measurement. PMID:27134399

  1. Stroke plane angle controls leading edge vortex in a bat-inspired flapper

    NASA Astrophysics Data System (ADS)

    Koekkoek, Gide; Muijres, Florian T.; Johansson, L. Christoffer; Stuiver, Melanie; van Oudheusden, Bas W.; Hedenström, Anders

    2012-01-01

    The present interest in micro air vehicles has given the research on bat flight a new impulse. With the use of high speed cameras and improved PIV techniques, the kinematics and aerodynamics of bats have been studied in great detail. A robotic flapper makes it possible to do measurements by systematically changing only one parameter at a time and investigate the parameter space outside the natural flight envelope of bats without risking animal safety. For this study, a robotic flapper (RoBat), inspired by Leptonycteris yerbabuenae was developed and tested over the speed range 1-7 m/s, with variable maximum angles of attacks ( AoA=55° and 15°, respectively) and constant AoA=55°. These measurements show the presence of a leading edge vortex (LEV) for low speeds and a fully attached flow for high speeds at low AoA, which is in line with natural bat flight. A LEV occurs for AoA=55° throughout the complete flight speed range, and throughout which the LEV circulation coefficient remains rather constant. This implies that bats and micro air vehicles could use LEVs for high load maneuvers also at relatively high flight speeds. However, at high flight speeds the LEV bursts, which causes increased drag, most likely due to a decrease in Strouhal number.

  2. Comparative analysis on viewing angle change in Fresnel and Fourier holographic images reconstructed by a tilted plane wave.

    PubMed

    Chae, Byung Gyu

    2014-05-20

    We carry out a comparative analysis on a viewing angle change in Fresnel and Fourier holographic images reconstructed by a tilted plane wave. A tilted plane wave illuminating an on-axis hologram generates a diffractive wave carrying the holographic image in a paraxial region of a new diffraction axis. The reconstructed image in the Fresnel hologram is deformed along the new viewing direction, which is well described as Affine transformation. In the Fourier holographic image, the replica of the image is formed without its deformation when the hologram is placed in the front focal plane of the lens, whereas in the case of a hologram that is located at a distance different from a focal length, image deformation arises. This property is investigated through numerical simulation based on a wide-angle diffraction phenomenon. We also perform a similar interpretation for high-order diffraction images appearing in the sampled Fourier hologram and discuss a method for enlarging the viewing angle of the holographic image.

  3. Magnetic prism alignment system for measuring large-angle strabismus.

    PubMed

    Bishop, John Edward

    2014-02-01

    Prismatic measurement of large-angle strabismus requires the simultaneous use of two or more prisms for neutralization. To facilitate the clinical measurement of large-angle strabismus a new prism system was designed utilizing a flat plate and a ferrous metal surface coupled with prisms containing rare earth magnets implanted in their base and bottom surfaces. PMID:24569000

  4. Unitarity Triangle Angle Measurements at BaBar

    SciTech Connect

    Latham, Thomas E.; /SLAC

    2005-06-30

    We present recent results of measurements of the Unitarity Triangle angles alpha, beta and gamma made with the BaBar detector at the PEP-II asymmetric B factory. We present recent results of measurements of the Unitarity Triangle angles alpha, beta and gamma made with the BaBar detector at the PEP-II asymmetric B factory.

  5. Magnetic prism alignment system for measuring large-angle strabismus.

    PubMed

    Bishop, John Edward

    2014-02-01

    Prismatic measurement of large-angle strabismus requires the simultaneous use of two or more prisms for neutralization. To facilitate the clinical measurement of large-angle strabismus a new prism system was designed utilizing a flat plate and a ferrous metal surface coupled with prisms containing rare earth magnets implanted in their base and bottom surfaces.

  6. Measure Guideline: Guidance on Taped Insulating Sheathing Drainage Planes

    SciTech Connect

    Grin, A.; Lstiburek, J.

    2014-09-01

    The goal of this research is to provide durable and long-term water management solutions using exterior insulating sheathing as part of the water management system. It is possible to tape or seal the joints in insulating sheathing to create a drainage plane and even an air control layer. There exists the material durability component of the tape as well as the system durability component being the taped insulating sheathing as the drainage plane. This measure guideline provides best practice and product recommendations from the interviewed contractors and homebuilders who collectively have a vast amount of experience. Three significant issues were discussed with the group, which are required to make taped insulating sheathing a simple, long-term, and durable drainage plane: horizontal joints should be limited or eliminated wherever possible; where a horizontal joint exists use superior materials; and frequent installation inspection and regular trade training are required to maintain proper installation.

  7. Goniometric measurements of light scattered in the principal plane from leaves

    NASA Technical Reports Server (NTRS)

    Brakke, Thomas W.

    1992-01-01

    A laboratory goniometer was designed and built by NASA for acquiring bidirectional scattering data in the principal plane from leaves. Goniometric measurements were taken on individual tree leaves of yellow poplar, red maple, and red oak. Reflectance measurements were taken every 5* and transmittance measurements every 10 in the principal plane. The results indicate that light reflected from leaves usually has a significant specular component. Reflectances measured for 60 incident angle were the most specular. The most isotropic scattering occurred with transmitted light and with 0 incident light reflected from the abaxial surface. The most significant difference observed between the species was due to the heavy wax layer found on the abaxial surface of red oak, which caused the abaxial reflectance to be more specular than it was in the other two species.

  8. Availability of Software-Based Correction of Mandibular Plane for the Vertical Measurement of the Mandible in Cone Beam Computed Tomography

    PubMed Central

    Han, Sang-Sun; Lee, Kwang-Min; Kim, Kee-Deog

    2015-01-01

    Objectives. To investigate the availability of correction of mandibular plane using software for vertical measurements in cone beam computed tomography (CBCT) according to the sites of the mandible. Methods. CBCT scans of six dry mandibles were performed at 0-, 5-, 10-, 15-, and 20-degree angles relative to CBCT scanning table. Using the imaging software, mandibular planes of the different angles were corrected to that of 0-degree angle on the CBCT images. Before and after correction of the mandibular planes, the distance from the mandibular canal to the alveolar crest was measured at M1, M2, and M3 areas of the mandible and vertical measurements were statistically compared with those of 0-angle location using the paired t-test. Results. Prior to correction, the vertical measurements increased as the angle increased. The greatest differences of measurements were observed in M3 areas (P < 0.05). After correction, a strong correlation was found in measurements between the 0-degree angle and the other angles in all sites of the mandible (P > 0.05). Conclusions. The vertical measurements of CBCT were significantly influenced by mandibular positioning. When CBCT scans are performed at angles other than 0-degree angle, software-based correction of the mandibular plane can be a reliable tool for the accurate vertical measurements in CBCT. PMID:26579540

  9. Optical measurements of the mutual reflection of two-plane shock waves

    SciTech Connect

    Barbosa, F.J.; Skews, B.W.

    1995-12-31

    A bifurcated shock tube is used to create two synchronized waves of equal strength. Essentially a single shock wave is split symmetrically in two, the two waves then are later brought back together at a trailing edge of a wedge to interact, the plane of symmetry acting as an ideal rigid wall. The normal method of studying mach reflections is to allow a plane shock wave to impinge on a wedge, however the boundary layer growth on the wedge surface effectively ensures that the flow direction behind the Mach stem does not have to satisfy the boundary condition of being parallel to the surface of the wedge. Thus the transition from regular to Mach reflection occurs at higher angles of incidence than theory allows. The present experiment was initiated to generate data on the ideal cause of reflection off a plane wall. The advantage of the new system is that like classical theory and computational solutions of the inviscid Euler equations, the boundary layer no slip condition is not imposed at the plane of reflection. Optical methods are used to investigate the post-shock flow, as well as to help explain the complex interactions which occur when the two shock waves are not synchronized. These interactions show many very interesting features and clearly indicate the need for higher resolution measurements such as are obtained using holographic interferometry, and also to extend the work to different wedge angles and Mach numbers.

  10. Terahertz Wide-Angle Imaging and Analysis on Plane-wave Criteria Based on Inverse Synthetic Aperture Techniques

    NASA Astrophysics Data System (ADS)

    Gao, Jing Kun; Qin, Yu Liang; Deng, Bin; Wang, Hong Qiang; Li, Jin; Li, Xiang

    2016-04-01

    This paper presents two parts of work around terahertz imaging applications. The first part aims at solving the problems occurred with the increasing of the rotation angle. To compensate for the nonlinearity of terahertz radar systems, a calibration signal acquired from a bright target is always used. Generally, this compensation inserts an extra linear phase term in the intermediate frequency (IF) echo signal which is not expected in large-rotation angle imaging applications. We carried out a detailed theoretical analysis on this problem, and a minimum entropy criterion was employed to estimate and compensate for the linear-phase errors. In the second part, the effects of spherical wave on terahertz inverse synthetic aperture imaging are analyzed. Analytic criteria of plane-wave approximation were derived in the cases of different rotation angles. Experimental results of corner reflectors and an aircraft model based on a 330-GHz linear frequency-modulated continuous wave (LFMCW) radar system validated the necessity and effectiveness of the proposed compensation. By comparing the experimental images obtained under plane-wave assumption and spherical-wave correction, it also showed to be highly consistent with the analytic criteria we derived.

  11. Inversion of Multi-Angle Radiation Measurement

    SciTech Connect

    Cairns, B.; Alexandrov, M. Lacis, A.; Carlson, B.

    2005-03-18

    Our need to reconcile models and measurements in an efficient manner that allows for the operational retrieval of particle sizes for a two layer cloud led us to develop a new method for calculating the Green's functions for radiative transfer. The method uses the fact that doubling/adding codes can be easily used to calculate internal radiation fields at arbitrarily high resolution. We have also determined that the adjoint downwelling and upwelling vector radiation fields are simply related to the usual downwelling and upwelling vector radiation fields so that the entire Green's function can be determined from a single calculation. The Green's functions have then been used to calculate the particle sizes in a two layer cloud that are consistent with both the reflectance and polarization measurements. This approach may be of use in other applications where adjoint calculations are used, particularly if multiangle measurements are being analyzed.

  12. In-plane displacement measurement using optical vortex phase shifting.

    PubMed

    Sun, Haibin; Wang, Xinghai; Sun, Ping

    2016-07-20

    In this paper, we propose a new method for in-plane displacement measurement by application of phase shifting based on an optical vortex. The phase shifts are obtained by displaying computer-generated fork holograms on the screen of a liquid-crystal spatial light modulator (LC-SLM). Furthermore, the vortex beam that is generated by the LC-SLM can be used as a reference light in the experiment. Eight speckle patterns with phase-shift increments of 0, π/2, π, and 3π/2 were captured by a CCD camera before and after the deformation. The displacement of the deformed object was obtained by unwrapping. Experimental results demonstrated the efficacy of the proposed method for in-plane displacement measurement. PMID:27463914

  13. Measurements of the CKM Angle beta

    SciTech Connect

    Bartoldus, Rainer; /SLAC

    2005-12-14

    In this article I report on new and updated measurements of the CP-violating parameter {beta}({phi}{sub 1}), which is related to the phase of the Cabibbo-Kobayashi-Maskawa (CKM) quark-mixing matrix of the electroweak interaction. Over the past few years, {beta} has become the most precisely known parameter of the CKM unitarity triangle that governs the B system. The results presented here were produced by the two B Factories, BABAR and Belle, based on their most recent datasets of over 600 million B{bar B} events combined. The new world average for sin2{beta}, measured in the theoretically and experimentally cleanest charmonium modes, such as B{sup 0} {yields} J/{Psi}K{sub S}{sup 0}, is sin 2{beta} = 0.685 {+-} 0.032. In addition to these tree-level dominated decays, independent measurements of sin2{beta} are obtained from gluonic b {yields} s penguin decays, including B{sup 0} {yields} {phi}K{sub S}{sup 0}, B{sup 0} {yields} {eta}'K{sub S}{sup 0} and others. There are hints, albeit somewhat weaker than earlier this year, that these measurements tend to come out low compared to the charmonium average, giving rise to the tantalizing possibility that New Physics amplitudes could be contributing to the corresponding loop diagrams. Clearly, more data from both experiments are needed to elucidate these intriguing differences.

  14. Holographic particle velocity measurement in the Fraunhofer plane.

    PubMed

    Ewan, B C

    1979-03-01

    Double exposure holograms of a moving particle field having a 1-D velocity distribution are produced. The Fraunhofer plane is observed on reconstruction, and it is shown that for a Gaussian velocity distribution, the fringes which modulate the diffraction pattern have spacings characteristic of the peak velocity. Known and measured peak velocities are compared, and the effect of the velocity distribution width on the fringe contrast is demonstrated.

  15. An in-plane cantilever for wall shear stress measurement

    NASA Astrophysics Data System (ADS)

    Allen, N. J.; Sims-Williams, D. B.; Wood, D.

    2012-07-01

    A sensor capable of measuring small shear stresses in wind tunnel applications is presented. The sensor utilizes an in-plane cantilever concept for shear stress measurement, designed to minimize intrusiveness into the airflow and allow easy incorporation into wind tunnel test models. The sensor operates independently of input voltage, and can measure <1 Pa shear stresses with a sensitivity of 8.6 (mV V-1) Pa. Altering the geometry of the sensor has a direct effect on the sensitivity and so can be used to adapt the sensor for different applications.

  16. Adaptive control of a vibratory angle measuring gyroscope.

    PubMed

    Park, Sungsu

    2010-01-01

    This paper presents an adaptive control algorithm for realizing a vibratory angle measuring gyroscope so that rotation angle can be directly measured without integration of angular rate, thus eliminating the accumulation of numerical integration errors. The proposed control algorithm uses a trajectory following approach and the reference trajectory is generated by an ideal angle measuring gyroscope driven by the estimate of angular rate and the auxiliary sinusoidal input so that the persistent excitation condition is satisfied. The developed control algorithm can compensate for all types of fabrication imperfections such as coupled damping and stiffness, and mismatched stiffness and un-equal damping term in an on-line fashion. The simulation results show the feasibility and effectiveness of the developed control algorithm that is capable of directly measuring rotation angle without the integration of angular rate.

  17. Measurement of the angle of superficial tension by images

    NASA Astrophysics Data System (ADS)

    Yanez M., Javier; Alonso R., Sergio

    2006-02-01

    When a liquid is deposited on a surface, this one form a certain angle with respect to the surface, where depending on its value, it will conclude that so hard it is his adhesion with the surface. By means of the analysis of images we looked for to measure this angle of superficial tension. In order to make this measurement, we propose a technique by means of projective transformations and one method of regression to estimation parameters to conic fitting.

  18. 2DFFT: Measuring Galactic Spiral Arm Pitch Angle

    NASA Astrophysics Data System (ADS)

    Davis, Benjamin L.; Berrier, Joel C.; Shields, Douglas W.; Kennefick, Julia; Kennefick, Daniel; Seigar, Marc S.; Lacy, Claud H. S.; Puerari, Ivânio

    2016-08-01

    2DFFT utilizes two-dimensional fast Fourier transformations of images of spiral galaxies to isolate and measure the pitch angles of their spiral arms; this provides a quantitative way to measure this morphological feature and allows comparison of spiral galaxy pitch angle to other galactic parameters and test spiral arm genesis theories. 2DFFT requires fourn.c from Numerical Recipes in C (Press et al. 1989).

  19. Receivers in American football use a constant optical projection plane angle to pursue and catch thrown footballs.

    PubMed

    Shaffer, Dennis M; Dolgov, Igor; Maynor, Andrew; Reed, Cody

    2013-01-01

    In the present work we test how well two interceptive strategies, which have been proposed for catching balls hit high in the air in baseball and cricket, account for receivers in American football catching footballs. This is an important test of the domain generality of these strategies as this is the first study examining a situation where the pursuer's locomotor axis is directed away from the origin of the ball, and because the flight characteristics of an American football are far different from targets studied in prior work. The first strategy is to elicit changes in the ball's lateral optical position that match changes in the vertical optical position so that the optical projection plane angle, psi, remains constant, thus resulting in a linear optical trajectory (LOT). The second is keeping vertical optical ball velocity decreasing while maintaining constant lateral optical velocity (generalized optical acceleration cancellation, or GOAC). We found that the optical projection plane angle was maintained as constant significantly more often than maintaining vertical and lateral optical velocities as GOAC predicted. The present experiment extends previous research by showing that the constancy of psi resulting in an LOT is used by humans pursuing American footballs and demonstrates the domain generality of the LOT heuristic. PMID:24303746

  20. Receivers in American football use a constant optical projection plane angle to pursue and catch thrown footballs.

    PubMed

    Shaffer, Dennis M; Dolgov, Igor; Maynor, Andrew; Reed, Cody

    2013-01-01

    In the present work we test how well two interceptive strategies, which have been proposed for catching balls hit high in the air in baseball and cricket, account for receivers in American football catching footballs. This is an important test of the domain generality of these strategies as this is the first study examining a situation where the pursuer's locomotor axis is directed away from the origin of the ball, and because the flight characteristics of an American football are far different from targets studied in prior work. The first strategy is to elicit changes in the ball's lateral optical position that match changes in the vertical optical position so that the optical projection plane angle, psi, remains constant, thus resulting in a linear optical trajectory (LOT). The second is keeping vertical optical ball velocity decreasing while maintaining constant lateral optical velocity (generalized optical acceleration cancellation, or GOAC). We found that the optical projection plane angle was maintained as constant significantly more often than maintaining vertical and lateral optical velocities as GOAC predicted. The present experiment extends previous research by showing that the constancy of psi resulting in an LOT is used by humans pursuing American footballs and demonstrates the domain generality of the LOT heuristic.

  1. The In-Plane Anisotropy of WTe2 Investigated by Angle-Dependent and Polarized Raman Spectroscopy.

    PubMed

    Song, Qingjun; Pan, Xingchen; Wang, Haifeng; Zhang, Kun; Tan, Qinghai; Li, Pan; Wan, Yi; Wang, Yilun; Xu, Xiaolong; Lin, Miaoling; Wan, Xiangang; Song, Fengqi; Dai, Lun

    2016-01-01

    Tungsten ditelluride (WTe2) is a semi-metallic layered transition metal dichalcogenide with a stable distorted 1T phase. The reduced symmetry of this system leads to in-plane anisotropy in various materials properties. We have systemically studied the in-plane anisotropy of Raman modes in few-layer and bulk WTe2 by angle-dependent and polarized Raman spectroscopy (ADPRS). Ten Raman modes are clearly resolved. Their intensities show periodic variation with sample rotating. We identify the symmetries of the detected modes by quantitatively analyzing the ADPRS results based on the symmetry selection rules. Material absorption effect on the phonon modes with high vibration frequencies is investigated by considering complex Raman tensor elements. We also provide a rapid and nondestructive method to identify the crystallographic orientation of WTe2. The crystallographic orientation is further confirmed by the quantitative atomic-resolution force image. Finally, we find that the atomic vibrational tendency and complexity of detected modes are also reflected in the shrinkage degree defined based on ADPRS, which is confirmed by corresponding density functional calculation. Our work provides a deep understanding of the interaction between WTe2 and light, which will benefit in future studies about the anisotropic physical properties of WTe2 and other in-plane anisotropic materials. PMID:27404226

  2. The In-Plane Anisotropy of WTe2 Investigated by Angle-Dependent and Polarized Raman Spectroscopy

    PubMed Central

    Song, Qingjun; Pan, Xingchen; Wang, Haifeng; Zhang, Kun; Tan, Qinghai; Li, Pan; Wan, Yi; Wang, Yilun; Xu, Xiaolong; Lin, Miaoling; Wan, Xiangang; Song, Fengqi; Dai, Lun

    2016-01-01

    Tungsten ditelluride (WTe2) is a semi-metallic layered transition metal dichalcogenide with a stable distorted 1T phase. The reduced symmetry of this system leads to in-plane anisotropy in various materials properties. We have systemically studied the in-plane anisotropy of Raman modes in few-layer and bulk WTe2 by angle-dependent and polarized Raman spectroscopy (ADPRS). Ten Raman modes are clearly resolved. Their intensities show periodic variation with sample rotating. We identify the symmetries of the detected modes by quantitatively analyzing the ADPRS results based on the symmetry selection rules. Material absorption effect on the phonon modes with high vibration frequencies is investigated by considering complex Raman tensor elements. We also provide a rapid and nondestructive method to identify the crystallographic orientation of WTe2. The crystallographic orientation is further confirmed by the quantitative atomic-resolution force image. Finally, we find that the atomic vibrational tendency and complexity of detected modes are also reflected in the shrinkage degree defined based on ADPRS, which is confirmed by corresponding density functional calculation. Our work provides a deep understanding of the interaction between WTe2 and light, which will benefit in future studies about the anisotropic physical properties of WTe2 and other in-plane anisotropic materials. PMID:27404226

  3. The In-Plane Anisotropy of WTe2 Investigated by Angle-Dependent and Polarized Raman Spectroscopy

    NASA Astrophysics Data System (ADS)

    Song, Qingjun; Pan, Xingchen; Wang, Haifeng; Zhang, Kun; Tan, Qinghai; Li, Pan; Wan, Yi; Wang, Yilun; Xu, Xiaolong; Lin, Miaoling; Wan, Xiangang; Song, Fengqi; Dai, Lun

    2016-07-01

    Tungsten ditelluride (WTe2) is a semi-metallic layered transition metal dichalcogenide with a stable distorted 1T phase. The reduced symmetry of this system leads to in-plane anisotropy in various materials properties. We have systemically studied the in-plane anisotropy of Raman modes in few-layer and bulk WTe2 by angle-dependent and polarized Raman spectroscopy (ADPRS). Ten Raman modes are clearly resolved. Their intensities show periodic variation with sample rotating. We identify the symmetries of the detected modes by quantitatively analyzing the ADPRS results based on the symmetry selection rules. Material absorption effect on the phonon modes with high vibration frequencies is investigated by considering complex Raman tensor elements. We also provide a rapid and nondestructive method to identify the crystallographic orientation of WTe2. The crystallographic orientation is further confirmed by the quantitative atomic-resolution force image. Finally, we find that the atomic vibrational tendency and complexity of detected modes are also reflected in the shrinkage degree defined based on ADPRS, which is confirmed by corresponding density functional calculation. Our work provides a deep understanding of the interaction between WTe2 and light, which will benefit in future studies about the anisotropic physical properties of WTe2 and other in-plane anisotropic materials.

  4. Simultaneous in-plane and out-of-plane displacement measurement based on a dual-camera imaging system and its application to inspection of large-scale space structures

    NASA Astrophysics Data System (ADS)

    Ri, Shien; Tsuda, Hiroshi; Yoshida, Takeshi; Umebayashi, Takashi; Sato, Akiyoshi; Sato, Eiichi

    2015-07-01

    Optical methods providing full-field deformation data have potentially enormous interest for mechanical engineers. In this study, an in-plane and out-of-plane displacement measurement method based on a dual-camera imaging system is proposed. The in-plane and out-of-plane displacements are determined simultaneously using two measured in-plane displacement data observed from two digital cameras at different view angles. The fundamental measurement principle and experimental results of accuracy confirmation are presented. In addition, we applied this method to the displacement measurement in a static loading and bending test of a solid rocket motor case (CFRP material; 2.2 m diameter and 2.3 m long) for an up-to-date Epsilon rocket developed by JAXA. The effectiveness and measurement accuracy is confirmed by comparing with conventional displacement sensor. This method could be useful to diagnose the reliability of large-scale space structures in the rocket development.

  5. Automated small tilt-angle measurement using Lau interferometry

    SciTech Connect

    Prakash, Shashi; Singh, Sumitra; Rana, Santosh

    2005-10-01

    A technique for a tilt-angle measurement of reflecting objects based on the Lau interferometry coupled with the moire readout has been proposed. A white-light incoherent source illuminates a set of two gratings, resulting in the generation of the Fresnel image due to the Lau effect. The Fresnel image is projected onto a reflecting object. The image reflected from the object is superimposed onto an identical grating, which results in the formation of a moire fringe pattern. The inclination angle of moire fringes is a function of tilt angle of the object. Theory and experimental arrangement of the proposed technique is presented and results of the investigation are reported.

  6. A measurement methodology for dynamic angle of sight errors in hardware-in-the-loop simulation

    NASA Astrophysics Data System (ADS)

    Zhang, Wen-pan; Wu, Jun-hui; Gan, Lin; Zhao, Hong-peng; Liang, Wei-wei

    2015-10-01

    In order to precisely measure dynamic angle of sight for hardware-in-the-loop simulation, a dynamic measurement methodology was established and a set of measurement system was built. The errors and drifts, such as synchronization delay, CCD measurement error and drift, laser spot error on diffuse reflection plane and optics axis drift of laser, were measured and analyzed. First, by analyzing and measuring synchronization time between laser and time of controlling data, an error control method was devised and lowered synchronization delay to 21μs. Then, the relationship between CCD device and laser spot position was calibrated precisely and fitted by two-dimension surface fitting. CCD measurement error and drift were controlled below 0.26mrad. Next, angular resolution was calculated, and laser spot error on diffuse reflection plane was estimated to be 0.065mrad. Finally, optics axis drift of laser was analyzed and measured which did not exceed 0.06mrad. The measurement results indicate that the maximum of errors and drifts of the measurement methodology is less than 0.275mrad. The methodology can satisfy the measurement on dynamic angle of sight of higher precision and lager scale.

  7. Automated measurement of diagnostic angles for hip dysplasia

    NASA Astrophysics Data System (ADS)

    de Raedt, Sepp; Mechlenburg, Inger; Stilling, Maiken; Rømer, Lone; Søballe, Kjeld; de Bruijne, Marleen

    2013-03-01

    A fully automatic method for measuring diagnostic angles of hip dysplasia is presented. The method consists of the automatic segmentation of CT images and detection of anatomical landmarks on the femur and acetabulum. The standard angles used in the diagnosis of hip dysplasia are subsequently automatically calculated. Previous work in automating the measuring of angles required the manual segmentation or delineation of the articular joint surface. In the current work automatic segmentation is established using graph-cuts with a cost function based on a sheetness score to detect the sheet-like structure of the bone. Anatomical landmarks are subsequently detected using heuristics based on ray-tracing and the distance to the approximated acetabulur joint surface. Standard diagnositic angles are finally calculated and presented for interpretation. Experiments using 26 patients, showed a good agreement with gold standard manual measurements by an expert radiologist as performed in daily practice. The mean difference for the five angles was between -1:1 and 2:0 degrees with a concordance correlation coefficient between 0:87 and 0:93. The standard deviation varied between 2:3 and 4:1 degrees. These values correspond to values found in evaluating interobserver and intraobserver variation for manual measurements. The method can be used in clinical practice to replace the current manual measurements performed by radiologists. In the future, the method will be integrated into an intraoperative surgical guidance system.

  8. A direct in vivo measurement of the three-dimensional orientation of the occlusal plane and of the sagittal discrepancy of the jaws.

    PubMed

    Ferrario, Virgilio F.; Sforza, Chiarella; Serrao, Graziano; Ciusa, Veronica

    2000-02-01

    The aim of the present investigation was to three dimensionally assess craniofacial relationships in vivo. Specifically, by using a non-invasive direct technique, the following measurements were made: 1) natural head position relative to the ground; 2) orientation of the occlusal plane relative to the subject's intrinsic facial planes; and 3) anteroposterior discrepancy of the dental bases, taking into consideration all the facial hard- and soft-tissue structures. Several dental and soft-tissue facial landmarks were directly digitized from 24 adult healthy volunteers with Angle Class I occlusions by means of an electromagnetic three-dimensional computerized digitizer. In natural head position, the three-dimensional orientation of Camper's, occlusal, and mandibular planes were measured along with the anteroposterior maxillo-mandibular discrepancies. In the frontal plane projection, all the measured planes appeared about horizontal. In the lateral plane projection, on average, Camper's plane deviated from the true horizontal by approximately 18 degrees (in a 'head flexed' direction). The occlusal plane deviated from the same horizontal by about 14 degrees, while the mandibular plane had a steeper inclination (about 30 degrees ); both planes were significantly correlated to Camper's plane. The measurements of anteroposterior jaw discrepancy revealed a wide range of sagittal relationships in the analyzed subjects. The method was found to be repeatable and fast. This direct three-dimensional in vivo assessment of the orientation of occlusal plane relative to the other facial planes could allow for a more comprehensive analysis of maxillo-mandibular sagittal discrepancies.

  9. Contextual phase estimation from two-plane intensity measurements.

    PubMed

    Deepak, V Joshua; Ivan, J Solomon

    2016-06-01

    In this work we construct examples of paraxial light fields whose intensities defined at all points in space do not have a corresponding cross-spectrally pure field amplitude reproducing the same set of transported intensities at all transverse planes. Nevertheless, two spatially separated transverse plane intensities as drawn from these examples are shown to have a corresponding cross-spectrally pure field amplitude, which, through paraxial free propagation between these two planes, reproduces the drawn transverse plane intensities. And the phase associated with such a field amplitude at a given transverse plane is found to be contextual, and intrinsically dependent on the pairing plane. PMID:27409450

  10. Measurement of image plane illumination uniformity of photoelectric imaging system

    NASA Astrophysics Data System (ADS)

    Kang, Deng-kui; Yang, Hong; Sha, Ding-guo; Jiang, Chang-lu; Chen, Min; Zhong, Xing-hui; Ma, Shi-bang; Yuan, Liang

    2014-09-01

    The image plane illumination nonuniformity caused by optical system or detector will affect the detection precision of photoelectric imaging system, especially in image guidance, positioning and recognition. An image plane illumination uniformity measurement device was set up, which was characteristiced of high uniformity and wide dynamic range. The device was composed of an asymmetric integrating sphere,the image collection and processing system, as well as the electrical control system.The asymmetric integrating sphere had two different radius,which was respectively 800mm and 1000mm.The spectral region was (0.4~1.1)μm, the illumination range was (1×10-4~2×104)lx. The image collection and processing system had two different acquisition card,which were respectively used for analog and digital signals. The software can process for dynamic image or static image. The TracePro software was used to make a internal ray tracing of integrating sphere, the illumination uniformity at the export was simulated for the size of 330mm×230mm and Φ 100mm export, the results were respectively 97.95% and 98.33%. Then,an illuminometer was used to measure the actual illumination uniformity of integrating sphere, the result was shown the actual illumination uniformity was 98.8%. Finally, a visible photoelectric imaging system was tested ,and three different uniformity indicators results were given.

  11. Anisotropic In-Plane Conductivity and Dichroic Gold Plasmon Resonance in Plasma-Assisted ITO Thin Films e-Beam-Evaporated at Oblique Angles.

    PubMed

    Parra-Barranco, Julián; García-García, Francisco J; Rico, Víctor; Borrás, Ana; López-Santos, Carmen; Frutos, Fabián; Barranco, Angel; González-Elipe, Agustín R

    2015-05-27

    ITO thin films have been prepared by electron beam evaporation at oblique angles (OA), directly and while assisting their growth with a downstream plasma. The films microstructure, characterized by scanning electron microscopy, atomic force microscopy, and glancing incidence small-angle X-ray scattering, consisted of tilted and separated nanostructures. In the plasma assisted films, the tilting angle decreased and the nanocolumns became associated in the form of bundles along the direction perpendicular to the flux of evaporated material. The annealed films presented different in-depth and sheet resistivity as confirmed by scanning conductivity measurements taken for the individual nanocolumns. In addition, for the plasma-assisted thin films, two different sheet resistance values were determined by measuring along the nanocolumn bundles or the perpendicular to it. This in-plane anisotropy induces the electrochemical deposition of elongated gold nanostructures. The obtained Au-ITO composite thin films were characterized by anisotropic plasmon resonance absorption and a dichroic behavior when examined with linearly polarized light. PMID:25938593

  12. Dataglove measurement of joint angles in sign language handshapes

    PubMed Central

    Eccarius, Petra; Bour, Rebecca; Scheidt, Robert A.

    2012-01-01

    In sign language research, we understand little about articulatory factors involved in shaping phonemic boundaries or the amount (and articulatory nature) of acceptable phonetic variation between handshapes. To date, there exists no comprehensive analysis of handshape based on the quantitative measurement of joint angles during sign production. The purpose of our work is to develop a methodology for collecting and visualizing quantitative handshape data in an attempt to better understand how handshapes are produced at a phonetic level. In this pursuit, we seek to quantify the flexion and abduction angles of the finger joints using a commercial data glove (CyberGlove; Immersion Inc.). We present calibration procedures used to convert raw glove signals into joint angles. We then implement those procedures and evaluate their ability to accurately predict joint angle. Finally, we provide examples of how our recording techniques might inform current research questions. PMID:23997644

  13. Laser system for distance, velocity, and angle measurements

    NASA Astrophysics Data System (ADS)

    Pienkowski, Janusz; Rzepka, Janusz

    1995-03-01

    The two frequency laser interferometer, using frequency stabilized HeNe laser 0.63 micrometers , is presented in this paper. The system consists of a laser head, meteo station, and measurement display. The laser system fundamentally measures linear displacement (distance) but can also measure velocity and angle. The resolution and the accuracy of measurements are comparable with parameters of lasers systems produced by Hewlett-Packard 5526A and Spindler & Hoyer ZLI 150.

  14. Measure Guideline: Guidance on Taped Insulating Sheathing Drainage Planes

    SciTech Connect

    Grin, A.; Lstiburek, J.

    2014-09-01

    This guide provides information and recommendations to the following groups: insulation contractors; general contractors; builders; home remodelers; mechanical contractors; and homeowners, as a guide to the work that needs to be done. The order of work completed during home construction and retrofit improvements is important. Health and safety issues must be addressed first and are more important than durability issues. And durability issues are more important than saving energy. Not all techniques can apply to all houses. Special conditions will require special action. Some builders or homeowners will wish to do more than the important but basic retrofit strategies outlined by this guide. The following are best practice and product recommendations from the interviewed contractors and homebuilders who collectively have a vast amount of experience. Three significant items were discussed with the group which are required to make taped insulating sheathing a simple, long term, and durable drainage plane: 1. Horizontal joints should be limited or eliminated wherever possible; 2. Where a horizontal joint exists use superior materials; 3. Frequent installation inspection and regular trade training are required to maintain proper installation. Section 5 of this measure guideline contains the detailed construction procedure for the three recommended methods to effectively seal the joints in exterior insulating sheathing to create a simple, long term, and durable drainage plane.

  15. Multiple reflectors based autocollimator for three-dimensional angle measurement

    NASA Astrophysics Data System (ADS)

    Su, Ang; Liu, Haibo; Yu, Qifeng

    2015-03-01

    This paper designs a multiple reflectors based autocollimator, and proposes a direct linear solution for three-dimensional (3D) angle measurement with the observation vectors of the reflected lights from the reflectors. In the measuring apparatus, the multiple reflectors is fixed with the object to be measured and the reflected lights are received by a CCD camera, then the light spots in the image are extracted to obtain the vectors of the reflected lights in space. Any rotation of the object will induce a change in the observation vectors of the reflected lights, which is used to solve the rotation matrix of the object by finding a linear solution of Wahba problem with the quaternion method, and then the 3D angle is obtained by decomposing the rotation matrix. This measuring apparatus can be implemented easily as the light path is simple, and the computation of 3D angle with observation vectors is efficient as there is no need to iterate. The proposed 3D angle measurement method is verified by a set of simulation experiments.

  16. Drop shape visualization and contact angle measurement on curved surfaces.

    PubMed

    Guilizzoni, Manfredo

    2011-12-01

    The shape and contact angles of drops on curved surfaces is experimentally investigated. Image processing, spline fitting and numerical integration are used to extract the drop contour in a number of cross-sections. The three-dimensional surfaces which describe the surface-air and drop-air interfaces can be visualized and a simple procedure to determine the equilibrium contact angle starting from measurements on curved surfaces is proposed. Contact angles on flat surfaces serve as a reference term and a procedure to measure them is proposed. Such procedure is not as accurate as the axisymmetric drop shape analysis algorithms, but it has the advantage of requiring only a side view of the drop-surface couple and no further information. It can therefore be used also for fluids with unknown surface tension and there is no need to measure the drop volume. Examples of application of the proposed techniques for distilled water drops on gemstones confirm that they can be useful for drop shape analysis and contact angle measurement on three-dimensional sculptured surfaces.

  17. Drop shape visualization and contact angle measurement on curved surfaces.

    PubMed

    Guilizzoni, Manfredo

    2011-12-01

    The shape and contact angles of drops on curved surfaces is experimentally investigated. Image processing, spline fitting and numerical integration are used to extract the drop contour in a number of cross-sections. The three-dimensional surfaces which describe the surface-air and drop-air interfaces can be visualized and a simple procedure to determine the equilibrium contact angle starting from measurements on curved surfaces is proposed. Contact angles on flat surfaces serve as a reference term and a procedure to measure them is proposed. Such procedure is not as accurate as the axisymmetric drop shape analysis algorithms, but it has the advantage of requiring only a side view of the drop-surface couple and no further information. It can therefore be used also for fluids with unknown surface tension and there is no need to measure the drop volume. Examples of application of the proposed techniques for distilled water drops on gemstones confirm that they can be useful for drop shape analysis and contact angle measurement on three-dimensional sculptured surfaces. PMID:21889152

  18. A portable system with sample rate of 250 Hz for characterization of knee and hip angles in the sagittal plane during gait

    PubMed Central

    2014-01-01

    Background Gait analysis and research have been developed to obtain characteristics of movement patterns of people while walking. However, traditional measuring systems present different drawbacks that reduce their use and application. Among those drawbacks one can find: high price, low sampling frequency and limiting number of steps to be analyzed. Traditional measuring gait systems carry out their measurement at frequencies oscillating between 60 to 100 Hz. It can be argued about the need of higher sampling rates for gait measurements. However small displacements of the knee or hip for example, cannot be seen with low frequencies required a more detailed sampling and higher frequency sampling. Bearing this in mind, in this paper is presented a 250 Hz system based on accelerometers for gait measurement, and the particularities of knee and hip angles during gait are highlighted. Methods The system was designed with a PCI data acquisition card instrumented with an FPGA to achieve a rate sample of 250 Hz. The accelerometers were placed in thighs and legs to calculate the joint angles of hip and knee in the sagittal plane. The angles were estimated using the acceleration polygon method without integrating the acceleration and without filters. Results The gait of thirty healthy people of Mexican phenotype was analyzed over a flat floor free of obstacles. The results showed the gait phases and particularities associated with the walking style and people's laterality; the movement patterns were similar in the thirty persons. Based on the results, the particularities as the maximum amplitude in the angles and the shape in the movement patterns were related to the anthropometry and people phenotype. Conclusions The sampling frequency was essential to record 340 samples in single gait cycle and so registering the gait cycle with its particularities. In this work were recorded an average of 8 to 10 gait cycles, and the results showed variation regarding works carried out

  19. Roll angle measurement using a polarization scanning reference source

    NASA Astrophysics Data System (ADS)

    Dhadwal, Harbans S.; Rastegar, Jahangir; Kankipati, Varun

    2014-06-01

    On board measurement of attitude position, for example roll angle, of autonomous vehicles is critical to the execution of a successful mission. This paper describes a real-time technique, which combines a polarization scanning reference source and a priori knowledge of the scanning pattern. Measurements in an anechoic chamber, as well as, field tests in a busy parking lot, verify the efficacy of the technique, for both line of sight and non-line of sight capability.

  20. Laser Tracker Calibration - Testing the Angle Measurement System -

    SciTech Connect

    Gassner, Georg; Ruland, Robert; /SLAC

    2008-12-05

    Physics experiments at the SLAC National Accelerator Laboratory (SLAC) usually require high accuracy positioning, e. g. 100 {micro}m over a distance of 150 m or 25 {micro}m in a 10 x 10 x 3 meter volume. Laser tracker measurement systems have become one of the most important tools for achieving these accuracies when mapping components. The accuracy of these measurements is related to the manufacturing tolerances of various individual components, the resolutions of measurement systems, the overall precision of the assembly, and how well imperfections can be modeled. As with theodolites and total stations, one can remove the effects of most assembly and calibration errors by measuring targets in both direct and reverse positions and computing the mean to obtain the result. However, this approach does not compensate for errors originating from the encoder system. In order to improve and gain a better understanding of laser tracker angle measurement tolerances we extended our laboratory's capabilities with the addition of a horizontal angle calibration test stand. This setup is based on the use of a high precision rotary table providing an angular accuracy of better than 0.2 arcsec. Presently, our setup permits only tests of the horizontal angle measurement system. A test stand for vertical angle calibration is under construction. Distance measurements (LECOCQ & FUSS, 2000) are compared to an interferometer bench for distances of up to 32 m. Together both tests provide a better understanding of the instrument and how it should be operated. The observations also provide a reasonable estimate of covariance information of the measurements according to their actual performance for network adjustments.

  1. Does anterior knee pain severity and function relate to the frontal plane projection angle and trunk and hip strength in women with patellofemoral pain?

    PubMed

    Almeida, Gabriel Peixoto Leão; Carvalho E Silva, Ana Paula de Moura Campos; França, Fábio Jorge Renovato; Magalhães, Maurício Oliveira; Burke, Thomaz Nogueira; Marques, Amélia Pasqual

    2015-07-01

    The aim of the present study was to determine the relationship between knee pain severity and function with the frontal plane projection angle (FPPA) and trunk and hip peak torque (PT) in women with patellofemoral pain (PFPS). Twenty-two women with PFPS were assessed. Knee pain severity (KPS) was assessed with an 11-point visual analog scale and function with an Anterior Knee Pain Scale. The FPPA was recorded with a digital camera. PT of extensors, abductors, and the lateral rotators of hip and lateral core stability were measured with a handheld dynamometer. FPPA was the only predictor for the KPS. Regarding predictors of function, PT of lateral core stability and the extensor and abductor of the hip explained 41.4% of the function. Increase in FPPA was associated with greater KPS, and the lowest PT of lateral core stability, hip abductors, and extensors was associated with lower function in women with PFPS.

  2. The effect of oblique angle of sound incidence, realistic edge conditions, curvature and in-plane panel stresses on the noise reduction characteristics of general aviation type panels

    NASA Technical Reports Server (NTRS)

    Grosveld, F.; Lameris, J.; Dunn, D.

    1979-01-01

    Experiments and a theoretical analysis were conducted to predict the noise reduction of inclined and curved panels. These predictions are compared to the experimental results with reasonable agreement between theory and experiment for panels under an oblique angle of sound incidence. Theoretical as well as experimental results indicate a big increase in noise reduction when a flat test panel is curved. Further curving the panel slightly decreases the noise reduction. Riveted flat panels are shown to give a higher noise reduction in the stiffness-controlled frequency region, while bonded panels are superior in this region when the test panel is curved. Experimentally measured noise reduction characteristics of flat aluminum panels with uniaxial in-plane stresses are presented and discussed. These test results indicate an important improvement in the noise reduction of these panels in the frequency range below the fundamental panel/cavity frequency.

  3. Does anterior knee pain severity and function relate to the frontal plane projection angle and trunk and hip strength in women with patellofemoral pain?

    PubMed

    Almeida, Gabriel Peixoto Leão; Carvalho E Silva, Ana Paula de Moura Campos; França, Fábio Jorge Renovato; Magalhães, Maurício Oliveira; Burke, Thomaz Nogueira; Marques, Amélia Pasqual

    2015-07-01

    The aim of the present study was to determine the relationship between knee pain severity and function with the frontal plane projection angle (FPPA) and trunk and hip peak torque (PT) in women with patellofemoral pain (PFPS). Twenty-two women with PFPS were assessed. Knee pain severity (KPS) was assessed with an 11-point visual analog scale and function with an Anterior Knee Pain Scale. The FPPA was recorded with a digital camera. PT of extensors, abductors, and the lateral rotators of hip and lateral core stability were measured with a handheld dynamometer. FPPA was the only predictor for the KPS. Regarding predictors of function, PT of lateral core stability and the extensor and abductor of the hip explained 41.4% of the function. Increase in FPPA was associated with greater KPS, and the lowest PT of lateral core stability, hip abductors, and extensors was associated with lower function in women with PFPS. PMID:26118529

  4. Mid-sagittal plane and mid-sagittal surface optimization in brain MRI using a local symmetry measure

    NASA Astrophysics Data System (ADS)

    Stegmann, Mikkel B.; Skoglund, Karl; Ryberg, Charlotte

    2005-04-01

    This paper describes methods for automatic localization of the mid-sagittal plane (MSP) and mid-sagittal surface (MSS). The data used is a subset of the Leukoaraiosis And DISability (LADIS) study consisting of three-dimensional magnetic resonance brain data from 62 elderly subjects (age 66 to 84 years). Traditionally, the mid-sagittal plane is localized by global measures. However, this approach fails when the partitioning plane between the brain hemispheres does not coincide with the symmetry plane of the head. We instead propose to use a sparse set of profiles in the plane normal direction and maximize the local symmetry around these using a general-purpose optimizer. The plane is parameterized by azimuth and elevation angles along with the distance to the origin in the normal direction. This approach leads to solutions confirmed as the optimal MSP in 98 percent of the subjects. Despite the name, the mid-sagittal plane is not always planar, but a curved surface resulting in poor partitioning of the brain hemispheres. To account for this, this paper also investigates an optimization strategy which fits a thin-plate spline surface to the brain data using a robust least median of squares estimator. Albeit computationally more expensive, mid-sagittal surface fitting demonstrated convincingly better partitioning of curved brains into cerebral hemispheres.

  5. Making Sense by Measuring Arcs: A Teaching Experiment in Angle Measure

    ERIC Educational Resources Information Center

    Moore, Kevin C.

    2013-01-01

    I discuss a teaching experiment that sought to characterize precalculus students' angle measure understandings. The study's findings indicate that the students initially conceived angle measures in terms of geometric objects. As the study progressed, the students formed more robust understandings of degree and radian measures by constructing an…

  6. On Orbit Measurement of Response vs. Scan Angle for the Infrared Bands on TRMM/VIRS

    NASA Technical Reports Server (NTRS)

    Barnes, William L.; Lyu, Cheng-Hsuan; Barnes, Robert A.

    1999-01-01

    The Visible and Infrared Scanner on the Tropical Rainfall Measuring Mission (TRMM/VIRS) is a whiskbroom imaging radiometer with two reflected solar bands and three emissive infrared bands. All five detectors are on a single cooled focal plane. This configuration necessitated the use of a paddlewheel scan mirror to avoid the effects of focal plane rotation that arise when using a scan mirror that is inclined to its axis of rotation. System radiometric requirements led to the need for protected silver as the mirror surface. Unfortunately, the SiO(x) coatings currently used to protect silver from oxidation introduce a change in reflectance with angle of incidence (AOI). This AOI dependence results in a modulation of system level response with scan angle. Measurement of system response vs. scan angle (RVS) was not difficult for the VIRS reflected solar bands, but attaining the required accuracy for the IR bands in the laboratory was not possible without a large vacuum chamber and a considerable amount of custom designed testing apparatus. Therefore, the decision was made to conduct the measurement on-orbit. On three separate occasions, the TRMM spacecraft was rotated about its pitch axis and, after the nadir view passed over the Earth's limb, the VIRS performed several thousand scans while viewing deep space. The resulting data has been analyzed and the RVS curves generated for the three IR bands are being used in the VIRS radiometric calibration algorithm. This, to our knowledge, the first time this measurement has been made on-orbit. Similar measurements are planned for the EOS-AM and EOS-PM MODIS sensors and are being considered for several systems under development. The VIRS on-orbit results will be compared to VIRS and MODIS system level laboratory measurements, MODIS scan mirror witness sample measurements and modeled data.

  7. A preliminary study into the effect of jumping-landing training and strength training on frontal plane projection angle.

    PubMed

    Herrington, Lee; Munro, Allan; Comfort, Paul

    2015-10-01

    The presence of increased knee valgus angles during functional tasks has been associated with a range of knee pathologies. A number of different exercise interventions have been undertaken to improve knee alignment during functional tasks. The most successful of these interventions are multi-modal incorporating both strength and jump-landing training. Little research has been undertaken to compare these elements individually to assess if success is due to an individual element or the training as a whole. The study assessed the between group effects of strength training or jump-landing training alone on knee valgus alignment during a number of functional tasks, using a cohort specific treatment superiority design. Thirty asymptomatic female participants undertook a 6 week (minimum 15 sessions) strength or jump-landing programme, the effects of which were examined by assessing for any change in frontal plane projection angle (FPPA) during single leg squat and landing and bilateral drop jump landing. Both training methods had positive effects of FPPA during some but not all of the tasks. Strength training brought about significant changes in FPPA during single leg squat and landing, whilst jump-landing training significantly influenced single leg landing and drop jump landing performance. The changes reported, therefore appear to be related to the nature of the training and the tasks undertaken during that training. The findings indicating that a combined training protocol incorporating both strengthening and jump-landing training may bring about the greatest improvement across a spectrum of tasks for the patient, supporting the previous work on multimodal training. PMID:25920339

  8. Spirality: A Noval Way to Measure Spiral Arm Pitch Angle

    NASA Astrophysics Data System (ADS)

    Shields, Douglas W.; Boe, Benjamin; Henderson, Casey L.; Hartley, Matthew; Davis, Benjamin L.; Pour Imani, Hamed; Kennefick, Daniel; Kennefick, Julia D.

    2015-01-01

    We present the MATLAB code Spirality, a novel method for measuring spiral arm pitch angles by fitting galaxy images to spiral templates of known pitch. For a given pitch angle template, the mean pixel value is found along each of typically 1000 spiral axes. The fitting function, which shows a local maximum at the best-fit pitch angle, is the variance of these means. Error bars are found by varying the inner radius of the measurement annulus and finding the standard deviation of the best-fit pitches. Computation time is typically on the order of 2 minutes per galaxy, assuming at least 8 GB of working memory. We tested the code using 128 synthetic spiral images of known pitch. These spirals varied in the number of spiral arms, pitch angle, degree of logarithmicity, radius, SNR, inclination angle, bar length, and bulge radius. A correct result is defined as a result that matches the true pitch within the error bars, with error bars no greater than ±7°. For the non-logarithmic spiral sample, the correct answer is similarly defined, with the mean pitch as function of radius in place of the true pitch. For all synthetic spirals, correct results were obtained so long as SNR > 0.25, the bar length was no more than 60% of the spiral's diameter (when the bar was included in the measurement), the input center of the spiral was no more than 6% of the spiral radius away from the true center, and the inclination angle was no more than 30°. The synthetic spirals were not deprojected prior to measurement. The code produced the correct result for all barred spirals when the measurement annulus was placed outside the bar. Additionally, we compared the code's results against 2DFFT results for 203 visually selected spiral galaxies in GOODS North and South. Among the entire sample, Spirality's error bars overlapped 2DFFT's error bars 64% of the time. For those galaxies in which Source code is available by email request from the primary author.

  9. Developments in moire interferometry for out-of-plane displacement measurement

    NASA Astrophysics Data System (ADS)

    Asundi, A.; Cheung, M. T.

    Moire interferometry is used to measure out-of-plane displacements with very high sensitivity. The experimental set-up is similar to that used for in-plane displacement measurement with a small modification. In the in-plane method, the deformed real specimen grating interferes with the fixed virtual reference grating to produce the moire fringes; while for the out-of-plane displacement method, the deformed virtual grating interferes with a real reference grating to produce the moire pattern.

  10. Investigation vignetting beams in optoelectronic autocollimation angle measurement system

    NASA Astrophysics Data System (ADS)

    Konyakhin, Igor; Sakhariyanova, Aiganym M.; Smekhov, Andrey

    2015-06-01

    Autocollimation systems are widely used to measure angular values, in particular, angular deformations in the critical points of large objects, angles of optical components, and for controlling the straightness and parallelism. Autocollimator measures the rotation angle of the mirror as the sensitive element at angular deformation point with a potential accuracy up to 0.005 ". In fact, the error may significantly exceed the specified value because of systematic error existence, one of which main components is the error due to vignetting of working beam. The reason of vignetting error is changing of irradiance distribution of the image on the autocollimator analyzer due to cutting of a bundle of optical beams at a mirror deviation in case of angular deformation. On the basis of a computer simulation image model was investigated the influence of vignetting error and was found compensation algorithm of this error

  11. 12C(p,p‧) scattering measurement at forward angles

    NASA Astrophysics Data System (ADS)

    Tamii, A.; Adachi, T.; Fujita, K.; Hatanaka, K.; Hashimoto, H.; Itoh, M.; Matsubara, H.; Nakanishi, K.; Sakemi, Y.; Shimbara, Y.; Shimizu, Y.; Tameshige, Y.; Yosoi, M.; Fujita, Y.; Sakaguchi, H.; Zenihiro, J.; Kawabata, T.; Sasamoto, Y.; Dozono, M.; Carter, J.; Fujita, H.; Rubio, B.; Perez, A.

    Experimental method of measuring inelastic proton scattering with high-resolution at forward angles including zero degrees has been developed. An energy resolution of 20 keV and a scattering angle resolution of 0.5 degrees have been achieved as well as low background condition and a reliable background subtraction method. The experimental technique was applied to the 12C(p,p‧) reaction for studying the property of the second 0+ state at 7.7 MeV and a broad bump around Ex~10 MeV, where the presence of a 2+ state was reported from the 12C(α,α‧) measurement. Preliminary spectra and angular distributions are shown.

  12. Contact Angle Measurements Using a Simplified Experimental Setup

    ERIC Educational Resources Information Center

    Lamour, Guillaume; Hamraoui, Ahmed; Buvailo, Andrii; Xing, Yangjun; Keuleyan, Sean; Prakash, Vivek; Eftekhari-Bafrooei, Ali; Borguet, Eric

    2010-01-01

    A basic and affordable experimental apparatus is described that measures the static contact angle of a liquid drop in contact with a solid. The image of the drop is made with a simple digital camera by taking a picture that is magnified by an optical lens. The profile of the drop is then processed with ImageJ free software. The ImageJ contact…

  13. Angle-dependent infrared reflectance measurements in support of VIIRS

    NASA Astrophysics Data System (ADS)

    Kaplan, Simon G.; Iglesias, Enrique J.; Hanssen, Leonard M.

    2008-08-01

    We have developed a goniometric reflectometer using a Fourier-transform infrared (FTIR) spectrometer source for polarized reflectance measurements from 1 μm to 20 μm wavelength at angles of incidence from 10° to 80°, with an incident beam geometry of approximately f/25. Measurements are performed in either absolute mode, or relative to a reference mirror that has been calibrated at near-normal incidence using an integrating sphere-based reflectometer. Uncertainties in the 0.2 % to 0.5 % range are achieved using a photoconductive 77 K InSb detector from 1 μm to 5 μm and a 12 K Si:As BIB detector from 2 μm to 20 μm. The performance of the system has been tested using dielectric materials such as Si as well as high-quality Au mirrors. We describe measurements of SiOx-coated Ag mirrors to assess their performance for such applications as the half-angle mirror (HAM) in the VIIRS optical scanning system. Various coatings are analyzed to help assess the effect of p-polarized absorption bands at angles of incidence from 10° to 65° and wavelengths between 3 μm and 13 μm.

  14. Estimation of the in-plane vibrations of a rotating spindle, using out-of-plane laser vibrometry measurements

    NASA Astrophysics Data System (ADS)

    Tatar, Kourosh; Gren, Per

    2016-05-01

    A method for estimating the in-plane vibrations of a rotating spindle using out-of-plane laser vibrometry measurements is described. This method enables the possibility to obtain the two orthogonal radial vibration components of a rotating spindle. The method uses the fact that the laser vibrometer signal is a total surface velocity of the measurement point in the laser direction. Measurements are conducted on a rotating milling machine spindle. The spindle is excited in a controlled manner by an active magnetic bearing and the response is measured by laser vibrometer in one of the two orthogonal directions and inductive displacement sensors in two orthogonal directions simultaneously. The work shows how the laser vibrometry crosstalk can be used for resolving the in-plane vibration component, that is the vibrations in the laser vibrometer cross direction. The result is compared to independent measurement signals from the displacement sensors. The measurement method can be used for vibration measurements on rotating parts, for example, where there is lack of space for orthogonal measurements.

  15. An Experimental Study on the Iso-Content-Based Angle Similarity Measure.

    ERIC Educational Resources Information Center

    Zhang, Jin; Rasmussen, Edie M.

    2002-01-01

    Retrieval performance of the iso-content-based angle similarity measure within the angle, distance, conjunction, disjunction, and ellipse retrieval models is compared with retrieval performance of the distance similarity measure and the angle similarity measure. Results show the iso-content-based angle similarity measure achieves satisfactory…

  16. Measurement of the CKM Angle Alpha at BaBar

    SciTech Connect

    Yeche, C.; /Saclay

    2006-04-14

    We present BABAR experiment studies to measure the CKM angle {alpha} of the Unitarity Triangle. The measurements are based on the B meson decays into the two-body state ({pi}{pi}), the quasi two-body state ({rho}{rho}), and the three-body state ({pi}{sup +}{pi}{sup -}{pi}{sup 0}). The results are obtained from data samples of about 230 million {Upsilon}(4S) {yields} B{bar B} decays collected between 1999 and 2004 with the BABAR detector at the PEP-II asymmetric-energy B Factory at SLAC.

  17. Angle resolved scatter measurement of bulk scattering in transparent ceramics

    NASA Astrophysics Data System (ADS)

    Sharma, Saurabh; Miller, J. Keith; Shori, Ramesh K.; Goorsky, Mark S.

    2015-02-01

    Bulk scattering in polycrystalline laser materials (PLM), due to non-uniform refractive index across the bulk, is regarded as the primary loss mechanism leading to degradation of laser performance with higher threshold and lower output power. The need for characterization techniques towards identifying bulk scatter and assessing the quality. Assessment of optical quality and the identification of bulk scatter have been by simple visual inspection of thin samples of PLMs, thus making the measurements highly subjective and inaccurate. Angle Resolved Scatter (ARS) measurement allows for the spatial mapping of scattered light at all possible angles about a sample, mapping the intensity for both forward scatter and back-scatter regions. The cumulative scattered light intensity, in the forward scatter direction, away from the specular beam is used for the comparison of bulk scattering between samples. This technique employ the detection of scattered light at all angles away from the specular beam directions and represented as a 2-D polar map. The high sensitivity of the ARS technique allows us to compare bulk scattering in different PLM samples which otherwise had similar transmitted beam wavefront distortions.

  18. Modeled and measured image-plane polychromatic speckle contrast

    NASA Astrophysics Data System (ADS)

    Van Zandt, Noah R.; McCrae, Jack E.; Fiorino, Steven T.

    2016-02-01

    The statistical properties of speckle relevant to short- to medium-range (tactical) active tracking involving polychromatic illumination are investigated. A numerical model is developed to allow rapid simulation of speckled images including the speckle contrast reduction effects of illuminator bandwidth, surface slope, and roughness, and the polarization properties of both the source and the reflection. Regarding surface slope (relative orientation of the surface normal and illumination/observation directions), Huntley's theory for speckle contrast, which employs geometrical approximations to decrease computation time, is modified to increase accuracy by incorporation of a geometrical correction factor and better treatment of roughness and polarization. The resulting model shows excellent agreement with more exact theory over a wide range. An experiment is conducted to validate both the numerical model developed here and existing theory. A diode laser source with coherence length of 259±7 μm is reflected off of a silver-coated diffuse surface. Speckle data are gathered for 16 surface slope angles corresponding to speckle contrast between about 0.55 and 1. Taking the measured data as truth, both equations show error mean and standard deviation of less than 3%. Thus, the theory is validated over the range of this experiment.

  19. Simultaneous Multi-angle Measurements of Plasma Turbulence at HAARP

    NASA Astrophysics Data System (ADS)

    Watanabe, Naomi; Golkowski, Mark; Sheerin, James; University of Colorado Denver Team

    2013-10-01

    We report the results from a recent series of experiments employing the HAARP HF transmitter to generate and study strong Langmuir turbulence (SLT) in the interaction region of overdense ionospheric plasma. Diagnostics included the Modular UHF Ionospheric Radar (MUIR) located at HAARP, the Super DARN-Kodiak HF radar, and HF receivers to record stimulated electromagnetic emissions (SEE). Short pulse, low duty cycle experiments demonstrate control and suppression of artificial field-aligned irregularities (AFAI). This allows the isolation of ponderomotive plasma turbulence effects. For the first time, plasma line spectra measured simultaneously in different spots of the interaction region displayed marked but contemporaneous differences dependent on the aspect angle of the HF pump beam and the pointing angle of the MUIR diagnostic radar. Outshifted Plasma Line (OPL) spectra, rarely observed in past experiments, occurred with sufficient regularity for experimentation. Experimental results are compared to previous high latitude experiments and predictions from recent modeling efforts.

  20. Comparison of Angle of Attack Measurements for Wind Tunnel Testing

    NASA Technical Reports Server (NTRS)

    Jones, Thomas, W.; Hoppe, John C.

    2001-01-01

    Two optical systems capable of measuring model attitude and deformation were compared to inertial devices employed to acquire wind tunnel model angle of attack measurements during the sting mounted full span 30% geometric scale flexible configuration of the Northrop Grumman Unmanned Combat Air Vehicle (UCAV) installed in the NASA Langley Transonic Dynamics Tunnel (TDT). The overall purpose of the test at TDT was to evaluate smart materials and structures adaptive wing technology. The optical techniques that were compared to inertial devices employed to measure angle of attack for this test were: (1) an Optotrak (registered) system, an optical system consisting of two sensors, each containing a pair of orthogonally oriented linear arrays to compute spatial positions of a set of active markers; and (2) Video Model Deformation (VMD) system, providing a single view of passive targets using a constrained photogrammetric solution whose primary function was to measure wing and control surface deformations. The Optotrak system was installed for this test for the first time at TDT in order to assess the usefulness of the system for future static and dynamic deformation measurements.

  1. A comparison of the 3D kinematic measurements obtained by single-plane 2D-3D image registration and RSA.

    PubMed

    Muhit, Abdullah A; Pickering, Mark R; Ward, Tom; Scarvell, Jennie M; Smith, Paul N

    2010-01-01

    3D computed tomography (CT) to single-plane 2D fluoroscopy registration is an emerging technology for many clinical applications such as kinematic analysis of human joints and image-guided surgery. However, previous registration approaches have suffered from the inaccuracy of determining precise motion parameters for out-of-plane movements. In this paper we compare kinematic measurements obtained by a new 2D-3D registration algorithm with measurements provided by the gold standard Roentgen Stereo Analysis (RSA). In particular, we are interested in the out-of-plane translation and rotations which are difficult to measure precisely using a single plane approach. Our experimental results show that the standard deviation of the error for out-of-plane translation is 0.42 mm which compares favourably to RSA. It is also evident that our approach produces very similar flexion/extension, abduction/adduction and external knee rotation angles when compared to RSA.

  2. The measurement and modelling of light scattering by phytoplankton cells at narrow forward angles

    NASA Astrophysics Data System (ADS)

    MacCallum, Iain; Cunningham, Alex; McKee, David

    2004-07-01

    A procedure has been devised for measuring the angular dependence of light scattering from suspensions of phytoplankton cells at forward angles from 0.25° to 8°. The cells were illuminated with a spatially-filtered laser beam and the angular distribution of scattered light measured by tracking a photodetector across the Fourier plane of a collecting lens using a stepper-motor driven stage. The procedure was calibrated by measuring scattering from latex bead suspensions with known size distributions. It was then used to examine the scattering from cultures of the unicellular algae Isochrysis galbana (4 µm × 5 µm), Dunaliella primolecta (6 µm × 7 µm) and Rhinomonas reticulata (5 µm × 11 µm). The results were compared with the predictions of Mie theory. Excellent agreement was obtained for spherical particles. A suitable choice of spherical-equivalent scattering parameters was required to enable reasonable agreement within the first diffraction lobe for ellipsoidal particles.

  3. Coming to Understand Angle and Angle Measure: A Design-Based Research Curriculum Study Using Context-Aware Ubiquitous Learning

    ERIC Educational Resources Information Center

    Crompton, Helen

    2013-01-01

    This study uses design-based research (DBR) to develop an empirically-substantiated instructional theory about students' development of angle and angle measure, with real-world connections and technological tools through the use of context-aware ubiquitous learning. The research questions guiding this research are: 1) How do students come to…

  4. G0 Electronics and Data Acquisition (Forward-Angle Measurements)

    SciTech Connect

    D. Marchand; J. Arvieux; L. Bimbot; A. Biselli; J. Bouvier; H. Breuer; R. Clark; J.-C. Cuzon; M. Engrand; R. Foglio; C. Furget; X. Grave; B. Guillon; H. Guler; P.M. King; S. Kox; J. Kuhn; Y. Ky; J. Lachniet; J. Lenoble; E. Liatard; J. Liu; E. Munoz; J. Pouxe; G. Quéméne; B. Quinn; J.-S. Réal; O. Rossetto; R. Sellem

    2007-04-18

    The G$^0$ parity-violation experiment at Jefferson Lab (Newport News, VA) is designed to determine the contribution of strange/anti-strange quark pairs to the intrinsic properties of the proton. In the forward-angle part of the experiment, the asymmetry in the cross section was measured for $\\vec{e}p$ elastic scattering by counting the recoil protons corresponding to the two beam-helicity states. Due to the high accuracy required on the asymmetry, the G$^0$ experiment was based on a custom experimental setup with its own associated electronics and data acquisition (DAQ) system. Highly specialized time-encoding electronics provided time-of-flight spectra for each detector for each helicity state. More conventional electronics was used for monitoring (mainly FastBus). The time-encoding electronics and the DAQ system have been designed to handle events at a mean rate of 2 MHz per detector with low deadtime and to minimize helicity-correlated systematic errors. In this paper, we outline the general architecture and the main features of the electronics and the DAQ system dedicated to G$^0$ forward-angle measurements.

  5. Investigating hard sphere interactions through spin echo scattering angle measurement

    NASA Astrophysics Data System (ADS)

    Washington, Adam

    Spin Echo Scattering Angle Measurement (SESAME) allows neutron scattering instruments to perform real space measurements on large micron scale samples by encoding the scattering angle into the neutron's spin state via Larmor precession. I have built a SESAME instrument at the Low Energy Neutron Source. I have also assisted in the construction of a modular SESAME instrument on the ASTERIX beamline at Los Alamos National lab. The ability to tune these instruments has been proved mathematically and optimized and automated experimentally. Practical limits of the SESAME technique with respect to polarization analyzers, neutron spectra, Larmor elements, and data analysis were investigated. The SESAME technique was used to examine the interaction of hard spheres under depletion. Poly(methyl methacrylate) spheres suspended in decalin had previously been studied as a hard sphere solution. The interparticle correlations between the spheres were found to match the Percus-Yevick closure, as had been previously seen in dynamical light scattering experiments. To expand beyond pure hard spheres, 900kDa polystyrene was added to the solution in concentrations of less than 1% by mass. The steric effects of the polystyrene were expected to produce a short-range, attractive, "sticky" potential. Experiment showed, however, that the "sticky" potential was not a stable state and that the spheres would eventually form long range aggregates.

  6. Understanding Angle and Angle Measure: A Design-Based Research Study Using Context Aware Ubiquitous Learning

    ERIC Educational Resources Information Center

    Crompton, Helen

    2015-01-01

    Mobile technologies are quickly becoming tools found in the educational environment. The researchers in this study use a form of mobile learning to support students in learning about angle concepts. Design-based research is used in this study to develop an empirically-substantiated local instruction theory about students' develop of angle and…

  7. High-resolution Angle Measurement based on Michelson Interferometry

    NASA Astrophysics Data System (ADS)

    Cheng, Fang; Fan, Kuang-Chao

    In this paper a reconfigured Michelson interferometer for high-resolution angle measurement is proposed. The anglular displacement of the object mirror will cause optical path difference that generates interference. With an optical phase shift module the photodetectors will collect quadrature signals with 90° phase shift. With pulse counting and phase subdivision processing the optical path change can be calculated and then converted to anglular displacement. The proposed structure is also featured by its miniature design. The optical system is only 55 mm by 55 mm in area. In order to facilitate the alignment of optical components and improve the signal quality, a new optical bonding technology by mechanical fixture is proposed so that the optics can be permanently pressed together without air gap in between. Experiments show that the resolution is 0.01", the accuracy is less than 0.03", and the repeatability is within 0.1" for the measurement range of ± 50 arc seconds.

  8. Note: Differential amplified high-resolution tilt angle measurement system.

    PubMed

    Zhao, Shijie; Li, Yan; Zhang, Enyao; Huang, Pei; Wei, Haoyun

    2014-09-01

    A high-resolution tilt angle measurement system is presented in this paper. In this system, the measurement signal is amplified by two steps: (1) amplified by operational amplifier and (2) differential amplified by two MEMS-based inclinometers. The novel application not only amplifies the signal but, more importantly, substantially reduces the electrical interference and common-mode noise among the same circuit design. Thus, both the extremely high resolution and great long-term stability are achieved in this system. Calibrated by an autocollimator, the system shows a resolution of 2 arc sec. The accuracy is better than ±1.5 arc sec. The zero-drift error is below ±1 arc sec and ±2 arc sec in the short and long term, respectively.

