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Sample records for additional angle parameter

  1. Nonlinearity Analysis and Parameters Optimization for an Inductive Angle Sensor

    PubMed Central

    Ye, Lin; Yang, Ming; Xu, Liang; Zhuang, Xiaoqi; Dong, Zhaopeng; Li, Shiyang

    2014-01-01

    Using the finite element method (FEM) and particle swarm optimization (PSO), a nonlinearity analysis based on parameter optimization is proposed to design an inductive angle sensor. Due to the structure complexity of the sensor, understanding the influences of structure parameters on the nonlinearity errors is a critical step in designing an effective sensor. Key parameters are selected for the design based on the parameters' effects on the nonlinearity errors. The finite element method and particle swarm optimization are combined for the sensor design to get the minimal nonlinearity error. In the simulation, the nonlinearity error of the optimized sensor is 0.053% in the angle range from −60° to 60°. A prototype sensor is manufactured and measured experimentally, and the experimental nonlinearity error is 0.081% in the angle range from −60° to 60°. PMID:24590353

  2. Angle parameter changes of phacoemulsification and combined phacotrabeculectomy for acute primary angle closure

    PubMed Central

    Li, Shi-Wei; Chen, Yan; Wu, Qiang; Lu, Bin; Wang, Wen-Qing; Fang, Jian

    2015-01-01

    AIM To evaluate the difference in angle parameters and clinical outcome following phacoemulsification and combined phacotrabeculectomy in patients with acute primary angle closure (APAC) using ultrasound biomicroscopy (UBM). METHODS Patients (n=23, 31 eyes) were randomized to receive phacoemulsification or combined phacotrabeculectomy (n=24, 31 eyes). Best-corrected visual acuity (BCVA), intraocular pressure (IOP), the main complications following surgery, and indentation gonioscopy and angle parameters measured using UBM were documented preoperatively and postoperatively. RESULTS The improvement in BCVA in the phacoemulsification group was significantly greater than in the combined group (P<0.05). IOP in the phacoemulsification group was slightly higher than in the combined group following 1wk of follow-up (P<0.05), whereas there was no significant difference between the two groups at the latter follow-up (P>0.05). Phacoemulsification alone resulted in a slight increase in the trabecular ciliary processes distance compared with the combined surgery (P<0.05), whereas the other angle parameters showed no significant difference between the groups. Complications in combined group were greater than phacoemulsification only group. CONCLUSION Both surgeries effectively opened the drainage angle and deepened the anterior chamber, and IOP was well controlled postoperatively. However, phacoemulsification showed better efficacy in improving visual function and showed reduced complications following surgery. PMID:26309873

  3. On non-coplanar Hohmann transfer using angles as parameters

    NASA Astrophysics Data System (ADS)

    Rincón, Ángel; Rojo, Patricio; Lacruz, Elvis; Abellán, Gabriel; Díaz, Sttiwuer

    2015-09-01

    We study a more complex case of Hohmann orbital transfer of a satellite by considering non-coplanar and elliptical orbits, instead of planar and circular orbits. We use as parameter the angle between the initial and transference planes that minimizes the energy, and therefore the fuel of a satellite, through the application of two non-tangential impulses for all possible cases. We found an analytical expression that minimizes the energy for each configuration. Some reasonable physical constraints are used: we apply impulses at perigee or apogee of the orbit, we consider the duration of the impulse to be short compared to the duration of the trip, we take the nodal line of three orbits to be coincident and the three semimajor axes to lie in the same plane. We study the only four possible cases but assuming non-coplanar elliptic orbits. In addition, we validate our method through a numerical solution obtained by using some of the actual orbital elements of Sputnik I and Vanguard I satellites. For these orbits, we found that the most fuel-efficient transfer is obtained by applying the initial impulse at apocenter and keeping the transfer orbit aligned with the initial orbit.

  4. Correlating lepton mixing angles and mixing maxtrix with Wolfenstein parameters

    NASA Astrophysics Data System (ADS)

    Zhang, Xinyi; Ma, Bo-Qiang

    2012-11-01

    Inspired by a new relation θ13PMNS=θC/2 observed from the relatively large θ13PMNS, we find that the combination of this relation with the quark-lepton complementarity and the self-complementarity results in correlations of the lepton mixing angles with the quark mixing angles. We find that the three mixing angles in the Pontecorvo-Maki-Nakagawa-Sakata (PMNS) matrix are all related to the Wolfenstein parameter λ in the quark mixing, so they are also correlated. Consequently, the PMNS matrix can be parameterized by λ, A, and a Dirac CP-violating phase δ. Such parametrizations for the PMNS matrix have the same explicitly hierarchical structure as the Wolfenstein parametrization for the Cabibbo-Kobayashi-Maskawa matrix in the quark mixing, and the bimaximal mixing pattern is deduced at the leading order. We also discuss implications of these phenomenological relations in parametrizations.

  5. Car Gestures - Advisory warning using additional steering wheel angles.

    PubMed

    Maag, Christian; Schneider, Norbert; Lübbeke, Thomas; Weisswange, Thomas H; Goerick, Christian

    2015-10-01

    Advisory warning systems (AWS) notify the driver about upcoming hazards. This is in contrast to the majority of currently deployed advanced driver assistance systems (ADAS) that manage emergency situations. The target of this study is to investigate the effectiveness, acceptance, and controllability of a specific kind of AWS that uses the haptic information channel for warning the driver. This could be beneficial, as alternatives for using the visual modality can help to reduce the risk of visual overload. The driving simulator study (N=24) compared an AWS based on additional steering wheel angle control (Car Gestures) with a visual warning presented in a simulated head-up display (HUD). Both types of warning were activated 3.5s before the hazard object was reached. An additional condition of unassisted driving completed the experimental design. The subjects encountered potential hazards in a variety of urban situations (e.g. a pedestrian standing on the curbs). For the investigated situations, subjective ratings show that a majority of drivers prefer visual warnings over haptic information via gestures. An analysis of driving behavior indicates that both warning approaches guide the vehicle away from the potential hazard. Whereas gestures lead to a faster lateral driving reaction (compared to HUD warnings), the visual warnings result in a greater safety benefit (measured by the minimum distance to the hazard object). A controllability study with gestures in the wrong direction (i.e. leading toward the hazard object) shows that drivers are able to cope with wrong haptic warnings and safety is not reduced compared to unassisted driving as well as compared to (correct) haptic gestures and visual warnings. PMID:26264518

  6. Optimal VLF Parameters for Pitch Angle Scattering of Trapped Electrons

    NASA Astrophysics Data System (ADS)

    Albert, J. M.; Inan, U. S.

    2001-12-01

    VLF waves are known to determine the lifetimes of energetic radiation belt electrons in the inner radiation belt and slot regions. Artificial injection of such waves from ground- or space-based transmitters may thus be used to affect the trapped electron population. In this paper, we seek to determine the optimal parameters (frequency and wave normal angle) of a quasi-monochromatic VLF wave using bounce-averaged quasi-linear theory. We consider the cumulative effects of all harmonic resonances and determine the diffusion rates of particles with selected energies on particular L-shells. We also compare the effects of the VLF wave to diffusion driven by other whistler-mode waves (plasmaspheric hiss, lightning, and VLF transmitters). With appropriate choice of the wave parameters, it may be possible to substantially reduce the lifetime of selected classes of particles.

  7. Cloak based on the angle dependent constitutive parameters tensors.

    PubMed

    Gurvitz, Egor; Andronaki, Semen; Vozianova, Anna; Khodzitsky, Mikhail

    2015-10-01

    The transformation optics cloak was proposed for the medium with the angle dependent tensors of permittivity and permeability consisted of the right-handed and left-handed metamaterial media. The cloaking effect was numerically simulated using finite element method in the terahertz frequency range for different wave sources. The impact of cloaking medium thickness on the invisibility effect was demonstrated. PMID:26480088

  8. Linear parameter-varying control of an F-16 aircraft at high angle of attack

    NASA Astrophysics Data System (ADS)

    Lu, Bei

    To improve the aircraft capability at high angle of attack and expand the flight envelope, advanced linear parameter-varying (LPV) control methodologies are studied in this thesis with particular applications of actuator saturation control and switching control. A standard two-step LPV antiwindup control scheme and a systematic switching LPV control approach are derived, and the advantages of LPV control techniques are demonstrated through nonlinear simulations of an F-16 longitudinal autopilot control system. The aerodynamic surface saturation is one of the major issues of flight control in the high angle of attack region. The incorporated unconventional actuators such as thrust vectoring can provide additional control power, but may have a potentially significant pay-off. The proposed LPV antiwindup control scheme is advantageous from the implementation standpoint because it can be thought of as an augmented control algorithm to the existing control system. Moreover, the synthesis condition for an antiwindup compensator is formulated as a linear matrix inequality (LMI) optimization problem and can be solved efficiently. By treating the input saturation as a sector bounded nonlinearity with a tight sector bound, the synthesized antiwindup compensator can stabilize the open-loop exponentially unstable systems. The LPV antiwindup control scheme is applied to the nonlinear F-16 longitudinal model, and compared with the thrust vectoring control approach. The simulation results show that the LPV antiwindup compensator improves the flight quality, and offers advantages over thrust vectoring in a high angle of attack region. For a thrust vectoring augmented aircraft, the actuator sets may be different at low and high angles of attack. Also due to different control objectives, a single controller may not exist over a wide angle of attack region. The proposed switching LPV control approach based on multiple parameter-dependent Lyapunov functions provides a flexible design

  9. Experimental model and analytic solution for real-time observation of vehicle's additional steer angle

    NASA Astrophysics Data System (ADS)

    Zhang, Xiaolong; Li, Liang; Pan, Deng; Cao, Chengmao; Song, Jian

    2014-03-01

    The current research of real-time observation for vehicle roll steer angle and compliance steer angle(both of them comprehensively referred as the additional steer angle in this paper) mainly employs the linear vehicle dynamic model, in which only the lateral acceleration of vehicle body is considered. The observation accuracy resorting to this method cannot meet the requirements of vehicle real-time stability control, especially under extreme driving conditions. The paper explores the solution resorting to experimental method. Firstly, a multi-body dynamic model of a passenger car is built based on the ADAMS/Car software, whose dynamic accuracy is verified by the same vehicle's roadway test data of steady static circular test. Based on this simulation platform, several influencing factors of additional steer angle under different driving conditions are quantitatively analyzed. Then ɛ-SVR algorithm is employed to build the additional steer angle prediction model, whose input vectors mainly include the sensor information of standard electronic stability control system(ESC). The method of typical slalom tests and FMVSS 126 tests are adopted to make simulation, train model and test model's generalization performance. The test result shows that the influence of lateral acceleration on additional steer angle is maximal (the magnitude up to 1°), followed by the longitudinal acceleration-deceleration and the road wave amplitude (the magnitude up to 0.3°). Moreover, both the prediction accuracy and the calculation real-time of the model can meet the control requirements of ESC. This research expands the accurate observation methods of the additional steer angle under extreme driving conditions.

  10. Additional Investigations of Ice Shape Sensitivity to Parameter Variations

    NASA Technical Reports Server (NTRS)

    Miller, Dean R.; Potapczuk, Mark G.; Langhals, Tammy J.

    2006-01-01

    A second parameter sensitivity study was conducted at the NASA Glenn Research Center's Icing Research Tunnel (IRT) using a 36 in. chord (0.91 m) NACA-0012 airfoil. The objective of this work was to further investigate the feasibility of using ice shape feature changes to define requirements for the simulation and measurement of SLD and appendix C icing conditions. A previous study concluded that it was feasible to use changes in ice shape features (e.g., ice horn angle, ice horn thickness, and ice shape mass) to detect relatively small variations in icing spray condition parameters (LWC, MVD, and temperature). The subject of this current investigation extends the scope of this previous work, by also examining the effect of icing tunnel spray-bar parameter variations (water pressure, air pressure) on ice shape feature changes. The approach was to vary spray-bar water pressure and air pressure, and then evaluate the effects of these parameter changes on the resulting ice shapes. This paper will provide a description of the experimental method, present selected experimental results, and conclude with an evaluation of these results.

  11. 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.

  12. Parameters optimization for wavelet denoising based on normalized spectral angle and threshold constraint machine learning

    NASA Astrophysics Data System (ADS)

    Li, Hao; Ma, Yong; Liang, Kun; Tian, Yong; Wang, Rui

    2012-01-01

    Wavelet parameters (e.g., wavelet type, level of decomposition) affect the performance of the wavelet denoising algorithm in hyperspectral applications. Current studies select the best wavelet parameters for a single spectral curve by comparing similarity criteria such as spectral angle (SA). However, the method to find the best parameters for a spectral library that contains multiple spectra has not been studied. In this paper, a criterion named normalized spectral angle (NSA) is proposed. By comparing NSA, the best combination of parameters for a spectral library can be selected. Moreover, a fast algorithm based on threshold constraint and machine learning is developed to reduce the time of a full search. After several iterations of learning, the combination of parameters that constantly surpasses a threshold is selected. The experiments proved that by using the NSA criterion, the SA values decreased significantly, and the fast algorithm could save 80% time consumption, while the denoising performance was not obviously impaired.

  13. Attitude angle effects on Nimbus-7 Scanning Multichannel Microwave Radiometer radiances and geophysical parameter retrievals

    NASA Technical Reports Server (NTRS)

    Macmillan, Daniel S.; Han, Daesoo

    1989-01-01

    The attitude of the Nimbus-7 spacecraft has varied significantly over its lifetime. A summary of the orbital and long-term behavior of the attitude angles and the effects of attitude variations on Scanning Multichannel Microwave Radiometer (SMMR) brightness temperatures is presented. One of the principal effects of these variations is to change the incident angle at which the SMMR views the Earth's surface. The brightness temperatures depend upon the incident angle sensitivities of both the ocean surface emissivity and the atmospheric path length. Ocean surface emissivity is quite sensitive to incident angle variation near the SMMR incident angle, which is about 50 degrees. This sensitivity was estimated theoretically for a smooth ocean surface and no atmosphere. A 1-degree increase in the angle of incidence produces a 2.9 C increase in the retrieved sea surface temperature and a 5.7 m/sec decrease in retrieved sea surface wind speed. An incident angle correction is applied to the SMMR radiances before using them in the geophysical parameter retrieval algorithms. The corrected retrieval data is compared with data obtained without applying the correction.

  14. Determination of aerodynamic parameters of a fighter airplane from flight data at high angles of attack

    NASA Technical Reports Server (NTRS)

    Klein, V.; Batterson, J. G.; Abbasy, I.

    1983-01-01

    A procedure for the estimation of airplane model structure and parameters is applied to data from a modern fighter airplane operating within an angle of attack range of 5 to 60 deg. The paper briefly describes the airplane, flight and wind tunnel data available, and the estimation method. The results presented contain basic longitudinal characteristics of the airplane and the estimates of aerodynamic parameters in the yawing-moment equations. These estimates are obtained from small and large amplitude maneuvers. Because the latter set of data was not suitable for airplane identification, some of the large amplitude maneuvers were joined together and then partitioned into subsets according to the values of angle of attack. Each subset was then analyzed as a separate data set. Most of the estimated parameters and functions are in good agreement with the wind tunnel measurements. The estimated lateral parameters in the model equations also demonstrate good prediction capabilities.

  15. [Radiometric assessment of wrist angle values, linear parameters of the forearm and wrist ratios].

    PubMed

    Baczkowski, Bogusław; Mechlińska-Baczkowska, Janina; Lorczyński, Adam

    2006-01-01

    With the device of our own invention suitable for static X-ray examination of the wrist 12 radiographic parameters were evaluated. 100 radiograms regarded normal were analyzed, obtained as a comparative in unilateral wrist trauma patients group. Age of the patients ranged from 18 to 60 years. No comparative studies in regard to sex were performed. Obtained data were statistically analyzed. Subsequent values of the radiometric parameters were obtained: scaphoid-lunate angle (SL) 48.61 degrees, radio-lunate angle (RL): -0.83 degrees, palmar inclination of the distal radius metaphysis (RI): 25.96. The most significant linear parameters measured: ulnar length 0.18 mm, ulnar transposition (UT): 0.339 mm. PMID:17131729

  16. Hannay Angle: Yet Another Symmetry-Protected Topological Order Parameter in Classical Mechanics

    NASA Astrophysics Data System (ADS)

    Kariyado, Toshikaze; Hatsugai, Yasuhiro

    2016-04-01

    The topological way of thinking now goes beyond quantum solids, and topological characters of classical mechanical systems obeying Newton's law are attracting current interest. To provide a physical insight into the topological numbers in mechanics, we demonstrate the use of the Hannay angle, a "classical" Berry phase, as a symmetry-protected topological order parameter. The Hannay angle is derived using a canonical transformation that maps Newton's equation to a Schrödinger-type equation, and the condition for the quantization is discussed in connection with the symmetry in mechanics. Also, we demonstrate the use of the Hannay angle for a topological characterization of a spring-mass model focusing on the bulk-edge correspondence.

  17. Aerosol and Surface Parameter Retrievals for a Multi-Angle, Multiband Spectrometer

    NASA Technical Reports Server (NTRS)

    Broderick, Daniel

    2012-01-01

    This software retrieves the surface and atmosphere parameters of multi-angle, multiband spectra. The synthetic spectra are generated by applying the modified Rahman-Pinty-Verstraete Bidirectional Reflectance Distribution Function (BRDF) model, and a single-scattering dominated atmosphere model to surface reflectance data from Multiangle Imaging SpectroRadiometer (MISR). The aerosol physical model uses a single scattering approximation using Rayleigh scattering molecules, and Henyey-Greenstein aerosols. The surface and atmosphere parameters of the models are retrieved using the Lavenberg-Marquardt algorithm. The software can retrieve the surface and atmosphere parameters with two different scales. The surface parameters are retrieved pixel-by-pixel while the atmosphere parameters are retrieved for a group of pixels where the same atmosphere model parameters are applied. This two-scale approach allows one to select the natural scale of the atmosphere properties relative to surface properties. The software also takes advantage of an intelligent initial condition given by the solution of the neighbor pixels.

  18. Band structure parameters of metallic diamond from angle-resolved photoemission spectroscopy

    NASA Astrophysics Data System (ADS)

    Guyot, H.; Achatz, P.; Nicolaou, A.; Le Fèvre, P.; Bertran, F.; Taleb-Ibrahimi, A.; Bustarret, E.

    2015-07-01

    The electronic band structure of heavily boron doped diamond was investigated by angle-resolved photoemission spectroscopy on (100)-oriented epilayers. A unique set of Luttinger parameters was deduced from a comparison of the experimental band structure of metallic diamond along the Δ (Γ X ) and Σ (Γ K ) high-symmetry directions of the reciprocal space, with theoretical band structure calculations performed both within the local density approximation and by an analytical k . p approach. In this way, we were able to describe the experimental band structure over a large three-dimensional region of the reciprocal space and to estimate hole effective masses in agreement with previous theoretical and experimental papers.

  19. Method for determining the position, angle and other injection parameters of a short pulsed beam in the Brookhaven AGS

    SciTech Connect

    Gardner, C.; Ahrens, L.

    1985-01-01

    As part of the effort to improve the monitoring of the injection process at the Brookhaven Alternating Gradient Synchrotron (AGS), we have developed a beam diagnostics package which processes the signals from the plates of a pick-up electrode (PUE) located near the injection region of the AGS and provides measurements of the position and angle (with respect to the equilibrium orbit) of the injected beam at the stripping foil where the incident H/sup -/ beam is converted into protons. In addition the package provides measurements of the tune and chromaticity of the AGS at injection, and a measurement of the momentum spread of the injected beam. Since these parameters are obtained for a short-pulsed beam at injection we shall refer to the diagnostics package as PIP which stands for Pulsed Injection Parameters.

  20. Can the Viscoelastic Parameter α-Angle Distinguish Fibrinogen from Platelet Deficiency and Guide Fibrinogen Supplementation?

    PubMed

    Solomon, Cristina; Schöchl, Herbert; Ranucci, Marco; Schlimp, Christoph J

    2015-08-01

    Viscoelastic tests such as thrombelastography (TEG, Haemoscope Inc., Niles, IL) and thromboelastometry (ROTEM, Tem International GmbH, Munich, Germany), performed in whole blood, are increasingly used at the point-of-care to characterize coagulopathic states and guide hemostatic therapy. An algorithm, based on a mono-analysis (kaolin-activated assay) approach, was proposed in the TEG patent (issued in 2004) where the α-angle and the maximum amplitude parameters are used to guide fibrinogen supplementation and platelet administration, respectively. Although multiple assays for both the TEG and ROTEM devices are now available, algorithms based on TEG mono-analysis are still used in many institutions. In light of more recent findings, we discuss here the limitations and inaccuracies of the mono-analysis approach. Research shows that both α-angle and maximum amplitude parameters reflect the combined contribution of fibrinogen and platelets to clot strength. Therefore, although TEG mono-analysis is useful for identifying a coagulopathic state, it cannot be used to discriminate between fibrin/fibrinogen and/or platelet deficits, respectively. Conversely, the use of viscoelastic methods where 2 assays can be run simultaneously, one with platelet inhibitors and one without, can effectively allow for the identification of specific coagulopathic states, such as insufficient fibrin formation or an insufficient contribution of platelets to clot strength. Such information is critical for making the appropriate choice of hemostatic therapy. PMID:26197367

  1. A method to calculate Stokes parameters and angle of polarization of skylight from polarized CIMEL sun/sky radiometers

    NASA Astrophysics Data System (ADS)

    Li, L.; Li, Z.; Li, K.; Blarel, L.; Wendisch, M.

    2014-12-01

    The polarized CIMEL sun/sky radiometers have been routinely operated within the Sun/sky-radiometer Observation NETwork (SONET) in China and some sites of the AErosol RObotic NETwork (AERONET) around the world. However, the polarization measurements are not yet widely used due to in a certain degree the lack of Stokes parameters derived directly from these polarization measurements. Meanwhile, it have been shown that retrievals of several microphysical properties of aerosol particles can be significantly improved by using degree of linear polarization (DoLP) measurements of polarized CIMEL sun/sky radiometers (CE318-DP). The Stokes parameters Q and U, as well as angle of polarization (AoP) contain additional information about linear polarization and its orientation. A method to calculate Stokes parameters Q, U, and AoP from CE318-DP polarized skylight measurements is introduced in this study. A new polarized almucantar geometry based on CE318-DP is measured to illustrate abundant variation features of these parameters. The polarization parameters calculated in this study are consistent with previous results of DoLP and I, and also comparable to vector radiative transfer simulations.

  2. Transferability and additivity of dihedral parameters in polarizable and nonpolarizable empirical force fields.

    PubMed

    Zgarbová, Marie; Rosnik, Andreana M; Luque, F Javier; Curutchet, Carles; Jurečka, Petr

    2015-09-30

    Recent advances in polarizable force fields have revealed that major reparameterization is necessary when the polarization energy is treated explicitly. This study is focused on the torsional parameters, which are crucial for the accurate description of conformational equilibria in biomolecules. In particular, attention is paid to the influence of polarization on the (i) transferability of dihedral terms between molecules, (ii) transferability between different environments, and (iii) additivity of dihedral energies. To this end, three polarizable force fields based on the induced point dipole model designed for use in AMBER are tested, including two recent ff02 reparameterizations. Attention is paid to the contributions due to short range interactions (1-2, 1-3, and 1-4) within the four atoms defining the dihedral angle. The results show that when short range 1-2 and 1-3 polarization interactions are omitted, as for instance in ff02, the 1-4 polarization contribution is rather small and unlikely to improve the description of the torsional energy. Conversely, when screened 1-2 and 1-3 interactions are included, the polarization contribution is sizeable and shows potential to improve the transferability of parameters between different molecules and environments as well as the additivity of dihedral terms. However, to reproduce intramolecular polarization effects accurately, further fine-tuning of the short range damping of polarization is necessary. PMID:26224547

  3. Small angle neutron scattering study of sodium dodecyl sulfate micellar growth driven by addition of a hydrotropic salt.

    PubMed

    Hassan, P A; Fritz, Gerhard; Kaler, Eric W

    2003-01-01

    The structures of aggregates formed in aqueous solutions of an anionic surfactant, sodium dodecyl sulfate (SDS), with the addition of a cationic hydrotropic salt, p-toluidine hydrochloride (PTHC), have been investigated by small angle neutron scattering (SANS). The SANS spectra exhibit a pronounced peak at low salt concentration, indicating the presence of repulsive intermicellar interactions. Model-independent real space information about the structure is obtained from a generalized indirect Fourier transformation (GIFT) technique in combination with a suitable model for the interparticle structure factor. The interparticle interaction is captured using the rescaled mean spherical approximation (RMSA) closure relation and a Yukawa form of the interaction potential. Further quantification of the geometrical parameters of the micelles was achieved by a complete fit of the SANS data using a prolate ellipsoidal form factor and the RMSA structure factor. The present study shows that PTHC induces a decrease in the fractional charge of the micelles due to adsorption at the micellar surface and consequent growth of the SDS micelles from nearly globular to rodlike as the concentration of PTHC increases. PMID:16256467

  4. Constraining the UT angle γ by CP violation parameters in B0 → π+π-

    NASA Astrophysics Data System (ADS)

    Qin, Qin; Zou, Zhi-Tian; Li, Ying; Lü, Cai-Dian

    2016-03-01

    We calculate the tree and penguin amplitudes in the B0 → π+π- decay channel employing the perturbative QCD factorization approach. Using the amplitudes as input with the theoretical uncertainties sufficiently considered, we constrain the UT angle γ to 53° ⩽ γ ⩽ 70°, from the measurements of the CP violation parameters C π+π- and S π+π- in B0 → π+π-. The U-spin breaking effect between B0 → π+π- and is estimated to be around 30%. Partly Supported by National Science Foundation of China (11175151, 11235005, 11375208, 11447032, 11575151), Natural Science Foundation of Shandong Province (ZR2014AQ013) and the Program for New Century Excellent Talents in University (NCET) by Ministry of Education of P.R. China (NCET-13-0991)

  5. Parameter identification for X-31A at high angles of attack

    NASA Technical Reports Server (NTRS)

    Weiss, S.; Rohlf, D.; Plaetschke, Ermin

    1994-01-01

    The U.S./German experimental aircraft X-31A was designed and constructed to demonstrate enhanced fighter maneuverability. Post-stall maneuvering is enabled by applying new technologies such as high angle of attack aerodynamics and flight control system integrated thrust vectoring. Two demonstrator aircraft have been built by the main contractors, Rockwell International and Deutsche Aerospace (formerly MBB). Flight testing started in October 1990 and before the end of 1992 both aircraft had accomplished a significant number of flights covering the entire AoA regime from about -5 to 70 deg. Throughout the envelope expansion, DLR Institute of Flight Mechanics conducted parameter identification (PID) to determine the aerodynamic parameters of the aircraft from flight test data and to compare the results to the predictions from the aerodynamic dataset (ADS). The application of system identification to high AoA / post-stall flight data raises some major problems, which are discussed in this paper. Results from both longitudinal and lateral-directional motion will be presented.

  6. Tuning the Receding Contact Angle on Hydrogels by Addition of Particles.

    PubMed

    Boulogne, François; Ingremeau, François; Limat, Laurent; Stone, Howard A

    2016-06-01

    Control of the swelling, chemical functionalization, and adhesivity of hydrogels are finding new applications in a wide range of material systems. We investigate experimentally the effect of adsorbed particles on hydrogels on the depinning of contact lines. In our experiments, a water drop containing polystyrene microspheres is deposited on a swelling hydrogel, which leads to the drop absorption and particle deposition. Two regimes are observed: a decreasing drop height with a pinned contact line followed by a receding contact line. We show that increasing the particles concentration increases the duration of the first regime and significantly decreases the total absorption time. The adsorbed particles increase the pinning force at the contact line. Finally, we develop a method to measure the receding contact angle with the consideration of the hydrogel swelling. PMID:27185647

  7. 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.

  8. Estimates of forest structure parameters from GLAS data and multi-angle imaging spectrometer data

    NASA Astrophysics Data System (ADS)

    Yu, Ying; Yang, Xiguang; Fan, Wenyi

    2015-06-01

    Quantitative estimates of forest vertical and spatial distribution using remote sensing technology play an important role in better understanding forest ecosystem function, forest carbon storage and the global carbon cycle. Although most remote sensing systems can provide horizontal distribution of canopies, information concerning the vertical distribution of canopies cannot be detected. Fortunately, laser radars have become available, such as GLAS (Geoscience laser altimeter system). Because laser radar can penetrate foliage, it is superior to other remote sensing technologies for detecting vertical forest structure and has higher accuracy. GLAS waveform data were used in this study to retrieve average tree height and biomass in a GLAS footprint area in Heilongjiang Province. However, GLAS data are not spatially continuous. To fill the gaps, MISR (multi- angle imaging spectrometer) spectral radiance was chosen to predict the regional continuous tree height by developing a multivariate linear regression model. We compared tree height estimated by the regression model and GLAS data. The results confirmed that estimates of tree height and biomass based on GLAS data are considerably more accurate than estimates based on traditional methods. The accuracy is approximately 90%. MISR can be used to estimate tree height in continuous areas with a robust regression model. The R2, precision and root mean square error of the regression model were 0.8, 83% and 1 m, respectively. This study provides an important reference for mapping forest vertical parameters.

  9. Superplastic Constitutive Equation Including Percentage of High-Angle Grain Boundaries as a Microstructural Parameter

    NASA Astrophysics Data System (ADS)

    Wang, K.; Liu, F. C.; Xue, P.; Wang, D.; Xiao, B. L.; Ma, Z. Y.

    2016-01-01

    Fifteen Al-Mg-Sc samples with subgrain/grain sizes in the range of 1.8 to 4.9 μm were prepared through the processing methods of friction stir processing (FSP), equal-channel-angular pressing (ECAP), rolling, annealing, and combinations of the above. The percentages of high-angle grain boundaries (HAGBs) of these fine-grained alloys were distributed from 39 to 97 pct. The samples processed through FSP had a higher percentage of HAGBs compared to other samples. Superplasticity was achieved in all fifteen samples, but the FSP samples exhibited better superplasticity than other samples because their fine equiaxed grains, which were mostly surrounded by HAGBs, were conducive to the occurrence of grain boundary sliding (GBS) during superplastic deformation. The dominant deformation mechanism was the same for all fifteen samples, i.e., GBS controlled by grain boundary diffusion. However, the subgrains were the GBS units for the rolled or ECAP samples, which contained high percentages of unrecrystallized grains, whereas the fine grains were the GBS units for the FSP samples. Superplastic data analysis revealed that the dimensionless A in the classical constitutive equation for superplasticity of fine-grained Al alloys was not a constant, but increased with an increase in the percentage of HAGBs, demonstrating that the enhanced superplastic deformation kinetics can be ascribed to the high percentage of HAGBs. A modified superplastic constitutive equation with the percentage of HAGBs as a new microstructural parameter was established.

  10. Structure Parameters of Synaptic Vesicles Quantified by Small-Angle X-Ray Scattering

    PubMed Central

    Castorph, Simon; Riedel, Dietmar; Arleth, Lise; Sztucki, Michael; Jahn, Reinhard; Holt, Matthew; Salditt, Tim

    2010-01-01

    Synaptic vesicles (SVs) are small, membrane-bound organelles that are found in the synaptic terminal of neurons, and which are crucial in neurotransmission. After a rise in internal [Ca2+] during neuronal stimulation, SVs fuse with the plasma membrane releasing their neurotransmitter content, which then signals neighboring neurons. SVs are subsequently recycled and refilled with neurotransmitter for further rounds of release. Recently, tremendous progress has been made in elucidating the molecular composition of SVs, as well as putative protein-protein interactions. However, what is lacking is an empirical description of SV structure at the supramolecular level—which is necessary to enable us to fully understand the processes of membrane fusion, retrieval, and recycling. Using small-angle x-ray scattering, we have directly investigated the size and structure of purified SVs. From this information, we deduced detailed size and density parameters for the protein layers responsible for SV function, as well as information about the lipid bilayer. To achieve a convincing model fit, a laterally anisotropic structure for the protein shell is needed, as a rotationally symmetric density profile does not explain the data. Not only does our model confirm many of the preexisting ideas concerning SV structure, but also for the first time, to our knowledge, it indicates structural refinements, such as the presence of protein microdomains. PMID:20371319

  11. Near-infrared stokes parameter method for determining two-dimensional cell thickness and twist angle distributions of liquid crystal color displays

    NASA Astrophysics Data System (ADS)

    Kawamura, Marenori; Sato, Susumu

    2002-12-01

    We propose a two-dimensional (2D) and hyperfine measurement method for precisely determining cell parameter distributions such as a cell thickness and twist angle in color liquid crystal (LC) displays. The 2D cell thickness and twist angle distributions can easily be determined by measuring Stokes parameters of all pixels for red, green and blue in LCD panel at a wavelength of near-infrared region, because the transmission light at the wavelength is not absorbed by each color filter. In addition, the spatial resolution can be improved by increasing the magnification of the objective lens in front of a high resolution CCD camera. These cell parameters of each pixel in the practical LCD panel are compared and discussed.

  12. The Shank-to-Vertical-Angle as a parameter to evaluate tuning of Ankle-Foot Orthoses.

    PubMed

    Kerkum, Yvette L; Houdijk, Han; Brehm, Merel-Anne; Buizer, Annemieke I; Kessels, Manon L C; Sterk, Arjan; van den Noort, Josien C; Harlaar, Jaap

    2015-09-01

    The effectiveness of an Ankle-Foot Orthosis footwear combination (AFO-FC) may be partly dependent on the alignment of the ground reaction force with respect to lower limb joint rotation centers, reflected by joint angles and moments. Adjusting (i.e. tuning) the AFO-FC's properties could affect this alignment, which may be guided by monitoring the Shank-to-Vertical-Angle. This study aimed to investigate whether the Shank-to-Vertical-Angle during walking responds to variations in heel height and footplate stiffness, and if this would reflect changes in joint angles and net moments in healthy adults. Ten subjects walked on an instrumented treadmill and performed six trials while walking with bilateral rigid Ankle-Foot Orthoses. The AFO-FC heel height was increased, aiming to impose a Shank-to-Vertical-Angle of 5°, 11° and 20°, and combined with a flexible or stiff footplate. For each trial, the Shank-to-Vertical-Angle, joint flexion-extension angles and net joint moments of the right leg at midstance were averaged over 25 gait cycles. The Shank-to-Vertical-Angle significantly increased with increasing heel height (p<0.001), resulting in an increase in knee flexion angle and internal knee extensor moment (p<0.001). The stiff footplate reduced the effect of heel height on the internal knee extensor moment (p=0.030), while the internal ankle plantar flexion moment increased (p=0.035). Effects of heel height and footplate stiffness on the hip joint were limited. Our results support the potential to use the Shank-to-Vertical-Angle as a parameter to evaluate AFO-FC tuning, as it is responsive to changes in heel height and reflects concomitant changes in the lower limb angles and moments. PMID:26050873

  13. Correlation between anatomical parameters of intertubercular sulcus and retroversion angle of humeral head

    PubMed Central

    Pan, Zhaoxun; Chen, Jun; Qu, Lianjun; Cui, Yan; Sun, Chao; Zhang, Hongxin; Yang, Xiaoming; Guan, Qingli

    2015-01-01

    Objective: To obtain anatomical data on intertubercular sulcus of humerus, evaluate the correlation between intertubercular sulcus and retroversion angle of humeral head, to guide the positioning of torsion angle of prosthesis during total shoulder arthroplasty and provide references for shoulder prosthesis design. Methods: Using a Siemens Ultrahigh speed 64- rows multi-slices spiral CT scanner and 20 dried adult humeral specimens (intact specimen, no fractures or pathological damage), of these, left lateral in 10 cases, right lateral in 10 cases, male or female all inclusive, specimens are all provided by Anatomy Department of Weifang Medical College, scan ranged from the highest point of humeral head to the distal ends of trochlea. And scanned data were subjected to statistical analysis. Results: There is a linear correlation between the distance from intertubercular sulcus to central axis line of humeral head, position angle of intertubercular sulcus and retroversion angle of humeral head at the beginning slice of intertubercular sulcus. There is a linear correlation between position angle of intertubercular sulcus and retroversion angle of humeral head at the slice of surgical neck. Conclusion: There is a linear correlation between position of intertubercular sulcus and retroversion angle of humeral head, in total shoulder arthroplasty, using intertubercular sulcus as anatomical landmark will help to accurately position torsion angle of individualized prosthesis. Position angle of intertubercular sulcus is an objective, flexible positioning indicator. PMID:26131058

  14. Parameter estimation applied to Nimbus 6 wide-angle longwave radiation measurements

    NASA Technical Reports Server (NTRS)

    Green, R. N.; Smith, G. L.

    1978-01-01

    A parameter estimation technique was used to analyze the August 1975 Nimbus 6 Earth radiation budget data to demonstrate the concept of deconvolution. The longwave radiation field at the top of the atmosphere is defined from satellite data by a fifth degree and fifth order spherical harmonic representation. The variations of the major features of the radiation field are defined by analyzing the data separately for each two-day duty cycle. A table of coefficient values for each spherical harmonic representation is given along with global mean, gradients, degree variances, and contour plots. In addition, the entire data set is analyzed to define the monthly average radiation field.

  15. The Effect of Detonation Wave Incidence Angle on the Acceleration of Flyers by Explosives Heavily Laden with Inert Additives

    NASA Astrophysics Data System (ADS)

    Loiseau, Jason; Georges, William; Frost, David; Higgins, Andrew

    2015-06-01

    The incidence angle of a detonation wave is often assumed to weakly influence the terminal velocity of an explosively driven flyer. For explosives heavily loaded with dense additives, this may not be true due to differences in momentum and energy transfer between detonation products, additive particles, and the flyer. For tangential incidence the particles are first accelerated against the flyer via an expansion fan, whereas they are first accelerated by the detonation wave in the normal case. In the current study we evaluate the effect of normal versus tangential incidence on the acceleration of flyers by nitromethane heavily loaded with a variety of additives. Normal detonation was initiated via an explosively driven slapper. Flyer acceleration was measured with heterodyne laser interferometry (PDV). The influence of wave angle is evaluated by comparing the terminal velocity in the two cases (i.e., normal and grazing) for the heavily loaded mixtures. The decrement in flyer velocity correlated primarily with additive volume fraction and had a weak dependence on additive density or particle size. The Gurney energy of the heterogeneous explosive was observed to increase with flyer mass, presumably due to the timescale over which impinging particles could transfer momentum.

  16. Evaluation of the significance of some diagnostic parameters in making an early diagnose of primary open-angle glaucoma

    PubMed Central

    Polaczek-Krupa, Barbara; Grabska-Liberek, Iwona

    2012-01-01

    Summary Background The aim of this study was to evaluate diagnostic parameters and analysis of their advantages and limitations in early diagnostics of primary open-angle glaucoma (POAG). Cup/disc ratio (C/D), nerve fiber index (NFI) and mean deviation of retinal sensitivity (MD) were considered. Material/Methods Fifty primary open-angle glaucoma patients (95 eyes), 67 primary open-angle glaucoma suspects (128 eyes), and 77 healthy subjects (148 eyes) underwent full ophthalmologic examination and also HRT, GDx and FDT examinations for determination of C/D, NFI, and MD parameters. Student’s t test was used to confirm the statistical significance of the differences between the particular group pairs. Histograms of distribution of the occurrence frequency of the parameter values in the groups were plotted. Results The mean values of C/D were 0.65±0.11, 0.58±0.11 and 0.43±0.11, NFI 37.0±22.7, 18.5±5.6 and 15.1±4.8 and MD −3.00±5.07, −077±2.49 and −0.29±1.94, respectively. Statistically significant differences between the particular groups were found. There was a partial overlapping of the histograms of distribution of the occurrence frequency of the parameter values. Conclusions The basic diagnostic C/D NFI and MD parameters in primary open-angle glaucoma patients, primary open-angle glaucoma suspects and healthy subjects differed significantly. These parameters are important diagnostic tools in glaucoma diagnosis. A limitation of their applicability is related to a high scatter of the results and their overlapping in particular groups. PMID:22739736

  17. Effect of Three Different Grip Angles on Physiological Parameters During Laboratory Handcycling Test in Able-Bodied Participants

    PubMed Central

    Abel, Thomas; Burkett, Brendan; Thees, Barbara; Schneider, Stefan; Askew, Christopher D.; Strüder, Heiko K.

    2015-01-01

    Introduction: Handcycling is a relatively new wheelchair sport that has gained increased popularity for people with lower limb disabilities. The aim of this study was to examine the effect of three different grip positions on physical parameters during handcycling in a laboratory setting. Methods: Twenty one able-bodied participants performed three maximum incremental handcycling tests until exhaustion, each with a different grip angle. The angle between the grip and the crank was randomly set at 90° (horizontal), 0° (vertical), or 10° (diagonal). The initial load was 20 W and increased by 20 W each 5 min. In addition, participants performed a 20 s maximum effort. Results: The relative peak functional performance (W/kg), peak heart rate (bpm), associated lactate concentrations (mmol/l) and peak oxygen uptake per kilogram body weight (ml.min−1.kg−1) for the different grip positions during the stage test were: (a) Horizontal: 1.43 ± 0.21 W/kg, 170.14 ± 12.81 bpm, 9.54 ± 1.93 mmol/l, 30.86 ± 4.57 ml/kg; (b) Vertical: 1.38 ± 0.20 W/kg, 171.81 ± 13.87 bpm, 9.91 ± 2.29 mmol/l, 29.75 ± 5.13 ml/kg; (c) Diagonal: 1.40 ± 0.22 W/kg, 169.19 ± 13.31 bpm, 9.34 ± 2.36 mmol/l, 29.39 ± 4.70 ml/kg. Statistically significant (p < 0.05) differences could only be found for lactate concentration between the vertical grip position and the other grips during submaximal handcycling. Conclusion: The orientation of three different grip angles made no difference to the peak load achieved during an incremental handcycling test and a 20 s maximum effort. At submaximal load, higher lactate concentrations were found when the vertical grip position was used, suggesting that this position may be less efficient than the alternative diagonal or horizontal grip positions. PMID:26635617

  18. Analysis of iris structure and iridocorneal angle parameters with anterior segment optical coherence tomography in Fuchs' uveitis syndrome.

    PubMed

    Basarir, Berna; Altan, Cigdem; Pinarci, Eylem Yaman; Celik, Ugur; Satana, Banu; Demirok, Ahmet

    2013-06-01

    To evaluate the differences in the biometric parameters of iridocorneal angle and iris structure measured by anterior segment optical coherence tomography (AS-OCT) in Fuchs' uveitis syndrome (FUS). Seventy-six eyes of 38 consecutive patients with the diagnosis of unilateral FUS were recruited into this prospective, cross-sectional and comparative study. After a complete ocular examination, anterior segment biometric parameters were measured by Visante(®) AS-OCT. All parameters were compared between the two eyes of each patient statistically. The mean age of the 38 subjects was 32.5 ± 7.5 years (18 female and 20 male). The mean visual acuity was lower in eyes with FUS (0.55 ± 0.31) than in healthy eyes (0.93 ± 0.17). The central corneal thickness did not differ significantly between eyes. All iridocorneal angle parameters (angle-opening distance 500 and 750, scleral spur angle, trabecular-iris space (TISA) 500 and 750) except TISA 500 in temporal quadrant were significantly larger in eyes with FUS than in healthy eyes. Anterior chamber depth was deeper in the eyes with FUS than in the unaffected eyes. With regard to iris measurements, iris thickness in the thickest part, iris bowing and iris shape were all statistically different between the affected eye and the healthy eye in individual patients with FUS. However, no statistically significant differences were evident in iris thickness 500 μm, thickness in the middle and iris length. There were significant difference in iris shape between the two eyes of patients with glaucoma. AS-OCT as an imaging method provides us with many informative resultsin the analysis of anterior segment parameters in FUS. PMID:23277205

  19. Additional field verification of convective scaling for the lateral dispersion parameter

    SciTech Connect

    Sakiyama, S.K.; Davis, P.A.

    1988-07-01

    The results of a series of diffusion trials over the heterogeneous surface of the Canadian Precambrian Shield provide additional support for the convective scaling of the lateral dispersion parameter. The data indicate that under convective conditions, the lateral dispersion parameter can be scaled with the convective velocity scale and the mixing depth. 10 references.

  20. The effect of additional design parameters on the LQR based design of a control/structural system

    NASA Technical Reports Server (NTRS)

    Bainum, Peter M.; Xu, Jianke

    1990-01-01

    A multiobjective cost function that includes a form of the standard LQR regulator cost and its partial variation with respect to the additional design parameters is presented in connection with the design of an orbiting control/structural system. Simple models of uniform solid and tubular beams are demonstrated with two typical additional payload masses, i.e., symmetrically distributed and asymmetrically distributed, with respect to the center of the beam. By regarding the transient response of pitch angle and free-free beam deformations in the orbital plane, the optimal outer diameter of the beam and all feedback control can be determined by numerical analysis with this multicriterial approach. It is concluded that the multicriteria design approach should give better results from both the structural designer's and the control designer's standpoints.

  1. Rheological parameters of dough with inulin addition and its effect on bread quality

    NASA Astrophysics Data System (ADS)

    Bojnanska, T.; Tokar, M.; Vollmannova, A.

    2015-04-01

    The rheological properties of enriched flour prepared with an addition of inulin were studied. The addition of inulin caused changes of the rheological parameters of the recorder curve. 10% and more addition significantly extended development time and on the farinogram were two peaks of consistency, what is a non-standard shape. With increasing addition of inulin resistance to deformation grows and dough is difficult to process, over 15% addition make dough short and unsuitable for making bread. Bread volume, the most important parameter, significantly decreased with inulin addition. Our results suggest a level of 5% inulin to produce a functional bread of high sensory acceptance and a level of 10% inulin produce a bread of satisfactory sensory acceptance. Bread with a level over 10% of inulin was unsatisfactory.

  2. Asteroid observations at low phase angles. Average parameters for the new three-parameter H,G_1,G_2 magnitude system

    NASA Astrophysics Data System (ADS)

    Shevchenko, V.; Belskaya, I.; Muinonen, K.; Krugly, Y.; Velichko, F.; Chiorny, V.; Slyusarev, I.; Gaftonyuk, N.; Tereschenko, I.

    2014-07-01

    We present new observational data for selected main-belt asteroids of different compositional types, namely, 10 Hygiea, 176 Iduna, 214 Aschera, 250 Bettina, 419 Aurelia, 596 Scheila, 635 Vundtia, 671 Carnegia, 717 Wisibada, 1021 Flammario, and 1279 Uganda. The detailed magnitude-phase dependencies including low phase angles (<1 deg) were obtained for all these asteroids. For some asteroids the dependencies of color indexes B-V, V-R, and R-I with phase angle were investigated. We found a great diversity in opposition effect behavior both in magnitude and width of opposition surges. Some low albedo asteroids (e.g. ,10 Hygiea) display a broad opposition effect with an amplitude of 0.15--0.20 mag relative to the extrapolation of the linear part of the phase curve. Other asteroids (596 Scheila, 1021 Flammario) show linear magnitude phase functions down to very low phase angles (0.1--0.2 deg). Possible causes of the observed differences in the opposition effect behavior are discussed. Using numerous data sets on magnitude-phase dependencies with good phase angle coverage and small scatter within the observational data (e.g., Harris & Young 1989; Harris et al., 1992; Shevchenko et al. 2010; Shevchenko et al. 2012), we examined in more detail the new three-parameter H,G_1,G_2 magnitude system (Muinonen et al. 2010). We determined the values of the G_1 and G_2 parameters for each of the magnitude phase dependencies. We obtained average parameters for the main spectral classes of asteroids which can be used for the calculation of asteroid absolute magnitudes and the prediction of asteroid apparent magnitudes.

  3. Additional information on heavy quark parameters from charged lepton forward-backward asymmetry

    NASA Astrophysics Data System (ADS)

    Turczyk, Sascha

    2016-04-01

    The determination of | V cb | using inclusive and exclusive (semi-)leptonic decays exhibits a long-standing tension of varying O(3σ ) significance. For the inclusive determination the decay rate is expanded in 1/ m b using heavy quark expansion, and from moments of physical observables the higher order heavy quark parameters are extracted from experimental data in order to assess | V cb | from the normalisation. The drawbacks are high correlations both theoretically as well as experimentally among these observables. We will scrutinise the inclusive determination in order to add a new and less correlated observable. This observable is related to the decay angle of the charged lepton and can help to constrain the important heavy quark parameters in a new way. It may validate the current seemingly stable extraction of | V cb | from inclusive decays or hints to possible issues, and even may be sensitive to New Physics operators.

  4. Transformation from Multilamellar to Unilamellar Vesicles by Addition of a Cationic Lipid to PEGylated Liposomes Explored with Synchrotron Small Angle X-ray Scattering

    NASA Astrophysics Data System (ADS)

    Sakuragi, Mina; Koiwai, Kazunori; Nakamura, Kouji; Masunaga, Hiroyasu; Ogawa, Hiroki; Sakurai, Kazuo

    2011-01-01

    PEGylated liposomes composed of a benzamidine derivative (TRX), hydrogenated soybean phosphatidylcholine (HSPC), and N-(monomethoxy-polyethyleneglycolcarbamyl) distearoyl phosphatidylethanolamine (PEG-PE) were examined in terms of how the addition of TRX affects their structures with small angle x-ray scattering (SAXS) as well as transmission electron microscopy (TEM). TEM images showed the presence of unilamella vesicles for both with and without TRX, though a small amount of multilamella vesicles were observed in absence of TRX. We analyzed SAXS profiles at contained TRX composition combined with contrast variation technique by adding PEG solution and unilamella vesicle model could be reproduced. Subsequently, we analyzed SAXS profiles at no TRX composition. The mixture model of unilamella and multilamella vesicle was reconstructed and we estimated about 10 % multilamella vesicles from a fitting parameter.

  5. Spectral line polarization with angle-dependent partial frequency redistribution. I. A Stokes parameters decomposition for Rayleigh scattering

    NASA Astrophysics Data System (ADS)

    Frisch, H.

    2010-11-01

    Context. The linear polarization of a strong resonance lines observed near the solar limb is created by a multiple-scattering process. Partial frequency redistribution (PRD) effects must be accounted for to explain the polarization profiles. The redistribution matrix describing the scattering process is a sum of terms, each containing a PRD function multiplied by a Rayleigh type phase matrix. A standard approximation made in calculating the polarization is to average the PRD functions over all the scattering angles, because the numerical work needed to take the angle-dependence of the PRD functions into account is large and not always needed for reasonable evaluations of the polarization. Aims: This paper describes a Stokes parameters decomposition method, that is applicable in plane-parallel cylindrically symmetrical media, which aims at simplifying the numerical work needed to overcome the angle-average approximation. Methods: The decomposition method relies on an azimuthal Fourier expansion of the PRD functions associated to a decomposition of the phase matrices in terms of the Landi Degl'Innocenti irreducible spherical tensors for polarimetry T^K_Q(i, Ω) (i Stokes parameter index, Ω ray direction). The terms that depend on the azimuth of the scattering angle are retained in the phase matrices. Results: It is shown that the Stokes parameters I and Q, which have the same cylindrical symmetry as the medium, can be expressed in terms of four cylindrically symmetrical components I_Q^K (K = Q = 0, K = 2, Q = 0, 1, 2). The components with Q = 1, 2 are created by the angular dependence of the PRD functions. They go to zero at disk center, ensuring that Stokes Q also goes to zero. Each component I_Q^K is a solution to a standard radiative transfer equation. The source term S_Q^K are significantly simpler than the source terms corresponding to I and Q. They satisfy a set of integral equations that can be solved by an accelerated lambda iteration (ALI) method.

  6. Self-calibration of terrestrial laser scanners: selection of the best geometric additional parameters

    NASA Astrophysics Data System (ADS)

    Lerma, J. L.; García-San-Miguel, D.

    2014-05-01

    Systematic errors are present in laser scanning system observations due to manufacturer imperfections, wearing over time, vibrations, changing environmental conditions and, last but not least, involuntary hits. To achieve maximum quality and rigorous measurements from terrestrial laser scanners, a least squares estimation of additional calibration parameters can be used to model the a priori unknown systematic errors and therefore improve output observations. The selection of the right set of additional parameters is not trivial and requires laborious statistical analysis. Based on this requirement, this article presents an approach to determine the best set of additional parameters which provides the best mathematical solution based on a dimensionless quality index. The best set of additional parameters is the one which provides the maximum quality index (i.e. minimum value) for the group of observables, exterior orientation parameters and reference points. Calibration performance is tested using both a phase shift continuous wave scanner, FARO PHOTON 880, and a pulse-based time-of-flight system, Leica HDS3000. The improvement achieved after the geometric calibration is 30% for the former and 70% for the latter.

  7. Asteroid observations at low phase angles. IV. Average parameters for the new H, G1, G2 magnitude system

    NASA Astrophysics Data System (ADS)

    Shevchenko, Vasilij G.; Belskaya, Irina N.; Muinonen, Karri; Penttilä, Antti; Krugly, Yurij N.; Velichko, Feodor P.; Chiorny, Vasilij G.; Slyusarev, Ivan G.; Gaftonyuk, Ninel M.; Tereschenko, Igor A.

    2016-04-01

    We present new observational data for selected main-belt asteroids of different compositional types. The detailed magnitude-phase dependences including small phase angles (<1°) were obtained for these asteroids, namely: (10) Hygiea (down to the phase angle of 0.3°, C-type), (176) Iduna (0.2°, G-type), (214) Aschera (0.2°, E-type), (218) Bianca (0.3°, S-type), (250) Bettina (0.3°, M-type), (419) Aurelia (0.1°, F-type), (596) Scheila (0.2°, D-type), (635) Vundtia (0.2°, B-type), (671) Carnegia (0.2°, P-type), (717) Wisibada (0.1°, T-type), (1021) Flammario (0.6°, B-type), and (1279) Uganda (0.5°, E-type). For several asteroids, the dependences of brightness on the phase angle were investigated in the BVRI bands. We found a great diversity in the opposition-effect behavior both in the magnitude and the width of the opposition surges, especially for low-albedo asteroids. Some low-albedo asteroids (e.g., (10) Hygiea) display a broad opposition effect with an amplitude of 0.15-0.20 mag relative to the extrapolation of the linear part of the phase curve. Other asteroids (e.g., (596) Scheila, (1021) Flammario) show linear magnitude-phase dependences down to small phase angles (0.1-0.2°). Using numerous data sets on the magnitude-phase dependences with extensive phase-angle coverage, we examined in more detail the new three-parameter H, G1, G2 magnitude system. We determined the values of the G1 and G2 parameters for magnitude phase dependences of individual asteroids and obtained the average parameters for main asteroid compositional types. The values obtained can be used for the estimation of the absolute magnitude of an asteroid from a single observed magnitude when the magnitude-phase dependency is unknown and/or to calculate a visible magnitude for the ephemerides.

  8. Lens Position Parameters as Predictors of Intraocular Pressure Reduction After Cataract Surgery in Nonglaucomatous Patients With Open Angles

    PubMed Central

    Hsu, Chi-Hsin; Kakigi, Caitlin L.; Lin, Shuai-Chun; Wang, Yuan-Hung; Porco, Travis; Lin, Shan C.

    2015-01-01

    Purpose To evaluate the relationship between lens position parameters and intraocular pressure (IOP) reduction after cataract surgery in nonglaucomatous eyes with open angles. Methods The main outcome of the prospective study was percentage of IOP change, which was calculated using the preoperative IOP and the IOP 4 months after cataract surgery in nonglaucomatous eyes with open angles. Lens position (LP), defined as anterior chamber depth (ACD) + 1/2 lens thickness (LT), was assessed preoperatively using parameters from optical biometry. Preoperative IOP, central corneal thickness, ACD, LT, axial length (AXL), and the ratio of preoperative IOP to ACD (PD ratio) were also evaluated as potential predictors of percentage of IOP change. The predictive values of the parameters we found to be associated with the primary outcome were compared. Results Four months after cataract surgery, the average IOP reduction was 2.03 ± 2.42 mm Hg, a 12.74% reduction from the preoperative mean of 14.5 ± 3.05 mm Hg. Lens position was correlated with IOP reduction percentage after adjusting for confounders (P = 0.002). Higher preoperative IOP, shallower ACD, shorter AXL, and thicker LT were significantly associated with percentage of IOP decrease. Although not statistically significant, LP was a better predictor of percentage of IOP change compared to PD ratio, preoperative IOP, and ACD. Conclusions The percentage of IOP reduction after cataract surgery in nonglaucomatous eyes with open angles is greater in more anteriorly positioned lenses. Lens position, which is convenient to compute by basic ocular biometric data, is an accessible predictor with considerable predictive value for postoperative IOP change. PMID:26650901

  9. Determination of optimal imaging parameters for the reconstruction of a nuclear fuel assembly using limited angle neutron tomography

    NASA Astrophysics Data System (ADS)

    Abir, M. I.; Islam, F. F.; Craft, A.; Williams, W. J.; Wachs, D. M.; Chichester, D. L.; Meyer, M. K.; Lee, H. K.

    2016-01-01

    The core components of nuclear reactors (e.g., fuel assemblies, spacer grids, control rods) encounter harsh environments due to high temperature, physical stress, and a tremendous level of radiation. The integrity of these elements is crucial for safe operation of nuclear power plants; post-irradiation examination (PIE) can reveal information about the integrity of these components. Neutron computed tomography (CT) is one important PIE measurement tool for nondestructively evaluating the structural integrity of these items. CT typically requires many projections to be acquired from different view angles, after which a mathematical algorithm is used for image reconstruction. However, when working with heavily irradiated materials and irradiated nuclear fuel, obtaining many projections is laborious and expensive. Image reconstruction from a smaller number of projections has been explored to achieve faster and more cost-efficient PIE. Classical reconstruction methods (e.g., filtered backprojection), unfortunately, do not typically offer stable reconstructions from a highly asymmetric, few-projection data set and often create severe streaking artifacts. We propose an iterative reconstruction technique to reconstruct curved, plate-type nuclear fuel assemblies using limited-angle CT. The performance of the proposed method is assessed using simulated data and validated through real projections. We also discuss the systematic strategy for establishing the conditions of reconstructions and finding the optimal imaging parameters for reconstructions of the fuel assemblies from few projections using limited-angle CT. Results show that a fuel assembly can be reconstructed using limited-angle CT if 36 or more projections are taken from a particular direction with 1° angular increment.

  10. Laser-Assisted Bending of Sharp Angles With Small Fillet Radius on Stainless Steel Sheets: Analysis of Experimental Set-Up and Processing Parameters

    NASA Astrophysics Data System (ADS)

    Gisario, Annamaria; Barletta, Massimiliano; Venettacci, Simone; Veniali, Francesco

    2015-06-01

    Achievement of sharp bending angles with small fillet radius on stainless steel sheets by mechanical bending requires sophisticated bending device and troublesome operational procedures, which can involve expensive molds, huge presses and large loads. In addition, springback is always difficult to control, thus often leading to final parts with limited precision and accuracy. In contrast, laser-assisted bending of metals is an emerging technology, as it often allows to perform difficult and multifaceted manufacturing tasks with relatively small efforts. In the present work, laser-assisted bending of stainless steel sheets to achieve sharp angles is thus investigated. First, bending trials were performed by combining laser irradiation with an auxiliary bending device triggered by a pneumatic actuator and based on kinematic of deformable quadrilaterals. Second, laser operational parameters, that is, scanning speed, power and number of passes, were varied to identify the most suitable processing settings. Bending angles and fillet radii were measured by coordinate measurement machine. Experimental data were elaborated by combined ANalysis Of Mean (ANOM) and ANalysis Of VAriance (ANOVA). Based on experimental findings, the best strategy to achieve an aircraft prototype from a stainless steel sheet was designed and implemented.

  11. Additives

    NASA Technical Reports Server (NTRS)

    Smalheer, C. V.

    1973-01-01

    The chemistry of lubricant additives is discussed to show what the additives are chemically and what functions they perform in the lubrication of various kinds of equipment. Current theories regarding the mode of action of lubricant additives are presented. The additive groups discussed include the following: (1) detergents and dispersants, (2) corrosion inhibitors, (3) antioxidants, (4) viscosity index improvers, (5) pour point depressants, and (6) antifouling agents.

  12. Comparison of Schlemm's canal's biological parameters in primary open-angle glaucoma and normal human eyes with swept source optical

    NASA Astrophysics Data System (ADS)

    Wang, Fei; Shi, Guohua; Li, Xiqi; Lu, Jing; Ding, Zhihua; Sun, Xinghuai; Jiang, Chunhui; Zhang, Yudong

    2012-11-01

    Thirty-seven normal and primary open angle glaucoma (POAG) subjects were noninvasively imaged by a tailor-made real-time anterior segment swept source optical coherence tomography (SS-OCT) to demonstrate the differences of the Schlemm's canal (SC) between POAG and normal eyes. After the cross-section images of the anterior chamber angle were acquired by SS-OCT, SC was confirmed by two independent masked observers and the average area, long diameter, and perimeter of the SC were measured. In normal subjects the circumference, area, and long diameter is 580.34±87.81 μm, 8023.89±1486.10 μ, and 272.83±49.39 μm, respectively, and these parameters were 393.25±98.04 μm, 3941.50±1210.69 μ, and 190.91±46.47 μm in the POAG subjects. The area of SC in the normal ones was significantly larger than that in POAG eyes (p<0.001), so as the long diameter and the perimeter (p<0.001 p<0.001).

  13. Molecular-orbital coefficients for dinuclear polymethyne dyes in the effective additive parameter method

    SciTech Connect

    Dyadyusha, G.G.; Ushomirskii, M.M.

    1986-09-01

    A method previously proposed for determining the energy structure of a polymethyne dye with any terminal groups is used in considering formulas for the molecularorbital coefficients and the differences in the distribution on the atoms in the polymethyne chain for localized and delocalized energy levels, as well as the accuracy in calculating the molecular-orbital coefficients by means of a finite number of effective additive parameters. It is found that the localized states are important to the electron-density distribution on the chain atoms characteristic of the polymethyne dyes.

  14. Electrical and ionic conductivity effects on magic-angle spinning nuclear magnetic resonance parameters of CuI

    NASA Astrophysics Data System (ADS)

    Yesinowski, James P.; Ladouceur, Harold D.; Purdy, Andrew P.; Miller, Joel B.

    2010-12-01

    conductor in a homogeneous magnetic field. We present a theoretical analysis and finite-element simulations that account for the magnitude and rapid time-scale of the resistive heating effects and the quadratic spinning speed dependence of the chemical shift observed experimentally. Known thermophysical properties are used as inputs to the model, the sole adjustable parameter being a scaling of the bulk thermal conductivity of CuI in order to account for the effective thermal conductivity of the rotating powdered sample. In addition to the dramatic consequences of electrical conductivity in the sample, ionic conductivity also influences the spectra. All three nuclei exhibit quadrupolar satellite transitions extending over several hundred kilohertz that reflect defects perturbing the cubic symmetry of the zincblende lattice. Broadening of these satellite transitions with increasing temperature arises from the onset of Cu+ ion jumps to sites with different electric field gradients, a process that interferes with the formation of rotational echoes. This broadening has been quantitatively analyzed for the 63Cu and 65Cu nuclei using a simple model in the literature to yield an activation barrier of 0.64 eV (61.7 kJ/mole) for the Cu+ ion jumping motion responsible for the ionic conductivity that agrees with earlier results based on 63Cu NMR relaxation times of static samples

  15. Electrical and ionic conductivity effects on magic-angle spinning nuclear magnetic resonance parameters of CuI.

    PubMed

    Yesinowski, James P; Ladouceur, Harold D; Purdy, Andrew P; Miller, Joel B

    2010-12-21

    rotating a conductor in a homogeneous magnetic field. We present a theoretical analysis and finite-element simulations that account for the magnitude and rapid time-scale of the resistive heating effects and the quadratic spinning speed dependence of the chemical shift observed experimentally. Known thermophysical properties are used as inputs to the model, the sole adjustable parameter being a scaling of the bulk thermal conductivity of CuI in order to account for the effective thermal conductivity of the rotating powdered sample. In addition to the dramatic consequences of electrical conductivity in the sample, ionic conductivity also influences the spectra. All three nuclei exhibit quadrupolar satellite transitions extending over several hundred kilohertz that reflect defects perturbing the cubic symmetry of the zincblende lattice. Broadening of these satellite transitions with increasing temperature arises from the onset of Cu(+) ion jumps to sites with different electric field gradients, a process that interferes with the formation of rotational echoes. This broadening has been quantitatively analyzed for the (63)Cu and (65)Cu nuclei using a simple model in the literature to yield an activation barrier of 0.64 eV (61.7 kJ/mole) for the Cu(+) ion jumping motion responsible for the ionic conductivity that agrees with earlier results based on (63)Cu NMR relaxation times of static samples. PMID:21186877

  16. Normal- and oblique-shock flow parameters in equilibrium air including attached-shock solutions for surfaces at angles of attack, sweep, and dihedral

    NASA Technical Reports Server (NTRS)

    Hunt, J. L.; Souders, S. W.