  9. Note: Differential amplified high-resolution tilt angle measurement system

    NASA Astrophysics Data System (ADS)

    Zhao, Shijie; Li, Yan; Zhang, Enyao; Huang, Pei; Wei, Haoyun

    2014-09-01

    A high-resolution tilt angle measurement system is presented in this paper. In this system, the measurement signal is amplified by two steps: (1) amplified by operational amplifier and (2) differential amplified by two MEMS-based inclinometers. The novel application not only amplifies the signal but, more importantly, substantially reduces the electrical interference and common-mode noise among the same circuit design. Thus, both the extremely high resolution and great long-term stability are achieved in this system. Calibrated by an autocollimator, the system shows a resolution of 2 arc sec. The accuracy is better than ±1.5 arc sec. The zero-drift error is below ±1 arc sec and ±2 arc sec in the short and long term, respectively.

  10. High accuracy subwavelength distance measurements: A variable-angle standing-wave total-internal-reflection optical microscope

    SciTech Connect

    Haynie, A.; Min, T.-J.; Luan, L.; Mu, W.; Ketterson, J. B.

    2009-04-15

    We describe an extension of the total-internal-reflection microscopy technique that permits direct in-plane distance measurements with high accuracy (<10 nm) over a wide range of separations. This high position accuracy arises from the creation of a standing evanescent wave and the ability to sweep the nodal positions (intensity minima of the standing wave) in a controlled manner via both the incident angle and the relative phase of the incoming laser beams. Some control over the vertical resolution is available through the ability to scan the incoming angle and with it the evanescent penetration depth.

  11. Fractal dimension and unscreened angles measured for radial viscous fingering.

    PubMed

    Praud, Olivier; Swinney, Harry L

    2005-07-01

    We have examined fractal patterns formed by the injection of air into oil in a thin (0.127 mm) layer contained between two cylindrical glass plates of 288 mm diameter (a Hele-Shaw cell), for pressure differences in the range 0.25 < or = DeltaP < or = 1.75 atm. We find that an asymptotic structure is reached at large values of the ratio r/b, where r is the pattern radius and b the gap between the plates. Both the driving force and the size of the pattern, which reaches r/b = 900, are far larger than in past experiments. The fractal dimension D0 of the pattern for large r/b is 1.70 +/- 0.02. Further, the generalized dimensions D(q) of the pattern are independent of q , D(q) approximately 1.70 for the range examined, -11 < q < 17; thus the pattern is self-similar within the experimental uncertainty. The results for D(q) agree well with recent calculations for diffusion-limited aggregation (DLA) clusters. We have also measured the probability distribution of unscreened angles. At late times, the distribution approaches a universal (i.e., forcing and size-independent) asymptotic form that has mean 145 degrees Celsius and standard deviation 36 degrees Celsius. These results indicate that the distribution function for the unscreened angle is an invariant property of the growth process. PMID:16089960

  12. Polarimetric spectra analysis for tokamak pitch angle measurements

    NASA Astrophysics Data System (ADS)

    Ko, J.; Chung, J.; Lange, A. G. G.; de Bock, M. F. M.

    2013-10-01

    Measurements of the internal magnetic field structures using conventional polarimetric approaches are considered extremely challenging in fusion-reactor environments whereas the information on current density profiles is essential to establish steady-state and advance operation scenarios in such reactor-relevant devices. Therefore, on ITER a hybrid system is proposed for the current density measurements that uses both polarimetry and spectral measurements. The spectrum-based approaches have been tested in the Korea Superconducting Tokamak Advanced Research (KSTAR) during the past two plasma campaigns. As such, KSTAR is a test-bed for the proposed ITER hybrid system. Measurements in the plasma core are based on the motional Stark effect (MSE) spectrum of the neutral beam emission. For the edge profiles, the Zeeman effect (ZE) acting on the lithium emission spectrum of the newly installed (2013) Lithium-beam-diagnostic is exploited. The neutral beam emission spectra, complicated by the multi-ion-source beam injection, are successfully fitted making use of the data provided by the Atomic Data and Analysis Structure (ADAS) database package. This way pitch angle profiles could be retrieved from the beam emission spectra. With the same spectrometer/CCD hardware as on MSE, but with a different wavelength range and different lines of sight, the first ZE spectrum measurements have been made. The Zeeman splitting comparable to and greater than the instrumental broadening has been routinely detected at high toroidal field operations ( ~ 3 Tesla).

  13. Reliability of sagittal plane hip, knee, and ankle joint angles from a single frame of video data using the GAITRite camera system.

    PubMed

    Ross, Sandy A; Rice, Clinton; Von Behren, Kristyn; Meyer, April; Alexander, Rachel; Murfin, Scott

    2015-01-01

    The purpose of this study was to establish intra-rater, intra-session, and inter-rater, reliability of sagittal plane hip, knee, and ankle angles with and without reflective markers using the GAITRite walkway and single video camera between student physical therapists and an experienced physical therapist. This study included thirty-two healthy participants age 20-59, stratified by age and gender. Participants performed three successful walks with and without markers applied to anatomical landmarks. GAITRite software was used to digitize sagittal hip, knee, and ankle angles at two phases of gait: (1) initial contact; and (2) mid-stance. Intra-rater reliability was more consistent for the experienced physical therapist, regardless of joint or phase of gait. Intra-session reliability was variable, the experienced physical therapist showed moderate to high reliability (intra-class correlation coefficient (ICC) = 0.50-0.89) and the student physical therapist showed very poor to high reliability (ICC = 0.07-0.85). Inter-rater reliability was highest during mid-stance at the knee with markers (ICC = 0.86) and lowest during mid-stance at the hip without markers (ICC = 0.25). Reliability of a single camera system, especially at the knee joint shows promise. Depending on the specific type of reliability, error can be attributed to the testers (e.g. lack of digitization practice and marker placement), participants (e.g. loose fitting clothing) and camera systems (e.g. frame rate and resolution). However, until the camera technology can be upgraded to a higher frame rate and resolution, and the software can be linked to the GAITRite walkway, the clinical utility for pre/post measures is limited.

  14. Influences of reference plane and direction of measurement on eye aberration measurement

    NASA Astrophysics Data System (ADS)

    Atchison, David A.; Charman, W. Neil

    2005-12-01

    We explored effects of measurement conditions on wave aberration estimates for uncorrected, axially myopic model eyes. Wave aberrations were initially referenced to either the anterior corneal pole or the natural entrance pupil of symmetrical eye models, with rays traced into the eye from infinity (into the eye) to simulate normal vision, into the eye from infinity and then back out of the eye from the retinal intercepts (into/out of the eye), or out of the eye from the retinal fovea (out of the eye). The into-the-eye and out-of-the-eye ray traces gave increases in spherical aberration as myopia increased, but the into/out-of-the-eye ray trace showed little variation in spherical aberration. Reference plane choice also affected spherical aberration. Corresponding residual aberrations were calculated after the models had been optically corrected, either by placing the object or image plane at the paraxial far point or by modifying corneas to simulate laser ablation corrections. Correcting aberrations by ablation was more complete if the original aberrations were referenced to the cornea rather than to the entrance pupil. For eyes corrected by spectacle lenses, failure to allow for effects of pupil magnification on apparent entrance pupil diameter produced larger changes in measured aberrations. The general findings regarding choice of reference plane and direction of measurement were found to be equally applicable to eyes that lacked rotational symmetry.

  15. Reliable measurement of 3D foot bone angles based on the frame-of-reference derived from a sole of the foot

    NASA Astrophysics Data System (ADS)

    Kim, Taeho; Lee, Dong Yeon; Park, Jinah

    2016-03-01

    Clinical management of foot pathology requires accurate and robust measurement of the anatomical angles. In order to measure a 3D angle, recent approaches have adopted a landmark-based local coordinate system to establish bone angles used in orthopedics. These measurement methods mainly assess the relative angle between bones using a representative axis derived from the morphological feature of the bone and therefore, the results can be affected by bone deformities. In this study, we propose a method of deriving a global frame-of-reference to acquire consistent direction of the foot by extracting the undersurface of the foot from the CT image data. The two lowest positions of the foot skin are identified from the surface to define the base plane, and the direction from the hallux to the fourth toe is defined together to construct the global coordinate system. We performed the experiment on 10 volumes of foot CT images of healthy subjects to verify that the proposed method provides reliable measurements. We measured 3D angles for talus-calcaneus and talus-navicular using facing articular surfaces of paired bones. The angle was reported in 3 projection angles based on both coordinate systems defined by proposed global frame-of-reference and by CT image planes (saggital, frontal, and transverse). The result shows that the quantified angle using the proposed method considerably reduced the standard deviation (SD) against the angle using the conventional projection planes, and it was also comparable with the measured angles obtained from local coordinate systems of the bones. Since our method is independent from any individual local shape of a bone, unlike the measurement method using the local coordinate system, it is suitable for inter-subject comparison studies.

  16. IR OPTICS MEASUREMENT WITH LINEAR COUPLING'S ACTION-ANGLE PARAMETERIZATION.

    SciTech Connect

    LUO, Y.; BAI, M.; PILAT, R.; SATOGATA, T.; TRBOJEVIC, D.

    2005-05-16

    A parameterization of linear coupling in action-angle coordinates is convenient for analytical calculations and interpretation of turn-by-turn (TBT) beam position monitor (BPM) data. We demonstrate how to use this parameterization to extract the twiss and coupling parameters in interaction regions (IRs), using BPMs on each side of the long IR drift region. The example of TBT BPM analysis was acquired at the Relativistic Heavy Ion Collider (RHIC), using an AC dipole to excite a single eigenmode. Besides the full treatment, a fast estimate of beta*, the beta function at the interaction point (IP), is provided, along with the phase advance between these BPMs. We also calculate and measure the waist of the beta function and the local optics.

  17. Measurements of the CKM Angle Alpha at BaBar

    SciTech Connect

    Stracka, Simone; /Milan U. /INFN, Milan

    2012-04-04

    The authors present improved measurements of the branching fractions and CP-asymmetries fin the B{sup 0} {yields} {pi}{sup +}{pi}{sup -}, B{sup 0} {yields} {pi}{sup 0}{pi}{sup 0}, and B{sup +} {yields} {rho}{sup +}{rho}{sup 0} decays, which impact the determination of {alpha}. The combined branching fractions of B {yields} K{sub 1}(1270){pi} and B {yields} K{sub 1}(1400){pi} decays are measured for the first time and allow a novel determination of {alpha} in the B{sup 0} {yields} {alpha}{sub 1}(1260){sup {+-}}{pi}{sup {-+}} decay channel. These measurements are performed using the final dataset collected by the BaBar detector at the PEP-II B-factory. The primary goal of the experiments based at the B factories is to test the Cabibbo-Kobayashi-Maskawa (CKM) picture of CP violation in the standard model of electroweak interactions. This can be achieved by measuring the angles and sides of the Unitarity Triangle in a redundant way.

  18. In-plane motion measurement by using digital sampling moiré method

    NASA Astrophysics Data System (ADS)

    Chen, Xinxing; Chang, Chih-Chen

    2016-04-01

    Digital sampling moiré (DSM) method is a newly developed vision-based technique that uses the phase information of moiré fringes to measure movement of an object. The moiré fringes are generated from a sequence of digital images, containing a cosinusoidal grating pattern attached to the object, through down-sampling and interpolation. As the moiré fringes can magnify the pattern's movement, this technique is expected to provide more accurate displacement measurement than the other vision based approaches. In this study, a method combining DSM with monocular videogrammetric technique is proposed to measure in-plane rotation and translation of structures. In this method, images of a two-dimensional (2D) grating pattern attached to a moving structure are acquired and decomposed into two perpendicular gratings through Fourier transform. The DSM method is used to obtain 2D phase distributions of the gratings which provide an estimation of physical coordinates for those points on the grating pattern. A previously developed monocular videogrammetric technique can then be used to obtain the rotation angle and the translation of the grating pattern. The proposed method is validated using both numerical simulation and laboratory tests.

  19. A Scheme for Solving the Plane-Plane Challenge in Force Measurements at the Nanoscale

    NASA Astrophysics Data System (ADS)

    Siria, Alessandro; Huant, Serge; Auvert, Geoffroy; Comin, Fabio; Chevrier, Joel

    2010-08-01

    Non-contact interaction between two parallel flat surfaces is a central paradigm in sciences. This situation is the starting point for a wealth of different models: the capacitor description in electrostatics, hydrodynamic flow, thermal exchange, the Casimir force, direct contact study, third body confinement such as liquids or films of soft condensed matter. The control of parallelism is so demanding that no versatile single force machine in this geometry has been proposed so far. Using a combination of nanopositioning based on inertial motors, of microcrystal shaping with a focused-ion beam (FIB) and of accurate in situ and real-time control of surface parallelism with X-ray diffraction, we propose here a “gedanken” surface-force machine that should enable one to measure interactions between movable surfaces separated by gaps in the micrometer and nanometer ranges.

  20. A scheme for solving the plane-plane challenge in force measurements at the nanoscale.

    PubMed

    Siria, Alessandro; Huant, Serge; Auvert, Geoffroy; Comin, Fabio; Chevrier, Joel

    2010-05-19

    Non-contact interaction between two parallel flat surfaces is a central paradigm in sciences. This situation is the starting point for a wealth of different models: the capacitor description in electrostatics, hydrodynamic flow, thermal exchange, the Casimir force, direct contact study, third body confinement such as liquids or films of soft condensed matter. The control of parallelism is so demanding that no versatile single force machine in this geometry has been proposed so far. Using a combination of nanopositioning based on inertial motors, of microcrystal shaping with a focused-ion beam (FIB) and of accurate in situ and real-time control of surface parallelism with X-ray diffraction, we propose here a "gedanken" surface-force machine that should enable one to measure interactions between movable surfaces separated by gaps in the micrometer and nanometer ranges.

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

    SciTech Connect

    Tao, X. D.; Feng, Z.; Miao, B. F.; Sun, L.; You, B.; Wu, D.; Du, J.; Zhang, W.; Ding, H. F.

    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.

  2. Results from electrostatic calibrations for measuring the Casimir force in the cylinder-plane geometry

    SciTech Connect

    Wei, Q.; Dalvit, D. A. R.; Lombardo, F. C.; Mazzitelli, F. D.; Onofrio, R.

    2010-05-15

    We report on measurements performed on an apparatus aimed to study the Casimir force in the cylinder-plane configuration. The electrostatic calibrations evidence anomalous behaviors in the dependence of the electrostatic force and the minimizing potential upon distance. We discuss analogies and differences of these anomalies with respect to those already observed in the sphere-plane configuration. At the smallest explored distances we observe frequency shifts of non-Coulombian nature preventing the measurement of the Casimir force in the same range. We also report on measurements performed in the parallel-plane configuration, showing that the dependence on distance of the minimizing potential, if present at all, is milder than in the sphere-plane or cylinder-plane geometries. General considerations on the interplay between the distance-dependent minimizing potential and the precision of Casimir force measurements in the range relevant to detect the thermal corrections for all geometries are finally reported.

  3. Accuracy Improvement on the Measurement of Human-Joint Angles.

    PubMed

    Meng, Dai; Shoepe, Todd; Vejarano, Gustavo

    2016-03-01

    A measurement technique that decreases the root mean square error (RMSE) of measurements of human-joint angles using a personal wireless sensor network is reported. Its operation is based on virtual rotations of wireless sensors worn by the user, and it focuses on the arm, whose position is measured on 5 degree of freedom (DOF). The wireless sensors use inertial magnetic units that measure the alignment of the arm with the earth's gravity and magnetic fields. Due to the biomechanical properties of human tissue (e.g., skin's elasticity), the sensors' orientation is shifted, and this shift affects the accuracy of measurements. In the proposed technique, the change of orientation is first modeled from linear regressions of data collected from 15 participants at different arm positions. Then, out of eight body indices measured with dual-energy X-ray absorptiometry, the percentage of body fat is found to have the greatest correlation with the rate of change in sensors' orientation. This finding enables us to estimate the change in sensors' orientation from the user's body fat percentage. Finally, an algorithm virtually rotates the sensors using quaternion theory with the objective of reducing the error. The proposed technique is validated with experiments on five different participants. In the DOF, whose error decreased the most, the RMSE decreased from 2.20(°) to 0.87(°). This is an improvement of 60%, and in the DOF whose error decreased the least, the RMSE decreased from 1.64(°) to 1.37(°). This is an improvement of 16%. On an average, the RMSE improved by 44%. PMID:25622331

  4. Cryocup - Compact spherical neutron polarimetry device for small angle measurement

    NASA Astrophysics Data System (ADS)

    Wang, Tianhao

    In my thesis I describe my research work of developing a compact device for Spherical Neutron Polarimetry (SNP) measurements at small neutron scattering angles. The thesis first introduced the purpose of this research project, which is developing an easy to use and maintain version of an advanced neutron experiment technique (SNP). After the introduction, the design principle and construction detail of the prototype device is demonstrated. The design principle is based on our finite element simulation of the device's magnetic field profile, and is later verified by the performance test experiment. The prototype device is tested at the SESAME neutron beamline at Indiana University and the HB-2D beamline at Oak Ridge National laboratory. The performance test data are analyzed and proof that the design is successful and the prototype is capable of perform accurate SNP measurement. Based on the test result, the prototype device is utilized to perform SNP measurement on two types of magnetic film sample: Permalloy and Metglas. Combined with other characterization method such as SQUID and MFM, I study the magnetization of these two samples both at zero magnetic field environment and in external field. The SNP data provided by the prototype device is discussed in the thesis and provide detailed information about the magnetization, which is also not accessible through other method. In the end, the possible improvement and the future application of the device is discussed.

  5. Sunspot group tilt angle measurements from historical observations

    NASA Astrophysics Data System (ADS)

    Senthamizh Pavai, V.; Arlt, R.; Diercke, A.; Denker, C.; Vaquero, J. M.

    2016-10-01

    Sunspot positions from various historical sets of solar drawings are analyzed with respect to the tilt angles of bipolar sunspot groups. Data by Scheiner, Hevelius, Staudacher, Zucconi, Schwabe, and Spörer deliver a series of average tilt angles spanning a period of 270 years, additional to previously found values for 20th-century data obtained by other authors. We find that the average tilt angles before the Maunder minimum were not significantly different from the modern values. However, the average tilt angles of a period 50 years after the Maunder minimum, namely for cycles 0 and 1, were much lower and near zero. The normal tilt angles before the Maunder minimum suggest that it was not abnormally low tilt angles which drove the solar cycle into a grand minimum.

  6. Measuring the 13 Neutrino Mixing Angle and the CP Phase with Neutrino Telescopes

    SciTech Connect

    Serpico, P.D.; Kachelriess, M.

    2005-06-03

    The observed excess of high-energy cosmic rays from the Galactic plane in the energy range around 10{sup 18} eV may be explained by neutron primaries generated in the photodissociation of heavy nuclei. In this scenario, lower-energy neutrons decay before reaching the Earth and produce a detectable flux in a 1 km{sup 3} neutrino telescope. The initial flavor composition of the neutrino flux, {phi}({nu}{sub e}):{phi}({nu}{sub {mu}}):{phi}({nu}{sub {tau}})=1:0:0, permits a combined {nu}{sub {mu}}/{nu}{sub {tau}} appearance and {nu}{sub e} disappearance experiment. The observable flux ratio {phi}({nu}{sub {mu}})/{phi}({nu}{sub e}+{nu}{sub {tau}}) at Earth depends on the 13 mixing angle {theta}{sub 13} and the leptonic CP phase {delta}{sub CP}, thus opening a new way to measure these two quantities.

  7. Dihedral angle entropy measures for intrinsically disordered proteins.

    PubMed

    Cukier, Robert I

    2015-03-01

    Protein stability is based on a delicate balance between energetic and entropic factors. Intrinsically disordered proteins (IDPs) interacting with a folded partner protein in the act of binding can order the IDP to form the correct functional interface by decrease in the overall free energy. In this work, we evaluate the part of the entropic cost of ordering an IDP arising from their dihedral states. The IDP studied is a leucine zipper dimer that we simulate with molecular dynamics and find that it does show disorder in six phi and psi dihedral angles of the N terminal sequence of one monomer. Essential to ascertain is the degree of disorder in the IDP, and we do so by considering the entire, discretized probability distribution function of N dihedrals with M conformers per dihedral. A compositional clustering method is introduced, whereby the NS = N(M) states are formed from the Cartesian product of each dihedral's conformational space. Clustering is carried out with a version of a k-means algorithm that accounts for the circular nature of dihedral angles. For the 12 dihedrals each found to have three conformers, among the resulting 531441 states, their populations show that the first 100 (500) most populated states account for ∼65% (∼90%) of the entire population, indicating that there are strong dependencies among the dihedrals' conformations. These state populations are used to evaluate a Kullback-Leibler divergence entropy measure and obtain the dihedral configurational entropy S. At 300 K, TS ∼ 3 kcal/mol, showing that IDP entropy, while roughly half that would be expected from independently distributed dihedrals, can be a decisive contributor to the free energy of this IDP binding and ordering.

  8. Out-of-plane (e , 2 e) measurements on He autoionizing levels using a novel electron gun

    NASA Astrophysics Data System (ADS)

    Weaver, C. M.; Martin, N. L. S.; Deharak, B. A.; Bartschat, K.

    2015-05-01

    In previous work we reported preliminary out-of-scattering-plane (e , 2 e) measurements for helium 2 l 2l' autoionizing levels at 150 eV incident electron energy and scattering angle 39.2°. The results were presented as (e , 2 e) angular distributions energy-integrated over each level, and were compared with our previous experiments and theory at 488eV incident electron energy and scattering angle 20.5°. The geometry is the same in both cases: ejected electrons are detected in a plane that contains the momentum transfer direction and is perpendicular to the scattering plane, and the momentum transfer is 2.1 a.u. in both cases. It was found that both experiments gave the same angular distributions, but only if instrument function corrections were ignored for the 150 eV experiment. We have now installed a new electron gun with a well controlled and narrow spatial profile. We will present new data with instrument function corrections applied. This work was supported by the National Science Foundation under grants Nos. PHY-0855040 (NLSM), PHY-1402899 (BAdH), and PHY-1212450 (KB).

  9. Effects of myofascial release leg pull and sagittal plane isometric contract-relax techniques on passive straight-leg raise angle.

    PubMed

    Hanten, W P; Chandler, S D

    1994-09-01

    Experimental evidence does not currently exist to support the claims of clinical effectiveness for myofascial release techniques. This presents an obvious need to document the effects of myofascial release. The purpose of this study was to compare the effects of two techniques, sagittal plane isometric contract-relax and myofascial release leg pull for increasing hip flexion range of motion (ROM) as measured by the angle of passive straight-leg raise. Seventy-five nondisabled, female subjects 18-29 years of age were randomly assigned to contract-relax, leg pull, or control groups. Pretest hip flexion ROM was measured for each subject's right hip with a passive straight-leg raise test using a fluid-filled goniometer. Subjects in the treatment groups received either contract-relax or leg pull treatment applied to the right lower extremity; subjects in the control group remained supine quietly for 5 minutes. Following treatment, posttest straight-leg raise measurements were performed. A one-way analysis of variance followed by a Newman-Keuls post hoc comparison of mean gain scores showed that subjects receiving contract-relax treatment increased their ROM significantly more than those who received leg pull treatment, and the increase in ROM of subjects in both treatment groups was significantly higher than those of the control group. The results suggest that while both contract-relax and leg pull techniques can significantly increase hip flexion ROM in normal subjects, contract-relax treatment may be more effective and efficient than leg pull treatment.

  10. Directional-sensitive differential laser Doppler vibrometry for in-plane motion measurement of specular surface

    NASA Astrophysics Data System (ADS)

    Agusanto, Kusuma; Lau, Gih-Keong; Wu, Kun; Liu, Ting; Zhu, Chuangui; Yuan, Ling

    2015-03-01

    A new method for measuring in-plane vibration velocity of glossy and specular surface using differential laser Doppler vibrometer (LDV) is proposed in this work. A standard tangential LDV using similar differential configuration is only able to measure in-plane velocity of objects with rough surface, due to its inherent on-axis optical design that collects backscatter light along its optical axis. The proposed method adopts an off-axis detection scheme, in which the photodetector is decoupled from LDV, and placed along the dominant direction of the scattered light. For optimal placement, the bidirectional reflectance distribution function (BRDF) of the sample must be considered ideally, but in our measurement tests, the off-axis detection along the direction of specular reflection is sufficient to obtain good measurement results. Another advantage with this setup is that it also works with the objects with rough surface. Experimental works using the standard tangential LDV and a prototype of this method were conducted to measure the in-plane motion of four different samples representing rough, glossy and mirror-like surface. An electrodynamic shaker was used to provide the in-plane motion of the samples at three different frequencies. A single point axial vibrometer was used to validate the in-plane velocity of the measurement from both in-plane LDVs. Some preliminary results showed that the in-plane motion of the object with glossy and specular surface can be measured using the proposed method.

  11. Measurements of Reflected and Transmitted Energies Near the Critical Angle

    ERIC Educational Resources Information Center

    Shaw, D. E.; And Others

    1973-01-01

    Describes the theoretical principles and experimental arrangement in determining the transmission and reflection coefficients for polarizations which are parallel and perpendicular to the plane of incidence. Indicates an error of the order of five percent in the results obtained. (CC)

  12. Stratospheric turbulence measurements and models for aerospace plane design

    NASA Technical Reports Server (NTRS)

    Ehernberger, L. J.

    1992-01-01

    Progress in computational atmospheric dynamics is exhibiting the ability of numerical simulation to describe instability processes associated with turbulence observed at altitudes between 15 and 25 km in the lower stratosphere. As these numerical simulation tools mature, they can be used to extend estimates of atmospheric perturbations from the present gust database for airplane design at altitudes below 15 km to altitudes between 25 and 50 km where aerospace plane operation would be at hypersonic speeds. The amount of available gust data and number of temperature perturbation observations are limited at altitudes between 15 and 25 km. On the other hand, in-situ gust data at higher altitudes are virtually nonexistent. The uncertain potential for future airbreathing hypersonic flight research vehicles to encounter strong turbulence at higher altitudes could penalize the design of these vehicles by undue cost or limitations on performance. Because the atmospheric structure changes markedly with altitude, direct extrapolation of gust magnitudes and encounter probabilities to the higher flight altitudes is not advisable. This paper presents a brief review of turbulence characteristics observed in the lower stratosphere and highlights the progress of computational atmospheric dynamics that may be used to estimate the severity of atmospheric transients at higher altitudes.

  13. Effects of stifle flexion angle and scan plane on visibility of the normal canine cranial cruciate ligament using low-field magnetic resonance imaging.

    PubMed

    Podadera, Juan; Gavin, Patrick; Saveraid, Travis; Hall, Evelyn; Chau, Jennifer; Makara, Mariano

    2014-01-01

    Low-field magnetic resonance imaging (MRI) is commonly used to evaluate dogs with suspected cranial cruciate ligament injury; however, effects of stifle positioning and scan plane on visualization of the ligament are incompletely understood. Six stifle joints (one pilot, five test) were collected from dogs that were scheduled for euthanasia due to reasons unrelated to the stifle joint. Each stifle joint was scanned in three angles of flexion (90°, 135°, 145°) and eight scan planes (three dorsal, three axial, two sagittal), using the same low-field MRI scanner and T2-weighted fast spin echo scan protocol. Two experienced observers who were unaware of scan technique independently scored visualization of the cranial cruciate ligament in each scan using a scale of 0-3. Visualization score rank sums were higher when the stifle was flexed at 90° compared to 145°, regardless of the scan plane. Visualization scores for the cranial cruciate ligament in the dorsal (H (2) = 19.620, P = 0.000), axial (H (2) = 14.633, P = 0.001), and sagittal (H (2) = 8.143, P = 0.017) planes were significantly affected by the angle of stifle flexion. Post hoc analysis showed that the ligament was best visualized at 90° compared to 145° in the dorsal (Z = -3.906, P = 0.000), axial (Z = -3.398, P = 0.001), and sagittal (Z = -2.530, P = 0.011) planes. Findings supported the use of a 90° flexed stifle position for maximizing visualization of the cranial cruciate ligament using low-field MRI in dogs. PMID:24450293

  14. IN-PLANE MODAL TESTING OF A FREE ISOTROPIC PLATE USING LASER DOPPLER VIBROMETER MEASUREMENTS

    SciTech Connect

    Batista, F. B.; Fabro, A. T.; Coser, L. F.; Arruda, J. R. F.; Albuquerque, E. L.

    2010-05-28

    In this work an experimental procedure is proposed to obtain the lowest free in-plane vibration modes of an aluminum plate. Responses are measured along two longitudinal directions on the plate surface at selected points by an out-of-plane laser Doppler vibrometer set up to measure in-plane vibrations. Excitation is made at one specific point of the plate edge using a light impact hammer. The plate is supported by silicone spheres to simulate the free edge boundary conditions and ensure a stable stationary position in order to keep the laser focus distance. Numerical finite element simulations are carried out to compute the in-plane modes and frequencies in order to compare them with the corresponding experimental results. The identified experimental modes agree very well with the numerical predictions. The smooth in-plane modes can be used to identify the plate material constitutive model parameters using existing methods proposed elsewhere by the authors.

  15. Sensor for measuring instantaneous angle of attack of helicopter blades

    NASA Technical Reports Server (NTRS)

    Barna, P. S.

    1980-01-01

    Systematic investigations were performed on a variety of probes to determine their potential for possible application as sensors attached to helicopter blades to measure both the instantaneous angle of attack as well as the dynamic head during actual flight operations. After some preliminary considerations a sensor of essentially spherical shape, about 30 mm in diameter, was designed. The sensor was provided with three pressure ports, and it housed two pressure transducers required for sensing the prevailing pressures acting outside on the surface. The sensors were subsequently tested in the laboratory under a variety of flow conditions to determine their aerodynamic characteristics. Two series of tests were performed: in the first series the sensor was fixed in space while exposed to steady uniform flow, while in the second series the sensor was made to oscillate, thus simulating the cyclic pitch change of the helicopter blades. While the cyclic pitch frequencies were of about the same magnitude as encountered in flight, the flow velocities during tests fell well below those experienced in a rotating blade. The tests showed that the sensors performed satisfactorily under low subsonic flow conditions with frequencies not exceeding five Hz.

  16. Efficient visible through SWIR focal plane MTF measurement

    NASA Astrophysics Data System (ADS)

    Malone, Neil; Fierro, Josh; Troup, Richard; Willberger, Gary; Wyles, Jessica; Boe, Raymond; Dixon, Andrew

    2015-09-01

    Raytheon Vision Systems (RVS) has developed an efficient method to measure MTF on Visible through MWIR small pixel FPAs. The measured data was obtained using an advanced but low cost test set with sub μm target projection on the FPA and real time display of the LSF as the slit is walked through focus. The test set is commercially procured, maintained and calibrated, provides target and filter holders and a light source. The analysis summary includes references from simplified MTF published analysis tools and a list of artifacts to be aware of when measuring MTF. The SWIR and MWIR detectors have a Mesa structure geometry for improved MTF performance and the Visible has state of the art crosstalk control to provide excellent MTF performance. The modeled data is compared to measured tilted slit MTF measured data and shows close agreement.

  17. A two-axis in-plane motion measurement system based on optical beam deflection

    SciTech Connect

    Sriramshankar, R.; Mrinalini, R. Sri Muthu; Jayanth, G. R.

    2013-10-15

    Measurement of in-plane motion with high resolution and large bandwidth enables model-identification and real-time control of motion-stages. This paper presents an optical beam deflection based system for measurement of in-plane motion of both macro- and micro-scale motion stages. A curved reflector is integrated with the motion stage to achieve sensitivity to in-plane translational motion along two axes. Under optimal settings, the measurement system is shown to theoretically achieve sub-angstrom measurement resolution over a bandwidth in excess of 1 kHz and negligible cross-sensitivity to linear motion. Subsequently, the proposed technique is experimentally demonstrated by measuring the in-plane motion of a piezo flexure stage and a scanning probe microcantilever. For the former case, reflective spherical balls of different radii are employed to measure the in-plane motion and the measured sensitivities are shown to agree with theoretical values, on average, to within 8.3%. For the latter case, a prototype polydimethylsiloxane micro-reflector is integrated with the microcantilever. The measured in-plane motion of the microcantilever probe is used to identify nonlinearities and the transient dynamics of the piezo-stage upon which the probe is mounted. These are subsequently compensated by means of feedback control.

  18. Autocollimating systems for roll angle measurement of large-scale object deformation

    NASA Astrophysics Data System (ADS)

    Turgalieva, Tatyana V.; Konyakhin, Igor A.

    2015-05-01

    Autocollimating systems for roll angle measurement with tetrahedral reflector, which has the small deviation from 90° in two dihedral angles between reflecting sides is considered. Established that autocollimator scheme with symmetrical track of the beam relative to roll axis with addition re-reflection allow implement precision measurement roll angle.

  19. Measurement of Critical Contact Angle in a Microgravity Space Experiment

    NASA Technical Reports Server (NTRS)

    Concus, P.; Finn, R.; Weislogel, M.

    1998-01-01

    Mathematical theory predicts that small changes in container shape or in contact angle can give rise to large shifts of liquid in a microgravity environment. This phenomenon was investigated in the Interface Configuration Experiment on board the USMT,2 Space Shuttle flight. The experiment's "double proboscis" containers were designed to strike a balance between conflicting requirements of sizable volume of liquid shift (for ease of observation) and abruptness of the shift (for accurate determination of critical contact angle). The experimental results support the classical concept of macroscopic contact angle and demonstrate the role of hysteresis in impeding orientation toward equilibrium.

  20. Measurement of Critical Contact Angle in a Microgravity Space Experiment

    NASA Technical Reports Server (NTRS)

    Concus, P.; Finn, R.; Weislogel, M.

    1998-01-01

    Mathematical theory predicts that small changes in container shape or in contact angle can give rise to large shifts of liquid in a microgravity environment. This phenomenon was investigated in the Interface Configuration Experiment on board the USML-2 Space Shuttle flight. The experiment's "double proboscis" containers were designed to strike a balance between conflicting requirements of sizable volume of liquid shift (for ease of observation) and abruptness of the shift (for accurate determination of critical contact angle). The experimental results support the classical concept of macroscopic contact angle and demonstrate the role of hysteresis in impeding orientation toward equilibrium.

  1. Measurement of critical contact angle in a microgravity space experiment

    NASA Astrophysics Data System (ADS)

    Concus, P.; Finn, R.; Weislogel, M.

    Mathematical theory predicts that small changes in container shape or in contact angle can give rise to large shifts of liquid in a microgravity environment. This phenomenon was investigated in the Interface Configuration Experiment on board the NASA USML-2 Space Shuttle flight. The experiment's ``double proboscis'' containers were designed to strike a balance between conflicting requirements of sizable volume of liquid shift (for ease of observation) and abruptness of the shift (for accurate determination of critical contact angle). The experimental results support the classical concept of macroscopic contact angle and demonstrate the role of hysteresis in impeding orientation toward equilibrium.

  2. Measurement of critical contact angle in a microgravity space experiment

    SciTech Connect

    Concus, P.; Finn, R.; Weislogel, M.

    1999-06-01

    Mathematical theory predicts that small changes in container shape or in contact angle can give rise to large shifts of liquid in a microgravity environment. This phenomenon was investigated in the Interface Configuration Experiment on board the NASA USML-2 Space Shuttle flight. The experiment's double proboscis containers were designed to strike a balance between conflicting requirements of sizable volume of liquid shift (for ease of observation) and abruptness of the shift (for accurate determination of critical contact angle). The experimental results support the classical concept of macroscopic contact angle and demonstrate the role of hysteresis in impeding orientation toward equilibrium.

  3. Versatile wide angle diffraction setup for simultaneous wide and small angle x-ray scattering measurements with synchrotron radiation

    SciTech Connect

    Rueda, D.R.; Garcia-Gutierrez, M.C.; Nogales, A.; Capitan, M.J.; Ezquerra, T.A.; Labrador, A.; Fraga, E.; Beltran, D.; Juanhuix, J.; Herranz, J.F.; Bordas, J.

    2006-03-15

    Here we present a novel, simple, and versatile experimental setup aimed to perform wide angle x-ray scattering (WAXS) measurements alone or in simultaneous combination with small angle x-ray scattering measurements. The design of the WAXS goniometer allows one to obtain high resolution diffraction patterns in a broad angular range. The setup can incorporate a hot stage in order to evaluate temperature resolved experiments. The performance of the equipment has been verified in the BM16 beam line of the European Synchrotron Radiation Facility with different well known samples such as alumina, isotropic film of high density polyethylene (HDPE), and oriented HPDE fiber.

  4. The execution of systematic measurements on plane cascades

    NASA Technical Reports Server (NTRS)

    Scholz, N.

    1978-01-01

    The present state of development of the experimental technique regarding the flow through cascades and several points to be specially observed in the design of cascade wind tunnels were discussed. The equations required for the evaluation of the momentum measurements in two dimensional flow through cascades were developed. Regarding the effect of the jet contraction due to the boundary layer along the side walls a simple method for correction was also given in order to obtain two dimensional flow characteristics. Also given were the equations for the evaluation of the pressure distribution measurements. Another contribution was made regarding the presentation of the test results in the form of nondimensional quantities. The results of systematic measurements of cascades with symmetrical aerofoil were reported, and the above suggested method was applied for the evaluation of the measurements.

  5. Measurements of the CKM Angle phi3/gamma

    SciTech Connect

    Tisserand, Vincent; /Annecy, LAPP

    2007-06-27

    We present a review on the measurements of the CKM angle {gamma} ({phi}{sub 3}){sup 1} as performed by the BABAR and Belle experiments at the asymmetric-energy e{sup +}e{sup -} B factories colliders PEP-II and KEKB. These measurements are using either charged or neutral B decays. For charged B decays the modes {tilde D}{sup 0}K{sup -}, {tilde D}*{sup 0}K{sup -}, and {tilde D}{sup 0}K*{sup -} are employed, where {tilde D}{sup 0} indicates either a D{sup 0} or a {bar D}{sup 0} meson. Direct CP violation is exploited. It is caused by interferences between V{sub ub} and V{sub cb} accessible transitions that generate asymmetries in the final states. For these decays various methods exist to enhance the sensitivity to the V{sub ub} transition, carrying the weak phase {gamma}. For neutral B decays, the modes D{sup (*){+-}}{pi}{sup {-+}} and D{sup {+-}}{rho}{sup {-+}} are used. In addition to the V{sub ub} and V{sub cb} interferences, these modes are sensitive to the B{sup 0}-{bar B}{sup 0} mixing, so that time dependent analyses are performed to extract sin(2{beta} + {gamma}). An alternative method would use the lower branching ratios decay modes {tilde D}{sup (*)0}{bar K}{sup (*)0} where much larger asymmetries are expected. The various available methods are mostly ''theoretically clean'' and always free of penguins diagrams. In some cases a high sensitivity to {gamma} is expected and large asymmetries may be seen. But these measurements are always experimentally difficult as one has to face with either low branching ratios, or small asymmetries, or additional technical/theoretical difficulties due to Dalitz/SU(3) and re-scattering models needed to treat/estimate nuisance parameters such as unknown strong phases and the relative magnitude of the amplitude of the interfering ''V{sub ub}'' transitions. Thus at the present time only a relatively limited precision on {gamma} can be extracted from these measurements. The current world average is {gamma} = (78{sub -26}{sup +19

  6. Beyond the plane-parallel and Newtonian approach: wide-angle redshift distortions and convergence in general relativity

    SciTech Connect

    Bertacca, Daniele; Maartens, Roy; Raccanelli, Alvise; Clarkson, Chris E-mail: Roy.Maartens@port.ac.uk E-mail: Clarkson@maths.uct.ac.za

    2012-10-01

    We extend previous analyses of wide-angle correlations in the galaxy power spectrum in redshift space to include all general relativistic effects. These general relativistic corrections to the standard approach become important on large scales and at high redshifts, and they lead to new terms in the wide-angle correlations. We show that in principle the new terms can produce corrections of nearly 10% on Gpc scales over the usual Newtonian approximation. General relativistic corrections will be important for future large-volume surveys such as SKA and Euclid, although the problem of cosmic variance will present a challenge in observing this.

  7. Continual in-plane displacement measurement with temporal wavelet transform speckle pattern interferometry.

    PubMed

    Gao, Zhan; Deng, Yan; Duan, Yiting; Zhang, Zhifeng; Wei, Cheng; Chen, Shiqian; Cui, Jianying; Feng, Qibo

    2012-01-01

    A heterodyne temporal speckle pattern interferometer that measures the in-plane displacement dynamically has been built. The object is displaced in its plane continuously and the frequency-modulated output signals with a carrier frequency are recorded by a CCD camera. The displacement information is extracted with wavelet transform technique. Preliminary experiments have been performed with such interferometer. The respective measurement results recovered from wavelet transform and Fourier transform are compared.

  8. Computer-aided method for automated selection of optimal imaging plane for measurement of total cerebral blood flow by MRI

    NASA Astrophysics Data System (ADS)

    Teng, Pang-yu; Bagci, Ahmet Murat; Alperin, Noam

    2009-02-01

    A computer-aided method for finding an optimal imaging plane for simultaneous measurement of the arterial blood inflow through the 4 vessels leading blood to the brain by phase contrast magnetic resonance imaging is presented. The method performance is compared with manual selection by two observers. The skeletons of the 4 vessels for which centerlines are generated are first extracted. Then, a global direction of the relatively less curved internal carotid arteries is calculated to determine the main flow direction. This is then used as a reference direction to identify segments of the vertebral arteries that strongly deviates from the main flow direction. These segments are then used to identify anatomical landmarks for improved consistency of the imaging plane selection. An optimal imaging plane is then identified by finding a plane with the smallest error value, which is defined as the sum of the angles between the plane's normal and the vessel centerline's direction at the location of the intersections. Error values obtained using the automated and the manual methods were then compared using 9 magnetic resonance angiography (MRA) data sets. The automated method considerably outperformed the manual selection. The mean error value with the automated method was significantly lower than the manual method, 0.09+/-0.07 vs. 0.53+/-0.45, respectively (p<.0001, Student's t-test). Reproducibility of repeated measurements was analyzed using Bland and Altman's test, the mean 95% limits of agreements for the automated and manual method were 0.01~0.02 and 0.43~0.55 respectively.

  9. On the angle between the average interplanetary magnetic field and the propagation direction of plane large amplitude Alfven waves

    NASA Technical Reports Server (NTRS)

    Lichtenstein, B. R.; Sonett, C. P.

    1979-01-01

    The paper shows that the experimentally observed close alignment of magnetic field minimum variance direction with the average magnetic field for Alfven waves in the solar wind is consistent with theoretically predicted properties of plane large amplitude Alfven waves in the MHD approximation. The theoretical properties of these Alfven waves constrain the time averaged magnetic field to cluster around the direction of minimum variance, which is aligned with the wave normal. Thus, spacecraft magnetometer observations in the solar wind of minimum variance directions strongly peaked about the average magnetic field direction are consistent with plane large amplitude Alfven waves which have wave normals aligned with the directions of minimum variance. This does not imply that geometrical hydromagnetic calculations for Alfven wave propagation direction in the solar wind are incorrect, but there is a discrepancy between geometrical hydromagnetics theory and observations that IMF minimum variance directions tend to be aligned with the ideal Parker spiral instead of the radial direction.

  10. The combined effect of frontal plane tibiofemoral knee angle and meniscectomy on the cartilage contact stresses and strains.

    PubMed

    Yang, Nicholas; Nayeb-Hashemi, Hamid; Canavan, Paul K

    2009-11-01

    Abnormal tibiofemoral alignment can create loading conditions at the knee that may lead to the initiation and progression of knee osteoarthritis (OA). The degenerative changes of the articular cartilage may occur earlier and with greater severity in individuals with abnormal frontal plane tibiofemoral alignment who undergo a partial or total meniscectomy. In this investigation, subject specific 3D finite element knee models were created from magnetic resonance images of two female subjects to study the combined effect of frontal plane tibiofemoral alignment and total and partial meniscectomy on the stress and strain at the knee cartilage. Different amounts of medial and lateral meniscectomies were modeled and subject specific loading conditions were determined from motion analysis and force platform data during single-leg support. The results showed that the maximum stresses and strains occurred on the medial tibial cartilage after medial meniscectomy but a greater percentage change in the contact stresses and strains occurred in the lateral cartilage after lateral meniscectomy for both subjects due to the resultant greater load bearing role of the lateral meniscus. The results indicate that individual's frontal plane knee alignment and their unique local force distribution between the cartilage and meniscus play an important role in the biomechanical effects of total and partial meniscectomy.

  11. Measurement of in-plane strain with dual beam spatial phase-shift digital shearography

    NASA Astrophysics Data System (ADS)

    Xie, Xin; Chen, Xu; Li, Junrui; Wang, Yonghong; Yang, Lianxiang

    2015-11-01

    Full-field in-plane strain measurement under dynamic loading by digital shearography remains a big challenge in practice. A phase measurement for in-plane strain information within one time frame has to be achieved to solve this problem. This paper presents a dual beam spatial phase-shift digital shearography system with the capacity to measure phase distribution corresponding to in-plane strain information within a single time frame. Two laser beams with different wavelengths are symmetrically arranged to illuminate the object under test, and two cameras with corresponding filters, which enable simultaneous recording of two shearograms, are utilized for data acquisition. The phase information from the recorded shearograms, which corresponds to the in-plane strain, is evaluated by the spatial phase-shift method. The spatial phase-shift shearography system realizes a measurement of the in-plane strain through the introduction of the spatial phase-shift technique, using one frame after the loading and one frame before loading. This paper presents the theory of the spatial phase-shift digital shearography for in-plane strain measurement and its derivation, experimental results, and the technique’s potential.

  12. Integrated application of gravity and seismic methods for determining the dip angle of a fault plane: Case of Mahjouba fault (Central Tunisian Atlas Province, North Africa)

    NASA Astrophysics Data System (ADS)

    Gabtni, H.; Hajji, O.; Jallouli, C.

    2016-07-01

    A procedure for a dip angle determination of a fault plane from gravity field data is presented to constrain a seismic profile interpretation. This procedure is applied on Mahjouba normal fault at the western border of Kalaa Khesba graben (Central Tunisian Atlas Province, North Africa). Seismic and detailed gravity data, in this region, were analyzed to provide more constraints on the geometry of the fault dip angle. The Mahjouba fault is mapped as three major parallel lineaments extended for 2 km with a NW-SE to N-S trend. The dip of the Mahjouba fault is estimated from the gravity modeling data to be 45°E. This study reveals that integrating gravity and seismic data provides accurate mapping of faults geometry and such result provides useful information and constraints on the exploration of natural resources.

  13. Integrated application of gravity and seismic methods for determining the dip angle of a fault plane: Case of Mahjouba fault (Central Tunisian Atlas Province, North Africa)

    NASA Astrophysics Data System (ADS)

    Gabtni, H.; Hajji, O.; Jallouli, C.

    2016-07-01

    A procedure for a dip angle determination of a fault plane from gravity field data is presented to constrain a seismic profile interpretation. This procedure is applied on Mahjouba normal fault at the western border of Kalaa Khesba graben (Central Tunisian Atlas Province, North Africa). Seismic and detailed gravity data, in this region, were analyzed to provide more constraints on the geometry of the fault dip angle. The Mahjouba fault is mapped as three major parallel lineaments extended for 2 km with a NW-SE to N-S trend. The dip of the Mahjouba fault is estimated from the gravity modeling data to be 45°E. This study reveals that integrating gravity and seismic data provides accurate mapping of faults geometry and such result provides useful information and constraints on the exploration of natural resources.

  14. Out-of-plane (e , 2 e) measurements on He autoionizing levels at 80, 150, and 488 eV

    NASA Astrophysics Data System (ADS)

    Martin, N. L. S.; Kim, B. N.; Weaver, C. M.; Deharak, B. A.; Bartschat, K.

    2016-05-01

    We report out-of-scattering-plane (e , 2 e) measurements on helium 2 l 2l' autoionizing levels for 80, 150, and 488 eV incident electron energies, and scattering angles 60°, 39. 2°, and 20. 5°, respectively. The kinematics are the same in all cases: ejected electrons are detected in a plane that contains the momentum transfer direction and is perpendicular to the scattering plane, and the momentum transfer is 2.1 a.u.. The 80 eV results complete our sets of measurements at low, intermediate, and high, incident energies. The results are presented as (e , 2 e) angular distributions energy-integrated over each level, and are compared with our theory calculated for 488 eV incident electron energy. The 150 eV and 488 eV experiments are characterized by recoil peaks appropriate to each autoionizing level. However, for the 80 eV angular distributions, these recoil peaks are largely absent for all levels, including the 3 P level observed at this energy. This work was supported by the National Science Foundation under Grants Nos. PHY-0855040 (NLSM), PHY-1402899 (BAdH), and PHY-1212450 (KB).

  15. LONG-TERM MEASUREMENTS OF SUNSPOT MAGNETIC TILT ANGLES

    SciTech Connect

    Li Jing; Ulrich, Roger K.

    2012-10-20

    Tilt angles of close to 30,600 sunspots are determined using Mount Wilson daily averaged magnetograms taken from 1974 to 2012, and SOHO/MDI magnetograms taken from 1996 to 2010. Within a cycle, more than 90% of sunspots have a normal polarity alignment along the east-west direction following Hale's law. The median tilts increase with increasing latitude (Joy's law) at a rate of {approx}0.{sup 0}5 per degree of latitude. Tilt angles of spots appear largely invariant with respect to time at a given latitude, but they decrease by {approx}0.{sup 0}9 per year on average, a trend that largely reflects Joy's law following the butterfly diagram. We find an asymmetry between the hemispheres in the mean tilt angles. On average, the tilts are greater in the Southern than in the Northern Hemisphere for all latitude zones, and the differences increase with increasing latitude.

  16. Long-Term Measurements of Sunspot Magnetic Tilt Angles

    NASA Astrophysics Data System (ADS)

    Li, J.; Ulrich, R. K.

    2012-12-01

    Tilt angles of close to 30,600 sunspots are determined using Mount Wilson daily averaged magnetograms taken from 1974 to 2012, and MDI/SoHO magnetograms taken from 1996 to 2010. Within a cycle, more than 90% of sunspots have a normal polarity alignment along the east-west direction following Hale's law. The median tilts increase with increasing latitude (Joy's law) at a rate of 0.5 degree per degree of latitude. Tilt angles of spots appear largely invariant with respect to time at a given latitude, but they decrease by 0.9 degree per year on average, a trend which largely reflects Joy's law following the butterfly diagram. We find an asymmetry between the hemispheres in the mean tilt angles. On average, the tilts are greater in the southern than in the northern hemisphere for all latitude zones, and the differences increases with increasing latitude.

  17. Long-term Measurements of Sunspot Magnetic Tilt Angles

    NASA Astrophysics Data System (ADS)

    Li, Jing; Ulrich, Roger K.

    2012-10-01

    Tilt angles of close to 30,600 sunspots are determined using Mount Wilson daily averaged magnetograms taken from 1974 to 2012, and SOHO/MDI magnetograms taken from 1996 to 2010. Within a cycle, more than 90% of sunspots have a normal polarity alignment along the east-west direction following Hale's law. The median tilts increase with increasing latitude (Joy's law) at a rate of ~0fdg5 per degree of latitude. Tilt angles of spots appear largely invariant with respect to time at a given latitude, but they decrease by ~0fdg9 per year on average, a trend that largely reflects Joy's law following the butterfly diagram. We find an asymmetry between the hemispheres in the mean tilt angles. On average, the tilts are greater in the Southern than in the Northern Hemisphere for all latitude zones, and the differences increase with increasing latitude.

  18. The influence of the plane wave spectrum of A source on measurements of the transmission coefficient of a panel

    NASA Astrophysics Data System (ADS)

    Humphrey, V. F.

    1986-07-01

    The transmission coefficient of a panel immersed in a fluid, as measured by a circular projector, is considered. An integral expression for the measured coefficient is derived, with account taken of the non-planar nature of the wavefield and the finite size of the receiver. Numerical integration of this expression shows that the measured transmission coefficient can deviate significantly from the value predicted for a plane wave. The theoretical predictions are compared with experimental measurements of the insertion loss at normal incidence of two Perspex (polymethylmethacrylate) panels 1·4 mm and 3·1 mm thick. These measurements, which were recorded as a function of frequency and transducer separation, were concentrated in the frequency bands where the panels were approximately half a compressional wavelength thick (i.e., for frequency-panel thickness products of the order of 1·35×10 3 Hzm). In this region the measured insertion loss varied rapidly with frequency and was observed to deviate significantly from the slowly varying loss predicted for plane waves. Such deviations were observed when a small hydrophone was used as the receiver and also when another transducer of the same radius as the projector was used as the receiver. For measurements made outside the "nearfield" of the transducer combination the results were in very good agreement with the predictions of the theoretical expression. At closer ranges the poorer quantitative agreement was attributed to the transducers not behaving as ideal pistons. The results and theoretical calculations show that the plane wave spectrum of a source can have a significant effect on the measured transmission coefficient of a panel, particularly at frequencies where the transmission coefficient changes rapidly with angle of incidence.

  19. Comparison of Two-dimensional Measurement Techniques for Predicting Knee Angle and Moment during a Drop Vertical Jump

    PubMed Central

    Mizner, Ryan L.; Chmielewski, Terese L.; Toepke, John J.; Tofte, Kari B.

    2011-01-01

    Objective To determine the association of two dimensional (2D) video-based techniques and three-dimensional (3D) motion analysis to assess potential knee injury risk factors during jump landing. Design Observational study Setting Research Laboratory Participants Thirty-six female athletes in cutting and pivoting sports. Assessment Athletes performed a drop vertical jump during which movement was recorded with a motion analysis system and a digital video camera positioned in the frontal plane. Main Outcome Measures The 2D variables were the frontal plane projection angle (FPPA), the angle formed between thigh and leg, and the knee:ankle separation ratio, the distance between knee joints divided by the distance between ankles. The 3D variables were knee abduction angle and external abduction moment. All variables were assessed at peak knee flexion. Linear regression assessed the relationship between the 2D and 3D variables. In addition, intraclass correlation coefficients determined rater reliability for the 2D variables and compared the 2D measurements made from digital video to the same measurements from the motion analysis. Results The knee:ankle separation ratio accounted for a higher variance of 3D knee abduction angle (r2 =0.350) and knee abduction moment (r2=0.394) when compared to the FPPA (r2=0.145, 0.254). The digital video measures had favorable rater reliability (ICC:0.89–0.94) and were comparable to the motion analysis system (ICC≥0.92). Conclusion When compared to the FPPA, the knee:ankle separation ratio had better association with previously cited knee injury risk factors in female athletes. The 2D measures have adequate consistency and validity to merit further clinical consideration in jump landing assessments. PMID:22544058

  20. Improved speckle projection profilometry for out-of-plane shape measurement

    SciTech Connect

    Pan Bing; Xie Huimin; Gao Jianxin; Asundi, Anand

    2008-10-10

    An improved speckle projection profilometry that combines the projection of computer generated random speckle patterns using an ordinary LCD projector and the two-dimensional digital image correlation technique for in-plane displacements measurement is proposed for accurate out-of-plane shape and displacement measurements. The improved technique employs a simple yet effective calibration technique to determine the linear relationship between the out-of-plane height and the measured in-plane displacements. In addition, the iterative spatial domain cross-correlation algorithm, i.e., the improved Newton-Raphson algorithm using the zero-normalized sum of squared differences correlation criterion and the second-order shape function was employed in image correlation analysis for in-plane displacement determination of the projected speckle patterns, which provides more reliable and accurate matching with a higher correlation coefficient. Experimental results of both a regular cylinder and a human hand demonstrate that the proposed technique is easy to implement and can be applied to a practical out-of-plane shape and displacement measurement with high accuracy.

  1. Measurements of CKM Angle Beta from BaBar

    SciTech Connect

    Ulmer, Keith A.; /Colorado U.

    2007-05-23

    We present recent results of hadronic B meson decays related to the CKM angle beta. The data used were collected by the BABAR detector at the PEP-II asymmetric-energy e{sup +}e{sup -} collider operating at the Upsilon(4S) resonance located at the Stanford Linear Accelerator Center.

  2. In-plane displacement measurement by using circular grating Talbot interferometer

    NASA Astrophysics Data System (ADS)

    Agarwal, Shilpi; Shakher, Chandra

    2015-12-01

    In this paper circular grating Talbot interferometer is presented to sense and measure the in-plane displacement. The Talbot interferometric fringe pattern is dilated to eliminate the residual grating lines while preserving the required interferometric fringe pattern. The position of the shift of zeroth, first, second and third order fringes from the center of the grating is calculated to determine the in-plane displacement in different measurement range. The method is simpler in comparison to existing Fourier transform and graphical analysis methods. Simulation of intensity distribution with linear displacement between the two gratings is presented to visualize the formation of Talbot interferometric fringes for slightly de-collimated (divergent) beam. The method is capable to measure in-plane displacement in the micrometer to millimeter range with reasonable precision and accuracy. The resolution and accuracy of measurement is found different in different measurement range.

  3. PREDICTING FOOT PROGRESSION ANGLE DURING GAIT USING TWO CLINICAL MEASURES IN HEALTHY ADULTS, A PRELIMINARY STUDY

    PubMed Central

    Winters, Kyle; Kampwerth, Teri; McAfee, Blake; Payne, Lisa; Roeckenhaus, Tara; Ross, Sandy A.

    2016-01-01

    ABSTRACT Background The foot progression angle (FPA) is related to the transverse plane rotation of the lower extremities and associated with many lower extremity conditions. Purpose The purpose of this study was to examine how two commonly used clinical measures, tibio-fibular torsion (TF) and hip rotation, can be used to predict FPA during gait in healthy adults. Study Design Cross-sectional study design Methods Passive hip internal and external rotation ranges of motion and TF torsion were measured with a 12-inch goniometer while the FPA (degree of toe-in/out) was measured with the GAITRite during midstance in sixty participants. The data was analyzed using a multiple regression model. Results Hip ER was not significant and was therefore excluded from the final model. The final model included passive hip IR and TF torsion (F = 19.64; p < .001; multiple R2 = .41; adjusted R2 = .39). Simple binary correlations showed that hip IR had a moderate negative correlation (r = -.40) with FPA (the greater the hip IR, the greater the in-toeing) while TF torsion had a positive correlation (r = .39) with FPA (the greater the external TF torsion. the greater the out-toeing). Conclusions Greater amount of passive hip IR predicts in-toeing while greater TF torsion predicts out-toeing of the foot during midstance phase of gait. Level of Evidence Level 2 PMID:27274426

  4. Gait stability improvement after fusion surgery for adolescent idiopathic scoliosis is influenced by corrective measures in coronal and sagittal planes.

    PubMed

    Paul, Justin C; Patel, Ashish; Bianco, Kristina; Godwin, Ellen; Naziri, Qais; Maier, Stephen; Lafage, Virginie; Paulino, Carl; Errico, Thomas J

    2014-09-01

    To achieve optimal results after fusion for adolescent idiopathic scoliosis (AIS), radiographic parameters must be aligned with motion and performance. The effects of fusion on balance are poorly understood. Center of mass (COM) excursion and instantaneous interaction with center of pressure (COP) provides information about patients' balancing ability during gait. This study investigates the interaction between COM and COP (COM-COP) in AIS patients before and one year after spine fusion and determines what radiographic goals predict restoration of harmonious COM-COP. This was a prospective study that investigated sixteen adolescents with AIS curvature >30˚ requiring surgical correction. Clinical outcomes measures, X-rays, and 3D motion-capture gait analysis were collected. Sagittal and coronal COM and COP offsets and inclination angles were calculated from positional data. COM excursion was calculated as peak COM displacement based on mediolateral and vertical deviation from a line fitted to the patient's path. Radiographic parameters were measured to determine variables predictive of change in COM excursion. Post-operatively, average COM peak displacement decreased (42.6 to 13.1 mm, p=0.001) and COM peak vertical displacement remained unchanged (17.0 to 16.3 mm, p=0.472). COM-COP inclination angles reduced in the coronal, but not sagittal plane. Coronal lower extremity peak inclination angles reduced (8.8˚ to 7.5˚, p=0.025), correlating with C7 plumb-line offset (R=0.581, p=0.018). Thoracic Cobb, thoracic kyphosis, and C7 plumb-line were predictors of change in COM excursion. Mediolateral COM excursion post-surgery may reflect an attempt to reduce kinetic demands with improved spinal alignment. Although AIS correction has historically focused on the coronal plane, sagittal parameters may be more important for motion than previously theorized.

  5. Measurement and modeling of solar irradiance components on horizontal and tilted planes

    SciTech Connect

    Padovan, Andrea; Col, Davide del

    2010-12-15

    In this work new measurements of global and diffuse solar irradiance on the horizontal plane and global irradiance on planes tilted at 20 and 30 oriented due South and at 45 and 65 oriented due East are used to discuss the modeling of solar radiation. Irradiance data are collected in Padova (45.4 N, 11.9 E, 12 m above sea level), Italy. Some diffuse fraction correlations have been selected to model the hourly diffuse radiation on the horizontal plane. The comparison with the present experimental data shows that their prediction accuracy strongly depends on the sky characteristics. The hourly irradiance measurements taken on the tilted planes are compared with the estimations given by one isotropic and three anisotropic transposition models. The use of an anisotropic model, based on a physical description of the diffuse radiation, provides a much better accuracy, especially when measurements of the diffuse irradiance on the horizontal plane are not available and thus transposition models have to be applied in combination with a diffuse fraction correlation. This is particularly significant for the planes oriented away from South. (author)

  6. SU-C-18C-02: Specifcation of X-Ray Projection Angles Which Are Aligned with the Aortic Valve Plane From a Planar Image of a Valvuloplasty Balloon Inflated Across the Aortic Valve

    SciTech Connect

    Fetterly, K; Mathew, V

    2014-06-01

    Purpose: Transcatheter aortic valve replacement (TAVR) procedures provide a method to implant a prosthetic aortic valve via a minimallyinvasive, catheter-based procedure. TAVR procedures require use of interventional fluoroscopy c-arm projection angles which are aligned with the aortic valve plane to minimize prosthetic valve positioning error due to x-ray imaging parallax. The purpose of this work is to calculate the continuous range of interventional fluoroscopy c-arm projection angles which are aligned with the aortic valve plane from a single planar image of a valvuloplasty balloon inflated across the aortic valve. Methods: Computational methods to measure the 3D angular orientation of the aortic valve were developed. Required inputs include a planar x-ray image of a known valvuloplasty balloon inflated across the aortic valve and specifications of x-ray imaging geometry from the DICOM header of the image. A-priori knowledge of the species-specific typical range of aortic orientation is required to specify the sign of the angle of the long axis of the balloon with respect to the x-ray beam. The methods were validated ex-vivo and in a live pig. Results: Ex-vivo experiments demonstrated that the angular orientation of a stationary inflated valvuloplasty balloon can be measured with precision less than 1 degree. In-vivo pig experiments demonstrated that cardiac motion contributed to measurement variability, with precision less than 3 degrees. Error in specification of x-ray geometry directly influences measurement accuracy. Conclusion: This work demonstrates that the 3D angular orientation of the aortic valve can be calculated precisely from a planar image of a valvuloplasty balloon inflated across the aortic valve and known x-ray geometry. This method could be used to determine appropriate c-arm angular projections during TAVR procedures to minimize x-ray imaging parallax and thereby minimize prosthetic valve positioning errors.

  7. Small roll angle measurement based on auto-collimation and moiré fringe

    NASA Astrophysics Data System (ADS)

    Bai, Xu-guang; Cai, Sheng; Qiao, Yan-feng; Dai, Ming

    2009-11-01

    A novel method for small roll angle measurement based on auto-collimation and moiré fringe is presented. A right-angle prism is used as an indicator of small roll angle around the optical axis, and a CCD is used to collect moiré fringes that are generated by scale grating image which is reflected by prism and index grating. Any small roll angle of the prism will change the include angle of the grating pair and meanwhile induce a change in the moiré fringe period. The relationship between roll angle and period of moiré fringes is established. The period data is obtained by image processing. The experimental result certifies that the principle of small angle measurement method based on auto-collimation and moiré fringe is correct and feasible. The measuring error is smaller than 0.2" within 7' range compared with 0.2" autocollimator.

  8. Real-Time Aerodynamic Parameter Estimation without Air Flow Angle Measurements

    NASA Technical Reports Server (NTRS)

    Morelli, Eugene A.

    2010-01-01

    A technique for estimating aerodynamic parameters in real time from flight data without air flow angle measurements is described and demonstrated. The method is applied to simulated F-16 data, and to flight data from a subscale jet transport aircraft. Modeling results obtained with the new approach using flight data without air flow angle measurements were compared to modeling results computed conventionally using flight data that included air flow angle measurements. Comparisons demonstrated that the new technique can provide accurate aerodynamic modeling results without air flow angle measurements, which are often difficult and expensive to obtain. Implications for efficient flight testing and flight safety are discussed.

  9. Sunspot Tilt Angles Measured with MDI/SOHO and HMI/SDO

    NASA Astrophysics Data System (ADS)

    Li, J.; Ulrich, R. K.

    2015-12-01

    We present sunspot magnetic tilt angles measured from 1996 to the present time, spanning almost two solar cycles. Full disk magnetograms from MDI/SoHO and HMI/SDO are used in our study. The data cadence in our analyses is 96 minutes per day giving about 90 measurements of the tilt angles for each sunspot during the disk passage between -40 to +40 longitudinal degree. In addition to an automated computation, we use a scheme to visually examine each sunspot efficiently to check the tilt angle determinations. Such measurements not only confirm Joy's and Hale's laws, but also reveal the tilt angle variations during the sunspot lifetime, the effect of Coriolis force on the magnetic flux tubes, and the tilt angle dependence of the cycle progress. The measurements also provide uncertainties on the tilt angle measurements.

  10. Measurement of the Root Mean Square (RMS) Temperature Fluctuations of a Turbulent Plane Jet Using an Optical Method

    NASA Astrophysics Data System (ADS)

    Borji, S.; Benzirar, M.; Sabri, L.; Bouabdellaoui, M.

    2016-07-01

    The purpose of this paper is to reach the root mean square (RMS) value of the fluctuating temperature along a jet plane by examining only the impact produced by a laser beam after having traversed the heated jet of air. This model is based on the Einstein-Fokker-Planck-Kolmogorov (EFPK) equation, which helped us to determine the value of the jet diffusion coefficient defined as a proportionality factor between the mean square of the deflection angle fluctuations and the length of the corresponding finite laser beam path. The numerical method of calculation in our work uses the value of the localized diffusion coefficient. This plays an essential role in measuring along the RMS of the temperature fluctuations. The obtained values are compared to the experimental measurements.

  11. Angle Measurement System (AMS) for Establishing Model Pitch and Roll Zero, and Performing Single Axis Angle Comparisons

    NASA Technical Reports Server (NTRS)

    Crawford, Bradley L.

    2007-01-01

    The angle measurement system (AMS) developed at NASA Langley Research Center (LaRC) is a system for many uses. It was originally developed to check taper fits in the wind tunnel model support system. The system was further developed to measure simultaneous pitch and roll angles using 3 orthogonally mounted accelerometers (3-axis). This 3-axis arrangement is used as a transfer standard from the calibration standard to the wind tunnel facility. It is generally used to establish model pitch and roll zero and performs the in-situ calibration on model attitude devices. The AMS originally used a laptop computer running DOS based software but has recently been upgraded to operate in a windows environment. Other improvements have also been made to the software to enhance its accuracy and add features. This paper will discuss the accuracy and calibration methodologies used in this system and some of the features that have contributed to its popularity.

  12. Polarization measurement analysis. I. Impact of the full covariance matrix on polarization fraction and angle measurements

    NASA Astrophysics Data System (ADS)

    Montier, L.; Plaszczynski, S.; Levrier, F.; Tristram, M.; Alina, D.; Ristorcelli, I.; Bernard, J.-P.

    2015-02-01

    With the forthcoming release of high precision polarization measurements, such as from the Planck satellite, the metrology of polarization needs to be improved. In particular, it is important to have full knowledge of the noise properties when estimating polarization fraction and polarization angle, which suffer from well-known biases. While strong simplifying assumptions have usually been made in polarization analysis, we present a method for including the full covariance matrix of the Stokes parameters in estimates of the distributions of the polarization fraction and angle. We thereby quantified the impact of the noise properties on the biases in the observational quantities and derived analytical expressions for the probability density functions of these quantities that take the full complexity of the covariance matrix into account, including the Stokes I intensity components. We performed Monte Carlo simulations to explore the impact of the noise properties on the statistical variance and bias of the polarization fraction and angle. We show that for low variations (< 10%) of the effective ellipticity between the Q and U components around the symmetrical case the covariance matrix may be simplified as is usually done, with a negligible impact on the bias. For S/Ns with intensity lower than 10, the uncertainty on the total intensity is shown to drastically increase the uncertainty of the polarization fraction but not the relative bias of the polarization fraction, while a 10% correlation between the intensity and the polarized components does not significantly affect the bias of the polarization fraction. We compare estimates of the uncertainties that affect polarization measurements, addressing limitations of the estimates of the S/N, and we show how to build conservative confidence intervals for polarization fraction and angle simultaneously. This study, which is the first in a set of papers dedicated to analysing polarization measurements, focuses on the

  13. Novel Control Scheme of Power Assisted Wheelchair for Preventing Overturn (Part II)-Variable Assistance Ratio Control Based on Estimation of Center-of-Gravity Angle and Phase Plane-

    NASA Astrophysics Data System (ADS)

    Hata, Naoki; Seki, Hirokazu; Koyasu, Yuichi; Hori, Yoichi

    Aged people and disabled people who have difficulty in walking are increasing. As one of mobility support, significance of a power assisted wheelchair which assists driving force using electric motors and spreads their living areas has been enhanced. However, the increased driving force often causes a dangerous overturn of wheelchair. This paper proposes a novel control method to prevent power assisted wheelchair from overturning. The man-wheelchair system can be regarded as an inverse pendulum model when the front wheels are rising. The center-of-gravity (COG) angle of the model is the most important information directly-linked to overturn. Behavior of the system can be analyzed using phase plane as shown in this paper. The COG angle cannot be directly measured using a sensor, therefore, COG observer based on its velocity is proposed. On the basis of the analysis on phase plane, a novel control method with variable assistance ratio to prevent a dangerous overturn is proposed. The effectiveness of the proposed method is verified by the practical experiments on the flat ground and uphill slope.

  14. Automated measurement of anterior and posterior acetabular sector angles

    NASA Astrophysics Data System (ADS)

    Ibragimov, Bulat; Likar, Boštjan; Pernuš, Franjo; Vrtovec, Tomaž

    2012-03-01

    In this paper, we propose a segmentation algorithm by which anatomical landmarks on the pelvis are extracted from computed tomography (CT) images. The landmarks are used to automatically define the anterior (AASA) and posterior acetabular sector angles (PASA) describing the degree of hip misalignment. The center of each femoral head is obtained by searching for the point at which most intensity gradient vectors defined at edge points intersect. The radius of each femoral head is computed by finding the sphere, positioned at the center of the femoral head, for which the normalized sum of gradient vector magnitudes on the sphere surface is maximal. The anterior and posterior corners of each acetabulum are searched for on a curve representing the acetabulum and defined by dynamic programming. The femoral head centers and anterior and posterior corners are used to calculate the AASA and PASA. The algorithm was applied to CT images of 120 normal subjects and the results were compared to ground truth values obtained by manual segmentation. The mean absolute difference (+/- standard deviation) between the obtained and ground truth values was 1.3 +/- 0.3 mm for the femoral head centers and 2.1 +/- 1.3 degrees for the acetabular angles.

  15. Comparisons of surface vs. volumetric model-based registration methods using single-plane vs. bi-plane fluoroscopy in measuring spinal kinematics.

    PubMed

    Lin, Cheng-Chung; Lu, Tung-Wu; Wang, Ting-Ming; Hsu, Chao-Yu; Shih, Ting-Fang

    2014-02-01

    Several 2D-to-3D image registration methods are available for measuring 3D vertebral motion but their performance has not been evaluated under the same experimental protocol. In this study, four major types of fluoroscopy-to-CT registration methods, with different use of surface vs. volumetric models, and single-plane vs. bi-plane fluoroscopy, were evaluated: STS (surface, single-plane), VTS (volumetric, single-plane), STB (surface, bi-plane) and VTB (volumetric, bi-plane). Two similarity measures were used: 'Contour Difference' for STS and STB and 'Weighted Edge-Matching Score' for VTS and VTB. Two cadaveric porcine cervical spines positioned in a box filled with paraffin and embedded with four radiopaque markers were CT scanned to obtain vertebral models and marker coordinates, and imaged at ten static positions using bi-plane fluoroscopy for subsequent registrations using different methods. The registered vertebral poses were compared to the gold standard poses defined by the marker positions determined using CT and Roentgen stereophotogrammetry analysis. The VTB was found to have the highest precision (translation: 0.4mm; rotation: 0.3°), comparable with the VTS in rotations (0.3°), and the STB in translations (0.6mm). The STS had the lowest precision (translation: 4.1mm; rotation: 2.1°). PMID:24011956

  16. Analysis of a range estimator which uses MLS angle measurements

    NASA Technical Reports Server (NTRS)

    Downing, David R.; Linse, Dennis

    1987-01-01

    A concept that uses the azimuth signal from a microwave landing system (MLS) combined with onboard airspeed and heading data to estimate the horizontal range to the runway threshold is investigated. The absolute range error is evaluated for trajectories typical of General Aviation (GA) and commercial airline operations (CAO). These include constant intercept angles for GA and CAO, and complex curved trajectories for CAO. It is found that range errors of 4000 to 6000 feet at the entry of MLS coverage which then reduce to 1000-foot errors at runway centerline intercept are possible for GA operations. For CAO, errors at entry into MLS coverage of 2000 feet which reduce to 300 feet at runway centerline interception are possible.

  17. A bioelectrical impedance phase angle measuring system for assessment of nutritional status.

    PubMed

    Zhang, Guanghao; Huo, Xiaolin; Wu, Changzhe; Zhang, Cheng; Duan, Zhongping

    2014-01-01

    Bioelectrical impedance phase angle has been recommended as a tool to assess nutrition state, but there are no measuring devices have been specially designed for hospital residents. In this study, a system was established for the measurement of bioelectrical impedance phase angle. The electrical composition, calculation method and measuring method of this system are presented in this paper. Experiments showed excellent performance of this system in measuring impedance made of resistors and capacitors. The designed system was also used to measure the bioelectrical impedance phase angle of both healthy subjects and patients with malnutrition, and the results demonstrated that the phase angle of patients with malnutrition is lower than that of healthy subjects (P < 0.01 for male and P < 0.05 for female). These results suggest that phase angle has the potential to be a useful tool for the quantitative assessment of nutritional status.

  18. Development of a body joint angle measurement system using IMU sensors.

    PubMed

    Bakhshi, Saba; Mahoor, Mohammad H; Davidson, Bradley S

    2011-01-01

    This paper presents an approach for measuring and monitoring human body joint angles using inertial measurement unit (IMU) sensors. This type of monitoring is beneficial for therapists and physicians because it facilitates remote assessment of patient activities. In our approach, two IMUs are mounted on the upper leg and the lower leg to measure the Euler angles of each segment. The Euler angles are sent via Bluetooth protocols to a pc for calculating the knee joint angle. In our experiments, we utilized a motion capture system to accurately measure the knee joint angle and used this as the ground truth to assess the accuracy of the IMU system. The range of average error of the system across a variety of motion trials was 0.08 to 3.06 degrees. In summary, the accuracy of the IMU measurement system currently outperforms existing wearable systems such as conductive fiber optic sensors and flex-sensors. PMID:22255930

  19. MSFC solar simulator test plane uniformity measurement. [for testing solar collectors

    NASA Technical Reports Server (NTRS)

    Griner, D. B.

    1976-01-01

    The equipment and procedure used to measure the test plane uniformity produced by the MSFC 405 lamp solar simulator array are described along with details of the computer program used to analyze the measurement data. The results of the first measurement show the uniformity not to be as good as expected. The best uniformity obtained had a standared deviation of 4 percent with peak-to-peak values of + or - 11 percent.

  20. Measurement of Three-Dimensional Flame Structure by Simultaneous Dual-plane CH PLIF, Single-plane OH PLIF and Stereoscopic PIV

    NASA Astrophysics Data System (ADS)

    Ueda, Takashi; Shimura, Masayasu; Choi, Gyung-Min; Tanahashi, Mamoru; Miyauchi, Toshio

    2008-11-01

    To investigate three-dimensional flame structures of turbulent premixed flame, dual-plane planar laser induced fluorescence (PLIF) of CH radical has been developed. The newly-developed dual-plane CH PLIF is combined with single-plane OH PLIF and stereoscopic particle image velocimetry (SPIV) to clarify the relation between flame geometry and turbulence characteristics. The laser sheets for OH PLIF and SPIV measurement are located at the center of two planes for CH PLIF. The separation between these two CH PLIF planes is selected to 500μm. The measurement was conducted in relatively high Reynolds number methane-air turbulent jet premixed flame. The experimental results show that various three-dimensional flame structures such as the handgrip structure, which has been shown by DNS, are included in high Reynolds number turbulent premixed flame. It was shown that the simultaneous measurement containing newly-developed dual- plane CH PLIF is useful for investigating the three-dimensional flame structure.

  1. Measuring the Flatness of Focal Plane for Very Large Mosaic CCD Camera

    SciTech Connect

    Hao, Jiangang; Estrada, Juan; Cease, Herman; Diehl, H.Thomas; Flaugher, Brenna L.; Kubik, Donna; Kuk, Keivin; Kuropatkine, Nickolai; Lin, Huan; Montes, Jorge; Scarpine, Vic; /Fermilab

    2010-06-08

    Large mosaic multiCCD camera is the key instrument for modern digital sky survey. DECam is an extremely red sensitive 520 Megapixel camera designed for the incoming Dark Energy Survey (DES). It is consist of sixty two 4k x 2k and twelve 2k x 2k 250-micron thick fully-depleted CCDs, with a focal plane of 44 cm in diameter and a field of view of 2.2 square degree. It will be attached to the Blanco 4-meter telescope at CTIO. The DES will cover 5000 square-degrees of the southern galactic cap in 5 color bands (g, r, i, z, Y) in 5 years starting from 2011. To achieve the science goal of constraining the Dark Energy evolution, stringent requirements are laid down for the design of DECam. Among them, the flatness of the focal plane needs to be controlled within a 60-micron envelope in order to achieve the specified PSF variation limit. It is very challenging to measure the flatness of the focal plane to such precision when it is placed in a high vacuum dewar at 173 K. We developed two image based techniques to measure the flatness of the focal plane. By imaging a regular grid of dots on the focal plane, the CCD offset along the optical axis is converted to the variation the grid spacings at different positions on the focal plane. After extracting the patterns and comparing the change in spacings, we can measure the flatness to high precision. In method 1, the regular dots are kept in high sub micron precision and cover the whole focal plane. In method 2, no high precision for the grid is required. Instead, we use a precise XY stage moves the pattern across the whole focal plane and comparing the variations of the spacing when it is imaged by different CCDs. Simulation and real measurements show that the two methods work very well for our purpose, and are in good agreement with the direct optical measurements.

  2. A basic study on variable-gain Kalman filter based on angle error calculated from acceleration signals for lower limb angle measurement with inertial sensors.

    PubMed

    Teruyama, Yuta; Watanabe, Takashi

    2013-01-01

    In this study, development of wearable motion measurement system using inertial sensors has been focused with the aim of rehabilitation support. For measurement of lower limb joint angles with inertial sensors, Kalman-filtering-based angle measurement method was developed. However, it was required to reduce variation of measurement errors that depended on movement speeds or subjects. In this report, variable-gain Kalman filter based on the difference between the estimated angle by the Kalman filter and the angle calculated from acceleration signals was tested. From angle measurement during treadmill walking with healthy subjects, it was shown that measurement accuracy of the foot inclination angle was significantly improved with the proposed method compared to the method of fixed parameter value. PMID:24110464

  3. Measurement of contact angles of aqueous solutions on some rock forming minerals

    NASA Astrophysics Data System (ADS)

    Takakura, M.; Katsura, M.; Nakashima, S.

    2007-12-01

    Wetting properties of fluids on earth's materials are controlling fluid flows and dynamics of the geological systems. Although the wetting behavior of industrial materials have been widely examined often by contact angle measurements, contact angles of rock-forming materials have not been commonly measured. Therefore, we have been measuring contact angles of some representative rock-forming minerals. The surfaces of solid samples were polished successively by emery papers then by grinding powders (alumina: up to \\sharp3000: grain size about 5 micrometers). Water droplet from a micro-syringe needle are placed on solid surfaces by moving up the sample stage. Images of water drops on the solid surfaces are captured from the horizontal direction with a CCD camera. Contact angles can be determined from the height and the length of the images by assuming them to be parts of circles. Over 60 measurements of contact angles of pure water on (101) and (011) faces plates cut from a natural quartz single crystal were repeated. The average contact angles of pure water on (101) and (011) faces of quartz were 48 ± 5 degrees and 52 ± 3 degrees, respectively. Contact angles of pure water on a natural calcite single crystal was also measured in the same way to be 37 ± 8 degrees. Contact angles of various aqueous solutions such as NaCl and NaHCO3 on these minerals will also be measured in order to evaluate wetting properties of natural rock-water systems.

  4. Measuring the distribution of cellulose microfibril angles in primary cell walls by small angle X-ray scattering

    PubMed Central

    2014-01-01

    Background X-ray scattering is a well-established method for measuring cellulose microfibril angles in secondary cell walls. However, little data is available on the much thinner primary cell walls. Here, we show that microfibril orientation distributions can be determined by small angle X-ray scattering (SAXS) even in primary cell walls. The technique offers a number of advantages: samples can be analyzed in the native hydrated state without any preparation which minimizes the risk of artifacts and allows for fast data acquisition. The method provides data averaged over a specimen region, determined by the size of the used X-ray beam and, thus, yields the microfibril orientation distribution within this region. Results Cellulose microfibril orientation distributions were obtained for single cells of the alga Chara corallina, as well as for the multicellular hypocotyl of Arabidopsis thaliana. In both, Chara and Arabidopsis, distributions with a broad scattering around mean microfibril angles of approximately 0° and 90° towards the longitudinal axis of the cells were found. Conclusions With SAXS, the structure of primary cell walls can be analysed in their native state and new insights into the cellulose microfibril orientation of primary cell walls can be gained. The data shows that SAXS can serve as a valuable tool for the analysis of cellulose microfibril orientation in primary cell walls and, in consequence, add to the understanding of its mechanical behaviour and the intriguing mechanisms behind cell growth. PMID:25170343

  5. Quantitative measurement of in-plane acoustic field components using surface-mounted fiber sensors

    NASA Technical Reports Server (NTRS)

    Claus, Richard O.; Dhawan, Rajat R.; Gunther, Michael F.; Murphy, Kent A.

    1993-01-01

    Extrinsic Fabry-Perot interferometric sensors have been used to obtain calibrated, quantitative measurements of the in-plane displacement components associated with the propagation of ultrasonic elastic stress waves on the surfaces of solids. The frequency response of the sensor is determined by the internal spacing between the two reflecting fiber endface surfaces which form the Fabry-Perot cavity, a distance which is easily controlled during fabrication. With knowledge of the material properties of the solid, the out-of-plane displacement component of the wave may also be determined, giving full field data.

  6. Effect of frontal plane tibiofemoral angle on the stress and strain at the knee cartilage during the stance phase of gait.

    PubMed

    Yang, Nicholas H; Nayeb-Hashemi, Hamid; Canavan, Paul K; Vaziri, Ashkan

    2010-12-01

    Subject-specific three-dimensional finite element models of the knee joint were created and used to study the effect of the frontal plane tibiofemoral angle on the stress and strain distribution in the knee cartilage during the stance phase of the gait cycle. Knee models of three subjects with different tibiofemoral angle and body weight were created based on magnetic resonance imaging of the knee. Loading and boundary conditions were determined from motion analysis and force platform data, in conjunction with the muscle-force reduction method. During the stance phase of walking, all subjects exhibited a valgus-varus-valgus knee moment pattern with the maximum compressive load and varus knee moment occurring at approximately 25% of the stance phase of the gait cycle. Our results demonstrated that the subject with varus alignment had the largest stresses at the medial compartment of the knee compared to the subjects with normal alignment and valgus alignment, suggesting that this subject might be most susceptible to developing medial compartment osteoarthritis (OA). In addition, the magnitude of stress and strain on the lateral cartilage of the subject with valgus alignment were found to be larger compared to subjects with normal alignment and varus alignment, suggesting that this subject might be most susceptible to developing lateral compartment knee OA.

  7. Agreement Between Panoramic and Lateral Cephalometric Radiographs for Measuring the Gonial Angle

    PubMed Central

    Zangouei-Booshehri, Maryam; Aghili, Hossein-Agha; Abasi, Mojtaba; Ezoddini-Ardakani, Fatemeh

    2012-01-01

    Background The gonial angle is one of the most important measurements required for orthodontic treatment and orthognathic surgery. It is difficult to determine the accurate measurement of each gonial angle on cephalometric radiographs because of superimposition of the left and right angles. Objectives The aim of the present study was to determine the right and left gonial angles on panoramic radiographs and to compare them with an evaluated cephalometric sample. Patients and Methods A total of 80 panoramic and 80 cephalometric radiographs were obtained from 6 to 12-year-old children and the gonial angle was determined by the tangent of the inferior border of the mandible and the most distal aspect of the ascending ramus and the condyleon both panoramic and cephalometric radiographs. We used Pearson’s correlation coefficient and paired t-test for comparison. Results The mean gonial angle was 127.07 ± 6.10 and 127.5 ± 6.67 degrees on panoramic and cephalometric radiographs, respectively. There was no statistically significant difference between the measured gonial angles on panoramic and cephalometric radiographs and also no difference between the right and left (both Ps = 0.18) Conclusion The value of the gonial angle measured on panoramic radiography was the same as that measured on the routinely used cephalometric radiography. PMID:23407613

  8. Measurement of the Weinberg angle in neutrino interactions

    NASA Astrophysics Data System (ADS)

    Dore, Ubaldo; Ferruccio Loverre, Pier; Ludovici, Lucio

    2016-06-01

    Neutrino physics with high energy neutrino beams has played a crucial role in establishing the Standard Model of the electroweak interaction, in particular with repeated measurements of increasing precision of the fundamental parameter sin2 θW which defines the electroweak mixing. This paper relates the history of these measurements, from the discovery of the neutral current interaction in 1973 until the latest high precision measurements in the years 2000. The review discusses in chronological order the important experiments performed at CERN, Fermilab and Brookhaven during the last thirty years of the 20th century.

  9. Large-scale spatial angle measurement and the pointing error analysis

    NASA Astrophysics Data System (ADS)

    Xiao, Wen-jian; Chen, Zhi-bin; Ma, Dong-xi; Zhang, Yong; Liu, Xian-hong; Qin, Meng-ze

    2016-05-01

    A large-scale spatial angle measurement method is proposed based on inertial reference. Common measurement reference is established in inertial space, and the spatial vector coordinates of each measured axis in inertial space are measured by using autocollimation tracking and inertial measurement technology. According to the spatial coordinates of each test vector axis, the measurement of large-scale spatial angle is easily realized. The pointing error of tracking device based on the two mirrors in the measurement system is studied, and the influence of different installation errors to the pointing error is analyzed. This research can lay a foundation for error allocation, calibration and compensation for the measurement system.

  10. Raman spectroscopy measurement of bilayer graphene's twist angle to boron nitride

    SciTech Connect

    Cheng, Bin; Wang, Peng; Pan, Cheng; Miao, Tengfei; Wu, Yong; Lau, C. N.; Bockrath, M.; Taniguchi, T.; Watanabe, K.

    2015-07-20

    When graphene is placed on hexagonal boron nitride with a twist angle, new properties develop due to the resulting moiré superlattice. Here, we report a method using Raman spectroscopy to make rapid, non-destructive measurements of the twist angle between bilayer graphene and hexagonal boron nitride. The lattice orientation is determined by using flakes with both bilayer and monolayer regions, and using the known Raman signature for the monolayer to measure the twist angle of the entire flake. The widths of the second order Raman peaks are found to vary linearly in the superlattice period and are used to determine the twist angle. The results are confirmed by using transport measurements to infer the superlattice period by the charge density required to reach the secondary resistance peaks. Small twist angles are also found to produce a significant modification of the first order Raman G band peak.

  11. Effectiveness of variable-gain Kalman filter based on angle error calculated from acceleration signals in lower limb angle measurement with inertial sensors.

    PubMed

    Teruyama, Yuta; Watanabe, Takashi

    2013-01-01

    The wearable sensor system developed by our group, which measured lower limb angles using Kalman-filtering-based method, was suggested to be useful in evaluation of gait function for rehabilitation support. However, it was expected to reduce variations of measurement errors. In this paper, a variable-Kalman-gain method based on angle error that was calculated from acceleration signals was proposed to improve measurement accuracy. The proposed method was tested comparing to fixed-gain Kalman filter and a variable-Kalman-gain method that was based on acceleration magnitude used in previous studies. First, in angle measurement in treadmill walking, the proposed method measured lower limb angles with the highest measurement accuracy and improved significantly foot inclination angle measurement, while it improved slightly shank and thigh inclination angles. The variable-gain method based on acceleration magnitude was not effective for our Kalman filter system. Then, in angle measurement of a rigid body model, it was shown that the proposed method had measurement accuracy similar to or higher than results seen in other studies that used markers of camera-based motion measurement system fixing on a rigid plate together with a sensor or on the sensor directly. The proposed method was found to be effective in angle measurement with inertial sensors.

  12. Effectiveness of Variable-Gain Kalman Filter Based on Angle Error Calculated from Acceleration Signals in Lower Limb Angle Measurement with Inertial Sensors

    PubMed Central

    Watanabe, Takashi

    2013-01-01

    The wearable sensor system developed by our group, which measured lower limb angles using Kalman-filtering-based method, was suggested to be useful in evaluation of gait function for rehabilitation support. However, it was expected to reduce variations of measurement errors. In this paper, a variable-Kalman-gain method based on angle error that was calculated from acceleration signals was proposed to improve measurement accuracy. The proposed method was tested comparing to fixed-gain Kalman filter and a variable-Kalman-gain method that was based on acceleration magnitude used in previous studies. First, in angle measurement in treadmill walking, the proposed method measured lower limb angles with the highest measurement accuracy and improved significantly foot inclination angle measurement, while it improved slightly shank and thigh inclination angles. The variable-gain method based on acceleration magnitude was not effective for our Kalman filter system. Then, in angle measurement of a rigid body model, it was shown that the proposed method had measurement accuracy similar to or higher than results seen in other studies that used markers of camera-based motion measurement system fixing on a rigid plate together with a sensor or on the sensor directly. The proposed method was found to be effective in angle measurement with inertial sensors. PMID:24282442

  13. Differences between the alpha angles measured manually and digitally from paediatric hip ultrasonograms.

    PubMed

    Sariyilmaz, Kerim; Saglam, Yavuz; Ozkunt, Okan; Yildiz, Fatih; Sungur, Mustafa; Hurmeydan, Onder Murat; Goksan, Suleyman Bora

    2015-07-01

    The aim of this study was to reveal whether a meaningful difference is caused by measuring the alpha angle in hip ultrasonography manually or digitally to help the early diagnosis and treatment of DDH and observe the treatment implications of any such difference. All ultrasound images were obtained by same orthopaedist, and each hip was measured twice by two investigators with different levels of experience. Standard images were taken, and a printout of the standard images were obtained. The alpha angle was measured digitally by using the sonography device. The alpha angle was also measured by pencil, ruler and goniometer on the printout after 2 days. One hundred and two hips of 51 babies, at a mean age of 14 weeks, were assessed. The mean alpha angle measured manually with a goniometer was 64.4° (±1.6°), while that measured on the ultrasonography device was 65.3° (±0.9°). This difference was found to be statistically different (p = 0.016). Typology changes occurred in a total of 10 hips out of 102 as a result of manual and digital measurements. However, this study showed reduction in alpha angle variation and considerable advantages for manual alpha angle measurement with pencil and goniometer on a printout compared to computer-based measurement; future studies are needed to understand these differences caused by each measurement method. PMID:25869106

  14. Evaluation of angle dependence in spectral emissivity of ceramic tiles measured by FT-IR

    NASA Astrophysics Data System (ADS)

    Kobayashi, C.; Ogasawara, N.; Yamada, H.; Yamada, S.; Kikuchi, T.

    2015-05-01

    Ceramic tiles are widely used for building walls. False detections are caused in inspections by infrared thermography because of the infrared reflection and angle dependence of emissivity. As the first problem, ceramic tile walls are influenced from backgrounds reflection. As the second problem, in inspection for tall buildings, the camera angles are changed against the height. Thus, to reveal the relation between the emissivity and angles is needed. However, there is very little data about it. It is impossible to decrease the false detection on ceramic tile walls without resolving these problems; background reflection and angle dependence of emissivity. In this study, the angle problem was investigated. The purpose is to establish a revision method in the angle dependence of the emissivity for infrared thermography. To reveal the relation between the emissivity and angles, the spectral emissivity of a ceramic tile at various angles was measured by FT-IR and infrared thermographic instrument. These two experimental results were compared with the emissivity-angle curves from the theoretical formula. In short wavelength range, the two experimental results showed similar behavior, but they did not agree with the theoretical curve. This will be the subject of further study. In long wavelength range, the both experimental results almost obeyed the theoretical curve. This means that it is possible to revise the angle dependence of spectral emissivity, for long wavelength range.

  15. Reliability and validity of goniometric and photographic measurements of clavicular tilt angle.

    PubMed

    Ha, Sung-min; Kwon, Oh-yun; Weon, Jong-hyuck; Kim, Moon-hwan; Kim, Su-jung

    2013-10-01

    The aims of the present study were to assess the reliability of clavicular tilt angle measurement using goniometric and photographic measurements and to test the validity of the measurement by comparing the results with radiographic findings (gold standard). Clavicular tilt angles were measured in 18 healthy subjects (36 clavicles) using goniometric, photographic, and radiographic measurement. Repeated measurements using goniometric and photographic measurements were made in two test sessions conducted on different days by two examiners to assess inter-rater and intra-rater reliability of the two methods. Radiographic measurement was taken once, and the correlation between the radiographic findings and those of the indirect methods was calculated to test the validity of the goniometric and photographic measurement of clavicular tilt angle. No significant difference in clavicular tilt angle measurement was found between test sessions. The reliability of goniometric measurement (inter-rater intraclass correlation coefficients (ICC) = 0.85 (95% CI = 0.72-0.92) - 0.87 (95% CI = 0.77-0.87); intra-rater ICC = 0.80 (95% CI = 0.64-0.89)) and photographic measurement (inter-rater ICC = 0.89 (95% CI = 0.80-0.94) - 0.95 (95% CI = 0.91-0.98); intra-rater ICC = 0.84 (95% CI = 0.71-0.92) - 0.84 (95% CI = 0.69-0.91)) were excellent. The goniometric and photographic measurements of clavicular tilt angle were highly correlated with the radiographic findings (r = 0.83, 0.78, respectively). Goniometric and photographic measurements of clavicular tilt angle obtained by raters in this study may be considered reliable, and data obtained using the goniometric and photographic measurements are representative of radiographic findings of clavicular tilt angle.

  16. Probing surface charge potentials of clay basal planes and edges by direct force measurements.

    PubMed

    Zhao, Hongying; Bhattacharjee, Subir; Chow, Ross; Wallace, Dean; Masliyah, Jacob H; Xu, Zhenghe

    2008-11-18

    The dispersion and gelation of clay suspensions have major impact on a number of industries, such as ceramic and composite materials processing, paper making, cement production, and consumer product formulation. To fundamentally understand controlling mechanisms of clay dispersion and gelation, it is necessary to study anisotropic surface charge properties and colloidal interactions of clay particles. In this study, a colloidal probe technique was employed to study the interaction forces between a silica probe and clay basal plane/edge surfaces. A muscovite mica was used as a representative of 2:1 phyllosilicate clay minerals. The muscovite basal plane was prepared by cleavage, while the edge surface was obtained by a microtome cutting technique. Direct force measurements demonstrated the anisotropic surface charge properties of the basal plane and edge surface. For the basal plane, the long-range forces were monotonically repulsive within pH 6-10 and the measured forces were pH-independent, thereby confirming that clay basal planes have permanent surface charge from isomorphic substitution of lattice elements. The measured interaction forces were fitted well with the classical DLVO theory. The surface potentials of muscovite basal plane derived from the measured force profiles were in good agreement with those reported in the literature. In the case of edge surfaces, the measured forces were monotonically repulsive at pH 10, decreasing with pH, and changed to be attractive at pH 5.6, strongly suggesting that the charge on the clay edge surfaces is pH-dependent. The measured force profiles could not be reasonably fitted with the classical DLVO theory, even with very small surface potential values, unless the surface roughness was considered. The surface element integration (SEI) method was used to calculate the DLVO forces to account for the surface roughness. The surface potentials of the muscovite edges were derived by fitting the measured force profiles with the

  17. High-speed measurement of nozzle swing angle of rocket engine based on monocular vision

    NASA Astrophysics Data System (ADS)

    Qu, Yufu; Yang, Haijuan

    2015-02-01

    A nozzle angle measurement system based on monocular vision is proposed to achieve high-speed and non-contact angle measurement of rocket engine nozzle. The measurement system consists of two illumination sources, a lens, a target board with spots, a high-speed camera, an image acquisition card and a PC. A target board with spots was fixed on the end of rocket engine nozzle. The image of the target board moved along with the rocket engine nozzle swing was captured by a high-speed camera and transferred to the PC by an image acquisition card. Then a data processing algorithm was utilized to acquire the swing angle of the engine nozzle. Experiment shows that the accuracy of swing angle measurement was 0.2° and the measurement frequency was up to 500Hz.

  18. Quad-plane stereoscopic PIV for fine-scale structure measurements in turbulence

    NASA Astrophysics Data System (ADS)

    Naka, Y.; Tomita, K.; Shimura, M.; Fukushima, N.; Tanahashi, M.; Miyauchi, T.

    2016-05-01

    The fine-scale structure in turbulence is investigated by quad-plane stereoscopic particle image velocimetry (QPSPIV). The quad-plane consists of two each of different polarizations and wavelengths, and it provides three velocity components at four independent parallel planes. Measurements have been undertaken in the developed region of a turbulent round jet with a spatial resolution sufficient to capture the small-scale structures. The advantage of the QPSPIV is presented in terms of the spectral response in the evaluation of the out-of-plane velocity gradient. The full velocity gradient tensor is computed with a fourth-order finite difference scheme in the out-of-plane direction as well as the in-plane directions. The turbulence quantities, such as the vorticity components, the energy dissipation rate and the second and third invariants of the velocity gradient tensor, are computed according to their faithful definitions. The coherent fine-scale eddies are extracted from the present QPSPIV data. The probability density functions of the diameter and the maximum azimuthal velocity of the extracted eddies exhibit their peak at approximately 8η and 1.5u_k, respectively, where η and u_k are the Kolmogorov length and velocity. These values agree well with the data in the literature. The phase-averaged distributions of turbulence quantities around the coherent fine-scale eddy indicate an apparent elliptic feature around the axis. Furthermore, the state of the strain rate exerting the eddy is quantified from the phase-averaged distributions of eigenvalues of the strain rate tensor and the alignment of the corresponding eigenvectors against the axis. The present study gives a solid experimental support of the coherent fine-scale structures in turbulence, and the technique can be applied to various flow fields and to the higher Reynolds number condition.

  19. In-plane displacement and strain measurements using a camera phone and digital image correlation

    NASA Astrophysics Data System (ADS)

    Yu, Liping; Pan, Bing

    2014-05-01

    In-plane displacement and strain measurements of planar objects by processing the digital images captured by a camera phone using digital image correlation (DIC) are performed in this paper. As a convenient communication tool for everyday use, the principal advantages of a camera phone are its low cost, easy accessibility, and compactness. However, when used as a two-dimensional DIC system for mechanical metrology, the assumed imaging model of a camera phone may be slightly altered during the measurement process due to camera misalignment, imperfect loading, sample deformation, and temperature variations of the camera phone, which can produce appreciable errors in the measured displacements. In order to obtain accurate DIC measurements using a camera phone, the virtual displacements caused by these issues are first identified using an unstrained compensating specimen and then corrected by means of a parametric model. The proposed technique is first verified using in-plane translation and out-of-plane translation tests. Then, it is validated through a determination of the tensile strains and elastic properties of an aluminum specimen. Results of the present study show that accurate DIC measurements can be conducted using a common camera phone provided that an adequate correction is employed.

  20. Beam splitting target reflector based compensation for angular drift of laser beam in laser autocollimation of measuring small angle deviations

    NASA Astrophysics Data System (ADS)

    Zhu, Fan; Tan, Jiubin; Cui, Jiwen

    2013-06-01

    Beam splitting target reflector based compensation for the angular drift of laser beam in laser autocollimation is proposed in this article to improve the measurement accuracy and stability of small angle deviations. A beam splitting target reflector is used to replace the plane mirror in laser autocollimation to generate a reference beam when returning the measurement beam. The reference beam and measurement beam have the same angular drift, but have different sensitivities to the rotation angle of the reflector due to the unique characteristics of the reflector. Thus, the angular drift of laser beam in laser autocollimation can be compensated in real time by using the drift of reference beam. Experimental results indicate that an output stability of 0.085 arc sec in 2 h can be achieved after compensation. And a measurement accuracy of ±0.032 arc sec can be obtained over the range of ±1190 arc sec with an effective resolution of 0.006 arc sec. It is confirmed that the compensation method for the angular drift of laser beam is necessary for improving the measurement accuracy and stability in laser autocollimation.

  1. Beam splitting target reflector based compensation for angular drift of laser beam in laser autocollimation of measuring small angle deviations

    SciTech Connect

    Zhu Fan; Tan Jiubin; Cui Jiwen

    2013-06-15

    Beam splitting target reflector based compensation for the angular drift of laser beam in laser autocollimation is proposed in this article to improve the measurement accuracy and stability of small angle deviations. A beam splitting target reflector is used to replace the plane mirror in laser autocollimation to generate a reference beam when returning the measurement beam. The reference beam and measurement beam have the same angular drift, but have different sensitivities to the rotation angle of the reflector due to the unique characteristics of the reflector. Thus, the angular drift of laser beam in laser autocollimation can be compensated in real time by using the drift of reference beam. Experimental results indicate that an output stability of 0.085 arc sec in 2 h can be achieved after compensation. And a measurement accuracy of {+-}0.032 arc sec can be obtained over the range of {+-}1190 arc sec with an effective resolution of 0.006 arc sec. It is confirmed that the compensation method for the angular drift of laser beam is necessary for improving the measurement accuracy and stability in laser autocollimation.

  2. Algorithm for automatic angles measurement and screening for Developmental Dysplasia of the Hip (DDH).

    PubMed

    Al-Bashir, Areen K; Al-Abed, Mohammad; Abu Sharkh, Fayez M; Kordeya, Mohamed N; Rousan, Fadi M

    2015-08-01

    Developmental Dysplasia of the Hip (DDH) is a medical term represent the hip joint instability that appear mainly in infants. The examination for this condition can be done by ultrasound for children under 6 months old and by X-ray for children over 6 months old. Physician's assessment is based on certain angles derived from those images, namely the Acetabular Angle, and the Center Edge Angle. In this paper, we are presenting a novel, fully automatic algorithm for measuring the diagnostic angles of DDH from the X-ray images. Our algorithm consists of Automatic segmentation and extraction of anatomical landmarks from X-ray images. Both of Acetabular angle and Center edge angle are automatically calculated. The analysis included X-ray images for 16 children recruited for the purposed of this study. The automatically acquired angles accuracy for Acetabular Angle was around 85%, and an absolute deviation of 3.4°±3.3° compared to the physician's manually calculated angle. The results of this method are very promising for the future development of an automatic method for screening X-ray images DDH that complement and aid the physicians' manual methods. PMID:26737754

  3. A vision-based dynamic rotational angle measurement system for large civil structures.

    PubMed

    Lee, Jong-Jae; Ho, Hoai-Nam; Lee, Jong-Han

    2012-01-01

    In this paper, we propose a vision-based rotational angle measurement system for large-scale civil structures. Despite the fact that during the last decade several rotation angle measurement systems were introduced, they however often required complex and expensive equipment. Therefore, alternative effective solutions with high resolution are in great demand. The proposed system consists of commercial PCs, commercial camcorders, low-cost frame grabbers, and a wireless LAN router. The calculation of rotation angle is obtained by using image processing techniques with pre-measured calibration parameters. Several laboratory tests were conducted to verify the performance of the proposed system. Compared with the commercial rotation angle measurement, the results of the system showed very good agreement with an error of less than 1.0% in all test cases. Furthermore, several tests were conducted on the five-story modal testing tower with a hybrid mass damper to experimentally verify the feasibility of the proposed system.

  4. A vision-based dynamic rotational angle measurement system for large civil structures.

    PubMed

    Lee, Jong-Jae; Ho, Hoai-Nam; Lee, Jong-Han

    2012-01-01

    In this paper, we propose a vision-based rotational angle measurement system for large-scale civil structures. Despite the fact that during the last decade several rotation angle measurement systems were introduced, they however often required complex and expensive equipment. Therefore, alternative effective solutions with high resolution are in great demand. The proposed system consists of commercial PCs, commercial camcorders, low-cost frame grabbers, and a wireless LAN router. The calculation of rotation angle is obtained by using image processing techniques with pre-measured calibration parameters. Several laboratory tests were conducted to verify the performance of the proposed system. Compared with the commercial rotation angle measurement, the results of the system showed very good agreement with an error of less than 1.0% in all test cases. Furthermore, several tests were conducted on the five-story modal testing tower with a hybrid mass damper to experimentally verify the feasibility of the proposed system. PMID:22969348

  5. Novel film-calliper method of measuring the contact angle of colloidal particles at liquid interfaces.

    PubMed

    Horozov, Tommy S; Braz, Dulce A; Fletcher, Paul D I; Binks, Bernard P; Clint, John H

    2008-03-01

    A simple and reliable film-calliper method of measuring the particle contact angle at the water-air (oil) interface in real time has been developed. Its applicability to submicrometer and micrometer latex and silica particles is demonstrated.

  6. Use of an amorphous silicon EPID for measuring MLC calibration at varying gantry angle

    NASA Astrophysics Data System (ADS)

    Clarke, M. F.; Budgell, G. J.

    2008-01-01

    Amorphous silicon electronic portal imaging devices (EPIDs) are used to perform routine quality control (QC) checks on the multileaf collimators (MLCs) at this centre. Presently, these checks are performed at gantry angle 0° and are considered to be valid for all other angles. Since therapeutic procedures regularly require the delivery of MLC-defined fields to the patient at a wide range of gantry angles, the accuracy of the QC checks at other gantry angles has been investigated. When the gantry is rotated to angles other than 0° it was found that the apparent pixel size measured using the EPID varies up to a maximum value of 0.0015 mm per pixel due to a sag in the EPID of up to 9.2 mm. A correction factor was determined using two independent methods at a range of gantry angles between 0° and 360°. The EPID was used to measure field sizes (defined by both x-jaws and MLC) at a range of gantry angles and, after this correction had been applied, any residual gravitational sag was studied. It was found that, when fields are defined by the x-jaws and y-back-up jaws, no errors of greater than 0.5 mm were measured and that these errors were no worse when the MLC was used. It was therefore concluded that, provided the correction is applied, measurements of the field size are, in practical terms, unaffected by gantry angle. Experiments were also performed to study how the reproducibility of individual leaves is affected by gantry angle. Measurements of the relative position of each individual leaf (minor offsets) were performed at a range of gantry angles and repeated three times. The position reproducibility was defined by the RMS error in the position of each leaf and this was found to be 0.24 mm and 0.21 mm for the two leaf banks at a gantry angle of 0°. When measurements were performed at a range of gantry angles, these reproducibility values remained within 0.09 mm and 0.11 mm. It was therefore concluded that the calibration of the Elekta MLC is stable at all

  7. Possibility of measuring Adler angles in charged current single pion neutrino-nucleus interactions

    NASA Astrophysics Data System (ADS)

    Sánchez, F.

    2016-05-01

    Uncertainties in modeling neutrino-nucleus interactions are a major contribution to systematic errors in long-baseline neutrino oscillation experiments. Accurate modeling of neutrino interactions requires additional experimental observables such as the Adler angles which carry information about the polarization of the Δ resonance and the interference with nonresonant single pion production. The Adler angles were measured with limited statistics in bubble chamber neutrino experiments as well as in electron-proton scattering experiments. We discuss the viability of measuring these angles in neutrino interactions with nuclei.

  8. Compensation method for the alignment angle error in pitch deviation measurement

    NASA Astrophysics Data System (ADS)

    Liu, Yongsheng; Fang, Suping; Wang, Huiyi; Taguchi, Tetsuya; Takeda, Ryohei

    2016-05-01

    When measuring the tooth flank of an involute helical gear by gear measuring center (GMC), the alignment angle error of a gear axis, which was caused by the assembly error and manufacturing error of the GMC, will affect the measurement accuracy of pitch deviation of the gear tooth flank. Based on the model of the involute helical gear and the tooth flank measurement theory, a method is proposed to compensate the alignment angle error that is included in the measurement results of pitch deviation, without changing the initial measurement method of the GMC. Simulation experiments are done to verify the compensation method and the results show that after compensation, the alignment angle error of the gear axis included in measurement results of pitch deviation declines significantly, more than 90% of the alignment angle errors are compensated, and the residual alignment angle errors in pitch deviation measurement results are less than 0.1 μm. It shows that the proposed method can improve the measurement accuracy of the GMC when measuring the pitch deviation of involute helical gear.

  9. Exit plane H2O concentration measurements correlated with OH PLIF near-injector mixing measurements for scramjet flows

    NASA Technical Reports Server (NTRS)

    Parker, T. E.; Allen, Mark G.; Foutter, R. R.; Sonnenfroh, D. M.; Rawlins, W. T.

    1992-01-01

    Mixing and combusting high enthalpy flows, similar to those encountered in scramjet engines, were investigated using a shock tunnel to produce the flow in conjunction with non-intrusive optical diagnostics which monitored the performance of two injector configurations. The shock tunnel is configured to produce Mach 3 flow and stagnation enthalpies corresponding to flight equivalent Mach numbers between 7 and 11. A pulsed hydrogen injection capability and interchangeable injector blocks provide a means of examining high speed, high enthalpy reacting flows. Planar laser induced fluorescence (PLIF) of OH molecules in the near injector region produced images which show the combusting and mixing zones for the reacting flow. Line-of-sight exit plane measurement of water concentration and temperature were used to provide a unique method of monitoring exit plane products. These results demonstrated that a velocity matched axial injection system produced a fuel jet that lifted off the floor of the duct. Mixing was observed to increase for this system as a velocity mismatch was introduced. Comparison of exit plane water concentrations for a wall jet injection system and a velocity matched injection system indicated similar mixing performance but an accurate pressure measurement is necessary to further validate the result. In addition, exit plane measurements indicated an approximate steady-state condition was achieved during the 1 to 2 ms test times.

  10. using multi-scale measurements of pitch angle distribution to test magnetospheric relativistic electron energization models

    NASA Astrophysics Data System (ADS)

    Kanekal, S. G.; Friedel, R. H. W.; Reeves, E. G. D.

    Detailed investigation of pitch angle distributions during the course of a relativistic electron energization event can aid in identifying the dominant physical process underlying the event. Current models of electron energization employ a variety physical processes ranging from radial diffusion to in-situ acceleration mechanisms. These processes result in different pitch angle distributions of energized electrons, for example radial diffusion dominated events have a pancake-type distribution. We present the results of a statistical survey of multi-scale electron pitch angle measurements during relativistic electron events. Measurements of in-situ pitch angle evolution at geosynchronous altitude are combined with measurements of global isotropization time scales. We use data from energetic particle sensors onboard SAMPEX and pitch angle data from the SOPA and ESP sensors onboard LANL spacecraft. The LANL measurements provide a microscopic view of the electron pitch angle distribution. Combining electron flux measurements at geosynchronous altitudes with those measured by SAMPEX which is in low earth orbit provides a macroscopic global view of the flux isotropization.

  11. Intervertebral anticollision constraints improve out-of-plane translation accuracy of a single-plane fluoroscopy-to-CT registration method for measuring spinal motion

    SciTech Connect

    Lin, Cheng-Chung; Tsai, Tsung-Yuan; Hsu, Shih-Jung; Lu, Tung-Wu; Shih, Ting-Fang; Wang, Ting-Ming

    2013-03-15

    Purpose: The study aimed to propose a new single-plane fluoroscopy-to-CT registration method integrated with intervertebral anticollision constraints for measuring three-dimensional (3D) intervertebral kinematics of the spine; and to evaluate the performance of the method without anticollision and with three variations of the anticollision constraints via an in vitro experiment. Methods: The proposed fluoroscopy-to-CT registration approach, called the weighted edge-matching with anticollision (WEMAC) method, was based on the integration of geometrical anticollision constraints for adjacent vertebrae and the weighted edge-matching score (WEMS) method that matched the digitally reconstructed radiographs of the CT models of the vertebrae and the measured single-plane fluoroscopy images. Three variations of the anticollision constraints, namely, T-DOF, R-DOF, and A-DOF methods, were proposed. An in vitro experiment using four porcine cervical spines in different postures was performed to evaluate the performance of the WEMS and the WEMAC methods. Results: The WEMS method gave high precision and small bias in all components for both vertebral pose and intervertebral pose measurements, except for relatively large errors for the out-of-plane translation component. The WEMAC method successfully reduced the out-of-plane translation errors for intervertebral kinematic measurements while keeping the measurement accuracies for the other five degrees of freedom (DOF) more or less unaltered. The means (standard deviations) of the out-of-plane translational errors were less than -0.5 (0.6) and -0.3 (0.8) mm for the T-DOF method and the R-DOF method, respectively. Conclusions: The proposed single-plane fluoroscopy-to-CT registration method reduced the out-of-plane translation errors for intervertebral kinematic measurements while keeping the measurement accuracies for the other five DOF more or less unaltered. With the submillimeter and subdegree accuracy, the WEMAC method was

  12. Quantitative measurement of in-plane cantilever torsion for calibrating lateral piezoresponse force microscopy.

    SciTech Connect

    Choi, H.; Hong, S.; No, K.

    2011-01-01

    A simple quantitative measurement procedure of in-plane cantilever torsion for calibrating lateral piezoresponse force microscopy is presented. This technique enables one to determine the corresponding lateral inverse optical lever sensitivity (LIOLS) of the cantilever on the given sample. Piezoelectric coefficient, d{sub 31} of BaTiO{sub 3} single crystal (-81.62 {+-} 40.22 pm/V) which was calculated using the estimated LIOLS was in good agreement with the reported value in literature.

  13. A Method to Measure the Flatness of the LSST Focal Plane Assembly in Situ

    SciTech Connect

    Langeveld, Willy; /SLAC

    2005-10-26

    In this note I describe an inexpensive and simple laser-based method to measure the flatness of the LSST focal plane assembly (FPA) in situ, i.e. while the FPA is inside its cryostat, at -100 C and under vacuum. The method may also allow measurement of the distance of the FPA to lens L3, and may be sensitive enough to measure gravity- and pressure-induced deformations of L3 as well. The accuracy of the method shows promise to be better than 1 micron.

  14. High-resolution angle-resolved measurements of light scattered at small angles by red blood cells in suspension.

    PubMed

    Turcu, Ioan; Pop, Cristian V L; Neamtu, Silvia

    2006-03-20

    Red blood cells (RBCs) scatter light mainly in the forward direction, where the scattering phase function has a narrow peak. We performed an experimental investigation into the angular distribution of light scattered by blood in the small-angle domain. A highly diluted suspension of RBCs (hematocrits in the range 5 x 10(-5)-10(-2)) was illuminated with a He-Ne laser with 633 nm wavelength. We focused our research on two main topics: the scattering efficiency of the RBCs given by the mean scattering cross section and the scattering anisotropy obtained from the angular distribution of the scattered photons. The collimated beam transmission and the angular distribution of scattered light were measured and compared with the predictions of the effective phase function model. The RBCs' mean scattering cross section and scattering anisotropy were obtained by fitting of the experimental data. PMID:16579566

  15. Pump-probe measurements of the thermal conductivity tensor for materials lacking in-plane symmetry

    SciTech Connect

    Feser, Joseph P.; Liu, Jun; Cahill, David G.

    2014-10-15

    We previously demonstrated an extension of time-domain thermoreflectance (TDTR) which utilizes offset pump and probe laser locations to measure in-plane thermal transport properties of multilayers. However, the technique was limited to systems of transversely isotropic materials studied using axisymmetric laser intensities. Here, we extend the mathematics so that data reduction can be performed on non-transversely isotropic systems. An analytic solution of the diffusion equation for an N-layer system is given, where each layer has a homogenous but otherwise arbitrary thermal conductivity tensor and the illuminating spots have arbitrary intensity profiles. As a demonstration, we use both TDTR and time-resolved magneto-optic Kerr effect measurements to obtain thermal conductivity tensor elements of <110> α-SiO{sub 2}. We show that the out-of-phase beam offset sweep has full-width half-maxima that contains nearly independent sensitivity to the in-plane thermal conductivity corresponding to the scanning direction. Also, we demonstrate a Nb-V alloy as a low thermal conductivity TDTR transducer layer that helps improve the accuracy of in-plane measurements.

  16. Pump-probe measurements of the thermal conductivity tensor for materials lacking in-plane symmetry

    NASA Astrophysics Data System (ADS)

    Feser, Joseph P.; Liu, Jun; Cahill, David G.

    2014-10-01

    We previously demonstrated an extension of time-domain thermoreflectance (TDTR) which utilizes offset pump and probe laser locations to measure in-plane thermal transport properties of multilayers. However, the technique was limited to systems of transversely isotropic materials studied using axisymmetric laser intensities. Here, we extend the mathematics so that data reduction can be performed on non-transversely isotropic systems. An analytic solution of the diffusion equation for an N-layer system is given, where each layer has a homogenous but otherwise arbitrary thermal conductivity tensor and the illuminating spots have arbitrary intensity profiles. As a demonstration, we use both TDTR and time-resolved magneto-optic Kerr effect measurements to obtain thermal conductivity tensor elements of <110> α-SiO2. We show that the out-of-phase beam offset sweep has full-width half-maxima that contains nearly independent sensitivity to the in-plane thermal conductivity corresponding to the scanning direction. Also, we demonstrate a Nb-V alloy as a low thermal conductivity TDTR transducer layer that helps improve the accuracy of in-plane measurements.

  17. Method and system of measuring ultrasonic signals in the plane of a moving web

    DOEpatents

    Hall, M.S.; Jackson, T.G.; Wink, W.A.; Knerr, C.

    1996-02-27

    An improved system for measuring the velocity of ultrasonic signals within the plane of moving web-like materials, such as paper, paperboard and the like is disclosed. In addition to velocity measurements of ultrasonic signals in the plane of the web in the machine direction, MD, and a cross direction, CD, generally perpendicular to the direction of the traveling web, therefore, one embodiment of the system in accordance with the present invention is also adapted to provide on-line indication of the polar specific stiffness of the moving web. In another embodiment of the invention, the velocity of ultrasonic signals in the plane of the web are measured by way of a plurality of ultrasonic transducers carried by synchronously driven wheels or cylinders, thus eliminating undue transducer wear due to any speed differences between the transducers and the web. In order to provide relatively constant contact force between the transducers and the webs, the transducers are mounted in a sensor housings which include a spring for biasing the transducer radially outwardly. The sensor housings are adapted to be easily and conveniently mounted to the carrier to provide a relatively constant contact force between the transducers and the moving web. 37 figs.

  18. Method and system of measuring ultrasonic signals in the plane of a moving web

    DOEpatents

    Hall, Maclin S.; Jackson, Theodore G.; Wink, Wilmer A.; Knerr, Christopher

    1996-01-01

    An improved system for measuring the velocity of ultrasonic signals within the plane of moving web-like materials, such as paper, paperboard and the like. In addition to velocity measurements of ultrasonic signals in the plane of the web in the machine direction, MD, and a cross direction, CD, generally perpendicular to the direction of the traveling web, therefor, one embodiment of the system in accordance with the present invention is also adapted to provide on-line indication of the polar specific stiffness of the moving web. In another embodiment of the invention, the velocity of ultrasonic signals in the plane of the web are measured by way of a plurality of ultrasonic transducers carried by synchronously driven wheels or cylinders, thus eliminating undue transducer wear due to any speed differences between the transducers and the web. In order to provide relatively constant contact force between the transducers and the webs, the transducers are mounted in a sensor housings which include a spring for biasing the transducer radially outwardly. The sensor housings are adapted to be easily and conveniently mounted to the carrier to provide a relatively constant contact force between the transducers and the moving web.

  19. Pump-probe measurements of the thermal conductivity tensor for materials lacking in-plane symmetry.

    PubMed

    Feser, Joseph P; Liu, Jun; Cahill, David G

    2014-10-01

    We previously demonstrated an extension of time-domain thermoreflectance (TDTR) which utilizes offset pump and probe laser locations to measure in-plane thermal transport properties of multilayers. However, the technique was limited to systems of transversely isotropic materials studied using axisymmetric laser intensities. Here, we extend the mathematics so that data reduction can be performed on non-transversely isotropic systems. An analytic solution of the diffusion equation for an N-layer system is given, where each layer has a homogenous but otherwise arbitrary thermal conductivity tensor and the illuminating spots have arbitrary intensity profiles. As a demonstration, we use both TDTR and time-resolved magneto-optic Kerr effect measurements to obtain thermal conductivity tensor elements of <110> α-SiO2. We show that the out-of-phase beam offset sweep has full-width half-maxima that contains nearly independent sensitivity to the in-plane thermal conductivity corresponding to the scanning direction. Also, we demonstrate a Nb-V alloy as a low thermal conductivity TDTR transducer layer that helps improve the accuracy of in-plane measurements.

  20. In plane oscillation of a bifilar pendulum

    NASA Astrophysics Data System (ADS)

    Hinrichsen, Peter F.

    2016-11-01

    The line tensions, the horizontal and vertical accelerations as well as the period of large angle oscillations parallel to the plane of a bifilar suspension are presented and have been experimentally investigated using strain gauges and a smart phone. This system has a number of advantages over the simple pendulum for studying large angle oscillations, and for measuring the acceleration due to gravity.

  1. Design of an automated device to measure sagittal plane stiffness of an articulated ankle-foot orthosis.

    PubMed

    Kobayashi, Toshiki; Leung, Aaron K L; Akazawa, Yasushi; Naito, Hisashi; Tanaka, Masao; Hutchins, Stephen W

    2010-12-01

    The purpose of this study was to design a new automated stiffness measurement device which could perform a simultaneous measurement of both dorsi- and plantarflexion angles and the corresponding resistive torque around the rotational centre of an articulated ankle-foot orthosis (AAFO). This was achieved by controlling angular velocities and range of motion in the sagittal plane. The device consisted of a hydraulic servo fatigue testing machine, a torque meter, a potentiometer, a rotary plate and an upright supporter to enable an AAFO to be attached to the device via a surrogate shank. The accuracy of the device in reproducing the range of motion and angular velocity was within 4% and 1% respectively in the range of motion of 30° (15° plantarflexion to 15° dorsiflexion) at the angular velocity of 10°/s, while that in the measurement of AAFO torque was within 8% at the 0° position. The device should prove useful to assist an orthotist or a manufacturer to quantify the stiffness of an AAFO and inform its clinical use. PMID:20681928

  2. Measurements of the streamwise vortical structures in a plane mixing layer

    NASA Technical Reports Server (NTRS)

    Bell, James H.; Mehta, Rabindra D.

    1992-01-01

    The 3D structure of a plane two-stream mixing layer of velocity ratio 0.6 and originating from laminar initial boundary layers was investigated through direct measurements made in a specially constructed mixing-layer wind tunnel. The main objective of the study was to establish quantitatively the presence and the role of the secondary streamwise vortex structure (of the kind that has been shown in past flow visualization investigations to ride among the primary spanwise vortices) in the development of a plane turbulent mixing layer at relatively high Reynolds numbers. Results indicate that the instability leading to the formation of streamwise vortices is initially amplified just downstream of the first spanwise roll-up. The streamwise vortices, which first appear in clusters containing vorticity of both signs, realign further downstream to form counterrotating pairs. Due to the amalgamation of like-sign vortices, the streamwise vortex spacing increases in a stepwise fashion.

  3. Research on high precision equal-angle scanning method in rotary kiln temperature measurement system

    NASA Astrophysics Data System (ADS)

    Dai, Shaosheng; Guo, Zhongyuan; You, Changhui; Liu, Jinsong; Cheng, Yang; Tang, Huaming

    2016-05-01

    Aiming at traditional horizontal equal-angle scanning method's disadvantage of measurement error, a high precision equal-angle scanning method is proposed, the proposed method establishes a tilt scanning model by the following steps: introducing height variable, precisely calculating the viewing angle, building scanning model. The model is used to calculate scanning position on rotary kiln's surface, which helps to locate and track temperature variation. The experiment shows that the proposed method can effectively improve the precision of temperature spots' location on the rotary kiln surface.

  4. Considering Hydrophobicity via Contact Angle Stability of Organic Thiols Measured with a Homemade Goniometer

    NASA Astrophysics Data System (ADS)

    Seraly, Mark; Ollander, Brooke; Statman, Ariel; Poynor, Adele

    2014-03-01

    When water meets an extended hydrophobic surface, an ultra-thin, low-density depletion layer is expected at the interface. Exactly how the depletion layer changes with change in hydrophobicity is still an open question. An accurate measure of contact angle is essential in determining how water meets a hydrophobic surface. Utilizing a homemade goniometer with ImageJ software we investigate the stability of self-assembled organic thiol monolayers, 1-octadecanethiol (ODT) and 11-mercaptoundecanoic acid (MUA). We report the changes in contact angle due to exposure to air, water, and ethanol. Other factors that affect contact angles were also considered in our investigation.

  5. Measurements of sunspot group tilt angles for solar cycles 19-24

    NASA Astrophysics Data System (ADS)

    Isik, Seda; Isik, Emre

    2016-07-01

    The tilt angle of a sunspot group is a critical quantity in the surface transport magnetic flux on global scales, playing a role in the solar dynamo. To investigate Joy's law for four cycles, we measured the tilt angles of sunspot groups for solar cycles 19-24. We have developed an IDL routine, which allows the user to interactively select and measure sunspot positions and areas on the solar disc, using the sunspot drawing database of Kandilli Observatory. The method is similar to that used by others in the literature, with the exception that sunspot groups were identified manually, which has improved the accuracy of the tilt angles. We present cycle averages of the tilt angle and compare the results with the existing data in the literature.

  6. Simulations of Convection Zone Flows and Measurements from Multiple Viewing Angles

    NASA Technical Reports Server (NTRS)

    Duvall, Thomas L.; Hanasoge, Shravan

    2011-01-01

    A deep-focusing time-distance measurement technique has been applied to linear acoustic simulations of a solar interior perturbed by convective flows. The simulations are for the full sphere for r/R greater than 0.2. From these it is straightforward to simulate the observations from different viewing angles and to test how multiple viewing angles enhance detectibility. Some initial results will be presented.

  7. Skin movement errors in measurement of sagittal lumbar and hip angles in young and elderly subjects.

    PubMed

    Kuo, Yi-Liang; Tully, Elizabeth A; Galea, Mary P

    2008-02-01

    Errors in measurement of sagittal lumbar and hip angles due to skin movement on the pelvis and/or lateral thigh were measured in young (n = 21, age = 18.6 +/- 2.1 years) and older (n = 23, age = 70.9 +/- 6.4 years) age groups. Skin reference markers were attached over specific landmarks of healthy young and elderly subjects, who were videotaped in three static positions of hip flexion using the 2D PEAK Motus video analysis system. Sagittal lumbar and hip angles were calculated from skin reference markers and manually palpated landmarks. The elderly subjects demonstrated greater errors in lumbar angle due to skin movement on the pelvis only in the maximal hip flexion position. The traditional model (ASIS-PSIS-GT-LFE) underestimated sagittal hip angle and the revised model (ASIS-PSIS-2/3Th-1/4Th) provided more accurate measurement of sagittal hip angle throughout the full available range of hip flexion. Skin movement on the pelvis had a small counterbalancing effect on the larger errors from lateral thigh markers (GT-LFE), thereby decreasing hip angle error.

  8. Assessing the accuracy of contact angle measurements for sessile drops on liquid-repellent surfaces.

    PubMed

    Srinivasan, Siddarth; McKinley, Gareth H; Cohen, Robert E

    2011-11-15

    Gravity-induced sagging can amplify variations in goniometric measurements of the contact angles of sessile drops on super-liquid-repellent surfaces. The very large value of the effective contact angle leads to increased optical noise in the drop profile near the solid-liquid free surface and the progressive failure of simple geometric approximations. We demonstrate a systematic approach to determining the effective contact angle of drops on super-repellent surfaces. We use a perturbation solution of the Bashforth-Adams equation to estimate the contact angles of sessile drops of water, ethylene glycol, and diiodomethane on an omniphobic surface using direct measurements of the maximum drop width and height. The results and analysis can be represented in terms of a dimensionless Bond number that depends on the maximum drop width and the capillary length of the liquid to quantify the extent of gravity-induced sagging. Finally, we illustrate the inherent sensitivity of goniometric contact angle measurement techniques to drop dimensions as the apparent contact angle approaches 180°. PMID:21923173

  9. Measuring contact angle and meniscus shape with a reflected laser beam

    SciTech Connect

    Eibach, T. F.; Nguyen, H.; Butt, H. J.; Auernhammer, G. K.; Fell, D.

    2014-01-15

    Side-view imaging of the contact angle between an extended planar solid surface and a liquid is problematic. Even when aligning the view perfectly parallel to the contact line, focusing one point of the contact line is not possible. We describe a new measurement technique for determining contact angles with the reflection of a widened laser sheet on a moving contact line. We verified this new technique measuring the contact angle on a cylinder, rotating partially immersed in a liquid. A laser sheet is inclined under an angle φ to the unperturbed liquid surface and is reflected off the meniscus. Collected on a screen, the reflection image contains information to determine the contact angle. When dividing the laser sheet into an array of laser rays by placing a mesh into the beam path, the shape of the meniscus can be reconstructed from the reflection image. We verified the method by measuring the receding contact angle versus speed for aqueous cetyltrimethyl ammonium bromide solutions on a smooth hydrophobized as well as on a rough polystyrene surface.

  10. Measurements of dissipation rate and some other characteristics of turbulent plane and circular jets

    NASA Astrophysics Data System (ADS)

    Antonia, R. A.; Satyaprakash, B. R.; Hussain, A. K. M. F.

    1980-04-01

    The rate of turbulent dissipation and the turbulent Reynolds number along the axes of a turbulent plane jet and three circular jets is measured in order to confirm universal relations between the turbulent dissipation rate and the streamwise position derived from the necessary requirements for self-preservation. Flow velocity was determined by a hot-wire anemometer located in a plane jet with exit Reynolds numbers of 20,400 and 42,800 and circular jets with exit Reynolds numbers of 55,600, 109,000 and 471,000. The universal relation for circular jets is found to be valid in the position/diameter ratio range of 20 to 140 in a large range of jet Reynolds numbers, while that for plane jets is confirmed in the range 30 to 160. For either type of jet, the turbulence Reynolds number is found to be proportional to 2.3 times the square root of the local Reynolds number, which is based on local velocity and length scales.

  11. Non-contact angle measurement based on parallel multiplex laser feedback interferometry

    NASA Astrophysics Data System (ADS)

    Zhang, Song; Tan, Yi-Dong; Zhang, Shu-Lian

    2014-11-01

    We present a novel precise angle measurement scheme based on parallel multiplex laser feedback interferometry (PLFI), which outputs two parallel laser beams and thus their displacement difference reflects the angle variation of the target. Due to its ultrahigh sensitivity to the feedback light, PLFI realizes the direct non-contact measurement of non-cooperative targets. Experimental results show that PLFI has an accuracy of 8″ within a range of 1400″. The yaw of a guide is also measured and the experimental results agree with those of the dual-frequency laser interferometer Agilent 5529A.

  12. Protein adsorption on surfaces: dynamic contact-angle (DCA) and quartz-crystal microbalance (QCM) measurements.

    PubMed

    Stadler, H; Mondon, M; Ziegler, C

    2003-01-01

    Adsorption of the protein bovine serum albumin (BSA) on gold has been tested at various concentrations in aqueous solution by dynamic contact-angle analysis (DCA) and quartz-crystal microbalance (QCM) measurements. With the Wilhelmy plate technique advancing and receding contact angles and the corresponding hysteresis were measured and correlated with the hydrophilicity and the homogeneity of the surface. With electrical admittance measurements of a gold-coated piezoelectrical quartz crystal, layer mass and viscoelastic contributions to the resonator's frequency shift during adsorption could be separated. A correlation was found between the adsorbed mass and the homogeneity and hydrophilicity of the adsorbed film.

  13. Velocity and flow angle measurements in the Langley 0.3-meter transonic cryogenic tunnel using a laser transit anemometer

    NASA Technical Reports Server (NTRS)

    Honaker, W. C.

    1982-01-01

    The Laser Transit Anemometer (LTA) system is described. In the LTA system two parallel laser beams of known separation and cross sectional area are focussed at the same location or plane. When a particle in a flow field passes through both beams and the time is recorded for its transit (time of flight), its velocity can be calculated knowing the distance between the beams. By rotating the two beams (spots) around a common center and recording the number of valid events (a particle which passes through both spots in the proper sequence) at each angle the flow angle can be determined by curve fitting a predetermined number of angles or points and calculating the peak of what should be a Gaussian curve. The best angle or flow angle is defined as the angle at which the maximum number of valid events occurs. The LTA system functioned properly although conditions were less than desirable.

  14. Investigations for an alternative to contact angle measurement after Hexamethyldisilazane deposition

    NASA Astrophysics Data System (ADS)

    Aßmann, H.; Krause, A.; Maurer, R.; Dankelmann, M.; Specht, M.; Usry, W.; Newcomb, R.

    2015-09-01

    The adhesion promoter Hexamethyldisilazane (HMDS) plays a crucial role in i-line lithography. According to HMDS deposition forms, a hydrophobic surface defines upwardly directed, non-polar trimethysilyl groups. This condition is of particular importance for wet chemical development and subsequent wet chemical etching processes, because the defined hydrophobic surface prevents water from creeping beneath the resist mask. Undesirable effects, such as (partial) loss of the resist structure or under etching can be prevented. Currently, a common and suitable method to control the success of HMDS deposition is the contact angle measurement. There, a drop of water is applied to the substrate and the contact angle / wetting angle is measured. As a result, conclusions can be drawn about the HMDS process. Unfortunately, however, this simple to implement measurement method raises some problems. The measurement is extremely dependent on the substrate, wherein the measurement results vary greatly. A possible reason for this is the different surface properties of the wafers which are due to adsorbate films. Typically, a contact angle measurement is performed just after the HMDS deposition. A difference between pre- and post-measurement cannot be determined. A deviation of the contact angle can be caused by either an insufficient HMDS seeding, or just as well by other, unknown surface properties. The studies presented here were performed with the measuring system ChemetriQ 5000 from Qcept Technologies. This measurement system was originally developed for Inspection on non-visible defects on the wafer level. It is able to detect differences of work functions as a result of surface coverage by thin film / adsorbate, materials or residues. The change in the surface work function due to the generated adsorbate layer during the HMDS deposition is determined by the measuring system by means of a difference between pre- and post-measurement.

  15. The reliability and variation of measurements of the os calcis angles in children.

    PubMed

    Clint, S A; Morris, T P; Shaw, O M; Oddy, M J; Rudge, B; Barry, M

    2010-04-01

    The databases of the Picture Archiving and Communication Systems of two hospitals were searched and all children who had a lateral radiograph of the ankle during their attendance at the emergency department were identified. In 227 radiographs, Bohler's and Gissane's angles were measured on two separate occasions and by two separate authors to allow calculation of inter- and intra-observer variation. Intraclass correlation coefficients were used to assess the reliability of the measurements. For Bohler's angle the overall inter-observer reliability, the intraclass correlation coefficient was 0.90 and the intra-observer reliability 0.95, giving excellent agreement. This reliability was maintained across the age groups. For Gissane's angle, inter- and intra-observer reliability was only fair or poor across most age groups. Further analysis of the Bohler's angle showed a significant variation in the mean angle with age. Contrary to published opinion, the angle is not uniformly lower than that of adults but varies with age, peaking towards the end of the first decade before attaining adult values. The age-related radiologic changes presented here may help in the interpretation of injuries to the hindfoot in children.

  16. Reproducibility of Scleral Spur Identification and Angle Measurements Using Fourier Domain Anterior Segment Optical Coherence Tomography

    PubMed Central

    Cumba, Ricardo J.; Radhakrishnan, Sunita; Bell, Nicholas P.; Nagi, Kundandeep S.; Chuang, Alice Z.; Lin, Shan C.; Mankiewicz, Kimberly A.; Feldman, Robert M.

    2012-01-01

    Purpose. To evaluate intraobserver and interobserver agreement in locating the scleral spur landmark (SSL) and anterior chamber angle measurements obtained using Fourier Domain Anterior Segment Optical Coherence Tomography (ASOCT) images. Methods. Two independent, masked observers (SR and AZC) identified SSLs on ASOCT images from 31 eyes with open and nonopen angles. A third independent reader, NPB, adjudicated SSL placement if identifications differed by more than 80 μm. Nine months later, SR reidentified SSLs. Intraobserver and interobserver agreement in SSL placement, trabecular-iris space area (TISA750), and angle opening distance (AOD750) were calculated. Results. In 84% of quadrants, SR's SSL placements during 2 sessions were within 80 μm in both the X- and Y-axes, and in 77% of quadrants, SR and AZC were within 80 μm in both axes. In adjudicated images, 90% of all quadrants were within 80 μm, 88% in nonopen-angle eyes, and 92% in open-angle eyes. The intraobserver and interobserver correlation coefficients (with and without adjudication) were above 0.9 for TISA750 and AOD750 for all quadrants. Conclusions. Reproducible identification of the SSL from images obtained with FD-ASOCT is possible. The ability to identify the SSL allows reproducible measurement of the anterior chamber angle using TISA750 and AOD750. PMID:23209880

  17. Reproducibility of scleral spur identification and angle measurements using fourier domain anterior segment optical coherence tomography.