    1975-01-01

    Normal- and oblique-shock flow parameters for air in thermochemical equilibrium are tabulated as a function of shock angle for altitudes ranging from 15.24 km to 91.44 km in increments of 7.62 km at selected hypersonic speeds. Post-shock parameters tabulated include flow-deflection angle, velocity, Mach number, compressibility factor, isentropic exponent, viscosity, Reynolds number, entropy difference, and static pressure, temperature, density, and enthalpy ratios across the shock. A procedure is presented for obtaining oblique-shock flow properties in equilibrium air on surfaces at various angles of attack, sweep, and dihedral by use of the two-dimensional tabulations. Plots of the flow parameters against flow-deflection angle are presented at altitudes of 30.48, 60.96, and 91.44 km for various stream velocities.

  17. Additional deleterious effects of alcohol consumption on sperm parameters and DNA integrity in diabetic mice.

    PubMed

    Pourentezari, M; Talebi, A R; Mangoli, E; Anvari, M; Rahimipour, M

    2016-06-01

    The aim of this study was to survey the impact of alcohol consumption on sperm parameters and DNA integrity in experimentally induced diabetic mice. A total of 32 adult male mice were divided into four groups: mice of group 1 served as control fed on basal diet, group 2 received streptozotocin (STZ) (200 mg kg(-1) , single dose, intraperitoneal) and basal diet, group 3 received alcohol (10 mg kg(-1) , water soluble) and basal diet, and group 4 received STZ and alcohol for 35 days. The cauda epididymidis of each mouse was dissected and placed in 1 ml of pre-warm Ham's F10 culture medium for 30 min. The swim-out spermatozoa were analysed for count, motility, morphology and viability. Sperm chromatin quality was evaluated with aniline blue, toluidine blue, acridine orange and chromomycin A3 staining. The results showed that all sperm parameters had significant differences (P < 0.05), also when sperm chromatin was assessed with cytochemical tests. There were significant differences (P < 0.001) between the groups. According to our results, alcohol and diabetes can cause abnormalities in sperm parameters and chromatin quality. In addition, alcohol consumption in diabetic mice can intensify sperm chromatin/DNA damage. PMID:26358836

  18. Microanisotropy imaging: quantification of microscopic diffusion anisotropy and orientational order parameter by diffusion MRI with magic-angle spinning of the q-vector

    NASA Astrophysics Data System (ADS)

    Lasič, Samo; Szczepankiewicz, Filip; Eriksson, Stefanie; Nilsson, Markus; Topgaard, Daniel

    2014-02-01

    Diffusion tensor imaging (DTI) is the method of choice for non-invasive investigations of the structure of human brain white matter. The results are conventionally reported as maps of the fractional anisotropy (FA), which is a parameter related to microstructural features such as axon density, diameter, and myelination. The interpretation of FA in terms of microstructure becomes ambiguous when there is a distribution of axon orientations within the image voxel. In this paper, we propose a procedure for resolving this ambiguity by determining a new parameter, the microscopic fractional anisotropy (µFA), which corresponds to the FA without the confounding influence of orientation dispersion. In addition, we suggest a method for measuring the orientational order parameter (OP) for the anisotropic objects. The experimental protocol is capitalizing on a recently developed diffusion NMR pulse sequence based on magic-angle spinning of the q-vector. Proof-of-principle experiments are carried out on microimaging and clinical MRI equipment using lyotropic liquid crystals and plant tissues as model materials with high µFA and low FA on account of orientation dispersion. We expect the presented method to be especially fruitful in combination with DTI and high angular resolution acquisition protocols for neuroimaging studies of grey and white matter.

  19. Magnetic resonance imaging of anterior cruciate ligament tears: reevaluation of quantitative parameters and imaging findings including a simplified method for measuring the anterior cruciate ligament angle.

    PubMed

    Mellado, J M; Calmet, J; Olona, M; Giné, J; Saurí, A

    2004-05-01

    We evaluated the diagnostic utility of magnetic resonance imaging (MRI) for predicting anterior cruciate ligament (ACL) tears using both quantitative parameters and nonquantitative imaging findings. MRI examinations were retrospectively evaluated in a group of patients with arthroscopically confirmed complete ACL tear and in a control group with arthroscopically confirmed intact ACL. We evaluated multiple MRI features to compare their sensitivity and specificity for detecting ACL tears. Particular emphasis is put on the evaluation of three different quantitative parameters, including a simplified method for measuring the ACL angle. With a threshold value of 45 degrees the ACL angle reached a sensitivity and specificity of 100% for detecting ACL tears. With a threshold value of 0 degrees the Blumensaat angle had a sensitivity of 90% and a specificity of 98%. Finally, a threshold value of 115 degrees gave the posterior cruciate ligament angle a sensitivity of 70% and a specificity of 82%. Discontinuity was found to be the most useful of the ACL abnormalities. Of the secondary findings anterior tibial displacement was the best predictor of ligamentous injury. However, ACL abnormalities and secondary findings, alone or combined, failed to surpass the diagnostic value of the ACL angle for predicting ACL tears. Quantitative parameters are thus good predictors of ACL tears and may increase the overall sensitivity and specificity of MRI. The ACL angle may be confidently measured in a single MRI section and can be considered to be the most reliable quantitative parameter for detecting ACL tears. PMID:14530852

  20. Short-term effects of acupuncture on open-angle glaucoma in retrobulbar circulation: additional therapy to standard medication.

    PubMed

    Takayama, Shin; Seki, Takashi; Nakazawa, Toru; Aizawa, Naoko; Takahashi, Seri; Watanabe, Masashi; Izumi, Masayuki; Kaneko, Soichiro; Kamiya, Tetsuharu; Matsuda, Ayane; Kikuchi, Akiko; Yambe, Tomoyuki; Yoshizawa, Makoto; Nitta, Shin-Ichi; Yaegashi, Nobuo

    2011-01-01

    Background. The relation between glaucoma and retrobulbar circulation in the prognosis has been indicated. Purpose. To investigate the effects of acupuncture on retrobulbar circulation in open-angle glaucoma (OAG) patients. Methods. Eleven OAG patients (20 eyes with OAG) who were treated by topical antiglaucoma medications for at least 3 months were enrolled. Acupuncture was performed once at acupoints BL2, M-HN9, ST2, ST36, SP6, KI3, LR3, GB20, BL18, and BL23 bilaterally. Retrobulbar circulation was measured with color Doppler imaging, and intraocular pressure (IOP) was also measured at rest and one hour after rest or before and after acupuncture. Results. The Δ value of the resistive index in the short posterior ciliary artery (P < .01) and the Δ value of IOP (P < .01) were decreased significantly by acupuncture compared with no acupuncture treatment. Conclusions. Acupuncture can improve the retrobulbar circulation and IOP, which may indicate the efficacy of acupuncture for OAG. PMID:21437193

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

    NASA Astrophysics Data System (ADS)

    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 φ 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 φ 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 φ to either the transverse or coronal planes of the patient.

  2. Effect of additives on distributions of lamellar structures in sheared polymer: a study of synchrotron small-angle x-ray scattering

    NASA Astrophysics Data System (ADS)

    Zhu, Peng-Wei; Edward, Graham; Nichols, Lance

    2009-12-01

    The effects of additives on the distributions of lamellar morphology and orientation in sheared isotactic polypropylene were investigated using the small beam of synchrotron small-angle x-ray scattering. The Cu-phthalocyanine can template the lamellar orientation even under low shear rates, whereas the ultramarine blue cannot. The surface contact is suggested to play a role in stabilizing the formation of oriented nuclei which subsequently direct the growth of oriented lamellae. The additives have no notable effects on the long spacing in the shear region. However, at high shear rates, they decrease the thickness of crystalline lamellae or increase the thickness of amorphous lamellae. Since the additives increase the degree of volume crystalline in the shear region, the number of crystalline lamellae should be increased. The results are helpful in designing and selecting suitable additives for controlling lamellar morphology and orientation.

  3. Fusion of Multi-Angle Imaging Spectrometer and LIDAR Data for Forest Structural Parameter Retrieval Using 3D Radiative Transfer Modeling

    NASA Astrophysics Data System (ADS)

    Rubio, J.; Sun, G.; Koetz, B.; Ranson, K. J.; Kimes, D.; Gastellu-Etchegorry, J.

    2008-12-01

    The potential of combined multi-angle/multi-spectral optical imagery and LIDAR waveform data to retrieve structural parameters on forest is explored. Our approach relies on two physically based radiative transfer models (RTM), the Discrete Anisotropic Radiative Transfer (DART) for the generation of the BRF images and Sun and Ranson's LIDAR waveform model for the large footprint LIDAR data. These RTM are based on the same basic physical principles and share common inputs parameters. We use the Zelig forest growth model to provide a synthetic but realistic data set to the two RTM. The forest canopy biophysical variables that are being investigated include the maximal tree height, fractional cover, LAI and vertical crown extension. We assess the inversion of forest structural parameters when considering each model separately, then we investigate the accuracy of a coupled inversion. Keywords: Forest, Radiative Transfer Model, Inversion, Fusion, Multi-Angle, LAI, Fractional cover, Tree height, Canopy structure, Biomass, LIDAR, Forest growth model

  4. Generalization of the Euler Angles

    NASA Technical Reports Server (NTRS)

    Bauer, Frank H. (Technical Monitor); Shuster, Malcolm D.; Markley, F. Landis

    2002-01-01

    It is shown that the Euler angles can be generalized to axes other than members of an orthonormal triad. As first shown by Davenport, the three generalized Euler axes, hereafter: Davenport axes, must still satisfy the constraint that the first two and the last two axes be mutually perpendicular if these axes are to define a universal set of attitude parameters. Expressions are given which relate the generalized Euler angles, hereafter: Davenport angles, to the 3-1-3 Euler angles of an associated direction-cosine matrix. The computation of the Davenport angles from the attitude matrix and their kinematic equation are presented. The present work offers a more direct development of the Davenport angles than Davenport's original publication and offers additional results.

  5. Estimation of Parameters Subject to Order Restrictions on a Circle With Application to Estimation of Phase Angles of Cell Cycle Genes

    PubMed Central

    Rueda, Cristina; Fernández, Miguel A.; Peddada, Shyamal Das

    2009-01-01

    Motivated by a problem encountered in the analysis of cell cycle gene expression data, this article deals with the estimation of parameters subject to order restrictions on a unit circle. A normal eukaryotic cell cycle has four major phases during cell division, and a cell cycle gene has its peak expression (phase angle) during the phase that may correspond to its biological function. Because the phases are ordered along a circle, the phase angles of cell cycle genes are ordered unknown parameters on a unit circle. The problem of interest is to estimate the phase angles using the information regarding the order among them. We address this problem by developing a circular version of the well-known isotonic regression for Euclidean data. Because of the underlying geometry, the standard pool adjacent violator algorithm (PAVA) cannot be used for deriving the circular isotonic regression estimator (CIRE). However, PAVA can be modified to obtain a computationally efficient algorithm for deriving the CIRE. We illustrate the CIRE by estimating the phase angles of some of well-known cell cycle genes using the unrestricted estimators obtained in the literature. PMID:19750145

  6. Effect of a phytogenic feed additive on performance, ovarian morphology, serum lipid parameters and egg sensory quality in laying hen

    PubMed Central

    Saki, Ali Asghar; Aliarabi, Hassan; Hosseini Siyar, Sayed Ali; Salari, Jalal; Hashemi, Mahdi

    2014-01-01

    This present study was conducted to evaluate the effects of dietary inclusion of 4, 8 and 12 g kg-1 phytogenic feed additives mixture on performance, egg quality, ovary parameters, serum biochemical parameters and yolk trimethylamine level in laying hens. The results of experiment have shown that egg weight was increased by supplementation of 12 g kg-1 feed additive whereas egg production, feed intake and feed conversion ratio (FCR) were not significantly affected. There were no significant differences in egg quality parameters by supplementation of phytogenic feed additive, whereas yolk trimethylamine level was decreased as the feed additive level increased. The sensory evaluation parameters did not differ significantly. No significant differences were found in serum cholesterol and triglyceride levels between the treatments but low- and high-density lipoprotein were significantly increased. Number of small follicles and ovary weight were significantly increased by supplementation of 12 g kg-1 feed additive. Overall, dietary supplementation of polyherbal additive increased egg weigh, improved ovary characteristics and declined yolk trimethylamine level. PMID:25610580

  7. Effect of argon addition on plasma parameters and dust charging in hydrogen plasma

    SciTech Connect

    Kakati, B. Kausik, S. S.; Saikia, B. K.; Bandyopadhyay, M.; Saxena, Y. C.

    2014-10-28

    Experimental results on effect of adding argon gas to hydrogen plasma in a multi-cusp dusty plasma device are reported. Addition of argon modifies plasma density, electron temperature, degree of hydrogen dissociation, dust current as well as dust charge. From the dust charging profile, it is observed that the dust current and dust charge decrease significantly up to 40% addition of argon flow rate in hydrogen plasma. But beyond 40% of argon flow rate, the changes in dust current and dust charge are insignificant. Results show that the addition of argon to hydrogen plasma in a dusty plasma device can be used as a tool to control the dust charging in a low pressure dusty plasma.

  8. Radiation processing of thermoplastic starch by blending aromatic additives: Effect of blend composition and radiation parameters

    NASA Astrophysics Data System (ADS)

    Khandal, Dhriti; Mikus, Pierre-Yves; Dole, Patrice; Coqueret, Xavier

    2013-03-01

    This paper reports on the effects of electron beam (EB) irradiation on poly α-1,4-glucose oligomers (maltodextrins) in the presence of water and of various aromatic additives, as model blends for gaining a better understanding at a molecular level the modifications occurring in amorphous starch-lignin blends submitted to ionizing irradiation for improving the properties of this type of bio-based thermoplastic material. A series of aromatic compounds, namely p-methoxy benzyl alcohol, benzene dimethanol, cinnamyl alcohol and some related carboxylic acids namely cinnamic acid, coumaric acid, and ferulic acid, was thus studied for assessing the ability of each additive to counteract chain scission of the polysaccharide and induce interchain covalent linkages. Gel formation in EB-irradiated blends comprising of maltodextrin was shown to be dependent on three main factors: the type of aromatic additive, presence of glycerol, and irradiation dose. The chain scission versus grafting phenomenon as a function of blend composition and dose were studied using Size Exclusion Chromatography by determining the changes in molecular weight distribution (MWD) from Refractive Index (RI) chromatograms and the presence of aromatic grafts onto the maltodextrin chains from UV chromatograms. The occurrence of crosslinking was quantified by gel fraction measurements allowing for ranking the cross-linking efficiency of the additives. When applying the method to destructurized starch blends, gel formation was also shown to be strongly affected by the moisture content of the sample submitted to irradiation. The results demonstrate the possibility to tune the reactivity of tailored blend for minimizing chain degradation and control the degree of cross-linking.

  9. Effects of number of side dumps and side dump angles on outlet parameters in a side-dump combustor

    NASA Astrophysics Data System (ADS)

    Mojtahedpoor, M.; Doustdar, M. M.; Soltani, H.; Chegini, M.

    2012-11-01

    A numerical study on the effect of side-dump number on fuel droplets sizing and effective mass fraction have been investigated in present paper. The mass of fuel vapor inside the flammability limit is named as the effective mass fraction. In the first step we have considered a side-dump combustor with two dumps and dump angle of 0o (plumb to cylinder) and by increasing the entrance airflow velocity from 20 to 30, 40 and 50 (m/s) respectively, the mean diameter of fuel droplets sizing and effective mass fraction have been studied. After this step, we have changed the number of dumps from two to four and we have repeated last examination again. To fulfill the calculations a modified version of KIVA-3V code which is a transient, three-dimensional, multiphase, multicomponent code for the analysis of chemically reacting flows with sprays, is used.

  10. Linear, position-sensitive x-ray detector used for real-time calculations of small-angle scattering parameters with submillisecond resolution

    SciTech Connect

    Borso, C.S.

    1984-01-01

    The advent of high-intensity X-ray synchrotron sources has made possible the measurement of fluctuations in small-angle scattering parameters from typical specimens on a submillisecond time scale in real-time. The fundamental design of any fast detector system optimized for such measurements will incorporate some type of solid state detector array capable of rapid encoding algorithms. A prototype with a self-scanning photodiode array has been designed and tested at beamline 1 to 4 at the Stanford Synchrotron Radiation Laboratory (SSRL), and the results indicate that the device will operate at speeds yielding submillisecond temporal resolution in real-time.

  11. Superposition-additive approach: thermodynamic parameters of clusterization of monosubstituted alkanes at the air/water interface.

    PubMed

    Vysotsky, Yu B; Belyaeva, E A; Fomina, E S; Fainerman, V B; Aksenenko, E V; Vollhardt, D; Miller, R

    2011-12-21

    The applicability of the superposition-additive approach for the calculation of the thermodynamic parameters of formation and atomization of conjugate systems, their dipole electric polarisabilities, molecular diamagnetic susceptibilities, π-electron circular currents, as well as for the estimation of the thermodynamic parameters of substituted alkanes, was demonstrated earlier. Now the applicability of the superposition-additive approach for the description of clusterization of fatty alcohols, thioalcohols, amines, carboxylic acids at the air/water interface is studied. Two superposition-additive schemes are used that ensure the maximum superimposition of the graphs of the considered molecular structures including the intermolecular CH-HC interactions within the clusters. The thermodynamic parameters of clusterization are calculated for dimers, trimers and tetramers. The calculations are based on the values of enthalpy, entropy and Gibbs' energy of clusterization calculated earlier using the semiempirical quantum chemical PM3 method. It is shown that the proposed approach is capable of the reproduction with sufficiently enough accuracy of the values calculated previously. PMID:22042000

  12. Microstructural Parameters in 8 MeV Electron-Irradiated BOMBYX MORI Silk Fibers by Wide-ANGLE X-Ray Scattering Studies (waxs)

    NASA Astrophysics Data System (ADS)

    Sangappa, Asha, S.; Sanjeev, Ganesh; Subramanya, G.; Parameswara, P.; Somashekar, R.

    2010-01-01

    The present work looks into the microstructural modification in electron irradiated Bombyx mori P31 silk fibers. The irradiation process was performed in air at room temperature using 8 MeV electron accelerator at different doses: 0, 25, 50 and 100 kGy. Irradiation of polymer is used to cross-link or degrade the desired component or to fix the polymer morphology. The changes in microstructural parameters in these natural polymer fibers have been computed using wide angle X-ray scattering (WAXS) data and employing line profile analysis (LPA) using Fourier transform technique of Warren. Exponential, Lognormal and Reinhold functions for the column length distributions have been used for the determination of crystal size, lattice strain and enthalpy parameters.

  13. Establishing Age-Adjusted Reference Ranges for Iris-Related Parameters in Open Angle Eyes with Anterior Segment Optical Coherence Tomography

    PubMed Central

    Peterson, Jeffrey R.; Blieden, Lauren S.; Chuang, Alice Z.; Baker, Laura A.; Rigi, Mohammed; Feldman, Robert M.; Bell, Nicholas P.

    2016-01-01

    Purpose Define criteria for iris-related parameters in an adult open angle population as measured with swept source Fourier domain anterior segment optical coherence tomography (ASOCT). Methods Ninety-eight eyes of 98 participants with open angles were included and stratified into 5 age groups (18–35, 36–45, 46–55, 56–65, and 66–79 years). ASOCT scans with 3D mode angle analysis were taken with the CASIA SS-1000 (Tomey Corporation, Nagoya, Japan) and analyzed using the Anterior Chamber Analysis and Interpretation software. Anterior iris surface length (AISL), length of scleral spur landmark (SSL) to pupillary margin (SSL-to-PM), iris contour ratio (ICR = AISL/SSL-to-PM), pupil radius, radius of iris centroid (RICe), and iris volume were measured. Outcome variables were summarized for all eyes and age groups, and mean values among age groups were compared using one-way analysis of variance. Stepwise regression analysis was used to investigate demographic and ocular characteristic factors that affected each iris-related parameter. Results Mean (±SD) values were 2.24 mm (±0.46), 4.06 mm (±0.27), 3.65 mm (±0.48), 4.16 mm (±0.47), 1.14 (±0.04), 1.51 mm2 (±0.23), and 38.42 μL (±4.91) for pupillary radius, RICe, SSL-to-PM, AISL, ICR, iris cross-sectional area, and iris volume, respectively. Both pupillary radius (P = 0.002) and RICe (P = 0.027) decreased with age, while SSL-to-PM (P = 0.002) and AISL increased with age (P = 0.001). ICR (P = 0.54) and iris volume (P = 0.49) were not affected by age. Conclusion This study establishes reference values for iris-related parameters in an adult open angle population, which will be useful for future studies examining the role of iris changes in pathologic states. PMID:26815917

  14. Effect of Operating Parameters and Chemical Additives on Crystal Habit and Specific Cake Resistance of Zinc Hydroxide Precipitates

    SciTech Connect

    Alwin, Jennifer Louise

    1999-08-01

    The effect of process parameters and chemical additives on the specific cake resistance of zinc hydroxide precipitates was investigated. The ability of a slurry to be filtered is dependent upon the particle habit of the solid and the particle habit is influenced by certain process variables. The process variables studied include neutralization temperature, agitation type, and alkalinity source used for neutralization. Several commercially available chemical additives advertised to aid in solid/liquid separation were also examined in conjunction with hydroxide precipitation. A statistical analysis revealed that the neutralization temperature and the source of alkalinity were statistically significant in influencing the specific cake resistance of zinc hydroxide precipitates in this study. The type of agitation did not significantly effect the specific cake resistance of zinc hydroxide precipitates. The use of chemical additives in conjunction with hydroxide precipitation had a favorable effect on the filterability. The morphology of the hydroxide precipitates was analyzed using scanning electron microscopy.

  15. Seismic reflection data imaging and interpretation from Braniewo2014 experiment using additional wide-angle refraction and reflection and well-logs data

    NASA Astrophysics Data System (ADS)

    Trzeciak, Maciej; Majdański, Mariusz; Białas, Sebastian; Gaczyński, Edward; Maksym, Andrzej

    2015-04-01

    Braniewo2014 reflection and refraction experiment was realized in cooperation between Polish Oil and Gas Company (PGNiG) and the Institute of Geophysics (IGF), Polish Academy of Sciences, near the locality of Braniewo in northern Poland. PGNiG realized a 20-km-long reflection profile, using vibroseis and dynamite shooting; the aim of the reflection survey was to characterise Silurian shale gas reservoir. IGF deployed 59 seismic stations along this profile and registered additional full-spread wide-angle refraction and reflection data, with offsets up to 12 km; maximum offsets from the seismic reflection survey was 3 km. To improve the velocity information two velocity logs from near deep boreholes were used. The main goal of the joint reflection-refraction interpretation was to find relations between velocity field from reflection velocity analysis and refraction tomography, and to build a velocity model which would be consistent for both, reflection and refraction, datasets. In this paper we present imaging results and velocity models from Braniewo2014 experiment and the methodology we used.

  16. Parameter Estimation for a Physically-Based Model Using Multi-Objective Approach Constrained With Additional Internal States

    NASA Astrophysics Data System (ADS)

    Zhang, G.; Fenicia, F.; Savenije, H. H.

    2007-12-01

    . Therefore, in addition to the use of stream flow measurements for model calibration and uncertainty analysis, groundwater table gauging data were also used to help constrain parameter space. In model parameter identification, objective functions in favor of both high flows and low flows were employed to optimize the model performance. Results of this study show that parameters for subsurface processes are better identifiable than those for surface processes. This work also demonstrates that MOSCEM-UA is an efficient tool in parameter identification giving more insight to the structural behavior of the model.

  17. In-situ surface wettability parameters of submerged in brackish water surfaces derived from captive bubble contact angle studies as indicators of surface condition level

    NASA Astrophysics Data System (ADS)

    Pogorzelski, S. J.; Mazurek, A. Z.; Szczepanska, A.

    2013-06-01

    The characterization of wetting properties (by contact angles) of several undersea artificial (glass plates,) and natural (stones, sand layers, soft-bottom structures, aquatic macrophytes, sediments, and seafloor communities) solid substrata in the Baltic Sea brackish water (Gulf of Gdansk). The studies were performed under laboratory and field conditions using a novel captive bubble air-pipette computer microscope system. A set of the surface wettability parameters: the apparent surface free energy γSV, adhesive layer film pressure Π, work of adhesion WA, and work of spreading WS were determined to quantify the wetting properties of model substrata using the contact angle hysteresis (CAH) approach. The useful technique to measure in situ the contact angle giving reproducible and accurate values of CA turned out to be a captive bubble method, for fully hydrated interfacial layers of highly hydrophilic and porous nature met at seabed (Rodrigues-Valverde et al., 2002). CA measurements revealed mostly hydrophilic nature of the studied solid material (CA < 90°) where the presence of adsorbed organic matter layer or crude oil film covering lead to surface hydrophobization (CA↑, γSV ↓,WA↓, WS more negative). The adhesion of biofouling was correlated both with CAH and the dispersive interaction term γSVd of the total γSV. Monitoring of the artificial substrata of the hydrophilic nature with a CA technique can be used to observe the development of the organisms community i.e., microfouling, and to carry out a comprehensive study of surfaces of the submerged macrophytes (Potamogeton lucens in particular). Since aquatic macrophytes can act as bio-indicators of water chemistry their surface wettability may reflect plant surface erosion and organic matter accumulation state being of particular value in biological assessment of ecosystems status.

  18. Failure of the addition of fresh seminal plasma to cryopreserved-thawed sperm to improve semen parameters.

    PubMed

    Check, D J; Check, M L; Bollendorf, A; Check, J H

    1993-01-01

    Previous data has shown that subnormal motility in some semen specimens can be improved by the addition of fresh human seminal plasma (HSP). However, if the HSP was first frozen the motility-enhancing factor was lost. We hypothesized that some of the reduction in sperm motility of cryopreserved-thawed sperm may be related to damage of the "motility-enhancing factor" of HSP. This study evaluated whether the addition of fresh HSP could improve the motility of frozen-thawed sperm. Each frozen-thawed specimen was evaluated for motile density and hypoosmotic swelling and then divided into two aliquots. Equal volumes of HSP, human tubal fluid (HTF), and control media were added and the semen parameters were reevaluated. The mean scores for motile density and percent motility did not change compared with baseline thawed volumes with either HSP or HTF additives. There were some isolated cases that did improve with either HSP (21%) or HTF (14%). Future studies are needed to determine whether this improvement is coincidental or consistent, and to determine whether at least some individuals can benefit from the addition of fresh HSP to frozen-thawed sperm. PMID:8215691

  19. Support vector machine to predict diesel engine performance and emission parameters fueled with nano-particles additive to diesel fuel

    NASA Astrophysics Data System (ADS)

    Ghanbari, M.; Najafi, G.; Ghobadian, B.; Mamat, R.; Noor, M. M.; Moosavian, A.

    2015-12-01

    This paper studies the use of adaptive Support Vector Machine (SVM) to predict the performance parameters and exhaust emissions of a diesel engine operating on nanodiesel blended fuels. In order to predict the engine parameters, the whole experimental data were randomly divided into training and testing data. For SVM modelling, different values for radial basis function (RBF) kernel width and penalty parameters (C) were considered and the optimum values were then found. The results demonstrate that SVM is capable of predicting the diesel engine performance and emissions. In the experimental step, Carbon nano tubes (CNT) (40, 80 and 120 ppm) and nano silver particles (40, 80 and 120 ppm) with nanostructure were prepared and added as additive to the diesel fuel. Six cylinders, four-stroke diesel engine was fuelled with these new blended fuels and operated at different engine speeds. Experimental test results indicated the fact that adding nano particles to diesel fuel, increased diesel engine power and torque output. For nano-diesel it was found that the brake specific fuel consumption (bsfc) was decreased compared to the net diesel fuel. The results proved that with increase of nano particles concentrations (from 40 ppm to 120 ppm) in diesel fuel, CO2 emission increased. CO emission in diesel fuel with nano-particles was lower significantly compared to pure diesel fuel. UHC emission with silver nano-diesel blended fuel decreased while with fuels that contains CNT nano particles increased. The trend of NOx emission was inverse compared to the UHC emission. With adding nano particles to the blended fuels, NOx increased compared to the net diesel fuel. The tests revealed that silver & CNT nano particles can be used as additive in diesel fuel to improve complete combustion of the fuel and reduce the exhaust emissions significantly.

  20. Enhancing endmember selection in multiple endmember spectral mixture analysis (MESMA) for urban impervious surface area mapping using spectral angle and spectral distance parameters

    NASA Astrophysics Data System (ADS)

    Fan, Fenglei; Deng, Yingbin

    2014-12-01

    Successful retrieval of urban impervious surface area is achieved with remote sensing data using the multiple endmember spectral mixture analysis (MESMA). MESMA is well suited for studying the urban impervious surface area because it allows the number and types of the endmembers to vary on a per-pixel basis, thereby, allowing the control of the large spectral variability. However, MESMA must calculate all potential endmember combinations of each pixel to determine the best-fit one. Therefore, it is a time-consuming and inefficient unmixing technology, especially for hyperspectral images because these images have more complicated endmember categories. Hence, in this paper, we design an improved MESMA (SASD-MESMA: spectral angle and spectral distance MESMA) to enhance the computational efficiency of conventional MESMA, and we validate this new method by analyzing the Hyperion image (Jan-2011) and the field-spectra data of Guangzhou (China). In SASD-MESMA, the parameters of spectral angle (SA) and spectral distance (SD) are used to evaluate the similarity degree between library spectra and image spectra in order to identify the most representative endmember combination for each pixel. Results demonstrate that the SA and SD parameters are useful to reduce misjudgment in selecting candidate endmembers and effective for determining the appropriate endmembers in one pixel. Meanwhile, this research indicates that the proposed SASD-MESMA performs very well in retrieving impervious surface area, forest, grass and soil distributions on the sub-pixel level (the overall root mean square error (RMSE) is 0.15 and the correlation coefficient of determination (R2) is 0.68).

  1. Effects of anodizing parameters and heat treatment on nanotopographical features, bioactivity, and cell culture response of additively manufactured porous titanium.

    PubMed

    Amin Yavari, S; Chai, Y C; Böttger, A J; Wauthle, R; Schrooten, J; Weinans, H; Zadpoor, A A

    2015-06-01

    Anodizing could be used for bio-functionalization of the surfaces of titanium alloys. In this study, we use anodizing for creating nanotubes on the surface of porous titanium alloy bone substitutes manufactured using selective laser melting. Different sets of anodizing parameters (voltage: 10 or 20V anodizing time: 30min to 3h) are used for anodizing porous titanium structures that were later heat treated at 500°C. The nanotopographical features are examined using electron microscopy while the bioactivity of anodized surfaces is measured using immersion tests in the simulated body fluid (SBF). Moreover, the effects of anodizing and heat treatment on the performance of one representative anodized porous titanium structures are evaluated using in vitro cell culture assays using human periosteum-derived cells (hPDCs). It has been shown that while anodizing with different anodizing parameters results in very different nanotopographical features, i.e. nanotubes in the range of 20 to 55nm, anodized surfaces have limited apatite-forming ability regardless of the applied anodizing parameters. The results of in vitro cell culture show that both anodizing, and thus generation of regular nanotopographical feature, and heat treatment improve the cell culture response of porous titanium. In particular, cell proliferation measured using metabolic activity and DNA content was improved for anodized and heat treated as well as for anodized but not heat-treated specimens. Heat treatment additionally improved the cell attachment of porous titanium surfaces and upregulated expression of osteogenic markers. Anodized but not heat-treated specimens showed some limited signs of upregulated expression of osteogenic markers. In conclusion, while varying the anodizing parameters creates different nanotube structure, it does not improve apatite-forming ability of porous titanium. However, both anodizing and heat treatment at 500°C improve the cell culture response of porous titanium. PMID

  2. The EBLM project. I. Physical and orbital parameters, including spin-orbit angles, of two low-mass eclipsing binaries on opposite sides of the brown dwarf limit

    NASA Astrophysics Data System (ADS)

    Triaud, A. H. M. J.; Hebb, L.; Anderson, D. R.; Cargile, P.; Collier Cameron, A.; Doyle, A. P.; Faedi, F.; Gillon, M.; Gomez Maqueo Chew, Y.; Hellier, C.; Jehin, E.; Maxted, P.; Naef, D.; Pepe, F.; Pollacco, D.; Queloz, D.; Ségransan, D.; Smalley, B.; Stassun, K.; Udry, S.; West, R. G.

    2013-01-01

    This paper introduces a series of papers aiming to study the dozens of low-mass eclipsing binaries (EBLM), with F, G, K primaries, that have been discovered in the course of the WASP survey. Our objects are mostly single-line binaries whose eclipses have been detected by WASP and were initially followed up as potential planetary transit candidates. These have bright primaries, which facilitates spectroscopic observations during transit and allows the study of the spin-orbit distribution of F, G, K+M eclipsing binaries through the Rossiter-McLaughlin effect. Here we report on the spin-orbit angle of WASP-30b, a transiting brown dwarf, and improve its orbital parameters. We also present the mass, radius, spin-orbit angle and orbital parameters of a new eclipsing binary, J1219-39b (1SWAPJ121921.03-395125.6, TYC 7760-484-1), which, with a mass of 95 ± 2 Mjup, is close to the limit between brown dwarfs and stars. We find that both objects have projected spin-orbit angles aligned with their primaries' rotation. Neither primaries are synchronous. J1219-39b has a modestly eccentric orbit and is in agreement with the theoretical mass-radius relationship, whereas WASP-30b lies above it. Using WASP-South photometric observations (Sutherland, South Africa) confirmed with radial velocity measurement from the CORALIE spectrograph, photometry from the EulerCam camera (both mounted on the Swiss 1.2 m Euler Telescope), radial velocities from the HARPS spectrograph on the ESO's 3.6 m Telescope (prog ID 085.C-0393), and photometry from the robotic 60 cm TRAPPIST telescope, all located at ESO, La Silla, Chile. The data is publicly available at the CDS Strasbourg and on demand to the main author.Tables A.1-A.3 are available in electronic form at http://www.aanda.orgPhotometry tables are only available at the CDS via anonymous ftp to cdsarc.u-strasbg.fr (130.79.128.5) or via http://cdsarc.u-strasbg.fr/viz-bin/qcat?J/A+A/549/A18

  3. Role of anaerobic fungi in wheat straw degradation and effects of plant feed additives on rumen fermentation parameters in vitro.

    PubMed

    Dagar, S S; Singh, N; Goel, N; Kumar, S; Puniya, A K

    2015-01-01

    In the present study, rumen microbial groups, i.e. total rumen microbes (TRM), total anaerobic fungi (TAF), avicel enriched bacteria (AEB) and neutral detergent fibre enriched bacteria (NEB) were evaluated for wheat straw (WS) degradability and different fermentation parameters in vitro. Highest WS degradation was shown for TRM, followed by TAF, NEB and least by AEB. Similar patterns were observed with total gas production and short chain fatty acid profiles. Overall, TAF emerged as the most potent individual microbial group. In order to enhance the fibrolytic and rumen fermentation potential of TAF, we evaluated 18 plant feed additives in vitro. Among these, six plant additives namely Albizia lebbeck, Alstonia scholaris, Bacopa monnieri, Lawsonia inermis, Psidium guajava and Terminalia arjuna considerably improved WS degradation by TAF. Further evaluation showed A. lebbeck as best feed additive. The study revealed that TAF plays a significant role in WS degradation and their fibrolytic activities can be improved by inclusion of A. lebbeck in fermentation medium. Further studies are warranted to elucidate its active constituents, effect on fungal population and in vivo potential in animal system. PMID:25391347

  4. Hematological parameters in Polish mixed breed rabbits with addition of meat breed blood in the annual cycle.

    PubMed

    Tokarz-Deptuła, B; Niedźwiedzka-Rystwej, P; Adamiak, M; Hukowska-Szematowicz, B; Trzeciak-Ryczek, A; Deptuła, W

    2015-01-01

    In the paper we studied haematologic values, such as haemoglobin concentration, haematocrit value, thrombocytes, leucocytes: lymphocytes, neutrophils, basophils, eosinophils and monocytes in the pheral blood in Polish mixed-breeds with addition of meat breed blood in order to obtain the reference values which are until now not available for this animals. In studying this indices we took into consideration the impact of the season (spring, summer, autumn, winter), and sex of the animals. The studies have shown a high impact of the season of the year on those rabbits, but only in spring and summer. Moreover we observed that the sex has mean impact on the studied values of haematological parameters in those rabbits. According to our knowledge, this is the first paper on haematologic values in this widely used group of rabbits, so they may serve as reference values. PMID:26812808

  5. Coupling parameters of many-body interactions for the Al(100) surface state: A high-resolution angle-resolved photoemission spectroscopy study

    NASA Astrophysics Data System (ADS)

    Jiang, J.; Shimada, K.; Hayashi, H.; Iwasawa, H.; Aiura, Y.; Namatame, H.; Taniguchi, M.

    2011-10-01

    We examined the dimensionless coupling parameters of many-body interactions for a free-electron-like surface-derived state in Al(100) by means of high-resolution angle-resolved photoemission spectroscopy. A kink structure was found to exist in the energy-band dispersion near the Fermi level (EF), which was attributed to the electron-phonon interaction. At 50 K, the coupling parameters of the electron-phonon and electron-electron interactions were estimated as λep=0.67±0.05 and λee˜0.003, respectively, indicating that the effective mass enhancement was mainly derived from the electron-phonon interaction. The temperature dependence of the kink structure, as measured by λep(T), was consistent with a theoretical calculation based on the Eliashberg function. A quasiparticle peak with a width of 15-20 meV was found near EF, which was explained well by the simulated spectral function incorporating the self-energy evaluated in this study. We found that the electrons at the surface were strongly scattered by the defects at the surface and that the linewidth was significantly broadened (Γ0=0.238±0.006 eV).

  6. 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. PMID:17072395

  7. Optimal welding parameters for very high power ultrasonic additive manufacturing of smart structures with aluminum 6061 matrix

    NASA Astrophysics Data System (ADS)

    Wolcott, Paul J.; Hehr, Adam; Dapino, Marcelo J.

    2014-03-01

    Ultrasonic additive manufacturing (UAM) is a recent solid state manufacturing process that combines ad- ditive joining of thin metal tapes with subtractive milling operations to generate near net shape metallic parts. Due to the minimal heating during the process, UAM is a proven method of embedding Ni-Ti, Fe-Ga, and PVDF to create active metal matrix composites. Recently, advances in the UAM process utilizing 9 kW very high power (VHP) welding has improved bonding properties, enabling joining of high strength materials previously unweldable with 1 kW low power UAM. Consequently, a design of experiments study was conducted to optimize welding conditions for aluminum 6061 components. This understanding is critical in the design of UAM parts containing smart materials. Build parameters, including weld force, weld speed, amplitude, and temperature were varied based on a Taguchi experimental design matrix and tested for me- chanical strength. Optimal weld parameters were identi ed with statistical methods including a generalized linear model for analysis of variance (ANOVA), mean e ects plots, and interaction e ects plots.

  8. The influence of non-solvent addition on the independent and dependent parameters in roller electrospinning of polyurethane.

    PubMed

    Cengiz-Callioglu, Funda; Jirsak, Oldrich; Dayik, Mehmet

    2013-07-01

    This paper discusses the effects of 1,1,2,2 tetrachlorethylen (TCE) non-solvent addition on the independent (electrical conductivity, dielectric constant, surface tension and the theological properties of the solution etc.) and dependent parameters (number of Taylor cones per square meter (NTC/m2), spinning performance for one Taylor cone (SP/TC), total spinning performance (SP), fiber properties such as diameter, diameter uniformity, non-fibrous area) in roller electrospinning of polyurethane (PU). The same process parameters (voltage, distance of the electrodes, humidity, etc.) were applied for all solutions during the spinning process. According to the results, the effect of TCE non-solvent concentration on the dielectric constant, surface tension, rheological properties of the solution and also spinning performance was important statistically. Beside these results, TCE non-solvent concentration effects quality of fiber and nano web structure. Generally high fiber density, low non-fibrous percentage and uniform nanofibers were obtained from fiber morphology analyses. PMID:23901497

  9. [Influence Additional Cognitive Tasks on EEG Beta Rhythm Parameters during Forming and Testing Set to Perception of the Facial Expression].

    PubMed

    Yakovenko, I A; Cheremushkin, E A; Kozlov, M K

    2015-01-01

    The research of changes of a beta rhythm parameters on condition of working memory loading by extension of a interstimuli interval between the target and triggering stimuli to 16 sec is investigated on 70 healthy adults in two series of experiments with set to a facial expression. In the second series at the middle of this interval for strengthening of the load was entered the additional cognitive task in the form of conditioning stimuli like Go/NoGo--circles of blue or green color. Data analysis of the research was carried out by means of continuous wavelet-transformation on the basis of "mather" complex Morlet-wavelet in the range of 1-35 Hz. Beta rhythm power was characterized by the mean level, maxima of wavelet-transformation coefficient (WLC) and latent periods of maxima. Introduction of additional cognitive task to pause between the target and triggering stimuli led to essential increase in absolute values of the mean level of beta rhythm WLC and relative sizes of maxima of beta rhythm WLC. In the series of experiments without conditioning stimulus subjects with large number of mistakes (from 6 to 40), i.e. rigid set, in comparison with subjects with small number of mistakes (to 5), i.e. plastic set, at the forming stage were characterized by higher values of the mean level of beta rhythm WLC. Introduction of the conditioning stimuli led to smoothing of intergroup distinctions throughout the experiment. PMID:26601500

  10. Sonochemical degradation of the pharmaceutical fluoxetine: Effect of parameters, organic and inorganic additives and combination with a biological system.

    PubMed

    Serna-Galvis, Efraím A; Silva-Agredo, Javier; Giraldo-Aguirre, Ana L; Torres-Palma, Ricardo A

    2015-08-15

    Fluoxetine (FLX), one of the most widely used antidepressants in the world, is an emergent pollutant found in natural waters that causes disrupting effects on the endocrine systems of some aquatic species. This work explores the total elimination of FLX by sonochemical treatment coupled to a biological system. The biological process acting alone was shown to be unable to remove the pollutant, even under favourable conditions of pH and temperature. However, sonochemical treatment (600 kHz) was shown to be able to remove the pharmaceutical. Several parameters were evaluated for the ultrasound application: the applied power (20-60 W), dissolved gas (air, Ar and He), pH (3-11) and initial concentration of fluoxetine (2.9-162.0 μmol L(-1)). Additionally, the presence of organic (1-hexanol and 2-propanol) and inorganic (Fe(2+)) compounds in the water matrix and the degradation of FLX in a natural mineral water were evaluated. The sonochemical treatment readily eliminates FLX following a kinetic Langmuir. After 360 min of ultrasonic irradiation, 15% mineralization was achieved. Analysis of the biodegradability provided evidence that the sonochemical process transforms the pollutant into biodegradable substances, which can then be mineralized in a subsequent biological treatment. PMID:25912531

  11. Nano-Fe as feed additive improves the hematological and immunological parameters of fish, Labeo rohita H.

    NASA Astrophysics Data System (ADS)

    Behera, T.; Swain, P.; Rangacharulu, P. V.; Samanta, M.

    2014-08-01

    An experiment was conducted to compare the effects of iron oxide nanoparticles ( T 1) and ferrous sulfate ( T 2) on Indian major carp, Labeo rohita H. There were significant differences ( P < 0.05) in the final weight of T 1 and T 2 compared with the control. Survival rates were not affected by the dietary treatments. Fish fed a basal diet (control) showed lower ( P < 0.05) iron content in muscle compared to T 1 and T 2. Furthermore, the highest value ( P < 0.05) of iron content was observed in T 1. In addition, RBCs and hemoglobin levels were significantly higher in T 1 as compared to other treated groups. Different innate immune parameters such as respiratory burst activity, bactericidal activity and myeloperoxidase activity were higher in nano-Fe-treated diet ( T 1) as compared to other iron source ( T 2) and control in 30 days post-feeding. Moreover, nano-Fe appeared to be more effective ( P < 0.05) than ferrous sulfate in increasing muscle iron and hemoglobin contents. Dietary administration of nano-Fe did not cause any oxidative damage, but improved antioxidant enzymatic activities (SOD and GSH level) irrespective of different iron sources in the basal diet.

  12. Behavior of Tilted Angle Shear Connectors

    PubMed Central

    Khorramian, Koosha; Maleki, Shervin; Shariati, Mahdi; Ramli Sulong, N. H.

    2015-01-01

    According to recent researches, angle shear connectors are appropriate to transfer longitudinal shear forces across the steel-concrete interface. Angle steel profile has been used in different positions as L-shaped or C-shaped shear connectors. The application of angle shear connectors in tilted positions is of interest in this study. This study investigates the behaviour of tilted-shaped angle shear connectors under monotonic loading using experimental push out tests. Eight push-out specimens are tested to investigate the effects of different angle parameters on the ultimate load capacity of connectors. Two different tilted angles of 112.5 and 135 degrees between the angle leg and steel beam are considered. In addition, angle sizes and lengths are varied. Two different failure modes were observed consisting of concrete crushing-splitting and connector fracture. By increasing the size of connector, the maximum load increased for most cases. In general, the 135 degrees tilted angle shear connectors have a higher strength and stiffness than the 112.5 degrees type. PMID:26642193

  13. What's Your Angle on Angles?

    ERIC Educational Resources Information Center

    Browning, Christine A.; Garza-Kling, Gina; Sundling, Elizabeth Hill

    2007-01-01

    Although the nature of the research varies, as do concepts of angle, research in general supports the supposition that angle is a complex idea, best understood from a variety of perspectives. In fact, the concept of angle tends to be threefold, consisting of: (1) the traditional, static notion of two rays meeting at a common vertex; (2) the idea…

  14. Parameters and pitfalls to consider in the conduct of food additive research, Carrageenan as a case study.

    PubMed

    Weiner, Myra L

    2016-01-01

    This paper provides guidance on the conduct of new in vivo and in vitro studies on high molecular weight food additives, with carrageenan, the widely used food additive, as a case study. It is important to understand the physical/chemical properties and to verify the identity/purity, molecular weight and homogeneity/stability of the additive in the vehicle for oral delivery. The strong binding of CGN to protein in rodent chow or infant formula results in no gastrointestinal tract exposure to free CGN. It is recommended that doses of high Mw non-caloric, non-nutritive additives not exceed 5% by weight of total solid diet to avoid potential nutritional effects. Addition of some high Mw additives at high concentrations to liquid nutritional supplements increases viscosity and may affect palatability, caloric intake and body weight gain. In in vitro studies, the use of well-characterized, relevant cell types and the appropriate composition of the culture media are necessary for proper conduct and interpretation. CGN is bound to media protein and not freely accessible to cells in vitro. Interpretation of new studies on food additives should consider the interaction of food additives with the vehicle components and the appropriateness of the animal or cell model and dose-response. PMID:26615870

  15. Separating response-execution bias from decision bias: arguments for an additional parameter in Ratcliff's diffusion model.

    PubMed

    Voss, Andreas; Voss, Jochen; Klauer, Karl Christoph

    2010-11-01

    Diffusion model data analysis permits the disentangling of different processes underlying the effects of experimental manipulations. Estimates can be provided for the speed of information accumulation, for the amount of information used to draw conclusions, and for a decision bias. One parameter describes the duration of non-decisional processes including the duration of motor-response execution. In the default diffusion model, it is implicitly assumed that both responses are executed with the same speed. In some applications of the diffusion model, this assumption will be violated. This will lead to biased parameter estimates. Consequently, we suggest accounting explicitly for differences in the speed of response execution for both responses. Results from a simulation study illustrate that parameter estimates from the default model are biased if the speed of response execution differs between responses. A second simulation study shows that large trial numbers (N>1,000) are needed to detect whether differences in response-execution times are based on different execution times. PMID:20030967

  16. The effects of additive gases (Ar, N2, H2, Cl2, O2) on HCl plasma parameters and composition

    NASA Astrophysics Data System (ADS)

    Efremov, A.; Yudina, A.; Davlyatshina, A.; Murin, D.; Svetsov, V.

    2013-01-01

    The direct current (dc) glow discharge plasma parameters and active species kinetics in HCl-X (X = Ar, N2, H2, Cl2, O2) mixtures were studied using both plasma diagnostics Langmuir probes and modeling. The 0-dimensional self-consistent steady-state model included the simultaneous solution of Boltzmann kinetic equation, the equations of chemical kinetics for neutral and charge particles, plasma conductivity equation and the quasi-neutrality conditions for volume densities of charged particles as well as for their fluxes to the reactor walls. The data on the steady-state electron energy distribution function, electron gas characteristics (mean energy, drift rate and transport coefficients), volume-averaged densities of plasma active species and their fluxed to the reactor walls were obtained as functions of gas mixing ratios and gas pressure at fixed discharge current.

  17. Study on the effect of hydrogen addition on the variation of plasma parameters of argon-oxygen magnetron glow discharge for synthesis of TiO2 films

    NASA Astrophysics Data System (ADS)

    Saikia, Partha; Saikia, Bipul Kumar; Bhuyan, Heman

    2016-04-01

    We report the effect of hydrogen addition on plasma parameters of argon-oxygen magnetron glow discharge plasma in the synthesis of H-doped TiO2 films. The parameters of the hydrogen-added Ar/O2 plasma influence the properties and the structural phases of the deposited TiO2 film. Therefore, the variation of plasma parameters such as electron temperature (Te), electron density (ne), ion density (ni), degree of ionization of Ar and degree of dissociation of H2 as a function of hydrogen content in the discharge is studied. Langmuir probe and Optical emission spectroscopy are used to characterize the plasma. On the basis of the different reactions in the gas phase of the magnetron discharge, the variation of plasma parameters and sputtering rate are explained. It is observed that the electron and heavy ion density decline with gradual addition of hydrogen in the discharge. Hydrogen addition significantly changes the degree of ionization of Ar which influences the structural phases of the TiO2 film.

  18. Anisotropic structure of the order parameter in FeSe0.45Te0.55 revealed by angle-resolved specific heat

    PubMed Central

    Zeng, B.; Mu, G.; Luo, H.Q.; Xiang, T.; Mazin, I.I.; Yang, H.; Shan, L.; Ren, C.; Dai, P.C.; Wen, H.-H.

    2010-01-01

    The central issues for understanding iron (Fe)-based superconductors are the symmetry and structure of the superconducting gap. So far the experimental data and theoretical models have been highly controversial. Some experiments favor two or more constant or nearly constant gaps, others indicate strong anisotropy and yet others suggest gap zeros ('nodes'). A unique method for addressing this issue, and one of very few methods that are bulk and angle resolved, is measuring the electronic-specific heat in a rotating magnetic field. In this study, we present the first such measurement for an Fe-based high-Tc superconductor. We observed a fourfold oscillation of the specific heat as a function of the in-plane magnetic field direction. Our results are consistent with the expectations for an extended s-wave model, with a significant gap anisotropy on the electron pockets and the gap minima along the ΓM (Fe–Fe bond) direction. PMID:21081910

  19. Detonation of highly dilute porous explosives; II: Influence of inert additives on the structure of the front, the parameters, and the reaction time

    SciTech Connect

    Shvedov, K.K.; Aniskin, A.I.; Dremin, A.N.; Il'in, A.N.

    1982-06-01

    For the detonation of porous explosives with inert additives, as for the detonation of individual porous explosives, the basic postulates and conclusions of the modern gasdynamic theory of detonation are valid. The influence of solid, refractory inert additives on the decomposition mechanism of porous explosives depends on the individual properties of the explosives and mainly on the dispersity of the additives. With the elimination of pronounced heating of the additives in mixtures with TNT, a certain positive influence on the appearance of decomposition sources and the total reaction time is observed. In cases with hexogen, no such influence is observed, which is evidently the result of physical inhomogeneity of the porous structure of the charge and the sufficiently high detonation pressures of the mixtures. The basic influence of inert additives on the critical diameter, front structure, detonation parameters, and reaction time of porous explosives is exerted through processes of energy absorption in the reaction region and factors leading to energy losses may lead to ambiguity of the detonation conditions in a system with specified chemical potential energy. The state of the additive in the reaction region must be taken into account for reliable theoretical description of the detonation conditions of porous explosives with a large content of inert additives.

  20. Angle detector

    NASA Technical Reports Server (NTRS)

    Parra, G. T. (Inventor)

    1978-01-01

    An angle detector for determining a transducer's angular disposition to a capacitive pickup element is described. The transducer comprises a pendulum mounted inductive element moving past the capacitive pickup element. The capacitive pickup element divides the inductive element into two parts L sub 1 and L sub 2 which form the arms of one side of an a-c bridge. Two networks R sub 1 and R sub 2 having a plurality of binary weighted resistors and an equal number of digitally controlled switches for removing resistors from the networks form the arms of the other side of the a-c bridge. A binary counter, controlled by a phase detector, balances the bridge by adjusting the resistance of R sub 1 and R sub 2. The binary output of the counter is representative of the angle.

  1. Development of a scanning angle total internal reflection Raman spectrometer.

    PubMed

    McKee, Kristopher J; Smith, Emily A

    2010-04-01

    A scanning angle total internal reflection (SATIR) Raman spectrometer has been developed for measuring interfacial phenomena with chemical specificity and high axial resolution perpendicular to the interface. The instrument platform is an inverted optical microscope with added automated variable angle optics to control the angle of an incident laser on a prism/sample interface. These optics include two motorized translation stages, the first containing a focusing lens and the second a variable angle galvanometer mirror. The movement of all instrument components is coordinated to ensure that the same sample location and area are probed at each angle. At angles greater than the critical angle, an evanescent wave capable of producing Raman scatter is generated in the sample. The Raman scatter is collected by a microscope objective and directed to a dispersive spectrometer and charge-coupled device detector. In addition to the collected Raman scatter, light reflected from the prism/sample interface is collected to provide calibration parameters that enable modeling the distance over which the Raman scatter is collected for depth profiling measurements. The developed instrument has an incident angle range of 25.5 degrees-75.5 degrees, with a 0.05 degrees angle resolution. Raman scatter can be collected from a ZnSe/organic interface over a range of roughly 35-180 nm. Far from the critical angle, the achieved axial resolution perpendicular to the focal plane is approximately 34 nm. This is roughly a 30-fold improvement relative to confocal Raman microscopy. PMID:20441324

  2. Numerical modeling of heat-transfer and the influence of process parameters on tailoring the grain morphology of IN718 in electron beam additive manufacturing

    DOE PAGESBeta

    Raghavan, Narendran; Dehoff, Ryan; Pannala, Sreekanth; Simunovic, Srdjan; Kirka, Michael; Turner, John; Carlson, Neil; Babu, Sudarsanam S.

    2016-04-26

    The fabrication of 3-D parts from CAD models by additive manufacturing (AM) is a disruptive technology that is transforming the metal manufacturing industry. The correlation between solidification microstructure and mechanical properties has been well understood in the casting and welding processes over the years. This paper focuses on extending these principles to additive manufacturing to understand the transient phenomena of repeated melting and solidification during electron beam powder melting process to achieve site-specific microstructure control within a fabricated component. In this paper, we have developed a novel melt scan strategy for electron beam melting of nickel-base superalloy (Inconel 718) andmore » also analyzed 3-D heat transfer conditions using a parallel numerical solidification code (Truchas) developed at Los Alamos National Laboratory. The spatial and temporal variations of temperature gradient (G) and growth velocity (R) at the liquid-solid interface of the melt pool were calculated as a function of electron beam parameters. By manipulating the relative number of voxels that lie in the columnar or equiaxed region, the crystallographic texture of the components can be controlled to an extent. The analysis of the parameters provided optimum processing conditions that will result in columnar to equiaxed transition (CET) during the solidification. Furthermore, the results from the numerical simulations were validated by experimental processing and characterization thereby proving the potential of additive manufacturing process to achieve site-specific crystallographic texture control within a fabricated component.« less

  3. Assessment of the aerobic preparation and bottom ash addition as pretreatment steps before landfilling: impact on methanogenesis kinetics and leachate parameters.

    PubMed

    Mansour, Alicia A; Motte, Antoine; Pallier, Virginie; Feuillade-Cathalifaud, Geneviève; Ponthieux, Arnaud

    2012-10-01

    This work focuses on assessing the impact of two types of waste pretreatment: addition of bottom ashes and aerobic pretreatment on both the onset and kinetics of methanogenesis and the evolution of different parameters in the leachate. It also studies the correlation between methane production and the different parameters measured in the leachate produced. A total of six 68-L pilots were thus used with fresh municipal solid waste (MSW) shredded to a 40-mm size. After 14 months of landfilling, the control has produced less than 10 NLkg(-1)DM, which corresponds to around 7% of its biochemical methane potential (BMP). Nevertheless, on one hand for aerobically pretreated waste, the lag phase before the onset of methanogenesis is significantly reduced to 0.9 month compared to more than 1 year for the control. In addition to that, on average 110 NLkg(-1)DM (90% of the BMP) is produced within around 6.5 months. On the other hand, the waste with added bottom ash shows a slight improvement of the lag phase over the control for one of the duplicate: 6.1 months of lag phase. At this stage, on average of 26 NLkg(-1)DM waste are detected (22% of the BMP) no final conclusion concerning the impact of bottom ashes could be made. The data obtained for the leachate parameters agrees with the observations on methane production. Statistical correlation study shows that the two components of the corrected PCA interpret 76% of the variability of the data: SUVA (specific UV absorbance at 254 nm) and HPI(*) (% of hydrophilic compounds) are identified as interesting parameters for following up the biodegradation in landfill conditions. PMID:22640801

  4. The Diffraction Pattern Calculator (DPC) toolkit: a user-friendly approach to unit-cell lattice parameter identification of two-dimensional grazing-incidence wide-angle X-ray scattering data

    PubMed Central

    Hailey, Anna K.; Hiszpanski, Anna M.; Smilgies, Detlef-M.; Loo, Yueh-Lin

    2014-01-01

    The DPC toolkit is a simple-to-use computational tool that helps users identify the unit-cell lattice parameters of a crystal structure that are consistent with a set of two-dimensional grazing-incidence wide-angle X-ray scattering data. The input data requirements are minimal and easy to assemble from data sets collected with any position-sensitive detector, and the user is required to make as few initial assumptions about the crystal structure as possible. By selecting manual or automatic modes of operation, the user can either visually match the positions of the experimental and calculated reflections by individually tuning the unit-cell parameters or have the program perform this process for them. Examples that demonstrate the utility of this program include determining the lattice parameters of a polymorph of a fluorinated contorted hexabenzocoronene in a blind test and refining the lattice parameters of the thin-film phase of 5,11-bis(triethylsilylethynyl)anthradithiophene with the unit-cell dimensions of its bulk crystal structure being the initial inputs. PMID:25484845

  5. Effectiveness of Phytogenic Feed Additive as Alternative to Bacitracin Methylene Disalicylate on Hematological Parameters, Intestinal Histomorphology and Microbial Population and Production Performance of Japanese Quails

    PubMed Central

    Manafi, M.; Hedayati, M.; Khalaji, S.

    2016-01-01

    This study was conducted to evaluate the effects of phytogenic additive and antibiotic growth promoter in laying Japanese quails. One hundred and sixty five quails were divided into three groups of 5 replicates and 11 quails (8 females and 3 males) in each replicate. Treatment 1 was fed control diet, treatment 2 was fed control diet supplemented with 0.05% bacitracin methylene disalicylate as antibiotic growth promoter and treatment 3 was fed control diet supplemented with 0.1% phytogenic feed additive (PFA) for two periods of 3 weeks each from 37 to 42 weeks of age. Results showed that egg production, eggshell strength, eggshell weight, villus height and villus height to crypt depth ratio were significantly (p≤0.05) increased and feed consumption, feed conversion ratio, albumen, Haugh unit, cholesterol, low-density lipoprotein, alanine transaminase, gamma glutamyltransferase, alkaline phosphatase, high-density lipoprotein, triglyceride, number of goblet cell, crypt depth and intestinal bacterial population of Coliforms, Salmonella and E. coli were significantly (p≤0.05) decreased in PFA fed group. It is concluded that addition of PFA containing phytomolecules and organic acids as main ingredients could significantly improve the production parameters and the general health of laying quails as an alternative to antibiotic growth promoters. PMID:27189636

  6. Effectiveness of Phytogenic Feed Additive as Alternative to Bacitracin Methylene Disalicylate on Hematological Parameters, Intestinal Histomorphology and Microbial Population and Production Performance of Japanese Quails.

    PubMed

    Manafi, M; Hedayati, M; Khalaji, S

    2016-09-01

    This study was conducted to evaluate the effects of phytogenic additive and antibiotic growth promoter in laying Japanese quails. One hundred and sixty five quails were divided into three groups of 5 replicates and 11 quails (8 females and 3 males) in each replicate. Treatment 1 was fed control diet, treatment 2 was fed control diet supplemented with 0.05% bacitracin methylene disalicylate as antibiotic growth promoter and treatment 3 was fed control diet supplemented with 0.1% phytogenic feed additive (PFA) for two periods of 3 weeks each from 37 to 42 weeks of age. Results showed that egg production, eggshell strength, eggshell weight, villus height and villus height to crypt depth ratio were significantly (p≤0.05) increased and feed consumption, feed conversion ratio, albumen, Haugh unit, cholesterol, low-density lipoprotein, alanine transaminase, gamma glutamyltransferase, alkaline phosphatase, high-density lipoprotein, triglyceride, number of goblet cell, crypt depth and intestinal bacterial population of Coliforms, Salmonella and E. coli were significantly (p≤0.05) decreased in PFA fed group. It is concluded that addition of PFA containing phytomolecules and organic acids as main ingredients could significantly improve the production parameters and the general health of laying quails as an alternative to antibiotic growth promoters. PMID:27189636

  7. Adaptive neuro-fuzzy inference system (ANFIS) to predict CI engine parameters fueled with nano-particles additive to diesel fuel

    NASA Astrophysics Data System (ADS)

    Ghanbari, M.; Najafi, G.; Ghobadian, B.; Mamat, R.; Noor, M. M.; Moosavian, A.