    PubMed

    Cumba, Ricardo J; Radhakrishnan, Sunita; Bell, Nicholas P; Nagi, Kundandeep S; Chuang, Alice Z; Lin, Shan C; Mankiewicz, Kimberly A; Feldman, Robert M

    2012-01-01

    Purpose. To evaluate intraobserver and interobserver agreement in locating the scleral spur landmark (SSL) and anterior chamber angle measurements obtained using Fourier Domain Anterior Segment Optical Coherence Tomography (ASOCT) images. Methods. Two independent, masked observers (SR and AZC) identified SSLs on ASOCT images from 31 eyes with open and nonopen angles. A third independent reader, NPB, adjudicated SSL placement if identifications differed by more than 80 μm. Nine months later, SR reidentified SSLs. Intraobserver and interobserver agreement in SSL placement, trabecular-iris space area (TISA750), and angle opening distance (AOD750) were calculated. Results. In 84% of quadrants, SR's SSL placements during 2 sessions were within 80 μm in both the X- and Y-axes, and in 77% of quadrants, SR and AZC were within 80 μm in both axes. In adjudicated images, 90% of all quadrants were within 80 μm, 88% in nonopen-angle eyes, and 92% in open-angle eyes. The intraobserver and interobserver correlation coefficients (with and without adjudication) were above 0.9 for TISA750 and AOD750 for all quadrants. Conclusions. Reproducible identification of the SSL from images obtained with FD-ASOCT is possible. The ability to identify the SSL allows reproducible measurement of the anterior chamber angle using TISA750 and AOD750.

  18. Improved system calibration for specular surface measurement by using reflections from a plane mirror.

    PubMed

    Zhou, Tian; Chen, Kun; Wei, Haoyun; Li, Yan

    2016-09-01

    In this paper, we introduce a flexible and simple system calibration method for specular surface metrology based on the combination of reflection rays determined by the varied points on a screen and reflection images of a plane mirror without fiducials placed at three different locations. This calibration procedure involves three steps. The camera is first calibrated based on plane patterns. Then the reflection ray directions are measured via correspondence matching. The last calibration step is the pose estimation by the orthogonal iteration algorithm and reflections in a plane mirror. Basically, the concept of replacing the coordinates of the camera center with the reflection ray can alleviate the trouble of imaging aberration. Then global optimization can be operated with the orthogonal projection defined by the reflection ray, providing precise initial values for the process of bundle adjustment, compared to the classical calibration approach directly using the local optimization algorithm. Simulations and experiments both demonstrate the validity, efficiency, and robustness of the proposed improved method. In the simulations, the proposed method achieves the absolute errors of the camera parameters within 3 pixels and the relative errors of the screen pose are below 0.5% when the noise level is 0.6 pixel. Furthermore, the calibration method shows strong anti-noise ability, relying on the application of the reflection rays and the global optimization before the final bundle adjustment. In addition, the reconstruction accuracy in our experiment improves by 60.11% by the proposed method compared with the calibration procedure, which only utilizes the bundle adjustment optimization. In general, this novel calibration method can make the measurement achieve high accuracy and robustness at a low cost and with a simple setup, providing an efficient, economical, and flexible approach for a phase measuring deflectometry system in practical situations. PMID:27607278

  19. Full-scale measurements of aerodynamic induction in a rotor plane

    NASA Astrophysics Data System (ADS)

    Larsen, Gunner Chr; Hansen, Kurt S.

    2014-12-01

    Reliable modelling of aerodynamic induction is imperative for successful prediction of wind turbine loads and wind turbine dynamics when based on state-of- the-art aeroelastic tools. Full-scale LiDAR based wind speed measurements, with high temporal and spatial resolution, have been conducted in the rotor plane of an operating 2MW/80m wind turbine to perform detailed analysis the aerodynamic induction. The experimental setup, analyses of the spatial structure of the aerodynamic induction and subsequent comparisons with numerical predictions, using the HAWC2 aerolastic code, are presented.

  20. Dynamic speckle pattern technique on measuring in-plane deformation of metal surface

    NASA Astrophysics Data System (ADS)

    Li, Jingzhen; Li, Shanxiang; Sun, Yiling; An, Henan

    2001-04-01

    In order to study the metal target surface in-place deformation induced by the laser beam or other ones effecting upon, three kinds of measuring dynamic in-plane deformation techniques by means of a laser speckle, which are the speckle field time sequence processing (that is the optical flow analysis of speckle pattern), the digital speckle pattern processing (in fact, it is a kind of pattern or picture enhancement technique), and the digital speckle pattern correlation metrology, have been studded and developed. The latter, the correlation metrology, has been made a big progress: better precision and higher processing speed.

  1. Detection method of inclination angle in image measurement based on improved triangulation.

    PubMed

    Zhang, Jinfeng; Zhang, Jiye

    2015-02-01

    Image distortion seriously affects the accuracy in microscope image measurement. One source of such distortion is related to the tilting of the microscope stage during laser scanning, thereby resulting in various degrees of inclination angles. This paper describes a novel technique that improves the traditional laser triangulation method by using multiple parallel laser beams that can solve the inclination problem. Moreover, a multi-light-spot measurement device, based on the improved laser triangulation technique, is proposed that can accurately detect the degree and directions of the inclination angles in real time. Furthermore, experimental results generated from a prototype of this device show that the new measurement system can effectively detect small inclination angles at a precision up to ±0.5  μrad.

  2. Full optical characterization of autostereoscopic 3D displays using local viewing angle and imaging measurements

    NASA Astrophysics Data System (ADS)

    Boher, Pierre; Leroux, Thierry; Bignon, Thibault; Collomb-Patton, Véronique

    2012-03-01

    Two commercial auto-stereoscopic 3D displays are characterized a using Fourier optics viewing angle system and an imaging video-luminance-meter. One display has a fixed emissive configuration and the other adapts its emission to the observer position using head tracking. For a fixed emissive condition, three viewing angle measurements are performed at three positions (center, right and left). Qualified monocular and binocular viewing spaces in front of the display are deduced as well as the best working distance. The imaging system is then positioned at this working distance and crosstalk homogeneity on the entire surface of the display is measured. We show that the crosstalk is generally not optimized on all the surface of the display. Display aspect simulation using viewing angle measurements allows understanding better the origin of those crosstalk variations. Local imperfections like scratches and marks generally increase drastically the crosstalk, demonstrating that cleanliness requirements for this type of display are quite critical.

  3. Design of a dual-axis optoelectronic level for precision angle measurements

    NASA Astrophysics Data System (ADS)

    Fan, Kuang-Chao; Wang, Tsung-Han; Lin, Sheng-Yi; Liu, Yen-Chih

    2011-05-01

    The accuracy of machine tools is mainly determined by angular errors during linear motion according to the well-known Abbe principle. Precision angle measurement is important to precision machines. This paper presents the theory and experiments of a new dual-axis optoelectronic level with low cost and high precision. The system adopts a commercial DVD pickup head as the angle sensor in association with the double-layer pendulum mechanism for two-axis swings, respectively. In data processing with a microprocessor, the measured angles of both axes can be displayed on an LCD or exported to an external PC. Calibrated by a triple-beam laser angular interferometer, the error of the dual-axis optoelectronic level is better than ±0.7 arcsec in the measuring range of ±30 arcsec, and the settling time is within 0.5 s. Experiments show the applicability to the inspection of precision machines.

  4. Evaluation of algorithms for calculating bioimpedance phase angle values from measured whole-body impedance modulus.

    PubMed

    Nordbotten, Bernt J; Tronstad, Christian; Martinsen, Ørjan G; Grimnes, Sverre

    2011-07-01

    This paper addresses the problem of calculating the bioimpedance phase angle from measurements of impedance modulus. A complete impedance measurement was performed on altogether 20 healthy persons using a Solatron 1260/1294 system. The obtained impedance modulus (absolute impedance value) values were used to calculate the Cole parameters and from them the phase angles. In addition, the phase angles were also calculated using a Kramers-Kronig approach. A correlation analysis for all subjects at each frequency (5, 50, 100 and 200 kHz) for both methods gave R(2) values ranging from 0.7 to 0.96 for the Cole approach and from 0.83 to 0.96 for the Kramers-Kronig approach; thus, both methods gave good results compared with the complete measurement results. From further statistical significance testing of the absolute value of the difference between measured and calculated phase angles, it was found that the Cole equation method gave significantly better agreement for the 50 and 100 kHz frequencies. In addition, the Cole equation method gives the four Cole parameters (R(0), R(∞), τ(z) and α) using measurements at frequencies up to 200 kHz while the Kramers-Kronig method used frequencies up to 500 kHz to reduce the effect of truncation on the calculated results. Both methods gave results that can be used for further bioimpedance calculations, thus improving the application potential of bioimpedance measurement results obtained using relatively inexpensive and portable measurement equipment.

  5. Influence of light sheet separation on SPIV measurement in a large field spanwise plane

    NASA Astrophysics Data System (ADS)

    Foucaut, J. M.; Coudert, S.; Braud, C.; Velte, C.

    2014-03-01

    Stereoscopic particle image velocimetry (SPIV) is nowadays a well-established measurement technique for turbulent flows. However, the accuracy and the spatial resolution are still highly questionable in the presence of complex flow with both strong gradients and out-of-plane motions. To give guidelines for both setup and measurements of such flow configurations, a large region of overlap between two SPIV systems on the same laser light sheet is acquired in a plane normal to the streamwise direction of a high Reynolds turbulent boundary layer flow. A simple separation of the two light sheets is used to improve the accuracy of the measurements by increasing the velocity dynamic range especially. It also presents the enhancement of accuracy due to the light sheet separation for characterizing streamwise vortices (i.e. perpendicular to the sheet). The proposed technique has been demonstrated in the Laboratoire de Mécanique de Lille wind tunnel facility which has been specially designed to study fully developed turbulent boundary layers at high Reynolds numbers. The outlook is to study in detail the physics of the streamwise vortices generated from vortex generators taking advantage of the large scales of this turbulent boundary layer.

  6. Assessment of novel digital and smartphone goniometers for measurement of canine stifle joint angles.

    PubMed

    Freund, Kristin A; Kieves, Nina R; Hart, Juliette L; Foster, Sasha A; Jeffery, Unity; Duerr, Felix M

    2016-07-01

    OBJECTIVE To evaluate accuracy and reliability of 3 novel goniometers for measurement of canine stifle joint angles and compare the results with those obtained with a universal goniometer (UG). SAMPLE 8 pelvic limbs from 4 canine cadavers. PROCEDURES Each limb was secured to a wooden platform at 3 arbitrarily selected fixed stifle joint angles. Goniometry was performed with 2 smartphone-based applications (novel goniometers A and B), a digital goniometer (novel goniometer C), and a UG; 3 evaluators performed measurements in triplicate for each angle with each device. Results were compared with stifle joint angle measurements on radiographs (used as a gold standard). Accuracy was determined by calculation of bias and total error, coefficients of variation were calculated to estimate reliability, and strength of linear association between radiographic and goniometer measurements was assessed by calculation of correlation coefficients. RESULTS Mean coefficient of variation was lowest for the UG (4.88%), followed by novel goniometers B (7.37%), A (7.57%), and C (12.71%). Correlation with radiographic measurements was highest for the UG (r = 0.97), followed by novel goniometers B (0.93), A (0.90), and C (0.78). Constant bias was present for all devices except novel goniometer B. The UG and novel goniometer A had positive constant bias; novel goniometer C had negative constant bias. Total error at 50° and 100° angles was > 5% for all devices. CONCLUSIONS AND CLINICAL RELEVANCE None of the devices accurately represented radiographically measured stifle joint angles. Additional veterinary studies are indicated prior to the use of novel goniometers in dogs.

  7. Measurements of the angles {alpha} and {gamma} of the CKM unitarity triangle with the BABAR experiment

    SciTech Connect

    Malcles, Julie

    2006-07-11

    Measurements of the modes B {yields} {pi}{pi} and B {yields} {rho}{rho} and their implications on the angle a of the CKM unitarity triangle are presented. Results of the Dalitz analysis of the modes B {yields} D(*)0K(*) and the derived constraints on the angle {gamma} are then shown. These measurements are based on a sample of approximately 230.106 B pairs taken at the {upsilon}(4S) resonance collected by the BABAR detector at the PEP-II asymmetric-energy beam factory at SLAC.

  8. Measurement And Shape Analysis Including Vertebral Rotation Of Scoliotic Spines From Single Plane Radiographs

    NASA Astrophysics Data System (ADS)

    Drerup, B.; Hierholzer, E.

    1986-07-01

    Radiological assessment and follow-up control of scoliosis, i.e. of a lateral and rotational deviation of the spine, is performed mainly by single plane radiographs. Additional information may be gained from these radiographs by introducing a parametrized vertebral model. By analyzing the radiographic contours according to this model, axial rotation can be determined for any position and orientation of the vertebra. In addition to rotation several other data are determined for each vertebra, such as the tilting angle and the two-dimensional coordinates of the centre. By handling the data as a function of the vertebral location in spine, characteristic curves are generated. In order to find simple shape parameters for these characteristics, a smooth curve has to be fitted to the data points by a least squares approximation. This problem may be solved by a Fourier decomposition of the spinal curves. It appears, that the Fourier coefficients (amplitudes and phases) and some derived shape parameters lend themselves to a medical interpretation, which is consistent with the existing classification of the scoliotic spine.

  9. [Development of a nonmagnetic angle encoder for active shielding during biomagnetic measurements].

    PubMed

    Giessler, F; Witt, C; Haueisen, J; Bellemann, M E

    2002-04-01

    Biomagnetic fields--in particular in the low-frequency range--are subject to environmental interference, which cannot be adequately reduced by most passive shielding methods. However, the signal-to-noise ratio can be increased by active compensation. For this purpose, the interference is detected by reference sensors and fed back through integrated compensation coils. To establish deviation of normal directions between reference sensors and compensation coils, an angle encoder was developed. The rotation of the reference sensors about two axes at right angles to each other, is converted into voltage pulses by means of codewheels and photoelectric beams. The pulses are counted by incremental encoders, and represent a measure of the angles. A cardanic suspension and a plumb-line act as a reference system. The pulses counted are converted into binary angle values, which are used for coordinate transformation of the interfering fields. The angle encoder can determine the tilt of the reference sensors with an accuracy of 1 degree within a range between -45 and +45 degrees. The noise level of the system remains unaffected during a biomagnetic measurement. Magnetic signals of up to 5 pT arising during the oscillation of the plumb-line can be neglected because of the static nature of the angular measurement. PMID:12051137

  10. Dynamic Adduction Angle of Forefoot Measured With a Novel Technique And Its Relationship With Functional Outcomes

    PubMed Central

    Amin, Nirav Hasmukh; Jakoi, Andre; Alexander, Volpi MS; Morrison, Martin Joseph; Trobisch, Per

    2016-01-01

    Background Idiopathic clubfoot is commonly treated with the Ponseti method with the extent of invasive treatment involving tendon-Achilles lengthening. Forefoot adduction is a common complication in surgically treated clubfeet. Yet, no method has been described to measure dynamic (walking) forefoot adduction. The aim of this study was to assess the persistent pes adductus in children whose clubfeet were surgically treated using a dorsomedial soft tissue release and to find out correlations between forefoot adduction and clinical outcome measures. Methods We analysed the dynamic adduction angle in 33 clubfeet using a pressure-sensitive foot platform and compared it to the healthy feet of an age- and weight-matched group of children without congenital foot deformities. The clinical outcome was analysed using the McKay score. Results Mean dynamic adduction angle was 4.1o in the surgically corrected clubfeet, whereas it was 6.4° in unaffected feet of patients with unilateral clubfoot and 7.1o in control group. The McKay score were excellent in 1 patient, good in 5, average in 13, and fair in 4 of the 23 patients. There was no correlation between dynamic adduction angle and McKay score using paired t test (P > 0.05). Conclusion High occurrence of dynamic adduction angle in surgically treated clubfeet was detected. In conclusion, no correlation between forefoot adduction, dynamic forefoot adduction angle and clinical outcome measures within the study was observed. PMID:27547113

  11. Measuring Relative-Story Displacement and Local Inclination Angle Using Multiple Position-Sensitive Detectors

    PubMed Central

    Matsuya, Iwao; Katamura, Ryuta; Sato, Maya; Iba, Miroku; Kondo, Hideaki; Kanekawa, Kiyoshi; Takahashi, Motoichi; Hatada, Tomohiko; Nitta, Yoshihiro; Tanii, Takashi; Shoji, Shuichi; Nishitani, Akira; Ohdomari, Iwao

    2010-01-01

    We propose a novel sensor system for monitoring the structural health of a building. The system optically measures the relative-story displacement during earthquakes for detecting any deformations of building elements. The sensor unit is composed of three position sensitive detectors (PSDs) and lenses capable of measuring the relative-story displacement precisely, even if the PSD unit was inclined in response to the seismic vibration. For verification, laboratory tests were carried out using an Xθ-stage and a shaking table. The static experiment verified that the sensor could measure the local inclination angle as well as the lateral displacement. The dynamic experiment revealed that the accuracy of the sensor was 150 μm in the relative-displacement measurement and 100 μrad in the inclination angle measurement. These results indicate that the proposed sensor system has sufficient accuracy for the measurement of relative-story displacement in response to the seismic vibration. PMID:22163434

  12. New Measurements of the Angle Gamma at the BabarExperiment

    SciTech Connect

    Orimoto, Toyoko Jennifer; /LBL, Berkeley

    2007-11-07

    Measuring the angle {gamma} is an important part of over-constraining the Unitarity Triangle to test Standard Model predictions. There are a number of methods to measure {gamma}, and we present results on the progress made in measuring {gamma} with B meson decays, using data collected with the BABAR detector at the PEP-II asymmetric energy e{sup +}e{sup -} collider at SLAC.

  13. Visibility measurements using two-angle forward scattering by liquid droplets.

    PubMed

    Peng, Peng; Li, Chengwei

    2016-05-20

    This study presents a two-angle forward scattering (TAFS) method that can be used to detect atmosphere visibility and distinguish different weather phenomena. The visibility measuring instrument has two receivers arranged at the forward scattering angles of 35° and 90°, and the atmosphere visibility is measured by the first receiver (35°). We use the ratio between the scattering phase functions P(35°) and P(90°) to judge the asymmetry parameter of atmospheric particles and to distinguish the weather phenomenon. Compared with multi-angle forward scattering (MAFS) that can distinguish fog, haze, and mist, TAFS can determine additional weather phenomena (i.e., normal weather and rain) and has fewer receivers. Thus, we improve the instrument design of this method whose visibility error is smaller than that of MAFS on rainy days. PMID:27411113

  14. MEASUREMENT OF GALACTIC LOGARITHMIC SPIRAL ARM PITCH ANGLE USING TWO-DIMENSIONAL FAST FOURIER TRANSFORM DECOMPOSITION

    SciTech Connect

    Davis, Benjamin L.; Berrier, Joel C.; Shields, Douglas W.; Kennefick, Julia; Kennefick, Daniel; Seigar, Marc S.; Lacy, Claud H. S.; Puerari, Ivanio

    2012-04-01

    A logarithmic spiral is a prominent feature appearing in a majority of observed galaxies. This feature has long been associated with the traditional Hubble classification scheme, but historical quotes of pitch angle of spiral galaxies have been almost exclusively qualitative. We have developed a methodology, utilizing two-dimensional fast Fourier transformations of images of spiral galaxies, in order to isolate and measure the pitch angles of their spiral arms. Our technique provides a quantitative way to measure this morphological feature. This will allow comparison of spiral galaxy pitch angle to other galactic parameters and test spiral arm genesis theories. In this work, we detail our image processing and analysis of spiral galaxy images and discuss the robustness of our analysis techniques.

  15. Angle estimation of simultaneous orthogonal rotations from 3D gyroscope measurements.

    PubMed

    Stančin, Sara; Tomažič, Sašo

    2011-01-01

    A 3D gyroscope provides measurements of angular velocities around its three intrinsic orthogonal axes, enabling angular orientation estimation. Because the measured angular velocities represent simultaneous rotations, it is not appropriate to consider them sequentially. Rotations in general are not commutative, and each possible rotation sequence has a different resulting angular orientation. None of these angular orientations is the correct simultaneous rotation result. However, every angular orientation can be represented by a single rotation. This paper presents an analytic derivation of the axis and angle of the single rotation equivalent to three simultaneous rotations around orthogonal axes when the measured angular velocities or their proportions are approximately constant. Based on the resulting expressions, a vector called the simultaneous orthogonal rotations angle (SORA) is defined, with components equal to the angles of three simultaneous rotations around coordinate system axes. The orientation and magnitude of this vector are equal to the equivalent single rotation axis and angle, respectively. As long as the orientation of the actual rotation axis is constant, given the SORA, the angular orientation of a rigid body can be calculated in a single step, thus making it possible to avoid computing the iterative infinitesimal rotation approximation. The performed test measurements confirm the validity of the SORA concept. SORA is simple and well-suited for use in the real-time calculation of angular orientation based on angular velocity measurements derived using a gyroscope. Moreover, because of its demonstrated simplicity, SORA can also be used in general angular orientation notation.

  16. Angle Estimation of Simultaneous Orthogonal Rotations from 3D Gyroscope Measurements

    PubMed Central

    Stančin, Sara; Tomažič, Sašo

    2011-01-01

    A 3D gyroscope provides measurements of angular velocities around its three intrinsic orthogonal axes, enabling angular orientation estimation. Because the measured angular velocities represent simultaneous rotations, it is not appropriate to consider them sequentially. Rotations in general are not commutative, and each possible rotation sequence has a different resulting angular orientation. None of these angular orientations is the correct simultaneous rotation result. However, every angular orientation can be represented by a single rotation. This paper presents an analytic derivation of the axis and angle of the single rotation equivalent to three simultaneous rotations around orthogonal axes when the measured angular velocities or their proportions are approximately constant. Based on the resulting expressions, a vector called the simultaneous orthogonal rotations angle (SORA) is defined, with components equal to the angles of three simultaneous rotations around coordinate system axes. The orientation and magnitude of this vector are equal to the equivalent single rotation axis and angle, respectively. As long as the orientation of the actual rotation axis is constant, given the SORA, the angular orientation of a rigid body can be calculated in a single step, thus making it possible to avoid computing the iterative infinitesimal rotation approximation. The performed test measurements confirm the validity of the SORA concept. SORA is simple and well-suited for use in the real-time calculation of angular orientation based on angular velocity measurements derived using a gyroscope. Moreover, because of its demonstrated simplicity, SORA can also be used in general angular orientation notation. PMID:22164090

  17. Roll angle measurement with a large range based on the photoelectronic autocollimator

    NASA Astrophysics Data System (ADS)

    Li, Wen-jie; Mu, Quan-quan; Wang, Shao-xin; Wang, Hai-ping; Yang, Cheng-liang; Cao, Zhao-liang; Xuan, Li

    2016-01-01

    In this paper, we propose a roll angle measurement method with a large range based on the photoelectronic autocollimator. According to the corresponding relationship between the rotation position of the measured shaft and the spot position on the circular trajectory, the roll angle is calculated quickly and conveniently using a simple algorithm. Only a mirror, a coupler and a fine shaft are contained in the measurement system besides the photoelectronic autocollimator. Aiming at the terrible measurement error induced by the axis wobbly error, two measurement schemes are proposed, which are linking the fine precision shaft to the measured shaft for reducing the axis wobbly error and using the segment measurement to enlarge the radius of the circular trajectory. The experimental results show that the measurement error is decreased by ±0.38°. The roll angle error of the mechanism is ±0.14°, and the measurement precision is about ±2'. The proposed method can be widely used in the engineering fields.

  18. Drag measurements on long thin cylinders at small angles and high Reynolds numbers

    NASA Astrophysics Data System (ADS)

    Keith, William L.; Cipolla, Kimberly M.; Hart, David R.; Furey, Deborah A.

    2005-06-01

    Measurements of the drag caused by turbulent boundary layer mean wall shear stress on cylinders at small angles of attack and high length Reynolds numbers (8×106angles, resulting in linear cylinder geometry for tow speeds ranging from 2.6 m/s to 20.7 m/s and angles between 0° and 12°. Towing angles were measured with digital photography, and streamwise drag was measured with a strut-mounted load cell at the tow point. The measured tangential drag was very sensitive to small increases in angle at all tow speeds. A momentum thickness length scale is proposed to scale the tangential drag coefficient. The effects of the cross-flow resulting from the small angles of tow have a significant effect on the tangential drag coefficient values. A scaling for the orthogonal force on the cylinders was determined and provides a correction to published normal drag coefficient values for pure cross-flow. The presence of the axial turbulent boundary layer has a significant effect on these orthogonal forces.

  19. A shearing-based method for the simultaneous calibration of angle measuring devices

    NASA Astrophysics Data System (ADS)

    Geckeler, Ralf D.; Just, Andreas

    2014-10-01

    In this paper, we present a novel adaptation of the shearing method to the simultaneous calibration of angle measuring devices which is based on multiple comparisons of their angle readings in different relative angular orientations. Without recourse to an external standard, the errors of the two devices can be recovered, up to their linear components, from a set of three comparisons. We demonstrate the method by the use of an autocollimator and an angle encoder. It proved to be ideally suited for the calibration of interpolation errors of the devices at small angular scales which are difficult to characterize with other methods. In the case that the linear components of the errors are needed, too, only two angle differences, which correspond to the changes in the relative angular orientations of the devices, need to be traced back to an external standard. A comprehensive overview, both theoretical and experimental, of the capabilities and limitations of the method is presented, including experimental data obtained with the high-precision primary angle standard of PTB. We demonstrate error-separation with a standard measurement uncertainty at a level of 1 milliarcsecond (5 nrad) which, when compared to uncertainties reachable by conventional calibration methods for autocollimators, represents an improvement by a factor of 2-3.

  20. Rotational positioning measurement for the absolute angle based on a hetero-core fiber optics sensor

    NASA Astrophysics Data System (ADS)

    Nishiyama, Michiko; Watanabe, Kazuhiro

    2009-10-01

    We proposed a new approach to measure the rotational angle and describe how the rotational positioning sensor could be devised arranging the hetero-core fiber-optic macro-bending sensors in terms of detecting the absolute rotational angle. The hetero-core fiber optic sensor has many advantages such as ability of macro-bend sensing with optical intensity-based measurement, single-mode transmission basis and independence of temperature fluctuation for external environment. Therefore, it is suitable that the rotational positioning sensor is fabricated with the hetero-core fiber-optic technique. We designed two types of the absolute rotational position sensor modules to convert the absolute rotational angle to the displacement. The result showed that the proposed rotational positioning modules were sufficiently sensitive to the given rotational angle with monotonic loss change characteristics. The hetero-core rotational positioning sensors were successfully perceptive with typical sensitivities approximately 0.77 and 0.71 dB in the rotational angle ranges of 60 - 360 and 60 - 180 degrees. The deviation of the module in the range of 60 - 180 degrees induced 1.74 % that corresponded to 2.13 degrees.

  1. Determination of basic friction angle using various laboratory tests.

    NASA Astrophysics Data System (ADS)

    Jang, Bo-An

    2016-04-01

    The basic friction angle of rock is an important factor of joint shear strength and is included within most shear strength criteria. It can be measured by direct shear test, triaxial compression test and tilt test. Tilt test is mostly used because it is the simplest method. However, basic friction angles measured using tilt test for same rock type or for one sample are widely distributed and often do not show normal distribution. In this research, the basic friction angles for the Hangdeung granite form Korea and Berea sandstone from USA are measured accurately using direct shear test and triaxial compression test. Then basic friction angles are again measured using tilt tests with various conditions and are compared with those measured using direct shear test and triaxial compression test to determine the optimum condition of tilt test. Three types of sliding planes, such as planes cut by saw and planes polished by #100 and #600 grinding powders, are prepared. When planes are polished by #100 grinding powder, the basic friction angles measured using direct shear test and triaxial compression test are very consistent and show narrow ranges. However, basic friction angles show wide ranges when planes are cut by saw and are polished by #600 grinding powder. The basic friction angle measured using tilt test are very close to those measured using direct shear test and triaxial compression test when plane is polished by #100 grinding powder. When planes are cut by saw and are polished by #600 grinding powder, basic friction angles measured using tilt test are slightly different. This indicates that tilt test with plane polished by #100 grinding powder can yield an accurate basic friction angle. In addition, the accurate values are obtained not only when planes are polished again after 10 times of tilt test, but values are averaged by more 30 times of tests.

  2. Photoacoustic clutter reduction by inversion of a linear scatter model using plane wave ultrasound measurements.

    PubMed

    Schwab, Hans-Martin; Beckmann, Martin F; Schmitz, Georg

    2016-04-01

    Photoacoustic imaging aims to visualize light absorption properties of biological tissue by receiving a sound wave that is generated inside the observed object as a result of the photoacoustic effect. In clinical applications, the strong light absorption in human skin is a major problem. When high amplitude photoacoustic waves that originate from skin absorption propagate into the tissue, they are reflected back by acoustical scatterers and the reflections contribute to the received signal. The artifacts associated with these reflected waves are referred to as clutter or skin echo and limit the applicability of photoacoustic imaging for medical applications severely. This study seeks to exploit the acoustic tissue information gained by plane wave ultrasound measurements with a linear array in order to correct for reflections in the photoacoustic image. By deriving a theory for clutter waves in k-space and a matching inversion approach, photoacoustic measurements compensated for clutter are shown to be recovered. PMID:27446669

  3. Photoacoustic clutter reduction by inversion of a linear scatter model using plane wave ultrasound measurements.

    PubMed

    Schwab, Hans-Martin; Beckmann, Martin F; Schmitz, Georg

    2016-04-01

    Photoacoustic imaging aims to visualize light absorption properties of biological tissue by receiving a sound wave that is generated inside the observed object as a result of the photoacoustic effect. In clinical applications, the strong light absorption in human skin is a major problem. When high amplitude photoacoustic waves that originate from skin absorption propagate into the tissue, they are reflected back by acoustical scatterers and the reflections contribute to the received signal. The artifacts associated with these reflected waves are referred to as clutter or skin echo and limit the applicability of photoacoustic imaging for medical applications severely. This study seeks to exploit the acoustic tissue information gained by plane wave ultrasound measurements with a linear array in order to correct for reflections in the photoacoustic image. By deriving a theory for clutter waves in k-space and a matching inversion approach, photoacoustic measurements compensated for clutter are shown to be recovered.

  4. Photoacoustic clutter reduction by inversion of a linear scatter model using plane wave ultrasound measurements

    PubMed Central

    Schwab, Hans-Martin; Beckmann, Martin F.; Schmitz, Georg

    2016-01-01

    Photoacoustic imaging aims to visualize light absorption properties of biological tissue by receiving a sound wave that is generated inside the observed object as a result of the photoacoustic effect. In clinical applications, the strong light absorption in human skin is a major problem. When high amplitude photoacoustic waves that originate from skin absorption propagate into the tissue, they are reflected back by acoustical scatterers and the reflections contribute to the received signal. The artifacts associated with these reflected waves are referred to as clutter or skin echo and limit the applicability of photoacoustic imaging for medical applications severely. This study seeks to exploit the acoustic tissue information gained by plane wave ultrasound measurements with a linear array in order to correct for reflections in the photoacoustic image. By deriving a theory for clutter waves in k-space and a matching inversion approach, photoacoustic measurements compensated for clutter are shown to be recovered. PMID:27446669

  5. Measurements of UV radiation on rotating vertical plane at the ALOMAR Observatory (69° N, 16° E), Norway, June 2007

    NASA Astrophysics Data System (ADS)

    Sobolewski, P.; Krzyścin, J. W.; Jarosławski, J.; Stebel, K.

    2008-01-01

    Erythemaly weighted UV and total UVA irradiance measured at the ALOMAR (Arctic Lidar Observatory for Middle Atmosphere Research; 69° N, 16° E) in June 2007 by two Kipp & Zonen UV broadband meters type, UV-S-AE-T, are examined. One unit is movable and mounted to rotating vertical plane, and the other is permanently fixed horizontally. The UV broadband meters measure simultaneously to allow the comparison of UV irradiances on vertical and horizontal plane. The entire range of relative exposure variations during clear-sky conditions over ALOMAR is examined using STAR and Radonic1 model (developed at the Meteorological Institute, Munich) for various action spectra (erythema, UVA, and vitamin D3). It seems that multiplication of the daily mean dose from a standard broadband meter placed horizontally by 0.5 gives reasonable estimation of the daily mean exposure on a vertical plane randomly oriented towards Sun. The extreme value and daily variability of relative exposure are the highest for UVA, next for UVB, then for vitamin D3 weighed UV irradiance. The minima of relative exposure (~0.20-0.30) are almost the same for all weighting functions. Specific cloud configuration could lead to significant enhancement of UV relative exposure of rotating plane being the most pronounced when biometer is in shadow. A statistical model is proposed, that it is able to simulate vitamin D3 weighted UV irradiances on vertical surface using explanatory variables: erythemal and total UVA irradiance from standard (horizontal) observations by Kipp & Zonen dual band biometer, the orientation of vertical plane, solar zenith angle, and column amount of total ozone. Statistical model will allow to reconstruct (or monitor) vitamin D3 weighted UV irradiances using available past (or actual) data.

  6. Nondestructive Determination of Moisture Content in Dry Fruits by Impedance and Phase angle measurements

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Impedance (Z), and phase angle (') of a cylindrical parallel-plate capacitor with dry fruits between the plates was measured using a CI meter (Chari’s Impedance meter), at 1 and 9 MHz . Capacitance, C was derived from Z and ', and using the C, ', and Z values of a set of cherries whose moisture con...

  7. Evaluating Radiometric Measurements Using a Fixed 45 Degrees Responsivity and Zenith Angle Dependent Responsivities (Poster)

    SciTech Connect

    Dooraghi, M.; Habte, A.; Reda, I.; Sengupta, M.; Gotseff, P.; Andreas, A.; Anderberg, M.

    2014-03-01

    This poster seeks to demonstrate the importance and application of an existing but unused approach that ultimately reduces the uncertainty of radiometric measurements. Current radiometric data is based on a single responsivity value that introduces significant uncertainty to the data, however, through using responsivity as a function of solar zenith angle, the uncertainty could be decreased by 50%.

  8. Measurement of the CKM Angle alpha with the B-factories.

    SciTech Connect

    Bevan, Adrian; /Liverpool U.

    2005-12-21

    B-meson decays involving b {yields} u transitions are sensitive to the Unitarity Triangle angle {alpha} (or {phi}{sub 2}). The B-factories at SLAC and KEK have made significant progress toward the measurement of {alpha} in recent years. This paper summarizes the results of the B-factories' constraints on {alpha}.

  9. Research on measurement of flying object nutation angle based on double linear CCD intersection

    NASA Astrophysics Data System (ADS)

    Ma, Weihong; Pang, Qiuhong; Ni, Jinping

    2012-01-01

    The importance of space scale matching of flying direction and object long axis is presented when we measure nutation angle of flying object with slit photography, and a new method to measure nutation angle of flying object combined slit photography and double linear CCD intersection is examined. A brief methodology of nutation angle computing by series double linear image analysis is discussed, and a nunation angle measurement system is designed. A series linear image analysis method is developed to obtain the image position of series point on object long axis at pixel scale, and then the double linear CCD intersection theory is used to find the space coordinate position of various points at actual space scale. They are also put forward in this paper that invalid coordinate data are rejected by line detecting and flying direction data space is decided by perpendicular flying distance of object at CCD sampling interval. At final, a practical test sample is given, and the feasibility of measurement method is proved.

  10. Models to relate wafer geometry measurements to in-plane distortion of wafers

    NASA Astrophysics Data System (ADS)

    Turner, Kevin T.; Vukkadala, Pradeep; Sinha, Jaydeep K.

    2016-04-01

    Achieving satisfactory overlay is increasingly challenging as feature sizes are reduced and allowable overlay budgets shrink to several nanometers and below. Overlay errors induced by wafer processing, such as film deposition and etching, constitute a meaningful fraction of overlay budgets. Wafer geometry measurements provide the opportunity to quantify stress-induced distortions at the wafer level and provide information that can be used in a feedback mode to alter wafer processing or in a feed-forward mode to set wafer-specific corrections in the lithography tool. In order for such feed-forward schemes based on wafer geometry to be realized, there is a need for mechanics models that relate in-plane distortion of a chucked wafer to the out-of-plane distortion of a wafer in a free state. Here, a simple analytical model is presented that shows the stress-induced component of overlay is correlated to a corrected local wafer slope metric for a wide range of cases. The analytical model is validated via finite element (FE) simulations of wafers with nonuniform stress distributions. Furthermore, FE modeling is used here to examine the effect of the spatial wavelength of stress variation on the connection between slope and the wafer stress-induced component of overlay.

  11. Building America Case Study: Measure Guideline: Guidance on Taped Insulating Sheathing Drainage Planes (Fact Sheet)

    SciTech Connect

    Not Available

    2014-11-01

    This guide provides information and recommendations to the following groups: Insulation contractors, General contractors, Builders, Home remodelers, Mechanical contractors, and Homeowners as a guide to the work that needs to be done. The order of work completed during home construction and retrofit improvements is important. Health and safety issues must be addressed first and are more important than durability issues. And durability issues are more important than saving energy. Not all techniques can apply to all houses. Special conditions will require special action. Some builders or homeowners will wish to do more than the important but basic retrofit strategies outlined by this guide. The following are best practice and product recommendations from the interviewed contractors and home builders who collectively have a vast amount of experience. Three significant items were discussed with the group which are required to make taped insulating sheathing a simple, long term, and durable drainage plane: 4. Horizontal joints should be limited or eliminated wherever possible 5. Where a horizontal joint exists use superior materials 6. Frequent installation inspection and regular trade training are required to maintain proper installation Section 5 of this measure guideline contains the detailed construction procedure for the three recommended methods to effectively seal the joints in exterior insulating sheathing to create a simple, long term, and durable drainage plane.

  12. The Availability of Radiological Measurement of Femoral Anteversion Angle: Three-Dimensional Computed Tomography Reconstruction

    PubMed Central

    Byun, Ha Young; Shin, Heesuk; Lee, Eun Shin; Kong, Min Sik; Lee, Seung Hun

    2016-01-01

    Objective To assess the intra-rater and inter-rater reliability for measuring femoral anteversion angle (FAA) by a radiographic method using three-dimensional computed tomography reconstruction (3D-CT). Methods The study included 82 children who presented with intoeing gait. 3D-CT data taken between 2006 and 2014 were retrospectively reviewed. FAA was measured by 3D-CT. FAA is defined as the angle between the long axis of the femur neck and condylar axis of the distal femur. FAA measurement was performed twice at both lower extremities by each rater. The intra-rater and inter-rater reliability were calculated by intraclass correlation coefficient (ICC). Results One hundred and sixty-four lower limbs of 82 children (31 boys and 51 girls, 6.3±3.2 years old) were included. The ICCs of intra-rater measurement for the angle of femoral neck axis (NA) were 0.89 for rater A and 0.96 for rater B, and those of condylar axis (CA) were 0.99 for rater A and 0.99 for rater B, respectively. The ICC of inter-rater measurement for the angle of NA was 0.89 and that of CA was 0.92. By each rater, the ICCs of the intrarater measurement for FAA were 0.97 for rater A and 0.95 for rater B, respectively and the ICC of the inter-rater measurement for FAA was 0.89. Conclusion The 3D-CT measures for FAA are reliable within individual raters and between different raters. The 3D-CT measures of FAA can be a useful method for accurate diagnosis and follow-up of femoral anteversion. PMID:27152273

  13. X-ray tomography of large objects with limited measurement angle

    SciTech Connect

    Vepsäläinen, Mikko; Markkanen, Markku; Sundberg, Pauli

    2014-02-18

    In this paper we present an efficient implementation of an algorithm for reconstructing a 3D volume from limited angle projection data, based on statistical inversion theory. We demonstrate the strength of the method for detecting structural defects in large composite aerospace components, whose dimensions prevent acquiring measurements over the full circle. In comparison with a number of other tomographic reconstruction methods that can be applied to the limited angle case, such as tomosynthesis or simultaneous algebraic reconstruction technique (SART), we achieve superior depth resolution with reduced noise and artifacts.

  14. Monitoring regional vegetation change using reflectance measurements from multiple solar zenith angles.

    PubMed

    Russell, M

    2001-09-01

    Many traditional models of vegetation canopy reflectance have commonly used one of two approaches. Either the canopy is assumed to consist of discrete objects of known reflectance and geometric-optics are then used to calculate shading effects, or, as in the turbid medium approach, the canopy is treated as a horizontally homogeneous layer of small elements of known optical properties and radiative transfer theory is used to calculate canopy reflectance. This paper examines the effect of solar zenith angle on the reflectance of red and near-infrared radiation from forests using a combination of these modelling approaches. Forests are first modelled as randomly spaced eucalypt crowns over a homogeneous understorey and the fractional coverage of four components: shaded and sunlit canopy and shaded and sunlit understorey are calculated. Reflectance from each fraction is then modelled for a range of solar zenith angles using the Verhoef SAIL model. The overall scene reflection as seen by a nadir viewing satellite sensor is compared for three forest types representing a gradient of crown density from open dry grassy woodlands to dense wetter closed forest with an understorey of mesophytic plants. Modelled trends in scene reflectance change are consistent with aircraft measurements carried out at three different solar zenith angles. Results indicate that an increase in both tree density and solar zenith angle leads to an increase in the dominance of shaded components. In the visible band, both the sparsely treed woodland and the medium density dry forest show similar trends to that predicted by a turbid medium model, however, the wet forest shows a less rapid decrease in reflectance with solar zenith angle. In the near-infrared band, as tree density increases from woodland to wet forest, overall scene reflectance shows increased departure from that modelled using the traditional assumption of smooth homogeneous canopies, changing from an increase with solar zenith angle

  15. Measurement of the CKM Angles at BaBar And Belle

    SciTech Connect

    Barlow, Nick; /Manchester U.

    2007-12-05

    The primary goal of the BaBar and Belle experiments is to overconstrain the CKM Unitarity Triangle. Measurements of the angles of this triangle, known as {beta}, {alpha}, and {gamma} (or {phi}{sub 1}, {phi}{sub 2}, and {phi}{sub 3}) give insight into the Standard Model description of CP violation in the quark sector. BaBar and Belle have recorded almost 1 ab{sup -1} combined, and have measured {beta} to high precision. Measurements of {alpha} and {gamma} are less precise at present, but both experiments are rapidly accumulating data and developing new analysis techniques, and measurements of these angles will continue to provide useful constraints on the Standard Model description of CP violation in the years to come.

  16. Calibration method of laser plane equation for vision measurement adopting objective function of uniform horizontal height of feature points

    NASA Astrophysics Data System (ADS)

    Xu, Guan; Hao, Zhaobing; Li, Xiaotao; Su, Jian; Liu, Huanping; Zhang, Xinyuan

    2016-02-01

    A calibration method with an objective function generated from a uniform horizontal height is presented in this work for the laser plane in active vision measurement. A height target is developed with a center mark as the initial point of the uniform height. The height target is located on the horizontal plane of the 3D calibration board so that the horizontal plane is considered as the terminal of the uniform horizontal height. Based on the pinhole model of the camera and the laser plane equation, we model the objective function to find the optimal coefficients of the laser plane equation. The goal of the objective function is the smallest difference of the uniform height and the reconstructed height according to the feature points of the target. The objective function is optimized by the local particle swarm optimization. The calibrated global equation of a laser plane is obtained from the optimal value 1.153 × 103 of the objective function in the experiments. Two projective laser lines of the calibration laser plane cover the original laser lines in the image. The reconstruction errors of the calibration plane are also analyzed in discussions.

  17. Noctilucent cloud polarimetry: Twilight measurements in a wide range of scattering angles

    NASA Astrophysics Data System (ADS)

    Ugolnikov, Oleg S.; Maslov, Igor A.; Kozelov, Boris V.; Dlugach, Janna M.

    2016-06-01

    Wide-field polarization measurements of the twilight sky background during several nights with bright and extended noctilucent clouds in central and northern Russia in 2014 and 2015 are used to build the phase dependence of the degree of polarization of sunlight scattered by cloud particles in a wide range of scattering angles (from 40° to 130°). This range covers the linear polarization maximum near 90° and large-angle slope of the curve. The polarization in this angle range is most sensitive to the particle size. The method of separation of scattering on cloud particles from the twilight background is presented. Results are compared with T-matrix simulations for different sizes and shapes of ice particles; the best-fit model radius of particles (0.06 μm) and maximum radius (about 0.1 μm) are estimated.

  18. Experimental measurement of the angle of repose of a pile of soft frictionless grains

    NASA Astrophysics Data System (ADS)

    Feitosa, Klebert; Shorts, Daniel

    It is well known that dry granular materials can flow like a liquid, but can also behave as a solid and sustain a finite angle of repose, partially as a result of inter-particle friction. Here we investigate the nature of piles formed with soft frictionless grains and measure its angle of repose. The pile is produced by a continuous bubbling of air into a soapy solution in a narrow container of rectangular cross section. We observe a gentle slope at the water-foam interface whose angle dependents on the viscosity of the liquid. In contrast with sand piles, the fluidized region along the interface is several layers deep. We also find that, unlike sand piles, upon interruption of the gas flux, the slope relaxes back to zero as a result of bubble rearrangements and liquid drainage.

  19. Method for Correcting Control Surface Angle Measurements in Single Viewpoint Photogrammetry

    NASA Technical Reports Server (NTRS)

    Burner, Alpheus W. (Inventor); Barrows, Danny A. (Inventor)

    2006-01-01

    A method of determining a corrected control surface angle for use in single viewpoint photogrammetry to correct control surface angle measurements affected by wing bending. First and second visual targets are spaced apart &om one another on a control surface of an aircraft wing. The targets are positioned at a semispan distance along the aircraft wing. A reference target separation distance is determined using single viewpoint photogrammetry for a "wind off condition. An apparent target separation distance is then computed for "wind on." The difference between the reference and apparent target separation distances is minimized by recomputing the single viewpoint photogrammetric solution for incrementally changed values of target semispan distances. A final single viewpoint photogrammetric solution is then generated that uses the corrected semispan distance that produced the minimized difference between the reference and apparent target separation distances. The final single viewpoint photogrammetric solution set is used to determine the corrected control surface angle.

  20. Flow Visualization in Evaporating Liquid Drops and Measurement of Dynamic Contact Angles and Spreading Rate

    NASA Technical Reports Server (NTRS)

    Zhang, Neng-Li; Chao, David F.

    2001-01-01

    A new hybrid optical system, consisting of reflection-refracted shadowgraphy and top-view photography, is used to visualize flow phenomena and simultaneously measure the spreading and instant dynamic contact angle in a volatile-liquid drop on a nontransparent substrate. Thermocapillary convection in the drop, induced by evaporation, and the drop real-time profile data are synchronously recorded by video recording systems. Experimental results obtained from this unique technique clearly reveal that thermocapillary convection strongly affects the spreading process and the characteristics of dynamic contact angle of the drop. Comprehensive information of a sessile drop, including the local contact angle along the periphery, the instability of the three-phase contact line, and the deformation of the drop shape is obtained and analyzed.

  1. A novel method for measuring the polarization angle of satellite radio waves

    NASA Technical Reports Server (NTRS)

    Antoniadis, D. A.

    1974-01-01

    One of the most important parameters for the study of the physics of the ionosphere is the columnar electron content. This can be obtained indirectly by measuring the Faraday rotation of signals emitted from satellites. Many different types of polarimeters have been developed for this purpose. Efforts to develop a new type of polarimeter, suitable for extensive network operation, led to a novel technique for measuring the polarization angle.

  2. Measurements of the CKM Angle Beta/Phi(1) at the B Factories

    SciTech Connect

    Ocariz, J.; /Paris U., VI-VII

    2006-08-23

    We report measurements of time-dependent CP asymmetries related to the CKM angle {beta}/{phi}{sub 1}, using decays of neutral B mesons to charmonium, open charm and in b {yields} s loop-dominated processes. A preliminary measurement of time-dependent CP asymmetries in B{sup 0} {yields} {rho}{sup 0}(770)K{sub S}{sup 0} decays from the BABAR experiment is given here.

  3. Contact angle measurements of a polyphenyl ether to 190 C on M-50 steel

    NASA Technical Reports Server (NTRS)

    Jones, W. R., Jr.

    1981-01-01

    Contact angle measurements were performed for a polyphenyl ether on steel in nitrogen. A tilting plate and a sessile drop apparatus were used. Surface tension was measured with a maximum bubble pressure apparatus. Critical surface energies of spreading were found to be 30.1 and 31.3 dynes/cm. It was concluded that the polyphenyl ether is inherently autophobic and will not spread on its own surface film.

  4. Dual-angle, self-calibrating Thomson scattering measurements in RFX-MOD

    SciTech Connect

    Giudicotti, L.

    2014-11-15

    In the multipoint Thomson scattering (TS) system of the RFX-MOD experiment the signals from a few spatial positions can be observed simultaneously under two different scattering angles. In addition the detection system uses optical multiplexing by signal delays in fiber optic cables of different length so that the two sets of TS signals can be observed by the same polychromator. Owing to the dependence of the TS spectrum on the scattering angle, it was then possible to implement self-calibrating TS measurements in which the electron temperature T{sub e}, the electron density n{sub e} and the relative calibration coefficients of spectral channels sensitivity C{sub i} were simultaneously determined by a suitable analysis of the two sets of TS data collected at the two angles. The analysis has shown that, in spite of the small difference in the spectra obtained at the two angles, reliable values of the relative calibration coefficients can be determined by the analysis of good S/N dual‑angle spectra recorded in a few tens of plasma shots. This analysis suggests that in RFX-MOD the calibration of the entire set of TS polychromators by means of the similar, dual-laser (Nd:YAG/Nd:YLF) TS technique, should be feasible.

  5. Dual-angle, self-calibrating Thomson scattering measurements in RFX-MOD

    NASA Astrophysics Data System (ADS)

    Giudicotti, L.; Pasqualotto, R.; Fassina, A.

    2014-11-01

    In the multipoint Thomson scattering (TS) system of the RFX-MOD experiment the signals from a few spatial positions can be observed simultaneously under two different scattering angles. In addition the detection system uses optical multiplexing by signal delays in fiber optic cables of different length so that the two sets of TS signals can be observed by the same polychromator. Owing to the dependence of the TS spectrum on the scattering angle, it was then possible to implement self-calibrating TS measurements in which the electron temperature Te, the electron density ne and the relative calibration coefficients of spectral channels sensitivity Ci were simultaneously determined by a suitable analysis of the two sets of TS data collected at the two angles. The analysis has shown that, in spite of the small difference in the spectra obtained at the two angles, reliable values of the relative calibration coefficients can be determined by the analysis of good S/N dual-angle spectra recorded in a few tens of plasma shots. This analysis suggests that in RFX-MOD the calibration of the entire set of TS polychromators by means of the similar, dual-laser (Nd:YAG/Nd:YLF) TS technique, should be feasible.

  6. Polarization measurement analysis. III. Analysis of the polarization angle dispersion function with high precision polarization data

    NASA Astrophysics Data System (ADS)

    Alina, D.; Montier, L.; Ristorcelli, I.; Bernard, J.-P.; Levrier, F.; Abdikamalov, E.

    2016-10-01

    High precision polarization measurements, such as those from the Planck satellite, open new opportunities for the study of the magnetic field structure as traced by polarimetric measurements of the interstellar dust emission. The polarization parameters suffer from bias in the presence of measurement noise. It is critical to take into account all the information available in the data in order to accurately derive these parameters. In our previous work, we studied the bias on polarization fraction and angle, various estimators of these quantities, and their associated uncertainties. The goal of this paper is to characterize the bias on the polarization angle dispersion function that is used to study the spatial coherence of the polarization angle. We characterize for the first time the bias on the conventional estimator of the polarization angle dispersion function and show that it can be positive or negative depending on the true value. Monte Carlo simulations were performed to explore the impact of the noise properties of the polarization data, as well as the impact of the distribution of the true polarization angles on the bias. We show that in the case where the ellipticity of the noise in (Q,U) varies by less than 10%, one can use simplified, diagonal approximation of the noise covariance matrix. In other cases, the shape of the noise covariance matrix should be taken into account in the estimation of the polarization angle dispersion function. We also study new estimators such as the dichotomic and the polynomial estimators. Though the dichotomic estimator cannot be directly used to estimate the polarization angle dispersion function, we show that, on the one hand, it can serve as an indicator of the accuracy of the conventional estimator and, on the other hand, it can be used for deriving the polynomial estimator. We propose a method for determining the upper limit of the bias on the conventional estimator of the polarization angle dispersion function. The

  7. Rapid spatial characterization measurements of a multi-element focal plane using derived geometrical information

    NASA Astrophysics Data System (ADS)

    Baer, James W.; Drouillard, Thomas F.

    2012-10-01

    While some instrument requirements are levied on a per-pixel basis, efficiencies and economies can be gained by testing them in parallel. Furthermore, the use of detector arrays as imagers with extended targets enables the derivation of geometrical information from select pixels in each image, and its propagation to neighboring pixels. We discuss the implementation of one such test regime for the Operational Landsat Imager (OLI) at Ball Aerospace and Technologies Corp. This enabled rapid measurement of spatial parameters, including Edge Response Function and aliasing, for all of the nearly 70,000 active pixels of the focal plane assembly with reduced reliance on the precision and stability of the supporting equipment. The derived geometrical information enabled us to replace a step-stare testing of individual pixels with a continuous scan of the entire assembly, without demanding precision motion or introducing noise from variations in the scan velocity. Three complete scans were performed in under 30 hours.

  8. Measurement of optical modulation functions in sparsely sampled mosaic focal plane arrays

    NASA Technical Reports Server (NTRS)

    Young, J. B.; Thurlow, P. E.

    1982-01-01

    It is pointed out that the measurement of optical modulation functions for detectors in focal plane arrays may be somewhat more difficult under 'full-up' systems conditions as compared to ideal laboratory conditions. An idealized optical modulation test arrangement is considered along with a full-up scanned system involving an earth mapper in polar orbit. In testing the system in full-up condition, a problem arises with respect to the acquisition of knife edge response data. In order to overcome this problem, a preferred method is developed for obtaining KER data on a single scan. A special 'phased edge' reticle is developed for use in the test set-up. Attention is given to aspects of knife edge reconstruction.

  9. Measuring In-Plane Displacements with Variable Sensitivity Using Diffractive Optic Interferometry

    NASA Technical Reports Server (NTRS)

    Shepherd, Robert L.; Gilbert, John A.; Cole, Helen J.; Ashley, Paul R.

    1998-01-01

    This paper introduces a method called diffractive optic interferometry (DOI) which allows in-plane displacement components to be measured with variable sensitivity. DOI relies on binary optical elements fabricated as phase-type Dammann gratings which produce multiple diffraction orders of nearly equal intensity. Sensitivity is varied by combining the different wavefronts produced by a conjugate pair of these binary optical elements; a transmission element is used to produce several illumination beams while a reflective element, replicated on the surface of a specimen, provides the reference for the undeformed state. The steps taken to design and fabricate these binary optical elements are described. The specimen grating is characterized, and tested on a disk subjected to diametrical compression. Overall, the results are excellent, with experimental data agreeing to within a few percent of the theoretical predictions.

  10. Radiographic angles in hallux valgus: Comparison between protractor and iPhone measurements.

    PubMed

    Meng, Hong-Zheng; Zhang, Wei-Lin; Li, Xiu-Cheng; Yang, Mao-Wei

    2015-08-01

    Radiographic angles are used to assess the severity of hallux valgus deformity, make preoperative plans, evaluate outcomes after surgery, and compare results between different methods. Traditionally, hallux valgus angle (HVA) has been measured by using a protractor and a marker pen with hardcopy radiographs. The main objective of this study is to compare HVA measurements performed using a smartphone and a traditional protractor. The secondary objective was to compare the time taken between those two methods. Six observers measured major HVA on 20 radiographs of hallux valgus deformity with both a standard protractor and an Apple iPhone. Four of the observers repeated the measurements at least a week after the original measurements. The mean absolute difference between pairs of protractor and smartphone measurements was 3.2°. The 95% confidence intervals for intra-observer variability were ±3.1° for the smartphone measurement and ±3.2° for the protractor method. The 95% confidence intervals for inter-observer variability were ±9.1° for the smartphone measurement and ±9.6° for the protractor measurement. We conclude that the smartphone is equivalent to the protractor for the accuracy of HVA measurement. But, the time taken in smartphone measurement was also reduced. PMID:25763918

  11. Radiographic angles in hallux valgus: Comparison between protractor and iPhone measurements.

    PubMed

    Meng, Hong-Zheng; Zhang, Wei-Lin; Li, Xiu-Cheng; Yang, Mao-Wei

    2015-08-01

    Radiographic angles are used to assess the severity of hallux valgus deformity, make preoperative plans, evaluate outcomes after surgery, and compare results between different methods. Traditionally, hallux valgus angle (HVA) has been measured by using a protractor and a marker pen with hardcopy radiographs. The main objective of this study is to compare HVA measurements performed using a smartphone and a traditional protractor. The secondary objective was to compare the time taken between those two methods. Six observers measured major HVA on 20 radiographs of hallux valgus deformity with both a standard protractor and an Apple iPhone. Four of the observers repeated the measurements at least a week after the original measurements. The mean absolute difference between pairs of protractor and smartphone measurements was 3.2°. The 95% confidence intervals for intra-observer variability were ±3.1° for the smartphone measurement and ±3.2° for the protractor method. The 95% confidence intervals for inter-observer variability were ±9.1° for the smartphone measurement and ±9.6° for the protractor measurement. We conclude that the smartphone is equivalent to the protractor for the accuracy of HVA measurement. But, the time taken in smartphone measurement was also reduced.

  12. A wearable system to assess risk for anterior cruciate ligament injury during jump landing: measurements of temporal events, jump height, and sagittal plane kinematics.

    PubMed

    Dowling, Ariel V; Favre, Julien; Andriacchi, Thomas P

    2011-07-01

    The incidence of anterior cruciate ligament (ACL) injury remains high, and there is a need for simple, cost effective methods to identify athletes at a higher risk for ACL injury. Wearable measurement systems offer potential methods to assess the risk of ACL injury during jumping tasks. The objective of this study was to assess the capacity of a wearable inertial-based system to evaluate ACL injury risk during jumping tasks. The system accuracy for measuring temporal events (initial contact, toe-off), jump height, and sagittal plane angles (knee, trunk) was assessed by comparing results obtained with the wearable system to simultaneous measurements obtained with a marker-based optoelectronic reference system. Thirty-eight healthy participants (20 male and 18 female) performed drop jumps with bilateral and unilateral support landing. The mean differences between the temporal events obtained with both systems were below 5 ms, and the precisions were below 24 ms. The mean jump heights measured with both systems differed by less than 1 mm, and the associations (Pearson correlation coefficients) were above 0.9. For the discrete angle parameters, there was an average association of 0.91 and precision of 3.5° for the knee flexion angle and an association of 0.77 and precision of 5.5° for the trunk lean. The results based on the receiver-operating characteristic (ROC) also demonstrated that the proposed wearable system could identify movements at higher risk for ACL injury. The area under the ROC plots was between 0.89 and 0.99 for the knee flexion angle and between 0.83 and 0.95 for the trunk lean. The wearable system demonstrated good concurrent validity with marker-based measurements and good discriminative performance in terms of the known risk factors for ACL injury. This study suggests that a wearable system could be a simple cost-effective tool for conducting risk screening or for providing focused feedback. PMID:21823747

  13. Quantitative measures of sagittal plane head-neck control: a test-retest reliability study.

    PubMed

    Popovich, John M; Reeves, N Peter; Priess, M Cody; Cholewicki, Jacek; Choi, Jongeun; Radcliffe, Clark J

    2015-02-01

    Determining the reliability of measurements used to quantify head-neck motor control is necessary before they can be used to study the effects of injury or treatment interventions. Thus, the purpose of this study was to determine the within- and between-day reliability of position tracking, position stabilization and force tracking tasks to quantify head-neck motor control. Ten asymptomatic subjects performed these tasks on two separate days. Position and force tracking tasks required subjects to track a pseudorandom square wave input signal by controlling their head-neck angular position (position tracking) or the magnitude of isometric force generated against a force sensor by the neck musculature (force tracking) in the sagittal plane. Position stabilization required subjects to maintain an upright head position while pseudorandom perturbations were applied to the upper body using a robotic platform. Within-day and between-day reliability of the frequency response curves were assessed using coefficients of multiple correlations (CMC). Root mean square error (RMSE) and mean bandpass signal energy, were computed for each task and between-day reliability was calculated using intra-class correlation coefficients (ICC). Within- and between-day CMCs for the position and force tracking tasks were all ≥0.96, while CMCs for position stabilization ranged from 0.72 to 0.82. ICCs for the position and force tracking tasks were all ≥0.93. For position stabilization, ICCs for RMSE and mean bandpass signal energy were 0.66 and 0.72, respectively. Measures of sagittal plane head-neck motor control using position tracking, position stabilization and force tracking tasks were demonstrated to be reliable.

  14. Quantitative measures of sagittal plane head-neck control: a test-retest reliability study

    PubMed Central

    Popovich, John M.; Reeves, N. Peter; Priess, M. Cody; Cholewicki, Jacek; Choi, Jongeun; Radcliffe, Clark J.

    2015-01-01

    Determining the reliability of measurements used to quantify head-neck motor control is necessary before they can be used to study the effects of injury or treatment interventions. Thus, the purpose of this study was to determine the within- and between-day reliability of position tracking, position stabilization and force tracking tasks to quantify head-neck motor control. Ten asymptomatic subjects performed these tasks on two separate days. Position and force tracking tasks required subjects to track a pseudorandom square wave input signal by controlling their head-neck angular position (position tracking) or the magnitude of isometric force generated against a force sensor by the neck musculature (force tracking) in the sagittal plane. Position stabilization required subjects to maintain an upright head position while pseudorandom perturbations were applied to the upper body using a robotic platform. Within-day and between-day reliability of the frequency response curves were assessed using coefficients of multiple correlations (CMC). Root mean square error (RMSE) and mean bandpass signal energy, were computed for each task and between-day reliability was calculated using intra-class correlation coefficients (ICC). Within- and between-day CMCs for the position and force tracking tasks were all 0.96, while CMCs for position stabilization ranged from 0.72-0.82. ICCs for the position and force tracking tasks were all 0.93. For position stabilization, ICCs for RMSE and mean bandpass signal energy were 0.66 and 0.72, respectively. Measures of sagittal plane head-neck motor control using position tracking, position stabilization and force tracking tasks were demonstrated to be reliable. PMID:25553673

  15. Precision Measurement of the Weak Mixing Angle in Møller Scattering

    NASA Astrophysics Data System (ADS)

    Anthony, P. L.; Arnold, R. G.; Arroyo, C.; Bega, K.; Biesiada, J.; Bosted, P. E.; Bower, G.; Cahoon, J.; Carr, R.; Cates, G. D.; Chen, J.-P.; Chudakov, E.; Cooke, M.; Decowski, P.; Deur, A.; Emam, W.; Erickson, R.; Fieguth, T.; Field, C.; Gao, J.; Gary, M.; Gustafsson, K.; Hicks, R. S.; Holmes, R.; Hughes, E. W.; Humensky, T. B.; Jones, G. M.; Kaufman, L. J.; Keller, L.; Kolomensky, Yu. G.; Kumar, K. S.; Laviolette, P.; Lhuillier, D.; Lombard-Nelsen, R. M.; Marshall, Z.; Mastromarino, P.; McKeown, R. D.; Michaels, R.; Niedziela, J.; Olson, M.; Paschke, K. D.; Peterson, G. A.; Pitthan, R.; Relyea, D.; Rock, S. E.; Saxton, O.; Singh, J.; Souder, P. A.; Szalata, Z. M.; Turner, J.; Tweedie, B.; Vacheret, A.; Walz, D.; Weber, T.; Weisend, J.; Woods, M.; Younus, I.

    2005-08-01

    We report on a precision measurement of the parity-violating asymmetry in fixed target electron-electron (Møller) scattering: APV=[-131±14(stat)±10(syst)]×10-9, leading to the determination of the weak mixing angle sin⁡2θWeff=0.2397±0.0010(stat)±0.0008(syst), evaluated at Q2=0.026GeV2. Combining this result with the measurements of sin⁡2θWeff at the Z0 pole, the running of the weak mixing angle is observed with over 6σ significance. The measurement sets constraints on new physics effects at the TeV scale.

  16. Measuring emissions from oil and natural gas well pads using the mobile flux plane technique.

    PubMed

    Rella, Chris W; Tsai, Tracy R; Botkin, Connor G; Crosson, Eric R; Steele, David

    2015-04-01

    We present a study of methane emissions from oil and gas producing well pad facilities in the Barnett Shale region of Texas, measured using an innovative ground-based mobile flux plane (MFP) measurement system, as part of the Barnett Coordinated Campaign.1 Using only public roads, we measured the emissions from nearly 200 well pads over 2 weeks in October 2013. The population of measured well pads is split into well pads with detectable emissions (N = 115) and those with emissions below the detection limit of the MFP instrument (N = 67). For those well pads with nonzero emissions, the distribution was highly skewed, with a geometric mean of 0.63 kg/h, a geometric standard deviation of 4.2, and an arithmetic mean of 1.72 kg/h. Including the population of nonemitting well pads, we find that the arithmetic mean of the well pads sampled in this study is 1.1 kg/h. This distribution implies that 50% of the emissions is due to the 6.6% highest emitting well pads, and 80% of the emissions is from the 22% highest emitting well pads.

  17. Sensitivity of magnetic field-line pitch angle measurements to sawtooth events in tokamaks

    NASA Astrophysics Data System (ADS)

    Ko, J.

    2016-11-01

    The sensitivity of the pitch angle profiles measured by the motional Stark effect (MSE) diagnostic to the evolution of the safety factor, q, profiles during the tokamak sawtooth events has been investigated for Korea Superconducting Tokamak Advanced Research (KSTAR). An analytic relation between the tokamak pitch angle, γ, and q estimates that Δγ ˜ 0.1° is required for detecting Δq ˜ 0.05 near the magnetic axis (not at the magnetic axis, though). The pitch angle becomes less sensitive to the same Δq for the middle and outer regions of the plasma (Δγ ˜ 0.5°). At the magnetic axis, it is not straightforward to directly relate the γ sensitivity to Δq since the gradient of γ(R), where R is the major radius of the tokamak, is involved. Many of the MSE data obtained from the 2015 KSTAR campaign, when calibrated carefully, can meet these requirements with the time integration down to 10 ms. The analysis with the measured data shows that the pitch angle profiles and their gradients near the magnetic axis can resolve the change of the q profiles including the central safety factor, q0, during the sawtooth events.

  18. Shallow-water acoustic tomography from angle measurements instead of travel-time measurements.

    PubMed

    Aulanier, Florian; Nicolas, Barbara; Mars, Jérôme I; Roux, Philippe; Brossier, Romain

    2013-10-01

    For shallow-water waveguides and mid-frequency broadband acoustic signals, ocean acoustic tomography (OAT) is based on the multi-path aspect of wave propagation. Using arrays in emission and reception and advanced array processing, every acoustic arrival can be isolated and matched to an eigenray that is defined not only by its travel time but also by its launch and reception angles. Classically, OAT uses travel-time variations to retrieve sound-speed perturbations; this assumes very accurate source-to-receiver clock synchronization. This letter uses numerical simulations to demonstrate that launch-and-reception-angle tomography gives similar results to travel-time tomography without the same requirement for high-precision synchronization.

  19. In situ measurements of particle friction angles in steep, narrow channels

    NASA Astrophysics Data System (ADS)

    Prancevic, J.; Lamb, M. P.

    2013-12-01

    The persistent observation that sediment requires increased fluid stresses to move on steeper channels has inspired a wide range of explanations, which can loosely be divided into those that invoke increased grain stability (friction angle, φ) and those that require altered flow hydraulics in steep channels. Measurements of bulk fluid forces over a wide range of channel slopes (θ ≤ 22°) have been obtained using laboratory flume experiments that can control for grain stability and show that altered flow hydraulics do play a role in increased critical shear stress. However, measurements of grain stability are almost all limited to channel slopes less than a few degrees. These friction angle studies have been conducted by tilting a fixed gravel bed with a single loose particle until dislodgment, or by directly measuring the forces required to dislodge a particle using a load cell. The latter methodology is less common but offers the advantage of quickly measuring the friction angles of in situ grains in natural river channels. Indeed, it has enabled the collection of extremely large datasets at low slopes [e.g., Johnston et al., 1998]. We are adding to this dataset with measurements from several natural steep channels in the San Gabriel Mountains, CA to test if the particle friction angle changes systematically as a function of slope or width-to-grain size ratio (W/D50), which is thought to determine the propensity for particle jamming. Using a load cell that records peak forces we measure the minimum force required to pull a particle from its pocket in the downstream direction and the particle weight. Particles are sampled over a regular grid and we record the percentage of the particle buried by fines and the qualitative degree of interlocking. Preliminary results from three sites with bed slopes of θ = 2.9°, 3.2°, and 9.0° suggest that the at-a-site variability in friction angle is much higher than between-site variability, and that median values do not

  20. Large field distributed aperture laser semiactive angle measurement system design with imaging fiber bundles.

    PubMed

    Xu, Chunyun; Cheng, Haobo; Feng, Yunpeng; Jing, Xiaoli

    2016-09-01

    A type of laser semiactive angle measurement system is designed for target detecting and tracking. Only one detector is used to detect target location from four distributed aperture optical systems through a 4×1 imaging fiber bundle. A telecentric optical system in image space is designed to increase the efficiency of imaging fiber bundles. According to the working principle of a four-quadrant (4Q) detector, fiber diamond alignment is adopted between an optical system and a 4Q detector. The structure of the laser semiactive angle measurement system is, we believe, novel. Tolerance analysis is carried out to determine tolerance limits of manufacture and installation errors of the optical system. The performance of the proposed method is identified by computer simulations and experiments. It is demonstrated that the linear region of the system is ±12°, with measurement error of better than 0.2°. In general, this new system can be used with large field of view and high accuracy, providing an efficient, stable, and fast method for angle measurement in practical situations. PMID:27607276

  1. Evaluation of electrolytic tilt sensors for measuring model angle of attack in wind tunnel tests

    NASA Technical Reports Server (NTRS)

    Wong, Douglas T.