    2015-12-01

    This paper studies the use of adaptive neuro-fuzzy inference system (ANFIS) to predict the performance parameters and exhaust emissions of a diesel engine operating on nanodiesel blended fuels. In order to predict the engine parameters, the whole experimental data were randomly divided into training and testing data. For ANFIS modelling, Gaussian curve membership function (gaussmf) and 200 training epochs (iteration) were found to be optimum choices for training process. The results demonstrate that ANFIS is capable of predicting the diesel engine performance and emissions. In the experimental step, Carbon nano tubes (CNT) (40, 80 and 120 ppm) and nano silver particles (40, 80 and 120 ppm) with nanostructure were prepared and added as additive to the diesel fuel. Six cylinders, four-stroke diesel engine was fuelled with these new blended fuels and operated at different engine speeds. Experimental test results indicated the fact that adding nano particles to diesel fuel, increased diesel engine power and torque output. For nano-diesel it was found that the brake specific fuel consumption (bsfc) was decreased compared to the net diesel fuel. The results proved that with increase of nano particles concentrations (from 40 ppm to 120 ppm) in diesel fuel, CO2 emission increased. CO emission in diesel fuel with nano-particles was lower significantly compared to pure diesel fuel. UHC emission with silver nano-diesel blended fuel decreased while with fuels that contains CNT nano particles increased. The trend of NOx emission was inverse compared to the UHC emission. With adding nano particles to the blended fuels, NOx increased compared to the net diesel fuel. The tests revealed that silver & CNT nano particles can be used as additive in diesel fuel to improve combustion of the fuel and reduce the exhaust emissions significantly.

  8. The additive effect of dorzolamide hydrochloride (Trusopt) and a morning dose of bimatoprost (Lumigan) on intraocular pressure and retrobulbar blood flow in patients with primary open-angle glaucoma

    PubMed Central

    Stankiewicz, Andrzej; Siemiątkowska, Anna; Fuksińska, Beata; Robaszkiewicz, Jacek; Zegadło, Arkadiusz; Ehrlich, Rita; Siesky, Brent; Harris, Alon

    2010-01-01

    Aims To assess the additive effect of dorzolamide hydrochloride 2% on the diurnal intraocular pressure (IOP) curve and retrobulbar haemodynamics in patients with primary open-angle glaucoma (POAG) treated with morning-dosed bimatoprost 0.03%. Methods Twenty-five patients with POAG were evaluated in a prospective, single-masked study. After a 1 week run-in period with bimatoprost all patients were treated with bimatoprost dosed once in the morning for 1 month, after which dorzolamide was added twice daily for 2 months. Goldmann applanation IOP, arterial blood pressure (ABP) and heart rate were measured every 2 h for 24 h and diurnal ocular perfusion pressure (OPP) was calculated. Colour Doppler imaging (CDI) of the ophthalmic artery (OA) and the central retinal artery (CRA) was recorded five times daily. All measurements were taken after the two phases of treatment and were compared. Results The mean baseline IOP was 14.8±3.5 mm Hg. Mean IOP following bimatoprost monotherapy (12.8±2.9 mm Hg) and after 2 months of dorzolamide adjunctive therapy (12.2±2.6 mm Hg) were not statistically significantly different (p=0.544). Only at the 4:00 h time point was IOP significantly reduced using the bimatoprost/dorzolamide combined treatment (p=0.013). The 24 h IOP fluctuations were lower when dorzolamide was added (6.0±2.3 mm Hg vs 4.6±1.5 mm Hg, p=0.0016). Repeated analysis of variance detected a significant decrease of vascular resistance in the OA (p=0.0167) with adjunctive dorzolamide treatment. Conclusions The addition of dorzolamide to morning-dosed bimatoprost had an additive hypotensive effect only on the night-time IOP curve at 4:00 h and resulted in a lower IOP fluctuation. Dorzolamide added to bimatoprost may reduce vascular resistance in the OA. PMID:20558428

  9. Superposition-additive approach in the description of thermodynamic parameters of formation and clusterization of substituted alkanes at the air/water interface.

    PubMed

    Vysotsky, Yu B; Belyaeva, E A; Fomina, E S; Vasylyev, A O; Vollhardt, D; Fainerman, V B; Aksenenko, E V; Miller, R

    2012-12-01

    The superposition-additive approach developed previously was shown to be applicable for the calculations of the thermodynamic parameters of formation and atomization of conjugate systems, their dipole polarizability, molecular diamagnetic susceptibility, π-electronic ring currents, etc. In the present work, the applicability of this approach for the calculation of the thermodynamic parameters of formation and clusterization at the water/air interface of alkanes, fatty alcohols, thioalcohols, amines, nitriles, fatty acids (C(n)H(2n+1)X, X is the functional group) and cis-unsaturated carboxylic acids (C(n)H(2n-1)COOH) is studied. Using the proposed approach the thermodynamic quantities determined agree well with the available data, either calculated using the semiempirical (PM3) quantum chemical method, or obtained in experiments. In particular, for enthalpy and Gibbs' energy of the formation of substituted alkane monomers from the elementary substances, and their absolute entropy, the standard deviations of the values calculated according to the superposition-additive scheme with the mutual superimposition domain C(n-2)H(2n-4) (n is the number of carbon atoms in the alkyl chain) from the results of PM3 calculations for alkanes, alcohols, thioalcohols, amines, fatty acids, nitriles and cis-unsaturated carboxylic acids are respectively: 0.05, 0.004, 2.87, 0.02, 0.01, 0.77, and 0.01 kJ/mol for enthalpy; 2.32, 5.26, 4.49, 0.53, 1.22, 1.02, 5.30 J/(molK) for absolute entropy; 0.69, 1.56, 3.82, 0.15, 0.37, 0.69, 1.58 kJ/mol for Gibbs' energy, whereas the deviations from the experimental data are: 0.52, 5.75, 1.40, 1.00, 4.86 kJ/mol; 0.52, 0.63, 1.40, 6.11, 2.21 J/(molK); 2.52, 5.76, 1.58, 1.78, 4.86 kJ/mol, respectively (for nitriles and cis-unsaturated carboxylic acids experimental data are not available). The proposed approach provides also quite accurate estimates of enthalpy, entropy and Gibbs' energy of boiling and melting, critical temperatures and standard heat

  10. Kinetic analysis of HO{sub 2} addition to ethylene, propene, and isobutene, and thermochemical parameters of alkyl hydroperoxides and hydroperoxide alkyl radicals

    SciTech Connect

    Chen, C.J.; Bozzelli, J.W.

    2000-06-01

    Thermochemical kinetic analysis for the reactions of HO{sub 2} radical addition to the primary, secondary, and tertiary carbon-carbon double bonds of ethylene, propene, and isobutene are studied using canonical transition state theory (TST). Thermochemical properties of reactants, alkyl hydroperoxides (ROOH), hydroperoxy alkyl radicals (R-OOH), and transition states (TSs) are determined by ab initio and density functional calculations. Enthalpies of formation ({Delta}H{sub f 298}{degree}) of product radicals (R-OOH) are determined using isodesmic reactions with group balance at MP4(full)6-31G(d,p)/MP2(full)/6-31G(d), MP2(full)/6-31G(d), complete basis set model chemistry (CBS-q with MP2(full)/6-31g(d) and B3LYP/6-31g(d) optimized geometries), and density functional (B3LYP/6-31g(d) and B3LYP/6-311+g(3df,2p)//B3LYP/6-31g(d)) calculations. {Delta}H{sub f 298}{degree} of TSs are obtained from the {Delta}H{sub f 298}{degree} of reactants plus energy differences between reactants and TSs. Entropies (S{sub 298}{degree}) and heat capacities (Cp(T) 300 {le} T/K {le} 1,500) contributions from vibrational, translational, and external rotational are calculated using the rigid-rotor-harmonic-oscillator approximation based on geometric parameters and vibrational frequencies obtained at MP2(full)/6-31G(d) and B3LYP/6-31G(d) levels of theory. Selected potential barriers of internal rotations for hydroperoxy alkyl radicals and TSs are calculated at MP2(full)/6-31G(d) and CBS-Q//MP2(full)/6-31G(d) levels. Contributions from hindered rotors of S{sub 298}{degree} and Cp(T) are calculated by the method of Pitzer and Gwinn and by summation over the energy levels obtained by direct diagonalization of the Hamiltonian matrix of hindered internal rotations when the potential barriers of internal rotations are available. calculated rate constants obtained at CBS-q/MP2(full)/6-31G(d) and CBS-q//B3LYP/6-31G(d) levels of theory show similar trends with experimental data: HO{sub 2} radical

  11. Additive Manufacturing of Single-Crystal Superalloy CMSX-4 Through Scanning Laser Epitaxy: Computational Modeling, Experimental Process Development, and Process Parameter Optimization

    NASA Astrophysics Data System (ADS)

    Basak, Amrita; Acharya, Ranadip; Das, Suman

    2016-06-01

    This paper focuses on additive manufacturing (AM) of single-crystal (SX) nickel-based superalloy CMSX-4 through scanning laser epitaxy (SLE). SLE, a powder bed fusion-based AM process was explored for the purpose of producing crack-free, dense deposits of CMSX-4 on top of similar chemistry investment-cast substrates. Optical microscopy and scanning electron microscopy (SEM) investigations revealed the presence of dendritic microstructures that consisted of fine γ' precipitates within the γ matrix in the deposit region. Computational fluid dynamics (CFD)-based process modeling, statistical design of experiments (DoE), and microstructural characterization techniques were combined to produce metallurgically bonded single-crystal deposits of more than 500 μm height in a single pass along the entire length of the substrate. A customized quantitative metallography based image analysis technique was employed for automatic extraction of various deposit quality metrics from the digital cross-sectional micrographs. The processing parameters were varied, and optimal processing windows were identified to obtain good quality deposits. The results reported here represent one of the few successes obtained in producing single-crystal epitaxial deposits through a powder bed fusion-based metal AM process and thus demonstrate the potential of SLE to repair and manufacture single-crystal hot section components of gas turbine systems from nickel-based superalloy powders.

  12. Additive Manufacturing of Single-Crystal Superalloy CMSX-4 Through Scanning Laser Epitaxy: Computational Modeling, Experimental Process Development, and Process Parameter Optimization

    NASA Astrophysics Data System (ADS)

    Basak, Amrita; Acharya, Ranadip; Das, Suman

    2016-08-01

    This paper focuses on additive manufacturing (AM) of single-crystal (SX) nickel-based superalloy CMSX-4 through scanning laser epitaxy (SLE). SLE, a powder bed fusion-based AM process was explored for the purpose of producing crack-free, dense deposits of CMSX-4 on top of similar chemistry investment-cast substrates. Optical microscopy and scanning electron microscopy (SEM) investigations revealed the presence of dendritic microstructures that consisted of fine γ' precipitates within the γ matrix in the deposit region. Computational fluid dynamics (CFD)-based process modeling, statistical design of experiments (DoE), and microstructural characterization techniques were combined to produce metallurgically bonded single-crystal deposits of more than 500 μm height in a single pass along the entire length of the substrate. A customized quantitative metallography based image analysis technique was employed for automatic extraction of various deposit quality metrics from the digital cross-sectional micrographs. The processing parameters were varied, and optimal processing windows were identified to obtain good quality deposits. The results reported here represent one of the few successes obtained in producing single-crystal epitaxial deposits through a powder bed fusion-based metal AM process and thus demonstrate the potential of SLE to repair and manufacture single-crystal hot section components of gas turbine systems from nickel-based superalloy powders.

  13. 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

  14. Optimized Parameters for a Mercury Jet Target

    SciTech Connect

    Ding, X.; Kirk, H.

    2010-12-01

    A study of target parameters for a high-power, liquid mercury jet target system for a neutrino factory or muon collider is presented. Using the MARS code, we simulate particle production initiated by incoming protons with kinetic energies between 2 and 100 GeV. For each proton beam energy, we maximize production by varying the geometric parameters of the target: the mercury jet radius, the incoming proton beam angle, and the crossing angle between the mercury jet and the proton beam. The number of muons surviving through an ionization cooling channel is determined as a function of the proton beam energy. We optimize the mercury jet target parameters: the mercury jet radius, the incoming proton beam angle and the crossing angle between the mercury jet and the proton beam for each proton beam energy. The optimized target radius varies from about 0.4 cm to 0.6 cm as the proton beam energy increases. The optimized beam angle varies from 75 mrad to 120 mrad. The optimized crossing angle is near 20 mrad for energies above 5 GeV. These values differ from earlier choices of 67 mrad for the beam angle and 33 mrad for the crossing angle. These new choices for the beam parameters increase the meson production by about 20% compared to the earlier parameters. Our study demonstrates that the maximum meson production efficiency per unit proton beam power occurs when the proton kinetic energy is in the range of 5-15 GeV. Finally, the dependence on energy of the number of muons at the end of the cooling channel is nearly identical to the dependence on energy of the meson production 50 m from the target. This demonstrates that the target parameters can be optimized without the additional step of running the distribution through a code such as ICOOL that simulates the bunching, phase rotation, and cooling.

  15. Estimation of aerosol optical depth and additional atmospheric parameters for the calculation of apparent reflectance from radiance measured by the Airborne Visible/Infrared Imaging Spectrometer

    NASA Technical Reports Server (NTRS)

    Green, Robert O.; Conel, James E.; Roberts, Dar A.

    1993-01-01

    The Airborne Visible/Infrared Imaging Spectrometer (AVIRIS) measures spatial images of the total upwelling spectral radiance from 400 to 2500 nm through 10 nm spectral channels. Quantitative research and application objectives for surface investigations require inversion of the measured radiance of surface reflectance or surface leaving radiance. To calculate apparent surface reflectance, estimates of atmospheric water vapor abundance, cirrus cloud effects, surface pressure elevation, and aerosol optical depth are required. Algorithms for the estimation of these atmospheric parameters from the AVIRIS data themselves are described. From these atmospheric parameters we show an example of the calculation of apparent surface reflectance from the AVIRIS-measured radiance using a radiative transfer code.

  16. Variable angle correlation spectroscopy

    SciTech Connect

    Lee, Y K

    1994-05-01

    In this dissertation, a novel nuclear magnetic resonance (NMR) technique, variable angle correlation spectroscopy (VACSY) is described and demonstrated with {sup 13}C nuclei in rapidly rotating samples. These experiments focus on one of the basic problems in solid state NMR: how to extract the wealth of information contained in the anisotropic component of the NMR signal while still maintaining spectral resolution. Analysis of the anisotropic spectral patterns from poly-crystalline systems reveal information concerning molecular structure and dynamics, yet in all but the simplest of systems, the overlap of spectral patterns from chemically distinct sites renders the spectral analysis difficult if not impossible. One solution to this problem is to perform multi-dimensional experiments where the high-resolution, isotropic spectrum in one dimension is correlated with the anisotropic spectral patterns in the other dimensions. The VACSY technique incorporates the angle between the spinner axis and the static magnetic field as an experimental parameter that may be incremented during the course of the experiment to help correlate the isotropic and anisotropic components of the spectrum. The two-dimensional version of the VACSY experiments is used to extract the chemical shift anisotropy tensor values from multi-site organic molecules, study molecular dynamics in the intermediate time regime, and to examine the ordering properties of partially oriented samples. The VACSY technique is then extended to three-dimensional experiments to study slow molecular reorientations in a multi-site polymer system.

  17. Asymmetric Conjugate Addition of Benzofuran-2-ones to Alkyl 2-Phthalimidoacrylates: Modeling Structure-Stereoselectivity Relationships with Steric and Electronic Parameters.

    PubMed

    Yang, Chen; Zhang, En-Ge; Li, Xin; Cheng, Jin-Pei

    2016-05-23

    A highly predictive model to correlate the steric and electronic parameters of tertiary amine thiourea catalysts with the stereoselectivity of Michael reactions of 3-substituted benzofuranones and alkyl 2-phthalimidoacrylates is described. As predicted, new 3,5-bis(trifluoromethyl)benzyl- and methyl-substituted tertiary amine thioureas turned out to be highly suitable catalysts for this reaction and enabled the synthesis of enantioenriched α-amino acid derivatives with 1,3-nonadjacent stereogenic centers. PMID:27080558

  18. Atlas of relations between climatic parameters and distributions of important trees and shrubs in North America; additional conifers, hardwoods, and monocots

    USGS Publications Warehouse

    Thompson, Robert S.; Anderson, Katherine H.; Bartlein, Patrick J.; Smith, Sharon A.

    2000-01-01

    This volume explores the continental-scale relations between climate and the geographic ranges of woody plant species in North America. A 25-km equal-area grid of modern climatic and bioclimatic parameters for North America was constructed from instrumental weather records. The geographic distributions of selected tree and shrub species were digitized, and the presence or absence of each species was determined for each cell on the 25-km grid, thus providing a basis for comparing climatic data and species' distribution.

  19. 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.

  20. 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

  1. Perception of Perspective Angles

    PubMed Central

    2015-01-01

    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

  2. Contact Angles and Surface Tension of Germanium-Silicon Melts

    NASA Technical Reports Server (NTRS)

    Croell, A.; Kaiser, N.; Cobb, S.; Szofran, F. R.; Volz, M.; Rose, M. Franklin (Technical Monitor)

    2001-01-01

    Precise knowledge of material parameters is more and more important for improving crystal growth processes. Two important parameters are the contact (wetting) angle and the surface tension, determining meniscus shapes and surface-tension driven flows in a variety of methods (Czochralski, EFG, floating-zone, detached Bridgman growth). The sessile drop technique allows the measurement of both parameters simultaneously and has been used to measure the contact angles and the surface tension of Ge(1-x)Si(x) (0 less than or equal to x less than or equal to 1.3) alloys on various substrate materials. Fused quartz, Sapphire, glassy carbon, graphite, SiC, carbon-based aerogel, pyrolytic boron nitride (pBN), AIN, Si3N4, and polycrystalline CVD diamond were used as substrate materials. In addition, the effect of different cleaning procedures and surface treatments on the wetting behavior were investigated. Measurements were performed both under dynamic vacuum and gas atmospheres (argon or forming gas), with temperatures up to 1100 C. In some experiments, the sample was processed for longer times, up to a week, to investigate any changes of the contact angle and/or surface tension due to slow reactions with the substrate. For pure Ge, stable contact angles were found for carbon-based substrates and for pBN, for Ge(1-x)Si(x) only for pBN. The highest wetting angles were found for pBN substrates with angles around 170deg. For the surface tension of Ge, the most reliable values resulted in gamma(T) = (591- 0.077 (T-T(sub m)) 10(exp -3)N/m. The temperature dependence of the surface tension showed similar values for Ge(1-x)Si(x), around -0.08 x 10(exp -3)N/m K, and a compositional dependence of 2.2 x 10(exp -3)N/m at%Si.

  3. Circuitry for Angle Measurements

    NASA Technical Reports Server (NTRS)

    Currie, J. R.; Kissel, R. R.

    1983-01-01

    Angle resolver pulsed and read under microprocessor control. Pulse generator excites resolver windings with dual slope pulse. System sequentially reads sine and cosine windings. Microprocessor determines angle through which resolver shaft turned from reference angle. Suitable applications include rate tables, antenna direction controllers, and machine tools.

  4. Pitch angle of galactic spiral arms

    SciTech Connect

    Michikoshi, Shugo; Kokubo, Eiichiro E-mail: kokubo@th.nao.ac.jp

    2014-06-01

    One of the key parameters that characterizes spiral arms in disk galaxies is a pitch angle that measures the inclination of a spiral arm to the direction of galactic rotation. The pitch angle differs from galaxy to galaxy, which suggests that the rotation law of galactic disks determines it. In order to investigate the relation between the pitch angle of spiral arms and the shear rate of galactic differential rotation, we perform local N-body simulations of pure stellar disks. We find that the pitch angle increases with the epicycle frequency and decreases with the shear rate and obtain the fitting formula. This dependence is explained by the swing amplification mechanism.

  5. Detection and characterisation of frauds in bovine meat in natura by non-meat ingredient additions using data fusion of chemical parameters and ATR-FTIR spectroscopy.

    PubMed

    Nunes, Karen M; Andrade, Marcus Vinícius O; Santos Filho, Antônio M P; Lasmar, Marcelo C; Sena, Marcelo M

    2016-08-15

    Concerns about meat authenticity are increasing recently, due to great fraud scandals. This paper analysed real samples (43 adulterated and 12 controls) originated from criminal networks dismantled by the Brazilian Police. This fraud consisted of injecting solutions of non-meat ingredients (NaCl, phosphates, carrageenan, maltodextrin) in bovine meat, aiming to increase its water holding capacity. Five physico-chemical variables were determined, protein, ash, chloride, sodium, phosphate. Additionally, infrared spectra were recorded. Supervised classification PLS-DA models were built with each data set individually, but the best model was obtained with data fusion, correctly detecting 91% of the adulterated samples. From this model, a variable selection based on the highest VIPscores was performed and a new data fusion model was built with only one chemical variable, providing slightly lower predictions, but a good cost/performance ratio. Finally, some of the selected infrared bands were specifically associated to the presence of adulterants NaCl, tripolyphosphate and carrageenan. PMID:27006208

  6. The Cabibbo angle as a universal seed for quark and lepton mixings

    NASA Astrophysics Data System (ADS)

    Roy, S.; Morisi, S.; Singh, N. N.; Valle, J. W. F.

    2015-09-01

    A model-independent ansatz to describe lepton and quark mixing in a unified way is suggested based upon the Cabibbo angle. In our framework neutrinos mix in a "Bi-Large" fashion, while the charged leptons mix as the "down-type" quarks do. In addition to the standard Wolfenstein parameters (λ, A) two other free parameters (ψ, δ) are needed to specify the physical lepton mixing matrix. Through this simple assumption one makes specific predictions for the atmospheric angle as well as leptonic CP violation in good agreement with current observations.

  7. Fractal Approach in Petrology: Combining Ultra-Small Angle (USANA) and Small Angle Neutron Scattering (SANS)

    SciTech Connect

    LoCelso, F.; Triolo, F.; Triolo, A.; Lin, J.S.; Lucido, G.; Triolo, R.

    1999-10-14

    Ultra small angle neutron scattering instruments have recently covered the gap between the size resolution available with conventional intermediate angle neutron scattering and small angle neutron scattering instruments on one side and optical microscopy on the other side. Rocks showing fractal behavior in over two decades of momentum transfer and seven orders of magnitude of intensity are examined and fractal parameters are extracted from the combined USANS and SANS curves.

  8. Solar angle reference manual

    SciTech Connect

    Sibson, R.

    1983-01-01

    The introduction is the only text in the volume; the rest of the book contains easy-to-use graphical methods for building design and construction using solar energy. Isogonic charts and solar angle diagrams are included. Isogonic charts. Solar angle diagrams.

  9. Reading Angles in Maps

    ERIC Educational Resources Information Center

    Izard, Véronique; O'Donnell, Evan; Spelke, Elizabeth S.

    2014-01-01

    Preschool children can navigate by simple geometric maps of the environment, but the nature of the geometric relations they use in map reading remains unclear. Here, children were tested specifically on their sensitivity to angle. Forty-eight children (age 47:15-53:30 months) were presented with fragments of geometric maps, in which angle sections…

  10. Divergent-ray projection method for measuring the flapping angle, lag angle, and torsional angle of a bumblebee wing

    NASA Astrophysics Data System (ADS)

    Zeng, Lijiang; Matsumoto, Hirokazu; Kawachi, Keiji

    1996-11-01

    A divergent-ray projection (DRP) method was developed for measuring the flapping angle, lag angle, and torsional angle of bumblebee wing during beating motion. This new method can measure the spatial coordinates of an insect wing by digitizing the images that are projected by two divergent laser rays from different directions. The advantage of the DRP method is its ability to measure those three angles simultaneously using only one high-speed camera. The resolution of the DRP method can be changed easily by adjusting system parameters to meet the needs of different types of objects. The measurement results for these angles of a bumblebee wing probe the effectiveness of the DRP method in studying the flight performance of insects.

  11. Photoelectric angle converter

    NASA Astrophysics Data System (ADS)

    Podzharenko, Volodymyr A.; Kulakov, Pavlo I.

    2001-06-01

    The photo-electric angle transmitter of rotation is offered, at which the output voltage is linear function of entering magnitude. In a transmitter the linear phototransducer is used on the basis of pair photo diode -- operating amplifier, which output voltage is linear function of the area of an illuminated photosensitive stratum, and modulator of a light stream of the special shape, which ensures a linear dependence of this area from an angle of rotation. The transmitter has good frequent properties and can be used for dynamic measurements of an angular velocity and angle of rotation, in systems of exact drives and systems of autocontrol.

  12. CKM angle γ measurements at LHCb

    NASA Astrophysics Data System (ADS)

    Vallier, Alexis

    2014-11-01

    The CKM angle γ remains the least known parameter of the CKM mixing matrix. The precise measurement of this angle, as a Standard Model benchmark, is a key goal of the LHCb experiment. We present four recent CP violation studies related to the measurement of γ, including amplitude analysis of B± → DK± decays, the ADS/GLW analysis of B± → DK*0 decays and the time-dependent analysis of B± → DK±sK± decays.

  13. Corrigendum to "Enhancing endmember selection in multiple endmember spectral mixture analysis (MESMA) for urban impervious surface area mapping using spectral angle and spectral distance parameters" [Int. J. Appl. Earth Observ. Geoinf. 33 (2014) 290-301

    NASA Astrophysics Data System (ADS)

    Fan, Fenglei; Deng, Yingbin

    2015-04-01

    Since publication, the authors have been advised of one prior methodological article not cited in our original paper. The missed reference from the paper is "Andreou, C., Karathanassi, V., 2012. A novel multiple endmember spectral mixture analysis using spectral angle distance. Geoscience and Remote Sensing Symposium (IGARSS) 2012 IEEE International, 4110-4113." This reference "Andreou, C., Karathanassi, V., 2012 in proceeding of IGARSS" should be cited in the Part 3 and Table 1, whereby in the fist sentence of Part 3 and the last sentence of caption of Table 1. The following should be added (in Part 3: According to the traditional MESMA and referring to MESMA-SAD method which is reported by Andreou and Karathanassi; in caption of Table 1: Based on the MESMA-SAD method of Andreou and Karathanassi). We apologize to the authors and workers concerned for this oversight and are pleased to acknowledge their contributions.

  14. Reading Angles in Maps

    PubMed Central

    Izard, Véronique; O'Donnell, Evan; Spelke, Elizabeth S.

    2013-01-01

    Preschool children can navigate by simple geometric maps of the environment, but the nature of the geometric relations they use in map reading remains unclear. Here, children were tested specifically on their sensitivity to angle. Forty-eight children (age 47:15–53:30 months) were presented with fragments of geometric maps, in which angle sections appeared without any relevant length or distance information. Children were able to read these map fragments and compare 2D to 3D angles. However, this ability appeared both variable and fragile among the youngest children of the sample. These findings suggest that 4-year-old children begin to form an abstract concept of angle that applies both to 2D and 3D displays and that serves to interpret novel spatial symbols. PMID:23647223

  15. Angles, Time, and Proportion

    ERIC Educational Resources Information Center

    Pagni, David L.

    2005-01-01

    This article describes an investigation making connections between the time on an analog clock and the angle between the minute hand and the hour hand. It was posed by a middle school mathematics teacher. (Contains 8 tables and 6 figures.)

  16. Reading angles in maps.

    PubMed

    Izard, Véronique; O'Donnell, Evan; Spelke, Elizabeth S

    2014-01-01

    Preschool children can navigate by simple geometric maps of the environment, but the nature of the geometric relations they use in map reading remains unclear. Here, children were tested specifically on their sensitivity to angle. Forty-eight children (age 47:15-53:30 months) were presented with fragments of geometric maps, in which angle sections appeared without any relevant length or distance information. Children were able to read these map fragments and compare two-dimensional to three-dimensional angles. However, this ability appeared both variable and fragile among the youngest children of the sample. These findings suggest that 4-year-old children begin to form an abstract concept of angle that applies both to two-dimensional and three-dimensional displays and that serves to interpret novel spatial symbols. PMID:23647223

  17. 'Magic Angle Precession'

    SciTech Connect

    Binder, Bernd

    2008-01-21

    An advanced and exact geometric description of nonlinear precession dynamics modeling very accurately natural and artificial couplings showing Lorentz symmetry is derived. In the linear description it is usually ignored that the geometric phase of relativistic motion couples back to the orbital motion providing for a non-linear recursive precession dynamics. The high coupling strength in the nonlinear case is found to be a gravitomagnetic charge proportional to the precession angle and angular velocity generated by geometric phases, which are induced by high-speed relativistic rotations and are relevant to propulsion technologies but also to basic interactions. In the quantum range some magic precession angles indicating strong coupling in a phase-locked chaotic system are identified, emerging from a discrete time dynamical system known as the cosine map showing bifurcations at special precession angles relevant to heavy nuclei stability. The 'Magic Angle Precession' (MAP) dynamics can be simulated and visualized by cones rolling in or on each other, where the apex and precession angles are indexed by spin, charge or precession quantum numbers, and corresponding magic angles. The most extreme relativistic warping and twisting effect is given by the Dirac spinor half spin constellation with 'Hyperdiamond' MAP, which resembles quark confinement.

  18. The Relationship between T1 Sagittal Angle and Sagittal Balance: A Retrospective Study of 119 Healthy Volunteers

    PubMed Central

    Li, Ming

    2016-01-01

    T1 sagittal angle has been reported to be used as a parameter for assessing sagittal balance and cervical lordosis. However, no study has been performed to explore the relationship between T1 sagittal angle and sagittal balance, and whether T1 sagittal angle could be used for osteotomy guidelines remains unknown. The aim of our study is to explore the relationship between T1 sagittal angle and sagittal balance, determine the predictors for T1 sagittal angle, and determine whether T1 sagittal angle could be used for osteotomy guidelines to restore sagittal balance. Medical records of healthy volunteers in our outpatient clinic from January 2014 to August 2015 were reviewed, and their standing full-spine lateral radiographs were evaluated. Demographic and radiological parameters were collected and analyzed, including age, gender, T1 sagittal angle, maxTK, maxLL, SS, PT, and PI. Correlation coefficients between T1 sagittal angle and other spinopelvic parameters were determined. In addition, multiple regression analysis was performed to establish predictive radiographic parameters for T1 sagittal angle as the primary contributors. A total of 119 healthy volunteers were recruited in our study with a mean age of 34.7 years. It was found that T1 sagittal angle was correlated with maxTK with very good significance (r = 0.697, P<0.001), maxLL with weak significance (r = 0.206, P = 0.024), SS with weak significance (r = 0.237, P = 0.009), PI with very weak significance (r = 0.189, P = 0.039), SVA with moderate significance (r = 0.445, P<0.001), TPA with weak significance (r = 0.207, P = 0.023), and T1SPI with weak significance (r = 0.309, P = 0.001). The result of multiple regression analysis showed that T1 sagittal angle could be predicted by using the following regression equation: T1 sagittal angle = 0.6 * maxTK—0.2 * maxLL + 8. In the healthy population, T1 sagittal angle could be considered as a useful parameter for sagittal balance; however, it could not be

  19. Food additives

    MedlinePlus

    Food additives are substances that become part of a food product when they are added during the processing or making of that food. "Direct" food additives are often added during processing to: Add nutrients ...

  20. Surface texture measurement for additive manufacturing

    NASA Astrophysics Data System (ADS)

    Triantaphyllou, Andrew; Giusca, Claudiu L.; Macaulay, Gavin D.; Roerig, Felix; Hoebel, Matthias; Leach, Richard K.; Tomita, Ben; Milne, Katherine A.

    2015-06-01

    The surface texture of additively manufactured metallic surfaces made by powder bed methods is affected by a number of factors, including the powder’s particle size distribution, the effect of the heat source, the thickness of the printed layers, the angle of the surface relative to the horizontal build bed and the effect of any post processing/finishing. The aim of the research reported here is to understand the way these surfaces should be measured in order to characterise them. In published research to date, the surface texture is generally reported as an Ra value, measured across the lay. The appropriateness of this method for such surfaces is investigated here. A preliminary investigation was carried out on two additive manufacturing processes—selective laser melting (SLM) and electron beam melting (EBM)—focusing on the effect of build angle and post processing. The surfaces were measured using both tactile and optical methods and a range of profile and areal parameters were reported. Test coupons were manufactured at four angles relative to the horizontal plane of the powder bed using both SLM and EBM. The effect of lay—caused by the layered nature of the manufacturing process—was investigated, as was the required sample area for optical measurements. The surfaces were also measured before and after grit blasting.

  1. Implant Angle Monitor System of MC3-II

    SciTech Connect

    Sato, Fumiaki; Sano, Makoto; Nakaoka, Hiroaki; Fujii, Yoshito; Kudo, Tetuya; Nakanishi, Makoto; Koike, Masazumi; Fujino, Yasushi

    2008-11-03

    Precise implant angle control is required for the latest generation of ion implanters to meet further shrink semiconductor device requirements. Especially, the highest angle accuracy is required for Halo implant process of Logic devices. The Halo implant angle affects the device performance, because slight differences of beam divergence change the overlap profile towards the extension. Additionally, twist angle accuracy is demanded in case of channeling angle implant. Therefore monitoring beam angles and wafer twist angles is important. A new monitoring system for the MC3-II, SEN Corp.'s single wafer type medium current implanter has been developed. This paper describes the angle control performance and monitoring system of the MC3-II. For the twist angle control, we developed a wafer notch angle monitor. The system monitors the wafer notch image on the platen. And the notch angle variation is calculated by using image processing method. It is also able to adjust the notch angle according to the angle error. For the tilt angle control, we developed a vertical beam profile monitor. The monitor system can detect beam profile of vertical directions with horizontally scanning beam. It also measures beam angles of a tilt direction to a wafer. The system configuration and sample beam data are presented.

  2. Food additives

    PubMed Central

    Spencer, Michael

    1974-01-01

    Food additives are discussed from the food technology point of view. The reasons for their use are summarized: (1) to protect food from chemical and microbiological attack; (2) to even out seasonal supplies; (3) to improve their eating quality; (4) to improve their nutritional value. The various types of food additives are considered, e.g. colours, flavours, emulsifiers, bread and flour additives, preservatives, and nutritional additives. The paper concludes with consideration of those circumstances in which the use of additives is (a) justified and (b) unjustified. PMID:4467857

  3. Morphology Parameters for Intracranial Aneurysm Rupture Risk Assessment

    PubMed Central

    Dhar, Sujan; Tremmel, Markus; Mocco, J; Kim, Minsuok; Yamamoto, Junichi; Siddiqui, Adnan H.; Hopkins, L. Nelson; Meng, Hui

    2008-01-01

    OBJECTIVE The aim of this study is to identify image-based morphological parameters that correlate with human intracranial aneurysm (IA) rupture. METHODS For 45 patients with terminal or sidewall saccular IAs (25 unruptured, 20 ruptured), three-dimensional geometries were evaluated for a range of morphological parameters. In addition to five previously studied parameters (aspect ratio, aneurysm size, ellipticity index, nonsphericity index, and undulation index), we defined three novel parameters incorporating the parent vessel geometry (vessel angle, aneurysm [inclination] angle, and [aneurysm-to-vessel] size ratio) and explored their correlation with aneurysm rupture. Parameters were analyzed with a two-tailed independent Student's t test for significance; significant parameters (P < 0.05) were further examined by multivariate logistic regression analysis. Additionally, receiver operating characteristic analyses were performed on each parameter. RESULTS Statistically significant differences were found between mean values in ruptured and unruptured groups for size ratio, undulation index, nonsphericity index, ellipticity index, aneurysm angle, and aspect ratio. Logistic regression analysis further revealed that size ratio (odds ratio, 1.41; 95% confidence interval, 1.03−1.92) and undulation index (odds ratio, 1.51; 95% confidence interval, 1.08−2.11) had the strongest independent correlation with ruptured IA. From the receiver operating characteristic analysis, size ratio and aneurysm angle had the highest area under the curve values of 0.83 and 0.85, respectively. CONCLUSION Size ratio and aneurysm angle are promising new morphological metrics for IA rupture risk assessment. Because these parameters account for vessel geometry, they may bridge the gap between morphological studies and more qualitative location-based studies. PMID:18797347

  4. Casting and Angling.

    ERIC Educational Resources Information Center

    Little, Mildred J.; Bunting, Camille

    The self-contained packet contains background information, lesson plans, 15 transparency and student handout masters, drills and games, 2 objective examinations, and references for teaching a 15-day unit on casting and angling to junior high and senior high school students, either as part of a regular physical education program or as a club…

  5. The Rainbow Angle.

    ERIC Educational Resources Information Center

    Sims, B.

    1978-01-01

    Two articles in the "Scientific American" form the background of this note. The rainbow angle for the primary bow of a monochromatic Cartesian rainbow is calculated. Special projects for senior high school students could be patterned after this quantitative study. (MP)

  6. An Iterative Angle Trisection

    ERIC Educational Resources Information Center

    Muench, Donald L.

    2007-01-01

    The problem of angle trisection continues to fascinate people even though it has long been known that it can't be done with straightedge and compass alone. However, for practical purposes, a good iterative procedure can get you as close as you want. In this note, we present such a procedure. Using only straightedge and compass, our procedure…

  7. Yaw Angle Demonstration

    NASA Technical Reports Server (NTRS)

    1994-01-01

    The Large Angle Magnetic Suspension Test Fixture (LAMSTF) is a 5 degree-of -freedom repulsive force magnetic suspension system designed to study the control of objects over large magnetic gaps. A digital control algorithm uses 6 sets of laser-sheet sensors and 5 control coils to position a cylinder 3' above the plane of electromagnetics

  8. Casting and Angling.

    ERIC Educational Resources Information Center

    Smith, Julian W.

    As part of a series of books and pamphlets on outdoor education, this manual consists of easy-to-follow instructions for fishing activities dealing with casting and angling. The manual may be used as a part of the regular physical education program in schools and colleges or as a club activity for the accomplished weekend fisherman or the…

  9. Identifying Differences and Similarities in Static and Dynamic Contact Angles between Nanoscale and Microscale Textured Surfaces Using Molecular Dynamics Simulations.

    PubMed

    Slovin, Mitchell R; Shirts, Michael R

    2015-07-28

    We quantify some of the effects of patterned nanoscale surface texture on static contact angles, dynamic contact angles, and dynamic contact angle hysteresis using molecular dynamics simulations of a moving Lennard-Jones droplet in contact with a solid surface. We observe static contact angles that change with the introduction of surface texture in a manner consistent with theoretical and experimental expectations. However, we find that the introduction of nanoscale surface texture at the length scale of 5-10 times the fluid particle size does not affect dynamic contact angle hysteresis even though it changes both the advancing and receding contact angles significantly. This result differs significantly from microscale experimental results where dynamic contact angle hysteresis decreases with the addition of surface texture due to an increase in the receding contact angle. Instead, we find that molecular-kinetic theory, previously applied only to nonpatterned surfaces, accurately describes dynamic contact angle and dynamic contact angle hysteresis behavior as a function of terminal fluid velocity. Therefore, at length scales of tens of nanometers, the kinetic phenomena such as contact line pinning observed at larger scales become insignificant in comparison to the effects of molecular fluctuations for moving droplets, even though the static properties are essentially scale-invariant. These findings may have implications for the design of highly hierarchical structures with particular wetting properties. We also find that quantitatively determining the trends observed in this article requires the careful selection of system and analysis parameters in order to achieve sufficient accuracy and precision in calculated contact angles. Therefore, we provide a detailed description of our two-surface, circular-fit approach to calculating static and dynamic contact angles on surfaces with nanoscale texturing. PMID:26110823

  10. 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…

  11. Trabecular-Iris Circumference Volume in Open Angle Eyes Using Swept-Source Fourier Domain Anterior Segment Optical Coherence Tomography

    PubMed Central

    Rigi, Mohammed; Blieden, Lauren S.; Nguyen, Donna; Chuang, Alice Z.; Baker, Laura A.; Bell, Nicholas P.; Lee, David A.; Mankiewicz, Kimberly A.; Feldman, Robert M.

    2014-01-01

    Purpose. To introduce a new anterior segment optical coherence tomography parameter, trabecular-iris circumference volume (TICV), which measures the integrated volume of the peripheral angle, and establish a reference range in normal, open angle eyes. Methods. One eye of each participant with open angles and a normal anterior segment was imaged using 3D mode by the CASIA SS-1000 (Tomey, Nagoya, Japan). Trabecular-iris space area (TISA) and TICV at 500 and 750 µm were calculated. Analysis of covariance was performed to examine the effect of age and its interaction with spherical equivalent. Results. The study included 100 participants with a mean age of 50 (±15) years (range 20–79). TICV showed a normal distribution with a mean (±SD) value of 4.75 µL (±2.30) for TICV500 and a mean (±SD) value of 8.90 µL (±3.88) for TICV750. Overall, TICV showed an age-related reduction (P = 0.035). In addition, angle volume increased with increased myopia for all age groups, except for those older than 65 years. Conclusions. This study introduces a new parameter to measure peripheral angle volume, TICV, with age-adjusted normal ranges for open angle eyes. Further investigation is warranted to determine the clinical utility of this new parameter. PMID:25210623

  12. Trabecular-iris circumference volume in open angle eyes using swept-source fourier domain anterior segment optical coherence tomography.

    PubMed

    Rigi, Mohammed; Blieden, Lauren S; Nguyen, Donna; Chuang, Alice Z; Baker, Laura A; Bell, Nicholas P; Lee, David A; Mankiewicz, Kimberly A; Feldman, Robert M

    2014-01-01

    Purpose. To introduce a new anterior segment optical coherence tomography parameter, trabecular-iris circumference volume (TICV), which measures the integrated volume of the peripheral angle, and establish a reference range in normal, open angle eyes. Methods. One eye of each participant with open angles and a normal anterior segment was imaged using 3D mode by the CASIA SS-1000 (Tomey, Nagoya, Japan). Trabecular-iris space area (TISA) and TICV at 500 and 750 µm were calculated. Analysis of covariance was performed to examine the effect of age and its interaction with spherical equivalent. Results. The study included 100 participants with a mean age of 50 (±15) years (range 20-79). TICV showed a normal distribution with a mean (±SD) value of 4.75 µL (±2.30) for TICV500 and a mean (±SD) value of 8.90 µL (±3.88) for TICV750. Overall, TICV showed an age-related reduction (P = 0.035). In addition, angle volume increased with increased myopia for all age groups, except for those older than 65 years. Conclusions. This study introduces a new parameter to measure peripheral angle volume, TICV, with age-adjusted normal ranges for open angle eyes. Further investigation is warranted to determine the clinical utility of this new parameter. PMID:25210623

  13. Angles in the Sky?

    NASA Astrophysics Data System (ADS)

    Behr, Bradford

    2005-09-01

    Tycho Brahe lived and worked in the late 1500s before the telescope was invented. He made highly accurate observations of the positions of planets, stars, and comets using large angle-measuring devices of his own design. You can use his techniques to observe the sky as well. For example, the degree, a common unit of measurement in astronomy, can be measured by holding your fist at arm's length up to the sky. Open your fist and observe the distance across the sky covered by the width of your pinky fingernail. That is, roughly, a degree! After some practice, and knowing that one degree equals four minutes, you can measure elapsed time by measuring the angle of the distance that the Moon appears to have moved and multiplying that number by four. You can also figure distances and sizes of things. These are not precise measurements, but rough estimates that can give you a "close-enough" answer.

  14. Laser angle sensor

    NASA Technical Reports Server (NTRS)

    Pond, C. R.; Texeira, P. D.

    1985-01-01

    A laser angle measurement system was designed and fabricated for NASA Langley Research Center. The instrument is a fringe counting interferometer that monitors the pitch attitude of a model in a wind tunnel. A laser source and detector are mounted above the model. Interference fringes are generated by a small passive element on the model. The fringe count is accumulated and displayed by a processor in the wind tunnel control room. This report includes optical and electrical schematics, system maintenance and operation procedures.

  15. Angle states in quantum mechanics

    NASA Astrophysics Data System (ADS)

    de la Torre, A. C.; Iguain, J. L.

    1998-12-01

    Angle states and angle operators are defined for a system with arbitrary angular momentum. They provide a reasonable formalization of the concept of angle provided that we accept that the angular orientation is quantized. The angle operator is the generator of boosts in angular momentum and is, almost everywhere, linearly related to the logarithm of the shift operator. Angle states for fermions and bosons behave differently under parity transformation.

  16. Small Angle Neutron Scattering

    SciTech Connect

    Urban, Volker S

    2012-01-01

    Small Angle Neutron Scattering (SANS) probes structural details at the nanometer scale in a non-destructive way. This article gives an introduction to scientists who have no prior small-angle scattering knowledge, but who seek a technique that allows elucidating structural information in challenging situations that thwart approaches by other methods. SANS is applicable to a wide variety of materials including metals and alloys, ceramics, concrete, glasses, polymers, composites and biological materials. Isotope and magnetic interactions provide unique methods for labeling and contrast variation to highlight specific structural features of interest. In situ studies of a material s responses to temperature, pressure, shear, magnetic and electric fields, etc., are feasible as a result of the high penetrating power of neutrons. SANS provides statistical information on significant structural features averaged over the probed sample volume, and one can use SANS to quantify with high precision the structural details that are observed, for example, in electron microscopy. Neutron scattering is non-destructive; there is no need to cut specimens into thin sections, and neutrons penetrate deeply, providing information on the bulk material, free from surface effects. The basic principles of a SANS experiment are fairly simple, but the measurement, analysis and interpretation of small angle scattering data involves theoretical concepts that are unique to the technique and that are not widely known. This article includes a concise description of the basics, as well as practical know-how that is essential for a successful SANS experiment.

  17. Analysis of factors affecting angle ANB.

    PubMed

    Hussels, W; Nanda, R S

    1984-05-01

    Cephalometric analyses based on angular and linear measurements have obvious fallacies, which have been discussed in detail by Moyers and Bookstein. However, the clinical application of such an analysis by the orthodontic profession in treatment planning is widely accepted. Variations of angle ANB are commonly used to determine relative jaw relationships in most of the cephalometric evaluations. Several authors, including points A and B influences angle ANB, as does rotational growth of the upper and lower jaws. In addition, the authors point out that growth in a vertical direction (distance N to B) and an increase of the dental height (distance A to B) may contribute to changes in angle ANB. For a Class I relation (Wits = 0 mm), a mathematical formula has been developed which enables the authors to study the geometric influence of angle ANB caused by the following four effects: (1) rotation of the jaws and/or occlusal plane relative to the anterior cranial base; (2) anteroposterior position of N relative to point B, (3) vertical growth (distance N to B); (4) increase in dental height (distance A to B). It was observed that, contrary to the common belief that an ANB angle of 2 +/- 3.0 degrees is considered normal for a skeletal Class I relation, the calculated values of angle ANB will vary widely with changes in these four controlling factors under the same skeletal Class I conditions (Wits = 0 mm). Therefore, in a case under consideration, angle ANB must be corrected for these geometric effects in order to get a proper perspective of the skeletal discrepancy. This is facilitated by comparing the measured ANB angle with the corresponding ANB angle calculated by a formula for a Class I relationship. The corresponding calculated angle ANB can be taken from the tables which are based upon the formula using the same values for SNB, omega (angle between occlusal plane and anterior cranial base), b (which is distance N to B) and a (dental height measured as perpendicular

  18. Influence of crossing angles of columnar defects on vortex glass transition in YBCO thin films

    NASA Astrophysics Data System (ADS)

    Sueyoshi, T.; Sogo, T.; Yonekura, K.; Fujiyoshi, T.; Mitsugi, F.; Ikegami, T.; Ishikawa, N.; Awaji, S.; Watanabe, K.

    2011-11-01

    To investigate the influence of the crossing angles of columnar defects (CDs) on the in-field properties of the critical current density Jc and the scaling parameter m derived from the isothermal current-voltage characteristics near the glass-liquid transition at B|| c-axis, YBCO thin films were irradiated using the 200 MeV Xe ions at two angles ± θ i relative to the c-axis. For the thin films, the obvious effect of the crossing angle of CDs occurred on the vortex glass-liquid transition more than the Jc properties. On the glass-liquid transition line, two inflection points induced by the c-axis correlated pinning were confirmed even for the samples of θ i = ±45°. In the magnetic field dependence of m, the peak or kink appeared near B/ B ϕ = 1/3 for the smaller crossing angles, whereas that was slightly visible for the samples of θ i = ±45°. In addition, the values of m for the small crossing angle were larger than those for the parallel CD configuration, while those for the larger crossing angle became smaller. These results suggested that the morphologies of correlated pinning centers strongly affect the dynamics of flux lines even in the disordered system such as thin films.

  19. Optimality in the variation of average branching angle with generation in the human bronchial tree.

    PubMed

    Lee, Eugene; Kang, Min Y; Yang, Hoe J; Lee, Jin W

    2008-06-01

    In the human bronchial tree the branching angle becomes larger with generation or for the smaller branches. Previous theories based on single parameter optimization have not been successful at all in predicting the consistent increasing trend of branching angle with continued bifurcation. In this study a new theory for the optimality of the branching angle is proposed, which is based on the optimization between dual competing performances, the maximum space-filling capability at the expense of minimum energy loss. A large-angle branching gives an effect of delivering air into a new direction away from the preceding airways. It then has an effect of utilizing the lung volume with better uniformity, but at the same time inevitably requires a high pressure loss. It is shown in this paper that the ever increasing branching angle with generation can be well explained as the optimum branching structure where the dual opposing performance of space filling and pressure loss is optimized. In estimating the pressure loss, branching loss is considered in addition to the Poiseuille loss. Change of predicted optimum branching angle with generation shows an excellent agreement with the observed data found in the human conducting airways. PMID:18317928

  20. Food additives.

    PubMed

    Berglund, F

    1978-01-01

    The use of additives to food fulfils many purposes, as shown by the index issued by the Codex Committee on Food Additives: Acids, bases and salts; Preservatives, Antioxidants and antioxidant synergists; Anticaking agents; Colours; Emulfifiers; Thickening agents; Flour-treatment agents; Extraction solvents; Carrier solvents; Flavours (synthetic); Flavour enhancers; Non-nutritive sweeteners; Processing aids; Enzyme preparations. Many additives occur naturally in foods, but this does not exclude toxicity at higher levels. Some food additives are nutrients, or even essential nutritents, e.g. NaCl. Examples are known of food additives causing toxicity in man even when used according to regulations, e.g. cobalt in beer. In other instances, poisoning has been due to carry-over, e.g. by nitrate in cheese whey - when used for artificial feed for infants. Poisonings also occur as the result of the permitted substance being added at too high levels, by accident or carelessness, e.g. nitrite in fish. Finally, there are examples of hypersensitivity to food additives, e.g. to tartrazine and other food colours. The toxicological evaluation, based on animal feeding studies, may be complicated by impurities, e.g. orthotoluene-sulfonamide in saccharin; by transformation or disappearance of the additive in food processing in storage, e.g. bisulfite in raisins; by reaction products with food constituents, e.g. formation of ethylurethane from diethyl pyrocarbonate; by metabolic transformation products, e.g. formation in the gut of cyclohexylamine from cyclamate. Metabolic end products may differ in experimental animals and in man: guanylic acid and inosinic acid are metabolized to allantoin in the rat but to uric acid in man. The magnitude of the safety margin in man of the Acceptable Daily Intake (ADI) is not identical to the "safety factor" used when calculating the ADI. The symptoms of Chinese Restaurant Syndrome, although not hazardous, furthermore illustrate that the whole ADI

  1. Study on self-calibration angle encoder using simulation method

    NASA Astrophysics Data System (ADS)

    Wang, Yan; Xue, Zi; Huang, Yao; Wang, Xiaona

    2016-01-01

    The angle measurement technology is very important in precision manufacture, optical industry, aerospace, aviation and navigation, etc. Further, the angle encoder, which uses concept `subdivision of full circle (2π rad=360°)' and transforms the angle into number of electronic pulse, is the most common instrument for angle measurement. To improve the accuracy of the angle encoder, a novel self-calibration method was proposed that enables the angle encoder to calibrate itself without angle reference. An angle deviation curve among 0° to 360° was simulated with equal weights Fourier components for the study of the self-calibration method. In addition, a self-calibration algorithm was used in the process of this deviation curve. The simulation result shows the relationship between the arrangement of multi-reading heads and the Fourier components distribution of angle encoder deviation curve. Besides, an actual self-calibration angle encoder was calibrated by polygon angle standard in national institute of metrology, China. The experiment result indicates the actual self-calibration effect on the Fourier components distribution of angle encoder deviation curve. In the end, the comparison, which is between the simulation self-calibration result and the experiment self-calibration result, reflects good consistency and proves the reliability of the self-calibration angle encoder.

  2. Angle-Polarization Estimation for Coherent Sources with Linear Tripole Sensor Arrays.

    PubMed

    Wang, Kun; He, Jin; Shu, Ting; Liu, Zhong

    2016-01-01

    We propose a parallel factor (PARAFAC) analysis-based angle and polarization estimation algorithm for multiple coherent sources using a uniformly-spaced linear tripole sensor array. By forming a PARAFAC model using the spatial signature of the tripole array, the new algorithm requires neither spatial smoothing nor vector-field smoothing to decorrelate the signal coherency. We also establish that the angle-polarization parameters of K coherent signals can be uniquely determined by PARAFAC analysis, as long as the number of tripoles L ≥ 2K - 1 . In addition, the proposed algorithm can offer enhanced angle and polarization estimation accuracy by extending the interspacing of the tripoles beyond a half wavelength. PMID:26907273

  3. 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

  4. Shape of menisci in spinning horizontal tubes: Application to contact angle determination

    SciTech Connect

    Princen, H.M.; Vaidya, R.N.

    1995-09-01

    The authors have computed the shape of an axisymmetric fluid/liquid meniscus in a capillary that is spun about its horizontal axis. The solutions were used to establish the relationship between the fluid/liquid/solid contact angle on the one hand and several experimentally accessible parameters (tube radius, interfacial tension, densities, angular velocity, and certain meniscus dimensions) on the other. This opens the way to a novel method for determining contact angles. Using the results for single menisci, the authors have in addition developed a method whereby the contact angle may be obtained from the critical speed at which a finite drop (or slug) is either released from the tube wall (if the drop phase is the less dense phase) or penetrated axially by the other phase (if the drop phase is the denser phase).

  5. Angle-Polarization Estimation for Coherent Sources with Linear Tripole Sensor Arrays

    PubMed Central

    Wang, Kun; He, Jin; Shu, Ting; Liu, Zhong

    2016-01-01

    We propose a parallel factor (PARAFAC) analysis-based angle and polarization estimation algorithm for multiple coherent sources using a uniformly-spaced linear tripole sensor array. By forming a PARAFAC model using the spatial signature of the tripole array, the new algorithm requires neither spatial smoothing nor vector-field smoothing to decorrelate the signal coherency. We also establish that the angle-polarization parameters of K coherent signals can be uniquely determined by PARAFAC analysis, as long as the number of tripoles L≥2K−1. In addition, the proposed algorithm can offer enhanced angle and polarization estimation accuracy by extending the interspacing of the tripoles beyond a half wavelength. PMID:26907273

  6. Wide Angle Movie

    NASA Technical Reports Server (NTRS)

    1999-01-01

    This brief movie illustrates the passage of the Moon through the Saturn-bound Cassini spacecraft's wide-angle camera field of view as the spacecraft passed by the Moon on the way to its closest approach with Earth on August 17, 1999. From beginning to end of the sequence, 25 wide-angle images (with a spatial image scale of about 14 miles per pixel (about 23 kilometers)were taken over the course of 7 and 1/2 minutes through a series of narrow and broadband spectral filters and polarizers, ranging from the violet to the near-infrared regions of the spectrum, to calibrate the spectral response of the wide-angle camera. The exposure times range from 5 milliseconds to 1.5 seconds. Two of the exposures were smeared and have been discarded and replaced with nearby images to make a smooth movie sequence. All images were scaled so that the brightness of Crisium basin, the dark circular region in the upper right, is approximately the same in every image. The imaging data were processed and released by the Cassini Imaging Central Laboratory for Operations (CICLOPS)at the University of Arizona's Lunar and Planetary Laboratory, Tucson, AZ.

    Photo Credit: NASA/JPL/Cassini Imaging Team/University of Arizona

    Cassini, launched in 1997, is a joint mission of NASA, the European Space Agency and Italian Space Agency. The mission is managed by NASA's Jet Propulsion Laboratory, Pasadena, CA, for NASA's Office of Space Science, Washington DC. JPL is a division of the California Institute of Technology, Pasadena, CA.

  7. Laser angle measurement system

    NASA Technical Reports Server (NTRS)

    Pond, C. R.; Texeira, P. D.; Wilbert, R. E.

    1980-01-01

    The design and fabrication of a laser angle measurement system is described. The instrument is a fringe counting interferometer that monitors the pitch attitude of a model in a wind tunnel. A laser source and detector are mounted above the mode. Interference fringes are generated by a small passive element on the model. The fringe count is accumulated and displayed by a processor in the wind tunnel control room. Optical and electrical schematics, system maintenance and operation procedures are included, and the results of a demonstration test are given.

  8. The Influence of Structure Heights and Opening Angles of Micro- and Nanocones on the Macroscopic Surface Wetting Properties

    NASA Astrophysics Data System (ADS)

    Schneider, Ling; Laustsen, Milan; Mandsberg, Nikolaj; Taboryski, Rafael

    2016-02-01

    We discuss the influence of surface structure, namely the height and opening angles of nano- and microcones on the surface wettability. We show experimental evidence that the opening angle of the cones is the critical parameter on sample superhydrophobicity, namely static contact angles and roll-off angles. The textured surfaces are fabricated on silicon wafers by using a simple one-step method of reactive ion etching at different processing time and gas flow rates. By using hydrophobic coating or hydrophilic surface treatment, we are able to switch the surface wettability from superhydrophilic to superhydrophobic without altering surface structures. In addition, we show examples of polymer replicas (polypropylene and poly(methyl methacrylate) with different wettability, fabricated by injection moulding using templates of the silicon cone-structures.

  9. The Influence of Structure Heights and Opening Angles of Micro- and Nanocones on the Macroscopic Surface Wetting Properties.

    PubMed

    Schneider, Ling; Laustsen, Milan; Mandsberg, Nikolaj; Taboryski, Rafael

    2016-01-01

    We discuss the influence of surface structure, namely the height and opening angles of nano- and microcones on the surface wettability. We show experimental evidence that the opening angle of the cones is the critical parameter on sample superhydrophobicity, namely static contact angles and roll-off angles. The textured surfaces are fabricated on silicon wafers by using a simple one-step method of reactive ion etching at different processing time and gas flow rates. By using hydrophobic coating or hydrophilic surface treatment, we are able to switch the surface wettability from superhydrophilic to superhydrophobic without altering surface structures. In addition, we show examples of polymer replicas (polypropylene and poly(methyl methacrylate) with different wettability, fabricated by injection moulding using templates of the silicon cone-structures. PMID:26892169

  10. The Influence of Structure Heights and Opening Angles of Micro- and Nanocones on the Macroscopic Surface Wetting Properties

    PubMed Central

    Schneider, Ling; Laustsen, Milan; Mandsberg, Nikolaj; Taboryski, Rafael

    2016-01-01

    We discuss the influence of surface structure, namely the height and opening angles of nano- and microcones on the surface wettability. We show experimental evidence that the opening angle of the cones is the critical parameter on sample superhydrophobicity, namely static contact angles and roll-off angles. The textured surfaces are fabricated on silicon wafers by using a simple one-step method of reactive ion etching at different processing time and gas flow rates. By using hydrophobic coating or hydrophilic surface treatment, we are able to switch the surface wettability from superhydrophilic to superhydrophobic without altering surface structures. In addition, we show examples of polymer replicas (polypropylene and poly(methyl methacrylate) with different wettability, fabricated by injection moulding using templates of the silicon cone-structures. PMID:26892169

  11. A low bioimpedance phase angle predicts a higher mortality and lower nutritional status in chronic dialysis patients

    NASA Astrophysics Data System (ADS)

    Dumler Md, Francis

    2010-04-01

    Bioelectrical impedance analysis is an established technique for body composition analysis. The phase angle parameter, an index of body cell mass, tissue hydration, and membrane integrity, makes it suitable for assessing nutritional status and survivability. We evaluated the significance of a low phase angle value on nutritional status and mortality in 285 chronic dialysis patients during a longitudinal prospective observational study. Patients in the lower phase angle tertile had decreased body weight, body mass index, fat free mass, body cell mass, and lower serum albumin concentrations than those in the higher tertile (P<001). In addition, mortality rates were significantly lower (P=0.05) in the highest tertile patients. In conclusion, the phase angle is a useful method for identifying dialysis patients at high risk for malnutrition and increased mortality.

  12. Measures on mixing angles

    SciTech Connect

    Gibbons, Gary W.; Gielen, Steffen; Pope, C. N.; Turok, Neil

    2009-01-01

    We address the problem of the apparently very small magnitude of CP violation in the standard model, measured by the Jarlskog invariant J. In order to make statements about probabilities for certain values of J, we seek to find a natural measure on the space of Kobayashi-Maskawa matrices, the double quotient U(1){sup 2}/SU(3)/U(1){sup 2}. We review several possible, geometrically motivated choices of the measure, and compute expectation values for powers of J for these measures. We find that different choices of the measure generically make the observed magnitude of CP violation appear finely tuned. Since the quark masses and the mixing angles are determined by the same set of Yukawa couplings, we then do a second calculation in which we take the known quark mass hierarchy into account. We construct the simplest measure on the space of 3x3 Hermitian matrices which reproduces this known hierarchy. Calculating expectation values for powers of J in this second approach, we find that values of J close to the observed value are now rather likely, and there does not seem to be any fine-tuning. Our results suggest that the choice of Kobayashi-Maskawa angles is closely linked to the observed mass hierarchy. We close by discussing the corresponding case of neutrinos.

  13. Potlining Additives

    SciTech Connect

    Rudolf Keller

    2004-08-10

    In this project, a concept to improve the performance of aluminum production cells by introducing potlining additives was examined and tested. Boron oxide was added to cathode blocks, and titanium was dissolved in the metal pool; this resulted in the formation of titanium diboride and caused the molten aluminum to wet the carbonaceous cathode surface. Such wetting reportedly leads to operational improvements and extended cell life. In addition, boron oxide suppresses cyanide formation. This final report presents and discusses the results of this project. Substantial economic benefits for the practical implementation of the technology are projected, especially for modern cells with graphitized blocks. For example, with an energy savings of about 5% and an increase in pot life from 1500 to 2500 days, a cost savings of $ 0.023 per pound of aluminum produced is projected for a 200 kA pot.

  14. Phosphazene additives

    SciTech Connect

    Harrup, Mason K; Rollins, Harry W

    2013-11-26

    An additive comprising a phosphazene compound that has at least two reactive functional groups and at least one capping functional group bonded to phosphorus atoms of the phosphazene compound. One of the at least two reactive functional groups is configured to react with cellulose and the other of the at least two reactive functional groups is configured to react with a resin, such as an amine resin of a polycarboxylic acid resin. The at least one capping functional group is selected from the group consisting of a short chain ether group, an alkoxy group, or an aryloxy group. Also disclosed are an additive-resin admixture, a method of treating a wood product, and a wood product.

  15. METHODOLOGICAL NOTES: Permutation asymmetry of the relativistic velocity addition law and non-Euclidean geometry

    NASA Astrophysics Data System (ADS)

    Ritus, V. I.

    2008-07-01

    The asymmetry of the relativistic addition law for noncollinear velocities under the velocity permutation leads to two modified triangles on a Euclidean plane depicting the addition of unpermuted and permuted velocities and the appearance of a nonzero angle ω between two resulting velocities. A particle spin rotates through the same angle ω under a Lorentz boost with a velocity noncollinear to the particle velocity. Three mutually connected three-parameter representations of the angle ω, obtained by the author earlier, express the three-parameter symmetry of the sides and angles of two Euclidean triangles identical to the sine and cosine theorems for the sides and angles of a single geodesic triangle on the surface of a pseudosphere. Namely, all three representations of the angle ω, after a transformation of one of them, coincide with the representations of the area of a pseudospherical triangle expressed in terms of any two of its sides and the angle between them. The angle ω is also symmetrically expressed in terms of three angles or three sides of a geodesic triangle, and therefore it is an invariant of the group of triangle motions over the pseudo-sphere surface, the group that includes the Lorentz group. Although the pseudospheres in Euclidean and pseudo-Euclidean spaces are locally isometric, only the latter is isometric to the entire Lobachevsky plane and forms a homogeneous isotropic curved 4-velocity space in the flat Minkowski space. In this connection, relativistic physical processes that may be related to the pseudosphere in Euclidean space are especially interesting.

  16. A Note on Angle Construction

    ERIC Educational Resources Information Center

    Francis, Richard L.

    1978-01-01

    The author investigates the construction of angles (using Euclidean tools) through a numerical approach. He calls attention to the surprising impossibility of constructing the conventional units of angle measure--the degree, minute, second, radian, and mil. (MN)

  17. Angle performance on optima MDxt

    SciTech Connect

    David, Jonathan; Kamenitsa, Dennis

    2012-11-06

    Angle control on medium current implanters is important due to the high angle-sensitivity of typical medium current implants, such as halo implants. On the Optima MDxt, beam-to-wafer angles are controlled in both the horizontal and vertical directions. In the horizontal direction, the beam angle is measured through six narrow slits, and any angle adjustment is made by electrostatically steering the beam, while cross-wafer beam parallelism is adjusted by changing the focus of the electrostatic parallelizing lens (P-lens). In the vertical direction, the beam angle is measured through a high aspect ratio mask, and any angle adjustment is made by slightly tilting the wafer platen prior to implant. A variety of tests were run to measure the accuracy and repeatability of Optima MDxt's angle control. SIMS profiles of a high energy, channeling sensitive condition show both the cross-wafer angle uniformity, along with the small-angle resolution of the system. Angle repeatability was quantified by running a channeling sensitive implant as a regular monitor over a seven month period and measuring the sheet resistance-to-angle sensitivity. Even though crystal cut error was not controlled for in this case, when attributing all Rs variation to angle changes, the overall angle repeatability was measured as 0.16 Degree-Sign (1{sigma}). A separate angle repeatability test involved running a series of V-curves tests over a four month period using low crystal cut wafers selected from the same boule. The results of this test showed the angle repeatability to be <0.1 Degree-Sign (1{sigma}).

  18. 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.

  19. Sun angle calculator

    NASA Technical Reports Server (NTRS)

    Flippin, A.; Schmitt, A. L. (Inventor)

    1976-01-01

    A circular computer and system is disclosed for determining the sun angle relative to the horizon from any given place and at any time. The computer includes transparent, rotatably mounted discs on both sides of the circular disc member. Printed on one side of the circular disc member are outer and inner circular sets of indicia respectively representative of site longitude and Greenwich Mean Time. Printed on an associated one of the rotatable discs is a set of indicia representative of Solar Time. Printed on the other side of the circular disc member are parallel lines representative of latitude between diametral representations of North and South poles. Elliptical lines extending between the North and South poles are proportionally disposed on the surface to scale Solar Time in hours.

  20. Narrow Angle movie

    NASA Technical Reports Server (NTRS)

    1999-01-01

    This brief three-frame movie of the Moon was made from three Cassini narrow-angle images as the spacecraft passed by the Moon on the way to its closest approach with Earth on August 17, 1999. The purpose of this particular set of images was to calibrate the spectral response of the narrow-angle camera and to test its 'on-chip summing mode' data compression technique in flight. From left to right, they show the Moon in the green, blue and ultraviolet regions of the spectrum in 40, 60 and 80 millisecond exposures, respectively. All three images have been scaled so that the brightness of Crisium basin, the dark circular region in the upper right, is the same in each image. The spatial scale in the blue and ultraviolet images is 1.4 miles per pixel (2.3 kilometers). The original scale in the green image (which was captured in the usual manner and then reduced in size by 2x2 pixel summing within the camera system) was 2.8 miles per pixel (4.6 kilometers). It has been enlarged for display to the same scale as the other two. The imaging data were processed and released by the Cassini Imaging Central Laboratory for Operations (CICLOPS) at the University of Arizona's Lunar and Planetary Laboratory, Tucson, AZ.

    Photo Credit: NASA/JPL/Cassini Imaging Team/University of Arizona

    Cassini, launched in 1997, is a joint mission of NASA, the European Space Agency and Italian Space Agency. The mission is managed by NASA's Jet Propulsion Laboratory, Pasadena, CA, for NASA's Office of Space Science, Washington DC. JPL is a division of the California Institute of Technology, Pasadena, CA.

  1. Optimal Number of Angle Images for Calculating Anterior Angle Volume and Iris Volume Measurements

    PubMed Central

    Blieden, Lauren S.; Chuang, Alice Z.; Baker, Laura A.; Bell, Nicholas P.; Fuller, Timothy S.; Mankiewicz, Kimberly A.; Feldman, Robert M.

    2015-01-01

    Purpose. We determined the optimal number of angle images required to obtain reliable measurements of trabecular-iris circumferential volume (TICV) and iris volume (IV) using swept-source Fourier domain anterior segment optical coherence tomography (SSFD-ASOCT) scans in narrow angle eyes. Methods. Scleral spur landmarks (SSL) were manually identified on ASOCT angle images from 128 meridians from each of 24 eyes with chronic primary angle closure (PAC) spectrum of disease. The anterior and posterior corneal curves, and the anterior and posterior iris surfaces were identified automatically by the anterior chamber analysis and interpretation (ACAI) software, then manually examined and edited by the reader if required. Trabecular-iris circumferential volume at 750 μm from SSL (TICV750) and IV were subsequently calculated using varying numbers of angle images. Threshold error was determined to be less than the lower 95% confidence limit of mean absolute percent error (MAPE) of the change in TICV or IV resulting from laser peripheral iridotomy, which would be 17% for TICV and 5% for IV, based on previous studies. The optimal number of angle images was the smallest number of images where MAPE was less than this threshold for TICV and IV. Results. A total of 32 equally-spaced angle images (16 meridians) was required to estimate TICV750 and 16 angle images (8 meridians) to estimate IV. Both were within 4.6% and 1.6% of MAPE, respectively. Conclusions. It is possible to determine TICV and IV parameters reliably in narrow angles without evaluating all 128 meridians obtained with SSFD-ASOCT. PMID:25829412

  2. Detailed statistical contact angle analyses; "slow moving" drops on inclining silicon-oxide surfaces.

    PubMed

    Schmitt, M; Groß, K; Grub, J; Heib, F

    2015-06-01

    Contact angle determination by sessile drop technique is essential to characterise surface properties in science and in industry. Different specific angles can be observed on every solid which are correlated with the advancing or the receding of the triple line. Different procedures and definitions for the determination of specific angles exist which are often not comprehensible or reproducible. Therefore one of the most important things in this area is to build standard, reproducible and valid methods for determining advancing/receding contact angles. This contribution introduces novel techniques to analyse dynamic contact angle measurements (sessile drop) in detail which are applicable for axisymmetric and non-axisymmetric drops. Not only the recently presented fit solution by sigmoid function and the independent analysis of the different parameters (inclination, contact angle, velocity of the triple point) but also the dependent analysis will be firstly explained in detail. These approaches lead to contact angle data and different access on specific contact angles which are independent from "user-skills" and subjectivity of the operator. As example the motion behaviour of droplets on flat silicon-oxide surfaces after different surface treatments is dynamically measured by sessile drop technique when inclining the sample plate. The triple points, the inclination angles, the downhill (advancing motion) and the uphill angles (receding motion) obtained by high-precision drop shape analysis are independently and dependently statistically analysed. Due to the small covered distance for the dependent analysis (<0.4mm) and the dominance of counted events with small velocity the measurements are less influenced by motion dynamics and the procedure can be called "slow moving" analysis. The presented procedures as performed are especially sensitive to the range which reaches from the static to the "slow moving" dynamic contact angle determination. They are characterised by

  3. Dirac leptonic angle matrix versus Majorana leptonic angle matrix and their renormalization group running behaviors

    NASA Astrophysics Data System (ADS)

    Luo, Shu

    2012-01-01

    Enlightened by the idea of the 3×3 Cabibbo-Kobayashi-Maskawa angle matrix proposed recently by Harrison , we introduce the Dirac angle matrix Φ and the Majorana angle matrix Ψ in the lepton sector for Dirac and Majorana neutrinos, respectively. We show that in the presence of CP violation, the angle matrix Φ or Ψ is entirely equivalent to the complex Maki-Nakagawa-Sakata matrix V itself, but has the advantage of being real, phase rephasing invariant, directly associated to the leptonic unitarity triangles and do not depend on any particular parametrization of V. In this paper, we further analyzed how the angle matrices evolve with the energy scale. The one-loop renormalization group equations of Φ, Ψ and some other rephasing invariant parameters are derived and a numerical analysis is performed to compare between the case of Dirac and Majorana neutrinos. Different neutrino mass spectra are taken into account in our calculation. We find that apparently different from the case of Dirac neutrinos, for Majorana neutrinos the renormalization group equation evolutions of Φ, Ψ and J strongly depend on the Majorana-type CP-violating parameters and are more sensitive to the sign of Δm312. They may receive significant radiative corrections in the minimal supersymmetric standard model with large tan⁡β if three neutrino masses are nearly degenerate.

  4. [Screening in open angle glaucoma].

    PubMed

    Mocanu, Carmen; Mocanu, Andrei

    2012-01-01

    Primary open angle glaucoma (POAG) represents the second cause of mondial cecity, after retinal diabetes complications, with extremely severe implications in quality of life. Screening testing for glaucoma is justified, because only the diagnosis in very incipient stage will preserve the visual function; any treatment will not assure the reversibility of pre-existent optic nerve lesions. Screening of glaucoma, will take into a consideration the costs, the time of investigation, the adverse effects, and the sensitivity and specificity of tests; the last parameter also will strongly influence the positive predictive value. An ideal screening identifies all subjects that present the disease (sensitivity) and will exclude all healthy subjects (specificity). In this moment, in Dolj district, the diagnosis is based on active diagnosis of new cases of glaucoma on the high risk level population, therefore in a 210000 habitants. 4723 patients with glaucoma are diagnosed, screened and follow-up on medical cabinets and on Center of Glaucoma, which coordinates their activity. To better monitored patients, automatized programs with acquisition and storage for different types of medical imaging facilities had become indispensable to any routine practice. PMID:23755511

  5. Relating lepton mixing angles with lepton mass hierarchy

    NASA Astrophysics Data System (ADS)

    Borah, Debasish

    2016-01-01

    We revisit the possibility of relating lepton mixing angles with lepton mass hierarchies in a model-independent way. Guided by the existence of such relations in the quark sector, we first consider all the mixing angles, both in charged lepton and neutrino sectors to be related to the respective mass ratios. This allows us to calculate the leptonic mixing angles observed in neutrino oscillations as functions of the lightest neutrino mass. We show that for both normal and inverted hierarchical neutrino masses, this scenario does not give rise to correct leptonic mixing angles. We then show that correct leptonic mixing angles can be generated with normal hierarchical neutrino masses if the relation between mixing angle and mass ratio is restricted to 1-2 and 1-3 mixing in both charged lepton and neutrino sectors leaving the 2-3 mixing angles as free parameters. We then restrict the lightest neutrino mass as well as the difference between 2-3 mixing angles in charged lepton and neutrino sectors from the requirement of producing correct leptonic mixing angles. We constrain the lightest neutrino mass to be around 0.002 eV and leptonic Dirac CP phase δCP such that sin2δ CP ˜ (0.35-0.50). We also construct the leptonic mass matrices in terms of 2-3 mixing angles and lightest neutrino mass and briefly comment on the possibility of realizing texture zeros in the neutrino mass matrix.

  6. Small angle neutron scattering

    NASA Astrophysics Data System (ADS)

    Cousin, Fabrice

    2015-10-01

    Small Angle Neutron Scattering (SANS) is a technique that enables to probe the 3-D structure of materials on a typical size range lying from ˜ 1 nm up to ˜ a few 100 nm, the obtained information being statistically averaged on a sample whose volume is ˜ 1 cm3. This very rich technique enables to make a full structural characterization of a given object of nanometric dimensions (radius of gyration, shape, volume or mass, fractal dimension, specific area…) through the determination of the form factor as well as the determination of the way objects are organized within in a continuous media, and therefore to describe interactions between them, through the determination of the structure factor. The specific properties of neutrons (possibility of tuning the scattering intensity by using the isotopic substitution, sensitivity to magnetism, negligible absorption, low energy of the incident neutrons) make it particularly interesting in the fields of soft matter, biophysics, magnetic materials and metallurgy. In particular, the contrast variation methods allow to extract some informations that cannot be obtained by any other experimental techniques. This course is divided in two parts. The first one is devoted to the description of the principle of SANS: basics (formalism, coherent scattering/incoherent scattering, notion of elementary scatterer), form factor analysis (I(q→0), Guinier regime, intermediate regime, Porod regime, polydisperse system), structure factor analysis (2nd Virial coefficient, integral equations, characterization of aggregates), and contrast variation methods (how to create contrast in an homogeneous system, matching in ternary systems, extrapolation to zero concentration, Zero Averaged Contrast). It is illustrated by some representative examples. The second one describes the experimental aspects of SANS to guide user in its future experiments: description of SANS spectrometer, resolution of the spectrometer, optimization of spectrometer

  7. What convention is used for the illumination and view angles?

    Atmospheric Science Data Center

    2014-12-08

    ... Azimuth angles are measured clockwise from the direction of travel to local north. For both the Sun and cameras, azimuth describes the ... to the equator, because of its morning equator crossing time. Additionally, the difference in view and solar azimuth angle will be near ...

  8. [Angle-closure chronic glaucoma].

    PubMed

    Lachkar, Y

    2003-10-01

    The incidence of chronic angle closure glaucoma is considerably greater than the incidence of the acute type. This type of glaucoma may mimic primary open angle glaucoma with visual field deterioration, optic nerve alteration and intraocular pressure elevation with a quiet painless eye. Its diagnosis is based on indentation gonioscopy showing peripheral anterior synechiae. The mechanisms of angle closure are the pupillary block, the plateau iris configuration and the creeping form. The treatment of chronic angle closure glaucoma is based on laser peripheral iridotomy. PMID:14646832

  9. The Critical Angle Can Override the Brewster Angle

    ERIC Educational Resources Information Center

    Froehle, Peter H.

    2009-01-01

    As a culminating activity in their study of optics, my students investigate polarized light and the Brewster angle. In this exercise they encounter a situation in which it is impossible to measure the Brewster angle for light reflecting from a particular surface. This paper describes the activity and explains the students' observations.

  10. The vectorial small angle modification of the spherical harmonics method for an arbitrary angle of irradiance of a slab

    NASA Astrophysics Data System (ADS)

    Budak, V. P.; Korkin, S. V.

    2006-11-01

    We offer the generalization of the vectorial small angle modification of the spherical harmonics method (VMSH) for an arbitrary angle and polarization sate of irradiance of a slab. Non diagonal elements of an aerosol scattering matrix were admitted. The smooth addition part for the VMSH is given. Thus we obtain a complete and accelerated solution of the vectorial radiative transfer equation.

  11. The SNOOPY Angle of Repose Experiment: Calibration of an Instrument to Determine the Angle of Repose of Martian Dust

    NASA Technical Reports Server (NTRS)

    Moeller, L. E.; Kuhlman, K. R.; Marshall, J. R.; Towner, M. C.

    2002-01-01

    The present work calibrates the Student Nanoexperiments for Outreach and Observational Planetary Inquiry (SNOOPY) Angle of Repose experiment. Using particulate collection on small marbles, the measured angles of repose compare well to experimental data and theoretical predictions. Additional information is contained in the original extended abstract.

  12. Dynamic contact angle cycling homogenizes heterogeneous surfaces.

    PubMed

    Belibel, R; Barbaud, C; Mora, L

    2016-12-01

    In order to reduce restenosis, the necessity to develop the appropriate coating material of metallic stent is a challenge for biomedicine and scientific research over the past decade. Therefore, biodegradable copolymers of poly((R,S)-3,3 dimethylmalic acid) (PDMMLA) were prepared in order to develop a new coating exhibiting different custom groups in its side chain and being able to carry a drug. This material will be in direct contact with cells and blood. It consists of carboxylic acid and hexylic groups used for hydrophilic and hydrophobic character, respectively. The study of this material wettability and dynamic surface properties is of importance due to the influence of the chemistry and the potential motility of these chemical groups on cell adhesion and polymer kinetic hydrolysis. Cassie theory was used for the theoretical correction of contact angles of these chemical heterogeneous surfaces coatings. Dynamic Surface Analysis was used as practical homogenizer of chemical heterogeneous surfaces by cycling during many cycles in water. In this work, we confirmed that, unlike receding contact angle, advancing contact angle is influenced by the difference of only 10% of acidic groups (%A) in side-chain of polymers. It linearly decreases with increasing acidity percentage. Hysteresis (H) is also a sensitive parameter which is discussed in this paper. Finally, we conclude that cycling provides real information, thus avoiding theoretical Cassie correction. H(10)is the most sensible parameter to %A. PMID:27612817

  13. Positron Emission Mammography with Multiple Angle Acquisition

    SciTech Connect

    Mark F. Smith; Stan Majewski; Raymond R. Raylman

    2002-11-01

    Positron emission mammography (PEM) of F-18 fluorodeoxyglucose (FDG) uptake in breast tumors with dedicated detectors typically has been accomplished with two planar detectors in a fixed position with the breast under compression. The potential use of PEM imaging at two detector positions to guide stereotactic breast biopsy has motivated us to use PEM coincidence data acquired at two or more detector positions together in a single image reconstruction. Multiple angle PEM acquisition and iterative image reconstruction were investigated using point source and compressed breast phantom acquisitions with 5, 9, 12 and 15 mm diameter spheres and a simulated tumor:background activity concentration ratio of 6:1. Image reconstruction was performed with an iterative MLEM algorithm that used coincidence events between any two detector pixels on opposed detector heads at each detector position. This present study compared two acquisition protocols: 2 angle acquisition with detector angular positions of -15 and +15 degrees and 11 angle acquisition with detector positions spaced at 3 degree increments over the range -15 to +15 degrees. Three- dimensional image resolution was assessed for the point source acquisitions, and contrast and signal-to-noise metrics were evaluated for the compressed breast phantom with different simulated tumor sizes. Radial and tangential resolutions were similar for the two protocols, while normal resolution was better for the 2 angle acquisition. Analysis is complicated by the asymmetric point spread functions. Signal- to-noise vs. contrast tradeoffs were better for 11 angle acquisition for the smallest visible 9 mm sphere, while tradeoff results were mixed for the larger and more easily visible 12 mm and 15 mm diameter spheres. Additional study is needed to better understand the performance of limited angle tomography for PEM. PEM tomography experiments with complete angular sampling are planned.

  14. Positron Emission Mammography with Multiple Angle Acquisition

    SciTech Connect

    Mark F. Smith; Stan Majewski; Raymond R. Raylman

    2002-11-01

    Positron emission mammography (PEM) of F-18 fluorodeoxyglucose (FbG) uptake in breast tumors with dedicated detectors typically has been accomplished with two planar detectors in a fixed position with the breast under compression. The potential use of PEM imaging at two detector positions to guide stereotactic breast biopsy has motivated us to use PEM coincidence data acquired at two or more detector positions together in a single image reconstruction. Multiple angle PEM acquisition and iterative image reconstruction were investigated using point source and compressed breast phantom acquisitions with 5, 9, 12 and 15 mm diameter spheres and a simulated tumor:background activity concentration ratio of 6:1. Image reconstruction was performed with an iterative MLEM algorithm that used coincidence events between any two detector pixels on opposed detector heads at each detector position. This present study compared two acquisition protocols: 2 angle acquisition with detector angular positions of -15 and +15 degrees and 11 angle acquisition with detector positions spaced at 3 degree increments over the range -15 to +15 degrees. Three-dimensional image resolution was assessed for the point source acquisitions, and contrast and signal-to-noise metrics were evaluated for the compressed breast phantom with different simulated tumor sizes. Radial and tangential resolutions were similar for the two protocols, while normal resolution was better for the 2 angle acquisition. Analysis is complicated by the asymmetric point spread functions. Signal- to-noise vs. contrast tradeoffs were better for 11 angle acquisition for the smallest visible 9 mm sphere, while tradeoff results were mixed for the larger and more easily visible 12 mm and 15 mm diameter spheres. Additional study is needed to better understand the performance of limited angle tomography for PEM. PEM tomography experiments with complete angular sampling are planned.

  15. Manifold angles, the concept of self-similarity, and angle-enhanced bifurcation diagrams

    NASA Astrophysics Data System (ADS)

    Beims, Marcus W.; Gallas, Jason A. C.

    2016-01-01

    Chaos and regularity are routinely discriminated by using Lyapunov exponents distilled from the norm of orthogonalized Lyapunov vectors, propagated during the temporal evolution of the dynamics. Such exponents are mean-field-like averages that, for each degree of freedom, squeeze the whole temporal evolution complexity into just a single number. However, Lyapunov vectors also contain a step-by-step record of what exactly happens with the angles between stable and unstable manifolds during the whole evolution, a big-data information permanently erased by repeated orthogonalizations. Here, we study changes of angles between invariant subspaces as observed during temporal evolution of Hénon’s system. Such angles are calculated numerically and analytically and used to characterize self-similarity of a chaotic attractor. In addition, we show how standard tools of dynamical systems may be angle-enhanced by dressing them with informations not difficult to extract. Such angle-enhanced tools reveal unexpected and practical facts that are described in detail. For instance, we present a video showing an angle-enhanced bifurcation diagram that exposes from several perspectives the complex geometrical features underlying the attractors. We believe such findings to be generic for extended classes of systems.

  16. Manifold angles, the concept of self-similarity, and angle-enhanced bifurcation diagrams

    PubMed Central

    Beims, Marcus W.; Gallas, Jason A. C.

    2016-01-01

    Chaos and regularity are routinely discriminated by using Lyapunov exponents distilled from the norm of orthogonalized Lyapunov vectors, propagated during the temporal evolution of the dynamics. Such exponents are mean-field-like averages that, for each degree of freedom, squeeze the whole temporal evolution complexity into just a single number. However, Lyapunov vectors also contain a step-by-step record of what exactly happens with the angles between stable and unstable manifolds during the whole evolution, a big-data information permanently erased by repeated orthogonalizations. Here, we study changes of angles between invariant subspaces as observed during temporal evolution of Hénon’s system. Such angles are calculated numerically and analytically and used to characterize self-similarity of a chaotic attractor. In addition, we show how standard tools of dynamical systems may be angle-enhanced by dressing them with informations not difficult to extract. Such angle-enhanced tools reveal unexpected and practical facts that are described in detail. For instance, we present a video showing an angle-enhanced bifurcation diagram that exposes from several perspectives the complex geometrical features underlying the attractors. We believe such findings to be generic for extended classes of systems. PMID:26732416

  17. Goniometer-rotation-angle recorder

    SciTech Connect

    Shchagin, A.V.

    1985-12-01

    This paper describes a goniometer-rotation-angle recorder with a discrete drive. The rotation angle in a given plane is recorded by bidirectional sign counter of positive and negative drive-actuation numbers for rotations in positive and negative directions. The maximum capacity of the counter is + or - 9 decimal digits.

  18. Additive CHARMM force field for naturally occurring modified ribonucleotides.

    PubMed

    Xu, You; Vanommeslaeghe, Kenno; Aleksandrov, Alexey; MacKerell, Alexander D; Nilsson, Lennart

    2016-04-15

    More than 100 naturally occurring modified nucleotides have been found in RNA molecules, in particular in tRNAs. We have determined molecular mechanics force field parameters compatible with the CHARMM36 all-atom additive force field for all these modifications using the CHARMM force field parametrization strategy. Emphasis was placed on fine tuning of the partial atomic charges and torsion angle parameters. Quantum mechanics calculations on model compounds provided the initial set of target data, and extensive molecular dynamics simulations of nucleotides and oligonucleotides in aqueous solutions were used for further refinement against experimental data. The presented parameters will allow for computational studies of a wide range of RNAs containing modified nucleotides, including the ribosome and transfer RNAs. PMID:26841080

  19. Additive CHARMM force field for naturally occurring modified ribonucleotides

    PubMed Central

    Xu, You; Vanommeslaeghe, Kenno; Aleksandrov, Alexey; MacKerell, Alexander D.

    2016-01-01

    More than 100 naturally occurring modified nucleotides have been found in RNA molecules, in particular in tRNAs. We have determined molecular mechanics force field parameters compatible with the CHARMM36 all‐atom additive force field for all these modifications using the CHARMM force field parametrization strategy. Emphasis was placed on fine tuning of the partial atomic charges and torsion angle parameters. Quantum mechanics calculations on model compounds provided the initial set of target data, and extensive molecular dynamics simulations of nucleotides and oligonucleotides in aqueous solutions were used for further refinement against experimental data. The presented parameters will allow for computational studies of a wide range of RNAs containing modified nucleotides, including the ribosome and transfer RNAs. © 2016 The Authors. Journal of Computational Chemistry Published by Wiley Periodicals, Inc. PMID:26841080

  20. Spinning angle optical calibration apparatus

    DOEpatents

    Beer, Stephen K.; Pratt, II, Harold R.

    1991-01-01

    An optical calibration apparatus is provided for calibrating and reproducing spinning angles in cross-polarization, nuclear magnetic resonance spectroscopy. An illuminated magnifying apparatus enables optical setting an accurate reproducing of spinning "magic angles" in cross-polarization, nuclear magnetic resonance spectroscopy experiments. A reference mark scribed on an edge of a spinning angle test sample holder is illuminated by a light source and viewed through a magnifying scope. When the "magic angle" of a sample material used as a standard is attained by varying the angular position of the sample holder, the coordinate position of the reference mark relative to a graduation or graduations on a reticle in the magnifying scope is noted. Thereafter, the spinning "magic angle" of a test material having similar nuclear properties to the standard is attained by returning the sample holder back to the originally noted coordinate position.

  1. Dancing droplets: Contact angle, drag, and confinement

    NASA Astrophysics Data System (ADS)

    Benusiglio, Adrien; Cira, Nate; Prakash, Manu

    2015-11-01

    When deposited on a clean glass slide, a mixture of water and propylene glycol forms a droplet of given contact angle, when both pure liquids spread. (Cira, Benusiglio, Prakash: Nature, 2015). The droplet is stabilized by a gradient of surface tension due to evaporation that induces a Marangoni flow from the border to the apex of the droplets. The apparent contact angle of the droplets depends on both their composition and the external humidity as captured by simple models. These droplets present remarkable properties such as lack of a large pinning force. We discuss the drag on these droplets as a function of various parameters. We show theoretical and experimental results of how various confinement geometries change the vapor gradient and the dynamics of droplet attraction.

  2. Taper Angle Evolution in Taiwan Accretionary Wedge

    NASA Astrophysics Data System (ADS)

    Chen, L.; Chi, W.; Liu, C.

    2011-12-01

    Liwen Chena,b, Wu-Cheng Chia, Char-Shine Liuc aInstitute of Earth Sciences, Academia Sinica, Taipei, Taiwan bInstitute of Geosciences, National Taiwan University, Taipei, Taiwan cInstitute of Oceanography, National Taiwan University, Taipei, Taiwan The critical taper model, originally developed using onland Taiwan as an example, is governed by force balance of a horizontal compressional wedge. This model has been successfully applied to many mountainous regions around the world. Among them, Taiwan is located in an oblique collision between the Luzon Arc and the Chinese Passive margin. Previous critical taper angle studies of Taiwan are mainly focusing on utilizing land data. In this study we want to extend these studies to offshore region from the subduction zone to collision zone. Here we study the varying taper angles of the double-vergent wedge derived from 1,000 km of reflection seismic profiles in both the pro-wedge and retro-wedge locations. These profiles were collected in the last two decades. For the retro-wedge, the topography slope angle changes from 2 to 8.8 degrees; some of the steep slope suggests that some part of the retrowedge is currently in a super-critical angle state. Such dramatic changes in taper angle probably strongly affect regional sedimentary processes, including slumping, in addition to structural deformation. These complex processes might even help develop a mélange or re-open a closed basin. We are currently working on studying the taper angle evolution of the pro-wedge from subduction to arc-continent collision zone in the offshore region. Though further works are needed, our preliminary results show that the evolution of wedge angles and the geometry of the wedge are closely linked and inseparable. The structures of the subducting plate might have strong influence on the deformation style of the over-riding plate. It would be interesting to combine the angle variation with the structure interpretation of the accretionary wedge

  3. Military display performance parameters

    NASA Astrophysics Data System (ADS)

    Desjardins, Daniel D.; Meyer, Frederick

    2012-06-01

    The military display market is analyzed in terms of four of its segments: avionics, vetronics, dismounted soldier, and command and control. Requirements are summarized for a number of technology-driving parameters, to include luminance, night vision imaging system compatibility, gray levels, resolution, dimming range, viewing angle, video capability, altitude, temperature, shock and vibration, etc., for direct-view and virtual-view displays in cockpits and crew stations. Technical specifications are discussed for selected programs.

  4. Timolol in operated closed-angle glaucoma.

    PubMed Central

    Phillips, C I

    1980-01-01

    Tonometry in 9 eyes (7 patients) provides some evidence that timolol eye drops are useful in improving control of pressure in eyes operated for closed-angle glaucoma. In cases 1 and 2 (Figs, 1 and 2) this beta 1 and 2 blocker reduced pressure consistently. Case 3 (Fig. 3) showed that timolol 0.5% twice daily was as effective as pilocarpine 2% or 4% with adrenaline 1%. The effect of timolol 0.5% in case 4 (Fig. 4) and case 6 (Fig. 6) was additive to pilocarpine and adrenaline; in case 5 (Fig. 5) it probably improved the effect of adrenaline, but in cases 4 and 5 there may have been some loss of effect with time. Case 7 (Fig. 7) showed a good effect of timolol, reversed on withdrawal, but pressure fell again in spite of continued withholding of timolol. Timolol will be especially valuable in the control of pressure if an operation involving iridectomy has not been completely successful in open-angle glaucoma or more especially in closed-angle glaucoma because it has no effect on the pupil. Miotics will tend to produce posterior pupillary synechiae because aqueous humour will go through the iridectomy, not under the edge of the pupil. The danger will be greater in eyes with closed-angle glaucoma because the pupil is closely applied to the anterior lens surface, which will also tend to produce irritative iridocyclitis. PMID:7387959

  5. Ischemia detection from morphological QRS angle changes.

    PubMed

    Romero, Daniel; Martínez, Juan Pablo; Laguna, Pablo; Pueyo, Esther

    2016-07-01

    In this paper, an ischemia detector is presented based on the analysis of QRS-derived angles. The detector has been developed by modeling ischemic effects on the QRS angles as a gradual change with a certain transition time and assuming a Laplacian additive modeling error contaminating the angle series. Both standard and non-standard leads were used for analysis. Non-standard leads were obtained by applying the PCA technique over specific lead subsets to represent different potential locations of the ischemic zone. The performance of the proposed detector was tested over a population of 79 patients undergoing percutaneous coronary intervention in one of the major coronary arteries (LAD (n  =  25), RCA (n  =  16) and LCX (n  =  38)). The best detection performance, obtained for standard ECG leads, was achieved in the LAD group with values of sensitivity and specificity of [Formula: see text], [Formula: see text], followed by the RCA group with [Formula: see text], Sp  =  94.4 and the LCX group with [Formula: see text], [Formula: see text], notably outperforming detection based on the ST series in all cases, with the same detector structure. The timing of the detected ischemic events ranged from 30 s up to 150 s (mean  =  66.8 s) following the start of occlusion. We conclude that changes in the QRS angles can be used to detect acute myocardial ischemia. PMID:27243441

  6. New mixing angles in the left-right symmetric model

    NASA Astrophysics Data System (ADS)

    Kokado, Akira; Saito, Takesi

    2015-12-01

    In the left-right symmetric model neutral gauge fields are characterized by three mixing angles θ12,θ23,θ13 between three gauge fields Bμ,WLμ 3,WRμ 3, which produce mass eigenstates Aμ,Zμ,Zμ', when G =S U (2 )L×S U (2 )R×U (1 )B-L×D is spontaneously broken down until U (1 )em . We find a new mixing angle θ', which corresponds to the Weinberg angle θW in the standard model with the S U (2 )L×U (1 )Y gauge symmetry, from these mixing angles. It is then shown that any mixing angle θi j can be expressed by ɛ and θ', where ɛ =gL/gR is a ratio of running left-right gauge coupling strengths. We observe that light gauge bosons are described by θ' only, whereas heavy gauge bosons are described by two parameters ɛ and θ'.

  7. Multi-angle technique for measurement of ground source emission

    SciTech Connect

    Henderson, J.R.

    1995-04-01

    TAISIR, the Temperature and Imaging System Infrared, is a nominally satellite based platform for remote sensing of the earth. One of its design features is to acquire atmospheric data simultaneous with ground data, resulting in minimal dependence on external atmospheric models for data correction. One technique we employ to acquire atmospheric data is a true multi-angle data acquisition technique. Previous techniques have used only two angles. Here we demonstrate the advantage of using a large number of viewing angles to overconstrain the inversion problem for critical atmospheric and source parameters. For reasonable data acquisition scenarios, simulations show source temperature errors of less than 1K should be possible. Tradeoffs between flight geometry, number of look angles,, and system signal-to-noise are given for typical parameter ranges.

  8. First statistics of the isopistonic angle for long baseline interferometry

    NASA Astrophysics Data System (ADS)

    Ziad, A.; Elhalkouj, T.; Petrov, R. G.; Borgnino, J.; Lazrek, M.; Benkhaldoun, Z.; Martin, F.; Elazhari, Y.

    2016-06-01

    To reach a suitable limiting magnitude with a multi-aperture interferometer, we need to cophase the different telescopes using a reference source. The latter should be located in the same isopistonic domain as the science source. We developed a direct analytical expression of deducing the isopistonic angle from atmospheric optical parameters as seeing, isoplanatic angle and outer scale. All of these atmospheric turbulence parameters are measured by the Generalized Seeing Monitor (GSM). The first statistics of the isopistonic angle obtained from the GSM data are presented and comparison between the major sites over the world are discussed (La Silla, Cerro Pachon, Paranal, San Pedro, Mt Palomar, Mauna Kea, La Palma, Oukaïmeden, Maydanak, Dome C). Implications of these isopistonic angle statistics on large interferometers cophasing in terms of sky coverage and limiting magnitude are discussed.

  9. 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. PMID:20060981

  10. Computer programs for calculation of sting pitch and roll angles required to obtain angles of attack and sideslip on wind tunnel models

    NASA Technical Reports Server (NTRS)

    Peterson, John B., Jr.

    1988-01-01

    Two programs have been developed to calculate the pitch and roll angles of a wind-tunnel sting drive system that will position a model at the desired angle of attack and and angle of sideslip in the wind tunnel. These programs account for the effects of sting offset angles, sting bending angles and wind-tunnel stream flow angles. In addition, the second program incorporates inputs from on-board accelerometers that measure model pitch and roll with respect to gravity. The programs are presented in the report and a description of the numerical operation of the programs with a definition of the variables used in the programs is given.

  11. Compression failure of angle-ply laminates

    NASA Technical Reports Server (NTRS)

    Peel, Larry D.; Hyer, Michael W.; Shuart, Mark J.

    1991-01-01

    parameter, such as a ratio of wave amplitude to wave length, to describe waviness in a laminate would be inaccurate. Throughout, results for AS4/3502, studied previously, are included for comparison. At low off-axis angles, the AS4/3502 material system was found to be less sensitive to layer waviness than IM7/8551-7a. Analytical predictions were also obtained for laminates with waviness in only some of the layers. For this type of waviness, laminate compression strength could also be considered a function of which layers in the laminate were wavy, and where those wavy layers were. Overall, the geometrically nonlinear model correlates well with experimental results.

  12. Management of mandibular angle fracture.

    PubMed

    Braasch, Daniel Cameron; Abubaker, A Omar

    2013-11-01

    Fractures through the angle of the mandible are one of the most common facial fractures. The management of such fractures has been controversial, however. This controversy is related to the anatomic relations and complex biomechanical aspects of the mandibular angle. The debate has become even more heated since the evolution of rigid fixation and the ability to provide adequate stability of the fractured segments. This article provides an overview of the special anatomic and biomechanical features of the mandibular angle and their impact on the management of these fractures. PMID:24183373

  13. Ring magnet firing angle control

    DOEpatents

    Knott, M.J.; Lewis, L.G.; Rabe, H.H.

    1975-10-21

    A device is provided for controlling the firing angles of thyratrons (rectifiers) in a ring magnet power supply. A phase lock loop develops a smooth ac signal of frequency equal to and in phase with the frequency of the voltage wave developed by the main generator of the power supply. A counter that counts from zero to a particular number each cycle of the main generator voltage wave is synchronized with the smooth AC signal of the phase lock loop. Gates compare the number in the counter with predetermined desired firing angles for each thyratron and with coincidence the proper thyratron is fired at the predetermined firing angle.

  14. Light airplane crash tests at three pitch angles

    NASA Technical Reports Server (NTRS)

    Vaughan, V. L., Jr.; Alfaro-Bou, E.

    1979-01-01

    Three similar twin-engine general aviation airplane specimens were crash tested at an impact dynamics research facility at 27 m/sec, a flight path angle of -15 deg, and pitch angles of -15 deg, 0 deg, and 15 deg. Other crash parameters were held constant. The test facility, instrumentation, test specimens, and test method are briefly described. Structural damage and accelerometer data for each of the three impact conditions are presented and discussed.

  15. 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.

  16. 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).

  17. Morphometric assessment of the canine hip joint using the dorsal acetabular rim view and the centre-edge angle.

    PubMed

    Meomartino, L; Fatone, G; Potena, A; Brunetti, A

    2002-01-01

    The dorsal acetabular rim (DAR) view of the hip joint can be used to assess the weightbearing portion of the acetabulum and the acetabular coverage, providing an adjunct to the conventional ventrodorsal (VD) view in the radiographic evaluation of hip dysplasia in the dog. A quantitative index of acetabular coverage in the DAR view, the acetabular slope (AS) angle, was originally proposed in 1990. The aim of the present study was to make a prospective, comparative assessment of a new parameter, the centre-edge (CE) angle, with the AS angle, for the evaluation of the acetabular coverage of the femoral head in the DAR view. The reliability and repeatability of the two parameters was assessed using the r(I) value of intraclass correlation coefficient (ICC) in a prospective study of 208 hip joints in large and giant breed dogs. An estimation of the added value of using the DAR view, compared with that of the VD standard view alone, was also assessed. The CE angle showed a higher r(I) value compared with the AS angle; in 26 per cent of hips of FCI classes A, B and C, the DAR view provided additional diagnostic information compared with the VD view, with respect to lateralisation and/or initial changes to the dorsal rim. It is concluded that the CE angle is more reliable than the AS angle in the evaluation of acetabular coverage, and that the DAR view provides valuable data compared with the VD view alone in the early stages of canine hip dysplasia. PMID:11833819

  18. Analyzing biomolecular interactions by variable angle ellipsometry

    NASA Astrophysics Data System (ADS)

    Wu, Jiun-Yan; Lee, Chih-Kung; Lee, J. H.; Shiue, Shuen-Chen; Lee, Shu-Sheng; Lin, Shiming

    2001-10-01

    In this paper, an innovative ellipsometer is developed and applied to metrology of the biomolecular interaction on a protein biochip. Both the theory, optical and opto-mechanical configurations of this newly developed ellipsometer and methodologies adopted in system design to improve the system performance are presented. It will be shown that by measuring the ellipsometric parameters, the corresponding concentration variation in biochemical reaction can be calculated according to stoichiometry analysis. By applying the variable angle ellipsometry to analysis of a multi-layered sample, the thickness and concentration are resolved. It is believed that the newly developed ellipsometer biosensor is able to undertake an accurate measurement on biomedical interaction.

  19. Relativistic Transformation of Solid Angle.

    ERIC Educational Resources Information Center

    McKinley, John M.

    1980-01-01

    Rederives the relativistic transformations of light intensity from compact sources (stars) to show where and how the transformation of a solid angle contributes. Discusses astrophysical and other applications of the transformations. (Author/CS)

  20. Determination of an angle of attack sensor correction for a general aviation airplane at large angles of attack as determined from wind tunnel and flight tests

    NASA Technical Reports Server (NTRS)

    Moul, T. M.; Taylor, L. W., Jr.

    1980-01-01

    A comprehensive investigation into the flow correction for an angle of attack sensor mounted ahead of the wing tip of a general aviation research airplane has been conducted at the Langley Research Center. This correction has been determined in wind tunnels using a full-scale model up to angles of attack of 45 deg and a 1/5-scale model up to 80 deg angle of attack. The flow correction has also been obtained in flight by using a standard technique at low angles of attack and in spinning flight at larger angles of attack, by using both a simple approximate technique and a parameter estimation technique. The results show the correction is significant, reaching 10 deg at a measured angle of attack of about 90 deg. The flow correction was sensitive to the angle of sideslip at measured angles of attack greater than 60 deg and was not influenced by wing leading-edge modifications or aileron deflections.

  1. Irena : tool suite for modeling and analysis of small-angle scattering.

    SciTech Connect

    Ilavsky, J.; Jemian, P.

    2009-04-01

    Irena, a tool suite for analysis of both X-ray and neutron small-angle scattering (SAS) data within the commercial Igor Pro application, brings together a comprehensive suite of tools useful for investigations in materials science, physics, chemistry, polymer science and other fields. In addition to Guinier and Porod fits, the suite combines a variety of advanced SAS data evaluation tools for the modeling of size distribution in the dilute limit using maximum entropy and other methods, dilute limit small-angle scattering from multiple non-interacting populations of scatterers, the pair-distance distribution function, a unified fit, the Debye-Bueche model, the reflectivity (X-ray and neutron) using Parratt's formalism, and small-angle diffraction. There are also a number of support tools, such as a data import/export tool supporting a broad sampling of common data formats, a data modification tool, a presentation-quality graphics tool optimized for small-angle scattering data, and a neutron and X-ray scattering contrast calculator. These tools are brought together into one suite with consistent interfaces and functionality. The suite allows robust automated note recording and saving of parameters during export.

  2. Role of Optical Coherence Tomography in Assessing Anterior Chamber Angles

    PubMed Central

    Kochupurakal, Reema Thomas; Jha, Kirti Nath; Rajalakshmi, A.R.; Nagarajan, Swathi; Ezhumalai, G.

    2016-01-01

    Introduction Gonioscopy is the gold standard in assessing anterior chamber angles. However, interobserver variations are common and there is a need for reliable objective method of assessment. Aim To compare the anterior chamber angle by gonioscopy and Spectral Domain Optical Coherence Tomography (SD-OCT) in individuals with shallow anterior chamber. Materials and Methods This comparative observational study was conducted in a rural tertiary multi-speciality teaching hospital. A total of 101 eyes of 54 patients with shallow anterior chamber on slit lamp evaluation were included. Anterior chamber angle was graded by gonioscopy using the shaffer grading system. Angles were also assessed by SD-OCT with Trabecular Iris Angle (TIA) and Angle Opening Distance (AOD). Chi-square test, sensitivity, specificity, positive and negative predictive value to find correlation between OCT parameters and gonioscopy grading. Results Females represented 72.7%. The mean age was 53.93 ±8.24 years and mean anterior chamber depth was 2.47 ± 0.152 mm. Shaffer grade ≤ 2 were identified in 95(94%) superior, 42(41.5%) inferior, 65(64.3%) nasal and 57(56.4%) temporal quadrants. Cut-off values of TIA ≤ 22° and AOD ≤ 290 μm were taken as narrow angles on SD-OCT. TIA of ≤ 22° were found in 88(92.6%) nasal and 87(87%) temporal angles. AOD of ≤ 290 μm was found in 73(76.8%) nasal and 83(83%) temporal quadrants. Sensitivity in detecting narrow angles was 90.7% and 82.2% for TIA and AOD, while specificity was 11.7% and 23.4%, respectively. Conclusion Individuals were found to have narrow angles more with SD-OCT. Sensitivity was high and specificity was low in detecting narrow angles compared to gonioscopy, making it an unreliable tool for screening. PMID:27190851

  3. On the Euler angles for SU(N)

    SciTech Connect

    Cerchiai, Bianca L; Bertini, S.; Cacciatori, Sergio L.

    2005-10-20

    In this paper we reconsider the problem of the Euler parametrization for the unitary groups. After constructing the generic group element in terms of generalized angles, we compute the invariant measure on SU(N) and then we determine the full range of the parameters, using both topological and geometrical methods. In particular, we show that the given parametrization realizes the group SU(N+1) as a fibration of U(N) over the complex projective space CP{sup n}. This justifies the interpretation of the parameters as generalized Euler angles.

  4. Association of the Frontal QRS-T Angle with Adverse Cardiac Remodeling, Impaired Left and Right Ventricular Function, and Worse Outcomes in Heart Failure with Preserved Ejection Fraction

    PubMed Central

    Selvaraj, Senthil; Ilkhanoff, Leonard; Burke, Michael A.; Freed, Benjamin H.; Lang, Roberto M.; Martinez, Eva E.; Shah, Sanjiv J.

    2013-01-01

    Background No prior studies have investigated the association of QRS-T angle with cardiac structure/function and outcomes in heart failure with preserved ejection fraction (HFpEF). We hypothesized that increased frontal QRS-T angle is associated with worse cardiac function/remodeling and adverse outcomes in HFpEF. Methods We prospectively studied 376 patients with HFpEF (i.e. symptomatic HF with left ventricular [LV] ejection fraction >50%.) The frontal QRS-T angle was calculated from the 12-lead electrocardiogram. Patients were divided into tertiles by frontal QRS-T angle (0–26°, 27–75°, and 76–179°), and clinical, laboratory, and echocardiographic data were compared among groups. Cox proportional hazards analyses were performed to determine the association between QRS-T angle and outcomes. Results The mean age of the cohort was 64±13 years, 65% were women, and the mean QRS-T angle was 61±51°. Patients with increased QRS-T angle were older, had a lower body-mass index, more frequently had coronary artery disease, diabetes, chronic kidney disease, and atrial fibrillation, and had higher B-type natriuretic peptide (BNP) levels (P<0.05 for all comparisons). After multivariable adjustment, patients with increased QRS-T angle had higher BNP levels in addition to higher LV mass index, worse diastolic function parameters, more right ventricular (RV) remodeling, and worse RV systolic function (P<0.05 for all associations). QRS-T angle was independently associated with the composite outcome of cardiovascular hospitalization or death on multivariable analysis, even after adjusting for BNP (HR for the highest QRS-T tertile = 2.0, 95% CI 1.2–3.4; P=0.008). Conclusions In HFpEF, increased QRS-T angle is independently associated with worse left and right ventricular function/remodeling and adverse outcomes. PMID:24075945

  5. Applications of parameter estimation in the study of spinning airplanes

    NASA Technical Reports Server (NTRS)

    W Taylor, L., Jr.

    1982-01-01

    Spinning airplanes offer challenges to estimating dynamic parameters because of the nonlinear nature of the dynamics. In this paper, parameter estimation techniques are applied to spin flight test data for estimating the error in measuring post-stall angles of attack, deriving Euler angles from angular velocity data, and estimating nonlinear aerodynamic characteristics. The value of the scale factor for post-stall angles of attack agrees closely with that obtained from special wind-tunnel tests. The independently derived Euler angles are seen to be valid in spite of steep pitch angles. Estimates of flight derived nonlinear aerodynamic parameters are evaluated in terms of the expected fit error.

  6. Spectral data of specular reflectance, narrow-angle transmittance and angle-resolved surface scattering of materials for solar concentrators

    PubMed Central

    Good, Philipp; Cooper, Thomas; Querci, Marco; Wiik, Nicolay; Ambrosetti, Gianluca; Steinfeld, Aldo

    2015-01-01

    The spectral specular reflectance of conventional and novel reflective materials for solar concentrators is measured with an acceptance angle of 17.5 mrad over the wavelength range 300−2500 nm at incidence angles 15–60° using a spectroscopic goniometry system. The same experimental setup is used to determine the spectral narrow-angle transmittance of semi-transparent materials for solar collector covers at incidence angles 0–60°. In addition, the angle-resolved surface scattering of reflective materials is recorded by an area-scan CCD detector over the spectral range 350–1050 nm. A comprehensive summary, discussion, and interpretation of the results are included in the associated research article “Spectral reflectance, transmittance, and angular scattering of materials for solar concentrators” in Solar Energy Materials and Solar Cells. PMID:26862556

  7. From hygrophilic to superhygrophobic: theoretical conditions for making high-contact-angle surfaces from low-contact-angle materials.

    PubMed

    Marmur, Abraham

    2008-07-15

    The possibility of making high-contact-angle, rough surfaces from low-contact-angle materials has recently been suggested and demonstrated. A thermodynamic analysis of this possibility in terms of feasibility and stability is presented. It turns out that only roughness topographies that conform to a feasibility condition which is developed in the present paper can support this phenomenon. Even under conditions that support the phenomenon, the high-contact-angle state may not be stable, and transition from the heterogeneous (Cassie-Baxter) wetting regime to the homogeneous (Wenzel) regime with a lower contact angle may occur. In addition, it is suggested to use the general terms hygrophilic and hygrophobic (based on the Greek prefix hygro- that means liquid) to describe low- and high-contact-angle surfaces, respectively. PMID:18543997

  8. Metrology of angles in astronomy

    NASA Astrophysics Data System (ADS)

    Kovalevsky, Jean

    2004-10-01

    In astronomy, measurements of angles play a major role. After defining the units in use in astronomy, three methods of measuring angles are presented, with an application to the transit instrument. The interferometric techniques for measuring large angles are described in optical and radio wavelengths. Due to the atmospheric and mechanical limitation on ground, space astrometry has multiple advantages. The satellite Hipparcos is described and the data reduction procedures and results obtained are sketched. In the future, two new astrometric space missions are approved: GAIA, based on Hipparcos principles and SIM, a space interferometer. They are described and the expected accuracies are presented. To cite this article: J. Kovalevsky, C. R. Physique 5 (2004).

  9. Critical rolling angle of microparticles

    NASA Astrophysics Data System (ADS)

    Farzi, Bahman; Vallabh, Chaitanya K. P.; Stephens, James D.; Cetinkaya, Cetin

    2016-03-01

    At the micrometer-scale and below, particle adhesion becomes particularly relevant as van der Waals force often dominates volume and surface proportional forces. The rolling resistance of microparticles and their critical rolling angles prior to the initiation of free-rolling and/or complete detachment are critical in numerous industrial processes and natural phenomenon involving particle adhesion and granular dynamics. The current work describes a non-contact measurement approach for determining the critical rolling angle of a single microparticle under the influence of a contact-point base-excitation generated by a transient displacement field of a prescribed surface acoustic wave pulse and reports the critical rolling angle data for a set of polystyrene latex microparticles.

  10. Using imaging ellipsometry to determine angular distribution of ellipsometric parameters without scanning mechanism

    NASA Astrophysics Data System (ADS)

    Tang, Chien-Jen; Chang, Ruey-Shyan; Han, Chien-Yuan

    2016-02-01

    This work presents a focused beam approach using a polarizer-sample-analyzer (PSA) imaging ellipsometer to deduce multiple sets of ellipsometric parameters with the information of multiple incident angles in one measurement. Using a three-intensity measurement technique, an additional parameter α can be obtained to locate the ideal incident plane of a focused beam. Meanwhile, the ellipsometric parameters on the ideal incident plane are also analyzed. Based on α and the ellipsometric parameters, the variation in the intensity and phase response with a range of incident angles are examined without using a mechanical scanning apparatus. Measurements made of two zones on a reference wafer with different film thicknesses demonstrate results that are almost consistent with those predicted by the theoretical model.

  11. Process Damping Parameters

    NASA Astrophysics Data System (ADS)

    Turner, Sam

    2011-12-01

    The phenomenon of process damping as a stabilising effect in milling has been encountered by machinists since milling and turning began. It is of great importance when milling aerospace alloys where maximum surface speed is limited by excessive tool wear and high speed stability lobes cannot be attained. Much of the established research into regenerative chatter and chatter avoidance has focussed on stability lobe theory with different analytical and time domain models developed to expand on the theory first developed by Trusty and Tobias. Process damping is a stabilising effect that occurs when the surface speed is low relative to the dominant natural frequency of the system and has been less successfully modelled and understood. Process damping is believed to be influenced by the interference of the relief face of the cutting tool with the waveform traced on the cut surface, with material properties and the relief geometry of the tool believed to be key factors governing performance. This study combines experimental trials with Finite Element (FE) simulation in an attempt to identify and understand the key factors influencing process damping performance in titanium milling. Rake angle, relief angle and chip thickness are the variables considered experimentally with the FE study looking at average radial and tangential forces and surface compressive stress. For the experimental study a technique is developed to identify the critical process damping wavelength as a means of measuring process damping performance. For the range of parameters studied, chip thickness is found to be the dominant factor with maximum stable parameters increased by a factor of 17 in the best case. Within the range studied, relief angle was found to have a lesser effect than expected whilst rake angle had an influence.

  12. Systematic variations in divergence angle.

    PubMed

    Okabe, Takuya

    2012-11-21

    Practical methods for quantitative analysis of radial and angular coordinates of leafy organs of vascular plants are presented and applied to published phyllotactic patterns of various real systems from young leaves on a shoot tip to florets on a flower head. The constancy of divergence angle is borne out with accuracy of less than a degree. It is shown that apparent fluctuations in divergence angle are in large part systematic variations caused by the invalid assumption of a fixed center and/or by secondary deformations, while random fluctuations are of minor importance. PMID:22906592

  13. FT-Raman and chemometric tools for rapid determination of quality parameters in milk powder: Classification of samples for the presence of lactose and fraud detection by addition of maltodextrin.

    PubMed

    Rodrigues Júnior, Paulo Henrique; de Sá Oliveira, Kamila; de Almeida, Carlos Eduardo Rocha; De Oliveira, Luiz Fernando Cappa; Stephani, Rodrigo; Pinto, Michele da Silva; de Carvalho, Antônio Fernandes; Perrone, Ítalo Tuler

    2016-04-01

    FT-Raman spectroscopy has been explored as a quick screening method to evaluate the presence of lactose and identify milk powder samples adulterated with maltodextrin (2.5-50% w/w). Raman measurements can easily differentiate samples of milk powder, without the need for sample preparation, while traditional quality control methods, including high performance liquid chromatography, are cumbersome and slow. FT-Raman spectra were obtained from samples of whole lactose and low-lactose milk powder, both without and with addition of maltodextrin. Differences were observed between the spectra involved in identifying samples with low lactose content, as well as adulterated samples. Exploratory data analysis using Raman spectroscopy and multivariate analysis was also developed to classify samples with PCA and PLS-DA. The PLS-DA models obtained allowed to correctly classify all samples. These results demonstrate the utility of FT-Raman spectroscopy in combination with chemometrics to infer about the quality of milk powder. PMID:26593531

  14. Seasonal and vertical changes in leaf angle distribution for selected deciduous broadleaf tree species common to Europe

    NASA Astrophysics Data System (ADS)

    Raabe, Kairi; Pisek, Jan; Sonnentag, Oliver; Annuk, Kalju

    2014-05-01

    Leaf inclination angle distribution is a key parameter in determining the transmission and reflection of radiation by vegetation canopies. It has been previously observed that leaf inclination angle might change gradually from more vertical in the upper canopy and in high light habitats to more horizontal in the lower canopy and in low light habitats [1]. Despite its importance, relatively few measurements on actual leaf angle distributions have been reported for different tree species. Even smaller number of studies have dealt with the possible seasonal changes in leaf angle distribution [2]. In this study the variation of leaf inclination angle distributions was examined both temporally throughout the growing season and vertically at different heights of trees. We report on leaf inclination angle distributions for five deciduous broadleaf species found commonly in several parts of Europe: grey alder (Alnus incana), Silver birch (Betula pendula Roth), chestnut (Castanea), Norway maple (Acer platanoides), and aspen (Populus tremula). The angles were measured using the leveled camera method [3], with the data collected at several separate heights and four times during the period of May-September 2013. The results generally indicate the greatest change in leaf inclination angles for spring, with the changes usually being the most pronounced at the top of the canopy. It should also be noted, however, that whereas the temporal variation proved to be rather consistent for different species, the vertical variation differed more between species. The leveled camera method was additionally tested in terms of sensitivity to different users. Ten people were asked to measure the leaf angles for four different species. The results indicate the method is quite robust in providing coinciding distributions irrespective of the user and level of previous experience with the method. However, certain caution must be exercised when measuring long narrow leaves. References [1] G.G. Mc

  15. Effects of black pepper (piper nigrum), turmeric powder (curcuma longa) and coriander seeds (coriandrum sativum) and their combinations as feed additives on growth performance, carcass traits, some blood parameters and humoral immune response of broiler chickens.

    PubMed

    Abou-Elkhair, R; Ahmed, H A; Selim, S

    2014-06-01

    Different herbs and spices have been used as feed additives for various purposes in poultry production. This study was conducted to assess the effect of feed supplemented with black pepper (Piper nigrum), turmeric powder (Curcuma longa), coriander seeds (Coriandrum sativum) and their combinations on the performance of broilers. A total of 210 (Cobb) one-d-old chicks were divided into seven groups of 30 birds each. The treatments were: a control group received no supplement, 0.5% black pepper (T1), 0.5% turmeric powder (T2), 2% coriander seeds (T3), a mixture of 0.5% black pepper and 0.5% turmeric powder (T4), a mixture of 0.5% black pepper and 2% coriander seed (T5), and a mixture of 0.5% black pepper, 0.5% turmeric powder and 2% coriander seeds (T6). Higher significant values of body weight gain during the whole period of 5 weeks (p<0.001) were observed in broilers on T1, T3, T5, and T6 compared to control. Dietary supplements with T1, T2, T3, and T6 improved the cumulative G:F of broilers during the whole period of 5 weeks (p<0.001) compared with control. The dressing percentage and edible giblets were not influenced by dietary supplements, while higher values of relative weight of the liver (p<0.05) were obtained in T5 and T6 compared to control. The addition of feed supplements in T5 and T6 significantly increased serum total protein and decreased serum glucose, triglycerides and alkaline phosphatase concentrations compared with the control group (p<0.05). Broilers on T6 showed significant decrease in the serum glutamate pyruvate transaminase concentration (p<0.05) compared to control. The broilers having T5 and T6 supplemented feed had relatively greater antibody titre (p<0.001) at 35 d of age than control. It is concluded that dietary supplements with black pepper or coriander seeds or their combinations enhanced the performance and health status of broiler chickens. PMID:25050023

  16. Association between choroidal thickness and anterior chamber segment in eyes with narrow or open-angle

    PubMed Central

    Li, Song-Feng; Wu, Ge-Wei; Chen, Chang-Xi; Shen, Ling; Zhang, Zhi-Bao; Gao, Fei; Wang, Ning-Li

    2016-01-01

    AIM To investigate the relationship between choroidal thickness and anterior chamber segment in subjects with eyes with narrow or open-angle. METHODS The subfoveal choroidal thickness was measured with enhanced depth-imaging optical coherence tomography and anterior chamber parameters were measured with ultrasound biomicroscopy in one eye of 23 subjects with open-angle eyes and 38 subjects with narrow-angle eyes. The mean age was 59.52±7.04y for narrow-angle subjects and 60.76±7.23y for open-angle subjects (P=0.514). Multivariate linear regression analysis was performed to assess the association between choroidal thickness and narrow-angle parameters. RESULTS There were no differences in subfoveal choroidal thickness between open- and narrow-angle subjects (P=0.231). Anterior chamber parameters, including central anterior chamber depth, trabecular iris angle, iris thickness 500 µm from the scleral spur (IT500), and ciliary body thickness at 1 mm and 2 mm from the scleral spur (CBT1, CBT2) showed significant differences between the two groups (P<0.05). Subfoveal choroidal thickness showed negative correlation (β=-0.496, P=0.016) only with anterior chamber depth in the open-angle group and with age (β=-0.442, P=0.003) and IT500 (β=-0.399, P=0.008) in the narrow-angle group. However, subfoveal choroidal thickness was not correlated with trabecular iris angle, anterior chamber depth, ciliary body thickness, or central corneal thickness in the narrow-angle group. CONCLUSION Choroidal thickness does not differ in the two groups and has not correlated with anterior chamber parameters in narrow-angle subjects, suggesting a lack of relationship between choroidal thickness and primary angle-closure glaucoma. PMID:27588269

  17. Discovering the Inscribed Angle Theorem

    ERIC Educational Resources Information Center

    Roscoe, Matt B.

    2012-01-01

    Learning to play tennis is difficult. It takes practice, but it also helps to have a coach--someone who gives tips and pointers but allows the freedom to play the game on one's own. Learning to act like a mathematician is a similar process. Students report that the process of proving the inscribed angle theorem is challenging and, at times,…

  18. Angle between principal axis triples

    NASA Astrophysics Data System (ADS)

    Tape, Walter; Tape, Carl

    2012-09-01

    The principal axis angle ξ0, or Kagan angle, is a measure of the difference between the orientations of two seismic moment tensors. It is the smallest angle needed to rotate the principal axes of one moment tensor to the corresponding principal axes of the other. This paper is a conceptual review of the main features of ξ0. We give a concise formula for calculating ξ0, but our main goal is to illustrate the behaviour of ξ0 geometrically. When the first of two moment tensors is fixed, the angle ξ0 between them becomes a function on the unit ball. The level surfaces of ξ0 can then be depicted in the unit ball, and they give insights into ξ0 that are not obvious from calculations alone. We also include a derivation of the known probability density inline image of ξ0. The density inline image is proportional to the area of a certain surface inline image. The easily seen variation of inline image with t then explains the rather peculiar shape of inline image. Because the curve inline image is highly non-uniform, its shape needs to be considered when analysing distributions of empirical ξ0 values. We recall an example of Willemann which shows that ξ0 may not always be the most appropriate measure of separation for moment tensor orientations, and we offer an alternative measure.

  19. Influence of Contact Angle, Growth Angle and Melt Surface Tension on Detached Solidification of InSb

    NASA Technical Reports Server (NTRS)

    Wang, Yazhen; Regel, Liya L.; Wilcox, William R.

    2000-01-01

    We extended the previous analysis of detached solidification of InSb based on the moving meniscus model. We found that for steady detached solidification to occur in a sealed ampoule in zero gravity, it is necessary for the growth angle to exceed a critical value, the contact angle for the melt on the ampoule wall to exceed a critical value, and the melt-gas surface tension to be below a critical value. These critical values would depend on the material properties and the growth parameters. For the conditions examined here, the sum of the growth angle and the contact angle must exceed approximately 130, which is significantly less than required if both ends of the ampoule are open.

  20. Comparisons of Plasmaspheric Hiss and Lightning-generated Whistler Wave Electron Pitch Angle Diffusion Models

    NASA Astrophysics Data System (ADS)

    O'Malley, S. M.; Alvidrez, V., Jr.; Ling, A. G.; Albert, J.; Colman, J. J.; Quinn, R. A.; Selcher, C. A.; Starks, M. J.

    2014-12-01

    Two of the largest contributors to electron pitch angle diffusion in the plasmasphere are plasmaspheric hiss and lightning-generated whistler mode waves. Several modeling efforts have been made to describe the interaction between electrons and waves associated with these natural processes, most notably by Abel and Thorne [1998] and Meredith et al [2007,2009]. We present an additional lightning-generated whistler diffusion model based on the recent VLF spectral density climatology of Colman and Starks [2013]. Monthly averages of the wave power distribution used to develop this model are provided. A polynomial fit to the spectral intensity profiles is used to describe the power distribution instead of the normal Gaussian formalization. Comparisons between these models are facilitated via a program based on quasi-linear theory, using input parameters that are representative of each model. Diffusion coefficients are presented as a function of equatorial pitch angle and L-shell for L-shells in the range 2.5-4.0 at electron energies of 0.1, 0.5, 1.0, and 5.0 MeV. The diffusion coefficients are applied to the CRRESELE radiation belt model to determine electron loss timescales. The diffused electron flux pitch angle distributions are presented for CRRESELE energies of 0.65, 2.0, 3.15, and 5.75 MeV and at elapsed times of 30 days, 90 days, 1 year, and 4 years after the start of diffusion. Our results are found to be consistent with prior modeling determinations for small wave normal angle propagation, but less diffusive for large wave normal angles.