    1992-01-01

    The results of a laboratory evaluation of electrolytic tilt sensors as potential candidates for measuring model attitude or angle of attack in wind tunnel tests are presented. The performance of eight electrolytic tilt sensors was compared with that of typical servo accelerometers used for angle-of-attack measurements. The areas evaluated included linearity, hysteresis, repeatability, temperature characteristics, roll-on-pitch interaction, sensitivity to lead-wire resistance, step response time, and rectification. Among the sensors being evaluated, the Spectron model RG-37 electrolytic tilt sensors have the highest overall accuracy in terms of linearity, hysteresis, repeatability, temperature sensitivity, and roll sensitivity. A comparison of the sensors with the servo accelerometers revealed that the accuracy of the RG-37 sensors was on the average about one order of magnitude worse. Even though a comparison indicates that the cost of each tilt sensor is about one-third the cost of each servo accelerometer, the sensors are considered unsuitable for angle-of-attack measurements. However, the potential exists for other applications such as wind tunnel wall-attitude measurements where the errors resulting from roll interaction, vibration, and response time are less and sensor temperature can be controlled.

  2. Broadband wide-angle dispersion measurements: Instrumental setup, alignment, and pitfalls

    SciTech Connect

    Farhang, A.; Abasahl, B.; Dutta-Gupta, S.; Lovera, A.; Martin, O. J. F.; Mandracci, P.; Descrovi, E.

    2013-03-15

    The construction, alignment, and performance of a setup for broadband wide-angle dispersion measurements, with emphasis on surface plasmon resonance (SPR) measurements, are presented in comprehensive detail. In contrast with most SPR instruments working with a monochromatic source, this setup takes advantage of a broadband/white light source and has full capability for automated angle vs. wavelength dispersion measurements for any arbitrary nanostructure array. A cylindrical prism is used rather than a triangular one in order to mitigate refraction induced effects and allow for such measurements. Although seemingly simple, this instrument requires use of many non-trivial methods in order to achieve proper alignment over all angles of incidence. Here we describe the alignment procedure for such a setup, the pitfalls introduced from the finite beam width incident onto the cylindrical prism, and deviations in the reflected/transmitted beam resulting from the finite thickness of the sample substrate. We address every one of these issues and provide experimental evidences on the success of this instrument and the alignment procedure used.

  3. Measuring the beaming angle of GRB 030329 by fitting the rebrightenings in its multiband afterglow

    NASA Astrophysics Data System (ADS)

    Deng, Wei; Huang, Yong-Feng; Kong, Si-Wei

    2010-11-01

    Multiple rebrightenings have been observed in the multiband afterglow of GRB 030329. In particular, a marked and quick rebrightening occurred at about t ~ 1.2 × 105 s. Energy injection from late and slow shells seems to be the best interpretation for these rebrightenings. Usually it is assumed that the energy is injected into the whole external shock. However, in the case of GRB 030329, the rebrightenings are so quick that the usual consideration fails to give a satisfactory fit to the observed light curves. Actually, since these late/slow shells freely coast in the wake of the external shock, they should be cold and may not expand laterally. The energy injection then should only occur at the central region of the external shock. Considering this effect, we numerically re-fit the quick rebrightenings observed in GRB 030329. By doing this, we were able to derive the beaming angle of the energy injection process. Our result, with a relative residual of only 5% - 10% during the major rebrightening, is better than any previous modeling. The derived energy injection angle is about 0.035. We assume that these late shells are ejected by the central engine via the same mechanism as those early shells that produce the prompt gamma-ray burst. The main difference is that their velocities are much slower, so that they catch up with the external shock relatively late and are manifested as the observed quick rebrightenings. If this were true, then the derived energy injection angle can give a good measure of the beaming angle of the prompt γ-ray emission. Our study may hopefully provide a novel method to measure the beaming angle of gamma-ray bursts.

  4. Measurement of shear-wave velocity by ultrasound critical-angle reflectometry (UCR)

    NASA Technical Reports Server (NTRS)

    Mehta, S.; Antich, P.; Blomqvist, C. G. (Principal Investigator)

    1997-01-01

    There exists a growing body of research that relates the measurement of pressure-wave velocity in bone to different physiological conditions and treatment modalities. The shear-wave velocity has been less studied, although it is necessary for a more complete understanding of the mechanical properties of bone. Ultrasound critical-angle reflectometry (UCR) is a noninvasive and nondestructive technique previously used to measure pressure-wave velocities both in vitro and in vivo. This note describes its application to the measurement of shear-wave velocity in bone, whether directly accessible or covered by soft tissue.

  5. Fallspeed measurement and high-resolution multi-angle photography of hydrometeors in freefall

    NASA Astrophysics Data System (ADS)

    Garrett, T. J.; Fallgatter, C.; Shkurko, K.; Howlett, D.

    2012-07-01

    We describe here a new instrument for imaging hydrometeors in freefall. The Multi-Angle Snowflake Camera (MASC) captures high resolution photographs of hydrometeors from three angles while simultaneously measuring their fallspeed. Based on the stereoscopic photographs captured over the two months of continuous measurements obtained at a high altitude location within the Wasatch Front in Utah, we derive statistics for fallspeed, hydrometeor size, shape, orientation and aspect ratio. From a selection of the photographed hydrometeors, an illustration is provided for how the instrument might be used for making improved microwave scattering calculations. Complex, aggregated snowflake shapes appear to be more strongly forward scattering, at the expense of reduced back-scatter, than graupel particles of similar size.

  6. Fall speed measurement and high-resolution multi-angle photography of hydrometeors in free fall

    NASA Astrophysics Data System (ADS)

    Garrett, T. J.; Fallgatter, C.; Shkurko, K.; Howlett, D.

    2012-11-01

    We describe here a new instrument for imaging hydrometeors in free fall. The Multi-Angle Snowflake Camera (MASC) captures high-resolution photographs of hydrometeors from three angles while simultaneously measuring their fall speed. Based on the stereoscopic photographs captured over the two months of continuous measurements obtained at a high altitude location within the Wasatch Front in Utah, we derive statistics for fall speed, hydrometeor size, shape, orientation and aspect ratio. From a selection of the photographed hydrometeors, an illustration is provided for how the instrument might be used for making improved microwave scattering calculations. Complex, aggregated snowflake shapes appear to be more strongly forward scattering, at the expense of reduced back-scatter, than heavily rimed graupel particles of similar size.

  7. The weak mixing angle from low energy neutrino measurements: A global update

    NASA Astrophysics Data System (ADS)

    Cañas, B. C.; Garcés, E. A.; Miranda, O. G.; Tórtola, M.; Valle, J. W. F.

    2016-10-01

    Taking into account recent theoretical and experimental inputs on reactor fluxes we reconsider the determination of the weak mixing angle from low energy experiments. We perform a global analysis to all available neutrino-electron scattering data from reactor antineutrino experiments, obtaining sin2 ⁡θW = 0.252 ± 0.030. We discuss the impact of the new theoretical prediction for the neutrino spectrum, the new measurement of the reactor antineutrino spectrum by the Daya Bay collaboration, as well as the effect of radiative corrections. We also reanalyze the measurements of the νe - e cross section at accelerator experiments including radiative corrections. By combining reactor and accelerator data we obtain an improved determination for the weak mixing angle, sin2 ⁡θW = 0.254 ± 0.024.

  8. Low elevation angle KU-band satellite measurements at Austin, Texas

    NASA Technical Reports Server (NTRS)

    Vogel, Wolfhard J.; Torrence, Geoffrey W.; Ranganathan, Murali

    1989-01-01

    At low elevation angles, the propagation of satellite signals is affected by precipitation as well as by inhomogeneties of the refractive index. Whereas precipitation causes fades for relatively small percentages of time, the refractive index variability causes scintillations which can be observed for most of the time. An experiment is now under way in Austin, Texas, in which the right hand circularly polarized 12 GHz beacon of INTELSAT-V/F10 is observed at a 5.8 deg elevation angle, along with the radiometric sky temperature, rainfall rate, humidity, pressure, temperature, and wind speed and direction. The objective of these measurements is to accumulate a database over a period of 2 years and to analyze the probabilities and dynamical behavior of the signal variations in relation to the meteorological parameters. The hardware and software used for the data acquisition and analysis is described and the results from the first year of measurements are presented.

  9. New analysis of the small-angle-magnetization-rotation method for magnetostriction measurements on amorphous ribbons

    NASA Astrophysics Data System (ADS)

    Severino, A. M.; Missell, F. P.

    1987-09-01

    The small-angle-magnetization-rotation (SAMR) method for measuring the saturation magnetostrictin λ s has been reanalyzed, taking into account the underlying domain structure of the amorphous ribbon. Although the condition for determining λ s reamins unchenged, the modifications introduced allow one to understand many additional features of the experimental data. With the appropriate modifications, the SAMR method can be used to study stress relaxation in amorphous alloys. Examples are given Fe-based and Co-based alloys.

  10. Interpreting vegetation reflectance measurements as a function of solar zenith angle

    NASA Technical Reports Server (NTRS)

    Kimes, D. S.; Smith, J. A.; Ranson, K. J.

    1979-01-01

    Spectral hemispherical-conical reflectances of a nadir looking sensor were taken throughout the day for a lodgepole pine and two grass canopies. Mathematical simulations of both spectral hemispherical-conical and bi-hemispherical reflectances were performed for two theoretical canopies of contrasting geometric structure. These results and comparisons with literature studies showed a great amount of variability of vegetation canopy reflectances as a function of solar zenith angle. Explanations for this variability are discussed and recommendations for further measurements are proposed.

  11. Using a Hexagonal Mirror for Varying Light Intensity in the Measurement of Small-Angle Variation.

    PubMed

    Hsieh, Meng-Chang; Lin, Jiun-You; Chang, Chia-Ou

    2016-08-16

    Precision positioning and control are critical to industrial-use processing machines. In order to have components fabricated with excellent precision, the measurement of small-angle variations must be as accurate as possible. To achieve this goal, this study provides a new and simple optical mechanism by varying light intensity. A He-Ne laser beam was passed through an attenuator and into a beam splitter. The reflected light was used as an intensity reference for calibrating the measurement. The transmitted light as a test light entered the optical mechanism hexagonal mirror, the optical mechanism of which was created by us, and then it entered the power detector after four consecutive reflections inside the mirror. When the hexagonal mirror was rotated by a small angle, the laser beam was parallel shifted. Once the laser beam was shifted, the hitting area on the detector was changed; it might be partially outside the sensing zone and would cause the variation of detection intensity. This variation of light intensity can be employed to measure small-angle variations. The experimental results demonstrate the feasibility of this method. The resolution and sensitivity are 3 × 10(-40) and 4 mW/° in the angular range of 0.6°, respectively, and 9.3 × 10(-50) and 13 mW/° in the angular range of 0.25°.

  12. Using a Hexagonal Mirror for Varying Light Intensity in the Measurement of Small-Angle Variation.

    PubMed

    Hsieh, Meng-Chang; Lin, Jiun-You; Chang, Chia-Ou

    2016-01-01

    Precision positioning and control are critical to industrial-use processing machines. In order to have components fabricated with excellent precision, the measurement of small-angle variations must be as accurate as possible. To achieve this goal, this study provides a new and simple optical mechanism by varying light intensity. A He-Ne laser beam was passed through an attenuator and into a beam splitter. The reflected light was used as an intensity reference for calibrating the measurement. The transmitted light as a test light entered the optical mechanism hexagonal mirror, the optical mechanism of which was created by us, and then it entered the power detector after four consecutive reflections inside the mirror. When the hexagonal mirror was rotated by a small angle, the laser beam was parallel shifted. Once the laser beam was shifted, the hitting area on the detector was changed; it might be partially outside the sensing zone and would cause the variation of detection intensity. This variation of light intensity can be employed to measure small-angle variations. The experimental results demonstrate the feasibility of this method. The resolution and sensitivity are 3 × 10(-40) and 4 mW/° in the angular range of 0.6°, respectively, and 9.3 × 10(-50) and 13 mW/° in the angular range of 0.25°. PMID:27537893

  13. Using a Hexagonal Mirror for Varying Light Intensity in the Measurement of Small-Angle Variation

    PubMed Central

    Hsieh, Meng-Chang; Lin, Jiun-You; Chang, Chia-Ou

    2016-01-01

    Precision positioning and control are critical to industrial-use processing machines. In order to have components fabricated with excellent precision, the measurement of small-angle variations must be as accurate as possible. To achieve this goal, this study provides a new and simple optical mechanism by varying light intensity. A He-Ne laser beam was passed through an attenuator and into a beam splitter. The reflected light was used as an intensity reference for calibrating the measurement. The transmitted light as a test light entered the optical mechanism hexagonal mirror, the optical mechanism of which was created by us, and then it entered the power detector after four consecutive reflections inside the mirror. When the hexagonal mirror was rotated by a small angle, the laser beam was parallel shifted. Once the laser beam was shifted, the hitting area on the detector was changed; it might be partially outside the sensing zone and would cause the variation of detection intensity. This variation of light intensity can be employed to measure small-angle variations. The experimental results demonstrate the feasibility of this method. The resolution and sensitivity are 3 × 10−40 and 4 mW/° in the angular range of 0.6°, respectively, and 9.3 × 10−50 and 13 mW/° in the angular range of 0.25°. PMID:27537893

  14. A semi-empirical equation for the response time of in-plane switching liquid crystal display and measurement of twist elastic constant

    NASA Astrophysics Data System (ADS)

    Xu, Daming; Peng, Fenglin; Tan, Guanjun; He, Juan; Wu, Shin-Tson

    2015-05-01

    A semi-empirical equation is developed to characterize the optical decay time of in-plane switching (IPS) and fringe field switching (FFS) liquid crystal displays. This equation takes the effects of elastic constants, cell gap, liquid crystal material, rubbing angle, and anchoring strength into account simultaneously. Good agreement between simulation and experiment is obtained. Moreover, this equation can be used to measure the twist elastic constant K22 of liquid crystals. The measured temperature-dependent K22 values of 5CB agree well with previously published results. Hence, our equation not only describes the response time of IPS and FFS cells but also provides a simple yet accurate method to determine the twist elastic constant of liquid crystal materials.

  15. Rapid Measurement of Molecular Transport and Interaction inside Living Cells Using Single Plane Illumination

    PubMed Central

    Hedde, Per Niklas; Stakic, Milka; Gratton, Enrico

    2014-01-01

    The ability to measure biomolecular dynamics within cells and tissues is very important to understand fundamental physiological processes including cell adhesion, signalling, movement, division or metabolism. Usually, such information is obtained using particle tracking methods or single point fluctuation spectroscopy. We show that image mean square displacement analysis, applied to single plane illumination microscopy data, is a faster and more efficient way of unravelling rapid, three-dimensional molecular transport and interaction within living cells. From a stack of camera images recorded in seconds, the type of dynamics such as free diffusion, flow or binding can be identified and quantified without being limited by current camera frame rates. Also, light exposure levels are very low and the image mean square displacement method does not require calibration of the microscope point spread function. To demonstrate the advantages of our approach, we quantified the dynamics of several different proteins in the cyto- and nucleoplasm of living cells. For example, from a single measurement, we were able to determine the diffusion coefficient of free clathrin molecules as well as the transport velocity of clathrin-coated vesicles involved in endocytosis. Used in conjunction with dual view detection, we further show how protein-protein interactions can be quantified. PMID:25394360

  16. Parametric study of the reflective periodic grating for in-plane displacement measurement using optical fibers.

    PubMed

    Lee, Yeon-Gwan; Kim, Dae-Hyun; Kim, Chun-Gon

    2012-01-01

    This paper presents a technique for a simple sensing principle that can be used for the measurement of displacement. The proposed sensor head is composed of a reflective grating panel and an optical fiber as a transceiver. The simplified layout contributes to resolving the issues of space restraints during installation and complex cabling problems in transmission fiber optic sensors. In order to verify the effectiveness of the proposed technique, it is important to obtain the sinusoidal signal reflected from the grating for reasonable phase tracking. In the numerical analysis, a real wave based optical beam model is proposed for the extraction of predicted signal according to the grating width and ratio of reflection bar width to spacing. The grating pattern design to obtain a sine wave reflected sensor signal was determined within an R-square value of 0.98 after sine curve fitting analysis. Consequently, the proposed sensor principle achieved the in-plane displacement measurement with a maximum accuracy error of 5.34 μm. PMID:22666030

  17. Discrepancies in measuring acetabular coverage: revisiting the anterior and lateral center edge angles

    PubMed Central

    Hanson, Joey A.; Kapron, Ashley L.; Swenson, Kathryn M.; Maak, Travis G.; Peters, Christopher L.; Aoki, Stephen K.

    2015-01-01

    The lateral center edge angle (LCEA) and the anterior center edge angle (ACEA) are commonly used to assess acetabular coverage of the femoral head. There are two distinct methods found in the literature to obtain these angles, specifically, measuring to the most lateral bone edge versus the sclerotic lateral sourcil edge. A difference between these two methods may contribute to inconsistent estimates of acetabular coverage, and potentially lead to clinical misdiagnosis and treatment mismanagement. The objectives of this study were to quantify the difference between bone edge and sourcil edge measurements and to determine how the difference influences the classification of acetabular coverage in adult patients with suspected hip pathomorphology. Two observers completed the measurements independently using preoperative anteroposterior and false profile radiographs. Bland–Altman plots and paired t-tests were used to compare measurement methods. Bone and sourcil measurements of the LCEA and ACEA were significantly different (both P < 0.001). On average, the bone LCEA was 4° (95% limits of agreement = −2° to 10°) greater than the sourcil LCEA. The bone ACEA was, on average, 10° (95% limit of agreement = −2° to 22°) greater than the sourcil ACEA. The differences often led to different clinical classifications for the same hip. With a statistically and clinically significant difference in the quantification of acetabular coverage using bone edge versus sourcil edge methods for measuring the LCEA and ACEA in adult patients, it should be mandatory to clearly identify which method was used in each study. PMID:27011850

  18. Orientation-independent rapid pulsatile flow measurement using dual-angle Doppler OCT

    PubMed Central

    Peterson, Lindsy M; Gu, Shi; Jenkins, Michael W; Rollins, Andrew M

    2014-01-01

    Doppler OCT (DOCT) can provide blood flow velocity information which is valuable for investigation of microvascular structure and function. However, DOCT is only sensitive to motion parallel with the imaging beam, so that knowledge of flow direction is needed for absolute velocity determination. Here, absolute volumetric flow is calculated by integrating velocity components perpendicular to the B-scan plane. These components are acquired using two illumination beams with a predetermined angular separation, produced by a delay encoded technique. This technology enables rapid pulsatile flow measurement from single B-scans without the need for 3-D volumetric data or knowledge of blood vessel orientation. PMID:24575344

  19. Laser-based spin- and angle-resolved photoemission spectroscopy for rapid, high-resolution measurements

    NASA Astrophysics Data System (ADS)

    Gotlieb, Kenneth; Bostwick, Aaron; Hussain, Zahid; Lanzara, Alessandra; Jozwiak, Christopher

    2014-03-01

    A unique spin-and angle-resolved photoemission spectrometer (spin-ARPES) is coupled with a 6 eV laser to achieve unprecedented measurements of near-EF physics in topological insulators and Rashba systems. The pairing of the spin-ARPES system with the laser allows for energy and angular resolutions never before seen in a spin-ARPES experiment. Most importantly, the high efficiency of the system and high photon flux of the laser make measurements very rapid, permitting exploration of a large experimental phase space.

  20. Fabrication and characteristic evaluation of a rotary type SDA with a rotation angle measuring scale

    NASA Astrophysics Data System (ADS)

    Nagao, Shinya; Oohira, Fumikazu; Matsui, Takashi; Hosogi, Maho; Hashiguchi, Gen

    2005-12-01

    Recently, there are a lot of studies on the micro motors using an electrostatic actuator as the driving force in the micro electro mechanical systems (MEMS) field. However, the electrostatic actuator has a problem concerning the precise actuation control. In the conventional researches, the rotary type electrostatic actuators have been reported, but the rotation angle has not been precisely controlled in the actuators. This paper describes a new micro motor by a rotary type scratch drive actuator (SDA) with a Poly-Si scale to measure the rotation angle based on the MEMS technology. In this study, we make it possible to measure the rotation angle of th rotary type SDA motor by a fiber type micro encoder. For this purpose, we formed the Poly-Si scale around the outside of the micro SDA motor, and achieved a reflection type optical fiber micro encoder. In this presentation, we describe the fabrication process for this device and the evaluation results of the optical characteristic of the fiber type micro encoder.

  1. Comparison of bend angle measurements in fresh cryopreserved cartilage specimens after electromechanical reshaping

    NASA Astrophysics Data System (ADS)

    Karimi, Koohyar; Protsenko, Dimitry; Wu, Edward C.; Foulad, Allen; Manuel, Cyrus T.; Lim, Amanda; Wong, Brian J. F.

    2010-02-01

    Cryopreservation of cartilage has been investigated for decades and is currently an established protocol. However, the reliability and applicability of cartilage cryopreservation for the use in electromechanical reshaping (EMR) has not been studied exclusively. A system to cryopreserve large numbers of tissue specimens provides a steady source of cartilage of similar quality for experimentation at later dates. This will reduce error that may arise from different cartilage stock, and has the potential to maximize efficiency under time constraints. Our study utilizes a unique methodology to cryopreserve septal cartilage for use in EMR studies. Rabbit septal cartilage specimens were harvested and standardized to 20 x 8 x 1 mm, and placed in one of three solutions (normal saline, PBS, 10% DMSO in PBS) for four hours in a cold storage room at 4 degrees Celsius. Then, each cartilage specimen was vacuumed and sealed in an anti-frost plastic bag and stored in a freezer at -80 degrees Celsius for 1 to 3 weeks duration. EMR was performed using 2 and 6 volts for 2 minutes application time. Bend angle measurements of the cryopreserved cartilage specimens were compared to bend angles of fresh cartilage which underwent EMR using the same parameters. Results demonstrate that normal saline, phosphate buffered saline (PBS), and PBS with DMSO were effective in cryopreservation, and indicated no significant differences in bend angle measurements when compared to no cryopreservation. Our methodology to cryopreserve cartilage specimens provides a successful approach for use in conducting large-scale EMR studies.

  2. Method and Apparatus for Measuring Near-Angle Scattering of Mirror Coatings

    NASA Technical Reports Server (NTRS)

    Chipman, Russell A. (Inventor); Daugherty, Brian J. (Inventor); McClain, Stephen C. (Inventor); Macenka, Steven A. (Inventor)

    2013-01-01

    Disclosed herein is a method of determining the near angle scattering of a sample reflective surface comprising the steps of: a) splitting a beam of light having a coherence length of greater than or equal to about 2 meters into a sample beam and a reference beam; b) frequency shifting both the sample beam and the reference beam to produce a fixed beat frequency between the sample beam and the reference beam; c) directing the sample beam through a focusing lens and onto the sample reflective surface, d) reflecting the sample beam from the sample reflective surface through a detection restriction disposed on a movable stage; e) recombining the sample beam with the reference beam to form a recombined beam, followed by f) directing the recombined beam to a detector and performing heterodyne analysis on the recombined beam to measure the near-angle scattering of the sample reflective surface, wherein the position of the detection restriction relative to the sample beam is varied to occlude at least a portion of the sample beam to measure the near-angle scattering of the sample reflective surface. An apparatus according to the above method is also disclosed.

  3. Capacitance and phase-angle measurement for estimating moisture content in nuts and grain nondestructively

    NASA Astrophysics Data System (ADS)

    Kandala, Chari V.; Butts, Chris L.

    2006-03-01

    The design and performance of an electrical instrument that would be useful in estimating the moisture content (mc) of agricultural products such as grain and nuts nondestructively and rapidly is described here. The instrument, here after called the impedance meter, determines the capacitance and phase angle of a sample of the produce (about 100 g), filling the space between two parallel-plate electrodes, at two frequencies 1 and 5 MHz. The measured values were used in a semi-empirical equation to obtain the mc of the sample. In this paper, capacitance and phase angle were determined for in-shell peanuts in the moisture range between 6 and 25% by the impedance meter, and their moisture contents were calculated. The calculated values were compared with the mc values obtained by the standard air-oven method. The estimated values were in good agreement with the standard values. This method is applicable to produce such as corn, wheat and pecans also.

  4. A sensitive, high resolution magic angle turning experiment for measuring chemical shift tensor principal values

    NASA Astrophysics Data System (ADS)

    Alderman, D. W.

    1998-12-01

    A sensitive, high-resolution 'FIREMAT' two-dimensional (2D) magic-angle-turning experiment is described that measures chemical shift tensor principal values in powdered solids. The spectra display spinning-sideband patterns separated by their isotropic shifts. The new method's sensitivity and high resolution in the isotropic-shift dimension result from combining the 5pi magic-angle-turning pulse sequence, an extension of the pseudo-2D sideband-suppression data rearrangement, and the TIGER protocol for processing 2D data. TPPM decoupling is used to enhance resolution. The method requires precise synchronization of the pulses and sampling to the rotor position. It is shown that the technique obtains 35 natural-abundance 13C tensors from erythromycin in 19 hours, and high quality naturalabundance 15N tensors from eight sites in potassium penicillin V in three days on a 400MHz spectrometer.

  5. Retrieval of vertical profiles of atmospheric refraction angles by inversion of optical dilution measurements

    NASA Astrophysics Data System (ADS)

    Fussen, D.; Tetard, C.; Dekemper, E.; Pieroux, D.; Mateshvili, N.; Vanhellemont, F.; Franssens, G.; Demoulin, P.

    2015-08-01

    In this paper, we consider occultations of celestial bodies through the atmospheric limb from low Earth orbit satellites and we show how the usual change of tangent altitude associated with atmospheric refraction is inseparably connected to a variation of the observed apparent intensity, for extended and pointlike sources. We demonstrate, in the regime of weak refraction angles, that atmospheric optical dilution and image deformation are strictly concomitant. The approach leads to the integration of a simple differential equation related to the observed transmittance in the absence of other absorbing molecules along the optical path. The algorithm does not rely on the absolute knowledge of the radiometer pointing angle that is related to the accurate knowledge of the satellite attitude. We successfully applied the proposed method to the measurements performed by two past occultation experiments: GOMOS for stellar and ORA for solar occultations. The developed algorithm (named ARID) will be applied to the imaging of solar occultations in a forthcoming pico-satellite mission.

  6. Three-dimensional temporally resolved measurements of turbulence-flame interactions using orthogonal-plane cinema-stereoscopic PIV

    NASA Astrophysics Data System (ADS)

    Steinberg, Adam Michael; Driscoll, James F.; Ceccio, Steven L.

    2009-09-01

    A new orthogonal-plane cinema-stereoscopic particle image velocimetry (OPCS-PIV) diagnostic has been used to measure the dynamics of three-dimensional turbulence-flame interactions. The diagnostic employed two orthogonal PIV planes, with one aligned perpendicular and one aligned parallel to the streamwise flow direction. In the plane normal to the flow, temporally resolved slices of the nine-component velocity gradient tensor were determined using Taylor’s hypothesis. Volumetric reconstruction of the 3D turbulence was performed using these slices. The PIV plane parallel to the streamwise flow direction was then used to measure the evolution of the turbulence; the path and strength of 3D turbulent structures as they interacted with the flame were determined from their image in this second plane. Structures of both vorticity and strain-rate magnitude were extracted from the flow. The geometry of these structures agreed well with predictions from direct numerical simulations. The interaction of turbulent structures with the flame also was observed. In three dimensions, these interactions had complex geometries that could not be reflected in either planar measurements or simple flame-vortex configurations.

  7. An efficient plane wave spectral analysis to predict the focal region fields of parabolic reflector antennas for small and wide angle scanning

    NASA Astrophysics Data System (ADS)

    Nagamune, Akio; Pathak, Prabhakar H.

    1990-11-01

    An efficient approach is described for calculating the field distribution in the focal region of an electrically large, symmetric or offset parabolic reflector antenna with an arbitrary rim contour, when the concave reflector surface is fully illuminated by an obliquely incident arbitrary electromagnetic plane wave. This solution is useful for synthesizing feed arrays in scanning multiple and contour beam reflector antennas via reciprocity. The dominant contribution to the focal-region fields is found by transforming the physical-optics integral over the reflector surface into a plane-wave spectral (PWS) integral. An important feature of the approach is that the spectrum (or the PWS integrand) is obtained in closed form containing relatively simple functions upon dividing the reflector surface into just a few sections that yield rectangular projected apertures. The PWS integral is evaluated rapidly via the fast Fourier transform (FFT) algorithm to furnish, in only a single computation, the field for every place in the focal plane (or any plane parallel to it) within the focal region for a given direction of the incident wave. The correction to the physical-optics field is relatively small in the focal region and may therefore be neglected. Numerical results based on this PWS approach are presented, and their accuracy is established by comparison with results based on other approaches.

  8. Nonlinear Observability for Relative Orbit Determination with Angles-Only Measurements

    NASA Astrophysics Data System (ADS)

    Kaufman, Evan; Lovell, T. Alan; Lee, Taeyoung

    2016-03-01

    This paper presents nonlinear observability criteria for the relative orbital dynamics represented by the solutions of the two-body problem. It is assumed that a chief is on a circular orbit with a prescribed orbital radius, and it measures lines-of-sight toward a deputy only. A differential geometric method, based on the Lie derivatives, is used to derive sufficient conditions for observability of the orbital properties of the deputy. It is shown that under certain geometric conditions on the relative configuration between the chief and the deputy, the nonlinear relative motion is observable from angles-only measurements. The second part of this paper presents a quantitative measure of observability for the relative orbits, and it is formulated by generalizing the observability Gramian of linear dynamic systems. An extended Kalman filter is also developed to numerically illustrate the observability of nonlinear relative orbits with angles-only measurements and to show correspondence between the proposed observability measure and filtered solution accuracy.

  9. A new fast scanning system for the measurement of large angle tracks in nuclear emulsions

    NASA Astrophysics Data System (ADS)

    Alexandrov, A.; Buonaura, A.; Consiglio, L.; D'Ambrosio, N.; De Lellis, G.; Di Crescenzo, A.; Di Marco, N.; Galati, G.; Lauria, A.; Montesi, M. C.; Pupilli, F.; Shchedrina, T.; Tioukov, V.; Vladymyrov, M.

    2015-11-01

    Nuclear emulsions have been widely used in particle physics to identify new particles through the observation of their decays thanks to their unique spatial resolution. Nevertheless, before the advent of automatic scanning systems, the emulsion analysis was very demanding in terms of well trained manpower. Due to this reason, they were gradually replaced by electronic detectors, until the '90s, when automatic microscopes started to be developed in Japan and in Europe. Automatic scanning was essential to conceive large scale emulsion-based neutrino experiments like CHORUS, DONUT and OPERA. Standard scanning systems have been initially designed to recognize tracks within a limited angular acceptance (θ lesssim 30°) where θ is the track angle with respect to a line perpendicular to the emulsion plane. In this paper we describe the implementation of a novel fast automatic scanning system aimed at extending the track recognition to the full angular range and improving the present scanning speed. Indeed, nuclear emulsions do not have any intrinsic limit to detect particle direction. Such improvement opens new perspectives to use nuclear emulsions in several fields in addition to large scale neutrino experiments, like muon radiography, medical applications and dark matter directional detection.

  10. Plane Strain Testing with Passive Restraint

    NASA Astrophysics Data System (ADS)

    Makhnenko, Roman; Labuz, Joseph

    2014-11-01

    A plane strain condition for testing rock is developed through passive restraint in the form of a thick-walled cylinder. The so-called biaxial frame generates the intermediate principal stress that imposes a triaxial state of stress on a prismatic specimen. Major and minor principal stresses and corresponding strains are accurately measured, providing data to calculate the elastic (Young's modulus and Poisson's ratio), inelastic (dilatancy angle), and strength (friction angle and cohesion) parameters of the rock. Results of experiments conducted on Indiana limestone in plane strain compression are compared with the results of axisymmetric compression and extension. With proper system calibration, Young's modulus and Poisson's ratio are consistent among the tests. The plane strain apparatus enforces in-plane deformation with the three principal stresses at failure being different, and it allows one to determine the Paul-Mohr-Coulomb failure surface, which includes an intermediate stress effect.

  11. Tank tests to determine the effect of varying design parameters of planing-tail hulls II : effect of varying depth of step, angle of after- body keel, length of afterbody chine, and gross load

    NASA Technical Reports Server (NTRS)

    Dawson, John R; Mckann, Robert; Hay, Elizabeth S

    1946-01-01

    The second part of a series of tests made in Langley tank no. 2 to determine the effect of varying design parameters of planing-tail hulls is presented. Results are given to show the effects on resistance characteristics of varying angle of afterbody keel, depth of step, and length of afterbody chine. The effect of varying the gross load is shown for one configuration. The resistance characteristics of planing-tail hulls are compared with those of a conventional flying-boat hull. The forces on the forebody and afterbody of one configuration are compared with the forces on a conventional hull. Increasing the angle of afterbody keel had small effect on hump resistance and no effect on high-speed resistance but increased free-to-trim resistance at intermediate speeds. Increasing the depth of step increased hump resistance, had little effect on high-speed resistance, and increased free-to-trim resistance at intermediate speeds. Omitting the chines on the forward 25 percent of the afterbody had no appreciable effect on resistance. Omitting 70 percent of the chine length had almost no effect on maximum resistance but broadened the hump and increased spray around the afterbody. Load-resistance ratio at the hump decreased more rapidly with increasing load coefficient for the planing-tail hull than for the representative conventional hull, although the load-resistance ratio at the hump was greater for the planing-tail hull than for the conventional hull throughout the range of loads tested. At speeds higher than hump speed, load-resistance ratio for the planing-tail hull was a maximum at a particular gross load and was slightly less at heavier and lighter gross loads. The planing-tail hull was found to have lower resistance than the conventional hull at both the hump and at high speeds, but at intermediate speeds there was little difference. The lower hump resistance of the planing-tail hull was attributed to the ability of the afterbody to carry a greater percentage of the

  12. Heterodyne Interferometer Angle Metrology

    NASA Technical Reports Server (NTRS)

    Hahn, Inseob; Weilert, Mark A.; Wang, Xu; Goullioud, Renaud

    2010-01-01

    A compact, high-resolution angle measurement instrument has been developed that is based on a heterodyne interferometer. The common-path heterodyne interferometer metrology is used to measure displacements of a reflective target surface. In the interferometer setup, an optical mask is used to sample the measurement laser beam reflecting back from a target surface. Angular rotations, around two orthogonal axes in a plane perpendicular to the measurement- beam propagation direction, are determined simultaneously from the relative displacement measurement of the target surface. The device is used in a tracking telescope system where pitch and yaw measurements of a flat mirror were simultaneously performed with a sensitivity of 0.1 nrad, per second, and a measuring range of 0.15 mrad at a working distance of an order of a meter. The nonlinearity of the device is also measured less than one percent over the measurement range.

  13. Expand the measurement range of a critical angle refractometer by a centroid method for transparent fluids

    NASA Astrophysics Data System (ADS)

    Ye, Junwei; Yang, Kecheng; Liu, Hao; Dai, Jie; Guo, Wenping; Li, Wei; Xia, Min

    2015-01-01

    A simple approach to expand the measurement range of a critical angle refractometer (CAR) is demonstrated. Our method is based on measuring the centroid point of the angular reflective ratio of the CAR. According to the Snell's reflective law, the CAR with a divergent beam source has a limited measurement range. When the refractive index (RI) is higher than the upper limit, the reflective ratio curve is gradual changing without cutoff edge between the total internal reflection (TIR) and non-TIR. We find that the centroid point of the gradual changing curve is associated with the RI value of a liquid. Theorectical analysis and experimental results on sugar solutions with RI that varying from 1.359 to 1.3766 show that this method is effective and accurate to expand the measurement range.

  14. A high precision optical angle measuring instrument for large optical axis offsets

    NASA Astrophysics Data System (ADS)

    Xie, Jing; Tan, Zuojun

    2014-09-01

    In many industrial activities such as manufacturing and inspection, optical axis offsets measurement is an essential process for keeping and improving the quality of products. The laser autocollimation method is improved to detect the large angular displacement with high precision by using a re-imaging technology. A large optical screen made of frosted glass is located at the focal position of the objective lens instead of the detector. A precision CCD imaging system was employed to measure the displacement of the light spot on the optical screen. The sub-pixel position of center of the light spot can be obtained accurately through the centroid and Gaussian fit methods. The actual test results show that the total systematic error of the optical angle measuring instrument in the mode of measuring the range 8°×8° does not exceed 0.16'.

  15. Second harmonic measurement of multi-beam laser heterodyne with ultra-precision for the small angle

    NASA Astrophysics Data System (ADS)

    Li, Y. Chao; Ding, Q.; Wang, Y. Qiao; Yang, J. Ru; Liu, C. Yu; Wang, C. Hui; Sun, J. Feng

    2015-08-01

    In order to improve the measurement accuracy of the angle and signal processing speed of operation, this paper proposes a novel method of second harmonic measurement of multi-beam laser heterodyne for the angle, which based on the combination of Doppler effect and heterodyne technology, loaded the information of the angle to the frequency difference of second harmonic of the multi-beam laser heterodyne signal by frequency modulation of the oscillating mirror, which is in the light path. Heterodyne signal frequency can be obtained by fast Fourier transform, and can obtain values of the angle accurately after the multi-beam laser heterodyne signal demodulation. This novel method is used to simulate measurement for incident angle of standard mirror by Matlab, the obtained result shows that the relative measurement error of this method is just 0.5213%.

  16. Measurement of angle and axis of rotation in a carousel interferometer: a detailed analysis

    SciTech Connect

    Hussain, Ghazanfar; Ikram, Masroor

    2010-02-20

    A detailed analysis of a carousel interferometer is presented for the measurement of an unknown angle and axis of rotation. The technique exploits a set of compensator glass plates and a right-angle prism that is placed in each of the two arms of the interferometer. The two sets are placed at the same rotational stage, while the end mirrors of the interferometer are static. When rotation takes place, individual and relative optical path differences are generated in the two beams of the interferometer. The generated phase differences contribute toward finding the angle and axis of rotation. The analysis is presented for any initial position of the interferometer, i.e., the radial vector from the axis of rotation to the apex of one of the prisms used. The results show the slight variations in the error and nonlinearity when different parameters are manipulated. Moreover, the trade-off between the maximum size of the prisms and the radial distances are also presented.

  17. Measurement of Lumbosacral Angle in Normal Radiographs: A Retrospective Study in Southeast Nigeria

    PubMed Central

    Okpala, FO

    2014-01-01

    Background: A retrospective study of lumbosacral angle (LSA) in normal lateral supine lumbosacral radiographs of 274 Nigerians (aged 15-74 years) of Southeast region. A supine lateral lumbar spine radiograph is a very accurate means of measuring lordotic angles. The LSA is one of such angles, and can be used in the investigation, treatment and follow-up of low back disorders. Little is known about what the normal value for our population is and therefore, what constitutes hypo-/hyper-lordosis; most of the data in use in medical practice are based on studies on other races. Aim: To quantify the normal LSA in our population. Materials and Methods: LSA was measured by the Ferguson's technique and the data analyzed with SPSS Statistics version 17.0 (Chicago IL, USA). Results: LSA varied between 18° and 71°. With a 95.0 confidence interval of 43.3-45.6°, the mean (standard deviation) was 44.5 (9.9)° and showed no significant variation with sex and between various age groups; it compared favorably (though with small difference) with some of the literature values currently in use. Conclusion: This study had established the normal lordosis and the possible values at which to consider hypo-lordosis (below 15°), and hyper-lordosis (above 75°) in our population. Also established is that the development of lumbar lordosis ceases at spinal maturity, and that in normal lumbar lordosis measurement, the retrospective approach is a credible alternative to the prospective method. PMID:25328789

  18. Contact Angle of Drops Measured on Nontransparent Surfaces and Capillary Flow Visualized

    NASA Technical Reports Server (NTRS)

    Chao, David F.; Zhang, Nengli

    2003-01-01

    The spreading of a liquid on a solid surface is important for various practical processes, and contact-angle measurements provide an elegant method to characterize the interfacial properties of the liquid with the solid substrates. The complex physical processes occurring when a liquid contacts a solid play an important role in determining the performance of chemical processes and materials. Applications for these processes are in printing, coating, gluing, textile dyeing, and adhesives and in the pharmaceutical industry, biomedical research, adhesives, flat panel display manufacturing, surfactant chemistry, and thermal engineering.

  19. Status of CKM angle measurements, a report from BaBar and Belle

    SciTech Connect

    Long, Owen; /UC, Riverside

    2010-08-26

    I will review the latest developments in determining the CP-violating phases of the CKM matrix elements from measurements by the BaBar and BELLE experiments at the high-luminosity B factories (PEP-II and KEKB). The emphasis will be on the angle {gamma}/{phi}{sub 3} of the Unitarity Triangle, which is the relative phase arg(-V{sub ud}V*{sub ub}/V{sub cd}V*{sub cb}), or the CP-violating phase of the b {yields} u transition in the commonly used Wolfenstein convention.

  20. Miniature On-Board Angle of Attack Measurement System for Hypersonic Facilities

    NASA Technical Reports Server (NTRS)

    Crawford, Bradley L.; Rhode, Matthew N.

    2006-01-01

    The most prevalent method of establishing model angle of attack (AoA) in hypersonic wind tunnel facilities is using an encoder in the model support system then calculating sting/balance deflections based on balance output. This method has been shown to be less accurate than on-board methods in subsonic and transonic facilities and preliminary indications, as compared to optical methods, show large discrepancies in a hypersonic facility as well. With improvements in Micro-Electro- Mechanical Systems (MEMS) accelerometer technology more accurate onboard AoA measurement systems are now available for the small models usually found in hypersonic research facilities.

  1. Effects of enamel abrasion, salivary pellicle, and measurement angle on the optical assessment of dental erosion.

    PubMed

    Lussi, Adrian; Bossen, Anke; Höschele, Christoph; Beyeler, Barbara; Megert, Brigitte; Meier, Christoph; Rakhmatullina, Ekaterina

    2012-09-01

    The present study assessed the effects of abrasion, salivary proteins, and measurement angle on the quantification of early dental erosion by the analysis of reflection intensities from enamel. Enamel from 184 caries-free human molars was used for in vitro erosion in citric acid (pH 3.6). Abrasion of the eroded enamel resulted in a 6% to 14% increase in the specular reflection intensity compared to only eroded enamel, and the reflection increase depended on the erosion degree. Nevertheless, monitoring of early erosion by reflection analysis was possible even in the abraded eroded teeth. The presence of the salivary pellicle induced up to 22% higher reflection intensities due to the smoothing of the eroded enamel by the adhered proteins. However, this measurement artifact could be significantly minimized (p<0.05) by removing the pellicle layer with 3% NaOCl solution. Change of the measurement angles from 45 to 60 deg did not improve the sensitivity of the analysis at late erosion stages. The applicability of the method for monitoring the remineralization of eroded enamel remained unclear in a demineralization/remineralization cycling model of early dental erosion in vitro.

  2. Effects of enamel abrasion, salivary pellicle, and measurement angle on the optical assessment of dental erosion

    NASA Astrophysics Data System (ADS)

    Lussi, Adrian; Bossen, Anke; Höschele, Christoph; Beyeler, Barbara; Megert, Brigitte; Meier, Christoph; Rakhmatullina, Ekaterina

    2012-09-01

    The present study assessed the effects of abrasion, salivary proteins, and measurement angle on the quantification of early dental erosion by the analysis of reflection intensities from enamel. Enamel from 184 caries-free human molars was used for in vitro erosion in citric acid (pH 3.6). Abrasion of the eroded enamel resulted in a 6% to 14% increase in the specular reflection intensity compared to only eroded enamel, and the reflection increase depended on the erosion degree. Nevertheless, monitoring of early erosion by reflection analysis was possible even in the abraded eroded teeth. The presence of the salivary pellicle induced up to 22% higher reflection intensities due to the smoothing of the eroded enamel by the adhered proteins. However, this measurement artifact could be significantly minimized (p<0.05) by removing the pellicle layer with 3% NaOCl solution. Change of the measurement angles from 45 to 60 deg did not improve the sensitivity of the analysis at late erosion stages. The applicability of the method for monitoring the remineralization of eroded enamel remained unclear in a demineralization/remineralization cycling model of early dental erosion in vitro.

  3. Effects of enamel abrasion, salivary pellicle, and measurement angle on the optical assessment of dental erosion.

    PubMed

    Lussi, Adrian; Bossen, Anke; Höschele, Christoph; Beyeler, Barbara; Megert, Brigitte; Meier, Christoph; Rakhmatullina, Ekaterina

    2012-09-01

    The present study assessed the effects of abrasion, salivary proteins, and measurement angle on the quantification of early dental erosion by the analysis of reflection intensities from enamel. Enamel from 184 caries-free human molars was used for in vitro erosion in citric acid (pH 3.6). Abrasion of the eroded enamel resulted in a 6% to 14% increase in the specular reflection intensity compared to only eroded enamel, and the reflection increase depended on the erosion degree. Nevertheless, monitoring of early erosion by reflection analysis was possible even in the abraded eroded teeth. The presence of the salivary pellicle induced up to 22% higher reflection intensities due to the smoothing of the eroded enamel by the adhered proteins. However, this measurement artifact could be significantly minimized (p<0.05) by removing the pellicle layer with 3% NaOCl solution. Change of the measurement angles from 45 to 60 deg did not improve the sensitivity of the analysis at late erosion stages. The applicability of the method for monitoring the remineralization of eroded enamel remained unclear in a demineralization/remineralization cycling model of early dental erosion in vitro. PMID:23085926

  4. Contact angle and surface tension measurements of a five-ring polyphenyl ether

    NASA Technical Reports Server (NTRS)

    Jones, W. R., Jr.

    1985-01-01

    Contact angle measurements were performed for a five-ring polyphenyl ether isomeric mixture on M-50 steel in a dry nitrogen atmosphere. Two different techniques were used: (1) a tilting plate apparatus, and (2) a sessile drop apparatus. Measurements were made for the temperature range 25 to 190 C. Surface tension was measured by a differential maximum bubble pressure technique over the range 23 to 220C in room air. The critical surface energy of spreading (gamma (sub c)) was determined for the polyphenyl ether by plotting the cosine of the contact angle (theta) versus the surface tension (gamma (sub LV)). The straight line intercept at cosine theta = 1 is defined as gamma (sub c). Gamma (sub c) was found to be 30.1 dyn/cm for the tilting plate technique and 31.3 dyn/cm for the sessile drop technique. These results indicate that the polyphenyl ether is inherently autophobic (i.e., it will not spread on its own surface film until its surface tension is less than gamma (sub c). This phenomenon is discussed in light of the wettability and wear problems encountered with this fluid.

  5. Evaluation of electrolytic tilt sensors for wind tunnel model angle-of-attack (AOA) measurements

    NASA Technical Reports Server (NTRS)

    Wong, Douglas T.

    1991-01-01

    The results of a laboratory evaluation of three types of electrolytic tilt sensors as potential candidates for model attitude or angle of attack (AOA) measurements in wind tunnel tests are presented. Their performance was also compared with that from typical servo accelerometers used for AOA measurements. Model RG-37 electrolytic tilt sensors were found to have the highest overall accuracy among the three types. Compared with the servo accelerometer, their accuracies are about one order of magnitude worse and each of them cost about two-thirds less. Therefore, the sensors are unsuitable for AOA measurements although they are less expensive. However, the potential for other applications exists where the errors resulting from roll interaction, vibration, and response time are less, and sensor temperature can be controlled.

  6. Cellular organization and substructure measured using angle-resolved low-coherence interferometry.

    PubMed Central

    Wax, Adam; Yang, Changhuei; Backman, Vadim; Badizadegan, Kamran; Boone, Charles W; Dasari, Ramachandra R; Feld, Michael S

    2002-01-01

    We measure the organization and substructure of HT29 epithelial cells in a monolayer using angle-resolved low-coherence interferometry. This new technique probes cellular structure by measuring scattered light, as in flow cytometry, but offers an advantage in that the structure can be examined in situ, avoiding the need to disrupt the cell monolayer. We determine the size distribution of the cell nuclei by fitting measured light-scattering spectra to the predictions of Mie theory. In addition, we obtain information about the cellular organization and substructure by examining the spatial correlations within the monolayer. A remarkable finding is that the spatial correlations over small length scales take the form of an inverse power law, indicating the fractal nature of the packing of the subcellular structures. We also identify spatial correlations on a scale large compared with the size of a cell, indicating an overlying order within the monolayer. PMID:11916880

  7. Sample holder for small-angle x-ray scattering static and flow cell measurements

    SciTech Connect

    Lipfert, Jan; Millett, Ian S.; Seifert, Soenke; Doniach, Sebastian

    2006-04-15

    We present the design of a sample holder for small-angle x-ray scattering (SAXS) that can be used for both static and flow cell measurements, allowing to switch between these two types of measurement without having to realign the detector and camera geometry. The device makes possible high signal-to-noise experiments with sample volumes as small as 16 {mu}l and can be thermocontrolled using a standard circulating water bath. The setup has been used successfully for a range of biological SAXS measurements, including peptides, detergent micelles, membrane proteins, and nucleic acids. As a performance test, we present scattering data for horse heart cytochrome c, collected at the BESSRC CAT beam line 12-ID of the Advanced Photon Source. The design drawings are provided in the supplementary material.

  8. An architecture for measuring joint angles using a long period fiber grating-based sensor.

    PubMed

    Perez-Ramirez, Carlos A; Almanza-Ojeda, Dora L; Guerrero-Tavares, Jesus N; Mendoza-Galindo, Francisco J; Estudillo-Ayala, Julian M; Ibarra-Manzano, Mario A

    2014-01-01

    The implementation of signal filters in a real-time form requires a tradeoff between computation resources and the system performance. Therefore, taking advantage of low lag response and the reduced consumption of resources, in this article, the Recursive Least Square (RLS) algorithm is used to filter a signal acquired from a fiber-optics-based sensor. In particular, a Long-Period Fiber Grating (LPFG) sensor is used to measure the bending movement of a finger. After that, the Gaussian Mixture Model (GMM) technique allows us to classify the corresponding finger position along the motion range. For these measures to help in the development of an autonomous robotic hand, the proposed technique can be straightforwardly implemented on real time platforms such as Field Programmable Gate Array (FPGA) or Digital Signal Processors (DSP). Different angle measurements of the finger's motion are carried out by the prototype and a detailed analysis of the system performance is presented.

  9. An Architecture for Measuring Joint Angles Using a Long Period Fiber Grating-Based Sensor

    PubMed Central

    Perez-Ramirez, Carlos A.; Almanza-Ojeda, Dora L.; Guerrero-Tavares, Jesus N.; Mendoza-Galindo, Francisco J.; Estudillo-Ayala, Julian M.; Ibarra-Manzano, Mario A.

    2014-01-01

    The implementation of signal filters in a real-time form requires a tradeoff between computation resources and the system performance. Therefore, taking advantage of low lag response and the reduced consumption of resources, in this article, the Recursive Least Square (RLS) algorithm is used to filter a signal acquired from a fiber-optics-based sensor. In particular, a Long-Period Fiber Grating (LPFG) sensor is used to measure the bending movement of a finger. After that, the Gaussian Mixture Model (GMM) technique allows us to classify the corresponding finger position along the motion range. For these measures to help in the development of an autonomous robotic hand, the proposed technique can be straightforwardly implemented on real time platforms such as Field Programmable Gate Array (FPGA) or Digital Signal Processors (DSP). Different angle measurements of the finger's motion are carried out by the prototype and a detailed analysis of the system performance is presented. PMID:25536002

  10. Measurements of the unsteady vortex flow over a wing-body at angle of attack

    NASA Technical Reports Server (NTRS)

    Debry, Benoit; Komerath, Narayanan M.; Liou, Shiuh-Guang; Caplin, J.; Lenakos, Jason

    1992-01-01

    Measurements of the unsteady vortex flow over a wing-body at high angles of attack were carried out on a generic test model of a pointed body of revolution with double-delta wings. Vortex patterns and trajectories were quantified from digitized laser sheet video images. The velocity-field measurements showed the jetlike flow in the unburst vortex, unsteady secondary structures below the primary core, and then the reversed flow in the burst vortex. Results of hot-film anemometry revealed the presence of peak frequencies in the velocity spectra over the wing and near the trailing edge, which varied linearly with freestream speed and increased as the measurement point moved upstream. Good Strouhal correlation was found with previous results obtained for a smaller generic wing-body model.

  11. An architecture for measuring joint angles using a long period fiber grating-based sensor.

    PubMed

    Perez-Ramirez, Carlos A; Almanza-Ojeda, Dora L; Guerrero-Tavares, Jesus N; Mendoza-Galindo, Francisco J; Estudillo-Ayala, Julian M; Ibarra-Manzano, Mario A

    2014-01-01

    The implementation of signal filters in a real-time form requires a tradeoff between computation resources and the system performance. Therefore, taking advantage of low lag response and the reduced consumption of resources, in this article, the Recursive Least Square (RLS) algorithm is used to filter a signal acquired from a fiber-optics-based sensor. In particular, a Long-Period Fiber Grating (LPFG) sensor is used to measure the bending movement of a finger. After that, the Gaussian Mixture Model (GMM) technique allows us to classify the corresponding finger position along the motion range. For these measures to help in the development of an autonomous robotic hand, the proposed technique can be straightforwardly implemented on real time platforms such as Field Programmable Gate Array (FPGA) or Digital Signal Processors (DSP). Different angle measurements of the finger's motion are carried out by the prototype and a detailed analysis of the system performance is presented. PMID:25536002

  12. High-speed light field camera and frequency division multiplexing for fast multi-plane velocity measurements.

    PubMed

    Fischer, Andreas; Kupsch, Christian; Gürtler, Johannes; Czarske, Jürgen

    2015-09-21

    Non-intrusive fast 3d measurements of volumetric velocity fields are necessary for understanding complex flows. Using high-speed cameras and spectroscopic measurement principles, where the Doppler frequency of scattered light is evaluated within the illuminated plane, each pixel allows one measurement and, thus, planar measurements with high data rates are possible. While scanning is one standard technique to add the third dimension, the volumetric data is not acquired simultaneously. In order to overcome this drawback, a high-speed light field camera is proposed for obtaining volumetric data with each single frame. The high-speed light field camera approach is applied to a Doppler global velocimeter with sinusoidal laser frequency modulation. As a result, a frequency multiplexing technique is required in addition to the plenoptic refocusing for eliminating the crosstalk between the measurement planes. However, the plenoptic refocusing is still necessary in order to achieve a large refocusing range for a high numerical aperture that minimizes the measurement uncertainty. Finally, two spatially separated measurement planes with 25×25 pixels each are simultaneously acquired with a measurement rate of 0.5 kHz with a single high-speed camera.

  13. Phase angle and impedance measurements for nondestructive moisture content determination of in-shell peanuts using a cylindrical sample holder

    Technology Transfer Automated Retrieval System (TEKTRAN)

    A simple, low cost instrument that measures impedance and phase angle was used along with a parallel-plate capacitance system to estimate the moisture content (MC) of yellow corn. A sample of corn weighing about 100g was placed between the parallel-plate electrodes and the impedance and phase angle...

  14. Measurements of the anisotropic in-plane resistivity of underdoped FeAs-based pnictide superconductors.

    PubMed

    Ying, J J; Wang, X F; Wu, T; Xiang, Z J; Liu, R H; Yan, Y J; Wang, A F; Zhang, M; Ye, G J; Cheng, P; Hu, J P; Chen, X H

    2011-08-01

    We systematically investigated the in-plane resistivity anisotropy of electron-underdoped EuFe(2-x)Co(x)As(2) and BaFe(2-x)Co(x)As(2) and hole-underdoped Ba(1-x)K(x)Fe(2)As(2). Large in-plane resistivity anisotropy was found in the former samples, while tiny in-plane resistivity anisotropy was detected in the latter ones. When it is detected, the anisotropy starts above the structural transition temperature and increases smoothly through it. As the temperature is lowered further, the anisotropy takes a dramatic enhancement through the magnetic transition temperature. We found that the anisotropy is universally tied to the presence of T-linear behavior of resistivity. Our results demonstrate that the nematic state is caused by electronic degrees of freedom, and the microscopic orbital involvement in the magnetically ordered state must be fundamentally different between the hole- and electron-doped materials.

  15. A poloidal field measurement technique: Pitch angle measurements via injected He/sup +/ ions

    SciTech Connect

    Jobes, F.C.

    1989-07-01

    The poloidal field of a tokamak can be determined by observing the light emitted by He/sup +/ ions injected into the plasma by a perpendicular He/sup 0/ beam. These ions will orbit in small circles located where the neutral atom became ionized, and they will remain there for a few microseconds. During this time, some of these ions will also emit light at various spectral lines. The observed spectrum of any of these lines will have a peculiar and very wide shape, and it will be offset (Doppler shifted) with respect to the natural line location. The location and width of the spectral pattern provide independent information about the components of the poloidal field which are parallel and perpendicular to the beam velocity, and this information is local to the point where the light is emitted. For a horizontal beam, these components are b/sub x/ and b/sub y/, respectively. The difference in Doppler shift between two measurement points above one another (at the top and bottom of the beam) is directly proportional to /delta/b/sub x/, which in turn is proportional to the transform on that flux surface. Thus, this technique provides a means to measure directly local values of q(r). Simulation studies indicate that accurate measurements can be made in milliseconds. 6 refs., 8 figs.

  16. Structure-property relationships in Waspaloy via small angle scattering and electrical resistivity measurements

    SciTech Connect

    Whelchel, R.; Gerhardt, Dr. Rosario; Littrell, Ken

    2010-01-01

    The mechanical properties in superalloys are controlled by the distribution of the {gamma}{prime} precipitate phase. Electrical measurements have been shown to be sensitive to certain aspects of the precipitation process and show promise for predicting the evolving microstructural state in superalloys. Aging experiments were conducted on Waspaloy samples for temperatures between 600 and 950 C for times ranging from 2min to 500h. Particle size distributions were obtained by modeling of small angle scattering (SAS) data, whereas, small precipitate size information, strain, and lattice mismatch data were obtained from X-ray diffraction. The microstructural information was then used to create a figure of merit of electron scattering intended to correlate electrical properties to the precipitate microstructure. The proposed figure of merit shows an empirical correlation with the electrical resistivity data, demonstrating the sensitivity of the resistivity measurements to the precipitation process and coarsening behavior.

  17. Multiple angle measurement and modeling of M-band x-ray fluxes from vacuum hohlraum

    NASA Astrophysics Data System (ADS)

    Guo, Liang; Li, Shanwei; Li, Zhichao; Jing, Longfei; Xie, Xufei; Jiang, Xiaohua; Yang, Dong; Du, Huabin; Hou, Lifei; Yang, Jiamin; Liu, Shenye; Jiang, Shaoen; Ding, Yongkun; Hu, Guangyue; Zheng, Jian

    2016-09-01

    The energetics experiment of vacuum gold hohlraums is implemented on the Shenguang-II laser facility. The total and M-band x-ray fluxes from the laser entrance holes are measured by the flat response x-ray diodes which are set at multiple angles with respect to the axis of the hohlraums. The measured M-band fractions are from 5.72% to 7.71%, which present a specific angular distribution. Based on the fact that the M-band x-rays are mainly emitted from the under-dense high-temperature plasmas, a simplified model is developed to give a quantitative prediction of the intensity, temporal behavior, and angular distribution of the M-band x-ray flux. The results obtained with our model are in good agreement with the experimental data, showing that our model can be a useful tool for M-band x-ray investigation.

  18. Measurement of 13C chemical shift tensor principal values with a magic-angle turning experiment.

    PubMed

    Hu, J Z; Orendt, A M; Alderman, D W; Pugmire, R J; Ye, C; Grant, D M

    1994-08-01

    The magic-angle turning (MAT) experiment introduced by Gan is developed into a powerful and routine method for measuring the principal values of 13C chemical shift tensors in powdered solids. A large-volume MAT probe with stable rotation frequencies down to 22 Hz is described. A triple-echo MAT pulse sequence is introduced to improve the quality of the two-dimensional baseplane. It is shown that measurements of the principal values of chemical shift tensors in complex compounds can be enhanced by using either short contact times or dipolar dephasing pulse sequences to isolate the powder patterns from protonated or non-protonated carbons, respectively. A model compound, 1,2,3-trimethoxybenzene, is used to demonstrate these techniques, and the 13C principal values in 2,3-dimethylnaphthalene and Pocahontas coal are reported as typical examples.

  19. Vehicle sideslip angle measurement based on sensor data fusion using an integrated ANFIS and an Unscented Kalman Filter algorithm

    NASA Astrophysics Data System (ADS)

    Boada, B. L.; Boada, M. J. L.; Diaz, V.

    2016-05-01

    Most existing ESC (Electronic Stability Control) systems rely on the measurement of both yaw rate and sideslip angle. However, one of the main issues is that the sideslip angle cannot be measured directly because the sensors are too expensive. For this reason, sideslip angle estimation has been widely discussed in the relevant literature. The modeling of sideslip angle is complex due to the non-linear dynamics of the vehicle. In this paper, we propose a novel observer based on ANFIS, combined with Kalman Filters in order to estimate the sideslip angle, which in turn is used to control the vehicle dynamics and improve its behavior. For this reason, low-cost sensor measurements which are integrated into the actual vehicle and executed in real time have to be used. The ANFIS system estimates a "pseudo-sideslip angle" through parameters which are easily measured, using sensors equipped in actual vehicles (inertial sensors and steering wheel sensors); this value is introduced in UKF in order to filter noise and to minimize the variance of the estimation mean square error. The estimator has been validated by comparing the observed proposal with the values provided by the CARSIM model, which is a piece of experimentally validated software. The advantage of this estimation is the modeling of the non-linear dynamics of the vehicle, by means of signals which are directly measured from vehicle sensors. The results show the effectiveness of the proposed ANFIS+UKF-based sideslip angle estimator.

  20. Three-dimensional reconstruction method for measuring the knee valgus angle of the femur in northern Chinese adults*

    PubMed Central

    Liu, Tong; Wang, Chen-yu; Xiao, Jian-lin; Zhu, Lan-yu; Li, Xue-zhou; Qin, Yan-guo; Gao, Zhong-li

    2014-01-01

    The purpose of this study was to establish a method for measuring the knee valgus angle from the anatomical and mechanical axes on three-dimensional reconstruction imaging models, and to use this method for estimating an average knee valgus angle value for northern Chinese adults. Computed tomographic angiography data in DICOM format for 128 normal femurs from 64 adult subjects were chosen for analysis. After the femur images were subjected to three-dimensional reconstruction, the deepest point in the intercondylar notch (point A), the midpoint of the medullary cavity 20 cm above the knee-joint line (point B), and the landmark of the femoral head rotation center (point C) were identified on each three-dimensional model. The knee valgus angle was defined as the angle enclosed by the distal femoral anatomical axis (line AB) and the femoral mechanical axis (line AC). The average (mean±SD) of knee valgus angle for the 128 femurs was 6.20°±1.20° (range, 3.05° to 10.64°). Significant positive correlations were found between the knee valgus angles of the right and left sides and between the knee valgus angle and age. During total knee arthroplasty, choosing a valgus cut angle of approximately 6° may achieve a good result in reestablishing the natural mechanical alignment of the lower extremity for patients of northern Chinese ethnicity. Larger valgus cut angles should be chosen for older patients. PMID:25091990

  1. Process and apparatus for measuring degree of polarization and angle of major axis of polarized beam of light

    DOEpatents

    Decker, Derek E.; Toeppen, John S.

    1994-01-01

    Apparatus and process are disclosed for calibrating measurements of the phase of the polarization of a polarized beam and the angle of the polarized optical beam's major axis of polarization at a diagnostic point with measurements of the same parameters at a point of interest along the polarized beam path prior to the diagnostic point. The process is carried out by measuring the phase angle of the polarization of the beam and angle of the major axis at the point of interest, using a rotatable polarizer and a detector, and then measuring these parameters again at a diagnostic point where a compensation apparatus, including a partial polarizer, which may comprise a stack of glass plates, is disposed normal to the beam path between a rotatable polarizer and a detector. The partial polarizer is then rotated both normal to the beam path and around the axis of the beam path until the detected phase of the beam polarization equals the phase measured at the point of interest. The rotatable polarizer at the diagnostic point may then be rotated manually to determine the angle of the major axis of the beam and this is compared with the measured angle of the major axis of the beam at the point of interest during calibration. Thereafter, changes in the polarization phase, and in the angle of the major axis, at the point of interest can be monitored by measuring the changes in these same parameters at the diagnostic point.

  2. Antennas for Terahertz Applications: Focal Plane Arrays and On-chip Non-contact Measurement Probes

    NASA Astrophysics Data System (ADS)

    Trichopoulos, Georgios C.

    The terahertz (THz) band provides unique sensing opportunities that enable several important applications such as biomedical imaging, remote non-destructive inspection of packaged goods, and security screening. THz waves can penetrate most materials and can provide unique spectral information in the 0.1--10 THz band with high resolution. In contrast, other imaging modalities, like infrared (IR), suffer from low penetration depths and are thus not attractive for non-destructive evaluation. However, state-of-the-art THz imaging systems typically employ mechanical raster scans using a single detector to acquire two-dimensional images. Such devices tend to be bulky and complicated due to the mechanical parts, and are thus rather expensive to develop and operate. Thus, large-format (e.g. 100x100 pixels) and all-electronics based THz imaging systems are badly needed to alleviate the space, weight and power (SWAP) factors and enable cost effective utilization of THz waves for sensing and high-data-rate communications. In contrast, photonic sensors are very compact because light can couple directly to the photodiode without residing to radiation coupling topologies. However, in the THz band, due to the longer wavelengths and much lower photon energies, highly efficient antennas with optimized input impedance have to be integrated with THz sensors. Here, we implement novel antenna engineering techniques that are optimized to take advantage of recent technological advances in solid-state THz sensing devices. For example, large-format focal plane arrays (FPAs) have been the Achilles' heel of THz imaging systems. Typically, optical components (lenses, mirrors) are employed in order to improve the optical performance of FPAs, however, antenna sensors suffer from degraded performance when they are far from the optical axis, thus minimizing the number of useful FPA elements. By modifying the radiation pattern of FPA antennas we manage to alleviate the off-axis aberration

  3. Optical characterization of liposomes by right angle light scattering and turbidity measurement.

    PubMed

    Matsuzaki, K; Murase, O; Sugishita, K; Yoneyama, S; Akada, K; Ueha, M; Nakamura, A; Kobayashi, S

    2000-07-31

    Liposomes have frequently been used as models of biomembranes or vehicles for drug delivery. However, the systematic characterization of lipid vesicles by right angle light scattering and turbidity has not been carried out despite the usefulness of such studies for size estimation. In this study, liposomes of various sizes were prepared by sonication and extrusion. The mean cumulant radii of the vesicles were determined by dynamic light scattering. The lamellarities were estimated based on fluorescence quenching of N-(7-nitrobenz-2-oxa-1,3-diazol-4-yl)dipalmitoyl-L-alpha-phosph ati dylethanolamine by sodium dithionite. Right angle light scattering intensity and optical density at 436 nm per unit lipid concentration were measured as a function of vesicle radius. With a vesicle radius < or =100 nm, the optical parameters could be well explained by the Rayleigh-Gans-Debye theory in which the liposomes were modeled as homogeneous spheres with mean refractive indices determined by the volume fractions of lipids in vesicles.

  4. Surface energy of silicas, grafted with alkyl chains of increasing lengths, as measured by contact angle techniques

    SciTech Connect

    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.

  5. Coincidence measurements of electron-impact coherence parameters for e-He scattering in the full range of scattering angles

    SciTech Connect

    Klosowski, Lukasz; Piwinski, Mariusz; Dziczek, Dariusz; Pleskacz, Katarzyna; Chwirot, Stanislaw

    2009-12-15

    Electron impact coherence parameters for inelastic e-He scattering have been measured for the excitation to the 2 {sup 1}P{sub 1} state at collision energy of 100 eV. The experiment was conducted using angular correlation electron-photon coincidence technique with a magnetic angle changer allowing measurements in full range of scattering angles. The results are compared with other experimental data and theoretical predictions available for this collisional system.