  1. The Probabilistic Admissible Region with Additional Constraints

    NASA Astrophysics Data System (ADS)

    Roscoe, C.; Hussein, I.; Wilkins, M.; Schumacher, P.

    The admissible region, in the space surveillance field, is defined as the set of physically acceptable orbits (e.g., orbits with negative energies) consistent with one or more observations of a space object. Given additional constraints on orbital semimajor axis, eccentricity, etc., the admissible region can be constrained, resulting in the constrained admissible region (CAR). Based on known statistics of the measurement process, one can replace hard constraints with a probabilistic representation of the admissible region. This results in the probabilistic admissible region (PAR), which can be used for orbit initiation in Bayesian tracking and prioritization of tracks in a multiple hypothesis tracking framework. The PAR concept was introduced by the authors at the 2014 AMOS conference. In that paper, a Monte Carlo approach was used to show how to construct the PAR in the range/range-rate space based on known statistics of the measurement, semimajor axis, and eccentricity. An expectation-maximization algorithm was proposed to convert the particle cloud into a Gaussian Mixture Model (GMM) representation of the PAR. This GMM can be used to initialize a Bayesian filter. The PAR was found to be significantly non-uniform, invalidating an assumption frequently made in CAR-based filtering approaches. Using the GMM or particle cloud representations of the PAR, orbits can be prioritized for propagation in a multiple hypothesis tracking (MHT) framework. In this paper, the authors focus on expanding the PAR methodology to allow additional constraints, such as a constraint on perigee altitude, to be modeled in the PAR. This requires re-expressing the joint probability density function for the attributable vector as well as the (constrained) orbital parameters and range and range-rate. The final PAR is derived by accounting for any interdependencies between the parameters. Noting that the concepts presented are general and can be applied to any measurement scenario, the idea

  2. CHARMM Additive All-Atom Force Field for Acyclic Polyalcohols, Acyclic Carbohydrates and Inositol

    PubMed Central

    Hatcher, Elizabeth; Guvench, Olgun; MacKerell, Alexander D.

    2009-01-01

    Parametrization of the additive all-atom CHARMM force field for acyclic polyalcohols, acyclic carbohydrates and inositol is conducted. Initial parameters were transferred from the alkanes and hexopyranose carbohydrates, with subsequent development and optimization of parameters unique to the molecules considered in this study. Using the model compounds acetone and acetaldehyde, nonbonded parameters for carbonyls were optimized targeting quantum mechanical interaction data for solute-water pairs and pure solvent thermodynamic data. Bond and angle parameters were adjusted by comparing optimized geometries to small molecule crystal survey data and by performing vibrational analyses on acetone, acetaldehyde and glycerol. C-C-C-C, C-C-C-O, C-C-OH and O-C-C-O torsional parameters for polyol chains were fit to quantum mechanical dihedral potential energy scans comprising over 1500 RIMP2/cc-pVTZ//MP2/6-31G(d) conformations using an automated Monte Carlo simulated annealing procedure. Comparison of computed condensed-phase data, including crystal lattice parameters and densities, NMR proton-proton couplings, densities and diffusion coefficients of aqueous solutions, to experimental data validated the optimized parameters. Parameter development for these compounds proved particularly challenging because of the flexibility of the acyclic sugars and polyalcohols as well as the intramolecular hydrogen bonding between vicinal hydroxyls for all of the compounds. The newly optimized additive CHARMM force field parameters are anticipated to be of utility for atomic level of detail simulations of acyclic polyalcohols, acyclic carbohydrates and inositol in solution. PMID:20160980

  3. Hidden Topological Angles in Path Integrals

    NASA Astrophysics Data System (ADS)

    Behtash, Alireza; Sulejmanpasic, Tin; Schäfer, Thomas; Ünsal, Mithat

    2015-07-01

    We demonstrate the existence of hidden topological angles (HTAs) in a large class of quantum field theories and quantum mechanical systems. HTAs are distinct from theta parameters in the Lagrangian. They arise as invariant angles associated with saddle points of the complexified path integral and their descent manifolds (Lefschetz thimbles). Physical effects of HTAs become most transparent upon analytic continuation in nf to a noninteger number of flavors, reducing in the integer nf limit to a Z2 valued phase difference between dominant saddles. In N =1 super Yang-Mills theory we demonstrate the microscopic mechanism for the vanishing of the gluon condensate. The same effect leads to an anomalously small condensate in a QCD-like S U (N ) gauge theory with fermions in the two-index representation. The basic phenomenon is that, contrary to folklore, the gluon condensate can receive both positive and negative contributions in a semiclassical expansion. In quantum mechanics, a HTA leads to a difference in semiclassical expansion of integer and half-integer spin particles.

  4. Hidden Topological Angles in Path Integrals.

    PubMed

    Behtash, Alireza; Sulejmanpasic, Tin; Schäfer, Thomas; Ünsal, Mithat

    2015-07-24

    We demonstrate the existence of hidden topological angles (HTAs) in a large class of quantum field theories and quantum mechanical systems. HTAs are distinct from theta parameters in the Lagrangian. They arise as invariant angles associated with saddle points of the complexified path integral and their descent manifolds (Lefschetz thimbles). Physical effects of HTAs become most transparent upon analytic continuation in n_{f} to a noninteger number of flavors, reducing in the integer n_{f} limit to a Z_{2} valued phase difference between dominant saddles. In N=1 super Yang-Mills theory we demonstrate the microscopic mechanism for the vanishing of the gluon condensate. The same effect leads to an anomalously small condensate in a QCD-like SU(N) gauge theory with fermions in the two-index representation. The basic phenomenon is that, contrary to folklore, the gluon condensate can receive both positive and negative contributions in a semiclassical expansion. In quantum mechanics, a HTA leads to a difference in semiclassical expansion of integer and half-integer spin particles. PMID:26252675

  5. NEW ESTIMATES OF THE INCLINATION, POSITION ANGLE, PITCH ANGLE, AND SCALE HEIGHT OF THE WHIRLPOOL GALAXY

    SciTech Connect

    Hu Tao; Shao Zhengyi; Peng Qiuhe E-mail: taohu.nju@gmail.com

    2013-01-10

    The inclination (i) and position angle (PA) of the Whirlpool galaxy (M51) are critical to modeling and interpreting observations. Here we make improved estimates of these parameters by fitting logarithmic spirals to the main arms. From separate fits to each major arm, we obtain i = 20. Degree-Sign 3 {+-} 2. Degree-Sign 8 and PA = 12. Degree-Sign 0 {+-} 2. Degree-Sign 5. We then use Poisson's equation for the logarithmic perturbation of the density to estimate the mean vertical scale height (H) of M51 to be 95-178 pc.

  6. Supercritical Angle Fluorescence Correlation Spectroscopy

    PubMed Central

    Ries, Jonas; Ruckstuhl, Thomas; Verdes, Dorinel; Schwille, Petra

    2008-01-01

    We explore the potential of a supercritical angle (SA) objective for fluorescence correlation spectroscopy (FCS). This novel microscope objective combines tight focusing by an aspheric lens with strong axial confinement of supercritical angle fluorescence collection by a parabolic mirror lens, resulting in a small detection volume. The tiny axial extent of the detection volume features an excellent surface sensitivity, as is demonstrated by diffusion measurements in model membranes with an excess of free dye in solution. All SA-FCS measurements are directly compared to standard confocal FCS, demonstrating a clear advantage of SA-FCS, especially for diffusion measurements in membranes. We present an extensive theoretical framework that allows for accurate and quantitative evaluation of the SA-FCS correlation curves. PMID:17827221

  7. Light Scattering at Various Angles

    PubMed Central

    Latimer, Paul; Pyle, B. E.

    1972-01-01

    The Mie theory of scattering is used to provide new information on how changes in particle volume, with no change in dry weight, should influence light scattering for various scattering angles and particle sizes. Many biological cells (e.g., algal cells, erythrocytes) and large subcellular structures (e.g., chloroplasts, mitochondria) in suspension undergo this type of reversible volume change, a change which is related to changes in the rates of cellular processes. A previous study examined the effects of such volume changes on total scattering. In this paper scattering at 10° is found to follow total scattering closely, but scattering at 45°, 90°, 135°, and 170° behaves differently. Small volume changes can cause very large observable changes in large angle scattering if the sample particles are uniform in size; however, the natural particle size heterogeneity of most samples would mask this effect. For heterogeneous samples of most particle size ranges, particle shrink-age is found to increase large angle scattering. PMID:4556610

  8. OPENING ANGLES OF COLLAPSAR JETS

    SciTech Connect

    Mizuta, Akira; Ioka, Kunihito

    2013-11-10

    We investigate the jet propagation and breakout from the stellar progenitor for gamma-ray burst (GRB) collapsars by performing two-dimensional relativistic hydrodynamic simulations and analytical modeling. We find that the jet opening angle is given by θ{sub j} ∼ 1/5Γ{sub 0} and infer the initial Lorentz factor of the jet at the central engine, Γ{sub 0}, is a few for existing observations of θ{sub j}. The jet keeps the Lorentz factor low inside the star by converging cylindrically via collimation shocks under the cocoon pressure and accelerates at jet breakout before the free expansion to a hollow-cone structure. In this new picture, the GRB duration is determined by the sound crossing time of the cocoon, after which the opening angle widens, reducing the apparent luminosity. Some bursts violating the maximum opening angle θ{sub j,{sub max}} ∼ 1/5 ∼ 12° imply the existence of a baryon-rich sheath or a long-acting jet. We can explain the slopes in both Amati and Yonetoku spectral relations using an off-centered photosphere model, if we make only one assumption that the total jet luminosity is proportional to the initial Lorentz factor of the jet. We also numerically calibrate the pre-breakout model (Bromberg et al.) for later use.

  9. [Open-angle glaucoma clinical presentation and management].

    PubMed

    Kitazawa, Y

    2001-12-01

    Both primary open-angle and normal-tension glaucoma belong to an identical spectrum of diseases. Clinical presentations of primary open-angle or high-tension glaucoma (POAG) and normal-tension glaucoma (NTG) were studied in an attempt to determine prognostic, clinical factors and define the appropriate management. Clinical data obtained from 826 primary open-angle and normal-tension glaucoma patients were analyzed. In addition, the results of laboratory studies, including the immunological assay of heat shock protein (hsp) and gene analyses which were undertaken to identify risk factors at the molecular level, are discussed. 1. The identified prognostic factors were disk hemorrhage, peripapillary chorioretinal atrophy (PPA), maximum intraocular pressure (IOP), the recovery rate of skin temperature after exposure to cold, family history of glaucoma, systemic systolic channel blood pressure, and oral administration of Ca(2+)-channel antagonists. 2. Disk hemorrhage was observed in 30.5% of NTG patients and 15.4% of POAG patients. Cumulative probability of hemorrhagic events was 16.9% in POAG and 38.4% in NTG patients at the end of a 14.8-year follow-up. 3. The hazard ratio of disk hemorrhage decreased with the increase of IOP(26%/5 mmHg) and was 1.46 times higher in females than in males. Disk hemorrhage was closely associated with PPA: PPA becomes greater in association with the progression of glaucomatous optic neuropathy in both POAG and NTG. No such correlation was noted in primary angle-closure glaucoma. 4. Color Doppler imaging analyses and the hourly determination of ocular perfusion pressure (OPP) indicated a difference in retrobulbar hemodynamics between OPP-mean deviation concordant and OPP-mean deviation discordant patients: a circulatory disturbance causally unrelated to OPP seems to be involved in the OPP-mean deviation discordant patients. 5. The oral administration of Ca(2+)-channel antagonists was shown to favorably influence retrobulbar hemodynamics

  10. Influence of Different Diffuser Angle on Sedan's Aerodynamic Characteristics

    NASA Astrophysics Data System (ADS)

    Hu, Xingjun; Zhang, Rui; Ye, Jian; Yan, Xu; Zhao, Zhiming

    The aerodynamic characteristics have a great influence on the fuel economics and the steering stability of a high speed vehicle. The underbody rear diffuser is one of important aerodynamic add-on devices. The parameters of the diffuser, including the diffuser angle, the number and the shape of separators, the shape of the end plate and etc, will affect the underbody flow and the wake. Here, just the influence of the diffuser angle was investigated without separator and the end plate. The method of Computational Fluid Dynamics was adopted to study the aerodynamic characteristics of a simplified sedan with a different diffuser angle respectively. The diffuser angle was set to 0°, 3°, 6°, 9.8° and 12° respectively. The diffuser angle of the original model is 9.8°. The conclusions were drawn that when the diffuser angle increases, the underbody flow and especially the wake change greatly and the pressure change correspondingly; as a result, the total aerodynamic drag coefficients of car first decrease and then increases, while the total aerodynamic lift coefficients decrease.

  11. Gasoline additives, emissions, and performance

    SciTech Connect

    1995-12-31

    The papers included in this publication deal with the influence of fuel, additive, and hardware changes on a variety of vehicle performance characteristics. Advanced techniques for measuring these performance parameters are also described. Contents include: Fleet test evaluation of gasoline additives for intake valve and combustion chamber deposit clean up; A technique for evaluating octane requirement additives in modern engines on dynamometer test stands; A fleet test of two additive technologies comparing their effects on tailpipe emissions; Investigation into the vehicle exhaust emissions of high percentage ethanol blends; Variability in hydrocarbon speciation measurements at low emission (ULEV) levels; and more.

  12. Analysis of low-angle x-ray scattering peaks from lyophilized biological samples

    NASA Astrophysics Data System (ADS)

    Desouky, Omar S.; Elshemey, Wael M.; Selim, Nabila S.; Ashour, Ahmed H.

    2001-08-01

    Low-angle x-ray scattering (LAXS) from lyophilized blood and its constituents is characterized by the presence of two peaks in the forward direction of scattering. These peaks are found to be sensitive to the variations in the molecular structure of a given sample. The present work aims to explore the nature of LAXS from a variety of lyophilized biological samples. It also aims to investigate the possibility that a certain biological macromolecule is responsible of the production of LAXS peaks. This is carried out through measurements of LAXS from complex biological samples and their basic constituents. Among the measured samples are haemoglobin (Hb), globin, haem, packed red blood cells, bovine albumin, egg albumin, milk, casein, glutamine, alanine, fat, muscle and DNA. A table containing some characteristic parameters of the LAXS profiles of these samples is also presented. Analysis of measured profiles shows that all lyophilized samples produce at least one relatively broad peak at a scattering angle around 10.35°. The full width at half maximum (FWHM) of this peak varies considerably among the measured samples. Except for milk and casein, one additional peak at a scattering angle around 4.65° is observed only in the LAXS profiles of proteins or protein-rich samples. This fact strongly suggests protein to be the biological macromolecule from which this characteristic peak originates. The same idea is further strengthened through discussion of some previous observations.

  13. Wettability transparency and the quasiuniversal relationship between hydrodynamic slip and contact angle

    NASA Astrophysics Data System (ADS)

    Ramos-Alvarado, Bladimir; Kumar, Satish; Peterson, G. P.

    2016-02-01

    The universality of the scaling laws that correlate the hydrodynamic slip length and static contact angle was investigated by introducing the concept of the wettability transparency of graphene-coated surfaces. Equilibrium molecular dynamics simulations of droplet wettability for Si(111), Si(100), and graphene-coated silicon surfaces were performed to determine the conditions required to obtain similar contact angles between bare and graphene-coated surfaces (wettability transparency). The hydrodynamic slip length was determined by means of equilibrium calculations for silicon and graphene-coated silicon nanochannels. The results indicate that the slip-wettability scaling laws can be used to describe the slip behavior of the bare silicon nanochannels in general terms; however, clear departures from a general universal description were observed for hydrophobic conditions. In addition, a significant difference in the hydrodynamic slippage was observed under wettability transparency conditions. Alternatively, the hydrodynamic boundary condition for silicon and graphene-coated silicon nanochannels was more accurately predicted by observing the density depletion length, posing this parameter as a better alternative than the contact angle to correlate with the slip length.

  14. Variable-angle high-angle annular dark-field imaging: application to three-dimensional dopant atom profiling

    PubMed Central

    Zhang, Jack Y.; Hwang, Jinwoo; Isaac, Brandon J.; Stemmer, Susanne

    2015-01-01

    Variable-angle high-angle annular dark-field (HAADF) imaging in scanning transmission electron microscopy is developed for precise and accurate determination of three-dimensional (3D) dopant atom configurations. Gd-doped SrTiO3 films containing Sr columns containing zero, one, or two Gd dopant atoms are imaged in HAADF mode using two different collection angles. Variable-angle HAADF significantly increases both the precision and accuracy of 3D dopant profiling. Using image simulations, it is shown that the combined information from the two detectors reduces the uncertainty in the dopant depth position measurement and can uniquely identify certain atomic configurations that are indistinguishable with a single detector setting. Additional advances and applications are discussed. PMID:26206489

  15. Pennation angles of the intrinsic muscles of the foot.

    PubMed

    Ledoux, W R; Hirsch, B E; Church, T; Caunin, M

    2001-03-01

    As mathematical models of the musculoskeletal system become increasingly detailed and precise, they require more accurate information about the architectural parameters of the individual muscles. These muscles are typically represented as Hill-type models, which require data on fiber length, physiological cross-sectional area (PCSA) and pennation angle. Most of this information for lower limb muscles has been published, except for data on the pennation angle of the intrinsic muscles of the foot. Each (n=20) intrinsic muscle of three human feet was dissected free. The dorsal and plantar surfaces were photographed and a digitized color image was imported into Abobe Photoshop. The muscles were divided into "anatomical units". For each anatomical unit (n=26), a line was drawn along the tendon axis and a number of other lines were drawn along individual muscle fibers. The angle between the tendon line and each fiber line was defined as the pennation angle of that fiber. By visual inspection, an effort was made to take measurements such that they represented the distribution of fibers in various parts of the muscle. Although some individual muscles had higher or lower pennation angles, when averaged for all specimens, the second dorsal interosseous had the smallest pennation angle (6.7+/-6.81 degrees) while the abductor digiti minimi had the largest (19.1+/-11.19 degrees). Since the cosines of the angles range from 0.9932 to 0.9449, the effect of the pennation angle on the force generated by the muscle was not great. PMID:11182133

  16. Radar altimeter waveform modeled parameter recovery. [SEASAT-1 data

    NASA Technical Reports Server (NTRS)

    1981-01-01

    Satellite-borne radar altimeters include waveform sampling gates providing point samples of the transmitted radar pulse after its scattering from the ocean's surface. Averages of the waveform sampler data can be fitted by varying parameters in a model mean return waveform. The theoretical waveform model used is described as well as a general iterative nonlinear least squares procedures used to obtain estimates of parameters characterizing the modeled waveform for SEASAT-1 data. The six waveform parameters recovered by the fitting procedure are: (1) amplitude; (2) time origin, or track point; (3) ocean surface rms roughness; (4) noise baseline; (5) ocean surface skewness; and (6) altitude or off-nadir angle. Additional practical processing considerations are addressed and FORTRAN source listing for subroutines used in the waveform fitting are included. While the description is for the Seasat-1 altimeter waveform data analysis, the work can easily be generalized and extended to other radar altimeter systems.

  17. Effects on Diagnostic Parameters After Removing Additional Synchronous Gear Meshes

    NASA Technical Reports Server (NTRS)

    Decker, Harry J.

    2003-01-01

    Gear cracks are typically difficult to diagnose with sufficient time before catastrophic damage occurs. Significant damage must be present before algorithms appear to be able to detect the damage. Frequently there are multiple gear meshes on a single shaft. Since they are all synchronous with the shaft frequency, the commonly used synchronous averaging technique is ineffective in removing other gear mesh effects. Carefully applying a filter to these extraneous gear mesh frequencies can reduce the overall vibration signal and increase the accuracy of commonly used vibration metrics. The vibration signals from three seeded fault tests were analyzed using this filtering procedure. Both the filtered and unfiltered vibration signals were then analyzed using commonly used fault detection metrics and compared. The tests were conducted on aerospace quality spur gears in a test rig. The tests were conducted at speeds ranging from 2500 to 5000 revolutions per minute and torques from 184 to 228 percent of design load. The inability to detect these cracks with high confidence results from the high loading which is causing fast fracture as opposed to stable crack growth. The results indicate that these techniques do not currently produce an indication of damage that significantly exceeds experimental scatter.

  18. SU-E-I-56: Scan Angle Reduction for a Limited-Angle Intrafraction Verification (LIVE) System

    SciTech Connect

    Ren, L; Zhang, Y; Yin, F

    2014-06-01

    Purpose: To develop a novel adaptive reconstruction strategy to further reduce the scanning angle required by the limited-angle intrafraction verification (LIVE) system for intrafraction verification. Methods: LIVE acquires limited angle MV projections from the exit fluence of the arc treatment beam or during gantry rotation between static beams. Orthogonal limited-angle kV projections are also acquired simultaneously to provide additional information. LIVE considers the on-board 4D-CBCT images as a deformation of the prior 4D-CT images, and solves the deformation field based on deformation models and data fidelity constraint. LIVE reaches a checkpoint after a limited-angle scan, and reconstructs 4D-CBCT for intrafraction verification at the checkpoint. In adaptive reconstruction strategy, a larger scanning angle of 30° is used for the first checkpoint, and smaller scanning angles of 15° are used for subsequent checkpoints. The onboard images reconstructed at the previous adjacent checkpoint are used as the prior images for reconstruction at the current checkpoint. As the algorithm only needs to reconstruct the small deformation occurred between adjacent checkpoints, projections from a smaller scan angle provide enough information for the reconstruction. XCAT was used to simulate tumor motion baseline drift of 2mm along sup-inf direction at every subsequent checkpoint, which are 15° apart. Adaptive reconstruction strategy was used to reconstruct the images at each checkpoint using orthogonal 15° kV and MV projections. Results: Results showed that LIVE reconstructed the tumor volumes accurately using orthogonal 15° kV-MV projections. Volume percentage differences (VPDs) were within 5% and center of mass shifts (COMS) were within 1mm for reconstruction at all checkpoints. Conclusion: It's feasible to use an adaptive reconstruction strategy to further reduce the scan angle needed by LIVE to allow faster and more frequent intrafraction verification to minimize the

  19. Controlling pre-tilt angles of liquid crystal using mixed polyimide alignment layer.

    PubMed

    Wu, Wei-Yen; Wang, Chen-Chen; Fuh, Andy Y

    2008-10-13

    Three approaches to controlling liquid crystal (LC) pre-tilt angle in a cell are demonstrated using a polyimide (PI) alignment layer on substrates, in the form of a mixture of horizontal (H) and vertical (V) polyimides. The concentration ratio of H- to V-PI, baking temperature, and rubbing strength influence the pre-tilt angle, and highlight parameters for controlling the pre-tilt angle of an LC cell. Finally, a variable polarization converter is demonstrated using this approach. PMID:18852824

  20. A study on difference and importance of sacral slope and pelvic sacral angle that affect lumbar curvature.

    PubMed

    Choi, Seyoung; Lee, Minsun; Kwon, Byongan

    2014-01-01

    Individual pelvic sacral angle was measured, compared and analyzed for the 6 male and female adults who were diagnosed with lumbar spinal stenosis, foraminal stenosis and mild spondylolisthesis in accordance with spinal parameters, pelvic parameters and occlusion state of sacroiliac joint presented by the author of this thesis based on the fact that the degree of lumbar excessive lordosis that was one of the causes for lumbar pain was determined by sacral slope. The measured values were compared with the standard values of the average normal range from 20 s to 40 s of normal Koreans stated in the study on the change in lumbar lordosis angle, lumbosacral angle and sacral slope in accordance with the age by Oh et al. [5] and sacral slope and pelvic sacral slope of each individual of the subjects for measurement were compared. Comparing the difference between the two tilt angles possessed by an individual is a comparison to determine how much the sacroiliac joint connecting pelvis and sacral vertebrae compensated and corrected the sacral vertebrae slope by pelvic tilt under the condition of synarthrodial joint.Under the condition that the location conforming to the line in which the sagittal line of gravity connects with pelvic ASIS and pubic pubic tuberele is the neutral location of pelvic tilt, sacral slope being greater than pelvic sacral slope means pelvic anterior tilting, whereas sacral slope being smaller than pelvic sacral slope means pelvic posterior tilting. On that account, male B, female A and female C had a pelvic posterior tilting of 16 degrees, 1 degree and 5 degrees respectively, whereas male A, male C and female B had a pelvic anterior tilting of 3 degrees, 9 degrees and 4 degrees respectively. In addition, the 6 patients the values of lumbar lordosis angle, lumbosacral angle and sacral slope that were almost twice as much as the normal standard values of Koreans. It is believed that this is because the pelvic sacral slope maintaining an angle that is

  1. Wide angle holographic display system with spatiotemporal multiplexing.

    PubMed

    Kozacki, Tomasz; Finke, Grzegorz; Garbat, Piotr; Zaperty, Weronika; Kujawińska, Małgorzata

    2012-12-01

    This paper presents a wide angle holographic display system with extended viewing angle in both horizontal and vertical directions. The display is constructed from six spatial light modulators (SLM) arranged on a circle and an additional SLM used for spatiotemporal multiplexing and a viewing angle extension in two perpendicular directions. The additional SLM, that is synchronized with the SLMs on the circle is placed in the image space. This method increases effective space bandwidth product of display system data from 12.4 to 50 megapixels. The software solution based on three Nvidia graphic cards is developed and implemented in order to achieve fast and synchronized displaying. The experiments presented for both synthetic and real 3D data prove the possibility to view binocularly having good quality images reconstructed in full FoV of the display. PMID:23262697

  2. Dynamic response of a forward-swept-wing model at angles of attack up to 15 deg at a Mach number of 0.8. [Langley transonic dynamics tunnel tests

    NASA Technical Reports Server (NTRS)

    Doggett, R. V., Jr.; Ricketts, R. H.

    1980-01-01

    Root mean square (rms) bending moments for a dynamically scaled, aeroelastic wing of a proposed forward swept wing, flight demonstrator airplane are presented for angles of attack up to 15 deg at a Mach number of 0.8 The 0.6 size semispan model had a leading edge forward sweep of 44 deg and was constructed of composite material. In addition to broad band responses, individual rms responses and total damping ratios are presented for the first two natural modes. The results show that the rms response increases with angle of attack and has a peak value at an angle of attack near 13 deg. In general, the response was characteristic of buffeting and similar to results often observed for aft swept wings. At an angle of attack near 13 deg, however, the response had characteristics associated with approaching a dynamic instability, although no instability was observed over the range of parameters investigated.

  3. CHARMM Additive All-Atom Force Field for Phosphate and Sulfate Linked to Carbohydrates

    PubMed Central

    Mallajosyula, Sairam S.; Guvench, Olgun; Hatcher, Elizabeth; MacKerell, Alexander D.

    2012-01-01

    Presented is an extension of the CHARMM additive all-atom carbohydrate force field to enable the modeling of phosphate and sulfate linked to carbohydrates. The parameters are developed in a hierarchical fashion using model compounds containing the key atoms in the full carbohydrates. Target data for parameter optimization included full two-dimensional energy surfaces defined by the glycosidic dihedral angle pairs in the phosphate/sulfate model compound analogs of hexopyranose monosaccharide phosphates and sulfates, as determined by quantum mechanical (QM) MP2/cc-pVTZ single point energies on MP2/6-31+G(d) optimized structures. In order to achieve balanced, transferable dihedral parameters for the dihedral angles, surfaces for all possible anomeric and conformational states were included during the parametrization process. In addition, to model physiologically relevant systems both the mono- and di-anionic charged states were studied for the phosphates. This resulted in over 7000 MP2/cc-pVTZ//MP2/6-31G+(d) model compound conformational energies which, supplemented with QM geometries, were the main target data for the parametrization. Parameters were validated against crystals of relevant monosaccharide derivatives obtained from the Cambridge Structural Database (CSD) and larger systems, namely inositol-(tri/tetra/penta) phosphates non-covalently bound to the pleckstrin homology (PH) domain and oligomeric chondroitin sulfate in solution and in complex with cathepsin K protein. PMID:22685386

  4. Amplitude-versus-angle analysis and wide-angle-inversion of crosswell seismic data in a carbonate reservoir

    NASA Astrophysics Data System (ADS)

    Ibrahim, Mohamed S.

    Crosswell data set contains a range of angles limited only by the geometry of the source and receiver configuration, the separation of the boreholes and the depth to the target. However, the wide angles reflections present in crosswell imaging result in amplitude-versus-angle (AVA) features not usually observed in surface data. These features include reflections from angles that are near critical and beyond critical for many of the interfaces; some of these reflections are visible only for a small range of angles, presumably near their critical angle. High-resolution crosswell seismic surveys were conducted over a Silurian (Niagaran) reef at two fields in northern Michigan, Springdale and Coldspring. The Springdale wells extended to much greater depths than the reef, and imaging was conducted from above and from beneath the reef. Combining the results from images obtained from above with those from beneath provides additional information, by exhibiting ranges of angles that are different for the two images, especially for reflectors at shallow depths, and second, by providing additional constraints on the solutions for Zoeppritz equations. Inversion of seismic data for impedance has become a standard part of the workflow for quantitative reservoir characterization. Inversion of crosswell data using either deterministic or geostatistical methods can lead to poor results with phase change beyond the critical angle, however, the simultaneous pre-stack inversion of partial angle stacks may be best conducted with restrictions to angles less than critical. Deterministic inversion is designed to yield only a single model of elastic properties (best-fit), while the geostatistical inversion produces multiple models (realizations) of elastic properties, lithology and reservoir properties. Geostatistical inversion produces results with far more detail than deterministic inversion. The magnitude of difference in details between both types of inversion becomes increasingly

  5. Equilibrium properties of the fluxoid lattice in single-crystal niobium. II. Small-angle neutron-diffraction measurements

    SciTech Connect

    Christen, D.K.; Kerchner, H.R.; Sekula, S.T.; Thorel, P.

    1980-01-01

    A small-angle neutron-diffraction technique has been used to measure several properties of the flux-line lattice (FLL) in a single-crystal sphere of pure niobium. For applied fields parallel to several crystallographic directions in the (100) and (110) planes, the low-field mixed state and intermediate mixed state were investigated. From these results, the orientation dependence of the low-field critical parameters H/sub c/1 and B/sub 0/ are deduced. The consistency of these results is verified by comparison with direct measurements of the equilibrium misalignment angle between the applied-field direction and the fluxoid axes. In addition, results are reported which extend the available information concerning correlations between the FLL and crystal lattice (CL) symmetry properties.

  6. Method for producing angled optical fiber tips in the laboratory

    NASA Astrophysics Data System (ADS)

    Davenport, John J.; Hickey, Michelle; Phillips, Justin P.; Kyriacou, Panicos A.

    2016-02-01

    A simple laboratory method is presented for producing optical fibers with tips polished at various angles. Angled optical fiber tips are used in applications such as optical sensing and remote laser surgery, where they can be used to control the angle of light leaving the fiber or direct it to the side. This allows for greater control and allows areas to be reached that otherwise could not. Optical fibers were produced with tip angles of 45 deg using a Perspex mounting block with an aluminum base plate. The dispersion of light leaving the tip was tested using a blue (470 nm) LED. The angle imposed an angular shift on the light diffracting out of the tip of approximately 30 deg. Additionally, some light reflected from the tip surface to diffract at 90 deg through the side of the fiber. These observations are consistent with theory and those seen by other studies, validating the method. The method was simple to perform and does not require advanced manufacturing tools. The method is suitable for producing small quantities of angle-tipped optical fibers for research applications.

  7. Radiation Belt Electron Pitch Angle Measurements from the GOES Satellites

    NASA Astrophysics Data System (ADS)

    Onsager, T. G.; Green, J. C.; Singer, H. J.

    2004-12-01

    Radiation belt electron pitch angle distributions provide important information regarding the source and loss processes that control the electron flux levels. As the flux levels vary, it is important to understand the extent to which the distinctive pitch angle distributions are formed through specific source and loss processes versus adiabatic drifts. In addition, pitch angle information is critical when mapping electron fluxes from one location to another. In this presentation, we give an analysis of the pitch angle distribution of >2 MeV electrons measured at geosynchronous orbit by the GOES satellites. Although the current GOES satellites are three-axis stabilized during normal operation, extensive data coverage is available during on-orbit storage of the satellites when they were spinning. During these times, well resolved pitch angle distributions have been obtained using the simultaneous electron and magnetic field measurements. These measurements are available from late 1998 to the present, allowing us to characterize the radiation belt electron pitch angle distributions as a function of local time, flux level, and geomagnetic activity during key phases of the current solar cycle.

  8. Limbus Impact on Off-angle Iris Degradation

    SciTech Connect

    Karakaya, Mahmut; Barstow, Del R; Santos-Villalobos, Hector J; Thompson, Joseph W; Bolme, David S; Boehnen, Chris Bensing

    2013-01-01

    The accuracy of iris recognition depends on the quality of data capture and is negatively affected by several factors such as angle, occlusion, and dilation. Off-angle iris recognition is a new research focus in biometrics that tries to address several issues including corneal refraction, complex 3D iris texture, and blur. In this paper, we present an additional significant challenge that degrades the performance of the off-angle iris recognition systems, called the limbus effect . The limbus is the region at the border of the cornea where the cornea joins the sclera. The limbus is a semitransparent tissue that occludes a side portion of the iris plane. The amount of occluded iris texture on the side nearest the camera increases as the image acquisition angle increases. Without considering the role of the limbus effect, it is difficult to design an accurate off-angle iris recognition system. To the best of our knowledge, this is the first work that investigates the limbus effect in detail from a biometrics perspective. Based on results from real images and simulated experiments with real iris texture, the limbus effect increases the hamming distance score between frontal and off-angle iris images ranging from 0.05 to 0.2 depending upon the limbus height.

  9. Ion Implantation Angle Variation to Device Performance and the Control in Production

    SciTech Connect

    Zhao, Z.Y.; Hendrix, D.; Wu, L.Y.; Cusson, B.K.

    2003-08-26

    As the device features get smaller and aspect ratios of photoresist openings get steeper, shadowing effect has more impact on the performance of devices. Many of the traditional 7 deg. tilt implants have progressed to 0 deg. implants. But shadowing may still occur if the tilt angle deviates from normal direction. Some implants, such as halo implants, demand even more stringent angle control to reduce device performance variation. The demand for implant angle control and monitoring thus becomes more obvious and important. However, statistical process control (SPC) cannot be done on shadowing effect without special test structures. Channeling, on the other hand, provides good sensitivity in regard to implant angle changes. It is the authors' intention to introduce channeling implant in different channels to monitor the implant angle variation. The incoming <100> silicon wafers have a cut-angle spec of +/- 1.0 deg. This poses a difficulty if one wants to control the implant angle's accuracy within +/- 0.5 deg. Other measures have to be taken to ensure the consistency of test wafers and to have prompt diagnosis feedback when needed. This paper will discuss the effect of implant tilt angle on device parameters and how to control the angle variation in production. Correlations of implant tilt angle variation to ThermaWave, sheet resistance (Rs), Secondary Ion Mass Spectrometry (SIMS) and device parameters will be covered with certain implant conditions.

  10. Ion Implantation Angle Variation to Device Performance and the Control in Production

    NASA Astrophysics Data System (ADS)

    Zhao, Z. Y.; Hendrix, D.; Wu, L. Y.; Cusson, B. K.

    2003-08-01

    As the device features get smaller and aspect ratios of photoresist openings get steeper, shadowing effect has more impact on the performance of devices. Many of the traditional 7° tilt implants have progressed to 0° implants. But shadowing may still occur if the tilt angle deviates from normal direction. Some implants, such as halo implants, demand even more stringent angle control to reduce device performance variation. The demand for implant angle control and monitoring thus becomes more obvious and important. However, statistical process control (SPC) cannot be done on shadowing effect without special test structures. Channeling, on the other hand, provides good sensitivity in regard to implant angle changes. It is the authors' intention to introduce channeling implant in different channels to monitor the implant angle variation. The incoming <100> silicon wafers have a cut-angle spec of +/- 1.0°. This poses a difficulty if one wants to control the implant angle's accuracy within +/- 0.5°. Other measures have to be taken to ensure the consistency of test wafers and to have prompt diagnosis feedback when needed. This paper will discuss the effect of implant tilt angle on device parameters and how to control the angle variation in production. Correlations of implant tilt angle variation to ThermaWave™, sheet resistance (Rs), Secondary Ion Mass Spectrometry (SIMS) and device parameters will be covered with certain implant conditions.

  11. Moderate Positive Spin Hall Angle in Uranium

    NASA Astrophysics Data System (ADS)

    Anguera, Marta; Singh, Simran; Del Barco, Enrique; Springell, Ross; Miller, Casey W.

    We will present results on FMR and voltage measurements of magnetic damping and the inverse spin Hall effect, respectively, in Ni80Fe20/Uranium bilayers. A pure spin current is injected into an Uranium film from the ferromagnetic resonance dynamics of the magnetization of an adjacent Ni80Fe20 (permalloy) film. The spin current generated is then converted into an electric field by the inverse spin Hall effect. Our results suggest a spin mixing conductance of order 2x1019 m-2 and a positive spin Hall angle of 0.004, which are both unexpected based on trends in d-electron systems. These results support the idea that materials with unfilled f-electron orbitals may require additional exploration for spin physics. Work at UCF was supported by NSF-ECCS grant # 1402990. Work at RIT was supported by NSF-ECCS Grant 1515677.

  12. Large angle magnetic suspension test fixture

    NASA Technical Reports Server (NTRS)

    Britcher, Colin P.

    1993-01-01

    Progress made under the subject grant in the period from 1 Nov. 1992 to 31 May 1993 is presented. The research involves the continued development of the Large Angle Magnetic Suspension Test Fixture (LAMSTF) and also the recommissioning of an additional piece of exisiting hardware. During the period in question, the initial configuration of LAMSTF was completed and made routinely and reliably operational. A digital phase advance controller was completed and documented. The goal of a controlled 360 deg rotation was achieved. Work started on the recommissioning of the Annular Suspension and Pointing System (ASPS). Work completed during the report period included: modeling; position sensing; controller; support of the Second International Symposium on Magnetic Suspension Technology; and recommissioning of the Annular Suspension and Pointing System.

  13. Large-area wide-angle spectrally selective plasmonic absorber

    NASA Astrophysics Data System (ADS)

    Wu, Chihhui; Neuner, Burton, III; Shvets, Gennady; John, Jeremy; Milder, Andrew; Zollars, Byron; Savoy, Steve

    2011-08-01

    A simple metamaterial-based wide-angle plasmonic absorber is introduced, fabricated, and experimentally characterized using angle-resolved infrared spectroscopy. The metamaterials are prepared by nano-imprint lithography, an attractive low-cost technology for making large-area samples. The matching of the metamaterial’s impedance to that of vacuum is responsible for the observed spectrally selective “perfect” absorption of infrared light. The impedance is theoretically calculated in the single-resonance approximation, and the responsible resonance is identified as a short-range surface plasmon. The spectral position of the absorption peak (which is as high as 95%) is experimentally shown to be controlled by the metamaterial’s dimensions. The persistence of “perfect” absorption with variable metamaterial parameters is theoretically explained. The wide-angle nature of the absorber can be utilized for subdiffraction-scale infrared pixels exhibiting spectrally selective absorption/emissivity.

  14. Numerical analysis on the effect of angle of attack on evaluating radio-frequency blackout in atmospheric reentry

    NASA Astrophysics Data System (ADS)

    Jung, Minseok; Kihara, Hisashi; Abe, Ken-ichi; Takahashi, Yusuke

    2016-06-01

    A three-dimensional numerical simulation model that considers the effect of the angle of attack was developed to evaluate plasma flows around reentry vehicles. In this simulation model, thermochemical nonequilibrium of flowfields is considered by using a four-temperature model for high-accuracy simulations. Numerical simulations were performed for the orbital reentry experiment of the Japan Aerospace Exploration Agency, and the results were compared with experimental data to validate the simulation model. A comparison of measured and predicted results showed good agreement. Moreover, to evaluate the effect of the angle of attack, we performed numerical simulations around the Atmospheric Reentry Demonstrator of the European Space Agency by using an axisymmetric model and a three-dimensional model. Although there were no differences in the flowfields in the shock layer between the results of the axisymmetric and the three-dimensional models, the formation of the electron number density, which is an important parameter in evaluating radio-frequency blackout, was greatly changed in the wake region when a non-zero angle of attack was considered. Additionally, the number of altitudes at which radio-frequency blackout was predicted in the numerical simulations declined when using the three-dimensional model for considering the angle of attack.

  15. Solar-phase-angle effects on the taxonomic classification of asteroids

    NASA Astrophysics Data System (ADS)

    Carvano, J.; Davallos, J.

    2014-07-01

    Asteroid taxonomy is the effort of grouping asteroids into classes based on similarities of a number of their observational properties. The most used properties include measurements of their spectral reflectance (by means of low-resolution spectra, spectro-photometry, or colors), and geometric albedo. The usefulness of asteroid taxonomic classes derived in this way relies on the assumption that the classes bear some correspondence to the mineralogy of the asteroids, and on the fact that such classification can be made using types of observations that presently are available to a large number of asteroids. Therefore, asteroid taxonomy can be used to infer trends in the distribution of compositions in the main belt and other populations, as an additional parameter in defining asteroid families, and as a selection tool to identify candidates for more detailed observations. However, the fact that the correspondence between taxonomic class and composition is far from perfect is still sometimes overlooked in the literature. Indeed, although a taxonomic classification narrows down the possible mineralogies of a given asteroid, it will seldom point univocally to one particular mineralogy. This happens for a number of reasons, some linked to the intrinsic difficulty involved in the remote characterization of the mineralogy of an asteroid, since it depends on the presence of absorption bands in its reflectance spectrum which may be absent or not completely sampled by the observations used to derive taxonomy. Other problem here is the exposure of the material on the surface of the asteroid to space-weathering effects, such as solar wind implantation and micro-meteorite bombardment, which can change the optical properties of the material. Finally, the overall shape of the reflectance spectrum of an asteroid is also affected by the geometry of the observation, as well as by its shape. In this work, we analyze how the classification of asteroids observed by the Sloan Digital Sky

  16. Inline sidewall angle monitoring of memory capacitor profiles

    NASA Astrophysics Data System (ADS)

    Rathsack, Ben M.; Bushman, Scott G.; Celii, Francis G.; Ayres, Stephen F.; Kris, Roman

    2005-05-01

    The integration of embedded ferroelectric random access memory (FRAM) into a standard CMOS flow requires significant control and characterization of the patterned capacitor sidewall angle. The electrical functionality of the FRAM capacitor is highly dependent on the post-etch sidewall characteristics of the TiAlN hardmask and Ir/PZT/Ir capacitor film stack. In this study, we explored various options for determining the sidewall profile of these capacitors including scanning electron microscope (SEM), atomic force microscopy (AFM) and scatterometry. A series of capacitor samples with ranges of sidewall slopes from 60 degrees to 80 degrees was generated to test each measuring technique's robustness. All of the techniques demonstrated relatively accurate sidewall angle measurements of the high-angle capacitor profiles relative to cross-section SEMs. However, the CD SEM had difficulty identifying the top edge of the low-angle capacitor samples due to the large amount of profile roughness, which induced a large measurement error range. Additional optimization is required to improve the CD SEM's precision, before it would be a viable in-line monitor for the FRAM process. The AFM provided good accuracy and precision on the high-angle capacitor profiles, but the tip size limited the measurements to spaces larger than 120 nm. Furthermore, the AFM had a long move-acquire-measure (MAM) time of 5 minutes/site, which limited its throughput as an inline monitor. The scatterometer predicted bottom-stack sidewall angle measurements (2 trapezoid model) that were consistent with the cross-section SEMs, and it produced the lowest across wafer sidewall angle range. It also had the fastest MAM time of 5 seconds/site compared to the other techniques. However, it was difficult to generate an accurate scatterometry model due to the complex optical film stack that incorporated low surface reflectivity and higher surface roughness. While each technique had limitations, scatterometry

  17. 30 CFR 56.19037 - Fleet angles.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Fleet angles. 56.19037 Section 56.19037 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND NONMETAL MINE SAFETY AND... Sheaves § 56.19037 Fleet angles. Fleet angles on hoists installed after November 15, 1979, shall not...

  18. 30 CFR 57.19037 - Fleet angles.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Fleet angles. 57.19037 Section 57.19037 Mineral Resources MINE SAFETY AND HEALTH ADMINISTRATION, DEPARTMENT OF LABOR METAL AND NONMETAL MINE SAFETY AND... Sheaves § 57.19037 Fleet angles. Fleet angles on hoists installed after November 15, 1979, shall not...

  19. 30 CFR 57.19037 - Fleet angles.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 30 Mineral Resources 1 2011-07-01 2011-07-01 false Fleet angles. 57.19037 Section 57.19037 Mineral... Sheaves § 57.19037 Fleet angles. Fleet angles on hoists installed after November 15, 1979, shall not be greater than one and one-half degrees for smooth drums or two degrees for grooved drums....

  20. Matching the Best Viewing Angle in Depth Cameras for Biomass Estimation Based on Poplar Seedling Geometry

    PubMed Central

    Andújar, Dionisio; Fernández-Quintanilla, César; Dorado, José

    2015-01-01

    In energy crops for biomass production a proper plant structure is important to optimize wood yields. A precise crop characterization in early stages may contribute to the choice of proper cropping techniques. This study assesses the potential of the Microsoft Kinect for Windows v.1 sensor to determine the best viewing angle of the sensor to estimate the plant biomass based on poplar seedling geometry. Kinect Fusion algorithms were used to generate a 3D point cloud from the depth video stream. The sensor was mounted in different positions facing the tree in order to obtain depth (RGB-D) images from different angles. Individuals of two different ages, e.g., one month and one year old, were scanned. Four different viewing angles were compared: top view (0°), 45° downwards view, front view (90°) and ground upwards view (−45°). The ground-truth used to validate the sensor readings consisted of a destructive sampling in which the height, leaf area and biomass (dry weight basis) were measured in each individual plant. The depth image models agreed well with 45°, 90° and −45° measurements in one-year poplar trees. Good correlations (0.88 to 0.92) between dry biomass and the area measured with the Kinect were found. In addition, plant height was accurately estimated with a few centimeters error. The comparison between different viewing angles revealed that top views showed poorer results due to the fact the top leaves occluded the rest of the tree. However, the other views led to good results. Conversely, small poplars showed better correlations with actual parameters from the top view (0°). Therefore, although the Microsoft Kinect for Windows v.1 sensor provides good opportunities for biomass estimation, the viewing angle must be chosen taking into account the developmental stage of the crop and the desired parameters. The results of this study indicate that Kinect is a promising tool for a rapid canopy characterization, i.e., for estimating crop biomass

  1. Matching the best viewing angle in depth cameras for biomass estimation based on poplar seedling geometry.

    PubMed

    Andújar, Dionisio; Fernández-Quintanilla, César; Dorado, José

    2015-01-01

    In energy crops for biomass production a proper plant structure is important to optimize wood yields. A precise crop characterization in early stages may contribute to the choice of proper cropping techniques. This study assesses the potential of the Microsoft Kinect for Windows v.1 sensor to determine the best viewing angle of the sensor to estimate the plant biomass based on poplar seedling geometry. Kinect Fusion algorithms were used to generate a 3D point cloud from the depth video stream. The sensor was mounted in different positions facing the tree in order to obtain depth (RGB-D) images from different angles. Individuals of two different ages, e.g., one month and one year old, were scanned. Four different viewing angles were compared: top view (0°), 45° downwards view, front view (90°) and ground upwards view (-45°). The ground-truth used to validate the sensor readings consisted of a destructive sampling in which the height, leaf area and biomass (dry weight basis) were measured in each individual plant. The depth image models agreed well with 45°, 90° and -45° measurements in one-year poplar trees. Good correlations (0.88 to 0.92) between dry biomass and the area measured with the Kinect were found. In addition, plant height was accurately estimated with a few centimeters error. The comparison between different viewing angles revealed that top views showed poorer results due to the fact the top leaves occluded the rest of the tree. However, the other views led to good results. Conversely, small poplars showed better correlations with actual parameters from the top view (0°). Therefore, although the Microsoft Kinect for Windows v.1 sensor provides good opportunities for biomass estimation, the viewing angle must be chosen taking into account the developmental stage of the crop and the desired parameters. The results of this study indicate that Kinect is a promising tool for a rapid canopy characterization, i.e., for estimating crop biomass

  2. Estimation of crank angle for cycling with a powered prosthesis.

    PubMed

    Lawson, B E; Shultz, A; Ledoux, E; Goldfarb, M

    2014-01-01

    In order for a prosthesis to restore power generation during cycling, it must supply torque in a manner that is coordinated with the motion of the bicycle crank. This paper outlines an algorithm for the real time estimation of the angular position of a bicycle crankshaft using only measurements internal to an intelligent knee and ankle prosthesis. The algorithm assumes that the rider/prosthesis/bicycle system can be modeled as a four-bar mechanism. Assuming that a prosthesis can generate two independent angular measurements of the mechanism (in this case the knee angle and the absolute orientation of the shank), Freudenstein's equation can be used to synthesize the mechanism continuously. A recursive least-squares algorithm is implemented to estimate the Freudenstein coefficients, and the resulting link lengths are used to reformulate the equation in terms of input-output relationships mapping both measured angles to the crank angle. Using two independent measurements allows the algorithm to uniquely determine the crank angle from multi-valued functions. In order to validate the algorithm, a bicycle was mounted on a trainer and configured with the prosthesis using an artificial hip joint attached to the seat post. Motion capture was used to monitor the mechanism for forward and backward pedaling and the results are compared to the output of the presented algorithm. Once the parameters have converged, the algorithm is shown to predict the crank angle within 15° of the externally measured value throughout the entire crank cycle during forward rotation. PMID:25571415

  3. The Influence of Dynamic Contact Angle on Wetting Dynamics

    NASA Technical Reports Server (NTRS)

    Rame, Enrique; Garoff, Steven

    2005-01-01

    When surface tension forces dominate, and regardless of whether the situation is static or dynamic, the contact angle (the angle the interface between two immiscible fluids makes when it contacts a solid) is the key parameter that determines the shape of a fluid-fluid interface. The static contact angle is easy to measure and implement in models predicting static capillary surface shapes and such associated quantities as pressure drops. By contrast, when the interface moves relative to the solid (as in dynamic wetting processes) the dynamic contact angle is not identified unambiguously because it depends on the geometry of the system Consequently, its determination becomes problematic and measurements in one geometry cannot be applied in another for prediction purposes. However, knowing how to measure and use the dynamic contact angle is crucial to determine such dynamics as a microsystem throughput reliably. In this talk we will present experimental and analytical efforts aimed at resolving modeling issues present in dynamic wetting. We will review experiments that show the inadequacy of the usual hydrodynamic model when a fluid-fluid meniscus moves over a solid surface such as the wall of a small tube or duct. We will then present analytical results that show how to parametrize these problems in a predictive manner. We will illustrate these ideas by showing how to implement the method in numerical fluid mechanical calculations.

  4. Determination of Load Angle for Salient-pole Synchronous Machine

    NASA Astrophysics Data System (ADS)

    Sumina, D.; Šala, A.; Malarić, R.

    2010-01-01

    This paper presents two methods for load angle determination for salient-pole synchronous generator. The first method uses optical encoder to detect the rotor position. In some cases the end of the rotor shaft is not free to be used and mounting of an encoder is impossible. Therefore, the second method proposes estimation of the load angle based on the measured electrical values that have been already used in excitation control system of the synchronous generator. Estimation method uses corresponding voltage-current vector diagram and parameters of the synchronous generator, transformer and transmission lines. Both methods were experimentally verified on the digital control system and synchronous generator connected to power system. The estimation and measured results were compared. The accuracy of load angle estimation method depends on voltage and current measurement accuracy as well as generator, transformer and transmission line parameter accuracy. The estimation method gives satisfactory accuracy for load angles less than 120° el. Thus, it can be applied in excitation control system to provide stable work of synchronous generator in under-excitation operating area.

  5. [Chronic closed-angle glaucoma].

    PubMed

    Valtot, F

    2004-06-01

    Five times more frequent than the acute form, chronic closed-angle glaucoma often goes unrecognized for a long time, resulting in considerable visual field deficiencies, even in loss of the eye. It is sometimes confused with chronic glaucoma and treated as such, which is inadequate to halt the progression of the disease. Only gonioscopy can diagnose it. If doubt persists, UBM (ultrasound biomicroscopy) can detect goniosynechiae, a malposition of the ciliary body or of the lens, or the existence of iridociliary cysts. Nine times out of ten, pupillary block initiates the process and an iridotomy should always be done to remediate it, even if this procedure alone does not always suffice to solve the problem. PMID:15319750

  6. The 2mrad Crossing Angle Interaction Region and Extraction Line

    SciTech Connect

    Appleby, R.; U., Manchester; Angal-Kalinin, D.; Dadoun, O.; Bambade, P.; Parker, B.; Keller, L.; Moffeit, K.; Nosochkov, Y.; Seryi, A.; Spencer, C.; Carter, J.; Royal Holloway, U.of London; Napoly, O.; /DAPNIA, Saclay

    2006-07-12

    A complete optics design for the 2mrad crossing angle interaction region and extraction line was presented at Snowmass 2005. Since this time, the design task force has been working on developing and improving the performance of the extraction line. The work has focused on optimizing the final doublet parameters and on reducing the power losses resulting from the disrupted beam transport. In this paper, the most recent status of the 2mrad layout and the corresponding performance are presented.

  7. Light airplane crash tests at three flight-path angles

    NASA Technical Reports Server (NTRS)

    Castle, C. B.; Alfaro-Bou, E.

    1978-01-01

    Three similar twin engine general aviation airplane specimens were crash tested at Langley impact dynamics research facility at 27 m/sec and at flight-path angles of -15 deg, -30 deg, and -45 deg. Other flight parameters were held constant. The test facility, instrumentation, test specimens, and test method are briefly described. Structural damage and accelerometer data for each of the three impact conditions are presented and discussed.

  8. Light airplane crash tests at three roll angles

    NASA Technical Reports Server (NTRS)

    Castle, C. B.; Alfaro-Bou, E.

    1979-01-01

    Three similar twin engine general aviation airplanes were crash tested at the Langley impact dynamics research facility at 27 m/sec and at nominal roll angles of 0 deg, -15 deg, and -30 deg. Other flight parameters were held constant. The test facility, instrumentation, test specimens, and test method are briefly described. Structural damage and accelerometer data for each of the three impact conditions are presented and discussed.

  9. Wide-angle point-to-point x-ray imaging with almost arbitrarily large angles of incidence

    SciTech Connect

    Bitter, M.; Hill, K. W.; Scott, S.; Feder, R.; Ko, Jinseok; Ince-Cushman, A.; Rice, J. E.

    2008-10-15

    The paper describes a new scheme for wide-angle point-to-point x-ray imaging with almost arbitrarily large angles of incidence by a matched pair of spherically bent crystals to eliminate the astigmatism, which is a well-known imaging error of spherical mirrors. In addition to x rays, the scheme should be applicable to a very broad spectrum of the electromagnetic radiation, including microwaves, infrared and visible light, as well as UV and extreme UV radiation, if the crystals are replaced with appropriate spherical reflectors. The scheme may also be applicable to the imaging with ultrasound.

  10. Low-cost large-angle steering mirror development

    NASA Astrophysics Data System (ADS)

    Wassom, Steven R.

    2009-08-01

    The Space Dynamics Laboratory has combined internal funds with its background in space-rated mechanisms to develop a prototype low-cost large-angle 2-axis fine steering mirror (FSM). The FSM has a 75-mm clear aperture, 30-degree mechanical elevation angle, 120-degree mechanical azimuth angle, and a 70-Hertz small-amplitude bandwidth. Key components include a rotary voice coil, unique patent-pending feedback sensor, brushless DC motor and optical encoder. Average error is <1 arcsec and total mechanical mass is <1 kg. Additional accomplishments include a passive launch lock, launch vibration testing, portable demonstration electronics development, and thermal-vacuum testing to pressures down to 1e-7 torr and temperatures down to 164 K.

  11. Supergranular Parameters

    NASA Astrophysics Data System (ADS)

    Udayashankar, Paniveni

    2016-07-01

    I study the complexity of supergranular cells using intensity patterns from Kodaikanal solar observatory. The chaotic and turbulent aspect of the solar supergranulation can be studied by examining the interrelationships amongst the parameters characterizing supergranular cells namely size, horizontal flow field, lifetime and physical dimensions of the cells and the fractal dimension deduced from the size data. The findings are supportive of Kolmogorov's theory of turbulence. The Data consists of visually identified supergranular cells, from which a fractal dimension 'D' for supergranulation is obtained according to the relation P α AD/2 where 'A' is the area and 'P' is the perimeter of the supergranular cells. I find a fractal dimension close to about 1.3 which is consistent with that for isobars and suggests a possible turbulent origin. The cell circularity shows a dependence on the perimeter with a peak around (1.1-1.2) x 105 m. The findings are supportive of Kolmogorov's theory of turbulence.

  12. Sensitivity analysis of Stirling engine design parameters

    SciTech Connect

    Naso, V.; Dong, W.; Lucentini, M.; Capata, R.

    1998-07-01

    In the preliminary Stirling engine design process, the values of some design parameters (temperature ratio, swept volume ratio, phase angle and dead volume ratio) have to be assumed; as a matter of fact it can be difficult to determine the best values of these parameters for a particular engine design. In this paper, a mathematical model is developed to analyze the sensitivity of engine's performance variations corresponding to variations of these parameters.

  13. The effect of vapor incidence angle upon thin film columnar growth

    SciTech Connect

    Mazor, A.; Bukiet, B.G.; Srolovitz, D.J.

    1988-01-01

    We present a generalized theory for the growth of columnar microstructure in vapor deposited thin films under the joint influence of a constant uniform deposition flux coming down with arbitrarily chosen incidence angle, and surface diffusion. The dependences of the Zone I to Zone II transition temperature, and the characteristic length scales associated with the unstable modes on the deposition angle are predicted. The surface morphology is obtained as a function of vapor incidence angle. For a specific deposition angle, there is a one-parameter family of steady-state surface profiles which corresponds to a range of possible columnar orientation angles, among which only one angle is associated with the tangent rule. These results agree with experimental observations. 10 refs., 6 figs.

  14. Optic Disc - Fovea Angle: The Beijing Eye Study 2011

    PubMed Central

    Jonas, Rahul A.; Wang, Ya Xing; Yang, Hua; Li, Jian Jun; Xu, Liang; Panda-Jonas, Songhomitra; Jonas, Jost B.

    2015-01-01

    Purpose To determine the optic disc-fovea angle (defined as angle between the horizontal and the line between the optic disc center and the fovea) and to assess its relationships with ocular and systemic parameters. Methods The population-based cross-sectional Beijing Eye Study 2011 included 3468 individuals. A detailed ophthalmic examination was carried out. Using fundus photographs, we measured the disc-fovea angle. Results Readable fundus photographs were available for 6043 eyes of 3052 (88.0%) individuals with a mean age of 63.6±9.3 years (range: 50–91 years) and a mean axial length of 23.2±1.0 mm (range: 18.96–28.87 mm). Mean disc-fovea angle was 7.76 ± 3.63° (median: 7.65°; range: -6.3° to 28.9°). The mean inter-eye difference was 4.01 ± 2.94° (median: 3.49°; range: 0.00–22.3°). In multivariate analysis, larger disc-fovea angle was associated (regression coefficient r2: 0.08) with older age (P = 0.009; standardized regression coefficient beta: 0.05), thinner RNFL in the nasal superior sector (P<0.001; beta: -0.17), superior sector (P<0.001; beta: -0.10) and temporal superior sector (P<0.001; beta: -0.11) and thicker RNFL in the inferior sector (P<001; beta: 0.13), nasal inferior sector (P<001; beta: 0.13) and nasal sector (P = 0.007; beta: 0.06), higher prevalence of retinal vein occlusion (P = 0.02; beta: 0.04), and with larger cylindrical refractive error (P = 0.04; beta: 0.04). Conclusions The optic disc-fovea angle markedly influences the regional distribution of the RNFL thickness pattern. The disc-fovea angle may routinely be taken into account in the morphological glaucoma diagnosis and in the assessment of structure-function relationship in optic nerve diseases. Future studies may address potential associations between a larger disc-fovea angle and retinal vein occlusions and between the disc-fovea angle and the neuroretinal rim shape. PMID:26545259

  15. Autonomous satellite navigation using starlight refraction angle measurements

    NASA Astrophysics Data System (ADS)

    Ning, Xiaolin; Wang, Longhua; Bai, Xinbei; Fang, Jiancheng

    2013-05-01

    An on-board autonomous navigation capability is required to reduce the operation costs and enhance the navigation performance of future satellites. Autonomous navigation by stellar refraction is a type of autonomous celestial navigation method that uses high-accuracy star sensors instead of Earth sensors to provide information regarding Earth's horizon. In previous studies, the refraction apparent height has typically been used for such navigation. However, the apparent height cannot be measured directly by a star sensor and can only be calculated by the refraction angle and an atmospheric refraction model. Therefore, additional errors are introduced by the uncertainty and nonlinearity of atmospheric refraction models, which result in reduced navigation accuracy and reliability. A new navigation method based on the direct measurement of the refraction angle is proposed to solve this problem. Techniques for the determination of the refraction angle are introduced, and a measurement model for the refraction angle is established. The method is tested and validated by simulations. When the starlight refraction height ranges from 20 to 50 km, a positioning accuracy of better than 100 m can be achieved for a low-Earth-orbit (LEO) satellite using the refraction angle, while the positioning accuracy of the traditional method using the apparent height is worse than 500 m under the same conditions. Furthermore, an analysis of the factors that affect navigation accuracy, including the measurement accuracy of the refraction angle, the number of visible refracted stars per orbit and the installation azimuth of star sensor, is presented. This method is highly recommended for small satellites in particular, as no additional hardware besides two star sensors is required.

  16. Angled Layers in Super Resolution

    NASA Technical Reports Server (NTRS)

    2004-01-01

    Researchers used a special imaging technique with the panoramic camera on NASA's Mars Exploration Rover Opportunity to get as detailed a look as possible at a target region near eastern foot of 'Burns Cliff.' The intervening terrain was too difficult for driving the rover closer. The target is the boundary between two sections of layered rock. The layers in lower section (left) run at a marked angle to the layers in next higher section (right).

    This view is the product of a technique called super resolution. It was generated from data acquired on sol 288 of Opportunity's mission (Nov. 14, 2004) from a position along the southeast wall of 'Endurance Crater.' Resolution slightly higher than normal for the panoramic camera was synthesized for this view by combining 17 separate images of this scene, each one 'dithered' or pointed slightly differently from the previous one. Computer manipulation of the individual images was then used to generate a new synthetic view of the scene in a process known mathematically as iterative deconvolution, but referred to informally as super resolution. Similar methods have been used to enhance the resolution of images from the Mars Pathfinder mission and the Hubble Space Telescope.

  17. Large Angle Satellite Attitude Maneuvers

    NASA Technical Reports Server (NTRS)

    Cochran, J. E.; Junkins, J. L.

    1975-01-01

    Two methods are proposed for performing large angle reorientation maneuvers. The first method is based upon Euler's rotation theorem; an arbitrary reorientation is ideally accomplished by rotating the spacecraft about a line which is fixed in both the body and in space. This scheme has been found to be best suited for the case in which the initial and desired attitude states have small angular velocities. The second scheme is more general in that a general class of transition trajectories is introduced which, in principle, allows transfer between arbitrary orientation and angular velocity states. The method generates transition maneuvers in which the uncontrolled (free) initial and final states are matched in orientation and angular velocity. The forced transition trajectory is obtained by using a weighted average of the unforced forward integration of the initial state and the unforced backward integration of the desired state. The current effort is centered around practical validation of this second class of maneuvers. Of particular concern is enforcement of given control system constraints and methods for suboptimization by proper selection of maneuver initiation and termination times. Analogous reorientation strategies which force smooth transition in angular momentum and/or rotational energy are under consideration.

  18. Chronic open-angle glaucoma

    PubMed Central

    Adatia, Feisal A.; Damji, Karim F.

    2005-01-01

    INTRODUCTION Chronic open-angle glaucoma (COAG) is a leading cause of irreversible blindness worldwide, including in Canada. It presents a challenge in diagnosis, as disease often progresses without symptoms; an estimated 50% of cases are undetected. SOURCES OF INFORMATION MEDLINE searches, reference lists of articles, and expert knowledge from one of the authors (K.F.D.), a glaucoma specialist, were used. MAIN MESSAGE A casefinding approach using early referral to optometrists and ophthalmologists for early detection of COAG is helpful for patients with risk factors such as age above 50, a positive family history, black race, and myopia. Moderate evidence for referral also exists for the following risk factors: hypertension, type 2 diabetes mellitus, hypothyroidism, and sleep apnea. Treatment with intraocular pressure–lowering medication can arrest or slow the course of the disease, permitting patients to retain good visual function. Family physicians should be aware that some intraocular pressure–lowering medications, particularly topical beta-blockers, can pose iatrogenic harm to patients and result in or exacerbate such conditions as asthma, cardiovascular disturbances, depression, and sexual dysfunction. CONCLUSION Appropriate referral patterns and an understanding of common as well as serious side effects of glaucoma medications are important in optimizing management of patients at risk of developing, or who have, COAG. PMID:16190176

  19. A two-reflection divergent differentiating critical angle refractometer

    NASA Astrophysics Data System (ADS)

    Guo, Wenping; Xia, Min; Li, Wei; Dai, Jie; Yang, Kecheng

    2011-05-01

    A new critical angle refractometer (CAR) for high accuracy refractive index measurement of liquid has been developed. The instrument improves the accuracy by two reflections in an elongated parallelogram prism, and acquires the angular reflectivity without any angle scanning parts through introduction of a point source with a divergent beam and a charge coupled device. In addition, it employs a simple and robust measurement method that gets the critical angle by differentiating the angular reflectivity. Through investigating absorbing media with absorption index κ (the imaginary part of refractive index) from 0 to 10-2.1, the theoretical calculation shows that the proposed two-reflection CAR would outperform the traditional one-reflection CAR on lowering the principal error from the differentiation method and improving the ability of getting the critical angle. By testing two typical liquids-salt-water solution and milk, the preliminary experiment indicates that this two-reflection divergent differentiating critical angle refractometer is feasible and of high accuracy.

  20. Torsional Angle Driver (TorAD) System for HyperChem/Excel

    NASA Astrophysics Data System (ADS)

    Starkey, Ronald

    1999-02-01

    The torsional angle driver system for HyperChem/Excel is a package of several Excel spreadsheets and macro programs to be used with HyperChem to obtain and plot information, such as total energy, for the conformations that result from a 360° rotation about a torsional angle system in a molecule. The TorAD system also includes several HyperChem scripts to facilitate its use. TorAD was developed for use in the undergraduate organic chemistry laboratory. The results obtained with TorAD could be obtained manually with HyperChem, but it would take considerable time and would not be instructive to the students. Use of the TorAD system allows students to spend their time on the more important aspect of conformation analysisinterpretation of results. The Excel spreadsheet/macro programs in TorAD include:

    · Tor_xl_a and tor_xl obtain and plot the total energy at 5° torsional-angle intervals. The calculation method, the torsional-angle restraint, and the structure to be used at each angle can be set by the user. The advanced version, tor_xl_a, which requires HyperChem 4.5 or later, also allows torsional-angle structures to be saved for later recall as individual structures or, using a HyperChem script, in a movie format. It also provides a rapid scan of the 360° rotation where only single-point calculations, rather than geometry optimizations, are performed. The tor_xl system will perform routine tasks in a manner suitable for most instructional settings. · Tor_Comp performs molecular mechanics optimizations at 5° intervals and obtains and plots four energy parameters (total, torsional, nonbonded, and bond [bend plus stretch] energy) as a function of torsional angle. The calculation method and the restraint can be specified. · TorDipol produces a plot of the total energy and the calculated dipole moment at 5° steps of the torsional angle. The default calculation is the semi-empirical AM

  1. Parameters for the AMBER force field for the molecular mechanics modeling of the cobalt corrinoids

    NASA Astrophysics Data System (ADS)

    Marques, H. M.; Ngoma, B.; Egan, T. J.; Brown, K. L.

    2001-04-01

    Additional parameters for the AMBER force field have been developed for the molecular mechanics modeling of the cobalt corrinoids. Parameter development was based on a statistical analysis of the reported structures of these compounds. The resulting force field reproduces bond lengths, bond angles, and torsional angles within 0.01 Å, 0.8°, and 4.0° of the mean crystallographic values, respectively. Parameters for the Co-C bond length and the Co-C-C bond angle for modeling the alkylcobalamins were developed by modeling six alkylcobalamins. The validity of the force field was tested by comparing the results obtained with known experimental features of the structures of the cobalt corrinoids as well as with the results from their modeling using a parameter set for the MM2 force field that has been previously developed and extensively tested. The AMBER force field reproduces the structures of the cobalt corrinoids as well as the MM2 force field, although it tends to underestimate the corrin fold angle, the angle between mean planes through the corrin atoms in the northern and southern half of the molecules, respectively. The force field was applied to a study of the structures of 5'-deoxy-5'-(3-isoadenosyl)cobalamin, 2',5'-dideoxy-5'-adenosylcobalamin and 2',3',5'-trideoxy-5'-adenosylcobalamin. This expansion of the standard AMBER force field provides a force field that can be used for modeling the structures of the B 12-dependent proteins, the structures of some of which are now beginning to emerge. This was verified in a preliminary modeling of the coenzyme B 12 binding site of methylmalonyl coenzyme A mutase.

  2. Apparent contact angle of an evaporating drop

    NASA Astrophysics Data System (ADS)

    Morris, S. J. S.

    2012-11-01

    In experiments by Poulard et al. (2005), a sessile drop of perfectly wetting liquid evaporates from a non-heated substrate into an under-saturated mixture of vapour with an inert gas; evaporation is limited by vapour diffusion. The system exhibits an apparent contact angle θ that is a flow property. Under certain conditions, the apparent contact line was stationary relative to the substrate; we predict θ for this case. Observed values of θ are small, allowing lubrication analysis of the liquid film. The liquid and vapour flows are coupled through conditions holding at the phase interface; in particular, vapour partial pressure there is related to the local value of liquid pressure through the Kelvin condition. Because the droplet is shallow, the interfacial conditions can be transferred to the solid-liquid interface at y = 0 . We show that the dimensionless partial pressure p (x , y) and the film thickness h (x) are determined by solving ∇2 p = 0 for y > 0 subject to a matching condition at infinity, and the conditions - p = L hxx +h-3 and (h3px) x + 3py = 0 at y = 0 . The parameter L controls the ratio of Laplace to disjoining pressure. We analyse this b.v.p. for the experimentally-relevant case L --> 0 .

  3. Optical and infrared properties of glancing angle-deposited nanostructured tungsten films.

    PubMed

    Ungaro, Craig; Shah, Ankit; Kravchenko, Ivan; Hensley, Dale K; Gray, Stephen K; Gupta, Mool C

    2015-02-15

    Nanotextured tungsten thin films were obtained on a stainless steel (SS) substrate using the glancing-angle-deposition (GLAD) method. It was found that the optical absorption and thermal emittance of the SS substrate can be controlled by varying the parameters used during deposition. Finite-difference time-domain (FDTD) simulations were used to predict the optical absorption and infrared (IR) reflectance spectra of the fabricated samples, and good agreement was found between simulated and measured data. FDTD simulations were also used to predict the effect of changes in the height and periodicity of the nanotextures. These simulations show that good control over the absorption can be achieved by altering the height and periodicity of the nanostructure. These nanostructures were shown to be temperature stable up to 500°C with the addition of a protective HfO2 layer. Applications for this structure are explored, including a promising application for solar thermal energy systems. PMID:25680136

  4. Automatic control of the ion-illumination angle in a spark-source mass spectrometer.

    PubMed

    Conzemius, R J; Svec, H J

    1973-05-01

    Automatic adjustment of only the spark-gap width in a spark-source mass spectrometer does not ensure that optimum conditions of electrode geometry are maintained with respect to the ion-optics system. A device has been developed which simultaneously maintains a constant gap width and also a more constant z-axis ion-illumination angle. This is the first development to utilize ion-optics parameters to adjust the sparking electrodes automatically. The system maintains the electrodes in an optimum configuration such that higher and more constant instrument sensitivity is maintained automatically. In addition, a significant improvement in the precision of instrumental response is demonstrated. It appears that relative isotopic abundances can be determined directly by the spark-source method which are comparable to those obtained in some cases by surface ionization or by electron bombardment. Results are given that support this contention. PMID:18961307

  5. The optical field angle distortion calibration feasibility study for the Hubble Space Telescope fine guidance sensors

    NASA Technical Reports Server (NTRS)

    Luchetti, K.; Abshire, G.; Hallock, L.; Mccutcheon, R.

    1988-01-01

    The results of an analytical study to investigate the feasibility of calibrating the Hubble Space Telescope's (HST's) fine guidance sensors (FGSs) within HST mission accuracy limits are presented. The study has two purposes: (1) to determine the mathematical feasibility of the optical field angle distortion (OFAD) calibration algorithm and (2) to confirm that the OFAD, plate scale, and FGS-to-FGS alignment calibration algorithms produced a calibration of the FGSs that satisfied mission requirements. The study concluded that the mathematical specification of the OFAD algorithm is adequate and permits a determination of the FGS calibration parameters (accurate to better than 0.003 arc-second) sufficient to meet the mission requirements. The algorithms implemented, the characteristics of the simulated data and procedures for data analysis, and the study's results are discussed. In addition, several useful techniques for improving the stability and accuracy of the OFAD solution are outlined.

  6. Body composition and phase angle in Russian children in remission from acute lymphoblastic leukemia

    NASA Astrophysics Data System (ADS)

    Tseytlin, G. Ja; Khomyakova, I. A.; Nikolaev, D. V.; Konovalova, M. V.; Vashura, A. Yu; Tretyak, A. V.; Godina, E. Z.; Rudnev, S. G.

    2010-04-01

    Elevated degree of body fatness and changes in other body composition parameters are known to be common effects of treatment for acute lymphoblastic leukemia (ALL) in children. In order to study peculiarities of somatic growth and development in ALL survivors, we describe the results of BIA body composition analysis of 112 boys and 108 girls aged 5-18 years in remission from ALL (remission time range 1-13 years) compared to data from the same number of age- and sex-matched healthy controls (n=220). Detrimental effect on height in ALL boys was observed, whereas girls experienced additional weight gain compared to healthy subjects. In ALL patients, resistance, body fat, and percent body fat were significantly increased. The reactance, phase angle, absolute and relative values of skeletal muscle and body cell mass were significantly decreased. Principal component analysis revealed an early prevalence of adiposity traits in the somatic growth and development of ALL girls compared to healthy controls.

  7. 1. WEST SIDE, NORTH END OF BUILDING 1. SHOWS ADDITIONAL ...

    Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

    1. WEST SIDE, NORTH END OF BUILDING 1. SHOWS ADDITIONAL ANGLES IN BUILDING AT SOUTHERN END. - Chollas Heights Naval Radio Transmitting Facility, Transmitter Building, 6410 Zero Road, San Diego, San Diego County, CA

  8. A Clinical Study of Mandibular Angle Fracture

    PubMed Central

    Yoon, Wook-Jae; Kim, Su-Gwan; Oh, Ji-Su; You, Jae-Seek; Lim, Kyung-Seop; Shin, Seung-Min; Kim, Cheol-Man

    2014-01-01

    Purpose: To establish management protocol for mandibular angle fracture, we describe pertinent factors including cause, impacted third molar and recent treatment tendency. Methods: We examined the records of 62 patients who had unilateral mandibular angle fracture. Sixty patients who had open reduction surgery were examined at postoperative weeks 1, 4, 8, 12, and 28. Results: Left mandibular angle fracture is frequent in younger males. Presence of the mandibular third molar can increase fracture risk. Because of attached muscle, favorable fractures occurred primarily in the mandibular angle area. Conclusion: Extracting the mandibular third molar can prevent angle fractures, and open reduction with only one plate adaptation is generally the proper treatment method for mandibular angle fracture. PMID:27489834

  9. Signature extension for sun angle, volume 1

    NASA Technical Reports Server (NTRS)

    Smith, J. A. (Principal Investigator); Berry, J. K.; Heimes, F.

    1975-01-01

    The author has identified the following significant results. Within a restricted zenith sun angle range of 35 - 50 degrees, it was empirically observed that canopy reflectance is mainly Lambertian. Reflectance changes with crop stage were simple shifts in scale in the sun angle range. It was noted that sun angle variations depend on canopy characteristics. Effects of the vegetative canopy were most pronounced at the larger solar zenith angles (20 %). The linear sun angle correction coefficients demonstrate a dependency on both crop stage (15-20 %) and crop type (10-20 %). The use of canopy reflectance modeling allowed for the generation of a simulated data set over an extremely broad envelope of sun angles.

  10. Best Angle to Orient Two Intersecting Lines

    SciTech Connect

    Awwal, A S; Ferguson, S W; Shull, P B

    2006-07-25

    Fiducials in the form of intersecting straight lines are used to align the target in the final target chamber of the National Ignition Facility of Lawrence Livermore National Laboratory. One of the techniques used to locate these lines is the Hough transform. When two lines intersect at a 90 degree angle, it is tempting to orient the lines to horizontal and vertical directions. There are other possible angles at which the lines may be oriented. One question that arises while designing the fiducials is whether there is a preferred angle or range of angles that leads to higher accuracy. This work attempts to answer this question through detailed computer simulation.

  11. High-speed pitch angle sorter

    NASA Technical Reports Server (NTRS)

    Keller, John W.; Torbert, R. B.; Vandiver, James

    1991-01-01

    A high-speed method was developed to compress the two-dimensional angular distribution of space particles gathered by space plasma instrumentation into the angle distribution, where the pitch angle is polar angle with respect to the ambient magnetic field. The pitch angle sorter can handle rates of up to 2 MHz and it is designed to accommodate high angular resolution plasma analyzers that are placed on a rotating spacecraft. This compression is achieved by relying on digitally encoded lookup tables to eliminate all arithmetic operations while applying the high symmetry of this compression to reduce the amount of digital memory.

  12. Angle-dependent bandgap engineering in gated graphene superlattices

    NASA Astrophysics Data System (ADS)

    García-Cervantes, H.; Gaggero-Sager, L. M.; Sotolongo-Costa, O.; Naumis, G. G.; Rodríguez-Vargas, I.

    2016-03-01

    Graphene Superlattices (GSs) have attracted a lot of attention due to its peculiar properties as well as its possible technological implications. Among these characteristics we can mention: the extra Dirac points in the dispersion relation and the highly anisotropic propagation of the charge carriers. However, despite the intense research that is carried out in GSs, so far there is no report about the angular dependence of the Transmission Gap (TG) in GSs. Here, we report the dependence of TG as a function of the angle of the incident Dirac electrons in a rather simple Electrostatic GS (EGS). Our results show that the angular dependence of the TG is intricate, since for moderated angles the dependence is parabolic, while for large angles an exponential dependence is registered. We also find that the TG can be modulated from meV to eV, by changing the structural parameters of the GS. These characteristics open the possibility for an angle-dependent bandgap engineering in graphene.

  13. Safety Ellipse Motion with Coarse Sun Angle Optimization

    NASA Technical Reports Server (NTRS)

    Naasz, Bo

    2005-01-01

    The Hubble Space Telescope Robotic Servicing and De-orbit Mission (HRSDM) was t o be performed by the unmanned Hubble Robotic Vehicle (HRV) consisting of a Deorbit Module (DM), responsible for the ultimate disposal of Hubble Space Telescope (HST) at the end of science operations, and an Ejection Module (EM), responsible for robotically servicing the HST to extend its useful operational lifetime. HRSDM consisted of eight distinct phases, including: launch, pursuit, proximity operations, capture, servicing, EM jettison and disposal, science operations, and deorbit. The scope of this paper is limited to the Proximity Operations phase of HRSDM. It introduces a relative motion strategy useful for Autonomous Rendezvous and Docking (AR&D) or Formation Flying missions where safe circumnavigation trajectories, or close proximity operations (tens or hundreds of meters) are required for extended periods of time. Parameters and algorithms used to model the relative motion of HRV with respect to HST during the Proximity Operations phase of the HRSDM are described. Specifically, the Safety Ellipse (SE) concept, convenient parameters for describing SE motion, and a concept for initializing SE motion around a target vehicle to coarsely optimize sun and relative navigation sensor angles are presented. The effects of solar incidence angle variations on sun angle optimization, and the effects of orbital perturbations and navigation uncertainty on long term SE motion are discussed.

  14. Monitoring of desert dune field migration process by multi angle sensors

    NASA Astrophysics Data System (ADS)

    Park, Ho-Jun; Yoon, Ji-Ye; Yun, Hye-Won; Kim, Jung-Rack; Choi, Yun-Soo

    2013-04-01

    and EO-ALi images were compared with NDAI values. In addition, ICESat beam-broadening effects, which are interpreted as topographic roughness parameters, were analyzed over the target area. These tasks revealed the correlations between the meter-scale height variations and NDAI values over the desert dune fields, proving the effectiveness of NDAI to represent the surface condition for the progress of aeolian interaction. In conclusion, we proved that the trace of the sandy-desert boundaries for a long observation period is feasible with the multi-angle orbital sensor observation by investigating the expanded NDAIs from various sample sand-dune fields. However, it is quite uncertain whether the consistency of MISR NDAIs over sandy deserts originated from the aeolian microstructures, the reflectance of sand, or the aspect angle of dune morphology. Therefore, in the next stage, the local roughness properties extracted from MISR data analysis will be compared with the topographic information from high-resolution stereo satellite imagery. Consequently, this will correctly evaluate the suitability of multi-angle observation parameters as a dune-activity indicator.

  15. Quartz-Enhanced Photoacoustic Spectroscopy with Right-Angle Prism

    PubMed Central

    Liu, Yongning; Chang, Jun; Lian, Jie; Liu, Zhaojun; Wang, Qiang; Qin, Zengguang

    2016-01-01

    A right-angle prism was used to enhance the acoustic signal of a quartz-enhanced photoacoustic spectroscopy (QEPAS) system. The incident laser beam was parallelly inverted by the right-angle prism and passed through the gap between two tuning fork prongs again to produce another acoustic excitation. Correspondingly, two pairs of rigid metal tubes were used as acoustic resonators with resonance enhancement factors of 16 and 12, respectively. The QEPAS signal was enhanced by a factor of 22.4 compared with the original signal, which was acquired without resonators or a prism. In addition, the system noise was reduced a little with double resonators due to the Q factor decrease. The signal-to-noise ratio (SNR) was greatly improved. Additionally, a normalized noise equivalent absorption coefficient (NNEA) of 5.8 × 10−8 W·cm−1·Hz−1/2 was achieved for water vapor detection in the atmosphere. PMID:26861344

  16. Acoustic pulse propagation near a right-angle wall.

    PubMed

    Liu, Lanbo; Albert, Donald G

    2006-04-01

    Experimental measurements were conducted around a right-angle wall to investigate the effect of this obstacle on sound propagation outdoors. Using small explosions as the source of the acoustic waves allowed reflected and diffracted arrivals to be discerned and investigated in detail. The measurements confirm that diffraction acts as a low-pass filter on acoustic waveforms in agreement with simple diffraction theory, reducing the peak pressure and broadening the waveform shape received by a sensor in the shadow zone. In addition, sensors mounted directly on the wall registered pressure doubling for nongrazing angles of incidence in line-of-sight conditions. A fast two-dimensional finite difference time domain (FDTD) model was developed and provided additional insight into the propagation around the wall. Calculated waveforms show good agreement with the measured waveforms. PMID:16642821

  17. Kinetic small angle neutron scattering of the skyrmion lattice in MnSi

    NASA Astrophysics Data System (ADS)

    Mühlbauer, S.; Kindervater, J.; Adams, T.; Bauer, A.; Keiderling, U.; Pfleiderer, C.

    2016-07-01

    We report a kinetic small angle neutron scattering (SANS) study of the skyrmion lattice (SL) in MnSi. Induced by an oscillatory tilting of the magnetic field direction, the elasticity and relaxation of the SL along the magnetic field direction have been measured with microsecond resolution. For the excitation frequency of 325 {{Hz}} the SL begins to track the tilting motion of the applied magnetic field under tilting angles exceeding {α }{{c}}≳ 0.4^\\circ . Empirically the associated angular velocity of the tilting connects quantitatively with the critical charge carrier velocity of ∼ 0.1 {{mm}} {{{s}}}-1 under current driven spin transfer torques, for which the SL unpins. In addition, a pronounced temperature dependence of the skyrmion motion is attributed to the variation of the skyrmion stiffness. Taken together our study highlights the power of kinetic SANS as a new experimental tool to explore, in a rather general manner, the elasticity and impurity pinning of magnetic textures across a wide parameter space without parasitic signal interferences due to ohmic heating or Oersted magnetic fields.

  18. Small-angle x-ray scattering to discern microstructure of semicrystalline polyanhydrides for drug delivery.

    SciTech Connect

    Kipper, M. J.; Seifert, S.; Thiyagarajan, P.; Narasimhan, B.; Iowa State Univ.

    2005-01-01

    Polyanhydride copolymers based on 1,6-bis(p-carboxyphenoxy)hexane (CPH) and sebacic acid (SA) are bioerodible, semicrystalline polymers that have been used for drug delivery. In addition to their semicrystallinity, these materials also exhibit microphase separation in the amorphous phase. This complex phase behavior, combined with the disparity in the erosion rates of the two different chemical moieties, leads to a complex erosion kinetics that can be used to tailor drug release kinetics. Thus, accurate design of drug delivery devices requires a detailed description of the microphase separation. Here, we employ in situ synchrotron small-angle X-ray scattering (SAXS) to explore the microstructure of these materials. First, we examine the crystallization kinetics of the homopolymers and CPH-SA copolymers. Next, we perform experiments on poly(CPH)/poly(SA) homopolymer blends in the miscible melt in order to discern the segment-segment interaction parameter, {chi}{sub CPH-SA}. This parameter predicts the enthalpy of mixing poly(CPH) and poly(SA) at the monomer level and can be used to predict the phase behavior of the blend. It also offers insights into the thermodynamics that drive the microphase separation in the copolymers. The homopolymer phase diagram has an upper-critical solution temperature and compares well with cloud point data obtained from optical microscopy and predictions of the interaction parameter from molecular simulation.

  19. A novel parameter-induced stochastic resonance phenomena in fractional Fourier domain

    NASA Astrophysics Data System (ADS)

    Lin, Lifeng; Wang, Huiqi; Lv, Wangyong; Zhong, Suchuan

    2016-08-01

    The parameter-induced stochastic resonance (SR) phenomenon in a novel self-adaptive dynamical system driven by linear frequency modulated (LFM) signal and additive noise is considered from the view of the signal-to-noise ratio (SNR). It is found that the dynamical system can be perfectly analyzed by equivalently transforming it into a traditional first-order linear dynamical system driven by periodic signal and additive noise in fractional Fourier transform (FrFT) domain with an optimal rotated angle, and the theoretical analysis and simulation results show that output SNR exhibits the SR behavior when it is plotted as a function of the system parameter. Furthermore, the optimal value of adjusted parameter is obtained, and the possible area of SNR gain is theoretically determined only by center-frequency and modulated frequency of the driving LFM signal.

  20. Identified Parameters, Parameters of Interest and Their Relationships

    ERIC Educational Resources Information Center

    San Martin, Ernesto; Gonzalez, Jorge; Tuerlinckx, Francis

    2009-01-01

    The goal of this commentary is to provide some additional results to the interesting and provocative paper of Maris and Bechger ("On Interpreting the Model Parameters for the Three Parameter Logistic Model," this issue). In this article, the authors have three aims. First, the authors distinguish between three fundamental concepts that are…

  1. Short-term effects of relaxation music on patients suffering from primary open-angle glaucoma

    PubMed Central

    Bertelmann, Thomas; Strempel, Ilse

    2015-01-01

    Purpose To evaluate whether additive relaxation music (RM) has an adjuvant short-term effect on physiological and psychological parameters in patients with primary open-angle glaucoma. Methods Prospective, randomized clinical trial. Patients in the therapy group (TG) received a 30-minute RM via headphones, whereas members of the control group (CG) did not. Best corrected visual acuity, intraocular pressure, visual field testing, short- and long-term mental states, and blood levels of different stress hormones were analyzed and compared. Results A total of 25 (61%)/16 (39%) patients were assigned to the TG/CG. Best corrected visual acuity, daily intraocular pressure, and short-term mental state (KAB) development were significantly better in the TG in comparison to controls. Visual field testing, long-term mental well-being (profile of mood states), and adrenalin, cortisol, and endothelin-I blood levels did not differ significantly between both groups. Conclusion Additive RM applied on a daily basis can positively impact various physiological and psychological parameters in the short term. PMID:26543350

  2. Reconditioning of Cassini Narrow-Angle Camera

    NASA Technical Reports Server (NTRS)

    2002-01-01

    These five images of single stars, taken at different times with the narrow-angle camera on NASA's Cassini spacecraft, show the effects of haze collecting on the camera's optics, then successful removal of the haze by warming treatments.

    The image on the left was taken on May 25, 2001, before the haze problem occurred. It shows a star named HD339457.

    The second image from left, taken May 30, 2001, shows the effect of haze that collected on the optics when the camera cooled back down after a routine-maintenance heating to 30 degrees Celsius (86 degrees Fahrenheit). The star is Maia, one of the Pleiades.

    The third image was taken on October 26, 2001, after a weeklong decontamination treatment at minus 7 C (19 F). The star is Spica.

    The fourth image was taken of Spica January 30, 2002, after a weeklong decontamination treatment at 4 C (39 F).

    The final image, also of Spica, was taken July 9, 2002, following three additional decontamination treatments at 4 C (39 F) for two months, one month, then another month.

    Cassini, on its way toward arrival at Saturn in 2004, is a cooperative project of NASA, the European Space Agency and the Italian Space Agency. The Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the Cassini mission for NASA's Office of Space Science, Washington, D.C.

  3. Moderate positive spin Hall angle in uranium

    NASA Astrophysics Data System (ADS)

    Singh, Simranjeet; Anguera, Marta; del Barco, Enrique; Springell, Ross; Miller, Casey W.

    2015-12-01

    We report measurements of spin pumping and the inverse spin Hall effect in Ni80Fe20/uranium bilayers designed to study the efficiency of spin-charge interconversion in a super-heavy element. We employ broad-band ferromagnetic resonance on extended films to inject a spin current from the Ni80Fe20 (permalloy) into the uranium layer, which is then converted into an electric field by the inverse spin Hall effect. Surprisingly, our results suggest a spin mixing conductance of order 2 × 1019 m-2 and a positive spin Hall angle of 0.004, which are both merely comparable with those of several transition metals. These results thus support the idea that the electronic configuration may be at least as important as the atomic number in governing spin pumping across interfaces and subsequent spin Hall effects. In fact, given that both the magnitude and the sign are unexpected based on trends in d-electron systems, materials with unfilled f-electron orbitals may hold additional exploration avenues for spin physics.

  4. Moderate positive spin Hall angle in uranium

    SciTech Connect

    Singh, Simranjeet; Anguera, Marta; Barco, Enrique del E-mail: cwmsch@rit.edu; Springell, Ross; Miller, Casey W. E-mail: cwmsch@rit.edu

    2015-12-07

    We report measurements of spin pumping and the inverse spin Hall effect in Ni{sub 80}Fe{sub 20}/uranium bilayers designed to study the efficiency of spin-charge interconversion in a super-heavy element. We employ broad-band ferromagnetic resonance on extended films to inject a spin current from the Ni{sub 80}Fe{sub 20} (permalloy) into the uranium layer, which is then converted into an electric field by the inverse spin Hall effect. Surprisingly, our results suggest a spin mixing conductance of order 2 × 10{sup 19} m{sup −2} and a positive spin Hall angle of 0.004, which are both merely comparable with those of several transition metals. These results thus support the idea that the electronic configuration may be at least as important as the atomic number in governing spin pumping across interfaces and subsequent spin Hall effects. In fact, given that both the magnitude and the sign are unexpected based on trends in d-electron systems, materials with unfilled f-electron orbitals may hold additional exploration avenues for spin physics.

  5. 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.

  6. [Determination of contact angle of pharmaceutical excipients and regulating effect of surfactants on their wettability].

    PubMed

    Hua, Dong-dong; Li, He-ran; Yang, Bai-xue; Song, Li-na; Liu, Tiao-tiao; Cong, Yu-tang; Li, San-ming

    2015-10-01

    To study the effects of surfactants on wettability of excipients, the contact angles of six types of surfactants on the surface of two common excipients and mixture of three surfactants with excipients were measured using hypsometry method. The results demonstrated that contact angle of water on the surface of excipients was associated with hydrophilcity of excipients. Contact angle was lowered with increase in hydrophilic groups of excipient molecules. The sequence of contact angle from small to large was starch < sodium benzoate < polyvinylpyrrolidone < sodium carboxymethylcellulose < sodium alginate < chitosan < hydroxypropyl methyl cellulose addition, surfactants both in droplets and mixed in excipients significantly reduced the contact angle of excipients, and their abilities to lower contact angle varied. The results of the present study offer a guideline in the formulation design of tablets. PMID:26837184

  7. 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.

  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. Tree branch angle: maximizing effective leaf area.

    PubMed

    Honda, H; Fisher, J B

    1978-02-24

    In a computer simulation of branching pattern and leaf cluster in Terminalia catappa, right and left branch angles were varied, and the effective leaf surface areas were calculated. Theoretical branch angles that result in maximum effective leaf area are close to the values observed in nature. PMID:17757590

  10. Small-angle neutron scattering from micellar solutions

    NASA Astrophysics Data System (ADS)

    Aswal, V. K.; Goyal, P. S.

    2004-07-01

    Micellar solutions are the suspension of the colloidal aggregates of the sur- factant molecules in aqueous solutions. The structure (shape and size) and the interaction of these aggregates, referred to as micelles, depend on the molecular architecture of the surfactant molecule, presence of additives and the solution conditions such as tempera- ture, concentration etc. This paper gives the usefulness of small-angle neutron scattering to the study of micellar solutions with some of our recent results.

  11. [Food additives and healthiness].

    PubMed

    Heinonen, Marina

    2014-01-01

    Additives are used for improving food structure or preventing its spoilage, for example. Many substances used as additives are also naturally present in food. The safety of additives is evaluated according to commonly agreed principles. If high concentrations of an additive cause adverse health effects for humans, a limit of acceptable daily intake (ADI) is set for it. An additive is a risk only when ADI is exceeded. The healthiness of food is measured on the basis of nutrient density and scientifically proven effects. PMID:24772784

  12. Polyimide processing additives

    NASA Technical Reports Server (NTRS)

    Pratt, J. R.; St. Clair, T. L.; Burks, H. D.; Stoakley, D. M.

    1987-01-01

    A method has been found for enhancing the melt flow of thermoplastic polyimides during processing. A high molecular weight 422 copoly(amic acid) or copolyimide was fused with approximately 0.05 to 5 pct by weight of a low molecular weight amic acid or imide additive, and this melt was studied by capillary rheometry. Excellent flow and improved composite properties on graphite resulted from the addition of a PMDA-aniline additive to LARC-TPI. Solution viscosity studies imply that amic acid additives temporarily lower molecular weight and, hence, enlarge the processing window. Thus, compositions containing the additive have a lower melt viscosity for a longer time than those unmodified.

  13. Utilizing dynamic tensiometry to quantify contact angle hysteresis and wetting state transitions on nonwetting surfaces.

    PubMed

    Kleingartner, Justin A; Srinivasan, Siddarth; Mabry, Joseph M; Cohen, Robert E; McKinley, Gareth H

    2013-11-01

    Goniometric techniques traditionally quantify two parameters, the advancing and receding contact angles, that are useful for characterizing the wetting properties of a solid surface; however, dynamic tensiometry, which measures changes in the net force on a surface during the repeated immersion and emersion of a solid into a probe liquid, can provide further insight into the wetting properties of a surface. We detail a framework for analyzing tensiometric results that allows for the determination of wetting hysteresis, wetting state transitions, and characteristic topographical length scales on textured, nonwetting surfaces, in addition to the more traditional measurement of apparent advancing and receding contact angles. Fluorodecyl POSS, a low-surface-energy material, was blended with commercially available poly(methyl methacrylate) (PMMA) and then dip- or spray-coated onto glass substrates. These surfaces were probed with a variety of liquids to illustrate the effects of probe liquid surface tension, solid surface chemistry, and surface texture on the apparent contact angles and wetting hysteresis of nonwetting surfaces. Woven meshes were then used as model structured substrates to add a second, larger length scale for the surface texture. When immersed into a probe liquid, these spray-coated mesh surfaces can form a metastable, solid-liquid-air interface on the largest length scale of surface texture. The increasing hydrostatic pressure associated with progressively greater immersion depths disrupts this metastable, composite interface and forces penetration of the probe liquid into the mesh structure. This transition is marked by a sudden change in the wetting hysteresis, which can be systematically probed using spray-coated, woven meshes of varying wire radius and spacing. We also show that dynamic tensiometry can accurately and quantitatively characterize topographical length scales that are present on microtextured surfaces. PMID:24070378

  14. Use of gait parameters of persons in video surveillance systems

    NASA Astrophysics Data System (ADS)

    Geradts, Zeno J.; Merlijn, Menno; de Groot, Gert; Bijhold, Jurrien

    2002-07-01

    The gait parameters of eleven subjects were evaluated to provide data for recognition purposes of subjects. Video images of these subjects were acquired in frontal, transversal, and sagittal (a plane parallel to the median of the body) view. The subjects walked by at their usual walking speed. The measured parameters were hip, knee and ankle joint angle and their time averaged values, thigh, foot and trunk angle, step length and width, cycle time and walking speed. Correlation coefficients within and between subjects for the hip, knee and ankle rotation pattern in the sagittal aspect and for the trunk rotation pattern in the transversal aspect were almost similar. (were similar or were almost identical) This implies that the intra and inter individual variance were equal. Therefore, these gait parameters could not distinguish between subjects. A simple ANOVA with a follow-up test was used to detect significant differences for the mean hip, knee and ankle joint angle, thigh angle, step length, step width, walking speed, cycle time and foot angle. The number of significant differences between subjects defined the usefulness of the gait parameter. The parameter with the most significant difference between subjects was the foot angle (64 % - 73 % of the maximal attainable significant differences), followed by the time average hip joint angle (58 %) and the step length (45 %). The other parameters scored less than 25 %, which is poor for recognition purposes. The use of gait for identification purposes it not yet possible based on this research.

  15. Experimental study of crossing angle collision

    SciTech Connect

    Chen, T.; Rice, D.; Rubin, D.; Sagan, D.; Tigner, M.

    1993-05-01

    The non-linear coupling due to the beam-beam interaction with crossing angle has been studied. The major effect of a small ({approximately}12mrad) crossing angle is to excite 5Q{sub x}{plus_minus}Q{sub s}=integer coupling resonance family on large amplitude particles, which results in bad lifetime. On the CESR, a small crossing angle ({approximately}2.4mr) was created at the IP and a reasonable beam-beam tune-shift was achieved. The decay rate of the beam is measured as a function of horizontal tune with and without crossing angle. The theoretical analysis, simulation and experimental measurements have a good agreement. The resonance strength as a function of crossing angle is also measured.

  16. Let's Do It! Using Geostrips and "Angle-Fixers" to Develop Ideas About Shapes and Angles

    ERIC Educational Resources Information Center

    Bruni, James V.; Silverman, Helene

    1975-01-01

    Homemade geostrips, "angle-fixers" (cardboard circular sectors) and brass fasteners can be used by students to explore properties of angles, triangles and other polygons. Several games and other activities are suggested. (SD)

  17. Implications of the small aspect angles of equatorial spread F

    SciTech Connect

    Hysell, D.L.; Farley, D.T.

    1996-03-01

    Small-scale equatorial spread F irregularities are almost perfectly aligned with the geomagnetic field. The authors develop here an analytic plasma kinetic theory of small-scale, quasi-field-aligned irregularities that include ion viscosity and finite Larmor radius effects. They conclude, for one thing, that the measured aspect angles are too small to be consistent with a dissipative drift wave source of 3-m irregularities. Nonlinearly driven flute modes appear to be the only available mechanism. The authors compare the relative influence of parallel and perpendicular dissipation and conclude that the aspect width depends only weakly on any single geophysical parameters, such as collision frequency, gradient length, temperature, etc. This finding is consistent with their observation that the measured aspect angles vary little with altitude and only weakly with instability level. 29 refs., 5 figs.

  18. Water adsorption kinetics and contact angles of pharmaceutical powders.

    PubMed

    Muster, Tim H; Prestidge, Clive A

    2005-04-01

    Water sorption kinetics and water contact angles have been characterized for a range of pharmaceutical powders: ambroxol hydrochloride, griseofulvin, N,n-octyl-D-gluconamide, paracetamol, sulfathiazole, and theophylline. The uptake of water by powder samples at saturated vapor pressure was modeled using a pseudo first-order kinetic relationship. Parameters from this model have been correlated with the concentration and reactivity of the active surface sites of the pharmaceutical powders and their contact angles. The study has shown that analysis of water adsorption kinetics can be a powerful technique for characterizing the surface chemistry and wettability of pharmaceutical powders, and is particularly sensitive to their surface modification through excipient adsorption: ethyl(hydroxyethyl)cellulose treatment of griseofulvin and butyryl chloride treatment of sulfathiazole are reported as case studies. PMID:15736196

  19. Buffeting of NACA 0012 airfoil at high angle of attack

    NASA Astrophysics Data System (ADS)

    Zhou, Tong; Dowell, Earl

    2014-11-01

    Buffeting is a fluid instability caused by flow separation or shock wave oscillations in the flow around a bluff body. Typically there is a dominant frequency of these flow oscillations called Strouhal or buffeting frequency. In prior work several researchers at Duke University have noted the analogy between the classic Von Karman Vortex Street behind a bluff body and the flow oscillations that occur for flow around a NACA 0012 airfoil at sufficiently large angle of attack. Lock-in is found for certain combinations of airfoil oscillation (pitching motion) frequencies and amplitudes when the frequency of the airfoil motion is sufficiently close to the buffeting frequency. The goal of this paper is to explore the flow around a static and an oscillating airfoil at high angle of attack by developing a method for computing buffet response. Simulation results are compared with experimental data. Conditions for the onset of buffeting and lock-in of a NACA 0012 airfoil at high angle of attack are determined. Effects of several parameters on lift coefficient and flow response frequency are studied including Reynolds number, angle of attack and blockage ratio of the airfoil size to the wind tunnel dimensions. Also more detailed flow field characteristics are determined. For a static airfoil, a universal Strouhal number scaling has been found for angles of attack from 30° to 90°, where the flow around airfoil is fully separated. For an oscillating airfoil, conditions for lock-in are discussed. Differences between the lock-in case and the unlocked case are also studied. The second affiliation: Duke University.

  20. In situ estimation of sediment sound speed and critical angle

    PubMed

    Maguer; Bovio; Fox; Schmidt

    2000-09-01

    Understanding the basic physics of sound penetration into ocean sediments is essential for the design of sonar systems that can detect, localize, classify, and identify buried objects. In this regard the sound speed of the sediment is a crucial parameter as the ratio of sound speed at the water-sediment interface determines the critical angle. Sediment sound speed is typically measured from core samples using high frequency (100's of kHz) pulsed travel time measurements. Earlier experimental work on subcritical penetration into sandy sediments has suggested that the effective sound speed in the 2-20 kHz range is significantly lower than the core measurement results. Simulations using Biot theory for propagation in porous media confirmed that sandy sediments may be highly dispersive in the range 1-100 kHz for the type of sand in which the experiments were performed. Here it is shown that a direct and robust estimate of the critical angle, and therefore the sediment sound speed, at the lower frequencies can be achieved by analyzing the grazing angle dependence of the phase delays observed on a buried array. A parametric source with secondary frequencies in the 2-16 kHz range was directed toward a sandy bottom similar to the one investigated in the earlier study. An array of 14 hydrophones was used to measure penetrated field. The critical angle was estimated by analyzing the variations of signal arrival times versus frequency, burial depth, and grazing angle. Matching the results with classical transmission theory yielded a sound speed estimate in the sand of 1626 m/s in the frequency range 2-5 kHz, again significantly lower the 1720 m/s estimated from the cores at 200 kHz. However, as described here, this dispersion is consistent with the predictions of the Biot theory for this type of sand. PMID:11008802

  1. Measurement of Capillary Radius and Contact Angle within Porous Media.

    PubMed

    Ravi, Saitej; Dharmarajan, Ramanathan; Moghaddam, Saeed

    2015-12-01

    The pore radius (i.e., capillary radius) and contact angle determine the capillary pressure generated in a porous medium. The most common method to determine these two parameters is through measurement of the capillary pressure generated by a reference liquid (i.e., a liquid with near-zero contact angle) and a test liquid. The rate of rise technique, commonly used to determine the capillary pressure, results in significant uncertainties. In this study, we utilize a recently developed technique for independently measuring the capillary pressure and permeability to determine the equivalent minimum capillary radii and contact angle of water within micropillar wick structures. In this method, the experimentally measured dryout threshold of a wick structure at different wicking lengths is fit to Darcy's law to extract the maximum capillary pressure generated by the test liquid. The equivalent minimum capillary radii of different wick geometries are determined by measuring the maximum capillary pressures generated using n-hexane as the working fluid. It is found that the equivalent minimum capillary radius is dependent on the diameter of pillars and the spacing between pillars. The equivalent capillary radii of micropillar wicks determined using the new method are found to be up to 7 times greater than the current geometry-based first-order estimates. The contact angle subtended by water at the walls of the micropillars is determined by measuring the capillary pressure generated by water within the arrays and the measured capillary radii for the different geometries. This mean contact angle of water is determined to be 54.7°. PMID:26538412

  2. Parameter estimation for distributed parameter models of complex, flexible structures

    NASA Technical Reports Server (NTRS)

    Taylor, Lawrence W., Jr.

    1991-01-01

    Distributed parameter modeling of structural dynamics has been limited to simple spacecraft configurations because of the difficulty of handling several distributed parameter systems linked at their boundaries. Although there is other computer software able to generate such models or complex, flexible spacecraft, unfortunately, neither is suitable for parameter estimation. Because of this limitation the computer software PDEMOD is being developed for the express purposes of modeling, control system analysis, parameter estimation and structure optimization. PDEMOD is capable of modeling complex, flexible spacecraft which consist of a three-dimensional network of flexible beams and rigid bodies. Each beam has bending (Bernoulli-Euler or Timoshenko) in two directions, torsion, and elongation degrees of freedom. The rigid bodies can be attached to the beam ends at any angle or body location. PDEMOD is also capable of performing parameter estimation based on matching experimental modal frequencies and static deflection test data. The underlying formulation and the results of using this approach for test data of the Mini-MAST truss will be discussed. The resulting accuracy of the parameter estimates when using such limited data can impact significantly the instrumentation requirements for on-orbit tests.

  3. Analysis and design of wide-angle foveated optical systems

    NASA Astrophysics Data System (ADS)

    Curatu, George

    2009-12-01

    different fast wide-angle lens designs that can be used to build practical FOSs were developed, revealing additional challenges specific to the optical design of fast wide-angle systems, such as controlling the relative illumination, distortion, and distribution of aberrations across a wide FOV. One of the lens design examples was chosen as a study case to demonstrate the design, analysis, and optimization of a practical wide-angle FOS based on the current state-of-the-art transmissive LC SLM technology. The effects of fabrication and assembly tolerances on the image quality of fast wide-angle FOSs were also investigated, revealing the sensitivity of these fast well-corrected optical systems to manufacturing errors. The theoretical study presented in this dissertation sets fundamental analysis, design, and optimization guidelines for future developments in fast wide-angle FOSs based on transmissive SLM devices.

  4. Optical Enhancement of Exoskeleton-Based Estimation of Glenohumeral Angles

    PubMed Central

    Cortés, Camilo; Unzueta, Luis; de los Reyes-Guzmán, Ana; Ruiz, Oscar E.; Flórez, Julián

    2016-01-01

    In Robot-Assisted Rehabilitation (RAR) the accurate estimation of the patient limb joint angles is critical for assessing therapy efficacy. In RAR, the use of classic motion capture systems (MOCAPs) (e.g., optical and electromagnetic) to estimate the Glenohumeral (GH) joint angles is hindered by the exoskeleton body, which causes occlusions and magnetic disturbances. Moreover, the exoskeleton posture does not accurately reflect limb posture, as their kinematic models differ. To address the said limitations in posture estimation, we propose installing the cameras of an optical marker-based MOCAP in the rehabilitation exoskeleton. Then, the GH joint angles are estimated by combining the estimated marker poses and exoskeleton Forward Kinematics. Such hybrid system prevents problems related to marker occlusions, reduced camera detection volume, and imprecise joint angle estimation due to the kinematic mismatch of the patient and exoskeleton models. This paper presents the formulation, simulation, and accuracy quantification of the proposed method with simulated human movements. In addition, a sensitivity analysis of the method accuracy to marker position estimation errors, due to system calibration errors and marker drifts, has been carried out. The results show that, even with significant errors in the marker position estimation, method accuracy is adequate for RAR. PMID:27403044

  5. Oscillations of relative inclination angles in compact extrasolar planetary systems

    NASA Astrophysics Data System (ADS)

    Becker, Juliette C.; Adams, Fred C.

    2016-01-01

    The Kepler mission has detected dozens of compact planetary systems with more than four transiting planets. This sample provides a collection of close-packed planetary systems with relatively little spread in the inclination angles of the inferred orbits. A large fraction of the observational sample contains limited multiplicity, begging the question whether there is a true diversity of multitransiting systems, or if some systems merely possess high mutual inclinations, allowing them to appear as single-transiting systems in a transit-based survey. This paper begins an exploration of the effectiveness of dynamical mechanisms in exciting orbital inclination within exoplanetary systems of this class. For these tightly packed systems, we determine that the orbital inclination angles are not spread out appreciably through self-excitation. In contrast, the two Kepler multiplanet systems with additional non-transiting planets are susceptible to oscillations of their inclination angles, which means their currently observed configurations could be due to planet-planet interactions alone. We also provide constraints and predictions for the expected transit duration variations for each planet. In these multiplanet compact Kepler systems, oscillations of their inclination angles are remarkably hard to excite; as a result, they tend to remain continually mutually transiting (CMT-stable). We study this issue further by augmenting the planet masses and determining the enhancement factor required for oscillations to move the systems out of transit. The oscillations of inclination found here inform the recently suggested dichotomy in the sample of Solar systems observed by Kepler.

  6. X-31 high angle of attack control system performance

    NASA Technical Reports Server (NTRS)

    Huber, Peter; Seamount, Patricia

    1994-01-01

    The design goals for the X-31 flight control system were: (1) level 1 handling qualities during post-stall maneuvering (30 to 70 degrees angle-of-attack); (2) thrust vectoring to enhance performance across the flight envelope; and (3) adequate pitch-down authority at high angle-of-attack. Additional performance goals are discussed. A description of the flight control system is presented, highlighting flight control system features in the pitch and roll axes and X-31 thrust vectoring characteristics. The high angle-of-attack envelope clearance approach will be described, including a brief explanation of analysis techniques and tools. Also, problems encountered during envelope expansion will be discussed. This presentation emphasizes control system solutions to problems encountered in envelope expansion. An essentially 'care free' envelope was cleared for the close-in-combat demonstrator phase. High angle-of-attack flying qualities maneuvers are currently being flown and evaluated. These results are compared with pilot opinions expressed during the close-in-combat program and with results obtained from the F-18 HARV for identical maneuvers. The status and preliminary results of these tests are discussed.

  7. Optical Enhancement of Exoskeleton-Based Estimation of Glenohumeral Angles.

    PubMed

    Cortés, Camilo; Unzueta, Luis; de Los Reyes-Guzmán, Ana; Ruiz, Oscar E; Flórez, Julián

    2016-01-01

    In Robot-Assisted Rehabilitation (RAR) the accurate estimation of the patient limb joint angles is critical for assessing therapy efficacy. In RAR, the use of classic motion capture systems (MOCAPs) (e.g., optical and electromagnetic) to estimate the Glenohumeral (GH) joint angles is hindered by the exoskeleton body, which causes occlusions and magnetic disturbances. Moreover, the exoskeleton posture does not accurately reflect limb posture, as their kinematic models differ. To address the said limitations in posture estimation, we propose installing the cameras of an optical marker-based MOCAP in the rehabilitation exoskeleton. Then, the GH joint angles are estimated by combining the estimated marker poses and exoskeleton Forward Kinematics. Such hybrid system prevents problems related to marker occlusions, reduced camera detection volume, and imprecise joint angle estimation due to the kinematic mismatch of the patient and exoskeleton models. This paper presents the formulation, simulation, and accuracy quantification of the proposed method with simulated human movements. In addition, a sensitivity analysis of the method accuracy to marker position estimation errors, due to system calibration errors and marker drifts, has been carried out. The results show that, even with significant errors in the marker position estimation, method accuracy is adequate for RAR. PMID:27403044

  8. Method on camouflaged target recognition using the angle of ellipsometry

    NASA Astrophysics Data System (ADS)

    Zhuansun, Xiao-bo; Wu, Wen-Yuan; Huang, Yan-hua; Li, Zhao-zhao

    2015-10-01

    Using polarimetric information of the camouflaged target surface to identify camouflage has been a hot research area in camouflage detecting. The main method is to use the difference in the degree of polarization(DOP) between background and target to add the contrast ratio of them. The measurement of the DOP has some requirements on the intensity of reflected radiation. In case of low reflected radiation intensity, the difference in the DOP for different materials is not so distinguishable. In addition, the linear degree of polarization is largely under the effects of detection angle and surface roughness, so it is hard to differentiate the degree of polarization when the targets with similar surface roughness are detected at the same detection angle. By analyzing the elements affecting the reflected electromagnetic radiation amplitudes and phase on the camouflaged target surface, this article makes a research on the polarization character of reflected radiation A method on camouflaged target recognition directly or indirectly by taking the angle of ellipsometry (AOE) imaging under the linear polarized light. The function model of the angle of incidence, complex refractive index and AOE was modeled, then the model was simulated by MATLAB and the results showed it can describe the distribution properties of AOE. A new thought for the approach of identifying camouflaged target recognition by detecting polarimetric information was proposed, and it has a deep theoretical and practical significance in camouflaged target recognition.

  9. Additive usage levels.

    PubMed

    Langlais, R

    1996-01-01

    With the adoption of the European Parliament and Council Directives on sweeteners, colours and miscellaneous additives the Commission is now embarking on the project of coordinating the activities of the European Union Member States in the collection of the data that are to make up the report on food additive intake requested by the European Parliament. This presentation looks at the inventory of available sources on additive use levels and concludes that for the time being national legislation is still the best source of information considering that the directives have yet to be transposed into national legislation. Furthermore, this presentation covers the correlation of the food categories as found in the additives directives with those used by national consumption surveys and finds that in a number of instances this correlation still leaves a lot to be desired. The intake of additives via food ingestion and the intake of substances which are chemically identical to additives but which occur naturally in fruits and vegetables is found in a number of cases to be higher than the intake of additives added during the manufacture of foodstuffs. While the difficulties are recognized in contributing to the compilation of food additive intake data, industry as a whole, i.e. the food manufacturing and food additive manufacturing industries, are confident that in a concerted effort, use data on food additives by industry can be made available. Lastly, the paper points out that with the transportation of the additives directives into national legislation and the time by which the food industry will be able to make use of the new food legislative environment several years will still go by; food additives use data by the food industry will thus have to be reviewed at the beginning of the next century. PMID:8792135

  10. An additional middle cuneiform?

    PubMed Central

    Brookes-Fazakerley, S.D.; Jackson, G.E.; Platt, S.R.

    2015-01-01

    Additional cuneiform bones of the foot have been described in reference to the medial bipartite cuneiform or as small accessory ossicles. An additional middle cuneiform has not been previously documented. We present the case of a patient with an additional ossicle that has the appearance and location of an additional middle cuneiform. Recognizing such an anatomical anomaly is essential for ruling out second metatarsal base or middle cuneiform fractures and for the preoperative planning of arthrodesis or open reduction and internal fixation procedures in this anatomical location. PMID:26224890

  11. Vortex age as a wake turbulence scaling parameter

    NASA Technical Reports Server (NTRS)

    Marshall, J. R.; Marchman, J. F., III

    1973-01-01

    Research which was conducted to determine the significance of vortex age as a scaling parameter in wake turbulence development and dissipation is reported. Tests were conducted at three angles of attack, three free stream speeds, and seven downstream positions from 2 to 30 chordlengths using an NACA 0012 wing and a five hole yawhead pitot probe. The end surface of the wing tip was flat. Speeds were selected to give a predetermined range of vortex ages. The complete velocity structure of the vortex was measured at each station and speed. The resulting plots of maximum tangential velocity and vortex core diameter versus downstream distance and vortex age indicate that vortex age is not a self sufficient scaling parameter. In addition to the expected effect of lift coefficient there is also a definite free stream speed influence at high wing angles of attack. The exact cause and nature of this effect is not fully understood, but it does not appear to be explainable in terms of Mach number or Reynolds number; however, the influence of tip edge shape on spanwise flow separation appears to be an important factor.

  12. Automatic Kappa Angle Estimation for Air Photos Based on Phase Only Correlation

    NASA Astrophysics Data System (ADS)

    Xiong, Z.; Stanley, D.; Xin, Y.

    2016-06-01

    The approximate value of exterior orientation parameters is needed for air photo bundle adjustment. Usually the air borne GPS/IMU can provide the initial value for the camera position and attitude angle. However, in some cases, the camera's attitude angle is not available due to lack of IMU or other reasons. In this case, the kappa angle needs to be estimated for each photo before bundle adjustment. The kappa angle can be obtained from the Ground Control Points (GCPs) in the photo. Unfortunately it is not the case that enough GCPs are always available. In order to overcome this problem, an algorithm is developed to automatically estimate the kappa angle for air photos based on phase only correlation technique. This function has been embedded in PCI software. Extensive experiments show that this algorithm is fast, reliable, and stable.

  13. Design of second order grating couplers to detect the angle and polarization of the laser beam

    NASA Astrophysics Data System (ADS)

    Saha, Tapas Kumar; Lu, Mingyu; Zhao, Deyin; Ma, Zhenqiang; Zhou, Weidong

    2012-03-01

    On-chip laser beam tracking finds innumerable applications. Popularly adopted quadrant photodiodes can only detect laser beam's angle variation up to 0.2° reliably. In this paper, a novel angle detector is designed based on grating coupling. It consists of a grating layer on top of a silicon-on-insulator slab waveguide. The incident light is coupled into guided modes within the waveguide via the grating layer, and then, the incident light's angle can be determined by reading the outputs of light detectors within the waveguide. Performance of the laser angle detector in this paper is demonstrated by full-wave finite-difference-time-domain simulations. Numerical results show that, the detectable angle range can be adjusted by several design parameters and can reach [-4°, 4°]. The device structure in this paper can be straightforwardly extended to two-dimensional photonic crystal configurations.

  14. Experimental observation of moiré angles in parallax barrier 3D displays.

    PubMed

    Saveljev, Vladimir; Kim, Sung-Kyu

    2014-07-14

    Angles of visible moiré patterns are observed experimentally. Experiments were made across the angular range 0 - 90° in a wide range of parameters. Two kinds of clusterization were observed, ray and discrete. In rational cells (LCD pixels), the moiré patterns appear at a few fixed discrete angles. The list of preferable moiré-less angles is presented basing on the experimental data; preferable areas in the parameter space are found. The problem of minimization of the moiré effect is formulated as the Diophantine inequality with complex coefficients. The classification of moiré angles basing on the probability of the moiré effect can be practically useful. PMID:25090529

  15. Mandibular Angle Fractures: Comparison of One Miniplate vs. Two Miniplates

    PubMed Central

    Yazdani, Javad; Taheri Talesh, Kourosh; Kalantar Motamedi, Mohammad Hosein; Khorshidi, Reza; Fekri, Sasan; Hajmohammadi, Saeed

    2013-01-01

    Background Monocortical miniplate fixation is an accepted and reliable method for internal fixation of mandibular angle fractures. Although placement of a second miniplate may theoretically provide more stability; however, the clinical importance of this issue remains controversial. Objectives The present study assessed the postoperative complications and outcomes associated with the fixation of mandibular angle fractures using 1 and 2 miniplates in patients with favorable mandibular angle fractures. Patients and Methods A prospective study of 87 patients (73 males, 14 females) with favorable mandibular angle fractures was done. In the first group, a 4-hole miniplate was placed at the superior border through an intraoral approach. In group 2, patients were treated with 2 miniplates, one placed at the superior border (similar to group 1) and the other on the lateral aspect of the angle at the inferior border through an intraoral and transcutaneous approach using a trocar. Postoperative complications including malocclusion, malunion and sensory disturbances associated with surgery, additional maxillomandibular fixation (MMF) by means of an arch bar and wires for a longer period (for delayed union) and infection were assessed in patients of both groups up to 12 months postoperatively. The data were analyzed using the chi-square test. Results In the single miniplate group, 25 patients showed lip numbness associated with surgery (55.6%), 22 patients required additional use of MMF (48.9%) and 3 patients developed infections (6.7%). In the double miniplate group 20 patients showed lip numbness associated with surgery (47.6%), 18 patients required additional use of MMF (42.9%) and 1 patient developed infection (2.4%). None of the patients in either group showed malocclusion or malunion. No significant difference was observed between the groups regarding overall complication rate. Conclusions In this study, use of one miniplate or two miniplates for treatment of favorable

  16. The influence of incidence angle on the aerodynamics of condensing flow around a rotor tip section of steam turbine

    NASA Astrophysics Data System (ADS)

    Beheshti Amiri, H.; Salmaniyeh, F.; Izadi, A.

    2016-01-01

    In this paper, the influence of incidence angle on the aerodynamics of the steam flow field around a rotor tip section is investigated. An Eulerian-Eulerian method, based on a non-equilibrium thermodynamics model for simulating the wet flow is employed. In this study, the effects of incidence angle on different design parameters such as: outflow Mach number, outflow gas phase mass fraction, loss coefficient and deviation angle are studied.

  17. CHARMM Additive All-Atom Force Field for Aldopentofuranoses, Methyl-Aldopentofuranosides and Fructofuranose

    PubMed Central

    Hatcher, Elizabeth; Guvench, Olgun; MacKerell, Alexander D.

    2009-01-01

    An additive all-atom empirical force field for aldopentofuranoses, methyl-aldopentofuranosides (Me-aldopentofuranosides) and fructofuranose carbohydrates, compatible with existing CHARMM carbohydrate parameters, is presented. Building on existing parameters transferred from cyclic ethers and hexopyranoses, parameters were further developed using target data for complete furanose carbohydrates as well as O-methyl tetrahydrofuran. The bond and angle equilibrium parameters were adjusted to reproduce target geometries from a survey of furanose crystal structures, and dihedral parameters were fit to over 1700 quantum mechanical (QM) MP2/cc-pVTZ//MP2/6-31G(d) conformational energies. The conformational energies were for a variety of complete furanose monosaccharides, and included two-dimensional ring pucker energy surfaces. Bonded parameter optimization led to the correct description of the ring pucker for a large set of furanose compounds, while furanose-water interaction energies and distances reproduced QM HF/6-31G(d) results for a number of furanose monosaccharides, thereby validating the nonbonded parameters. Crystal lattice unit cell parameters and volumes, aqueous-phase densities, and aqueous NMR ring pucker and exocyclic data were used to validate the parameters in condensed-phase environments. Conformational sampling analysis of the ring pucker and exocyclic group showed excellent agreement with experimental NMR data, demonstrating that the conformational energetics in aqueous solution are accurately described by the optimized force field. Overall, the parameters reproduce available experimental data well and are anticipated to be of utility in future computational studies of carbohydrates, including in the context of proteins, nucleic acids and/or lipids when combined with existing CHARMM biomolecular force fields. PMID:19694450

  18. Branes at angles from worldvolume actions

    NASA Astrophysics Data System (ADS)

    Abbaspur, Reza

    2016-05-01

    We investigate possible stable configurations of two arbitrary branes at general angles using the dynamics of DBI + WZ action. The analysis naturally reveals two types of solutions which we identify as the "marginal" and "non-marginal" configurations. We characterize possible configurations of a pair of identical or non-identical branes in either of these two classes by specifying their proper intersection rules and allowed intersection angles. We also perform a partial analysis of configurations with multiple angles of a system of asymptotically flat curved branes.

  19. Phase-angle controller for Stirling engines

    SciTech Connect

    Frosch, R.A.; McDougal, A.R.

    1980-12-23

    A first embodiment incorporating an actuator including a restraint link adapted to be connected with a pivotal carrier arm for a force transfer gear interposed between the crankshaft for an expander portion of a stirling engine and a crankshaft for the displacer portion of the engine is described. The restraint link is releasably supported against axial displacement by releasably trapped hydraulic fluid for selectively establishing a phase angle relationship between the crankshaft and a second embodiment incorporating a hydraulic coupler for use in varying the phase angle of gear-coupled crankshafts for a Stirling engine whereby phase angle changes are obtainable.

  20. Phase-angle controller for Stirling engines

    NASA Technical Reports Server (NTRS)

    Mcdougal, A. R. (Inventor)

    1980-01-01

    An actuator includes a restraint link adapted to be connected with a pivotal carrier arm for a force transfer gear interposed between the crankshaft for an expander portion of a Stirling engine and a crankshaft for the displacer portion of the engine. The restraint link is releasably trapped hydraulic fluid for selectively establishing a phase angle relationship between the crankshaft. A second embodiment incorporates a hydraulic coupler for use in varying the phase angle of gear-coupled crank fpr a Stirling engine whereby phase angle changes are obtainable.

  1. Wide-angle vision for road views

    NASA Astrophysics Data System (ADS)

    Huang, F.; Fehrs, K.-K.; Hartmann, G.; Klette, R.

    2013-03-01

    The field-of-view of a wide-angle image is greater than (say) 90 degrees, and so contains more information than available in a standard image. A wide field-of-view is more advantageous than standard input for understanding the geometry of 3D scenes, and for estimating the poses of panoramic sensors within such scenes. Thus, wide-angle imaging sensors and methodologies are commonly used in various road-safety, street surveillance, street virtual touring, or street 3D modelling applications. The paper reviews related wide-angle vision technologies by focusing on mathematical issues rather than on hardware.

  2. Carbamate deposit control additives

    SciTech Connect

    Honnen, L.R.; Lewis, R.A.

    1980-11-25

    Deposit control additives for internal combustion engines are provided which maintain cleanliness of intake systems without contributing to combustion chamber deposits. The additives are poly(oxyalkylene) carbamates comprising a hydrocarbyloxyterminated poly(Oxyalkylene) chain of 2-5 carbon oxyalkylene units bonded through an oxycarbonyl group to a nitrogen atom of ethylenediamine.

  3. Validating Solution Ensembles from Molecular Dynamics Simulation by Wide-Angle X-ray Scattering Data

    PubMed Central

    Chen, Po-chia; Hub, Jochen S.