  6. Simultaneous Cotton-Mouton and Faraday rotation angle measurements on JET

    SciTech Connect

    Boboc, A.; Zabeo, L.; Murari, A.

    2006-10-15

    The change in the ellipticity of a laser beam that passes through plasma due to the Cotton-Mouton effect can provide additional information on the plasma density. This approach, complementary to the more traditional interferometric methods, has been implemented recently using the JET interferometer-polarimeter with a new setup. Routine Cotton-Mouton phase shift measurements are made on the vertical central chords simultaneously with the Faraday rotation angle data. These new data are used to provide robust line-integrated density measurements in difficult plasma scenarios, with strong Edge Localized Modes (ELMs) or pellets. These always affect interferometry, causing fringe jumps and preventing good control of the plasma density. A comparison of line-integrated density from polarimetry and interferometry measurements shows an agreement within 10%. Moreover, in JET the measurements can be performed close to a reactor relevant range of parameters, in particular, at high densities and temperatures. This provides a unique opportunity to assess the quality of the Faraday rotation and Cotton-Mouton phase shift measurements where both effects are strong and mutual nonlinear interaction between the two effects takes place.

  7. Simultaneous Cotton-Mouton and Faraday rotation angle measurements on JET

    NASA Astrophysics Data System (ADS)

    Boboc, A.; Zabeo, L.; Murari, A.

    2006-10-01

    The change in the ellipticity of a laser beam that passes through plasma due to the Cotton-Mouton effect can provide additional information on the plasma density. This approach, complementary to the more traditional interferometric methods, has been implemented recently using the JET interferometer-polarimeter with a new setup. Routine Cotton-Mouton phase shift measurements are made on the vertical central chords simultaneously with the Faraday rotation angle data. These new data are used to provide robust line-integrated density measurements in difficult plasma scenarios, with strong Edge Localized Modes (ELMs) or pellets. These always affect interferometry, causing fringe jumps and preventing good control of the plasma density. A comparison of line-integrated density from polarimetry and interferometry measurements shows an agreement within 10%. Moreover, in JET the measurements can be performed close to a reactor relevant range of parameters, in particular, at high densities and temperatures. This provides a unique opportunity to assess the quality of the Faraday rotation and Cotton-Mouton phase shift measurements where both effects are strong and mutual nonlinear interaction between the two effects takes place.

  8. Estimation of cometary surface layer properties from grazing angle measurements done by the CONSERT instrument

    NASA Astrophysics Data System (ADS)

    Statz, C.; Ciarletti, V.; Hegler, S.; Plettemeier, D.; Angeli, K.; Herique, A.; Kofman, W.

    2013-09-01

    The main scientific objective of the Comet Nucleus Sounding Experiment by Radiowave Transmission (CONSERT) [1] is to determine the dielectric properties of comet 67P/Chuyurmov-Gerasimenko's nucleus. This will be achieved by performing a sounding of the comet's core between the lander "Philae" launched onto the comet's surface and the orbiter "Rosetta". For the sounding the lander will receive and process the radio signal emitted by the CONSERT instrument aboard the orbiter and retransmit a signal to the orbiter. With data measured during the first science phase, a three-dimensional model of the material distribution with regard to the complex ielectric permittivity of the comet's nucleus is to be reconstructed. In addition to the sounding through the comet's core the instrument will be operated under grazing incidence, i.e. on a part of the orbit where the orbiter moves below the horizon and the direct path between orbiter and lander vanishes. From these measurements the the properties of the surfaces layers are to be estimated. In order to investigate and understand the influence of the permittivity distribution of the surface layers on the grazing angle and the CONSERT signal in case of grazing incidence, simulations of the electromagnetic wave propagation were performed using the well know pseudo-spectral-time-domain method and differential raytracing. The simulations were performed on actual shape models of comet 67P/Chuyurmov-Gerasimenko and material models described in [2]. Exemplary results of these simulations are shown in Fig. 1 and indicate the feasibility of using grazing angle measurements to estimate properties of the surface layering.

  9. Estimating cometary surface layer properties from grazing angle measurements derived from CONSERT data

    NASA Astrophysics Data System (ADS)

    Statz, Christoph; Ciarletti, Valerie; Hegler, Sebastian; Plettemeier, Dirk; Herique, Alain; Kofman, Wlodek

    2014-05-01

    The main scientific objective of the Comet Nucleus Sounding Experiment by Radiowave Transmission (CONSERT) is to determine the dielectric properties of comet 67P/Chuyurmov-Gerasimenko's nucleus. This will be achieved by performing a sounding of the comet's core between the lander Philae launched onto the comet's surface and the orbiter Rosetta. For the sounding the lander will receive and process the radio signal emitted by the CONSERT instrument aboard the orbiter and retransmit a signal to the orbiter. With data measured during the first science phase, a three-dimensional model of the material distribution with regard to the complex dielectric permittivity of the comet's nucleus is to be reconstructed. In addition to the sounding through the comet's core the instrument will be operated under grazing incidence, i.e. on a part of the orbit where the orbiter moves below the horizon and the direct path between orbiter and lander vanishes. From these measurements the the properties of the surfaces layers are to be estimated. In order to investigate and understand the influence of the permittivity distribution of the surface layers on the grazing angle and the CONSERT signal in case of grazing incidence, simulations of the electromagnetic wave propagation were performed using the well know pseudo-spectral-time-domain method and differential raytracing. The simulations were performed on actual shape models of comet 67P/Chuyurmov-Gerasimenko and a variety of material models. In this paper we present exemplary results of these simulations which indicate the feasibility of using grazing angle measurements to estimate properties of the surface layering.

  10. Precision measurement of disc height, vertebral height and sagittal plane displacement from lateral radiographic views of the lumbar spine.

    PubMed

    Frobin, W.; Brinckmann, P.; Biggemann, M.; Tillotson, M.; Burton, K.

    1997-01-01

    OBJECTIVE.: To compile a database of disc height, vertebral height and sagittal plane displacement from lateral radiographic views of the lumbar spine, valid for male and female subjects in the age range 16-57 years. The protocols used to measure these parameters compensate for distortion in central projection, off-centre position, axial rotation and lateral tilt of the spine as well as for variation in radiographic magnification and stature. STUDY DESIGN.: The study comprised designing and testing of measurement protocols, together with subsequent data collection from archive radiographs. BACKGROUND.: Attempts to quantify primary mechanical damage to lumbar vertebrae and discs have been limited due to imprecision when measuring disc height, vertebral height and sagittal plane displacement. Age-related, normative values for these parameters were not previously available. Consequently, important issues like the effectiveness of past and present guidelines for safe manual handling with respect to prevention of overload injuries could not be resolved and judgement on pathological alterations in the morphology of the individual lumbar spine could only be performed in a qualitative, subjective manner. METHODS.: Based on the analysis of vertebral contours in the lateral radiographic image of the lumbar spine, new protocols for measuring disc height, vertebral height and sagittal plane displacement were developed. The measured data are virtually independent of distortion, axial rotation and lateral tilt. Furthermore, description of height and displacement using dimensionless parameters guarantees independence of radiographic magnification and stature. Subjective influence in the measurement procedure was minimized by automatic computation of contour-landmarks and derived parameters. Measurement errors were assessed from sets of radiographs of spine specimens and serial flexion-extension radiographs; interobserver and intraobserver errors were assessed from repeated

  11. Validity of an inertial measurement unit to assess pelvic orientation angles during gait, sit-stand transfers and step-up transfers: Comparison with an optoelectronic motion capture system.

    PubMed

    Bolink, S A A N; Naisas, H; Senden, R; Essers, H; Heyligers, I C; Meijer, K; Grimm, B

    2016-03-01

    An inertial measurement unit (IMU) allows kinematic evaluation of human motion with fewer operational constraints than a gold standard optoelectronic motion capture (MOCAP) system. The study's aim was to compare IMU and MOCAP measurements of dynamic pelvic orientation angles during different activities of daily life (ADL): gait, sit-to-stand (STS) transfers and block step-up (BS) transfers. A single IMU was attached onto the lower back in seventeen healthy participants (8F/9 M, age 19-31 years; BMI < 25) and optical skin markers were attached onto anatomical pelvic landmarks for MOCAP measurements. Comparisons between IMU and MOCAP by Bland-Altman plots demonstrated that measurements were between 2SD of the absolute difference and Pearson's correlation coefficients were between 0.85 and 0.94. Frontal plane pelvic angle estimations achieved a RMSE in the range of [2.7°-4.5°] and sagittal plane measurements achieved a RMSE in the range of [2.7°-8.9°] which were both lowest in gait. Waveform peak detection times demonstrated ICCs between 0.96 and 1.00. These results are in accordance to other studies comparing IMU and MOCAP measurements with different applications and suggest that an IMU is a valid tool to measure dynamic pelvic angles during various activities of daily life which could be applied to monitor rehabilitation in a wide variety of musculoskeletal disorders. PMID:26711470

  12. A surface energy analysis of mucoadhesion: contact angle measurements on polycarbophil and pig intestinal mucosa in physiologically relevant fluids.

    PubMed

    Lehr, C M; Bouwstra, J A; Boddé, H E; Junginger, H E

    1992-01-01

    The possible role of surface energy thermodynamics in mucoadhesion was investigated with Polycarbophil and pig intestinal mucosa. In separate experiments, the surface energy parameters of the substrate (mucosa) and the adhesive (polymer film) were determined by contact angle measurements on captive air/octane bubbles in three physiologically relevant test fluids (isotonic saline, artificial gastric fluid, and artificial intestinal fluid). Whereas the swollen Polycarbophil films were relatively hydrophilic as indicated by small water contact angles (22, 23, and 16 degrees), the water contact angles measured on mucosal tissue were significantly larger (61, 48, and 57 degrees). Hence, mucus was found to possess an appreciable hydrophobicity. The measured adhesive performance (force of detachment) between Polycarbophil and pig small intestinal mucosa was highest in nonbuffered saline medium, intermediate in gastric fluid, and minimal in intestinal fluid. In agreement with this trend, the mismatch in surface polarities between substrate and adhesive, calculated from the contact angle data, increased in the same order.

  13. Measurement of the absolute differential cross section of proton–proton elastic scattering at small angles

    DOE PAGES

    Mchedlishvili, D.; Chiladze, D.; Dymov, S.; Bagdasarian, Z.; Barsov, S.; Gebel, R.; Gou, B.; Hartmann, M.; Kacharava, A.; Keshelashvili, I.; et al

    2016-02-03

    The differential cross section for proton-proton elastic scattering has been measured at a beam kinetic energy of 1.0 GeV and in 200 MeV steps from 1.6 to 2.8 GeV for centre-of-mass angles in the range from 12°-16° to 25°-30°, depending on the energy. A precision in the overall normalisation of typically 3% was achieved by studying the energy losses of the circulating beam of the COSY storage ring as it passed repeatedly through the windowless hydrogen target of the ANKE magnetic spectrometer. It is shown that the data have a significant impact upon the results of a partial wave analysis.more » Furthermore, after extrapolating the differential cross sections to the forward direction, the results are broadly compatible with the predictions of forward dispersion relations.« less

  14. Retrieval of vertical profiles of atmospheric refraction angles by inversion of optical dilution measurements

    NASA Astrophysics Data System (ADS)

    Fussen, D.; Tétard, C.; Dekemper, E.; Pieroux, D.; Mateshvili, N.; Vanhellemont, F.; Franssens, G.; Demoulin, P.

    2015-04-01

    In this paper, we show how the usual change of tangent altitude associated with atmospheric refraction is inseparably connected to a variation of the observed apparent intensity, for extended and pointlike sources. We demonstrate, in the regime of weak refraction angles, that atmospheric optical dilution and image deformation are strictly concomitant. The approach leads to the integration of a simple differential equation related to the observed transmittance in the absence of other absorbing molecules along the optical path. We successfully applied the proposed method to the measurements performed by two past occultation experiments: GOMOS for stellar and ORA for solar occultations. The developed algorithm (named ARID) will be applied to the imaging of solar occultations in a forthcoming pico-satellite mission.

  15. Use of PIXE-PIGE under variable incident angle for ancient glass corrosion measurements

    NASA Astrophysics Data System (ADS)

    Weber, G.; Strivay, D.; Martinot, L.; Garnir, H. P.

    2002-04-01

    Although glass is usually considered as a very stable archaeological material, it can undergo severe degradation. Soda-lime glass, the most common glass throughout ancient times, is particularly sensitive to this problem. The glass surface absorbs moisture from its environment and the contact with CO 2 causes Na 2O and NaOH to convert to Na 2CO 3, which is extremely hygroscopic. The subsequent unstable glass layer can be leached out and causes decomposition of the glass. The non-destructive PIGE-PIXE method of investigation allows detection of this phenomenon even if no visible effect appears. The variable incident angle method is able to discern the depth of the degradation. One aim of such studies is the possible dating or at least fake detecting of archaeological materials. Furthermore, even objects of large size can be investigated with the atmospheric PIGE-PIXE set-up. Some examples of measurements on ancient glass are given.

  16. Mobile Phone-Based Joint Angle Measurement for Functional Assessment and Rehabilitation of Proprioception

    PubMed Central

    Mourcou, Quentin; Fleury, Anthony; Diot, Bruno; Franco, Céline; Vuillerme, Nicolas

    2015-01-01

    Assessment of joint functional and proprioceptive abilities is essential for balance, posture, and motor control rehabilitation. Joint functional ability refers to the capacity of movement of the joint. It may be evaluated thereby measuring the joint range of motion (ROM). Proprioception can be defined as the perception of the position and of the movement of various body parts in space. Its role is essential in sensorimotor control for movement acuity, joint stability, coordination, and balance. Its clinical evaluation is commonly based on the assessment of the joint position sense (JPS). Both ROM and JPS measurements require estimating angles through goniometer, scoliometer, laser-pointer, and bubble or digital inclinometer. With the arrival of Smartphones, these costly clinical tools tend to be replaced. Beyond evaluation, maintaining and/or improving joint functional and proprioceptive abilities by training with physical therapy is important for long-term management. This review aims to report Smartphone applications used for measuring and improving functional and proprioceptive abilities. It identifies that Smartphone applications are reliable for clinical measurements and are mainly used to assess ROM and JPS. However, there is lack of studies on Smartphone applications which can be used in an autonomous way to provide physical therapy exercises at home. PMID:26583101

  17. Wearable Goniometer and Accelerometer Sensory Fusion for Knee Joint Angle Measurement in Daily Life.

    PubMed

    Tognetti, Alessandro; Lorussi, Federico; Carbonaro, Nicola; de Rossi, Danilo

    2015-01-01

    Human motion analysis is crucial for a wide range of applications and disciplines. The development and validation of low cost and unobtrusive sensing systems for ambulatory motion detection is still an open issue. Inertial measurement systems and e-textile sensors are emerging as potential technologies for daily life situations. We developed and conducted a preliminary evaluation of an innovative sensing concept that combines e-textiles and tri-axial accelerometers for ambulatory human motion analysis. Our sensory fusion method is based on a Kalman filter technique and combines the outputs of textile electrogoniometers and accelerometers without making any assumptions regarding the initial accelerometer position and orientation. We used our technique to measure the flexion-extension angle of the knee in different motion tasks (monopodalic flexions and walking at different velocities). The estimation technique was benchmarked against a commercial measurement system based on inertial measurement units and performed reliably for all of the various tasks (mean and standard deviation of the root mean square error of 1:96 and 0:96, respectively). In addition, the method showed a notable improvement in angular estimation compared to the estimation derived by the textile goniometer and accelerometer considered separately. In future work, we will extend this method to more complex and multi-degree of freedom joints. PMID:26569249

  18. Mobile Phone-Based Joint Angle Measurement for Functional Assessment and Rehabilitation of Proprioception.

    PubMed

    Mourcou, Quentin; Fleury, Anthony; Diot, Bruno; Franco, Céline; Vuillerme, Nicolas

    2015-01-01

    Assessment of joint functional and proprioceptive abilities is essential for balance, posture, and motor control rehabilitation. Joint functional ability refers to the capacity of movement of the joint. It may be evaluated thereby measuring the joint range of motion (ROM). Proprioception can be defined as the perception of the position and of the movement of various body parts in space. Its role is essential in sensorimotor control for movement acuity, joint stability, coordination, and balance. Its clinical evaluation is commonly based on the assessment of the joint position sense (JPS). Both ROM and JPS measurements require estimating angles through goniometer, scoliometer, laser-pointer, and bubble or digital inclinometer. With the arrival of Smartphones, these costly clinical tools tend to be replaced. Beyond evaluation, maintaining and/or improving joint functional and proprioceptive abilities by training with physical therapy is important for long-term management. This review aims to report Smartphone applications used for measuring and improving functional and proprioceptive abilities. It identifies that Smartphone applications are reliable for clinical measurements and are mainly used to assess ROM and JPS. However, there is lack of studies on Smartphone applications which can be used in an autonomous way to provide physical therapy exercises at home. PMID:26583101

  19. Wearable Goniometer and Accelerometer Sensory Fusion for Knee Joint Angle Measurement in Daily Life

    PubMed Central

    Tognetti, Alessandro; Lorussi, Federico; Carbonaro, Nicola; de Rossi, Danilo

    2015-01-01

    Human motion analysis is crucial for a wide range of applications and disciplines. The development and validation of low cost and unobtrusive sensing systems for ambulatory motion detection is still an open issue. Inertial measurement systems and e-textile sensors are emerging as potential technologies for daily life situations. We developed and conducted a preliminary evaluation of an innovative sensing concept that combines e-textiles and tri-axial accelerometers for ambulatory human motion analysis. Our sensory fusion method is based on a Kalman filter technique and combines the outputs of textile electrogoniometers and accelerometers without making any assumptions regarding the initial accelerometer position and orientation. We used our technique to measure the flexion-extension angle of the knee in different motion tasks (monopodalic flexions and walking at different velocities). The estimation technique was benchmarked against a commercial measurement system based on inertial measurement units and performed reliably for all of the various tasks (mean and standard deviation of the root mean square error of 1.96 and 0.96∘, respectively). In addition, the method showed a notable improvement in angular estimation compared to the estimation derived by the textile goniometer and accelerometer considered separately. In future work, we will extend this method to more complex and multi-degree of freedom joints. PMID:26569249

  20. Effects of wind-driven telescope vibrations on measurements of turbulent angle-of-arrival fluctuations.

    PubMed

    Tichkule, Shiril; Muschinski, Andreas

    2014-07-20

    Turbulence in the atmospheric refractive-index field causes optical angle-of-arrival (AOA) fluctuations that can be used for atmospheric remote sensing of various parameters, including wind velocities and the optical refractive-index turbulence structure parameter, C(n)2. If AOA measurements are contaminated by wind-induced telescope vibrations, the underlying retrieval algorithms may fail. In order to study the effects of wind-driven telescope vibrations on optical-turbulence measurements, we conducted a field experiment in which we exposed two small telescopes deliberately to the wind. We measured AOA fluctuations of visible light propagating along a horizontal, 174 m long path 1.7 m above flat terrain, and we used fast-response ultrasonic anemometers to measure the wind velocity at multiple locations along the path. We found (1) that the AOA turbulence spectra were contaminated by multiple resonance peaks, (2) that the resonance frequencies were independent of the wind speed, and (3) that the AOA variance associated with the dominating vibration mode was proportional to the fourth power of the wind speed.

  1. Determining the in-plane Fermi surface topology in high T(c) superconductors using angle-dependent magnetic quantum oscillations.

    PubMed

    Harrison, N; McDonald, R D

    2009-05-13

    We propose a quantum oscillation experiment by which the rotation of an underdoped YBa(2)Cu(3)O(6+x) sample about two different axes with respect to the orientation of the magnetic field can be used to infer the shape of the in-plane cross-section of corrugated Fermi surface cylinder(s). Deep corrugations in the Fermi surface are expected to give rise to nodes in the quantum oscillation amplitude that depend on the magnitude and orientation of the magnetic induction B. Because the symmetries of electron and hole cylinders within the Brillouin zone are expected to be very different, the topology can provide essential clues as to the broken symmetry responsible for the observed oscillations. The criterion for the applicability of this method to the cuprate superconductors (as well as other layered metals) is that the difference in quantum oscillation frequency 2ΔF between the maximum (belly) and minimum (neck) extremal cross-sections of the corrugated Fermi surface exceeds |B|.

  2. In-plane ultrasonic velocity measurement of longitudinal and shear waves in the machine direction with transducers in rotating wheels

    DOEpatents

    Hall, Maclin S.; Jackson, Theodore G.; Knerr, Christopher

    1998-02-17

    An improved system for measuring the velocity of ultrasonic signals within the plane of moving web-like materials, such as paper, paperboard and the like. In addition to velocity measurements of ultrasonic signals in the plane of the web in the MD and CD, one embodiment of the system in accordance with the present invention is also adapted to provide on-line indication of the polar specific stiffness of the moving web. In another embodiment of the invention, the velocity of ultrasonic signals in the plane of the web are measured by way of a plurality of ultrasonic transducers carried by synchronously driven wheels or cylinders, thus eliminating undue transducer wear due to any speed differences between the transducers and the web. In order to provide relatively constant contact force between the transducers and the webs, the transducers are mounted in a sensor housings which include a spring for biasing the transducer radially outwardly. The sensor housings are adapted to be easily and conveniently mounted to the carrier to provide a relatively constant contact force between the transducers and the moving web.

  3. In-plane ultrasonic velocity measurement of longitudinal and shear waves in the machine direction with transducers in rotating wheels

    DOEpatents

    Hall, M.S.; Jackson, T.G.; Knerr, C.

    1998-02-17

    An improved system for measuring the velocity of ultrasonic signals within the plane of moving web-like materials, such as paper, paperboard and the like. In addition to velocity measurements of ultrasonic signals in the plane of the web in the MD and CD, one embodiment of the system in accordance with the present invention is also adapted to provide on-line indication of the polar specific stiffness of the moving web. In another embodiment of the invention, the velocity of ultrasonic signals in the plane of the web are measured by way of a plurality of ultrasonic transducers carried by synchronously driven wheels or cylinders, thus eliminating undue transducer wear due to any speed differences between the transducers and the web. In order to provide relatively constant contact force between the transducers and the webs, the transducers are mounted in a sensor housings which include a spring for biasing the transducer radially outwardly. The sensor housings are adapted to be easily and conveniently mounted to the carrier to provide a relatively constant contact force between the transducers and the moving web. 37 figs.

  4. Bistatic, above-critical angle scattering measurements of fully buried unexploded ordnance (UXO) and clutter.

    PubMed

    Waters, Z J; Simpson, H J; Sarkissian, A; Dey, S; Houston, B H; Bucaro, J A; Yoder, T J

    2012-11-01

    Laboratory grade bistatic scattering measurements are conducted in order to examine the acoustic response of realistic fully buried unexploded ordnance (UXO) from above-critical angle insonification, between 2 and 40 kHz. A 127 mm diameter rocket UXO, a 155 mm diameter artillery shell, a natural rock of approximately the same size, and a cinder block are fully buried in water-saturated medium grained sand (mean grain diameter, 240 μm) at depths of 10 cm below the water-sediment interface. A two-dimensional array of bistatic scattering measurements is generated synthetically by scanning a single hydrophone in steps of 3 cm over a 1 m × 1 m patch directly above the targets at a height of 20 cm above the water-sediment interface. Three-dimensional volumetric acoustic images generated from the return waveforms reveal scattering components attributed to geometric and elastic scattering, as well as multiple-scattering interactions of returns between the sediment-water interface and the buried objects. The far-field target strength of the objects is estimated through extrapolation of the angular spectrum. Agreement is found between experimental data and simulated data generated from a finite-element-based, three-dimensional time-harmonic model (2-25 kHz). Separation of the measured UXO from the clutter objects is demonstrated through exploitation of structural-acoustics-based features.

  5. Bistatic, above-critical angle scattering measurements of fully buried unexploded ordnance (UXO) and clutter.

    PubMed

    Waters, Z J; Simpson, H J; Sarkissian, A; Dey, S; Houston, B H; Bucaro, J A; Yoder, T J

    2012-11-01

    Laboratory grade bistatic scattering measurements are conducted in order to examine the acoustic response of realistic fully buried unexploded ordnance (UXO) from above-critical angle insonification, between 2 and 40 kHz. A 127 mm diameter rocket UXO, a 155 mm diameter artillery shell, a natural rock of approximately the same size, and a cinder block are fully buried in water-saturated medium grained sand (mean grain diameter, 240 μm) at depths of 10 cm below the water-sediment interface. A two-dimensional array of bistatic scattering measurements is generated synthetically by scanning a single hydrophone in steps of 3 cm over a 1 m × 1 m patch directly above the targets at a height of 20 cm above the water-sediment interface. Three-dimensional volumetric acoustic images generated from the return waveforms reveal scattering components attributed to geometric and elastic scattering, as well as multiple-scattering interactions of returns between the sediment-water interface and the buried objects. The far-field target strength of the objects is estimated through extrapolation of the angular spectrum. Agreement is found between experimental data and simulated data generated from a finite-element-based, three-dimensional time-harmonic model (2-25 kHz). Separation of the measured UXO from the clutter objects is demonstrated through exploitation of structural-acoustics-based features. PMID:23145593

  6. EquiTest modification with shank and hip angle measurements: differences with age among normal subjects.

    PubMed

    Speers, R A; Shepard, N T; Kuo, A D

    1999-01-01

    The Sensory Organization Test protocol of the EquiTest system (NeuroCom International, Clackamas Oregon) tests utilization of visual, vestibular, and proprioceptive sensors by manipulating the accuracy of visual and/or somatosensory inputs during quiet stance. In the standard Sensory Organization Test, both manipulation of sensory input (sway-referencing) and assessment of postural sway are based on ground reaction forces measured from a forceplate. The purpose of our investigation was to examine the use of kinematic measurements to provide a more direct feedback signal for sway-referencing and for assessment of sway. We compared three methods of sway-referencing: the standard EquiTest method based on ground reaction torque, kinematic feedback based on servo-controlling to shank motion, and a more complex kinematic feedback based on servo-controlling to follow position of the center of mass (COM) as calculated from a two-link biomechanical model. Fifty-one normal subjects (ages 20-79) performed the randomized protocol. When using either shank or COM angle for sway-referencing feedback as compared to the standard EquiTest protocol, the Equilibrium Quotient and Strategy Score assessments were decreased for all age groups in the platform sway-referenced conditions (SOT 4, 5, 6). For all groups of subjects, there were significant differences in one or more of the kinematic sway measures of shank, hip, or COM angle when using either of the alternative sway-referencing parameters as compared to the standard EquiTest protocol. The increased sensitivities arising from use of kinematics had the effect of amplifying differences with age. For sway-referencing, the direct kinematic feedback may enhance ability to reduce proprioceptive information by servo-controlling more closely to actual ankle motion. For assessment, kinematics measurements can potentially increase sensitivity for detection of balance disorders, because it may be possible to discriminate between body sway

  7. Limits of the plane wave approximation in the measurement of molecular properties.

    PubMed

    Walters, Zachary B; Tonzani, Stefano; Greene, Chris H

    2008-10-01

    Rescattering electrons offer great potential as probes of molecular properties on ultrafast timescales. The most famous example is molecular tomography, in which high harmonic spectra of oriented molecules are mapped to "tomographic images" of the relevant molecular orbitals. The accuracy of such reconstructions can be greatly affected by the distortion of scattering wave functions from their asymptotic forms due to interactions with the parent ion. We investigate the validity of the commonly used plane wave approximation in molecular tomography, showing how such distortions affect the resulting orbital reconstructions.

  8. In-plane thermal conductivity determination through thermoreflectance analysis and measurements

    NASA Astrophysics Data System (ADS)

    Aubain, Max S.; Bandaru, Prabhakar R.

    2011-10-01

    A scanning thermoreflectance (TR) technique through which the surface temperature profile of heated thin films may be ascertained and modeled to yield the in-plane thermal conductivity (κip) is discussed. The TR intensity is shown to be a sensitive function of the film thickness, its thermo-optic materials properties, and the substrate geometry. A reduction in the thermal conductivity of silicon thin films is then demonstrated deploying the technique. A comparison of the estimated conductivity values to those obtained using other methodologies supports the validity of our method and suggests that complete isolation of the thin film from the substrate may not be required for extracting κip.

  9. Measuring different types of transverse momentum correlations in the biphoton's Fourier plane.

    PubMed

    Calderón-Losada, Omar; Flórez, Jefferson; Villabona-Monsalve, Juan P; Valencia, Alejandra

    2016-03-15

    In this Letter, we present a theoretical and experimental study about the spatial correlations of paired photons generated by Type II spontaneous parametric down-conversion. In particular, we show how these correlations can be positive or negative, depending on the direction in which the far-field plane is scanned and the polarization postselected. Our results provide a straightforward way to observe different kind of correlations that complement other well-known methods to tune the spatial correlations of paired photons. PMID:26977660

  10. Energy- and angle-differential neutron fluence measurements with superheated drop (bubble) detectors

    NASA Astrophysics Data System (ADS)

    d'Errico, Francesco; Matzke, Manfred; Siebert, Bernd R. L.

    2002-01-01

    One of the latest additions to the field of neutron spectrometry is based on the active control of the response functions of superheated emulsions. By varying the superheat of the detectors, either changing their operating temperature or applied pressure, it is possible to generate a matrix consisting of nested responses suitable for few-channel energy spectrometry. In the device presented here, a detector is embedded in a recess milled on the surface of a moderating sphere. This sphere has the purpose of introducing an angular dependence in the otherwise nearly isotropic response of the detector. The device relies on the acoustical detection of bubbles and on temperature stepping to vary the superheated emulsion thresholds. In correspondence to each temperature/threshold, measurements are sequentially performed at different angular orientations of the sphere. The response matrix of the system to monoenergetic neutrons was determined as a function of angular position by means of Monte Carlo neutron transport simulations. The directional spectrometer was tested by means of irradiations with a californium neutron source. Energy- and angle-differential unfolding of the detector readings was performed by means of a maximum-entropy technique which does not require a-priori information. The spectrometer operates well with large energy-angle groups, and produces accurate integral values of total fluence, which can be used to derive quantities such as ambient dose equivalent H*(10) or directional dose equivalent H'(10). However, the device presents limitations in unfolding spectra over a finer group structure, and will require the future developments outlined in the conclusions.

  11. Measurement of the Azimuthal Angle Dependence of Inclusive Jet Yields in Pb+Pb Collisions at sNN=2.76TeV with the ATLAS Detector

    NASA Astrophysics Data System (ADS)

    Aad, G.; Abajyan, T.; Abbott, B.; Abdallah, J.; Abdel Khalek, S.; Abdinov, O.; Aben, R.; Abi, B.; Abolins, M.; AbouZeid, O. S.; Abramowicz, H.; Abreu, H.; Abulaiti, Y.; Acharya, B. S.; Adamczyk, L.; Adams, D. L.; Addy, T. N.; Adelman, J.; Adomeit, S.; Adye, T.; Aefsky, S.; Agatonovic-Jovin, T.; Aguilar-Saavedra, J. A.; Agustoni, M.; Ahlen, S. P.; Ahmad, A.; Ahsan, M.; Aielli, G.; Åkesson, T. P. A.; Akimoto, G.; Akimov, A. V.; Alam, M. A.; Albert, J.; Albrand, S.; Alconada Verzini, M. J.; Aleksa, M.; Aleksandrov, I. N.; Alessandria, F.; Alexa, C.; Alexander, G.; Alexandre, G.; Alexopoulos, T.; Alhroob, M.; Aliev, M.; Alimonti, G.; Alio, L.; Alison, J.; Allbrooke, B. M. M.; Allison, L. J.; Allport, P. P.; Allwood-Spiers, S. E.; Almond, J.; Aloisio, A.; Alon, R.; Alonso, A.; Alonso, F.; Altheimer, A.; Alvarez Gonzalez, B.; Alviggi, M. G.; Amako, K.; Amaral Coutinho, Y.; Amelung, C.; Ammosov, V. V.; Amor Dos Santos, S. P.; Amorim, A.; Amoroso, S.; Amram, N.; Anastopoulos, C.; Ancu, L. S.; Andari, N.; Andeen, T.; Anders, C. F.; Anders, G.; Anderson, K. J.; Andreazza, A.; Andrei, V.; Anduaga, X. S.; Angelidakis, S.; Anger, P.; Angerami, A.; Anghinolfi, F.; Anisenkov, A. V.; Anjos, N.; Annovi, A.; Antonaki, A.; Antonelli, M.; Antonov, A.; Antos, J.; Anulli, F.; Aoki, M.; Aperio Bella, L.; Apolle, R.; Arabidze, G.; Aracena, I.; Arai, Y.; Arce, A. T. H.; Arfaoui, S.; Arguin, J.-F.; Argyropoulos, S.; Arik, E.; Arik, M.; Armbruster, A. J.; Arnaez, O.; Arnal, V.; Artamonov, A.; Artoni, G.; Arutinov, D.; Asai, S.; Asbah, N.; Ask, S.; Åsman, B.; Asquith, L.; Assamagan, K.; Astalos, R.; Astbury, A.; Atkinson, M.; Atlay, N. B.; Auerbach, B.; Auge, E.; Augsten, K.; Aurousseau, M.; Avolio, G.; Axen, D.; Azuelos, G.; Azuma, Y.; Baak, M. A.; Bacci, C.; Bach, A. M.; Bachacou, H.; Bachas, K.; Backes, M.; Backhaus, M.; Backus Mayes, J.; Badescu, E.; Bagiacchi, P.; Bagnaia, P.; Bai, Y.; Bailey, D. C.; Bain, T.; Baines, J. T.; Baker, O. K.; Baker, S.; Balek, P.; Balli, F.; Banas, E.; Banerjee, Sw.; Banfi, D.; Bangert, A.; Bansal, V.; Bansil, H. S.; Barak, L.; Baranov, S. P.; Barber, T.; Barberio, E. L.; Barberis, D.; Barbero, M.; Bardin, D. Y.; Barillari, T.; Barisonzi, M.; Barklow, T.; Barlow, N.; Barnett, B. M.; Barnett, R. M.; Baroncelli, A.; Barone, G.; Barr, A. J.; Barreiro, F.; Barreiro Guimarães da Costa, J.; Bartoldus, R.; Barton, A. E.; Bartsch, V.; Basye, A.; Bates, R. L.; Batkova, L.; Batley, J. R.; Battistin, M.; Bauer, F.; Bawa, H. S.; Beale, S.; Beau, T.; Beauchemin, P. H.; Beccherle, R.; Bechtle, P.; Beck, H. P.; Becker, K.; Becker, S.; Beckingham, M.; Becks, K. H.; Beddall, A. J.; Beddall, A.; Bedikian, S.; Bednyakov, V. A.; Bee, C. P.; Beemster, L. J.; Beermann, T. A.; Begel, M.; Belanger-Champagne, C.; Bell, P. J.; Bell, W. H.; Bella, G.; Bellagamba, L.; Bellerive, A.; Bellomo, M.; Belloni, A.; Beloborodova, O. L.; Belotskiy, K.; Beltramello, O.; Benary, O.; Benchekroun, D.; Bendtz, K.; Benekos, N.; Benhammou, Y.; Benhar Noccioli, E.; Benitez Garcia, J. A.; Benjamin, D. P.; Bensinger, J. R.; Benslama, K.; Bentvelsen, S.; Berge, D.; Bergeaas Kuutmann, E.; Berger, N.; Berghaus, F.; Berglund, E.; Beringer, J.; Bernard, C.; Bernat, P.; Bernhard, R.; Bernius, C.; Bernlochner, F. U.; Berry, T.; Bertella, C.; Bertolucci, F.; Besana, M. I.; Besjes, G. J.; Bessidskaia, O.; Besson, N.; Bethke, S.; Bhimji, W.; Bianchi, R. M.; Bianchini, L.; Bianco, M.; Biebel, O.; Bieniek, S. P.; Bierwagen, K.; Biesiada, J.; Biglietti, M.; Bilbao De Mendizabal, J.; Bilokon, H.; Bindi, M.; Binet, S.; Bingul, A.; Bini, C.; Bittner, B.; Black, C. W.; Black, J. E.; Black, K. M.; Blackburn, D.; Blair, R. E.; Blanchard, J.-B.; Blazek, T.; Bloch, I.; Blocker, C.; Blocki, J.; Blum, W.; Blumenschein, U.; Bobbink, G. J.; Bobrovnikov, V. S.; Bocchetta, S. S.; Bocci, A.; Boddy, C. R.; Boehler, M.; Boek, J.; Boek, T. T.; Boelaert, N.; Bogaerts, J. A.; Bogdanchikov, A. G.; Bogouch, A.; Bohm, C.; Bohm, J.; Boisvert, V.; Bold, T.; Boldea, V.; Bolnet, N. M.; Bomben, M.; Bona, M.; Boonekamp, M.; Bordoni, S.; Borer, C.; Borisov, A.; Borissov, G.; Borri, M.; Borroni, S.; Bortfeldt, J.; Bortolotto, V.; Bos, K.; Boscherini, D.; Bosman, M.; Boterenbrood, H.; Bouchami, J.; Boudreau, J.; Bouhova-Thacker, E. V.; Boumediene, D.; Bourdarios, C.; Bousson, N.; Boutouil, S.; Boveia, A.; Boyd, J.; Boyko, I. R.; Bozovic-Jelisavcic, I.; Bracinik, J.; Branchini, P.; Brandt, A.; Brandt, G.; Brandt, O.; Bratzler, U.; Brau, B.; Brau, J. E.; Braun, H. M.; Brazzale, S. F.; Brelier, B.; Bremer, J.; Brendlinger, K.; Brenner, R.; Bressler, S.; Bristow, T. M.; Britton, D.; Brochu, F. M.; Brock, I.; Brock, R.; Broggi, F.; Bromberg, C.; Bronner, J.; Brooijmans, G.; Brooks, T.; Brooks, W. K.; Brost, E.; Brown, G.; Brown, J.; Bruckman de Renstrom, P. A.; Bruncko, D.; Bruneliere, R.; Brunet, S.; Bruni, A.; Bruni, G.; Bruschi, M.; Bryngemark, L.; Buanes, T.; Buat, Q.; Bucci, F.; Buchanan, J.; Buchholz, P.; Buckingham, R. M.; Buckley, A. G.; Buda, S. I.; Budagov, I. A.; Budick, B.; Bugge, L.; Bulekov, O.; Bundock, A. C.; Bunse, M.; Buran, T.; Burckhart, H.; Burdin, S.; Burgess, T.; Burke, S.; Busato, E.; Büscher, V.; Bussey, P.; Buszello, C. P.; Butler, B.; Butler, J. M.; Buttar, C. M.; Butterworth, J. M.; Buttinger, W.; Byszewski, M.; Cabrera Urbán, S.; Caforio, D.; Cakir, O.; Calafiura, P.; Calderini, G.; Calfayan, P.; Calkins, R.; Caloba, L. P.; Caloi, R.; Calvet, D.; Calvet, S.; Camacho Toro, R.; Camarri, P.; Cameron, D.; Caminada, L. M.; Caminal Armadans, R.; Campana, S.; Campanelli, M.; Canale, V.; Canelli, F.; Canepa, A.; Cantero, J.; Cantrill, R.; Cao, T.; Capeans Garrido, M. D. M.; Caprini, I.; Caprini, M.; Capriotti, D.; Capua, M.; Caputo, R.; Cardarelli, R.; Carli, T.; Carlino, G.; Carminati, L.; Caron, S.; Carquin, E.; Carrillo-Montoya, G. D.; Carter, A. A.; Carter, J. R.; Carvalho, J.; Casadei, D.; Casado, M. P.; Cascella, M.; Caso, C.; Castaneda-Miranda, E.; Castelli, A.; Castillo Gimenez, V.; Castro, N. F.; Cataldi, G.; Catastini, P.; Catinaccio, A.; Catmore, J. R.; Cattai, A.; Cattani, G.; Caughron, S.; Cavaliere, V.; Cavalli, D.; Cavalli-Sforza, M.; Cavasinni, V.; Ceradini, F.; Cerio, B.; Cerqueira, A. S.; Cerri, A.; Cerrito, L.; Cerutti, F.; Cervelli, A.; Cetin, S. A.; Chafaq, A.; Chakraborty, D.; Chalupkova, I.; Chan, K.; Chang, P.; Chapleau, B.; Chapman, J. D.; Chapman, J. W.; Charlton, D. G.; Chavda, V.; Chavez Barajas, C. A.; Cheatham, S.; Chekanov, S.; Chekulaev, S. V.; Chelkov, G. A.; Chelstowska, M. A.; Chen, C.; Chen, H.; Chen, S.; Chen, X.; Chen, Y.; Cheng, Y.; Cheplakov, A.; Cherkaoui El Moursli, R.; Chernyatin, V.; Cheu, E.; Chevalier, L.; Chiarella, V.; Chiefari, G.; Childers, J. T.; Chilingarov, A.; Chiodini, G.; Chisholm, A. S.; Chislett, R. T.; Chitan, A.; Chizhov, M. V.; Choudalakis, G.; Chouridou, S.; Chow, B. K. B.; Christidi, I. A.; Christov, A.; Chromek-Burckhart, D.; Chu, M. L.; Chudoba, J.; Ciapetti, G.; Ciftci, A. K.; Ciftci, R.; Cinca, D.; Cindro, V.; Ciocio, A.; Cirilli, M.; Cirkovic, P.; Citron, Z. H.; Citterio, M.; Ciubancan, M.; Clark, A.; Clark, P. J.; Clarke, R. N.; Clemens, J. C.; Clement, B.; Clement, C.; Coadou, Y.; Cobal, M.; Coccaro, A.; Cochran, J.; Coelli, S.; Coffey, L.; Cogan, J. G.; Coggeshall, J.; Colas, J.; Cole, B.; Cole, S.; Colijn, A. P.; Collins-Tooth, C.; Collot, J.; Colombo, T.; Colon, G.; Compostella, G.; Conde Muiño, P.; Coniavitis, E.; Conidi, M. C.; Consonni, S. M.; Consorti, V.; Constantinescu, S.; Conta, C.; Conti, G.; Conventi, F.; Cooke, M.; Cooper, B. D.; Cooper-Sarkar, A. M.; Cooper-Smith, N. J.; Copic, K.; Cornelissen, T.; Corradi, M.; Corriveau, F.; Corso-Radu, A.; Cortes-Gonzalez, A.; Cortiana, G.; Costa, G.; Costa, M. J.; Costanzo, D.; Côté, D.; Cottin, G.; Courneyea, L.; Cowan, G.; Cox, B. E.; Cranmer, K.; Crépé-Renaudin, S.; Crescioli, F.; Cristinziani, M.; Crosetti, G.; Cuciuc, C.-M.; Cuenca Almenar, C.; Cuhadar Donszelmann, T.; Cummings, J.; Curatolo, M.; Cuthbert, C.; Czirr, H.; Czodrowski, P.; Czyczula, Z.; D'Auria, S.; D'Onofrio, M.; D'Orazio, A.; Da Cunha Sargedas De Sousa, M. J.; Da Via, C.; Dabrowski, W.; Dafinca, A.; Dai, T.; Dallaire, F.; Dallapiccola, C.; Dam, M.; Damiani, D. S.; Daniells, A. C.; Danielsson, H. O.; Dao, V.; Darbo, G.; Darlea, G. L.; Darmora, S.; Dassoulas, J. A.; Davey, W.; David, C.; Davidek, T.; Davies, E.; Davies, M.; Davignon, O.; Davison, A. R.; Davygora, Y.; Dawe, E.; Dawson, I.; Daya-Ishmukhametova, R. K.; De, K.; de Asmundis, R.; De Castro, S.; De Cecco, S.; de Graat, J.; De Groot, N.; de Jong, P.; De La Taille, C.; De la Torre, H.; De Lorenzi, F.; De Nooij, L.; De Pedis, D.; De Salvo, A.; De Sanctis, U.; De Santo, A.; De Vivie De Regie, J. B.; De Zorzi, G.; Dearnaley, W. J.; Debbe, R.; Debenedetti, C.; Dechenaux, B.; Dedovich, D. V.; Degenhardt, J.; Del Peso, J.; Del Prete, T.; Delemontex, T.; Deliyergiyev, M.; Dell'Acqua, A.; Dell'Asta, L.; Della Pietra, M.; della Volpe, D.; Delmastro, M.; Delsart, P. A.; Deluca, C.; Demers, S.; Demichev, M.; Demilly, A.; Demirkoz, B.; Denisov, S. P.; Derendarz, D.; Derkaoui, J. E.; Derue, F.; Dervan, P.; Desch, K.; Deviveiros, P. O.; Dewhurst, A.; DeWilde, B.; Dhaliwal, S.; Dhullipudi, R.; Di Ciaccio, A.; Di Ciaccio, L.; Di Donato, C.; Di Girolamo, A.; Di Girolamo, B.; Di Luise, S.; Di Mattia, A.; Di Micco, B.; Di Nardo, R.; Di Simone, A.; Di Sipio, R.; Diaz, M. A.; Diehl, E. B.; Dietrich, J.; Dietzsch, T. A.; Diglio, S.; Dindar Yagci, K.; Dingfelder, J.; Dinut, F.; Dionisi, C.; Dita, P.; Dita, S.; Dittus, F.; Djama, F.; Djobava, T.; do Vale, M. A. B.; Do Valle Wemans, A.; Doan, T. K. O.; Dobos, D.; Dobson, E.; Dodd, J.; Doglioni, C.; Doherty, T.; Dohmae, T.; Doi, Y.; Dolejsi, J.; Dolezal, Z.; Dolgoshein, B. A.; Donadelli, M.; Donini, J.; Dopke, J.; Doria, A.; Dos Anjos, A.; Dotti, A.; Dova, M. T.; Doyle, A. T.; Dris, M.; Dubbert, J.; Dube, S.; Dubreuil, E.; Duchovni, E.; Duckeck, G.; Duda, D.; Dudarev, A.; Dudziak, F.; Duflot, L.; Dufour, M.-A.; Duguid, L.; Dührssen, M.; Dunford, M.; Duran Yildiz, H.; Düren, M.; Dwuznik, M.; Ebke, J.; Edson, W.; Edwards, C. A.; Edwards, N. C.; Ehrenfeld, W.; Eifert, T.; Eigen, G.; Einsweiler, K.; Eisenhandler, E.; Ekelof, T.; El Kacimi, M.; Ellert, M.; Elles, S.; Ellinghaus, F.; Ellis, K.; Ellis, N.; Elmsheuser, J.; Elsing, M.; Emeliyanov, D.; Enari, Y.; Endner, O. C.; Engelmann, R.; Engl, A.; Erdmann, J.; Ereditato, A.; Eriksson, D.; Ernst, J.; Ernst, M.; Ernwein, J.; Errede, D.; Errede, S.; Ertel, E.; Escalier, M.; Esch, H.; Escobar, C.; Espinal Curull, X.; Esposito, B.; Etienne, F.; Etienvre, A. I.; Etzion, E.; Evangelakou, D.; Evans, H.; Fabbri, L.; Fabre, C.; Facini, G.; Fakhrutdinov, R. M.; Falciano, S.; Fang, Y.; Fanti, M.; Farbin, A.; Farilla, A.; Farooque, T.; Farrell, S.; Farrington, S. M.; Farthouat, P.; Fassi, F.; Fassnacht, P.; Fassouliotis, D.; Fatholahzadeh, B.; Favareto, A.; Fayard, L.; Federic, P.; Fedin, O. L.; Fedorko, W.; Fehling-Kaschek, M.; Feligioni, L.; Feng, C.; Feng, E. J.; Feng, H.; Fenyuk, A. B.; Ferencei, J.; Fernando, W.; Ferrag, S.; Ferrando, J.; Ferrara, V.; Ferrari, A.; Ferrari, P.; Ferrari, R.; Ferreira de Lima, D. E.; Ferrer, A.; Ferrere, D.; Ferretti, C.; Ferretto Parodi, A.; Fiascaris, M.; Fiedler, F.; Filipčič, A.; Filipuzzi, M.; Filthaut, F.; Fincke-Keeler, M.; Finelli, K. D.; Fiolhais, M. C. N.; Fiorini, L.; Firan, A.; Fischer, J.; Fisher, M. J.; Fitzgerald, E. A.; Flechl, M.; Fleck, I.; Fleischmann, P.; Fleischmann, S.; Fletcher, G. T.; Fletcher, G.; Flick, T.; Floderus, A.; Flores Castillo, L. R.; Florez Bustos, A. C.; Flowerdew, M. J.; Fonseca Martin, T.; Formica, A.; Forti, A.; Fortin, D.; Fournier, D.; Fox, H.; Francavilla, P.; Franchini, M.; Franchino, S.; Francis, D.; Franklin, M.; Franz, S.; Fraternali, M.; Fratina, S.; French, S. T.; Friedrich, C.; Friedrich, F.; Froidevaux, D.; Frost, J. A.; Fukunaga, C.; Fullana Torregrosa, E.; Fulsom, B. G.; Fuster, J.; Gabaldon, C.; Gabizon, O.; Gabrielli, A.; Gabrielli, A.; Gadatsch, S.; Gadfort, T.; Gadomski, S.; Gagliardi, G.; Gagnon, P.; Galea, C.; Galhardo, B.; Gallas, E. J.; Gallo, V.; Gallop, B. J.; Gallus, P.; Galster, G.; Gan, K. K.; Gandrajula, R. P.; Gao, Y. S.; Gaponenko, A.; Garay Walls, F. M.; Garberson, F.; García, C.; García Navarro, J. E.; Garcia-Sciveres, M.; Gardner, R. W.; Garelli, N.; Garonne, V.; Gatti, C.; Gaudio, G.; Gaur, B.; Gauthier, L.; Gauzzi, P.; Gavrilenko, I. L.; Gay, C.; Gaycken, G.; Gazis, E. N.; Ge, P.; Gecse, Z.; Gee, C. N. P.; Geerts, D. A. A.; Geich-Gimbel, Ch.; Gellerstedt, K.; Gemme, C.; Gemmell, A.; Genest, M. H.; Gentile, S.; George, M.; George, S.; Gerbaudo, D.; Gershon, A.; Ghazlane, H.; Ghodbane, N.; Giacobbe, B.; Giagu, S.; Giangiobbe, V.; Giannetti, P.; Gianotti, F.; Gibbard, B.; Gibson, S. M.; Gilchriese, M.; Gillam, T. P. S.; Gillberg, D.; Gillman, A. R.; Gingrich, D. M.; Giokaris, N.; Giordani, M. P.; Giordano, R.; Giorgi, F. M.; Giovannini, P.; Giraud, P. F.; Giugni, D.; Giuliani, C.; Giunta, M.; Gjelsten, B. K.; Gkialas, I.; Gladilin, L. K.; Glasman, C.; Glatzer, J.; Glazov, A.; Glonti, G. L.; Goblirsch-Kolb, M.; Goddard, J. R.; Godfrey, J.; Godlewski, J.; Goebel, M.; Goeringer, C.; Goldfarb, S.; Golling, T.; Golubkov, D.; Gomes, A.; Gomez Fajardo, L. S.; Gonçalo, R.; Goncalves Pinto Firmino Da Costa, J.; Gonella, L.; González de la Hoz, S.; Gonzalez Parra, G.; Gonzalez Silva, M. L.; Gonzalez-Sevilla, S.; Goodson, J. J.; Goossens, L.; Gorbounov, P. A.; Gordon, H. A.; Gorelov, I.; Gorfine, G.; Gorini, B.; Gorini, E.; Gorišek, A.; Gornicki, E.; Goshaw, A. T.; Gössling, C.; Gostkin, M. I.; Gough Eschrich, I.; Gouighri, M.; Goujdami, D.; Goulette, M. P.; Goussiou, A. G.; Goy, C.; Gozpinar, S.; Grabas, H. M. X.; Graber, L.; Grabowska-Bold, I.; Grafström, P.; Grahn, K.-J.; Gramstad, E.; Grancagnolo, F.; Grancagnolo, S.; Grassi, V.; Gratchev, V.; Gray, H. M.; Gray, J. A.; Graziani, E.; Grebenyuk, O. G.; Greenshaw, T.; Greenwood, Z. D.; Gregersen, K.; Gregor, I. M.; Grenier, P.; Griffiths, J.; Grigalashvili, N.; Grillo, A. A.; Grimm, K.; Grinstein, S.; Gris, Ph.; Grishkevich, Y. V.; Grivaz, J.-F.; Grohs, J. P.; Grohsjean, A.; Gross, E.; Grosse-Knetter, J.; Groth-Jensen, J.; Grybel, K.; Guescini, F.; Guest, D.; Gueta, O.; Guicheney, C.; Guido, E.; Guillemin, T.; Guindon, S.; Gul, U.; Gunther, J.; Guo, J.; Gupta, S.; Gutierrez, P.; Gutierrez Ortiz, N. G.; Guttman, N.; Gutzwiller, O.; Guyot, C.; Gwenlan, C.; Gwilliam, C. B.; Haas, A.; Haas, S.; Haber, C.; Hadavand, H. K.; Haefner, P.; Hajduk, Z.; Hakobyan, H.; Hall, D.; Halladjian, G.; Hamacher, K.; Hamal, P.; Hamano, K.; Hamer, M.; Hamilton, A.; Hamilton, S.; Han, L.; Hanagaki, K.; Hanawa, K.; Hance, M.; Handel, C.; Hanke, P.; Hansen, J. R.; Hansen, J. B.; Hansen, J. D.; Hansen, P. H.; Hansson, P.; Hara, K.; Hard, A. S.; Harenberg, T.; Harkusha, S.; Harper, D.; Harrington, R. D.; Harris, O. M.; Hartert, J.; Hartjes, F.; Harvey, A.; Hasegawa, S.; Hasegawa, Y.; Hassani, S.; Haug, S.; Hauschild, M.; Hauser, R.; Havranek, M.; Hawkes, C. M.; Hawkings, R. J.; Hawkins, A. D.; Hayashi, T.; Hayden, D.; Hays, C. P.; Hayward, H. S.; Haywood, S. J.; Head, S. J.; Heck, T.; Hedberg, V.; Heelan, L.; Heim, S.; Heinemann, B.; Heisterkamp, S.; Hejbal, J.; Helary, L.; Heller, C.; Heller, M.; Hellman, S.; Hellmich, D.; Helsens, C.; Henderson, J.; Henderson, R. C. W.; Henrichs, A.; Henriques Correia, A. M.; Henrot-Versille, S.; Hensel, C.; Herbert, G. H.; Hernandez, C. M.; Hernández Jiménez, Y.; Herrberg-Schubert, R.; Herten, G.; Hertenberger, R.; Hervas, L.; Hesketh, G. G.; Hessey, N. P.; Hickling, R.; Higón-Rodriguez, E.; Hill, J. C.; Hiller, K. H.; Hillert, S.; Hillier, S. J.; Hinchliffe, I.; Hines, E.; Hirose, M.; Hirschbuehl, D.; Hobbs, J.; Hod, N.; Hodgkinson, M. C.; Hodgson, P.; Hoecker, A.; Hoeferkamp, M. R.; Hoffman, J.; Hoffmann, D.; Hofmann, J. I.; Hohlfeld, M.; Holmgren, S. O.; Holzbauer, J. L.; Hong, T. M.; Hooft van Huysduynen, L.; Hostachy, J.-Y.; Hou, S.; Hoummada, A.; Howard, J.; Howarth, J.; Hrabovsky, M.; Hristova, I.; Hrivnac, J.; Hryn'ova, T.; Hsu, P. J.; Hsu, S.-C.; Hu, D.; Hu, X.; Hubacek, Z.; Hubaut, F.; Huegging, F.; Huettmann, A.; Huffman, T. B.; Hughes, E. W.; Hughes, G.; Huhtinen, M.; Hülsing, T. A.; Hurwitz, M.; Huseynov, N.; Huston, J.; Huth, J.; Iacobucci, G.; Iakovidis, G.; Ibragimov, I.; Iconomidou-Fayard, L.; Idarraga, J.; Iengo, P.; Igonkina, O.; Ikegami, Y.; Ikematsu, K.; Ikeno, M.; Iliadis, D.; Ilic, N.; Ince, T.; Ioannou, P.; Iodice, M.; Iordanidou, K.; Ippolito, V.; Irles Quiles, A.; Isaksson, C.; Ishino, M.; Ishitsuka, M.; Ishmukhametov, R.; Issever, C.; Istin, S.; Ivashin, A. V.; Iwanski, W.; Iwasaki, H.; Izen, J. M.; Izzo, V.; Jackson, B.; Jackson, J. N.; Jackson, P.; Jaekel, M. R.; Jain, V.; Jakobs, K.; Jakobsen, S.; Jakoubek, T.; Jakubek, J.; Jamin, D. O.; Jana, D. K.; Jansen, E.; Jansen, H.; Janssen, J.; Janus, M.; Jared, R. C.; Jarlskog, G.; Jeanty, L.; Jeng, G.-Y.; Jen-La Plante, I.; Jennens, D.; Jenni, P.; Jentzsch, J.; Jeske, C.; Jézéquel, S.; Jha, M. K.; Ji, H.; Ji, W.; Jia, J.; Jiang, Y.; Jimenez Belenguer, M.; Jin, S.; Jinnouchi, O.; Joergensen, M. D.; Joffe, D.; Johansson, K. E.; Johansson, P.; Johnert, S.; Johns, K. A.; Jon-And, K.; Jones, G.; Jones, R. W. L.; Jones, T. J.; Jorge, P. M.; Joshi, K. D.; Jovicevic, J.; Ju, X.; Jung, C. A.; Jungst, R. M.; Jussel, P.; Juste Rozas, A.; Kaci, M.; Kaczmarska, A.; Kadlecik, P.; Kado, M.; Kagan, H.; Kagan, M.; Kajomovitz, E.; Kalinin, S.; Kama, S.; Kanaya, N.; Kaneda, M.; Kaneti, S.; Kanno, T.; Kantserov, V. A.; Kanzaki, J.; Kaplan, B.; Kapliy, A.; Kar, D.; Karakostas, K.; Karastathis, N.; Karnevskiy, M.; Karpov, S. N.; Kartvelishvili, V.; Karyukhin, A. N.; Kashif, L.; Kasieczka, G.; Kass, R. D.; Kastanas, A.; Kataoka, Y.; Katre, A.; Katzy, J.; Kaushik, V.; Kawagoe, K.; Kawamoto, T.; Kawamura, G.; Kazama, S.; Kazanin, V. F.; Kazarinov, M. Y.; Keeler, R.; Keener, P. T.; Kehoe, R.; Keil, M.; Keller, J. S.; Keoshkerian, H.; Kepka, O.; Kerševan, B. P.; Kersten, S.; Kessoku, K.; Keung, J.; Khalil-zada, F.; Khandanyan, H.; Khanov, A.; Kharchenko, D.; Khodinov, A.; Khomich, A.; Khoo, T. J.; Khoriauli, G.; Khoroshilov, A.; Khovanskiy, V.; Khramov, E.; Khubua, J.; Kim, H.; Kim, S. H.; Kimura, N.; Kind, O.; King, B. T.; King, M.; King, R. S. B.; King, S. B.; Kirk, J.; Kiryunin, A. E.; Kishimoto, T.; Kisielewska, D.; Kitamura, T.; Kittelmann, T.; Kiuchi, K.; Kladiva, E.; Klein, M.; Klein, U.; Kleinknecht, K.; Klemetti, M.; Klimek, P.; Klimentov, A.; Klingenberg, R.; Klinger, J. A.; Klinkby, E. B.; Klioutchnikova, T.; Klok, P. F.; Kluge, E.-E.; Kluit, P.; Kluth, S.; Kneringer, E.; Knoops, E. B. F. G.; Knue, A.; Ko, B. R.; Kobayashi, T.; Kobel, M.; Kocian, M.; Kodys, P.; Koenig, S.; Koevesarki, P.; Koffas, T.; Koffeman, E.; Kogan, L. A.; Kohlmann, S.; Kohn, F.; Kohout, Z.; Kohriki, T.; Koi, T.; Kolanoski, H.; Koletsou, I.; Koll, J.; Komar, A. A.; Komori, Y.; Kondo, T.; Köneke, K.; König, A. C.; Kono, T.; Kononov, A. I.; Konoplich, R.; Konstantinidis, N.; Kopeliansky, R.; Koperny, S.; Köpke, L.; Kopp, A. K.; Korcyl, K.; Kordas, K.; Korn, A.; Korol, A. A.; Korolkov, I.; Korolkova, E. V.; Korotkov, V. A.; Kortner, O.; Kortner, S.; Kostyukhin, V. V.; Kotov, S.; Kotov, V. M.; Kotwal, A.; Kourkoumelis, C.; Kouskoura, V.; Koutsman, A.; Kowalewski, R.; Kowalski, T. Z.; Kozanecki, W.; Kozhin, A. S.; Kral, V.; Kramarenko, V. A.; Kramberger, G.; Krasny, M. W.; Krasznahorkay, A.; Kraus, J. K.; Kravchenko, A.; Kreiss, S.; Kretzschmar, J.; Kreutzfeldt, K.; Krieger, N.; Krieger, P.; Kroeninger, K.; Kroha, H.; Kroll, J.; Kroseberg, J.; Krstic, J.; Kruchonak, U.; Krüger, H.; Kruker, T.; Krumnack, N.; Krumshteyn, Z. V.; Kruse, A.; Kruse, M. K.; Kruskal, M.; Kubota, T.; Kuday, S.; Kuehn, S.; Kugel, A.; Kuhl, T.; Kukhtin, V.; Kulchitsky, Y.; Kuleshov, S.; Kuna, M.; Kunkle, J.; Kupco, A.; Kurashige, H.; Kurata, M.; Kurochkin, Y. A.; Kus, V.; Kuwertz, E. S.; Kuze, M.; Kvita, J.; Kwee, R.; La Rosa, A.; La Rotonda, L.; Labarga, L.; Lablak, S.; Lacasta, C.; Lacava, F.; Lacey, J.; Lacker, H.; Lacour, D.; Lacuesta, V. R.; Ladygin, E.; Lafaye, R.; Laforge, B.; Lagouri, T.; Lai, S.; Laier, H.; Laisne, E.; Lambourne, L.; Lampen, C. L.; Lampl, W.; Lançon, E.; Landgraf, U.; Landon, M. P. J.; Lang, V. S.; Lange, C.; Lankford, A. J.; Lanni, F.; Lantzsch, K.; Lanza, A.; Laplace, S.; Lapoire, C.; Laporte, J. F.; Lari, T.; Larner, A.; Lassnig, M.; Laurelli, P.; Lavorini, V.; Lavrijsen, W.; Laycock, P.; Le, B. T.; Le Dortz, O.; Le Guirriec, E.; Le Menedeu, E.; LeCompte, T.; Ledroit-Guillon, F.; Lee, C. A.; Lee, H.; Lee, J. S. H.; Lee, S. C.; Lee, L.; Lefebvre, G.; Lefebvre, M.; Legendre, M.; Legger, F.; Leggett, C.; Lehan, A.; Lehmacher, M.; Lehmann Miotto, G.; Leister, A. G.; Leite, M. A. L.; Leitner, R.; Lellouch, D.; Lemmer, B.; Lendermann, V.; Leney, K. J. C.; Lenz, T.; Lenzen, G.; Lenzi, B.; Leone, R.; Leonhardt, K.; Leontsinis, S.; Leroy, C.; Lessard, J.-R.; Lester, C. G.; Lester, C. M.; Levêque, J.; Levin, D.; Levinson, L. J.; Lewis, A.; Lewis, G. H.; Leyko, A. M.; Leyton, M.; Li, B.; Li, B.; Li, H.; Li, H. L.; Li, S.; Li, X.; Liang, Z.; Liao, H.; Liberti, B.; Lichard, P.; Lie, K.; Liebal, J.; Liebig, W.; Limbach, C.; Limosani, A.; Limper, M.; Lin, S. C.; Linde, F.; Lindquist, B. E.; Linnemann, J. T.; Lipeles, E.; Lipniacka, A.; Lisovyi, M.; Liss, T. M.; Lissauer, D.; Lister, A.; Litke, A. M.; Liu, B.; Liu, D.; Liu, J. B.; Liu, K.; Liu, L.; Liu, M.; Liu, M.; Liu, Y.; Livan, M.; Livermore, S. S. A.; Lleres, A.; Llorente Merino, J.; Lloyd, S. L.; Lo Sterzo, F.; Lobodzinska, E.; Loch, P.; Lockman, W. S.; Loddenkoetter, T.; Loebinger, F. K.; Loevschall-Jensen, A. E.; Loginov, A.; Loh, C. W.; Lohse, T.; Lohwasser, K.; Lokajicek, M.; Lombardo, V. P.; Long, R. E.; Lopes, L.; Lopez Mateos, D.; Lopez Paredes, B.; Lorenz, J.; Lorenzo Martinez, N.; Losada, M.; Loscutoff, P.; Losty, M. J.; Lou, X.; Lounis, A.; Loureiro, K. F.; Love, J.; Love, P. A.; Lowe, A. J.; Lu, F.; Lubatti, H. J.; Luci, C.; Lucotte, A.; Ludwig, D.; Ludwig, I.; Ludwig, J.; Luehring, F.; Lukas, W.; Luminari, L.; Lund, E.; Lundberg, J.; Lundberg, O.; Lund-Jensen, B.; Lungwitz, M.; Lynn, D.; Lysak, R.; Lytken, E.; Ma, H.; Ma, L. L.; Maccarrone, G.; Macchiolo, A.; Maček, B.; Machado Miguens, J.; Macina, D.; Mackeprang, R.; Madar, R.; Madaras, R. J.; Maddocks, H. J.; Mader, W. F.; Madsen, A.; Maeno, M.; Maeno, T.; Magnoni, L.; Magradze, E.; Mahboubi, K.; Mahlstedt, J.; Mahmoud, S.; Mahout, G.; Maiani, C.; Maidantchik, C.; Maio, A.; Majewski, S.; Makida, Y.; Makovec, N.; Mal, P.; Malaescu, B.; Malecki, Pa.; Malecki, P.; Maleev, V. P.; Malek, F.; Mallik, U.; Malon, D.; Malone, C.; Maltezos, S.; Malyshev, V. M.; Malyukov, S.; Mamuzic, J.; Mandelli, L.; Mandić, I.; Mandrysch, R.; Maneira, J.; Manfredini, A.; Manhaes de Andrade Filho, L.; Manjarres Ramos, J. A.; Mann, A.; Manning, P. M.; Manousakis-Katsikakis, A.; Mansoulie, B.; Mantifel, R.; Mapelli, L.; March, L.; Marchand, J. F.; Marchese, F.; Marchiori, G.; Marcisovsky, M.; Marino, C. P.; Marques, C. N.; Marroquim, F.; Marshall, Z.; Marti, L. F.; Marti-Garcia, S.; Martin, B.; Martin, B.; Martin, J. P.; Martin, T. A.; Martin, V. J.; Martin dit Latour, B.; Martinez, H.; Martinez, M.; Martin-Haugh, S.; Martyniuk, A. C.; Marx, M.; Marzano, F.; Marzin, A.; Masetti, L.; Mashimo, T.; Mashinistov, R.; Masik, J.; Maslennikov, A. L.; Massa, I.; Massol, N.; Mastrandrea, P.; Mastroberardino, A.; Masubuchi, T.; Matsunaga, H.; Matsushita, T.; Mättig, P.; Mättig, S.; Mattmann, J.; Mattravers, C.; Maurer, J.; Maxfield, S. J.; Maximov, D. A.; Mazini, R.; Mazzaferro, L.; Mazzanti, M.; Mc Kee, S. P.; McCarn, A.; McCarthy, R. L.; McCarthy, T. G.; McCubbin, N. A.; McFarlane, K. W.; Mcfayden, J. A.; Mchedlidze, G.; Mclaughlan, T.; McMahon, S. J.; McPherson, R. A.; Meade, A.; Mechnich, J.; Mechtel, M.; Medinnis, M.; Meehan, S.; Meera-Lebbai, R.; Mehlhase, S.; Mehta, A.; Meier, K.; Meineck, C.; Meirose, B.; Melachrinos, C.; Mellado Garcia, B. R.; Meloni, F.; Mendoza Navas, L.; Mengarelli, A.; Menke, S.; Meoni, E.; Mercurio, K. M.; Meric, N.; Mermod, P.; Merola, L.; Meroni, C.; Merritt, F. S.; Merritt, H.; Messina, A.; Metcalfe, J.; Mete, A. S.; Meyer, C.; Meyer, C.; Meyer, J.-P.; Meyer, J.; Meyer, J.; Michal, S.; Middleton, R. P.; Migas, S.; Mijović, L.; Mikenberg, G.; Mikestikova, M.; Mikuž, M.; Miller, D. W.; Mills, W. J.; Mills, C.; Milov, A.; Milstead, D. A.; Milstein, D.; Minaenko, A. A.; Miñano Moya, M.; Minashvili, I. A.; Mincer, A. I.; Mindur, B.; Mineev, M.; Ming, Y.; Mir, L. M.; Mirabelli, G.; Mitani, T.; Mitrevski, J.; Mitsou, V. A.; Mitsui, S.; Miyagawa, P. S.; Mjörnmark, J. U.; Moa, T.; Moeller, V.; Mohapatra, S.; Mohr, W.; Moles-Valls, R.; Molfetas, A.; Mönig, K.; Monini, C.; Monk, J.; Monnier, E.; Montejo Berlingen, J.; Monticelli, F.; Monzani, S.; Moore, R. W.; Mora Herrera, C.; Moraes, A.; Morange, N.; Morel, J.; Moreno, D.; Moreno Llácer, M.; Morettini, P.; Morgenstern, M.; Morii, M.; Moritz, S.; Morley, A. K.; Mornacchi, G.; Morris, J. D.; Morvaj, L.; Moser, H. G.; Mosidze, M.; Moss, J.; Mount, R.; Mountricha, E.; Mouraviev, S. V.; Moyse, E. J. W.; Mudd, R. D.; Mueller, F.; Mueller, J.; Mueller, K.; Mueller, T.; Mueller, T.; Muenstermann, D.; Munwes, Y.; Murillo Quijada, J. A.; Murray, W. J.; Mussche, I.; Musto, E.; Myagkov, A. G.; Myska, M.; Nackenhorst, O.; Nadal, J.; Nagai, K.; Nagai, R.; Nagai, Y.; Nagano, K.; Nagarkar, A.; Nagasaka, Y.; Nagel, M.; Nairz, A. M.; Nakahama, Y.; Nakamura, K.; Nakamura, T.; Nakano, I.; Namasivayam, H.; Nanava, G.; Napier, A.; Narayan, R.; Nash, M.; Nattermann, T.; Naumann, T.; Navarro, G.; Neal, H. A.; Nechaeva, P. Yu.; Neep, T. J.; Negri, A.; Negri, G.; Negrini, M.; Nektarijevic, S.; Nelson, A.; Nelson, T. K.; Nemecek, S.; Nemethy, P.; Nepomuceno, A. A.; Nessi, M.; Neubauer, M. S.; Neumann, M.; Neusiedl, A.; Neves, R. M.; Nevski, P.; Newcomer, F. M.; Newman, P. R.; Nguyen, D. H.; Nguyen Thi Hong, V.; Nickerson, R. B.; Nicolaidou, R.; Nicquevert, B.; Nielsen, J.; Nikiforou, N.; Nikiforov, A.; Nikolaenko, V.; Nikolic-Audit, I.; Nikolics, K.; Nikolopoulos, K.; Nilsson, P.; Ninomiya, Y.; Nisati, A.; Nisius, R.; Nobe, T.; Nodulman, L.; Nomachi, M.; Nomidis, I.; Norberg, S.; Nordberg, M.; Novakova, J.; Nozaki, M.; Nozka, L.; Ntekas, K.; Nuncio-Quiroz, A.-E.; Nunes Hanninger, G.; Nunnemann, T.; Nurse, E.; O'Brien, B. J.; O'grady, F.; O'Neil, D. C.; O'Shea, V.; Oakes, L. B.; Oakham, F. G.; Oberlack, H.; Ocariz, J.; Ochi, A.; Ochoa, M. I.; Oda, S.; Odaka, S.; Odier, J.; Ogren, H.; Oh, A.; Oh, S. H.; Ohm, C. C.; Ohshima, T.; Okamura, W.; Okawa, H.; Okumura, Y.; Okuyama, T.; Olariu, A.; Olchevski, A. G.; Olivares Pino, S. A.; Oliveira, M.; Oliveira Damazio, D.; Oliver Garcia, E.; Olivito, D.; Olszewski, A.; Olszowska, J.; Onofre, A.; Onyisi, P. U. E.; Oram, C. J.; Oreglia, M. J.; Oren, Y.; Orestano, D.; Orlando, N.; Oropeza Barrera, C.; Orr, R. S.; Osculati, B.; Ospanov, R.; Otero y Garzon, G.; Otono, H.; Ottersbach, J. P.; Ouchrif, M.; Ouellette, E. A.; Ould-Saada, F.; Ouraou, A.; Oussoren, K. P.; Ouyang, Q.; Ovcharova, A.; Owen, M.; Owen, S.; Ozcan, V. E.; Ozturk, N.; Pachal, K.; Pacheco Pages, A.; Padilla Aranda, C.; Pagan Griso, S.; Paganis, E.; Pahl, C.; Paige, F.; Pais, P.; Pajchel, K.; Palacino, G.; Paleari, C. P.; Palestini, S.; Pallin, D.; Palma, A.; Palmer, J. D.; Pan, Y. B.; Panagiotopoulou, E.; Panduro Vazquez, J. G.; Pani, P.; Panikashvili, N.; Panitkin, S.; Pantea, D.; Papadelis, A.; Papadopoulou, Th. D.; Papageorgiou, K.; Paramonov, A.; Paredes Hernandez, D.; Parker, M. A.; Parodi, F.; Parsons, J. A.; Parzefall, U.; Pashapour, S.; Pasqualucci, E.; Passaggio, S.; Passeri, A.; Pastore, F.; Pastore, Fr.; Pásztor, G.; Pataraia, S.; Patel, N. D.; Pater, J. R.; Patricelli, S.; Pauly, T.; Pearce, J.; Pedersen, M.; Pedraza Lopez, S.; Pedraza Morales, M. I.; Peleganchuk, S. V.; Pelikan, D.; Peng, H.; Penning, B.; Penson, A.; Penwell, J.; Perepelitsa, D. V.; Perez Cavalcanti, T.; Perez Codina, E.; Pérez García-Estañ, M. T.; Perez Reale, V.; Perini, L.; Pernegger, H.; Perrino, R.; Peshekhonov, V. D.; Peters, K.; Peters, R. F. Y.; Petersen, B. A.; Petersen, J.; Petersen, T. C.; Petit, E.; Petridis, A.; Petridou, C.; Petrolo, E.; Petrucci, F.; Petteni, M.; Pezoa, R.; Phan, A.; Phillips, P. W.; Piacquadio, G.; Pianori, E.; Picazio, A.; Piccaro, E.; Piccinini, M.; Piec, S. M.; Piegaia, R.; Pignotti, D. T.; Pilcher, J. E.; Pilkington, A. D.; Pina, J.; Pinamonti, M.; Pinder, A.; Pinfold, J. L.; Pingel, A.; Pinto, B.; Pizio, C.; Pleier, M.-A.; Pleskot, V.; Plotnikova, E.; Plucinski, P.; Poddar, S.; Podlyski, F.; Poettgen, R.; Poggioli, L.; Pohl, D.; Pohl, M.; Polesello, G.; Policicchio, A.; Polifka, R.; Polini, A.; Pollard, C. S.; Polychronakos, V.; Pomeroy, D.; Pommès, K.; Pontecorvo, L.; Pope, B. G.; Popeneciu, G. A.; Popovic, D. S.; Poppleton, A.; Portell Bueso, X.; Pospelov, G. E.; Pospisil, S.; Potrap, I. N.; Potter, C. J.; Potter, C. T.; Poulard, G.; Poveda, J.; Pozdnyakov, V.; Prabhu, R.; Pralavorio, P.; Pranko, A.; Prasad, S.; Pravahan, R.; Prell, S.; Price, D.; Price, J.; Price, L. E.; Prieur, D.; Primavera, M.; Proissl, M.; Prokofiev, K.; Prokoshin, F.; Protopapadaki, E.; Protopopescu, S.; Proudfoot, J.; Prudent, X.; Przybycien, M.; Przysiezniak, H.; Psoroulas, S.; Ptacek, E.; Pueschel, E.; Puldon, D.; Purohit, M.; Puzo, P.; Pylypchenko, Y.; Qian, J.; Quadt, A.; Quarrie, D. R.; Quayle, W. B.; Quilty, D.; Raas, M.; Radeka, V.; Radescu, V.; Radloff, P.; Ragusa, F.; Rahal, G.; Rajagopalan, S.; Rammensee, M.; Rammes, M.; Randle-Conde, A. S.; Rangel-Smith, C.; Rao, K.; Rauscher, F.; Rave, T. C.; Ravenscroft, T.; Raymond, M.; Read, A. L.; Rebuzzi, D. M.; Redelbach, A.; Redlinger, G.; Reece, R.; Reeves, K.; Reinsch, A.; Reisinger, I.; Relich, M.; Rembser, C.; Ren, Z. L.; Renaud, A.; Rescigno, M.; Resconi, S.; Resende, B.; Reznicek, P.; Rezvani, R.; Richter, R.; Richter-Was, E.; Ridel, M.; Rieck, P.; Rijssenbeek, M.; Rimoldi, A.; Rinaldi, L.; Rios, R. R.; Ritsch, E.; Riu, I.; Rivoltella, G.; Rizatdinova, F.; Rizvi, E.; Robertson, S. H.; Robichaud-Veronneau, A.; Robinson, D.; Robinson, J. E. M.; Robson, A.; Rocha de Lima, J. G.; Roda, C.; Roda Dos Santos, D.; Roe, A.; Roe, S.; Røhne, O.; Rolli, S.; Romaniouk, A.; Romano, M.; Romeo, G.; Romero Adam, E.; Rompotis, N.; Roos, L.; Ros, E.; Rosati, S.; Rosbach, K.; Rose, A.; Rose, M.; Rosendahl, P. L.; Rosenthal, O.; Rossetti, V.; Rossi, E.; Rossi, L. P.; Rotaru, M.; Roth, I.; Rothberg, J.; Rousseau, D.; Royon, C. R.; Rozanov, A.; Rozen, Y.; Ruan, X.; Rubbo, F.; Rubinskiy, I.; Ruckstuhl, N.; Rud, V. I.; Rudolph, C.; Rudolph, M. S.; Rühr, F.; Ruiz-Martinez, A.; Rumyantsev, L.; Rurikova, Z.; Rusakovich, N. A.; Ruschke, A.; Rutherfoord, J. P.; Ruthmann, N.; Ruzicka, P.; Ryabov, Y. F.; Rybar, M.; Rybkin, G.; Ryder, N. C.; Saavedra, A. F.; Saddique, A.; Sadeh, I.; Sadrozinski, H. F.-W.; Sadykov, R.; Safai Tehrani, F.; Sakamoto, H.; Salamanna, G.; Salamon, A.; Saleem, M.; Salek, D.; Salihagic, D.; Salnikov, A.; Salt, J.; Salvachua Ferrando, B. M.; Salvatore, D.; Salvatore, F.; Salvucci, A.; Salzburger, A.; Sampsonidis, D.; Sanchez, A.; Sánchez, J.; Sanchez Martinez, V.; Sandaker, H.; Sander, H. G.; Sanders, M. P.; Sandhoff, M.; Sandoval, T.; Sandoval, C.; Sandstroem, R.; Sankey, D. P. C.; Sansoni, A.; Santoni, C.; Santonico, R.; Santos, H.; Santoyo Castillo, I.; Sapp, K.; Saraiva, J. G.; Sarangi, T.; Sarkisyan-Grinbaum, E.; Sarrazin, B.; Sarri, F.; Sartisohn, G.; Sasaki, O.; Sasaki, Y.; Sasao, N.; Satsounkevitch, I.; Sauvage, G.; Sauvan, E.; Sauvan, J. B.; Savard, P.; Savinov, V.; Savu, D. O.; Sawyer, C.; Sawyer, L.; Saxon, D. H.; Saxon, J.; Sbarra, C.; Sbrizzi, A.; Scannicchio, D. A.; Scarcella, M.; Schaarschmidt, J.; Schacht, P.; Schaefer, D.; Schaelicke, A.; Schaepe, S.; Schaetzel, S.; Schäfer, U.; Schaffer, A. C.; Schaile, D.; Schamberger, R. D.; Scharf, V.; Schegelsky, V. A.; Scheirich, D.; Schernau, M.; Scherzer, M. I.; Schiavi, C.; Schieck, J.; Schillo, C.; Schioppa, M.; Schlenker, S.; Schmidt, E.; Schmieden, K.; Schmitt, C.; Schmitt, C.; Schmitt, S.; Schneider, B.; Schnellbach, Y. J.; Schnoor, U.; Schoeffel, L.; Schoening, A.; Schorlemmer, A. L. S.; Schott, M.; Schouten, D.; Schovancova, J.; Schram, M.; Schroeder, C.; Schroer, N.; Schultens, M. J.; Schultz-Coulon, H.-C.; Schulz, H.; Schumacher, M.; Schumm, B. A.; Schune, Ph.; Schwartzman, A.; Schwegler, Ph.; Schwemling, Ph.; Schwienhorst, R.; Schwindling, J.; Schwindt, T.; Schwoerer, M.; Sciacca, F. G.; Scifo, E.; Sciolla, G.; Scott, W. G.; Scutti, F.; Searcy, J.; Sedov, G.; Sedykh, E.; Seidel, S. C.; Seiden, A.; Seifert, F.; Seixas, J. M.; Sekhniaidze, G.; Sekula, S. J.; Selbach, K. E.; Seliverstov, D. M.; Sellers, G.; Seman, M.; Semprini-Cesari, N.; Serfon, C.; Serin, L.; Serkin, L.; Serre, T.; Seuster, R.; Severini, H.; Sfyrla, A.; Shabalina, E.; Shamim, M.; Shan, L. Y.; Shank, J. T.; Shao, Q. T.; Shapiro, M.; Shatalov, P. B.; Shaw, K.; Sherwood, P.; Shimizu, S.; Shimojima, M.; Shin, T.; Shiyakova, M.; Shmeleva, A.; Shochet, M. J.; Short, D.; Shrestha, S.; Shulga, E.; Shupe, M. A.; Shushkevich, S.; Sicho, P.; Sidoti, A.; Siegert, F.; Sijacki, Dj.; Silbert, O.; Silva, J.; Silver, Y.; Silverstein, D.; Silverstein, S. B.; Simak, V.; Simard, O.; Simic, Lj.; Simion, S.; Simioni, E.; Simmons, B.; Simoniello, R.; Simonyan, M.; Sinervo, P.; Sinev, N. B.; Sipica, V.; Siragusa, G.; Sircar, A.; Sisakyan, A. N.; Sivoklokov, S. Yu.; Sjölin, J.; Sjursen, T. B.; Skinnari, L. A.; Skottowe, H. P.; Skovpen, K. Yu.; Skubic, P.; Slater, M.; Slavicek, T.; Sliwa, K.; Smakhtin, V.; Smart, B. H.; Smestad, L.; Smirnov, S. Yu.; Smirnov, Y.; Smirnova, L. N.; Smirnova, O.; Smith, K. M.; Smizanska, M.; Smolek, K.; Snesarev, A. A.; Snidero, G.; Snow, J.; Snyder, S.; Sobie, R.; Sodomka, J.; Soffer, A.; Soh, D. A.; Solans, C. A.; Solar, M.; Solc, J.; Soldatov, E. Yu.; Soldevila, U.; Solfaroli Camillocci, E.; Solodkov, A. A.; Solovyanov, O. V.; Solovyev, V.; Soni, N.; Sood, A.; Sopko, V.; Sopko, B.; Sosebee, M.; Soualah, R.; Soueid, P.; Soukharev, A. M.; South, D.; Spagnolo, S.; Spanò, F.; Spearman, W. R.; Spighi, R.; Spigo, G.; Spiwoks, R.; Spousta, M.; Spreitzer, T.; Spurlock, B.; St. Denis, R. D.; Stahlman, J.; Stamen, R.; Stanecka, E.; Stanek, R. W.; Stanescu, C.; Stanescu-Bellu, M.; Stanitzki, M. M.; Stapnes, S.; Starchenko, E. A.; Stark, J.; Staroba, P.; Starovoitov, P.; Staszewski, R.; Staude, A.; Stavina, P.; Steele, G.; Steinbach, P.; Steinberg, P.; Stekl, I.; Stelzer, B.; Stelzer, H. J.; Stelzer-Chilton, O.; Stenzel, H.; Stern, S.; Stewart, G. A.; Stillings, J. A.; Stockton, M. C.; Stoebe, M.; Stoerig, K.; Stoicea, G.; Stonjek, S.; Stradling, A. R.; Straessner, A.; Strandberg, J.; Strandberg, S.; Strandlie, A.; Strang, M.; Strauss, E.; Strauss, M.; Strizenec, P.; Ströhmer, R.; Strom, D. M.; Strong, J. A.; Stroynowski, R.; Stugu, B.; Stumer, I.; Stupak, J.; Sturm, P.; Styles, N. A.; Su, D.; Subramania, HS.; Subramaniam, R.; Succurro, A.; Sugaya, Y.; Suhr, C.; Suk, M.; Sulin, V. V.; Sultansoy, S.; Sumida, T.; Sun, X.; Sundermann, J. E.; Suruliz, K.; Susinno, G.; Sutton, M. R.; Suzuki, Y.; Svatos, M.; Swedish, S.; Swiatlowski, M.; Sykora, I.; Sykora, T.; Ta, D.; Tackmann, K.; Taffard, A.; Tafirout, R.; Taiblum, N.; Takahashi, Y.; Takai, H.; Takashima, R.; Takeda, H.; Takeshita, T.; Takubo, Y.; Talby, M.; Talyshev, A. A.; Tam, J. Y. C.; Tamsett, M. C.; Tan, K. G.; Tanaka, J.; Tanaka, R.; Tanaka, S.; Tanaka, S.; Tanasijczuk, A. J.; Tani, K.; Tannoury, N.; Tapprogge, S.; Tarem, S.; Tarrade, F.; Tartarelli, G. F.; Tas, P.; Tasevsky, M.; Tashiro, T.; Tassi, E.; Tavares Delgado, A.; Tayalati, Y.; Taylor, C.; Taylor, F. E.; Taylor, G. N.; Taylor, W.; Teinturier, M.; Teischinger, F. A.; Teixeira Dias Castanheira, M.; Teixeira-Dias, P.; Temming, K. K.; Ten Kate, H.; Teng, P. K.; Terada, S.; Terashi, K.; Terron, J.; Testa, M.; Teuscher, R. J.; Therhaag, J.; Theveneaux-Pelzer, T.; Thoma, S.; Thomas, J. P.; Thompson, E. N.; Thompson, P. D.; Thompson, P. D.; Thompson, A. S.; Thomsen, L. A.; Thomson, E.; Thomson, M.; Thong, W. M.; Thun, R. P.; Tian, F.; Tibbetts, M. J.; Tic, T.; Tikhomirov, V. O.; Tikhonov, Yu. A.; Timoshenko, S.; Tiouchichine, E.; Tipton, P.; Tisserant, S.; Todorov, T.; Todorova-Nova, S.; Toggerson, B.; Tojo, J.; Tokár, S.; Tokushuku, K.; Tollefson, K.; Tomlinson, L.; Tomoto, M.; Tompkins, L.; Toms, K.; Tonoyan, A.; Topfel, C.; Topilin, N. D.; Torrence, E.; Torres, H.; Torró Pastor, E.; Toth, J.; Touchard, F.; Tovey, D. R.; Tran, H. L.; Trefzger, T.; Tremblet, L.; Tricoli, A.; Trigger, I. M.; Trincaz-Duvoid, S.; Tripiana, M. F.; Triplett, N.; Trischuk, W.; Trocmé, B.; Troncon, C.; Trottier-McDonald, M.; Trovatelli, M.; True, P.; Trzebinski, M.; Trzupek, A.; Tsarouchas, C.; Tseng, J. C.-L.; Tsiakiris, M.; Tsiareshka, P. V.; Tsionou, D.; Tsipolitis, G.; Tsiskaridze, S.; Tsiskaridze, V.; Tskhadadze, E. G.; Tsukerman, I. I.; Tsulaia, V.; Tsung, J.-W.; Tsuno, S.; Tsybychev, D.; Tua, A.; Tudorache, A.; Tudorache, V.; Tuggle, J. M.; Tuna, A. N.; Turala, M.; Turchikhin, S.; Turecek, D.; Turk Cakir, I.; Turra, R.; Tuts, P. M.; Tykhonov, A.; Tylmad, M.; Tyndel, M.; Uchida, K.; Ueda, I.; Ueno, R.; Ughetto, M.; Ugland, M.; Uhlenbrock, M.; Ukegawa, F.; Unal, G.; Undrus, A.; Unel, G.; Ungaro, F. C.; Unno, Y.; Urbaniec, D.; Urquijo, P.; Usai, G.; Usanova, A.; Vacavant, L.; Vacek, V.; Vachon, B.; Vahsen, S.; Valencic, N.; Valentinetti, S.; Valero, A.; Valery, L.; Valkar, S.; Valladolid Gallego, E.; Vallecorsa, S.; Valls Ferrer, J. A.; Van Berg, R.; Van Der Deijl, P. C.; van der Geer, R.; van der Graaf, H.; Van Der Leeuw, R.; van der Ster, D.; van Eldik, N.; van Gemmeren, P.; Van Nieuwkoop, J.; van Vulpen, I.; Vanadia, M.; Vandelli, W.; Vaniachine, A.; Vankov, P.; Vannucci, F.; Vari, R.; Varnes, E. W.; Varol, T.; Varouchas, D.; Vartapetian, A.; Varvell, K. E.; Vassilakopoulos, V. I.; Vazeille, F.; Vazquez Schroeder, T.; Veatch, J.; Veloso, F.; Veneziano, S.; Ventura, A.; Ventura, D.; Venturi, M.; Venturi, N.; Vercesi, V.; Verducci, M.; Verkerke, W.; Vermeulen, J. C.; Vest, A.; Vetterli, M. C.; Vichou, I.; Vickey, T.; Vickey Boeriu, O. E.; Viehhauser, G. H. A.; Viel, S.; Vigne, R.; Villa, M.; Villaplana Perez, M.; Vilucchi, E.; Vincter, M. G.; Vinogradov, V. B.; Virzi, J.; Vitells, O.; Viti, M.; Vivarelli, I.; Vives Vaque, F.; Vlachos, S.; Vladoiu, D.; Vlasak, M.; Vogel, A.; Vokac, P.; Volpi, G.; Volpi, M.; Volpini, G.; von der Schmitt, H.; von Radziewski, H.; von Toerne, E.; Vorobel, V.; Vos, M.; Voss, R.; Vossebeld, J. H.; Vranjes, N.; Vranjes Milosavljevic, M.; Vrba, V.; Vreeswijk, M.; Vu Anh, T.; Vuillermet, R.; Vukotic, I.; Vykydal, Z.; Wagner, W.; Wagner, P.; Wahrmund, S.; Wakabayashi, J.; Walch, S.; Walder, J.; Walker, R.; Walkowiak, W.; Wall, R.; Waller, P.; Walsh, B.; Wang, C.; Wang, H.; Wang, H.; Wang, J.; Wang, J.; Wang, K.; Wang, R.; Wang, S. M.; Wang, T.; Wang, X.; Warburton, A.; Ward, C. P.; Wardrope, D. R.; Warsinsky, M.; Washbrook, A.; Wasicki, C.; Watanabe, I.; Watkins, P. M.; Watson, A. T.; Watson, I. J.; Watson, M. F.; Watts, G.; Watts, S.; Waugh, A. T.; Waugh, B. M.; Weber, M. S.; Webster, J. S.; Weidberg, A. R.; Weigell, P.; Weingarten, J.; Weiser, C.; Weits, H.; Wells, P. S.; Wenaus, T.; Wendland, D.; Weng, Z.; Wengler, T.; Wenig, S.; Wermes, N.; Werner, M.; Werner, P.; Werth, M.; Wessels, M.; Wetter, J.; Whalen, K.; White, A.; White, M. J.; White, R.; White, S.; Whiteson, D.; Whittington, D.; Wicke, D.; Wickens, F. J.; Wiedenmann, W.; Wielers, M.; Wienemann, P.; Wiglesworth, C.; Wiik-Fuchs, L. A. M.; Wijeratne, P. A.; Wildauer, A.; Wildt, M. A.; Wilhelm, I.; Wilkens, H. G.; Will, J. Z.; Williams, E.; Williams, H. H.; Williams, S.; Willis, W.; Willocq, S.; Wilson, J. A.; Wilson, A.; Wingerter-Seez, I.; Winkelmann, S.; Winklmeier, F.; Wittgen, M.; Wittig, T.; Wittkowski, J.; Wollstadt, S. J.; Wolter, M. W.; Wolters, H.; Wong, W. C.; Wooden, G.; Wosiek, B. K.; Wotschack, J.; Woudstra, M. J.; Wozniak, K. W.; Wraight, K.; Wright, M.; Wrona, B.; Wu, S. L.; Wu, X.; Wu, Y.; Wulf, E.; Wynne, B. M.; Xella, S.; Xiao, M.; Xu, C.; Xu, D.; Xu, L.; Yabsley, B.; Yacoob, S.; Yamada, M.; Yamaguchi, H.; Yamaguchi, Y.; Yamamoto, A.; Yamamoto, K.; Yamamoto, S.; Yamamura, T.; Yamanaka, T.; Yamauchi, K.; Yamazaki, Y.; Yan, Z.; Yang, H.; Yang, H.; Yang, U. K.; Yang, Y.; Yang, Z.; Yanush, S.; Yao, L.; Yasu, Y.; Yatsenko, E.; Yau Wong, K. H.; Ye, J.; Ye, S.; Yen, A. L.; Yildirim, E.; Yilmaz, M.; Yoosoofmiya, R.; Yorita, K.; Yoshida, R.; Yoshihara, K.; Young, C.; Young, C. J. S.; Youssef, S.; Yu, D. R.; Yu, J.; Yu, J.; Yuan, L.; Yurkewicz, A.; Zabinski, B.; Zaidan, R.; Zaitsev, A. M.; Zambito, S.; Zanello, L.; Zanzi, D.; Zaytsev, A.; Zeitnitz, C.; Zeman, M.; Zemla, A.; Zenin, O.; Ženiš, T.; Zerwas, D.; Zevi della Porta, G.; Zhang, D.; Zhang, H.; Zhang, J.; Zhang, L.; Zhang, X.; Zhang, Z.; Zhao, Z.; Zhemchugov, A.; Zhong, J.; Zhou, B.; Zhou, N.; Zhu, C. G.; Zhu, H.; Zhu, J.; Zhu, Y.; Zhuang, X.; Zibell, A.; Zieminska, D.; Zimin, N. I.; Zimmermann, C.; Zimmermann, R.; Zimmermann, S.; Zimmermann, S.; Zinonos, Z.; Ziolkowski, M.; Zitoun, R.; Živković, L.; Zobernig, G.; Zoccoli, A.; zur Nedden, M.; Zutshi, V.; Zwalinski, L.