    2014-01-01

    Wide-angle x-ray scattering (WAXS) experiments of biomolecules in solution have become increasingly popular because of technical advances in light sources and detectors. However, the structural interpretation of WAXS profiles is problematic, partly because accurate calculations of WAXS profiles from structural models have remained challenging. In this work, we present the calculation of WAXS profiles from explicit-solvent molecular dynamics (MD) simulations of five different proteins. Using only a single fitting parameter that accounts for experimental uncertainties because of the buffer subtraction and dark currents, we find excellent agreement to experimental profiles both at small and wide angles. Because explicit solvation eliminates free parameters associated with the solvation layer or the excluded solvent, which would require fitting to experimental data, we minimize the risk of overfitting. We further find that the influence from water models and protein force fields on calculated profiles are insignificant up to q≈15nm−1. Using a series of simulations that allow increasing flexibility of the proteins, we show that incorporating thermal fluctuations into the calculations significantly improves agreement with experimental data, demonstrating the importance of protein dynamics in the interpretation of WAXS profiles. In addition, free MD simulations up to one microsecond suggest that the calculated profiles are highly sensitive with respect to minor conformational rearrangements of proteins, such as an increased flexibility of a loop or an increase of the radius of gyration by < 1%. The present study suggests that quantitative comparison between MD simulations and experimental WAXS profiles emerges as an accurate tool to validate solution ensembles of biomolecules. PMID:25028885

  4. Multi-Parameter Scattering Sensor and Methods

    NASA Technical Reports Server (NTRS)

    Greenberg, Paul S. (Inventor); Fischer, David G. (Inventor)

    2016-01-01

    Methods, detectors and systems detect particles and/or measure particle properties. According to one embodiment, a detector for detecting particles comprises: a sensor for receiving radiation scattered by an ensemble of particles; and a processor for determining a physical parameter for the detector, or an optimal detection angle or a bound for an optimal detection angle, for measuring at least one moment or integrated moment of the ensemble of particles, the physical parameter, or detection angle, or detection angle bound being determined based on one or more of properties (a) and/or (b) and/or (c) and/or (d) or ranges for one or more of properties (a) and/or (b) and/or (c) and/or (d), wherein (a)-(d) are the following: (a) is a wavelength of light incident on the particles, (b) is a count median diameter or other characteristic size parameter of the particle size distribution, (c) is a standard deviation or other characteristic width parameter of the particle size distribution, and (d) is a refractive index of particles.

  5. Improved wide-angle, fisheye and omnidirectional camera calibration

    NASA Astrophysics Data System (ADS)

    Urban, Steffen; Leitloff, Jens; Hinz, Stefan

    2015-10-01

    In this paper an improved method for calibrating wide-angle, fisheye and omnidirectional imaging systems is presented. We extend the calibration procedure proposed by Scaramuzza et al. by replacing the residual function and joint refinement of all parameters. In doing so, we achieve a more stable, robust and accurate calibration (up to factor 7) and can reduce the number of necessary calibration steps from five to three. After introducing the camera model and highlighting the differences from the current calibration procedure, we perform a comprehensive performance evaluation using several data sets and show the impact of the proposed calibration procedure on the calibration results.

  6. Misorientation-angle-dependent electrical transport across molybdenum disulfide grain boundaries.

    PubMed

    Ly, Thuc Hue; Perello, David J; Zhao, Jiong; Deng, Qingming; Kim, Hyun; Han, Gang Hee; Chae, Sang Hoon; Jeong, Hye Yun; Lee, Young Hee

    2016-01-01

    Grain boundaries in monolayer transition metal dichalcogenides have unique atomic defect structures and band dispersion relations that depend on the inter-domain misorientation angle. Here, we explore misorientation angle-dependent electrical transport at grain boundaries in monolayer MoS2 by correlating the atomic defect structures of measured devices analysed with transmission electron microscopy and first-principles calculations. Transmission electron microscopy indicates that grain boundaries are primarily composed of 5-7 dislocation cores with periodicity and additional complex defects formed at high angles, obeying the classical low-angle theory for angles <22°. The inter-domain mobility is minimized for angles <9° and increases nonlinearly by two orders of magnitude before saturating at ∼ 16 cm(2) V(-1) s(-1) around misorientation angle ≈ 20°. This trend is explained via grain-boundary electrostatic barriers estimated from density functional calculations and experimental tunnelling barrier heights, which are ≈ 0.5 eV at low angles and ≈ 0.15 eV at high angles (≥ 20°). PMID:26813605

  7. Misorientation-angle-dependent electrical transport across molybdenum disulfide grain boundaries

    NASA Astrophysics Data System (ADS)

    Ly, Thuc Hue; Perello, David J.; Zhao, Jiong; Deng, Qingming; Kim, Hyun; Han, Gang Hee; Chae, Sang Hoon; Jeong, Hye Yun; Lee, Young Hee

    2016-01-01

    Grain boundaries in monolayer transition metal dichalcogenides have unique atomic defect structures and band dispersion relations that depend on the inter-domain misorientation angle. Here, we explore misorientation angle-dependent electrical transport at grain boundaries in monolayer MoS2 by correlating the atomic defect structures of measured devices analysed with transmission electron microscopy and first-principles calculations. Transmission electron microscopy indicates that grain boundaries are primarily composed of 5-7 dislocation cores with periodicity and additional complex defects formed at high angles, obeying the classical low-angle theory for angles <22°. The inter-domain mobility is minimized for angles <9° and increases nonlinearly by two orders of magnitude before saturating at ~16 cm2 V-1 s-1 around misorientation angle~20°. This trend is explained via grain-boundary electrostatic barriers estimated from density functional calculations and experimental tunnelling barrier heights, which are ~0.5 eV at low angles and ~0.15 eV at high angles (>=20°).

  8. View angle tilting echo planar imaging for distortion correction.

    PubMed

    Ahn, Sinyeob; Hu, Xiaoping P

    2012-10-01

    Geometric distortion caused by field inhomogeneity along the phase-encode direction is one of the most prominent artifacts due to a relatively low effective bandwidth along that direction in magnetic resonance echo planar imaging. This work describes a method for correcting in-plane image distortion along the phase-encode direction using a view angle tilting imaging technique in spin-echo echo planar imaging. Spin-echo echo planar imaging with view angle tilting uses the addition of gradient blips along the slice-select direction, concurrently applied with the phase-encode gradient blips, producing an additional phase. This phase effectively offsets an unwanted phase accumulation caused by field inhomogeneity, resulting in the removal of image distortion along the phase-encode direction. The proposed method is simple and straightforward both in implementation and application with no scan time penalty. Therefore, it is readily applicable on commercial scanners without having any customized postprocessing. The efficacy of the spin-echo echo planar imaging with view angle tilting technique in the correction of image distortion is demonstrated in phantom and in vivo brain imaging. PMID:22213567

  9. Improving the minimally invasive approach to mandible angle repair.

    PubMed

    Cole, Patrick; Rottgers, Stephen A; Cameron, Hunter; Hollier, Larry H

    2008-03-01

    Mandible angle fractures can be exceedingly difficult to manage and are associated with the highest complication rate of all mandible fractures. Although technically demanding, minimally invasive plate repair of angle fractures offers minimal morbidity and effective fragment stabilization while providing optimal aesthetic outcome. Although minimally invasive fixation provides attractive results, full mobilization of the operative site is often substantially limited by the inherent nature of local masseteric and deeper tissues. Although access limitations often prompt creation of an additional facial incision, trocar withdrawal into subcutaneous tissue followed by repositioning and deep tissue penetration greatly enhances operative mobility. Although this modification may seem simple, the senior author's experience at several outside institutions demonstrates that surgeons will all-too-often resort to additional facial incisions when access is severely limited. In review of our 5-year experience with minimally invasive angle repair, this straightforward innovation significantly decreased operative challenge, improved instrument range-of-motion, and eased the steep learning curve of these often-difficult procedures. PMID:18362737

  10. SOLARMAX/Electron Pitch Angle Anisotropy Distributions

    NASA Technical Reports Server (NTRS)

    McKenzie, David L.; Anderson, Phillip C.

    2002-01-01

    This final research report summarizes the scientific work performed by The Aerospace Corporation on SOLARMAX/Electron Pitch Angle Anisotropy Distributions. The period of performance was from June 1, 2000 to December 31, 2001.

  11. Gonioscopy in primary angle closure glaucoma.

    PubMed

    Bruno, Christina A; Alward, Wallace L M

    2002-06-01

    Primary angle closure is a condition characterized by obstruction to aqueous humor outflow by the peripheral iris, and results in changes in the iridocorneal angle that are visible through gonioscopic examination. Gonioscopy in these eyes, however, can be difficult. This chapter discusses techniques that might help in the examination. These include beginning the examination with the inferior angle, methods to help in looking over the iris, cycloplegia, locating the corneal wedge, indentation, van Herick estimation, examining the other eye, and topical glycerin. Finally, there is a discussion about the pathology associated with the closed angle, with emphasis on the appearance of iris bombé, plateau iris, and the distinction between iris processes and peripheral anterior synechiae. PMID:15513458

  12. The solid angle through the isosceles triangle

    NASA Astrophysics Data System (ADS)

    Schröer, H.

    We want to determine the solid angle through the isosceles triangle. We use the cosine law for sides and the spherical law of sines. The relation to luminous flux(radiant flux or radiant power) is shown.

  13. The solid angle through the inclined rectangle

    NASA Astrophysics Data System (ADS)

    Schröer, H.

    We want to determine the solid angle through the inclined rectangle. We use the cosine law for sides and the spherical law of sines. The relation to luminous flux(radiant flux or radiant power) is shown.

  14. The solid angle through the vertical rectangle

    NASA Astrophysics Data System (ADS)

    Schröer, H.

    We want to determine the solid angle through the vertical rectangle. We use the cosine law for sides and the spherical law of sines. The relation to luminous flux (radiant flux or radiant power) is shown.

  15. Influence of Process Parameter on Grit Blasting as a Pretreatment Process for Thermal Spraying

    NASA Astrophysics Data System (ADS)

    Bobzin, K.; Öte, M.; Linke, T. F.; Sommer, J.; Liao, X.

    2016-01-01

    In thermal spraying, uncoated substrates usually require roughening. As the most common roughening method, grit blasting increases the surface area and produces undercuts in almost all cases, which facilitate mechanical interlocking and thus promote the bonding between the substrate and coating. The effects of grit blasting parameters, i.e., the particle size, the blasting angle, the stand-off distance, and the pressure, on the resulting surface topography are investigated. Furthermore, the efficiency and wear behavior of the blasting media are analyzed. Influences of three different blasting media, corundum, alumina zirconia, and steel shot, on the surface roughening, are compared. By varying adjusted blasting parameters, different initial conditions (surface topography) are created. Subsequently, the substrate is coated, and the coating bond strength is measured. One of the main results of this publication is that alumina zirconia and steel grit show a longer lifetime than pure alumina as a blasting media. Moreover, it has been shown that the blasting parameters such as grain size, working pressure, and history (wear status) of the abrasive particles have a significant effect on the resulting surface topography. Additionally, systematical analysis in this study shows that the blasting parameters such as stand-off distance and blasting angle have a small influence on the results of the blasting process. Another important conclusion of this study is that the conventional surface parameters that have been analyzed in this study did not turn out to be suitable for describing the relationship between the surface topography of the substrate and resulting bond strength.

  16. Polyimide processing additives

    NASA Technical Reports Server (NTRS)

    Fletcher, James C. (Inventor); Pratt, J. Richard (Inventor); St.clair, Terry L. (Inventor); Stoakley, Diane M. (Inventor); Burks, Harold D. (Inventor)

    1992-01-01

    A process for preparing polyimides having enhanced melt flow properties is described. The process consists of heating a mixture of a high molecular weight poly-(amic acid) or polyimide with a low molecular weight amic acid or imide additive in the range of 0.05 to 15 percent by weight of additive. The polyimide powders so obtained show improved processability, as evidenced by lower melt viscosity by capillary rheometry. Likewise, films prepared from mixtures of polymers with additives show improved processability with earlier onset of stretching by TMA.

  17. Polyimide processing additives

    NASA Technical Reports Server (NTRS)

    Pratt, J. Richard (Inventor); St.clair, Terry L. (Inventor); Stoakley, Diane M. (Inventor); Burks, Harold D. (Inventor)

    1993-01-01

    A process for preparing polyimides having enhanced melt flow properties is described. The process consists of heating a mixture of a high molecular weight poly-(amic acid) or polyimide with a low molecular weight amic acid or imide additive in the range of 0.05 to 15 percent by weight of the additive. The polyimide powders so obtained show improved processability, as evidenced by lower melt viscosity by capillary rheometry. Likewise, films prepared from mixtures of polymers with additives show improved processability with earlier onset of stretching by TMA.

  18. Solar Cell Angle of Incidence Corrections

    NASA Technical Reports Server (NTRS)

    Burger, Dale R.; Mueller, Robert L.

    1995-01-01

    The Mars Pathfinder mission has three different solar arrays each of which sees changes in incidence angle during normal operation. When solar array angle of incidence effects was researched little published data was found. The small amount of-published data created a need to obtain and evaluate such data. The donation of the needed data, which was taken in the fall of 1994, was a major factor in the preparation of this paper.

  19. Nucleation of small-angle boundaries

    SciTech Connect

    Nabarro, F.R.N. |; Wilsdorf, D.K.

    1996-12-01

    The internal stresses induced by the strain gradients in an array of lattice cells delineated by low-angle dislocation boundaries are partially relieved by the creation of new low-angle boundaries. This is shown to be a first-order transition, the new boundaries having finite misorientations. The calculated misorientations both of the new boundaries and of the existing boundaries which provoke the transition agree well with observations.

  20. The magic angle: a solved mystery.

    PubMed

    Jouffrey, B; Schattschneider, P; Hébert, C

    2004-12-01

    We resolve the long-standing mysterious discrepancy between the experimental magic angle in EELS--approximately 2theta(E)--and the quantum mechanical prediction of approximately 4theta(E). A relativistic approach surpassing the usually applied kinematic correction yields a magic angle close to the experimental value. The reason is that the relativistic correction of the inelastic scattering cross section in anisotropic systems is significantly higher than in isotropic ones. PMID:15556701

  1. Angle only tracking with particle flow filters

    NASA Astrophysics Data System (ADS)

    Daum, Fred; Huang, Jim

    2011-09-01

    We show the results of numerical experiments for tracking ballistic missiles using only angle measurements. We compare the performance of an extended Kalman filter with a new nonlinear filter using particle flow to compute Bayes' rule. For certain difficult geometries, the particle flow filter is an order of magnitude more accurate than the EKF. Angle only tracking is of interest in several different sensors; for example, passive optics and radars in which range and Doppler data are spoiled by jamming.

  2. Radiographic Relevance of the Distal Medial Cuneiform Angle in Hallux Valgus Assessment.

    PubMed

    Hatch, Daniel J; Smith, Abigail; Fowler, Troy

    2016-01-01

    The angle formed by the distal articular facet of the medial cuneiform has been evaluated and discussed by various investigators. However, no consistent method has been available to radiograph and measure this entity. The wide variability of the angle is not conducive to comparative analysis. Additionally, investigators have noted that the angles observed (obliquity) vary greatly because of changes in radiographic angle, foot position, rotation of the first ray, and declination of the first metatarsal. Recognizing that these variables exist, we propose a reproducible assessment using digital radiography and application of deformity of correction principles. Our results have indicated a mean distal medial cuneiform angle of 20.69° in normal feet, 23.51° with moderate hallux valgus, and 20.41° with severe hallux valgus deformity. The radiograph beam was kept at 15° from the coronal plane. An inverse relationship was found between the distal medial cuneiform angle and bunion severity. This was in contrast to our expected hypothesis. The overall angle of the first metatarsal-medial cuneiform did, however, correlate with the severity of the bunion deformity (p < .000). The obliquity values and intermetatarsal angles changed in direct relationship to the radiographic projection angle. This illustrates the importance of using standardized radiographic projection angles. We conclude that the 1-dimensional standard anteroposterior radiograph with assessment of the distal medial cuneiform angle cannot adequately demonstrate the pathologic features of hallux valgus. A better indicator appears to be the first metatarsal-medial cuneiform angle. This pathologic entity is a 3-dimensional one that incorporates the joint morphology of the first ray, triplane osseous positioning, and soft tissue imbalances. Perhaps, 3-dimensional computed tomography imaging will provide better insight into this entity. PMID:26359620

  3. Smog control fuel additives

    SciTech Connect

    Lundby, W.

    1993-06-29

    A method is described of controlling, reducing or eliminating, ozone and related smog resulting from photochemical reactions between ozone and automotive or industrial gases comprising the addition of iodine or compounds of iodine to hydrocarbon-base fuels prior to or during combustion in an amount of about 1 part iodine per 240 to 10,000,000 parts fuel, by weight, to be accomplished by: (a) the addition of these inhibitors during or after the refining or manufacturing process of liquid fuels; (b) the production of these inhibitors for addition into fuel tanks, such as automotive or industrial tanks; or (c) the addition of these inhibitors into combustion chambers of equipment utilizing solid fuels for the purpose of reducing ozone.

  4. Food Additives and Hyperkinesis

    ERIC Educational Resources Information Center

    Wender, Ester H.

    1977-01-01

    The hypothesis that food additives are causally associated with hyperkinesis and learning disabilities in children is reviewed, and available data are summarized. Available from: American Medical Association 535 North Dearborn Street Chicago, Illinois 60610. (JG)

  5. Additional Types of Neuropathy

    MedlinePlus

    ... A A Listen En Español Additional Types of Neuropathy Charcot's Joint Charcot's Joint, also called neuropathic arthropathy, ... can stop bone destruction and aid healing. Cranial Neuropathy Cranial neuropathy affects the 12 pairs of nerves ...

  6. 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.

  7. Viewing angle analysis of integral imaging

    NASA Astrophysics Data System (ADS)

    Wang, Hong-Xia; Wu, Chun-Hong; Yang, Yang; Zhang, Lan

    2007-12-01

    Integral imaging (II) is a technique capable of displaying 3D images with continuous parallax in full natural color. It is becoming the most perspective technique in developing next generation three-dimensional TV (3DTV) and visualization field due to its outstanding advantages. However, most of conventional integral images are restricted by its narrow viewing angle. One reason is that the range in which a reconstructed integral image can be displayed with consistent parallax is limited. The other is that the aperture of system is finite. By far many methods , an integral imaging method to enhance the viewing angle of integral images has been proposed. Nevertheless, except Ren's MVW (Maximum Viewing Width) most of these methods involve complex hardware and modifications of optical system, which usually bring other disadvantages and make operation more difficult. At the same time the cost of these systems should be higher. In order to simplify optical systems, this paper systematically analyzes the viewing angle of traditional integral images instead of modified ones. Simultaneously for the sake of cost the research was based on computer generated integral images (CGII). With the analysis result we can know clearly how the viewing angle can be enhanced and how the image overlap or image flipping can be avoided. The result also promotes the development of optical instruments. Based on theoretical analysis, preliminary calculation was done to demonstrate how the other viewing properties which are closely related with the viewing angle, such as viewing distance, viewing zone, lens pitch, and etc. affect the viewing angle.

  8. Primary angle-closure glaucoma: an update.

    PubMed

    Wright, Carrie; Tawfik, Mohammed A; Waisbourd, Michael; Katz, Leslie J

    2016-05-01

    Primary angle-closure glaucoma is potentially a devastating disease, responsible for half of glaucoma-related blindness worldwide. Angle closure is characterized by appositional approximation or contact between the iris and trabecular meshwork. It tends to develop in eyes with shallow anterior chambers, anteriorly positioned or pushed lenses, and angle crowding. Risk of primary angle-closure glaucoma is high among women, the elderly and the hyperopic, and it is most prevalent in Asia. Investigation into genetic mechanisms of glaucoma inheritance is underway. Diagnosis relies on gonioscopy and may be aided by anterior segment optical coherence tomography and ultrasound biomicroscopy. Treatment is designed to control intraocular pressure while monitoring changes to the angle and optic nerve head. Treatment typically begins with medical management through pressure-reducing topical medications. Peripheral iridotomy is often performed to alleviate pupillary block, while laser iridoplasty has been found effective for mechanisms of closure other than pupillary block, such as plateau iris syndrome. Phacoemulsification, with or without goniosynechialysis, both in eyes with existing cataracts and in those with clear lenses, is thus far a viable treatment alternative. Long-term research currently underway will examine its efficacy in cases of angle closure in early stages of the disease. Endoscopic cyclophotocoagulation is another treatment option, which can be combined with cataract surgery. Trabeculectomy remains effective therapy for more advanced cases. PMID:26119516

  9. Determination of the Nip Angle in Roller Compactors With Serrated Rolls.

    PubMed

    Tan, Bernice Mei Jin; Chan, Lai Wah; Heng, Paul Wan Sia

    2016-06-01

    In roller compaction, the nip angle defines the critical transition interface between the slip and nip regions which is used to model material densification behavior and the properties of compacted ribbons. Current methods to determine the nip angle require either sophisticated instrumentation on smooth rolls or input parameters that are difficult to obtain experimentally. In this study, a practical method to determine nip angles for serrated rolls was developed based on mass balance considerations established around the nip region. Experimental input relating to roll geometry, powder density, and mass output from the compactor were required and they could be obtained reliably. The calculated nip angles were validated against those obtained from physical measurements during actual roll compaction. These nip angles were in agreement for various powder formulations containing plastic and brittle materials. The nip angles ranged from 4° to 12° and decreased significantly when the proportion of brittle material increased. Nip angles were also calculated using the widely used Johanson model. However, wall friction measurement on serrated roll surfaces could be impractical. The Johanson model-derived nip angles could differ by 3°-8° just by altering the roughness of the reference wall and this had compromised their reliability. PMID:27238494

  10. Mechanical properties of potato starch modified by moisture content and addition of lubricant

    NASA Astrophysics Data System (ADS)

    Stasiak, Mateusz; Molenda, Marek; Horabik, Józef; Mueller, Peter; Opaliński, Ireneusz

    2014-10-01

    Laboratory testing was conducted to deliver a set of characteristics of structure and mechanical properties of pure starch and starch with an addition of a lubricant - magnesium stearate. Considerable influence of moisture content of potato starch was found in the case of density, parameters of internal friction, coefficients of wall friction and flowability. Elasticity was found to be strongly influenced by water content of the material. Addition of magnesium stearate affected density and parameters of flowability, internal friction and elasticity. Bulk density increased from 604 to 774 kg m-3 with decrease in moisture content of potato starch from 17 to for 6%. Addition of magnesium stearate resulted in approximately 10% decrease in bulk density. Angle of internal friction obtained for 10 kPa of consolidation stress decreased from 33 to 24º with increase in moisture content, and to approximately 22º with addition of the lubricant. With an increase of moisture content from 6 to 18% and with addition of the lubricant, the modulus of elasticity during loading decreased from approximately 1.0 to 0.1 MPa. Modulus of elasticity during unloading was found in the range from 19 to 42 MPa and increased with increase of moisture content and amount of lubricant.

  11. Forebody tangential blowing for control at high angles of attack

    NASA Technical Reports Server (NTRS)

    Kroo, I.; Rock, S.; Roberts, L.

    1991-01-01

    A feasibility study to determine if the use of tangential leading edge blowing over the forebody could produce effective and practical control of the F-18 HARV aircraft at high angles of attack was conducted. A simplified model of the F-18 configuration using a vortex-lattice model was developed to obtain a better understanding of basic aerodynamic coupling effects and the influence of forebody circulation on lifting surface behavior. The effect of tangential blowing was estimated using existing wind tunnel data on normal forebody blowing and analytical studies of tangential blowing over conical forebodies. Incorporation of forebody blowing into the flight control system was investigated by adding this additional yaw control and sideforce generating actuator into the existing F-18 HARV simulation model. A control law was synthesized using LQG design methods that would schedule blowing rates as a function of vehicle sideslip, angle of attack, and roll and yaw rates.

  12. Angle resolved electron energy loss spectroscopy on graphite

    NASA Astrophysics Data System (ADS)

    Diebold, U.; Preisinger, A.; Schattschneider, P.; Varga, P.

    We report on angle resolved electron energy loss spectroscopy (EELS) in reflection mode with low primary energy on a graphite single crystal. Measurements with primary electron energy of 175 eV have been performed in off-Bragg-reflex geometry in two different directions within the (0001) surface plane of the graphite single crystal. In addition, EELS measurements in specular reflection mode with different primary energies and angles of incidence were done in order to distinguish between surface and bulk plasmon losses. The energy losses and the transferred momenta of the losses have been analyzed. The results are compared with the loss functions for bulk and surface excitations calculated from the dielectric function ɛ(ω, q) obtained from TEELS-data (EELS in transmission mode) [Springer Tracts Mod. Phys. 54 (1970) 77].

  13. Serous retinal detachment after trabeculectomy in angle recession glaucoma

    PubMed Central

    Roy, Avik Kumar; Padhy, Debananda

    2015-01-01

    An 18-year-old male with 360 degree angle recession after blunt trauma in his right eye developed uncontrolled intraocular pressure (IOP) despite four antiglaucoma medications (AGM) with advancing disc damage. He underwent trabeculectomy with intraoperative mitomycin-c (MMC) application. There was an intraoperative vitreous prolapse which was managed accordingly. On post-surgery day 1, he had shallow choroidal detachment superiorly with non-recordable IOP. This was deteriorated 1 week postoperatively as choroidal detachment proceeded to serous retinal detachment. He was started with systemic steroid in addition to topical route. The serous effusions subsided within 2 weeks time. At the last follow up at 3 months, he was enjoying good visual acuity, deep anterior chamber, diffuse bleb, an IOP in low teens off any AGM and attached retina. This case highlights the rare occurrence of serous retinal detachment after surgical management of angle recession glaucoma.

  14. Fuzzy adaptive strong tracking scaled unscented Kalman filter for initial alignment of large misalignment angles.

    PubMed

    Li, Jing; Song, Ningfang; Yang, Gongliu; Jiang, Rui

    2016-07-01

    In the initial alignment process of strapdown inertial navigation system (SINS), large misalignment angles always bring nonlinear problem, which can usually be processed using the scaled unscented Kalman filter (SUKF). In this paper, the problem of large misalignment angles in SINS alignment is further investigated, and the strong tracking scaled unscented Kalman filter (STSUKF) is proposed with fixed parameters to improve convergence speed, while these parameters are artificially constructed and uncertain in real application. To further improve the alignment stability and reduce the parameters selection, this paper proposes a fuzzy adaptive strategy combined with STSUKF (FUZZY-STSUKF). As a result, initial alignment scheme of large misalignment angles based on FUZZY-STSUKF is designed and verified by simulations and turntable experiment. The results show that the scheme improves the accuracy and convergence speed of SINS initial alignment compared with those based on SUKF and STSUKF. PMID:27475606

  15. Fuzzy adaptive strong tracking scaled unscented Kalman filter for initial alignment of large misalignment angles

    NASA Astrophysics Data System (ADS)

    Li, Jing; Song, Ningfang; Yang, Gongliu; Jiang, Rui

    2016-07-01

    In the initial alignment process of strapdown inertial navigation system (SINS), large misalignment angles always bring nonlinear problem, which can usually be processed using the scaled unscented Kalman filter (SUKF). In this paper, the problem of large misalignment angles in SINS alignment is further investigated, and the strong tracking scaled unscented Kalman filter (STSUKF) is proposed with fixed parameters to improve convergence speed, while these parameters are artificially constructed and uncertain in real application. To further improve the alignment stability and reduce the parameters selection, this paper proposes a fuzzy adaptive strategy combined with STSUKF (FUZZY-STSUKF). As a result, initial alignment scheme of large misalignment angles based on FUZZY-STSUKF is designed and verified by simulations and turntable experiment. The results show that the scheme improves the accuracy and convergence speed of SINS initial alignment compared with those based on SUKF and STSUKF.

  16. Design and manufacture of angle modulated surface plasmon resonance spectrometer

    NASA Astrophysics Data System (ADS)

    Zhou, Xinlei; Chen, Ke; Mao, Xuefeng; Yu, Qingxu; Peng, Wei

    2015-08-01

    As an emerging biosensing technology, Surface Plasmon Resonance (SPR) technique, characterized by high sensitivity, label-free detection and real-time monitoring, has been extensively applied in biochemical analysis, environmental monitoring and refractive index measurement. In this paper, an angle modulated SPR spectrometer with high resolution is designed and manufactured. First, according to the modeling and simulation for the SPR spectrometer, several key parameters such as the light source, the thickness of golden film and Cr film are determined. Then, an angle modulated SPR spectrometer system based on 5-layers Kretchmann prism structure is developed for biochemical analysis. System performance is tested after the SPR spectrometer established. We test the power stability of the laser first, which is up to 1.504% (5min). Different concentrations of glycerol are measured to demarcate the system. Then, we measured the deionized water ten times continuously, and a resolution of 1.5×10-5 RIU is achieved. At last, different concentrations of glucose solution are measured, and the resonance angles are used to calculate the refractive index of the glucose solutions, which is more accurate than the result of Abbe refractometer. The relationship between concentration and refractive index is presented by liner fitting.

  17. Surgical treatment of the nasolabial angle in balanced rhinoplasty.

    PubMed

    Honrado, Carlo P; Pearlman, Steven J

    2003-01-01

    Nasal analysis and surgical planning are crucial for a successful, aesthetically pleasing rhinoplasty. One of the key parameters for evaluation is the nasolabial angle. The nasal spine, caudal septum, and medial crura of the lower lateral cartilages provide the framework for this area. Alteration of these structures, as well as nasal tip rotation and projection, may affect the resultant nasolabial angle, length of the upper lip, and overall harmony of the nose. Fullness at the nasolabial junction caused by a pushing philtrum may also result in an unbalanced appearance. The literature is replete with methods for categorizing the nasal tip and with recommendations for surgical treatment. Treatment of the caudal septum and nasal spine is often an afterthought that is left up to the aesthetic judgment of the surgeon. To make this a more systematic decision, in 1990 we devised a classification for analysis and treatment of this area. This study included the length of the nose, the nasolabial angle, and the presence of a pushing philtrum, with suggested treatment to allow proper tip placement and to provide aesthetic balance to the nose. The only modification was in the order of presentation of nasal types. Since that publication, the senior author has consistently followed these guidelines and has found them to be a reliable tool in creating a harmonious result in rhinoplasty. PMID:12873873

  18. Effect of Process Parameters on Dynamic Mechanical Performance of FDM PC/ABS Printed Parts Through Design of Experiment

    NASA Astrophysics Data System (ADS)

    Mohamed, Omar Ahmed; Masood, Syed Hasan; Bhowmik, Jahar Lal; Nikzad, Mostafa; Azadmanjiri, Jalal

    2016-07-01

    In fused deposition modeling (FDM) additive manufacturing process, it is often difficult to determine the actual levels of process parameters in order to achieve the best dynamic mechanical properties of FDM manufactured part. This is mainly due to the large number of FDM parameters and a high degree of interaction between the parameters affecting such properties. This requires a large number of experiments to be determined. This paper presents a study on the influence of six FDM process parameters (layer thickness, air gap, raster angle, build orientation, road width, and number of contours) on the dynamic mechanical properties of the FDM manufactured parts using the fraction factorial design. The most influential parameters were statistically obtained through the analysis of variance (ANOVA) technique, and the results indicate that the layer thickness, the air gap, and the number of contours have the largest impact on dynamic mechanical properties. The optimal parameters for maximum dynamic mechanical properties were found to be layer thickness of 0.3302 mm, air gap of 0.00 mm, raster angle of 0.0°, build orientation of 0.0°, road width of 0.4572 mm, and 10 contours. Finally, a confirmation experiment was performed using optimized levels of process parameters, which showed good fit with the estimated values.

  19. Effect of Process Parameters on Dynamic Mechanical Performance of FDM PC/ABS Printed Parts Through Design of Experiment

    NASA Astrophysics Data System (ADS)

    Mohamed, Omar Ahmed; Masood, Syed Hasan; Bhowmik, Jahar Lal; Nikzad, Mostafa; Azadmanjiri, Jalal

    2016-06-01

    In fused deposition modeling (FDM) additive manufacturing process, it is often difficult to determine the actual levels of process parameters in order to achieve the best dynamic mechanical properties of FDM manufactured part. This is mainly due to the large number of FDM parameters and a high degree of interaction between the parameters affecting such properties. This requires a large number of experiments to be determined. This paper presents a study on the influence of six FDM process parameters (layer thickness, air gap, raster angle, build orientation, road width, and number of contours) on the dynamic mechanical properties of the FDM manufactured parts using the fraction factorial design. The most influential parameters were statistically obtained through the analysis of variance (ANOVA) technique, and the results indicate that the layer thickness, the air gap, and the number of contours have the largest impact on dynamic mechanical properties. The optimal parameters for maximum dynamic mechanical properties were found to be layer thickness of 0.3302 mm, air gap of 0.00 mm, raster angle of 0.0°, build orientation of 0.0°, road width of 0.4572 mm, and 10 contours. Finally, a confirmation experiment was performed using optimized levels of process parameters, which showed good fit with the estimated values.

  20. Simulation of uphill/downhill running on a level treadmill using additional horizontal force.

    PubMed

    Gimenez, Philippe; Arnal, Pierrick J; Samozino, Pierre; Millet, Guillaume Y; Morin, Jean-Benoit

    2014-07-18

    Tilting treadmills allow a convenient study of biomechanics during uphill/downhill running, but they are not commonly available and there is even fewer tilting force-measuring treadmill. The aim of the present study was to compare uphill/downhill running on a treadmill (inclination of ± 8%) with running on a level treadmill using additional backward or forward pulling forces to simulate the effect of gravity. This comparison specifically focused on the energy cost of running, stride frequency (SF), electromyographic activity (EMG), leg and foot angles at foot strike, and ground impact shock. The main results are that SF, impact shock, and leg and foot angle parameters determined were very similar and significantly correlated between the two methods, the intercept and slope of the linear regression not differing significantly from zero and unity, respectively. The correlation of oxygen uptake (V̇O2) data between both methods was not significant during uphill running (r=0.42; P>0.05). V̇O2 data were correlated during downhill running (r=0.74; P<0.01) but there was a significant difference between the methods (bias=-2.51 ± 1.94 ml min(-1) kg(-1)). Linear regressions for EMG of vastus lateralis, biceps femoris, gastrocnemius lateralis, soleus and tibialis anterior were not different from the identity line but the systematic bias was elevated for this parameter. In conclusion, this method seems appropriate for the study of SF, leg and foot angle, impact shock parameters but is less applicable for physiological variables (EMG and energy cost) during uphill/downhill running when using a tilting force-measuring treadmill is not possible. PMID:24811045

  1. Solar cell angle of incidence corrections

    NASA Technical Reports Server (NTRS)

    Burger, Dale R.; Mueller, Robert L.

    1995-01-01

    Literature on solar array angle of incidence corrections was found to be sparse and contained no tabular data for support. This lack along with recent data on 27 GaAs/Ge 4 cm by 4 cm cells initiated the analysis presented in this paper. The literature cites seven possible contributors to angle of incidence effects: cosine, optical front surface, edge, shadowing, UV degradation, particulate soiling, and background color. Only the first three are covered in this paper due to lack of sufficient data. The cosine correction is commonly used but is not sufficient when the incident angle is large. Fresnel reflection calculations require knowledge of the index of refraction of the coverglass front surface. The absolute index of refraction for the coverglass front surface was not known nor was it measured due to lack of funds. However, a value for the index of refraction was obtained by examining how the prediction errors varied with different assumed indices and selecting the best fit to the set of measured values. Corrections using front surface Fresnel reflection along with the cosine correction give very good predictive results when compared to measured data, except there is a definite trend away from predicted values at the larger incident angles. This trend could be related to edge effects and is illustrated by a use of a box plot of the errors and by plotting the deviation of the mean against incidence angle. The trend is for larger deviations at larger incidence angles and there may be a fourth order effect involved in the trend. A chi-squared test was used to determine if the measurement errors were normally distributed. At 10 degrees the chi-squared test failed, probably due to the very small numbers involved or a bias from the measurement procedure. All other angles showed a good fit to the normal distribution with increasing goodness-of-fit as the angles increased which reinforces the very small numbers hypothesis. The contributed data only went to 65 degrees

  2. Incidence angle modifiers in cylindrical solar collector design. Final report, June 1996--May 1997

    SciTech Connect

    Ryan, J.P.

    1997-05-01

    This thesis presents an analysis of the thermal performance of cylindrical solar collectors. A major contributor to performance is optics, the principle focus of this work. A tool used to compute the incidence angle modifiers (IAM`s) for cylindrical solar collectors is presented. The Monte Carlo Method is employed in a Fortran 90 computer code to compute the hemispheric IAM`s of cylindrical solar collectors. Using concentric cylinders, the tubes are modeled with and without back plane reflectors of varying size. The computed IAM`s are verified both analytically and experimentally. Outdoor experiments on an array of cylindrical tubes with various back planes and two different tube spacings are described. Agreement with TRNSYS runs in daily energy gain is excellent. Over the 38 data sets, taken on different days, a maximum error of 11.2% is observed, with an average error of 3%. Heat loss tests, used to calculate an overall heat loss coefficient for the collector, are also described. A parametric variation study is used to illustrate the effect of varying many of the collector parameters. This study provides insight into the significant design parameters for cylindrical solar collectors. This insight is used to analyze the effect of these design parameters on the annual energy delivered by the collector. In addition, a simple cost analysis illustrates the benefits of varying the design parameters. The use of this new program and a detailed Life Cycle Cost analysis are the tools needed for optimizing the design of a cylindrical solar collector. 27 figs., 9 tabs.

  3. Angle-domain imaging condition for elastic reverse time migration

    NASA Astrophysics Data System (ADS)

    Yan, R.; Xie, X.; Wu, R.

    2010-12-01

    . Furthermore, having obtained the angle-domain information of the wavefields, it is quite straightforward to output the common reflection angle gather and perform AVA (amplitude versus angle) analysis for elastic parameter inversion.

  4. Longitudinal Changes of Angle Configuration in Primary Angle-Closure Suspects

    PubMed Central

    Jiang, Yuzhen; Chang, Dolly S.; Zhu, Haogang; Khawaja, Anthony P.; Aung, Tin; Huang, Shengsong; Chen, Qianyun; Munoz, Beatriz; Grossi, Carlota M.

    2015-01-01

    Objective To determine longitudinal changes in angle configuration in the eyes of primary angle-closure suspects (PACS) treated by laser peripheral iridotomy (LPI) and in untreated fellow eyes. Design Longitudinal cohort study. Participants Primary angle-closure suspects aged 50 to 70 years were enrolled in a randomized, controlled clinical trial. Methods Each participant was treated by LPI in 1 randomly selected eye, with the fellow eye serving as a control. Angle width was assessed in a masked fashion using gonioscopy and anterior segment optical coherence tomography (AS-OCT) before and at 2 weeks, 6 months, and 18 months after LPI. Main Outcome Measures Angle width in degrees was calculated from Shaffer grades assessed under static gonioscopy. Angle configuration was also evaluated using angle opening distance (AOD250, AOD500, AOD750), trabecular-iris space area (TISA500, TISA750), and angle recess area (ARA) measured in AS-OCT images. Results No significant difference was found in baseline measures of angle configuration between treated and untreated eyes. At 2 weeks after LPI, the drainage angle on gonioscopy widened from a mean of 13.5° at baseline to a mean of 25.7° in treated eyes, which was also confirmed by significant increases in all AS-OCT angle width measures (P<0.001 for all variables). Between 2 weeks and 18 months after LPI, a significant decrease in angle width was observed over time in treated eyes (P<0.001 for all variables), although the change over the first 5.5 months was not statistically significant for angle width measured under gonioscopy (P = 0.18), AOD250 (P = 0.167) and ARA (P = 0.83). In untreated eyes, angle width consistently decreased across all follow-up visits after LPI, with a more rapid longitudinal decrease compared with treated eyes (P values for all variables ≤0.003). The annual rate of change in angle width was equivalent to 1.2°/year (95% confidence interval [CI], 0.8–1.6) in treated eyes and 1.6°/year (95% CI, 1

  5. Additive Manufacturing Infrared Inspection

    NASA Technical Reports Server (NTRS)

    Gaddy, Darrell

    2014-01-01

    Additive manufacturing is a rapid prototyping technology that allows parts to be built in a series of thin layers from plastic, ceramics, and metallics. Metallic additive manufacturing is an emerging form of rapid prototyping that allows complex structures to be built using various metallic powders. Significant time and cost savings have also been observed using the metallic additive manufacturing compared with traditional techniques. Development of the metallic additive manufacturing technology has advanced significantly over the last decade, although many of the techniques to inspect parts made from these processes have not advanced significantly or have limitations. Several external geometry inspection techniques exist such as Coordinate Measurement Machines (CMM), Laser Scanners, Structured Light Scanning Systems, or even traditional calipers and gages. All of the aforementioned techniques are limited to external geometry and contours or must use a contact probe to inspect limited internal dimensions. This presentation will document the development of a process for real-time dimensional inspection technique and digital quality record of the additive manufacturing process using Infrared camera imaging and processing techniques.

  6. Microstructure of 3D-Printed Polymer Composites Investigated by Small-Angle Neutron Scattering

    NASA Astrophysics Data System (ADS)

    Kang, Tae Hui; Compton, Brett G.; Heller, William T.; Urban, Voker S.; Duty, Chad E.; Do, Changwoo

    Polymer composites printed from the large scale printer at Manufacturing Demonstration Facility at Oak Ridge National Laboratory have been investigated by small-angle neutron scattering (SANS). For the Acrylonitrile Butadiene Styrene (ABS)/Carbon Fiber (CF) composites, the microstructure of polymer domains and the alignment of CF have been characterized across the layer from the printed piece. CF shows strong anisotropic alignment along the printing direction due to the flow of polymer melt at the nozzle. Order parameter of the anisotropy which ranges from -0.11 to -0.06 exhibits strong correlation with the position within the layer: stronger alignment near the layer interface. It is also confirmed that the existence of CF reduces the polymer domain correlation length significantly and reinforces the mechanical strength of the polymer composites. For the Epoxy/nano-clay platelet composites, the effect of processing condition, nozzle size, and the addition of the another filler, Silicon Carbide (SC), have been investigated by SANS. Nano-clay platelet shows strong anisotropic alignment along the printing direction as well. Order parameter of the anisotropy varies according to nozzle size and presence of the SC, and difference disappears at high Q region. Scientific User Facilities Division and Materials Sciences and Energy Division, Office of Basic Energy Sciences, U.S. Department of Energy.

  7. Influence of spatial and temporal coherences on atomic resolution high angle annular dark field imaging.

    PubMed

    Beyer, Andreas; Belz, Jürgen; Knaub, Nikolai; Jandieri, Kakhaber; Volz, Kerstin

    2016-10-01

    Aberration-corrected (scanning) transmission electron microscopy ((S)TEM) has become a widely used technique when information on the chemical composition is sought on an atomic scale. To extract the desired information, complementary simulations of the scattering process are inevitable. Often the partial spatial and temporal coherences are neglected in the simulations, although they can have a huge influence on the high resolution images. With the example of binary gallium phosphide (GaP) we elucidate the influence of the source size and shape as well as the chromatic aberration on the high angle annular dark field (HAADF) intensity. We achieve a very good quantitative agreement between the frozen phonon simulation and experiment for different sample thicknesses when a Lorentzian source distribution is assumed and the effect of the chromatic aberration is considered. Additionally the influence of amorphous layers introduced by the preparation of the TEM samples is discussed. Taking into account these parameters, the intensity in the whole unit cell of GaP, i.e. at the positions of the different atomic columns and in the region between them, is described correctly. With the knowledge of the decisive parameters, the determination of the chemical composition of more complex, multinary materials becomes feasible. PMID:27391526

  8. Intermittent acute angle closure glaucoma and chronic angle closure following topiramate use with plateau iris configuration

    PubMed Central

    Rajjoub, Lamise Z; Chadha, Nisha; Belyea, David A

    2014-01-01

    This is a case report describing recurrent intermittent acute angle closure episodes in the setting of topiramate use in a female suffering from migraines. Despite laser peripheral iridotomy placement for the pupillary block component, and the discontinuation of topiramate, the acute angle closure did not resolve in the left eye with chronic angle closure and the patient required urgent trabeculectomy. The right eye responded to laser peripheral iridotomy immediately and further improved after the cessation of topiramate. While secondary angle closure glaucoma due to topiramate use has been widely reported, its effects in patients with underlying primary angle closure glaucoma have not been discussed. Our report highlights the importance of recognizing the often multifactorial etiology of angle closure glaucoma to help guide clinical management. PMID:25114497

  9. Measurement of the γ→p→K+Λ reaction at backward angles

    NASA Astrophysics Data System (ADS)

    Hicks, K.; Mibe, T.; Sumihama, M.; Ahn, D. S.; Ahn, J. K.; Akimune, H.; Asano, Y.; Chang, W. C.; Daté, S.; Ejiri, H.; Fukui, S.; Fujimura, H.; Fujiwara, M.; Hasegawa, S.; Hosaka, A.; Hotta, T.; Imai, K.; Ishikawa, T.; Iwata, T.; Juliá-Díaz, B.; Kato, Y.; Kawai, H.; Kim, Z. Y.; Kino, K.; Kohri, H.; Kumagai, N.; Lee, T.-S. H.; Makino, S.; Matsuda, T.; Matsumura, T.; Matsuoka, N.; Miyabe, M.; Miyachi, Y.; Morita, M.; Muramatsu, N.; Nakano, T.; Niiyama, M.; Nomachi, M.; Ohashi, Y.; Ooba, T.; Ohkuma, H.; Oshuev, D. S.; Ozaki, S.; Rangacharyulu, C.; Sakaguchi, A.; Sasaki, T.; Shagin, P. M.; Shiino, Y.; Shimizu, A.; Shimizu, H.; Sugaya, Y.; Toi, Y.; Toyokawa, H.; Wakai, A.; Wang, C. W.; Wang, S. C.; Yonehara, K.; Yorita, T.; Yoshimura, M.; Yosoi, M.; Zegers, R. G. T.

    2007-10-01

    Cross sections for the γp→K+Λ reaction were measured at backward angles using linearly polarized photons in the range 1.50 to 2.37 GeV. In addition, the beam asymmetry for this reaction was measured for the first time at backward angles. The Λ was detected at forward angles in the LEPS spectrometer via its decay to pπ- and the K+ was inferred using the technique of missing mass. These measurements, corresponding to kaons at far backward angles in the center-of-mass frame, complement similar CLAS data at other angles. Comparison with theoretical models shows that the reactions in these kinematics provide further opportunities to investigate the reaction mechanisms of hadron dynamics.

  10. 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.

  11. Phenylethynyl Containing Reactive Additives

    NASA Technical Reports Server (NTRS)

    Connell, John W. (Inventor); Smith, Joseph G., Jr. (Inventor); Hergenrother, Paul M. (Inventor)

    2002-01-01

    Phenylethynyl containing reactive additives were prepared from aromatic diamine, containing phenylethvnvl groups and various ratios of phthalic anhydride and 4-phenylethynviphthalic anhydride in glacial acetic acid to form the imide in one step or in N-methyl-2-pvrrolidinone to form the amide acid intermediate. The reactive additives were mixed in various amounts (10% to 90%) with oligomers containing either terminal or pendent phenylethynyl groups (or both) to reduce the melt viscosity and thereby enhance processability. Upon thermal cure, the additives react and become chemically incorporated into the matrix and effect an increase in crosslink density relative to that of the host resin. This resultant increase in crosslink density has advantageous consequences on the cured resin properties such as higher glass transition temperature and higher modulus as compared to that of the host resin.

  12. Additives in plastics.

    PubMed Central

    Deanin, R D

    1975-01-01

    The polymers used in plastics are generally harmless. However, they are rarely used in pure form. In almost all commercial plastics, they are "compounded" with monomeric ingredients to improve their processing and end-use performance. In order of total volume used, these monomeric additives may be classified as follows: reinforcing fibers, fillers, and coupling agents; plasticizers; colorants; stabilizers (halogen stabilizers, antioxidants, ultraviolet absorbers, and biological preservatives); processing aids (lubricants, others, and flow controls); flame retardants, peroxides; and antistats. Some information is already available, and much more is needed, on potential toxicity and safe handling of these additives during processing and manufacture of plastics products. PMID:1175566

  13. The Effect of Taper Angle and Spline Geometry on the Initial Stability of Tapered, Splined Modular Titanium Stems.

    PubMed

    Pierson, Jeffery L; Small, Scott R; Rodriguez, Jose A; Kang, Michael N; Glassman, Andrew H

    2015-07-01

    Design parameters affecting initial mechanical stability of tapered, splined modular titanium stems (TSMTSs) are not well understood. Furthermore, there is considerable variability in contemporary designs. We asked if spline geometry and stem taper angle could be optimized in TSMTS to improve mechanical stability to resist axial subsidence and increase torsional stability. Initial stability was quantified with stems of varied taper angle and spline geometry implanted in a foam model replicating 2cm diaphyseal engagement. Increased taper angle and a broad spline geometry exhibited significantly greater axial stability (+21%-269%) than other design combinations. Neither taper angle nor spline geometry significantly altered initial torsional stability. PMID:25754255

  14. Biobased lubricant additives

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Fully biobased lubricants are those formulated using all biobased ingredients, i.e. biobased base oils and biobased additives. Such formulations provide the maximum environmental, safety, and economic benefits expected from a biobased product. Currently, there are a number of biobased base oils that...

  15. Multifunctional fuel additives

    SciTech Connect

    Baillargeon, D.J.; Cardis, A.B.; Heck, D.B.

    1991-03-26

    This paper discusses a composition comprising a major amount of a liquid hydrocarbyl fuel and a minor low-temperature flow properties improving amount of an additive product of the reaction of a suitable diol and product of a benzophenone tetracarboxylic dianhydride and a long-chain hydrocarbyl aminoalcohol.

  16. Comparative morphometry of coxal joint angles.

    PubMed

    Sugiyama, S; Fujiwara, K

    1997-10-01

    The angles related to the coxal joints were comparatively studied in four-limbed walking animals and two-limbed ones including man and birds. Between animals with both types of walking, no significant difference was observed in the neck-shaft angles (NSA), which was equivalent to the acetabulum angles (ACA) at the connection of the femoral head with the acetabulum. The anteversion angles (AVA) were equivalent to the horizontal ACA. Canine species showed two different forms of the femoral neck with or without modification by the femoral AVA, probably being breed-specific and nutrition-dependent. In the narrow-striped wallaby as well as avian species, the femoral head showed a postversion with a minus-version angle for lifting the body axis in the frontal and upward direction to hold the whole body weight on the hind-limbs, in particular at the anterior part of the acetabulum. In man, the connection between the femur and acetabulum greatly varied among individuals, possibly according to differences in the life style. PMID:9353634

  17. 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.

  18. Moment-angle relations after specific exercise.

    PubMed

    Ullrich, B; Kleinöder, H; Brüggemann, G P

    2009-04-01

    This study examined the amount and time-course of shifts in the moment-knee angle relation of the quadriceps (QF) and hamstring (HAM) muscles in response to different length-restricted strength training regimens. Thirty-two athletes were divided into three different training groups (G1-3): G1 performed isometric training at knee joint angles corresponding to long muscle-tendon unit (MTU) length for QF and HAM; G2 conducted concentric-eccentric contraction cycles that were restricted to a knee joint range of motion corresponding to predominantly long MTU length for QF and HAM; G3 combined the protocols of G1 and G2. Moment-knee angle and EMG-knee angle relations of QF and HAM were measured on five different occasions: two times before, after five and eight weeks of training and four weeks post training. Moments and EMG-data of each subject were normalized to the largest value produced at any knee joint position [% Max.]. Obtained by curve fitting, the optimal knee joint angle for QF moment production was significantly (P<0.05) shifted to longer MTU length in G1 and G3 after 5 weeks of training and in G2 after 8 weeks of training. Contrary, no significant shifts were detected for HAM. Our data suggest that the predominant MTU length during loading is a major trigger for human force-length adaptations. PMID:19199195

  19. NORAD LOOK ANGLES AND PIO SATELLITE PACKAGE

    NASA Technical Reports Server (NTRS)

    ANONYMOUS

    1994-01-01

    This program package consists of two programs. First is the NORAD Look Angles Program, which computes satellite look angles (azimuth, elevation, and range) as well as the subsatellite points (latitude, longitude, and height). The second program in this package is the PIO Satellite Program, which computes sighting directions, visibility times, and the maximum elevation angle attained during each pass of an earth-orbiting satellite. Computations take into consideration the observing location and the effect of the earth's shadow on the satellite visibility. Input consists of a magnetic tape prepared by the NORAD Look Angles Program and punched cards containing reference Julian date, right ascension, declination, mean sidereal time at zero hours universal time of the reference date, and daily changes of these quantities. Output consists of a tabulated listing of the satellite's rise and set times, direction, and the maximum elevation angle visible from each observing location. This program has been implemented on the GE 635. The program Assembler code can easily be replaced by FORTRAN statements.

  20. Complementary interference method for determining optical parameters of liquid crystals

    NASA Astrophysics Data System (ADS)

    Kowiorski, K.; Kędzierski, J.; Raszewski, Z.; Kojdecki, M. A.; Chojnowska, O.; Garbat, K.; Miszczyk, E.; Piecek, W.

    2016-04-01

    Wedge cells of small apex angle, filled with liquid crystals, were used to determining optical characteristics as functions of temperature for three liquid crystalline mixtures recently produced and a reference nematic. The interference fringes appearing in polarised monochromatic light (of sodium yellow line) normally incident on the cell were exploited to measure the ordinary and extraordinary refractive indices in the reflection mode and birefringence in the transmission mode. The measurements were repeated using Abbe's refractometer for 6CHBT as the reference to verifying the precision. Additionally the order parameter was computed from birefringence as a function of temperature. The results confirm the usefulness of the method and provide the properties of two nematic liquid crystals of small and large birefringence and one smectic liquid crystal of medium birefringence, recently produced. The experimental systems served also to investigating phase transition between the liquid crystals and the isotropic liquid at near-clearing temperature.

  1. A comparative study of limited-angle cone-beam reconstruction methods for breast tomosynthesis

    SciTech Connect

    Zhang Yiheng; Chan, H.-P.; Sahiner, Berkman; Wei, Jun; Goodsitt, Mitchell M.; Hadjiiski, Lubomir M.; Ge Jun; Zhou Chuan

    2006-10-15

    Digital tomosynthesis mammography (DTM) is a promising new modality for breast cancer detection. In DTM, projection-view images are acquired at a limited number of angles over a limited angular range and the imaged volume is reconstructed from the two-dimensional projections, thus providing three-dimensional structural information of the breast tissue. In this work, we investigated three representative reconstruction methods for this limited-angle cone-beam tomographic problem, including the backprojection (BP) method, the simultaneous algebraic reconstruction technique (SART) and the maximum likelihood method with the convex algorithm (ML-convex). The SART and ML-convex methods were both initialized with BP results to achieve efficient reconstruction. A second generation GE prototype tomosynthesis mammography system with a stationary digital detector was used for image acquisition. Projection-view images were acquired from 21 angles in 3 deg. increments over a {+-}30 deg. angular range. We used an American College of Radiology phantom and designed three additional phantoms to evaluate the image quality and reconstruction artifacts. In addition to visual comparison of the reconstructed images of different phantom sets, we employed the contrast-to-noise ratio (CNR), a line profile of features, an artifact spread function (ASF), a relative noise power spectrum (NPS), and a line object spread function (LOSF) to quantitatively evaluate the reconstruction results. It was found that for the phantoms with homogeneous background, the BP method resulted in less noisy tomosynthesized images and higher CNR values for masses than the SART and ML-convex methods. However, the two iterative methods provided greater contrast enhancement for both masses and calcification, sharper LOSF, and reduced interplane blurring and artifacts with better ASF behaviors for masses. For a contrast-detail phantom with heterogeneous tissue-mimicking background, the BP method had strong blurring

  2. High angle of attack flying qualities criteria for longitudinal rate command systems

    NASA Technical Reports Server (NTRS)

    Wilson, David J.; Citurs, Kevin D.; Davidson, John B.

    1994-01-01

    This study was designed to investigate flying qualities requirements of alternate pitch command systems for fighter aircraft at high angle of attack. Flying qualities design guidelines have already been developed for angle of attack command systems at 30, 45, and 60 degrees angle of attack, so this research fills a similar need for rate command systems. Flying qualities tasks that require post-stall maneuvering were tested during piloted simulations in the McDonnell Douglas Aerospace Manned Air Combat Simulation facility. A generic fighter aircraft model was used to test angle of attack rate and pitch rate command systems for longitudinal gross acquisition and tracking tasks at high angle of attack. A wide range of longitudinal dynamic variations were tested at 30, 45, and 60 degrees angle of attack. Pilot comments, Cooper-Harper ratings, and pilot induced oscillation ratings were taken from five pilots from NASA, USN, CAF, and McDonnell Douglas Aerospace. This data was used to form longitudinal design guidelines for rate command systems at high angle of attack. These criteria provide control law design guidance for fighter aircraft at high angle of attack, low speed flight conditions. Additional time history analyses were conducted using the longitudinal gross acquisition data to look at potential agility measures of merit and correlate agility usage to flying qualities boundaries. This paper presents an overview of this research.

  3. Misorientation-angle-dependent electrical transport across molybdenum disulfide grain boundaries

    PubMed Central

    Ly, Thuc Hue; Perello, David J.; Zhao, Jiong; Deng, Qingming; Kim, Hyun; Han, Gang Hee; Chae, Sang Hoon; Jeong, Hye Yun; Lee, Young Hee

    2016-01-01

    Grain boundaries in monolayer transition metal dichalcogenides have unique atomic defect structures and band dispersion relations that depend on the inter-domain misorientation angle. Here, we explore misorientation angle-dependent electrical transport at grain boundaries in monolayer MoS2 by correlating the atomic defect structures of measured devices analysed with transmission electron microscopy and first-principles calculations. Transmission electron microscopy indicates that grain boundaries are primarily composed of 5–7 dislocation cores with periodicity and additional complex defects formed at high angles, obeying the classical low-angle theory for angles <22°. The inter-domain mobility is minimized for angles <9° and increases nonlinearly by two orders of magnitude before saturating at ∼16 cm2 V−1 s−1 around misorientation angle≈20°. This trend is explained via grain-boundary electrostatic barriers estimated from density functional calculations and experimental tunnelling barrier heights, which are ≈0.5 eV at low angles and ≈0.15 eV at high angles (≥20°). PMID:26813605

  4. High brightness angled cavity quantum cascade lasers

    NASA Astrophysics Data System (ADS)

    Heydari, D.; Bai, Y.; Bandyopadhyay, N.; Slivken, S.; Razeghi, M.

    2015-03-01

    A quantum cascade laser (QCL) with an output power of 203 W is demonstrated in pulsed mode at 283 K with an angled cavity. The device has a ridge width of 300 μm, a cavity length of 5.8 mm, and a tilt angle of 12°. The back facet is high reflection coated, and the front facet is anti-reflection coated. The emitting wavelength is around 4.8 μm. In distinct contrast to a straight cavity broad area QCL, the lateral far field is single lobed with a divergence angle of only 3°. An ultrahigh brightness value of 156 MW cm-2 sr-1 is obtained, which marks the brightest QCL to date.

  5. On the dip angle of subducting plates

    NASA Technical Reports Server (NTRS)

    Hsui, Albert T.; Tang, Xiao-Ming; Toksoz, M. Nafi

    1990-01-01

    A new approximate analytic model is developed for the thermal structure of a subducting plate with a finite length. This model provides the capability of easily examining the thermal and mechanical structure of a subducting plate with different lengths and at different angles. Also, the torque balance of a descending plate can be examined, and effects such as the leading edge effect, the adiabatic compression effect, and the phase change effect can be incorporated. A comparison with observed data indicates that short slabs are likely under torque equilibrium at present, while long slabs are probably dominated by their gravitational torques such that their dip angles are transient, moving toward a steeper dip angle similar to that of the Mariana slab.

  6. Data for phase angle shift with frequency.

    PubMed

    Paul, T; Banerjee, D; Kargupta, K

    2016-06-01

    Phase angle shift between the current and voltage with frequency has been reported for a single phosphoric acid fuel cell in the cell temperature from 100 °C to 160 °C and the humidifier temperature from 40 °C to 90 °C. An electrochemical workbench is employed to find the shift. The figure of phase angle shift shows a peak in high humidifier temperatures. The peak in phase angle shift directs to lower frequency side with decreasing humidifier temperature. The estimation of electrochemical reaction time is also evaluated in the humidifier temperature zone from 50 °C to 90 °C. PMID:27158655

  7. Data for phase angle shift with frequency

    PubMed Central

    Paul, T.; Banerjee, D.; Kargupta, K.

    2016-01-01

    Phase angle shift between the current and voltage with frequency has been reported for a single phosphoric acid fuel cell in the cell temperature from 100 °C to 160 °C and the humidifier temperature from 40 °C to 90 °C. An electrochemical workbench is employed to find the shift. The figure of phase angle shift shows a peak in high humidifier temperatures. The peak in phase angle shift directs to lower frequency side with decreasing humidifier temperature. The estimation of electrochemical reaction time is also evaluated in the humidifier temperature zone from 50 °C to 90 °C. PMID:27158655

  8. Advancing contact angles on large structured surfaces

    NASA Astrophysics Data System (ADS)

    Yoshitake, Yumiko; Itakura, Yoshinori; Gobo, Junichi; Takahashi, Tsutomu

    2014-11-01

    To understand wetting phenomena on complex surfaces, simple modeling experiments in two-dimension system would be one of the most efficient approaches. We develop a new experimental method for wetting dynamics using a large pseudo two- dimensional droplet. This method is useful to examine theoretical studies developed in two dimensional systems. In this study, we examine a pinning and depinning phenomena on millimeter-size structured surface to explain the origin of contact angle hysteresis. Contact lines of the droplet are pinned and deppined at the edge of surface texture. The contact lines can move when the contact angle is equal to the Young's contact angle which are determined by the balance of the surface and interfacial tension immediate vicinity of the contact lines, which is different from the Wenzel's low. Our approach enables to realize a macroscopic modelling experiment of wetting on complex surfaces, which opens a path to design functional surfaces with chemical and physical structure.

  9. Flocking and invariance of velocity angles.

    PubMed

    Liu, Le; Huang, Lihong; Wu, Jianhong

    2016-04-01

    Motsch and Tadmor considered an extended Cucker-Smale model to investigate the flocking behavior of self-organized systems of interacting species. In this extended model, a cone of the vision was introduced so that outside the cone the influence of one agent on the other is lost and hence the corresponding influence function takes the value zero. This creates a problem to apply the Motsch-Tadmor and Cucker-Smale method to prove the flocking property of the system. Here, we examine the variation of the velocity angles between two arbitrary agents, and obtain a monotonicity property for the maximum cone of velocity angles. This monotonicity permits us to utilize existing arguments to show the flocking property of the system under consideration, when the initial velocity angles satisfy some minor technical constraints. PMID:27105986

  10. High brightness angled cavity quantum cascade lasers

    SciTech Connect

    Heydari, D.; Bai, Y.; Bandyopadhyay, N.; Slivken, S.; Razeghi, M.

    2015-03-02

    A quantum cascade laser (QCL) with an output power of 203 W is demonstrated in pulsed mode at 283 K with an angled cavity. The device has a ridge width of 300 μm, a cavity length of 5.8 mm, and a tilt angle of 12°. The back facet is high reflection coated, and the front facet is anti-reflection coated. The emitting wavelength is around 4.8 μm. In distinct contrast to a straight cavity broad area QCL, the lateral far field is single lobed with a divergence angle of only 3°. An ultrahigh brightness value of 156 MW cm{sup −2 }sr{sup −1} is obtained, which marks the brightest QCL to date.

  11. A heterodyne interferometer for angle metrology

    SciTech Connect

    Hahn, Inseob; Weilert, M.; Wang, X.; Goullioud, R.