    2013-10-01

    Measurements of the variation of inclusive jet suppression as a function of relative azimuthal angle, Δϕ, with respect to the elliptic event plane provide insight into the path-length dependence of jet quenching. ATLAS has measured the Δϕ dependence of jet yields in 0.14nb-1 of sNN=2.76TeV Pb+Pb collisions at the LHC for jet transverse momenta pT>45GeV in different collision centrality bins using an underlying event subtraction procedure that accounts for elliptic flow. The variation of the jet yield with Δϕ was characterized by the parameter, v2jet, and the ratio of out-of-plane (Δϕ˜π/2) to in-plane (Δϕ˜0) yields. Nonzero v2jet values were measured in all centrality bins for pT<160GeV. The jet yields are observed to vary by as much as 20% between in-plane and out-of-plane directions.

  12. An angle-dependent estimation of CT x-ray spectrum from rotational transmission measurements

    SciTech Connect

    Lin, Yuan Samei, Ehsan; Ramirez-Giraldo, Juan Carlos; Gauthier, Daniel J.; Stierstorfer, Karl

    2014-06-15

    Purpose: Computed tomography (CT) performance as well as dose and image quality is directly affected by the x-ray spectrum. However, the current assessment approaches of the CT x-ray spectrum require costly measurement equipment and complicated operational procedures, and are often limited to the spectrum corresponding to the center of rotation. In order to address these limitations, the authors propose an angle-dependent estimation technique, where the incident spectra across a wide range of angular trajectories can be estimated accurately with only a single phantom and a single axial scan in the absence of the knowledge of the bowtie filter. Methods: The proposed technique uses a uniform cylindrical phantom, made of ultra-high-molecular-weight polyethylene and positioned in an off-centered geometry. The projection data acquired with an axial scan have a twofold purpose. First, they serve as a reflection of the transmission measurements across different angular trajectories. Second, they are used to reconstruct the cross sectional image of the phantom, which is then utilized to compute the intersection length of each transmission measurement. With each CT detector element recording a range of transmission measurements for a single angular trajectory, the spectrum is estimated for that trajectory. A data conditioning procedure is used to combine information from hundreds of collected transmission measurements to accelerate the estimation speed, to reduce noise, and to improve estimation stability. The proposed spectral estimation technique was validated experimentally using a clinical scanner (Somatom Definition Flash, Siemens Healthcare, Germany) with spectra provided by the manufacturer serving as the comparison standard. Results obtained with the proposed technique were compared against those obtained from a second conventional transmission measurement technique with two materials (i.e., Cu and Al). After validation, the proposed technique was applied to measure

  13. Study of M1 and E1 excitations by high-resolution proton inelastic scattering measurement at forward angles

    SciTech Connect

    Tamii, A.; Adachi, T.; Hatanaka, K.; Hashimoto, H.; Kaneda, T.; Matsubara, H.; Okamura, H.; Sakemi, Y.; Shimizu, Y.; Tameshige, Y.; Yosoi, M.; Carter, J.; Dozono, M.; Fujita, H.; Fujita, Y.; Itoh, M.; Kawabata, T.; Nakanishi, K.; Sasamoto, Y.; Neumann-Cosel, P. von

    2007-06-13

    Experimental technique for measuring proton inelastic scattering with high-resolution at 295 MeV and at forward angles including zero degrees is described. The method is useful for extracting spin part of the M1 strength via nuclear excitation as well as E1 strength via Coulomb excitation. An excitation energy resolution of 20 keV, good scattering angle resolution, and low background condition have been achieved. The experimental technique was applied for several sd and pf shell nuclei.

  14. In-Plane Electronic Anisotropy of Underdoped ___122___ Fe-Arsenide Superconductors Revealed by Measurements of Detwinned Single Crystals

    SciTech Connect

    Fisher, Ian Randal

    2012-05-08

    The parent phases of the Fe-arsenide superconductors harbor an antiferromagnetic ground state. Significantly, the Neel transition is either preceded or accompanied by a structural transition that breaks the four fold symmetry of the high-temperature lattice. Borrowing language from the field of soft condensed matter physics, this broken discrete rotational symmetry is widely referred to as an Ising nematic phase transition. Understanding the origin of this effect is a key component of a complete theoretical description of the occurrence of superconductivity in this family of compounds, motivating both theoretical and experimental investigation of the nematic transition and the associated in-plane anisotropy. Here we review recent experimental progress in determining the intrinsic in-plane electronic anisotropy as revealed by resistivity, reflectivity and ARPES measurements of detwinned single crystals of underdoped Fe arsenide superconductors in the '122' family of compounds.

  15. Improved Correction System for Vibration Sensitive Inertial Angle of Attack Measurement Devices

    NASA Technical Reports Server (NTRS)

    Crawford, Bradley L.; Finley, Tom D.

    2000-01-01

    Inertial angle of attack (AoA) devices currently in use at NASA Langley Research Center (LaRC) are subject to inaccuracies due to centrifugal accelerations caused by model dynamics, also known as sting whip. Recent literature suggests that these errors can be as high as 0.25 deg. With the current AoA accuracy target at LaRC being 0.01 deg., there is a dire need for improvement. With other errors in the inertial system (temperature, rectification, resolution, etc.) having been reduced to acceptable levels, a system is currently being developed at LaRC to measure and correct for the sting-whip-induced errors. By using miniaturized piezoelectric accelerometers and magnetohydrodynamic rate sensors, not only can the total centrifugal acceleration be measured, but yaw and pitch dynamics in the tunnel can also be characterized. These corrections can be used to determine a tunnel's past performance and can also indicate where efforts need to be concentrated to reduce these dynamics. Included in this paper are data on individual sensors, laboratory testing techniques, package evaluation, and wind tunnel test results on a High Speed Research (HSR) model in the Langley 16-Foot Transonic Wind Tunnel.

  16. The band structure of VO2 measured by angle-resolved photoemission

    NASA Astrophysics Data System (ADS)

    Moreschini, Luca; Chang, Young Jun; Innocenti, Davide; Walter, Andrew L.; Kim, Young Su; Gaines, Geoffrey; Bostwick, Aaron; Denlinger, Jonathan; Rotenberg, Eli

    2011-03-01

    The origin of the 340K metal-insulator transition (MIT) in VO2 is still under debate. the main reason is that no direct experimental verifications of the electronic structure of VO2 exist up to this point. The quality of the available single crystals is not sufficient for ARPES measurements, so that photoemission is limited to angle-integrated mode. New opportunities are offered by oxide films, on which data of equal or even higher quality have been reported (Saeki et al., PRB 2009). WIth the in situ pulsed-laser-deposition (PLD) system available on beamline 7.0.1 at the Advanced Light Source we have grown VO2(001) films on a TiO2 substrate and measured the Fermi surface of the metallic phase. These results will permit a direct comparison with the existing band calculations and open the way to the study of the MIT as a function, e.g., of film thickness or electron doping with Cr. Work supported by U.S. DOE (DE-AC02-05CH11231 for ALS), the Max Planck Society, and the Swiss National Science Foundation (PBELP2-125484).

  17. New method for improving angle measurement precision of laser collimation system under complex background

    NASA Astrophysics Data System (ADS)

    Zhao, Xiaofeng; Chen, He; Tan, Lilong; Zhang, Zhili; Cai, Wei

    2014-09-01

    We have proposed a new method for improving angle measurement precision based on the principle of CCD laser collimation in this paper. First, through the control of the laser's state, on or off, by the Digital Signal Processor (DSP), the collimation light and the background light can be sampled, individually. Second, with the comparison between the sampled value of the background light intensity and the threshold value which has been set in the DSP previously, the DSP can automatically control Complex Programmable Logic Device (CPLD) to adjust the light integral time of CCD to adapt to different environment background and the changeable scanning driver of CCD is realized. Last, by the digital wave filtering the impact of the background light on the collimation light can be removed. With the comprehensive application of the controlling technology of automatically changeable scanning driving, collimation light on or off, A/D conversion and adaptive filtering, the integration time of the collimation system can automatically adjust to the proper value according to the change of the environment and the impact of the background light on the collimation system can be well removed. The simulation results show that the new method can achieve the self-adaptable control with the change of the environment and can improve the measurement precision of the laser collimation system under the complex environment.

  18. Caustics and Caustic-Interference in Measurements of Contact Angle and Flow Visualization Through Laser Shadowgraphy

    NASA Technical Reports Server (NTRS)

    Chao, David F.; Zhang, Neng-Li

    2002-01-01

    As one of the basic elements of the shadowgraphy optical system, the image of the far field from the droplet implicates plentiful information on the droplet profile. An analysis of caustics by wave theory shows that a droplet with a cylindrically symmetric Gaussian-hill-type profile produces a circular directional caustic in far field, which arises from the singularities (inflection line on the surface). The sessile liquid droplets, which profiles are restricted by surface tension, usually have a 'protruding foot' where the surface inflects. Simple geometrical optics indicates that the circular caustic stemming from the surface inflection at the protruding-foot takes the shape of the outmost ring on the image of the far field. It is the diameter of the outmost ring that is used as one of the key parameters in the measurements of contact angle through the laser shadowgraphic method. Different surface characteristics of the droplets produce different type of caustics, and therefore, the shape of the caustics can be used to determine the surface property of the sessile droplets. The present paper describes the measurement method of contact angIe using the circular caustics and the estimation of the protruding-foot height through the caustic interference.

  19. New procedure to measure simultaneously the surface tension and contact angle

    NASA Astrophysics Data System (ADS)

    Champmartin, S.; Ambari, A.; Le Pommelec, J. Y.

    2016-05-01

    This paper proposes a new procedure to simultaneously measure the static contact angle and the surface tension of a liquid using a spherical geometry. Unlike the other existing methods, the knowledge of one of both previous parameters and the displacement of the sphere are not mandatory. The technique is based on the measurement of two simple physical quantities: the height of the meniscus formed on a sphere at the very contact with a liquid bath and the resulting vertical force exerted on this object at equilibrium. The meniscus height, whose exact value requires the numerical resolution of the Laplace equation, is often estimated with an approximate 2D model, valid only for very large spheres compared to the capillary length. We develop instead another simplified solution of the Young-Laplace equation based on the work of Ferguson for the meniscus on a cylinder and adapted for the spherical shape. This alternative model, which is less restrictive in terms of the sphere size, is successfully compared to numerical solutions of the complete Young-Laplace equation. It appears to be accurate for sphere radii larger than only two capillary lengths. Finally the feasibility of the method is experimentally tested and validated for three common liquids and two "small" steel spheres.

  20. Measurement of CKM-angle γ with Charmed B0 Meson Decays

    SciTech Connect

    Baak, Max Arjen

    2007-02-05

    This thesis reports measurements of the time-dependent CP asymmetries in fully reconstructed B0 → (D (*)∓π± and B0 → D ρ± ) decays in approximately 232 million Y(4S) → B$\\bar{B}$ events, collected with the BABAR detector at the PEP-II asymmetric-energy B factory at the Stanford Linear Accelerator Center in California, as published in Ref. [14]. The phenomenon of CP violation allows one to distinguish between matter and antimatter, and, as such, is one of the essential ingredients needed to explain the apparent abundance of matter over antimatter in the universe. The Standard Model describes the observed elementary particles in terms of three generations of quarks and leptons, as well as the weak, electromagnetic, and strong interactions between them. In the Standard Model, CP violation is incorporated in the Cabibbo-Kobayashi-Maskawa (CKM) matrix, which describes the weak interactions between the quarks. The weak interactions between quarks are described by coupling constants that are functions of three real parameters and one irreducible complex phase. The magnitude of all CP violating effects in the Standard Model is related to this complex phase. The measurement of the CP violating phase of the CKM matrix is an important part of the present scientific program in particle physics. Violation of the CP symmetry manifests itself as a non-zero area of the Unitarity Triangle. The Unitarity Triangle needs to be overconstrained by experimental measurements in order to demonstrate that the CKM mechanism is the correct explanation of this phenomenon. No stringent measurement of the CKM-angle γ is yet available.

  1. A Different Angle on Perspective

    ERIC Educational Resources Information Center

    Frantz, Marc

    2012-01-01

    When a plane figure is photographed from different viewpoints, lengths and angles appear distorted. Hence it is often assumed that lengths, angles, protractors, and compasses have no place in projective geometry. Here we describe a sense in which certain angles are preserved by projective transformations. These angles can be constructed with…

  2. Vectorial Kerr magnetometer for simultaneous and quantitative measurements of the in-plane magnetization components.

    PubMed

    Jiménez, E; Mikuszeit, N; Cuñado, J L F; Perna, P; Pedrosa, J; Maccariello, D; Rodrigo, C; Niño, M A; Bollero, A; Camarero, J; Miranda, R

    2014-05-01

    A vectorial magneto-optic Kerr effect (v-MOKE) setup with simultaneous and quantitative determination of the two in-plane magnetization components is described. The setup provides both polarization rotations and reflectivity changes at the same time for a given sample orientation with respect to a variable external magnetic field, as well as allowing full angular studies. A classical description based on the Jones formalism is used to calculate the setup's properties. The use of different incoming light polarizations and/or MOKE geometries, as well as the errors due to misalignment and solutions are discussed. To illustrate the capabilities of the setup a detailed study of a model four-fold anisotropy system is presented. Among others, the setup allows to study the angular dependence of the hysteresis phenomena, remanences, critical fields, and magnetization reversal processes, as well as the accurate determination of the easy and hard magnetization directions, domain wall orientations, and magnetic anisotropies.

  3. Post-trial anatomical frame alignment procedure for comparison of 3D joint angle measurement from magnetic/inertial measurement units and camera-based systems.

    PubMed

    Li, Qingguo; Zhang, Jun-Tian

    2014-11-01

    Magnetic and inertial measurement units (MIMUs) have been widely used as an alternative to traditional camera-based motion capture systems for 3D joint kinematics measurement. Since these sensors do not directly measure position, a pre-trial anatomical calibration, either with the assistance of a special protocol/apparatus or with another motion capture system is required to establish the transformation matrices between the local sensor frame and the anatomical frame (AF) of each body segment on which the sensors are attached. Because the axes of AFs are often used as the rotational axes in the joint angle calculation, any difference in the AF determination will cause discrepancies in the calculated joint angles. Therefore, a direct comparison of joint angles between MIMU systems and camera-based systems is less meaningful because the calculated joint angles contain a systemic error due to the differences in the AF determination. To solve this problem a new post-trial AF alignment procedure is proposed. By correcting the AF misalignments, the joint angle differences caused by the difference in AF determination are eliminated and the remaining discrepancies are mainly from the measurement accuracy of the systems themselves. Lower limb joint angles from 30 walking trials were used to validate the effectiveness of the proposed AF alignment procedure. This technique could serve as a new means for calibrating magnetic/inertial sensor-based motion capture systems and correcting for AF misalignment in scenarios where joint angles are compared directly.

  4. a Comparison of the Measured and Modelled Effects of Brewster Angle Anisotropies upon Pulsed Xenon Chloride Excimer Laser Output

    NASA Astrophysics Data System (ADS)

    Hahn, John Frederick

    We have demonstrated the effectiveness of stacked, fused-silica, intra-cavity Brewster angle plates in generating highly polarized XeCl^{*} laser output. Output polarization in excess of 95%, with coincident energy degradation of less than 20%, have been observed, data which compare favorably with results obtained with more sophisticated, more expensive intra-cavity laser polarizers (DOB 81). The optimal arrangement of the polarizing plates is shown to be at the rear of the cavity, near the mirror. We have observed the temporal development of the component pulses and the degree of polarization. For the optimal rear polarizer arrangements, the polarization has been shown to be large throughout the entire observable pulse. We have observed the dependence of the polarization upon the gas mixture pressure when weaker anisotropies are in place. We have developed a model to simulate the experimental results. The model is an innovative use of established rate equation techniques and also makes use of the short coherence length of XeCl* emissions to permit decoupling of the p- and s-plane polarization components. We thus avoid the more complicated semi-classical model which makes explicit use of the vector properties of the polarization components. We account for the presence of Brewster angle plates in the cavity as changes in the effective mirror/outcoupler reflectivities in the respective planes of polarization. We successfully simulate the output energy, E, the peak-to -peak polarization, {cal P}_ {o} and the temporally averaged polarization, |{cal P}, for the tested polarizer configurations. We attain only moderate success with our simulations of the temporally resolved polarizations. We use the model also to predict what operating conditions are required to successfully implement the use of Brewster angle end windows in generating highly polarized output.

  5. Studies of powder flow using a recording powder flowmeter and measurement of the dynamic angle of repose.

    PubMed

    Hegde, R P; Rheingold, J L; Welch, S; Rhodes, C T

    1985-01-01

    This paper describes the utility of the dynamic measurement of the angle of repose for pharmaceutical systems, using a variable rotating cylinder to quantify powder flow. The dynamic angle of repose of sodium chloride powder sieve fractions was evaluated using a variable rotating cylinder. The relationship between the static and the dynamic angle of repose is discussed. The dynamic angle of repose of six lots of a multivitamin preparation were compared for inter- and intralot variation. In both cases, no significant differences (p greater than 0.05) were observed. In the multivitamin formulation, lubricants at lower concentration levels did not show a significant effect (p greater than 0.05) on the dynamic angle of repose when compared with flow rates. The effect of different hopper sizes and geometry has been evaluated using the recording powder flowmeter. The results indicate that although different hoppers affect the quantitative nature of the results, the same general trends are apparent. Thus, it appears possible to use a recording powder flowmeter with small quantities of material to predict the effect of formulation and processing variables on the flow of production scale quantities. This paper does not describe a comprehensive evaluation of the pharmaceutical utility of measuring the dynamic angle of repose. However, the results discussed are not encouraging and suggest that the recording powder flowmeter is more sensitive to the effects of formulation and production variables on powder flow.

  6. A multiple-plane approach to measure the structural properties of functionally active regions in the human cortex.

    PubMed

    Wang, Xin; Garfinkel, Sarah N; King, Anthony P; Angstadt, Mike; Dennis, Michael J; Xie, Hong; Welsh, Robert C; Tamburrino, Marijo B; Liberzon, Israel

    2010-02-15

    Advanced magnetic resonance imaging (MRI) techniques provide the means of studying both the structural and the functional properties of various brain regions, allowing us to address the relationship between the structural changes in human brain regions and the activity of these regions. However, analytical approaches combining functional (fMRI) and structural (sMRI) information are still far from optimal. In order to improve the accuracy of measurement of structural properties in active regions, the current study tested a new analytical approach that repeated a surface-based analysis at multiple planes crossing different depths of cortex. Twelve subjects underwent a fear conditioning study. During these tasks, fMRI and sMRI scans were acquired. The fMRI images were carefully registered to the sMRI images with an additional correction for cortical borders. The fMRI images were then analyzed with the new multiple-plane surface-based approach as compared to the volume-based approach, and the cortical thickness and volume of an active region were measured. The results suggested (1) using an additional correction for cortical borders and an intermediate template image produced an acceptable registration of fMRI and sMRI images; (2) surface-based analysis at multiple depths of cortex revealed more activity than the same analysis at any single depth; (3) projection of active surface vertices in a ribbon fashion improved active volume estimates; and (4) correction with gray matter segmentation removed non-cortical regions from the volumetric measurement of active regions. In conclusion, the new multiple-plane surface-based analysis approaches produce improved measurement of cortical thickness and volume of active brain regions. These results support the use of novel approaches for combined analysis of functional and structural neuroimaging. PMID:19922802

  7. Quantitative diffusion and swelling kinetic measurements using large-angle interferometric refractometry.

    PubMed

    Saunders, John E; Chen, Hao; Brauer, Chris; Clayton, McGregor; Chen, Weijian; Barnes, Jack A; Loock, Hans-Peter

    2015-12-01

    The uptake and release of sorbates into films and coatings is typically accompanied by changes of the films' refractive index and thickness. We provide a comprehensive model to calculate the concentration of the sorbate from the average refractive index and the film thickness, and validate the model experimentally. The mass fraction of the analyte partitioned into a film is described quantitatively by the Lorentz-Lorenz equation and the Clausius-Mosotti equation. To validate the model, the uptake kinetics of water and other solvents into SU-8 films (d = 40-45 μm) were explored. Large-angle interferometric refractometry measurements can be used to characterize films that are between 15 μm to 150 μm thick and, Fourier analysis, is used to determine independently the thickness, the average refractive index and the refractive index at the film-substrate interface at one-second time intervals. From these values the mass fraction of water in SU-8 was calculated. The kinetics were best described by two independent uptake processes having different rates. Each process followed one-dimensional Fickian diffusion kinetics with diffusion coefficients for water into SU-8 photoresist film of 5.67 × 10(-9) cm(2) s(-1) and 61.2 × 10(-9) cm(2) s(-1). PMID:26458138

  8. Understanding properties of engineered catalyst supports using contact angle measurements and X-ray reflectivity.

    PubMed

    Amama, Placidus B; Islam, Ahmad E; Saber, Sammy M; Huffman, Daniel R; Maruyama, Benji

    2016-02-01

    There is significant interest in broadening the type of catalyst substrates that support the growth of high-quality carbon nanotube (CNT) carpets. In this study, ion beam bombardment has been utilized to modify catalyst substrates for CNT carpet growth. Using a combination of contact angle measurements (CAMs) and X-ray reflectivity (XRR) for the first time, new correlations between the physicochemical properties of pristine and engineered catalyst substrates and CNT growth behavior have been established. The engineered surfaces obtained after exposure to different degrees of ion beam damage have distinct physicochemical properties (porosity, layer thickness, and acid-base properties). The CAM data were analyzed using the van Oss-Chaudhury-Good model, enabling the determination of the acid-base properties of the substrate surfaces. For the XRR data, a Fourier analysis of the interference patterns enabled extraction of layer thickness, while the atomic density and interfacial roughness were extracted by analyzing the amplitude of the interference oscillations. The dramatic transformation of the substrate from "inactive" to "active" is attributed to a combined effect of substrate porosity or damage depth and Lewis basicity. The results reveal that the efficiency of catalyst substrates can be further improved by increasing the substrate basicity, if the minimum surface porosity is established. This study advances the use of a non-thermochemical approach for catalyst substrate engineering, as well as demonstrates the combined utility of CAM and XRR as a powerful, nondestructive, and reliable tool for rational catalyst design.

  9. Accurate measurements of cross-plane thermal conductivity of thin films by dual-frequency time-domain thermoreflectance (TDTR).

    PubMed

    Jiang, Puqing; Huang, Bin; Koh, Yee Kan

    2016-07-01

    Accurate measurements of the cross-plane thermal conductivity Λcross of a high-thermal-conductivity thin film on a low-thermal-conductivity (Λs) substrate (e.g., Λcross/Λs > 20) are challenging, due to the low thermal resistance of the thin film compared with that of the substrate. In principle, Λcross could be measured by time-domain thermoreflectance (TDTR), using a high modulation frequency fh and a large laser spot size. However, with one TDTR measurement at fh, the uncertainty of the TDTR measurement is usually high due to low sensitivity of TDTR signals to Λcross and high sensitivity to the thickness hAl of Al transducer deposited on the sample for TDTR measurements. We observe that in most TDTR measurements, the sensitivity to hAl only depends weakly on the modulation frequency f. Thus, we performed an additional TDTR measurement at a low modulation frequency f0, such that the sensitivity to hAl is comparable but the sensitivity to Λcross is near zero. We then analyze the ratio of the TDTR signals at fh to that at f0, and thus significantly improve the accuracy of our Λcross measurements. As a demonstration of the dual-frequency approach, we measured the cross-plane thermal conductivity of a 400-nm-thick nickel-iron alloy film and a 3-μm-thick Cu film, both with an accuracy of ∼10%. The dual-frequency TDTR approach is useful for future studies of thin films. PMID:27475589

  10. Accurate measurements of cross-plane thermal conductivity of thin films by dual-frequency time-domain thermoreflectance (TDTR).

    PubMed

    Jiang, Puqing; Huang, Bin; Koh, Yee Kan

    2016-07-01

    Accurate measurements of the cross-plane thermal conductivity Λcross of a high-thermal-conductivity thin film on a low-thermal-conductivity (Λs) substrate (e.g., Λcross/Λs > 20) are challenging, due to the low thermal resistance of the thin film compared with that of the substrate. In principle, Λcross could be measured by time-domain thermoreflectance (TDTR), using a high modulation frequency fh and a large laser spot size. However, with one TDTR measurement at fh, the uncertainty of the TDTR measurement is usually high due to low sensitivity of TDTR signals to Λcross and high sensitivity to the thickness hAl of Al transducer deposited on the sample for TDTR measurements. We observe that in most TDTR measurements, the sensitivity to hAl only depends weakly on the modulation frequency f. Thus, we performed an additional TDTR measurement at a low modulation frequency f0, such that the sensitivity to hAl is comparable but the sensitivity to Λcross is near zero. We then analyze the ratio of the TDTR signals at fh to that at f0, and thus significantly improve the accuracy of our Λcross measurements. As a demonstration of the dual-frequency approach, we measured the cross-plane thermal conductivity of a 400-nm-thick nickel-iron alloy film and a 3-μm-thick Cu film, both with an accuracy of ∼10%. The dual-frequency TDTR approach is useful for future studies of thin films.

  11. Accurate measurements of cross-plane thermal conductivity of thin films by dual-frequency time-domain thermoreflectance (TDTR)

    NASA Astrophysics Data System (ADS)

    Jiang, Puqing; Huang, Bin; Koh, Yee Kan

    2016-07-01

    Accurate measurements of the cross-plane thermal conductivity Λcross of a high-thermal-conductivity thin film on a low-thermal-conductivity (Λs) substrate (e.g., Λcross/Λs > 20) are challenging, due to the low thermal resistance of the thin film compared with that of the substrate. In principle, Λcross could be measured by time-domain thermoreflectance (TDTR), using a high modulation frequency fh and a large laser spot size. However, with one TDTR measurement at fh, the uncertainty of the TDTR measurement is usually high due to low sensitivity of TDTR signals to Λcross and high sensitivity to the thickness hAl of Al transducer deposited on the sample for TDTR measurements. We observe that in most TDTR measurements, the sensitivity to hAl only depends weakly on the modulation frequency f. Thus, we performed an additional TDTR measurement at a low modulation frequency f0, such that the sensitivity to hAl is comparable but the sensitivity to Λcross is near zero. We then analyze the ratio of the TDTR signals at fh to that at f0, and thus significantly improve the accuracy of our Λcross measurements. As a demonstration of the dual-frequency approach, we measured the cross-plane thermal conductivity of a 400-nm-thick nickel-iron alloy film and a 3-μm-thick Cu film, both with an accuracy of ˜10%. The dual-frequency TDTR approach is useful for future studies of thin films.

  12. 'Illusional' nano-size effect due to artifacts of in-plane conductivity measurements of ultra-thin films.

    PubMed

    Kim, Hae-Ryoung; Kim, Jong-Cheol; Lee, Kyung-Ryul; Ji, Ho-Il; Lee, Hae-Weon; Lee, Jong-Ho; Son, Ji-Won

    2011-04-01

    The nano-size effect, which indicates a drastic increase in conductivity in solid electrolyte materials of nano-scale microstructures, has drawn substantial attention in various research fields including in the field of solid oxide fuel cells (SOFCs). However, especially in the cases of the conductivity of ultra-thin films measured in an in-plane configuration, it is highly possible that the 'apparent' conductivity increase originates from electrical current flowing through other conduction paths than the thin film. As a systematic study to interrogate those measurement artifacts, we report various sources of electrical current leaks regarding in-plane conductivity measurements, specifically insulators in the measurement set-up. We have observed a 'great conductivity increase' up to an order of magnitude at a very thin thickness of a single layer yttria-stabilized zirconia (YSZ) film in a set-up with an intentional artifact current flow source. Here we propose that the nano-size effect, reported to appear in ultra-thin single layer YSZ, can be a result of misinterpretation.

  13. A new technique for retrieval of tropospheric and stratospheric ozone profiles using sky radiance measurements at multiple view angles: Application to a Brewer spectrometer

    NASA Astrophysics Data System (ADS)

    Tzortziou, Maria; Krotkov, Nickolay A.; Cede, Alexander; Herman, Jay R.; Vasilkov, Alexander

    2008-03-01

    This paper describes and applies a new technique for retrieving diurnal variability in tropospheric ozone vertical distribution using ground-based measurements of ultraviolet sky radiances. The measured radiances are obtained by a polarization-insensitive modified Brewer double spectrometer located at Goddard Space Flight Center, in Greenbelt, Maryland, USA. Results demonstrate that the Brewer angular (0-72° viewing zenith angle) and spectral (303-320 nm) measurements of sky radiance in the solar principal plane provide sufficient information to derive tropospheric ozone diurnal variability. In addition, the Brewer measurements provide stratospheric ozone vertical distributions at least twice per day near sunrise and sunset. Frequent measurements of total column ozone amounts from direct-sun observations are used as constraints in the retrieval. The vertical ozone profile resolution is shown in terms of averaging kernels to yield at least four points in the troposphere-low stratosphere, including good information in Umkehr layer 0 (0-5 km). The focus of this paper is on the derivation of stratospheric and tropospheric ozone profiles using both simulated and measured radiances. We briefly discuss the necessary modifications of the Brewer spectrometer that were used to eliminate instrumental polarization sensitivity so that accurate sky radiances can be obtained in the presence of strong Rayleigh scattering and aerosols. The results demonstrate that including a site-specific and time-dependent aerosol correction, based on Brewer direct-sun observations of aerosol optical thickness, is critical to minimize the sky radiance residuals as a function of observing angle in the optimal estimation inversion algorithm and improve the accuracy of the retrieved ozone profile.

  14. Proximity effect on hydrodynamic interaction between a sphere and a plane measured by force feedback microscopy at different frequencies

    NASA Astrophysics Data System (ADS)

    Carpentier, Simon; Rodrigues, Mario S.; Charlaix, Elisabeth; Chevrier, Joël

    2015-07-01

    In this article, we measure the viscous damping G″, and the associated stiffness G', of a liquid flow in sphere-plane geometry over a large frequency range. In this regime, the lubrication approximation is expected to dominate. We first measure the static force applied to the tip. This is made possible thanks to a force feedback method. Adding a sub-nanometer oscillation of the tip, we obtain the dynamic part of the interaction with solely the knowledge of the lever properties in the experimental context using a linear transformation of the amplitude and phase change. Using a Force Feedback Microscope (FFM), we are then able to measure simultaneously the static force, the stiffness, and the dissipative part of the interaction in a broad frequency range using a single AFM probe. Similar measurements have been performed by the Surface Force Apparatus (SFA) with a probe radius hundred times bigger. In this context, the FFM can be called nano-SFA.

  15. Use of projection moiré for measuring the instantaneous out-of-plane deflections of composite plates subject to bird strike

    NASA Astrophysics Data System (ADS)

    Van Paepegem, W.; Shulev, A.; Moentjens, A.; Harizanova, J.; Degrieck, J.; Sainov, V.

    2008-07-01

    For the new generation aircraft families, the use of fibre-reinforced plastics is considered for the leading edge of the wings. However, this leading edge is very prone to bird strike impact. This paper presents the use of the projection moiré technique to measure the instantaneous out-of-plane deflections of composite plates subject to bird strike. Very strict constraints with regard to (i) high-speed image acquisition, (ii) vibrations of the impact chamber, and (iii) projection and observation angles, complicated substantially the development of the set-up. Moreover, the high frame rates (12,000 fps) required a very intensive illumination. In the optimized configuration, a specially designed grating with gradually changing period is projected by means of special halide hydride lamps through one of the side windows of the impact chamber onto the composite plate riveted in a steel frame. The digital high-speed camera is mounted on the roof of the impact chamber and records through a mirror the object surface with the projected fringe pattern on it. Numerical routines based on local Fourier transform were developed to process the digital images to extract the phase and the out-of-plane displacements. The phase evaluation is possible due to the carrier frequency nature of the projected moiré pattern. This carrier frequency allows separation of the unwanted additive and multiplicative fringe pattern components in the frequency domain via the application of a proper mask. The numerical calculations were calibrated for the bird strike on an aluminum plate, where the plastic deformation could be checked after the test.

  16. Accurate measurement of relative tilt and azimuth angles in electron tomography: A comparison of fiducial marker method with electron diffraction

    NASA Astrophysics Data System (ADS)

    Hayashida, Misa; Malac, Marek; Bergen, Michael; Egerton, Ray F.; Li, Peng

    2014-08-01

    Electron tomography is a method whereby a three-dimensional reconstruction of a nanoscale object is obtained from a series of projected images measured in a transmission electron microscope. We developed an electron-diffraction method to measure the tilt and azimuth angles, with Kikuchi lines used to align a series of diffraction patterns obtained with each image of the tilt series. Since it is based on electron diffraction, the method is not affected by sample drift and is not sensitive to sample thickness, whereas tilt angle measurement and alignment using fiducial-marker methods are affected by both sample drift and thickness. The accuracy of the diffraction method benefits reconstructions with a large number of voxels, where both high spatial resolution and a large field of view are desired. The diffraction method allows both the tilt and azimuth angle to be measured, while fiducial marker methods typically treat the tilt and azimuth angle as an unknown parameter. The diffraction method can be also used to estimate the accuracy of the fiducial marker method, and the sample-stage accuracy. A nano-dot fiducial marker measurement differs from a diffraction measurement by no more than ±1°.

  17. Accurate measurement of relative tilt and azimuth angles in electron tomography: A comparison of fiducial marker method with electron diffraction

    SciTech Connect

    Hayashida, Misa; Malac, Marek; Egerton, Ray F.; Bergen, Michael; Li, Peng

    2014-08-15

    Electron tomography is a method whereby a three-dimensional reconstruction of a nanoscale object is obtained from a series of projected images measured in a transmission electron microscope. We developed an electron-diffraction method to measure the tilt and azimuth angles, with Kikuchi lines used to align a series of diffraction patterns obtained with each image of the tilt series. Since it is based on electron diffraction, the method is not affected by sample drift and is not sensitive to sample thickness, whereas tilt angle measurement and alignment using fiducial-marker methods are affected by both sample drift and thickness. The accuracy of the diffraction method benefits reconstructions with a large number of voxels, where both high spatial resolution and a large field of view are desired. The diffraction method allows both the tilt and azimuth angle to be measured, while fiducial marker methods typically treat the tilt and azimuth angle as an unknown parameter. The diffraction method can be also used to estimate the accuracy of the fiducial marker method, and the sample-stage accuracy. A nano-dot fiducial marker measurement differs from a diffraction measurement by no more than ±1°.

  18. Effect of Surface Roughness on Contact Angle Measurement of Nanofluid on Surface of Stainless Steel 304 by Sessile Drop Method

    NASA Astrophysics Data System (ADS)

    Prajitno, D. H.; Maulana, A.; Syarif, D. G.

    2016-08-01

    Contact angles play an important role in the mass and heat transfer. Stainless steel 304 has been used for nuclear power plan structure material until now. An experiment to measure contact angle of demineralized aqua and nanofluid containing nano particle of zirconia on metal surface of stainless steel 304 with sessile drop method was conducted. The measurement to measure the static contact angle and drop of nano fluid containing nano particle zirconia on stainless steel with different surface roughness was carried out. It was observed that stainless steel 304 was good hydrophylic properties with decreasing surface roughness of stainless steel during drop of aqua demineralized and nano fluid respectively. As a result the contact angle of demineralized aqua is decreased from 97.39 to 78.42 and contact angle of nano fluid from 94.3 to 67.50, respectively with decreasing surface roughness of stainless stee 304. Wettability of nanofluid on surface stainless steel 304 is better than aqua demineralized.

  19. Street canyon flow patterns in a horizontal plane : measurements from the Joint URBAN 2003 field experiment

    SciTech Connect

    Brown, M. J.; Khalsa, H. S.; Nelson, M. A.; Boswell, D.

    2004-01-01

    As part of the larger Joint URBAN 2003 tracer field experiment performed in Oklahoma City from June 29 to July 30, 2003, a collaborative team of government and university researchers instrumented a downtown street canyon with a high density of wind sensor instrumentation (Brown et al., 2003). The goal of the Park Avenue street canyon experiment was to garner flow field information in order to better understand the transport and dispersion of tracers released in the street canyon and to test and improve the next generation of urban dispersion models. In this paper, we focus on describing the mean flow patterns that developed in the street canyon in a horizontal plane near the surface. We look at the patterns that develop over entire Intensive Operating Periods (IOP's) lasting from 6-9 hours in length, and as a function of inflow wind direction. Most prior street canyon experiments have generally focused on the vertical structure of the flow; this work contributes to the understanding of the horizontal nature of the flow.

  20. Chemical potential of water from measurements of optic axial angle of zeolites

    USGS Publications Warehouse

    Donald, Eberlein G.; Christ, C.L.

    1968-01-01

    Values of the uncorrected optic axial angle (2H??) of a crystal of the calcium zeolite stellerite (CaAl2Si7O 18 ?? 7H2O) immersed in calcium chloride solutions of known activity of water (aw) are directly proportional to log aw. A general relationship between the chemical potential of water in the crystal and the optic axial angle is obeyed.

  1. New optical sensing technique of tissue viability and blood flow based on nanophotonic iterative multi-plane reflectance measurements

    PubMed Central

    Yariv, Inbar; Haddad, Menashe; Duadi, Hamootal; Motiei, Menachem; Fixler, Dror

    2016-01-01

    Physiological substances pose a challenge for researchers since their optical properties change constantly according to their physiological state. Examination of those substances noninvasively can be achieved by different optical methods with high sensitivity. Our research suggests the application of a novel noninvasive nanophotonics technique, ie, iterative multi-plane optical property extraction (IMOPE) based on reflectance measurements, for tissue viability examination and gold nanorods (GNRs) and blood flow detection. The IMOPE model combines an experimental setup designed for recording light intensity images with the multi-plane iterative Gerchberg-Saxton algorithm for reconstructing the reemitted light phase and calculating its standard deviation (STD). Changes in tissue composition affect its optical properties which results in changes in the light phase that can be measured by its STD. We have demonstrated this new concept of correlating the light phase STD and the optical properties of a substance, using transmission measurements only. This paper presents, for the first time, reflectance based IMOPE tissue viability examination, producing a decrease in the computed STD for older tissues, as well as investigating their organic material absorption capability. Finally, differentiation of the femoral vein from adjacent tissues using GNRs and the detection of their presence within blood circulation and tissues are also presented with high sensitivity (better than computed tomography) to low quantities of GNRs (<3 mg). PMID:27785024

  2. Accuracy of a Custom Physical Activity and Knee Angle Measurement Sensor System for Patients with Neuromuscular Disorders and Gait Abnormalities

    PubMed Central

    Feldhege, Frank; Mau-Moeller, Anett; Lindner, Tobias; Hein, Albert; Markschies, Andreas; Zettl, Uwe Klaus; Bader, Rainer

    2015-01-01

    Long-term assessment of ambulatory behavior and joint motion are valuable tools for the evaluation of therapy effectiveness in patients with neuromuscular disorders and gait abnormalities. Even though there are several tools available to quantify ambulatory behavior in a home environment, reliable measurement of joint motion is still limited to laboratory tests. The aim of this study was to develop and evaluate a novel inertial sensor system for ambulatory behavior and joint motion measurement in the everyday environment. An algorithm for behavior classification, step detection, and knee angle calculation was developed. The validation protocol consisted of simulated daily activities in a laboratory environment. The tests were performed with ten healthy subjects and eleven patients with multiple sclerosis. Activity classification showed comparable performance to commercially available activPAL sensors. Step detection with our sensor system was more accurate. The calculated flexion-extension angle of the knee joint showed a root mean square error of less than 5° compared with results obtained using an electro-mechanical goniometer. This new system combines ambulatory behavior assessment and knee angle measurement for long-term measurement periods in a home environment. The wearable sensor system demonstrated high validity for behavior classification and knee joint angle measurement in a laboratory setting. PMID:25954954

  3. A Wireless Swing Angle Measurement Scheme Using Attitude Heading Reference System Sensing Units Based on Microelectromechanical Devices

    PubMed Central

    Gao, Bingtuan; Zhu, Zhenyu; Zhao, Jianguo; Huang, Boran

    2014-01-01

    Feasible real-time swing angle measurement is significant to improve the efficiency and safety of industrial crane systems. This paper presents a wireless microelectromechanical system (MEMS)-based swing angle measurement system. The system consists of two attitude heading reference system (AHRS) sensing units with a wireless communication function, which are mounted on the hook (or payload) and the jib (or base) of the crane, respectively. With a combination of a three-axis accelerometer, a three-axis gyroscope and a three-axis magnetometer, the standard extended Kalman filter (EKF) is used to estimate the desired orientation of the payload and the base. Wireless ZigBee communication is employed to transmit the orientation of the payload to the sensing unit mounted on the base, which measures the orientation of the base. Because several physical parameters from the payload to the base can be acquired from the original crane control system, the swing angles of the payload can be calculated based on the two measured orientation parameters together with the known physical parameters. Experiments were performed to show the feasibility and effectiveness of the proposed swing angle measurement system. PMID:25436657

  4. Accuracy of a custom physical activity and knee angle measurement sensor system for patients with neuromuscular disorders and gait abnormalities.

    PubMed

    Feldhege, Frank; Mau-Moeller, Anett; Lindner, Tobias; Hein, Albert; Markschies, Andreas; Zettl, Uwe Klaus; Bader, Rainer

    2015-05-06

    Long-term assessment of ambulatory behavior and joint motion are valuable tools for the evaluation of therapy effectiveness in patients with neuromuscular disorders and gait abnormalities. Even though there are several tools available to quantify ambulatory behavior in a home environment, reliable measurement of joint motion is still limited to laboratory tests. The aim of this study was to develop and evaluate a novel inertial sensor system for ambulatory behavior and joint motion measurement in the everyday environment. An algorithm for behavior classification, step detection, and knee angle calculation was developed. The validation protocol consisted of simulated daily activities in a laboratory environment. The tests were performed with ten healthy subjects and eleven patients with multiple sclerosis. Activity classification showed comparable performance to commercially available activPAL sensors. Step detection with our sensor system was more accurate. The calculated flexion-extension angle of the knee joint showed a root mean square error of less than 5° compared with results obtained using an electro-mechanical goniometer. This new system combines ambulatory behavior assessment and knee angle measurement for long-term measurement periods in a home environment. The wearable sensor system demonstrated high validity for behavior classification and knee joint angle measurement in a laboratory setting.