    2010-04-15

    We have developed a compact, high-resolution, angle measurement instrument based on a heterodyne interferometer. Common-path heterodyne interferometer metrology is used to measure displacements of a reflective target surface. In the interferometer set up, an optical mask is used to sample the laser beam reflecting back from four areas on a target surface. From the relative displacement measurements of the target surface areas, we can simultaneously determine angular rotations around two orthogonal axes in a plane perpendicular to the measurement beam propagation direction. The device is used in a testbed for a tracking telescope system where pitch and yaw angle measurements of a flat mirror are performed. Angle noise measurement of the device shows 0.1 nrad/{radical}(Hz) at 1 Hz, at a working distance of 1 m. The operation range and nonlinearity of the device when used with a flat mirror is approximately {+-}0.15 mrad, and 3 {mu}rad rms, respectively.

  12. Automatic evaluation of progression angle and fetal head station through intrapartum echographic monitoring.

    PubMed

    Casciaro, Sergio; Conversano, Francesco; Casciaro, Ernesto; Soloperto, Giulia; Perrone, Emanuele; Di Renzo, Gian Carlo; Perrone, Antonio

    2013-01-01

    Labor progression is routinely assessed through transvaginal digital inspections, meaning that the clinical decisions taken during the most delicate phase of pregnancy are subjective and scarcely supported by technological devices. In response to such inadequacies, we combined intrapartum echographic acquisitions with advanced tracking algorithms in a new method for noninvasive, quantitative, and automatic monitoring of labor. Aim of this work is the preliminary clinical validation and accuracy evaluation of our automatic algorithm in assessing progression angle (PA) and fetal head station (FHS). A cohort of 10 parturients underwent conventional labor management, with additional translabial echographic examinations after each uterine contraction. PA and FHS were evaluated by our automatic algorithm on the acquired images. Additionally, an experienced clinical sonographer, blinded regarding the algorithm results, quantified on the same acquisitions of the two parameters through manual contouring, which were considered as the standard reference in the evaluation of automatic algorithm and routine method accuracies. The automatic algorithm (mean error ± 2SD) provided a global accuracy of 0.9 ± 4.0 mm for FHS and 4° ± 9° for PA, which is far above the diagnostic ability shown by the routine method, and therefore it resulted in a reliable method for earlier identification of abnormal labor patterns in support of clinical decisions. PMID:24106524

  13. Automatic Evaluation of Progression Angle and Fetal Head Station through Intrapartum Echographic Monitoring

    PubMed Central

    Casciaro, Ernesto; Di Renzo, Gian Carlo; Perrone, Antonio

    2013-01-01

    Labor progression is routinely assessed through transvaginal digital inspections, meaning that the clinical decisions taken during the most delicate phase of pregnancy are subjective and scarcely supported by technological devices. In response to such inadequacies, we combined intrapartum echographic acquisitions with advanced tracking algorithms in a new method for noninvasive, quantitative, and automatic monitoring of labor. Aim of this work is the preliminary clinical validation and accuracy evaluation of our automatic algorithm in assessing progression angle (PA) and fetal head station (FHS). A cohort of 10 parturients underwent conventional labor management, with additional translabial echographic examinations after each uterine contraction. PA and FHS were evaluated by our automatic algorithm on the acquired images. Additionally, an experienced clinical sonographer, blinded regarding the algorithm results, quantified on the same acquisitions of the two parameters through manual contouring, which were considered as the standard reference in the evaluation of automatic algorithm and routine method accuracies. The automatic algorithm (mean error ± 2SD) provided a global accuracy of 0.9 ± 4.0 mm for FHS and 4° ± 9° for PA, which is far above the diagnostic ability shown by the routine method, and therefore it resulted in a reliable method for earlier identification of abnormal labor patterns in support of clinical decisions. PMID:24106524

  14. Vector Doppler Method Based on an Automatic Transverse Angle Tracking Procedure

    NASA Astrophysics Data System (ADS)

    Dallai, A.; Boni, E.; Francalanci, L.; Tortoli, P.

    Traditional Doppler methods only measure the axial component of the velocity vector. The lack of information on the beam-to-flow (Doppler) angle creates an ambiguity which can lead to large errors in velocity magnitude estimates. An original approach was recently introduced, in which two ultrasound beams with known relative orientation are directed towards the same vessel, one being committed to perform a Doppler measurement, while the second beam has the specific task of detecting the beam-to-flow angle. In this paper, an angle-tracking procedure allowing the Doppler angle to be automatically determined with high accuracy is presented. The procedure is based on the real-time estimation of suitable Doppler spectrum parameters obtained from an M-line associated to a sub-aperture of a linear array probe. Such parameters are used to steer the M-line towards a direction corresponding to a desired beam-flow angle. Knowledge of this angle is finally exploited to obtain the velocity magnitude through the classic Doppler equation related to the second beam. The implementation of the method on a new ultrasound machine and its validation through in vitro and in vivo tests are reported.

  15. View Angle Effects on MODIS Snow Mapping in Forests

    NASA Technical Reports Server (NTRS)

    Xin, Qinchuan; Woodcock, Curtis E.; Liu, Jicheng; Tan, Bin; Melloh, Rae A.; Davis, Robert E.

    2012-01-01

    Binary snow maps and fractional snow cover data are provided routinely from MODIS (Moderate Resolution Imaging Spectroradiometer). This paper investigates how the wide observation angles of MODIS influence the current snow mapping algorithm in forested areas. Theoretical modeling results indicate that large view zenith angles (VZA) can lead to underestimation of fractional snow cover (FSC) by reducing the amount of the ground surface that is viewable through forest canopies, and by increasing uncertainties during the gridding of MODIS data. At the end of the MODIS scan line, the total modeled error can be as much as 50% for FSC. Empirical analysis of MODIS/Terra snow products in four forest sites shows high fluctuation in FSC estimates on consecutive days. In addition, the normalized difference snow index (NDSI) values, which are the primary input to the MODIS snow mapping algorithms, decrease as VZA increases at the site level. At the pixel level, NDSI values have higher variances, and are correlated with the normalized difference vegetation index (NDVI) in snow covered forests. These findings are consistent with our modeled results, and imply that consideration of view angle effects could improve MODIS snow monitoring in forested areas.

  16. Emerging applications of small angle solution scattering in structural biology

    PubMed Central

    Chaudhuri, Barnali N

    2015-01-01

    Small angle solution X-ray and neutron scattering recently resurfaced as powerful tools to address an array of biological problems including folding, intrinsic disorder, conformational transitions, macromolecular crowding, and self or hetero-assembling of biomacromolecules. In addition, small angle solution scattering complements crystallography, nuclear magnetic resonance spectroscopy, and other structural methods to aid in the structure determinations of multidomain or multicomponent proteins or nucleoprotein assemblies. Neutron scattering with hydrogen/deuterium contrast variation, or X-ray scattering with sucrose contrast variation to a certain extent, is a convenient tool for characterizing the organizations of two-component systems such as a nucleoprotein or a lipid-protein assembly. Time-resolved small and wide-angle solution scattering to study biological processes in real time, and the use of localized heavy-atom labeling and anomalous solution scattering for applications as FRET-like molecular rulers, are amongst promising newer developments. Despite the challenges in data analysis and interpretation, these X-ray/neutron solution scattering based approaches hold great promise for understanding a wide variety of complex processes prevalent in the biological milieu. PMID:25516491

  17. PULSAR BINARY BIRTHRATES WITH SPIN-OPENING ANGLE CORRELATIONS

    SciTech Connect

    O'Shaughnessy, Richard; Kim, Chunglee E-mail: ckim@astro.lu.s

    2010-05-20

    with spin period between 10 ms and 100 ms, where few measurements of misalignment and opening angle provide a sound basis for extrapolation, we marginalized our posterior birthrate distribution P(R) over a range of plausible beaming correction factors. We explore several alternative beaming geometry distributions, demonstrating that our predictions are robust except in (untestable) scenarios with many highly aligned recycled pulsars. Finally, in addition to exploring alternative beam geometries, we also briefly summarize how uncertainties in each pulsar binary's lifetime and in the pulsar luminosity distribution can be propagated into P(R).

  18. Boron addition to alloys

    SciTech Connect

    Coad, B. C.

    1985-08-20

    A process for addition of boron to an alloy which involves forming a melt of the alloy and a reactive metal, selected from the group consisting of aluminum, titanium, zirconium and mixtures thereof to the melt, maintaining the resulting reactive mixture in the molten state and reacting the boric oxide with the reactive metal to convert at least a portion of the boric oxide to boron which dissolves in the resulting melt, and to convert at least portion of the reactive metal to the reactive metal oxide, which oxide remains with the resulting melt, and pouring the resulting melt into a gas stream to form a first atomized powder which is subsequently remelted with further addition of boric oxide, re-atomized, and thus reprocessed to convert essentially all the reactive metal to metal oxide to produce a powdered alloy containing specified amounts of boron.

  19. Tackifier for addition polyimides

    NASA Technical Reports Server (NTRS)

    Butler, J. M.; St.clair, T. L.

    1980-01-01

    A modification to the addition polyimide, LaRC-160, was prepared to improve tack and drape and increase prepeg out-time. The essentially solventless, high viscosity laminating resin is synthesized from low cost liquid monomers. The modified version takes advantage of a reactive, liquid plasticizer which is used in place of solvent and helps solve a major problem of maintaining good prepeg tack and drape, or the ability of the prepeg to adhere to adjacent plies and conform to a desired shape during the lay up process. This alternate solventless approach allows both longer life of the polymer prepeg and the processing of low void laminates. This approach appears to be applicable to all addition polyimide systems.

  20. Vinyl capped addition polyimides

    NASA Technical Reports Server (NTRS)

    Vannucci, Raymond D. (Inventor); Malarik, Diane C. (Inventor); Delvigs, Peter (Inventor)

    1991-01-01

    Polyimide resins (PMR) are generally useful where high strength and temperature capabilities are required (at temperatures up to about 700 F). Polyimide resins are particularly useful in applications such as jet engine compressor components, for example, blades, vanes, air seals, air splitters, and engine casing parts. Aromatic vinyl capped addition polyimides are obtained by reacting a diamine, an ester of tetracarboxylic acid, and an aromatic vinyl compound. Low void materials with improved oxidative stability when exposed to 700 F air may be fabricated as fiber reinforced high molecular weight capped polyimide composites. The aromatic vinyl capped polyimides are provided with a more aromatic nature and are more thermally stable than highly aliphatic, norbornenyl-type end-capped polyimides employed in PMR resins. The substitution of aromatic vinyl end-caps for norbornenyl end-caps in addition polyimides results in polymers with improved oxidative stability.

  1. [Biologically active food additives].

    PubMed

    Velichko, M A; Shevchenko, V P

    1998-07-01

    More than half out of 40 projects for the medical science development by the year of 2000 have been connected with the bio-active edible additives that are called "the food of XXI century", non-pharmacological means for many diseases. Most of these additives--nutricevtics and parapharmacevtics--are intended for the enrichment of food rations for the sick or healthy people. The ecologicaly safest and most effective are combined domestic adaptogens with immuno-modulating and antioxidating action that give anabolic and stimulating effect,--"leveton", "phytoton" and "adapton". The MKTs-229 tablets are residue discharge means. For atherosclerosis and general adiposis they recommend "tsar tablets" and "aiconol (ikhtien)"--on the base of cod-liver oil or "splat" made out of seaweed (algae). All these preparations have been clinically tested and received hygiene certificates from the Institute of Dietology of the Russian Academy of Medical Science. PMID:9752776

  2. Effect of fence height on joint angles of agility dogs.

    PubMed

    Birch, Emily; Leśniak, Kirsty

    2013-12-01

    The Kennel Club (KC) and United Kingdom Agility (UKA) govern major dog agility competitions in the UK. Dogs are categorised into different jump heights depending on their height at the withers, with fence heights ranging from 300 to 650 mm for both organisations. Dogs fall into one of three height categories when competing under KC rules and one of four height categories under UKA rules. The aim of this study was to investigate the influence of an additional height category for agility dogs measuring over 430 mm at the withers. Jump heights were selected that related to the percentage of body height that dogs of 430 mm (7% lower) and 431 mm (51% higher) height at the withers would be encouraged to jump under UKA regulations without the addition of their fourth ('standard height') category. Joint angles were determined from anatomical markers placed on the forelimb and hind limb joints, and at six points along the vertebral column. As fence height increased, flexion of the scapulohumeral joint increased significantly for both the take-off and bascule (arc) phases of the jump. The increase in flexion as a consequence of the increase in fence height is likely to result in intensified stretching of the biceps brachii and supraspinatus muscles. In addition, increasing fence high resulted in an increase in the sacroiliac joint angle during take-off. PMID:24360736

  3. 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.

  4. Angle-Resolved Auger Spectroscopy as a Sensitive Access to Vibronic Coupling

    NASA Astrophysics Data System (ADS)

    Knie, A.; Patanen, M.; Hans, A.; Petrov, I. D.; Bozek, J. D.; Ehresmann, A.; Demekhin, Ph. V.

    2016-05-01

    In the angle-averaged excitation and decay spectra of molecules, vibronic coupling may induce the usually weak dipole-forbidden transitions by the excitation intensity borrowing mechanism. The present complementary theoretical and experimental study of the resonant Auger decay of core-to-Rydberg excited CH4 and Ne demonstrates that vibronic coupling plays a decisive role in the formation of the angle-resolved spectra by additionally involving the decay rate borrowing mechanism. Thereby, we propose that the angle-resolved Auger spectroscopy can in general provide very insightful information on the strength of the vibronic coupling.

  5. Electrophilic addition of astatine

    SciTech Connect

    Norseev, Yu.V.; Vasaros, L.; Nhan, D.D.; Huan, N.K.

    1988-03-01

    It has been shown for the first time that astatine is capable of undergoing addition reactions to unsaturated hydrocarbons. A new compound of astatine, viz., ethylene astatohydrin, has been obtained, and its retention numbers of squalane, Apiezon, and tricresyl phosphate have been found. The influence of various factors on the formation of ethylene astatohydrin has been studied. It has been concluded on the basis of the results obtained that the univalent cations of astatine in an acidic medium is protonated hypoastatous acid.

  6. Hydrocarbon fuel additive

    SciTech Connect

    Ambrogio, S.

    1989-02-28

    This patent describes the method of fuel storage or combustion, wherein the fuel supply contains small amounts of water, the step of adding to the fuel supply an additive comprising a blend of a hydrophilic agent chosen from the group of ethylene glycol, n-butyl alcohol, and cellosolve in the range of 22-37% by weight; ethoxylated nonylphenol in the range of 26-35% by weight; nonylphenol polyethylene glycol ether in the range of 32-43% by weight.

  7. Functional Generalized Additive Models.

    PubMed

    McLean, Mathew W; Hooker, Giles; Staicu, Ana-Maria; Scheipl, Fabian; Ruppert, David

    2014-01-01

    We introduce the functional generalized additive model (FGAM), a novel regression model for association studies between a scalar response and a functional predictor. We model the link-transformed mean response as the integral with respect to t of F{X(t), t} where F(·,·) is an unknown regression function and X(t) is a functional covariate. Rather than having an additive model in a finite number of principal components as in Müller and Yao (2008), our model incorporates the functional predictor directly and thus our model can be viewed as the natural functional extension of generalized additive models. We estimate F(·,·) using tensor-product B-splines with roughness penalties. A pointwise quantile transformation of the functional predictor is also considered to ensure each tensor-product B-spline has observed data on its support. The methods are evaluated using simulated data and their predictive performance is compared with other competing scalar-on-function regression alternatives. We illustrate the usefulness of our approach through an application to brain tractography, where X(t) is a signal from diffusion tensor imaging at position, t, along a tract in the brain. In one example, the response is disease-status (case or control) and in a second example, it is the score on a cognitive test. R code for performing the simulations and fitting the FGAM can be found in supplemental materials available online. PMID:24729671

  8. Photometric theory for wide-angle phenomena

    NASA Technical Reports Server (NTRS)

    Usher, Peter D.

    1990-01-01

    An examination is made of the problem posed by wide-angle photographic photometry, in order to extract a photometric-morphological history of Comet P/Halley. Photometric solutions are presently achieved over wide angles through a generalization of an assumption-free moment-sum method. Standard stars in the field allow a complete solution to be obtained for extinction, sky brightness, and the characteristic curve. After formulating Newton's method for the solution of the general nonlinear least-square problem, an implementation is undertaken for a canonical data set. Attention is given to the problem of random and systematic photometric errors.

  9. Ship wakes: Kelvin or Mach angle?

    PubMed

    Rabaud, Marc; Moisy, Frédéric

    2013-05-24

    From the analysis of a set of airborne images of ship wakes, we show that the wake angles decrease as U(-1) at large velocities, in a way similar to the Mach cone for supersonic airplanes. This previously unnoticed Mach-like regime is in contradiction with the celebrated Kelvin prediction of a constant angle of 19.47° independent of the ship's speed. We propose here a model, confirmed by numerical simulations, in which the finite size of the disturbance explains this transition between the Kelvin and Mach regimes at a Froude number Fr=U/√[gL]~/=0.5, where L is the hull ship length. PMID:23745883

  10. Airfoil Lift with Changing Angle of Attack

    NASA Technical Reports Server (NTRS)

    Reid, Elliott G

    1927-01-01

    Tests have been made in the atmospheric wind tunnel of the National Advisory Committee for Aeronautics to determine the effects of pitching oscillations upon the lift of an airfoil. It has been found that the lift of an airfoil, while pitching, is usually less than that which would exist at the same angle of attack in the stationary condition, although exceptions may occur when the lift is small or if the angle of attack is being rapidly reduced. It is also shown that the behavior of a pitching airfoil may be qualitatively explained on the basis of accepted aerodynamic theory.

  11. Confocal zero-angle dynamic depolarized light scattering.

    PubMed

    Potenza, M A C; Sanvito, T; Alaimo, M D; Degiorgio, V; Giglio, M

    2010-01-01

    We present a novel Dynamic Depolarized Scattering method based on a tight confocal, zero scattering angle, heterodyne scheme. The method is highly immune from parasitic multiple-scattering contributions, so that it can operate with non-index-matched samples presenting large turbidity. It provides measurements of both rotational and translational diffusion coefficients, the latter via number fluctuation spectroscopy. In addition, the amplitude ratio between the two baselines for the fast rotational mode and the slow translational mode can be used to determine the particles intrinsic birefringence. PMID:20087622

  12. 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…

  13. A fringe shadow method for measuring flapping angle and torsional angle of a dragonfly wing

    NASA Astrophysics Data System (ADS)

    Zeng, Lijiang; Matsumoto, Hirokazu; Kawachi, Keiji

    1996-05-01

    A fringe shadow (FS) method was developed for measuring the flapping angle and torsional angle of a dragonfly wing during beating motion. This new method involves two sets of fringe patterns projected onto the wing from orthogonal directions. The torsional angle is determined using the length of the shadow of the wing chord that is cast by the two sets of fringe patterns. The flapping angle is determined using the shadowgraph of the wing projected by a laser. The advantages of the FS method are its capability (i) to measure the flapping angle and torsional angle of a dragonfly wing simultaneously using only one high-speed camera and (ii) to recognize the spanwise position of a section from the number of fringes, without having to use diffuse marks that are common in current methods. The resolution of the FS method can be changed easily by adjusting the fringe spacing. The measurement results for the torsional angle and flapping angle of a dragonfly wing prove the effectiveness of the FS method in studying the flight performance of dragonflies.

  14. Using Digital Technology to See Angles from Different Angles. Part 2: Openings and Turns

    ERIC Educational Resources Information Center

    Host, Erin; Baynham, Emily; McMaster, Heather

    2015-01-01

    Ever wondered how to use technology to teach angles? This article follows on from an earlier article published last year, providing a range of ideas for integrating technology and concrete materials with the teaching of angle concepts. The authors also provide a comprehensive list of free online games and learning objects that can be used to teach…

  15. Improvement in B1+ Homogeneity and Average Flip Angle Using Dual-Source Parallel RF Excitation for Cardiac MRI in Swine Hearts.

    PubMed

    Schär, Michael; Ding, Haiyan; Herzka, Daniel A

    2015-01-01

    Cardiac MRI may benefit from increased polarization at high magnetic field strength of 3 Tesla but is challenged by increased field inhomogeneity. Initial human studies have shown that the radiofrequency (RF) excitation field (B1+) used for signal excitation in the heart is both inhomogeneous and significantly lower than desired, potentially leading to image artifacts and biased quantitative measures. Recently, multi-channel transmit systems have been introduced allowing localized patient specific RF shimming based on acquired calibration B1+ maps. Some prior human studies have shown lower than desired mean flip angles in the hearts of large patients even after RF shimming. Here, 100 cardiac B1+ map pairs before and after RF shimming were acquired in 55 swine. The mean flip angle and the coefficient of variation (CV) of the flip angle in the heart were determined before and after RF shimming. Mean flip angle, CV, and RF shim values (power ratio and phase difference between the two transmit channels) were tested for correlation with cross sectional body area and the Right-Left/Anterior-Posterior ratio. RF shimming significantly increased the mean flip angle in swine heart from 74.4±6.7% (mean ± standard deviation) to 94.7±4.8% of the desired flip angle and significantly reduced CV from 0.11±0.03 to 0.07±0.02 (p<1e-10 for both). These results compare well with several previous human studies, except that the mean flip angle in the human heart only improved to 89% with RF shimming, possibly because the RF shimming routine does not consider safety constraints in very large patients. Additionally, mean flip angle decreased and CV increased with larger cross sectional body area, however, the RF shimming parameters did not correlate with cross sectional body area. RF shim power ratio correlated weakly with Right-Left/Anterior-Posterior ratio but phase difference did not, further substantiating the need for subject specific cardiac RF shimming. PMID:26436658

  16. Improvement in B1+ Homogeneity and Average Flip Angle Using Dual-Source Parallel RF Excitation for Cardiac MRI in Swine Hearts

    PubMed Central

    Schär, Michael; Ding, Haiyan; Herzka, Daniel A.

    2015-01-01

    Cardiac MRI may benefit from increased polarization at high magnetic field strength of 3 Tesla but is challenged by increased field inhomogeneity. Initial human studies have shown that the radiofrequency (RF) excitation field (B1+) used for signal excitation in the heart is both inhomogeneous and significantly lower than desired, potentially leading to image artifacts and biased quantitative measures. Recently, multi-channel transmit systems have been introduced allowing localized patient specific RF shimming based on acquired calibration B1+ maps. Some prior human studies have shown lower than desired mean flip angles in the hearts of large patients even after RF shimming. Here, 100 cardiac B1+ map pairs before and after RF shimming were acquired in 55 swine. The mean flip angle and the coefficient of variation (CV) of the flip angle in the heart were determined before and after RF shimming. Mean flip angle, CV, and RF shim values (power ratio and phase difference between the two transmit channels) were tested for correlation with cross sectional body area and the Right-Left/Anterior-Posterior ratio. RF shimming significantly increased the mean flip angle in swine heart from 74.4±6.7% (mean ± standard deviation) to 94.7±4.8% of the desired flip angle and significantly reduced CV from 0.11±0.03 to 0.07±0.02 (p<<1e-10 for both). These results compare well with several previous human studies, except that the mean flip angle in the human heart only improved to 89% with RF shimming, possibly because the RF shimming routine does not consider safety constraints in very large patients. Additionally, mean flip angle decreased and CV increased with larger cross sectional body area, however, the RF shimming parameters did not correlate with cross sectional body area. RF shim power ratio correlated weakly with Right-Left/Anterior-Posterior ratio but phase difference did not, further substantiating the need for subject specific cardiac RF shimming. PMID:26436658

  17. 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.

  18. An investigation of the dose distribution effect related with collimator angle for VMAT method

    NASA Astrophysics Data System (ADS)

    Tas, B.; Bilge, H.; Ozturk, S. Tokdemir

    2016-03-01

    Aim of this study is to investigate the efficacy of dose distribution in eleven prostate cancer patients with single VMAT and double VMAT when varying collimator angle. We generated optimum single and double VMAT treatment plans when collimator angle was 0°. We recalculated single VMAT plans at different collimator angles(0°,15°,30°,45°,60°,75°,90°) for double VMAT plans(0°-0°,15°-345°,30°-330°,45°-315°,60°-300°,75°-285°,90°-270°) without changing any optimization parameters. HI, DVH and %95 dose coverage of PTV calculated and analyzed. We determined better dose distribution with some collimator angles. Plans were verified using the 2 dimensional ion chamber array Matrixx® and 3 dimensional Compass® software program. A higher %95 dose coverage of PTV was found for single VMAT in the 15° collimator angle, for double VMAT in the 60°-300° and 75°-285° collimator angles. Because of lower rectum doses, we suggested 75°-285°. When we compared single and double VMAT's dose distribution, we had better % 95 dose coverage of PTV and lower HI with double VMAT. Our result was significant statistically. These finds are informative for choosing 75°-285° collimator angles in double VMAT plans for prostate cancer.

  19. Computational Process Modeling for Additive Manufacturing

    NASA Technical Reports Server (NTRS)

    Bagg, Stacey; Zhang, Wei

    2014-01-01

    Computational Process and Material Modeling of Powder Bed additive manufacturing of IN 718. Optimize material build parameters with reduced time and cost through modeling. Increase understanding of build properties. Increase reliability of builds. Decrease time to adoption of process for critical hardware. Potential to decrease post-build heat treatments. Conduct single-track and coupon builds at various build parameters. Record build parameter information and QM Meltpool data. Refine Applied Optimization powder bed AM process model using data. Report thermal modeling results. Conduct metallography of build samples. Calibrate STK models using metallography findings. Run STK models using AO thermal profiles and report STK modeling results. Validate modeling with additional build. Photodiode Intensity measurements highly linear with power input. Melt Pool Intensity highly correlated to Melt Pool Size. Melt Pool size and intensity increase with power. Applied Optimization will use data to develop powder bed additive manufacturing process model.

  20. 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

  1. Microstructure-related properties of magnesium fluoride films at 193nm by oblique-angle deposition.

    PubMed

    Guo, Chun; Kong, Mingdong; Lin, Dawei; Liu, Cunding; Li, Bincheng

    2013-01-14

    Magnesium fluoride (MgF2) films deposited by resistive heating evaporation with oblique-angle deposition have been investigated in details. The optical and micro-structural properties of single-layer MgF2 films were characterized by UV-VIS and FTIR spectrophotometers, scanning electron microscope (SEM), atomic force microscope (AFM), and x-ray diffraction (XRD), respectively. The dependences of the optical and micro-structural parameters of the thin films on the deposition angle were analyzed. It was found that the MgF2 film in a columnar microstructure was negatively inhomogeneous of refractive index and polycrystalline. As the deposition angle increased, the optical loss, extinction coefficient, root-mean-square (rms) roughness, dislocation density and columnar angle of the MgF2 films increased, while the refractive index, packing density and grain size decreased. Furthermore, IR absorption of the MgF2 films depended on the columnar structured growth. PMID:23388989

  2. A Vision-Based Dynamic Rotational Angle Measurement System for Large Civil Structures

    PubMed Central

    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

  3. Additional first-trimester ultrasound markers.

    PubMed

    Sonek, J; Nicolaides, K

    2010-09-01

    The first trimester (11-13 +6 weeks) ultrasound examination is useful for several reasons: determination of an accurate date of confinement, diagnostic purposes, and screening for fetal defects. Nuchal translucency measurement combined with maternal serum markers (free b-human chorionic gonadotropin and pregnancy-associated plasma protein A) is the mainstay of first-trimester screening for chromosomal defects. However, over the past decade additional ultrasound markers have been developed that improve the performance of this type of screening. The novel markers include evaluation of the nasal bone, fronto-maxillary angle measurement, and Doppler evaluations of the blood flow across the tricuspid valve and in the ductus venosus. PMID:20638573

  4. Angle at the Medial Border: The Spinovertebra Angle and Its Significance

    PubMed Central

    Oladipo, G. S.; Aigbogun, E. O.; Akani, G. L.

    2015-01-01

    Background. The evolution from quadrupedalism to bipedalism has adjusted the balance of the upper limb to extensive movement at the shoulder. The scapular angles provide the point of attachment and control to various muscles and have been associated with the different movements of the shoulder girdle and joint. This has made the morphometric and anthropometric study of scapula a subject of extensive investigation. Aim. In the present study, the angle at the medial border was measured in the South-Southern Nigerian population and an anatomical name was ascribed to the angle. Method. The study was conducted on 173 scapulae (75 right and 98 left) obtained from various Anatomy Department of South-Sothern Nigerian Universities. The angle at medial border was obtained by pinning the edge of the superior and inferior angles, the lined traced out, and the angle measured using a protractor. SPSS version 20 was used to analyse the data. t-test was used to determine mean angular difference in the sides. Result. The mean ± SD of the medial angle was observed to be 136.88 ± 7.70° (R = 138.13 ± 7.06° : L = 135.92 ± 8.05°). Statistical analysis using the Z-test for mean difference showed the medial angle was found to be higher in the right side of the scapula (mean difference of 2.214 ± 1.152°), but the observed difference was not statistically significant (P > 0.05). The above findings have adjusted the scapula from three to four angles (lateral, superior, inferior, and medial) formed from four borders (lateral, superior, inferior, and superomedial and inferomedial). The medial angle because of its anatomical location was named “spinovertebral” angle, owing to its position at the scapulae spine, and located in medial proximity to the vertebra column. Conclusion. The medial angle (now referred to as the spinovertebral angle) of the right side of the scapula is wider than the left. The representation of the spinovertebral angle is very important, as the

  5. Angle at the Medial Border: The Spinovertebra Angle and Its Significance.

    PubMed

    Oladipo, G S; Aigbogun, E O; Akani, G L

    2015-01-01

    Background. The evolution from quadrupedalism to bipedalism has adjusted the balance of the upper limb to extensive movement at the shoulder. The scapular angles provide the point of attachment and control to various muscles and have been associated with the different movements of the shoulder girdle and joint. This has made the morphometric and anthropometric study of scapula a subject of extensive investigation. Aim. In the present study, the angle at the medial border was measured in the South-Southern Nigerian population and an anatomical name was ascribed to the angle. Method. The study was conducted on 173 scapulae (75 right and 98 left) obtained from various Anatomy Department of South-Sothern Nigerian Universities. The angle at medial border was obtained by pinning the edge of the superior and inferior angles, the lined traced out, and the angle measured using a protractor. SPSS version 20 was used to analyse the data. t-test was used to determine mean angular difference in the sides. Result. The mean ± SD of the medial angle was observed to be 136.88 ± 7.70° (R = 138.13 ± 7.06° : L = 135.92 ± 8.05°). Statistical analysis using the Z-test for mean difference showed the medial angle was found to be higher in the right side of the scapula (mean difference of 2.214 ± 1.152°), but the observed difference was not statistically significant (P > 0.05). The above findings have adjusted the scapula from three to four angles (lateral, superior, inferior, and medial) formed from four borders (lateral, superior, inferior, and superomedial and inferomedial). The medial angle because of its anatomical location was named "spinovertebral" angle, owing to its position at the scapulae spine, and located in medial proximity to the vertebra column. Conclusion. The medial angle (now referred to as the spinovertebral angle) of the right side of the scapula is wider than the left. The representation of the spinovertebral angle is very important, as the directional

  6. Enhanced shear strength of sodium bentonite using frictional additives

    SciTech Connect

    Schmitt, K.E.; Bowders, J.J.; Gilbert, R.B.; Daniel, D.E.

    1997-12-31

    One of the most important obstacles to using geosynthetic clay liners (GCLs) in landfill cover systems is the low shear strength provided by the bentonitic portion of the GCL. In this study, the authors propose that granular, frictional materials might be added to the bentonite to form an admixture that would have greater shear strength than the bentonite alone while still raining low hydraulic conductivity. Bentonite was mixed with two separate granular additives, expanded shale and recycled to form mixtures consisting of 20-70% bentonite by weight. In direct shear tests at normal stresses of 34.5-103.5 kPa, effective friction angles were measured as 45{degrees} for the expanded 36{degrees} for the recycled glass, and 7{degrees} for the hydrated granular bentonite. The strength of the expanded shale mixtures increased nearly linearly as the percentage shale in the mixture increased, to 44{degrees} for a bentonite mixture with 80% shale. The addition of recycled glass showed little effect on the shear strength of the mixtures of glass and bentonite. Hydraulic conductivity measurements for both types of mixtures indicated a linear increase with log(k) as the amount of granular additive increased. For applications involving geosynthetic clay liners for cover systems, a mixture of 40% expanded shale and 60% bentonite is recommended, although further testing must be done. The 40/60 mixture satisfies the hydraulic equivalency requirement, with k = 5.1X10{sup -9} cm/sec, while increasing the shear strength parameters of the bentonitic mixture to {phi}{prime} = 17{degrees} and c{prime} = 0.

  7. Siloxane containing addition polyimides

    NASA Technical Reports Server (NTRS)

    Maudgal, S.; St. Clair, T. L.

    1984-01-01

    Addition polyimide oligomers have been synthesized from bis(gamma-aminopropyl) tetramethyldisiloxane and 3, 3', 4, 4'-benzophenonetetracarboxylic dianhydride using a variety of latent crosslinking groups as endcappers. The prepolymers were isolated and characterized for solubility (in amide, chlorinated and ether solvents), melt flow and cure properties. The most promising systems, maleimide and acetylene terminated prepolymers, were selected for detailed study. Graphite cloth reinforced composites were prepared and properties compared with those of graphite/Kerimid 601, a commercially available bismaleimide. Mixtures of the maleimide terminated system with Kerimid 601, in varying proportions, were also studied.

  8. Oil additive process

    SciTech Connect

    Bishop, H.

    1988-10-18

    This patent describes a method of making an additive comprising: (a) adding 2 parts by volume of 3% sodium hypochlorite to 45 parts by volume of diesel oil fuel to form a sulphur free fuel, (b) removing all water and foreign matter formed by the sodium hypochlorite, (c) blending 30 parts by volume of 24% lead naphthanate with 15 parts by volume of the sulphur free fuel, 15 parts by volume of light-weight material oil to form a blended mixture, and (d) heating the blended mixture slowly and uniformly to 152F.

  9. {l_angle}110{r_angle} dendrite growth in aluminum feathery grains

    SciTech Connect

    Henry, S.; Rappaz, M.; Jarry, P.

    1998-11-01

    Automatic indexing of electron backscattered diffraction patterns, scanning electron microscopy, and optical microscopy observations have been carried out on aluminum-magnesium-silicon, aluminum-copper, and aluminum-silicon alloys directionally solidified or semicontinuously cast using the direct chill casting process. From these combined observations, it is shown that the feathery grains are made of {l_angle}110{r_angle} primary dendrite trunks (e.g., [011{bar 1}]) split in their centers by a coherent (111) twin plane. The average spacing of the dendrite trunks in the twin plane (about 10 to 20 {micro}m) is typically one order of magnitude smaller than that separating successive rows of trunks (or twin planes). The [011{bar 1}] orientation of these trunks is close to the thermal gradient direction (typically within 15 deg)--a feature probably resulting from a growth competition mechanism similar to that occurring during normal <100> columnar dendrite growth. On both sides of these trunks, secondary dendrite arms also grow along {l_angle}110{r_angle} directions. Their impingement creates wavy noncoherent twin boundaries between the coherent twin planes. In the twin plane, evidence is shown that {l_angle}110{r_angle} branching mechanisms lead to the propagation of the twinned regions, to the regular arrangement of the primary dendrite trunks along a [{bar 2}11] direction, and to coherent planar twin boundaries. From these observations, it is concluded that the feathery grains are probably the result of a change from a normal <100> to a {l_angle}110{r_angle} surface tension/attachment kinetics anisotropy growth mode. Finally, the proposed mechanisms of leathery grain growth are further supported by the observation of {l_angle}110{r_angle} dendrite growth morphologies in thin aluminum-zinc coatings.

  10. Infrared Drying Parameter Optimization

    NASA Astrophysics Data System (ADS)

    Jackson, Matthew R.

    In recent years, much research has been done to explore direct printing methods, such as screen and inkjet printing, as alternatives to the traditional lithographic process. The primary motivation is reduction of the material costs associated with producing common electronic devices. Much of this research has focused on developing inkjet or screen paste formulations that can be printed on a variety of substrates, and which have similar conductivity performance to the materials currently used in the manufacturing of circuit boards and other electronic devices. Very little research has been done to develop a process that would use direct printing methods to manufacture electronic devices in high volumes. This study focuses on developing and optimizing a drying process for conductive copper ink in a high volume manufacturing setting. Using an infrared (IR) dryer, it was determined that conductive copper prints could be dried in seconds or minutes as opposed to tens of minutes or hours that it would take with other drying devices, such as a vacuum oven. In addition, this study also identifies significant parameters that can affect the conductivity of IR dried prints. Using designed experiments and statistical analysis; the dryer parameters were optimized to produce the best conductivity performance for a specific ink formulation and substrate combination. It was determined that for an ethylene glycol, butanol, 1-methoxy 2- propanol ink formulation printed on Kapton, the optimal drying parameters consisted of a dryer height of 4 inches, a temperature setting between 190 - 200°C, and a dry time of 50-65 seconds depending on the printed film thickness as determined by the number of print passes. It is important to note that these parameters are optimized specifically for the ink formulation and substrate used in this study. There is still much research that needs to be done into optimizing the IR dryer for different ink substrate combinations, as well as developing a

  11. THE EFFECTS OF THREE DIFFERENT REAR KNEE ANGLES ON KINEMATICS IN THE SPRINT START

    PubMed Central

    Bertucco, M.; Zancanaro, C.

    2014-01-01

    The purpose of this study was to investigate the rear knee angle range in the set position that allows sprinters to reach greater propulsion on the rear block during the sprint start. Eleven university-track team sprinters performed the sprint start using three rear knee angle conditions: 90°, 115° and 135°. A motion capture system consisting of 8 digital cameras (250 Hz) was used to record kinematic parameters at the starting block phase and the acceleration phase. The following variables were considered: horizontal velocity of the centre of mass (COM), COM height, block time, pushing time on the rear block, percentage of pushing time on the rear block, force impulse, push-off angle and length of the first two strides. The main results show that first, horizontal block velocity is significantly greater at 90° vs 115° and 135° rear knee angle (p<0.05 and p<0.001 respectively) at block clearance and the first two strides; second, during the pushing phase, the percentage of pushing time of the rear leg is significantly greater at 90° vs 135° rear knee angle (p<0.01). No significant difference was found for block time among the conditions. These results indicate that block velocity is the main kinematic parameter affected by rear knee angle during the starting block phase and acceleration phase. Furthermore, the 90° rear knee angle allows for a better push-off of the rear leg than larger angles at the set position. The findings of this study provide some direction and useful practical advice in defining an efficient rear leg biomechanical configuration at the set position. PMID:25177099

  12. Recent Results on the CKM Angle Alpha

    SciTech Connect

    Mihalyi, A.; /Wisconsin U., Madison

    2005-10-18

    The method to measure the CKM angle {alpha} and the modes sensitive to it are discussed. It is shown that the B {yields} {rho}{rho} decays provide the most stringent constraint on {alpha}, which is found to be {alpha} = 96{sup o} {+-} 10{sup o}(stat) {+-} 4{sup o}(syst){+-} 13{sup o}(penguin).

  13. Nonschwannoma tumors of the cerebellopontine angle.

    PubMed

    Friedmann, David R; Grobelny, Bartosz; Golfinos, John G; Roland, J Thomas

    2015-06-01

    Although the preponderance of cerebellopontine angle lesions are schwannomas, focused attention to patient clinical history, imaging studies, and tissue biopsies when indicated will aid in detection of less common lesions that might otherwise be misdiagnosed. This is most critical for pathologies that dictate different management paradigms be undertaken. PMID:26043142

  14. Looking at Faces from a New Angle.

    ERIC Educational Resources Information Center

    Mulkey, Mary McNamara; Malm, Susanne

    2000-01-01

    Describes a fifth grade art activity inspired by a restaurant logo that consisted of angled faces fragmented down the middle, with geometric profiles, in bold colors. Explains the process of creating the abstract split faces, from the initial drawing to adding colors. (CMK)

  15. Transmitting rotary motion at an angle

    NASA Technical Reports Server (NTRS)

    Appleberry, W. T.

    1979-01-01

    Transmission consisting of corrugated metal tube that can bend along its axis can transmit torques in range of 100 to 1000 pound-inches at corner angles as great as 180 deg. Possible uses include submerged mechanisms and food processing machinery where sealed drive line without contaminating lubricants is required.

  16. 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.

  17. Mixed glioma of the cerebellopontine angle.

    PubMed

    Millen, S J; Campbell, B H; Meyer, G A; Ho, K C

    1985-11-01

    A rare case of mixed ependymoma and astrocytoma of the cerebellopontine angle is reported. Its clinical presentation, characteristics on evaluation, and prognosis are compared with those of the acoustic neuroma and glioma. The central form of von Recklinghausen's disease and familial multiple lipomatosis as it applies to the patient is also discussed. PMID:3878094

  18. Improved Beam Angle Control with SPV Metrology

    NASA Astrophysics Data System (ADS)

    Steeples, K.; Tsidilkovski, E.; Bertuch, A.; Ishida, E.; Agarwal, A.

    2008-11-01

    A method of real-time monitoring of implant angle for state-of-the-art ion implant doping in integrated circuit manufacturing has been developed using Surface Photo Voltage measurements on conventional monitor wafers. Measurement results are analyzed and compared to other techniques.

  19. Instrument accurately measures weld angle and offset

    NASA Technical Reports Server (NTRS)

    Boyd, W. G.

    1967-01-01

    Weld angle is measured to the nearest arc minute and offset to one thousandth of an inch by an instrument designed to use a reference plane at two locations on a test coupon. A special table for computation has been prepared for use with the instrument.

  20. Wide-Angle, Flat-Field Telescope

    NASA Technical Reports Server (NTRS)

    Hallam, K. L.; Howell, B. J.; Wilson, M. E.

    1987-01-01

    All-reflective system unvignetted. Wide-angle telescope uses unobstructed reflecting elements to produce flat image. No refracting elements, no chromatic aberration, and telescope operates over spectral range from infrared to far ultraviolet. Telescope used with such image detectors as photographic firm, vidicons, and solid-state image arrays.

  1. Association between Bolton discrepancy and Angle malocclusions.

    PubMed

    Cançado, Rodrigo Hermont; Gonçalves Júnior, Waldir; Valarelli, Fabrício Pinelli; Freitas, Karina Maria Salvatore de; Crêspo, Janaina Aparecida Lima

    2015-01-01

    This study aimed to assess and compare the overall and anterior ratios of tooth size discrepancies in all Angle malocclusion groups. The following null hypothesis (H0) was tested: no difference between tooth size discrepancies (overall and anterior) would be observed among Angle malocclusion groups. The sample comprised of 711 pre-orthodontic treatment study casts of Brazilian patients with a mean age of 17.42 years selected from private practices in Brazil. The casts were divided into 3 groups according to the type of malocclusion: Class I (n = 321), Class II (n = 324), and Class III patients (n = 66). The measurement of the greatest mesiodistal width of the teeth was performed using a centesimal precision digital caliper directly on the study casts, from the distal surface of the left first molar to the distal surface of the right first molar. The overall and anterior ratios between the maxillary and mandibular teeth were evaluated using Bolton's method. The following statistical tests were applied: chi-square, independent t-test, and one-way ANOVA. Results showed that all Angle malocclusions groups exhibited a ratio compatible with those recommended by Bolton. With respect to the overall and anterior ratios among the malocclusion groups, no statistically significant differences were found. The null hypothesis was accepted because the results showed no differences in the overall and anterior ratios of tooth size discrepancies among different Angle malocclusion groups. PMID:26486769

  2. Incidence angle normalization of radar backscatter data

    Technology Transfer Automated Retrieval System (TEKTRAN)

    NASA’s Soil Moisture Passive Active (SMAP) satellite (~2014) will include a radar system that will provide L-band multi-polarization backscatter at a constant incidence angle of 40º. During the pre-launch phase of the project there is a need for observations that will support the radar-based soil mo...

  3. Partitioning Pythagorean Triangles Using Pythagorean Angles

    ERIC Educational Resources Information Center

    Swenson, Carl E.; Yandl, Andre L.

    2012-01-01

    Inside any Pythagorean right triangle, it is possible to find a point M so that drawing segments from M to each vertex of the triangle yields angles whose sines and cosines are all rational. This article describes an algorithm that generates an infinite number of such points.

  4. Incident velocity and incident angle of saltating sand grains on Mars

    NASA Astrophysics Data System (ADS)

    Zheng, Xiao-Jing; Fu, Lin-Tao; Bo, Tian-Li

    2013-04-01

    Incident velocity and incident angle are important parameters for Martian aeolian research. In this paper we have established a model for investigating the saltation of sand in steady state, mainly considering the hopping of sand in the air and sand-bed collision process. The model proves to be able to predict sand motion in steady-state saltation on Earth well both qualitatively and quantitatively. Thus, it was applied to the study of sand saltation on Mars. With the help of the model, we found incident velocities and incident angles of Martian grains in steady-state saltation in cases of various wind strengths. Then, these predicted velocities and angles were compared with previous studies. Besides, the model also can show information on lift-off parameters of saltating particles. Therefore, it allows us to study other features in aeolian processes such as the saltation length and sand transport rate.

  5. 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.

  6. Solid-state {sup 17}O magic-angle and dynamic-angle spinning NMR study of the SiO{sub 2} polymorph coesite

    SciTech Connect

    Grandinetti, P.J.; Baltisberger, J.H.; Farnan, I.; Stebbins, J.F.; Werner, U.; Pines, A. |

    1995-08-10

    Five distinctly resolved {sup 17}O solid-state NMR resonances in room temperature coesite, an SiO{sub 2} polymorph, have been observed and assigned using dynamic angle spinning (DAS) at 11.7 T along with magic angle spinning (MAS) spectra at 9.4 and 11.7 T. The {sup 17}O quadrupolar parameters for each of the five oxygen environments in coesite are correlated with the Si-O-Si bridging bond angles determined by diffraction experiments. The sign of e{sup 2}-qQ/h along with the orientation of the electric field gradient for oxygen in the Si-O-Si linkage were determined from a Townes-Dailey analysis of the data. 41 refs., 7 figs., 5 tabs.

  7. Performance Boosting Additive

    NASA Technical Reports Server (NTRS)

    1999-01-01

    Mainstream Engineering Corporation was awarded Phase I and Phase II contracts from Goddard Space Flight Center's Small Business Innovation Research (SBIR) program in early 1990. With support from the SBIR program, Mainstream Engineering Corporation has developed a unique low cost additive, QwikBoost (TM), that increases the performance of air conditioners, heat pumps, refrigerators, and freezers. Because of the energy and environmental benefits of QwikBoost, Mainstream received the Tibbetts Award at a White House Ceremony on October 16, 1997. QwikBoost was introduced at the 1998 International Air Conditioning, Heating, and Refrigeration Exposition. QwikBoost is packaged in a handy 3-ounce can (pressurized with R-134a) and will be available for automotive air conditioning systems in summer 1998.

  8. Sewage sludge additive

    NASA Technical Reports Server (NTRS)

    Kalvinskas, J. J.; Mueller, W. A.; Ingham, J. D. (Inventor)

    1980-01-01

    The additive is for a raw sewage treatment process of the type where settling tanks are used for the purpose of permitting the suspended matter in the raw sewage to be settled as well as to permit adsorption of the dissolved contaminants in the water of the sewage. The sludge, which settles down to the bottom of the settling tank is extracted, pyrolyzed and activated to form activated carbon and ash which is mixed with the sewage prior to its introduction into the settling tank. The sludge does not provide all of the activated carbon and ash required for adequate treatment of the raw sewage. It is necessary to add carbon to the process and instead of expensive commercial carbon, coal is used to provide the carbon supplement.

  9. Perspectives on Additive Manufacturing

    NASA Astrophysics Data System (ADS)

    Bourell, David L.

    2016-07-01

    Additive manufacturing (AM) has skyrocketed in visibility commercially and in the public sector. This article describes the development of this field from early layered manufacturing approaches of photosculpture, topography, and material deposition. Certain precursors to modern AM processes are also briefly described. The growth of the field over the last 30 years is presented. Included is the standard delineation of AM technologies into seven broad categories. The economics of AM part generation is considered, and the impacts of the economics on application sectors are described. On the basis of current trends, the future outlook will include a convergence of AM fabricators, mass-produced AM fabricators, enabling of topology optimization designs, and specialization in the AM legal arena. Long-term developments with huge impact are organ printing and volume-based printing.

  10. New addition curing polyimides

    NASA Technical Reports Server (NTRS)

    Frimer, Aryeh A.; Cavano, Paul

    1991-01-01

    In an attempt to improve the thermal-oxidative stability (TOS) of PMR-type polymers, the use of 1,4-phenylenebis (phenylmaleic anhydride) PPMA, was evaluated. Two series of nadic end-capped addition curing polyimides were prepared by imidizing PPMA with either 4,4'-methylene dianiline or p-phenylenediamine. The first resulted in improved solubility and increased resin flow while the latter yielded a compression molded neat resin sample with a T(sub g) of 408 C, close to 70 C higher than PME-15. The performance of these materials in long term weight loss studies was below that of PMR-15, independent of post-cure conditions. These results can be rationalized in terms of the thermal lability of the pendant phenyl groups and the incomplete imidization of the sterically congested PPMA. The preparation of model compounds as well as future research directions are discussed.

  11. Anterior segment changes after pharmacologic mydriasis using Pentacam and optical coherence tomography in angle closure suspects

    PubMed Central

    Guo, Jing-Min; Li, Mu; Xu, Xiao-Lan; Zhang, Hong; Wang, Jun-Ming

    2015-01-01

    AIM To compare the dynamic changes of anterior segment parameters especially iris morphology induced by pharmacologic mydriasis between angle closure suspects and normal controls. METHODS The study group comprised 19 eyes of 19 angle closure suspects and 19 eyes of 19 age- and sex-matched normal open-angle eyes. Pentacam and optical coherence tomography measurements before and 30min after instillation of compound tropicamide eye drop were performed and compared. Biometric evaluations of iris tomography and anterior chamber angle were estimated by a customized image-processing software. RESULTS Baseline axial length, iris cross sectional area and volume did not differ significantly between angle closure suspects and normal controls. Angle closure suspects had smaller pupil size, narrower anterior segment dimension and axial length, thinner iris with greater curve in comparison with normal controls. Pharmacologic mydriasis led to significant increments in iris thickness at 750 µm, anterior chamber depth and volume, whereas significant decrements in iris curve, cross sectional area and volume in both groups. Angle opening distance at 500 µm was increased significantly in normal controls (from 0.465±0.115 mm to 0.539±0.167 mm, P=0.009), but not in angle closure suspects (from 0.125±0.100 mm to 0.145±0.131 mm, P=0.326). Iris volume change per millimeter of pupil dilation (ΔIV/ΔPD) decreased significantly less in angle closure suspects than normal controls (−2.47±1.33 mm2 vs −3.63±1.58 mm2, P=0.019). Linear regression analysis showed that the change of angle opening distance at 500 µm was associated most with the change of central anterior chamber depth (β=0.841, P=0.002) and ΔIV/ΔPD (β=0.028, P=0.002), followed by gender (β=0.062, P=0.032). CONCLUSION Smaller iris volume decrement per millimeter of pupil dilation is related significantly with the less anterior angle opening in angle closure suspects after pharmacologic mydriasis. Dynamic iris change

  12. Modeling granular material flows: The angle of repose, fluidization and the cliff collapse problem

    NASA Astrophysics Data System (ADS)

    Holsapple, Keith A.

    2013-07-01

    I discuss theories of granular material flows, with application to granular flows on the earth and planets. There are two goals. First, there is a lingering belief of some that the standard continuum plasticity Mohr-Coulomb and/or Drucker-Prager models are not adequate for many large-scale granular flow problems. The stated reason for those beliefs is the fact that the final slopes of the run-outs in collapse, landslide problems, and large-scale cratering are well below the angle of repose of the material. That observation, combined with the supposition that in those models flow cannot occur with slopes less than the angle of repose, has led to a number of researchers suggesting a need for lubrication or fluidization mechanisms and modeling. That issue is investigated in detail and shown to be false. A complete analysis of slope failures according to the Mohr-Coulomb model is presented, with special attention to the relations between the angle of repose and slope failures. It is shown that slope failure can occur for slope angles both larger than and smaller than the angle of repose. Second, to study the details of landslide run-outs, finite-difference continuum code simulations of the prototypical cliff collapse problem, using the classical plasticity models, are presented, analyzed and compared to experiments. Although devoid of any additional fluidization models, those simulations match experiments in the literature extremely well. The dynamics of this problem introduces additional important features relating to the run-out and final slope angles. The vertical free surface begins to fall at the initial 90° and flow continues to a final slope less than 10°. The detail in the calculation is examined to show why flow persists at slope angles that appear to be less than the angle of repose. The motions include regions of solid-like, fluid-like, and gas-like flows without invoking any additional models.

  13. Validation of aerodynamic parameters at high angles of attack for RAE high incidence research models

    NASA Technical Reports Server (NTRS)

    Ross, A. Jean; Edwards, Geraldine F.; Klein, Vladislav; Batterson, James G.

    1987-01-01

    Two series of free-flight tests have been conducted for combat aircraft configuration research models in order to investigate flight behavior near departure conditions as well as to obtain response data from which aerodynamic characteristics can be derived. The structure of the mathematical model and values for the mathematical derivatives have been obtained through an analysis of the first series, using stepwise regression. The results thus obtained are the bases of the design of active control laws. Flight test results for a novel configuration are compared with predicted responses.

  14. SU-E-T-604: Dosimetric Dependence On the Collimator Angle in Prostate Volumetric Modulated Arc Therapy

    SciTech Connect

    Khan, M; Rehman, J; Khan, M; Chow, J

    2014-06-01

    Purpose: The purpose of this study is to investigate the dose-volume variations of planning target volume (PTV) and organs-at-risk (OARs) in prostate volumetric modulated arc therapy (VMAT) when using different collimator angles. It is because collimator angle awareness is essential for planner to produce an optimal prostate VMAT plan in a rational time. Methods: Single-arc VMAT plans at different collimator angles (0o, 15o, 30o, 45o, 60o, 75o and 90o) were created systematically using a Harold heterogeneous pelvis phantom. For each change of collimator angle, a new plan was re-optimized for that angle. The prescription dose was 78 Gy per 39 fractions. Conformity index (CI), homogeneity index (HI), gradient index, machine monitor unit, dose-volume histogram, the mean and maximum doses of the PTV were calculated and analyzed. On the other hand, dose-volume histogram, the mean and maximum doses of the OARs such as bladder, rectum and femoral heads for different collimator angles were determined from the plans. Results: There was no significance difference, based on the plan dose-volume evaluation criteria, found in the VMAT optimizations for all studied collimator angles. Higher CI and lower HI were found for the 45o collimator angle. In addition, the 15o collimator angle provided lower HI similar to the 45o collimator angle. The 75o and 90o collimator angle were found good for the rectum sparing, and the 75o and 30o collimator angle were found good for the right and left femur sparing, respectively. The PTV dose coverage for each plan was comparatively independent of the collimator angle. Conclusion: The dosimetric results in this study are useful to the planner to select different collimator angles to improve the PTV coverage and OAR sparing in prostate VMAT.

  15. Design of a small angle spectrometer: Application to food systems

    NASA Astrophysics Data System (ADS)

    Alexander, Marcela

    This thesis describes the design of a new class of spectrometer developed for the study of light scattering phenomena at very low angles. Its detection system is a state of the art Charged Couple Device (CCD) camera of short data gathering time and very high sensitivity and dynamic range. The Small Angle Light Scattering technique in this work is shown to be a useful tool for determining size distributions of particles whose diameter is larger than approximately 300 nm. For particles smaller than this size, the technique is a sensitive probe of Rayleigh scattering. The advantages presented by the use of a solid state camera enables the study of relatively fast dynamic phenomena such as aggregation. In this particular work, we followed the aggregation of casein micelles caused by the addition of rennet, and the aggregation of β- Lactoglobulin stabilized oil in water emulsions caused by the addition of CaCl2. For this last case, a discrete inversion technique, incorporating the Mie scattering theory, was applied to obtain size distribution histograms of the emulsion droplets as a function of aggregation time.

  16. Adult Degenerative Scoliosis: Can Cobb Angle on a Supine Posteroanterior Radiograph Be Used to Predict the Cobb Angle in a Standing Position?

    PubMed Central

    Yang, Changwei; Li, Yanming; Zhao, Yunfei; Zhu, Xiaodong; Li, Ming; Liu, Gabriel

    2016-01-01

    Abstract It is necessary to assess coronal Cobb angle in the diagnosis and treatment of patients with adult degenerative scoliosis (ADS). But as most ADS patients are elderly patients who are difficult or unable to stand upright without assistance, it is difficult to obtain standing posteroanterior X-ray radiographs. Whether it is possible to use Cobb angle obtained on a supine posteroanterior X-ray radiograph to predict Cobb angle in a standing position remains unanswered. To study the correlation between X-ray plain radiographic parameters obtained from the supine position and those obtained from the standing position in ADS patients. Medical records and radiological information were obtained from ADS patients prospectively. Posteroanterior X-ray views of the spine were taken in both standing and supine positions simultaneously in the same ADS patients to record information about the position of the apical and end vertebrae in the coronal position and measure Cobb angle and rotation degree of the apical vertebra. Correlation and linear regression were used to analyze the correlation between the Cobb angle and the rotation degree of the apical vertebra on the X-ray plain radiographs obtained from the standing and supine positions. Of 94 ADS patients who met the inclusion criteria, 14 (15%) patients were male and 80 (85%) patients were female who ranged in age from 41 to 92 years with a mean of 67 years. The mean Cobb angle on the supine X-ray radiographs was 21 ± 10° versus 26 ± 12° on the standing X-ray radiographs, the difference being statistically significant (P < 0.01). The rotation angle of the apical vertebra in the supine and standing positions was 1.8 ± 0.7 and 1.9 ± 0.7, respectively, the difference being statistically significant (P < 0.05). Correlation analysis showed a strong correlation in Cobb angle between the supine and standing X-ray plain radiographs (r = 0.92, P < 0.01). The correlation coefficient of the

  17. Calculation of shielding parameters

    NASA Astrophysics Data System (ADS)

    Montoya, Zeferino Jorge

    Within the nuclear reaction exists three types of energy producing reactions: (1) radioactive disintegration; (2) fission; and (3) fusion. Besides the radiation produced in these reactions there are radioactive emissions of a different type, and in some of these cases they are of great penetration power and scope. The radiation produces great damage when interacted with materials, in particular the most dangerous are neutrons and gamma photons. For this reason it is necessary to protect people who work in places which operate with radioactive sources from the radiation, in addition to reducing the radiation doses to the most reasonably possible, considering the circumstances of the installations. The three determining factors in the proposition of reducing exposure to radiation are: (1) to maintain control over the reduced exposure in the time of the permanence in the irradiated areas; (2) to increase the distance between the source and the operating personnel as much as possible; and (3) to place an armor-plate between the source and the receptor. The work described in this paper has its objective a calculation of the parameters of an armor-plate in radioactive sources, with the goal of estimating the doses of radiation in protecting people and other biological systems from exposure to radiation produced during the nuclear reactions. The parameters to be principally considered are: (1) characteristics of the source; (2) geometry of the source at the point of exposure; and (3) material and thickness of the armor-plate.

  18. Relation of thromboelastography parameters to conventional coagulation tests used to evaluate the hypercoagulable state of aged fracture patients.

    PubMed

    Liu, Chen; Guan, Zhao; Xu, Qinzhu; Zhao, Lei; Song, Ying; Wang, Hui

    2016-06-01

    Fractures are common among aged people, and rapid assessment of the coagulation status is important. The thromboelastography (TEG) test can give a series of coagulation parameters and has been widely used in clinics. In this research, we looked at fracture patients over 60 and compared their TEG results with those of healthy controls. Since there is a paucity of studies comparing TEG assessments with conventional coagulation tests, we aim to clarify the relationship between TEG values and the values given by conventional coagulation tests.Forty fracture patients (27 femur and 13 humerus) over 60 years old were included in the study. The change in their coagulation status was evaluated by TEG before surgery within 4 hours after the fracture. Changes in TEG parameters were analyzed compared with controls. Conventional coagulation test results for the patients, including activated partial thromboplastin time (APTT), international normalized ratio (INR), fibrinogen, and platelets, were also acquired, and correlation analysis was done with TEG parameters, measuring similar aspects of the coagulation cascade. In addition, the sensitivity and specificity of TEG parameters for detecting raised fibrinogen levels were also analyzed.The K (time to 20 mm clot amplitude) and R (reaction time) values of aged fracture patients were lower than controls. The values for angle, maximal amplitude (MA), and coagulation index (CI) were raised compared with controls, indicating a hypercoagulable state. Correlation analysis showed that there were significant positive correlations between fibrinogen and MA/angle, between platelets and MA, and between APTT and R as well. There was significant negative correlation between fibrinogen and K. In addition, K values have better sensitivity and specificity for detecting elevated fibrinogen concentration than angle and MA values.Aged fracture patients tend to be in a hypercoagulable state, and this could be effectively reflected by a TEG test

  19. Modeling Electron Pitch-Angle Scattering Rates by EMIC Waves

    NASA Astrophysics Data System (ADS)

    Usanova, Maria; Shprits, Yuri; Drozdov, Alexander

    2016-07-01

    The response of electron fluxes to different geomagnetic activity is determined by competing electron acceleration and loss processes. Interaction with EMIC waves is believed to be an important loss mechanism for the radiation belt electrons, which can undergo cyclotron resonance with EMIC waves and consequent pitch-angle scattering into the atmosphere. The recent study by Usanova et al. [2014] reported the first definitive proof of EMIC waves scattering electrons into the atmosphere. These new results are particularly interesting and significant as EMIC is the only wave mode that can scatter ultra-relativistic electrons much faster and more efficient than other wave modes (e.g., chorus and hiss) and therefore, is supposed to be a dominant internal loss mechanism for ˜>2 MeV energy electrons. In this talk we will focus on numerical modeling of EMIC-related electron losses. We compute bounce-averaged pitch-angle diffusion coefficients of electrons due to EMIC waves using a quasi-linear approach and use these coefficients as further input to the Versatile Electron Radiation Belt (VERB) diffusion code to simulate the evolution of electron phase space density during selected events. We will present a comparison of the simulation results and observed pitch angle distributions on the Van Allen Probes during selected events. We will also address the following questions: Where and under which conditions signatures of EMIC-related electron loss are typically observed? What are the EMIC wave and background plasma parameters required for this interaction? Can we reproduce observed losses of radiation belt electrons using numerical modeling?

  20. Large mixing angles from many right-handed neutrinos

    NASA Astrophysics Data System (ADS)

    Feldstein, Brian; Klemm, William

    2012-03-01

    A beautiful understanding of the smallness of the neutrino masses may be obtained via the seesaw mechanism, whereby one takes advantage of the key qualitative distinction between the neutrinos and the other fermions: right-handed neutrinos are gauge singlets, and may therefore have large Majorana masses. The standard seesaw mechanism, however, does not address the apparent lack of hierarchy in the neutrino masses compared to the quarks and charged leptons, nor the large leptonic mixing angles compared to the small angles of the Cabibbo-Kobayashi-Maskawa matrix. In this paper, we will show that the singlet nature of the right-handed neutrinos may be taken advantage of in one further way in order to solve these remaining problems: Unlike particles with gauge interactions, whose numbers are constrained by anomaly cancellation, the number of gauge singlet particles is essentially undetermined. If large numbers of gauge singlet fermions are present at high energies—as is suggested, for example, by various string constructions—then the effective low-energy neutrino mass matrix may be determined as a sum over many distinct Yukawa couplings, with the largest ones being the most important. This can reduce hierarchy, and lead to large mixing angles. Assuming a statistical distribution of fundamental parameters, we will show that this scenario leads to a good fit to low-energy phenomenology, with only a few qualitative assumptions guided by the known quark and lepton masses. The scenario leads to predictions of a normal hierarchy for the neutrino masses, and a value for the |mee| mass matrix element of about 1-6 meV.