  5. Angle-independent measure of motion for image-based gating in 3D coronary angiography

    SciTech Connect

    Lehmann, Glen C.; Holdsworth, David W.; Drangova, Maria

    2006-05-15

    The role of three-dimensional (3D) image guidance for interventional procedures and minimally invasive surgeries is increasing for the treatment of vascular disease. Currently, most interventional procedures are guided by two-dimensional x-ray angiography, but computed rotational angiography has the potential to provide 3D geometric information about the coronary arteries. The creation of 3D angiographic images of the coronary arteries requires synchronization of data acquisition with respect to the cardiac cycle, in order to minimize motion artifacts. This can be achieved by inferring the extent of motion from a patient's electrocardiogram (ECG) signal. However, a direct measurement of motion (from the 2D angiograms) has the potential to improve the 3D angiographic images by ensuring that only projections acquired during periods of minimal motion are included in the reconstruction. This paper presents an image-based metric for measuring the extent of motion in 2D x-ray angiographic images. Adaptive histogram equalization was applied to projection images to increase the sharpness of coronary arteries and the superior-inferior component of the weighted centroid (SIC) was measured. The SIC constitutes an image-based metric that can be used to track vessel motion, independent of apparent motion induced by the rotational acquisition. To evaluate the technique, six consecutive patients scheduled for routine coronary angiography procedures were studied. We compared the end of the SIC rest period ({rho}) to R-waves (R) detected in the patient's ECG and found a mean difference of 14{+-}80 ms. Two simultaneous angular positions were acquired and {rho} was detected for each position. There was no statistically significant difference (P=0.79) between {rho} in the two simultaneously acquired angular positions. Thus we have shown the SIC to be independent of view angle, which is critical for rotational angiography. A preliminary image-based gating strategy that employed the SIC

  6. Time-domain effects of rigid sphere scattering on measurement of transient plane waves.

    PubMed

    Muhlestein, Michael B; Thomas, Derek C; Gee, Kent L

    2014-07-01

    Transient waves, like all other acoustic waves, will diffract around solid objects, such as measurement instrumentation. A derivation of an impulse response function on the surface of a rigid sphere, based on linear, classical scattering theory, is presented. The theoretical impulse response function is validated using an experiment with blast noise. An application of the impulse response function to a rocket noise measurement is discussed. The impulse response function shows that the presence of the rigid sphere significantly affects the measurement and estimation of rocket-noise waveforms, power spectral densities, and statistical measures. PMID:24993191

  7. Understanding properties of engineered catalyst supports using contact angle measurements and X-Ray reflectivity

    NASA Astrophysics Data System (ADS)

    Amama, Placidus B.; Islam, Ahmad E.; Saber, Sammy M.; Huffman, Daniel R.; Maruyama, Benji

    2016-01-01

    There is significant interest in broadening the type of catalyst substrates that support the growth of high-quality carbon nanotube (CNT) carpets. In this study, ion beam bombardment has been utilized to modify catalyst substrates for CNT carpet growth. Using a combination of contact angle measurements (CAMs) and X-ray reflectivity (XRR) for the first time, new correlations between the physicochemical properties of pristine and engineered catalyst substrates and CNT growth behavior have been established. The engineered surfaces obtained after exposure to different degrees of ion beam damage have distinct physicochemical properties (porosity, layer thickness, and acid-base properties). The CAM data were analyzed using the van Oss-Chaudhury-Good model, enabling the determination of the acid-base properties of the substrate surfaces. For the XRR data, a Fourier analysis of the interference patterns enabled extraction of layer thickness, while the atomic density and interfacial roughness were extracted by analyzing the amplitude of the interference oscillations. The dramatic transformation of the substrate from ``inactive'' to ``active'' is attributed to a combined effect of substrate porosity or damage depth and Lewis basicity. The results reveal that the efficiency of catalyst substrates can be further improved by increasing the substrate basicity, if the minimum surface porosity is established. This study advances the use of a non-thermochemical approach for catalyst substrate engineering, as well as demonstrates the combined utility of CAM and XRR as a powerful, nondestructive, and reliable tool for rational catalyst design.There is significant interest in broadening the type of catalyst substrates that support the growth of high-quality carbon nanotube (CNT) carpets. In this study, ion beam bombardment has been utilized to modify catalyst substrates for CNT carpet growth. Using a combination of contact angle measurements (CAMs) and X-ray reflectivity (XRR) for the

  8. Simulation Study of the Direct Measurement of the Pitch Angle Scattering of Energetic Electrons by Whistler-Mode Chorus Emissions

    NASA Astrophysics Data System (ADS)

    Kitahara, M.; Katoh, Y.; Kojima, H.; Omura, Y.

    2014-12-01

    Wave-Particle Interaction Analyzer (WPIA), which is a new instrumentation proposed by Fukuhara et al. (2009), measures a relative phase angle between a wave magnetic field vector and a velocity vector of each particle and calculates the energy exchange from waves to particles. The WPIA has a potential to directly detect wave-particle interactions in space plasmas and will be installed on the ERG satellite of JAXA/ISAS. In the present study, in addition to the energy exchange proposed by Fukuhara et al. (2009), we propose the direct measurement of the pitch angle scattering of resonant particles by plasma waves via the WPIA by computing the Lorentz force of wave electromagnetic fields acting on each particle. We apply the proposed method to results of the one-dimensional electron hybrid simulation reproducing the generation of whistler-mode chorus emissions around the magnetic equator [Katoh and Omura, 2007]. By using the wave and particle data obtained at fixed observation points assumed in the simulation system, we analyze the Lorentz force acting on each particle and compute the averaged force in the whole simulation time, corresponding to 20,000 gyro periods. We use 200 keV electrons and the time, kinetic energy, and pitch angle resolutions of 500 gyro-periods, ±10%, and 1 degree, respectively, for the analysis of the averaged Lorentz force. In the result of the analysis, we obtain significant values for electrons in the kinetic energy and pitch angle ranges satisfying the cyclotron resonance condition with the reproduced chorus emissions. The obtained value is three times larger than the magnitude of perturbations in other pitch angle ranges. We compared the result of the analysis with the temporal variation of pitch angle distributions and wave spectra observed at fixed points in the simulation. While the pitch angle distribution varies similarly in both hemispheres, the obtained Lorentz force is only significant in the pitch angle range corresponding to the

  9. Bias and uncertainty in the absorption emission measurement of atomic sodium density in the SSME exit plane

    NASA Technical Reports Server (NTRS)

    Bauman, Leslie E.

    1990-01-01

    The measurement of atomic sodium concentration in the TTB 019 firing of April 1990 is significant in that it represents the first measurement of density at the exit plane of the space shuttle main engine. The knowledge of the sodium density, combined with the certainty that the exit plane of the plume is optically thin at the sodium D-line wavelengths, provides essential information for evaluation of diagnostic techniques using sodium atoms, such as resonant Doppler velocimetry for temperature, pressure, and velocity through high resolution fluorescent lineshape analysis. The technique used for the sodium atom line transmission (SALT) measurements is that of resonant absorption emission using a hollow cathode lamp as the reference source. Through the use of two-dimensional kinetic (TDK) predictions of temperature and density for the flight engine case and radiative transfer calculations, this line-of-sight spectrally integrated transmission indicates a sodium atom concentration, i.e., mole fraction, of 0.91e-10. The subject of this paper is the assumptions and measurement uncertainties tied into the calculation. Because of the narrow shape of the source emission, the uncertainties in the absorption profile could introduce considerable bias in the measurement. The following were investigated: (1) the inclusion of hyperfine splitting of the D-lines in the calculation; (2) the use of the flight engine predictions of plume temperature and density versus those for the large throat engine; (3) the assumption of a Gaussian, i.e., Doppler, distribution for the source radiance with a temperature of 400 K; (4) the use of atomic collisional shift and width values for the work by Jongerius; and (5) a Doppler shift for a 7 degree outward velocity vector at the plume edge. Also included in the study was the bias introduced by an uncertainty in the measurement of the D1/D2 line ratio in the source.

  10. Constraining variable density of ice shelves using wide-angle radar measurements

    NASA Astrophysics Data System (ADS)

    Drews, Reinhard; Brown, Joel; Matsuoka, Kenichi; Witrant, Emmanuel; Philippe, Morgane; Hubbard, Bryn; Pattyn, Frank

    2016-04-01

    The thickness of ice shelves, a basic parameter for mass balance estimates, is typically inferred using hydrostatic equilibrium, for which knowledge of the depth-averaged density is essential. The densification from snow to ice depends on a number of local factors (e.g., temperature and surface mass balance) causing spatial and temporal variations in density-depth profiles. However, direct measurements of firn density are sparse, requiring substantial logistical effort. Here, we infer density from radio-wave propagation speed using ground-based wide-angle radar data sets (10 MHz) collected at five sites on Roi Baudouin Ice Shelf (RBIS), Dronning Maud Land, Antarctica. We reconstruct depth to internal reflectors, local ice thickness, and firn-air content using a novel algorithm that includes traveltime inversion and ray tracing with a prescribed shape of the depth-density relationship. For the particular case of an ice-shelf channel, where ice thickness and surface slope change substantially over a few kilometers, the radar data suggest that firn inside the channel is about 5 % denser than outside the channel. Although this density difference is at the detection limit of the radar, it is consistent with a similar density anomaly reconstructed from optical televiewing, which reveals that the firn inside the channel is 4.7 % denser than that outside the channel. Hydrostatic ice thickness calculations used for determining basal melt rates should account for the denser firn in ice-shelf channels. The radar method presented here is robust and can easily be adapted to different radar frequencies and data-acquisition geometries.

  11. Measurement of in-plane magnetic relaxation in RE-123 coated conductors by use of scanning Hall probe microscopy

    NASA Astrophysics Data System (ADS)

    Shiohara, K.; Higashikawa, K.; Inoue, M.; Kiss, T.; Iijima, Y.; Saitoh, T.; Yoshizumi, M.; Izumi, T.

    2013-01-01

    We have investigated electric field criterion of in-plane critical current density in a coated conductor characterized by scanning Hall-probe microscopy (SHPM). From remanent field distribution and its relaxation measurements, we could obtain critical current distribution and induced electric field simultaneously by considering the Biot-Savart law and the Faraday’s law, respectively. These results lead us to evaluate a distribution of local critical current density and the corresponding criterion of electric field. As a result, it was found that the electric field criterion for the SHPM analysis was several orders lower than that used in the conventional 4-probe resistive method. However, the data point obtained by the SHPM shows good agreement with E-J curve analytically extended from the measurements by the 4-probe method. This means that we could characterize in-plane distribution of critical current density in a coated conductor at an electric field criterion quantitatively by this method in a nondestructive manner. These findings will be very important information since the uniformity of local critical current density in a coated conductor at extremely low electric fields is a key issue (1) especially for DC applications, (2) for quality control of coated conductors, and (3) for the standardization of the characterization of critical current among different methods.

  12. Polarization Methods of Measuring the Roll Angle of an Object in Motion in Radio Beacon Navigation Systems

    NASA Astrophysics Data System (ADS)

    Gulko, V. L.; Mescheryakov, A. A.

    2016-06-01

    Polarization methods of measuring the roll angle of an object in motion with the help of radio beacon systems are considered. The polarization properties of the beacon signals received on board the object and amplitude-phase processing of their orthogonal polarized components are used to accomplish this goal.

  13. Automated 3D quantitative assessment and measurement of alpha angles from the femoral head-neck junction using MR imaging

    NASA Astrophysics Data System (ADS)

    Xia, Ying; Fripp, Jurgen; Chandra, Shekhar S.; Walker, Duncan; Crozier, Stuart; Engstrom, Craig

    2015-10-01

    To develop an automated approach for 3D quantitative assessment and measurement of alpha angles from the femoral head-neck (FHN) junction using bone models derived from magnetic resonance (MR) images of the hip joint. Bilateral MR images of the hip joints were acquired from 30 male volunteers (healthy active individuals and high-performance athletes, aged 18-49 years) using a water-excited 3D dual echo steady state (DESS) sequence. In a subset of these subjects (18 water-polo players), additional True Fast Imaging with Steady-state Precession (TrueFISP) images were acquired from the right hip joint. For both MR image sets, an active shape model based algorithm was used to generate automated 3D bone reconstructions of the proximal femur. Subsequently, a local coordinate system of the femur was constructed to compute a 2D shape map to project femoral head sphericity for calculation of alpha angles around the FHN junction. To evaluate automated alpha angle measures, manual analyses were performed on anterosuperior and anterior radial MR slices from the FHN junction that were automatically reformatted using the constructed coordinate system. High intra- and inter-rater reliability (intra-class correlation coefficients  >  0.95) was found for manual alpha angle measurements from the auto-extracted anterosuperior and anterior radial slices. Strong correlations were observed between manual and automatic measures of alpha angles for anterosuperior (r  =  0.84) and anterior (r  =  0.92) FHN positions. For matched DESS and TrueFISP images, there were no significant differences between automated alpha angle measures obtained from the upper anterior quadrant of the FHN junction (two-way repeated measures ANOVA, F  <  0.01, p  =  0.98). Our automatic 3D method analysed MR images of the hip joints to generate alpha angle measures around the FHN junction circumference with very good reliability and reproducibility. This work has the

  14. Surface forces and drag coefficients of microspheres near a plane surface measured with optical tweezers.

    PubMed

    Schäffer, Erik; Nørrelykke, Simon F; Howard, Jonathon

    2007-03-27

    Optical tweezers are widely used to measure molecular forces in biology. Such measurements are often influenced by a nearby surface that can perturb both the calibration of the tweezers as well as the hydrodynamic forces acting on microspheres to which the biomolecules are attached. In this study, we have used a very stable optical tweezers setup employing a recently developed calibration method (Tolić-Nørrelykke, S. F.; Schäffer, E.; Howard, J.; Pavone, F. S.; Jülicher, F.; Flyvbjerg, H. Rev. Sci. Instrum. 2006, 77 (10), 103101) to determine how the calibration of the tweezers and the forces on the microspheres depend on the height above the surface. We show that the displacement sensitivity of the tweezers is modulated by a standing light wave between the microsphere and the surface. We measured the dependence of the drag coefficient on height and compared it to exact and closed-form solutions to the Navier-Stokes equations. Also, we measured the surface force gradients in different salt solutions and for different surface blocking methods. For a given blocking method, our data suggest that microspheres can experience attractive and/or repulsive forces close to surfaces. For example, a Teflon layer reduces attractive interactions, and the presence of casein can lead to long-range repulsive interactions. These measurements are a prerequisite for the accurate measurement of normal forces with respect to an interface that occur in biological molecules held between surfaces.

  15. High-precision topography measurement through accurate in-focus plane detection with hybrid digital holographic microscope and white light interferometer module.

    PubMed

    Liżewski, Kamil; Tomczewski, Sławomir; Kozacki, Tomasz; Kostencka, Julianna

    2014-04-10

    High-precision topography measurement of micro-objects using interferometric and holographic techniques can be realized provided that the in-focus plane of an imaging system is very accurately determined. Therefore, in this paper we propose an accurate technique for in-focus plane determination, which is based on coherent and incoherent light. The proposed method consists of two major steps. First, a calibration of the imaging system with an amplitude object is performed with a common autofocusing method using coherent illumination, which allows for accurate localization of the in-focus plane position. In the second step, the position of the detected in-focus plane with respect to the imaging system is measured with white light interferometry. The obtained distance is used to accurately adjust a sample with the precision required for the measurement. The experimental validation of the proposed method is given for measurement of high-numerical-aperture microlenses with subwavelength accuracy.

  16. Measurement of refractive-index change at a liquid-solid interface close to the critical angle.

    PubMed

    Martinelli, M; Gugliotti, M; Horowicz, R J

    2000-06-01

    We measured the refractive-index change on a liquid sample, using the reflection of a polarized Gaussian laser beam close to the angle of total reflection. We applied this technique to a solution of nickel (ii) phthalocyanine tetrasulfonated (NiPTS) in water-ethanol (1/1 v/v), in which the nonlinearity of the refractive index is due to optically induced thermal effects. We show that close to the angle of total reflection the sensitivity of this technique is four times bigger than at normal incidence. PMID:18345195

  17. Measurement of yarn twist based on backward light scattering and small-angle far-field diffraction

    NASA Astrophysics Data System (ADS)

    Pei, Z. G.; Tao, X. M.

    2015-12-01

    This paper presents a non-destructive, non-contact method for measuring the twist of a yarn based on light scattering and diffraction. The surface twist angle is measured by determining the direction of the line with the highest intensity on the backward light scattering pattern which is perpendicular to the surface fibers, which is verified by both theoretical analysis based on Beckmann’s scattering model and experiments. The yarn diameter is measured with good accuracy by using the small-angle far-field diffraction pattern of the yarn body. Yarn twist is then derived from the measured surface twist angle and yarn diameter. Further studies reveal that the measured yarn twists by the proposed method are comparable to those measured based on microscopic images of the yarn. This method requires no high-magnification optics and is able to pick up short-term variations of twist with less labor intensity, indicating its potential application in the on-line measuring of yarn twist and its distribution.

  18. Effect of measurement error on tests of density dependence of catchability for walleyes in northern Wisconsin angling and spearing fisheries

    USGS Publications Warehouse

    Hansen, M.J.; Beard, T.D.; Hewett, S.W.

    2005-01-01

    We sought to determine how much measurement errors affected tests of density dependence of spearing and angling catchability for walleye Sander vitreus by quantifying relationships between spearing and angling catch rates (catch/h) and walleye population density (number/acre) in northern Wisconsin lakes. The mean measurement error of spearing catch rates was 43.5 times greater than the mean measurement error of adult walleye population densities, whereas the mean measurement error of angling catch rates was only 5.6 times greater than the mean measurement error of adult walleye population densities. The bias-corrected estimate of the relationship between spearing catch rate and adult walleye population density was similar to the ordinary-least-squares regression estimate but differed significantly from the geometric mean (GM) functional regression estimate. In contrast, the bias-corrected estimate of the relationship between angling catch rate and total walleye population density was intermediate between ordinary-least-squares and GM functional regression estimates. Catch rates of walleyes in both spearing and angling fisheries were not linearly related to walleye population density, which indicated that catch rates in both fisheries were hyperstable in relation to walleye population density. For both fisheries, GM functional regression overestimated the degree of hyperdepletion in catch rates and ordinary-least-squares regression overestimated the degree of hyperstability in catch rates. However, ordinary-least-squares regression induced significantly less bias in tests of density dependence than GM functional regression, so it may be suitable for testing the degree of density dependence in fisheries for which fish population density is estimated with mark-recapture methods similar to those used in our study. ?? Copyright by the American Fisheries Society 2005.

  19. Models of the Membrane-Bound Cytochromes: Mössbauer Spectra of Crystalline Low-Spin Ferriheme Complexes Having Axial Ligand Plane Dihedral Angles Ranging from 0° to 90°

    PubMed Central

    Teschner, Thomas; Yatsunyk, Liliya; Schünemann, Volker; Paulsen, Hauke; Winkler, Heiner; Hu, Chuanjiang; Scheidt, W. Robert; Walker, F. Ann; Trautwein, Alfred X.

    2006-01-01

    Crystalline samples of four low-spin Fe(III) octaalkyltetraphenylporphyrinate and two low-spin Fe(III) tetramesitylporphyrinate complexes, all of which are models of the bis-histidine-coordinated cytochromes of mitochondrial complexes II, III and IV, and chloroplast complex b6f, and whose molecular structures and EPR spectra have been reported previously, have been investigated in detail by Mössbauer spectroscopy. The six complexes and the dihedral angles between axial ligand planes of each are [(TMP)Fe(1-MeIm)2]ClO4 (0°, paral-[(OMTPP)Fe(1-MeIm)2]Cl (19.5°, paral-[(TMP)Fe(5-MeHIm)2]ClO4 (26°, 30° for two molecules in the unit cell whose EPR spectra overlap), [(OETPP)Fe(4-Me2NPy)2]Cl (70°, perp-[(OETPP)Fe(1-MeIm)2]Cl (73°, and perp-[(OMTPP)Fe(1-MeIm)2]Cl (90°. Of these, the first three have been shown to exhibit normal rhombic EPR spectra with three clearly-resolved g-values, while the last three have been shown to exhibit “large gmax” EPR spectra at 4.2 K. It is found that the hyperfine coupling constants of the complexes are consistent with those reported previously for low-spin ferriheme systems, with the largest-magnitude hyperfine coupling constant, Azz, being considerably smaller for the “parallel” complexes (400-540 kG) than for the strictly perpendicular complex (902 kG), Axx being negative for all six complexes, and Azz and Axx being of similar magnitude for the “parallel” complexes (for example, for [(TMP)Fe(1-MeIm)2]Cl, Azz = 400 kG, Axx = - 400 kG), and finally, Ayy is small, but difficult to estimate with accuracy for all complexes. With results for six structurally-characterized model systems we find qualitative correlations of gzz, Azz, and △EQ with axial ligand plane dihedral angle △φ. PMID:16433558

  20. Auditory spatial resolution in horizontal, vertical, and diagonal planes.

    PubMed

    Grantham, D Wesley; Hornsby, Benjamin W Y; Erpenbeck, Eric A

    2003-08-01

    Minimum audible angle (MAA) and minimum audible movement angle (MAMA) thresholds were measured for stimuli in horizontal, vertical, and diagonal (60 degrees) planes. A pseudovirtual technique was employed in which signals were recorded through KEMAR's ears and played back to subjects through insert earphones. Thresholds were obtained for wideband, high-pass, and low-pass noises. Only 6 of 20 subjects obtained wideband vertical-plane MAAs less than 10 degrees, and only these 6 subjects were retained for the complete study. For all three filter conditions thresholds were lowest in the horizontal plane, slightly (but significantly) higher in the diagonal plane, and highest for the vertical plane. These results were similar in magnitude and pattern to those reported by Perrott and Saberi [J. Acoust. Soc. Am. 87, 1728-1731 (1990)] and Saberi and Perrott [J. Acoust. Soc. Am. 88, 2639-2644 (1990)], except that these investigators generally found that thresholds for diagonal planes were as good as those for the horizontal plane. The present results are consistent with the hypothesis that diagonal-plane performance is based on independent contributions from a horizontal-plane system (sensitive to interaural differences) and a vertical-plane system (sensitive to pinna-based spectral changes). Measurements of the stimuli recorded through KEMAR indicated that sources presented from diagonal planes can produce larger interaural level differences (ILDs) in certain frequency regions than would be expected based on the horizontal projection of the trajectory. Such frequency-specific ILD cues may underlie the very good performance reported in previous studies for diagonal spatial resolution. Subjects in the present study could apparently not take advantage of these cues in the diagonal-plane condition, possibly because they did not externalize the images to their appropriate positions in space or possibly because of the absence of a patterned visual field.

  1. The knee adduction moment during gait is associated with the adduction angle measured during computer-assisted total knee arthroplasty.

    PubMed

    Roda, Richard D; Wilson, Janie L Astephen; Wilson, David A J; Richardson, Glen; Dunbar, Michael J

    2012-06-01

    Computer-assisted surgery can be used to measure 3-dimensional knee function during arthroplasty surgery; however, it is unknown if the movement of the knee measured during surgery is related to the in vitro, dynamic state of the knee joint, specifically the knee adduction moment during gait, which has been related to implant migration. The purpose of this study was to determine if the preoperative adduction moment is correlated with the knee abduction/adduction angle measured intraoperatively. A statistically significant correlation was found between the mean (r(2) = 0.59; P = .001) and peak (r(2) = 0.53; P = .003) preoperative knee adduction moment and the mean abduction/adduction angle measured intraoperatively. The association found in this study suggests the potential for incorporating functional information that relates to surgical outcome into surgical decision making using computer-assisted surgery.

  2. Retrieval of aerosol properties over land surfaces: capabilities of multiple-viewing-angle intensity and polarization measurements

    NASA Astrophysics Data System (ADS)

    Hasekamp, Otto P.; Landgraf, Jochen

    2007-06-01

    We investigate the capabilities of different instrument concepts for the retrieval of aerosol properties over land. It was found that, if the surface reflection properties are unknown, only multiple-viewing-angle measurements of both intensity and polarization are able to provide the relevant aerosol parameters with sufficient accuracy for climate research. Furthermore, retrieval errors are only little affected when the number of viewing angles is increased at the cost of the number of spectral sampling points and vice versa. This indicates that there is a certain amount of freedom for the instrument design of dedicated aerosol instruments. The final choice on the trade-off between the spectral sampling and the number of viewing angles should be made taking other factors into account, such as instrument complexity and the ability to obtain global coverage.

  3. The impact of the detection angle on the quantitative measurement of hemoglobin oxygen saturation in optical-resolution photoacoustic microscopy

    NASA Astrophysics Data System (ADS)

    Wu, Ning; Li, Changhui

    2016-10-01

    Optical-resolution photoacoustic microscopy (OR-PAM) plays an important role in the quantitative measurement of hemoglobin oxygen saturation (SO2) at a single vessel level. In this study, we reported that the relative angle between light illumination and ultrasonic detection could have a significant impact on the SO2 measurement. Both simulation and phantom studies were provided, and this result will help the system design and result interpretation of the functional OR-PAM.

  4. Reliability and concurrent validity of knee angle measurement: smart phone app versus universal goniometer used by experienced and novice clinicians.

    PubMed

    Milanese, Steven; Gordon, Susan; Buettner, Petra; Flavell, Carol; Ruston, Sally; Coe, Damien; O'Sullivan, William; McCormack, Steven

    2014-12-01

    The use of goniometers to measure joint angles is a key part of musculoskeletal practice. Recently smartphone goniometry applications have become available to clinicians. This study examined the intra- and inter-measurer reliability of novice and experienced clinicians and the concurrent validity of assessing knee range of motion using a smartphone application (the Knee Goniometer App (Ockendon(©))) (KGA) and a standard universal goniometer (UG). Three clinicians, each with over seven years' experience as musculoskeletal physiotherapists and three final year physiotherapy students, measured 18 different knee joint angles three times, using both the universal goniometer and the smartphone goniometric application. The universal goniometer and the smartphone goniometric application were reliable in repeated measures of knee flexion angles (average Concordance Correlation Coefficient (CCC) > 0.98) with both experienced clinicians and final year physiotherapy students (average CCCs > 0.96). There were no significant differences in reliability between the experienced and the novice practitioners for either device. Agreement between the universal goniometer and smartphone goniometric application measurements was also high for all examiners with average CCCs all above 0.96. The Standard Error of Measurement ranged between 1.56° (0.52-2.66) for the UG and 0.62° (0.29-1.27) for the KGA. The universal goniometer and the smartphone goniometric application were reliable in repeated measures of knee flexion angles. Smaller error of measurement values for the smartphone goniometric application might indicate superiority for assessment where clinical situations demand greater precision of knee range of motion.

  5. Simultaneous measurement of contact angle and surface tension using axisymmetric drop-shape analysis-no apex (ADSA-NA).

    PubMed

    Kalantarian, A; David, R; Chen, J; Neumann, A W

    2011-04-01

    Axisymmetric drop-shape analysis-no apex (ADSA-NA) is a recent drop-shape method that allows the simultaneous measurement of contact angles and surface tensions of drop configurations without an apex (i.e., a sessile drop with a capillary protruding into the drop). Although ADSA-NA significantly enhanced the accuracy of contact angle and surface tension measurements compared to that of original ADSA using a drop with an apex, it is still not as accurate as a surface tension measurement using a pendant drop suspended from a holder. In this article, the computational and experimental aspects of ADSA-NA were scrutinized to improve the accuracy of the simultaneous measurement of surface tensions and contact angles. It was found that the results are relatively insensitive to different optimization methods and edge detectors. The precision of contact angle measurement was enhanced by improving the location of the contact points of the liquid meniscus with the solid substrate to subpixel resolution. To optimize the experimental design, the capillary was replaced with an inverted sharp-edged pedestal, or holder, to control the drop height and to ensure the axisymmetry of the drops. It was shown that the drop height is the most important experimental parameter affecting the accuracy of the surface tension measurement, and larger drop heights yield lower surface tension errors. It is suggested that a minimum nondimensional drop height (drop height divided by capillary length) of 1.7 is required to reach an error of less than 0.2 mJ/m(2) for the measured surface tension. As an example, the surface tension of water was measured to be 72.46 ± 0.04 at 24 °C by ADSA-NA, compared to 72.39 ± 0.01 mJ/m(2) obtained with pendant drop experiments.

  6. Correlation between Extraocular Muscle Size Measured by Computed Tomography and the Vertical Angle of Deviation in Thyroid Eye Disease.

    PubMed

    Lee, Ju-Yeun; Bae, Kunho; Park, Kyung-Ah; Lyu, In Jeong; Oh, Sei Yeul

    2016-01-01

    The aim of this study was to investigate extraocular muscle (EOM) volume and cross-sectional area using computed tomography (CT), and to determine the relationship between EOM size and the vertical angle of deviation in thyroid eye disease (TED). Twenty-nine TED patients (58 orbits) with vertical strabismus were enrolled in the study. All patients underwent complete ophthalmic examination including prism, alternate cover, and Krimsky tests. Orbital CT scans were also performed on each patient. Digital image analysis was used to quantify superior rectus (SR) and inferior rectus (IR) muscle cross-sectional areas and volumes. Measurements were compared with those of controls. The correlation between muscle size and degree of vertical angle deviation was evaluated. The mean vertical angle of deviation was 26.2 ± 4.1 prism diopters. The TED group had a greater maximum cross-sectional area and EOM volume in the SR and IR than the control group (all p<0.001). Area and volume of the IR were correlated with the angle of deviation, but the SR alone did not show a significant correlation. The maximum cross-sectional area and volume of [Right IR + Left SR - Right SR - Left IR] was strongly correlated with the vertical angle of deviation (P<0.001). Quantitative CT of the orbit with evaluation of the area and volume of EOMs may be helpful in anticipating and monitoring vertical strabismus in TED patients.

  7. Anthropometric Measurements as Predictors of the Degree of Carrying Angle in College Baseball Players

    ERIC Educational Resources Information Center

    Cox, Chris

    2011-01-01

    Scope and Method of Study: The goal of this study was to examine whether or not height, shoulder range of motion, hip width, shoulder width, and pitching experience were predictors for increased carrying angle of the throwing side. The premise of the study is based on an assumption that valgus extension overload produces tensile strain on the…

  8. Measurement of the in-plane ion flow and space potential profiles in the diffusion region of magnetic reconnection

    NASA Astrophysics Data System (ADS)

    Yoo, J.; Yamada, M.; Stein, G.; Ji, H.; Tharp, T.

    2011-12-01

    The Magnetic Reconnection Experiment (MRX) is a toroidal device dedicated to the study of magnetic reconnection in the laboratory. Here, we have modified the standard operation of MRX to include additional internal Shaping Field coils which control the current sheet motion. Controlled sweeping of the current sheet enables us to measure radial profiles of various physical quantities across the diffusion region with probes that contain only a single measurement point. With the help of this current sheet jogging, in-plane ion velocity and electric field profiles are measured using 5-tip Langmuir-Mach probe assemblies. The ion outflow is measured to reach speeds up to 40 km/s, about the half of the Alfven velocity. The electric field is simultaneously measured and points downstream (in the outflow direction) with a magnitude of 300-700 V/m. Radial floating potential profiles are measured using a floating potential array and additional Langmuir probes. Similar to those seen in numerical simulations and space observations, potential wells develop across the diffusion region. The potential well becomes deeper and broader further downstream in the outflow direction: the magnitude of the potential well is about 10-15V at the center and 15-35V downstream. The magnitude of this potential well is related to the dip in the sum of magnetic pressure and electron pressure, indicating ions are heated by the potential well.

  9. Generalized in-line digital holographic technique based on intensity measurements at two different planes

    NASA Astrophysics Data System (ADS)

    Situ, Guohai; Ryle, James P.; Gopinathan, Unnikrishnan; Sheridan, John T.

    2008-02-01

    In-line digital holography based on two-intensity measurements [Zhang et al. Opt. Lett. 29, 1787 (2004)], is modified by introducing a π shifting in the reference phase. Such an improvement avoids the assumption that the object beam must be much weaker than the reference beam in strength and results in a simplified experimental implementation. Computer simulations and optical experiments are carried out to validate the method, which we refer to as position-phase-shifting digital holography.

  10. Perception of Perspective Angles.

    PubMed

    Erkelens, Casper J

    2015-06-01

    We perceive perspective angles, that is, angles that have an orientation in depth, differently from what they are in physical space. Extreme examples are angles between rails of a railway line or between lane dividers of a long and straight road. In this study, subjects judged perspective angles between bars lying on the floor of the laboratory. Perspective angles were also estimated from pictures taken from the same point of view. Converging and diverging angles were judged to test three models of visual space. Four subjects evaluated the perspective angles by matching them to nonperspective angles, that is, angles between the legs of a compass oriented in the frontal plane. All subjects judged both converging and diverging angles larger than the physical angle and smaller than the angles in the proximal stimuli. A model of shallow visual space describes the results. According to the model, lines parallel to visual lines, vanishing at infinity in physical space, converge to visual lines in visual space. The perceived shape of perspective angles is incompatible with the perceived length and width of the bars. The results have significance for models of visual perception and practical implications for driving and flying in poor visibility conditions. PMID:27433312

  11. Modeling and Analysis of Phase Fluctuation in a High-Precision Roll Angle Measurement Based on a Heterodyne Interferometer.

    PubMed

    Huang, Junhui; Wang, Zhao; Gao, Jianmin; Yu, Bao

    2016-01-01

    Heterodyne interferometry is a high-precision method applied in roll angle measurements. Phase metering is essential for high precision. During a high-precision measurement, a phase fluctuation appears even when the roll angle does not vary, which has never been analyzed before. Herein, the reason for the phase fluctuation is revealed, which results from the frequency-difference fluctuation and time difference between measurement and reference beams. A mathematical model of that phase-fluctuation mechanism is established, and that model provides a theoretical basis for analyzing and reducing the phase fluctuation. The impact that the main factors have on the phase metering is analyzed quantitatively, and experiments are carried out to validate the model. Finally, the phase fluctuation decreases to 0.02° by frequency reduction, which conversely verifies the theoretical model. PMID:27490552

  12. Measurement of the Effective Weak Mixing Angle in pp[over ¯]→Z/γ^{*}→e^{+}e^{-} Events.

    PubMed

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

    2015-07-24

    We present a measurement of the fundamental parameter of the standard model, the weak mixing angle sin^{2}θ_{eff}^{ℓ} which determines the relative strength of weak and electromagnetic interactions, in pp[over ¯]→Z/γ^{*}→e^{+}e^{-} events at a center of mass energy of 1.96 TeV, using data corresponding to 9.7 fb^{-1} of integrated luminosity collected by the D0 detector at the Fermilab Tevatron. The effective weak mixing angle is extracted from the forward-backward charge asymmetry as a function of the invariant mass around the Z boson pole. The measured value of sin^{2}θ_{eff}^{ℓ}=0.23147±0.00047 is the most precise measurement from light quark interactions to date, with a precision close to the best LEP and SLD results.

  13. Modeling and Analysis of Phase Fluctuation in a High-Precision Roll Angle Measurement Based on a Heterodyne Interferometer

    PubMed Central

    Huang, Junhui; Wang, Zhao; Gao, Jianmin; Yu, Bao

    2016-01-01

    Heterodyne interferometry is a high-precision method applied in roll angle measurements. Phase metering is essential for high precision. During a high-precision measurement, a phase fluctuation appears even when the roll angle does not vary, which has never been analyzed before. Herein, the reason for the phase fluctuation is revealed, which results from the frequency-difference fluctuation and time difference between measurement and reference beams. A mathematical model of that phase-fluctuation mechanism is established, and that model provides a theoretical basis for analyzing and reducing the phase fluctuation. The impact that the main factors have on the phase metering is analyzed quantitatively, and experiments are carried out to validate the model. Finally, the phase fluctuation decreases to 0.02° by frequency reduction, which conversely verifies the theoretical model. PMID:27490552

  14. Measurement of the Effective Weak Mixing Angle in p p ¯→Z /γ*→e+e- Events

    NASA Astrophysics Data System (ADS)

    Abazov, V. M.; Abbott, B.; Acharya, B. S.; Adams, M.; Adams, T.; Agnew, J. P.; Alexeev, G. D.; Alkhazov, G.; Alton, A.; Askew, A.; Atkins, S.; Augsten, K.; Avila, C.; Badaud, F.; Bagby, L.; Baldin, B.; Bandurin, D. V.; Banerjee, S.; Barberis, E.; Baringer, P.; Bartlett, J. F.; Bassler, U.; Bazterra, V.; Bean, A.; Begalli, M.; Bellantoni, L.; Beri, S. B.; Bernardi, G.; Bernhard, R.; Bertram, I.; Besançon, M.; Beuselinck, R.; Bhat, P. C.; Bhatia, S.; Bhatnagar, V.; Blazey, G.; Blessing, S.; Bloom, K.; Boehnlein, A.; Boline, D.; Boos, E. E.; Borissov, G.; Borysova, M.; Brandt, A.; Brandt, O.; Brock, R.; Bross, A.; Brown, D.; Bu, X. B.; Buehler, M.; Buescher, V.; Bunichev, V.; Burdin, S.; Buszello, C. P.; Camacho-Pérez, E.; Casey, B. C. K.; Castilla-Valdez, H.; Caughron, S.; Chakrabarti, S.; Chan, K. M.; Chandra, A.; Chapon, E.; Chen, G.; Cho, S. W.; Choi, S.; Choudhary, B.; Cihangir, S.; Claes, D.; Clutter, J.; Cooke, M.; Cooper, W. E.; Corcoran, M.; Couderc, F.; Cousinou, M.-C.; Cutts, D.; Das, A.; Davies, G.; de Jong, S. J.; De La Cruz-Burelo, E.; Déliot, F.; Demina, R.; Denisov, D.; Denisov, S. P.; Desai, S.; Deterre, C.; DeVaughan, K.; Diehl, H. T.; Diesburg, M.; Ding, P. F.; Dominguez, A.; Dubey, A.; Dudko, L. V.; Duperrin, A.; Dutt, S.; Eads, M.; Edmunds, D.; Ellison, J.; Elvira, V. D.; Enari, Y.; Evans, H.; Evdokimov, V. N.; Fauré, A.; Feng, L.; Ferbel, T.; Fiedler, F.; Filthaut, F.; Fisher, W.; Fisk, H. E.; Fortner, M.; Fox, H.; Fuess, S.; Garbincius, P. H.; Garcia-Bellido, A.; García-González, J. A.; Gavrilov, V.; Geng, W.; Gerber, C. E.; Gershtein, Y.; Ginther, G.; Gogota, O.; Golovanov, G.; Grannis, P. D.; Greder, S.; Greenlee, H.; Grenier, G.; Gris, Ph.; Grivaz, J.-F.; Grohsjean, A.; Grünendahl, S.; Grünewald, M. W.; Guillemin, T.; Gutierrez, G.; Gutierrez, P.; Haley, J.; Han, L.; Harder, K.; Harel, A.; Hauptman, J. M.; Hays, J.; Head, T.; Hebbeker, T.; Hedin, D.; Hegab, H.; Heinson, A. P.; Heintz, U.; Hensel, C.; Heredia-De La Cruz, I.; Herner, K.; Hesketh, G.; Hildreth, M. D.; Hirosky, R.; Hoang, T.; Hobbs, J. D.; Hoeneisen, B.; Hogan, J.; Hohlfeld, M.; Holzbauer, J. L.; Howley, I.; Hubacek, Z.; Hynek, V.; Iashvili, I.; Ilchenko, Y.; Illingworth, R.; Ito, A. S.; Jabeen, S.; Jaffré, M.; Jayasinghe, A.; Jeong, M. S.; Jesik, R.; Jiang, P.; Johns, K.; Johnson, E.; Johnson, M.; Jonckheere, A.; Jonsson, P.; Joshi, J.; Jung, A. W.; Juste, A.; Kajfasz, E.; Karmanov, D.; Katsanos, I.; Kaur, M.; Kehoe, R.; Kermiche, S.; Khalatyan, N.; Khanov, A.; Kharchilava, A.; Kharzheev, Y. N.; Kiselevich, I.; Kohli, J. M.; Kozelov, A. V.; Kraus, J.; Kumar, A.; Kupco, A.; Kurča, T.; Kuzmin, V. A.; Lammers, S.; Lebrun, P.; Lee, H. S.; Lee, S. W.; Lee, W. M.; Lei, X.; Lellouch, J.; Li, D.; Li, H.; Li, L.; Li, Q. Z.; Lim, J. K.; Lincoln, D.; Linnemann, J.; Lipaev, V. V.; Lipton, R.; Liu, H.; Liu, Y.; Lobodenko, A.; Lokajicek, M.; Lopes de Sa, R.; Luna-Garcia, R.; Lyon, A. L.; Maciel, A. K. A.; Madar, R.; Magaña-Villalba, R.; Malik, S.; Malyshev, V. L.; Mansour, J.; Martínez-Ortega, J.; McCarthy, R.; McGivern, C. L.; Meijer, M. M.; Melnitchouk, A.; Menezes, D.; Mercadante, P. G.; Merkin, M.; Meyer, A.; Meyer, J.; Miconi, F.; Mondal, N. K.; Mulhearn, M.; Nagy, E.; Narain, M.; Nayyar, R.; Neal, H. A.; Negret, J. P.; Neustroev, P.; Nguyen, H. T.; Nunnemann, T.; Orduna, J.; Osman, N.; Osta, J.; Pal, A.; Parashar, N.; Parihar, V.; Park, S. K.; Partridge, R.; Parua, N.; Patwa, A.; Penning, B.; Perfilov, M.; Peters, Y.; Petridis, K.; Petrillo, G.; Pétroff, P.; Pleier, M.-A.; Podstavkov, V. M.; Popov, A. V.; Prewitt, M.; Price, D.; Prokopenko, N.; Qian, J.; Quadt, A.; Quinn, B.; Ratoff, P. N.; Razumov, I.; Ripp-Baudot, I.; Rizatdinova, F.; Rominsky, M.; Ross, A.; Royon, C.; Rubinov, P.; Ruchti, R.; Sajot, G.; Sánchez-Hernández, A.; Sanders, M. P.; Santos, A. S.; Savage, G.; Savitskyi, M.; Sawyer, L.; Scanlon, T.; Schamberger, R. D.; Scheglov, Y.; Schellman, H.; Schwanenberger, C.; Schwienhorst, R.; Sekaric, J.; Severini, H.; Shabalina, E.; Shary, V.; Shaw, S.; Shchukin, A. A.; Simak, V.; Skubic, P.; Slattery, P.; Smirnov, D.; Snow, G. R.; Snow, J.; Snyder, S.; Söldner-Rembold, S.; Sonnenschein, L.; Soustruznik, K.; Stark, J.; Stoyanova, D. A.; Strauss, M.; Suter, L.; Svoisky, P.; Titov, M.; Tokmenin, V. V.; Tsai, Y.-T.; Tsybychev, D.; Tuchming, B.; Tully, C.; Uvarov, L.; Uvarov, S.; Uzunyan, S.; Van Kooten, R.; van Leeuwen, W. M.; Varelas, N.; Varnes, E. W.; Vasilyev, I. A.; Verkheev, A. Y.; Vertogradov, L. S.; Verzocchi, M.; Vesterinen, M.; Vilanova, D.; Vokac, P.; Wahl, H. D.; Wang, M. H. L. S.; Warchol, J.; Watts, G.; Wayne, M.; Weichert, J.; Welty-Rieger, L.; Williams, M. R. J.; Wilson, G. W.; Wobisch, M.; Wood, D. R.; Wyatt, T. R.; Xie, Y.; Yamada, R.; Yang, S.; Yasuda, T.; Yatsunenko, Y. A.; Ye, W.; Ye, Z.; Yin, H.; Yip, K.; Youn, S. W.; Yu, J. M.; Zennamo, J.; Zhao, T. G.; Zhou, B.; Zhu, J.; Zielinski, M.; Zieminska, D.; Zivkovic, L.; D0 Collaboration

    2015-07-01

    We present a measurement of the fundamental parameter of the standard model, the weak mixing angle sin2θeffℓ which determines the relative strength of weak and electromagnetic interactions, in p p ¯ →Z /γ*→e+e- events at a center of mass energy of 1.96 TeV, using data corresponding to 9.7 fb-1 of integrated luminosity collected by the D0 detector at the Fermilab Tevatron. The effective weak mixing angle is extracted from the forward-backward charge asymmetry as a function of the invariant mass around the Z boson pole. The measured value of sin2θeffℓ =0.23147 ±0.00047 is the most precise measurement from light quark interactions to date, with a precision close to the best LEP and SLD results.

  15. Measurement of the Effective Weak Mixing Angle inpp¯→Z/γ*→e+e-Events

    DOE PAGES

    Abazov, V.  M.; Abbott, B.; Acharya, B.  S.; Adams, M.; Adams, T.; Agnew, J.  P.; Alexeev, G.  D.; Alkhazov, G.; Alton, A.; Askew, A.; et al

    2015-07-22

    We present a measurement of the fundamental parameter of the standard model, the weak mixing angle sin2θℓeff which determines the relative strength of weak and electromagnetic interactions, in pp¯→Z/γ*→e+e- events at a center of mass energy of 1.96 TeV, using data corresponding to 9.7 fb-1 of integrated luminosity collected by the D0 detector at the Fermilab Tevatron. The effective weak mixing angle is extracted from the forward-backward charge asymmetry as a function of the invariant mass around the Z boson pole. The measured value of sin2θℓeff=0.23147±0.00047 is the most precise measurement from light quark interactions to date, with a precisionmore » close to the best LEP and SLD results.« less

  16. Simple method to measure power density entering a plane biological sample at millimeter wavelengths.

    PubMed

    Shen, Z Y; Birenbaum, L; Chu, A; Motzkin, S; Rosenthal, S; Sheng, K M

    1987-01-01

    A simple method for measuring microwave power density is described. It is applicable to situations where exposure of samples in the near field of a horn is necessary. A transmitted power method is used to calibrate the power density entering the surface of the sample. Once the calibration is available, the power density is known in terms of the incident and reflected powers within the waveguide. The calibration has been carried out for liquid samples in a quartz cell. Formulas for calculating specific absorption rate (SAR) are derived in terms of the power density and the complex dielectric constant of the sample. An error analysis is also given.

  17. Cremated human remains: is measurement of the lateral angle of the meatus acusticus internus a reliable method of sex determination?

    PubMed

    Masotti, Sabrina; Succi-Leonelli, Elisa; Gualdi-Russo, Emanuela

    2013-09-01

    The purpose of this study was to evaluate the lateral angle (LA) method-based on the measurement of the angle at which the internal acoustic canal opens up to the surface of the petrous bone-for sex determination in cremated skeletal remains of Italians. The sample consisted of 160 adult individuals of known age and sex who had recently died and were cremated in the crematorium of Ferrara (northern Italy). Several studies have demonstrated that the petrous portion of the temporal bone may be a valuable tool for sex diagnosis in unburned skeletal remains. Since petrous bones are usually preserved after cremation, this method could be of particular interest in the case of burned skeletal remains. The repeatability of intra- and inter-observer measurements was good. The results indicated that male and female lateral angles were significantly different but that the values did not differ among age-groups. There was no bilateral difference in LA. However, neither the 45° angle, proposed in earlier studies as the sectioning point for this variable from male and female data distributions, nor another angular value allowed satisfactory discrimination between the sexes in our sample. The influence of the "age" factor (about 82 % of females were of ≥ 75 years of age) on the results is critically discussed. The results of this study suggest that the LA method is not sufficiently reliable to assess the sex of elderly Italian individuals from their burned remains and thus should only be used in conjunction with other sexing techniques.

  18. Complexity-Entropy Causality Plane as a Complexity Measure for Two-Dimensional Patterns

    PubMed Central

    Ribeiro, Haroldo V.; Zunino, Luciano; Lenzi, Ervin K.; Santoro, Perseu A.; Mendes, Renio S.

    2012-01-01

    Complexity measures are essential to understand complex systems and there are numerous definitions to analyze one-dimensional data. However, extensions of these approaches to two or higher-dimensional data, such as images, are much less common. Here, we reduce this gap by applying the ideas of the permutation entropy combined with a relative entropic index. We build up a numerical procedure that can be easily implemented to evaluate the complexity of two or higher-dimensional patterns. We work out this method in different scenarios where numerical experiments and empirical data were taken into account. Specifically, we have applied the method to fractal landscapes generated numerically where we compare our measures with the Hurst exponent; liquid crystal textures where nematic-isotropic-nematic phase transitions were properly identified; 12 characteristic textures of liquid crystals where the different values show that the method can distinguish different phases; and Ising surfaces where our method identified the critical temperature and also proved to be stable. PMID:22916097

  19. Measurements of the cross-phase angle between density and electron temperature fluctuations and comparison with gyrokinetic simulations

    SciTech Connect

    White, A. E.; Peebles, W. A.; Rhodes, T. L.; Schmitz, L.; Carter, T. A.; Hillesheim, J. C.; Doyle, E. J.; Zeng, L.; Holland, C. H.; Wang, G.; McKee, G. R.; Staebler, G. M.; Waltz, R. E.; DeBoo, J. C.; Petty, C. C.; Burrell, K. H.

    2010-05-15

    This paper presents new measurements of the cross-phase angle, alpha{sub n{sub eT{sub e}}}, between long-wavelength (k{sub t}hetarho{sub s}<0.5) density, n-tilde{sub e}, and electron temperature, T-tilde{sub e}, fluctuations in the core of DIII-D [J. L. Luxon, Nucl. Fusion 42, 614 (2002)] tokamak plasmas. The coherency and cross-phase angle between n-tilde{sub e} and T-tilde{sub e} are measured using coupled reflectometer and correlation electron cyclotron emission diagnostics that view the same plasma volume. In addition to the experimental results, two sets of local, nonlinear gyrokinetic turbulence simulations that are performed with the GYRO code [J. Candy and R. E. Waltz, J. Comput. Phys. 186, 545 (2003)] are described. One set, called the pre-experiment simulations, was performed prior to the experiment in order to predict a change in alpha{sub n{sub eT{sub e}}} given experimentally realizable increases in the electron temperature, T{sub e}. In the experiment the cross-phase angle was measured at three radial locations (rho=0.55, 0.65, and 0.75) in both a 'Base' case and a 'High T{sub e}' case. The measured cross-phase angle is in good qualitative agreement with the pre-experiment simulations, which predicted that n-tilde{sub e} and T-tilde{sub e} would be out of phase. The pre-experiment simulations also predicted a decrease in cross-phase angle as T{sub e} is increased. Experimentally, this trend is observed at the inner two radial locations only. The second set of simulations, the postexperiment simulations, is carried out using local parameters taken from measured experimental profiles as input to GYRO. These postexperiment simulation results are in good quantitative agreement with the measured cross-phase angle, despite disagreements with transport fluxes. Directions for future modeling and experimental work are discussed.

  20. Energetic Particles Measured in and out of the Ecliptic Plane During the Last Gnevyshev Gap

    NASA Astrophysics Data System (ADS)

    Rodríguez-Pacheco, J.; Blanco, J. J.; Heber, B.; Gómez-Herrero, R.

    2012-11-01

    We analyzed the temporal variation of energetic particles measured by the Low Energy Telescope (LET), the Kiel Electron Telescope (KET), and the High Energy Telescope (HET) instruments aboard Ulysses and the Electron Proton Helium Instrument (EPHIN) aboard SOHO during the last solar magnetic field polarity reversal in 2001. We have found two periods with anomalous low fluxes during that time that are present both at low and high heliolatitudes. We compared the energetic particle fluxes with solar energetic phenomena that traditionally have been associated with solar energetic particle (SEP) events at 1 AU. Our results show that these periods are related to relative minima in the number of X-ray flares and CMEs. Since Ulysses scanned the whole latitude range from 80 °S to 80 °N, we conclude that this process affects the inner three-dimensional heliosphere globally.

  1. [Determination of torsion angle after shaft fractures of the lower extremity--clinical relevance and measurement techniques].

    PubMed

    Grützner, P; Hochstein, P; Simon, R; Wentzensen, A

    1999-03-01

    In the treatment of femoral and tibial fractures the frontal and sagittal planes are controlled and documented by conventional X-ray films. Computed tomography permits exact measurement of the coronal plane. Between June 1993 and December 1997, 161 computed tomographic measurements of femoral torsion and 55 of tibial torsion after shaft fracture were carried out. The results were analyzed in a clinical study. A CT examination was carried out if the clinical examination aroused suspicion of a difference in torsion. 28.5% of the patients examined with femoral fractures and 23.8% of those with tibial fractures and torsion differences of more than 20 degrees. Between June 1993 and June 1997, 30 corrective derotating osteotomies of the femur and 9 of the tibia were carried out. The average preoperative difference of torsion of the femur was 29 degrees and of the tibia 25 degrees. After the operation the average femur difference was 7 degrees and of the lower leg 6.5 degrees, which are inside normal physiological limits. The osteotomies were carried out in the metaphysis near the fracture. Additional corrections in other planes were necessary on the femur in 27% and on the lower leg in 46%. With the aim of avoiding torsion differences, or at least to recognize them at an early stage, CT measurements of torsion after osteosythetic treatment of fresh unilateral femur-shaft fractures were carried out in 49 patients between October 1996 and December 1997. The torsion measurements during the operations had to be carried out clinically. No sufficiently exact method of measurement is available in the operating room. Three patients with increased differences of 28 degrees, 26 degrees or 19 degrees had their osteosyntheses corrected. The measurements after correction were inside the normal spread.

  2. Laboratory photometric measurement of particulate soils out to very large phase angles

    NASA Technical Reports Server (NTRS)

    Helfenstein, Paul; Bonne, Ulrich A.; Stolovy, Susan; Veverka, Joseph

    1991-01-01

    In the present study, the objectives were to develop the laboratory methods and tools to conduct photometric observations of dark particulate samples over a large range of phase angles and to demonstrate whether forward scattering behavior can be seen in a surface constructed of low albedo material. The researchers also examined the adequacy of various model formulations of P (alpha) to describe the effective scattering properties of their sample.

  3. Inelastic scattering of NO from Ag(111): Internal state, angle, and velocity resolved measurements

    SciTech Connect

    Rettner, C.T.; Kimman, J.; Auerbach, D.J. )

    1991-01-01

    We have determined the velocity distributions of individual quantum states of NO scattering from Ag(111) at specific scattering angles {theta}{sub {ital f}} using molecular beam techniques to control the incidence energy {ital E}{sub {ital i}} and angle {theta}{sub {ital i}}. We find that the mean energies of scattered species {ital E}{sub {ital f}} depend weakly on {theta}{sub {ital f}} at low collision energies, but become increasingly independent of this parameter as {ital E}{sub {ital i}} approaches 1.0 eV. This is true for all final rotation states {ital J}. The previously reported insensitivity of the final kinetic energy to {ital J} is found to apply at all scattering angles, so that {ital E}{sub {ital f}} vs {theta}{sub {ital f}} curves for high {ital J} fall only slightly below those for low {ital J}. This system is highly translationally inelastic at high incidence energies, with up to 55% of {ital E}{sub {ital i}} being lost to phonons at {ital E}{sub {ital i}}=1.0 eV. Angular distributions are relatively insensitive to {ital J} at low {ital E}{sub {ital i}} , but for high {ital E}{sub {ital i}} the peak flux is found to shift away from the surface normal as {ital E}{sub {ital i}} increases. The effect of the surface temperature only becomes apparent at low incidence energies. A search for supernumerary rotational rainbows reveals no discernible oscillations even for the lowest surface temperatures. We believe that these supernumerary oscillations may be damped by surface corrugation'' effects for this system. Discussion focuses on the observed anticorrelation between kinetic energy transfer to phonons and to rotation, the extent to which parallel momentum is conserved in this system, and energy-angle scaling laws for energy transfer.

  4. The Q/U Imaging Experiment: Polarization Measurements of the Galactic Plane at 43 and 95 GHz

    NASA Astrophysics Data System (ADS)

    Ruud, T. M.; Fuskeland, U.; Wehus, I. K.; Vidal, M.; Araujo, D.; Bischoff, C.; Buder, I.; Chinone, Y.; Cleary, K.; Dumoulin, R. N.; Kusaka, A.; Monsalve, R.; Næss, S. K.; Newburgh, L. B.; Reeves, R. A.; Zwart, J. T. L.; Bronfman, L.; Davies, R. D.; Davis, R.; Dickinson, C.; Eriksen, H. K.; Gaier, T.; Gundersen, J. O.; Hasegawa, M.; Hazumi, M.; Huffenberger, K. M.; Jones, M. E.; Lawrence, C. R.; Leitch, E. M.; Limon, M.; Miller, A. D.; Pearson, T. J.; Piccirillo, L.; Radford, S. J. E.; Readhead, A. C. S.; Samtleben, D.; Seiffert, M.; Shepherd, M. C.; Staggs, S. T.; Tajima, O.; Thompson, K. L.; QUIET Collaboration

    2015-10-01

    We present polarization observations of two Galactic plane fields centered on Galactic coordinates (l, b) = (0°, 0°) and (329°, 0°) at both Q (43 GHz) and W bands (95 GHz), covering between 301 and 539 square degrees depending on frequency and field. These measurements were made with the QUIET instrument between 2008 October and 2010 December, and include a total of 1263 hr of observations. The resulting maps represent the deepest large-area Galactic polarization observations published to date at the relevant frequencies with instrumental rms noise varying between 1.8 and 2.8 μK deg, 2.3–6 times deeper than corresponding WMAP and Planck maps. The angular resolution is 27.‧3 and 12.‧8 FWHM at Q and W bands, respectively. We find excellent agreement between the QUIET and WMAP maps over the entire fields, and no compelling evidence for significant residual instrumental systematic errors in either experiment, whereas the Planck 44 GHz map deviates from these in a manner consistent with reported systematic uncertainties for this channel. We combine QUIET and WMAP data to compute inverse-variance-weighted average maps, effectively retaining small angular scales from QUIET and large angular scales from WMAP. From these combined maps, we derive constraints on several important astrophysical quantities, including a robust detection of polarized synchrotron spectral index steepening of ≈0.2 off the plane, as well as the Faraday rotation measure toward the Galactic center (RM = ‑4000 ± 200 rad m‑2), all of which are consistent with previously published results. Both the raw QUIET and the co-added QUIET+WMAP maps are made publicly available together with all necessary ancillary information.

  5. The "RED Versa NIR" Plane to Retrieve Broken-Cloud Optical Depth from Ground-Based Measurements"

    NASA Technical Reports Server (NTRS)

    Marshak, A.; Knyazikhin, Y.; Evans, K.; Wiscombe, W.

    2003-01-01

    A new method for retrieving cloud optical depth from ground-based measurements of zenith radiance in the RED and near infrared (MR) spectral regions is introduced. Because zenith radiance does not have a one-to-one relationship with optical depth, it is absolutely impossible to use a monochromatic retrieval. On the other side, algebraic combinations of spectral radiances such as NDCI while largely removing nouniquiness and the radiative effects of cloud inhomogeneity, can result in poor retrievals due to its insensitivity to cloud fraction. Instead, both RED and NIR radiances as points on the 'RED vs. NIR' plane are proposed to be used for retrieval. The proposed retrieval method is applied to Cimel measurements at the Atmospheric Radiation Measurements (ARM) site in Oklahoma. Cimel, a multi-channel sunphotometer, is a part of AERONET - a ground-based network for monitoring aerosol optical properties. The results of retrieval are compared with the ones from Microwave Radiometer (MWR) and Multi-Filter Rotating Shadowband Radiometers (MFRSR) located next to Cimel at the ARM site. In addition, the performance of the retrieval method is assessed using a fractal model of cloud inhomogeneity and broken cloudiness. The preliminary results look very promising both theoretically and from measurements.

  6. A New Approach to Measure Contact Angle and Evaporation Rate with Flow Visualization in a Sessile Drop

    NASA Technical Reports Server (NTRS)

    Zhang, Nengli; Chao, David F.

    1999-01-01

    The contact angle and the spreading process of sessile droplet are very crucial in many technological processes, such as painting and coating, material processing, film-cooling applications, lubrication, and boiling. Additionally, as it is well known that the surface free energy of polymers cannot be directly, measured for their elastic and viscous restraints. The measurements of liquid contact angle on the polymer surfaces become extremely important to evaluate the surface free energy of polymers through indirect methods linked with the contact angle data. Due to the occurrence of liquid evaporation is inevitable, the effects of evaporation on the contact angle and the spreading become very important for more complete understanding of these processes. It is of interest to note that evaporation can induce Marangoni-Benard convection in sessile drops. However, the impacts of the inside convection on the wetting and spreading processes are not clear. The experimental methods used by previous investigators cannot simultaneously measure the spreading process and visualize the convection inside. Based on the laser shadowgraphic system used by the present author, a very simple optical procedure has been developed to measure the contact angle, the spreading speed, the evaporation rate, and to visualize inside convection of a sessile drop simultaneously. Two CCD cameras were used to synchronously record the real-time diameter of the sessile drop, which is essential for determination of both spreading speed and evaporation rate, and the shadowgraphic image magnified by the sessile drop acting as a thin plano-convex lens. From the shadowgraph, the inside convection of the drop can be observed if any and the image outer diameter, which linked to the drop profile, can be measured. Simple equations have been derived to calculate the drop profile, including the instantaneous contact angle, height, and volume of the sessile drop, as well as the evaporation rate. The influence of

  7. A new beam emission polarimetry diagnostic for measuring the magnetic field line angle at the plasma edge of ASDEX Upgrade

    NASA Astrophysics Data System (ADS)

    Viezzer, E.; Dux, R.; Dunne, M. G.

    2016-11-01

    A new edge beam emission polarimetry diagnostic dedicated to the measurement of the magnetic field line angle has been installed on the ASDEX Upgrade tokamak. The new diagnostic relies on the motional Stark effect and is based on the simultaneous measurement of the polarization direction of the linearly polarized π (parallel to the electric field) and σ (perpendicular to the electric field) lines of the Balmer line Dα. The technical properties of the system are described. The calibration procedures are discussed and first measurements are presented.

  8. Application of moiré technique to the measurement of the atmospheric turbulence parameters related to the angle of arrival fluctuations.

    PubMed

    Rasouli, Saifollah; Tavassoly, M Taghi

    2006-11-15

    There are several methods for measuring ground-level atmospheric turbulence parameters, such as the refractive index profile and its fluctuations, correlations of the fluctuations in space and time, and the atmospheric refractive-index structure constant. These methods are based mainly on the measurement of fluctuations in intensity and location of an image formed by light propagating in the turbulent atmosphere or the fluctuations in impinging points of narrow light beams traversing the ground-level atmosphere. Exploiting the moiré technique, we suggest a high-precision approach for determining fluctuaions in the angle of arrival. When a low-frequency grating (carrier grating) is installed at a suitable distance from a telescope, its image, practically, forms on the focal plane of the telescope objective. Superimposing a physical grating (probe grating) of the same pitch as the image grating on the image forms the moiré pattern. The atmospheric turbulence distorts the image grating. Processing the fluctuations of successive moiré fringes can yield the mentioned parameters across a rather large cross section of the atmosphere with high accuracy, because of the moiré technique's magnifying character and access to a large volume of data, and does so in a comparatively simple and reliable manner.

  9. An Improved Instrument for Angular Scattering Measurements of Candidate Planetary Surface Regolith Materials at Extremely Small Phase Angles: Relevance to the Outer Solar System

    NASA Astrophysics Data System (ADS)

    Nelson, R. M.; Boryta, M. D.; Hapke, B. W.; Manatt, K.; Kroner, D. O.; Smythe, W. D.

    2014-12-01

    The reflection variation and the polarization change with phase angle of radiation scattered from particulate materials has been studied for a century in efforts to understand the nature of clouds, aerosols, planetary ring systems and planetary regolith materials. The increase in reflectance as phase angle decreases, the 'Opposition Effect', has been well documented in astronomical observations and laboratory studies. Variations in linear polarization near small phase angles have also been well studied (e.g. Shkuratov et al.,2002, Rosenbush et al. 2015). While the phenomena have been well documented, a generally accepted physical explanation is still lacking despite many excellent theoretical modeling efforts. We have undertaken a reductionist approach in deconstructing the process. We have fabricated a goniometer which permits us to present samples with discrete wavelengths of monochromatic light that is linearly polarized in and perpendicular to the scattering plane. We also can illuminate our samples with both right handed and left handed circular polarization senses. Silicon Avalanche Photodiodes record the reflected radiation from the sample after it has passed through linear and circular polarizing analyzers(Kroner et al.). This reductionist approach permits us to measure the reflectance and polarization phase curves and the change in linear and circular polarization ratio (LPR and CPR) with phase angle between 0.056 and 17 degrees. LPR and CPR are found to be important indicators of the amount of multiple scattering in the medium (Hapke, 1990, Nelson et al, 1998, 2000;Hapke, 2012). This approach provides a way to distinguish between suggested models and to gain greater insight into the process of the scattering of electromagnetic radiation in a variety of media. This work was supported by NASA's Cassini Science Program Hapke, B. (1990), Icarus, 88, 407-217. Hapke, B. (2012). Theory of Reflectance and Emittance Spectroscopy, Cambridge U. Press, New York

  10. A New Approach to Micro-arcsecond Astrometry with SIM Allowing Early Mission Narrow Angle Measurements of Compelling Astronomical Targets

    NASA Technical Reports Server (NTRS)

    Shaklan, Stuart; Pan, Xiaopei

    2004-01-01

    The Space Interferometry Mission (SIM) is capable of detecting and measuring the mass of terrestrial planets around stars other than our own. It can measure the mass of black holes and the visual orbits of radio and x-ray binary sources. SIM makes possible a new level of understanding of complex astrophysical processes. SIM achieves its high precision in the so-called narrow-angle regime. This is defined by a 1 degree diameter field in which the position of a target star is measured with respect to a set of reference stars. The observation is performed in two parts: first, SIM observes a grid of stars that spans the full sky. After a few years, repeated observations of the grid allow one to determine the orientation of the interferometer baseline. Second, throughout the mission, SIM periodically observes in the narrow-angle mode. Every narrow-angle observation is linked to the grid to determine the precise attitude and length of the baseline. The narrow angle process demands patience. It is not until five years after launch that SIM achieves its ultimate accuracy of 1 microarcsecond. The accuracy is degraded by a factor of approx. 2 at mid-mission. Our work proposes a technique for narrow angle astrometry that does not rely on the measurement of grid stars. This technique, called Gridless Narrow Angle Astrometry (GNAA) can obtain microarcsecond accuracy and can detect extra-solar planets and other exciting objects with a few days of observation. It can be applied as early as during the first six months of in-orbit calibration (IOC). The motivations for doing this are strong. First, and obviously, it is an insurance policy against a catastrophic mid-mission failure. Second, at the start of the mission, with several space-based interferometers in the planning or implementation phase, NASA will be eager to capture the public's imagination with interferometric science. Third, early results and a technique that can duplicate those results throughout the mission will

  11. Measurement of body joint angles for physical therapy based on mean shift tracking using two low cost Kinect images.

    PubMed

    Chen, Y C; Lee, H J; Lin, K H

    2015-08-01

    Range of motion (ROM) is commonly used to assess a patient's joint function in physical therapy. Because motion capture systems are generally very expensive, physical therapists mostly use simple rulers to measure patients' joint angles in clinical diagnosis, which will suffer from low accuracy, low reliability, and subjective. In this study we used color and depth image feature from two sets of low-cost Microsoft Kinect to reconstruct 3D joint positions, and then calculate moveable joint angles to assess the ROM. A Gaussian background model is first used to segment the human body from the depth images. The 3D coordinates of the joints are reconstructed from both color and depth images. To track the location of joints throughout the sequence more precisely, we adopt the mean shift algorithm to find out the center of voxels upon the joints. The two sets of Kinect are placed three meters away from each other and facing to the subject. The joint moveable angles and the motion data are calculated from the position of joints frame by frame. To verify the results of our system, we take the results from a motion capture system called VICON as golden standard. Our 150 test results showed that the deviation of joint moveable angles between those obtained by VICON and our system is about 4 to 8 degree in six different upper limb exercises, which are acceptable in clinical environment.

  12. Measurement of energy spectra of small-angle scattering and distribution of optical microinhomogeneities in laser ceramics

    SciTech Connect

    Tverdokhleb, P E; Shepetkin, Yu A; Steinberg, I Sh; Belikov, A Yu; Vatnik, S M; Vedin, I A; Kurbatov, P F

    2014-06-30

    The energy spectra of small-angle light scattering from the samples of Nd:YAG ceramics and the spatial distributions of optical microinhomogeneities in them are measured. The spatial profiles of microinhomogeneities are found using the collinear heterodyne microprobe technique. Based on the obtained data, the comparison of noise and lasing characteristics of foreign and domestic samples of laser ceramics is carried out. (extreme light fields and their applications)

  13. Method for measuring the cone angle and the shape of the axicon simultaneously using computer-generated holograms.

    PubMed

    Chen, Qiang; Zhang, Yonghong; Qiu, Chuankai; Wan, Yongjian; Hou, Xi

    2015-10-01

    An axicon is an optical element with rotational symmetry and cone shape, which is nowadays widely used in many fields of engineering, like laser beam shaping, imaging systems, optical testing, laser machining, etc. In this paper, we propose a new method to measure the cone angle and the shape of the axicon simultaneously by using a computer-generated hologram. This test is performed in a null-test configuration. PMID:26479598

  14. Critical dimension small angle X-ray scattering measurements of FinFET and 3D memory structures

    NASA Astrophysics Data System (ADS)

    Settens, Charles; Bunday, Benjamin; Thiel, Brad; Kline, R. Joseph; Sunday, Daniel; Wang, Chengqing; Wu, Wen-li; Matyi, Richard

    2013-04-01

    We have demonstrated that transmission critical dimension small angle X-ray scattering (CD-SAXS) provides high accuracy and precision CD measurements on advanced 3D microelectronic architectures. The competitive advantage of CD-SAXS over current 3D metrology methods such as optical scatterometry is that CD-SAXS is able to decouple and fit cross-section parameters without any significant parameter cross-correlations. As the industry aggressively scales beyond the 22 nm node, CD-SAXS can be used to quantitatively measure nanoscale deviations in the average crosssections of FinFETs and high-aspect ratio (HAR) memory devices. Fitting the average